src: add library documentation in doxygen

This patch adds the library documentation in doxygen format.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

3 files changed, 342 insertions, 25 deletions

diff --git a/configure.ac b/configure.ac
index 0f8da1f..80191fd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -29,5 +29,5 @@ regular_CFLAGS="-Wall -Waggregate-return -Wmissing-declarations \
 	-Wformat=2 -pipe"
 AC_SUBST([regular_CPPFLAGS])
 AC_SUBST([regular_CFLAGS])
-AC_CONFIG_FILES([Makefile src/Makefile include/Makefile include/libnetfilter_acct/Makefile include/linux/Makefile include/linux/netfilter/Makefile examples/Makefile libnetfilter_acct.pc])
+AC_CONFIG_FILES([Makefile src/Makefile include/Makefile include/libnetfilter_acct/Makefile include/linux/Makefile include/linux/netfilter/Makefile examples/Makefile libnetfilter_acct.pc doxygen.cfg])
 AC_OUTPUT
diff --git a/doxygen.cfg.in b/doxygen.cfg.in
new file mode 100644
index 0000000..7f4bd04
--- /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_acct.h
+RECURSIVE              = YES
+EXCLUDE                = 
+EXCLUDE_SYMLINKS       = NO
+EXCLUDE_PATTERNS       = */.git/* .*.d
+EXCLUDE_SYMBOLS        = EXPORT_SYMBOL nfacct
+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/src/libnetfilter_acct.c b/src/libnetfilter_acct.c
index 86d7b96..9fe7d51 100644
--- a/src/libnetfilter_acct.c
+++ b/src/libnetfilter_acct.c
@@ -20,6 +20,41 @@
 
 #include <libnetfilter_acct/libnetfilter_acct.h>
 
+/**
+ * \mainpage
+ *
+ * libnetfilter_acct is the userspace library that provides a programming
+ * interface (API) to the extended accounting infrastructure. Basically, you
+ * can find here a set of helper functions that you can use together with
+ * libmnl.
+ *
+ * libnetfilter_acct homepage is:
+ *      http://netfilter.org/projects/libnetfilter_acct/
+ *
+ * \section Dependencies
+ * libnetfilter_acct requires libmnl >= 1.0.0 and the Linux kernel that
+ * includes the nfnetlink_acct subsystem (i.e. 3.3.x or any later).
+ *
+ * \section Main Features
+ *  - listing/retrieving existing accounting objects.
+ *  - atomically retrieving and reset accounting objects.
+ *  - inserting/modifying/deleting accounting objects.
+ *
+ * \section Git Tree
+ * The current development version of libnetfilter_acct can be accessed at
+ * https://git.netfilter.org/cgi-bin/gitweb.cgi?p=libnetfilter_acct.git
+ *
+ * \section using Using libnetfilter_acct
+ * To write your own program using libnetfilter_acct, 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_acct source code. You can compile
+ * these examples by invoking `make check'.
+ *
+ * \section Authors
+ * libnetfilter_acct has been written by Pablo Neira Ayuso.
+ */
+
 struct nfacct {
 	char		name[NFACCT_NAME_MAX];
 	uint64_t	pkts;
@@ -27,18 +62,39 @@ struct nfacct {
 	uint32_t	bitset;
 };
 
+/**
+ * \defgroup nfacct Accounting object handling
+ * @{
+ */
+
+/**
+ * nfacct_alloc - allocate a new accounting object
+ *
+ * In case of success, this function returns a valid pointer, otherwise NULL
+ * s returned and errno is appropriately set.
+ */
 struct nfacct *nfacct_alloc(void)
 {
 	return calloc(1, sizeof(struct nfacct));
 }
 EXPORT_SYMBOL(nfacct_alloc);
 
+/**
+ * nfacct_free - release one accounting object
+ * \param nfacct pointer to the accounting object
+ */
 void nfacct_free(struct nfacct *nfacct)
 {
 	free(nfacct);
 }
 EXPORT_SYMBOL(nfacct_free);
 
