From 82fe2dd0c6ae24da5b4cd3a66c0fd8f80c9b11e0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?F=C3=A9lix=20Arreola=20Rodr=C3=ADguez?= Date: Sat, 27 Aug 2022 20:52:58 -0500 Subject: [PATCH] Importacion de la libdnsc. --- .gitignore | 48 ++ AUTHORS | 0 COPYING | 674 ++++++++++++++++++++++++ ChangeLog | 0 INSTALL | 368 +++++++++++++ Makefile.am | 6 + NEWS | 0 README | 0 configure.ac | 76 +++ src/Makefile.am | 25 + src/constants.h | 305 +++++++++++ src/dns-c.pc.in | 11 + src/dns2-private.h | 50 ++ src/dns2.c | 774 +++++++++++++++++++++++++++ src/dns2.h | 63 +++ src/glist.c | 1258 ++++++++++++++++++++++++++++++++++++++++++++ src/glist.h | 152 ++++++ src/header.c | 40 ++ src/header.h | 60 +++ src/libdnsc.sym | 24 + src/packet.c | 601 +++++++++++++++++++++ src/packet.h | 62 +++ src/question.c | 87 +++ src/question.h | 18 + src/resolver.c | 57 ++ src/rr.c | 726 +++++++++++++++++++++++++ src/rr.h | 95 ++++ src/updater.c | 157 ++++++ src/utils.c | 124 +++++ src/utils.h | 10 + 30 files changed, 5871 insertions(+) create mode 100644 .gitignore create mode 100644 AUTHORS create mode 100644 COPYING create mode 100644 ChangeLog create mode 100644 INSTALL create mode 100644 Makefile.am create mode 100644 NEWS create mode 100644 README create mode 100644 configure.ac create mode 100644 src/Makefile.am create mode 100644 src/constants.h create mode 100644 src/dns-c.pc.in create mode 100644 src/dns2-private.h create mode 100644 src/dns2.c create mode 100644 src/dns2.h create mode 100644 src/glist.c create mode 100644 src/glist.h create mode 100644 src/header.c create mode 100644 src/header.h create mode 100644 src/libdnsc.sym create mode 100644 src/packet.c create mode 100644 src/packet.h create mode 100644 src/question.c create mode 100644 src/question.h create mode 100644 src/resolver.c create mode 100644 src/rr.c create mode 100644 src/rr.h create mode 100644 src/updater.c create mode 100644 src/utils.c create mode 100644 src/utils.h diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..46f72fb --- /dev/null +++ b/.gitignore @@ -0,0 +1,48 @@ +# http://www.gnu.org/software/automake +Makefile.in + +# http://www.gnu.org/software/autoconf +autom4te.cache +aclocal.m4 +compile +configure +depcomp +install-sh +missing + +build-aux/ + +config.h.in +config.h +Makefile +config.log +config.status +.deps +src/dns-c.pc + +*.o +*.lo +*.la +src/.libs +stamp-h1 + +*~ + +m4 + +po/Makefile.in.in +po/Makevars.template +po/POTFILES +po/Rules-quot +po/boldquot.sed +po/en@boldquot.header +po/en@quot.header +po/insert-header.sin +po/quot.sed +po/remove-potcdate.sed +po/remove-potcdate.sin +po/stamp-po + +*.gmo +*.mo + diff --git a/AUTHORS b/AUTHORS new file mode 100644 index 0000000..e69de29 diff --git a/COPYING b/COPYING new file mode 100644 index 0000000..94a9ed0 --- /dev/null +++ b/COPYING @@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. 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It is safest +to attach them to the start of each source file to most effectively +state the exclusion of warranty; and each file should have at least +the "copyright" line and a pointer to where the full notice is found. + + + Copyright (C) + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . + +Also add information on how to contact you by electronic and paper mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + Copyright (C) + This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, your program's commands +might be different; for a GUI interface, you would use an "about box". + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU GPL, see +. + + The GNU General Public License does not permit incorporating your program +into proprietary programs. If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. diff --git a/ChangeLog b/ChangeLog new file mode 100644 index 0000000..e69de29 diff --git a/INSTALL b/INSTALL new file mode 100644 index 0000000..8865734 --- /dev/null +++ b/INSTALL @@ -0,0 +1,368 @@ +Installation Instructions +************************* + + Copyright (C) 1994-1996, 1999-2002, 2004-2016 Free Software +Foundation, Inc. + + Copying and distribution of this file, with or without modification, +are permitted in any medium without royalty provided the copyright +notice and this notice are preserved. This file is offered as-is, +without warranty of any kind. + +Basic Installation +================== + + Briefly, the shell command './configure && make && make install' +should configure, build, and install this package. The following +more-detailed instructions are generic; see the 'README' file for +instructions specific to this package. Some packages provide this +'INSTALL' file but do not implement all of the features documented +below. The lack of an optional feature in a given package is not +necessarily a bug. More recommendations for GNU packages can be found +in *note Makefile Conventions: (standards)Makefile Conventions. + + The 'configure' shell script attempts to guess correct values for +various system-dependent variables used during compilation. It uses +those values to create a 'Makefile' in each directory of the package. +It may also create one or more '.h' files containing system-dependent +definitions. 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If GNU CC +is not installed, it is recommended to use the following options in +order to use an ANSI C compiler: + + ./configure CC="cc -Ae -D_XOPEN_SOURCE=500" + +and if that doesn't work, install pre-built binaries of GCC for HP-UX. + + HP-UX 'make' updates targets which have the same time stamps as their +prerequisites, which makes it generally unusable when shipped generated +files such as 'configure' are involved. Use GNU 'make' instead. + + On OSF/1 a.k.a. Tru64, some versions of the default C compiler cannot +parse its '' header file. The option '-nodtk' can be used as a +workaround. If GNU CC is not installed, it is therefore recommended to +try + + ./configure CC="cc" + +and if that doesn't work, try + + ./configure CC="cc -nodtk" + + On Solaris, don't put '/usr/ucb' early in your 'PATH'. This +directory contains several dysfunctional programs; working variants of +these programs are available in '/usr/bin'. So, if you need '/usr/ucb' +in your 'PATH', put it _after_ '/usr/bin'. + + On Haiku, software installed for all users goes in '/boot/common', +not '/usr/local'. It is recommended to use the following options: + + ./configure --prefix=/boot/common + +Specifying the System Type +========================== + + There may be some features 'configure' cannot figure out +automatically, but needs to determine by the type of machine the package +will run on. Usually, assuming the package is built to be run on the +_same_ architectures, 'configure' can figure that out, but if it prints +a message saying it cannot guess the machine type, give it the +'--build=TYPE' option. TYPE can either be a short name for the system +type, such as 'sun4', or a canonical name which has the form: + + CPU-COMPANY-SYSTEM + +where SYSTEM can have one of these forms: + + OS + KERNEL-OS + + See the file 'config.sub' for the possible values of each field. 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Or, you can set the +'CONFIG_SITE' environment variable to the location of the site script. +A warning: not all 'configure' scripts look for a site script. + +Defining Variables +================== + + Variables not defined in a site shell script can be set in the +environment passed to 'configure'. However, some packages may run +configure again during the build, and the customized values of these +variables may be lost. In order to avoid this problem, you should set +them in the 'configure' command line, using 'VAR=value'. For example: + + ./configure CC=/usr/local2/bin/gcc + +causes the specified 'gcc' to be used as the C compiler (unless it is +overridden in the site shell script). + +Unfortunately, this technique does not work for 'CONFIG_SHELL' due to an +Autoconf limitation. Until the limitation is lifted, you can use this +workaround: + + CONFIG_SHELL=/bin/bash ./configure CONFIG_SHELL=/bin/bash + +'configure' Invocation +====================== + + 'configure' recognizes the following options to control how it +operates. + +'--help' +'-h' + Print a summary of all of the options to 'configure', and exit. + +'--help=short' +'--help=recursive' + Print a summary of the options unique to this package's + 'configure', and exit. The 'short' variant lists options used only + in the top level, while the 'recursive' variant lists options also + present in any nested packages. + +'--version' +'-V' + Print the version of Autoconf used to generate the 'configure' + script, and exit. + +'--cache-file=FILE' + Enable the cache: use and save the results of the tests in FILE, + traditionally 'config.cache'. FILE defaults to '/dev/null' to + disable caching. + +'--config-cache' +'-C' + Alias for '--cache-file=config.cache'. + +'--quiet' +'--silent' +'-q' + Do not print messages saying which checks are being made. To + suppress all normal output, redirect it to '/dev/null' (any error + messages will still be shown). + +'--srcdir=DIR' + Look for the package's source code in directory DIR. Usually + 'configure' can determine that directory automatically. + +'--prefix=DIR' + Use DIR as the installation prefix. *note Installation Names:: for + more details, including other options available for fine-tuning the + installation locations. + +'--no-create' +'-n' + Run the configure checks, but stop before creating any output + files. + +'configure' also accepts some other, not widely useful, options. Run +'configure --help' for more details. diff --git a/Makefile.am b/Makefile.am new file mode 100644 index 0000000..44861e4 --- /dev/null +++ b/Makefile.am @@ -0,0 +1,6 @@ +SUBDIRS = src + +#ACLOCAL_AMFLAGS = -I m4 + +#EXTRA_DIST = build-aux/config.rpath + diff --git a/NEWS b/NEWS new file mode 100644 index 0000000..e69de29 diff --git a/README b/README new file mode 100644 index 0000000..e69de29 diff --git a/configure.ac b/configure.ac new file mode 100644 index 0000000..85d5928 --- /dev/null +++ b/configure.ac @@ -0,0 +1,76 @@ +AC_INIT([dns-c], [0.1.0], [], [dns_c]) + +AC_REVISION([Revision 1]) + +AC_CONFIG_AUX_DIR([build-aux]) + +AC_CONFIG_MACRO_DIR([m4]) +# We need automake +AM_INIT_AUTOMAKE([-Wall -Werror]) + +AM_PROG_AR + +AC_CONFIG_SRCDIR([src/dns2.c]) + +LT_INIT + +# For debian systems, /usr as default +AC_PREFIX_DEFAULT([/usr]) + +# We need Gcc +AC_PROG_CC +# We need OBJC, for MAC +AC_PROG_OBJC + + +# Translate this program +#AM_GNU_GETTEXT_VERSION([0.19.3]) +#AM_GNU_GETTEXT([external]) + +ALL_LINGUAS="" +AC_SUBST(ALL_LINGUAS) + +AM_PROG_CC_C_O + +# Revisar el host +AC_CANONICAL_HOST + +case $host_os in + *mingw32* ) MINGW32=yes;; + * ) MINGW32=no;; +esac +case $host_os in + *cygwin* ) CYGWIN=yes;; + * ) CYGWIN=no;; +esac +case $host_os in + *linux* ) LINUX=yes;; + * ) LINUX=no;; +esac +case $host_os in + *darwin* ) MACOSX=yes;; + * ) MACOSX=no;; +esac + +AM_CONDITIONAL(MINGW32, test x$MINGW32 = xyes) +AM_CONDITIONAL(LINUX, test x$LINUX = xyes) +AM_CONDITIONAL(MACOSX, test x$MACOSX = xyes) + +# Check for pkg-config +PKG_PROG_PKG_CONFIG + +OPENSSL_VERSION=0.9.8 + +AC_MSG_CHECKING([if you have openssl installed on your system]) +PKG_CHECK_EXISTS([openssl >= $OPENSSL_VERSION], [AC_MSG_RESULT([yes])], [AC_MSG_FAILURE([openssl not found in your system])]) +PKG_CHECK_MODULES(OPENSSL, [openssl >= $OPENSSL_VERSION], [], []) + +AC_CONFIG_HEADERS([config.h]) + +AC_CONFIG_FILES([ + Makefile + src/Makefile + src/dns-c.pc +]) + +AC_OUTPUT diff --git a/src/Makefile.am b/src/Makefile.am new file mode 100644 index 0000000..286552d --- /dev/null +++ b/src/Makefile.am @@ -0,0 +1,25 @@ +# Automake file for dns-c + +lib_LTLIBRARIES = libdnsc.la + +libdnsc_la_SOURCES = dns2.c dns2.h dns2-private.h \ + glist.c glist.h \ + header.c header.h \ + packet.c packet.h \ + question.c question.h \ + rr.c rr.h \ + utils.c utils.h \ + resolver.c updater.c \ + constants.h + +libdnsc_la_CFLAGS = $(OPENSSL_CFLAGS) +libdnsc_la_LDFLAGS = $(OPENSSL_LIBS) -version-info 0:1:0 -no-undefined -export-symbols $(srcdir)/libdnsc.sym +libdnsc_la_DEPENDENCIES = libdnsc.sym +libdnscdir = $(includedir)/libdns_c/dns_c +libdnsc_HEADERS = dns2.h rr.h constants.h + +pkgconfigdir = $(libdir)/pkgconfig +dist_pkgconfig_DATA = dns-c.pc + +EXTRA_DIST = libdnsc.sym + diff --git a/src/constants.h b/src/constants.h new file mode 100644 index 0000000..a533fe7 --- /dev/null +++ b/src/constants.h @@ -0,0 +1,305 @@ +#ifndef __CONSTANTS_H__ +#define __CONSTANTS_H__ + +#include +#include + +#define DNS_HEADER_SIZE 12 + +/* + * max size of a UDP packet + */ +#define DNS_MAX_UDP_SIZE 512 + +/* + * Query/Response flag + */ +// RFC 1035 +#define QR_QUERY 0 +// RFC 1035 +#define QR_RESPONSE 1 + +/* + * DNS Op Codes + */ +// RFC 1035 +#define OPCODE_QUERY 0 +// RFC 1035, RFC 3425 +#define OPCODE_IQUERY 1 +// RFC 1035 +#define OPCODE_STATUS 2 +// RFC 1996 +#define OPCODE_NOTIFY 4 +// RFC 2136 +#define OPCODE_UPDATE 5 + +/* + * Resource Record Classes + */ +// RFC 1035 +#define RR_CLASS_IN 1 +// RFC 1035 +#define RR_CLASS_CH 3 +// RFC 1035 +#define RR_CLASS_HS 4 +// RFC 2136 +#define RR_CLASS_NONE 254 +// RFC 1035 +#define RR_CLASS_ANY 255 + +/* + * DNS Response Codes + */ +// RFC 1035 +#define RCODE_NOERROR 0 +// RFC 1035 +#define RCODE_FORMERR 1 +// RFC 1035 +#define RCODE_SERVFAIL 2 +// RFC 1035 +#define RCODE_NXDOMAIN 3 +// RFC 1035 +#define RCODE_NOTIMP 4 +// RFC 1035 +#define RCODE_REFUSED 5 +// RFC 2136 +#define RCODE_YXDOMAIN 6 +// RFC 2136 +#define RCODE_YXRRSET 7 +// RFC 2136 +#define RCODE_NXRRSET 8 +// RFC 2136 +#define RCODE_NOTAUTH 9 +// RFC 2136 +#define RCODE_NOTZONE 10 + +// 11-15 reserved + +// RFC 2845 +#define RCODE_BADSIG 16 +// RFC 6891 +#define RCODE_BADVERS 16 +// RFC 2845 +#define RCODE_BADKEY 17 +// RFC 2845 +#define RCODE_BADTIME 18 +// RFC 2930 +#define RCODE_BADMODE 19 +// RFC 2930 +#define RCODE_BADNAME 20 +// RFC 2930 +#define RCODE_BADALG 21 +// RFC 4635 +#define RCODE_BADTRUNC 22 +// RFC 7873 +#define RCODE_BADCOOKIE 23 + +/* + * DNS RR TYPES + */ + +// RFC 2931 pseudo type +#define RR_TYPE_SIG0 0 +// RFC 1035 +#define RR_TYPE_A 1 +// RFC 1035 +#define RR_TYPE_NS 2 +// RFC 1035 - obsolete, Not implemented +#define RR_TYPE_MD 3 +// RFC 1035 - obsolete, Not implemented +#define RR_TYPE_MF 4 +// RFC 1035 +#define RR_TYPE_CNAME 5 +// RFC 1035 +#define RR_TYPE_SOA 6 +// RFC 1035 - obsolete, Not implemented +#define RR_TYPE_MB 7 +// RFC 1035 - obsolete, Not implemented +#define RR_TYPE_MG 8 +// RFC 1035 - obsolete, Not implemented +#define RR_TYPE_MR 9 +// RFC 1035 - obsolete, Not implemented +#define RR_TYPE_NULL 10 +// RFC 1035 +#define RR_TYPE_WKS 11 +// RFC 1035 +#define RR_TYPE_PTR 12 +// RFC 1035 +#define RR_TYPE_HINFO 13 +// RFC 1035 - obsolete, Not implemented +#define RR_TYPE_MINFO 14 +// RFC 1035 +#define RR_TYPE_MX 15 +// RFC 1035 +#define RR_TYPE_TXT 16 +// RFC 1183 +#define RR_TYPE_RP 17 +// RFC 1183 +#define RR_TYPE_AFSDB 18 +// RFC 1183 +#define RR_TYPE_X25 19 +// RFC 1183 +#define RR_TYPE_ISDN 20 +// RFC 1183 +#define RR_TYPE_RT 21 +// RFC 1706 +#define RR_TYPE_NSAP 22 +// RFC 1348 - obsolete, Not implemented +#define RR_TYPE_NSAP_PTR 23 +// RFC 2535 +#define RR_TYPE_SIG 24 +// RFC 2535, RFC 2930 +#define RR_TYPE_KEY 25 +// RFC 2163 +#define RR_TYPE_PX 26 +// RFC 1712 - Not implemented +#define RR_TYPE_GPOS 27 +// RFC 3596 +#define RR_TYPE_AAAA 28 +// RFC 1876 +#define RR_TYPE_LOC 29 +// RFC 2065, obsoleted by by RFC 3755 +#define RR_TYPE_NXT 30 +// [Patton][Patton1995] +#define RR_TYPE_EID 31 +// [Patton][Patton1995] +#define RR_TYPE_NIMLOC 32 +// RFC 2782 +#define RR_TYPE_SRV 33 +// Windows only +#define RR_TYPE_ATMA 34 +// RFC 2915 +#define RR_TYPE_NAPTR 35 +// RFC 2230 +#define RR_TYPE_KX 36 +// RFC 4398 +#define RR_TYPE_CERT 37 +// downgraded to experimental by RFC 3363 +#define RR_TYPE_A6 38 +// RFC 2672 +#define RR_TYPE_DNAME 39 +// Not implemented +#define RR_TYPE_SINK 40 +// RFC 2671 +#define RR_TYPE_OPT 41 +// RFC 3123 +#define RR_TYPE_APL 42 +// RFC 4034 +#define RR_TYPE_DS 43 +// RFC 4255 +#define RR_TYPE_SSHFP 44 +// RFC 4025 +#define RR_TYPE_IPSECKEY 45 +// RFC 4034 +#define RR_TYPE_RRSIG 46 +// RFC 4034 +#define RR_TYPE_NSEC 47 +// RFC 4034 +#define RR_TYPE_DNSKEY 48 +// RFC 4701 +#define RR_TYPE_DHCID 49 +// RFC 5155 +#define RR_TYPE_NSEC3 50 +// RFC 5155 +#define RR_TYPE_NSEC3PARAM 51 +// RFC 6698 +#define RR_TYPE_TLSA 52 +// draft-ietf-dane-smime-10 +#define RR_TYPE_SMIMEA 53 + + // 54 unassigned + +// RFC 5205 +#define RR_TYPE_HIP 55 +// Not implemented +#define RR_TYPE_NINFO 56 +// Not implemented +#define RR_TYPE_RKEY 57 +// +#define RR_TYPE_TALINK 58 +// RFC 7344 +#define RR_TYPE_CDS 59 +// RFC 7344 +#define RR_TYPE_CDNSKEY 60 +// RFC 7929 +#define RR_TYPE_OPENPGPKEY 61 +// RFC 7477 +#define RR_TYPE_CSYNC 62 + + // 63 - 98 unassigned + +// RFC 4408 +#define RR_TYPE_SPF 99 +// no RFC, Not implemented +#define RR_TYPE_UINFO 100 +// no RFC, Not implemented +#define RR_TYPE_UID 101 +// no RFC, Not implemented +#define RR_TYPE_GID 102 +// no RFC, Not implemented +#define RR_TYPE_UNSPEC 103 +// RFC 6742 +#define RR_TYPE_NID 104 +// RFC 6742 +#define RR_TYPE_L32 105 +// RFC 6742 +#define RR_TYPE_L64 106 +// RFC 6742 +#define RR_TYPE_LP 107 +// RFC 7043 +#define RR_TYPE_EUI48 108 +// RFC 7043 +#define RR_TYPE_EUI64 109 + + // 110 - 248 unassigned + +// RFC 2930 +#define RR_TYPE_TKEY 249 +// RFC 2845 +#define RR_TYPE_TSIG 250 +// RFC 1995 - only a full (AXFR) is supported +#define RR_TYPE_IXFR 251 +// RFC 1035 +#define RR_TYPE_AXFR 252 +// RFC 883, Not implemented +#define RR_TYPE_MAILB 253 +// RFC 973, Not implemented +#define RR_TYPE_MAILA 254 +// RFC 1035 - we support both 'ANY' and '*' +#define RR_TYPE_ANY 255 +// tools.ietf.org/html/draft-faltstrom-uri-06 +#define RR_TYPE_URI 256 +// tools.ietf.org/html/draft-ietf-pkix-caa-03 +#define RR_TYPE_CAA 257 +// Application Visibility and Control +#define RR_TYPE_AVC 258 + + // 259 - 32767 unassigned + +// same as DS +#define RR_TYPE_TA 32768 +// RFC 4431 +#define RR_TYPE_DLV 32769 +// Private Bind record +#define RR_TYPE_TYPE65534 65534 + +/* + * TSIG TYPES + */ + +// RFC 2845, required +#define RR_TSIG_HMAC_MD5 "hmac-md5.sig-alg.reg.int" +// unsupported, optional +#define RR_TSIG_GSS_TSIG "gss-tsig" +// RFC 4635, required +#define RR_TSIG_HMAC_SHA1 "hmac-sha1" +// RFC 4635, optional +#define RR_TSIG_HMAC_SHA224 "hmac-sha224" +// RFC 4635, required +#define RR_TSIG_HMAC_SHA256 "hmac-sha256" +// RFC 4635, optional +#define RR_TSIG_HMAC_SHA384 "hmac-sha384" +// RFC 4635, optional +#define RR_TSIG_HMAC_SHA512 "hmac-sha512" + +#endif /* __CONSTANTS_H__ */ diff --git a/src/dns-c.pc.in b/src/dns-c.pc.in new file mode 100644 index 0000000..dc21306 --- /dev/null +++ b/src/dns-c.pc.in @@ -0,0 +1,11 @@ +prefix=@prefix@ +exec_prefix=@exec_prefix@ +libdir=@libdir@ +includedir=@includedir@ + +Name: DNS-C Library +Description: Client Library for doing DNS queries or updates +Version: @VERSION@ +Libs: -L${libdir} -ldnsc +Requires.private: openssl >= 0.9.8 +Cflags: -I${includedir}/libdns_c diff --git a/src/dns2-private.h b/src/dns2-private.h new file mode 100644 index 0000000..279cc8d --- /dev/null +++ b/src/dns2-private.h @@ -0,0 +1,50 @@ +#ifndef __DNS2_PRIVATE_H__ +#define __DNS2_PRIVATE_H__ + +#include +#include + +#include + +#include "packet.h" +#include "glist.h" +#include "rr.h" +#include "dns2.h" + +struct _DNS2 { + int type; + int timeout; + + /* Lista nameservers a los cuáles mandar la petición */ + GList *nameservers; + + /* Se utiliza para las actualizaciones de zona */ + char *zone; + + DNSPacket *packet; + + /* Para la recepción de datos */ + unsigned char buffer_read[8192]; + int buffer_read_pos; + + DNSPacket *packet_response; + int force_use_tcp; + + /* Usado para saber si quiere recursión en las consultas */ + int want_recursion; + + DNSRR *auth_signature; + + /* Para el envio de red */ + int state; + int direction; + int retry_count; + struct timespec last_time_sent; + + GList *current_ns; +}; + +DNS2 *dns2_new (void); + +#endif /* __DNS2_PRIVATE_H__ */ + diff --git a/src/dns2.c b/src/dns2.c new file mode 100644 index 0000000..4274ccd --- /dev/null +++ b/src/dns2.c @@ -0,0 +1,774 @@ +#include +#include +#include + +#include +#include +#include + +#include + +#include + +#include + +#include + +#include + +#include "dns2.h" +#include "utils.h" +#include "packet.h" +#include "constants.h" +#include "glist.h" +#include "rr.h" +#include "question.h" + +#include "dns2-private.h" + +typedef struct { + char name[512]; + + struct sockaddr_storage server_addr; + socklen_t addr_size; + + int socket; +} NameServer; + + +/* Prototipos de función */ +int _dns2_internal_tcp_start_connect (DNS2 *obj); +int _dns2_internal_udp_create (DNS2 *obj); + +int _dns2_internal_tcp_connect_continue (DNS2 *obj); +int _dns2_internal_udp_send (DNS2 *obj); +int _dns2_internal_tcp_send (DNS2 *obj); +int _dns2_internal_udp_recv (DNS2 *obj); +int _dns2_internal_tcp_recv (DNS2 *obj); +int _dns2_internal_tcp_next_or_error (DNS2 *obj); +void dns2_clean_network (DNS2 *obj); + +double _dns2_diff_timespec (const struct timespec *time1, const struct timespec *time0) { + return (time1->tv_sec - time0->tv_sec) + + (time1->tv_nsec - time0->tv_nsec) / 1000000000.0; +} + +int dns2_async (DNS2 *obj) { + int length; + // checkServers + DNSRR *signature; + DNSQuestion *question; + int max_udp_size; + + if (obj->state != DNS_STATE_FREE) { + return DNS_COMMAND_ERROR; + } + + if (obj->packet == NULL) { + return DNS_COMMAND_ERROR; + } + + /* Resetear el estado del paquete */ + dns_packet_reset (obj->packet); + + obj->current_ns = g_list_first (obj->nameservers); + obj->retry_count = 0; + if (obj->current_ns == NULL) { + return DNS_COMMAND_ERROR; + } + + /* Actualizar el contador de paquetes */ + dns_packet_recount_items (obj->packet); + + if (obj->type == DNS_UPDATER && (obj->packet->header.qdcount == 0 || obj->packet->header.nscount == 0)) { + + /* Error, nada que mandar en el update */ + return DNS_COMMAND_ERROR; + } + + max_udp_size = DNS_MAX_UDP_SIZE; + + /* Si tiene una firma, generar la firma */ + if (obj->auth_signature != NULL) { + if (obj->auth_signature->type == RR_TYPE_TSIG /*|| + obj->auth_signature->tipo == RR_TYPE_SIG*/) { + + signature = dns2_rr_dup (obj->auth_signature); + dns_rr_pack_generate_signature (signature, obj->packet); + obj->packet->additional = g_list_append (obj->packet->additional, signature); + obj->packet->header.arcount = g_list_length (obj->packet->additional); + } + max_udp_size = 4000; + } + + dns_packet_pack_data (obj->packet); + + /* ------ Para depuración ------ + unsigned char *data; + + length = dns_packet_get_data (obj->packet, &data); + for (int g = 0; gpacket->questions->data; + + if (question->qtype == RR_TYPE_ANY || question->qtype == RR_TYPE_AXFR) { + obj->force_use_tcp = 1; + } + + length = dns_packet_get_data (obj->packet, NULL); + if (length > max_udp_size || obj->force_use_tcp == 1) { + obj->state = DNS_STATE_TCP_CONNECT; + + return _dns2_internal_tcp_start_connect (obj); + } else { + obj->state = DNS_STATE_UDP; + + return _dns2_internal_udp_create (obj); + } +} + +int dns2_async_continue (DNS2 *obj, int happen) { + if (obj->state == DNS_STATE_FREE) { + return DNS_COMMAND_ERROR; + } + + if (obj->direction == DNS_POLL_WANT_READ) { + if ((happen & DNS_POLL_WANT_READ) == 0) { + return DNS_COMMAND_POLL; + } + + switch (obj->state) { + case DNS_STATE_UDP: + return _dns2_internal_udp_recv (obj); + case DNS_STATE_TCP: + return _dns2_internal_tcp_recv (obj); + } + } else if (obj->direction == DNS_POLL_WANT_WRITE) { + if ((happen & DNS_POLL_WANT_WRITE) == 0) { + return DNS_COMMAND_POLL; + } + + switch (obj->state) { + case DNS_STATE_TCP_CONNECT: + return _dns2_internal_tcp_connect_continue (obj); + case DNS_STATE_UDP: + return _dns2_internal_udp_send (obj); + case DNS_STATE_TCP: + return _dns2_internal_tcp_send (obj); + } + } + + return DNS_COMMAND_ERROR; +} + +int dns2_sync (DNS2 *obj) { + int res, res_poll; + struct pollfd poller; + int wanted_events; + int events; + + res = dns2_async (obj); + + while (res == DNS_COMMAND_POLL) { + poller.fd = dns2_get_socket (obj); + poller.revents = 0; + poller.events = 0; + /* FIXME AQUI */ + wanted_events = dns2_get_socket_poll_flags (obj); + if (wanted_events == DNS_POLL_WANT_READ) { + poller.events = POLLIN; + } else if (wanted_events == DNS_POLL_WANT_WRITE) { + poller.events = POLLOUT; + } + + res_poll = poll (&poller, 1, 30); + + if (res_poll == 0) { + /* Si no ocurrió evento, mandar a llamar por timeouts: */ + res = dns2_check_timeout (obj); + continue; + } else if (res_poll < 0) { + if (errno == EINTR) continue; + /* Caso contrario, salir */ + res = DNS_COMMAND_ERROR; + break; + } + + /* Ocurrió un evento, revisar cuál se quería y retornarlo para el continue */ + if (poller.revents & POLLOUT) { + events = DNS_POLL_WANT_WRITE; + } else if (poller.revents & POLLIN) { + events = DNS_POLL_WANT_READ; + } + res = dns2_async_continue (obj, events); + } + + /* Leer el paquete respuesta y regresarlo */ + return res; +} + +int _dns2_internal_tcp_start_connect (DNS2 *obj) { + NameServer *ns; + int flags; + int res; + + ns = (NameServer *) obj->current_ns->data; + ns->socket = socket (ns->server_addr.ss_family, SOCK_STREAM, 0); + + /* Si no pude crear un socket, ni siquiera intentar con el siguiente nameserver */ + if (ns->socket < 0) { + obj->state = DNS_STATE_FREE; + obj->direction = DNS_POLL_WANT_NONE; + + return DNS_COMMAND_ERROR; + } + + /* Aplicar el no-bloqueante */ + flags = fcntl (ns->socket, F_GETFL, 0); + flags = flags | O_NONBLOCK; + fcntl (ns->socket, F_SETFL, flags); + + /* Ejecutar el connect */ + res = connect (ns->socket, (struct sockaddr *) &ns->server_addr, ns->addr_size); + + if (res < 0) { + if (errno == EINPROGRESS) { + obj->direction = DNS_POLL_WANT_WRITE; + return DNS_COMMAND_POLL; + } + + return _dns2_internal_tcp_next_or_error (obj); + } + + /* Tengo conexión, pasar de estado */ + obj->state = DNS_STATE_TCP; + obj->direction = DNS_POLL_WANT_WRITE; + + return dns2_async_continue (obj, DNS_POLL_WANT_WRITE); +} + +int _dns2_internal_tcp_connect_continue (DNS2 *obj) { + int optval; + socklen_t optlen; + int res; + NameServer *ns; + + ns = (NameServer *) obj->current_ns->data; + optlen = sizeof (optval); + + res = getsockopt (ns->socket, SOL_SOCKET, SO_ERROR, &optval, &optlen); + + if (res < 0 || optval != 0) { + return _dns2_internal_tcp_next_or_error (obj); + } + + /* Pasar de estado */ + obj->state = DNS_STATE_TCP; + obj->direction = DNS_POLL_WANT_WRITE; + + return dns2_async_continue (obj, DNS_POLL_WANT_WRITE); +} + +int _dns2_internal_tcp_next_or_error (DNS2 *obj) { + NameServer *ns; + + ns = (NameServer *) obj->current_ns->data; + close (ns->socket); + ns->socket = -1; + + obj->current_ns = g_list_next (obj->current_ns); + if (obj->current_ns != NULL) { + obj->state = DNS_STATE_TCP_CONNECT; + + return _dns2_internal_tcp_start_connect (obj); + } else { + obj->state = DNS_STATE_FREE; + obj->direction = DNS_POLL_WANT_NONE; + + /* Como ya no hay más nameservers en la lista, entregar error */ + return DNS_COMMAND_ERROR; + } +} + +int _dns2_internal_udp_next_or_error (DNS2 *obj) { + /* Los sockets UDP no se cierran, se dejan para usar después */ + + obj->current_ns = g_list_next (obj->current_ns); + if (obj->current_ns != NULL) { + /* Aún hay siguiente servidor, intentarlo con éste */ + obj->state = DNS_STATE_UDP; + + return _dns2_internal_udp_create (obj); + } else { + /* Como ya no hay mas en la lista, esperar al timeout */ + obj->direction = DNS_POLL_WANT_READ; + + return DNS_COMMAND_POLL; + } +} + +int _dns2_internal_udp_send (DNS2 *obj) { + int res; + void *data; + int data_length; + NameServer *ns; + + ns = (NameServer *) obj->current_ns->data; + + data_length = dns_packet_get_data (obj->packet, (unsigned char **) &data); + + clock_gettime (CLOCK_MONOTONIC, &obj->last_time_sent); + + res = sendto (ns->socket, data, data_length, 0, (struct sockaddr *) &ns->server_addr, ns->addr_size); + + if (res < 0) { + if (errno == EWOULDBLOCK || errno == EAGAIN || errno == EINTR) { + obj->direction = DNS_POLL_WANT_WRITE; + + return DNS_COMMAND_POLL; + } + + return _dns2_internal_udp_next_or_error (obj); + } else if (res < data_length) { + /* Envié la petición incompleta, manejar este error */ + + return _dns2_internal_udp_next_or_error (obj); + } + + /* Cambio de estado, esperar la lectura */ + obj->direction = DNS_POLL_WANT_READ; + + return dns2_async_continue (obj, DNS_POLL_WANT_READ); +} + +int _dns2_internal_tcp_send (DNS2 *obj) { + int res; + void *data; + int data_length; + unsigned char data_plus[8192 + 2]; + uint16_t t16; + NameServer *ns; + + ns = (NameServer *) obj->current_ns->data; + data_length = dns_packet_get_data (obj->packet, (unsigned char **) &data); + + /* En TCP, agregar la longitud previa a los datos */ + t16 = htons (data_length); + memcpy (data_plus, &t16, 2); + + memcpy (&data_plus[2], data, data_length); + + res = write (ns->socket, data_plus, data_length + 2); + + if (res < 0) { + if (errno == EWOULDBLOCK || errno == EAGAIN || errno == EINTR) { + obj->direction = DNS_POLL_WANT_WRITE; + + return DNS_COMMAND_POLL; + } + + return _dns2_internal_tcp_next_or_error (obj); + } else if (res < data_length) { + /* Envié la petición incompleta, manejar este error */ + + return _dns2_internal_tcp_next_or_error (obj); + } + + /* Cambio de estado, esperar la lectura */ + obj->direction = DNS_POLL_WANT_READ; + + return dns2_async_continue (obj, DNS_POLL_WANT_READ); +} + +int _dns2_internal_udp_recv (DNS2 *obj) { + int res; + struct sockaddr_storage origen; + socklen_t origen_size; + unsigned char buffer[8192]; + NameServer *ns; + + ns = (NameServer *) obj->current_ns->data; + + origen_size = sizeof (origen); + res = recvfrom (ns->socket, buffer, sizeof (buffer), 0, (struct sockaddr *) &origen, &origen_size); + + if (res < 0) { + if (errno == EWOULDBLOCK || errno == EAGAIN || errno == EINTR) { + obj->direction = DNS_POLL_WANT_READ; + + return DNS_COMMAND_POLL; + } + + /* ¿Otro error en un socket UDP? -> Mejor seguir esperando una lectura */ + + obj->direction = DNS_POLL_WANT_READ; + + return DNS_COMMAND_POLL; + } /* Revisar que el paquete venga del mismo origen a donde envié la petición original */ + else if (sockaddr_cmp ((struct sockaddr *) &origen, (struct sockaddr *) &ns->server_addr) == 0) { + /* Por el momento, dumpear la información + int g; + printf ("Respuesta recibida:\n"); + for (g = 0; g < res; g++) { + printf ("%02x", ((unsigned int) buffer[g])); + } + + printf ("\nEnd response\n");*/ + + if (obj->packet_response != NULL) { + dns_packet_free_full (obj->packet_response); + obj->packet_response = NULL; + } + + obj->packet_response = dns_packet_create_response (SOCK_DGRAM, buffer, res); + + if (obj->packet_response == NULL) { + /* Como no es válida la respuesta, pasar al siguiente servidor */ + return _dns2_internal_udp_next_or_error (obj); + } else { + if (obj->packet_response->header.id != obj->packet->header.id) { + /* Esta no es la respuesta que esperaba */ + obj->direction = DNS_POLL_WANT_READ; + + return DNS_COMMAND_POLL; + } + /* Finalizar la petición */ + dns2_clean_network (obj); + + obj->state = DNS_STATE_FREE; + obj->direction = DNS_POLL_WANT_NONE; + + return DNS_COMMAND_SUCCESS; + } + } + obj->direction = DNS_POLL_WANT_READ; + + return DNS_COMMAND_POLL; +} + +int _dns2_internal_tcp_recv (DNS2 *obj) { + int res; + uint16_t t16; + NameServer *ns; + + ns = (NameServer *) obj->current_ns->data; + + res = read (ns->socket, &obj->buffer_read[obj->buffer_read_pos], sizeof (obj->buffer_read) - obj->buffer_read_pos); + + if (res < 0) { + if (errno == EWOULDBLOCK || errno == EAGAIN || errno == EINTR) { + obj->direction = DNS_POLL_WANT_READ; + + return DNS_COMMAND_POLL; + } + + /* Si obtuvimos un error, pasar al siguiente servidor */ + return _dns2_internal_tcp_next_or_error (obj); + } else if (res == 0) { + /* ¿Socket cerrado? -> Pasar al siguiente servidor */ + return _dns2_internal_tcp_next_or_error (obj); + } else { + /* Por el momento, dumpear la información + int g; + printf ("Bytes recibidos por TCP:\n"); + for (g = obj->buffer_read_pos; g < obj->buffer_read_pos + res; g++) { + printf ("%02x", ((unsigned int) obj->buffer_read[g])); + } + + printf ("\nFin bytes\n");*/ + + /* Incrementar el buffer */ + obj->buffer_read_pos = obj->buffer_read_pos + res; + + /* Validar la longitud de los datos TCP aquí */ + memcpy (&t16, obj->buffer_read, 2); + t16 = ntohs (t16); + + if (t16 + 2 < obj->buffer_read_pos) { + /* Datos incompletos TCP, seguir haciendo POLL */ + obj->direction = DNS_POLL_WANT_READ; + + return DNS_COMMAND_POLL; + } + + if (obj->packet_response != NULL) { + dns_packet_free_full (obj->packet_response); + obj->packet_response = NULL; + } + + obj->packet_response = dns_packet_create_response (SOCK_STREAM, &obj->buffer_read[2], res - 2); + + if (obj->packet_response == NULL) { + /* Error de parseo */ + return _dns2_internal_tcp_next_or_error (obj); + } else { + /* If packet == good */ + //dns2_updater_packet_has_valid_tsig (obj, packet); + + /* Pasar de estado */ + close (ns->socket); + ns->socket = -1; + + obj->state = DNS_STATE_FREE; + obj->direction = DNS_POLL_WANT_NONE; + + return DNS_COMMAND_SUCCESS; + } + } +} + +int _dns2_internal_udp_create (DNS2 *obj) { + NameServer *ns; + int flags; + + obj->direction = DNS_POLL_WANT_WRITE; + + ns = (NameServer *) obj->current_ns->data; + + /* Crear el socket UDP de una buena vez */ + if (ns->socket < 0) { + ns->socket = socket (ns->server_addr.ss_family, SOCK_DGRAM, 0); + + /* Aplicar el no-bloqueante */ + flags = fcntl (ns->socket, F_GETFL, 0); + flags = flags | O_NONBLOCK; + fcntl (ns->socket, F_SETFL, flags); + } + + /* Si no pude crear un socket, tenemos un serio problema */ + if (ns->socket < 0) { + obj->state = DNS_STATE_FREE; + obj->direction = DNS_POLL_WANT_NONE; + + return DNS_COMMAND_ERROR; + } + + return dns2_async_continue (obj, DNS_POLL_WANT_WRITE); +} + +void dns2_sign_tsig (DNS2 *obj, const char *keyname, const char *signature, const char *algorithm) { + DNSRR *rr; + + /* TODO: Revisar si deberíamos liberar el auth_signature anterior */ + rr = dns2_rr_create_tsig (keyname, signature, algorithm); + + if (rr != NULL) { + obj->auth_signature = rr; + } +} + +/* Crear un objeto */ +DNS2 *dns2_new (void) { + DNS2 *obj; + + obj = (DNS2 *) malloc (sizeof (DNS2)); + + if (obj == NULL) { + return NULL; + } + + obj->packet = NULL; + + obj->state = DNS_STATE_FREE; + obj->direction = DNS_POLL_WANT_NONE; + obj->nameservers = NULL; + obj->timeout = 5; + + obj->current_ns = NULL; + obj->zone = NULL; + obj->force_use_tcp = 0; + obj->want_recursion = 0; + obj->buffer_read_pos = 0; + obj->auth_signature = NULL; + obj->packet_response = NULL; + + return obj; +} + +void dns2_add_nserver (DNS2 *obj, const char *ip) { + int res; + struct sockaddr_in v4; + struct sockaddr_in6 v6; + NameServer *ns; + + memset (&v4, 0, sizeof (v4)); + res = inet_pton (AF_INET, ip, &v4.sin_addr); + if (res > 0) { + /* Es una IP de 4 */ + ns = (NameServer *) malloc (sizeof (NameServer)); + + if (ns == NULL) return; + + v4.sin_family = AF_INET; + v4.sin_port = htons (53); + + memcpy (&ns->server_addr, &v4, sizeof (v4)); + ns->addr_size = sizeof (v4); + strncpy (ns->name, ip, sizeof (ns->name)); + ns->socket = -1; + + obj->nameservers = g_list_append (obj->nameservers, ns); + + return; + } + + memset (&v6, 0, sizeof (v6)); + res = inet_pton (AF_INET6, ip, &v6.sin6_addr); + if (res > 0) { + ns = (NameServer *) malloc (sizeof (NameServer)); + + if (ns == NULL) return; + + v6.sin6_family = AF_INET6; + v6.sin6_port = htons (53); + + memcpy (&ns->server_addr, &v6, sizeof (v6)); + ns->addr_size = sizeof (v6); + strncpy (ns->name, ip, sizeof (ns->name)); + + obj->nameservers = g_list_append (obj->nameservers, ns); + + return; + } +} + +void dns2_clean_network (DNS2 *obj) { + GList *g; + NameServer *ns; + + for (g = obj->nameservers; g != NULL; g = g->next) { + ns = (NameServer *) g->data; + + if (ns->socket >= 0) { + close (ns->socket); + ns->socket = -1; + } + } +} + +void dns2_free (DNS2 *obj) { + + /* Cerrar el socket, si es que hay alguno abierto */ + dns2_clean_network (obj); + + /* Liberar la lista de NS */ + g_list_free_full (obj->nameservers, (GDestroyNotify) free); + + if (obj->zone != NULL) { + free (obj->zone); + } + + /* Ahora, buscar si el auth_signature ya está en la lista de additionals. Si lo está, no hay necesidad de liberarlo, se liberará cuando se libere el paquete */ + if (obj->auth_signature != NULL) { + /* Liberar la firma, porque está fuera del paquete */ + dns2_rr_free (obj->auth_signature); + obj->auth_signature = NULL; + } + + if (obj->packet != NULL) { + dns_packet_free_full (obj->packet); + } + + if (obj->packet_response != NULL) { + dns_packet_free_full (obj->packet_response); + } + + free (obj); +} + +int dns2_check_timeout (DNS2 *obj) { + struct timespec now; + double d; + + if (obj->state != DNS_STATE_UDP) return DNS_COMMAND_POLL; + + clock_gettime (CLOCK_MONOTONIC, &now); + + d = _dns2_diff_timespec (&now, &obj->last_time_sent); + if (obj->current_ns->next == NULL) { + /* Si estamos al borde del último servidor, necesitamos el timeout largo */ + if (d > (double) obj->timeout) { + /* Como cayó el timeout largo, incrementar los retries y regresar al primer servidor */ + obj->retry_count++; + if (obj->retry_count >= 3) { + /* Ya agoté todos los reintentos y servidores, bye */ + dns2_clean_network (obj); + obj->current_ns = NULL; + + return DNS_COMMAND_ERROR; + } + + obj->current_ns = obj->nameservers; + return _dns2_internal_udp_create (obj); + } + } else if (d > 1.0) { + /* 1 segundo entre servidor y servidor */ + return _dns2_internal_udp_next_or_error (obj); + } + + return DNS_COMMAND_POLL; +} + +int dns2_get_socket (DNS2 *obj) { + NameServer *ns; + + if (obj == NULL) return -1; + + if (obj->state == DNS_STATE_FREE) return -1; + + ns = (NameServer *) obj->current_ns->data; + + return ns->socket; +} + +int dns2_get_socket_poll_flags (DNS2 *obj) { + if (obj == NULL) return -1; + + if (obj->direction == DNS_POLL_WANT_READ) { + return DNS_POLL_WANT_READ; + } else if (obj->direction == DNS_POLL_WANT_WRITE) { + return DNS_POLL_WANT_WRITE; + } + + return 0; +} + +void dns2_set_use_tcp (DNS2 *obj) { + if (obj == NULL) return; + + obj->force_use_tcp = 1; +} + +DNSRR **dns2_get_answers_from_response (DNS2 *obj) { + if (obj == NULL) return NULL; + if (obj->packet_response == NULL) return NULL; + + return dns_packet_get_answers (obj->packet_response); +} + +DNSRR **dns2_get_authority_from_response (DNS2 *obj) { + if (obj == NULL) return NULL; + if (obj->packet_response == NULL) return NULL; + + return dns_packet_get_authority (obj->packet_response); +} + +DNSRR **dns2_get_additional_from_response (DNS2 *obj) { + if (obj == NULL) return NULL; + if (obj->packet_response == NULL) return NULL; + + return dns_packet_get_additional (obj->packet_response); +} + +int dns2_get_rcode (DNS2 *obj) { + if (obj == NULL) return -1; + if (obj->packet_response == NULL) return -1; + + return obj->packet_response->header.rcode; +} + diff --git a/src/dns2.h b/src/dns2.h new file mode 100644 index 0000000..28d08d7 --- /dev/null +++ b/src/dns2.h @@ -0,0 +1,63 @@ +#ifndef __DNS2_H__ +#define __DNS2_H__ + +#include +#include + +#include + +#include "rr.h" + +enum { + DNS_RESOLVER = 0, + DNS_UPDATER +}; + +enum { + DNS_STATE_FREE = 0, + DNS_STATE_UDP, + DNS_STATE_TCP_CONNECT, + DNS_STATE_TCP +}; + +enum { + DNS_COMMAND_ERROR_UNSIGNED = -2, + DNS_COMMAND_ERROR = -1, + DNS_COMMAND_POLL = 0, + DNS_COMMAND_SUCCESS = 1 +}; + +#define DNS_POLL_WANT_NONE 0x00 +#define DNS_POLL_WANT_READ 0x01 +#define DNS_POLL_WANT_WRITE 0x02 + +typedef struct _DNS2 DNS2; + +DNS2 *dns2_resolver_new (int recursion); +void dns2_resolver_set_question (DNS2 *resolver, const char *name, int type, int klass); + +DNS2 *dns2_updater_new (const char *zone); +void dns2_updater_add (DNS2 *updater, DNSRR *rr); + +void dns2_add_nserver (DNS2 *obj, const char *ip); +void dns2_free (DNS2 *obj); + +void dns2_sign_tsig (DNS2 *obj, const char *keyname, const char *signature, const char *algorithm); + +int dns2_sync (DNS2 *obj); +int dns2_async (DNS2 *obj); +int dns2_async_continue (DNS2 *obj, int happen); + +int dns2_check_timeout (DNS2 *obj); +int dns2_get_socket (DNS2 *obj); +int dns2_get_socket_poll_flags (DNS2 *obj); +void dns2_set_use_tcp (DNS2 *obj); + +DNSRR **dns2_get_answers_from_response (DNS2 *obj); +DNSRR **dns2_get_authority_from_response (DNS2 *obj); +DNSRR **dns2_get_additional_from_response (DNS2 *obj); + +int dns2_get_rcode (DNS2 *obj); + +#endif /* __DNS2_H__ */ + diff --git a/src/glist.c b/src/glist.c new file mode 100644 index 0000000..82a6950 --- /dev/null +++ b/src/glist.c @@ -0,0 +1,1258 @@ +/* GLIB - Library of useful routines for C programming + * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see . + */ + +/* + * Modified by the GLib Team and others 1997-2000. See the AUTHORS + * file for a list of people on the GLib Team. See the ChangeLog + * files for a list of changes. These files are distributed with + * GLib at ftp://ftp.gtk.org/pub/gtk/. + */ + +/* + * MT safe + */ + +#include +#include + +#include "glist.h" + +/** + * SECTION:linked_lists_double + * @title: Doubly-Linked Lists + * @short_description: linked lists that can be iterated over in both directions + * + * The #GList structure and its associated functions provide a standard + * doubly-linked list data structure. + * + * Each element in the list contains a piece of data, together with + * pointers which link to the previous and next elements in the list. + * Using these pointers it is possible to move through the list in both + * directions (unlike the singly-linked [GSList][glib-Singly-Linked-Lists], + * which only allows movement through the list in the forward direction). + * + * The double linked list does not keep track of the number of items + * and does not keep track of both the start and end of the list. If + * you want fast access to both the start and the end of the list, + * and/or the number of items in the list, use a + * [GQueue][glib-Double-ended-Queues] instead. + * + * The data contained in each element can be either integer values, by + * using one of the [Type Conversion Macros][glib-Type-Conversion-Macros], + * or simply pointers to any type of data. + * + * List elements are allocated from the [slice allocator][glib-Memory-Slices], + * which is more efficient than allocating elements individually. + * + * Note that most of the #GList functions expect to be passed a pointer + * to the first element in the list. The functions which insert + * elements return the new start of the list, which may have changed. + * + * There is no function to create a #GList. %NULL is considered to be + * a valid, empty list so you simply set a #GList* to %NULL to initialize + * it. + * + * To add elements, use g_list_append(), g_list_prepend(), + * g_list_insert() and g_list_insert_sorted(). + * + * To visit all elements in the list, use a loop over the list: + * |[ + * GList *l; + * for (l = list; l != NULL; l = l->next) + * { + * // do something with l->data + * } + * ]| + * + * To call a function for each element in the list, use g_list_foreach(). + * + * To loop over the list and modify it (e.g. remove a certain element) + * a while loop is more appropriate, for example: + * |[ + * GList *l = list; + * while (l != NULL) + * { + * GList *next = l->next; + * if (should_be_removed (l)) + * { + * // possibly free l->data + * list = g_list_delete_link (list, l); + * } + * l = next; + * } + * ]| + * + * To remove elements, use g_list_remove(). + * + * To navigate in a list, use g_list_first(), g_list_last(), + * g_list_next(), g_list_previous(). + * + * To find elements in the list use g_list_nth(), g_list_nth_data(), + * g_list_find() and g_list_find_custom(). + * + * To find the index of an element use g_list_position() and + * g_list_index(). + * + * To free the entire list, use g_list_free() or g_list_free_full(). + */ + +/** + * GList: + * @data: holds the element's data, which can be a pointer to any kind + * of data, or any integer value using the + * [Type Conversion Macros][glib-Type-Conversion-Macros] + * @next: contains the link to the next element in the list + * @prev: contains the link to the previous element in the list + * + * The #GList struct is used for each element in a doubly-linked list. + **/ + +/** + * g_list_previous: + * @list: an element in a #GList + * + * A convenience macro to get the previous element in a #GList. + * Note that it is considered perfectly acceptable to access + * @list->previous directly. + * + * Returns: the previous element, or %NULL if there are no previous + * elements + **/ + +/** + * g_list_next: + * @list: an element in a #GList + * + * A convenience macro to get the next element in a #GList. + * Note that it is considered perfectly acceptable to access + * @list->next directly. + * + * Returns: the next element, or %NULL if there are no more elements + **/ + +#define _g_list_alloc() ((GList *) malloc (sizeof (GList))) +#define _g_list_alloc0() ((GList *) calloc (1, sizeof (GList))) +#define _g_list_free1(list) free (list) + +/** + * g_list_alloc: + * + * Allocates space for one #GList element. It is called by + * g_list_append(), g_list_prepend(), g_list_insert() and + * g_list_insert_sorted() and so is rarely used on its own. + * + * Returns: a pointer to the newly-allocated #GList element + **/ +GList * +g_list_alloc (void) +{ + return _g_list_alloc0 (); +} + +/** + * g_list_free: + * @list: a #GList + * + * Frees all of the memory used by a #GList. + * The freed elements are returned to the slice allocator. + * + * If list elements contain dynamically-allocated memory, you should + * either use g_list_free_full() or free them manually first. + */ +void +g_list_free (GList *list) +{ + GList *n; + + while (list != NULL) { + n = list->next; + + free (list); + list = n; + } +} + +/** + * g_list_free_1: + * @list: a #GList element + * + * Frees one #GList element, but does not update links from the next and + * previous elements in the list, so you should not call this function on an + * element that is currently part of a list. + * + * It is usually used after g_list_remove_link(). + */ +/** + * g_list_free1: + * + * Another name for g_list_free_1(). + **/ +void +g_list_free_1 (GList *list) +{ + _g_list_free1 (list); +} + +/** + * g_list_free_full: + * @list: a pointer to a #GList + * @free_func: the function to be called to free each element's data + * + * Convenience method, which frees all the memory used by a #GList, + * and calls @free_func on every element's data. + * + * Since: 2.28 + */ +void +g_list_free_full (GList *list, + GDestroyNotify free_func) +{ + g_list_foreach (list, (GFunc) free_func, NULL); + g_list_free (list); +} + +/** + * g_list_append: + * @list: a pointer to a #GList + * @data: the data for the new element + * + * Adds a new element on to the end of the list. + * + * Note that the return value is the new start of the list, + * if @list was empty; make sure you store the new value. + * + * g_list_append() has to traverse the entire list to find the end, + * which is inefficient when adding multiple elements. A common idiom + * to avoid the inefficiency is to use g_list_prepend() and reverse + * the list with g_list_reverse() when all elements have been added. + * + * |[ + * // Notice that these are initialized to the empty list. + * GList *string_list = NULL, *number_list = NULL; + * + * // This is a list of strings. + * string_list = g_list_append (string_list, "first"); + * string_list = g_list_append (string_list, "second"); + * + * // This is a list of integers. + * number_list = g_list_append (number_list, int_TO_POINTER (27)); + * number_list = g_list_append (number_list, int_TO_POINTER (14)); + * ]| + * + * Returns: either @list or the new start of the #GList if @list was %NULL + */ +GList * +g_list_append (GList *list, + gpointer data) +{ + GList *new_list; + GList *last; + + new_list = _g_list_alloc (); + new_list->data = data; + new_list->next = NULL; + + if (list) + { + last = g_list_last (list); + /* g_assert (last != NULL); */ + last->next = new_list; + new_list->prev = last; + + return list; + } + else + { + new_list->prev = NULL; + return new_list; + } +} + +/** + * g_list_prepend: + * @list: a pointer to a #GList, this must point to the top of the list + * @data: the data for the new element + * + * Prepends a new element on to the start of the list. + * + * Note that the return value is the new start of the list, + * which will have changed, so make sure you store the new value. + * + * |[ + * // Notice that it is initialized to the empty list. + * GList *list = NULL; + * + * list = g_list_prepend (list, "last"); + * list = g_list_prepend (list, "first"); + * ]| + * + * Do not use this function to prepend a new element to a different + * element than the start of the list. Use g_list_insert_before() instead. + * + * Returns: a pointer to the newly prepended element, which is the new + * start of the #GList + */ +GList * +g_list_prepend (GList *list, + gpointer data) +{ + GList *new_list; + + new_list = _g_list_alloc (); + new_list->data = data; + new_list->next = list; + + if (list) + { + new_list->prev = list->prev; + if (list->prev) + list->prev->next = new_list; + list->prev = new_list; + } + else + new_list->prev = NULL; + + return new_list; +} + +/** + * g_list_insert: + * @list: a pointer to a #GList, this must point to the top of the list + * @data: the data for the new element + * @position: the position to insert the element. If this is + * negative, or is larger than the number of elements in the + * list, the new element is added on to the end of the list. + * + * Inserts a new element into the list at the given position. + * + * Returns: the (possibly changed) start of the #GList + */ +GList * +g_list_insert (GList *list, + gpointer data, + int position) +{ + GList *new_list; + GList *tmp_list; + + if (position < 0) + return g_list_append (list, data); + else if (position == 0) + return g_list_prepend (list, data); + + tmp_list = g_list_nth (list, position); + if (!tmp_list) + return g_list_append (list, data); + + new_list = _g_list_alloc (); + new_list->data = data; + new_list->prev = tmp_list->prev; + tmp_list->prev->next = new_list; + new_list->next = tmp_list; + tmp_list->prev = new_list; + + return list; +} + +/** + * g_list_insert_before: + * @list: a pointer to a #GList, this must point to the top of the list + * @sibling: the list element before which the new element + * is inserted or %NULL to insert at the end of the list + * @data: the data for the new element + * + * Inserts a new element into the list before the given position. + * + * Returns: the (possibly changed) start of the #GList + */ +GList * +g_list_insert_before (GList *list, + GList *sibling, + gpointer data) +{ + if (!list) + { + list = g_list_alloc (); + list->data = data; + //if (sibling != NULL) return list; + //g_return_val_if_fail (sibling == NULL, list); + return list; + } + else if (sibling) + { + GList *node; + + node = _g_list_alloc (); + node->data = data; + node->prev = sibling->prev; + node->next = sibling; + sibling->prev = node; + if (node->prev) + { + node->prev->next = node; + return list; + } + else + { + //g_return_val_if_fail (sibling == list, node); + return node; + } + } + else + { + GList *last; + + last = list; + while (last->next) + last = last->next; + + last->next = _g_list_alloc (); + last->next->data = data; + last->next->prev = last; + last->next->next = NULL; + + return list; + } +} + +/** + * g_list_concat: + * @list1: a #GList, this must point to the top of the list + * @list2: the #GList to add to the end of the first #GList, + * this must point to the top of the list + * + * Adds the second #GList onto the end of the first #GList. + * Note that the elements of the second #GList are not copied. + * They are used directly. + * + * This function is for example used to move an element in the list. + * The following example moves an element to the top of the list: + * |[ + * list = g_list_remove_link (list, llink); + * list = g_list_concat (llink, list); + * ]| + * + * Returns: the start of the new #GList, which equals @list1 if not %NULL + */ +GList * +g_list_concat (GList *list1, + GList *list2) +{ + GList *tmp_list; + + if (list2) + { + tmp_list = g_list_last (list1); + if (tmp_list) + tmp_list->next = list2; + else + list1 = list2; + list2->prev = tmp_list; + } + + return list1; +} + +static inline GList * +_g_list_remove_link (GList *list, + GList *link) +{ + if (link == NULL) + return list; + + if (link->prev) + { + if (link->prev->next == link) + link->prev->next = link->next; + //else + printf ("corrupted double-linked list detected"); + } + if (link->next) + { + if (link->next->prev == link) + link->next->prev = link->prev; + else + printf ("corrupted double-linked list detected"); + } + + if (link == list) + list = list->next; + + link->next = NULL; + link->prev = NULL; + + return list; +} + +/** + * g_list_remove: + * @list: a #GList, this must point to the top of the list + * @data: the data of the element to remove + * + * Removes an element from a #GList. + * If two elements contain the same data, only the first is removed. + * If none of the elements contain the data, the #GList is unchanged. + * + * Returns: the (possibly changed) start of the #GList + */ +GList * +g_list_remove (GList *list, + gconstpointer data) +{ + GList *tmp; + + tmp = list; + while (tmp) + { + if (tmp->data != data) + tmp = tmp->next; + else + { + list = _g_list_remove_link (list, tmp); + _g_list_free1 (tmp); + + break; + } + } + return list; +} + +/** + * g_list_remove_all: + * @list: a #GList, this must point to the top of the list + * @data: data to remove + * + * Removes all list nodes with data equal to @data. + * Returns the new head of the list. Contrast with + * g_list_remove() which removes only the first node + * matching the given data. + * + * Returns: the (possibly changed) start of the #GList + */ +GList * +g_list_remove_all (GList *list, + gconstpointer data) +{ + GList *tmp = list; + + while (tmp) + { + if (tmp->data != data) + tmp = tmp->next; + else + { + GList *next = tmp->next; + + if (tmp->prev) + tmp->prev->next = next; + else + list = next; + if (next) + next->prev = tmp->prev; + + _g_list_free1 (tmp); + tmp = next; + } + } + return list; +} + +/** + * g_list_remove_link: + * @list: a #GList, this must point to the top of the list + * @llink: an element in the #GList + * + * Removes an element from a #GList, without freeing the element. + * The removed element's prev and next links are set to %NULL, so + * that it becomes a self-contained list with one element. + * + * This function is for example used to move an element in the list + * (see the example for g_list_concat()) or to remove an element in + * the list before freeing its data: + * |[ + * list = g_list_remove_link (list, llink); + * free_some_data_that_may_access_the_list_again (llink->data); + * g_list_free (llink); + * ]| + * + * Returns: the (possibly changed) start of the #GList + */ +GList * +g_list_remove_link (GList *list, + GList *llink) +{ + return _g_list_remove_link (list, llink); +} + +/** + * g_list_delete_link: + * @list: a #GList, this must point to the top of the list + * @link_: node to delete from @list + * + * Removes the node link_ from the list and frees it. + * Compare this to g_list_remove_link() which removes the node + * without freeing it. + * + * Returns: the (possibly changed) start of the #GList + */ +GList * +g_list_delete_link (GList *list, + GList *link_) +{ + list = _g_list_remove_link (list, link_); + _g_list_free1 (link_); + + return list; +} + +/** + * g_list_copy: + * @list: a #GList, this must point to the top of the list + * + * Copies a #GList. + * + * Note that this is a "shallow" copy. If the list elements + * consist of pointers to data, the pointers are copied but + * the actual data is not. See g_list_copy_deep() if you need + * to copy the data as well. + * + * Returns: the start of the new list that holds the same data as @list + */ +GList * +g_list_copy (GList *list) +{ + return g_list_copy_deep (list, NULL, NULL); +} + +/** + * g_list_copy_deep: + * @list: a #GList, this must point to the top of the list + * @func: a copy function used to copy every element in the list + * @user_data: user data passed to the copy function @func, or %NULL + * + * Makes a full (deep) copy of a #GList. + * + * In contrast with g_list_copy(), this function uses @func to make + * a copy of each list element, in addition to copying the list + * container itself. + * + * @func, as a #GCopyFunc, takes two arguments, the data to be copied + * and a @user_data pointer. It's safe to pass %NULL as user_data, + * if the copy function takes only one argument. + * + * For instance, if @list holds a list of GObjects, you can do: + * |[ + * another_list = g_list_copy_deep (list, (GCopyFunc) g_object_ref, NULL); + * ]| + * + * And, to entirely free the new list, you could do: + * |[ + * g_list_free_full (another_list, g_object_unref); + * ]| + * + * Returns: the start of the new list that holds a full copy of @list, + * use g_list_free_full() to free it + * + * Since: 2.34 + */ +GList * +g_list_copy_deep (GList *list, + GCopyFunc func, + gpointer user_data) +{ + GList *new_list = NULL; + + if (list) + { + GList *last; + + new_list = _g_list_alloc (); + if (func) + new_list->data = func (list->data, user_data); + else + new_list->data = list->data; + new_list->prev = NULL; + last = new_list; + list = list->next; + while (list) + { + last->next = _g_list_alloc (); + last->next->prev = last; + last = last->next; + if (func) + last->data = func (list->data, user_data); + else + last->data = list->data; + list = list->next; + } + last->next = NULL; + } + + return new_list; +} + +/** + * g_list_reverse: + * @list: a #GList, this must point to the top of the list + * + * Reverses a #GList. + * It simply switches the next and prev pointers of each element. + * + * Returns: the start of the reversed #GList + */ +GList * +g_list_reverse (GList *list) +{ + GList *last; + + last = NULL; + while (list) + { + last = list; + list = last->next; + last->next = last->prev; + last->prev = list; + } + + return last; +} + +/** + * g_list_nth: + * @list: a #GList, this must point to the top of the list + * @n: the position of the element, counting from 0 + * + * Gets the element at the given position in a #GList. + * + * This iterates over the list until it reaches the @n-th position. If you + * intend to iterate over every element, it is better to use a for-loop as + * described in the #GList introduction. + * + * Returns: the element, or %NULL if the position is off + * the end of the #GList + */ +GList * +g_list_nth (GList *list, + unsigned int n) +{ + while ((n-- > 0) && list) + list = list->next; + + return list; +} + +/** + * g_list_nth_prev: + * @list: a #GList + * @n: the position of the element, counting from 0 + * + * Gets the element @n places before @list. + * + * Returns: the element, or %NULL if the position is + * off the end of the #GList + */ +GList * +g_list_nth_prev (GList *list, + unsigned int n) +{ + while ((n-- > 0) && list) + list = list->prev; + + return list; +} + +/** + * g_list_nth_data: + * @list: a #GList, this must point to the top of the list + * @n: the position of the element + * + * Gets the data of the element at the given position. + * + * This iterates over the list until it reaches the @n-th position. If you + * intend to iterate over every element, it is better to use a for-loop as + * described in the #GList introduction. + * + * Returns: the element's data, or %NULL if the position + * is off the end of the #GList + */ +gpointer +g_list_nth_data (GList *list, + unsigned int n) +{ + while ((n-- > 0) && list) + list = list->next; + + return list ? list->data : NULL; +} + +/** + * g_list_find: + * @list: a #GList, this must point to the top of the list + * @data: the element data to find + * + * Finds the element in a #GList which contains the given data. + * + * Returns: the found #GList element, or %NULL if it is not found + */ +GList * +g_list_find (GList *list, + gconstpointer data) +{ + while (list) + { + if (list->data == data) + break; + list = list->next; + } + + return list; +} + +/** + * g_list_find_custom: + * @list: a #GList, this must point to the top of the list + * @data: user data passed to the function + * @func: the function to call for each element. + * It should return 0 when the desired element is found + * + * Finds an element in a #GList, using a supplied function to + * find the desired element. It iterates over the list, calling + * the given function which should return 0 when the desired + * element is found. The function takes two #gconstpointer arguments, + * the #GList element's data as the first argument and the + * given user data. + * + * Returns: the found #GList element, or %NULL if it is not found + */ +GList * +g_list_find_custom (GList *list, + gconstpointer data, + GCompareFunc func) +{ + if (func == NULL) return list; + //g_return_val_if_fail (func != NULL, list); + + while (list) + { + if (! func (list->data, data)) + return list; + list = list->next; + } + + return NULL; +} + +/** + * g_list_position: + * @list: a #GList, this must point to the top of the list + * @llink: an element in the #GList + * + * Gets the position of the given element + * in the #GList (starting from 0). + * + * Returns: the position of the element in the #GList, + * or -1 if the element is not found + */ +int +g_list_position (GList *list, + GList *llink) +{ + int i; + + i = 0; + while (list) + { + if (list == llink) + return i; + i++; + list = list->next; + } + + return -1; +} + +/** + * g_list_index: + * @list: a #GList, this must point to the top of the list + * @data: the data to find + * + * Gets the position of the element containing + * the given data (starting from 0). + * + * Returns: the index of the element containing the data, + * or -1 if the data is not found + */ +int +g_list_index (GList *list, + gconstpointer data) +{ + int i; + + i = 0; + while (list) + { + if (list->data == data) + return i; + i++; + list = list->next; + } + + return -1; +} + +/** + * g_list_last: + * @list: any #GList element + * + * Gets the last element in a #GList. + * + * Returns: the last element in the #GList, + * or %NULL if the #GList has no elements + */ +GList * +g_list_last (GList *list) +{ + if (list) + { + while (list->next) + list = list->next; + } + + return list; +} + +/** + * g_list_first: + * @list: any #GList element + * + * Gets the first element in a #GList. + * + * Returns: the first element in the #GList, + * or %NULL if the #GList has no elements + */ +GList * +g_list_first (GList *list) +{ + if (list) + { + while (list->prev) + list = list->prev; + } + + return list; +} + +/** + * g_list_length: + * @list: a #GList, this must point to the top of the list + * + * Gets the number of elements in a #GList. + * + * This function iterates over the whole list to count its elements. + * Use a #GQueue instead of a GList if you regularly need the number + * of items. To check whether the list is non-empty, it is faster to check + * @list against %NULL. + * + * Returns: the number of elements in the #GList + */ +unsigned int +g_list_length (GList *list) +{ + unsigned int length; + + length = 0; + while (list) + { + length++; + list = list->next; + } + + return length; +} + +/** + * g_list_foreach: + * @list: a #GList, this must point to the top of the list + * @func: the function to call with each element's data + * @user_data: user data to pass to the function + * + * Calls a function for each element of a #GList. + */ +/** + * GFunc: + * @data: the element's data + * @user_data: user data passed to g_list_foreach() or g_slist_foreach() + * + * Specifies the type of functions passed to g_list_foreach() and + * g_slist_foreach(). + */ +void +g_list_foreach (GList *list, + GFunc func, + gpointer user_data) +{ + while (list) + { + GList *next = list->next; + (*func) (list->data, user_data); + list = next; + } +} + +static GList* +g_list_insert_sorted_real (GList *list, + gpointer data, + GFunc func, + gpointer user_data) +{ + GList *tmp_list = list; + GList *new_list; + int cmp; + + if (func == NULL) return list; + //g_return_val_if_fail (func != NULL, list); + + if (!list) + { + new_list = _g_list_alloc0 (); + new_list->data = data; + return new_list; + } + + cmp = ((GCompareDataFunc) func) (data, tmp_list->data, user_data); + + while ((tmp_list->next) && (cmp > 0)) + { + tmp_list = tmp_list->next; + + cmp = ((GCompareDataFunc) func) (data, tmp_list->data, user_data); + } + + new_list = _g_list_alloc0 (); + new_list->data = data; + + if ((!tmp_list->next) && (cmp > 0)) + { + tmp_list->next = new_list; + new_list->prev = tmp_list; + return list; + } + + if (tmp_list->prev) + { + tmp_list->prev->next = new_list; + new_list->prev = tmp_list->prev; + } + new_list->next = tmp_list; + tmp_list->prev = new_list; + + if (tmp_list == list) + return new_list; + else + return list; +} + +/** + * g_list_insert_sorted: + * @list: a pointer to a #GList, this must point to the top of the + * already sorted list + * @data: the data for the new element + * @func: the function to compare elements in the list. It should + * return a number > 0 if the first parameter comes after the + * second parameter in the sort order. + * + * Inserts a new element into the list, using the given comparison + * function to determine its position. + * + * If you are adding many new elements to a list, and the number of + * new elements is much larger than the length of the list, use + * g_list_prepend() to add the new items and sort the list afterwards + * with g_list_sort(). + * + * Returns: the (possibly changed) start of the #GList + */ +GList * +g_list_insert_sorted (GList *list, + gpointer data, + GCompareFunc func) +{ + return g_list_insert_sorted_real (list, data, (GFunc) func, NULL); +} + +/** + * g_list_insert_sorted_with_data: + * @list: a pointer to a #GList, this must point to the top of the + * already sorted list + * @data: the data for the new element + * @func: the function to compare elements in the list. It should + * return a number > 0 if the first parameter comes after the + * second parameter in the sort order. + * @user_data: user data to pass to comparison function + * + * Inserts a new element into the list, using the given comparison + * function to determine its position. + * + * If you are adding many new elements to a list, and the number of + * new elements is much larger than the length of the list, use + * g_list_prepend() to add the new items and sort the list afterwards + * with g_list_sort(). + * + * Returns: the (possibly changed) start of the #GList + * + * Since: 2.10 + */ +GList * +g_list_insert_sorted_with_data (GList *list, + gpointer data, + GCompareDataFunc func, + gpointer user_data) +{ + return g_list_insert_sorted_real (list, data, (GFunc) func, user_data); +} + +static GList * +g_list_sort_merge (GList *l1, + GList *l2, + GFunc compare_func, + gpointer user_data) +{ + GList list, *l, *lprev; + int cmp; + + l = &list; + lprev = NULL; + + while (l1 && l2) + { + cmp = ((GCompareDataFunc) compare_func) (l1->data, l2->data, user_data); + + if (cmp <= 0) + { + l->next = l1; + l1 = l1->next; + } + else + { + l->next = l2; + l2 = l2->next; + } + l = l->next; + l->prev = lprev; + lprev = l; + } + l->next = l1 ? l1 : l2; + l->next->prev = l; + + return list.next; +} + +static GList * +g_list_sort_real (GList *list, + GFunc compare_func, + gpointer user_data) +{ + GList *l1, *l2; + + if (!list) + return NULL; + if (!list->next) + return list; + + l1 = list; + l2 = list->next; + + while ((l2 = l2->next) != NULL) + { + if ((l2 = l2->next) == NULL) + break; + l1 = l1->next; + } + l2 = l1->next; + l1->next = NULL; + + return g_list_sort_merge (g_list_sort_real (list, compare_func, user_data), + g_list_sort_real (l2, compare_func, user_data), + compare_func, + user_data); +} + +/** + * g_list_sort: + * @list: a #GList, this must point to the top of the list + * @compare_func: the comparison function used to sort the #GList. + * This function is passed the data from 2 elements of the #GList + * and should return 0 if they are equal, a negative value if the + * first element comes before the second, or a positive value if + * the first element comes after the second. + * + * Sorts a #GList using the given comparison function. The algorithm + * used is a stable sort. + * + * Returns: the (possibly changed) start of the #GList + */ +/** + * GCompareFunc: + * @a: a value + * @b: a value to compare with + * + * Specifies the type of a comparison function used to compare two + * values. The function should return a negative integer if the first + * value comes before the second, 0 if they are equal, or a positive + * integer if the first value comes after the second. + * + * Returns: negative value if @a < @b; zero if @a = @b; positive + * value if @a > @b + */ +GList * +g_list_sort (GList *list, + GCompareFunc compare_func) +{ + return g_list_sort_real (list, (GFunc) compare_func, NULL); +} + +/** + * g_list_sort_with_data: + * @list: a #GList, this must point to the top of the list + * @compare_func: comparison function + * @user_data: user data to pass to comparison function + * + * Like g_list_sort(), but the comparison function accepts + * a user data argument. + * + * Returns: the (possibly changed) start of the #GList + */ +/** + * GCompareDataFunc: + * @a: a value + * @b: a value to compare with + * @user_data: user data + * + * Specifies the type of a comparison function used to compare two + * values. The function should return a negative integer if the first + * value comes before the second, 0 if they are equal, or a positive + * integer if the first value comes after the second. + * + * Returns: negative value if @a < @b; zero if @a = @b; positive + * value if @a > @b + */ +GList * +g_list_sort_with_data (GList *list, + GCompareDataFunc compare_func, + gpointer user_data) +{ + return g_list_sort_real (list, (GFunc) compare_func, user_data); +} diff --git a/src/glist.h b/src/glist.h new file mode 100644 index 0000000..7b08976 --- /dev/null +++ b/src/glist.h @@ -0,0 +1,152 @@ +/* GLIB - Library of useful routines for C programming + * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see . + */ + +/* + * Modified by the GLib Team and others 1997-2000. See the AUTHORS + * file for a list of people on the GLib Team. See the ChangeLog + * files for a list of changes. These files are distributed with + * GLib at ftp://ftp.gtk.org/pub/gtk/. + */ + +#ifndef __G_LIST_H__ +#define __G_LIST_H__ + +#define G_GNUC_WARN_UNUSED_RESULT __attribute__((warn_unused_result)) + +typedef void * gpointer; +typedef const void * gconstpointer; +typedef void (*GDestroyNotify) (gpointer data); +typedef void (*GFunc) (gpointer data, gpointer user_data); +typedef int (*GCompareDataFunc) (gconstpointer a, gconstpointer b, gpointer user_data); +typedef int (*GCompareFunc) (gconstpointer a, gconstpointer b); +typedef gpointer (*GCopyFunc) (gconstpointer src, gpointer data); + +typedef struct _GList GList; + +struct _GList +{ + gpointer data; + GList *next; + GList *prev; +}; + +/* Doubly linked lists + */ + +GList* g_list_alloc (void) G_GNUC_WARN_UNUSED_RESULT; + +void g_list_free (GList *list); + +void g_list_free_1 (GList *list); +#define g_list_free1 g_list_free_1 + +void g_list_free_full (GList *list, + GDestroyNotify free_func); + +GList* g_list_append (GList *list, + gpointer data) G_GNUC_WARN_UNUSED_RESULT; + +GList* g_list_prepend (GList *list, + gpointer data) G_GNUC_WARN_UNUSED_RESULT; + +GList* g_list_insert (GList *list, + gpointer data, + int position) G_GNUC_WARN_UNUSED_RESULT; + +GList* g_list_insert_sorted (GList *list, + gpointer data, + GCompareFunc func) G_GNUC_WARN_UNUSED_RESULT; + +GList* g_list_insert_sorted_with_data (GList *list, + gpointer data, + GCompareDataFunc func, + gpointer user_data) G_GNUC_WARN_UNUSED_RESULT; + +GList* g_list_insert_before (GList *list, + GList *sibling, + gpointer data) G_GNUC_WARN_UNUSED_RESULT; + +GList* g_list_concat (GList *list1, + GList *list2) G_GNUC_WARN_UNUSED_RESULT; + +GList* g_list_remove (GList *list, + gconstpointer data) G_GNUC_WARN_UNUSED_RESULT; + +GList* g_list_remove_all (GList *list, + gconstpointer data) G_GNUC_WARN_UNUSED_RESULT; + +GList* g_list_remove_link (GList *list, + GList *llink) G_GNUC_WARN_UNUSED_RESULT; + +GList* g_list_delete_link (GList *list, + GList *link_) G_GNUC_WARN_UNUSED_RESULT; + +GList* g_list_reverse (GList *list) G_GNUC_WARN_UNUSED_RESULT; + +GList* g_list_copy (GList *list) G_GNUC_WARN_UNUSED_RESULT; + + +GList* g_list_copy_deep (GList *list, + GCopyFunc func, + gpointer user_data) G_GNUC_WARN_UNUSED_RESULT; + + +GList* g_list_nth (GList *list, + unsigned int n); + +GList* g_list_nth_prev (GList *list, + unsigned int n); + +GList* g_list_find (GList *list, + gconstpointer data); + +GList* g_list_find_custom (GList *list, + gconstpointer data, + GCompareFunc func); + +int g_list_position (GList *list, + GList *llink); + +int g_list_index (GList *list, + gconstpointer data); + +GList* g_list_last (GList *list); + +GList* g_list_first (GList *list); + +unsigned int g_list_length (GList *list); + +void g_list_foreach (GList *list, + GFunc func, + gpointer user_data); + +GList* g_list_sort (GList *list, + GCompareFunc compare_func) G_GNUC_WARN_UNUSED_RESULT; + +GList* g_list_sort_with_data (GList *list, + GCompareDataFunc compare_func, + gpointer user_data) G_GNUC_WARN_UNUSED_RESULT; + +gpointer g_list_nth_data (GList *list, + unsigned int n); + + +#define g_list_previous(list) ((list) ? (((GList *)(list))->prev) : NULL) +#define g_list_next(list) ((list) ? (((GList *)(list))->next) : NULL) + + +#endif /* __G_LIST_H__ */ diff --git a/src/header.c b/src/header.c new file mode 100644 index 0000000..cf4430d --- /dev/null +++ b/src/header.c @@ -0,0 +1,40 @@ +#include +#include +#include + +#include + +#include + +#include "header.h" +#include "constants.h" + +static uint16_t next_packet_id = 0; + +static uint16_t dns_header_get_next_packet_id (void) { + if (next_packet_id == 0) { + next_packet_id = 1 + ((int) (65534.0 * rand () / (RAND_MAX + 1.0))); + } + + return next_packet_id++;; +} + +void dns_header_init (DNSHeader *header) { + header->id = dns_header_get_next_packet_id (); + //header->id = 0x72de; + header->qr = QR_QUERY; + header->opcode = OPCODE_QUERY; + header->aa = 0; + header->tc = 0; + header->rd = 1; + header->ra = 0; + header->z = 0; + header->ad = 0; + header->cd = 0; + header->rcode = RCODE_NOERROR; + header->qdcount = 1; + header->ancount = 0; + header->nscount = 0; + header->arcount = 0; +} + diff --git a/src/header.h b/src/header.h new file mode 100644 index 0000000..a531290 --- /dev/null +++ b/src/header.h @@ -0,0 +1,60 @@ +#ifndef __HEADER_H__ +#define __HEADER_H__ + +#include +#include +#include + +/** + * DNS Packet Header class + * + * This class handles parsing and constructing DNS Packet Headers as defined + * by section 4.1.1 of RFC1035. + * + * DNS header format - RFC1035 section 4.1.1 + * DNS header