[PATCH 1/2] netlink: decode NETLINK_SELINUX protocol

[JingPiao Chen]

* netlink_selinux.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* defs.h (decode_netlink_selinux): New prototype.
* netlink.c (netlink_decoders): Add NETLINK_SELINUX.
---
 Makefile.am       |  1 +
 defs.h            |  1 +
 netlink.c         |  1 +
 netlink_selinux.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 72 insertions(+)
 create mode 100644 netlink_selinux.c

diff --git a/Makefile.am b/Makefile.am
index 05c2475..b98554f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -182,6 +182,7 @@ strace_SOURCES =	\
 	net.c		\
 	netlink.c       \
 	netlink.h	\
+	netlink_selinux.c \
 	netlink_sock_diag.c \
 	nlattr.c	\
 	nlattr.h	\
diff --git a/defs.h b/defs.h
index 5b378a9..bc9a3e0 100644
--- a/defs.h
+++ b/defs.h
@@ -709,6 +709,7 @@ typedef bool (*netlink_decoder_t)(struct tcb *, const struct nlmsghdr *,
 extern bool								\
 decode_netlink_ ## name(struct tcb *, const struct nlmsghdr *,		\
 			kernel_ulong_t addr, kernel_ulong_t len)
+DECL_NETLINK(selinux);
 DECL_NETLINK(sock_diag);
 
 extern int tv_nz(const struct timeval *);
diff --git a/netlink.c b/netlink.c
index 0ae9a46..e054ae3 100644
--- a/netlink.c
+++ b/netlink.c
@@ -327,6 +327,7 @@ decode_nlmsgerr(struct tcb *const tcp,
 }
 
 static const netlink_decoder_t netlink_decoders[] = {
+	[NETLINK_SELINUX] = decode_netlink_selinux,
 	[NETLINK_SOCK_DIAG] = decode_netlink_sock_diag
 };
 
diff --git a/netlink_selinux.c b/netlink_selinux.c
new file mode 100644
index 0000000..43885ff
--- /dev/null
+++ b/netlink_selinux.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2017 JingPiao Chen <chenjingpiao at gmail.com>
+ * Copyright (c) 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"
+#include "print_fields.h"
+
+#include <linux/selinux_netlink.h>
+
+bool
+decode_netlink_selinux(struct tcb *const tcp,
+		       const struct nlmsghdr *const nlmsghdr,
+		       const kernel_ulong_t addr,
+		       const kernel_ulong_t len)
+{
+	switch (nlmsghdr->nlmsg_type) {
+	case SELNL_MSG_SETENFORCE: {
+		struct selnl_msg_setenforce msg;
+
+		if (len < sizeof(msg))
+			printstr_ex(tcp, addr, len, QUOTE_FORCE_HEX);
+		else if (!umove_or_printaddr(tcp, addr, &msg)) {
+			PRINT_FIELD_D("{", msg, val);
+			tprints("}");
+		}
+		break;
+	}
+	case SELNL_MSG_POLICYLOAD: {
+		struct selnl_msg_policyload msg;
+
+		if (len < sizeof(msg))
+			printstr_ex(tcp, addr, len, QUOTE_FORCE_HEX);
+		else if (!umove_or_printaddr(tcp, addr, &msg)) {
+			PRINT_FIELD_U("{", msg, seqno);
+			tprints("}");
+		}
+		break;
+	}
+	default:
+		return false;
+	}
+
+	return true;
+}
-- 
2.7.4