Annotation of embedaddon/sudo/src/load_plugins.c, revision 1.1
1.1 ! misho 1: /*
! 2: * Copyright (c) 2009-2011 Todd C. Miller <Todd.Miller@courtesan.com>
! 3: *
! 4: * Permission to use, copy, modify, and distribute this software for any
! 5: * purpose with or without fee is hereby granted, provided that the above
! 6: * copyright notice and this permission notice appear in all copies.
! 7: *
! 8: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
! 9: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
! 10: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
! 11: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
! 12: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
! 13: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
! 14: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
! 15: */
! 16:
! 17: #include <config.h>
! 18:
! 19: #include <sys/types.h>
! 20: #include <sys/param.h>
! 21: #include <sys/stat.h>
! 22: #include <stdio.h>
! 23: #ifdef STDC_HEADERS
! 24: # include <stdlib.h>
! 25: # include <stddef.h>
! 26: #else
! 27: # ifdef HAVE_STDLIB_H
! 28: # include <stdlib.h>
! 29: # endif
! 30: #endif /* STDC_HEADERS */
! 31: #ifdef HAVE_STRING_H
! 32: # include <string.h>
! 33: #endif /* HAVE_STRING_H */
! 34: #ifdef HAVE_STRINGS_H
! 35: # include <strings.h>
! 36: #endif /* HAVE_STRINGS_H */
! 37: #ifdef HAVE_UNISTD_H
! 38: # include <unistd.h>
! 39: #endif /* HAVE_UNISTD_H */
! 40: #ifdef HAVE_DLOPEN
! 41: # include <dlfcn.h>
! 42: #else
! 43: # include "compat/dlfcn.h"
! 44: #endif
! 45: #include <errno.h>
! 46:
! 47: #include "sudo.h"
! 48: #include "sudo_plugin.h"
! 49: #include "sudo_plugin_int.h"
! 50:
! 51: #ifndef RTLD_GLOBAL
! 52: # define RTLD_GLOBAL 0
! 53: #endif
! 54:
! 55: #ifdef _PATH_SUDO_NOEXEC
! 56: const char *noexec_path = _PATH_SUDO_NOEXEC;
! 57: #endif
! 58:
! 59: /*
! 60: * Read in /etc/sudo.conf
! 61: * Returns a list of plugins.
! 62: */
! 63: static struct plugin_info_list *
! 64: sudo_read_conf(const char *conf_file)
! 65: {
! 66: FILE *fp;
! 67: char *cp, *name, *path;
! 68: struct plugin_info *info;
! 69: static struct plugin_info_list pil; /* XXX */
! 70:
! 71: if ((fp = fopen(conf_file, "r")) == NULL)
! 72: goto done;
! 73:
! 74: while ((cp = sudo_parseln(fp)) != NULL) {
! 75: /* Skip blank or comment lines */
! 76: if (*cp == '\0')
! 77: continue;
! 78:
! 79: /* Look for a line starting with "Path" */
! 80: if (strncasecmp(cp, "Path", 4) == 0) {
! 81: /* Parse line */
! 82: if ((name = strtok(cp + 4, " \t")) == NULL ||
! 83: (path = strtok(NULL, " \t")) == NULL) {
! 84: continue;
! 85: }
! 86: if (strcasecmp(name, "askpass") == 0)
! 87: askpass_path = estrdup(path);
! 88: #ifdef _PATH_SUDO_NOEXEC
! 89: else if (strcasecmp(name, "noexec") == 0)
! 90: noexec_path = estrdup(path);
! 91: #endif
! 92: continue;
! 93: }
! 94:
! 95: /* Look for a line starting with "Plugin" */
! 96: if (strncasecmp(cp, "Plugin", 6) == 0) {
! 97: /* Parse line */
! 98: if ((name = strtok(cp + 6, " \t")) == NULL ||
! 99: (path = strtok(NULL, " \t")) == NULL) {
! 100: continue;
! 101: }
! 102: info = emalloc(sizeof(*info));
! 103: info->symbol_name = estrdup(name);
! 104: info->path = estrdup(path);
! 105: info->prev = info;
! 106: info->next = NULL;
! 107: tq_append(&pil, info);
! 108: continue;
! 109: }
! 110: }
! 111: fclose(fp);
! 112:
! 113: done:
! 114: if (tq_empty(&pil)) {
! 115: /* Default policy plugin */
! 116: info = emalloc(sizeof(*info));
! 117: info->symbol_name = "sudoers_policy";
! 118: info->path = SUDOERS_PLUGIN;
! 119: info->prev = info;
! 120: info->next = NULL;
! 121: tq_append(&pil, info);
! 122:
! 123: /* Default I/O plugin */
! 124: info = emalloc(sizeof(*info));
! 125: info->symbol_name = "sudoers_io";
! 126: info->path = SUDOERS_PLUGIN;
! 127: info->prev = info;
! 128: info->next = NULL;
! 129: tq_append(&pil, info);
! 130: }
! 131:
! 132: return &pil;
! 133: }
! 134:
! 135: /*
! 136: * Load the plugins listed in conf_file.
