/*
- * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
- * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@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.
+ * SPDX-License-Identifier: GPL-2.0-only
*
- * 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 _GNU_SOURCE
#define _LGPL_SOURCE
#include <errno.h>
#include <limits.h>
#include <unistd.h>
#include <fcntl.h>
#include <sched.h>
-#include <sys/signal.h>
+#include <signal.h>
+#include <assert.h>
+#include <signal.h>
+#include <common/bytecode/bytecode.h>
+#include <common/lttng-kernel.h>
#include <common/common.h>
#include <common/utils.h>
-#include <common/compat/mman.h>
-#include <common/compat/clone.h>
#include <common/compat/getenv.h>
+#include <common/compat/string.h>
+#include <common/unix.h>
+#include <common/defaults.h>
+#include <common/lttng-elf.h>
+#include <common/thread.h>
-#include "runas.h"
-
-#define RUNAS_CHILD_STACK_SIZE 10485760
-
-#ifndef MAP_STACK
-#define MAP_STACK 0
-#endif
+#include <lttng/constant.h>
-#ifdef __FreeBSD__
-/* FreeBSD MAP_STACK always return -ENOMEM */
-#define LTTNG_MAP_STACK 0
-#else
-#define LTTNG_MAP_STACK MAP_STACK
-#endif
+#include <common/sessiond-comm/sessiond-comm.h>
+#include <common/filter/filter-ast.h>
-#ifndef MAP_GROWSDOWN
-#define MAP_GROWSDOWN 0
-#endif
+#include "runas.h"
-#ifndef MAP_ANONYMOUS
-#define MAP_ANONYMOUS MAP_ANON
-#endif
+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_data {
- int (*cmd)(void *data);
- void *data;
- uid_t uid;
- gid_t gid;
- int retval_pipe;
+enum run_as_cmd {
+ RUN_AS_MKDIR,
+ RUN_AS_MKDIRAT,
+ RUN_AS_MKDIR_RECURSIVE,
+ RUN_AS_MKDIRAT_RECURSIVE,
+ RUN_AS_OPEN,
+ RUN_AS_OPENAT,
+ RUN_AS_UNLINK,
+ RUN_AS_UNLINKAT,
+ RUN_AS_RMDIR,
+ RUN_AS_RMDIRAT,
+ RUN_AS_RMDIR_RECURSIVE,
+ RUN_AS_RMDIRAT_RECURSIVE,
+ RUN_AS_RENAME,
+ RUN_AS_RENAMEAT,
+ RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET,
+ RUN_AS_EXTRACT_SDT_PROBE_OFFSETS,
+ RUN_AS_GENERATE_FILTER_BYTECODE,
};
struct run_as_mkdir_data {
- const char *path;
+ int dirfd;
+ char path[LTTNG_PATH_MAX];
mode_t mode;
-};
+} LTTNG_PACKED;
struct run_as_open_data {
- const char *path;
+ int dirfd;
+ char path[LTTNG_PATH_MAX];
int flags;
mode_t mode;
-};
+} LTTNG_PACKED;
struct run_as_unlink_data {
- const char *path;
-};
+ int dirfd;
+ char path[LTTNG_PATH_MAX];
+} LTTNG_PACKED;
-struct run_as_recursive_rmdir_data {
- const char *path;
-};
+struct run_as_rmdir_data {
+ int dirfd;
+ char path[LTTNG_PATH_MAX];
+ int flags; /* enum lttng_directory_handle_rmdir_recursive_flags. */
+} LTTNG_PACKED;
+
+struct run_as_extract_elf_symbol_offset_data {
+ int fd;
+ char function[LTTNG_SYMBOL_NAME_LEN];
+} LTTNG_PACKED;
+
+struct run_as_extract_sdt_probe_offsets_data {
+ int fd;
+ char probe_name[LTTNG_SYMBOL_NAME_LEN];
+ char provider_name[LTTNG_SYMBOL_NAME_LEN];
+} LTTNG_PACKED;
+
+struct run_as_generate_filter_bytecode_data {
+ char filter_expression[LTTNG_FILTER_MAX_LEN];
+} LTTNG_PACKED;
+
+struct run_as_rename_data {
+ /*
+ * [0] = old_dirfd
+ * [1] = new_dirfd
+ */
+ int dirfds[2];
+ char old_path[LTTNG_PATH_MAX];
+ char new_path[LTTNG_PATH_MAX];
+} LTTNG_PACKED;
+
+struct run_as_open_ret {
+ int fd;
+} LTTNG_PACKED;
+
+struct run_as_extract_elf_symbol_offset_ret {
+ uint64_t offset;
+} LTTNG_PACKED;
+
+struct run_as_extract_sdt_probe_offsets_ret {
+ uint32_t num_offset;
+ uint64_t offsets[LTTNG_KERNEL_MAX_UPROBE_NUM];
+} LTTNG_PACKED;
+
+struct run_as_generate_filter_bytecode_ret {
+ /* A lttng_bytecode_filter struct with 'dynamic' payload. */
+ char bytecode[LTTNG_FILTER_MAX_LEN];
+} LTTNG_PACKED;
+
+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_data rmdir;
+ struct run_as_rename_data rename;
+ struct run_as_extract_elf_symbol_offset_data extract_elf_symbol_offset;
+ struct run_as_extract_sdt_probe_offsets_data extract_sdt_probe_offsets;
+ struct run_as_generate_filter_bytecode_data generate_filter_bytecode;
+ } u;
+ uid_t uid;
+ gid_t gid;
+} LTTNG_PACKED;
+/*
+ * 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 ret;
+ union {
+ int ret;
+ struct run_as_open_ret open;
+ struct run_as_extract_elf_symbol_offset_ret extract_elf_symbol_offset;
+ struct run_as_extract_sdt_probe_offsets_ret extract_sdt_probe_offsets;
+ struct run_as_generate_filter_bytecode_ret generate_filter_bytecode;
+ } u;
int _errno;
+ bool _error;
+} LTTNG_PACKED;
+
+#define COMMAND_IN_FDS(data_ptr) ({ \
+ int *fds = NULL; \
+ if (command_properties[data_ptr->cmd].in_fds_offset != -1) { \
+ fds = (int *) ((char *) data_ptr + command_properties[data_ptr->cmd].in_fds_offset); \
