parse: add mnl_attr_for_each_payload

This function allows you to parse the payload of the Netlink message.
Thus, you can skip the headers and go down to the part of the message
you want to parse.

This patch has updated the LIBVERSION and it also bumps the version
to 1.0.3, in case that someone wants to package some snapshot, not to
mess with the new symbol we have added.

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

5 files changed, 45 insertions, 6 deletions

diff --git a/Make_global.am b/Make_global.am
index 1c9ed63..3665b68 100644
--- a/Make_global.am
+++ b/Make_global.am
@@ -18,7 +18,7 @@
 # set age to 0.
 # </snippet>
 #
-LIBVERSION=0:1:0
+LIBVERSION=1:0:1
 
 AM_CPPFLAGS = ${regular_CPPFLAGS} -I${top_srcdir}/include
 AM_CFLAGS = ${regular_CFLAGS} ${GCC_FVISIBILITY_HIDDEN}
diff --git a/configure.ac b/configure.ac
index 49c4fc0..718ab1c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,6 +1,6 @@
 dnl Process this file with autoconf to create configure.
 
-AC_INIT([libmnl], [1.0.2])
+AC_INIT([libmnl], [1.0.3])
 AC_CONFIG_AUX_DIR([build-aux])
 AC_CANONICAL_HOST
 AC_CONFIG_MACRO_DIR([m4])
diff --git a/include/libmnl/libmnl.h b/include/libmnl/libmnl.h
index 1e170a9..a647fd9 100644
--- a/include/libmnl/libmnl.h
+++ b/include/libmnl/libmnl.h
@@ -156,11 +156,17 @@ extern struct nlattr *mnl_attr_next(const struct nlattr *attr);
 	     mnl_attr_ok((attr), (char *)mnl_attr_get_payload(nest) + mnl_attr_get_payload_len(nest) - (char *)(attr)); \
 	     (attr) = mnl_attr_next(attr))
 
+#define mnl_attr_for_each_payload(payload, payload_size) \
+	for ((attr) = (payload); \
+	     mnl_attr_ok((attr), (char *)(payload) + payload_size - (char *)(attr)); \
+	     (attr) = mnl_attr_next(attr))
+
 /* TLV callback-based attribute parsers */
 typedef int (*mnl_attr_cb_t)(const struct nlattr *attr, void *data);
 
 extern int mnl_attr_parse(const struct nlmsghdr *nlh, unsigned int offset, mnl_attr_cb_t cb, void *data);
 extern int mnl_attr_parse_nested(const struct nlattr *attr, mnl_attr_cb_t cb, void *data);
+extern int mnl_attr_parse_payload(const void *payload, size_t payload_len, mnl_attr_cb_t cb, void *data);
 
 /*
  * callback API
diff --git a/src/attr.c b/src/attr.c
index 55a80d6..1136c50 100644
--- a/src/attr.c
+++ b/src/attr.c
@@ -1,5 +1,5 @@
 /*
- * (C) 2008-2010 by Pablo Neira Ayuso <pablo@netfilter.org>
+ * (C) 2008-2012 by Pablo Neira Ayuso <pablo@netfilter.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
@@ -304,6 +304,39 @@ mnl_attr_parse_nested(const struct nlattr *nested, mnl_attr_cb_t cb,
 EXPORT_SYMBOL(mnl_attr_parse_nested);
 
 /**
+ * mnl_attr_parse_payload - parse attributes in payload of Netlink message
+ * \param payload pointer to payload of the Netlink message
+ * \param payload_len payload length that contains the attributes
+ * \param cb callback function that is called for each attribute
+ * \param data pointer to data that is passed to the callback function
+ *
+ * This function takes a pointer to the area that contains the attributes,
+ * commonly known as the payload of the Netlink message. Thus, you have to
+ * pass a pointer to the Netlink message payload, instead of the entire
+ * message.
+ *
+ * This function allows you to iterate over the sequence of attributes that are
+ * located at some payload offset. You can then put the attributes in one array
+ * as usual, or you can use any other data structure (such as lists or trees).
+ *
+ * This function propagates the return value of the callback, which can be
+ * MNL_CB_ERROR, MNL_CB_OK or MNL_CB_STOP.
+ */
+int
+mnl_attr_parse_payload(const void *payload, size_t payload_len,
+		       mnl_attr_cb_t cb, void *data)
+{
+	int ret = MNL_CB_OK;
+	const struct nlattr *attr;
+
+	mnl_attr_for_each_payload(payload, payload_len)
+		if ((ret = cb(attr, data)) <= MNL_CB_STOP)
+			return ret;
+	return ret;
+}
+EXPORT_SYMBOL(mnl_attr_parse_payload);
+
+/**
  * mnl_attr_get_u8 - returns 8-bit unsigned integer attribute payload
  * \param attr pointer to netlink attribute
  *
diff --git a/src/libmnl.map b/src/libmnl.map
index 3147ae0..dbc332e 100644
--- a/src/libmnl.map
+++ b/src/libmnl.map
@@ -69,6 +69,6 @@ global:
 local: *;
 };
 
-#LIBMNL_1.1 {
-#  mnl_my_new_func;
-#} LIBMNL_1.0;
+LIBMNL_1.1 {
+  mnl_attr_parse_payload;
+} LIBMNL_1.0;