1/*	$NetBSD: net_read.c,v 1.2 2017/01/28 21:31:50 christos Exp $	*/
2
3/*
4 * Copyright (c) 1995, 1996, 1997, 1998 Kungliga Tekniska H��gskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
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 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <config.h>
37
38#include <krb5/roken.h>
39
40/*
41 * Like read but never return partial data.
42 */
43
44#ifndef _WIN32
45
46ROKEN_LIB_FUNCTION ssize_t ROKEN_LIB_CALL
47net_read (rk_socket_t fd, void *buf, size_t nbytes)
48{
49    char *cbuf = (char *)buf;
50    ssize_t count;
51    size_t rem = nbytes;
52
53    while (rem > 0) {
54	count = read (fd, cbuf, rem);
55	if (count < 0) {
56	    if (errno == EINTR)
57		continue;
58	    else
59		return count;
60	} else if (count == 0) {
61	    return count;
62	}
63	cbuf += count;
64	rem -= count;
65    }
66    return nbytes;
67}
68
69#else
70
71ROKEN_LIB_FUNCTION ssize_t ROKEN_LIB_CALL
72net_read(rk_socket_t sock, void *buf, size_t nbytes)
73{
74    char *cbuf = (char *)buf;
75    ssize_t count;
76    size_t rem = nbytes;
77
78#ifdef SOCKET_IS_NOT_AN_FD
79    int use_read = 0;
80#endif
81
82    while (rem > 0) {
83#ifdef SOCKET_IS_NOT_AN_FD
84	if (use_read)
85	    count = _read (sock, cbuf, rem);
86	else
87	    count = recv (sock, cbuf, rem, 0);
88
89	if (use_read == 0 &&
90	    rk_IS_SOCKET_ERROR(count) &&
91            (rk_SOCK_ERRNO == WSANOTINITIALISED ||
92             rk_SOCK_ERRNO == WSAENOTSOCK)) {
93	    use_read = 1;
94
95	    count = _read (sock, cbuf, rem);
96	}
97#else
98	count = recv (sock, cbuf, rem, 0);
99#endif
100	if (count < 0) {
101
102	    /* With WinSock, the error EINTR (WSAEINTR), is used to
103	       indicate that a blocking call was cancelled using
104	       WSACancelBlockingCall(). */
105
106#ifndef HAVE_WINSOCK
107	    if (rk_SOCK_ERRNO == EINTR)
108		continue;
109#endif
110	    return count;
111	} else if (count == 0) {
112	    return count;
113	}
114	cbuf += count;
115	rem -= count;
116    }
117    return nbytes;
118}
119
120#endif
121