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Importacion de la libdnsc.

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Félix Arreola Rodríguez 2022-08-27 20:52:58 -05:00
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# 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

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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
<http://www.gnu.org/licenses/>.
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
<http://www.gnu.org/philosophy/why-not-lgpl.html>.

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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. Finally, it creates a shell script 'config.status' that
you can run in the future to recreate the current configuration, and a
file 'config.log' containing compiler output (useful mainly for
debugging 'configure').
It can also use an optional file (typically called 'config.cache' and
enabled with '--cache-file=config.cache' or simply '-C') that saves the
results of its tests to speed up reconfiguring. Caching is disabled by
default to prevent problems with accidental use of stale cache files.
If you need to do unusual things to compile the package, please try
to figure out how 'configure' could check whether to do them, and mail
diffs or instructions to the address given in the 'README' so they can
be considered for the next release. If you are using the cache, and at
some point 'config.cache' contains results you don't want to keep, you
may remove or edit it.
The file 'configure.ac' (or 'configure.in') is used to create
'configure' by a program called 'autoconf'. You need 'configure.ac' if
you want to change it or regenerate 'configure' using a newer version of
'autoconf'.
The simplest way to compile this package is:
1. 'cd' to the directory containing the package's source code and type
'./configure' to configure the package for your system.
Running 'configure' might take a while. While running, it prints
some messages telling which features it is checking for.
2. Type 'make' to compile the package.
3. Optionally, type 'make check' to run any self-tests that come with
the package, generally using the just-built uninstalled binaries.
4. Type 'make install' to install the programs and any data files and
documentation. When installing into a prefix owned by root, it is
recommended that the package be configured and built as a regular
user, and only the 'make install' phase executed with root
privileges.
5. Optionally, type 'make installcheck' to repeat any self-tests, but
this time using the binaries in their final installed location.
This target does not install anything. Running this target as a
regular user, particularly if the prior 'make install' required
root privileges, verifies that the installation completed
correctly.
6. You can remove the program binaries and object files from the
source code directory by typing 'make clean'. To also remove the
files that 'configure' created (so you can compile the package for
a different kind of computer), type 'make distclean'. There is
also a 'make maintainer-clean' target, but that is intended mainly
for the package's developers. If you use it, you may have to get
all sorts of other programs in order to regenerate files that came
with the distribution.
7. Often, you can also type 'make uninstall' to remove the installed
files again. In practice, not all packages have tested that
uninstallation works correctly, even though it is required by the
GNU Coding Standards.
8. Some packages, particularly those that use Automake, provide 'make
distcheck', which can by used by developers to test that all other
targets like 'make install' and 'make uninstall' work correctly.
This target is generally not run by end users.
Compilers and Options
=====================
Some systems require unusual options for compilation or linking that
the 'configure' script does not know about. Run './configure --help'
for details on some of the pertinent environment variables.
You can give 'configure' initial values for configuration parameters
by setting variables in the command line or in the environment. Here is
an example:
./configure CC=c99 CFLAGS=-g LIBS=-lposix
*Note Defining Variables::, for more details.
Compiling For Multiple Architectures
====================================
You can compile the package for more than one kind of computer at the
same time, by placing the object files for each architecture in their
own directory. To do this, you can use GNU 'make'. 'cd' to the
directory where you want the object files and executables to go and run
the 'configure' script. 'configure' automatically checks for the source
code in the directory that 'configure' is in and in '..'. This is known
as a "VPATH" build.
With a non-GNU 'make', it is safer to compile the package for one
architecture at a time in the source code directory. After you have
installed the package for one architecture, use 'make distclean' before
reconfiguring for another architecture.
On MacOS X 10.5 and later systems, you can create libraries and
executables that work on multiple system types--known as "fat" or
"universal" binaries--by specifying multiple '-arch' options to the
compiler but only a single '-arch' option to the preprocessor. Like
this:
./configure CC="gcc -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
CXX="g++ -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
CPP="gcc -E" CXXCPP="g++ -E"
This is not guaranteed to produce working output in all cases, you
may have to build one architecture at a time and combine the results
using the 'lipo' tool if you have problems.
Installation Names
==================
By default, 'make install' installs the package's commands under
'/usr/local/bin', include files under '/usr/local/include', etc. You
can specify an installation prefix other than '/usr/local' by giving
'configure' the option '--prefix=PREFIX', where PREFIX must be an
absolute file name.
You can specify separate installation prefixes for
architecture-specific files and architecture-independent files. If you
pass the option '--exec-prefix=PREFIX' to 'configure', the package uses
PREFIX as the prefix for installing programs and libraries.
Documentation and other data files still use the regular prefix.
In addition, if you use an unusual directory layout you can give
options like '--bindir=DIR' to specify different values for particular
kinds of files. Run 'configure --help' for a list of the directories
you can set and what kinds of files go in them. In general, the default
for these options is expressed in terms of '${prefix}', so that
specifying just '--prefix' will affect all of the other directory
specifications that were not explicitly provided.
The most portable way to affect installation locations is to pass the
correct locations to 'configure'; however, many packages provide one or
both of the following shortcuts of passing variable assignments to the
'make install' command line to change installation locations without
having to reconfigure or recompile.
The first method involves providing an override variable for each
affected directory. For example, 'make install
prefix=/alternate/directory' will choose an alternate location for all
directory configuration variables that were expressed in terms of
'${prefix}'. Any directories that were specified during 'configure',
but not in terms of '${prefix}', must each be overridden at install time
for the entire installation to be relocated. The approach of makefile
variable overrides for each directory variable is required by the GNU
Coding Standards, and ideally causes no recompilation. However, some
platforms have known limitations with the semantics of shared libraries
that end up requiring recompilation when using this method, particularly
noticeable in packages that use GNU Libtool.
The second method involves providing the 'DESTDIR' variable. For
example, 'make install DESTDIR=/alternate/directory' will prepend
'/alternate/directory' before all installation names. The approach of
'DESTDIR' overrides is not required by the GNU Coding Standards, and
does not work on platforms that have drive letters. On the other hand,
it does better at avoiding recompilation issues, and works well even
when some directory options were not specified in terms of '${prefix}'
at 'configure' time.
Optional Features
=================
If the package supports it, you can cause programs to be installed
with an extra prefix or suffix on their names by giving 'configure' the
option '--program-prefix=PREFIX' or '--program-suffix=SUFFIX'.
Some packages pay attention to '--enable-FEATURE' options to
'configure', where FEATURE indicates an optional part of the package.
They may also pay attention to '--with-PACKAGE' options, where PACKAGE
is something like 'gnu-as' or 'x' (for the X Window System). The
'README' should mention any '--enable-' and '--with-' options that the
package recognizes.
For packages that use the X Window System, 'configure' can usually
find the X include and library files automatically, but if it doesn't,
you can use the 'configure' options '--x-includes=DIR' and
'--x-libraries=DIR' to specify their locations.
Some packages offer the ability to configure how verbose the
execution of 'make' will be. For these packages, running './configure
--enable-silent-rules' sets the default to minimal output, which can be
overridden with 'make V=1'; while running './configure
--disable-silent-rules' sets the default to verbose, which can be
overridden with 'make V=0'.
Particular systems
==================
On HP-UX, the default C compiler is not ANSI C compatible. 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 '<wchar.h>' 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. If
'config.sub' isn't included in this package, then this package doesn't
need to know the machine type.
If you are _building_ compiler tools for cross-compiling, you should
use the option '--target=TYPE' to select the type of system they will
produce code for.
If you want to _use_ a cross compiler, that generates code for a
platform different from the build platform, you should specify the
"host" platform (i.e., that on which the generated programs will
eventually be run) with '--host=TYPE'.
Sharing Defaults
================
If you want to set default values for 'configure' scripts to share,
you can create a site shell script called 'config.site' that gives
default values for variables like 'CC', 'cache_file', and 'prefix'.
'configure' looks for 'PREFIX/share/config.site' if it exists, then
'PREFIX/etc/config.site' if it exists. 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.

