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-rw-r--r--src/load_plugins.c369
1 files changed, 369 insertions, 0 deletions
diff --git a/src/load_plugins.c b/src/load_plugins.c
new file mode 100644
index 0000000..8cac77b
--- /dev/null
+++ b/src/load_plugins.c
@@ -0,0 +1,369 @@
+/*
+ * Copyright (c) 2009-2018 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif /* HAVE_STRINGS_H */
+#include <unistd.h>
+#include <errno.h>
+
+#include "sudo.h"
+#include "sudo_plugin.h"
+#include "sudo_plugin_int.h"
+#include "sudo_dso.h"
+
+/* We always use the same name for the sudoers plugin, regardless of the OS */
+#define SUDOERS_PLUGIN "sudoers.so"
+
+#ifdef ENABLE_SUDO_PLUGIN_API
+static int
+sudo_stat_plugin(struct plugin_info *info, char *fullpath,
+ size_t pathsize, struct stat *sb)
+{
+ int status = -1;
+ debug_decl(sudo_stat_plugin, SUDO_DEBUG_PLUGIN)
+
+ if (info->path[0] == '/') {
+ if (strlcpy(fullpath, info->path, pathsize) >= pathsize) {
+ sudo_warnx(U_("error in %s, line %d while loading plugin \"%s\""),
+ _PATH_SUDO_CONF, info->lineno, info->symbol_name);
+ sudo_warnx(U_("%s: %s"), info->path, strerror(ENAMETOOLONG));
+ goto done;
+ }
+ status = stat(fullpath, sb);
+ } else {
+ int len;
+
+#ifdef STATIC_SUDOERS_PLUGIN
+ /* Check static symbols. */
+ if (strcmp(info->path, SUDOERS_PLUGIN) == 0) {
+ if (strlcpy(fullpath, info->path, pathsize) >= pathsize) {
+ sudo_warnx(U_("error in %s, line %d while loading plugin \"%s\""),
+ _PATH_SUDO_CONF, info->lineno, info->symbol_name);
+ sudo_warnx(U_("%s: %s"), info->path, strerror(ENAMETOOLONG));
+ goto done;
+ }
+ /* Plugin is static, fake up struct stat. */
+ memset(sb, 0, sizeof(*sb));
+ sb->st_uid = ROOT_UID;
+ sb->st_mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH;
+ status = 0;
+ goto done;
+ }
+#endif /* STATIC_SUDOERS_PLUGIN */
+
+ if (sudo_conf_plugin_dir_path() == NULL) {
+ errno = ENOENT;
+ goto done;
+ }
+
+ len = snprintf(fullpath, pathsize, "%s%s", sudo_conf_plugin_dir_path(),
+ info->path);
+ if (len <= 0 || (size_t)len >= pathsize) {
+ sudo_warnx(U_("error in %s, line %d while loading plugin \"%s\""),
+ _PATH_SUDO_CONF, info->lineno, info->symbol_name);
+ sudo_warnx(U_("%s%s: %s"), sudo_conf_plugin_dir_path(), info->path,
+ strerror(ENAMETOOLONG));
+ goto done;
+ }
+ /* Try parent dir for compatibility with old plugindir default. */
+ if ((status = stat(fullpath, sb)) != 0) {
+ char *cp = strrchr(fullpath, '/');
+ if (cp > fullpath + 4 && cp[-5] == '/' && cp[-4] == 's' &&
+ cp[-3] == 'u' && cp[-2] == 'd' && cp[-1] == 'o') {
+ int serrno = errno;
+ strlcpy(cp - 4, info->path, pathsize - (cp - 4 - fullpath));
+ if ((status = stat(fullpath, sb)) != 0)
+ errno = serrno;
+ }
+ }
+ }
+done:
+ debug_return_int(status);
+}
+
+static bool
+sudo_check_plugin(struct plugin_info *info, char *fullpath, size_t pathsize)
+{
+ struct stat sb;
+ bool ret = false;
+ debug_decl(sudo_check_plugin, SUDO_DEBUG_PLUGIN)
+
+ if (sudo_stat_plugin(info, fullpath, pathsize, &sb) != 0) {
+ sudo_warnx(U_("error in %s, line %d while loading plugin \"%s\""),
+ _PATH_SUDO_CONF, info->lineno, info->symbol_name);
+ sudo_warn("%s%s",
+ sudo_conf_plugin_dir_path() ? sudo_conf_plugin_dir_path() : "",
+ info->path);
+ goto done;
+ }
+ if (sb.st_uid != ROOT_UID) {
+ sudo_warnx(U_("error in %s, line %d while loading plugin \"%s\""),
+ _PATH_SUDO_CONF, info->lineno, info->symbol_name);
+ sudo_warnx(U_("%s must be owned by uid %d"), fullpath, ROOT_UID);
+ goto done;
+ }
+ if ((sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) {
+ sudo_warnx(U_("error in %s, line %d while loading plugin \"%s\""),
+ _PATH_SUDO_CONF, info->lineno, info->symbol_name);
+ sudo_warnx(U_("%s must be only be writable by owner"), fullpath);
+ goto done;
+ }
+ ret = true;
+
+done:
+ debug_return_bool(ret);
+}
+#else
+static bool
+sudo_check_plugin(struct plugin_info *info, char *fullpath, size_t pathsize)
+{
+ debug_decl(sudo_check_plugin, SUDO_DEBUG_PLUGIN)
+ (void)strlcpy(fullpath, info->path, pathsize);
+ debug_return_bool(true);
+}
+#endif /* ENABLE_SUDO_PLUGIN_API */
+
+/*
+ * Load the plugin specified by "info".
