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-rw-r--r--src/shared/process-util.c538
1 files changed, 538 insertions, 0 deletions
diff --git a/src/shared/process-util.c b/src/shared/process-util.c
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--- /dev/null
+++ b/src/shared/process-util.c
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+/***
+ This file is part of systemd.
+
+ Copyright 2010 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdbool.h>
+#include <sys/types.h>
+#include <string.h>
+#include <stdio.h>
+#include <assert.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <ctype.h>
+
+#include "process-util.h"
+#include "fileio.h"
+#include "util.h"
+#include "log.h"
+
+int get_process_state(pid_t pid) {
+ const char *p;
+ char state;
+ int r;
+ _cleanup_free_ char *line = NULL;
+
+ assert(pid >= 0);
+
+ p = procfs_file_alloca(pid, "stat");
+ r = read_one_line_file(p, &line);
+ if (r < 0)
+ return r;
+
+ p = strrchr(line, ')');
+ if (!p)
+ return -EIO;
+
+ p++;
+
+ if (sscanf(p, " %c", &state) != 1)
+ return -EIO;
+
+ return (unsigned char) state;
+}
+
+int get_process_comm(pid_t pid, char **name) {
+ const char *p;
+ int r;
+
+ assert(name);
+ assert(pid >= 0);
+
+ p = procfs_file_alloca(pid, "comm");
+
+ r = read_one_line_file(p, name);
+ if (r == -ENOENT)
+ return -ESRCH;
+
+ return r;
+}
+
+int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char **line) {
+ _cleanup_fclose_ FILE *f = NULL;
+ char *r = NULL, *k;
+ const char *p;
+ int c;
+
+ assert(line);
+ assert(pid >= 0);
+
+ p = procfs_file_alloca(pid, "cmdline");
+
+ f = fopen(p, "re");
+ if (!f)
+ return -errno;
+
+ if (max_length == 0) {
+ size_t len = 0, allocated = 0;
+
+ while ((c = getc(f)) != EOF) {
+
+ if (!GREEDY_REALLOC(r, allocated, len+2)) {
+ free(r);
+ return -ENOMEM;
+ }
+
+ r[len++] = isprint(c) ? c : ' ';
+ }
+
+ if (len > 0)
+ r[len-1] = 0;
+
+ } else {
+ bool space = false;
+ size_t left;
+
+ r = new(char, max_length);
+ if (!r)
+ return -ENOMEM;
+
+ k = r;
+ left = max_length;
+ while ((c = getc(f)) != EOF) {
+
+ if (isprint(c)) {
+ if (space) {
+ if (left <= 4)
+ break;
+
+ *(k++) = ' ';
+ left--;
+ space = false;
+ }
+
+ if (left <= 4)
+ break;
+
+ *(k++) = (char) c;
+ left--;
+ } else
+ space = true;
+ }
+
+ if (left <= 4) {
+ size_t n = MIN(left-1, 3U);
+ memcpy(k, "...", n);
+ k[n] = 0;
+ } else
+ *k = 0;
+ }
+
+ /* Kernel threads have no argv[] */
+ if (isempty(r)) {
+ _cleanup_free_ char *t = NULL;
+ int h;
+
+ free(r);
+
+ if (!comm_fallback)
+ return -ENOENT;
+
+ h = get_process_comm(pid, &t);
+ if (h < 0)
+ return h;
+
+ r = strjoin("[", t, "]", NULL);
+ if (!r)
+ return -ENOMEM;
+ }
+
+ *line = r;
+ return 0;
+}
+
+int is_kernel_thread(pid_t pid) {
+ const char *p;
+ size_t count;
+ char c;
+ bool eof;
+ FILE *f;
+
+ if (pid == 0)
+ return 0;
+
+ assert(pid > 0);
+
+ p = procfs_file_alloca(pid, "cmdline");
+ f = fopen(p, "re");
+ if (!f)
+ return -errno;
+
+ count = fread(&c, 1, 1, f);
+ eof = feof(f);
+ fclose(f);
+
+ /* Kernel threads have an empty cmdline */
+
+ if (count <= 0)
+ return eof ? 1 : -errno;
+
+ return 0;
+}
+
+int get_process_capeff(pid_t pid, char **capeff) {
+ const char *p;
+
+ assert(capeff);
+ assert(pid >= 0);
+
+ p = procfs_file_alloca(pid, "status");
+
+ return get_status_field(p, "\nCapEff:", capeff);
+}
+
+static int get_process_link_contents(const char *proc_file, char **name) {
+ int r;
+