+ } \
+ fds; \
+})
+
+#define COMMAND_OUT_FDS(cmd, ret_ptr) ({ \
+ int *fds = NULL; \
+ if (command_properties[cmd].out_fds_offset != -1) { \
+ fds = (int *) ((char *) ret_ptr + command_properties[cmd].out_fds_offset); \
+ } \
+ fds; \
+})
+
+#define COMMAND_IN_FD_COUNT(data_ptr) ({ \
+ command_properties[data_ptr->cmd].in_fd_count; \
+})
+
+#define COMMAND_OUT_FD_COUNT(cmd) ({ \
+ command_properties[cmd].out_fd_count; \
+})
+
+#define COMMAND_USE_CWD_FD(data_ptr) command_properties[data_ptr->cmd].use_cwd_fd
+
+struct run_as_command_properties {
+ /* Set to -1 when not applicable. */
+ ptrdiff_t in_fds_offset, out_fds_offset;
+ unsigned int in_fd_count, out_fd_count;
+ bool use_cwd_fd;
+};
+
+static const struct run_as_command_properties command_properties[] = {
+ [RUN_AS_MKDIR] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
+ .in_fd_count = 1,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = true,
+ },
+ [RUN_AS_MKDIRAT] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
+ .in_fd_count = 1,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = false,
+ },
+ [RUN_AS_MKDIR_RECURSIVE] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
+ .in_fd_count = 1,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = true,
+ },
+ [RUN_AS_MKDIRAT_RECURSIVE] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.mkdir.dirfd),
+ .in_fd_count = 1,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = false,
+ },
+ [RUN_AS_OPEN] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.open.dirfd),
+ .in_fd_count = 1,
+ .out_fds_offset = offsetof(struct run_as_ret, u.open.fd),
+ .out_fd_count = 1,
+ .use_cwd_fd = true,
+ },
+ [RUN_AS_OPENAT] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.open.dirfd),
+ .in_fd_count = 1,
+ .out_fds_offset = offsetof(struct run_as_ret, u.open.fd),
+ .out_fd_count = 1,
+ .use_cwd_fd = false,
+ },
+ [RUN_AS_UNLINK] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.unlink.dirfd),
+ .in_fd_count = 1,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = true,
+ },
+ [RUN_AS_UNLINKAT] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.unlink.dirfd),
+ .in_fd_count = 1,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = false,
+ },
+ [RUN_AS_RMDIR_RECURSIVE] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
+ .in_fd_count = 1,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = true,
+ },
+ [RUN_AS_RMDIRAT_RECURSIVE] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
+ .in_fd_count = 1,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = false,
+ },
+ [RUN_AS_RMDIR] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
+ .in_fd_count = 1,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = true,
+ },
+ [RUN_AS_RMDIRAT] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.rmdir.dirfd),
+ .in_fd_count = 1,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = false,
+ },
+ [RUN_AS_RENAME] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.rename.dirfds),
+ .in_fd_count = 2,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = true,
+ },
+ [RUN_AS_RENAMEAT] = {
+ .in_fds_offset = offsetof(struct run_as_data, u.rename.dirfds),
+ .in_fd_count = 2,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = false,
+ },
+ [RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET] = {
+ .in_fds_offset = offsetof(struct run_as_data,
+ u.extract_elf_symbol_offset.fd),
+ .in_fd_count = 1,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = false,
+ },
+ [RUN_AS_EXTRACT_SDT_PROBE_OFFSETS] = {
+ .in_fds_offset = offsetof(struct run_as_data,
+ u.extract_sdt_probe_offsets.fd),
+ .in_fd_count = 1,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = false,
+ },
+ [RUN_AS_GENERATE_FILTER_BYTECODE] = {
+ .in_fds_offset = -1,
+ .in_fd_count = 0,
+ .out_fds_offset = -1,
+ .out_fd_count = 0,
+ .use_cwd_fd = false,
+ },
+};
+
+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)
}
#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 _mkdirat_recursive(struct run_as_data *data, struct run_as_ret *ret_value)
{
- struct run_as_mkdir_data *data = _data;
const char *path;
mode_t mode;
+ struct lttng_directory_handle *handle;
- path = data->path;
- mode = data->mode;
+ path = data->u.mkdir.path;
+ mode = data->u.mkdir.mode;
+ handle = lttng_directory_handle_create_from_dirfd(data->u.mkdir.dirfd);
+ if (!handle) {
+ ret_value->_errno = errno;
+ ret_value->_error = true;
+ ret_value->u.ret = -1;
+ goto end;
+ }
+ /* Ownership of dirfd is transferred to the handle. */
