1 /* $OpenBSD: atomicio.c,v 1.26 2010/09/22 22:58:51 djm 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 #else
38 # ifdef HAVE_SYS_POLL_H
39 # include <sys/poll.h>
40 # endif
41 #endif
42 #include <string.h>
43 #include <unistd.h>
44
45 #include "atomicio.h"
46
47 /*
48 * ensure all of data on socket comes through. f==read || f==vwrite
49 */
50 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)51 atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n,
52 int (*cb)(void *, size_t), void *cb_arg)
53 {
54 char *s = _s;
55 size_t pos = 0;
56 ssize_t res;
57 struct pollfd pfd;
58
59 pfd.fd = fd;
60 pfd.events = f == read ? POLLIN : POLLOUT;
61 while (n > pos) {
62 res = (f) (fd, s + pos, n - pos);
63 switch (res) {
64 case -1:
65 if (errno == EINTR)
66 continue;
67 if (errno == EAGAIN || errno == EWOULDBLOCK) {
68 (void)poll(&pfd, 1, -1);
69 continue;
70 }
71 return 0;
72 case 0:
73 errno = EPIPE;
74 return pos;
75 default:
76 pos += (size_t)res;
77 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
78 errno = EINTR;
79 return pos;
80 }
81 }
82 }
83 return pos;
84 }
85
86 size_t
atomicio(ssize_t (* f)(int,void *,size_t),int fd,void * _s,size_t n)87 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
88 {
89 return atomicio6(f, fd, _s, n, NULL, NULL);
90 }
91
92 /*
93 * ensure all of data on socket comes through. f==readv || f==writev
94 */
95 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)96 atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd,
97 const struct iovec *_iov, int iovcnt,
98 int (*cb)(void *, size_t), void *cb_arg)
99 {
100 size_t pos = 0, rem;
101 ssize_t res;
102 struct iovec iov_array[IOV_MAX], *iov = iov_array;
103 struct pollfd pfd;
104
105 if (iovcnt > IOV_MAX) {
106 errno = EINVAL;
107 return 0;
108 }
109 /* Make a copy of the iov array because we may modify it below */
110 memcpy(iov, _iov, iovcnt * sizeof(*_iov));
111
112 #ifndef BROKEN_READV_COMPARISON
113 pfd.fd = fd;
114 pfd.events = f == readv ? POLLIN : POLLOUT;
115 #endif
116 for (; iovcnt > 0 && iov[0].iov_len > 0;) {
117 res = (f) (fd, iov, iovcnt);
118 switch (res) {
119 case -1:
120 if (errno == EINTR)
121 continue;
122 if (errno == EAGAIN || errno == EWOULDBLOCK) {
123 #ifndef BROKEN_READV_COMPARISON
124 (void)poll(&pfd, 1, -1);
125 #endif
126 continue;
127 }
128 return 0;
129 case 0:
130 errno = EPIPE;
131 return pos;
132 default:
133 rem = (size_t)res;
134 pos += rem;
135 /* skip completed iov entries */
136 while (iovcnt > 0 && rem >= iov[0].iov_len) {
137 rem -= iov[0].iov_len;
138 iov++;
139 iovcnt--;
140 }
141 /* This shouldn't happen... */
142 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) {
143 errno = EFAULT;
144 return 0;
145 }
146 if (iovcnt == 0)
147 break;
148 /* update pointer in partially complete iov */
149 iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
150 iov[0].iov_len -= rem;
151 }
152 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
153 errno = EINTR;
154 return pos;
155 }
156 }
157 return pos;
158 }
159
160 size_t
atomiciov(ssize_t (* f)(int,const struct iovec *,int),int fd,const struct iovec * _iov,int iovcnt)161 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
162 const struct iovec *_iov, int iovcnt)
163 {
164 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL);
165 }
166