1 /* $OpenBSD: atomicio.c,v 1.28 2016/07/27 23:18:12 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 #include <limits.h>
45
46 #include "atomicio.h"
47
48 /*
49 * ensure all of data on socket comes through. f==read || f==vwrite
50 */
51 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)52 atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n,
53 int (*cb)(void *, size_t), void *cb_arg)
54 {
55 char *s = _s;
56 size_t pos = 0;
57 ssize_t res;
58 struct pollfd pfd;
59
60 #ifndef BROKEN_READ_COMPARISON
61 pfd.fd = fd;
62 pfd.events = f == read ? POLLIN : POLLOUT;
63 #endif
64 while (n > pos) {
65 res = (f) (fd, s + pos, n - pos);
66 switch (res) {
67 case -1:
68 if (errno == EINTR)
69 continue;
70 if (errno == EAGAIN || errno == EWOULDBLOCK) {
71 #ifndef BROKEN_READ_COMPARISON
72 (void)poll(&pfd, 1, -1);
73 #endif
74 continue;
75 }
76 return 0;
77 case 0:
78 errno = EPIPE;
79 return pos;
80 default:
81 pos += (size_t)res;
82 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
83 errno = EINTR;
84 return pos;
85 }
86 }
87 }
88 return pos;
89 }
90
91 size_t
atomicio(ssize_t (* f)(int,void *,size_t),int fd,void * _s,size_t n)92 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
93 {
94 return atomicio6(f, fd, _s, n, NULL, NULL);
95 }
96
97 /*
98 * ensure all of data on socket comes through. f==readv || f==writev
99 */
100 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)101 atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd,
102 const struct iovec *_iov, int iovcnt,
103 int (*cb)(void *, size_t), void *cb_arg)
104 {
105 size_t pos = 0, rem;
106 ssize_t res;
107 struct iovec iov_array[IOV_MAX], *iov = iov_array;
108 struct pollfd pfd;
109
110 if (iovcnt < 0 || iovcnt > IOV_MAX) {
111 errno = EINVAL;
112 return 0;
113 }
114 /* Make a copy of the iov array because we may modify it below */
115 memcpy(iov, _iov, (size_t)iovcnt * sizeof(*_iov));
116
117 #ifndef BROKEN_READV_COMPARISON
118 pfd.fd = fd;
119 pfd.events = f == readv ? POLLIN : POLLOUT;
120 #endif
121 for (; iovcnt > 0 && iov[0].iov_len > 0;) {
122 res = (f) (fd, iov, iovcnt);
123 switch (res) {
124 case -1:
125 if (errno == EINTR)
126 continue;
127 if (errno == EAGAIN || errno == EWOULDBLOCK) {
128 #ifndef BROKEN_READV_COMPARISON
129 (void)poll(&pfd, 1, -1);
130 #endif
131 continue;
132 }
133 return 0;
134 case 0:
135 errno = EPIPE;
136 return pos;
137 default:
138 rem = (size_t)res;
139 pos += rem;
140 /* skip completed iov entries */
141 while (iovcnt > 0 && rem >= iov[0].iov_len) {
142 rem -= iov[0].iov_len;
143 iov++;
144 iovcnt--;
145 }
146 /* This shouldn't happen... */
147 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) {
148 errno = EFAULT;
149 return 0;
150 }
151 if (iovcnt == 0)
152 break;
153 /* update pointer in partially complete iov */
154 iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
155 iov[0].iov_len -= rem;
156 }
157 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
158 errno = EINTR;
159 return pos;
160 }
161 }
162 return pos;
163 }
164
165 size_t
atomiciov(ssize_t (* f)(int,const struct iovec *,int),int fd,const struct iovec * _iov,int iovcnt)166 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
167 const struct iovec *_iov, int iovcnt)
168 {
169 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL);
170 }
171