--- /dev/null
+/*
+ * Copyright (C) 2014 Red Hat Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above
+ * copyright notice, this list of conditions and the
+ * following disclaimer.
+ * * Redistributions in binary form must reproduce the
+ * above copyright notice, this list of conditions and
+ * the following disclaimer in the documentation and/or
+ * other materials provided with the distribution.
+ * * The names of contributors to this software may not be
+ * used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * Author: Stef Walter <stefw@redhat.com>
+ */
+
+#include "config.h"
+
+#include "compat.h"
+#include "debug.h"
+#include "message.h"
+#include "path.h"
+#include "p11-kit.h"
+#include "remote.h"
+#include "unix-peer.h"
+#include "tool.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <pwd.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#ifdef HAVE_SIGHANDLER_T
+#define SIGHANDLER_T sighandler_t
+#elif HAVE_SIG_T
+#define SIGHANDLER_T sig_t
+#elif HAVE___SIGHANDLER_T
+#define SIGHANDLER_T __sighandler_t
+#else
+typedef void (*sighandler_t)(int);
+#define SIGHANDLER_T sighandler_t
+#endif
+
+static bool need_children_cleanup = false;
+static bool terminate = false;
+static unsigned children_avail = 0;
+static bool quiet = false;
+
+typedef struct {
+ char *module_name;
+
+ uid_t uid;
+ gid_t gid;
+
+ char *pkcs11_address;
+ int pkcs11_socket;
+} Server;
+
+static SIGHANDLER_T
+ocsignal (int signum, SIGHANDLER_T handler)
+{
+ struct sigaction new_action, old_action;
+
+ new_action.sa_handler = handler;
+ sigemptyset (&new_action.sa_mask);
+ new_action.sa_flags = 0;
+
+ sigaction (signum, &new_action, &old_action);
+ return old_action.sa_handler;
+}
+
+static void
+cleanup_children (void)
+{
+ int status;
+ pid_t pid;
+
+ while ((pid = waitpid (-1, &status, WNOHANG)) > 0) {
+ if (children_avail > 0)
+ children_avail--;
+ if (WIFSIGNALED (status)) {
+ if (WTERMSIG (status) == SIGSEGV)
+ p11_message ("child %u died with sigsegv", (unsigned)pid);
+ else
+ p11_message ("child %u died with signal %d", (unsigned)pid, (int)WTERMSIG (status));
+ }
+ }
+ need_children_cleanup = false;
+}
+
+static void
+handle_children (int signo)
+{
+ need_children_cleanup = true;
+}
+
+static void
+handle_term (int signo)
+{
+ terminate = true;
+}
+
+static int
+set_cloexec_on_fd (void *data,
+ int fd)
+{
+ int *max_fd = data;
+ if (fd >= *max_fd)
+ fcntl (fd, F_SETFD, FD_CLOEXEC);
+ return 0;
+}
+
+static int
+exec_external (int argc,
+ char *argv[])
+{
+ const char *private_dir;
+ char *path;
+ int rc;
+
+ return_val_if_fail (argc >= 1, -1);
+
+ private_dir = secure_getenv ("P11_KIT_PRIVATEDIR");
+ if (!private_dir || !private_dir[0])
+ private_dir = PRIVATEDIR;
+
+ /* Add our libexec directory to the path */
+ path = p11_path_build (private_dir, argv[0], NULL);
+ return_val_if_fail (path != NULL, -1);
+
+ argv[argc] = NULL;
+ rc = execv (path, argv);
+
+ free (path);
+ return rc;
+}
+
+static int
+create_socket (const char *address,
+ uid_t uid,
+ gid_t gid)
+{
+ int rc, sd;
+ struct sockaddr_un sa;
+ const char *socket_file;
+
+ memset (&sa, 0, sizeof(sa));
+ sa.sun_family = AF_UNIX;
+
