+++ /dev/null
-/*
- * 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/lttng-kernel.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 <common/lttng-elf.h>
-
-#include <lttng/constant.h>
-
-#include "runas.h"
-
-struct run_as_data;
-struct run_as_ret;
-typedef int (*run_as_fct)(struct run_as_data *data, struct run_as_ret *ret_value);
-
-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];
-};
-
-struct run_as_extract_elf_symbol_offset_data {
- char function[LTTNG_SYMBOL_NAME_LEN];
-};
-
-struct run_as_extract_sdt_probe_offsets_data {
- char probe_name[LTTNG_SYMBOL_NAME_LEN];
- char provider_name[LTTNG_SYMBOL_NAME_LEN];
-};
-
-struct run_as_mkdir_ret {
- int ret;
-};
-
-struct run_as_open_ret {
- int ret;
-};
-
-struct run_as_unlink_ret {
- int ret;
-};
-
-struct run_as_rmdir_recursive_ret {
- int ret;
-};
-
-struct run_as_extract_elf_symbol_offset_ret {
- uint64_t offset;
-};
-
-struct run_as_extract_sdt_probe_offsets_ret {
- uint32_t num_offset;
- uint64_t offsets[LTTNG_KERNEL_MAX_UPROBE_NUM];
-};
-
-enum run_as_cmd {
- RUN_AS_MKDIR,
- RUN_AS_OPEN,
- RUN_AS_UNLINK,
- RUN_AS_RMDIR_RECURSIVE,
- RUN_AS_MKDIR_RECURSIVE,
- RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET,
- RUN_AS_EXTRACT_SDT_PROBE_OFFSETS,
-};
-
-struct run_as_data {
- enum run_as_cmd cmd;
- int fd;
- 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;
- struct run_as_extract_elf_symbol_offset_data extract_elf_symbol_offset;
- struct run_as_extract_sdt_probe_offsets_data extract_sdt_probe_offsets;
- } u;
- uid_t uid;
- gid_t gid;
-};
-
-/*
- * The run_as_ret structure holds the returned value and status of the command.
- *
- * The `u` union field holds the return value of the command; in most cases it
- * represents the success or the failure of the command. In more complex
- * commands, it holds a computed value.
- *
- * The _errno field is the errno recorded after the execution of the command.
- *
- * The _error fields is used the signify that return status of the command. For
- * simple commands returning `int` the _error field will be the same as the
- * ret_int field. In complex commands, it signify the success or failure of the
- * command.
- *
- */
-struct run_as_ret {
- int fd;
- union {
- struct run_as_mkdir_ret mkdir;
- struct run_as_open_ret open;
- struct run_as_unlink_ret unlink;
- struct run_as_rmdir_recursive_ret rmdir_recursive;
- struct run_as_extract_elf_symbol_offset_ret extract_elf_symbol_offset;
- struct run_as_extract_sdt_probe_offsets_ret extract_sdt_probe_offsets;
- } u;
- int _errno;
- bool _error;
-};
-
-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, struct run_as_ret *ret_value)
-{
- 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. */
- ret_value->u.mkdir.ret = _utils_mkdir_recursive_unsafe(path, mode);
- ret_value->_errno = errno;
- ret_value->_error = (ret_value->u.mkdir.ret) ? true : false;
- return ret_value->u.mkdir.ret;
-}
-
-static
-int _mkdir(struct run_as_data *data, struct run_as_ret *ret_value)
-{
- ret_value->u.mkdir.ret = mkdir(data->u.mkdir.path, data->u.mkdir.mode);
- ret_value->_errno = errno;
- ret_value->_error = (ret_value->u.mkdir.ret) ? true : false;
- return ret_value->u.mkdir.ret;
-}
-
-static
-int _open(struct run_as_data *data, struct run_as_ret *ret_value)
-{
- ret_value->u.open.ret = open(data->u.open.path, data->u.open.flags, data->u.open.mode);
- ret_value->fd = ret_value->u.open.ret;
- ret_value->_errno = errno;
