Adding upstream version 1.8.27.upstream/1.8.27upstream

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

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);
+}