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mirror of https://github.com/systemd/systemd.git synced 2025-01-27 18:04:05 +03:00

process-util: rename FORK_NULL_STDIO -> FORK_REARRANGE_STDIO

And make safe_fork_full() takes fds to be assigned to stdio.
This commit is contained in:
Yu Watanabe 2023-02-07 18:19:55 +09:00
parent a324a8958b
commit 911f8f0183
12 changed files with 63 additions and 28 deletions

View File

@ -1134,6 +1134,7 @@ static void restore_sigsetp(sigset_t **ssp) {
int safe_fork_full(
const char *name,
const int stdio_fds[3],
const int except_fds[],
size_t n_except_fds,
ForkFlags flags,
@ -1292,6 +1293,27 @@ int safe_fork_full(
}
}
if (flags & FORK_REARRANGE_STDIO) {
if (stdio_fds) {
r = rearrange_stdio(stdio_fds[0], stdio_fds[1], stdio_fds[2]);
if (r < 0) {
log_full_errno(prio, r, "Failed to rearrange stdio fds: %m");
_exit(EXIT_FAILURE);
}
} else {
r = make_null_stdio();
if (r < 0) {
log_full_errno(prio, r, "Failed to connect stdin/stdout to /dev/null: %m");
_exit(EXIT_FAILURE);
}
}
} else if (flags & FORK_STDOUT_TO_STDERR) {
if (dup2(STDERR_FILENO, STDOUT_FILENO) < 0) {
log_full_errno(prio, errno, "Failed to connect stdout to stderr: %m");
_exit(EXIT_FAILURE);
}
}
if (flags & FORK_CLOSE_ALL_FDS) {
/* Close the logs here in case it got reopened above, as close_all_fds() would close them for us */
log_close();
@ -1317,20 +1339,6 @@ int safe_fork_full(
log_set_open_when_needed(false);
}
if (flags & FORK_NULL_STDIO) {
r = make_null_stdio();
if (r < 0) {
log_full_errno(prio, r, "Failed to connect stdin/stdout to /dev/null: %m");
_exit(EXIT_FAILURE);
}
} else if (flags & FORK_STDOUT_TO_STDERR) {
if (dup2(STDERR_FILENO, STDOUT_FILENO) < 0) {
log_full_errno(prio, errno, "Failed to connect stdout to stderr: %m");
_exit(EXIT_FAILURE);
}
}
if (flags & FORK_RLIMIT_NOFILE_SAFE) {
r = rlimit_nofile_safe();
if (r < 0) {
@ -1364,7 +1372,10 @@ int namespace_fork(
* process. This ensures that we are fully a member of the destination namespace, with pidns an all, so that
* /proc/self/fd works correctly. */
r = safe_fork_full(outer_name, except_fds, n_except_fds, (flags|FORK_DEATHSIG) & ~(FORK_REOPEN_LOG|FORK_NEW_MOUNTNS|FORK_MOUNTNS_SLAVE), ret_pid);
r = safe_fork_full(outer_name,
NULL,
except_fds, n_except_fds,
(flags|FORK_DEATHSIG) & ~(FORK_REOPEN_LOG|FORK_NEW_MOUNTNS|FORK_MOUNTNS_SLAVE), ret_pid);
if (r < 0)
return r;
if (r == 0) {
@ -1379,7 +1390,10 @@ int namespace_fork(
}
/* We mask a few flags here that either make no sense for the grandchild, or that we don't have to do again */
r = safe_fork_full(inner_name, except_fds, n_except_fds, flags & ~(FORK_WAIT|FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_NULL_STDIO), &pid);
r = safe_fork_full(inner_name,
NULL,
except_fds, n_except_fds,
flags & ~(FORK_WAIT|FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_REARRANGE_STDIO), &pid);
if (r < 0)
_exit(EXIT_FAILURE);
if (r == 0) {