- ret_value->_error = ret_value->u.open.ret < 0;
- return ret_value->u.open.ret;
-}
-
-static
-int _unlink(struct run_as_data *data, struct run_as_ret *ret_value)
-{
- ret_value->u.unlink.ret = unlink(data->u.unlink.path);
- ret_value->_errno = errno;
- ret_value->_error = (ret_value->u.unlink.ret) ? true : false;
- return ret_value->u.unlink.ret;
-}
-
-static
-int _rmdir_recursive(struct run_as_data *data, struct run_as_ret *ret_value)
-{
- ret_value->u.rmdir_recursive.ret = utils_recursive_rmdir(data->u.rmdir_recursive.path);
- ret_value->_errno = errno;
- ret_value->_error = (ret_value->u.rmdir_recursive.ret) ? true : false;
- return ret_value->u.rmdir_recursive.ret;
-}
-
-#ifdef HAVE_ELF_H
-static
-int _extract_elf_symbol_offset(struct run_as_data *data,
- struct run_as_ret *ret_value)
-{
- int ret = 0;
- ret_value->_error = false;
-
- ret = lttng_elf_get_symbol_offset(data->fd,
- data->u.extract_elf_symbol_offset.function,
- &ret_value->u.extract_elf_symbol_offset.offset);
- if (ret) {
- DBG("Failed to extract ELF function offset");
- ret_value->_error = true;
- }
-
- return ret;
-}
-
-static
-int _extract_sdt_probe_offsets(struct run_as_data *data,
- struct run_as_ret *ret_value)
-{
- int ret = 0;
- uint64_t *offsets = NULL;
- uint32_t num_offset;
-
- ret_value->_error = false;
-
- /* On success, this call allocates the offsets paramater. */
- ret = lttng_elf_get_sdt_probe_offsets(data->fd,
- data->u.extract_sdt_probe_offsets.provider_name,
- data->u.extract_sdt_probe_offsets.probe_name,
- &offsets, &num_offset);
-
- if (ret) {
- DBG("Failed to extract SDT probe offsets");
- ret_value->_error = true;
- goto end;
- }
-
- if (num_offset <= 0 || num_offset > LTTNG_KERNEL_MAX_UPROBE_NUM) {
- DBG("Wrong number of probes.");
- ret = -1;
- ret_value->_error = true;
- goto free_offset;
- }
-
- /* Copy the content of the offsets array to the ret struct. */
- memcpy(ret_value->u.extract_sdt_probe_offsets.offsets,
- offsets, num_offset * sizeof(uint64_t));
-
- ret_value->u.extract_sdt_probe_offsets.num_offset = num_offset;
-
-free_offset:
- free(offsets);
-end:
- return ret;
-}
-#else
-static
-int _extract_elf_symbol_offset(struct run_as_data *data,
- struct run_as_ret *ret_value)
-{
- ERR("Unimplemented runas command RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET");
- return -1;
-}
-
-static
-int _extract_sdt_probe_offsets(struct run_as_data *data,
- struct run_as_ret *ret_value)
-{
- ERR("Unimplemented runas command RUN_AS_EXTRACT_SDT_PROBE_OFFSETS");
- return -1;
-}
-#endif
-
-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;
- case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET:
- return _extract_elf_symbol_offset;
- case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS:
- return _extract_sdt_probe_offsets;
- default:
- ERR("Unknown command %d", (int) cmd);
- return NULL;
- }
-}
-
-static
-int do_send_fd(int sock, int fd)
-{
- ssize_t len;
-
- if (fd < 0) {
- ERR("Attempt to send invalid file descriptor to master (fd = %i)", fd);
- /* Return 0 as this is not a fatal error. */
- return 0;
- }
-
- len = lttcomm_send_fds_unix_sock(sock, &fd, 1);
- if (len < 0) {
- PERROR("lttcomm_send_fds_unix_sock");
- return -1;
- }
- return 0;
-}
-
-static
-int do_recv_fd(int sock, int *fd)
-{
- ssize_t len;
-
- len = lttcomm_recv_fds_unix_sock(sock, fd, 1);
-
- if (!len) {
- return -1;
- } else if (len < 0) {
- PERROR("lttcomm_recv_fds_unix_sock");
- return -1;
