Add a general netlink socket parser

Introduce a general socket netlink parser which prints the header and
a string for the remaining part of the buffer.  It doesn't handle all
the netlink flags and types yet because the parser needs more
information, this will be implemented later.

* net.c (decode_sockbuf): New function.
(SYS_FUNC(send), SYS_FUNC(sendto), SYS_FUNC(recv), SYS_FUNC(recvfrom)):
Use it instead of printstr.
* msghdr.c (print_msghdr): Pass IOV_DECODE_NETLINK to tprint_iov_upto()
for netlink sockets.
* netlink.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* defs.h (decode_netlink, getfdproto): New prototypes.
(iov_decode): Add IOV_DECODER_NETLINK.
* io.c (print_iovec): Use decode_netlink().
* util.c (getfdproto): Remove static keyword.
* xlat/netlink_flags.in: New file.
* xlat/netlink_types.in: New file.

diff --git a/Makefile.am b/Makefile.am
index 9241e1e7978607f5179d0995e3360fcee9c2a476..97f0b306897cc4ed1194905798c97b043046faef 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -160,6 +160,7 @@ strace_SOURCES =    \
        mtd.c           \
        native_defs.h   \
        net.c           \
+       netlink.c       \
        numa.c          \
        open.c          \
        or1k_atomic.c   \

diff --git a/defs.h b/defs.h
index bda74a3406102bc9aff23f67aa256004230f8137..62e6414d090cdd47c16f0eee395e9f35e29b7720 100644 (file)
--- a/defs.h
+++ b/defs.h
@@ -452,7 +452,8 @@ extern enum sock_proto get_proto_by_name(const char *);
 
 enum iov_decode {
        IOV_DECODE_ADDR,
-       IOV_DECODE_STR
+       IOV_DECODE_STR,
+       IOV_DECODE_NETLINK
 };
 
 typedef enum {
@@ -567,6 +568,7 @@ extern const char *signame(const int);
 extern void pathtrace_select(const char *);
 extern int pathtrace_match(struct tcb *);
 extern int getfdpath(struct tcb *, int, char *, unsigned);
+extern enum sock_proto getfdproto(struct tcb *, int);
 
 extern const char *xlookup(const struct xlat *, const uint64_t);
 extern const char *xlat_search(const struct xlat *, const size_t, const uint64_t);
@@ -679,6 +681,7 @@ extern void printsignal(int);
 extern void tprint_iov(struct tcb *, unsigned long, unsigned long, enum iov_decode);
 extern void tprint_iov_upto(struct tcb *, unsigned long, unsigned long,
                            enum iov_decode, unsigned long);
+extern void decode_netlink(struct tcb *, unsigned long, unsigned long);
 extern void tprint_open_modes(unsigned int);
 extern const char *sprint_open_modes(unsigned int);
 extern void print_seccomp_filter(struct tcb *, unsigned long);

diff --git a/io.c b/io.c
index da8b9d25fe8c83cfeb763b87b447afb897b70785..7ddeb78c8daf95eae0f2888766033204f2d9835e 100644 (file)
--- a/io.c
+++ b/io.c
@@ -88,6 +88,12 @@ print_iovec(struct tcb *tcp, void *elem_buf, size_t elem_size, void *data)
                        c->data_size -= len;
                        printstr(tcp, iov[0], len);
                        break;
+               case IOV_DECODE_NETLINK:
+                       if (len > c->data_size)
+                               len = c->data_size;
+                       c->data_size -= len;
+                       decode_netlink(tcp, iov[0], iov[1]);
+                       break;
                default:
                        printaddr(iov[0]);
                        break;

diff --git a/msghdr.c b/msghdr.c
index 3db95fa7803dd5b048cfd5a80991da041d09b32a..d93ab82e9abbd9e25a4f210dd50c548ae0b74c9e 100644 (file)
--- a/msghdr.c
+++ b/msghdr.c
@@ -335,13 +335,22 @@ decode_msg_control(struct tcb *tcp, unsigned long addr,
 static void
 print_msghdr(struct tcb *tcp, struct msghdr *msg, unsigned long data_size)
 {
+       int family;
+       enum iov_decode decode;
+
        tprints("{msg_name=");
-       decode_sockaddr(tcp, (long)msg->msg_name, msg->msg_namelen);
+       family = decode_sockaddr(tcp, (long)msg->msg_name, msg->msg_namelen);
        tprintf(", msg_namelen=%d", msg->msg_namelen);
 
        tprints(", msg_iov=");
+
+       if (family == AF_NETLINK)
+               decode = IOV_DECODE_NETLINK;
+       else
+               decode = IOV_DECODE_STR;
+
        tprint_iov_upto(tcp, (unsigned long) msg->msg_iovlen,
-                       (unsigned long) msg->msg_iov, IOV_DECODE_STR, data_size);
+                       (unsigned long) msg->msg_iov, decode, data_size);
        tprintf(", msg_iovlen=%lu", (unsigned long) msg->msg_iovlen);
 
        decode_msg_control(tcp, (unsigned long) msg->msg_control,

diff --git a/net.c b/net.c
index 75113dc6259c1f6b29bd2c7853b8ab69cb2d99ba..bcb9e4f642e734e92b935b64c89e12b2ca3f95d9 100644 (file)
--- a/net.c
+++ b/net.c
@@ -108,6 +108,19 @@ print_ifindex(unsigned int ifindex)
        tprintf("%u", ifindex);
 }
 