+ assert(proc_file);
+ assert(name);
+
+ r = readlink_malloc(proc_file, name);
+ if (r < 0)
+ return r == -ENOENT ? -ESRCH : r;
+
+ return 0;
+}
+
+int get_process_exe(pid_t pid, char **name) {
+ const char *p;
+ char *d;
+ int r;
+
+ assert(pid >= 0);
+
+ p = procfs_file_alloca(pid, "exe");
+ r = get_process_link_contents(p, name);
+ if (r < 0)
+ return r;
+
+ d = endswith(*name, " (deleted)");
+ if (d)
+ *d = '\0';
+
+ return 0;
+}
+
+static int get_process_id(pid_t pid, const char *field, uid_t *uid) {
+ _cleanup_fclose_ FILE *f = NULL;
+ char line[LINE_MAX];
+ const char *p;
+
+ assert(field);
+ assert(uid);
+
+ if (pid == 0)
+ return getuid();
+
+ p = procfs_file_alloca(pid, "status");
+ f = fopen(p, "re");
+ if (!f)
+ return -errno;
+
+ FOREACH_LINE(line, f, return -errno) {
+ char *l;
+
+ l = strstrip(line);
+
+ if (startswith(l, field)) {
+ l += strlen(field);
+ l += strspn(l, WHITESPACE);
+
+ l[strcspn(l, WHITESPACE)] = 0;
+
+ return parse_uid(l, uid);
+ }
+ }
+
+ return -EIO;
+}
+
+int get_process_uid(pid_t pid, uid_t *uid) {
+ return get_process_id(pid, "Uid:", uid);
+}
+
+int get_process_gid(pid_t pid, gid_t *gid) {
+ assert_cc(sizeof(uid_t) == sizeof(gid_t));
+ return get_process_id(pid, "Gid:", gid);
+}
+
+int get_process_cwd(pid_t pid, char **cwd) {
+ const char *p;
+
+ assert(pid >= 0);
+
+ p = procfs_file_alloca(pid, "cwd");
+
+ return get_process_link_contents(p, cwd);
+}
+
+int get_process_root(pid_t pid, char **root) {
+ const char *p;
+
+ assert(pid >= 0);
+
+ p = procfs_file_alloca(pid, "root");
+
+ return get_process_link_contents(p, root);
+}
+
+int get_process_environ(pid_t pid, char **env) {
+ _cleanup_fclose_ FILE *f = NULL;
+ _cleanup_free_ char *outcome = NULL;
+ int c;
+ const char *p;
+ size_t allocated = 0, sz = 0;
+
+ assert(pid >= 0);
+ assert(env);
+
+ p = procfs_file_alloca(pid, "environ");
+
+ f = fopen(p, "re");
+ if (!f)
+ return -errno;
+
+ while ((c = fgetc(f)) != EOF) {
+ if (!GREEDY_REALLOC(outcome, allocated, sz + 5))
+ return -ENOMEM;
+
+ if (c == '\0')
+ outcome[sz++] = '\n';
+ else
+ sz += cescape_char(c, outcome + sz);
+ }
+
+ outcome[sz] = '\0';
+ *env = outcome;
+ outcome = NULL;
+
+ return 0;
+}
+
+int get_parent_of_pid(pid_t pid, pid_t *_ppid) {
+ int r;
+ _cleanup_free_ char *line = NULL;
+ long unsigned ppid;
+ const char *p;
+
+ assert(pid >= 0);
+ assert(_ppid);
+
+ if (pid == 0) {
+ *_ppid = getppid();
+ return 0;
+ }
+
+ p = procfs_file_alloca(pid, "stat");
+ r = read_one_line_file(p, &line);
+ if (r < 0)
+ return r;
+
+ /* Let's skip the pid and comm fields. The latter is enclosed
+ * in () but does not escape any () in its value, so let's
+ * skip over it manually */
+
+ p = strrchr(line, ')');
+ if (!p)
+ return -EIO;
+
+ p++;
+
+ if (sscanf(p, " "
+ "%*c " /* state */
+ "%lu ", /* ppid */
+ &ppid) != 1)
+ return -EIO;
+
+ if ((long unsigned) (pid_t) ppid != ppid)
+ return -ERANGE;
+
+ *_ppid = (pid_t) ppid;
+
+ return 0;
+}
+
+int wait_for_terminate(pid_t pid, siginfo_t *status) {
+ siginfo_t dummy;
+
+ assert(pid >= 1);
+
+ if (!status)
+ status = &dummy;
+
+ for (;;) {
+ zero(*status);
+
+ if (waitid(P_PID, pid, status, WEXITED) < 0) {
+
+ if (errno == EINTR)
+ continue;
+
+ return -errno;
+ }
+
+ return 0;
+ }
+}
+
+/*
+ * Return values:
+ * < 0 : wait_for_terminate() failed to get the state of the
+ * process, the process was terminated by a signal, or
+ * failed for an unknown reason.