+/**
+ * nfacct_attr_set - set one attribute of the accounting object
+ * \param nfacct pointer to the accounting object
+ * \param type attribute type you want to set
+ * \param data pointer to data that will be used to set this attribute
+ */
 void
 nfacct_attr_set(struct nfacct *nfacct, enum nfacct_attr_type type,
 		const void *data)
@@ -61,6 +117,12 @@ nfacct_attr_set(struct nfacct *nfacct, enum nfacct_attr_type type,
 }
 EXPORT_SYMBOL(nfacct_attr_set);
 
+/**
+ * nfacct_attr_set_str - set one attribute the accounting object
+ * \param nfacct pointer to the accounting object
+ * \param type attribute type you want to set
+ * \param name string that will be used to set this attribute
+ */
 void
 nfacct_attr_set_str(struct nfacct *nfacct, enum nfacct_attr_type type,
 		    const char *name)
@@ -69,6 +131,12 @@ nfacct_attr_set_str(struct nfacct *nfacct, enum nfacct_attr_type type,
 }
 EXPORT_SYMBOL(nfacct_attr_set_str);
 
+/**
+ * nfacct_attr_set_u64 - set one attribute the accounting object
+ * \param nfacct pointer to the accounting object
+ * \param type attribute type you want to set
+ * \param value unsigned 64-bits integer
+ */
 void
 nfacct_attr_set_u64(struct nfacct *nfacct, enum nfacct_attr_type type,
 		    uint64_t value)
@@ -77,6 +145,11 @@ nfacct_attr_set_u64(struct nfacct *nfacct, enum nfacct_attr_type type,
 }
 EXPORT_SYMBOL(nfacct_attr_set_u64);
 
+/**
+ * nfacct_attr_unset - unset one attribute the accounting object
+ * \param nfacct pointer to the accounting object
+ * \param type attribute type you want to set
+ */
 void
 nfacct_attr_unset(struct nfacct *nfacct, enum nfacct_attr_type type)
 {
@@ -94,6 +167,14 @@ nfacct_attr_unset(struct nfacct *nfacct, enum nfacct_attr_type type)
 }
 EXPORT_SYMBOL(nfacct_attr_unset);
 
+/**
+ * nfacct_attr_get - get one attribute the accounting object
+ * \param nfacct pointer to the accounting 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 *nfacct_attr_get(struct nfacct *nfacct, enum nfacct_attr_type type)
 {
 	const void *ret = NULL;
@@ -113,6 +194,14 @@ const void *nfacct_attr_get(struct nfacct *nfacct, enum nfacct_attr_type type)
 }
 EXPORT_SYMBOL(nfacct_attr_get);
 
+/**
+ * nfacct_attr_get_str - get one attribute the accounting object
+ * \param nfacct pointer to the accounting 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 *
 nfacct_attr_get_str(struct nfacct *nfacct, enum nfacct_attr_type type)
 {
@@ -120,6 +209,14 @@ nfacct_attr_get_str(struct nfacct *nfacct, enum nfacct_attr_type type)
 }
 EXPORT_SYMBOL(nfacct_attr_get_str);
 
+/**
+ * nfacct_attr_get_u64 - get one attribute the accounting object
+ * \param nfacct pointer to the accounting object
+ * \param type attribute type you want to set
+ *
+ * This function returns a unsigned 64-bits integer. If the attribute is
+ * unsupported, this returns NULL.
+ */
 uint64_t nfacct_attr_get_u64(struct nfacct *nfacct, enum nfacct_attr_type type)
 {
 	return *((uint64_t *)nfacct_attr_get(nfacct, type));
@@ -127,11 +224,51 @@ uint64_t nfacct_attr_get_u64(struct nfacct *nfacct, enum nfacct_attr_type type)
 EXPORT_SYMBOL(nfacct_attr_get_u64);
 
