* Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
* Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the Free
- * Software Foundation; only version 2 of the License.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2 only,
+ * as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
- * Place - Suite 330, Boston, MA 02111-1307, USA.
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#define _GNU_SOURCE
+#define _LGPL_SOURCE
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <fcntl.h>
#include <sched.h>
#include <sys/signal.h>
+#include <assert.h>
+#include <signal.h>
-#include <common/error.h>
-#include <common/compat/mman.h>
-#include <common/compat/clone.h>
+#include <common/common.h>
+#include <common/utils.h>
+#include <common/compat/getenv.h>
+#include <common/compat/prctl.h>
+#include <common/sessiond-comm/unix.h>
#include "runas.h"
-#define RUNAS_CHILD_STACK_SIZE 10485760
+struct run_as_data;
+typedef int (*run_as_fct)(struct run_as_data *data);
-#ifndef __FreeBSD__
-# ifndef MAP_STACK
-# define MAP_STACK 0
-# endif
-#else /* FreeBSD MAP_STACK always return -ENOMEM */
-# define MAP_STACK 0
-#endif
+struct run_as_mkdir_data {
+ char path[PATH_MAX];
+ mode_t mode;
+};
-#ifndef MAP_GROWSDOWN
-#define MAP_GROWSDOWN 0
-#endif
+struct run_as_open_data {
+ char path[PATH_MAX];
+ int flags;
+ mode_t mode;
+};
-#ifndef MAP_ANONYMOUS
-#define MAP_ANONYMOUS MAP_ANON
-#endif
+struct run_as_unlink_data {
+ char path[PATH_MAX];
+};
+
+struct run_as_rmdir_recursive_data {
+ char path[PATH_MAX];
+};
+
+enum run_as_cmd {
+ RUN_AS_MKDIR,
+ RUN_AS_OPEN,
+ RUN_AS_UNLINK,
+ RUN_AS_RMDIR_RECURSIVE,
+ RUN_AS_MKDIR_RECURSIVE,
+};
struct run_as_data {
- int (*cmd)(void *data);
- void *data;
+ enum run_as_cmd cmd;
+ union {
+ struct run_as_mkdir_data mkdir;
+ struct run_as_open_data open;
+ struct run_as_unlink_data unlink;
+ struct run_as_rmdir_recursive_data rmdir_recursive;
+ } u;
uid_t uid;
gid_t gid;
- int retval_pipe;
};
-struct run_as_mkdir_data {
- const char *path;
- mode_t mode;
+struct run_as_ret {
+ int ret;
+ int _errno;
};
-struct run_as_open_data {
- const char *path;
- int flags;
- mode_t mode;
+struct run_as_worker {
+ pid_t pid; /* Worker PID. */
+ int sockpair[2];
+ char *procname;
};
+/* Single global worker per process (for now). */
+static struct run_as_worker *global_worker;
+/* Lock protecting the worker. */
+static pthread_mutex_t worker_lock = PTHREAD_MUTEX_INITIALIZER;
+
+#ifdef VALGRIND
+static
+int use_clone(void)
+{
+ return 0;
+}
+#else
+static
+int use_clone(void)
+{
+ return !lttng_secure_getenv("LTTNG_DEBUG_NOCLONE");
+}
+#endif
+
+LTTNG_HIDDEN
+int _utils_mkdir_recursive_unsafe(const char *path, mode_t mode);
+
/*
* Create recursively directory using the FULL path.
