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/uio.h>
32
33 #include <errno.h>
34 #include <poll.h>
35 #include <string.h>
36 #include <unistd.h>
37 #include <limits.h>
38
39 #include "atomicio.h"
40
41 /*
42 * ensure all of data on socket comes through. f==read || f==vwrite
43 */
44 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)45 atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n,
46 int (*cb)(void *, size_t), void *cb_arg)
47 {
48 char *s = _s;
49 size_t pos = 0;
50 ssize_t res;
51 struct pollfd pfd;
52
53 pfd.fd = fd;
54 #ifndef BROKEN_READ_COMPARISON
55 pfd.events = f == read ? POLLIN : POLLOUT;
56 #else
57 pfd.events = POLLIN|POLLOUT;
58 #endif
59 while (n > pos) {
60 res = (f) (fd, s + pos, n - pos);
61 switch (res) {
62 case -1:
63 if (errno == EINTR) {
64 /* possible SIGALARM, update callback */
65 if (cb != NULL && cb(cb_arg, 0) == -1) {
66 errno = EINTR;
67 return pos;
68 }
69 continue;
70 } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
71 (void)poll(&pfd, 1, -1);
72 continue;
73 }
74 return 0;
75 case 0:
76 errno = EPIPE;
77 return pos;
78 default:
79 pos += (size_t)res;
80 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
81 errno = EINTR;
82 return pos;
83 }
84 }
85 }
86 return pos;
87 }
88
89 size_t
atomicio(ssize_t (* f)(int,void *,size_t),int fd,void * _s,size_t n)90 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
91 {
92 return atomicio6(f, fd, _s, n, NULL, NULL);
93 }
94
95 /*
96 * ensure all of data on socket comes through. f==readv || f==writev
97 */
98 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)99 atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd,
100 const struct iovec *_iov, int iovcnt,
101 int (*cb)(void *, size_t), void *cb_arg)
102 {
103 size_t pos = 0, rem;
104 ssize_t res;
105 struct iovec iov_array[IOV_MAX], *iov = iov_array;
106 struct pollfd pfd;
107
108 if (iovcnt < 0 || iovcnt > IOV_MAX) {
109 errno = EINVAL;
110 return 0;
111 }
112 /* Make a copy of the iov array because we may modify it below */
113 memcpy(iov, _iov, (size_t)iovcnt * sizeof(*_iov));
114
115 pfd.fd = fd;
116 #ifndef BROKEN_READV_COMPARISON
117 pfd.events = f == readv ? POLLIN : POLLOUT;
118 #else
119 pfd.events = 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 /* possible SIGALARM, update callback */
127 if (cb != NULL && cb(cb_arg, 0) == -1) {
128 errno = EINTR;
129 return pos;
130 }
131 continue;
132 } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
133 (void)poll(&pfd, 1, -1);
134 continue;
135 }
136 return 0;
137 case 0:
138 errno = EPIPE;
139 return pos;
140 default:
141 rem = (size_t)res;
142 pos += rem;
143 /* skip completed iov entries */
144 while (iovcnt > 0 && rem >= iov[0].iov_len) {
145 rem -= iov[0].iov_len;
146 iov++;
147 iovcnt--;
148 }
149 /* This shouldn't happen... */
150 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) {
151 errno = EFAULT;
152 return 0;
153 }
154 if (iovcnt == 0)
155 break;
156 /* update pointer in partially complete iov */
157 iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
158 iov[0].iov_len -= rem;
159 }
160 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
161 errno = EINTR;
162 return pos;
163 }
164 }
165 return pos;
166 }
167
168 size_t
atomiciov(ssize_t (* f)(int,const struct iovec *,int),int fd,const struct iovec * _iov,int iovcnt)169 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
170 const struct iovec *_iov, int iovcnt)
171 {
172 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL);
173 }
174