[PATCH v8 1/4] Add a general netlink socket parser
Fabien Siron
fabien.siron at epita.fr
Wed Jun 29 12:19:58 UTC 2016
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 because the parser needs more information. It will be done soon.
* 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.
(decode_netlink): New function.
* Makefile.am (strace_SOURCES): Add it.
* defs.h (decode_netlink, getfdproto): New prototypes.
(printsock): Change return type to int.
(iov_decode): Add IOV_DECODER_NETLINK.
* io.c (print_iovec): Call decode_netlink().
* util.c (getfdproto): Remove the static keyword.
* xlat/netlink_flags.in: New file.
* xlat/netlink_types.in: New file.
---
Makefile.am | 1 +
defs.h | 5 +++-
io.c | 6 +++++
msghdr.c | 13 +++++++++--
net.c | 28 +++++++++++++++++-----
netlink.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++
util.c | 2 +-
xlat/netlink_flags.in | 6 +++++
xlat/netlink_types.in | 4 ++++
9 files changed, 119 insertions(+), 10 deletions(-)
create mode 100644 netlink.c
create mode 100644 xlat/netlink_flags.in
create mode 100644 xlat/netlink_types.in
diff --git a/Makefile.am b/Makefile.am
index 9241e1e..97f0b30 100644
--- 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 114b98e..ab48529 100644
--- 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 {
@@ -565,6 +566,7 @@ 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);
@@ -677,6 +679,7 @@ 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 da8b9d2..7ddeb78 100644
--- 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 931d3bd..5e5bbfc 100644
--- a/msghdr.c
+++ b/msghdr.c
@@ -334,13 +334,22 @@ decode_msg_control(struct tcb *tcp, unsigned long addr, size_t len)
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 75113dc..bcb9e4f 100644
--- 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
index 0000000..c43f6e7
--- /dev/null
+++ b/netlink.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2016 Fabien Siron <fabien.siron at 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 3122755..675a191 100644
--- 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
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
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
--
2.9.0
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