]>
Commit | Line | Data |
---|---|---|
2eecc8af | 1 | /* Check recvmsg results for netlink sockets. |
04277e02 | 2 | Copyright (C) 2015-2019 Free Software Foundation, Inc. |
2eecc8af FW |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
16 | License along with the GNU C Library; if not, see | |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
2eecc8af FW |
18 | |
19 | #include <errno.h> | |
20 | #include <fcntl.h> | |
21 | #include <stdio.h> | |
22 | #include <sys/socket.h> | |
23 | ||
24 | #include "netlinkaccess.h" | |
25 | ||
26 | static int | |
27 | get_address_family (int fd) | |
28 | { | |
29 | struct sockaddr_storage sa; | |
30 | socklen_t sa_len = sizeof (sa); | |
31 | if (__getsockname (fd, (struct sockaddr *) &sa, &sa_len) < 0) | |
32 | return -1; | |
33 | /* Check that the socket family number is preserved despite in-band | |
34 | signaling. */ | |
35 | _Static_assert (sizeof (sa.ss_family) < sizeof (int), "address family size"); | |
36 | _Static_assert (0 < (__typeof__ (sa.ss_family)) -1, | |
37 | "address family unsigned"); | |
38 | return sa.ss_family; | |
39 | } | |
40 | ||
41 | void | |
2eecc8af FW |
42 | __netlink_assert_response (int fd, ssize_t result) |
43 | { | |
44 | if (result < 0) | |
45 | { | |
46 | /* Check if the error is unexpected. */ | |
47 | bool terminate = false; | |
48 | int error_code = errno; | |
49 | int family = get_address_family (fd); | |
50 | if (family != AF_NETLINK) | |
51 | /* If the address family does not match (or getsockname | |
52 | failed), report the original error. */ | |
53 | terminate = true; | |
54 | else if (error_code == EBADF | |
55 | || error_code == ENOTCONN | |
56 | || error_code == ENOTSOCK | |
57 | || error_code == ECONNREFUSED) | |
58 | /* These errors indicate that the descriptor is not a | |
59 | connected socket. */ | |
60 | terminate = true; | |
61 | else if (error_code == EAGAIN || error_code == EWOULDBLOCK) | |
62 | { | |
63 | /* The kernel might return EAGAIN for other reasons than a | |
64 | non-blocking socket. But if the socket is not blocking, | |
65 | it is not ours, so report the error. */ | |
66 | int mode = __fcntl (fd, F_GETFL, 0); | |
67 | if (mode < 0 || (mode & O_NONBLOCK) != 0) | |
68 | terminate = true; | |
69 | } | |
70 | if (terminate) | |
71 | { | |
72 | char message[200]; | |
73 | if (family < 0) | |
74 | __snprintf (message, sizeof (message), | |
a6e8926f | 75 | "Unexpected error %d on netlink descriptor %d.\n", |
2eecc8af FW |
76 | error_code, fd); |
77 | else | |
78 | __snprintf (message, sizeof (message), | |
79 | "Unexpected error %d on netlink descriptor %d" | |
a6e8926f | 80 | " (address family %d).\n", |
2eecc8af FW |
81 | error_code, fd, family); |
82 | __libc_fatal (message); | |
83 | } | |
84 | else | |
85 | /* Restore orignal errno value. */ | |
86 | __set_errno (error_code); | |
87 | } | |
88 | else if (result < sizeof (struct nlmsghdr)) | |
89 | { | |
90 | char message[200]; | |
91 | int family = get_address_family (fd); | |
92 | if (family < 0) | |
93 | __snprintf (message, sizeof (message), | |
94 | "Unexpected netlink response of size %zd" | |
36f30c10 | 95 | " on descriptor %d\n", |
2eecc8af FW |
96 | result, fd); |
97 | else | |
98 | __snprintf (message, sizeof (message), | |
99 | "Unexpected netlink response of size %zd" | |
36f30c10 | 100 | " on descriptor %d (address family %d)\n", |
2eecc8af FW |
101 | result, fd, family); |
102 | __libc_fatal (message); | |
103 | } | |
104 | } | |
105 | libc_hidden_def (__netlink_assert_response) |