Adding upstream version 247.3.upstream/247.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 446 insertions, 0 deletions

diff --git a/src/shared/exec-util.c b/src/shared/exec-util.c
new file mode 100644
index 0000000..61ee3b1
--- /dev/null
+++ b/src/shared/exec-util.c
@@ -0,0 +1,446 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <dirent.h>
+#include <errno.h>
+#include <sys/prctl.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#include "alloc-util.h"
+#include "conf-files.h"
+#include "env-file.h"
+#include "env-util.h"
+#include "exec-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "hashmap.h"
+#include "macro.h"
+#include "process-util.h"
+#include "rlimit-util.h"
+#include "serialize.h"
+#include "set.h"
+#include "signal-util.h"
+#include "stat-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+#include "terminal-util.h"
+#include "tmpfile-util.h"
+#include "util.h"
+
+/* Put this test here for a lack of better place */
+assert_cc(EAGAIN == EWOULDBLOCK);
+
+static int do_spawn(const char *path, char *argv[], int stdout_fd, pid_t *pid) {
+
+        pid_t _pid;
+        int r;
+
+        if (null_or_empty_path(path)) {
+                log_debug("%s is empty (a mask).", path);
+                return 0;
+        }
+
+        r = safe_fork("(direxec)", FORK_DEATHSIG|FORK_LOG, &_pid);
+        if (r < 0)
+                return r;
+        if (r == 0) {
+                char *_argv[2];
+
+                if (stdout_fd >= 0) {
+                        r = rearrange_stdio(STDIN_FILENO, stdout_fd, STDERR_FILENO);
+                        if (r < 0)
+                                _exit(EXIT_FAILURE);
+                }
+
+                (void) rlimit_nofile_safe();
+
+                if (!argv) {
+                        _argv[0] = (char*) path;
+                        _argv[1] = NULL;
+                        argv = _argv;
+                } else
+                        argv[0] = (char*) path;
+
+                execv(path, argv);
+                log_error_errno(errno, "Failed to execute %s: %m", path);
+                _exit(EXIT_FAILURE);
+        }
+
+        *pid = _pid;
+        return 1;
+}
+
+static int do_execute(
+                char **directories,
+                usec_t timeout,
+                gather_stdout_callback_t const callbacks[_STDOUT_CONSUME_MAX],
+                void* const callback_args[_STDOUT_CONSUME_MAX],
+                int output_fd,
+                char *argv[],
+                char *envp[],
+                ExecDirFlags flags) {
+
+        _cleanup_hashmap_free_free_ Hashmap *pids = NULL;
+        _cleanup_strv_free_ char **paths = NULL;
+        char **path, **e;
+        int r;
+        bool parallel_execution;
+
+        /* We fork this all off from a child process so that we can somewhat cleanly make
+         * use of SIGALRM to set a time limit.
+         *
+         * We attempt to perform parallel execution if configured by the user, however
+         * if `callbacks` is nonnull, execution must be serial.
+         */
+        parallel_execution = FLAGS_SET(flags, EXEC_DIR_PARALLEL) && !callbacks;
+
+        r = conf_files_list_strv(&paths, NULL, NULL, CONF_FILES_EXECUTABLE|CONF_FILES_REGULAR|CONF_FILES_FILTER_MASKED, (const char* const*) directories);
+        if (r < 0)
+                return log_error_errno(r, "Failed to enumerate executables: %m");
+
+        if (parallel_execution) {
+                pids = hashmap_new(NULL);
+                if (!pids)
+                        return log_oom();
+        }
+
+        /* Abort execution of this process after the timeout. We simply rely on SIGALRM as
+         * default action terminating the process, and turn on alarm(). */
+
+        if (timeout != USEC_INFINITY)
+                alarm(DIV_ROUND_UP(timeout, USEC_PER_SEC));
+
+        STRV_FOREACH(e, envp)
+                if (putenv(*e) != 0)
+                        return log_error_errno(errno, "Failed to set environment variable: %m");
+
+        STRV_FOREACH(path, paths) {
+                _cleanup_free_ char *t = NULL;
+                _cleanup_close_ int fd = -1;
+                pid_t pid;
+
+                t = strdup(*path);
+                if (!t)
+                        return log_oom();
+
+                if (callbacks) {
+                        fd = open_serialization_fd(basename(*path));
+                        if (fd < 0)
+                                return log_error_errno(fd, "Failed to open serialization file: %m");
+                }
+
+                r = do_spawn(t, argv, fd, &pid);
