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@@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/> + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. By contrast, +the GNU General Public License is intended to guarantee your freedom to +share and change all versions of a program--to make sure it remains free +software for all its users. We, the Free Software Foundation, use the +GNU General Public License for most of our software; it applies also to +any other work released this way by its authors. You can apply it to +your programs, too. + + When we speak of free software, we are referring to freedom, not +price. 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It is safest +to attach them to the start of each source file to most effectively +state the exclusion of warranty; and each file should have at least +the "copyright" line and a pointer to where the full notice is found. + + <one line to give the program's name and a brief idea of what it does.> + Copyright (C) <year> <name of author> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. + +Also add information on how to contact you by electronic and paper mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + <program> Copyright (C) <year> <name of author> + This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, your program's commands +might be different; for a GUI interface, you would use an "about box". + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU GPL, see +<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>. diff --git a/Make_global.am b/Make_global.am new file mode 100644 index 0000000..1654f10 --- /dev/null +++ b/Make_global.am @@ -0,0 +1,24 @@ +# This is _NOT_ the library release version, it's an API version. +# Extracted from Chapter 6 "Library interface versions" of the libtool docs. +# +# <snippet> +# Here are a set of rules to help you update your library version information: +# +# 1. Start with version information of `0:0:0' for each libtool library. +# 2. Update the version information only immediately before a public release +# of your software. More frequent updates are unnecessary, and only guarantee +# that the current interface number gets larger faster. +# 3. If the library source code has changed at all since the last update, +# then increment revision (`c:r:a' becomes `c:r+1:a'). +# 4. If any interfaces have been added, removed, or changed since the last +# update, increment current, and set revision to 0. +# 5. If any interfaces have been added since the last public release, then +# increment age. +# 6. If any interfaces have been removed since the last public release, then +# set age to 0. +# </snippet> +# +LIBVERSION=0:0:0 + +AM_CPPFLAGS = ${regular_CPPFLAGS} -I${top_srcdir}/include ${LIBMNL_CFLAGS} +AM_CFLAGS = ${regular_CFLAGS} ${GCC_FVISIBILITY_HIDDEN} diff --git a/Makefile.am b/Makefile.am new file mode 100644 index 0000000..b8fd921 --- /dev/null +++ b/Makefile.am @@ -0,0 +1,11 @@ +include $(top_srcdir)/Make_global.am + +ACLOCAL_AMFLAGS = -I m4 + +SUBDIRS = src include examples +DIST_SUBDIRS = src include examples + +pkgconfigdir = $(libdir)/pkgconfig +pkgconfig_DATA = libnetfilter_cthelper.pc + +${pkgconfig_DATA}: ${top_builddir}/config.status @@ -0,0 +1,61 @@ += nfnl_cthelper: User-space infrastructure for connection tracking helpers = + +Author: Pablo Neira Ayuso <pablo@netfilter.org> + +== Introduction == + +Connection tracking helpers allows you to filter multi-flow protocols +that usually separate control and data traffic into different flows. +This is the case of application protocols like FTP, SIP and H.323 that +are already supported by Netfilter. These helpers are implemented in +kernel-space. + +There are good reasons to implement helpers in user-space instead: + +* Rapid connection tracking helper development, as developing code + in user-space is usually faster. + +* Reliability: A buggy helper does not crash the kernel. Moreover, + we can monitor the helper process and restart it in case of problems. + +* Security: Avoid complex string matching and mangling in kernel-space + running in unprivileged mode. Going further, we can even think about + running user-space helpers as a non-root process. + +* It allows the development of very specific helpers (most likely + non-standard proprietary protocols) that are very likely to be rejected + for mainline inclusion in the form of kernel-space connection tracking + helpers. + +== Basic operation == + +In a few steps: + +1) Register user-space helper + +# ./nfct-helper-add test 0 + +This adds a helper `test' that uses the queue number 0. + +2) Add rules to enable the `test' user-space helper + +For locally generated packets: +# iptables -I OUTPUT -t raw -p tcp -j CT --helper test + +For non-locally generated packets: +# iptables -I PREROUTING -t raw -p tcp -j CT --helper test + +3) Run the test libnetfilter_queue program + +# ./nfqnl_test + +4) Generate traffic, if everything is OK, then `nfqnl_test' program + displays lines like this: + + pkt received + hw_protocol=0x0800 hook=4 id=4 outdev=3 payload_len=60 + entering callback + [...] + +This means that the cthelper infrastructure is passing traffic to +user-space. diff --git a/configure.ac b/configure.ac new file mode 100644 index 0000000..22f3e20 --- /dev/null +++ b/configure.ac @@ -0,0 +1,35 @@ +dnl Process this file with autoconf to create configure. + +AC_INIT([libnetfilter_cthelper], [1.0.0alpha]) +AC_CONFIG_AUX_DIR([build-aux]) +AC_CANONICAL_HOST +AC_CONFIG_MACRO_DIR([m4]) +AC_CONFIG_HEADERS([config.h]) + +AM_INIT_AUTOMAKE([-Wall foreign tar-pax no-dist-gzip dist-bzip2 + 1.6 subdir-objects]) + +dnl kernel style compile messages +m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])]) + +dnl Dependencies +PKG_CHECK_MODULES([LIBMNL], [libmnl >= 1.0.0]) + +AC_PROG_CC +AM_PROG_CC_C_O +AC_DISABLE_STATIC +LT_INIT +CHECK_GCC_FVISIBILITY +case "$host" in +*-*-linux*) ;; +*) AC_MSG_ERROR([Linux only, dude!]);; +esac + +regular_CPPFLAGS="-D_FILE_OFFSET_BITS=64 -D_REENTRANT" +regular_CFLAGS="-Wall -Waggregate-return -Wmissing-declarations \ + -Wmissing-prototypes -Wshadow -Wstrict-prototypes \ + -Wformat=2 -pipe" +AC_SUBST([regular_CPPFLAGS]) +AC_SUBST([regular_CFLAGS]) +AC_CONFIG_FILES([Makefile src/Makefile include/Makefile include/libnetfilter_cthelper/Makefile include/linux/Makefile include/linux/netfilter/Makefile examples/Makefile libnetfilter_cthelper.pc doxygen.cfg]) +AC_OUTPUT diff --git a/doxygen.cfg.in b/doxygen.cfg.in new file mode 100644 index 0000000..cac9b05 --- /dev/null +++ b/doxygen.cfg.in @@ -0,0 +1,184 @@ +DOXYFILE_ENCODING = UTF-8 +PROJECT_NAME = @PACKAGE@ +PROJECT_NUMBER = @VERSION@ +OUTPUT_DIRECTORY = doxygen +CREATE_SUBDIRS = NO +OUTPUT_LANGUAGE = English +BRIEF_MEMBER_DESC = YES +REPEAT_BRIEF = YES +ABBREVIATE_BRIEF = +ALWAYS_DETAILED_SEC = NO +INLINE_INHERITED_MEMB = NO +FULL_PATH_NAMES = NO +STRIP_FROM_PATH = +STRIP_FROM_INC_PATH = +SHORT_NAMES = NO +JAVADOC_AUTOBRIEF = NO +QT_AUTOBRIEF = NO +MULTILINE_CPP_IS_BRIEF = NO +INHERIT_DOCS = YES +SEPARATE_MEMBER_PAGES = NO +TAB_SIZE = 8 +ALIASES = +OPTIMIZE_OUTPUT_FOR_C = YES +OPTIMIZE_OUTPUT_JAVA = NO +OPTIMIZE_FOR_FORTRAN = NO +OPTIMIZE_OUTPUT_VHDL = NO +BUILTIN_STL_SUPPORT = NO +CPP_CLI_SUPPORT = NO +SIP_SUPPORT = NO +DISTRIBUTE_GROUP_DOC = NO +SUBGROUPING = YES +TYPEDEF_HIDES_STRUCT = NO +EXTRACT_ALL = NO +EXTRACT_PRIVATE = NO +EXTRACT_STATIC = NO +EXTRACT_LOCAL_CLASSES = YES +EXTRACT_LOCAL_METHODS = NO +EXTRACT_ANON_NSPACES = NO +HIDE_UNDOC_MEMBERS = NO +HIDE_UNDOC_CLASSES = NO +HIDE_FRIEND_COMPOUNDS = NO +HIDE_IN_BODY_DOCS = NO +INTERNAL_DOCS = NO +CASE_SENSE_NAMES = YES +HIDE_SCOPE_NAMES = NO +SHOW_INCLUDE_FILES = YES +INLINE_INFO = YES +SORT_MEMBER_DOCS = YES +SORT_BRIEF_DOCS = NO +SORT_GROUP_NAMES = NO +SORT_BY_SCOPE_NAME = NO +GENERATE_TODOLIST = YES +GENERATE_TESTLIST = YES +GENERATE_BUGLIST = YES +GENERATE_DEPRECATEDLIST= YES +ENABLED_SECTIONS = +MAX_INITIALIZER_LINES = 30 +SHOW_USED_FILES = YES +SHOW_DIRECTORIES = NO +FILE_VERSION_FILTER = +QUIET = NO +WARNINGS = YES +WARN_IF_UNDOCUMENTED = YES +WARN_IF_DOC_ERROR = YES +WARN_NO_PARAMDOC = NO +WARN_FORMAT = "$file:$line: $text" +WARN_LOGFILE = +INPUT = . +INPUT_ENCODING = UTF-8 +FILE_PATTERNS = *.c libnetfilter_cthelper.h +RECURSIVE = YES +EXCLUDE = +EXCLUDE_SYMLINKS = NO +EXCLUDE_PATTERNS = */.git/* .*.d +EXCLUDE_SYMBOLS = EXPORT_SYMBOL +EXAMPLE_PATH = +EXAMPLE_PATTERNS = +EXAMPLE_RECURSIVE = NO +IMAGE_PATH = +INPUT_FILTER = +FILTER_PATTERNS = +FILTER_SOURCE_FILES = NO +SOURCE_BROWSER = YES +INLINE_SOURCES = NO +STRIP_CODE_COMMENTS = YES +REFERENCED_BY_RELATION = NO +REFERENCES_RELATION = NO +REFERENCES_LINK_SOURCE = YES +USE_HTAGS = NO +VERBATIM_HEADERS = YES +ALPHABETICAL_INDEX = NO +COLS_IN_ALPHA_INDEX = 5 +IGNORE_PREFIX = +GENERATE_HTML = YES +HTML_OUTPUT = html +HTML_FILE_EXTENSION = .html +HTML_HEADER = +HTML_STYLESHEET = +HTML_ALIGN_MEMBERS = YES +GENERATE_HTMLHELP = NO +GENERATE_DOCSET = NO +DOCSET_FEEDNAME = "Doxygen generated docs" +DOCSET_BUNDLE_ID = org.doxygen.Project +HTML_DYNAMIC_SECTIONS = NO +CHM_FILE = +HHC_LOCATION = +GENERATE_CHI = NO +BINARY_TOC = NO +TOC_EXPAND = NO +DISABLE_INDEX = NO +ENUM_VALUES_PER_LINE = 4 +GENERATE_TREEVIEW = NO +TREEVIEW_WIDTH = 250 +GENERATE_LATEX = NO +LATEX_OUTPUT = latex +LATEX_CMD_NAME = latex +MAKEINDEX_CMD_NAME = makeindex +COMPACT_LATEX = NO +PAPER_TYPE = a4wide +EXTRA_PACKAGES = +LATEX_HEADER = +PDF_HYPERLINKS = YES +USE_PDFLATEX = YES +LATEX_BATCHMODE = NO +LATEX_HIDE_INDICES = NO +GENERATE_RTF = NO +RTF_OUTPUT = rtf +COMPACT_RTF = NO +RTF_HYPERLINKS = NO +RTF_STYLESHEET_FILE = +RTF_EXTENSIONS_FILE = +GENERATE_MAN = YES +MAN_OUTPUT = man +MAN_EXTENSION = .3 +MAN_LINKS = NO +GENERATE_XML = NO +XML_OUTPUT = xml +XML_SCHEMA = +XML_DTD = +XML_PROGRAMLISTING = YES +GENERATE_AUTOGEN_DEF = NO +GENERATE_PERLMOD = NO +PERLMOD_LATEX = NO +PERLMOD_PRETTY = YES +PERLMOD_MAKEVAR_PREFIX = +ENABLE_PREPROCESSING = YES +MACRO_EXPANSION = NO +EXPAND_ONLY_PREDEF = NO +SEARCH_INCLUDES = YES +INCLUDE_PATH = +INCLUDE_FILE_PATTERNS = +PREDEFINED = +EXPAND_AS_DEFINED = +SKIP_FUNCTION_MACROS = YES +TAGFILES = +GENERATE_TAGFILE = +ALLEXTERNALS = NO +EXTERNAL_GROUPS = YES +PERL_PATH = /usr/bin/perl +CLASS_DIAGRAMS = YES +MSCGEN_PATH = +HIDE_UNDOC_RELATIONS = YES +HAVE_DOT = YES +CLASS_GRAPH = YES +COLLABORATION_GRAPH = YES +GROUP_GRAPHS = YES +UML_LOOK = NO +TEMPLATE_RELATIONS = NO +INCLUDE_GRAPH = YES +INCLUDED_BY_GRAPH = YES +CALL_GRAPH = NO +CALLER_GRAPH = NO +GRAPHICAL_HIERARCHY = YES +DIRECTORY_GRAPH = YES +DOT_IMAGE_FORMAT = png +DOT_PATH = +DOTFILE_DIRS = +DOT_GRAPH_MAX_NODES = 50 +MAX_DOT_GRAPH_DEPTH = 0 +DOT_TRANSPARENT = YES +DOT_MULTI_TARGETS = NO +GENERATE_LEGEND = YES +DOT_CLEANUP = YES +SEARCHENGINE = NO diff --git a/examples/.gitignore b/examples/.gitignore new file mode 100644 index 0000000..e86b7ca --- /dev/null +++ b/examples/.gitignore @@ -0,0 +1,3 @@ +/nfct-helper-add +/nfct-helper-del +/nfct-helper-get diff --git a/examples/Makefile.am b/examples/Makefile.am new file mode 100644 index 0000000..a59edaa --- /dev/null +++ b/examples/Makefile.am @@ -0,0 +1,12 @@ +include $(top_srcdir)/Make_global.am + +check_PROGRAMS = nfct-helper-get nfct-helper-add nfct-helper-del + +nfct_helper_add_SOURCES = nfct-helper-add.c +nfct_helper_add_LDADD = ../src/libnetfilter_cthelper.la ${LIBMNL_LIBS} + +nfct_helper_del_SOURCES = nfct-helper-del.c +nfct_helper_del_LDADD = ../src/libnetfilter_cthelper.la ${LIBMNL_LIBS} + +nfct_helper_get_SOURCES = nfct-helper-get.c +nfct_helper_get_LDADD = ../src/libnetfilter_cthelper.la ${LIBMNL_LIBS} diff --git a/examples/nfct-helper-add.c b/examples/nfct-helper-add.c new file mode 100644 index 0000000..4371761 --- /dev/null +++ b/examples/nfct-helper-add.c @@ -0,0 +1,75 @@ +/* This example is in the public domain. */ +#include <stdlib.h> +#include <time.h> +#include <string.h> +#include <netinet/in.h> +#include <libmnl/libmnl.h> +#include <libnetfilter_cthelper/libnetfilter_cthelper.h> + +int main(int argc, char *argv[]) +{ + struct mnl_socket *nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + uint32_t portid, seq; + struct nfct_helper *nfct_helper; + int ret; + + if (argc != 3) { + printf("Usage: %s [helper-name] [queue-num]\n", argv[0]); + exit(EXIT_FAILURE); + } + + nfct_helper = nfct_helper_alloc(); + if (nfct_helper == NULL) { + perror("OOM"); + exit(EXIT_FAILURE); + } + + nfct_helper_attr_set(nfct_helper, NFCTH_ATTR_NAME, argv[1]); + nfct_helper_attr_set_u32(nfct_helper, NFCTH_ATTR_QUEUE_NUM, atoi(argv[2])); + nfct_helper_attr_set(nfct_helper, NFCTH_ATTR_EXP_POLICY_NAME, "test"); + nfct_helper_attr_set_u16(nfct_helper, NFCTH_ATTR_PROTO_L3NUM, AF_INET); + nfct_helper_attr_set_u8(nfct_helper, NFCTH_ATTR_PROTO_L4NUM, IPPROTO_TCP); + nfct_helper_attr_set_u32(nfct_helper, NFCTH_ATTR_EXP_POLICY_TIMEOUT, 100); + nfct_helper_attr_set_u32(nfct_helper, NFCTH_ATTR_EXP_POLICY_MAX, 100); + + seq = time(NULL); + nlh = nfct_helper_nlmsg_build_hdr(buf, NFNL_MSG_CTHELPER_NEW, + NLM_F_CREATE | NLM_F_ACK, seq); + nfct_helper_nlmsg_build_payload(nlh, nfct_helper); + + nfct_helper_free(nfct_helper); + + nl = mnl_socket_open(NETLINK_NETFILTER); + if (nl == NULL) { + perror("mnl_socket_open"); + exit(EXIT_FAILURE); + } + + if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) { + perror("mnl_socket_bind"); + exit(EXIT_FAILURE); + } + portid = mnl_socket_get_portid(nl); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + perror("mnl_socket_send"); + exit(EXIT_FAILURE); + } + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret > 0) { + ret = mnl_cb_run(buf, ret, seq, portid, NULL, NULL); + if (ret <= 0) + break; + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + if (ret == -1) { + perror("error"); + exit(EXIT_FAILURE); + } + mnl_socket_close(nl); + + return EXIT_SUCCESS; +} diff --git a/examples/nfct-helper-del.c b/examples/nfct-helper-del.c new file mode 100644 index 0000000..a176055 --- /dev/null +++ b/examples/nfct-helper-del.c @@ -0,0 +1,68 @@ +/* This example is in the public domain. */ +#include <stdlib.h> +#include <time.h> +#include <string.h> +#include <libmnl/libmnl.h> +#include <libnetfilter_cthelper/libnetfilter_cthelper.h> + +int main(int argc, char *argv[]) +{ + struct mnl_socket *nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + uint32_t portid, seq; + struct nfct_helper *nfct_helper; + int ret; + + if (argc != 2) { + fprintf(stderr, "Usage: %s [name]\n", argv[0]); + exit(EXIT_FAILURE); + } + + nfct_helper = nfct_helper_alloc(); + if (nfct_helper == NULL) { + perror("OOM"); + exit(EXIT_FAILURE); + } + + nfct_helper_attr_set(nfct_helper, NFCTH_ATTR_NAME, argv[1]); + + seq = time(NULL); + nlh = nfct_helper_nlmsg_build_hdr(buf, NFNL_MSG_CTHELPER_DEL, + NLM_F_ACK, seq); + nfct_helper_nlmsg_build_payload(nlh, nfct_helper); + + nfct_helper_free(nfct_helper); + + nl = mnl_socket_open(NETLINK_NETFILTER); + if (nl == NULL) { + perror("mnl_socket_open"); + exit(EXIT_FAILURE); + } + + if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) { + perror("mnl_socket_bind"); + exit(EXIT_FAILURE); + } + portid = mnl_socket_get_portid(nl); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + perror("mnl_socket_send"); + exit(EXIT_FAILURE); + } + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret > 0) { + ret = mnl_cb_run(buf, ret, seq, portid, NULL, NULL); + if (ret <= 0) + break; + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + if (ret == -1) { + perror("error"); + exit(EXIT_FAILURE); + } + mnl_socket_close(nl); + + return EXIT_SUCCESS; +} diff --git a/examples/nfct-helper-get.c b/examples/nfct-helper-get.c new file mode 100644 index 0000000..634062a --- /dev/null +++ b/examples/nfct-helper-get.c @@ -0,0 +1,81 @@ +/* This example is in the public domain. */ +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <libmnl/libmnl.h> +#include <libnetfilter_cthelper/libnetfilter_cthelper.h> + +static int nfct_helper_cb(const struct nlmsghdr *nlh, void *data) +{ + struct nfct_helper *nfct_helper; + char buf[4096]; + + nfct_helper = nfct_helper_alloc(); + if (nfct_helper == NULL) { + perror("OOM"); + goto err; + } + + if (nfct_helper_nlmsg_parse_payload(nlh, nfct_helper) < 0) { + perror("nfct_helper_parse_nl_msg"); + goto err_free; + } + + nfct_helper_snprintf(buf, sizeof(buf), nfct_helper, 0); + printf("%s\n", buf); + +err_free: + nfct_helper_free(nfct_helper); +err: + return MNL_CB_OK; +} + +int main(int argc, char *argv[]) +{ + struct mnl_socket *nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + uint32_t portid, seq; + int ret, full = 1; + + if (argc != 1) { + fprintf(stderr, "Usage: %s\n", argv[0]); + exit(EXIT_FAILURE); + } + + seq = time(NULL); + nlh = nfct_helper_nlmsg_build_hdr(buf, NFNL_MSG_CTHELPER_GET, + NLM_F_DUMP, seq); + + nl = mnl_socket_open(NETLINK_NETFILTER); + if (nl == NULL) { + perror("mnl_socket_open"); + exit(EXIT_FAILURE); + } + + if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) { + perror("mnl_socket_bind"); + exit(EXIT_FAILURE); + } + portid = mnl_socket_get_portid(nl); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + perror("mnl_socket_send"); + exit(EXIT_FAILURE); + } + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret > 0) { + ret = mnl_cb_run(buf, ret, seq, portid, nfct_helper_cb, &full); + if (ret <= 0) + break; + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + if (ret == -1) { + perror("error"); + exit(EXIT_FAILURE); + } + mnl_socket_close(nl); + + return EXIT_SUCCESS; +} diff --git a/include/Makefile.am b/include/Makefile.am new file mode 100644 index 0000000..95692c0 --- /dev/null +++ b/include/Makefile.am @@ -0,0 +1 @@ +SUBDIRS = libnetfilter_cthelper linux diff --git a/include/libnetfilter_cthelper/Makefile.am b/include/libnetfilter_cthelper/Makefile.am new file mode 100644 index 0000000..34da41d --- /dev/null +++ b/include/libnetfilter_cthelper/Makefile.am @@ -0,0 +1 @@ +pkginclude_HEADERS = libnetfilter_cthelper.h diff --git a/include/libnetfilter_cthelper/libnetfilter_cthelper.h b/include/libnetfilter_cthelper/libnetfilter_cthelper.h new file mode 100644 index 0000000..13bfca8 --- /dev/null +++ b/include/libnetfilter_cthelper/libnetfilter_cthelper.h @@ -0,0 +1,43 @@ +#ifndef _LIBNETFILTER_ACCT_H_ +#define _LIBNETFILTER_ACCT_H_ + +#include <sys/types.h> +#include <linux/netfilter/nfnetlink_cthelper.h> + +struct nfct_helper; + +enum nfct_helper_attr_type { + NFCTH_ATTR_NAME = 0, + NFCTH_ATTR_QUEUE_NUM, + NFCTH_ATTR_PROTO_L3NUM, + NFCTH_ATTR_PROTO_L4NUM, + NFCTH_ATTR_EXP_POLICY_NAME, + NFCTH_ATTR_EXP_POLICY_TIMEOUT, + NFCTH_ATTR_EXP_POLICY_MAX, +}; + +struct nfct_helper *nfct_helper_alloc(void); +void nfct_helper_free(struct nfct_helper *nfct_helper); + +void nfct_helper_attr_set(struct nfct_helper *nfct_helper, enum nfct_helper_attr_type type, const void *data); +void nfct_helper_attr_set_str(struct nfct_helper *nfct_helper, enum nfct_helper_attr_type type, const char *name); +void nfct_helper_attr_set_u8(struct nfct_helper *nfct_helper, enum nfct_helper_attr_type type, uint8_t value); +void nfct_helper_attr_set_u16(struct nfct_helper *nfct_helper, enum nfct_helper_attr_type type, uint16_t value); +void nfct_helper_attr_set_u32(struct nfct_helper *nfct_helper, enum nfct_helper_attr_type type, uint32_t value); +void nfct_helper_attr_unset(struct nfct_helper *nfct_helper, enum nfct_helper_attr_type type); + +const void *nfct_helper_attr_get(struct nfct_helper *nfct_helper, enum nfct_helper_attr_type type); +const char *nfct_helper_attr_get_str(struct nfct_helper *nfct_helper, enum nfct_helper_attr_type type); +uint8_t nfct_helper_attr_get_u8(struct nfct_helper *nfct_helper, enum nfct_helper_attr_type type); +uint16_t nfct_helper_attr_get_u16(struct nfct_helper *nfct_helper, enum nfct_helper_attr_type type); +uint32_t nfct_helper_attr_get_u32(struct nfct_helper *nfct_helper, enum nfct_helper_attr_type type); + +struct nlmsghdr; + +struct nlmsghdr *nfct_helper_nlmsg_build_hdr(char *buf, uint8_t cmd, uint16_t flags, uint32_t seq); +void nfct_helper_nlmsg_build_payload(struct nlmsghdr *nlh, struct nfct_helper *nfct_helper); +int nfct_helper_nlmsg_parse_payload(const struct nlmsghdr *nlh, struct nfct_helper *nfct_helper); + +int nfct_helper_snprintf(char *buf, size_t size, struct nfct_helper *nfct_helper, unsigned int flags); + +#endif diff --git a/include/linux/Makefile.am b/include/linux/Makefile.am new file mode 100644 index 0000000..38eb109 --- /dev/null +++ b/include/linux/Makefile.am @@ -0,0 +1 @@ +SUBDIRS = netfilter diff --git a/include/linux/netfilter/Makefile.am b/include/linux/netfilter/Makefile.am new file mode 100644 index 0000000..0b16df8 --- /dev/null +++ b/include/linux/netfilter/Makefile.am @@ -0,0 +1 @@ +noinst_HEADERS = nfnetlink.h nfnetlink_cthelper.h diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h new file mode 100644 index 0000000..5441db0 --- /dev/null +++ b/include/linux/netfilter/nfnetlink.h @@ -0,0 +1,95 @@ +#ifndef _NFNETLINK_H +#define _NFNETLINK_H +#include <linux/types.h> +#include <linux/netfilter/nfnetlink_compat.h> + +enum nfnetlink_groups { + NFNLGRP_NONE, +#define NFNLGRP_NONE NFNLGRP_NONE + NFNLGRP_CONNTRACK_NEW, +#define NFNLGRP_CONNTRACK_NEW NFNLGRP_CONNTRACK_NEW + NFNLGRP_CONNTRACK_UPDATE, +#define NFNLGRP_CONNTRACK_UPDATE NFNLGRP_CONNTRACK_UPDATE + NFNLGRP_CONNTRACK_DESTROY, +#define NFNLGRP_CONNTRACK_DESTROY NFNLGRP_CONNTRACK_DESTROY + NFNLGRP_CONNTRACK_EXP_NEW, +#define NFNLGRP_CONNTRACK_EXP_NEW NFNLGRP_CONNTRACK_EXP_NEW + NFNLGRP_CONNTRACK_EXP_UPDATE, +#define NFNLGRP_CONNTRACK_EXP_UPDATE NFNLGRP_CONNTRACK_EXP_UPDATE + NFNLGRP_CONNTRACK_EXP_DESTROY, +#define NFNLGRP_CONNTRACK_EXP_DESTROY NFNLGRP_CONNTRACK_EXP_DESTROY + __NFNLGRP_MAX, +}; +#define NFNLGRP_MAX (__NFNLGRP_MAX - 1) + +/* General form of address family dependent message. + */ +struct nfgenmsg { + __u8 nfgen_family; /* AF_xxx */ + __u8 version; /* nfnetlink version */ + __be16 res_id; /* resource id */ +}; + +#define NFNETLINK_V0 0 + +/* netfilter netlink message types are split in two pieces: + * 8 bit subsystem, 8bit operation. + */ + +#define NFNL_SUBSYS_ID(x) ((x & 0xff00) >> 8) +#define NFNL_MSG_TYPE(x) (x & 0x00ff) + +/* No enum here, otherwise __stringify() trick of MODULE_ALIAS_NFNL_SUBSYS() + * won't work anymore */ +#define NFNL_SUBSYS_NONE 0 +#define NFNL_SUBSYS_CTNETLINK 1 +#define NFNL_SUBSYS_CTNETLINK_EXP 2 +#define NFNL_SUBSYS_QUEUE 3 +#define NFNL_SUBSYS_ULOG 4 +#define NFNL_SUBSYS_OSF 5 +#define NFNL_SUBSYS_IPSET 6 +#define NFNL_SUBSYS_ACCT 7 +#define NFNL_SUBSYS_CTHELPER 8 +#define NFNL_SUBSYS_COUNT 9 + +#ifdef __KERNEL__ + +#include <linux/netlink.h> +#include <linux/capability.h> +#include <net/netlink.h> + +struct nfnl_callback { + int (*call)(struct sock *nl, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const cda[]); + int (*call_rcu)(struct sock *nl, struct sk_buff *skb, + const struct nlmsghdr *nlh, + const struct nlattr * const cda[]); + const struct nla_policy *policy; /* netlink attribute policy */ + const u_int16_t attr_count; /* number of nlattr's */ +}; + +struct nfnetlink_subsystem { + const char *name; + __u8 subsys_id; /* nfnetlink subsystem ID */ + __u8 cb_count; /* number of callbacks */ + const struct nfnl_callback *cb; /* callback for individual types */ +}; + +extern int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n); +extern int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n); + +extern int nfnetlink_has_listeners(struct net *net, unsigned