+ */
+static bool
+sudo_load_plugin(struct plugin_container *policy_plugin,
+ struct plugin_container_list *io_plugins, struct plugin_info *info)
+{
+ struct plugin_container *container = NULL;
+ struct generic_plugin *plugin;
+ char path[PATH_MAX];
+ void *handle = NULL;
+ debug_decl(sudo_load_plugin, SUDO_DEBUG_PLUGIN)
+
+ /* Sanity check plugin and fill in path */
+ if (!sudo_check_plugin(info, path, sizeof(path)))
+ goto bad;
+
+ /* Open plugin and map in symbol */
+ handle = sudo_dso_load(path, SUDO_DSO_LAZY|SUDO_DSO_GLOBAL);
+ if (!handle) {
+ const char *errstr = sudo_dso_strerror();
+ sudo_warnx(U_("error in %s, line %d while loading plugin \"%s\""),
+ _PATH_SUDO_CONF, info->lineno, info->symbol_name);
+ sudo_warnx(U_("unable to load %s: %s"), path,
+ errstr ? errstr : "unknown error");
+ goto bad;
+ }
+ plugin = sudo_dso_findsym(handle, info->symbol_name);
+ if (!plugin) {
+ sudo_warnx(U_("error in %s, line %d while loading plugin \"%s\""),
+ _PATH_SUDO_CONF, info->lineno, info->symbol_name);
+ sudo_warnx(U_("unable to find symbol \"%s\" in %s"), info->symbol_name, path);
+ goto bad;
+ }
+
+ if (plugin->type != SUDO_POLICY_PLUGIN && plugin->type != SUDO_IO_PLUGIN) {
+ sudo_warnx(U_("error in %s, line %d while loading plugin \"%s\""),
+ _PATH_SUDO_CONF, info->lineno, info->symbol_name);
+ sudo_warnx(U_("unknown policy type %d found in %s"), plugin->type, path);
+ goto bad;
+ }
+ if (SUDO_API_VERSION_GET_MAJOR(plugin->version) != SUDO_API_VERSION_MAJOR) {
+ sudo_warnx(U_("error in %s, line %d while loading plugin \"%s\""),
+ _PATH_SUDO_CONF, info->lineno, info->symbol_name);
+ sudo_warnx(U_("incompatible plugin major version %d (expected %d) found in %s"),
+ SUDO_API_VERSION_GET_MAJOR(plugin->version),
+ SUDO_API_VERSION_MAJOR, path);
+ goto bad;
+ }
+ if (plugin->type == SUDO_POLICY_PLUGIN) {
+ if (policy_plugin->handle != NULL) {
+ /* Ignore duplicate entries. */
+ if (strcmp(policy_plugin->name, info->symbol_name) != 0) {
+ sudo_warnx(U_("ignoring policy plugin \"%s\" in %s, line %d"),
+ info->symbol_name, _PATH_SUDO_CONF, info->lineno);
+ sudo_warnx(U_("only a single policy plugin may be specified"));
+ goto bad;
+ }
+ sudo_warnx(U_("ignoring duplicate policy plugin \"%s\" in %s, line %d"),
+ info->symbol_name, _PATH_SUDO_CONF, info->lineno);
+ goto bad;
+ }
+ policy_plugin->handle = handle;
+ policy_plugin->path = strdup(path);
+ if (policy_plugin->path == NULL) {
+ sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+ goto bad;
+ }
+ policy_plugin->name = info->symbol_name;
+ policy_plugin->options = info->options;
+ policy_plugin->debug_instance = SUDO_DEBUG_INSTANCE_INITIALIZER;
+ policy_plugin->u.generic = plugin;
+ policy_plugin->debug_files = sudo_conf_debug_files(path);
+ } else if (plugin->type == SUDO_IO_PLUGIN) {
+ /* Check for duplicate entries. */
+ TAILQ_FOREACH(container, io_plugins, entries) {
+ if (strcmp(container->name, info->symbol_name) == 0) {
+ sudo_warnx(U_("ignoring duplicate I/O plugin \"%s\" in %s, line %d"),
+ info->symbol_name, _PATH_SUDO_CONF, info->lineno);
+ sudo_dso_unload(handle);
+ handle = NULL;
+ break;
+ }
+ }
+ container = calloc(1, sizeof(*container));
+ if (container == NULL || (container->path = strdup(path)) == NULL) {
+ sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+ goto bad;
+ }
+ container->handle = handle;
+ container->name = info->symbol_name;
+ container->options = info->options;
+ container->debug_instance = SUDO_DEBUG_INSTANCE_INITIALIZER;
