[PATCH v2 21/25] netlink: add a basic rtnetlink parser of mdb messages

[JingPiao Chen]

* rtnl_mdb.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* netlink_route.h (decode_br_port_msg): New prototype.
* configure.ac (AC_CHECK_TYPES): Check for struct br_port_msg
in <linux/if_bridge.h>.
* netlink_route.c (route_decoders): Add RTM_DELMDB,
RTM_GETMDB and RTM_NEWMDB.

Co-authored-by: Fabien Siron <fabien.siron at epita.fr>
---
 Makefile.am     |  1 +
 configure.ac    |  1 +
 netlink_route.c |  8 +++++++-
 netlink_route.h |  1 +
 rtnl_mdb.c      | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 69 insertions(+), 1 deletion(-)
 create mode 100644 rtnl_mdb.c

diff --git a/Makefile.am b/Makefile.am
index f9997e7..0a6ad03 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -251,6 +251,7 @@ strace_SOURCES =	\
 	rtnl_addrlabel.c \
 	rtnl_dcb.c	\
 	rtnl_link.c	\
+	rtnl_mdb.c	\
 	rtnl_neigh.c	\
 	rtnl_neightbl.c	\
 	rtnl_netconf.c	\
diff --git a/configure.ac b/configure.ac
index ca8726a..762b197 100644
--- a/configure.ac
+++ b/configure.ac
@@ -445,6 +445,7 @@ AC_CHECK_HEADERS([linux/bpf.h], [
 	st_CHECK_UNION_BPF_ATTR([prog_flags])
 ])
 
+AC_CHECK_TYPES([struct br_port_msg],,, [#include <linux/if_bridge.h>])
 AC_CHECK_TYPES([struct dcbmsg],,, [#include <linux/dcbnl.h>])
 AC_CHECK_TYPES([struct ifaddrlblmsg],,, [#include <linux/if_addrlabel.h>])
 AC_CHECK_TYPES([struct netconfmsg],,, [#include <linux/netconf.h>])
diff --git a/netlink_route.c b/netlink_route.c
index 07d4199..ec0595f 100644
--- a/netlink_route.c
+++ b/netlink_route.c
@@ -107,7 +107,13 @@ static const netlink_route_decoder_t route_decoders[] = {
 #ifdef HAVE_STRUCT_NETCONFMSG
 	[RTM_DELNETCONF - RTM_BASE] = decode_netconfmsg,
 	[RTM_GETNETCONF - RTM_BASE] = decode_netconfmsg,
-	[RTM_NEWNETCONF - RTM_BASE] = decode_netconfmsg
+	[RTM_NEWNETCONF - RTM_BASE] = decode_netconfmsg,
+#endif
+
+#ifdef HAVE_STRUCT_BR_PORT_MSG
+	[RTM_DELMDB - RTM_BASE] = decode_br_port_msg,
+	[RTM_GETMDB - RTM_BASE] = decode_br_port_msg,
+	[RTM_NEWMDB - RTM_BASE] = decode_br_port_msg
 #endif
 };
 
diff --git a/netlink_route.h b/netlink_route.h
index 497ecc1..bfe108d 100644
--- a/netlink_route.h
+++ b/netlink_route.h
@@ -39,6 +39,7 @@ route_decode_name(struct tcb *tcp,			\
 		  unsigned int len)			\
 /* End of DECL_NETLINK_ROUTE_DECODER definition. */
 
+extern DECL_NETLINK_ROUTE_DECODER(decode_br_port_msg);
 extern DECL_NETLINK_ROUTE_DECODER(decode_dcbmsg);
 extern DECL_NETLINK_ROUTE_DECODER(decode_fib_rule_hdr);
 extern DECL_NETLINK_ROUTE_DECODER(decode_ifaddrlblmsg);
diff --git a/rtnl_mdb.c b/rtnl_mdb.c
new file mode 100644
index 0000000..f0171fb
--- /dev/null
+++ b/rtnl_mdb.c
@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2016 Fabien Siron <fabien.siron at epita.fr>
+ * Copyright (c) 2017 JingPiao Chen <chenjingpiao at gmail.com>
+ * Copyright (c) 2016-2017 The strace developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "defs.h"
+
+#ifdef HAVE_STRUCT_BR_PORT_MSG
+
+# include "netlink_route.h"
+# include "print_fields.h"
+
+# include <netinet/in.h>
+# include <linux/if_bridge.h>
+
+DECL_NETLINK_ROUTE_DECODER(decode_br_port_msg)
+{
+	struct br_port_msg bpm = { .family = family };
+	const size_t offset = sizeof(bpm.family);
+
+	PRINT_FIELD_XVAL("{", bpm, family, addrfams, "AF_???");
+
+	tprints(", ");
+	if (len >= sizeof(bpm)) {
+		if (!umoven_or_printaddr(tcp, addr + offset,
+					 sizeof(bpm) - offset,
+					 (void *) &bpm + offset)) {
+			PRINT_FIELD_IFINDEX("", bpm, ifindex);
+		}
+	} else
+		tprints("...");
+	tprints("}");
+}
+
+#endif
-- 
2.7.4