1761efaa7SDag-Erling Smørgrav /* $OpenBSD: atomicio.c,v 1.30 2019/01/24 02:42:23 dtucker Exp $ */
2511b41d2SMark Murray /*
3761efaa7SDag-Erling Smørgrav * Copyright (c) 2006 Damien Miller. All rights reserved.
4043840dfSDag-Erling Smørgrav * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved.
51e8db6e2SBrian Feldman * Copyright (c) 1995,1999 Theo de Raadt. All rights reserved.
6511b41d2SMark Murray * All rights reserved.
7511b41d2SMark Murray *
8511b41d2SMark Murray * Redistribution and use in source and binary forms, with or without
9511b41d2SMark Murray * modification, are permitted provided that the following conditions
10511b41d2SMark Murray * are met:
11511b41d2SMark Murray * 1. Redistributions of source code must retain the above copyright
12511b41d2SMark Murray * notice, this list of conditions and the following disclaimer.
13511b41d2SMark Murray * 2. Redistributions in binary form must reproduce the above copyright
14511b41d2SMark Murray * notice, this list of conditions and the following disclaimer in the
15511b41d2SMark Murray * documentation and/or other materials provided with the distribution.
16511b41d2SMark Murray *
17511b41d2SMark Murray * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18511b41d2SMark Murray * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19511b41d2SMark Murray * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20511b41d2SMark Murray * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21511b41d2SMark Murray * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22511b41d2SMark Murray * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23511b41d2SMark Murray * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24511b41d2SMark Murray * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25511b41d2SMark Murray * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26511b41d2SMark Murray * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27511b41d2SMark Murray */
28511b41d2SMark Murray
29511b41d2SMark Murray #include "includes.h"
30761efaa7SDag-Erling Smørgrav
31761efaa7SDag-Erling Smørgrav #include <sys/uio.h>
32761efaa7SDag-Erling Smørgrav
33761efaa7SDag-Erling Smørgrav #include <errno.h>
34761efaa7SDag-Erling Smørgrav #ifdef HAVE_POLL_H
35761efaa7SDag-Erling Smørgrav #include <poll.h>
36511b41d2SMark Murray #else
371e8db6e2SBrian Feldman # ifdef HAVE_SYS_POLL_H
38511b41d2SMark Murray # include <sys/poll.h>
39511b41d2SMark Murray # endif
40d95e11bfSDag-Erling Smørgrav #endif
41511b41d2SMark Murray #include <string.h>
42043840dfSDag-Erling Smørgrav #include <unistd.h>
43761efaa7SDag-Erling Smørgrav #include <limits.h>
44511b41d2SMark Murray
45a8f6863aSKris Kennaway #include "atomicio.h"
46043840dfSDag-Erling Smørgrav
47043840dfSDag-Erling Smørgrav /*
48511b41d2SMark Murray * ensure all of data on socket comes through. f==read || f==vwrite
49511b41d2SMark Murray */
50511b41d2SMark Murray size_t
atomicio6(ssize_t (* f)(int,void *,size_t),int fd,void * _s,size_t n,int (* cb)(void *,size_t),void * cb_arg)51511b41d2SMark Murray atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n,
52511b41d2SMark Murray int (*cb)(void *, size_t), void *cb_arg)
5383d2307dSDag-Erling Smørgrav {
5483d2307dSDag-Erling Smørgrav char *s = _s;
5583d2307dSDag-Erling Smørgrav size_t pos = 0;
56511b41d2SMark Murray ssize_t res;
5783d2307dSDag-Erling Smørgrav struct pollfd pfd;
58511b41d2SMark Murray
59043840dfSDag-Erling Smørgrav pfd.fd = fd;
60511b41d2SMark Murray #ifndef BROKEN_READ_COMPARISON
61043840dfSDag-Erling Smørgrav pfd.events = f == read ? POLLIN : POLLOUT;
62043840dfSDag-Erling Smørgrav #else
63511b41d2SMark Murray pfd.events = POLLIN|POLLOUT;
64761efaa7SDag-Erling Smørgrav #endif
65511b41d2SMark Murray while (n > pos) {
66511b41d2SMark Murray res = (f) (fd, s + pos, n - pos);
67511b41d2SMark Murray switch (res) {
68511b41d2SMark Murray case -1:
69761efaa7SDag-Erling Smørgrav if (errno == EINTR) {
70761efaa7SDag-Erling Smørgrav /* possible SIGALARM, update callback */
71761efaa7SDag-Erling Smørgrav if (cb != NULL && cb(cb_arg, 0) == -1) {
72761efaa7SDag-Erling Smørgrav errno = EINTR;
73761efaa7SDag-Erling Smørgrav return pos;
