usr/src/lib/libbc/libc/sys/4.2/writev.c

   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 }