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/*
* Check decoding of struct msghdr.msg_name* arguments of recvmsg syscall.
*
* Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
* Copyright (c) 2016-2018 The strace developers.
* All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "tests.h"
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/un.h>
static int
send_recv(const int send_fd, const int recv_fd,
struct msghdr *const msg, const int flags)
{
if (send(send_fd, "A", 1, 0) != 1)
perror_msg_and_skip("send");
return recvmsg(recv_fd, msg, flags);
}
static void
test_msg_name(const int send_fd, const int recv_fd)
{
TAIL_ALLOC_OBJECT_CONST_PTR(char, recv_buf);
TAIL_ALLOC_OBJECT_CONST_PTR(struct iovec, iov);
iov->iov_base = recv_buf;
iov->iov_len = sizeof(*recv_buf);
TAIL_ALLOC_OBJECT_CONST_PTR(struct sockaddr_un, addr);
TAIL_ALLOC_OBJECT_CONST_PTR(struct msghdr, msg);
msg->msg_name = addr;
msg->msg_namelen = sizeof(*addr);
msg->msg_iov = iov;
msg->msg_iovlen = 1;
msg->msg_control = 0;
msg->msg_controllen = 0;
msg->msg_flags = 0;
int rc = send_recv(send_fd, recv_fd, msg, MSG_DONTWAIT);
if (rc < 0)
perror_msg_and_skip("recvmsg");
printf("recvmsg(%d, {msg_name={sa_family=AF_UNIX, sun_path=\"%s\"}"
", msg_namelen=%d->%d, msg_iov=[{iov_base=\"A\", iov_len=1}]"
", msg_iovlen=1, msg_controllen=0, msg_flags=0}, MSG_DONTWAIT)"
" = %d\n",
recv_fd, addr->sun_path, (int) sizeof(struct sockaddr_un),
(int) msg->msg_namelen, rc);
memset(addr, 0, sizeof(*addr));
rc = send_recv(send_fd, recv_fd, msg, MSG_DONTWAIT);
printf("recvmsg(%d, {msg_name={sa_family=AF_UNIX, sun_path=\"%s\"}"
", msg_namelen=%d, msg_iov=[{iov_base=\"A\", iov_len=1}]"
", msg_iovlen=1, msg_controllen=0, msg_flags=0}, MSG_DONTWAIT)"
" = %d\n",
recv_fd, addr->sun_path, (int) msg->msg_namelen, rc);
msg->msg_name = 0;
rc = send_recv(send_fd, recv_fd, msg, MSG_DONTWAIT);
printf("recvmsg(%d, {msg_name=NULL, msg_namelen=%d"
", msg_iov=[{iov_base=\"A\", iov_len=1}], msg_iovlen=1"
", msg_controllen=0, msg_flags=0}, MSG_DONTWAIT) = %d\n",
recv_fd, (int) msg->msg_namelen, rc);
const size_t offsetof_sun_path = offsetof(struct sockaddr_un, sun_path);
msg->msg_name = addr;
msg->msg_namelen = offsetof_sun_path;
memset(addr->sun_path, 'A', sizeof(addr->sun_path));
rc = send_recv(send_fd, recv_fd, msg, MSG_DONTWAIT);
printf("recvmsg(%d, {msg_name={sa_family=AF_UNIX}, msg_namelen=%d->%d"
", msg_iov=[{iov_base=\"A\", iov_len=1}], msg_iovlen=1"
", msg_controllen=0, msg_flags=0}, MSG_DONTWAIT) = %d\n",
recv_fd, (int) offsetof_sun_path, (int) msg->msg_namelen, rc);
msg->msg_namelen = sizeof(struct sockaddr);
msg->msg_name = ((void *) (addr + 1)) - msg->msg_namelen;
rc = send_recv(send_fd, recv_fd, msg, MSG_DONTWAIT);
printf("recvmsg(%d, {msg_name={sa_family=AF_UNIX, sun_path=\"%.*s\"}"
", msg_namelen=%d->%d, msg_iov=[{iov_base=\"A\", iov_len=1}]"
", msg_iovlen=1, msg_controllen=0, msg_flags=0}, MSG_DONTWAIT)"
" = %d\n",
recv_fd, (int) (sizeof(struct sockaddr) - offsetof_sun_path),
((struct sockaddr_un *) msg->msg_name)->sun_path,
(int) sizeof(struct sockaddr), (int) msg->msg_namelen, rc);
rc = send_recv(send_fd, recv_fd, msg, MSG_DONTWAIT);
printf("recvmsg(%d, {msg_namelen=%d}, MSG_DONTWAIT) = %d %s (%m)\n",
recv_fd, (int) msg->msg_namelen, rc, errno2name());
/*
* When recvmsg is called with a valid descriptor
* but inaccessible memory, it causes segfaults on some architectures.
* As in these cases we test decoding of failed recvmsg calls,
* it's ok to fail recvmsg with any reason as long as
* it doesn't read that inaccessible memory.
*/
/*
* Sadly, musl recvmsg wrapper blindly dereferences 2nd argument,
* so limit this test to glibc that doesn't.
*/
#ifdef __GLIBC__
rc = send_recv(send_fd, -1, msg + 1, 0);
printf("recvmsg(-1, %p, 0) = %d %s (%m)\n",
msg + 1, rc, errno2name());
#endif
rc = send_recv(send_fd, -1, 0, 0);
printf("recvmsg(-1, NULL, 0) = %d %s (%m)\n",
rc, errno2name());
}
int
main(void)
{
int fds[2];
if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds))
perror_msg_and_skip("socketpair");
const struct sockaddr_un un = {
.sun_family = AF_UNIX,
.sun_path = "msg_name-recvmsg.test.send.socket"
};
(void) unlink(un.sun_path);
if (bind(fds[1], (const void *) &un, sizeof(un)))
perror_msg_and_skip("bind");
(void) unlink(un.sun_path);
test_msg_name(fds[1], fds[0]);
puts("+++ exited with 0 +++");
return 0;
}
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