diff options
Diffstat (limited to 'src/shared/fdset.c')
| -rw-r--r-- | src/shared/fdset.c | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/src/shared/fdset.c b/src/shared/fdset.c new file mode 100644 index 0000000..87ad9b1 --- /dev/null +++ b/src/shared/fdset.c @@ -0,0 +1,297 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <fcntl.h> +#include <stddef.h> + +#include "sd-daemon.h" + +#include "alloc-util.h" +#include "dirent-util.h" +#include "fd-util.h" +#include "fdset.h" +#include "log.h" +#include "macro.h" +#include "parse-util.h" +#include "path-util.h" +#include "set.h" + +#define MAKE_SET(s) ((Set*) s) +#define MAKE_FDSET(s) ((FDSet*) s) + +FDSet *fdset_new(void) { + return MAKE_FDSET(set_new(NULL)); +} + +int fdset_new_array(FDSet **ret, const int *fds, size_t n_fds) { + size_t i; + FDSet *s; + int r; + + assert(ret); + + s = fdset_new(); + if (!s) + return -ENOMEM; + + for (i = 0; i < n_fds; i++) { + + r = fdset_put(s, fds[i]); + if (r < 0) { + set_free(MAKE_SET(s)); + return r; + } + } + + *ret = s; + return 0; +} + +void fdset_close(FDSet *s) { + void *p; + + while ((p = set_steal_first(MAKE_SET(s)))) { + int fd = PTR_TO_FD(p); + + /* Valgrind's fd might have ended up in this set here, due to fdset_new_fill(). We'll ignore + * all failures here, so that the EBADFD that valgrind will return us on close() doesn't + * influence us */ + + /* When reloading duplicates of the private bus connection fds and suchlike are closed here, + * which has no effect at all, since they are only duplicates. So don't be surprised about + * these log messages. */ + + if (DEBUG_LOGGING) { + _cleanup_free_ char *path = NULL; + + (void) fd_get_path(fd, &path); + log_debug("Closing set fd %i (%s)", fd, strna(path)); + } + + (void) close_nointr(fd); + } +} + +FDSet* fdset_free(FDSet *s) { + fdset_close(s); + set_free(MAKE_SET(s)); + return NULL; +} + +int fdset_put(FDSet *s, int fd) { + assert(s); + assert(fd >= 0); + + /* Avoid integer overflow in FD_TO_PTR() */ + if (fd == INT_MAX) + return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Refusing invalid fd: %d", fd); + + return set_put(MAKE_SET(s), FD_TO_PTR(fd)); +} + +int fdset_put_dup(FDSet *s, int fd) { + int copy, r; + + assert(s); + assert(fd >= 0); + + copy = fcntl(fd, F_DUPFD_CLOEXEC, 3); + if (copy < 0) + return -errno; + + r = fdset_put(s, copy); + if (r < 0) { + safe_close(copy); + return r; + } + + return copy; +} + +bool fdset_contains(FDSet *s, int fd) { + assert(s); + assert(fd >= 0); + + /* Avoid integer overflow in FD_TO_PTR() */ + if (fd == INT_MAX) { + log_debug("Refusing invalid fd: %d", fd); + return false; + } + + return !!set_get(MAKE_SET(s), FD_TO_PTR(fd)); +} + +int fdset_remove(FDSet *s, int fd) { + assert(s); + assert(fd >= 0); + + /* Avoid integer overflow in FD_TO_PTR() */ + if (fd == INT_MAX) + return log_debug_errno(SYNTHETIC_ERRNO(ENOENT), "Refusing invalid fd: %d", fd); + + return set_remove(MAKE_SET(s), FD_TO_PTR(fd)) ? fd : -ENOENT; +} + +int fdset_new_fill( + int filter_cloexec, /* if < 0 takes all fds, otherwise only those with O_CLOEXEC set (1) or unset (0) */ + FDSet **_s) { + _cleanup_closedir_ DIR *d = NULL; + int r = 0; + FDSet *s; + + assert(_s); + + /* Creates an fdset and fills in all currently open file descriptors. Also set all collected fds + * to CLOEXEC. */ + + d = opendir("/proc/self/fd"); + if (!d) + return -errno; + + s = fdset_new(); + if (!s) { + r = -ENOMEM; + goto finish; + } + + FOREACH_DIRENT(de, d, return -errno) { + int fd = -1; + + r = safe_atoi(de->d_name, &fd); + if (r < 0) + goto finish; + + if (fd < 3) + continue; + + if (fd == dirfd(d)) + continue; + + if (filter_cloexec >= 0) { + int fl; + + /* If user asked for that filter by O_CLOEXEC. This is useful so that fds that have + * been passed in can be collected and fds which have been created locally can be + * ignored, under the assumption that only the latter have O_CLOEXEC set. */ + + fl = fcntl(fd, F_GETFD); + if (fl < 0) + return -errno; + + if (FLAGS_SET(fl, FD_CLOEXEC) != !!filter_cloexec) + continue; + } + + /* We need to set CLOEXEC manually only if we're collecting non-CLOEXEC fds. */ + if (filter_cloexec <= 0) { + r = fd_cloexec(fd, true); + if (r < 0) + return r; + } + + r = fdset_put(s, fd); + if (r < 0) + goto finish; + } + + r = 0; + *_s = TAKE_PTR(s); + +finish: + /* We won't close the fds here! */ + if (s) + set_free(MAKE_SET(s)); + + return r; +} + +int fdset_cloexec(FDSet *fds, bool b) { + void *p; + int r; + + assert(fds); + + SET_FOREACH(p, MAKE_SET(fds)) { + r = fd_cloexec(PTR_TO_FD(p), b); + if (r < 0) + return r; + } + + return 0; +} + +int fdset_new_listen_fds(FDSet **_s, bool unset) { + int n, fd, r; + FDSet *s; + + assert(_s); + + /* Creates an fdset and fills in all passed file descriptors */ + + s = fdset_new(); + if (!s) { + r = -ENOMEM; + goto fail; + } + + n = sd_listen_fds(unset); + for (fd = SD_LISTEN_FDS_START; fd < SD_LISTEN_FDS_START + n; fd ++) { + r = fdset_put(s, fd); + if (r < 0) + goto fail; + } + + *_s = s; + return 0; + +fail: + if (s) + set_free(MAKE_SET(s)); + + return r; +} + +int fdset_close_others(FDSet *fds) { + void *e; + int *a = NULL; + size_t j = 0, m; + + m = fdset_size(fds); + + if (m > 0) { + a = newa(int, m); + SET_FOREACH(e, MAKE_SET(fds)) + a[j++] = PTR_TO_FD(e); + } + + assert(j == m); + + return close_all_fds(a, j); +} + +unsigned fdset_size(FDSet *fds) { + return set_size(MAKE_SET(fds)); +} + +bool fdset_isempty(FDSet *fds) { + return set_isempty(MAKE_SET(fds)); +} + +int fdset_iterate(FDSet *s, Iterator *i) { + void *p; + + if (!set_iterate(MAKE_SET(s), i, &p)) + return -ENOENT; + + return PTR_TO_FD(p); +} + +int fdset_steal_first(FDSet *fds) { + void *p; + + p = set_steal_first(MAKE_SET(fds)); + if (!p) + return -ENOENT; + + return PTR_TO_FD(p); +} |