*/
static
-int _mkdir_recursive(void *_data)
+int _mkdir_recursive(struct run_as_data *data)
{
- struct run_as_mkdir_data *data = _data;
const char *path;
- char *p, tmp[PATH_MAX];
- struct stat statbuf;
mode_t mode;
- size_t len;
- int ret;
- path = data->path;
- mode = data->mode;
-
- ret = snprintf(tmp, sizeof(tmp), "%s", path);
- if (ret < 0) {
- PERROR("snprintf mkdir");
- goto error;
- }
-
- len = ret;
- if (tmp[len - 1] == '/') {
- tmp[len - 1] = 0;
- }
-
- for (p = tmp + 1; *p; p++) {
- if (*p == '/') {
- *p = 0;
- ret = stat(tmp, &statbuf);
- if (ret < 0) {
- ret = mkdir(tmp, mode);
- if (ret < 0) {
- if (!(errno == EEXIST)) {
- PERROR("mkdir recursive");
- ret = -errno;
- goto error;
- }
- }
- }
- *p = '/';
- }
- }
+ path = data->u.mkdir.path;
+ mode = data->u.mkdir.mode;
- ret = mkdir(tmp, mode);
- if (ret < 0) {
- if (!(errno == EEXIST)) {
- PERROR("mkdir recursive last piece");
- ret = -errno;
- } else {
- ret = 0;
- }
- }
+ /* Safe to call as we have transitioned to the requested uid/gid. */
+ return _utils_mkdir_recursive_unsafe(path, mode);
+}
-error:
- return ret;
+static
+int _mkdir(struct run_as_data *data)
+{
+ return mkdir(data->u.mkdir.path, data->u.mkdir.mode);
}
static
-int _mkdir(void *_data)
+int _open(struct run_as_data *data)
{
- struct run_as_mkdir_data *data = _data;
- return mkdir(data->path, data->mode);
+ return open(data->u.open.path, data->u.open.flags, data->u.open.mode);
}
static
-int _open(void *_data)
+int _unlink(struct run_as_data *data)
{
- struct run_as_open_data *data = _data;
- return open(data->path, data->flags, data->mode);
+ return unlink(data->u.unlink.path);
}
static
-int child_run_as(void *_data)
+int _rmdir_recursive(struct run_as_data *data)
{
- struct run_as_data *data = _data;
- size_t writelen, writeleft, index;
- union {
- int i;
- char c[sizeof(int)];
- } sendret;
- int ret;
+ return utils_recursive_rmdir(data->u.rmdir_recursive.path);
+}
- /*
- * Child: it is safe to drop egid and euid while sharing the
- * file descriptors with the parent process, since we do not
- * drop "uid": therefore, the user we are dropping egid/euid to
- * cannot attach to this process with, e.g. ptrace, nor map this
- * process memory.
- */
- if (data->gid != getegid()) {
- ret = setegid(data->gid);
+static
+run_as_fct run_as_enum_to_fct(enum run_as_cmd cmd)
+{
+ switch (cmd) {
+ case RUN_AS_MKDIR:
+ return _mkdir;
+ case RUN_AS_OPEN:
+ return _open;
+ case RUN_AS_UNLINK:
+ return _unlink;
+ case RUN_AS_RMDIR_RECURSIVE:
+ return _rmdir_recursive;
+ case RUN_AS_MKDIR_RECURSIVE:
+ return _mkdir_recursive;
+ default:
+ ERR("Unknown command %d", (int) cmd)
+ return NULL;
+ }
+}
+
+static
+int do_send_fd(struct run_as_worker *worker,
+ enum run_as_cmd cmd, int fd)
+{
+ ssize_t len;
+
+ switch (cmd) {
+ case RUN_AS_OPEN:
+ break;
+ default:
+ return 0;
+ }
+ if (fd < 0) {
+ return 0;
+ }
+ len = lttcomm_send_fds_unix_sock(worker->sockpair[1], &fd, 1);
+ if (len < 0) {
+ PERROR("lttcomm_send_fds_unix_sock");
+ return -1;
+ }
+ if (close(fd) < 0) {
+ PERROR("close");
+ return -1;
+ }
+ return 0;
+}
+
+static
+int do_recv_fd(struct run_as_worker *worker,
+ enum run_as_cmd cmd, int *fd)
+{
+ ssize_t len;
+
+ switch (cmd) {
+ case RUN_AS_OPEN:
+ break;
+ default:
+ return 0;
+ }
+ if (*fd < 0) {
+ return 0;
+ }
+ len = lttcomm_recv_fds_unix_sock(worker->sockpair[0], fd, 1);
+ if (!len) {
+ return -1;
+ } else if (len < 0) {
+ PERROR("lttcomm_recv_fds_unix_sock");
+ return -1;
+ }
+ return 0;
+}
+
+/*
+ * Return < 0 on error, 0 if OK, 1 on hangup.