74761efaa7SDag-Erling Smørgrav }
75761efaa7SDag-Erling Smørgrav continue;
76761efaa7SDag-Erling Smørgrav } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
77761efaa7SDag-Erling Smørgrav (void)poll(&pfd, 1, -1);
78761efaa7SDag-Erling Smørgrav continue;
79761efaa7SDag-Erling Smørgrav }
80761efaa7SDag-Erling Smørgrav return 0;
81761efaa7SDag-Erling Smørgrav case 0:
82761efaa7SDag-Erling Smørgrav errno = EPIPE;
83761efaa7SDag-Erling Smørgrav return pos;
84761efaa7SDag-Erling Smørgrav default:
85761efaa7SDag-Erling Smørgrav pos += (size_t)res;
86761efaa7SDag-Erling Smørgrav if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
87761efaa7SDag-Erling Smørgrav errno = EINTR;
88761efaa7SDag-Erling Smørgrav return pos;
89761efaa7SDag-Erling Smørgrav }
90761efaa7SDag-Erling Smørgrav }
91761efaa7SDag-Erling Smørgrav }
92761efaa7SDag-Erling Smørgrav return pos;
93761efaa7SDag-Erling Smørgrav }
94761efaa7SDag-Erling Smørgrav
95761efaa7SDag-Erling Smørgrav size_t
atomicio(ssize_t (* f)(int,void *,size_t),int fd,void * _s,size_t n)96761efaa7SDag-Erling Smørgrav atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
97761efaa7SDag-Erling Smørgrav {
98761efaa7SDag-Erling Smørgrav return atomicio6(f, fd, _s, n, NULL, NULL);
99761efaa7SDag-Erling Smørgrav }
100761efaa7SDag-Erling Smørgrav
101761efaa7SDag-Erling Smørgrav /*
102761efaa7SDag-Erling Smørgrav * ensure all of data on socket comes through. f==readv || f==writev
103761efaa7SDag-Erling Smørgrav */
104761efaa7SDag-Erling Smørgrav size_t
atomiciov6(ssize_t (* f)(int,const struct iovec *,int),int fd,const struct iovec * _iov,int iovcnt,int (* cb)(void *,size_t),void * cb_arg)105761efaa7SDag-Erling Smørgrav atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd,
106761efaa7SDag-Erling Smørgrav const struct iovec *_iov, int iovcnt,
107761efaa7SDag-Erling Smørgrav int (*cb)(void *, size_t), void *cb_arg)
108761efaa7SDag-Erling Smørgrav {
109761efaa7SDag-Erling Smørgrav size_t pos = 0, rem;
110761efaa7SDag-Erling Smørgrav ssize_t res;
111761efaa7SDag-Erling Smørgrav struct iovec iov_array[IOV_MAX], *iov = iov_array;
112761efaa7SDag-Erling Smørgrav struct pollfd pfd;
113761efaa7SDag-Erling Smørgrav
114761efaa7SDag-Erling Smørgrav if (iovcnt < 0 || iovcnt > IOV_MAX) {
115761efaa7SDag-Erling Smørgrav errno = EINVAL;
116761efaa7SDag-Erling Smørgrav return 0;
117761efaa7SDag-Erling Smørgrav }
118761efaa7SDag-Erling Smørgrav /* Make a copy of the iov array because we may modify it below */
119761efaa7SDag-Erling Smørgrav memcpy(iov, _iov, (size_t)iovcnt * sizeof(*_iov));
120761efaa7SDag-Erling Smørgrav
121 pfd.fd = fd;
122 #ifndef BROKEN_READV_COMPARISON
123 pfd.events = f == readv ? POLLIN : POLLOUT;
124 #else
125 pfd.events = POLLIN|POLLOUT;
126 #endif
127 for (; iovcnt > 0 && iov[0].iov_len > 0;) {
128 res = (f) (fd, iov, iovcnt);
129 switch (res) {
130 case -1:
131 if (errno == EINTR) {
132 /* possible SIGALARM, update callback */
133 if (cb != NULL && cb(cb_arg, 0) == -1) {
134 errno = EINTR;
135 return pos;
136 }
137 continue;
138 } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
139 (void)poll(&pfd, 1, -1);
140 continue;
141 }
142 return 0;
143 case 0:
144 errno = EPIPE;
145 return pos;
146 default:
147 rem = (size_t)res;
148 pos += rem;
149 /* skip completed iov entries */
150 while (iovcnt > 0 && rem >= iov[0].iov_len) {
151 rem -= iov[0].iov_len;
152 iov++;
153 iovcnt--;
154 }
155 /* This shouldn't happen... */
156 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) {
157 errno = EFAULT;
158 return 0;
159 }
160 if (iovcnt == 0)
161 break;
162 /* update pointer in partially complete iov */
163 iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
164 iov[0].iov_len -= rem;
165 }
166 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
167 errno = EINTR;
168 return pos;
169 }
170 }
171 return pos;
172 }
173
174 size_t
atomiciov(ssize_t (* f)(int,const struct iovec *,int),int fd,const struct iovec * _iov,int iovcnt)175 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
176 const struct iovec *_iov, int iovcnt)
177 {
178 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL);
179 }
180