+ data->u.mkdir.dirfd = -1;
/* Safe to call as we have transitioned to the requested uid/gid. */
- return _utils_mkdir_recursive_unsafe(path, mode);
+ ret_value->u.ret = lttng_directory_handle_create_subdirectory_recursive(
+ handle, path, mode);
+ ret_value->_errno = errno;
+ ret_value->_error = (ret_value->u.ret) ? true : false;
+ lttng_directory_handle_put(handle);
+end:
+ return ret_value->u.ret;
}
static
-int _mkdir(void *_data)
+int _mkdirat(struct run_as_data *data, struct run_as_ret *ret_value)
{
- struct run_as_mkdir_data *data = _data;
+ const char *path;
+ mode_t mode;
+ struct lttng_directory_handle *handle;
+
+ path = data->u.mkdir.path;
+ mode = data->u.mkdir.mode;
- return mkdir(data->path, data->mode);
+ handle = lttng_directory_handle_create_from_dirfd(data->u.mkdir.dirfd);
+ if (!handle) {
+ ret_value->u.ret = -1;
+ ret_value->_errno = errno;
+ ret_value->_error = true;
+ goto end;
+ }
+ /* Ownership of dirfd is transferred to the handle. */
+ data->u.mkdir.dirfd = -1;
+ /* Safe to call as we have transitioned to the requested uid/gid. */
+ ret_value->u.ret = lttng_directory_handle_create_subdirectory(
+ handle, path, mode);
+ ret_value->_errno = errno;
+ ret_value->_error = (ret_value->u.ret) ? true : false;
+ lttng_directory_handle_put(handle);
+end:
+ return ret_value->u.ret;
}
static
-int _open(void *_data)
+int _open(struct run_as_data *data, struct run_as_ret *ret_value)
{
- struct run_as_open_data *data = _data;
+ int fd;
+ struct lttng_directory_handle *handle;
+
+ handle = lttng_directory_handle_create_from_dirfd(data->u.open.dirfd);
+ if (!handle) {
+ ret_value->_errno = errno;
+ ret_value->_error = true;
+ ret_value->u.ret = -1;
+ goto end;
+ }
+ /* Ownership of dirfd is transferred to the handle. */
+ data->u.open.dirfd = -1;
+
+ fd = lttng_directory_handle_open_file(handle,
+ data->u.open.path, data->u.open.flags,
+ data->u.open.mode);
+ if (fd < 0) {
+ ret_value->u.ret = -1;
+ ret_value->u.open.fd = -1;
+ } else {
+ ret_value->u.ret = 0;
+ ret_value->u.open.fd = fd;
+ }
- return open(data->path, data->flags, data->mode);
+ ret_value->_errno = errno;
+ ret_value->_error = fd < 0;
+ lttng_directory_handle_put(handle);
+end:
+ return ret_value->u.ret;
}
static
-int _unlink(void *_data)
+int _unlink(struct run_as_data *data, struct run_as_ret *ret_value)
{
- struct run_as_unlink_data *data = _data;
+ struct lttng_directory_handle *handle;
+
+ handle = lttng_directory_handle_create_from_dirfd(data->u.unlink.dirfd);
+ if (!handle) {
+ ret_value->u.ret = -1;
+ ret_value->_errno = errno;
+ ret_value->_error = true;
+ goto end;
+ }
- return unlink(data->path);
+ /* Ownership of dirfd is transferred to the handle. */
+ data->u.unlink.dirfd = -1;
+
+ ret_value->u.ret = lttng_directory_handle_unlink_file(handle,
+ data->u.unlink.path);
+ ret_value->_errno = errno;
+ ret_value->_error = (ret_value->u.ret) ? true : false;
+ lttng_directory_handle_put(handle);
+end:
+ return ret_value->u.ret;
}
static
-int _recursive_rmdir(void *_data)
+int _rmdir(struct run_as_data *data, struct run_as_ret *ret_value)
{
- struct run_as_recursive_rmdir_data *data = _data;
+ struct lttng_directory_handle *handle;
+
+ handle = lttng_directory_handle_create_from_dirfd(data->u.rmdir.dirfd);
+ if (!handle) {
+ ret_value->u.ret = -1;
+ ret_value->_errno = errno;
+ ret_value->_error = true;
+ goto end;
+ }
+
+ /* Ownership of dirfd is transferred to the handle. */
+ data->u.rmdir.dirfd = -1;
- return utils_recursive_rmdir(data->path);
+ ret_value->u.ret = lttng_directory_handle_remove_subdirectory(
+ handle, data->u.rmdir.path);
+ ret_value->_errno = errno;
+ ret_value->_error = (ret_value->u.ret) ? true : false;
+ lttng_directory_handle_put(handle);
+end:
+ return ret_value->u.ret;
}
static
-int child_run_as(void *_data)
+int _rmdir_recursive(struct run_as_data *data, struct run_as_ret *ret_value)
{
- int ret;
- struct run_as_data *data = _data;
- ssize_t writelen;
- struct run_as_ret sendret;
+ struct lttng_directory_handle *handle;
- /*
- * 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);
- if (ret < 0) {
- PERROR("setegid");
- goto write_return;
- }
- }
- if (data->uid != geteuid()) {
- ret = seteuid(data->uid);
- if (ret < 0) {
- PERROR("seteuid");
- goto write_return;
- }
+ handle = lttng_directory_handle_create_from_dirfd(data->u.rmdir.dirfd);
+ if (!handle) {
+ ret_value->u.ret = -1;
+ ret_value->_errno = errno;
+ ret_value->_error = true;
+ goto end;
}
- /*
- * Also set umask to 0 for mkdir executable bit.