+ */
+static
+int handle_one_cmd(struct run_as_worker *worker)
+{
+ int ret = 0;
+ struct run_as_data data;
+ ssize_t readlen, writelen;
+ struct run_as_ret sendret;
+ run_as_fct cmd;
+ uid_t prev_euid;
+
+ /* Read data */
+ readlen = lttcomm_recv_unix_sock(worker->sockpair[1], &data,
+ sizeof(data));
+ if (readlen == 0) {
+ /* hang up */
+ ret = 1;
+ goto end;
+ }
+ if (readlen < sizeof(data)) {
+ PERROR("lttcomm_recv_unix_sock error");
+ ret = -1;
+ goto end;
+ }
+
+ cmd = run_as_enum_to_fct(data.cmd);
+ if (!cmd) {
+ ret = -1;
+ goto end;
+ }
+
+ prev_euid = getuid();
+ if (data.gid != getegid()) {
+ ret = setegid(data.gid);
if (ret < 0) {
- perror("setegid");
- return EXIT_FAILURE;
+ PERROR("setegid");
+ goto write_return;
}
}
- if (data->uid != geteuid()) {
- ret = seteuid(data->uid);
+ if (data.uid != prev_euid) {
+ ret = seteuid(data.uid);
if (ret < 0) {
- perror("seteuid");
- return EXIT_FAILURE;
+ PERROR("seteuid");
+ goto write_return;
}
}
/*
* Also set umask to 0 for mkdir executable bit.
*/
umask(0);
- sendret.i = (*data->cmd)(data->data);
+ ret = (*cmd)(&data);
+
+write_return:
+ sendret.ret = ret;
+ sendret._errno = errno;
/* send back return value */
- writeleft = sizeof(sendret);
- index = 0;
- do {
- writelen = write(data->retval_pipe, &sendret.c[index],
- writeleft);
- if (writelen < 0) {
- perror("write");
- return EXIT_FAILURE;
+ writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret,
+ sizeof(sendret));
+ if (writelen < sizeof(sendret)) {
+ PERROR("lttcomm_send_unix_sock error");
+ ret = -1;
+ goto end;
+ }
+ ret = do_send_fd(worker, data.cmd, ret);
+ if (ret) {
+ PERROR("do_send_fd error");
+ ret = -1;
+ goto end;
+ }
+ if (seteuid(prev_euid) < 0) {
+ PERROR("seteuid");
+ ret = -1;
+ goto end;
+ }
+ ret = 0;
+end:
+ return ret;
+}
+
+static
+int run_as_worker(struct run_as_worker *worker)
+{
+ int ret;
+ ssize_t writelen;
+ struct run_as_ret sendret;
+ size_t proc_orig_len;
+
+ /*
+ * Initialize worker. Set a different process cmdline.