format - RFC4035 section 3.2 + * + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | ID | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * |QR| Opcode |AA|TC|RD|RA| Z|AD|CD| RCODE | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | QDCOUNT | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | ANCOUNT | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | NSCOUNT | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * | ARCOUNT | + * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * + * @category Networking + * @package Net_DNS2 + * @author Mike Pultz + * @license http://www.opensource.org/licenses/bsd-license.php BSD License + * @link http://pear.php.net/package/Net_DNS2 + * + */ + +typedef struct { + uint16_t id; // 16 bit - identifier + uint8_t qr; // 1 bit - 0 = query, 1 = response + uint8_t opcode; // 4 bit - op code + uint8_t aa; // 1 bit - Authoritative Answer + uint8_t tc; // 1 bit - TrunCation + uint8_t rd; // 1 bit - Recursion Desired + uint8_t ra; // 1 bit - Recursion Available + uint8_t z; // 1 bit - Reserved + uint8_t ad; // 1 bit - Authentic Data (RFC4035) + uint8_t cd; // 1 bit - Checking Disabled (RFC4035) + uint8_t rcode; // 4 bit - Response code + uint16_t qdcount; // 16 bit - entries in the question section + uint16_t ancount; // 16 bit - resource records in the answer section + uint16_t nscount; // 16 bit - name server rr in the authority records section + uint16_t arcount; // 16 bit - rr's in the additional records section +} DNSHeader; + +void dns_header_init (DNSHeader *header); + +#endif /* __HEADER_H__ */ diff --git a/src/libdnsc.sym b/src/libdnsc.sym new file mode 100644 index 0000000..a19fa5c --- /dev/null +++ b/src/libdnsc.sym @@ -0,0 +1,24 @@ +dns2_resolver_new +dns2_resolver_set_question +dns2_updater_new +dns2_updater_add +dns2_add_nserver +dns2_free +dns2_sign_tsig +dns2_sync +dns2_async +dns2_async_continue +dns2_check_timeout +dns2_get_socket +dns2_get_socket_poll_flags +dns2_set_use_tcp +dns2_get_answers_from_response +dns2_get_authority_from_response +dns2_get_additional_from_response +dns2_get_rcode +dns2_rr_create_a +dns2_rr_create_aaaa +dns2_rr_create_ns +dns2_rr_create_tsig +dns2_rr_dup +dns2_rr_free diff --git a/src/packet.c b/src/packet.c new file mode 100644 index 0000000..e5f9a56 --- /dev/null +++ b/src/packet.c @@ -0,0 +1,601 @@ +#include +#include +#include + +#include "constants.h" +#include "packet.h" +#include "question.h" +#include "rr.h" + +void dns_rr_pack_data (DNSRR *rr, DNSPacket *packet); +DNSRR * dns_rr_unpack_data (DNSPacket *packet); + +DNSPacket *dns_packet_create_request (const char *name, int type, int klass) { + DNSPacket *req; + DNSQuestion *q; + + req = (DNSPacket *) malloc (sizeof (DNSPacket)); + + if (req == NULL) return NULL; + + dns_header_init (&req->header); + + q = dns_question_create (name, type, klass); + + if (q == NULL) { + free (req); + + return NULL; + } + + req->questions = g_list_append (NULL, q); + + req->authority = NULL; + req->answers = NULL; + req->additional = NULL; + req->rdlength = 0; + + req->labels = NULL; + + return req; +} + +DNSPacket *dns_packet_create_response (int type, unsigned char *data, int size_data) { + DNSPacket *res; + DNSRR *rr; + + int g; + + res = (DNSPacket *) malloc (sizeof (DNSPacket)); + + if (res == NULL) return NULL; + + memset (res, 0, sizeof (DNSPacket)); + + res->answer_socket_type = type; + + memcpy (res->rdata, data, size_data); + res->rdlength = size_data; + res->rdread = 0; + + if (dns_header_init_from_packet (&res->header, res) < 0) { + dns_packet_free_full (res); + + return NULL; + } + + /* TODO: Revisar el bit de truncamiento */ + + /* Parsear las preguntas */ + for (g = 0; g < res->header.qdcount; g++) { + if (dns_question_parse_question_from_packet (res) < 0) { + dns_packet_free_full (res); + + return NULL; + } + } + + /* Parsear los answers */ + for (g = 0; g < res->header.ancount; g++) { + rr = dns_rr_unpack_data (res); + + if (rr == NULL) { + dns_packet_free_full (res); + + return NULL; + } + + res->answers = g_list_append (res->answers, rr); + } + + /* Parsear los authority */ + for (g = 0; g < res->header.nscount; g++) { + rr = dns_rr_unpack_data (res); + + if (rr == NULL) { + dns_packet_free_full (res); + + return NULL; + } + + res->authority = g_list_append (res->authority, rr); + } + + /* Parsear los aditional */ + for (g = 0; g < res->header.arcount; g++) { + rr = dns_rr_unpack_data (res); + + if (rr == NULL) { + dns_packet_free_full (res); + + return NULL; + } + + res->additional = g_list_append (res->additional, rr); + } + + dns_packet_recount_items (res); + + return res; +} + +int dns_packet_get_data (DNSPacket *packet, unsigned char **data) { + if (data != NULL) { + *data = packet->rdata; + } + + return packet->rdlength; +} + +void dns_packet_pack_data (DNSPacket *packet) { + GList *g; + DNSQuestion *qq; + DNSRR *rr; + + /* Reiniciar desde 0 */ + packet->rdlength = 0; + + dns_header_pack_data (&packet->header, packet); + + g = packet->questions; + while (g != NULL) { + qq = (DNSQuestion *) g->data; + + dns_question_pack_data (qq, packet); + + g = g->next; + } + + g = packet->answers; + while (g != NULL) { + rr = (DNSRR *) g->data; + + dns_rr_pack_data (rr, packet); + + g = g->next; + } + + g = packet->authority; + while (g != NULL) { + rr = (DNSRR *) g->data; + + dns_rr_pack_data (rr, packet); + + g = g->next; + } + + g = packet->additional; + while (g != NULL) { + rr = (DNSRR *) g->data; + + dns_rr_pack_data (rr, packet); + + g = g->next; + } +} + +static int dns_packet_search_label (gconstpointer left, gconstpointer right) { + PacketLabel *a = (PacketLabel *) left; + PacketLabel *b = (PacketLabel *) right; + + return strcmp (a->name, b->name); +} + +static void dns_packet_append_word (DNSPacket *packet, const char *name) { + const char *ending; + PacketLabel *new_label; + uint8_t t8; + + ending = strchr (name, '.'); + if (ending == NULL) { + ending = name + strlen (name); + } + + new_label = (PacketLabel *) malloc (sizeof (PacketLabel)); + + if (new_label == NULL) { + /* Oops, error */ + return; + } + + strncpy (new_label->name, name, sizeof (new_label->name)); + new_label->offset = packet->rdlength; + + packet->labels = g_list_append (packet->labels, new_label); + + /* Copiar solo la palabra */ + t8 = (ending - name); + packet->rdata[packet->rdlength] = t8; + memcpy (&packet->rdata[packet->rdlength + 1], name, t8); + + packet->rdlength += t8 + 1; +} + +void dns_packet_pack_name (DNSPacket *packet, const char *name) { + char * dot_pos; + + while (dot_pos = strchr (name, '.'), dot_pos != NULL) { + /* Buscar esta palabra en nuestro diccionario de palabras */ + name = dot_pos + 1; + + /* Agregar esta palabra al diccionario de etiquetas */ + dns_packet_append_word (packet, name); + } + + /* La palabra restante, copiarla */ + if (name[0] != 0) { + dns_packet_append_word (packet, name); + } + + packet->rdata[packet->rdlength] = 0; + packet->rdlength += 1; +} + +void dns_packet_compress_name (DNSPacket *packet, char *name) { + PacketLabel temp, *found; + char * dot_pos; + GList *search; + uint16_t t16; + + while (dot_pos = strchr (name, '.'), dot_pos != NULL) { + /* Buscar esta palabra en nuestro diccionario de palabras */ + + strncpy (temp.name, name, sizeof (temp.name)); + + search = g_list_find_custom (packet->labels, &temp, dns_packet_search_label); + + if (search != NULL) { + found = (PacketLabel *) search->data; + + t16 = htons (0xc000 | found->offset); + + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; + + return; + } + + /* Agregar esta palabra al direccionario de etiquetas */ + dns_packet_append_word (packet, name); + name = dot_pos + 1; + } + + /* La palabra restante, copiarla */ + if (name[0] != 0) { + dns_packet_append_word (packet, name); + } + + packet->rdata[packet->rdlength] = 0; + packet->rdlength += 1; +} + +DNSPacket *dns_packet_clone_simple (DNSPacket *packet) { + DNSPacket *clone; + + clone = (DNSPacket *) malloc (sizeof (DNSPacket)); + + if (clone == NULL) return NULL; + + memcpy (&clone->header, &packet->header, sizeof (DNSHeader)); + + clone->questions = g_list_copy (packet->questions); + clone->answers = g_list_copy (packet->answers); + clone->authority = g_list_copy (packet->authority); + clone->additional = g_list_copy (packet->additional); + + clone->labels = NULL; + + clone->rdlength = 0; + + /* NOTA: No se copian las labels */ + + return clone; +} + +void dns_packet_free_simple (DNSPacket *packet) { + /* Liberar las estructuras, excepto los datos que no duplicamos */ + g_list_free_full (packet->labels, (GDestroyNotify) free); + + g_list_free (packet->questions); + g_list_free (packet->answers); + g_list_free (packet->authority); + g_list_free (packet->additional); + + free (packet); +} + +void dns_packet_free_full (DNSPacket *packet) { + g_list_free_full (packet->labels, (GDestroyNotify) free); + + g_list_free_full (packet->questions, (GDestroyNotify) dns_question_free); + g_list_free_full (packet->answers, (GDestroyNotify) dns2_rr_free); + g_list_free_full (packet->authority, (GDestroyNotify) dns2_rr_free); + g_list_free_full (packet->additional, (GDestroyNotify) dns2_rr_free); + + free (packet); +} + +void dns_packet_reset (DNSPacket *packet) { + g_list_free_full (packet->labels, (GDestroyNotify) free); + packet->labels = NULL; + + packet->rdlength = 0; +} + +int dns_packet_expand_name (unsigned char *name, DNSPacket *packet, int *offset) { + int name_len = 0; + uint8_t t8; + uint16_t t16; + int local_offset; + int ptr, ptr_inicio; + int g; + + while (1) { + if (name_len >= 256) { + return -1; + } + + if (packet->rdlength < (*offset) + 1) { + return -1; + } + + t8 = packet->rdata[*offset]; + + if (t8 == 0) { + name[name_len] = 0; + + (*offset)++; + + return 0; + } else if ((t8 & 0xc0) == 0xc0) { + /* Tenemos un apuntador */ + if (packet->rdlength < (*offset) + 2) { + return -1; + } + + memcpy (&t16, &packet->rdata[*offset], sizeof (t16)); + t16 = ntohs (t16); + + ptr = t16 & 0x3fff; + ptr_inicio = ptr; + if (dns_packet_expand_name (&name[name_len], packet, &ptr) < 0) { + return -1; + } + + /* Sumar a la longitud de nombres lo recibido del apuntador */ + name_len = name_len + (ptr - ptr_inicio); + (*offset) += 2; + + break; + } else { + (*offset)++; + + if (packet->rdlength < (*offset) + t8) { + return -1; + } + + /* Una palabra */ + for (g = *offset; g < t8 + *offset; g++) { + name[name_len] = packet->rdata[g]; + name_len++; + } + + name[name_len] = '.'; + name_len++; + + (*offset) += t8; + } + } + + /* Limpiar el último punto */ + if (name[name_len - 1] == '.') { + name[name_len - 1] = 0; + name_len--; + } + + return 0; +} + +int dns_packet_expand_name_simple (unsigned char *name, unsigned char *buffer, int buffer_size) { + int name_len = 0; + uint8_t t8; + int g; + int offset = 0; + + while (1) { + if (name_len >= 256) { + return -1; + } + + if (buffer_size < offset + 1) { + return -1; + } + + t8 = buffer[offset]; + offset++; + + if (t8 == 0) { + /* Fin del nombre */ + name[name_len] = 0; + + return offset; + } else { + if (buffer_size < offset + t8) { + return -1; + } + + /* Una palabra */ + for (g = offset; g < t8 + offset; g++) { + name[name_len] = buffer[g]; + name_len++; + } + + name[name_len] = '.'; + name_len++; + + offset += t8; + } + } + + /* Limpiar el último punto */ + if (name[name_len - 1] == '.') { + name[name_len - 1] = 0; + name_len--; + } + + return offset; +} + +void dns_header_pack_data (DNSHeader *header, DNSPacket *packet) { + unsigned char *buf; + uint16_t t16; + uint8_t t8; + + buf = &packet->rdata[packet->rdlength]; + + /* Copiar el ID */ + t16 = htons (header->id); + memcpy (&buf[0], &t16, sizeof (t16)); + + t8 = (header->qr << 7) | (header->opcode << 3) | (header->aa << 2) | (header->tc << 1) | (header->rd); + buf[2] = t8; + + t8 = (header->ra << 7) | (header->ad << 5) | (header->cd << 4) | header->rcode; + buf[3] = t8; + + t16 = htons (header->qdcount); + memcpy (&buf[4], &t16, sizeof (t16)); + + t16 = htons (header->ancount); + memcpy (&buf[6], &t16, sizeof (t16)); + + t16 = htons (header->nscount); + memcpy (&buf[8], &t16, sizeof (t16)); + + t16 = htons (header->arcount); + memcpy (&buf[10], &t16, sizeof (t16)); + + packet->rdlength += DNS_HEADER_SIZE; +} + +int dns_header_init_from_packet (DNSHeader *header, DNSPacket *packet) { + uint16_t t16; + uint8_t t8; + unsigned char *buf; + + buf = &packet->rdata[packet->rdread]; + + if (packet->rdlength < packet->rdread + DNS_HEADER_SIZE) { + return -1; + } + + memcpy (&t16, &buf[0], sizeof (t16)); + header->id = ntohs (t16); + + t8 = buf[2]; + + header->qr = (t8 >> 7) & 0x1; + header->opcode = (t8 >> 3) & 0xf; + header->aa = (t8 >> 2) & 0x1; + header->tc = (t8 >> 1) & 0x1; + header->rd = t8 & 0x1; + + t8 = buf[3]; + header->ra = (t8 >> 7) & 0x1; + header->z = (t8 >> 6) & 0x1; + header->ad = (t8 >> 5) & 0x1; + header->cd = (t8 >> 4) & 0x1; + header->rcode = t8 & 0xf; + + memcpy (&t16, &buf[4], sizeof (t16)); + header->qdcount = ntohs (t16); + + memcpy (&t16, &buf[6], sizeof (t16)); + header->ancount = ntohs (t16); + + memcpy (&t16, &buf[8], sizeof (t16)); + header->nscount = ntohs (t16); + + memcpy (&t16, &buf[10], sizeof (t16)); + header->arcount = ntohs (t16); + + packet->rdread += DNS_HEADER_SIZE; + + return 0; +} + +void dns_packet_recount_items (DNSPacket *packet) { + if (packet == NULL) return; + + packet->header.qdcount = g_list_length (packet->questions); + packet->header.ancount = g_list_length (packet->answers); + packet->header.nscount = g_list_length (packet->authority); + packet->header.arcount = g_list_length (packet->additional); +} + +DNSRR **dns_packet_get_answers (DNSPacket *packet) { + DNSRR **array; + GList *g; + int n; + + dns_packet_recount_items (packet); + + if (packet->header.ancount == 0) { + return NULL; + } + + array = (DNSRR **) malloc ((packet->header.ancount + 1) * sizeof (DNSRR *)); + + for (n = 0, g = packet->answers; g != NULL; g = g->next, n++) { + array[n] = (DNSRR *) g->data; + } + + array[n] = NULL; + + return array; +} + +DNSRR **dns_packet_get_authority (DNSPacket *packet) { + DNSRR **array; + GList *g; + int n; + + dns_packet_recount_items (packet); + + if (packet->header.nscount == 0) { + return NULL; + } + + array = (DNSRR **) malloc ((packet->header.nscount + 1) * sizeof (DNSRR *)); + + for (n = 0, g = packet->authority; g != NULL; g = g->next, n++) { + array[n] = (DNSRR *) g->data; + } + + array[n] = NULL; + + return array; +} + +DNSRR **dns_packet_get_additional (DNSPacket *packet) { + DNSRR **array; + GList *g; + int n; + + dns_packet_recount_items (packet); + + if (packet->header.arcount == 0) { + return NULL; + } + + array = (DNSRR **) malloc ((packet->header.arcount + 1) * sizeof (DNSRR *)); + + for (n = 0, g = packet->additional; g != NULL; g = g->next, n++) { + array[n] = (DNSRR *) g->data; + } + + array[n] = NULL; + + return array; +} + diff --git a/src/packet.h b/src/packet.h new file mode 100644 index 0000000..85cd4d3 --- /dev/null +++ b/src/packet.h @@ -0,0 +1,62 @@ +#ifndef __PACKET_H__ +#define __PACKET_H__ + +#include "glist.h" +#include "header.h" +#include "rr.h" + +typedef struct { + unsigned char name[256]; + uint16_t offset; +} PacketLabel; + +typedef struct { + unsigned char rdata[8192]; + + int rdlength; + int rdread; + + DNSHeader header; + + GList *questions; + + GList *answers; + + GList *authority; + + GList *additional; + + GList *labels; + + int answer_socket_type; + /* Las respuestas tienen: + answer_from + answer_socket_type + + */ + +} DNSPacket; + +DNSPacket *dns_packet_create_request (const char *name, int type, int klass); +DNSPacket *dns_packet_create_response (int type, unsigned char *data, int size_data); +DNSPacket *dns_packet_clone_simple (DNSPacket *packet); +void dns_packet_compress_name (DNSPacket *packet, char *name); +void dns_packet_pack_name (DNSPacket *packet, const char *name); +void dns_packet_pack_data (DNSPacket *packet); +int dns_packet_get_data (DNSPacket *packet, unsigned char **data); +void dns_packet_free_simple (DNSPacket *packet); +void dns_packet_free_full (DNSPacket *packet); +void dns_header_pack_data (DNSHeader *header, DNSPacket *packet); +int dns_header_init_from_packet (DNSHeader *header, DNSPacket *packet); +void dns_packet_reset (DNSPacket *packet); +int dns_packet_expand_name (unsigned char *name, DNSPacket *packet, int *offset); +int dns_packet_expand_name_simple (unsigned char *name, unsigned char *buffer, int buffer_size); + +void dns_rr_pack_generate_signature (DNSRR *signature, DNSPacket *packet); + +void dns_packet_recount_items (DNSPacket *packet); +DNSRR **dns_packet_get_answers (DNSPacket *packet); +DNSRR **dns_packet_get_authority (DNSPacket *packet); +DNSRR **dns_packet_get_additional (DNSPacket *packet); + +#endif /* __PACKET_H__ */ diff --git a/src/question.c b/src/question.c new file mode 100644 index 0000000..0bf9e18 --- /dev/null +++ b/src/question.c @@ -0,0 +1,87 @@ +#include +#include +#include + +#include + +#include "constants.h" +#include "question.h" +#include "packet.h" + +DNSQuestion * dns_question_create (const char *name, int type, int klass) { + DNSQuestion *question; + + question = (DNSQuestion *) malloc (sizeof (DNSQuestion)); + + if (question == NULL) return NULL; + + memset (question, 0, sizeof (DNSQuestion)); + + strncpy (question->qname, name, 255); + + question->qtype = type; + question->qklass = klass; + + return question; +} + +void dns_question_pack_data (DNSQuestion *question, DNSPacket *packet) { + uint16_t t16; + + dns_packet_compress_name (packet, question->qname); + + t16 = htons (question->qtype); + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; + + t16 = htons (question->qklass); + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; +} + +void dns_question_free (DNSQuestion *question) { + free (question); +} + +int dns_question_parse_question_from_packet (DNSPacket *packet) { + DNSQuestion *question; + uint16_t t16; + + question = (DNSQuestion *) malloc (sizeof (DNSQuestion)); + + if (question == NULL) return -1; + + memset (question, 0, sizeof (DNSQuestion)); + + if (dns_packet_expand_name (question->qname, packet, &packet->rdread) < 0) { + dns_question_free (question); + return -1; + } + + if (packet->rdlength < packet->rdread + 4) { + dns_question_free (question); + return -1; + } + + memcpy (&t16, &packet->rdata[packet->rdread], sizeof (t16)); + question->qtype = ntohs (t16); + packet->rdread += 2; + + memcpy (&t16, &packet->rdata[packet->rdread], sizeof (t16)); + question->qklass = ntohs (t16); + packet->rdread += 2; + + if (question->qklass != RR_CLASS_IN && + question->qklass != RR_CLASS_CH && + question->qklass != RR_CLASS_HS) { + dns_question_free (question); + return -1; + } + + /* TODO: Validar el qtype */ + + /* Anexar a la lista de preguntas */ + packet->questions = g_list_append (packet->questions, question); + return 0; +} + diff --git a/src/question.h b/src/question.h new file mode 100644 index 0000000..683ea51 --- /dev/null +++ b/src/question.h @@ -0,0 +1,18 @@ +#ifndef __QUESTION_H__ +#define __QUESTION_H__ + +#include "packet.h" + +typedef struct { + char qname[256]; + + int qtype; + int qklass; +} DNSQuestion; + +DNSQuestion * dns_question_create (const char *name, int type, int klass); +void dns_question_pack_data (DNSQuestion *question, DNSPacket *packet); +void dns_question_free (DNSQuestion *question); +int dns_question_parse_question_from_packet (DNSPacket *packet); + +#endif /* __QUESTION_H__ */ diff --git a/src/resolver.c b/src/resolver.c new file mode 100644 index 0000000..be03ba0 --- /dev/null +++ b/src/resolver.c @@ -0,0 +1,57 @@ +#include +#include +#include + +#include +#include +#include + +#include + +#include + +#include + +#include + +#include "dns2.h" +#include "utils.h" +#include "packet.h" +#include "constants.h" +#include "glist.h" +#include "rr.h" + +#include "dns2-private.h" + +DNS2 *dns2_resolver_new (int recursion) { + DNS2 *resolver; + + resolver = dns2_new (); + + if (resolver == NULL) { + return NULL; + } + + resolver->want_recursion = recursion; + resolver->type = DNS_RESOLVER; + + return resolver; +} + +void dns2_resolver_set_question (DNS2 *resolver, const char *name, int type, int klass) { + if (resolver->packet != NULL) { + dns_packet_free_full (resolver->packet); + resolver->packet = NULL; + } + + resolver->packet = dns_packet_create_request (name, type, klass); + + if (resolver->packet == NULL) { + /* FIXME: ¿Qué hacemos? */ + return; + } + + resolver->packet->header.opcode = OPCODE_QUERY; + resolver->packet->header.rd = resolver->want_recursion; +} + diff --git a/src/rr.c b/src/rr.c new file mode 100644 index 0000000..612ba0b --- /dev/null +++ b/src/rr.c @@ -0,0 +1,726 @@ +#include +#include +#include + +#include + +#include + +#include + +#include "rr.h" +#include "utils.h" +#include "constants.h" +#include "packet.h" + +/* ----- Creadores ----- */ + +DNSRR *dns2_rr_create_a (const char *name, int klass, int ttl, struct in_addr address) { + DNSRR *rr; + + rr = (DNSRR *) malloc (sizeof (DNSRR)); + + if (rr == NULL) { + return NULL; + } + + strncpy (rr->name, name, sizeof (rr->name)); + dns2_trim_name (rr->name); + + if (rr->name[0] == 0) { + free (rr); + return NULL; + } + + rr->type = RR_TYPE_A; + rr->klass = klass; + rr->ttl = ttl; + + /* Copiar la IP */ + memcpy (&rr->a.address, &address, sizeof (rr->a.address)); + + return rr; +} + +DNSRR *dns2_rr_create_tsig (const char *name, const char *signature, const char *algorithm) { + DNSRR *rr; + + if (strcmp (algorithm, RR_TSIG_HMAC_MD5) != 0 && + strcmp (algorithm, RR_TSIG_HMAC_SHA1) != 0 && + strcmp (algorithm, RR_TSIG_HMAC_SHA224) != 0 && + strcmp (algorithm, RR_TSIG_HMAC_SHA256) != 0 && + strcmp (algorithm, RR_TSIG_HMAC_SHA384) != 0 && + strcmp (algorithm, RR_TSIG_HMAC_SHA512) != 0) { + /* Algoritmo no soportado */ + return NULL; + } + + rr = (DNSRR *) malloc (sizeof (DNSRR)); + + if (rr == NULL) { + return NULL; + } + + strncpy (rr->name, name, sizeof (rr->name)); + dns2_trim_name (rr->name); + + if (rr->name[0] == 0) { + free (rr); + return NULL; + } + + rr->type = RR_TYPE_TSIG; + rr->klass = RR_CLASS_ANY; + rr->ttl = 0; + + strncpy (rr->tsig.algorithm, algorithm, sizeof (rr->tsig.algorithm)); + rr->tsig.key = strdup (signature); + + if (rr->tsig.key == NULL) { + free (rr->name); + free (rr); + + return NULL; + } + + // El tiempo tiene que ser UTC + // El tiempo son 6 bytes. + rr->tsig.time_signed = time (NULL); + //exit (1); + //rr->tsig.time_signed = 1602910230u; + //printf ("Time: %i\n", ((unsigned int) rr->tsig.time_signed)); + rr->tsig.fudge = 300; + rr->tsig.mac_size = 0; + rr->tsig.original_id = 0; + + rr->tsig.error = 0; + rr->tsig.other_length = 0; + + return rr; +} + +DNSRR *dns2_rr_create_aaaa (const char *name, int klass, int ttl, struct in6_addr address) { + DNSRR *rr; + + rr = (DNSRR *) malloc (sizeof (DNSRR)); + + if (rr == NULL) { + return NULL; + } + + strncpy (rr->name, name, sizeof (rr->name)); + dns2_trim_name (rr->name); + + if (rr->name[0] == 0) { + free (rr); + return NULL; + } + + rr->type = RR_TYPE_AAAA; + rr->klass = klass; + rr->ttl = ttl; + + /* Copiar la IP */ + memcpy (&rr->aaaa.address, &address, sizeof (rr->aaaa.address)); + + return rr; +} + +DNSRR *dns2_rr_create_ns (const char *name, int klass, int ttl, const char *nsname) { + DNSRR *rr; + + rr = (DNSRR *) malloc (sizeof (DNSRR)); + + if (rr == NULL) { + return NULL; + } + + strncpy (rr->name, name, sizeof (rr->name)); + dns2_trim_name (rr->name); + + if (rr->name[0] == 0) { + free (rr); + return NULL; + } + + rr->type = RR_TYPE_NS; + rr->klass = klass; + rr->ttl = ttl; + + /* Copiar el nombre */ + memcpy (&rr->ns.name, &nsname, strlen (nsname) + 1); + dns2_trim_name (rr->ns.name); + + return rr; +} + +/* ----- Empaquetadores ----- */ +void dns_rr_pack_a_data (DNSRR *rr, DNSPacket *packet) { + char *buf; + uint16_t t16; + + buf = &packet->rdata[packet->rdlength]; + + t16 = htons (4); + memcpy (buf, &t16, 2); + + memcpy (&buf[2], &rr->a.address, 4); + packet->rdlength += 4 + 2; +} + +void dns_rr_pack_aaaa_data (DNSRR *rr, DNSPacket *packet) { + char *buf; + uint16_t t16; + + buf = &packet->rdata[packet->rdlength]; + + t16 = htons (16); + memcpy (buf, &t16, 2); + + memcpy (&buf[2], &rr->aaaa.address, 16); + packet->rdlength += 16 + 2; +} + +int dns_rr_sign_hmac (void *data, int data_len, const char *key, const char *algorithm, void *mac) { + HMAC_CTX *ctx; + const EVP_MD *md_algo; + char *decoded_key; + size_t key_length; + int total_len; + int g; + + printf ("About to sign, data is:\n"); + for (g = 0; g < data_len; g++) { + printf ("%02x", (unsigned int) (((unsigned char *) data)[g])); + } + printf ("\nEnd data sig\n"); + + if (strcmp (algorithm, RR_TSIG_HMAC_MD5) == 0) { + md_algo = EVP_md5 (); + } else if (strcmp (algorithm, RR_TSIG_HMAC_SHA1) == 0) { + md_algo = EVP_sha1 (); + } else if (strcmp (algorithm, RR_TSIG_HMAC_SHA224) == 0) { + md_algo = EVP_sha224 (); + } else if (strcmp (algorithm, RR_TSIG_HMAC_SHA256) == 0) { + md_algo = EVP_sha256 (); + } else if (strcmp (algorithm, RR_TSIG_HMAC_SHA384) == 0) { + md_algo = EVP_sha384 (); + } else if (strcmp (algorithm, RR_TSIG_HMAC_SHA512) == 0) { + md_algo = EVP_sha512 (); + } else { + return 0; + } + + ctx = HMAC_CTX_new (); + + if (ctx == NULL) { + return 0; + } + + if (base64_decode (key, (unsigned char **)&decoded_key, &key_length) != 0) { + HMAC_CTX_free (ctx); + + return 0; + } + + HMAC_Init_ex (ctx, decoded_key, key_length, md_algo, NULL); + + /* Enviar el mensaje a firmar */ + HMAC_Update (ctx, data, data_len); + + HMAC_Final (ctx, mac, &total_len); + + HMAC_CTX_free (ctx); + + free (decoded_key); + + return total_len; +} + +void dns_rr_pack_tsig_data (DNSRR *rr, DNSPacket *packet) { + uint16_t offset_rdlength, t16; + uint32_t t32; + + /* Tomar la posición actual para el rdlength */ + offset_rdlength = packet->rdlength; + packet->rdlength += 2; + + /* Agregar el algoritmo sin compresión */ + dns_packet_pack_name (packet, rr->tsig.algorithm); + + /* Empaquetar el tiempo, fudge y mac_size */ + t16 = 0; + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; + + t32 = htonl ((intmax_t) rr->tsig.time_signed); + memcpy (&packet->rdata[packet->rdlength], &t32, 4); + packet->rdlength += 4; + + /* El fudge */ + t16 = htons (rr->tsig.fudge); + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; + + t16 = htons (rr->tsig.mac_size); + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; + + /* Agregar el MAC */ + memcpy (&packet->rdata[packet->rdlength], rr->tsig.mac, rr->tsig.mac_size); + packet->rdlength += rr->tsig.mac_size; + + /* Copiar el packet id */ + t16 = htons (packet->header.id); + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; + + /* Error y other length */ + t16 = htons (rr->tsig.error); + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; + + t16 = htons (rr->tsig.other_length); + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; + + /* Agregar el other_data si other_length > 0 */ + if (rr->tsig.other_length > 0) { + memcpy (&packet->rdata[packet->rdlength], rr->tsig.other_data, rr->tsig.other_length); + packet->rdlength += rr->tsig.other_length; + } + + /* Regresar a la posición del rdlength y escribir el valor correcto */ + t16 = htons (packet->rdlength - offset_rdlength - 2); + memcpy (&packet->rdata[offset_rdlength], &t16, 2); +} + +void dns_rr_pack_generate_signature (DNSRR *signature, DNSPacket *packet) { + void *data; + int data_count; + uint16_t t16; + uint32_t t32; + + /* Reempaquetar todo el paquete para generar los bytes de la firma */ + dns_packet_reset (packet); + dns_packet_pack_data (packet); + + /* Agregar el nombre del tsig sin compresión */ + dns_packet_pack_name (packet, signature->name); + + t16 = htons (signature->klass); + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; + + t32 = htonl (signature->ttl); + memcpy (&packet->rdata[packet->rdlength], &t32, 4); + packet->rdlength += 4; + + /* Agregar el algoritmo sin compresión */ + dns_packet_pack_name (packet, signature->tsig.algorithm); + + /* Agregar la hora */ + t16 = 0; + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; + + t32 = htonl ((intmax_t) signature->tsig.time_signed); + memcpy (&packet->rdata[packet->rdlength], &t32, 4); + packet->rdlength += 4; + + /* El fudge */ + t16 = htons (signature->tsig.fudge); + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; + + /* Error y other length */ + t16 = htons (signature->tsig.error); + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; + t16 = htons (signature->tsig.other_length); + memcpy (&packet->rdata[packet->rdlength], &t16, 2); + packet->rdlength += 2; + + /* Agregar el other_data si other_length > 0 */ + if (signature->tsig.other_length > 0) { + memcpy (&packet->rdata[packet->rdlength], signature->tsig.other_data, signature->tsig.other_length); + packet->rdlength += signature->tsig.other_length; + } + + /* Recuperar la data */ + data_count = dns_packet_get_data (packet, (unsigned char **)&data); + + /* Realmente firmar la data */ + signature->tsig.mac_size = dns_rr_sign_hmac (data, data_count, signature->tsig.key, signature->tsig.algorithm, signature->tsig.mac); + + /* Pedir reempaquetar la data, otra vez */ + dns_packet_reset (packet); +} + +void dns_rr_pack_data (DNSRR *rr, DNSPacket *packet) { + uint16_t t16; + uint32_t t32; + char *buf; + + dns_packet_compress_name (packet, rr->name); + + buf = &packet->rdata[packet->rdlength]; + + /*if (rr->type == OPT) { + + } else { */ + t16 = htons (rr->type); + memcpy (&buf[0], &t16, 2); + + t16 = htons (rr->klass); + memcpy (&buf[2], &t16, 2); + + t32 = htonl (rr->ttl); + memcpy (&buf[4], &t32, 4); + /* } */ + + packet->rdlength += 8; + + /* Data por tipo */ + switch (rr->type) { + case RR_TYPE_A: + dns_rr_pack_a_data (rr, packet); + break; + case RR_TYPE_AAAA: + dns_rr_pack_aaaa_data (rr, packet); + break; + case RR_TYPE_TSIG: + dns_rr_pack_tsig_data (rr, packet); + break; + } +} + +/* ----- Desempaquetadores ----- */ +int dns_rr_unpack_a_data (DNSRR *rr, unsigned char *buf, int rd_length) { + if (rd_length < 4) { + return -1; + } + + memcpy (&rr->a.address, buf, 4); + + return 0; +} + +int dns_rr_unpack_aaaa_data (DNSRR *rr, unsigned char *buf, int rd_length) { + if (rd_length < 