1/* $NetBSD: atomicio.c,v 1.9 2019/04/20 17:16:40 christos Exp $ */
2/* $OpenBSD: atomicio.c,v 1.30 2019/01/24 02:42:23 dtucker Exp $ */
3/*
4 * Copyright (c) 2006 Damien Miller. All rights reserved.
5 * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved.
6 * Copyright (c) 1995,1999 Theo de Raadt. All rights reserved.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#include "includes.h"
31__RCSID("$NetBSD: atomicio.c,v 1.9 2019/04/20 17:16:40 christos Exp $");
32#include <sys/param.h>
33#include <sys/uio.h>
34
35#include <errno.h>
36#include <poll.h>
37#include <string.h>
38#include <unistd.h>
39#include <limits.h>
40
41#include "atomicio.h"
42
43/*
44 * ensure all of data on socket comes through. f==read || f==vwrite
45 */
46size_t
47atomicio6(ssize_t (*f) (int, void *, size_t), int fd, void *_s, size_t n,
48 int (*cb)(void *, size_t), void *cb_arg)
49{
50 char *s = _s;
51 size_t pos = 0;
52 ssize_t res;
53 struct pollfd pfd;
54
55 pfd.fd = fd;
56 /*
57 * check for vwrite instead of read to avoid read being renamed
58 * by SSP issues
59 */
60 pfd.events = f == vwrite ? POLLOUT : POLLIN;
61 while (n > pos) {
62 res = (f) (fd, s + pos, n - pos);
63 switch (res) {
64 case -1:
65 if (errno == EINTR) {
66 /* possible SIGALARM, update callback */
67 if (cb != NULL && cb(cb_arg, 0) == -1) {
68 errno = EINTR;
69 return pos;
70 }
71 continue;
72 } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
73 (void)poll(&pfd, 1, -1);
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
91size_t
92atomicio(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 */
100size_t
101atomiciov6(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 pfd.fd = fd;
118 pfd.events = f == readv ? POLLIN : POLLOUT;
119 for (; iovcnt > 0 && iov[0].iov_len > 0;) {
120 res = (f) (fd, iov, iovcnt);
121 switch (res) {
122 case -1:
123 if (errno == EINTR) {
124 /* possible SIGALARM, update callback */
125 if (cb != NULL && cb(cb_arg, 0) == -1) {
126 errno = EINTR;
127 return pos;
128 }
129 continue;
130 } else if (errno == EAGAIN || errno == EWOULDBLOCK) {
131 (void)poll(&pfd, 1, -1);
132 continue;
133 }
134 return 0;
135 case 0:
136 errno = EPIPE;
137 return pos;
138 default:
139 rem = (size_t)res;
140 pos += rem;
141 /* skip completed iov entries */
142 while (iovcnt > 0 && rem >= iov[0].iov_len) {
143 rem -= iov[0].iov_len;
144 iov++;
145 iovcnt--;
146 }
147 /* This shouldn't happen... */
148 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) {
149 errno = EFAULT;
150 return 0;
151 }
152 if (iovcnt == 0)
153 break;
154 /* update pointer in partially complete iov */
155 iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
156 iov[0].iov_len -= rem;
157 }
158 if (cb != NULL && cb(cb_arg, (size_t)res) == -1) {
159 errno = EINTR;
160 return pos;
161 }
162 }
163 return pos;
164}
165
166size_t
167atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
168 const struct iovec *_iov, int iovcnt)
169{
170 return atomiciov6(f, fd, _iov, iovcnt, NULL, NULL);
171}
172