+ */
+ proc_orig_len = strlen(worker->procname);
+ memset(worker->procname, 0, proc_orig_len);
+ strncpy(worker->procname, DEFAULT_RUN_AS_WORKER_NAME, proc_orig_len);
+
+ ret = lttng_prctl(PR_SET_NAME,
+ (unsigned long) DEFAULT_RUN_AS_WORKER_NAME, 0, 0, 0);
+ if (ret && ret != -ENOSYS) {
+ /* Don't fail as this is not essential. */
+ PERROR("prctl PR_SET_NAME");
+ ret = 0;
+ }
+
+ sendret.ret = 0;
+ sendret._errno = 0;
+ writelen = lttcomm_send_unix_sock(worker->sockpair[1], &sendret,
+ sizeof(sendret));
+ if (writelen < sizeof(sendret)) {
+ PERROR("lttcomm_send_unix_sock error");
+ ret = EXIT_FAILURE;
+ goto end;
+ }
+
+ for (;;) {
+ ret = handle_one_cmd(worker);
+ if (ret < 0) {
+ ret = EXIT_FAILURE;
+ goto end;
+ } else if (ret > 0) {
+ break;
+ } else {
+ continue; /* Next command. */
}
- writeleft -= writelen;
- index += writelen;
- } while (writeleft > 0);
- return EXIT_SUCCESS;
+ }
+ ret = EXIT_SUCCESS;
+end:
+ return ret;
}
static
-int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
+int run_as_cmd(struct run_as_worker *worker,
+ enum run_as_cmd cmd,
+ struct run_as_data *data,
+ uid_t uid, gid_t gid)
{
- struct run_as_data run_as_data;
- int ret = 0;
- int status;
- pid_t pid;
- int retval_pipe[2];
- ssize_t readlen, readleft, index;
- void *child_stack;
- union {
- int i;
- char c[sizeof(int)];
- } retval;
+ ssize_t readlen, writelen;
+ struct run_as_ret recvret;
/*
* If we are non-root, we can only deal with our own uid.
*/
if (geteuid() != 0) {
if (uid != geteuid()) {
+ recvret.ret = -1;
+ recvret._errno = EPERM;
ERR("Client (%d)/Server (%d) UID mismatch (and sessiond is not root)",
- uid, geteuid());
- return -EPERM;
+ (int) uid, (int) geteuid());
+ goto end;
}
}
- ret = pipe(retval_pipe);
- if (ret < 0) {
- perror("pipe");
- retval.i = ret;
+ data->cmd = cmd;
+ data->uid = uid;
+ data->gid = gid;
+
+ writelen = lttcomm_send_unix_sock(worker->sockpair[0], data,
+ sizeof(*data));
+ if (writelen < sizeof(*data)) {
+ PERROR("Error writing message to run_as");
+ recvret.ret = -1;
+ recvret._errno = errno;
goto end;
}
- run_as_data.data = data;
- run_as_data.cmd = cmd;
- run_as_data.uid = uid;
- run_as_data.gid = gid;
- run_as_data.retval_pipe = retval_pipe[1]; /* write end */
- child_stack = mmap(NULL, RUNAS_CHILD_STACK_SIZE,
- PROT_WRITE | PROT_READ,
- MAP_PRIVATE | MAP_GROWSDOWN | MAP_ANONYMOUS | MAP_STACK,
- -1, 0);
- if (child_stack == MAP_FAILED) {
- perror("mmap");
- retval.i = -ENOMEM;
- goto close_pipe;
+
+ /* receive return value */
+ readlen = lttcomm_recv_unix_sock(worker->sockpair[0], &recvret,
+ sizeof(recvret));
+ if (!readlen) {
+ ERR("Run-as worker has hung-up during run_as_cmd");
+ recvret.ret = -1;
+ recvret._errno = EIO;
+ goto end;
+ } else if (readlen < sizeof(recvret)) {
+ PERROR("Error reading response from run_as");
+ recvret.ret = -1;
+ recvret._errno = errno;
}
- /*
- * Pointing to the middle of the stack to support architectures
- * where the stack grows up (HPPA).
- */
- pid = lttng_clone_files(child_run_as, child_stack + (RUNAS_CHILD_STACK_SIZE / 2),
- &run_as_data);
- if (pid < 0) {
- perror("clone");
- retval.i = pid;
- goto unmap_stack;
+ if (do_recv_fd(worker, cmd, &recvret.ret)) {
+ recvret.ret = -1;
+ recvret._errno = EIO;
}
- /* receive return value */
- readleft = sizeof(retval);
- index = 0;
- do {
- readlen = read(retval_pipe[0], &retval.c[index], readleft);
- if (readlen < 0) {
- perror("read");
- ret = -1;
- break;
- }
- readleft -= readlen;
- index += readlen;
- } while (readleft > 0);
- /*
- * Parent: wait for child to return, in which case the
- * shared memory map will have been created.