+ return_val_if_fail (strlen (address) < sizeof (sa.sun_path), -1);
+ strncpy (sa.sun_path, address, sizeof (sa.sun_path));
+ socket_file = sa.sun_path;
+
+ remove (sa.sun_path);
+
+ sd = socket (AF_UNIX, SOCK_STREAM, 0);
+ if (sd == -1) {
+ p11_message_err (errno, "could not create socket %s", socket_file);
+ return -1;
+ }
+
+ umask (066);
+ rc = bind (sd, (struct sockaddr *)&sa, SUN_LEN (&sa));
+ if (rc == -1) {
+ p11_message_err (errno, "could not create socket %s", socket_file);
+ return -1;
+ }
+
+ if (uid != -1 && gid != -1) {
+ rc = chown (socket_file, uid, gid);
+ if (rc == -1) {
+ p11_message_err (errno, "could not chown socket %s", socket_file);
+ return -1;
+ }
+ }
+
+ return sd;
+}
+
+static bool
+check_credentials (int fd,
+ uid_t uid,
+ gid_t gid)
+{
+ int rc;
+ uid_t tuid;
+ gid_t tgid;
+
+ rc = p11_get_upeer_id (fd, &tuid, &tgid, NULL);
+ if (rc == -1) {
+ p11_message_err (errno, "could not check uid from socket");
+ close (fd);
+ return false;
+ }
+
+ if (uid != -1 && uid != tuid) {
+ p11_message ("connecting uid (%u) doesn't match expected (%u)",
+ (unsigned)tuid, (unsigned)uid);
+ close (fd);
+ return false;
+ }
+
+ if (gid != -1 && gid != tgid) {
+ p11_message ("connecting gid (%u) doesn't match expected (%u)",
+ (unsigned)tgid, (unsigned)gid);
+ close (fd);
+ return false;
+ }
+
+ return true;
+}
+
+static Server *
+server_new (const char *module_name, const char *socket_base, const char *socket_name, uid_t uid, gid_t gid)
+{
+ Server *server = calloc (1, sizeof (Server));
+ char *name;
+
+ server->module_name = strdup (module_name);
+ return_val_if_fail (server->module_name != NULL, NULL);
+
+ server->uid = uid;
+ server->gid = gid;
+
+ if (socket_name != NULL)
+ name = strdup (socket_name);
+ else if (asprintf (&name, "pkcs11-%d", getpid ()) < 0)
+ return_val_if_reached (NULL);
+
+ server->pkcs11_address = p11_path_build (socket_base, name, NULL);
+ free (name);
+
+ return_val_if_fail (server->pkcs11_address != NULL, NULL);
+ server->pkcs11_socket = -1;
+
+ return server;
+}
+
+static void
+server_free (Server *server)
+{
+ free (server->module_name);
+ free (server->pkcs11_address);
+ if (server->pkcs11_socket >= 0)
+ close (server->pkcs11_socket);
+ free (server);
+}
+
+static int
+server_loop (Server *server,
+ bool foreground,
+ struct timespec *timeout)
+{
+ int ret = 1, rc;
+ int cfd;
+ pid_t pid;
+ socklen_t sa_len;
+ struct sockaddr_un sa;
+ fd_set rd_set;
+ sigset_t emptyset, blockset;
+ char *args[] = { "p11-kit-remote", NULL, NULL };
+ int max_fd;
+ int errn;
+
+ sigemptyset (&blockset);
+ sigemptyset (&emptyset);
+ sigaddset (&blockset, SIGCHLD);
+ sigaddset (&blockset, SIGTERM);
+ sigaddset (&blockset, SIGINT);
+ ocsignal (SIGCHLD, handle_children);
+ ocsignal (SIGTERM, handle_term);
+ ocsignal (SIGINT, handle_term);
+
+ server->pkcs11_socket = create_socket (server->pkcs11_address, server->uid, server->gid);
+ if (server->pkcs11_socket == -1)
+ return 1;
+
+ /* run as daemon */
+ if (!foreground) {
+ pid = fork ();
+ switch (pid) {
+ case -1:
+ p11_message_err (errno, "could not fork() to daemonize");
+ return 1;
+ case 0:
+ break;
+ default:
+ _exit (0);
+ }