- }
- if (*fd < 0) {
- ERR("Invalid file descriptor received from worker (fd = %i)", *fd);
- /* Return 0 as this is not a fatal error. */
- return 0;
- }
-
- return 0;
-}
-
-static
-int send_fd_to_worker(struct run_as_worker *worker, enum run_as_cmd cmd, int fd)
-{
- int ret = 0;
-
- switch (cmd) {
- case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET:
- case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS:
- break;
- default:
- return 0;
- }
-
- if (fd < 0) {
- ERR("Refusing to send invalid fd to worker (fd = %i)", fd);
- return -1;
- }
-
- ret = do_send_fd(worker->sockpair[0], fd);
- if (ret < 0) {
- PERROR("do_send_fd");
- ret = -1;
- }
-
- return ret;
-}
-
-static
-int send_fd_to_master(struct run_as_worker *worker, enum run_as_cmd cmd, int fd)
-{
- int ret = 0, ret_close = 0;
-
- switch (cmd) {
- case RUN_AS_OPEN:
- break;
- default:
- return 0;
- }
-
- if (fd < 0) {
- DBG("Not sending file descriptor to master as it is invalid (fd = %i)", fd);
- return 0;
- }
- ret = do_send_fd(worker->sockpair[1], fd);
- if (ret < 0) {
- PERROR("do_send_fd error");
- ret = -1;
- }
-
- ret_close = close(fd);
- if (ret_close < 0) {
- PERROR("close");
- }
-
- return ret;
-}
-
-static
-int recv_fd_from_worker(struct run_as_worker *worker, enum run_as_cmd cmd, int *fd)
-{
- int ret = 0;
-
- switch (cmd) {
- case RUN_AS_OPEN:
- break;
- default:
- return 0;
- }
-
- ret = do_recv_fd(worker->sockpair[0], fd);
- if (ret < 0) {
- PERROR("do_recv_fd error");
- ret = -1;
- }
-
- return ret;
-}
-
-static
-int recv_fd_from_master(struct run_as_worker *worker, enum run_as_cmd cmd, int *fd)
-{
- int ret = 0;
-
- switch (cmd) {
- case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET:
- case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS:
- break;
- default:
- return 0;
- }
-
- ret = do_recv_fd(worker->sockpair[1], fd);
- if (ret < 0) {
- PERROR("do_recv_fd error");
- ret = -1;
- }
-
- return ret;
-}
-
-static
-int cleanup_received_fd(enum run_as_cmd cmd, int fd)
-{
- int ret = 0;
-
- switch (cmd) {
- case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET:
- case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS:
- break;
- default:
- return 0;
- }
-
- if (fd < 0) {
- return 0;
- }
- ret = close(fd);
- if (ret < 0) {
- PERROR("close error");
- ret = -1;
- }
-
- return ret;
-}
-
-/*
- * 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;
-
- memset(&sendret, 0, sizeof(sendret));
- sendret.fd = -1;
-
- /*
- * Stage 1: Receive run_as_data struct from the master.
- * The structure contains the command type and all the parameters needed for
- * its execution
- */
- 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;
- }
-
- /*
- * Stage 2: Receive file descriptor from master.
- * Some commands need a file descriptor as input so if it's needed we
- * receive the fd using the Unix socket.
- */
- ret = recv_fd_from_master(worker, data.cmd, &data.fd);
- if (ret < 0) {
- PERROR("recv_fd_from_master error");
- ret = -1;
- goto end;
- }
-
- prev_euid = getuid();
- if (data.gid != getegid()) {
- ret = setegid(data.gid);
- if (ret < 0) {
- sendret._error = true;
- sendret._errno = errno;
- PERROR("setegid");
- goto write_return;
- }
- }
- if (data.uid != prev_euid) {
- ret = seteuid(data.uid);
- if (ret < 0) {
- sendret._error = true;
- sendret._errno = errno;
- PERROR("seteuid");
- goto write_return;
- }
- }
-
- /*
- * Also set umask to 0 for mkdir executable bit.