- */
- umask(0);
- ret = (*data->cmd)(data->data);
-write_return:
- sendret.ret = ret;
- sendret._errno = errno;
- /* send back return value */
- writelen = lttng_write(data->retval_pipe, &sendret, sizeof(sendret));
- if (writelen < sizeof(sendret)) {
- PERROR("lttng_write error");
- return EXIT_FAILURE;
- } else {
- return EXIT_SUCCESS;
- }
+ /* Ownership of dirfd is transferred to the handle. */
+ data->u.rmdir.dirfd = -1;
+
+ ret_value->u.ret = lttng_directory_handle_remove_subdirectory_recursive(
+ handle, data->u.rmdir.path, data->u.rmdir.flags);
+ ret_value->_errno = errno;
+ ret_value->_error = (ret_value->u.ret) ? true : false;
+ lttng_directory_handle_put(handle);
+end:
+ return ret_value->u.ret;
}
static
-int run_as_clone(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
+int _rename(struct run_as_data *data, struct run_as_ret *ret_value)
{
- struct run_as_data run_as_data;
- int ret = 0;
- ssize_t readlen;
- int status;
- pid_t pid;
- int retval_pipe[2];
- void *child_stack;
- struct run_as_ret recvret;
+ const char *old_path, *new_path;
+ struct lttng_directory_handle *old_handle = NULL, *new_handle = NULL;
- /*
- * 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());
- goto end;
- }
- }
+ old_path = data->u.rename.old_path;
+ new_path = data->u.rename.new_path;
- ret = pipe(retval_pipe);
- if (ret < 0) {
- recvret.ret = -1;
- recvret._errno = errno;
- PERROR("pipe");
- 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 | LTTNG_MAP_STACK,
- -1, 0);
- if (child_stack == MAP_FAILED) {
- recvret.ret = -1;
- recvret._errno = ENOMEM;
- PERROR("mmap");
- goto close_pipe;
- }
- /*
- * 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) {
- recvret.ret = -1;
- recvret._errno = errno;
- PERROR("clone");
- goto unmap_stack;
+ old_handle = lttng_directory_handle_create_from_dirfd(
+ data->u.rename.dirfds[0]);
+ if (!old_handle) {
+ ret_value->u.ret = -1;
+ goto end;
}
- /* receive return value */
- readlen = lttng_read(retval_pipe[0], &recvret, sizeof(recvret));
- if (readlen < sizeof(recvret)) {
- recvret.ret = -1;
- recvret._errno = errno;
+ new_handle = lttng_directory_handle_create_from_dirfd(
+ data->u.rename.dirfds[1]);
+ if (!new_handle) {
+ ret_value->u.ret = -1;
+ goto end;
}
- /*
- * 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) {
- recvret.ret = -1;
- recvret._errno = errno;
- PERROR("wait");
- }
-unmap_stack:
- ret = munmap(child_stack, RUNAS_CHILD_STACK_SIZE);
- if (ret < 0) {
- recvret.ret = -1;
- recvret._errno = errno;
- PERROR("munmap");
- }
-close_pipe:
- ret = close(retval_pipe[0]);
+ /* Ownership of dirfds are transferred to the handles. */
+ data->u.rename.dirfds[0] = data->u.rename.dirfds[1] = -1;
+
+ /* Safe to call as we have transitioned to the requested uid/gid. */
+ ret_value->u.ret = lttng_directory_handle_rename(
+ old_handle, old_path, new_handle, new_path);
+end:
+ lttng_directory_handle_put(old_handle);
+ lttng_directory_handle_put(new_handle);
+ ret_value->_errno = errno;
+ ret_value->_error = (ret_value->u.ret) ? true : false;
+ return ret_value->u.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;
+ uint64_t offset;
+
+ ret_value->_error = false;
+ ret = lttng_elf_get_symbol_offset(data->u.extract_elf_symbol_offset.fd,
+ data->u.extract_elf_symbol_offset.function,
+ &offset);
if (ret) {
- recvret.ret = -1;
- recvret._errno = errno;
- PERROR("close");
+ DBG("Failed to extract ELF function offset");
+ ret_value->_error = true;
}
- ret = close(retval_pipe[1]);
+ ret_value->u.extract_elf_symbol_offset.offset = offset;
+
+ 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->u.extract_sdt_probe_offsets.fd,
+ data->u.extract_sdt_probe_offsets.provider_name,
+ data->u.extract_sdt_probe_offsets.probe_name,
+ &offsets, &num_offset);
+
if (ret) {
- recvret.ret = -1;
- recvret._errno = errno;
- PERROR("close");
+ 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:
- errno = recvret._errno;
- return recvret.ret;
+ 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;
}
-/*
- * To be used on setups where gdb has issues debugging programs using
- * clone/rfork. Note that this is for debuging ONLY, and should not be
- * considered secure.
