xref: /titanic_52/usr/src/lib/libbc/libc/sys/4.2/writev.c (revision 940d71d237794874e18a0eb72f6564821a823517)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include "../common/compat.h"
30 #include <stdio.h>
31 #include <sys/errno.h>
32 #include <sys/types.h>
33 #include <unistd.h>
34 #include <sys/uio.h>
35 
36 /*
37  * If writing to a utmp-like file, map the utmp structure to
38  * new format on the fly.
39  */
40 extern int errno;
41 
42 extern int conv2utmpx(char *, char *, int);
43 
44 int
45 writev(int fd, struct iovec *iov, int iovcnt)
46 {
47 	return (bc_writev(fd, iov, iovcnt));
48 }
49 
50 int
51 bc_writev(int fd, struct iovec *iov, int iovcnt)
52 {
53 	int ret, off;
54 	int nsize, total = 0;
55 	char *nbuf;
56 	int i;
57 
58 	if (fd_get(fd) != -1) { /* writing utmp (utmpx, actually) */
59 		for (i = 0; i < iovcnt; i++) {
60 			nsize = getmodsize(iov[i].iov_len,
61 			    sizeof (struct compat_utmp),
62 			    sizeof (struct utmpx));
63 
64 			if ((nbuf = (void *)malloc(nsize)) == NULL) {
65 				fprintf(stderr, "writev: malloc failed\n");
66 				exit(-1);
67 			}
68 
69 			(void) memset(nbuf, 0, nsize);
70 
71 			ret = conv2utmpx(nbuf, iov[i].iov_base, iov[i].iov_len);
72 
73 			if ((ret = _write(fd, nbuf, ret)) == -1) {
74 				if (errno == EAGAIN)
75 					errno = EWOULDBLOCK;
76 				free(nbuf);
77 				return (-1);
78 			}
79 
80 			free(nbuf);
81 
82 			ret = getmodsize(ret, sizeof (struct utmpx),
83 			    sizeof (struct compat_utmp));
84 			total += ret;
85 		}
86 		return (total);
87 	}
88 
89 	if ((ret = _writev(fd, iov, iovcnt)) == -1) {
90 		if (errno == EAGAIN)
91 			errno = EWOULDBLOCK;
92 	}
93 
94 	return (ret);
95 }
96