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-rw-r--r--src/basic/fd-util.c140
-rw-r--r--src/basic/fd-util.h2
-rw-r--r--src/basic/process-util.c7
-rw-r--r--src/basic/process-util.h4
-rw-r--r--src/shared/exec-util.c2
-rw-r--r--src/shared/exec-util.h2
6 files changed, 91 insertions, 66 deletions
diff --git a/src/basic/fd-util.c b/src/basic/fd-util.c
index 032f303789..dec083daaf 100644
--- a/src/basic/fd-util.c
+++ b/src/basic/fd-util.c
@@ -208,9 +208,10 @@ static int get_max_fd(void) {
return (int) (m - 1);
}
-int close_all_fds(int except[], size_t n_except) {
+int close_all_fds(const int except[], size_t n_except) {
static bool have_close_range = true; /* Assume we live in the future */
_cleanup_closedir_ DIR *d = NULL;
+ struct dirent *de;
int r = 0;
assert(n_except == 0 || except);
@@ -226,104 +227,129 @@ int close_all_fds(int except[], size_t n_except) {
/* Close everything. Yay! */
if (close_range(3, -1, 0) >= 0)
- return 0;
+ return 1;
- if (ERRNO_IS_NOT_SUPPORTED(errno) || ERRNO_IS_PRIVILEGE(errno))
- have_close_range = false;
- else
+ if (!ERRNO_IS_NOT_SUPPORTED(errno) && !ERRNO_IS_PRIVILEGE(errno))
return -errno;
+ have_close_range = false;
} else {
- typesafe_qsort(except, n_except, cmp_int);
+ _cleanup_free_ int *sorted_malloc = NULL;
+ size_t n_sorted;
+ int *sorted;
+
+ assert(n_except < SIZE_MAX);
+ n_sorted = n_except + 1;
+
+ if (n_sorted > 64) /* Use heap for large numbers of fds, stack otherwise */
+ sorted = sorted_malloc = new(int, n_sorted);
+ else
+ sorted = newa(int, n_sorted);
+
+ if (sorted) {
+ int c = 0;
+
+ memcpy(sorted, except, n_except * sizeof(int));
+
+ /* Let's add fd 2 to the list of fds, to simplify the loop below, as this
+ * allows us to cover the head of the array the same way as the body */
+ sorted[n_sorted-1] = 2;
- for (size_t i = 0; i < n_except; i++) {
- int start = i == 0 ? 2 : MAX(except[i-1], 2); /* The first three fds shall always remain open */
- int end = MAX(except[i], 2);
+ typesafe_qsort(sorted, n_sorted, cmp_int);
- assert(end >= start);
+ for (size_t i = 0; i < n_sorted-1; i++) {
+ int start, end;
- if (end - start <= 1)
- continue;
+ start = MAX(sorted[i], 2); /* The first three fds shall always remain open */
+ end = MAX(sorted[i+1], 2);
+
+ assert(end >= start);
+
+ if (end - start <= 1)
+ continue;
+
+ /* Close everything between the start and end fds (both of which shall stay open) */
+ if (close_range(start + 1, end - 1, 0) < 0) {
+ if (!ERRNO_IS_NOT_SUPPORTED(errno) && !ERRNO_IS_PRIVILEGE(errno))
+ return -errno;
- /* Close everything between the start and end fds (both of which shall stay open) */
- if (close_range(start + 1, end - 1, 0) < 0) {
- if (ERRNO_IS_NOT_SUPPORTED(errno) || ERRNO_IS_PRIVILEGE(errno))
have_close_range = false;
- else
- return -errno;
- goto opendir_fallback;
+ break;
+ }
+
+ c += end - start - 1;
}
- }
- /* The loop succeeded. Let's now close everything beyond the end */
+ if (have_close_range) {
+ /* The loop succeeded. Let's now close everything beyond the end */
- if (except[n_except-1] >= INT_MAX) /* Don't let the addition below overflow */
- return 0;
+ if (sorted[n_sorted-1] >= INT_MAX) /* Dont let the addition below overflow */
+ return c;
- int start = MAX(except[n_except-1], 2);
+ if (close_range(sorted[n_sorted-1] + 1, -1, 0) >= 0)
+ return c + 1;
- if (close_range(start + 1, -1, 0) >= 0)
- return 0;
+ if (!ERRNO_IS_NOT_SUPPORTED(errno) && !ERRNO_IS_PRIVILEGE(errno))
+ return -errno;
- if (ERRNO_IS_NOT_SUPPORTED(errno) || ERRNO_IS_PRIVILEGE(errno))
- have_close_range = false;
- else
- return -errno;
+ have_close_range = false;
+ }
+ }
}
+
+ /* Fallback on OOM or if close_range() is not supported */
}
- /* Fallback for when close_range() is not supported */
- opendir_fallback:
d = opendir("/proc/self/fd");
- if (d) {
- struct dirent *de;
+ if (!d) {
+ int fd, max_fd;
- FOREACH_DIRENT(de, d, return -errno) {
- int fd = -1, q;
+ /* When /proc isn't available (for example in chroots) the fallback is brute forcing through
+ * the fd table */
- if (safe_atoi(de->d_name, &fd) < 0)
- /* Let's better ignore this, just in case */
- continue;
+ max_fd = get_max_fd();
+ if (max_fd < 0)
+ return max_fd;
- if (fd < 3)
- continue;
+ /* Refuse to do the loop over more too many elements. It's better to fail immediately than to
+ * spin the CPU for a long time. */
+ if (max_fd > MAX_FD_LOOP_LIMIT)
+ return log_debug_errno(SYNTHETIC_ERRNO(EPERM),
+ "/proc/self/fd is inaccessible. Refusing to loop over %d potential fds.",