+ if (setsid () == -1) {
+ p11_message_err (errno, "could not create a new session");
+ return 1;
+ }
+ }
+
+ rc = listen (server->pkcs11_socket, 1024);
+ if (rc == -1) {
+ p11_message_err (errno, "could not listen to socket %s", server->pkcs11_address);
+ return 1;
+ }
+
+ sigprocmask (SIG_BLOCK, &blockset, NULL);
+
+ if (!quiet) {
+ char *path;
+
+ path = p11_path_encode (server->pkcs11_address);
+ printf ("P11_KIT_SERVER_ADDRESS=unix:path=%s\n", path);
+ free (path);
+ printf ("P11_KIT_SERVER_PID=%d\n", getpid ());
+ }
+
+ /* accept connections */
+ ret = 0;
+ for (;;) {
+ if (need_children_cleanup)
+ cleanup_children ();
+
+ if (terminate)
+ break;
+
+ FD_ZERO (&rd_set);
+ FD_SET (server->pkcs11_socket, &rd_set);
+
+ ret = pselect (server->pkcs11_socket + 1, &rd_set, NULL, NULL, timeout, &emptyset);
+ if (ret == -1 && errno == EINTR)
+ continue;
+
+ if (ret == 0 && children_avail == 0) { /* timeout */
+ p11_message ("no connections to %s for %lu secs, exiting", server->pkcs11_address, timeout->tv_sec);
+ break;
+ }
+
+ if (FD_ISSET (server->pkcs11_socket, &rd_set)) {
+ sa_len = sizeof (sa);
+ cfd = accept (server->pkcs11_socket, (struct sockaddr *)&sa, &sa_len);
+ if (cfd == -1) {
+ if (errno != EINTR)
+ p11_message_err (errno, "could not accept from socket %s", server->pkcs11_address);
+ continue;
+ }
+
+ if (!check_credentials (cfd, server->uid, server->gid))
+ continue;
+
+ pid = fork ();
+ switch (pid) {
+ case -1:
+ p11_message_err (errno, "failed to fork for accept");
+ continue;
+ /* Child */
+ case 0:
+ sigprocmask (SIG_UNBLOCK, &blockset, NULL);
+ if (dup2 (cfd, STDIN_FILENO) < 0 ||
+ dup2 (cfd, STDOUT_FILENO) < 0) {
+ errn = errno;
+ p11_message_err (errn, "couldn't dup file descriptors in remote child");
+ _exit (errn);
+ }
+
+ /* Close file descriptors, except for above on exec */
+ max_fd = STDERR_FILENO + 1;
+ fdwalk (set_cloexec_on_fd, &max_fd);
+
+ /* Execute 'p11-kit remote'; this shouldn't return */
+ args[1] = (char *) server->module_name;
+ exec_external (2, args);
+
+ errn = errno;
+ p11_message_err (errn, "couldn't execute 'p11-kit remote' for module '%s'", server->module_name);
+ _exit (errn);
+ default:
+ children_avail++;
+ break;
+ }
+ close (cfd);
+ }
+ }
+
+ remove (server->pkcs11_address);
+
+ return ret;
+}
+
+int
+main (int argc,
+ char *argv[])
+{
+ char *module_name;
+ char *socket_base;
+ uid_t uid = -1, run_as_uid = -1;
+ gid_t gid = -1, run_as_gid = -1;
+ int opt;
+ const struct passwd *pwd;
+ const struct group *grp;
+ bool foreground = false;
+ struct timespec *timeout = NULL, ts;
+ const char *name = NULL;
+ Server *server;
+ int ret;
+
+ enum {
+ opt_verbose = 'v',
+ opt_quiet = 'q',
+ opt_help = 'h',
+ opt_user = 'u',
+ opt_group = 'g',
+ opt_run_as_user = 'a',
+ opt_run_as_group = 'z',
+ opt_foreground = 'f',
+ opt_timeout = 't',
+ opt_name = 'n',
+ };
+
+ struct option options[] = {
+ { "verbose", no_argument, NULL, opt_verbose },
+ { "quiet", no_argument, NULL, opt_quiet },
+ { "help", no_argument, NULL, opt_help },
+ { "foreground", no_argument, NULL, opt_foreground },
+ { "user", required_argument, NULL, opt_user },
+ { "group", required_argument, NULL, opt_group },