- */
static
-int run_as_noclone(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
+int _extract_sdt_probe_offsets(struct run_as_data *data,
+ struct run_as_ret *ret_value)
{
- int ret, saved_errno;
- mode_t old_mask;
+ ERR("Unimplemented runas command RUN_AS_EXTRACT_SDT_PROBE_OFFSETS");
+ return -1;
+}
+#endif
- old_mask = umask(0);
- ret = cmd(data);
- saved_errno = errno;
- umask(old_mask);
- errno = saved_errno;
+static
+int _generate_filter_bytecode(struct run_as_data *data,
+ struct run_as_ret *ret_value) {
+ int ret = 0;
+ const char *filter_expression = NULL;
+ struct filter_parser_ctx *ctx = NULL;
+
+ ret_value->_error = false;
+
+ filter_expression = data->u.generate_filter_bytecode.filter_expression;
+
+ if (lttng_strnlen(filter_expression, LTTNG_FILTER_MAX_LEN - 1) == LTTNG_FILTER_MAX_LEN - 1) {
+ ret_value->_error = true;
+ ret = -1;
+ goto end;
+ }
+
+ ret = filter_parser_ctx_create_from_filter_expression(filter_expression, &ctx);
+ if (ret < 0) {
+ ret_value->_error = true;
+ ret = -1;
+ goto end;
+ }
+
+ DBG("Size of bytecode generated: %u bytes.",
+ bytecode_get_len(&ctx->bytecode->b));
+
+ /* Copy the lttng_bytecode_filter object to the return structure. */
+ memcpy(ret_value->u.generate_filter_bytecode.bytecode,
+ &ctx->bytecode->b,
+ sizeof(ctx->bytecode->b) +
+ bytecode_get_len(&ctx->bytecode->b));
+
+end:
+ if (ctx) {
+ filter_bytecode_free(ctx);
+ filter_ir_free(ctx);
+ filter_parser_ctx_free(ctx);
+ }
return ret;
}
+static
+run_as_fct run_as_enum_to_fct(enum run_as_cmd cmd)
+{
+ switch (cmd) {
+ case RUN_AS_MKDIR:
+ case RUN_AS_MKDIRAT:
+ return _mkdirat;
+ case RUN_AS_MKDIR_RECURSIVE:
+ case RUN_AS_MKDIRAT_RECURSIVE:
+ return _mkdirat_recursive;
+ case RUN_AS_OPEN:
+ case RUN_AS_OPENAT:
+ return _open;
+ case RUN_AS_UNLINK:
+ case RUN_AS_UNLINKAT:
+ return _unlink;
+ case RUN_AS_RMDIR:
+ case RUN_AS_RMDIRAT:
+ return _rmdir;
+ case RUN_AS_RMDIR_RECURSIVE:
+ case RUN_AS_RMDIRAT_RECURSIVE:
+ return _rmdir_recursive;
+ case RUN_AS_RENAME:
+ case RUN_AS_RENAMEAT:
+ return _rename;
+ case RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET:
+ return _extract_elf_symbol_offset;
+ case RUN_AS_EXTRACT_SDT_PROBE_OFFSETS:
+ return _extract_sdt_probe_offsets;
+ case RUN_AS_GENERATE_FILTER_BYTECODE:
+ return _generate_filter_bytecode;
+ default:
+ ERR("Unknown command %d", (int) cmd);
+ return NULL;
+ }
+}
static
-int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
+int do_send_fds(int sock, const int *fds, unsigned int fd_count)
{
- if (use_clone()) {
- int ret;
+ ssize_t len;
+ unsigned int i;
- DBG("Using run_as_clone");
- pthread_mutex_lock(<tng_libc_state_lock);
- ret = run_as_clone(cmd, data, uid, gid);
- pthread_mutex_unlock(<tng_libc_state_lock);
- return ret;
- } else {
- DBG("Using run_as_noclone");
- return run_as_noclone(cmd, data, uid, gid);
+ for (i = 0; i < fd_count; i++) {
+ if (fds[i] < 0) {
+ ERR("Attempt to send invalid file descriptor to master (fd = %i)",
+ fds[i]);
+ /* Return 0 as this is not a fatal error. */
+ return 0;
+ }
}
+
+ len = lttcomm_send_fds_unix_sock(sock, fds, fd_count);
+ return len < 0 ? -1 : 0;
}
-LTTNG_HIDDEN
-int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid)
+static
+int do_recv_fds(int sock, int *fds, unsigned int fd_count)
{
- struct run_as_mkdir_data data;
+ int ret = 0;
+ unsigned int i;
+ ssize_t len;
+
+ len = lttcomm_recv_fds_unix_sock(sock, fds, fd_count);
+ if (len == 0) {
+ ret = -1;
+ goto end;
+ } else if (len < 0) {
+ PERROR("Failed to receive file descriptors from socket");
+ ret = -1;
+ goto end;
+ }
- 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);
+ for (i = 0; i < fd_count; i++) {
+ if (fds[i] < 0) {
+ ERR("Invalid file descriptor received from worker (fd = %i)", fds[i]);
+ /* Return 0 as this is not a fatal error. */
+ }
+ }
+end:
+ return ret;
}
-LTTNG_HIDDEN
-int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid)
+static
+int send_fds_to_worker(const struct run_as_worker *worker,
+ const struct run_as_data *data)
{
- struct run_as_mkdir_data data;
+ int ret = 0;
+ unsigned int i;
+
+ if (COMMAND_USE_CWD_FD(data) || COMMAND_IN_FD_COUNT(data) == 0) {
+ goto end;
+ }
+
+ for (i = 0; i < COMMAND_IN_FD_COUNT(data); i++) {
+ if (COMMAND_IN_FDS(data)[i] < 0) {
+ ERR("Refusing to send invalid fd to worker (fd = %i)",
+ COMMAND_IN_FDS(data)[i]);
+ ret = -1;
+ goto end;
+ }
+ }
- 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);
+ ret = do_send_fds(worker->sockpair[0], COMMAND_IN_FDS(data),
+ COMMAND_IN_FD_COUNT(data));
+ if (ret < 0) {
+ PERROR("Failed to send file descriptor to run-as worker");
+ ret = -1;
+ goto end;
+ }
+end:
+ return ret;
}
-/*
- * 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)
+static
+int send_fds_to_master(struct run_as_worker *worker, enum run_as_cmd cmd,
+ struct run_as_ret *run_as_ret)
{
- struct run_as_open_data data;
