1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /* lib/krb5/os/net_write.c */
3 /*
4 * Copyright 1987, 1988, 1990, 2009 by the Massachusetts Institute of
5 * Technology. All Rights Reserved.
6 *
7 * Export of this software from the United States of America may
8 * require a specific license from the United States Government.
9 * It is the responsibility of any person or organization contemplating
10 * export to obtain such a license before exporting.
11 *
12 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
13 * distribute this software and its documentation for any purpose and
14 * without fee is hereby granted, provided that the above copyright
15 * notice appear in all copies and that both that copyright notice and
16 * this permission notice appear in supporting documentation, and that
17 * the name of M.I.T. not be used in advertising or publicity pertaining
18 * to distribution of the software without specific, written prior
19 * permission. Furthermore if you modify this software you must label
20 * your software as modified software and not distribute it in such a
21 * fashion that it might be confused with the original M.I.T. software.
22 * M.I.T. makes no representations about the suitability of
23 * this software for any purpose. It is provided "as is" without express
24 * or implied warranty.
25 */
26
27 #include "k5-int.h"
28 #include "os-proto.h"
29
30 /*
31 * krb5_net_write() writes "len" bytes from "buf" to the file
32 * descriptor "fd". It returns the number of bytes written or
33 * a write() error. (The calling interface is identical to
34 * write(2).)
35 *
36 * XXX must not use non-blocking I/O
37 */
38
39 int
krb5_net_write(krb5_context context,int fd,const char * buf,int len)40 krb5_net_write(krb5_context context, int fd, const char *buf, int len)
41 {
42 sg_buf sg;
43 SG_SET(&sg, buf, len);
44 return krb5int_net_writev(context, fd, &sg, 1);
45 }
46
47 int
krb5int_net_writev(krb5_context context,int fd,sg_buf * sgp,int nsg)48 krb5int_net_writev(krb5_context context, int fd, sg_buf *sgp, int nsg)
49 {
50 ssize_t cc, len = 0;
51 SOCKET_WRITEV_TEMP tmp;
52
53 while (nsg > 0) {
54 /* Skip any empty data blocks. */
55 if (SG_LEN(sgp) == 0) {
56 sgp++, nsg--;
57 continue;
58 }
59 cc = SOCKET_WRITEV((SOCKET)fd, sgp, nsg, tmp);
60 if (cc < 0) {
61 if (SOCKET_ERRNO == SOCKET_EINTR)
62 continue;
63
64 /* XXX this interface sucks! */
65 errno = SOCKET_ERRNO;
66 return -1;
67 }
68 len += cc;
69 while (cc > 0) {
70 if ((unsigned)cc < SG_LEN(sgp)) {
71 SG_ADVANCE(sgp, (unsigned)cc);
72 cc = 0;
73 } else {
74 cc -= SG_LEN(sgp);
75 sgp++, nsg--;
76 assert(nsg > 0 || cc == 0);
77 }
78 }
79 }
80 return len;
81 }
82