1 | /* Copyright (C) 2008-2017 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | Contributed by Ulrich Drepper <drepper@redhat.com>, 2008. |
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 <signal.h> |
21 | #include <sys/socket.h> |
22 | |
23 | #include <sysdep-cancel.h> |
24 | #include <sys/syscall.h> |
25 | #include <kernel-features.h> |
26 | |
27 | /* Do not use the accept4 syscall on socketcall architectures unless |
28 | it was added at the same time as the socketcall support or can be |
29 | assumed to be present. */ |
30 | #if defined __ASSUME_SOCKETCALL \ |
31 | && !defined __ASSUME_ACCEPT4_SYSCALL_WITH_SOCKETCALL \ |
32 | && !defined __ASSUME_ACCEPT4_SYSCALL |
33 | # undef __NR_accept4 |
34 | #endif |
35 | |
36 | #ifdef __NR_accept4 |
37 | int |
38 | accept4 (int fd, __SOCKADDR_ARG addr, socklen_t *addr_len, int flags) |
39 | { |
40 | return SYSCALL_CANCEL (accept4, fd, addr.__sockaddr__, addr_len, flags); |
41 | } |
42 | #elif defined __NR_socketcall |
43 | # include <socketcall.h> |
44 | # ifdef __ASSUME_ACCEPT4_SOCKETCALL |
45 | int |
46 | accept4 (int fd, __SOCKADDR_ARG addr, socklen_t *addr_len, int flags) |
47 | { |
48 | return SOCKETCALL_CANCEL (accept4, fd, addr.__sockaddr__, addr_len, flags); |
49 | } |
50 | # else |
51 | static int have_accept4; |
52 | |
53 | int |
54 | accept4 (int fd, __SOCKADDR_ARG addr, socklen_t *addr_len, int flags) |
55 | { |
56 | if (__glibc_likely (have_accept4 >= 0)) |
57 | { |
58 | int ret = SOCKETCALL_CANCEL (accept4, fd, addr.__sockaddr__, addr_len, |
59 | flags); |
60 | /* The kernel returns -EINVAL for unknown socket operations. |
61 | We need to convert that error to an ENOSYS error. */ |
62 | if (__builtin_expect (ret < 0, 0) |
63 | && have_accept4 == 0 |
64 | && errno == EINVAL) |
65 | { |
66 | /* Try another call, this time with the FLAGS parameter |
67 | cleared and an invalid file descriptor. This call will not |
68 | cause any harm and it will return immediately. */ |
69 | ret = SOCKETCALL_CANCEL (invalid, -1); |
70 | if (errno == EINVAL) |
71 | { |
72 | have_accept4 = -1; |
73 | __set_errno (ENOSYS); |
74 | } |
75 | else |
76 | { |
77 | have_accept4 = 1; |
78 | __set_errno (EINVAL); |
79 | } |
80 | return -1; |
81 | } |
82 | return ret; |
83 | } |
84 | __set_errno (ENOSYS); |
85 | return -1; |
86 | } |
87 | # endif /* __ASSUME_ACCEPT4_SOCKETCALL */ |
88 | #else /* __NR_socketcall */ |
89 | int |
90 | accept4 (int fd, __SOCKADDR_ARG addr, socklen_t *addr_len, int flags) |
91 | { |
92 | __set_errno (ENOSYS); |
93 | return -1; |
94 | } |
95 | stub_warning (accept4) |
96 | #endif |
97 | |