1 | /* Copyright (C) 2010-2017 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | Contributed by Andreas Schwab <schwab@redhat.com>, 2010. |
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 |
17 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <errno.h> |
20 | #include <sys/socket.h> |
21 | |
22 | #include <sysdep-cancel.h> |
23 | #include <sys/syscall.h> |
24 | #include <kernel-features.h> |
25 | |
26 | /* Do not use the recvmmsg syscall on socketcall architectures unless |
27 | it was added at the same time as the socketcall support or can be |
28 | assumed to be present. */ |
29 | #if defined __ASSUME_SOCKETCALL \ |
30 | && !defined __ASSUME_RECVMMSG_SYSCALL_WITH_SOCKETCALL \ |
31 | && !defined __ASSUME_RECVMMSG_SYSCALL |
32 | # undef __NR_recvmmsg |
33 | #endif |
34 | |
35 | #ifdef __NR_recvmmsg |
36 | int |
37 | recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags, |
38 | struct timespec *tmo) |
39 | { |
40 | return SYSCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, tmo); |
41 | } |
42 | #elif defined __NR_socketcall |
43 | # include <socketcall.h> |
44 | # ifdef __ASSUME_RECVMMSG_SOCKETCALL |
45 | int |
46 | recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags, |
47 | struct timespec *tmo) |
48 | { |
49 | return SOCKETCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, tmo); |
50 | } |
51 | # else |
52 | static int have_recvmmsg; |
53 | |
54 | int |
55 | recvmmsg (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags, |
56 | struct timespec *tmo) |
57 | { |
58 | if (__glibc_likely (have_recvmmsg >= 0)) |
59 | { |
60 | int ret = SOCKETCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, |
61 | tmo); |
62 | /* The kernel returns -EINVAL for unknown socket operations. |
63 | We need to convert that error to an ENOSYS error. */ |
64 | if (__builtin_expect (ret < 0, 0) |
65 | && have_recvmmsg == 0 |
66 | && errno == EINVAL) |
67 | { |
68 | /* Try another call, this time with an invalid file |
69 | descriptor and all other parameters cleared. This call |
70 | will not cause any harm and it will return |
71 | immediately. */ |
72 | ret = SOCKETCALL_CANCEL (invalid, -1); |
73 | if (errno == EINVAL) |
74 | { |
75 | have_recvmmsg = -1; |
76 | __set_errno (ENOSYS); |
77 | } |
78 | else |
79 | { |
80 | have_recvmmsg = 1; |
81 | __set_errno (EINVAL); |
82 | } |
83 | return -1; |
84 | } |
85 | return ret; |
86 | } |
87 | __set_errno (ENOSYS); |
88 | return -1; |
89 | } |
90 | # endif /* __ASSUME_RECVMMSG_SOCKETCALL */ |
91 | #else |
92 | # include <socket/recvmmsg.c> |
93 | #endif |
94 | |