1 /*************************************************************************** 2 * 3 * util_helper.c - HAL utilities for helper (as e.g. prober/addons) et al. 4 * 5 * Copyright (C) 2006 David Zeuthen, <david@fubar.dk> 6 * 7 * Licensed under the Academic Free License version 2.1 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 22 * 23 **************************************************************************/ 24 25 #ifdef HAVE_CONFIG_H 26 # include <config.h> 27 #endif 28 29 #include <grp.h> 30 #include <stdarg.h> 31 #include <stdlib.h> 32 #include <string.h> 33 #include <sys/time.h> 34 #include <time.h> 35 #include <pwd.h> 36 #include <unistd.h> 37 38 #include "logger.h" 39 40 #include "util_helper.h" 41 42 #ifdef __linux__ 43 extern char **environ; 44 #endif 45 46 static char **argv_buffer = NULL; 47 static size_t argv_size = 0; 48 49 #ifdef sun 50 #include <priv.h> 51 void 52 drop_privileges (int keep_auxgroups) 53 { 54 priv_set_t *pPrivSet = NULL; 55 priv_set_t *lPrivSet = NULL; 56 57 /* 58 * Start with the 'basic' privilege set and then remove any 59 * of the 'basic' privileges that will not be needed. 60 */ 61 if ((pPrivSet = priv_str_to_set("basic", ",", NULL)) == NULL) { 62 return; 63 } 64 65 /* Clear privileges we will not need from the 'basic' set */ 66 (void) priv_delset(pPrivSet, PRIV_FILE_LINK_ANY); 67 (void) priv_delset(pPrivSet, PRIV_PROC_INFO); 68 (void) priv_delset(pPrivSet, PRIV_PROC_SESSION); 69 70 /* for sysevent need to be root and have this privilege */ 71 (void) priv_addset(pPrivSet, PRIV_SYS_CONFIG); 72 73 /* Set the permitted privilege set. */ 74 if (setppriv(PRIV_SET, PRIV_PERMITTED, pPrivSet) != 0) { 75 return; 76 } 77 78 /* Clear the limit set. */ 79 if ((lPrivSet = priv_allocset()) == NULL) { 80 return; 81 } 82 83 priv_emptyset(lPrivSet); 84 85 if (setppriv(PRIV_SET, PRIV_LIMIT, lPrivSet) != 0) { 86 return; 87 } 88 89 priv_freeset(lPrivSet); 90 } 91 #else /* !sun */ 92 93 /** Drop root privileges: Set the running user id to HAL_USER and 94 * group to HAL_GROUP, and optionally retain auxiliary groups of HAL_USER. 95 */ 96 void 97 drop_privileges (int keep_auxgroups) 98 { 99 struct passwd *pw = NULL; 100 struct group *gr = NULL; 101 102 /* determine user id */ 103 pw = getpwnam (HAL_USER); 104 if (!pw) { 105 HAL_DEBUG (("drop_privileges: user " HAL_USER " does not exist")); 106 exit (-1); 107 } 108 109 /* determine primary group id */ 110 gr = getgrnam (HAL_GROUP); 111 if (!gr) { 112 HAL_DEBUG (("drop_privileges: group " HAL_GROUP " does not exist")); 113 exit (-1); 114 } 115 116 if (keep_auxgroups) { 117 if (initgroups (HAL_USER, gr->gr_gid)) { 118 HAL_DEBUG(("drop_privileges: could not initialize groups")); 119 exit (-1); 120 } 121 } 122 123 if (setgid (gr->gr_gid)) { 124 HAL_DEBUG (("drop_privileges: could not set group id")); 125 exit (-1); 126 } 127 128 if (setuid (pw->pw_uid)) { 129 HAL_DEBUG (("drop_privileges: could not set user id")); 130 exit (-1); 131 } 132 } 133 #endif /* !sun */ 134 135 void 136 hal_set_proc_title_init (int argc, char *argv[]) 137 { 138 #ifdef __linux__ 139 unsigned int i; 140 char **new_environ, *endptr; 141 142 /* This code is really really ugly. We make some memory layout 143 * assumptions and reuse the environment array as memory to store 144 * our process title in */ 145 146 for (i = 0; environ[i] != NULL; i++) 147 ; 148 149 endptr = i ? environ[i-1] + strlen (environ[i-1]) : argv[argc-1] + strlen (argv[argc-1]); 150 151 argv_buffer = argv; 152 argv_size = endptr - argv_buffer[0]; 153 154 /* Make a copy of environ */ 155 156 new_environ = malloc (sizeof(char*) * (i + 1)); 157 for (i = 0; environ[i] != NULL; i++) 158 new_environ[i] = strdup (environ[i]); 159 new_environ[i] = NULL; 160 161 environ = new_environ; 162 #endif 163 } 164 165 /* this code borrowed from avahi-daemon's setproctitle.c (LGPL v2) */ 166 void 167 hal_set_proc_title (const char *format, ...) 168 { 169 #ifdef __linux__ 170 size_t len; 171 va_list ap; 172 173 if (argv_buffer == NULL) 174 goto out; 175 176 va_start (ap, format); 177 vsnprintf (argv_buffer[0], argv_size, format, ap); 178 va_end (ap); 179 180 len = strlen (argv_buffer[0]); 181 182 memset (argv_buffer[0] + len, 0, argv_size - len); 183 argv_buffer[1] = NULL; 184 out: 185 ; 186 #endif 187 } 188 189