X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;ds=sidebyside;f=src%2Fcommon%2Frunas.c;h=930c973ff956ec2c13aeed57d2d2d69b8995775f;hb=HEAD;hp=946ea3101ab92771ec8fd45009bd00bf37e8fe8b;hpb=8446e5ebcadad1fbd043e37ed4f2862b5e628022;p=lttng-tools.git

diff --git a/src/common/runas.c b/src/common/runas.c
deleted file mode 100644
index 946ea3101..000000000
--- a/src/common/runas.c
+++ /dev/null
@@ -1,750 +0,0 @@
-/*
- * 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, 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
- * 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.,
- * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-#define _LGPL_SOURCE
-#include <errno.h>
-#include <limits.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/wait.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <sched.h>
-#include <signal.h>
-#include <assert.h>
-#include <signal.h>
-
-#include <common/common.h>
-#include <common/utils.h>
-#include <common/compat/getenv.h>
-#include <common/compat/prctl.h>
-#include <common/unix.h>
-#include <common/defaults.h>
-
-#include "runas.h"
-
-struct run_as_data;
-typedef int (*run_as_fct)(struct run_as_data *data);
-
-struct run_as_mkdir_data {
-	char path[PATH_MAX];
-	mode_t mode;
-};
-
-struct run_as_open_data {
-	char path[PATH_MAX];
-	int flags;
-	mode_t mode;
-};
-
-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 {
-	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;
-};
-
-struct run_as_ret {
-	int ret;
-	int _errno;
-};
-
-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(struct run_as_data *data)
-{
-	const char *path;
-	mode_t mode;
-
-	path = data->u.mkdir.path;
-	mode = data->u.mkdir.mode;
-
-	/* Safe to call as we have transitioned to the requested uid/gid. */
-	return _utils_mkdir_recursive_unsafe(path, mode);
-}
-
-static
-int _mkdir(struct run_as_data *data)
-{
-	return mkdir(data->u.mkdir.path, data->u.mkdir.mode);
-}
-
-static
-int _open(struct run_as_data *data)
-{
-	return open(data->u.open.path, data->u.open.flags, data->u.open.mode);
-}
-
-static
-int _unlink(struct run_as_data *data)
-{
-	return unlink(data->u.unlink.path);
-}
-
-static
-int _rmdir_recursive(struct run_as_data *data)
-{
-	return utils_recursive_rmdir(data->u.rmdir_recursive.path);
-}
-
-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");
-			goto write_return;
-		}
-	}
-	if (data.uid != prev_euid) {
-		ret = seteuid(data.uid);
-		if (ret < 0) {
-			PERROR("seteuid");
-			goto write_return;
-		}
-	}
-	/*
-	 * Also set umask to 0 for mkdir executable bit.
-	 */
-	umask(0);
-	ret = (*cmd)(&data);
-
-write_return:
-	sendret.ret = ret;
-	sendret._errno = errno;
-	/* send back return value */
-	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. */
-		}
-	}
-	ret = EXIT_SUCCESS;
-end:
-	return ret;
-}
-
-static
-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)
-{
-	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)",
-				(int) uid, (int) geteuid());
-			goto end;
-		}
-	}
-
-	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;
-	}
-
-	/* 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;
-	}
-	if (do_recv_fd(worker, cmd, &recvret.ret)) {
-		recvret.ret = -1;
-		recvret._errno = EIO;
-	}
-
-end:
-	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_data data;
-
-	memset(&data, 0, sizeof(data));
-	DBG3("mkdir() recursive %s with mode %d for uid %d and gid %d",
-			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_data data;
-
-	memset(&data, 0, sizeof(data));
-	DBG3("mkdir() %s with mode %d for uid %d and gid %d",
-			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);
-}
-
-LTTNG_HIDDEN
-int run_as_open(const char *path, int flags, mode_t mode, uid_t uid, gid_t gid)
-{
-	struct run_as_data data;
-
-	memset(&data, 0, sizeof(data));
-	DBG3("open() %s with flags %X mode %d for uid %d and gid %d",
-			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;
-
-	memset(&data, 0, sizeof(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 inherit 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 = NULL;
-	}
-
-	if (signame) {
-		DBG("run_as worker received signal %s", signame);
-	} else {
-		DBG("run_as_worker received signal %d", sig);
-	}
-}
-
-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);
-}