1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
/*
* Check decoding of struct msghdr.msg_name* arguments of recvmsg syscall.
*
* Copyright (c) 2016 Dmitry V. Levin <ldv@strace.io>
* Copyright (c) 2016-2023 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>
#undef TEST_RECVMSG_BOGUS_ADDR
/*
* Sadly, musl recvmsg wrapper blindly dereferences the 2nd argument,
* so limit these tests to glibc that hopefully doesn't.
*/
#ifndef __GLIBC__
# define TEST_RECVMSG_BOGUS_ADDR 0
#endif
/*
* Sadly, starting with commit
* glibc-2.33.9000-707-g13c51549e2077f2f3bf84e8fd0b46d8b0c615912, on every
* 32-bit architecture where 32-bit time_t support is enabled, glibc blindly
* dereferences the 2nd argument of recvmsg call.
*/
#if GLIBC_PREREQ_GE(2, 33) && defined __TIMESIZE && __TIMESIZE != 64
# define TEST_RECVMSG_BOGUS_ADDR 0
#endif
#ifndef TEST_RECVMSG_BOGUS_ADDR
# define TEST_RECVMSG_BOGUS_ADDR 1
#endif
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) = %s\n",
recv_fd, (int) msg->msg_namelen, sprintrc(rc));
#if TEST_RECVMSG_BOGUS_ADDR
/*
* 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.
*/
rc = send_recv(send_fd, -1, msg + 1, 0);
printf("recvmsg(-1, %p, 0) = %s\n",
msg + 1, sprintrc(rc));
rc = send_recv(send_fd, -1, 0, 0);
printf("recvmsg(-1, NULL, 0) = %s\n",
sprintrc(rc));
#endif
}
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;
}
|