- */
- umask(0);
-
- /*
- * Stage 3: Execute the command
- */
- ret = (*cmd)(&data, &sendret);
- if (ret < 0) {
- DBG("Execution of command returned an error");
- }
-
-write_return:
- ret = cleanup_received_fd(data.cmd, data.fd);
- if (ret < 0) {
- ERR("Error cleaning up FD");
- goto end;
- }
-
- /*
- * Stage 4: Send run_as_ret structure to the master.
- * This structure contain the return value of the command and the errno.
- */
- 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;
- }
-
- /*
- * Stage 5: Send file descriptor to the master
- * Some commands return a file descriptor so if it's needed we pass it back
- * to the master using the Unix socket.
- */
- ret = send_fd_to_master(worker, data.cmd, sendret.fd);
- if (ret < 0) {
- DBG("Sending FD to master returned an error");
- 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");
- }
-
- memset(&sendret, 0, sizeof(sendret));
-
- 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,
- struct run_as_ret *ret_value,
- uid_t uid, gid_t gid)
-{
- int ret = 0;
- ssize_t readlen, writelen;
-
- /*
- * If we are non-root, we can only deal with our own uid.
- */
- if (geteuid() != 0) {
- if (uid != geteuid()) {
- ret = -1;
- ret_value->_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;
-
- /*
- * Stage 1: Send the run_as_data struct to the worker process
- */
- writelen = lttcomm_send_unix_sock(worker->sockpair[0], data,
- sizeof(*data));
- if (writelen < sizeof(*data)) {
- PERROR("Error writing message to run_as");
- ret = -1;
- ret_value->_errno = EIO;
- goto end;
- }
-
- /*
- * Stage 2: Send file descriptor to the worker process if needed
- */
- ret = send_fd_to_worker(worker, data->cmd, data->fd);
- if (ret) {
- PERROR("do_send_fd error");
- ret = -1;
- ret_value->_errno = EIO;
- goto end;
- }
-
- /*
- * Stage 3: Wait for the execution of the command
- */
-
- /*
- * Stage 4: Receive the run_as_ret struct containing the return value and
- * errno
- */
- readlen = lttcomm_recv_unix_sock(worker->sockpair[0], ret_value,
- sizeof(*ret_value));
- if (!readlen) {
- ERR("Run-as worker has hung-up during run_as_cmd");
- ret = -1;
- ret_value->_errno = EIO;
- goto end;
- } else if (readlen < sizeof(*ret_value)) {
- PERROR("Error reading response from run_as");
- ret = -1;
- ret_value->_errno = errno;
- goto end;
- }
-
- if (ret_value->_error) {
- /* Skip stage 5 on error as there will be no fd to receive. */
- goto end;
- }
-
- /*
- * Stage 5: Receive file descriptor if needed
- */
- ret = recv_fd_from_worker(worker, data->cmd, &ret_value->fd);
- if (ret < 0) {
- ERR("Error receiving fd");
- ret = -1;
- ret_value->_errno = EIO;
- }
-
-end:
- return 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, struct run_as_ret *ret_value,
- 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, ret_value);
- saved_errno = ret_value->_errno;
- umask(old_mask);
- errno = saved_errno;
-end:
- return ret;
-}
-
-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;
-}
-
-static
-int run_as_create_worker_no_lock(const char *procname,
- post_fork_cleanup_cb clean_up_func,
- void *clean_up_user_data)
-{
- pid_t pid;
- int i, ret = 0;
- ssize_t readlen;
- struct run_as_ret recvret;
- struct run_as_worker *worker;
-
- 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 = strdup(procname);
- if (!worker->procname) {
- ret = -ENOMEM;
- goto error_procname_alloc;
- }
- /* 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();