+ int ret = 0;
+ unsigned int i;
+
+ if (COMMAND_OUT_FD_COUNT(cmd) == 0) {
+ goto end;
+ }
+
+ ret = do_send_fds(worker->sockpair[1], COMMAND_OUT_FDS(cmd, run_as_ret),
+ COMMAND_OUT_FD_COUNT(cmd));
+ if (ret < 0) {
+ PERROR("Failed to send file descriptor to master process");
+ goto end;
+ }
- 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);
+ for (i = 0; i < COMMAND_OUT_FD_COUNT(cmd); i++) {
+ int ret_close = close(COMMAND_OUT_FDS(cmd, run_as_ret)[i]);
+
+ if (ret_close < 0) {
+ PERROR("Failed to close result file descriptor");
+ }
+ }
+end:
+ return ret;
}
-LTTNG_HIDDEN
-int run_as_unlink(const char *path, uid_t uid, gid_t gid)
+static
+int recv_fds_from_worker(const struct run_as_worker *worker, enum run_as_cmd cmd,
+ struct run_as_ret *run_as_ret)
{
- struct run_as_unlink_data data;
+ int ret = 0;
+
+ if (COMMAND_OUT_FD_COUNT(cmd) == 0) {
+ goto end;
+ }
- DBG3("unlink() %s with for uid %d and gid %d",
- path, uid, gid);
- data.path = path;
- return run_as(_unlink, &data, uid, gid);
+ ret = do_recv_fds(worker->sockpair[0], COMMAND_OUT_FDS(cmd, run_as_ret),
+ COMMAND_OUT_FD_COUNT(cmd));
+ if (ret < 0) {
+ PERROR("Failed to receive file descriptor from run-as worker");
+ ret = -1;
+ }
+end:
+ return ret;
}
-LTTNG_HIDDEN
-int run_as_recursive_rmdir(const char *path, uid_t uid, gid_t gid)
+static
+int recv_fds_from_master(struct run_as_worker *worker, struct run_as_data *data)
{
- struct run_as_recursive_rmdir_data data;
+ int ret = 0;
+
+ if (COMMAND_USE_CWD_FD(data)) {
+ unsigned int i;
+
+ for (i = 0; i < COMMAND_IN_FD_COUNT(data); i++) {
+ COMMAND_IN_FDS(data)[i] = AT_FDCWD;
+ }
+ goto end;
+ }
+
+ if (COMMAND_IN_FD_COUNT(data) == 0) {
+ goto end;
+ }
+
+ ret = do_recv_fds(worker->sockpair[1], COMMAND_IN_FDS(data),
+ COMMAND_IN_FD_COUNT(data));
+ if (ret < 0) {
+ PERROR("Failed to receive file descriptors from master process");
+ ret = -1;
+ }
+end:
+ return ret;
+}
+
+static
+int cleanup_received_fds(struct run_as_data *data)
+{
+ int ret = 0, i;
+
+ for (i = 0; i < COMMAND_IN_FD_COUNT(data); i++) {
+ if (COMMAND_IN_FDS(data)[i] == -1) {
+ continue;
+ }
+ ret = close(COMMAND_IN_FDS(data)[i]);
+ if (ret) {
+ PERROR("Failed to close file descriptor received fd in run-as worker");
+ goto end;
+ }
+ }
+end:
+ 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;
+
+ /*
+ * 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_fds_from_master(worker, &data);
+ 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_fds(&data);
+ 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 resulting file descriptors to the master.
+ */
+ ret = send_fds_to_master(worker, data.cmd, &sendret);
+ 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_thread_setname(DEFAULT_RUN_AS_WORKER_NAME);
+ if (ret && ret != -ENOSYS) {
+ /* Don't fail as this is not essential. */
+ DBG("Failed to set pthread name attribute");
+ }
+
+ 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_fds_to_worker(worker, data);
+ 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_fds_from_worker(worker, cmd, ret_value);
+ 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();
- DBG3("recursive_rmdir() %s with for uid %d and gid %d",
- path, uid, gid);
- data.path = path;
- return run_as(_recursive_rmdir, &data, uid, gid);
+ /* 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)
+{
+ return run_as_mkdirat_recursive(AT_FDCWD, path, mode, uid, gid);
+}
+
+LTTNG_HIDDEN
+int run_as_mkdirat_recursive(int dirfd, const char *path, mode_t mode,
+ uid_t uid, gid_t gid)
+{
+ int ret;
+ struct run_as_data data = {};
+ struct run_as_ret run_as_ret = {};
+
+ DBG3("mkdirat() recursive fd = %d%s, path = %s, mode = %d, uid = %d, gid = %d",
+ dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
+ path, (int) mode, (int) uid, (int) gid);
+ ret = lttng_strncpy(data.u.mkdir.path, path,
+ sizeof(data.u.mkdir.path));
+ if (ret) {
+ ERR("Failed to copy path argument of mkdirat recursive command");
+ goto error;
+ }
+ data.u.mkdir.path[sizeof(data.u.mkdir.path) - 1] = '\0';
+ data.u.mkdir.mode = mode;
+ data.u.mkdir.dirfd = dirfd;
+ run_as(dirfd == AT_FDCWD ? RUN_AS_MKDIR_RECURSIVE : RUN_AS_MKDIRAT_RECURSIVE,
+ &data, &run_as_ret, uid, gid);
+ errno = run_as_ret._errno;
+ ret = run_as_ret.u.ret;
+error:
+ return ret;
+}
+
+LTTNG_HIDDEN
+int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid)
+{
+ return run_as_mkdirat(AT_FDCWD, path, mode, uid, gid);
+}
+
+LTTNG_HIDDEN
+int run_as_mkdirat(int dirfd, const char *path, mode_t mode,
+ uid_t uid, gid_t gid)
+{
+ int ret;
+ struct run_as_data data = {};
+ struct run_as_ret run_as_ret = {};
+
+ DBG3("mkdirat() recursive fd = %d%s, path = %s, mode = %d, uid = %d, gid = %d",
+ dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
+ path, (int) mode, (int) uid, (int) gid);
+ ret = lttng_strncpy(data.u.mkdir.path, path,
+ sizeof(data.u.mkdir.path));
+ if (ret) {
