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1 | /* $OpenBSD: atomicio.c,v 1.25 2007/06/25 12:02:27 dtucker Exp $ */ | |
2 | /* | |
3 | * Copyright (c) 2006 Damien Miller. All rights reserved. | |
4 | * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved. | |
5 | * Copyright (c) 1995,1999 Theo de Raadt. All rights reserved. | |
6 | * All rights reserved. | |
7 | * | |
8 | * Redistribution and use in source and binary forms, with or without | |
9 | * modification, are permitted provided that the following conditions | |
10 | * are met: | |
11 | * 1. Redistributions of source code must retain the above copyright | |
12 | * notice, this list of conditions and the following disclaimer. | |
13 | * 2. Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in the | |
15 | * documentation and/or other materials provided with the distribution. | |
16 | * | |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
27 | */ | |
28 | ||
29 | #include "includes.h" | |
30 | ||
31 | #include <sys/param.h> | |
32 | #include <sys/uio.h> | |
33 | ||
34 | #include <errno.h> | |
35 | #ifdef HAVE_POLL_H | |
36 | #include <poll.h> | |
37 | #endif | |
38 | #include <string.h> | |
39 | #include <unistd.h> | |
40 | ||
41 | #include "atomicio.h" | |
42 | ||
43 | /* | |
44 | * ensure all of data on socket comes through. f==read || f==vwrite | |
45 | */ | |
46 | size_t | |
47 | atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n) | |
48 | { | |
49 | char *s = _s; | |
50 | size_t pos = 0; | |
51 | ssize_t res; | |
52 | struct pollfd pfd; | |
53 | ||
54 | pfd.fd = fd; | |
55 | pfd.events = f == read ? POLLIN : POLLOUT; | |
56 | while (n > pos) { | |
57 | res = (f) (fd, s + pos, n - pos); | |
58 | switch (res) { | |
59 | case -1: | |
60 | #ifdef EWOULDBLOCK | |
61 | if (errno == EINTR || errno == EWOULDBLOCK) | |
62 | #else | |
63 | if (errno == EINTR) | |
64 | #endif | |
65 | continue; | |
66 | if (errno == EAGAIN) { | |
67 | (void)poll(&pfd, 1, -1); | |
68 | continue; | |
69 | } | |
70 | return 0; | |
71 | case 0: | |
72 | errno = EPIPE; | |
73 | return pos; | |
74 | default: | |
75 | pos += (size_t)res; | |
76 | } | |
77 | } | |
78 | return (pos); | |
79 | } | |
80 | ||
81 | /* | |
82 | * ensure all of data on socket comes through. f==readv || f==writev | |
83 | */ | |
84 | size_t | |
85 | atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd, | |
86 | const struct iovec *_iov, int iovcnt) | |
87 | { | |
88 | size_t pos = 0, rem; | |
89 | ssize_t res; | |
90 | struct iovec iov_array[IOV_MAX], *iov = iov_array; | |
91 | struct pollfd pfd; | |
92 | ||
93 | if (iovcnt > IOV_MAX) { | |
94 | errno = EINVAL; | |
95 | return 0; | |
96 | } | |
97 | /* Make a copy of the iov array because we may modify it below */ | |
98 | memcpy(iov, _iov, iovcnt * sizeof(*_iov)); | |
99 | ||
100 | pfd.fd = fd; | |
101 | pfd.events = f == readv ? POLLIN : POLLOUT; | |
102 | for (; iovcnt > 0 && iov[0].iov_len > 0;) { | |
103 | res = (f) (fd, iov, iovcnt); | |
104 | switch (res) { | |
105 | case -1: | |
106 | #ifdef EWOULDBLOCK | |
107 | if (errno == EINTR || errno == EWOULDBLOCK) | |
108 | #else | |
109 | if (errno == EINTR) | |
110 | #endif | |
111 | continue; | |
112 | if (errno == EAGAIN) { | |
113 | (void)poll(&pfd, 1, -1); | |
114 | continue; | |
115 | } | |
116 | return 0; | |
117 | case 0: | |
118 | errno = EPIPE; | |
119 | return pos; | |
120 | default: | |
121 | rem = (size_t)res; | |
122 | pos += rem; | |
123 | /* skip completed iov entries */ | |
124 | while (iovcnt > 0 && rem >= iov[0].iov_len) { | |
125 | rem -= iov[0].iov_len; | |
126 | iov++; | |
127 | iovcnt--; | |
128 | } | |
129 | /* This shouldn't happen... */ | |
130 | if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) { | |
131 | errno = EFAULT; | |
132 | return 0; | |
133 | } | |
134 | if (iovcnt == 0) | |
135 | break; | |
136 | /* update pointer in partially complete iov */ | |
137 | iov[0].iov_base = ((char *)iov[0].iov_base) + rem; | |
138 | iov[0].iov_len -= rem; | |
139 | } | |
140 | } | |
141 | return pos; | |
142 | } |