+static void
+decode_sockbuf(struct tcb *tcp, int fd, long addr, long addrlen)
+{
+
+       switch (verbose(tcp) ? getfdproto(tcp, fd) : SOCK_PROTO_UNKNOWN) {
+       case SOCK_PROTO_NETLINK:
+               decode_netlink(tcp, addr, addrlen);
+               break;
+       default:
+               printstr(tcp, addr, addrlen);
+       }
+}
+
 /*
  * low bits of the socket type define real socket type,
  * other bits are socket type flags.
@@ -220,7 +233,7 @@ SYS_FUNC(send)
 {
        printfd(tcp, tcp->u_arg[0]);
        tprints(", ");
-       printstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
+       decode_sockbuf(tcp, tcp->u_arg[0], tcp->u_arg[1], tcp->u_arg[2]);
        tprintf(", %lu, ", tcp->u_arg[2]);
        /* flags */
        printflags(msg_flags, tcp->u_arg[3], "MSG_???");
@@ -232,7 +245,7 @@ SYS_FUNC(sendto)
 {
        printfd(tcp, tcp->u_arg[0]);
        tprints(", ");
-       printstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
+       decode_sockbuf(tcp, tcp->u_arg[0], tcp->u_arg[1], tcp->u_arg[2]);
        tprintf(", %lu, ", tcp->u_arg[2]);
        /* flags */
        printflags(msg_flags, tcp->u_arg[3], "MSG_???");
@@ -287,10 +300,12 @@ SYS_FUNC(recv)
                printfd(tcp, tcp->u_arg[0]);
                tprints(", ");
        } else {
-               if (syserror(tcp))
+               if (syserror(tcp)) {
                        printaddr(tcp->u_arg[1]);
-               else
-                       printstr(tcp, tcp->u_arg[1], tcp->u_rval);
+               } else {
+                       decode_sockbuf(tcp, tcp->u_arg[0], tcp->u_arg[1],
+                                    tcp->u_rval);
+               }
 
                tprintf(", %lu, ", tcp->u_arg[2]);
                printflags(msg_flags, tcp->u_arg[3], "MSG_???");
@@ -310,7 +325,8 @@ SYS_FUNC(recvfrom)
                if (syserror(tcp)) {
                        printaddr(tcp->u_arg[1]);
                } else {
-                       printstr(tcp, tcp->u_arg[1], tcp->u_rval);
+                       decode_sockbuf(tcp, tcp->u_arg[0], tcp->u_arg[1],
+                                    tcp->u_rval);
                }
                /* len */
                tprintf(", %lu, ", tcp->u_arg[2]);

diff --git a/netlink.c b/netlink.c
new file mode 100644 (file)
index 0000000..c43f6e7
--- /dev/null
+++ b/netlink.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2016 Fabien Siron <fabien.siron@epita.fr>
+ * 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 <sys/socket.h>
+#include <linux/netlink.h>
+#include "xlat/netlink_flags.h"
+#include "xlat/netlink_types.h"
+
+void
+decode_netlink(struct tcb *tcp, unsigned long addr, unsigned long size)
+{
+       struct nlmsghdr nlmsghdr;
+
+       if (size < sizeof(struct nlmsghdr)) {
+               printstr(tcp, addr, size);
+               return;
+       }
+       if (umove_or_printaddr(tcp, addr, &nlmsghdr))
+               return;
+
+       tprintf("{{len=%u, type=", nlmsghdr.nlmsg_len);
+
+       printxval(netlink_types, nlmsghdr.nlmsg_type, "NLMSG_???");
+
+       tprints(", flags=");
+       printflags(netlink_flags, nlmsghdr.nlmsg_flags, "NLM_F_???");
+       /* manage get/new requests */
+
+       tprintf(", seq=%u, pid=%u}", nlmsghdr.nlmsg_seq,
+               nlmsghdr.nlmsg_pid);
+
+       if (size - sizeof(struct nlmsghdr) > 0) {
+               tprints(", ");
+               printstr(tcp, addr + sizeof(struct nlmsghdr),
+                        size - sizeof(struct nlmsghdr));
+       }
+
+       tprints("}");
+}

diff --git a/util.c b/util.c
index c99136d295c449a33e37342f9bb4b53620526979..782b414649e9652edb04c4c823725fd75ef85f30 100644 (file)
--- a/util.c
+++ b/util.c
@@ -472,7 +472,7 @@ sprinttime(time_t t)
        return buf;
 }
 
-static enum sock_proto
+enum sock_proto
 getfdproto(struct tcb *tcp, int fd)
 {
 #ifdef HAVE_SYS_XATTR_H

diff --git a/xlat/netlink_flags.in b/xlat/netlink_flags.in
new file mode 100644 (file)
index 0000000..d84f4dd
--- /dev/null
+++ b/xlat/netlink_flags.in
@@ -0,0 +1,6 @@
+NLM_F_REQUEST          0x1
+NLM_F_MULTI            0x2
+NLM_F_ACK              0x4
+NLM_F_ECHO             0x8
+NLM_F_DUMP_INTR                0x10
+NLM_F_DUMP_FILTERED    0x20

diff --git a/xlat/netlink_types.in b/xlat/netlink_types.in
new file mode 100644 (file)
index 0000000..9cb5297
--- /dev/null
+++ b/xlat/netlink_types.in
@@ -0,0 +1,4 @@
+NLMSG_NOOP             0x1
+NLMSG_ERROR            0x2
+NLMSG_DONE             0x3
+NLMSG_OVERRUN          0x4