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@ -143,7 +143,7 @@ typedef enum ForkFlags {
FORK_CLOSE_ALL_FDS = 1 << 1, /* Close all open file descriptors in the child, except for 0,1,2 */
FORK_DEATHSIG = 1 << 2, /* Set PR_DEATHSIG in the child to SIGTERM */
FORK_DEATHSIG_SIGINT = 1 << 3, /* Set PR_DEATHSIG in the child to SIGINT */
FORK_NULL_STDIO = 1 << 4, /* Connect 0,1,2 to /dev/null */
FORK_REARRANGE_STDIO = 1 << 4, /* Connect 0,1,2 to specified fds or /dev/null */
FORK_REOPEN_LOG = 1 << 5, /* Reopen log connection */
FORK_LOG = 1 << 6, /* Log above LOG_DEBUG log level about failures */
FORK_WAIT = 1 << 7, /* Wait until child exited */
@ -157,10 +157,16 @@ typedef enum ForkFlags {
FORK_CLOEXEC_OFF = 1 << 15, /* In the child: turn off O_CLOEXEC on all fds in except_fds[] */
} ForkFlags;
int safe_fork_full(const char *name, const int except_fds[], size_t n_except_fds, ForkFlags flags, pid_t *ret_pid);
int safe_fork_full(
const char *name,
const int stdio_fds[3],
const int except_fds[],
size_t n_except_fds,
ForkFlags flags,
pid_t *ret_pid);
static inline int safe_fork(const char *name, ForkFlags flags, pid_t *ret_pid) {
return safe_fork_full(name, NULL, 0, flags, ret_pid);
return safe_fork_full(name, NULL, NULL, 0, flags, ret_pid);
}
int namespace_fork(const char *outer_name, const char *inner_name, const int except_fds[], size_t n_except_fds, ForkFlags flags, int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd, pid_t *ret_pid);

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@ -1180,6 +1180,7 @@ static int home_start_work(Home *h, const char *verb, UserRecord *hr, UserRecord
return -errno;
r = safe_fork_full("(sd-homework)",
NULL,
(int[]) { stdin_fd, stdout_fd }, 2,
FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_DEATHSIG|FORK_LOG|FORK_REOPEN_LOG, &pid);
if (r < 0)

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@ -994,7 +994,10 @@ int bus_socket_exec(sd_bus *b) {
if (r < 0)
return -errno;
r = safe_fork_full("(sd-busexec)", s+1, 1, FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_RLIMIT_NOFILE_SAFE, &b->busexec_pid);
r = safe_fork_full("(sd-busexec)",
NULL,
s+1, 1,
FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_RLIMIT_NOFILE_SAFE, &b->busexec_pid);
if (r < 0) {
safe_close_pair(s);
return r;

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@ -136,7 +136,7 @@ static int brightness_writer_fork(BrightnessWriter *w) {
assert(w->child == 0);
assert(!w->child_event_source);
r = safe_fork("(sd-bright)", FORK_DEATHSIG|FORK_NULL_STDIO|FORK_CLOSE_ALL_FDS|FORK_LOG|FORK_REOPEN_LOG, &w->child);
r = safe_fork("(sd-bright)", FORK_DEATHSIG|FORK_REARRANGE_STDIO|FORK_CLOSE_ALL_FDS|FORK_LOG|FORK_REOPEN_LOG, &w->child);
if (r < 0)
return r;
if (r == 0) {

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@ -147,8 +147,10 @@ static void *tls_dns_server(void *p) {
fd_tls = fd[1];
}
r = safe_fork_full("(test-resolved-stream-tls-openssl)", (int[]) { fd_server, fd_tls }, 2,
FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_DEATHSIG|FORK_LOG|FORK_REOPEN_LOG, &openssl_pid);
r = safe_fork_full("(test-resolved-stream-tls-openssl)",
NULL,
(int[]) { fd_server, fd_tls }, 2,
FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_DEATHSIG|FORK_LOG|FORK_REOPEN_LOG, &openssl_pid);
assert_se(r >= 0);
if (r == 0) {
/* Child */

