/*
* Copyright (c) 2009-2011 Todd C. Miller <Todd.Miller@courtesan.com>
*
* 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.
*/
#include <config.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
# include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#ifdef HAVE_STRING_H
# include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */
#ifdef HAVE_DLOPEN
# include <dlfcn.h>
#else
# include "compat/dlfcn.h"
#endif
#include <errno.h>
#include "sudo.h"
#include "sudo_plugin.h"
#include "sudo_plugin_int.h"
#ifndef RTLD_GLOBAL
# define RTLD_GLOBAL 0
#endif
#ifdef _PATH_SUDO_NOEXEC
const char *noexec_path = _PATH_SUDO_NOEXEC;
#endif
/*
* Read in /etc/sudo.conf
* Returns a list of plugins.
*/
static struct plugin_info_list *
sudo_read_conf(const char *conf_file)
{
FILE *fp;
char *cp, *name, *path;
struct plugin_info *info;
static struct plugin_info_list pil; /* XXX */
if ((fp = fopen(conf_file, "r")) == NULL)
goto done;
while ((cp = sudo_parseln(fp)) != NULL) {
/* Skip blank or comment lines */
if (*cp == '\0')
continue;
/* Look for a line starting with "Path" */
if (strncasecmp(cp, "Path", 4) == 0) {
/* Parse line */
if ((name = strtok(cp + 4, " \t")) == NULL ||
(path = strtok(NULL, " \t")) == NULL) {
continue;
}
if (strcasecmp(name, "askpass") == 0)
askpass_path = estrdup(path);
#ifdef _PATH_SUDO_NOEXEC
else if (strcasecmp(name, "noexec") == 0)
noexec_path = estrdup(path);
#endif
continue;
}
/* Look for a line starting with "Plugin" */
if (strncasecmp(cp, "Plugin", 6) == 0) {
/* Parse line */
if ((name = strtok(cp + 6, " \t")) == NULL ||
(path = strtok(NULL, " \t")) == NULL) {
continue;
}
info = emalloc(sizeof(*info));
info->symbol_name = estrdup(name);
info->path = estrdup(path);
info->prev = info;
info->next = NULL;
tq_append(&pil, info);
continue;
}
}
fclose(fp);
done:
if (tq_empty(&pil)) {
/* Default policy plugin */
info = emalloc(sizeof(*info));
info->symbol_name = "sudoers_policy";
info->path = SUDOERS_PLUGIN;
info->prev = info;
info->next = NULL;
tq_append(&pil, info);
/* Default I/O plugin */
info = emalloc(sizeof(*info));
info->symbol_name = "sudoers_io";
info->path = SUDOERS_PLUGIN;
info->prev = info;
info->next = NULL;
tq_append(&pil, info);
}
return &pil;
}
/*
* Load the plugins listed in conf_file.
*/
int
sudo_load_plugins(const char *conf_file,
struct plugin_container *policy_plugin,
struct plugin_container_list *io_plugins)
{
struct generic_plugin *plugin;
struct plugin_container *container;
struct plugin_info *info;
struct plugin_info_list *plugin_list;
struct stat sb;
void *handle;
char path[PATH_MAX];
int rval = FALSE;
/* Parse sudo.conf */
plugin_list = sudo_read_conf(conf_file);
tq_foreach_fwd(plugin_list, info) {
if (info->path[0] == '/') {
if (strlcpy(path, info->path, sizeof(path)) >= sizeof(path)) {
warningx(_("%s: %s"), info->path, strerror(ENAMETOOLONG));
goto done;
}
} else {
if (snprintf(path, sizeof(path), "%s%s", _PATH_SUDO_PLUGIN_DIR,
info->path) >= sizeof(path)) {
warningx(_("%s%s: %s"), _PATH_SUDO_PLUGIN_DIR, info->path,
strerror(ENAMETOOLONG));
goto done;
}
}
if (stat(path, &sb) != 0) {
warning("%s", path);
goto done;
}
if (sb.st_uid != ROOT_UID) {
warningx(_("%s must be owned by uid %d"), path, ROOT_UID);
goto done;
}
if ((sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) {
warningx(_("%s must be only be writable by owner"), path);
goto done;
}
/* Open plugin and map in symbol */
handle = dlopen(path, RTLD_LAZY|RTLD_GLOBAL);
if (!handle) {
warningx(_("unable to dlopen %s: %s"), path, dlerror());
goto done;
}
plugin = dlsym(handle, info->symbol_name);
if (!plugin) {
warningx(_("%s: unable to find symbol %s"), path,
info->symbol_name);
goto done;
}
if (plugin->type != SUDO_POLICY_PLUGIN && plugin->type != SUDO_IO_PLUGIN) {
warningx(_("%s: unknown policy type %d"), path, plugin->type);
goto done;
}
if (SUDO_API_VERSION_GET_MAJOR(plugin->version) != SUDO_API_VERSION_MAJOR) {
warningx(_("%s: incompatible policy major version %d, expected %d"),
path, SUDO_API_VERSION_GET_MAJOR(plugin->version),
SUDO_API_VERSION_MAJOR);
goto done;
}
if (plugin->type == SUDO_POLICY_PLUGIN) {
if (policy_plugin->handle) {
warningx(_("%s: only a single policy plugin may be loaded"),
conf_file);
goto done;
}
policy_plugin->handle = handle;
policy_plugin->name = info->symbol_name;
policy_plugin->u.generic = plugin;
} else if (plugin->type == SUDO_IO_PLUGIN) {
container = emalloc(sizeof(*container));
container->prev = container;
container->next = NULL;
container->handle = handle;
container->name = info->symbol_name;
container->u.generic = plugin;
tq_append(io_plugins, container);
}
}
if (policy_plugin->handle == NULL) {
warningx(_("%s: at least one policy plugin must be specified"),
conf_file);
goto done;
}
if (policy_plugin->u.policy->check_policy == NULL) {
warningx(_("policy plugin %s does not include a check_policy method"),
policy_plugin->name);
goto done;
}
rval = TRUE;
done:
return rval;
}
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