int group); +extern int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, unsigned group, + int echo, gfp_t flags); +extern int nfnetlink_set_err(struct net *net, u32 pid, u32 group, int error); +extern int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u_int32_t pid, int flags); + +extern void nfnl_lock(void); +extern void nfnl_unlock(void); + +#define MODULE_ALIAS_NFNL_SUBSYS(subsys) \ + MODULE_ALIAS("nfnetlink-subsys-" __stringify(subsys)) + +#endif /* __KERNEL__ */ +#endif /* _NFNETLINK_H */ diff --git a/include/linux/netfilter/nfnetlink_cthelper.h b/include/linux/netfilter/nfnetlink_cthelper.h new file mode 100644 index 0000000..52c365b --- /dev/null +++ b/include/linux/netfilter/nfnetlink_cthelper.h @@ -0,0 +1,50 @@ +#ifndef _NFNL_CTHELPER_H_ +#define _NFNL_CTHELPER_H_ + +enum nfnl_acct_msg_types { + NFNL_MSG_CTHELPER_NEW, + NFNL_MSG_CTHELPER_GET, + NFNL_MSG_CTHELPER_DEL, + NFNL_MSG_CTHELPER_MAX +}; + +enum nfnl_cthelper_type { + NFCTH_UNSPEC, + NFCTH_NAME, + NFCTH_TUPLE, + NFCTH_QUEUE_NUM, + NFCTH_POLICY, + __NFCTH_MAX +}; +#define NFCTH_MAX (__NFCTH_MAX - 1) + +enum nfnl_cthelper_policy_type { + NFCTH_POLICY_SET_UNSPEC, + NFCTH_POLICY_SET_NUM, + NFCTH_POLICY_SET, + NFCTH_POLICY_SET1 = NFCTH_POLICY_SET, + NFCTH_POLICY_SET2, + NFCTH_POLICY_SET3, + NFCTH_POLICY_SET4, + __NFCTH_POLICY_SET_MAX +}; +#define NFCTH_POLICY_SET_MAX (__NFCTH_POLICY_SET_MAX - 1) + +enum nfnl_cthelper_pol_type { + NFCTH_POLICY_UNSPEC, + NFCTH_POLICY_NAME, + NFCTH_POLICY_EXPECT_MAX, + NFCTH_POLICY_EXPECT_TIMEOUT, + __NFCTH_POLICY_MAX +}; +#define NFCTH_POLICY_MAX (__NFCTH_POLICY_MAX - 1) + +enum nfnl_cthelper_tuple_type { + NFCTH_TUPLE_UNSPEC, + NFCTH_TUPLE_L3PROTONUM, + NFCTH_TUPLE_L4PROTONUM, + __NFCTH_TUPLE_MAX, +}; +#define NFCTH_TUPLE_MAX (__NFCTH_TUPLE_MAX - 1) + +#endif /* _NFNL_CTHELPER_H */ diff --git a/libnetfilter_cthelper.pc.in b/libnetfilter_cthelper.pc.in new file mode 100644 index 0000000..54e37a7 --- /dev/null +++ b/libnetfilter_cthelper.pc.in @@ -0,0 +1,15 @@ +# libnetfilter_acct pkg-config file + +prefix=@prefix@ +exec_prefix=@exec_prefix@ +libdir=@libdir@ +includedir=@includedir@ + +Name: libnetfilter_acct +Description: Netfilter extended accounting infrastructure library +URL: http://netfilter.org/projects/libnetfilter_acct/ +Version: @VERSION@ +Requires: +Conflicts: +Libs: -L${libdir} -lnetfilter_acct +Cflags: -I${includedir} diff --git a/m4/.gitignore b/m4/.gitignore new file mode 100644 index 0000000..64d9bbc --- /dev/null +++ b/m4/.gitignore @@ -0,0 +1,2 @@ +/libtool.m4 +/lt*.m4 diff --git a/m4/gcc4_visibility.m4 b/m4/gcc4_visibility.m4 new file mode 100644 index 0000000..214d3f3 --- /dev/null +++ b/m4/gcc4_visibility.m4 @@ -0,0 +1,21 @@ + +# GCC 4.x -fvisibility=hidden + +AC_DEFUN([CHECK_GCC_FVISIBILITY], [ + AC_LANG_PUSH([C]) + saved_CFLAGS="$CFLAGS" + CFLAGS="$saved_CFLAGS -fvisibility=hidden" + AC_CACHE_CHECK([whether compiler accepts -fvisibility=hidden], + [ac_cv_fvisibility_hidden], AC_COMPILE_IFELSE( + [AC_LANG_SOURCE()], + [ac_cv_fvisibility_hidden=yes], + [ac_cv_fvisibility_hidden=no] + )) + if test "$ac_cv_fvisibility_hidden" = "yes"; then + AC_DEFINE([HAVE_VISIBILITY_HIDDEN], [1], + [True if compiler supports -fvisibility=hidden]) + AC_SUBST([GCC_FVISIBILITY_HIDDEN], [-fvisibility=hidden]) + fi + CFLAGS="$saved_CFLAGS" + AC_LANG_POP([C]) +]) diff --git a/src/Makefile.am b/src/Makefile.am new file mode 100644 index 0000000..19dab7c --- /dev/null +++ b/src/Makefile.am @@ -0,0 +1,8 @@ +include $(top_srcdir)/Make_global.am +lib_LTLIBRARIES = libnetfilter_cthelper.la + +libnetfilter_cthelper_la_LIBADD = ${LIBMNL_LIBS} +libnetfilter_cthelper_la_LDFLAGS = -Wl,--version-script=$(srcdir)/libnetfilter_cthelper.map -version-info $(LIBVERSION) +libnetfilter_cthelper_la_SOURCES = libnetfilter_cthelper.c \ + libnetfilter_cthelper.map \ + internal.h diff --git a/src/internal.h b/src/internal.h new file mode 100644 index 0000000..3a88d1a --- /dev/null +++ b/src/internal.h @@ -0,0 +1,12 @@ +#ifndef INTERNAL_H +#define INTERNAL_H 1 + +#include "config.h" +#ifdef HAVE_VISIBILITY_HIDDEN +# define __visible __attribute__((visibility("default"))) +# define EXPORT_SYMBOL(x) typeof(x) (x) __visible +#else +# define EXPORT_SYMBOL +#endif + +#endif diff --git a/src/libnetfilter_cthelper.c b/src/libnetfilter_cthelper.c new file mode 100644 index 0000000..c70a5eb --- /dev/null +++ b/src/libnetfilter_cthelper.c @@ -0,0 +1,644 @@ +/* + * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org> + * (C) 2012 by Vyatta Inc. <http://www.vyatta.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the Lesser GNU General Public License as published + * by the Free Software Foundation; either version 2.1 of the License, or + * (at your option) any later version. + */ +#include "internal.h" + +#include <time.h> +#include <stdlib.h> +#include <string.h> +#include <arpa/inet.h> /* for htonl */ + +#include <libmnl/libmnl.h> +#include <linux/netfilter/nfnetlink.h> +#include <linux/netfilter/nfnetlink_cthelper.h> + +#include <libnetfilter_cthelper/libnetfilter_cthelper.h> + +/** + * \mainpage + * + * libnetfilter_cthelper is the userspace library that provides a programming + * interface (API) to user-space connection tracking helpers. Basically, you + * can find here a set of helper functions that you can use together with + * libmnl. + * + * libnetfilter_cthelper homepage is: + * http://netfilter.org/projects/libnetfilter_cthelper/ + * + * \section Dependencies + * libnetfilter_cthelper requires libmnl >= 1.0.0 and the Linux kernel that + * includes the nfnetlink_cthelper subsystem (i.e. 3.3.x or any later). + * + * \section Main Features + * - register new user-space connection tracking helpers. + * - unregister user-space connection tracking helpers. + * - list existing registered user-space connection tracking helpers. + * + * \section Git Tree + * The current development version of libnetfilter_cthelper can be accessed at + * https://git.netfilter.org/cgi-bin/gitweb.cgi?p=libnetfilter_cthelper.git + * + * \section using Using libnetfilter_cthelper + * To write your own program using libnetfilter_cthelper, you should start by + * reading the documentation for libmnl to understand basic operation with + * Netlink sockets. Moreover, you may want to check the examples available + * under examples/ in the libnetfilter_cthelper source code. You can compile + * these examples by invoking `make check'. + * + * \section Authors + * libnetfilter_cthelper has been written by Pablo Neira Ayuso. + */ + +/* XXX */ +#ifndef NF_CT_HELPER_NAME_MAX +#define NF_CT_HELPER_NAME_MAX 16 +#endif + +#ifndef NF_CT_HELPER_CLASS_MAX +#define NF_CT_HELPER_CLASS_MAX 4 +#endif + +struct nfct_helper { + char name[NF_CT_HELPER_NAME_MAX]; + uint32_t queue_num; + uint32_t policy_num; + struct { + uint16_t l3num; + uint8_t l4num; + uint16_t port; + } tuple; + struct { + char name[NF_CT_HELPER_NAME_MAX]; + uint32_t expect_timeout; + uint32_t expect_max; + } expect_policy[NF_CT_HELPER_CLASS_MAX]; + + uint32_t bitset; +}; + +/** + * \defgroup nfct_helper Accounting object handling + * @{ + */ + +/** + * nfct_helper_alloc - allocate a new helper object + * + * In case of success, this function returns a valid pointer, otherwise NULL + * s returned and errno is appropriately set. + */ +struct nfct_helper *nfct_helper_alloc(void) +{ + return calloc(1, sizeof(struct nfct_helper)); +} +EXPORT_SYMBOL(nfct_helper_alloc); + +/** + * nfct_helper_free - release one helper object + * \param nfct_helper pointer to the helper object + */ +void nfct_helper_free(struct nfct_helper *nfct_helper) +{ + free(nfct_helper); +} +EXPORT_SYMBOL(nfct_helper_free); + +/** + * nfct_helper_attr_set - set one attribute of the helper object + * \param nfct_helper pointer to the helper object + * \param type attribute type you want to set + * \param data pointer to data that will be used to set this attribute + */ +void +nfct_helper_attr_set(struct nfct_helper *nfct_helper, + enum nfct_helper_attr_type type, const void *data) +{ + switch(type) { + case NFCTH_ATTR_NAME: + strncpy(nfct_helper->name, data, NF_CT_HELPER_NAME_MAX); + nfct_helper->name[NF_CT_HELPER_NAME_MAX-1] = '\0'; + nfct_helper->bitset |= (1 << NFCTH_ATTR_NAME); + break; + case NFCTH_ATTR_PROTO_L3NUM: + nfct_helper->tuple.l3num = *((uint16_t *) data); + nfct_helper->bitset |= (1 << NFCTH_ATTR_PROTO_L3NUM); + break; + case NFCTH_ATTR_PROTO_L4NUM: + nfct_helper->tuple.l4num = *((uint8_t *) data); + nfct_helper->bitset |= (1 << NFCTH_ATTR_PROTO_L4NUM); + break; + case NFCTH_ATTR_QUEUE_NUM: + nfct_helper->queue_num = *((uint32_t *) data); + nfct_helper->bitset |= (1 << NFCTH_ATTR_QUEUE_NUM); + break; + case NFCTH_ATTR_EXP_POLICY_NAME: + strncpy(nfct_helper->expect_policy[0].name, + data, NF_CT_HELPER_NAME_MAX); + nfct_helper->expect_policy[0].name[NF_CT_HELPER_NAME_MAX-1] = '\0'; + nfct_helper->bitset |= (1 << NFCTH_ATTR_EXP_POLICY_NAME); + break; + case NFCTH_ATTR_EXP_POLICY_TIMEOUT: + nfct_helper->expect_policy[0].expect_timeout = + *((uint32_t *) data); + nfct_helper->bitset |= (1 << NFCTH_ATTR_EXP_POLICY_TIMEOUT); + break; + case NFCTH_ATTR_EXP_POLICY_MAX: + nfct_helper->expect_policy[0].expect_max = *((uint32_t *) data); + nfct_helper->bitset |= (1 << NFCTH_ATTR_EXP_POLICY_MAX); + break; + } +} +EXPORT_SYMBOL(nfct_helper_attr_set); + +/** + * nfct_helper_attr_set_str - set one attribute the helper object + * \param nfct_helper pointer to the helper object + * \param type attribute type you want to set + * \param name string that will be used to set this attribute + */ +void +nfct_helper_attr_set_str(struct nfct_helper *nfct_helper, enum nfct_helper_attr_type type, + const char *name) +{ + nfct_helper_attr_set(nfct_helper, type, name); +} +EXPORT_SYMBOL(nfct_helper_attr_set_str); + +void +nfct_helper_attr_set_u8(struct nfct_helper *nfct_helper, + enum nfct_helper_attr_type type, uint8_t value) +{ + nfct_helper_attr_set(nfct_helper, type, &value); +} +EXPORT_SYMBOL(nfct_helper_attr_set_u8); + +void +nfct_helper_attr_set_u16(struct nfct_helper *nfct_helper, + enum nfct_helper_attr_type type, uint16_t value) +{ + nfct_helper_attr_set(nfct_helper, type, &value); +} +EXPORT_SYMBOL(nfct_helper_attr_set_u16); + +void +nfct_helper_attr_set_u32(struct nfct_helper *nfct_helper, + enum nfct_helper_attr_type type, uint32_t value) +{ + nfct_helper_attr_set(nfct_helper, type, &value); +} +EXPORT_SYMBOL(nfct_helper_attr_set_u32); + +/** + * nfct_helper_attr_unset - unset one attribute the helper object + * \param nfct_helper pointer to the helper object + * \param type attribute type you want to set + */ +void +nfct_helper_attr_unset(struct nfct_helper *nfct_helper, enum nfct_helper_attr_type type) +{ + switch(type) { + case NFCTH_ATTR_NAME: + nfct_helper->bitset &= ~(1 << NFCTH_ATTR_NAME); + break; + default: + /* XXX */ + break; + } +} +EXPORT_SYMBOL(nfct_helper_attr_unset); + +/** + * nfct_helper_attr_get - get one attribute the helper object + * \param nfct_helper pointer to the helper object + * \param type attribute type you want to set + * + * This function returns a valid pointer to the attribute data. If a + * unsupported attribute is used, this returns NULL. + */ +const void *nfct_helper_attr_get(struct nfct_helper *helper, + enum nfct_helper_attr_type type) +{ + const void *ret = NULL; + + switch(type) { + case NFCTH_ATTR_NAME: + ret = helper->name; + break; + case NFCTH_ATTR_QUEUE_NUM: + ret = &helper->queue_num; + break; + case NFCTH_ATTR_PROTO_L3NUM: + ret = &helper->tuple.l3num; + break; + case NFCTH_ATTR_PROTO_L4NUM: + ret = &helper->tuple.l4num; + break; + default: + printf("boom\n"); + exit(EXIT_FAILURE); + break; + } + return ret; +} +EXPORT_SYMBOL(nfct_helper_attr_get); + +/** + * nfct_helper_attr_get_str - get one attribute the helper object + * \param nfct_helper pointer to the helper object + * \param type attribute type you want to set + * + * This function returns a valid pointer to the beginning of the string. + * If the attribute is unsupported, this returns NULL. + */ +const char * +nfct_helper_attr_get_str(struct nfct_helper *nfct_helper, + enum nfct_helper_attr_type type) +{ + return (const char *)nfct_helper_attr_get(nfct_helper, type); +} +EXPORT_SYMBOL(nfct_helper_attr_get_str); + +/** + * nfct_helper_attr_get_u8 - get one attribute the helper object + * \param nfct_helper pointer to the helper object + * \param type attribute type you want to set + * + * This function returns a unsigned 8-bits integer. If the attribute is + * unsupported, this returns NULL. + */ +uint8_t nfct_helper_attr_get_u8(struct nfct_helper *nfct_helper, + enum nfct_helper_attr_type type) +{ + return *((uint8_t *)nfct_helper_attr_get(nfct_helper, type)); +} +EXPORT_SYMBOL(nfct_helper_attr_get_u8); + +/** + * nfct_helper_attr_get_u16 - get one attribute the helper object + * \param nfct_helper pointer to the helper object + * \param type attribute type you want to set + * + * This function returns a unsigned 16-bits integer. If the attribute is + * unsupported, this returns NULL. + */ +uint16_t nfct_helper_attr_get_u16(struct nfct_helper *nfct_helper, + enum nfct_helper_attr_type type) +{ + return *((uint16_t *)nfct_helper_attr_get(nfct_helper, type)); +} +EXPORT_SYMBOL(nfct_helper_attr_get_u16); + +/** + * nfct_helper_attr_get_u32 - get one attribute the helper object + * \param nfct_helper pointer to the helper object + * \param type attribute type you want to set + * + * This function returns a unsigned 32-bits integer. If the attribute is + * unsupported, this returns NULL. + */ +uint32_t nfct_helper_attr_get_u32(struct nfct_helper *nfct_helper, + enum nfct_helper_attr_type type) +{ + return *((uint32_t *)nfct_helper_attr_get(nfct_helper, type)); +} +EXPORT_SYMBOL(nfct_helper_attr_get_u32); + +/** + * nfct_helper_snprintf - print helper object into one buffer + * \param buf: pointer to buffer that is used to print the object + * \param size: size of the buffer (or remaining room in it). + * \param nfct_helper: pointer to a valid helper object. + * \param flags: output flags (NFCTH_SNPRINTF_F_FULL). + * + * This function returns -1 in case that some mandatory attributes are + * missing. On sucess, it returns 0. + */ +int nfct_helper_snprintf(char *buf, size_t size, + struct nfct_helper *helper, unsigned int flags) +{ + int ret; + + ret = snprintf(buf, size, "{ name = %s, queuenum = %u," + " l3protonum = %u, l4protonum = %u };", + nfct_helper_attr_get_str(helper, NFCTH_ATTR_NAME), + nfct_helper_attr_get_u32(helper, NFCTH_ATTR_QUEUE_NUM), + nfct_helper_attr_get_u16(helper, NFCTH_ATTR_PROTO_L3NUM), + nfct_helper_attr_get_u8(helper, NFCTH_ATTR_PROTO_L4NUM)); + + return ret; +} +EXPORT_SYMBOL(nfct_helper_snprintf); + +/** + * @} + */ + +/** + * \defgroup nlmsg Netlink message helper functions + * @{ + */ + +/** + * nfct_helper_nlmsg_build_hdr - build netlink message header for nfct_helper subsystem + * \param buf: buffer where this function outputs the netlink message. + * \param cmd: nfct_helper nfnetlink command. + * \param flags: netlink flags. + * \param seq: sequence number for this message. + * + * Possible commands: + * - NFNL_MSG_ACCT_NEW: new helper object. + * - NFNL_MSG_ACCT_GET: get helper object. + * - NFNL_MSG_ACCT_GET_CTRZERO: get helper object and atomically reset. + * + * Examples: + * - Command NFNL_MSG_ACCT_NEW + flags NLM_F_CREATE | NLM_F_ACK, to create + * one new helper object (if it does not already exists). You receive + * one acknoledgment in any case with the result of the operation. + * + * - Command NFNL_MSG_ACCT_GET + flags NLM_F_DUMP, to obtain all the + * existing helper objects. + * + * - Command NFNL_MSG_ACCT_DEL, to delete all existing unused objects. + * + * - Command NFNL_MSG_ACCT_DEL, to delete one specific nfct_helper object (if + * unused, otherwise you hit EBUSY). + */ +struct nlmsghdr * +nfct_helper_nlmsg_build_hdr(char *buf, uint8_t cmd, + uint16_t flags, uint32_t seq) +{ + struct nlmsghdr *nlh; + struct nfgenmsg *nfh; + + nlh = mnl_nlmsg_put_header(buf); + nlh->nlmsg_type = (NFNL_SUBSYS_CTHELPER << 8) | cmd; + nlh->nlmsg_flags = NLM_F_REQUEST | flags; + nlh->nlmsg_seq = seq; + + nfh = mnl_nlmsg_put_extra_header(nlh, sizeof(struct nfgenmsg)); + nfh->nfgen_family = AF_UNSPEC; + nfh->version = NFNETLINK_V0; + nfh->res_id = 0; + + return nlh; +} +EXPORT_SYMBOL(nfct_helper_nlmsg_build_hdr); + +/** + * nfct_helper_nlmsg_build_payload - build payload from helper object + * \param nlh: netlink message that you want to use to add the payload. + * \param nfct_helper: pointer to a helper object + */ +void nfct_helper_nlmsg_build_payload(struct nlmsghdr *nlh, + struct nfct_helper *nfct_helper) +{ + struct nlattr *nest, *nest2; + + mnl_attr_put_strz(nlh, NFCTH_NAME, nfct_helper->name); + mnl_attr_put_u32(nlh, NFCTH_QUEUE_NUM, htonl(nfct_helper->queue_num)); + + nest = mnl_attr_nest_start(nlh, NFCTH_TUPLE); + mnl_attr_put_u16(nlh, NFCTH_TUPLE_L3PROTONUM, nfct_helper->tuple.l3num); + mnl_attr_put_u8(nlh, NFCTH_TUPLE_L4PROTONUM, nfct_helper->tuple.l4num); + mnl_attr_nest_end(nlh, nest); + + nest = mnl_attr_nest_start(nlh, NFCTH_POLICY); + mnl_attr_put_u32(nlh, NFCTH_POLICY_SET_NUM, htonl(1)); + + nest2 = mnl_attr_nest_start(nlh, NFCTH_POLICY_SET); + mnl_attr_put_strz(nlh, NFCTH_POLICY_NAME, + nfct_helper->expect_policy[0].name); + mnl_attr_put_u32(nlh, NFCTH_POLICY_EXPECT_MAX, + htonl(nfct_helper->expect_policy[0].expect_max)); + mnl_attr_put_u32(nlh, NFCTH_POLICY_EXPECT_TIMEOUT, + htonl(nfct_helper->expect_policy[0].expect_timeout)); + mnl_attr_nest_end(nlh, nest2); + mnl_attr_nest_end(nlh, nest); +} +EXPORT_SYMBOL(nfct_helper_nlmsg_build_payload); + +static