 /**
+ * nfacct_snprintf - print accounting 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 nfacct: pointer to a valid accounting object.
+ * \param flags: output flags (NFACCT_SNPRINTF_F_FULL).
+ *
+ * This function returns -1 in case that some mandatory attributes are
+ * missing. On sucess, it returns 0.
+ */
+int nfacct_snprintf(char *buf, size_t size, struct nfacct *nfacct,
+		    unsigned int flags)
+{
+	int ret;
+
+	if (flags & NFACCT_SNPRINTF_F_FULL) {
+		ret = snprintf(buf, size,
+			"%s = { pkts = %.12llu,\tbytes = %.12llu };",
+			nfacct_attr_get_str(nfacct, NFACCT_ATTR_NAME),
+			(unsigned long long)
+			nfacct_attr_get_u64(nfacct, NFACCT_ATTR_BYTES),
+			(unsigned long long)
+			nfacct_attr_get_u64(nfacct, NFACCT_ATTR_PKTS));
+	} else {
+		ret = snprintf(buf, size, "%s\n",
+			nfacct_attr_get_str(nfacct, NFACCT_ATTR_NAME));
+	}
+	return ret;
+}
+EXPORT_SYMBOL(nfacct_snprintf);
+
+/**
+ * @}
+ */
+
+/**
+ * \defgroup nlmsg Netlink message helper functions
+ * @{
+ */
+
+/**
  * nfacct_nlmsg_build_hdr - build netlink message header for nfacct subsystem
- * @buf: buffer where this function outputs the netlink message.
- * @cmd: nfacct nfnetlink command.
- * @flags: netlink flags.
- * @seq: sequence number for this message.
+ * \param buf: buffer where this function outputs the netlink message.
+ * \param cmd: nfacct nfnetlink command.
+ * \param flags: netlink flags.
+ * \param seq: sequence number for this message.
  *
  * Possible commands:
  * - NFNL_MSG_ACCT_NEW: new accounting object.
@@ -174,6 +311,11 @@ nfacct_nlmsg_build_hdr(char *buf, uint8_t cmd, uint16_t flags, uint32_t seq)
 }
 EXPORT_SYMBOL(nfacct_nlmsg_build_hdr);
 
+/**
+ * nfacct_nlmsg_build_payload - build payload from accounting object
+ * \param nlh: netlink message that you want to use to add the payload.
+ * \param nfacct: pointer to a accounting object
+ */
 void nfacct_nlmsg_build_payload(struct nlmsghdr *nlh, struct nfacct *nfacct)
 {
 	if (nfacct->name)
@@ -219,6 +361,14 @@ static int nfacct_nlmsg_parse_attr_cb(const struct nlattr *attr, void *data)
 	return MNL_CB_OK;
 }
 
+/**
+ * nfacct_nlmsg_parse_payload - set accounting object attributes from message
+ * \param nlh: netlink message that you want to use to add the payload.
+ * \param nfacct: pointer to a accounting object
+ *
+ * This function returns -1 in case that some mandatory attributes are
+ * missing. On sucess, it returns 0.
+ */
 int
 nfacct_nlmsg_parse_payload(const struct nlmsghdr *nlh, struct nfacct *nfacct)
 {
@@ -240,23 +390,6 @@ nfacct_nlmsg_parse_payload(const struct nlmsghdr *nlh, struct nfacct *nfacct)
 }
 EXPORT_SYMBOL(nfacct_nlmsg_parse_payload);
 
-int nfacct_snprintf(char *buf, size_t size, struct nfacct *nfacct,
-		    unsigned int flags)
-{
-	int ret;
-
-	if (flags & NFACCT_SNPRINTF_F_FULL) {
-		ret = snprintf(buf, size,
-			"%s = { pkts = %.12llu,\tbytes = %.12llu };",
-			nfacct_attr_get_str(nfacct, NFACCT_ATTR_NAME),
-			(unsigned long long)
-			nfacct_attr_get_u64(nfacct, NFACCT_ATTR_BYTES),
-			(unsigned long long)
-			nfacct_attr_get_u64(nfacct, NFACCT_ATTR_PKTS));
-	} else {
-		ret = snprintf(buf, size, "%s\n",
-			nfacct_attr_get_str(nfacct, NFACCT_ATTR_NAME));
-	}
-	return ret;
-}
-EXPORT_SYMBOL(nfacct_snprintf);
+/**
+ * @}
+ */