Adding upstream version 1.9.13p3.upstream/1.9.13p3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 488 insertions, 0 deletions

diff --git a/src/load_plugins.c b/src/load_plugins.c
new file mode 100644
index 0000000..5575c08
--- /dev/null
+++ b/src/load_plugins.c
@@ -0,0 +1,488 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * 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/stat.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "sudo.h"
+#include "sudo_plugin.h"
+#include "sudo_plugin_int.h"
+#include "sudo_dso.h"
+
+#ifdef ENABLE_SUDO_PLUGIN_API
+static bool
+sudo_qualify_plugin(struct plugin_info *info, char *fullpath, size_t pathsize)
+{
+    const char *plugin_dir = sudo_conf_plugin_dir_path();
+    int len;
+    debug_decl(sudo_stat_plugin, SUDO_DEBUG_PLUGIN);
+
+    if (info->path[0] == '/') {
+	if (strlcpy(fullpath, info->path, pathsize) >= pathsize) {
+	    errno = ENAMETOOLONG;
+	    goto bad;
+	}
+    } else {
+#ifdef STATIC_SUDOERS_PLUGIN
+	/* Check static symbols. */
+	if (strcmp(info->path, _PATH_SUDOERS_PLUGIN) == 0) {
+	    if (strlcpy(fullpath, info->path, pathsize) >= pathsize) {
+		errno = ENAMETOOLONG;
+		goto bad;
+	    }
+	    /* Plugin is static, do not fully-qualify. */
+	    debug_return_bool(true);
+	}
+#endif /* STATIC_SUDOERS_PLUGIN */
+
+	if (plugin_dir == NULL) {
+	    errno = ENOENT;
+	    goto bad;
+	}
+	len = snprintf(fullpath, pathsize, "%s%s", plugin_dir, info->path);
+	if (len < 0 || (size_t)len >= pathsize) {
+	    errno = ENAMETOOLONG;
+	    goto bad;
+	}
+    }
+    debug_return_bool(true);
+bad:
+    sudo_warnx(U_("error in %s, line %d while loading plugin \"%s\""),
+	_PATH_SUDO_CONF, info->lineno, info->symbol_name);
+    if (info->path[0] != '/' && plugin_dir != NULL)
+	sudo_warn("%s%s", plugin_dir, info->path);
+    else
+	sudo_warn("%s", info->path);
+    debug_return_bool(false);
+}
+#else
+static bool
+sudo_qualify_plugin(struct plugin_info *info, char *fullpath, size_t pathsize)
+{
+    debug_decl(sudo_qualify_plugin, SUDO_DEBUG_PLUGIN);
+    (void)strlcpy(fullpath, info->path, pathsize);
+    debug_return_bool(true);
+}
+#endif /* ENABLE_SUDO_PLUGIN_API */
+
+static bool
+fill_container(struct plugin_container *container, void *handle,
+     const char *path, struct generic_plugin *plugin, struct plugin_info *info)
+{
+    debug_decl(fill_container, SUDO_DEBUG_PLUGIN);
+
+    if ((container->path = strdup(path)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	debug_return_bool(false);
+    }
+    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);
+
+    /* Zero out info strings that the container now owns. */
+    info->symbol_name = NULL;
+    info->options = NULL;
+
+    debug_return_bool(true);
+}
+
+static struct plugin_container *
+new_container(void *handle, const char *path, struct generic_plugin *plugin,
+    struct plugin_info *info)
+{
+    struct plugin_container *container;
+    debug_decl(new_container, SUDO_DEBUG_PLUGIN);
+
+    if ((container = calloc(1, sizeof(*container))) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	goto bad;
+    }
+    if (!fill_container(container, handle, path, plugin, info))
+	goto bad;
+
+    debug_return_ptr(container);
+bad:
+    free(container);
+    debug_return_ptr(NULL);
+}
+
+static bool
+plugin_exists(struct plugin_container_list *plugins, const char *symbol_name)
+{
+    struct plugin_container *container;
+    debug_decl(plugin_exists, SUDO_DEBUG_PLUGIN);
+
+    TAILQ_FOREACH(container, plugins, entries) {
+	if (strcmp(container->name, symbol_name) == 0)
+	    debug_return_bool(true);
+    }
+    debug_return_bool(false);
+}
+
+typedef struct generic_plugin * (plugin_clone_func)(void);
+
+static struct generic_plugin *
+sudo_plugin_try_to_clone(void *so_handle, const char *symbol_name)
+{
+    debug_decl(sudo_plugin_try_to_clone, SUDO_DEBUG_PLUGIN);
+    struct generic_plugin *plugin = NULL;
+    plugin_clone_func *clone_func;