+ max_fd);
- if (fd == dirfd(d))
- continue;
+ for (fd = 3; fd >= 0; fd = fd < max_fd ? fd + 1 : -1) {
+ int q;
if (fd_in_set(fd, except, n_except))
continue;
q = close_nointr(fd);
- if (q < 0 && q != -EBADF && r >= 0) /* Valgrind has its own FD and doesn't want to have it closed */
+ if (q < 0 && q != -EBADF && r >= 0)
r = q;
}
return r;
}
- /* Fallback for when /proc isn't available (for example in chroots) by brute-forcing through the file
- * descriptor table. */
+ FOREACH_DIRENT(de, d, return -errno) {
+ int fd = -1, q;
- int max_fd = get_max_fd();
- if (max_fd < 0)
- return max_fd;
+ if (safe_atoi(de->d_name, &fd) < 0)
+ /* Let's better ignore this, just in case */
+ continue;
- /* Refuse to do the loop over more too many elements. It's better to fail immediately than to
- * spin the CPU for a long time. */
- if (max_fd > MAX_FD_LOOP_LIMIT)
- return log_debug_errno(SYNTHETIC_ERRNO(EPERM),
- "/proc/self/fd is inaccessible. Refusing to loop over %d potential fds.",
- max_fd);
+ if (fd < 3)
+ continue;
- for (int fd = 3; fd >= 0; fd = fd < max_fd ? fd + 1 : -1) {
- int q;
+ if (fd == dirfd(d))
+ continue;
if (fd_in_set(fd, except, n_except))
continue;
q = close_nointr(fd);
- if (q < 0 && q != -EBADF && r >= 0)
+ if (q < 0 && q != -EBADF && r >= 0) /* Valgrind has its own FD and doesn't want to have it closed */
r = q;
}
diff --git a/src/basic/fd-util.h b/src/basic/fd-util.h
index ab841b67e0..459059c64e 100644
--- a/src/basic/fd-util.h
+++ b/src/basic/fd-util.h
@@ -57,7 +57,7 @@ DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(DIR*, closedir, NULL);
int fd_nonblock(int fd, bool nonblock);
int fd_cloexec(int fd, bool cloexec);
-int close_all_fds(int except[], size_t n_except);
+int close_all_fds(const int except[], size_t n_except);
int same_fd(int a, int b);
diff --git a/src/basic/process-util.c b/src/basic/process-util.c
index fef0c742c7..5c56a59aab 100644
--- a/src/basic/process-util.c
+++ b/src/basic/process-util.c
@@ -1246,7 +1246,7 @@ static void restore_sigsetp(sigset_t **ssp) {
int safe_fork_full(
const char *name,
- int except_fds[],
+ const int except_fds[],
size_t n_except_fds,
ForkFlags flags,
pid_t *ret_pid) {
@@ -1441,7 +1441,7 @@ int safe_fork_full(
int namespace_fork(
const char *outer_name,
const char *inner_name,
- int except_fds[],
+ const int except_fds[],
size_t n_except_fds,
ForkFlags flags,
int pidns_fd,
@@ -1457,8 +1457,7 @@ 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, 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) {
diff --git a/src/basic/process-util.h b/src/basic/process-util.h
index 451d0a5ff4..c7622c98df 100644
--- a/src/basic/process-util.h
+++ b/src/basic/process-util.h
@@ -166,13 +166,13 @@ typedef enum ForkFlags {
FORK_NEW_USERNS = 1 << 13, /* Run child in its own user namespace */
} ForkFlags;
-int safe_fork_full(const char *name, int except_fds[], size_t n_except_fds, ForkFlags flags, pid_t *ret_pid);
+int safe_fork_full(const char *name, 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);
}
-int namespace_fork(const char *outer_name, const char *inner_name, 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);
+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);
int set_oom_score_adjust(int value);
int get_oom_score_adjust(int *ret);
diff --git a/src/shared/exec-util.c b/src/shared/exec-util.c
index fd0d95c530..f0a9ea9e9f 100644
--- a/src/shared/exec-util.c
+++ b/src/shared/exec-util.c
@@ -471,7 +471,7 @@ int fexecve_or_execve(int executable_fd, const char *executable, char *const arg
return -errno;
}
-int fork_agent(const char *name, int except[], size_t n_except, pid_t *ret_pid, const char *path, ...) {
+int fork_agent(const char *name, const int except[], size_t n_except, pid_t *ret_pid, const char *path, ...) {
bool stdout_is_tty, stderr_is_tty;
size_t n, i;
va_list ap;
diff --git a/src/shared/exec-util.h b/src/shared/exec-util.h
index 21d28608f9..ba4506e5aa 100644
--- a/src/shared/exec-util.h
+++ b/src/shared/exec-util.h
@@ -49,4 +49,4 @@ ExecCommandFlags exec_command_flags_from_string(const char *s);
int fexecve_or_execve(int executable_fd, const char *executable, char *const argv[], char *const envp[]);
-int fork_agent(const char *name, int except[], size_t n_except, pid_t *ret_pid, const char *path, ...) _sentinel_;
+int fork_agent(const char *name, const int except[], size_t n_except, pid_t *ret_pid, const char *path, ...) _sentinel_;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-01 23:33:29 +0100