- if (clean_up_func) {
- if (clean_up_func(clean_up_user_data) < 0) {
- ERR("Run-as post-fork clean-up failed, exiting.");
- exit(EXIT_FAILURE);
- }
- }
-
- /* Just close, no shutdown. */
- if (close(worker->sockpair[0])) {
- PERROR("close");
- exit(EXIT_FAILURE);
- }
-
- /*
- * Close all FDs aside from STDIN, STDOUT, STDERR and sockpair[1]
- * Sockpair[1] is used as a control channel with the master
- */
- for (i = 3; i < sysconf(_SC_OPEN_MAX); i++) {
- if (i != worker->sockpair[1]) {
- (void) close(i);
- }
- }
-
- 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;
- free(worker->procname);
- free(worker);
- 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:
- 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->procname);
-error_procname_alloc:
- free(worker);
- return ret;
-}
-
-static
-void run_as_destroy_worker_no_lock(void)
-{
- struct run_as_worker *worker = global_worker;
-
- DBG("Destroying run_as worker");
- if (!worker) {
- return;
- }
- /* 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->procname);
- free(worker);
- global_worker = NULL;
-}
-
-static
-int run_as_restart_worker(struct run_as_worker *worker)
-{
- int ret = 0;
- char *procname = NULL;
-
- procname = worker->procname;
-
- /* Close socket to run_as worker process and clean up the zombie process */
- run_as_destroy_worker_no_lock();
-
- /* Create a new run_as worker process*/
- ret = run_as_create_worker_no_lock(procname, NULL, NULL);
- if (ret < 0 ) {
- ERR("Restarting the worker process failed");
- ret = -1;
- goto err;
- }
-err:
- return ret;
-}
-
-static
-int run_as(enum run_as_cmd cmd, struct run_as_data *data,
- struct run_as_ret *ret_value, uid_t uid, gid_t gid)
-{
- int ret, saved_errno;
-
- pthread_mutex_lock(&worker_lock);
- if (use_clone()) {
- DBG("Using run_as worker");
-
- assert(global_worker);
-
- ret = run_as_cmd(global_worker, cmd, data, ret_value, uid, gid);
- saved_errno = ret_value->_errno;
-
- /*
- * If the worker thread crashed the errno is set to EIO. we log
- * the error and start a new worker process.
- */
- if (ret == -1 && saved_errno == EIO) {
- DBG("Socket closed unexpectedly... "
- "Restarting the worker process");
- ret = run_as_restart_worker(global_worker);
- if (ret == -1) {
- ERR("Failed to restart worker process.");
- goto err;
- }
- }
- } else {
- DBG("Using run_as without worker");
- ret = run_as_noworker(cmd, data, ret_value, uid, gid);
- }
-err:
- pthread_mutex_unlock(&worker_lock);
- 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;
- struct run_as_ret ret;
-
- memset(&data, 0, sizeof(data));
- memset(&ret, 0, sizeof(ret));
- 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;
-
- run_as(RUN_AS_MKDIR_RECURSIVE, &data, &ret, uid, gid);
- errno = ret._errno;
- return ret.u.mkdir.ret;
-}
-
-LTTNG_HIDDEN
-int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid)
-{
- struct run_as_data data;
- struct run_as_ret ret;
-
- memset(&data, 0, sizeof(data));
- memset(&ret, 0, sizeof(ret));
-
- 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;
- run_as(RUN_AS_MKDIR, &data, &ret, uid, gid);
- errno = ret._errno;
- return ret.u.mkdir.ret;
-}
-
-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;
- struct run_as_ret ret;
-
- memset(&data, 0, sizeof(data));
- memset(&ret, 0, sizeof(ret));
-
- 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;
- run_as(RUN_AS_OPEN, &data, &ret, uid, gid);
