1 /*
2 * Copyright (c) 2006 Damien Miller. All rights reserved.
3 * Copyright (c) 2005 Anil Madhavapeddy. All rights reserved.
4 * Copyright (c) 1995,1999 Theo de Raadt. All rights reserved.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include "includes.h"
29 RCSID("$OpenBSD: atomicio.c,v 1.10 2001/05/08 22:48:07 markus Exp $");
30
31 #pragma ident "%Z%%M% %I% %E% SMI"
32
33 #include "atomicio.h"
34
35 /*
36 * ensure all of data on socket comes through. f==read || f==write
37 */
38 ssize_t
39 atomicio(f, fd, _s, n)
40 ssize_t (*f) ();
41 int fd;
42 void *_s;
43 size_t n;
44 {
45 char *s = _s;
46 ssize_t res, pos = 0;
47
48 while (n > pos) {
49 res = (f) (fd, s + pos, n - pos);
50 switch (res) {
51 case -1:
52 #ifdef EWOULDBLOCK
53 if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
54 #else
55 if (errno == EINTR || errno == EAGAIN)
56 #endif
57 continue;
58 /* FALLTHROUGH */
59 case 0:
60 return (res);
61 default:
62 pos += res;
63 }
64 }
65 return (pos);
66 }
67
68 /*
69 * ensure all of data on socket comes through. f==readv || f==writev
70 */
71 size_t
atomiciov(ssize_t (* f)(int,const struct iovec *,int),int fd,const struct iovec * _iov,int iovcnt)72 atomiciov(ssize_t (*f) (int, const struct iovec *, int), int fd,
73 const struct iovec *_iov, int iovcnt)
74 {
75 size_t pos = 0, rem;
76 ssize_t res;
77 struct iovec iov_array[IOV_MAX], *iov = iov_array;
78
79 if (iovcnt > IOV_MAX) {
80 errno = EINVAL;
81 return 0;
82 }
83 /* Make a copy of the iov array because we may modify it below */
84 memcpy(iov, _iov, iovcnt * sizeof(*_iov));
85
86 for (; iovcnt > 0 && iov[0].iov_len > 0;) {
87 res = (f) (fd, iov, iovcnt);
88 switch (res) {
89 case -1:
90 if (errno == EINTR || errno == EAGAIN)
91 continue;
92 return 0;
93 case 0:
94 errno = EPIPE;
95 return pos;
96 default:
97 rem = (size_t)res;
98 pos += rem;
99 /* skip completed iov entries */
100 while (iovcnt > 0 && rem >= iov[0].iov_len) {
101 rem -= iov[0].iov_len;
102 iov++;
103 iovcnt--;
104 }
105 /* This shouldn't happen... */
106 if (rem > 0 && (iovcnt <= 0 || rem > iov[0].iov_len)) {
107 errno = EFAULT;
108 return 0;
109 }
110 if (iovcnt == 0)
111 break;
112 /* update pointer in partially complete iov */
113 iov[0].iov_base = ((char *)iov[0].iov_base) + rem;
114 iov[0].iov_len -= rem;
115 }
116 }
117 return pos;
118 }
119