+    char *clone_func_name = NULL;
+
+    if (asprintf(&clone_func_name, "%s_clone", symbol_name) < 0) {
+        sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+        goto cleanup;
+    }
+
+    clone_func = (plugin_clone_func *)sudo_dso_findsym(so_handle,
+	clone_func_name);
+    if (clone_func) {
+        plugin = (*clone_func)();
+    }
+
+cleanup:
+    free(clone_func_name);
+    debug_return_ptr(plugin);
+}
+
+static bool
+sudo_insert_plugin(struct plugin_container_list *plugin_list, void *handle,
+     const char *path, struct generic_plugin *plugin, struct plugin_info *info)
+{
+    struct plugin_container *container;
+    debug_decl(sudo_insert_plugin, SUDO_DEBUG_PLUGIN);
+
+    if (plugin_exists(plugin_list, info->symbol_name)) {
+	plugin = sudo_plugin_try_to_clone(handle, info->symbol_name);
+	if (plugin == NULL) {
+	    sudo_warnx(U_("ignoring duplicate plugin \"%s\" in %s, line %d"),
+		info->symbol_name, _PATH_SUDO_CONF, info->lineno);
+	    sudo_dso_unload(handle);
+	    goto done;
+	}
+    }
+
+    if ((container = new_container(handle, path, plugin, info)) == NULL)
+	debug_return_bool(false);
+    TAILQ_INSERT_TAIL(plugin_list, container, entries);
+
+done:
+    debug_return_bool(true);
+}
+
+/*
+ * Load the plugin specified by "info".
+ */
+static bool
+sudo_load_plugin(struct plugin_info *info, bool quiet)
+{
+    struct generic_plugin *plugin;
+    char path[PATH_MAX];
+    void *handle = NULL;
+    bool ret = false;
+    debug_decl(sudo_load_plugin, SUDO_DEBUG_PLUGIN);
+
+    /* Fill in path from info and plugin dir. */
+    if (!sudo_qualify_plugin(info, path, sizeof(path)))
+	goto done;
+
+    /* Open plugin and map in symbol */
+    handle = sudo_dso_load(path, SUDO_DSO_LAZY|SUDO_DSO_GLOBAL);
+    if (!handle) {
+	if (!quiet) {
+	    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 done;
+    }
+    plugin = sudo_dso_findsym(handle, info->symbol_name);
+    if (!plugin) {
+	if (!quiet) {
+	    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 done;
+    }
+
+    if (SUDO_API_VERSION_GET_MAJOR(plugin->version) != SUDO_API_VERSION_MAJOR) {
+	if (!quiet) {
+	    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 done;
+    }
+
+    switch (plugin->type) {
+    case SUDO_POLICY_PLUGIN:
+	if (policy_plugin.handle != NULL) {
+	    /* Ignore duplicate entries. */
+	    if (strcmp(policy_plugin.name, info->symbol_name) == 0) {
+		if (!quiet) {
+		    sudo_warnx(U_("ignoring duplicate plugin \"%s\" in %s, line %d"),
+			info->symbol_name, _PATH_SUDO_CONF, info->lineno);
+		}
+	    } else {
+		if (!quiet) {
+		    sudo_warnx(U_("ignoring policy plugin \"%s\" in %s, line %d"),
+			info->symbol_name, _PATH_SUDO_CONF, info->lineno);
+		    sudo_warnx("%s",
+			U_("only a single policy plugin may be specified"));
+		}
+		goto done;
+	    }
+	    ret = true;
+	    goto done;
+	}
+	if (!fill_container(&policy_plugin, handle, path, plugin, info))
+	    goto done;
+	break;
+    case SUDO_IO_PLUGIN:
+	if (!sudo_insert_plugin(&io_plugins, handle, path, plugin, info))
+	    goto done;
+	break;
+    case SUDO_AUDIT_PLUGIN:
+	if (!sudo_insert_plugin(&audit_plugins, handle, path, plugin, info))
+	    goto done;
+	break;
+    case SUDO_APPROVAL_PLUGIN:
+	if (!sudo_insert_plugin(&approval_plugins, handle, path, plugin, info))
+	    goto done;
+	break;
+    default:
+	if (!quiet) {
+	    sudo_warnx(U_("error in %s, line %d while loading plugin \"%s\""),
+		_PATH_SUDO_CONF, info->lineno, info->symbol_name);
+	    sudo_warnx(U_("unknown plugin type %d found in %s"), plugin->type, path);
+	}
+	goto done;
+    }
+
+    /* Handle is either in use or has been closed. */
+    handle = NULL;
+
+    ret = true;
+
+done:
+    if (handle != NULL)
+	sudo_dso_unload(handle);
+    debug_return_bool(ret);
+}
+
+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);
+}
+
+static void
+sudo_register_hooks(void)
+{
+    struct plugin_container *container;
+    debug_decl(sudo_register_hooks, SUDO_DEBUG_PLUGIN);
