[PATCH 1/5] netlink: decode NETLINK_ROUTE messages first one byte of family

[JingPiao Chen]

All the NETLINK_ROUTE messages first one byte it save family.

* netlink_route.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* defs.h (decode_netlink_route): New prototype.
* netlink.c (netlink_decoders): Add NETLINK_ROUTE.

Co-authored-by: Fabien Siron <fabien.siron at epita.fr>
---
 Makefile.am     |  1 +
 defs.h          |  1 +
 netlink.c       |  1 +
 netlink_route.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 65 insertions(+)
 create mode 100644 netlink_route.c

diff --git a/Makefile.am b/Makefile.am
index 5d365e2..d10811c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -188,6 +188,7 @@ strace_SOURCES =	\
 	netlink_inet_diag.c \
 	netlink_netlink_diag.c \
 	netlink_packet_diag.c \
+	netlink_route.c	\
 	netlink_selinux.c \
 	netlink_smc_diag.c \
 	netlink_sock_diag.c \
diff --git a/defs.h b/defs.h
index 87265bd..b41dff5 100644
--- a/defs.h
+++ b/defs.h
@@ -717,6 +717,7 @@ decode_netlink_ ## name(struct tcb *, const struct nlmsghdr *,		\
 /* End of DECL_NETLINK definition. */
 
 DECL_NETLINK(crypto);
+DECL_NETLINK(route);
 DECL_NETLINK(selinux);
 DECL_NETLINK(sock_diag);
 
diff --git a/netlink.c b/netlink.c
index 947e52d..d006b00 100644
--- a/netlink.c
+++ b/netlink.c
@@ -383,6 +383,7 @@ static const netlink_decoder_t netlink_decoders[] = {
 #ifdef HAVE_LINUX_CRYPTOUSER_H
 	[NETLINK_CRYPTO] = decode_netlink_crypto,
 #endif
+	[NETLINK_ROUTE] = decode_netlink_route,
 	[NETLINK_SELINUX] = decode_netlink_selinux,
 	[NETLINK_SOCK_DIAG] = decode_netlink_sock_diag
 };
diff --git a/netlink_route.c b/netlink_route.c
new file mode 100644
index 0000000..2e7faa4
--- /dev/null
+++ b/netlink_route.c
@@ -0,0 +1,62 @@
+/*
+ * 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"
+#include "netlink.h"
+
+static void
+decode_family(struct tcb *const tcp, const uint8_t family,
+	      const kernel_ulong_t addr, const unsigned int len)
+{
+	tprints("{family=");
+	printxval(addrfams, family, "AF_???");
+	if (len > sizeof(family)) {
+		tprints(", ");
+		printstr_ex(tcp, addr + sizeof(family),
+			    len - sizeof(family), QUOTE_FORCE_HEX);
+	}
+	tprints("}");
+}
+
+bool
+decode_netlink_route(struct tcb *const tcp,
+		     const struct nlmsghdr *const nlmsghdr,
+		     const kernel_ulong_t addr,
+		     const unsigned int len)
+{
+	uint8_t family;
+
+	if (nlmsghdr->nlmsg_type == NLMSG_DONE)
+		return false;
+
+	if (!umove_or_printaddr(tcp, addr, &family))
+		decode_family(tcp, family, addr, len);
+
+	return true;
+}
-- 
2.7.4