usr/src/cmd/pfexec/pfexec.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  * Copyright 2014 Gary Mills
  23  * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
  24  */
  25
  26 /*
  27  * New implementation of pfexec(1) and all of the profile shells.
  28  *
  29  * The algorithm is as follows:
  30  *      first try to derive the shell's path from getexecname();
  31  *      note that this requires a *hard* link to the program, so
  32  *      if we find that we are actually executing pfexec, we start
  33  *      looking at argv[0].
  34  *      argv[0] is also our fallback in case getexecname doesn't find it.
  35  */
  36 #include <sys/param.h>
  37 #include <alloca.h>
  38 #include <errno.h>
  39 #include <locale.h>
  40 #include <priv.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44 #include <unistd.h>
  45
  46 #define PFEXEC  "pfexec"
  47 #ifndef TEXT_DOMAIN
  48 #define TEXT_DOMAIN     "SYS_TEST"
  49 #endif
  50
  51 #define RES_PFEXEC      1
  52 #define RES_OK          0
  53 #define RES_FAILURE     -1
  54
  55 /*
  56  * Return the shellname
  57  */
  58 int
  59 shellname(const char *name, char buf[MAXPATHLEN])
  60 {
  61         const char *cmd = strrchr(name, '/');
  62
  63         if (cmd == NULL)
  64                 cmd = name;
  65         else
  66                 cmd++;
  67
  68         if (strncmp(cmd, "pf", 2) != 0)
  69                 return (RES_FAILURE);
  70
  71         if (strcmp(cmd, PFEXEC) == 0)
  72                 return (RES_PFEXEC);
  73
  74         if (strlen(name) >= MAXPATHLEN)
  75                 return (RES_FAILURE);
  76
  77         if (cmd == name) {
  78                 (void) strlcpy(buf, cmd + 2, MAXPATHLEN);
  79         } else {
  80                 (void) strncpy(buf, name, cmd - name);
  81                 (void) strcpy(buf + (cmd - name), cmd + 2);
  82         }
  83         return (RES_OK);
  84
  85 }
  86
  87 static void
  88 usage(void)
  89 {
  90         (void) fprintf(stderr, gettext("pfexec [-P privset] cmd [arg ..]\n"));
  91         exit(EXIT_FAILURE);
  92 }
  93
  94 int
  95 main(int argc, char **argv)
  96 {
  97         char *cmd;
  98         char *pset = NULL;
  99         char pathbuf[MAXPATHLEN];
 100         int c;
 101         priv_set_t *wanted;
 102         int oflag;
 103
 104         oflag = getpflags(PRIV_PFEXEC);
 105         if (setpflags(PRIV_PFEXEC, 1) != 0) {
 106                 (void) fprintf(stderr,
 107                     gettext("pfexec: unable to set PFEXEC flag: %s\n"),
 108                     strerror(errno));
 109                 exit(1);
 110         }
 111
 112         if (*argv[0] == '-')
 113                 cmd = argv[0] + 1;
 114         else
 115                 cmd = argv[0];
 116
 117         /* Strip "pf" from argv[0], it confuses some shells. */
 118         if (strncmp(cmd, "pf", 2) == 0) {
 119                 argv[0] += 2;
 120                 /* argv[0] will need to start with '-' again. */
 121                 if (argv[0][-2] == '-')
 122                         *argv[0] = '-';
 123         }
 124
 125         /* If this fails, we just continue with plan B */
 126         if (shellname(getexecname(), pathbuf) == RES_OK)
 127                 (void) execv(pathbuf, argv);
 128
 129         switch (shellname(cmd, pathbuf)) {
 130         case RES_OK:
 131                 (void) execv(pathbuf, argv);
 132                 (void) fprintf(stderr,
 133                     gettext("pfexec: unable to execute %s: %s\n"),
 134                     pathbuf, strerror(errno));
 135                 return (1);
 136         case RES_PFEXEC:
 137         case RES_FAILURE:
 138                 while ((c = getopt(argc, argv, "P:")) != EOF) {
 139                         switch (c) {
 140                         case 'P':
 141                                 if (pset == NULL) {
 142                                         pset = optarg;
 143                                         break;
 144                                 }
 145                                 /* FALLTHROUGH */
 146                         default:
 147                                 usage();
 148                         }
 149                 }
 150                 argc -= optind;
 151                 argv += optind;
 152                 if (argc < 1)
 153                         usage();
 154
 155                 if (pset != NULL) {
 156                         if ((wanted = priv_str_to_set(pset, ",", NULL)) ==
 157                             NULL) {
 158                                 (void) fprintf(stderr,
 159                                     gettext("pfexec: error parsing "
 160                                     "privileges: %s\n"), strerror(errno));
 161                                 exit(EXIT_FAILURE);
 162                         }
 163                         if (setppriv(PRIV_ON, PRIV_INHERITABLE, wanted) != 0) {
 164                                 (void) fprintf(stderr,
 165                                     gettext("pfexec: error setting "
 166                                     "privileges: %s\n"), strerror(errno));
 167                                 exit(EXIT_FAILURE);
 168                         }
 169                         (void) setpflags(PRIV_PFEXEC, oflag);
 170                 }
 171
 172                 (void) execvp(argv[0], argv);
 173                 (void) fprintf(stderr,
 174                     gettext("pfexec: unable to execute %s: %s\n"),
 175                     argv[0], strerror(errno));
 176                 return (1);
 177         }
 178         return (1);
 179 }