1 /* $OpenBSD: atomicio.c,v 1.30 2019/01/24 02:42:23 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 #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 pfd.fd = fd;
61 #ifndef BROKEN_READ_COMPARISON
62 pfd.events = f == read ? POLLIN : POLLOUT;
63 #else
64 pfd.events = POLLIN|POLLOUT;
65 #endif
66 while (n > pos) {
67 res = (f) (fd, s + pos, n - pos);
68 switch (res) {
69 case -1:
70 if (errno == EINTR) {
71 /* possible SIGALARM, update callback */
72 if (cb != NULL && cb(cb_arg, 0) == -1) {
73 errno = EINTR;
74 return pos;
75 }
76 continue;
77 } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
78 (void)poll(&pfd, 1, -1);
79 continue;
80 }
81 return 0;
82 case 0:
83 errno = EPIPE;
84 return pos;
85 default:
86 pos += (size_t)res;
87 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
88 errno = EINTR;
89 return pos;
90 }
91 }
92 }
93 return pos;
94 }
95
96 size_t
atomicio(ssize_t (* f)(int,void *,size_t),int fd,void * _s,size_t n)97 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
98 {
99 return atomicio6(f, fd, _s, n, NULL, NULL);
100 }
101
102 /*
103 * ensure all of data on socket comes through. f==readv || f==writev
104 */
105 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)106 atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd,
107 const struct iovec *_iov, int iovcnt,
108 int (*cb)(void *, size_t), void *cb_arg)
109 {
110 size_t pos = 0, rem;
111 ssize_t res;
112 struct iovec iov_array[IOV_MAX], *iov = iov_array;
113 struct pollfd pfd;
114
115 if (iovcnt < 0 || iovcnt > IOV_MAX) {
116 errno = EINVAL;
117 return 0;
118 }
119 /* Make a copy of the iov array because we may modify it below */
120 memcpy(iov, _iov, (size_t)iovcnt * sizeof(*_iov));
121
122 pfd.fd = fd;
123 #ifndef BROKEN_READV_COMPARISON
124 pfd.events = f == readv ? POLLIN : POLLOUT;
125 #else
126 pfd.events = POLLIN|POLLOUT;
127 #endif
128 for (; iovcnt > 0 && iov[0].iov_len > 0;) {
129 res = (f) (fd, iov, iovcnt);
130 switch (res) {
131 case -1:
132 if (errno == EINTR) {
133 /* possible SIGALARM, update callback */
134 if (cb != NULL && cb(cb_arg, 0) == -1) {
135 errno = EINTR;
136 return pos;
137 }
138 continue;
139 } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
140 (void)poll(&pfd, 1, -1);
141 continue;
142 }
143 return 0;
144 case 0:
145 errno = EPIPE;
146 return pos;
147 default:
148 rem = (size_t)res;
149 pos += rem;
150 /* skip completed iov entries */
151 while (iovcnt > 0 && rem >= iov[0].iov_len) {
152 rem -= iov[0].iov_len;
153 iov++;
154 iovcnt--;
155 }
156 /* This shouldn't happen... */
157 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) {
158 errno = EFAULT;
159 return 0;
160 }
161 if (iovcnt == 0)
162 break;
163 /* update pointer in partially complete iov */
164 iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
165 iov[0].iov_len -= rem;
166 }
167 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
168 errno = EINTR;
169 return pos;
170 }
171 }
172 return pos;
173 }
174
175 size_t
atomiciov(ssize_t (* f)(int,const struct iovec *,int),int fd,const struct iovec * _iov,int iovcnt)176 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
177 const struct iovec *_iov, int iovcnt)
178 {
179 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL);
180 }
181