1: /*
2: * Copyright (c) 2009-2013 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/stat.h>
21: #include <stdio.h>
22: #ifdef STDC_HEADERS
23: # include <stdlib.h>
24: # include <stddef.h>
25: #else
26: # ifdef HAVE_STDLIB_H
27: # include <stdlib.h>
28: # endif
29: #endif /* STDC_HEADERS */
30: #ifdef HAVE_STRING_H
31: # include <string.h>
32: #endif /* HAVE_STRING_H */
33: #ifdef HAVE_STRINGS_H
34: # include <strings.h>
35: #endif /* HAVE_STRINGS_H */
36: #ifdef HAVE_UNISTD_H
37: # include <unistd.h>
38: #endif /* HAVE_UNISTD_H */
39: #ifdef HAVE_DLOPEN
40: # include <dlfcn.h>
41: #else
42: # include "compat/dlfcn.h"
43: #endif
44: #include <errno.h>
45:
46: #include "sudo.h"
47: #include "sudo_plugin.h"
48: #include "sudo_plugin_int.h"
49: #include "sudo_conf.h"
50: #include "sudo_debug.h"
51:
52: #ifndef RTLD_GLOBAL
53: # define RTLD_GLOBAL 0
54: #endif
55:
56: #ifndef SUDOERS_PLUGIN
57: # define SUDOERS_PLUGIN "sudoers.la"
58: #endif
59:
60: #ifdef _PATH_SUDO_PLUGIN_DIR
61: static int
62: sudo_stat_plugin(struct plugin_info *info, char *fullpath,
63: size_t pathsize, struct stat *sb)
64: {
65: int status = -1;
66: debug_decl(sudo_stat_plugin, SUDO_DEBUG_PLUGIN)
67:
68: if (info->path[0] == '/') {
69: if (strlcpy(fullpath, info->path, pathsize) >= pathsize) {
70: warningx(_("error in %s, line %d while loading plugin `%s'"),
71: _PATH_SUDO_CONF, info->lineno, info->symbol_name);
72: warningx(_("%s: %s"), info->path, strerror(ENAMETOOLONG));
73: goto done;
74: }
75: status = stat(fullpath, sb);
76: } else {
77: if (snprintf(fullpath, pathsize, "%s%s", _PATH_SUDO_PLUGIN_DIR,
78: info->path) >= pathsize) {
79: warningx(_("error in %s, line %d while loading plugin `%s'"),
80: _PATH_SUDO_CONF, info->lineno, info->symbol_name);
81: warningx(_("%s%s: %s"), _PATH_SUDO_PLUGIN_DIR, info->path,
82: strerror(ENAMETOOLONG));
83: goto done;
84: }
85: /* Try parent dir for compatibility with old plugindir default. */
86: if ((status = stat(fullpath, sb)) != 0) {
87: char *cp = strrchr(fullpath, '/');
88: if (cp > fullpath + 4 && cp[-5] == '/' && cp[-4] == 's' &&
89: cp[-3] == 'u' && cp[-2] == 'd' && cp[-1] == 'o') {
90: int serrno = errno;
91: strlcpy(cp - 4, info->path, pathsize - (cp - 4 - fullpath));
92: if ((status = stat(fullpath, sb)) != 0)
93: errno = serrno;
94: }
95: }
96: # ifdef __hpux
97: /* Try .sl instead of .so on HP-UX for backwards compatibility. */
98: if (status != 0) {
99: size_t len = strlen(info->path);
100: if (len >= 3 && info->path[len - 3] == '.' &&
101: info->path[len - 2] == 's' && info->path[len - 1] == 'o') {
102: const char *sopath = info->path;
103: char *slpath = estrdup(info->path);
104: int serrno = errno;
105:
106: slpath[len - 1] = 'l';
107: info->path = slpath;
108: status = sudo_stat_plugin(info, fullpath, pathsize, sb);
109: if (status == 0) {
110: efree((void *)sopath);
111: } else {
112: efree(slpath);
113: info->path = sopath;
114: errno = serrno;
115: }
116: }
117: }
118: # endif /* __hpux */
119: }
120: done:
121: debug_return_int(status);
122: }
123:
124: static bool
125: sudo_check_plugin(struct plugin_info *info, char *fullpath, size_t pathsize)
126: {
127: struct stat sb;
128: int rval = false;
129: debug_decl(sudo_check_plugin, SUDO_DEBUG_PLUGIN)
130:
131: if (sudo_stat_plugin(info, fullpath, pathsize, &sb) != 0) {
132: warningx(_("error in %s, line %d while loading plugin `%s'"),
133: _PATH_SUDO_CONF, info->lineno, info->symbol_name);