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@ -1436,8 +1436,9 @@ static int run_fsck(int node_fd, const char *fstype) {
r = safe_fork_full(
"(fsck)",
NULL,
&node_fd, 1, /* Leave the node fd open */
FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG|FORK_NULL_STDIO|FORK_CLOEXEC_OFF,
FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_RLIMIT_NOFILE_SAFE|FORK_DEATHSIG|FORK_REARRANGE_STDIO|FORK_CLOEXEC_OFF,
&pid);
if (r < 0)
return log_debug_errno(r, "Failed to fork off fsck: %m");

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@ -784,6 +784,7 @@ int parse_elf_object(int fd, const char *executable, bool fork_disable_dump, cha
* system call or interacting with the system in any way, besides reading from
* the file descriptor and writing into these four pipes. */
r = safe_fork_full("(sd-parse-elf)",
NULL,
(int[]){ fd, error_pipe[1], return_pipe[1], json_pipe[1] },
4,
FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_NEW_MOUNTNS|FORK_MOUNTNS_SLAVE|FORK_NEW_USERNS|FORK_WAIT|FORK_REOPEN_LOG,

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@ -487,6 +487,7 @@ int fork_agent(const char *name, const int except[], size_t n_except, pid_t *ret
/* Spawns a temporary TTY agent, making sure it goes away when we go away */
r = safe_fork_full(name,
NULL,
except,
n_except,
FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_CLOSE_ALL_FDS|FORK_REOPEN_LOG|FORK_RLIMIT_NOFILE_SAFE,

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@ -316,7 +316,7 @@ int show_man_page(const char *desc, bool null_stdio) {
} else
args[1] = desc;
r = safe_fork("(man)", FORK_RESET_SIGNALS|FORK_DEATHSIG|(null_stdio ? FORK_NULL_STDIO : 0)|FORK_RLIMIT_NOFILE_SAFE|FORK_LOG, &pid);
r = safe_fork("(man)", FORK_RESET_SIGNALS|FORK_DEATHSIG|(null_stdio ? FORK_REARRANGE_STDIO : 0)|FORK_RLIMIT_NOFILE_SAFE|FORK_LOG, &pid);
if (r < 0)
return r;
if (r == 0) {

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@ -618,7 +618,10 @@ static int remount_with_timeout(MountPoint *m, bool last_try) {
/* Due to the possibility of a remount operation hanging, we fork a child process and set a
* timeout. If the timeout lapses, the assumption is that the particular remount failed. */
r = safe_fork_full("(sd-remount)", pfd, ELEMENTSOF(pfd), FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_LOG|FORK_REOPEN_LOG, &pid);
r = safe_fork_full("(sd-remount)",
NULL,
pfd, ELEMENTSOF(pfd),
FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_LOG|FORK_REOPEN_LOG, &pid);
if (r < 0)
return r;
if (r == 0) {
@ -671,7 +674,10 @@ static int umount_with_timeout(MountPoint *m, bool last_try) {
/* Due to the possibility of a umount operation hanging, we fork a child process and set a
* timeout. If the timeout lapses, the assumption is that the particular umount failed. */
r = safe_fork_full("(sd-umount)", pfd, ELEMENTSOF(pfd), FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_LOG|FORK_REOPEN_LOG, &pid);
r = safe_fork_full("(sd-umount)",
NULL,
pfd, ELEMENTSOF(pfd),
FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_LOG|FORK_REOPEN_LOG, &pid);
if (r < 0)
return r;
if (r == 0) {

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@ -589,7 +589,7 @@ TEST(safe_fork) {
BLOCK_SIGNALS(SIGCHLD);
r = safe_fork("(test-child)", FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_DEATHSIG|FORK_NULL_STDIO|FORK_REOPEN_LOG, &pid);
r = safe_fork("(test-child)", FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_DEATHSIG|FORK_REARRANGE_STDIO|FORK_REOPEN_LOG, &pid);
assert_se(r >= 0);
if (r == 0) {