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SUBDIRS = src
#ACLOCAL_AMFLAGS = -I m4
#EXTRA_DIST = build-aux/config.rpath

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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

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# 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

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#ifndef __CONSTANTS_H__
#define __CONSTANTS_H__
#include <stdio.h>
#include <stdlib.h>
#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__ */

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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

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#ifndef __DNS2_PRIVATE_H__
#define __DNS2_PRIVATE_H__
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#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__ */

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <sys/poll.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/time.h>
#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; g<length; g++) {
printf ("%02x", (unsigned int) data[g]);
}
printf ("\nEnd data.\n");
------ FIN de la depuración ------ */
/* Revisar el tipo de pregunta, algunos tipos de pregunta, como los ANY requieren TCP */
question = (DNSQuestion *) obj->packet->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;
}

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#ifndef __DNS2_H__
#define __DNS2_H__
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#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__ */

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/* 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 <http://www.gnu.org/licenses/>.
*/
/*
* 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__ */

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <netinet/in.h>
#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;
}

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src/header.h 100644
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#ifndef __HEADER_H__
#define __HEADER_H__
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
/**
* 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 <mike@mikepultz.com>
* @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__ */

24
src/libdnsc.sym 100644
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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

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src/packet.c 100644
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#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;
}

62
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#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__ */

87
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netinet/in.h>
#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;
}

18
src/question.h 100644
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#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__ */

57
src/resolver.c 100644
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <sys/poll.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#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;
}

726
src/rr.c 100644
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <time.h>
#include <openssl/hmac.h>
#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);
}

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#ifndef __RR_H__
#define __RR_H__
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
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__ */

157
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <sys/poll.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#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;
}

124
src/utils.c 100644
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/bio.h>
#include <openssl/evp.h>
#include <stdint.h>
#include <assert.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
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;
}

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src/utils.h 100644
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#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__ */