16) { + return -1; + } + + memcpy (&rr->aaaa.address, buf, 16); + + return 0; +} + +int dns_rr_unpack_ns_data (DNSRR *rr, unsigned char *buf, int rd_length, DNSPacket *packet) { + /* No hacemos validaciones sobre la longitud porque los nombres son variables */ + int save; + save = buf - packet->rdata; + + if (dns_packet_expand_name (rr->ns.name, packet, &save) < 0) { + return -1; + } + + return 0; +} + +int dns_rr_unpack_cname_data (DNSRR *rr, unsigned char *buf, int rd_length, DNSPacket *packet) { + /* No hacemos validaciones sobre la longitud porque los nombres son variables */ + int save; + save = buf - packet->rdata; + + if (dns_packet_expand_name (rr->cname.name, packet, &save) < 0) { + return -1; + } + + return 0; +} + +int dns_rr_unpack_soa_data (DNSRR *rr, unsigned char *buf, int rd_length, DNSPacket *packet) { + int save, start; + int tot; + uint32_t u32; + + if (rd_length < 20) { /* Al menos 5 enteros de 32 bits cada uno */ + return -1; + } + + start = save = buf - packet->rdata; + if (dns_packet_expand_name (rr->soa.mname, packet, &save) < 0) { + return -1; + } + + if (dns_packet_expand_name (rr->soa.rname, packet, &save) < 0) { + return -1; + } + + tot = save - start; + if (rd_length - tot < 20) { + return -1; + } + + /* Leer el serial */ + memcpy (&u32, &buf[tot], 4); + rr->soa.serial = ntohl (u32); + + /* Leer el refresh */ + memcpy (&u32, &buf[tot + 4], 4); + rr->soa.refresh = ntohl (u32); + + /* Leer el retry */ + memcpy (&u32, &buf[tot + 8], 4); + rr->soa.retry = ntohl (u32); + + /* El expire */ + memcpy (&u32, &buf[tot + 12], 4); + rr->soa.expire = ntohl (u32); + + /* El minimum */ + memcpy (&u32, &buf[tot + 16], 4); + rr->soa.minimum = ntohl (u32); + + return 0; +} + +int dns_rr_unpack_ptr_data (DNSRR *rr, unsigned char *buf, int rd_length, DNSPacket *packet) { + int save; + save = buf - packet->rdata; + + if (dns_packet_expand_name (rr->ptr.name, packet, &save) < 0) { + return -1; + } + + return 0; +} + +int dns_rr_unpack_mx_data (DNSRR *rr, unsigned char *buf, int rd_length, DNSPacket *packet) { + int save; + uint16_t u16; + + if (rd_length < 2) { + return -1; + } + + memcpy (&u16, buf, 2); + rr->mx.preference = ntohs (u16); + + save = &buf[2] - packet->rdata; + + if (dns_packet_expand_name (rr->mx.name, packet, &save) < 0) { + return -1; + } + + return 0; +} + +int dns_rr_unpack_txt_data (DNSRR *rr, unsigned char *buf, int rd_length) { + /* En la teoría, un TXT puede contener muchas cadenas, + * En la práctica, no creo que ocurra. + * Tomar solo la primer cadena */ + uint8_t txt_len; + + txt_len = buf[0]; + + if (txt_len > rd_length - 1) { + return -1; + } + memcpy (rr->txt.txt, &buf[1], txt_len); + + rr->txt.txt[txt_len] = 0; + + return 0; +} + +int dns_rr_unpack_tsig_data (DNSRR *rr, unsigned char *buf, int rd_length) { + uint32_t t32; + uint16_t t16; + uint8_t t8; + + int offset; + + offset = 0; + t8 = dns_packet_expand_name_simple (rr->tsig.algorithm, buf, rd_length); + + if (t8 < 0) { + return -1; + } + + offset += t8; + + /* Revisar el time, fudge y mac_size */ + if (offset + 10 > rd_length) { + return -1; + } + + /* ¿Ignorar los primeros dos bytes del tiempo? */ + memcpy (&t16, &buf[offset], 2); + + memcpy (&t32, &buf[offset + 2], 4); + rr->tsig.time_signed = ntohl (t32); + + memcpy (&t16, &buf[offset + 6], 2); + rr->tsig.fudge = ntohs (t16); + + memcpy (&t16, &buf[offset + 8], 2); + rr->tsig.mac_size = ntohs (t16); + + offset += 10; + + /* Copiar el MAC */ + if (offset + rr->tsig.mac_size > rd_length) { + return -1; + } + + memcpy (&rr->tsig.mac, &buf[offset], rr->tsig.mac_size); + offset += rr->tsig.mac_size; + + /* Revisar el packet id, error y other_len */ + if (offset + 6 > rd_length) { + return -1; + } + + /* Copiar el packet id original */ + memcpy (&t16, &buf[offset], 2); + rr->tsig.original_id = ntohs (t16); + + memcpy (&t16, &buf[offset + 2], 2); + rr->tsig.error = ntohs (t16); + + memcpy (&t16, &buf[offset + 4], 2); + rr->tsig.other_length = ntohs (t16); + + offset += 6; + if (rr->tsig.other_length > 0) { + if (offset + rr->tsig.other_length < rd_length) { + return -1; + } + + memcpy (&rr->tsig.other_data, &buf[offset], rr->tsig.other_length); + } + + return 0; +} + +DNSRR * dns_rr_unpack_data (DNSPacket *packet) { + DNSRR *rr; + uint16_t t16; + uint32_t t32; + unsigned char *buf; + int rd_length; + int res; + + rr = (DNSRR *) malloc (sizeof (DNSRR)); + + if (rr == NULL) { + return NULL; + } + + memset (rr, 0, sizeof (DNSRR)); + + if (dns_packet_expand_name (rr->name, packet, &packet->rdread) < 0) { + dns2_rr_free (rr); + + return NULL; + } + + /* Asegurar al menos 10 bytes */ + if (packet->rdlength < packet->rdread + 10) { + dns2_rr_free (rr); + + return NULL; + } + + buf = &packet->rdata[packet->rdread]; + packet->rdread += 10; + + memcpy (&t16, &buf[0], sizeof (t16)); + rr->type = ntohs (t16); + + memcpy (&t16, &buf[2], sizeof (t16)); + rr->klass = ntohs (t16); + + memcpy (&t32, &buf[4], sizeof (t32)); + rr->ttl = ntohl (t32); + + memcpy (&t16, &buf[8], sizeof (t16)); + rd_length = ntohs (t16); + + if (packet->rdlength < packet->rdread + rd_length) { + dns2_rr_free (rr); + + return NULL; + } + + buf = &packet->rdata[packet->rdread]; + packet->rdread += rd_length; + + res = 0; + switch (rr->type) { + case RR_TYPE_A: + res = dns_rr_unpack_a_data (rr, buf, rd_length); + break; + case RR_TYPE_AAAA: + res = dns_rr_unpack_aaaa_data (rr, buf, rd_length); + break; + case RR_TYPE_NS: + res = dns_rr_unpack_ns_data (rr, buf, rd_length, packet); + break; + case RR_TYPE_CNAME: + res = dns_rr_unpack_cname_data (rr, buf, rd_length, packet); + break; + case RR_TYPE_SOA: + res = dns_rr_unpack_soa_data (rr, buf, rd_length, packet); + break; + case RR_TYPE_PTR: + res = dns_rr_unpack_ptr_data (rr, buf, rd_length, packet); + break; + case RR_TYPE_MX: + res = dns_rr_unpack_mx_data (rr, buf, rd_length, packet); + break; + case RR_TYPE_TXT: + res = dns_rr_unpack_txt_data (rr, buf, rd_length); + break; + case RR_TYPE_TSIG: + res = dns_rr_unpack_tsig_data (rr, buf, rd_length); + break; + } + + if (res < 0) { + dns2_rr_free (rr); + + return NULL; + } + + return rr; +} + +DNSRR *dns2_rr_dup (const DNSRR *rr) { + DNSRR *new; + + new = (DNSRR *) malloc (sizeof (DNSRR)); + if (new == NULL) { + return NULL; + } + + memcpy (new, rr, sizeof (DNSRR)); + + if (rr->type == RR_TYPE_TSIG) { + new->tsig.key = strdup (rr->tsig.key); + } + + return new; +} + +void dns2_rr_free (DNSRR *rr) { + if (rr->type == RR_TYPE_TSIG) { + /* La llave se duplicó, liberarla */ + free (rr->tsig.key); + } + + free (rr); +} + diff --git a/src/rr.h b/src/rr.h new file mode 100644 index 0000000..2b886b6 --- /dev/null +++ b/src/rr.h @@ -0,0 +1,95 @@ +#ifndef __RR_H__ +#define __RR_H__ + +#include +#include +#include + +#include + +#include +#include +#include + +typedef struct { + struct in_addr address; +} DNSRR_A; + +typedef struct { + struct in6_addr address; +} DNSRR_AAAA; + +typedef struct { + unsigned char name[512]; +} DNSRR_NS; + +typedef struct { + unsigned char name[512]; +} DNSRR_CNAME; + +typedef struct { + uint16_t preference; + unsigned char name[512]; +} DNSRR_MX; + +typedef struct { + unsigned char txt[512]; +} DNSRR_TXT; + +typedef struct { + unsigned char mname[512]; + unsigned char rname[512]; + uint32_t serial, refresh, retry, expire, minimum; +} DNSRR_SOA; + +typedef struct { + unsigned char name[512]; +} DNSRR_PTR; + +typedef struct { + char algorithm[512]; + time_t time_signed; + uint16_t fudge; + int mac_size; + unsigned char mac[512]; + uint16_t original_id; + + int error; + int other_length; + unsigned char other_data[512]; + + char *key; +} DNSRR_TSIG; + +typedef struct { + char name[512]; + + uint16_t type; + + int klass; + + uint32_t ttl; + /*int rd_length; + void *rdata;*/ + + union { + DNSRR_A a; + DNSRR_AAAA aaaa; + DNSRR_TSIG tsig; + DNSRR_NS ns; + DNSRR_CNAME cname; + DNSRR_MX mx; + DNSRR_TXT txt; + DNSRR_SOA soa; + DNSRR_PTR ptr; + }; +} DNSRR; + +DNSRR *dns2_rr_create_a (const char *name, int klass, int ttl, struct in_addr address); +DNSRR *dns2_rr_create_aaaa (const char *name, int klass, int ttl, struct in6_addr address); +DNSRR *dns2_rr_create_ns (const char *name, int klass, int ttl, const char *nsname); +DNSRR *dns2_rr_create_tsig (const char *name, const char *signature, const char *algorithm); +DNSRR *dns2_rr_dup (const DNSRR *rr); +void dns2_rr_free (DNSRR *rr); + +#endif /* __RR_H__ */ diff --git a/src/updater.c b/src/updater.c new file mode 100644 index 0000000..f2b38a4 --- /dev/null +++ b/src/updater.c @@ -0,0 +1,157 @@ +#include +#include +#include + +#include +#include +#include + +#include + +#include + +#include + +#include + +#include "dns2.h" +#include "utils.h" +#include "packet.h" +#include "constants.h" +#include "glist.h" +#include "rr.h" + +#include "dns2-private.h" + +DNS2 *dns2_updater_new (const char *zone) { + DNS2 *updater; + + updater = dns2_new (); + + if (updater == NULL) { + return NULL; + } + + updater->type = DNS_UPDATER; + /* Sanitizar "zona" */ + updater->zone = dns_dup_trim_name (zone); + + if (updater->zone == NULL) { + free (updater); + + return NULL; + } + + updater->packet = dns_packet_create_request (updater->zone, RR_TYPE_SOA, RR_CLASS_IN); + + if (updater->packet == NULL) { + free (updater->zone); + free (updater); + + return NULL; + } + + updater->packet->header.opcode = OPCODE_UPDATE; + + return updater; +} + +int dns_updater_check_name (DNS2 *updater, const char *name) { + int len, nlen; + + /* TODO: ¿Usar la zona o el question[0]->qname? */ + len = strlen (updater->zone); + + nlen = strlen (name); + if (nlen < len) { + return 0; + } + + if (strcmp (name, updater->zone) == 0) { + return 1; + } + + if (strcmp (&name[nlen - len], updater->zone) != 0) { + return 0; + } + + if (name[nlen - len - 1] != '.') { + return 0; + } + + return 1; +} + +void dns2_updater_add (DNS2 *updater, DNSRR *rr) { + if (dns_updater_check_name (updater, rr->name) == 0) { + /* Fuera de la zona */ + return; + } + + if (g_list_find (updater->packet->authority, rr) == NULL) { + updater->packet->authority = g_list_append (updater->packet->authority, rr); + } +} + +DNSRR * dns_updater_packet_get_tsig (DNSPacket *response) { + int g; + GList *last; + DNSRR *rr; + + if (response->header.arcount == 0) { + return NULL; + } + + last = g_list_last (response->additional); + while (last != NULL) { + rr = (DNSRR *) last->data; + + if (rr->type == RR_TYPE_TSIG) { + return rr; + } + + last = last->prev; + } + + return NULL; +} + +int dns_updater_packet_has_valid_tsig (DNS2 *updater, DNSPacket *response) { + DNSRR *rr, *mysig; + DNSPacket *dup; + + rr = dns_updater_packet_get_tsig (response); + + if (rr == NULL) { + return 0; + } + + if (updater->auth_signature == NULL) { + return 0; + } + + /* Eliminar temporalmente el rr de la lista */ + response->additional = g_list_remove (response->additional, rr); + response->header.arcount = g_list_length (response->additional); + + /* Recalcular la firma, */ + mysig = dns2_rr_dup (updater->auth_signature); + + if (mysig->type == RR_TYPE_TSIG /*|| + mysig->tipo == RR_TYPE_SIG*/) { + + dns_rr_pack_generate_signature (mysig, response); + } + + /* Comparar firmas */ + + + /* Re-anexar la firma original */ + response->additional = g_list_append (response->additional, rr); + response->header.arcount = g_list_length (response->additional); + + return 1; +} + + + diff --git a/src/utils.c b/src/utils.c new file mode 100644 index 0000000..8c3402b --- /dev/null +++ b/src/utils.c @@ -0,0 +1,124 @@ +#include +#include +#include + +#include +#include +#include +#include + +#include +#include +#include + +void dns2_trim_name (char *name) { + int g; + + if (name == NULL) return; + + g = 0; + while (name[g] != 0 && (name[g] == ' ' || name[g] == '\r' || name[g] == '\n' || name[g] == '\t' || name[g] == '.')) { + g++; + } + + if (g < 0) { + memmove (name, &name[g], strlen (&name[g]) + 1); + } + + /* Hacer trim por el otro lado */ + g = strlen (name) - 1; + while (g > 0 && (name[g] == ' ' || name[g] == '\r' || name[g] == '\n' || name[g] == '\t' || name[g] == '.')) { + name[g] = 0; + } +} + +/* TODO: Buscar quitar esta función */ +char *dns_dup_trim_name (const char *name) { + char *zone; + int g; + + zone = strdup (name); + + if (zone == NULL) { + return NULL; + } + + g = 0; + while (zone[g] != 0 && (zone[g] == ' ' || zone[g] == '\r' || zone[g] == '\n' || zone[g] == '\t' || zone[g] == '.')) { + g++; + } + + if (g > 0) { + memmove (zone, &zone[g], strlen (&zone[g]) + 1); + } + + /* Hacer trim por el otro lado */ + g = strlen (zone) - 1; + while (g > 0 && (zone[g] == ' ' || zone[g] == '\r' || zone[g] == '\n' || zone[g] == '\t' || zone[g] == '.')) { + zone[g] = 0; + } + + return zone; +} + +size_t calc_decode_length (const char* b64input) { //Calculates the length of a decoded string + size_t len = strlen(b64input), + padding = 0; + + if (b64input[len-1] == '=' && b64input[len-2] == '=') //last two chars are = + padding = 2; + else if (b64input[len-1] == '=') //last char is = + padding = 1; + + return (len*3)/4 - padding; +} + +int base64_decode (const char* b64message, unsigned char** buffer, size_t* length) { //Decodes a base64 encoded string + BIO *bio, *b64; + + int decodeLen = calc_decode_length (b64message); + *buffer = (unsigned char*) malloc (decodeLen + 1); + if (*buffer == NULL) { + return -1; + } + (*buffer)[decodeLen] = '\0'; + + bio = BIO_new_mem_buf (b64message, -1); + b64 = BIO_new (BIO_f_base64 ()); + bio = BIO_push (b64, bio); + + BIO_set_flags (bio, BIO_FLAGS_BASE64_NO_NL); //Do not use newlines to flush buffer + *length = BIO_read (bio, *buffer, strlen (b64message)); + assert (*length == decodeLen); //length should equal decodeLen, else something went horribly wrong + BIO_free_all (bio); + + return 0; //success +} + +/* Función de Kazuho Oku + * https://gist.github.com/kazuho/45eae4f92257daceb73e + */ +int sockaddr_cmp (struct sockaddr *x, struct sockaddr *y) { +#define CMP(a, b) if (a != b) return a < b ? -1 : 1 + + CMP(x->sa_family, y->sa_family); + + if (x->sa_family == AF_INET) { + struct sockaddr_in *xin = (void*)x, *yin = (void*)y; + CMP(ntohl(xin->sin_addr.s_addr), ntohl(yin->sin_addr.s_addr)); + CMP(ntohs(xin->sin_port), ntohs(yin->sin_port)); + } else if (x->sa_family == AF_INET6) { + struct sockaddr_in6 *xin6 = (void*)x, *yin6 = (void*)y; + int r = memcmp (xin6->sin6_addr.s6_addr, yin6->sin6_addr.s6_addr, sizeof(xin6->sin6_addr.s6_addr)); + if (r != 0) return r; + CMP(ntohs(xin6->sin6_port), ntohs(yin6->sin6_port)); + CMP(xin6->sin6_flowinfo, yin6->sin6_flowinfo); + CMP(xin6->sin6_scope_id, yin6->sin6_scope_id); + } else { + return -1; /* Familia desconocida */ + } + +#undef CMP + return 0; +} + diff --git a/src/utils.h b/src/utils.h new file mode 100644 index 0000000..7964805 --- /dev/null +++ b/src/utils.h @@ -0,0 +1,10 @@ +#ifndef __UTILS_H__ +#define __UTILS_H__ + +void dns2_trim_name (char *name); +char *dns_dup_trim_name (const char *name); +int base64_decode (const char* b64message, unsigned char** buffer, size_t* length); +int sockaddr_cmp (struct sockaddr *x, struct sockaddr *y); + +#endif /* __UTILS_H__ */ +