134: warning("%s%s", _PATH_SUDO_PLUGIN_DIR, info->path);
135: goto done;
136: }
137: if (sb.st_uid != ROOT_UID) {
138: warningx(_("error in %s, line %d while loading plugin `%s'"),
139: _PATH_SUDO_CONF, info->lineno, info->symbol_name);
140: warningx(_("%s must be owned by uid %d"), fullpath, ROOT_UID);
141: goto done;
142: }
143: if ((sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) {
144: warningx(_("error in %s, line %d while loading plugin `%s'"),
145: _PATH_SUDO_CONF, info->lineno, info->symbol_name);
146: warningx(_("%s must be only be writable by owner"), fullpath);
147: goto done;
148: }
149: rval = true;
150:
151: done:
152: debug_return_bool(rval);
153: }
154: #else
155: static bool
156: sudo_check_plugin(struct plugin_info *info, char *fullpath, size_t pathsize)
157: {
158: debug_decl(sudo_check_plugin, SUDO_DEBUG_PLUGIN)
159: (void)strlcpy(fullpath, info->path, pathsize);
160: debug_return_bool(true);
161: }
162: #endif /* _PATH_SUDO_PLUGIN_DIR */
163:
164: /*
165: * Load the plugin specified by "info".
166: */
167: static bool
168: sudo_load_plugin(struct plugin_container *policy_plugin,
169: struct plugin_container_list *io_plugins, struct plugin_info *info)
170: {
171: struct plugin_container *container;
172: struct generic_plugin *plugin;
173: char path[PATH_MAX];
174: bool rval = false;
175: void *handle;
176: debug_decl(sudo_load_plugin, SUDO_DEBUG_PLUGIN)
177:
178: /* Sanity check plugin and fill in path */
179: if (!sudo_check_plugin(info, path, sizeof(path)))
180: goto done;
181:
182: /* Open plugin and map in symbol */
183: handle = dlopen(path, RTLD_LAZY|RTLD_GLOBAL);
184: if (!handle) {
185: warningx(_("error in %s, line %d while loading plugin `%s'"),
186: _PATH_SUDO_CONF, info->lineno, info->symbol_name);
187: warningx(_("unable to dlopen %s: %s"), path, dlerror());
188: goto done;
189: }
190: plugin = dlsym(handle, info->symbol_name);
191: if (!plugin) {
192: warningx(_("error in %s, line %d while loading plugin `%s'"),
193: _PATH_SUDO_CONF, info->lineno, info->symbol_name);
194: warningx(_("unable to find symbol `%s' in %s"), info->symbol_name, path);
195: goto done;
196: }
197:
198: if (plugin->type != SUDO_POLICY_PLUGIN && plugin->type != SUDO_IO_PLUGIN) {
199: warningx(_("error in %s, line %d while loading plugin `%s'"),
200: _PATH_SUDO_CONF, info->lineno, info->symbol_name);
201: warningx(_("unknown policy type %d found in %s"), plugin->type, path);
202: goto done;
203: }
204: if (SUDO_API_VERSION_GET_MAJOR(plugin->version) != SUDO_API_VERSION_MAJOR) {
205: warningx(_("error in %s, line %d while loading plugin `%s'"),
206: _PATH_SUDO_CONF, info->lineno, info->symbol_name);
207: warningx(_("incompatible plugin major version %d (expected %d) found in %s"),
208: SUDO_API_VERSION_GET_MAJOR(plugin->version),
209: SUDO_API_VERSION_MAJOR, path);
210: goto done;
211: }
212: if (plugin->type == SUDO_POLICY_PLUGIN) {
213: if (policy_plugin->handle) {
214: /* Ignore duplicate entries. */
215: if (strcmp(policy_plugin->name, info->symbol_name) != 0) {
216: warningx(_("ignoring policy plugin `%s' in %s, line %d"),
217: info->symbol_name, _PATH_SUDO_CONF, info->lineno);
218: warningx(_("only a single policy plugin may be specified"));
219: goto done;
220: }
221: warningx(_("ignoring duplicate policy plugin `%s' in %s, line %d"),
222: info->symbol_name, _PATH_SUDO_CONF, info->lineno);
223: dlclose(handle);