+                if (r <= 0)
+                        continue;
+
+                if (parallel_execution) {
+                        r = hashmap_put(pids, PID_TO_PTR(pid), t);
+                        if (r < 0)
+                                return log_oom();
+                        t = NULL;
+                } else {
+                        r = wait_for_terminate_and_check(t, pid, WAIT_LOG);
+                        if (FLAGS_SET(flags, EXEC_DIR_IGNORE_ERRORS)) {
+                                if (r < 0)
+                                        continue;
+                        } else if (r > 0)
+                                return r;
+
+                        if (callbacks) {
+                                if (lseek(fd, 0, SEEK_SET) < 0)
+                                        return log_error_errno(errno, "Failed to seek on serialization fd: %m");
+
+                                r = callbacks[STDOUT_GENERATE](fd, callback_args[STDOUT_GENERATE]);
+                                fd = -1;
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to process output from %s: %m", *path);
+                        }
+                }
+        }
+
+        if (callbacks) {
+                r = callbacks[STDOUT_COLLECT](output_fd, callback_args[STDOUT_COLLECT]);
+                if (r < 0)
+                        return log_error_errno(r, "Callback two failed: %m");
+        }
+
+        while (!hashmap_isempty(pids)) {
+                _cleanup_free_ char *t = NULL;
+                pid_t pid;
+
+                pid = PTR_TO_PID(hashmap_first_key(pids));
+                assert(pid > 0);
+
+                t = hashmap_remove(pids, PID_TO_PTR(pid));
+                assert(t);
+
+                r = wait_for_terminate_and_check(t, pid, WAIT_LOG);
+                if (!FLAGS_SET(flags, EXEC_DIR_IGNORE_ERRORS) && r > 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int execute_directories(
+                const char* const* directories,
+                usec_t timeout,
+                gather_stdout_callback_t const callbacks[_STDOUT_CONSUME_MAX],
+                void* const callback_args[_STDOUT_CONSUME_MAX],
+                char *argv[],
+                char *envp[],
+                ExecDirFlags flags) {
+
+        char **dirs = (char**) directories;
+        _cleanup_close_ int fd = -1;
+        char *name;
+        int r;
+        pid_t executor_pid;
+
+        assert(!strv_isempty(dirs));
+
+        name = basename(dirs[0]);
+        assert(!isempty(name));
+
+        if (callbacks) {
+                assert(callback_args);
+                assert(callbacks[STDOUT_GENERATE]);
+                assert(callbacks[STDOUT_COLLECT]);
+                assert(callbacks[STDOUT_CONSUME]);
+
+                fd = open_serialization_fd(name);
+                if (fd < 0)
+                        return log_error_errno(fd, "Failed to open serialization file: %m");
+        }
+
+        /* Executes all binaries in the directories serially or in parallel and waits for
+         * them to finish. Optionally a timeout is applied. If a file with the same name
+         * exists in more than one directory, the earliest one wins. */
+
+        r = safe_fork("(sd-executor)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &executor_pid);
+        if (r < 0)
+                return r;
+        if (r == 0) {
+                r = do_execute(dirs, timeout, callbacks, callback_args, fd, argv, envp, flags);
+                _exit(r < 0 ? EXIT_FAILURE : r);
+        }
+
+        r = wait_for_terminate_and_check("(sd-executor)", executor_pid, 0);
+        if (r < 0)
+                return r;
+        if (!FLAGS_SET(flags, EXEC_DIR_IGNORE_ERRORS) && r > 0)
+                return r;
+
+        if (!callbacks)
+                return 0;
+
+        if (lseek(fd, 0, SEEK_SET) < 0)
+                return log_error_errno(errno, "Failed to rewind serialization fd: %m");
+
+        r = callbacks[STDOUT_CONSUME](fd, callback_args[STDOUT_CONSUME]);
+        fd = -1;
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse returned data: %m");
+        return 0;
+}
+
+static int gather_environment_generate(int fd, void *arg) {
+        char ***env = arg, **x, **y;
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_strv_free_ char **new = NULL;
+        int r;
+
+        /* Read a series of VAR=value assignments from fd, use them to update the list of
+         * variables in env. Also update the exported environment.
+         *
+         * fd is always consumed, even on error.