+ container->u.generic = plugin;
+ container->debug_files = sudo_conf_debug_files(path);
+ TAILQ_INSERT_TAIL(io_plugins, container, entries);
+ }
+
+ /* Zero out info strings that we now own (see above). */
+ info->symbol_name = NULL;
+ info->options = NULL;
+
+ debug_return_bool(true);
+bad:
+ free(container);
+ if (handle != NULL)
+ sudo_dso_unload(handle);
+ debug_return_bool(false);
+}
+
+static void
+free_plugin_info(struct plugin_info *info)
+{
+ free(info->path);
+ free(info->symbol_name);
+ if (info->options != NULL) {
+ int i = 0;
+ while (info->options[i] != NULL)
+ free(info->options[i++]);
+ free(info->options);
+ }
+ free(info);
+}
+
+/*
+ * Load the plugins listed in sudo.conf.
+ */
+bool
+sudo_load_plugins(struct plugin_container *policy_plugin,
+ struct plugin_container_list *io_plugins)
+{
+ struct plugin_container *container;
+ struct plugin_info_list *plugins;
+ struct plugin_info *info, *next;
+ bool ret = false;
+ debug_decl(sudo_load_plugins, SUDO_DEBUG_PLUGIN)
+
+ /* Walk the plugin list from sudo.conf, if any and free it. */
+ plugins = sudo_conf_plugins();
+ TAILQ_FOREACH_SAFE(info, plugins, entries, next) {
+ ret = sudo_load_plugin(policy_plugin, io_plugins, info);
+ if (!ret)
+ goto done;
+ free_plugin_info(info);
+ }
+ TAILQ_INIT(plugins);
+
+ /*
+ * If no policy plugin, fall back to the default (sudoers).
+ * If there is also no I/O log plugin, use sudoers for that too.
+ */
+ if (policy_plugin->handle == NULL) {
+ /* Default policy plugin */
+ info = calloc(1, sizeof(*info));
+ if (info == NULL) {
+ sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+ goto done;
+ }
+ info->symbol_name = strdup("sudoers_policy");
+ info->path = strdup(SUDOERS_PLUGIN);
+ if (info->symbol_name == NULL || info->path == NULL) {
+ sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+ free_plugin_info(info);
+ goto done;
+ }
+ /* info->options = NULL; */
+ ret = sudo_load_plugin(policy_plugin, io_plugins, info);
+ free_plugin_info(info);
+ if (!ret)
+ goto done;
+
+ /* Default I/O plugin */
+ if (TAILQ_EMPTY(io_plugins)) {
+ info = calloc(1, sizeof(*info));
+ if (info == NULL) {
+ sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+ goto done;
+ }
+ info->symbol_name = strdup("sudoers_io");
+ info->path = strdup(SUDOERS_PLUGIN);
+ if (info->symbol_name == NULL || info->path == NULL) {
+ sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+ free_plugin_info(info);
+ goto done;
+ }
+ /* info->options = NULL; */
+ ret = sudo_load_plugin(policy_plugin, io_plugins, info);
+ free_plugin_info(info);
+ if (!ret)
+ goto done;
+ }
+ }
+ if (policy_plugin->u.policy->check_policy == NULL) {
+ sudo_warnx(U_("policy plugin %s does not include a check_policy method"),
+ policy_plugin->name);
+ ret = false;
+ goto done;
+ }
+
+ /* Install hooks (XXX - later). */
+ sudo_debug_set_active_instance(SUDO_DEBUG_INSTANCE_INITIALIZER);
+ if (policy_plugin->u.policy->version >= SUDO_API_MKVERSION(1, 2)) {
+ if (policy_plugin->u.policy->register_hooks != NULL)
+ policy_plugin->u.policy->register_hooks(SUDO_HOOK_VERSION, register_hook);
+ }
+ TAILQ_FOREACH(container, io_plugins, entries) {
+ if (container->u.io->version >= SUDO_API_MKVERSION(1, 2)) {
+ if (container->u.io->register_hooks != NULL)
+ container->u.io->register_hooks(SUDO_HOOK_VERSION, register_hook);
+ }
+ }
+ sudo_debug_set_active_instance(sudo_debug_instance);
+
+done:
+ debug_return_bool(ret);
+}