224: handle = NULL;
225: }
226: if (handle != NULL) {
227: policy_plugin->handle = handle;
228: policy_plugin->name = info->symbol_name;
229: policy_plugin->options = info->options;
230: policy_plugin->u.generic = plugin;
231: }
232: } else if (plugin->type == SUDO_IO_PLUGIN) {
233: /* Check for duplicate entries. */
234: tq_foreach_fwd(io_plugins, container) {
235: if (strcmp(container->name, info->symbol_name) == 0) {
236: warningx(_("ignoring duplicate I/O plugin `%s' in %s, line %d"),
237: info->symbol_name, _PATH_SUDO_CONF, info->lineno);
238: dlclose(handle);
239: handle = NULL;
240: break;
241: }
242: }
243: if (handle != NULL) {
244: container = ecalloc(1, sizeof(*container));
245: container->prev = container;
246: /* container->next = NULL; */
247: container->handle = handle;
248: container->name = info->symbol_name;
249: container->options = info->options;
250: container->u.generic = plugin;
251: tq_append(io_plugins, container);
252: }
253: }
254:
255: rval = true;
256: done:
257: debug_return_bool(rval);
258: }
259:
260: /*
261: * Load the plugins listed in sudo.conf.
262: */
263: bool
264: sudo_load_plugins(struct plugin_container *policy_plugin,
265: struct plugin_container_list *io_plugins)
266: {
267: struct plugin_container *container;
268: struct plugin_info_list *plugins;
269: struct plugin_info *info;
270: bool rval = false;
271: debug_decl(sudo_load_plugins, SUDO_DEBUG_PLUGIN)
272:
273: /* Walk the plugin list from sudo.conf, if any. */
274: plugins = sudo_conf_plugins();
275: tq_foreach_fwd(plugins, info) {
276: rval = sudo_load_plugin(policy_plugin, io_plugins, info);
277: if (!rval)
278: goto done;
279: }
280:
281: /*
282: * If no policy plugin, fall back to the default (sudoers).
283: * If there is also no I/O log plugin, sudoers for that too.
284: */
285: if (policy_plugin->handle == NULL) {
286: /* Default policy plugin */
287: info = ecalloc(1, sizeof(*info));
288: info->symbol_name = "sudoers_policy";
289: info->path = SUDOERS_PLUGIN;
290: /* info->options = NULL; */
291: info->prev = info;
292: /* info->next = NULL; */
293: rval = sudo_load_plugin(policy_plugin, io_plugins, info);
294: efree(info);
295: if (!rval)
296: goto done;
297:
298: /* Default I/O plugin */
299: if (tq_empty(io_plugins)) {
300: info = ecalloc(1, sizeof(*info));
301: info->symbol_name = "sudoers_io";
302: info->path = SUDOERS_PLUGIN;
303: /* info->options = NULL; */
304: info->prev = info;
305: /* info->next = NULL; */
306: rval = sudo_load_plugin(policy_plugin, io_plugins, info);
307: efree(info);
308: if (!rval)
309: goto done;
310: }
311: }
312: if (policy_plugin->u.policy->check_policy == NULL) {
313: warningx(_("policy plugin %s does not include a check_policy method"),
314: policy_plugin->name);
315: rval = false;
316: goto done;
317: }
318:
319: /* Install hooks (XXX - later). */
320: if (policy_plugin->u.policy->version >= SUDO_API_MKVERSION(1, 2)) {
321: if (policy_plugin->u.policy->register_hooks != NULL)
322: policy_plugin->u.policy->register_hooks(SUDO_HOOK_VERSION, register_hook);
323: }
324: tq_foreach_fwd(io_plugins, container) {
325: if (container->u.io->version >= SUDO_API_MKVERSION(1, 2)) {
326: if (container->u.io->register_hooks != NULL)
327: container->u.io->register_hooks(SUDO_HOOK_VERSION, register_hook);
328: }
329: }
330:
331: done:
332: debug_return_bool(rval);
333: }
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