+
+    if (policy_plugin.u.policy->version >= SUDO_API_MKVERSION(1, 2)) {
+	if (policy_plugin.u.policy->register_hooks != NULL) {
+	    sudo_debug_set_active_instance(policy_plugin.debug_instance);
+	    policy_plugin.u.policy->register_hooks(SUDO_HOOK_VERSION,
+		register_hook);
+	    sudo_debug_set_active_instance(sudo_debug_instance);
+	}
+    }
+
+    TAILQ_FOREACH(container, &io_plugins, entries) {
+	if (container->u.io->version >= SUDO_API_MKVERSION(1, 2)) {
+	    if (container->u.io->register_hooks != NULL) {
+		sudo_debug_set_active_instance(container->debug_instance);
+		container->u.io->register_hooks(SUDO_HOOK_VERSION,
+		    register_hook);
+		sudo_debug_set_active_instance(sudo_debug_instance);
+	    }
+	}
+    }
+
+    TAILQ_FOREACH(container, &audit_plugins, entries) {
+	if (container->u.audit->register_hooks != NULL) {
+	    sudo_debug_set_active_instance(container->debug_instance);
+	    container->u.audit->register_hooks(SUDO_HOOK_VERSION,
+		register_hook);
+	    sudo_debug_set_active_instance(sudo_debug_instance);
+	}
+    }
+
+    debug_return;
+}
+
+static void
+sudo_init_event_alloc(void)
+{
+    struct plugin_container *container;
+    debug_decl(sudo_init_event_alloc, SUDO_DEBUG_PLUGIN);
+
+    if (policy_plugin.u.policy->version >= SUDO_API_MKVERSION(1, 15))
+	policy_plugin.u.policy->event_alloc = sudo_plugin_event_alloc;
+
+    TAILQ_FOREACH(container, &io_plugins, entries) {
+	if (container->u.io->version >= SUDO_API_MKVERSION(1, 15))
+	    container->u.io->event_alloc = sudo_plugin_event_alloc;
+    }
+    TAILQ_FOREACH(container, &audit_plugins, entries) {
+	if (container->u.audit->version >= SUDO_API_MKVERSION(1, 17))
+	    container->u.audit->event_alloc = sudo_plugin_event_alloc;
+    }
+
+    debug_return;
+}
+
+/*
+ * Load the specified symbol from the sudoers plugin.
+ * Used to provide a default plugin when none are specified in sudo.conf.
+ */
+static bool
+sudo_load_sudoers_plugin(const char *symbol_name, bool optional)
+{
+    struct plugin_info *info;
+    bool ret = false;
+    debug_decl(sudo_load_sudoers_plugin, SUDO_DEBUG_PLUGIN);
+
+    /* 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(symbol_name);
+    info->path = strdup(_PATH_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(info, optional);
+    free_plugin_info(info);
+
+done:
+    debug_return_bool(ret);
+}
+
+/*
+ * Load the plugins listed in sudo.conf.
+ */
+bool
+sudo_load_plugins(void)
+{
+    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(info, false);
+	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 */
+	ret = sudo_load_sudoers_plugin("sudoers_policy", false);
+	if (!ret)
+	    goto done;
+
+	/* Default audit plugin, optional (sudoers < 1.9.1 lack this) */
+	(void)sudo_load_sudoers_plugin("sudoers_audit", true);
+
+	/* Default I/O plugin */
+	if (TAILQ_EMPTY(&io_plugins)) {
+	    ret = sudo_load_sudoers_plugin("sudoers_io", false);
+	    if (!ret)
+		goto done;
+	}
+    } else if (strcmp(policy_plugin.name, "sudoers_policy") == 0) {
+	/*
+	 * If policy plugin is sudoers_policy but there is no sudoers_audit
+	 * loaded, load it too, if possible.
+	 */
+	if (!plugin_exists(&audit_plugins, "sudoers_audit")) {
+	    if (sudo_load_sudoers_plugin("sudoers_audit", true)) {
+		/*
+		 * Move the plugin options from sudoers_policy to sudoers_audit
+		 * since the audit module is now what actually opens sudoers.
+		 */
+		if (policy_plugin.options != NULL) {
+		    TAILQ_LAST(&audit_plugins, plugin_container_list)->options =
+			policy_plugin.options;
+		    policy_plugin.options = NULL;
+		}
+	    }
+	}
+    }
+
+    /* TODO: check all plugins for open function too */
+    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;
+    }
+
+    /* Set event_alloc() in plugins. */
+    sudo_init_event_alloc();
+
+    /* Install hooks (XXX - later, after open). */
+    sudo_register_hooks();
+
+done:
+    debug_return_bool(ret);
+}