int +nfct_helper_nlmsg_parse_tuple_cb(const struct nlattr *attr, void *data) +{ + const struct nlattr **tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, NFCTH_TUPLE_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFCTH_TUPLE_L3PROTONUM: + if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + case NFCTH_TUPLE_L4PROTONUM: + if (mnl_attr_validate(attr, MNL_TYPE_U8) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + default: + break; + } + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nfct_helper_nlmsg_parse_tuple(const struct nlattr *attr, + struct nfct_helper *helper) +{ + struct nlattr *tb[NFCTH_TUPLE_MAX+1] = {}; + + mnl_attr_parse_nested(attr, nfct_helper_nlmsg_parse_tuple_cb, tb); + if (tb[NFCTH_TUPLE_L3PROTONUM]) { + nfct_helper_attr_set_u16(helper, NFCTH_ATTR_PROTO_L3NUM, + ntohs(mnl_attr_get_u16(tb[NFCTH_TUPLE_L3PROTONUM]))); + } + if (tb[NFCTH_TUPLE_L4PROTONUM]) { + nfct_helper_attr_set_u8(helper, NFCTH_ATTR_PROTO_L4NUM, + mnl_attr_get_u8(tb[NFCTH_TUPLE_L4PROTONUM])); + } +} + +static int +nfct_helper_nlmsg_parse_policy_cb(const struct nlattr *attr, void *data) +{ + const struct nlattr **tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, NFCTH_POLICY_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFCTH_POLICY_NAME: + if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + case NFCTH_POLICY_EXPECT_MAX: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + case NFCTH_POLICY_EXPECT_TIMEOUT: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + default: + break; + } + tb[type] = attr; + return MNL_CB_OK; +} + +static int +nfct_helper_nlmsg_parse_policy_set_cb(const struct nlattr *attr, void *data) +{ + const struct nlattr **tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, NFCTH_POLICY_SET_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFCTH_POLICY_SET_NUM: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + default: + /* NFCTH_POLICY_SET1, 2, 3 and 4. */ + break; + } + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nfct_helper_nlmsg_parse_policy(const struct nlattr *attr, + struct nfct_helper *helper) +{ + struct nlattr *tb[NFCTH_POLICY_MAX+1] = {}; + + mnl_attr_parse_nested(attr, nfct_helper_nlmsg_parse_policy_cb, tb); + if (tb[NFCTH_POLICY_NAME]) { + nfct_helper_attr_set_str(helper, NFCTH_ATTR_EXP_POLICY_NAME, + mnl_attr_get_str(tb[NFCTH_POLICY_NAME])); + } + if (tb[NFCTH_POLICY_EXPECT_MAX]) { + nfct_helper_attr_set_u32(helper, NFCTH_ATTR_EXP_POLICY_MAX, + ntohl(mnl_attr_get_u32(tb[NFCTH_POLICY_EXPECT_MAX]))); + } + if (tb[NFCTH_POLICY_EXPECT_TIMEOUT]) { + nfct_helper_attr_set_u32(helper, NFCTH_ATTR_EXP_POLICY_TIMEOUT, + ntohl(mnl_attr_get_u32(tb[NFCTH_POLICY_EXPECT_TIMEOUT]))); + } +} + +static void +nfct_helper_nlmsg_parse_policy_set(const struct nlattr *attr, + struct nfct_helper *helper) +{ + struct nlattr *tb[NFCTH_POLICY_SET_MAX+1] = {}; + int i; + + mnl_attr_parse_nested(attr, nfct_helper_nlmsg_parse_policy_set_cb, tb); + if (tb[NFCTH_POLICY_SET_NUM]) { + helper->policy_num = + ntohl(mnl_attr_get_u32(tb[NFCTH_POLICY_SET_NUM])); + } + for (i=0; i<helper->policy_num; i++) { + if (tb[NFCTH_POLICY_SET+i]) { + nfct_helper_nlmsg_parse_policy(tb[NFCTH_POLICY_SET+i], + helper); + } + } +} + +static int nfct_helper_nlmsg_parse_attr_cb(const struct nlattr *attr, void *data) +{ + const struct nlattr **tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, NFCTH_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFCTH_NAME: + if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + case NFCTH_QUEUE_NUM: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + case NFCTH_TUPLE: + if (mnl_attr_validate(attr, MNL_TYPE_NESTED) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + case NFCTH_POLICY: + if (mnl_attr_validate(attr, MNL_TYPE_NESTED) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + } + tb[type] = attr; + return MNL_CB_OK; +} + +/** + * nfct_helper_nlmsg_parse_payload - set helper object attributes from message + * \param nlh: netlink message that you want to use to add the payload. + * \param nfct_helper: pointer to a helper object + * + * This function returns -1 in case that some mandatory attributes are + * missing. On sucess, it returns 0. + */ +int +nfct_helper_nlmsg_parse_payload(const struct nlmsghdr *nlh, + struct nfct_helper *helper) +{ + struct nlattr *tb[NFCTH_MAX+1] = {}; + struct nfgenmsg *nfg = mnl_nlmsg_get_payload(nlh); + + mnl_attr_parse(nlh, sizeof(*nfg), nfct_helper_nlmsg_parse_attr_cb, tb); + if (!tb[NFCTH_NAME] || !tb[NFCTH_QUEUE_NUM] || + !tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY]) + return -1; + + nfct_helper_attr_set_str(helper, NFCTH_ATTR_NAME, + mnl_attr_get_str(tb[NFCTH_NAME])); + nfct_helper_attr_set_u32(helper, NFCTH_ATTR_QUEUE_NUM, + ntohl(mnl_attr_get_u32(tb[NFCTH_QUEUE_NUM]))); + + nfct_helper_nlmsg_parse_tuple(tb[NFCTH_TUPLE], helper); + nfct_helper_nlmsg_parse_policy_set(tb[NFCTH_POLICY], helper); + + return 0; +} +EXPORT_SYMBOL(nfct_helper_nlmsg_parse_payload); + +/** + * @} + */ diff --git a/src/libnetfilter_cthelper.map b/src/libnetfilter_cthelper.map new file mode 100644 index 0000000..199576b --- /dev/null +++ b/src/libnetfilter_cthelper.map @@ -0,0 +1,26 @@ +LIBNETFILTER_CTHELPER_1.0 { +global: + nfct_helper_alloc; + nfct_helper_free; + nfct_helper_attr_set; + nfct_helper_attr_set_str; + nfct_helper_attr_set_u8; + nfct_helper_attr_set_u16; + nfct_helper_attr_set_u32; + nfct_helper_attr_unset; + nfct_helper_attr_get; + nfct_helper_attr_get_str; + nfct_helper_attr_get_u8; + nfct_helper_attr_get_u16; + nfct_helper_attr_get_u32; + nfct_helper_nlmsg_build_hdr; + nfct_helper_nlmsg_build_payload; + nfct_helper_nlmsg_parse_payload; + nfct_helper_snprintf; + +local: *; +}; + +#LIBNETFILTER_CTHELPER_1.1 { +# _my_new_func; +#} LIBNETFILTER_CTHELPER_1.0; |