- */
- pid = waitpid(pid, &status, 0);
- if (pid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
- perror("wait");
- retval.i = -1;
- }
-unmap_stack:
- ret = munmap(child_stack, RUNAS_CHILD_STACK_SIZE);
- if (ret < 0) {
- perror("munmap");
- retval.i = ret;
- }
-close_pipe:
- close(retval_pipe[0]);
- close(retval_pipe[1]);
end:
- return retval.i;
+ errno = recvret._errno;
+ return recvret.ret;
+}
+
+/*
+ * This is for debugging ONLY and should not be considered secure.
+ */
+static
+int run_as_noworker(enum run_as_cmd cmd,
+ struct run_as_data *data, uid_t uid, gid_t gid)
+{
+ int ret, saved_errno;
+ mode_t old_mask;
+ run_as_fct fct;
+
+ fct = run_as_enum_to_fct(cmd);
+ if (!fct) {
+ errno = -ENOSYS;
+ ret = -1;
+ goto end;
+ }
+ old_mask = umask(0);
+ ret = fct(data);
+ saved_errno = errno;
+ umask(old_mask);
+ errno = saved_errno;
+end:
+ return ret;
+}
+
+static
+int run_as(enum run_as_cmd cmd, struct run_as_data *data, uid_t uid, gid_t gid)
+{
+ int ret;
+
+ if (use_clone()) {
+ DBG("Using run_as worker");
+ pthread_mutex_lock(&worker_lock);
+ assert(global_worker);
+ ret = run_as_cmd(global_worker, cmd, data, uid, gid);
+ pthread_mutex_unlock(&worker_lock);
+
+ } else {
+ DBG("Using run_as without worker");
+ ret = run_as_noworker(cmd, data, uid, gid);
+ }
+ return ret;
}
+LTTNG_HIDDEN
int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid)
{
- struct run_as_mkdir_data data;
+ struct run_as_data data;
DBG3("mkdir() recursive %s with mode %d for uid %d and gid %d",
- path, mode, uid, gid);
- data.path = path;
- data.mode = mode;
- return run_as(_mkdir_recursive, &data, uid, gid);
+ path, (int) mode, (int) uid, (int) gid);
+ strncpy(data.u.mkdir.path, path, PATH_MAX - 1);
+ data.u.mkdir.path[PATH_MAX - 1] = '\0';
+ data.u.mkdir.mode = mode;
+ return run_as(RUN_AS_MKDIR_RECURSIVE, &data, uid, gid);
}
+LTTNG_HIDDEN
int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid)
{
- struct run_as_mkdir_data data;
+ struct run_as_data data;
DBG3("mkdir() %s with mode %d for uid %d and gid %d",
- path, mode, uid, gid);
- data.path = path;
- data.mode = mode;
- return run_as(_mkdir, &data, uid, gid);
+ path, (int) mode, (int) uid, (int) gid);
+ strncpy(data.u.mkdir.path, path, PATH_MAX - 1);
+ data.u.mkdir.path[PATH_MAX - 1] = '\0';
+ data.u.mkdir.mode = mode;
+ return run_as(RUN_AS_MKDIR, &data, uid, gid);
}
/*
* Note: open_run_as is currently not working. We'd need to pass the fd
* opened in the child to the parent.
