usr/src/lib/libbc/libc/sys/4.2/read.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 <errno.h>
  31 #include <stdio.h>
  32 #include <sys/types.h>
  33 #include <unistd.h>
  34 #include <sys/syscall.h>
  35
  36 /*
  37  * If reading from the utmp file, map the data to the SunOS 4.1
  38  * format on the fly.
  39  */
  40 extern void to_utmp(char *, char *, int);
  41
  42 int
  43 read(int fd, char *buf, int size)
  44 {
  45         return (bc_read(fd, buf, size));
  46 }
  47
  48 int
  49 bc_read(int fd, char *buf, int size)
  50 {
  51         int fds, ret, off;
  52         char *nbuf;
  53
  54         if (fd_get(fd) != -1) { /* we're reading utmp (utmpx, really) */
  55                 size = getmodsize(size, sizeof (struct compat_utmp),
  56                                                         sizeof (struct utmpx));
  57
  58                 if ((nbuf = (void *)malloc(size)) == NULL) {
  59                         (void) fprintf(stderr, "read: malloc failed\n");
  60                         exit(-1);
  61                 }
  62
  63                 if ((ret = _read(fd, nbuf, size)) == -1) {
  64                         if (errno == EAGAIN)
  65                                 errno = EWOULDBLOCK;
  66                         free(nbuf);
  67                         return (-1);
  68                 }
  69                 to_utmp(buf, nbuf, ret);
  70
  71                 ret = getmodsize(ret, sizeof (struct utmpx),
  72                                                 sizeof (struct compat_utmp));
  73                 free(nbuf);
  74                 return (ret);
  75         }
  76
  77         if ((ret = _read(fd, buf, size)) == -1) {
  78                 if (errno == EAGAIN)
  79                         errno = EWOULDBLOCK;
  80         }
  81         return (ret);
  82 }
  83
  84 void
  85 to_utmp(char *buf, char *nbuf, int len)
  86 {
  87         struct compat_utmp *ut;
  88         struct utmpx *utx;
  89
  90         utx = (struct utmpx *)nbuf;
  91         ut  = (struct compat_utmp *)buf;
  92
  93         while ((char *)utx < (nbuf + len)) {
  94                 (void) strncpy(ut->ut_line, utx->ut_line, sizeof (ut->ut_line));
  95                 (void) strncpy(ut->ut_name, utx->ut_user, sizeof (ut->ut_name));
  96                 (void) strncpy(ut->ut_host, utx->ut_host, sizeof (ut->ut_host));
  97                 ut->ut_time = utx->ut_tv.tv_sec;
  98                 utx++;
  99                 ut++;
 100         }
 101 }