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 #ifndef BROKEN_READ_COMPARISON
60 pfd.fd = fd;
61 pfd.events = f == read ? POLLIN : POLLOUT;
62 #endif
63 while (n > pos) {
64 res = (f) (fd, s + pos, n - pos);
65 switch (res) {
66 case -1:
67 if (errno == EINTR)
68 continue;
69 if (errno == EAGAIN || errno == EWOULDBLOCK) {
70 #ifndef BROKEN_READ_COMPARISON
71 (void)poll(&pfd, 1, -1);
72 #endif
73 continue;
74 }
75 return 0;
76 case 0:
77 errno = EPIPE;
78 return pos;
79 default:
80 pos += (size_t)res;
81 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
82 errno = EINTR;
83 return pos;
84 }
85 }
86 }
87 return pos;
88 }
89
90 size_t
atomicio(ssize_t (* f)(int,void *,size_t),int fd,void * _s,size_t n)91 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
92 {
93 return atomicio6(f, fd, _s, n, NULL, NULL);
94 }
95
96 /*
97 * ensure all of data on socket comes through. f==readv || f==writev
98 */
99 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)100 atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd,
101 const struct iovec *_iov, int iovcnt,
102 int (*cb)(void *, size_t), void *cb_arg)
103 {
104 size_t pos = 0, rem;
105 ssize_t res;
106 struct iovec iov_array[IOV_MAX], *iov = iov_array;
107 struct pollfd pfd;
108
109 if (iovcnt > IOV_MAX) {
110 errno = EINVAL;
111 return 0;
112 }
113 /* Make a copy of the iov array because we may modify it below */
114 memcpy(iov, _iov, iovcnt * sizeof(*_iov));
115
116 #ifndef BROKEN_READV_COMPARISON
117 pfd.fd = fd;
118 pfd.events = f == readv ? POLLIN : POLLOUT;
119 #endif
120 for (; iovcnt > 0 && iov[0].iov_len > 0;) {
121 res = (f) (fd, iov, iovcnt);
122 switch (res) {
123 case -1:
124 if (errno == EINTR)
125 continue;
126 if (errno == EAGAIN || errno == EWOULDBLOCK) {
127 #ifndef BROKEN_READV_COMPARISON
128 (void)poll(&pfd, 1, -1);
129 #endif
130 continue;
131 }
132 return 0;
133 case 0:
134 errno = EPIPE;
135 return pos;
136 default:
137 rem = (size_t)res;
138 pos += rem;
139 /* skip completed iov entries */
140 while (iovcnt > 0 && rem >= iov[0].iov_len) {
141 rem -= iov[0].iov_len;
142 iov++;
143 iovcnt--;
144 }
145 /* This shouldn't happen... */
146 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) {
147 errno = EFAULT;
148 return 0;
149 }
150 if (iovcnt == 0)
151 break;
152 /* update pointer in partially complete iov */
153 iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
154 iov[0].iov_len -= rem;
155 }
156 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
157 errno = EINTR;
158 return pos;
159 }
160 }
161 return pos;
162 }
163
164 size_t
atomiciov(ssize_t (* f)(int,const struct iovec *,int),int fd,const struct iovec * _iov,int iovcnt)165 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
166 const struct iovec *_iov, int iovcnt)
167 {
168 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL);
169 }
170