- errno = ret._errno;
- ret.u.open.ret = ret.fd;
- return ret.u.open.ret;
-}
-
-LTTNG_HIDDEN
-int run_as_unlink(const char *path, uid_t uid, gid_t gid)
-{
- struct run_as_data data;
- struct run_as_ret ret;
-
- memset(&data, 0, sizeof(data));
- memset(&ret, 0, sizeof(ret));
-
- 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';
- run_as(RUN_AS_UNLINK, &data, &ret, uid, gid);
- errno = ret._errno;
- return ret.u.unlink.ret;
-}
-
-LTTNG_HIDDEN
-int run_as_rmdir_recursive(const char *path, uid_t uid, gid_t gid)
-{
- struct run_as_data data;
- struct run_as_ret ret;
-
- memset(&data, 0, sizeof(data));
- memset(&ret, 0, sizeof(ret));
-
- 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';
- run_as(RUN_AS_RMDIR_RECURSIVE, &data, &ret, uid, gid);
- errno = ret._errno;
- return ret.u.rmdir_recursive.ret;
-}
-
-LTTNG_HIDDEN
-int run_as_extract_elf_symbol_offset(int fd, const char* function,
- uid_t uid, gid_t gid, uint64_t *offset)
-{
- struct run_as_data data;
- struct run_as_ret ret;
-
- memset(&data, 0, sizeof(data));
- memset(&ret, 0, sizeof(ret));
-
- DBG3("extract_elf_symbol_offset() on fd=%d and function=%s "
- "with for uid %d and gid %d", fd, function, (int) uid, (int) gid);
-
- data.fd = fd;
-
- strncpy(data.u.extract_elf_symbol_offset.function, function, LTTNG_SYMBOL_NAME_LEN - 1);
-
- data.u.extract_elf_symbol_offset.function[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
-
- run_as(RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET, &data, &ret, uid, gid);
-
- errno = ret._errno;
-
- if (ret._error) {
- return -1;
- }
-
- *offset = ret.u.extract_elf_symbol_offset.offset;
- return 0;
-}
-
-LTTNG_HIDDEN
-int run_as_extract_sdt_probe_offsets(int fd, const char* provider_name,
- const char* probe_name, uid_t uid, gid_t gid,
- uint64_t **offsets, uint32_t *num_offset)
-{
- struct run_as_data data;
- struct run_as_ret ret;
-
- memset(&data, 0, sizeof(data));
- memset(&ret, 0, sizeof(ret));
-
- DBG3("extract_sdt_probe_offsets() on fd=%d, probe_name=%s and "
- "provider_name=%s with for uid %d and gid %d", fd, probe_name,
- provider_name, (int) uid, (int) gid);
-
- data.fd = fd;
-
- strncpy(data.u.extract_sdt_probe_offsets.probe_name, probe_name, LTTNG_SYMBOL_NAME_LEN - 1);
- strncpy(data.u.extract_sdt_probe_offsets.provider_name, provider_name, LTTNG_SYMBOL_NAME_LEN - 1);
-
- data.u.extract_sdt_probe_offsets.probe_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
- data.u.extract_sdt_probe_offsets.provider_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
-
- run_as(RUN_AS_EXTRACT_SDT_PROBE_OFFSETS, &data, &ret, uid, gid);
-
- errno = ret._errno;
-
- if (ret._error) {
- return -1;
- }
-
- *num_offset = ret.u.extract_sdt_probe_offsets.num_offset;
-
- *offsets = zmalloc(*num_offset * sizeof(uint64_t));
- if (!*offsets) {
- return -ENOMEM;
- }
-
- memcpy(*offsets, ret.u.extract_sdt_probe_offsets.offsets, *num_offset * sizeof(uint64_t));
- return 0;
-}
-
-LTTNG_HIDDEN
-int run_as_create_worker(const char *procname,
- post_fork_cleanup_cb clean_up_func,
- void *clean_up_user_data)
-{
- int ret;
-
- pthread_mutex_lock(&worker_lock);
- ret = run_as_create_worker_no_lock(procname, clean_up_func,
- clean_up_user_data);
- pthread_mutex_unlock(&worker_lock);
- return ret;
-}
-
-LTTNG_HIDDEN
-void run_as_destroy_worker(void)
-{
- pthread_mutex_lock(&worker_lock);
- run_as_destroy_worker_no_lock();
- pthread_mutex_unlock(&worker_lock);
-}