usr/src/cmd/cmd-inet/lib/ipmgmtd/ipmgmt_util.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 (c) 2010, Oracle and/or its affiliates. All rights reserved.
  24  */
  25
  26 /*
  27  * Utility functions used by the ipmgmtd daemon.
  28  */
  29
  30 #include <stddef.h>
  31 #include <stdlib.h>
  32 #include <stdio.h>
  33 #include <syslog.h>
  34 #include <stdarg.h>
  35 #include <unistd.h>
  36 #include <errno.h>
  37 #include "ipmgmt_impl.h"
  38
  39 #define IPMGMT_BUFSIZ   1024
  40
  41 void
  42 ipmgmt_log(int pri, const char *fmt, ...)
  43 {
  44         va_list alist;
  45
  46         va_start(alist, fmt);
  47         vsyslog(pri, fmt, alist);
  48         va_end(alist);
  49 }
  50
  51 /*
  52  * Copy a source file to a new destination. The source file will be
  53  * removed if rdonly is false (i.e., used when the source file resides
  54  * on a read-only file system).
  55  *
  56  * Returns 0 on success and errno on failure.
  57  */
  58 int
  59 ipmgmt_cpfile(const char *src, const char *dst, boolean_t rdonly)
  60 {
  61         struct stat statbuf;
  62         FILE *sfp, *dfp;
  63         char buf[IPMGMT_BUFSIZ];
  64         int err = 0;
  65
  66         errno = 0;
  67         /*
  68          * Attempt to open the destination file first since we
  69          * want to optimize for the case where it is read-only
  70          * and will return EROFS.
  71          */
  72         if ((dfp = fopen(dst, "w+")) == NULL)
  73                 return (errno);
  74
  75         /*
  76          * Require that the source file exists.
  77          */
  78         if (stat(src, &statbuf) != 0) {
  79                 err = errno;
  80                 (void) fclose(dfp);
  81                 return (err);
  82         }
  83         if ((sfp = fopen(src, "r")) == NULL) {
  84                 err = errno;
  85                 (void) fclose(dfp);
  86                 return (err);
  87         }
  88
  89         /*
  90          * Copy the file.
  91          */
  92         while (fgets(buf, sizeof (buf), sfp) != NULL && errno == 0) {
  93                 (void) fputs(buf, dfp);
  94                 if (errno != 0)
  95                         break;
  96         }
  97         if (errno != 0)
  98                 err = errno;
  99         else if (fflush(dfp) == EOF)
 100                 err = errno;
 101
 102         (void) fclose(sfp);
 103         (void) fclose(dfp);
 104
 105         /*
 106          * If any error occurred, then remove the destination file.
 107          */
 108         if (err != 0) {
 109                 (void) unlink(dst);
 110                 return (err);
 111         }
 112
 113         /*
 114          * Make sure the file attributes are correct.
 115          */
 116         if (chmod(dst, IPADM_FILE_MODE) != 0 ||
 117             chown(dst, UID_NETADM, GID_NETADM) != 0) {
 118                 err = errno;
 119                 (void) unlink(dst);
 120                 return (err);
 121         }
 122
 123         /*
 124          * If the source file does not reside on a read-only file system
 125          * then remove it.
 126          */
 127         if (!rdonly)
 128                 (void) unlink(src);
 129
 130         return (0);
 131 }