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Add a function for dumping iovec in msghdr used in sendmsg and recvmsg

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Here is an example session:

    $ ./strace -e write=all ip link change dev enp0s25 mtu 1501 > /dev/null
    sendmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000}, msg_iov(1)=[{"(...
     * 40 bytes in buffer 0
     | 00000  28 00 00 00 10 00 05 00  d0 d9 aa 53 00 00 00 00  (..........S.... |
     | 00010  00 00 00 00 02 00 00 00  00 00 00 00 00 00 00 00  ................ |
     | 00020  08 00 04 00 dd 05 00 00                           ........         |
    ...

    $ ./strace -e read=all ip link show > /dev/null
    recvmsg(3, {msg_name(12)={sa_family=AF_NETLINK, pid=0, groups=00000000}, msg_iov(1)=[{"...
     * 8192 bytes in buffer 0
     | 00000  34 00 00 00 02 00 00 00  00 00 00 00 ff 23 00 00  4............#.. |
     | 00010  ff ff ff ff 20 00 00 00  10 00 05 00 00 00 00 00  .... ........... |
    ...

* defs.h (dumpiov_in_msghdr): New prototype.
* net.c (extractmsghdr): New function derived from printmsghdr.
(printmsghdr): Use extractmsghdr.
(dumpiov_in_msghdr): New function.
* syscall.c (dumpio) [HAVE_SENDMSG]: Call dumpiov_in_msghdr for recvmsg
and sendmsg syscalls.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
This commit is contained in:
Masatake YAMATO 2014-10-15 22:11:43 +09:00 committed by Dmitry V. Levin
parent 40c174b38b
commit 02f9f6b386
3 changed files with 44 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
defs.h
View File

@ -673,6 +673,7 @@ extern int printargs_ld(struct tcb *);
extern void addflags(const struct xlat *, int);
extern int printflags(const struct xlat *, int, const char *);
extern const char *sprintflags(const char *, const struct xlat *, int);
extern void dumpiov_in_msghdr(struct tcb *, long);
extern void dumpiov(struct tcb *, int, long);
extern void dumpstr(struct tcb *, long, int);
extern void printstr(struct tcb *, long, long);

56
net.c
View File

@ -392,33 +392,47 @@ struct mmsghdr32 {
uint32_t /* unsigned */ msg_len;
};
static bool
extractmsghdr(struct tcb *tcp, long addr, struct msghdr *msg)
{
#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
if (current_wordsize == 4) {
struct msghdr32 msg32;
if (umove(tcp, addr, &msg32) < 0)
return false;
msg->msg_name = (void*)(long)msg32.msg_name;
msg->msg_namelen = msg32.msg_namelen;
msg->msg_iov = (void*)(long)msg32.msg_iov;
msg->msg_iovlen = msg32.msg_iovlen;
msg->msg_control = (void*)(long)msg32.msg_control;
msg->msg_controllen = msg32.msg_controllen;
msg->msg_flags = msg32.msg_flags;
} else
#endif
if (umove(tcp, addr, msg) < 0)
return false;
return true;
}
static void
printmsghdr(struct tcb *tcp, long addr, unsigned long data_size)
{
struct msghdr msg;
#if SUPPORTED_PERSONALITIES > 1 && SIZEOF_LONG > 4
if (current_wordsize == 4) {
struct msghdr32 msg32;
if (umove(tcp, addr, &msg32) < 0) {
tprintf("%#lx", addr);
return;
}
msg.msg_name = (void*)(long)msg32.msg_name;
msg.msg_namelen = msg32.msg_namelen;
msg.msg_iov = (void*)(long)msg32.msg_iov;
msg.msg_iovlen = msg32.msg_iovlen;
msg.msg_control = (void*)(long)msg32.msg_control;
msg.msg_controllen = msg32.msg_controllen;
msg.msg_flags = msg32.msg_flags;
} else
#endif
if (umove(tcp, addr, &msg) < 0) {
if (extractmsghdr(tcp, addr, &msg))
do_msghdr(tcp, &msg, data_size);
else
tprintf("%#lx", addr);
return;
}
do_msghdr(tcp, &msg, data_size);
}
void
dumpiov_in_msghdr(struct tcb *tcp, long addr)
{
struct msghdr msg;
if (extractmsghdr(tcp, addr, &msg))
dumpiov(tcp, msg.msg_iovlen, (long)msg.msg_iov);
}
static void

8
syscall.c
View File

@ -2497,6 +2497,10 @@ dumpio(struct tcb *tcp)
dumpstr(tcp, tcp->u_arg[1], tcp->u_rval);
else if (func == sys_readv)
dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
#if HAVE_SENDMSG
else if (func == sys_recvmsg)
dumpiov_in_msghdr(tcp, tcp->u_arg[1]);
#endif
return;
}
if (qual_flags[tcp->u_arg[0]] & QUAL_WRITE) {
@ -2507,6 +2511,10 @@ dumpio(struct tcb *tcp)
dumpstr(tcp, tcp->u_arg[1], tcp->u_arg[2]);
else if (func == sys_writev)
dumpiov(tcp, tcp->u_arg[2], tcp->u_arg[1]);
#if HAVE_SENDMSG
else if (func == sys_sendmsg)
dumpiov_in_msghdr(tcp, tcp->u_arg[1]);
#endif
return;
}
}