! 137: */
! 138: int
! 139: sudo_load_plugins(const char *conf_file,
! 140: struct plugin_container *policy_plugin,
! 141: struct plugin_container_list *io_plugins)
! 142: {
! 143: struct generic_plugin *plugin;
! 144: struct plugin_container *container;
! 145: struct plugin_info *info;
! 146: struct plugin_info_list *plugin_list;
! 147: struct stat sb;
! 148: void *handle;
! 149: char path[PATH_MAX];
! 150: int rval = FALSE;
! 151:
! 152: /* Parse sudo.conf */
! 153: plugin_list = sudo_read_conf(conf_file);
! 154:
! 155: tq_foreach_fwd(plugin_list, info) {
! 156: if (info->path[0] == '/') {
! 157: if (strlcpy(path, info->path, sizeof(path)) >= sizeof(path)) {
! 158: warningx(_("%s: %s"), info->path, strerror(ENAMETOOLONG));
! 159: goto done;
! 160: }
! 161: } else {
! 162: if (snprintf(path, sizeof(path), "%s%s", _PATH_SUDO_PLUGIN_DIR,
! 163: info->path) >= sizeof(path)) {
! 164: warningx(_("%s%s: %s"), _PATH_SUDO_PLUGIN_DIR, info->path,
! 165: strerror(ENAMETOOLONG));
! 166: goto done;
! 167: }
! 168: }
! 169: if (stat(path, &sb) != 0) {
! 170: warning("%s", path);
! 171: goto done;
! 172: }
! 173: if (sb.st_uid != ROOT_UID) {
! 174: warningx(_("%s must be owned by uid %d"), path, ROOT_UID);
! 175: goto done;
! 176: }
! 177: if ((sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) {
! 178: warningx(_("%s must be only be writable by owner"), path);
! 179: goto done;
! 180: }
! 181:
! 182: /* Open plugin and map in symbol */
! 183: handle = dlopen(path, RTLD_LAZY|RTLD_GLOBAL);
! 184: if (!handle) {
! 185: warningx(_("unable to dlopen %s: %s"), path, dlerror());
! 186: goto done;
! 187: }
! 188: plugin = dlsym(handle, info->symbol_name);
! 189: if (!plugin) {
! 190: warningx(_("%s: unable to find symbol %s"), path,
! 191: info->symbol_name);
! 192: goto done;
! 193: }
! 194:
! 195: if (plugin->type != SUDO_POLICY_PLUGIN && plugin->type != SUDO_IO_PLUGIN) {
! 196: warningx(_("%s: unknown policy type %d"), path, plugin->type);
! 197: goto done;
! 198: }
! 199: if (SUDO_API_VERSION_GET_MAJOR(plugin->version) != SUDO_API_VERSION_MAJOR) {
! 200: warningx(_("%s: incompatible policy major version %d, expected %d"),
! 201: path, SUDO_API_VERSION_GET_MAJOR(plugin->version),
! 202: SUDO_API_VERSION_MAJOR);
! 203: goto done;
! 204: }
! 205: if (plugin->type == SUDO_POLICY_PLUGIN) {
! 206: if (policy_plugin->handle) {
! 207: warningx(_("%s: only a single policy plugin may be loaded"),
! 208: conf_file);
! 209: goto done;
! 210: }
! 211: policy_plugin->handle = handle;
! 212: policy_plugin->name = info->symbol_name;
! 213: policy_plugin->u.generic = plugin;
! 214: } else if (plugin->type == SUDO_IO_PLUGIN) {
! 215: container = emalloc(sizeof(*container));
! 216: container->prev = container;
! 217: container->next = NULL;
! 218: container->handle = handle;
! 219: container->name = info->symbol_name;
! 220: container->u.generic = plugin;
! 221: tq_append(io_plugins, container);
! 222: }
! 223: }
! 224: if (policy_plugin->handle == NULL) {
! 225: warningx(_("%s: at least one policy plugin must be specified"),
! 226: conf_file);
! 227: goto done;
! 228: }
! 229: if (policy_plugin->u.policy->check_policy == NULL) {
! 230: warningx(_("policy plugin %s does not include a check_policy method"),
! 231: policy_plugin->name);
! 232: goto done;
! 233: }
! 234:
! 235: rval = TRUE;
! 236:
! 237: done:
! 238: return rval;
! 239: }
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