+         */
+
+        assert(env);
+
+        f = fdopen(fd, "r");
+        if (!f) {
+                safe_close(fd);
+                return -errno;
+        }
+
+        r = load_env_file_pairs(f, NULL, &new);
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH_PAIR(x, y, new) {
+                char *p;
+
+                if (!env_name_is_valid(*x)) {
+                        log_warning("Invalid variable assignment \"%s=...\", ignoring.", *x);
+                        continue;
+                }
+
+                p = strjoin(*x, "=", *y);
+                if (!p)
+                        return -ENOMEM;
+
+                r = strv_env_replace(env, p);
+                if (r < 0)
+                        return r;
+
+                if (setenv(*x, *y, true) < 0)
+                        return -errno;
+        }
+
+        return r;
+}
+
+static int gather_environment_collect(int fd, void *arg) {
+        _cleanup_fclose_ FILE *f = NULL;
+        char ***env = arg;
+        int r;
+
+        /* Write out a series of env=cescape(VAR=value) assignments to fd. */
+
+        assert(env);
+
+        f = fdopen(fd, "w");
+        if (!f) {
+                safe_close(fd);
+                return -errno;
+        }
+
+        r = serialize_strv(f, "env", *env);
+        if (r < 0)
+                return r;
+
+        r = fflush_and_check(f);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+static int gather_environment_consume(int fd, void *arg) {
+        _cleanup_fclose_ FILE *f = NULL;
+        char ***env = arg;
+        int r = 0;
+
+        /* Read a series of env=cescape(VAR=value) assignments from fd into env. */
+
+        assert(env);
+
+        f = fdopen(fd, "r");
+        if (!f) {
+                safe_close(fd);
+                return -errno;
+        }
+
+        for (;;) {
+                _cleanup_free_ char *line = NULL;
+                const char *v;
+                int k;
+
+                k = read_line(f, LONG_LINE_MAX, &line);
+                if (k < 0)
+                        return k;
+                if (k == 0)
+                        break;
+
+                v = startswith(line, "env=");
+                if (!v) {
+                        log_debug("Serialization line \"%s\" unexpectedly didn't start with \"env=\".", line);
+                        if (r == 0)
+                                r = -EINVAL;
+
+                        continue;
+                }
+
+                k = deserialize_environment(v, env);
+                if (k < 0) {
+                        log_debug_errno(k, "Invalid serialization line \"%s\": %m", line);
+
+                        if (r == 0)
+                                r = k;
+                }
+        }
+
+        return r;
+}
+
+int exec_command_flags_from_strv(char **ex_opts, ExecCommandFlags *flags) {
+        ExecCommandFlags ex_flag, ret_flags = 0;
+        char **opt;
+
+        assert(flags);
+
+        STRV_FOREACH(opt, ex_opts) {
+                ex_flag = exec_command_flags_from_string(*opt);
+                if (ex_flag >= 0)
+                        ret_flags |= ex_flag;
+                else
+                        return -EINVAL;
+        }
+
+        *flags = ret_flags;
+
+        return 0;
+}
+
+int exec_command_flags_to_strv(ExecCommandFlags flags, char ***ex_opts) {
+        _cleanup_strv_free_ char **ret_opts = NULL;
+        ExecCommandFlags it = flags;
+        const char *str;
+        int i, r;
+
+        assert(ex_opts);
+
+        for (i = 0; it != 0; it &= ~(1 << i), i++) {
+                if (FLAGS_SET(flags, (1 << i))) {
+                        str = exec_command_flags_to_string(1 << i);
+                        if (!str)
+                                return -EINVAL;
+
+                        r = strv_extend(&ret_opts, str);
+                        if (r < 0)
+                                return r;
+                }
+        }
+
+        *ex_opts = TAKE_PTR(ret_opts);
+
+        return 0;
+}
+
+const gather_stdout_callback_t gather_environment[] = {
+        gather_environment_generate,
+        gather_environment_collect,
+        gather_environment_consume,
+};
+
+static const char* const exec_command_strings[] = {
+        "ignore-failure", /* EXEC_COMMAND_IGNORE_FAILURE */
+        "privileged",     /* EXEC_COMMAND_FULLY_PRIVILEGED */
+        "no-setuid",      /* EXEC_COMMAND_NO_SETUID */
+        "ambient",        /* EXEC_COMMAND_AMBIENT_MAGIC */
+        "no-env-expand",  /* EXEC_COMMAND_NO_ENV_EXPAND */
+};
+
+const char* exec_command_flags_to_string(ExecCommandFlags i) {
+        size_t idx;
+
+        for (idx = 0; idx < ELEMENTSOF(exec_command_strings); idx++)
+                if (i == (1 << idx))
+                        return exec_command_strings[idx];
+
+        return NULL;
+}
+
+ExecCommandFlags exec_command_flags_from_string(const char *s) {
+        ssize_t idx;
+
+        idx = string_table_lookup(exec_command_strings, ELEMENTSOF(exec_command_strings), s);
+
+        if (idx < 0)
+                return _EXEC_COMMAND_FLAGS_INVALID;
+        else
+                return 1 << idx;
+}