*/
+LTTNG_HIDDEN
int run_as_open(const char *path, int flags, mode_t mode, uid_t uid, gid_t gid)
{
- struct run_as_open_data data;
+ struct run_as_data data;
DBG3("open() %s with flags %X mode %d for uid %d and gid %d",
- path, flags, mode, uid, gid);
- data.path = path;
- data.flags = flags;
- data.mode = mode;
- return run_as(_open, &data, uid, gid);
+ path, flags, (int) mode, (int) uid, (int) gid);
+ strncpy(data.u.open.path, path, PATH_MAX - 1);
+ data.u.open.path[PATH_MAX - 1] = '\0';
+ data.u.open.flags = flags;
+ data.u.open.mode = mode;
+ return run_as(RUN_AS_OPEN, &data, uid, gid);
+}
+
+LTTNG_HIDDEN
+int run_as_unlink(const char *path, uid_t uid, gid_t gid)
+{
+ struct run_as_data data;
+
+ DBG3("unlink() %s with for uid %d and gid %d",
+ path, (int) uid, (int) gid);
+ strncpy(data.u.unlink.path, path, PATH_MAX - 1);
+ data.u.unlink.path[PATH_MAX - 1] = '\0';
+ return run_as(RUN_AS_UNLINK, &data, uid, gid);
+}
+
+LTTNG_HIDDEN
+int run_as_rmdir_recursive(const char *path, uid_t uid, gid_t gid)
+{
+ struct run_as_data data;
+
+ DBG3("rmdir_recursive() %s with for uid %d and gid %d",
+ path, (int) uid, (int) gid);
+ strncpy(data.u.rmdir_recursive.path, path, PATH_MAX - 1);
+ data.u.rmdir_recursive.path[PATH_MAX - 1] = '\0';
+ return run_as(RUN_AS_RMDIR_RECURSIVE, &data, uid, gid);
+}
+
+static
+int reset_sighandler(void)
+{
+ int sig;
+
+ DBG("Resetting run_as worker signal handlers to default");
+ for (sig = 1; sig <= 31; sig++) {
+ (void) signal(sig, SIG_DFL);
+ }
+ return 0;
+}
+
+static
+void worker_sighandler(int sig)
+{
+ const char *signame;
+
+ /*
+ * The worker will its parent's signals since they are part of the same
+ * process group. However, in the case of SIGINT and SIGTERM, we want
+ * to give the worker a chance to teardown gracefully when its parent
+ * closes the command socket.
+ */
+ switch (sig) {
+ case SIGINT:
+ signame = "SIGINT";
+ break;
+ case SIGTERM:
+ signame = "SIGTERM";
+ break;
+ default:
+ signame = "Unknown";
+ }
+
+ DBG("run_as worker received signal %s", signame);
+}
+
+static
+int set_worker_sighandlers(void)
+{
+ int ret = 0;
+ sigset_t sigset;
+ struct sigaction sa;
+
+ if ((ret = sigemptyset(&sigset)) < 0) {
+ PERROR("sigemptyset");
+ goto end;
+ }
+
+ sa.sa_handler = worker_sighandler;
+ sa.sa_mask = sigset;
+ sa.sa_flags = 0;
+ if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
+ PERROR("sigaction SIGINT");
+ goto end;
+ }
+
+ if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
+ PERROR("sigaction SIGTERM");
+ goto end;
+ }
+
+ DBG("run_as signal handler set for SIGTERM and SIGINT");
+end:
+ return ret;
+}
+
+LTTNG_HIDDEN
+int run_as_create_worker(char *procname)
+{
+ pid_t pid;
+ int i, ret = 0;
+ ssize_t readlen;
+ struct run_as_ret recvret;
+ struct run_as_worker *worker;
+
+ pthread_mutex_lock(&worker_lock);
+ assert(!global_worker);
+ if (!use_clone()) {
+ /*
+ * Don't initialize a worker, all run_as tasks will be performed
+ * in the current process.
