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 <sys/uio.h>
30
31 #include <errno.h>
32 #include <poll.h>
33 #include <string.h>
34 #include <unistd.h>
35 #include <limits.h>
36
37 #include "atomicio.h"
38
39 /*
40 * ensure all of data on socket comes through. f==read || f==vwrite
41 */
42 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)43 atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n,
44 int (*cb)(void *, size_t), void *cb_arg)
45 {
46 char *s = _s;
47 size_t pos = 0;
48 ssize_t res;
49 struct pollfd pfd;
50
51 pfd.fd = fd;
52 pfd.events = f == read ? POLLIN : POLLOUT;
53 while (n > pos) {
54 res = (f) (fd, s + pos, n - pos);
55 switch (res) {
56 case -1:
57 if (errno == EINTR) {
58 /* possible SIGALARM, update callback */
59 if (cb != NULL && cb(cb_arg, 0) == -1) {
60 errno = EINTR;
61 return pos;
62 }
63 continue;
64 } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
65 (void)poll(&pfd, 1, -1);
66 continue;
67 }
68 return 0;
69 case 0:
70 errno = EPIPE;
71 return pos;
72 default:
73 pos += (size_t)res;
74 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
75 errno = EINTR;
76 return pos;
77 }
78 }
79 }
80 return pos;
81 }
82
83 size_t
atomicio(ssize_t (* f)(int,void *,size_t),int fd,void * _s,size_t n)84 atomicio(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n)
85 {
86 return atomicio6(f, fd, _s, n, NULL, NULL);
87 }
88
89 /*
90 * ensure all of data on socket comes through. f==readv || f==writev
91 */
92 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)93 atomiciov6(ssize_t (*f) (int, const struct iovec *, int), int fd,
94 const struct iovec *_iov, int iovcnt,
95 int (*cb)(void *, size_t), void *cb_arg)
96 {
97 size_t pos = 0, rem;
98 ssize_t res;
99 struct iovec iov_array[IOV_MAX], *iov = iov_array;
100 struct pollfd pfd;
101
102 if (iovcnt < 0 || iovcnt > IOV_MAX) {
103 errno = EINVAL;
104 return 0;
105 }
106 /* Make a copy of the iov array because we may modify it below */
107 memcpy(iov, _iov, (size_t)iovcnt * sizeof(*_iov));
108
109 pfd.fd = fd;
110 pfd.events = f == readv ? POLLIN : POLLOUT;
111 for (; iovcnt > 0 && iov[0].iov_len > 0;) {
112 res = (f) (fd, iov, iovcnt);
113 switch (res) {
114 case -1:
115 if (errno == EINTR) {
116 /* possible SIGALARM, update callback */
117 if (cb != NULL && cb(cb_arg, 0) == -1) {
118 errno = EINTR;
119 return pos;
120 }
121 continue;
122 } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
123 (void)poll(&pfd, 1, -1);
124 continue;
125 }
126 return 0;
127 case 0:
128 errno = EPIPE;
129 return pos;
130 default:
131 rem = (size_t)res;
132 pos += rem;
133 /* skip completed iov entries */
134 while (iovcnt > 0 && rem >= iov[0].iov_len) {
135 rem -= iov[0].iov_len;
136 iov++;
137 iovcnt--;
138 }
139 /* This shouldn't happen... */
140 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) {
141 errno = EFAULT;
142 return 0;
143 }
144 if (iovcnt == 0)
145 break;
146 /* update pointer in partially complete iov */
147 iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
148 iov[0].iov_len -= rem;
149 }
150 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
151 errno = EINTR;
152 return pos;
153 }
154 }
155 return pos;
156 }
157
158 size_t
atomiciov(ssize_t (* f)(int,const struct iovec *,int),int fd,const struct iovec * _iov,int iovcnt)159 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
160 const struct iovec *_iov, int iovcnt)
161 {
162 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL);
163 }
164