+ ERR("Failed to copy path argument of mkdirat command");
+ goto error;
+ }
+ data.u.mkdir.path[sizeof(data.u.mkdir.path) - 1] = '\0';
+ data.u.mkdir.mode = mode;
+ data.u.mkdir.dirfd = dirfd;
+ run_as(dirfd == AT_FDCWD ? RUN_AS_MKDIR : RUN_AS_MKDIRAT,
+ &data, &run_as_ret, uid, gid);
+ errno = run_as_ret._errno;
+ ret = run_as_ret.u.ret;
+error:
+ return ret;
+}
+
+LTTNG_HIDDEN
+int run_as_open(const char *path, int flags, mode_t mode, uid_t uid,
+ gid_t gid)
+{
+ return run_as_openat(AT_FDCWD, path, flags, mode, uid, gid);
+}
+
+LTTNG_HIDDEN
+int run_as_openat(int dirfd, const char *path, int flags, mode_t mode,
+ uid_t uid, gid_t gid)
+{
+ int ret;
+ struct run_as_data data = {};
+ struct run_as_ret run_as_ret = {};
+
+ DBG3("openat() fd = %d%s, path = %s, flags = %X, mode = %d, uid %d, gid %d",
+ dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
+ path, flags, (int) mode, (int) uid, (int) gid);
+ ret = lttng_strncpy(data.u.open.path, path, sizeof(data.u.open.path));
+ if (ret) {
+ ERR("Failed to copy path argument of open command");
+ goto error;
+ }
+ data.u.open.flags = flags;
+ data.u.open.mode = mode;
+ data.u.open.dirfd = dirfd;
+ run_as(dirfd == AT_FDCWD ? RUN_AS_OPEN : RUN_AS_OPENAT,
+ &data, &run_as_ret, uid, gid);
+ errno = run_as_ret._errno;
+ ret = run_as_ret.u.ret < 0 ? run_as_ret.u.ret :
+ run_as_ret.u.open.fd;
+error:
+ return ret;
+}
+
+LTTNG_HIDDEN
+int run_as_unlink(const char *path, uid_t uid, gid_t gid)
+{
+ return run_as_unlinkat(AT_FDCWD, path, uid, gid);
+}
+
+LTTNG_HIDDEN
+int run_as_unlinkat(int dirfd, const char *path, uid_t uid, gid_t gid)
+{
+ int ret;
+ struct run_as_data data = {};
+ struct run_as_ret run_as_ret = {};
+
+ DBG3("unlinkat() fd = %d%s, path = %s, uid = %d, gid = %d",
+ dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
+ path, (int) uid, (int) gid);
+ ret = lttng_strncpy(data.u.unlink.path, path,
+ sizeof(data.u.unlink.path));
+ if (ret) {
+ goto error;
+ }
+ data.u.unlink.dirfd = dirfd;
+ run_as(dirfd == AT_FDCWD ? RUN_AS_UNLINK : RUN_AS_UNLINKAT, &data,
+ &run_as_ret, uid, gid);
+ errno = run_as_ret._errno;
+ ret = run_as_ret.u.ret;
+error:
+ return ret;
+}
+
+LTTNG_HIDDEN
+int run_as_rmdir(const char *path, uid_t uid, gid_t gid)
+{
+ return run_as_rmdirat(AT_FDCWD, path, uid, gid);
+}
+
+LTTNG_HIDDEN
+int run_as_rmdirat(int dirfd, const char *path, uid_t uid, gid_t gid)
+{
+ int ret;
+ struct run_as_data data = {};
+ struct run_as_ret run_as_ret = {};
+
+ DBG3("rmdirat() fd = %d%s, path = %s, uid = %d, gid = %d",
+ dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
+ path, (int) uid, (int) gid);
+ ret = lttng_strncpy(data.u.rmdir.path, path,
+ sizeof(data.u.rmdir.path));
+ if (ret) {
+ goto error;
+ }
+ data.u.rmdir.dirfd = dirfd;
+ run_as(dirfd == AT_FDCWD ? RUN_AS_RMDIR : RUN_AS_RMDIRAT, &data,
+ &run_as_ret, uid, gid);
+ errno = run_as_ret._errno;
+ ret = run_as_ret.u.ret;
+error:
+ return ret;
+}
+
+LTTNG_HIDDEN
+int run_as_rmdir_recursive(const char *path, uid_t uid, gid_t gid, int flags)
+{
+ return run_as_rmdirat_recursive(AT_FDCWD, path, uid, gid, flags);
+}
+
+LTTNG_HIDDEN
+int run_as_rmdirat_recursive(int dirfd, const char *path, uid_t uid, gid_t gid, int flags)
+{
+ int ret;
+ struct run_as_data data = {};
+ struct run_as_ret run_as_ret = {};
+
+ DBG3("rmdirat() recursive fd = %d%s, path = %s, uid = %d, gid = %d",
+ dirfd, dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
+ path, (int) uid, (int) gid);
+ ret = lttng_strncpy(data.u.rmdir.path, path,
+ sizeof(data.u.rmdir.path));
+ if (ret) {
+ goto error;
+ }
+ data.u.rmdir.dirfd = dirfd;
+ data.u.rmdir.flags = flags;
+ run_as(dirfd == AT_FDCWD ? RUN_AS_RMDIR_RECURSIVE : RUN_AS_RMDIRAT_RECURSIVE,
+ &data, &run_as_ret, uid, gid);
+ errno = run_as_ret._errno;
+ ret = run_as_ret.u.ret;
+error:
+ return ret;
+}
+
+LTTNG_HIDDEN
+int run_as_rename(const char *old, const char *new, uid_t uid, gid_t gid)
+{
+ return run_as_renameat(AT_FDCWD, old, AT_FDCWD, new, uid, gid);
+}
+
+LTTNG_HIDDEN
+int run_as_renameat(int old_dirfd, const char *old_name,
+ int new_dirfd, const char *new_name, uid_t uid, gid_t gid)
+{
+ int ret;
+ struct run_as_data data = {};
+ struct run_as_ret run_as_ret = {};
+
+ DBG3("renameat() old_dirfd = %d%s, old_name = %s, new_dirfd = %d%s, new_name = %s, uid = %d, gid = %d",
+ old_dirfd, old_dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
+ old_name,
+ new_dirfd, new_dirfd == AT_FDCWD ? " (AT_FDCWD)" : "",
+ new_name, (int) uid, (int) gid);
+ ret = lttng_strncpy(data.u.rename.old_path, old_name,
+ sizeof(data.u.rename.old_path));
+ if (ret) {
+ goto error;
+ }
+ ret = lttng_strncpy(data.u.rename.new_path, new_name,
+ sizeof(data.u.rename.new_path));
+ if (ret) {
+ goto error;
+ }
+
+ data.u.rename.dirfds[0] = old_dirfd;
+ data.u.rename.dirfds[1] = new_dirfd;
+ run_as(old_dirfd == AT_FDCWD && new_dirfd == AT_FDCWD ?