+ { "run-as-user", required_argument, NULL, opt_run_as_user },
+ { "run-as-group", required_argument, NULL, opt_run_as_group },
+ { "timeout", required_argument, NULL, opt_timeout },
+ { "name", required_argument, NULL, opt_name },
+ { 0 },
+ };
+
+ p11_tool_desc usages[] = {
+ { 0, "usage: p11-kit server <token> [<directory>]" },
+ { opt_foreground, "run the server in foreground" },
+ { opt_user, "specify user who can connect to the socket" },
+ { opt_group, "specify group who can connect to the socket" },
+ { opt_run_as_user, "specify user who runs the server" },
+ { opt_run_as_group, "specify group who runs the server" },
+ { opt_timeout, "exit if no connection until the given timeout" },
+ { opt_name, "specify name of the socket (default: pkcs11-<pid>" },
+ { 0 },
+ };
+
+ while ((opt = p11_tool_getopt (argc, argv, options)) != -1) {
+ switch (opt) {
+ case opt_verbose:
+ p11_kit_be_loud ();
+ break;
+ case opt_quiet:
+ quiet = true;
+ break;
+ case opt_timeout:
+ ts.tv_sec = atoi (optarg);
+ ts.tv_nsec = 0;
+ timeout = &ts;
+ break;
+ case opt_name:
+ name = optarg;
+ break;
+ case opt_group:
+ grp = getgrnam (optarg);
+ if (grp == NULL) {
+ p11_message ("unknown group: %s", optarg);
+ return 2;
+ }
+ gid = grp->gr_gid;
+ break;
+ case opt_user:
+ pwd = getpwnam (optarg);
+ if (pwd == NULL) {
+ p11_message ("unknown user: %s", optarg);
+ return 2;
+ }
+ uid = pwd->pw_uid;
+ break;
+ case opt_run_as_group:
+ grp = getgrnam (optarg);
+ if (grp == NULL) {
+ p11_message ("unknown group: %s", optarg);
+ return 2;
+ }
+ run_as_gid = grp->gr_gid;
+ break;
+ case opt_run_as_user:
+ pwd = getpwnam (optarg);
+ if (pwd == NULL) {
+ p11_message ("unknown user: %s", optarg);
+ return 2;
+ }
+ run_as_uid = pwd->pw_uid;
+ break;
+ case opt_foreground:
+ foreground = true;
+ break;
+ case opt_help:
+ case '?':
+ p11_tool_usage (usages, options);
+ return 0;
+ default:
+ assert_not_reached ();
+ break;
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+
+ if (!(argc >= 1 && argc <= 2)) {
+ p11_tool_usage (usages, options);
+ return 2;
+ }
+
+ module_name = argv[0];
+
+ if (argc == 2)
+ socket_base = argv[1];
+ else {
+ const char *runtime_dir = secure_getenv ("XDG_RUNTIME_DIR");
+ if (!runtime_dir || !runtime_dir[0]) {
+ p11_message_err (errno, "cannot determine runtime directory");
+ return 1;
+ }
+ socket_base = p11_path_build (runtime_dir, "p11-kit", NULL);
+ return_val_if_fail (socket_base != NULL, 1);
+ mkdir (socket_base, 0700);
+ }
+
+ if (run_as_gid != -1) {
+ if (setgid (run_as_gid) == -1) {
+ p11_message_err (errno, "cannot set gid to %u", (unsigned)run_as_gid);
+ return 1;
+ }
+
+ if (setgroups (1, &run_as_gid) == -1) {
+ p11_message_err (errno, "cannot setgroups to %u", (unsigned)run_as_gid);
+ return 1;
+ }
+ }
+
+ if (run_as_uid != -1) {
+ if (setuid (run_as_uid) == -1) {
+ p11_message_err (errno, "cannot set uid to %u", (unsigned)run_as_uid);
+ return 1;
+ }
+ }
+
+ server = server_new (module_name, socket_base, name, uid, gid);
+ ret = server_loop (server, foreground, timeout);
+ server_free (server);
+ remove (socket_base);
+
+ return ret;
+}
projects / p11-kit / commitdiff