+ * >=0 : The process terminated normally, and its exit code is
+ * returned.
+ *
+ * That is, success is indicated by a return value of zero, and an
+ * error is indicated by a non-zero value.
+ *
+ * A warning is emitted if the process terminates abnormally,
+ * and also if it returns non-zero unless check_exit_code is true.
+ */
+int wait_for_terminate_and_warn(const char *name, pid_t pid, bool check_exit_code) {
+ int r;
+ siginfo_t status;
+
+ assert(name);
+ assert(pid > 1);
+
+ r = wait_for_terminate(pid, &status);
+ if (r < 0)
+ return log_warning_errno(r, "Failed to wait for %s: %m", name);
+
+ if (status.si_code == CLD_EXITED) {
+ if (status.si_status != 0)
+ log_full(check_exit_code ? LOG_WARNING : LOG_DEBUG,
+ "%s failed with error code %i.", name, status.si_status);
+ else
+ log_debug("%s succeeded.", name);
+
+ return status.si_status;
+ } else if (status.si_code == CLD_KILLED ||
+ status.si_code == CLD_DUMPED) {
+
+ log_warning("%s terminated by signal %s.", name, signal_to_string(status.si_status));
+ return -EPROTO;
+ }
+
+ log_warning("%s failed due to unknown reason.", name);
+ return -EPROTO;
+}
+
+int kill_and_sigcont(pid_t pid, int sig) {
+ int r;
+
+ r = kill(pid, sig) < 0 ? -errno : 0;
+
+ if (r >= 0)
+ kill(pid, SIGCONT);
+
+ return r;
+}
+
+int getenv_for_pid(pid_t pid, const char *field, char **_value) {
+ _cleanup_fclose_ FILE *f = NULL;
+ char *value = NULL;
+ int r;
+ bool done = false;
+ size_t l;
+ const char *path;
+
+ assert(pid >= 0);
+ assert(field);
+ assert(_value);
+
+ path = procfs_file_alloca(pid, "environ");
+
+ f = fopen(path, "re");
+ if (!f)
+ return -errno;
+
+ l = strlen(field);
+ r = 0;
+
+ do {
+ char line[LINE_MAX];
+ unsigned i;
+
+ for (i = 0; i < sizeof(line)-1; i++) {
+ int c;
+
+ c = getc(f);
+ if (_unlikely_(c == EOF)) {
+ done = true;
+ break;
+ } else if (c == 0)
+ break;
+
+ line[i] = c;
+ }
+ line[i] = 0;
+
+ if (memcmp(line, field, l) == 0 && line[l] == '=') {
+ value = strdup(line + l + 1);
+ if (!value)
+ return -ENOMEM;
+
+ r = 1;
+ break;
+ }
+
+ } while (!done);
+
+ *_value = value;
+ return r;
+}
+
+bool pid_is_unwaited(pid_t pid) {
+ /* Checks whether a PID is still valid at all, including a zombie */
+
+ if (pid <= 0)
+ return false;
+
+ if (kill(pid, 0) >= 0)
+ return true;
+
+ return errno != ESRCH;
+}
+
+bool pid_is_alive(pid_t pid) {
+ int r;
+
+ /* Checks whether a PID is still valid and not a zombie */
+
+ if (pid <= 0)
+ return false;
+
+ r = get_process_state(pid);
+ if (r == -ENOENT || r == 'Z')
+ return false;
+
+ return true;
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-15 08:28:47 +0000