usr/src/cmd/ypcmd/ypupdated/openchild.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, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  *      Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  24  *      Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
  28 /*        All Rights Reserved   */
  29
  30 /*
  31  * Portions of this source code were derived from Berkeley 4.3 BSD
  32  * under license from the Regents of the University of California.
  33  */
  34
  35 #pragma ident   "%Z%%M% %I%     %E% SMI"
  36
  37
  38 /*
  39  * openchild.c
  40  *
  41  * Open two pipes to a child process, one for reading, one for writing.
  42  * The pipes are accessed by FILE pointers. This is NOT a public
  43  * interface, but for internal use only!
  44  */
  45 #include <stdio.h>
  46
  47 extern void *malloc();
  48 extern char *strrchr();
  49
  50 static char *basename();
  51 static char SHELL[] = "/bin/sh";
  52
  53 extern int close();
  54 extern int dup();
  55 extern int execl();
  56 extern void exit();
  57 extern long fork();
  58 extern int pipe();
  59 extern unsigned int strlen();
  60
  61 /*
  62  * returns pid, or -1 for failure
  63  */
  64 int
  65 _openchild(command, fto, ffrom)
  66         char *command;
  67         FILE **fto;
  68         FILE **ffrom;
  69 {
  70         int i;
  71         int pid;
  72         int pdto[2];
  73         int pdfrom[2];
  74         char *com;
  75
  76
  77         if (pipe(pdto) < 0) {
  78                 goto error1;
  79         }
  80         if (pipe(pdfrom) < 0) {
  81                 goto error2;
  82         }
  83         switch (pid = fork()) {
  84         case -1:
  85                 goto error3;
  86
  87         case 0:
  88                 /*
  89                  * child: read from pdto[0], write into pdfrom[1]
  90                  */
  91                 (void) close(0);
  92                 (void) dup(pdto[0]);
  93                 (void) close(1);
  94                 (void) dup(pdfrom[1]);
  95
  96                 /*
  97                  * adding this closelog for bug id 1238429
  98                  */
  99                 closelog();
 100                 closefrom(3);
 101
 102                 com = malloc((unsigned)strlen(command) + 6);
 103                 if (com == NULL) {
 104                         exit(1);
 105                 }
 106                 (void) sprintf(com, "exec %s", command);
 107                 execl(SHELL, basename(SHELL), "-c", com, NULL);
 108                 exit(1);
 109
 110         default:
 111                 /*
 112                  * parent: write into pdto[1], read from pdfrom[0]
 113                  */
 114                 *fto = fdopen(pdto[1], "w");
 115                 (void) close(pdto[0]);
 116                 *ffrom = fdopen(pdfrom[0], "r");
 117                 (void) close(pdfrom[1]);
 118                 break;
 119         }
 120         return (pid);
 121
 122         /*
 123          * error cleanup and return
 124          */
 125 error3:
 126 printf("openchild: error3");
 127         (void) close(pdfrom[0]);
 128         (void) close(pdfrom[1]);
 129 error2:
 130 printf("openchild: error2");
 131         (void) close(pdto[0]);
 132         (void) close(pdto[1]);
 133 error1:
 134 printf("openchild: error1");
 135         return (-1);
 136 }
 137
 138 static char *
 139 basename(path)
 140         char *path;
 141 {
 142         char *p;
 143
 144         p = strrchr(path, '/');
 145         if (p == NULL) {
 146                 return (path);
 147         } else {
 148                 return (p + 1);
 149         }
 150 }