+ */
+ ret = 0;
+ goto end;
+ }
+ worker = zmalloc(sizeof(*worker));
+ if (!worker) {
+ ret = -ENOMEM;
+ goto end;
+ }
+ worker->procname = procname;
+ /* Create unix socket. */
+ if (lttcomm_create_anon_unix_socketpair(worker->sockpair) < 0) {
+ ret = -1;
+ goto error_sock;
+ }
+ /* Fork worker. */
+ pid = fork();
+ if (pid < 0) {
+ PERROR("fork");
+ ret = -1;
+ goto error_fork;
+ } else if (pid == 0) {
+ /* Child */
+
+ reset_sighandler();
+
+ set_worker_sighandlers();
+
+ /* The child has no use for this lock. */
+ pthread_mutex_unlock(&worker_lock);
+ /* Just close, no shutdown. */
+ if (close(worker->sockpair[0])) {
+ PERROR("close");
+ exit(EXIT_FAILURE);
+ }
+ worker->sockpair[0] = -1;
+ ret = run_as_worker(worker);
+ if (lttcomm_close_unix_sock(worker->sockpair[1])) {
+ PERROR("close");
+ ret = -1;
+ }
+ worker->sockpair[1] = -1;
+ LOG(ret ? PRINT_ERR : PRINT_DBG, "run_as worker exiting (ret = %d)", ret);
+ exit(ret ? EXIT_FAILURE : EXIT_SUCCESS);
+ } else {
+ /* Parent */
+
+ /* Just close, no shutdown. */
+ if (close(worker->sockpair[1])) {
+ PERROR("close");
+ ret = -1;
+ goto error_fork;
+ }
+ worker->sockpair[1] = -1;
+ worker->pid = pid;
+ /* Wait for worker to become ready. */
+ readlen = lttcomm_recv_unix_sock(worker->sockpair[0],
+ &recvret, sizeof(recvret));
+ if (readlen < sizeof(recvret)) {
+ ERR("readlen: %zd", readlen);
+ PERROR("Error reading response from run_as at creation");
+ ret = -1;
+ goto error_fork;
+ }
+ global_worker = worker;
+ }
+end:
+ pthread_mutex_unlock(&worker_lock);
+ return ret;
+
+ /* Error handling. */
+error_fork:
+ for (i = 0; i < 2; i++) {
+ if (worker->sockpair[i] < 0) {
+ continue;
+ }
+ if (lttcomm_close_unix_sock(worker->sockpair[i])) {
+ PERROR("close");
+ }
+ worker->sockpair[i] = -1;
+ }
+error_sock:
+ free(worker);
+ pthread_mutex_unlock(&worker_lock);
+ return ret;
+}
+
+LTTNG_HIDDEN
+void run_as_destroy_worker(void)
+{
+ struct run_as_worker *worker = global_worker;
+
+ DBG("Destroying run_as worker");
+ pthread_mutex_lock(&worker_lock);
+ if (!worker) {
+ goto end;
+ }
+ /* Close unix socket */
+ DBG("Closing run_as worker socket");
+ if (lttcomm_close_unix_sock(worker->sockpair[0])) {
+ PERROR("close");
+ }
+ worker->sockpair[0] = -1;
+ /* Wait for worker. */
+ for (;;) {
+ int status;
+ pid_t wait_ret;
+
+ wait_ret = waitpid(worker->pid, &status, 0);
+ if (wait_ret < 0) {
+ if (errno == EINTR) {
+ continue;
+ }
+ PERROR("waitpid");
+ break;
+ }
+
+ if (WIFEXITED(status)) {
+ LOG(WEXITSTATUS(status) == 0 ? PRINT_DBG : PRINT_ERR,
+ DEFAULT_RUN_AS_WORKER_NAME " terminated with status code %d",
+ WEXITSTATUS(status));
+ break;
+ } else if (WIFSIGNALED(status)) {
+ ERR(DEFAULT_RUN_AS_WORKER_NAME " was killed by signal %d",
+ WTERMSIG(status));
+ break;
+ }
+ }
+ free(worker);
+ global_worker = NULL;
+end:
+ pthread_mutex_unlock(&worker_lock);
}