+ RUN_AS_RENAME : RUN_AS_RENAMEAT,
+ &data, &run_as_ret, uid, gid);
+ errno = run_as_ret._errno;
+ ret = run_as_ret.u.ret;
+error:
+ return ret;
+}
+
+LTTNG_HIDDEN
+int run_as_extract_elf_symbol_offset(int fd, const char* function,
+ uid_t uid, gid_t gid, uint64_t *offset)
+{
+ int ret;
+ struct run_as_data data = {};
+ struct run_as_ret run_as_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.u.extract_elf_symbol_offset.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';
+ ret = lttng_strncpy(data.u.extract_elf_symbol_offset.function,
+ function,
+ sizeof(data.u.extract_elf_symbol_offset.function));
+ if (ret) {
+ goto error;
+ }
+
+ run_as(RUN_AS_EXTRACT_ELF_SYMBOL_OFFSET, &data, &run_as_ret, uid, gid);
+ errno = run_as_ret._errno;
+ if (run_as_ret._error) {
+ ret = -1;
+ goto error;
+ }
+
+ *offset = run_as_ret.u.extract_elf_symbol_offset.offset;
+error:
+ return ret;
+}
+
+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)
+{
+ int ret;
+ struct run_as_data data = {};
+ struct run_as_ret run_as_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.u.extract_sdt_probe_offsets.fd = fd;
+
+ ret = lttng_strncpy(data.u.extract_sdt_probe_offsets.probe_name, probe_name,
+ sizeof(data.u.extract_sdt_probe_offsets.probe_name));
+ if (ret) {
+ goto error;
+ }
+ ret = lttng_strncpy(data.u.extract_sdt_probe_offsets.provider_name,
+ provider_name,
+ sizeof(data.u.extract_sdt_probe_offsets.provider_name));
+ if (ret) {
+ goto error;
+ }
+
+ run_as(RUN_AS_EXTRACT_SDT_PROBE_OFFSETS, &data, &run_as_ret, uid, gid);
+ errno = run_as_ret._errno;
+ if (run_as_ret._error) {
+ ret = -1;
+ goto error;
+ }
+
+ *num_offset = run_as_ret.u.extract_sdt_probe_offsets.num_offset;
+ *offsets = zmalloc(*num_offset * sizeof(uint64_t));
+ if (!*offsets) {
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ memcpy(*offsets, run_as_ret.u.extract_sdt_probe_offsets.offsets,
+ *num_offset * sizeof(uint64_t));
+error:
+ return ret;
+}
+
+LTTNG_HIDDEN
+int run_as_generate_filter_bytecode(const char *filter_expression,
+ uid_t uid,
+ gid_t gid,
+ struct lttng_bytecode **bytecode)
+{
+ int ret;
+ struct run_as_data data = {};
+ struct run_as_ret run_as_ret = {};
+ const struct lttng_bytecode *view_bytecode = NULL;
+ struct lttng_bytecode *local_bytecode = NULL;
+
+ DBG3("generate_filter_bytecode() from expression=\"%s\" for uid %d and gid %d",
+ filter_expression, (int) uid, (int) gid);
+
+ ret = lttng_strncpy(data.u.generate_filter_bytecode.filter_expression, filter_expression,
+ sizeof(data.u.generate_filter_bytecode.filter_expression));
+ if (ret) {
+ goto error;
+ }
+
+ run_as(RUN_AS_GENERATE_FILTER_BYTECODE, &data, &run_as_ret, uid, gid);
+ errno = run_as_ret._errno;
+ if (run_as_ret._error) {
+ ret = -1;
+ goto error;
+ }
+
+ view_bytecode = (const struct lttng_bytecode *) run_as_ret.u.generate_filter_bytecode.bytecode;
+
+ local_bytecode = zmalloc(sizeof(*local_bytecode) + view_bytecode->len);
+ if (!local_bytecode) {
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ memcpy(local_bytecode, run_as_ret.u.generate_filter_bytecode.bytecode,
+ sizeof(*local_bytecode) + view_bytecode->len);
+ *bytecode = local_bytecode;
+error:
+ return ret;
+}
+
+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);
}
projects / lttng-tools.git / blobdiff