The macro determines the right length of a AF_UNIX "struct sockaddr_un" to pass to
connect() or bind(). It automatically figures out if the socket refers to an
abstract namespace socket, or a socket in the file system, and properly handles
the full length of the path field.
This macro is not only safer, but also simpler to use, than the usual
offsetof() + strlen() logic.
goto fail;
}
- if (connect(syslog_fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0) {
+ if (connect(syslog_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0) {
safe_close(syslog_fd);
/* Some legacy syslog systems still use stream
goto fail;
}
- if (connect(syslog_fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0) {
+ if (connect(syslog_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0) {
r = -errno;
goto fail;
}
goto fail;
}
- if (connect(journal_fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0) {
+ if (connect(journal_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0) {
r = -errno;
goto fail;
}
#define CMSG_FOREACH(cmsg, mh) \
for ((cmsg) = CMSG_FIRSTHDR(mh); (cmsg); (cmsg) = CMSG_NXTHDR((mh), (cmsg)))
+
+/* Covers only file system and abstract AF_UNIX socket addresses, but not unnamed socket addresses. */
+#define SOCKADDR_UN_LEN(sa) \
+ ({ \
+ const struct sockaddr_un *_sa = &(sa); \
+ assert(_sa->sun_family == AF_UNIX); \
+ offsetof(struct sockaddr_un, sun_path) + \
+ (_sa->sun_path[0] == 0 ? \
+ 1 + strnlen(_sa->sun_path+1, sizeof(_sa->sun_path)-1) : \
+ strnlen(_sa->sun_path, sizeof(_sa->sun_path))); \
+ })
l = strlen(argv[1]);
- n = sendto(fd, argv[1], l, 0, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path));
+ n = sendto(fd, argv[1], l, 0, &sa.sa, SOCKADDR_UN_LEN(sa.un));
if (n < 0) {
log_debug_errno(errno, "Failed to send cgroups agent message: %m");
return EXIT_FAILURE;
return 0;
strcpy(sa.un.sun_path, "/run/systemd/private");
- salen = offsetof(union sockaddr_union, un.sun_path) + strlen("/run/systemd/private");
+ salen = SOCKADDR_UN_LEN(sa.un);
} else {
size_t left = sizeof(sa.un.sun_path);
char *p = sa.un.sun_path;
}
}
- r = connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path));
+ r = connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
if (r < 0)
r = -errno;
(void) unlink(m->notify_socket);
strncpy(sa.un.sun_path, m->notify_socket, sizeof(sa.un.sun_path)-1);
- r = bind(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path));
+ r = bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
if (r < 0)
return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
/* Only allow root to connect to this socket */
RUN_WITH_UMASK(0077)
- r = bind(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path));
+ r = bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
if (r < 0)
return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
}
void manager_send_unit_plymouth(Manager *m, Unit *u) {
- union sockaddr_union sa = PLYMOUTH_SOCKET;
-
- int n = 0;
+ static const union sockaddr_union sa = PLYMOUTH_SOCKET;
_cleanup_free_ char *message = NULL;
_cleanup_close_ int fd = -1;
+ int n = 0;
/* Don't generate plymouth events if the service was already
* started and we're just deserializing */
return;
}
- if (connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + 1 + strlen(sa.un.sun_path+1)) < 0) {
+ if (connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0) {
if (!IN_SET(errno, EPIPE, EAGAIN, ENOENT, ECONNREFUSED, ECONNRESET, ECONNABORTED))
log_error_errno(errno, "connect() failed: %m");
if (fd < 0)
return log_error_errno(errno, "Failed to create coredump socket: %m");
- if (connect(fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path)) < 0)
+ if (connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0)
return log_error_errno(errno, "Failed to connect to coredump service: %m");
for (i = 0; i < n_iovec; i++) {
if (fd < 0)
return log_warning_errno(errno, "socket(): %m");
- if (connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0) {
+ if (connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0) {
r = log_full_errno(errno == ECONNREFUSED || errno == ENOENT ? LOG_DEBUG : LOG_WARNING,
errno, "Failed to connect to progress socket %s, ignoring: %m", sa.un.sun_path);
safe_close(fd);
(void) mkdir_parents_label(sa.un.sun_path, 0755);
(void) unlink(sa.un.sun_path);
- if (bind(m->notify_fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path)) < 0)
+ if (bind(m->notify_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0)
return -errno;
if (setsockopt(m->notify_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0)
struct iovec *w;
uint64_t *l;
int i, j = 0;
- struct sockaddr_un sa = {
- .sun_family = AF_UNIX,
- .sun_path = "/run/systemd/journal/socket",
+ static const union sockaddr_union sa = {
+ .un.sun_family = AF_UNIX,
+ .un.sun_path = "/run/systemd/journal/socket",
};
struct msghdr mh = {
- .msg_name = &sa,
- .msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(sa.sun_path),
+ .msg_name = (struct sockaddr*) &sa.sa,
+ .msg_namelen = SOCKADDR_UN_LEN(sa.un),
};
ssize_t k;
bool have_syslog_identifier = false;
}
_public_ int sd_journal_stream_fd(const char *identifier, int priority, int level_prefix) {
- union sockaddr_union sa = {
+ static const union sockaddr_union sa = {
.un.sun_family = AF_UNIX,
.un.sun_path = "/run/systemd/journal/stdout",
};
if (fd < 0)
return -errno;
- r = connect(fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path));
+ r = connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
if (r < 0)
return -errno;
}
int server_open_native_socket(Server*s) {
+
+ static const union sockaddr_union sa = {
+ .un.sun_family = AF_UNIX,
+ .un.sun_path = "/run/systemd/journal/socket",
+ };
static const int one = 1;
int r;
assert(s);
if (s->native_fd < 0) {
- union sockaddr_union sa = {
- .un.sun_family = AF_UNIX,
- .un.sun_path = "/run/systemd/journal/socket",
- };
-
s->native_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
if (s->native_fd < 0)
return log_error_errno(errno, "socket() failed: %m");
- unlink(sa.un.sun_path);
+ (void) unlink(sa.un.sun_path);
- r = bind(s->native_fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path));
+ r = bind(s->native_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
if (r < 0)
return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
if (sa.un.sun_path[0] == '@')
sa.un.sun_path[0] = 0;
- r = connect(s->notify_fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(e));
+ r = connect(s->notify_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
if (r < 0)
return log_error_errno(errno, "Failed to connect to notify socket: %m");
}
int server_open_stdout_socket(Server *s) {
+ static const union sockaddr_union sa = {
+ .un.sun_family = AF_UNIX,
+ .un.sun_path = "/run/systemd/journal/stdout",
+ };
int r;
assert(s);
if (s->stdout_fd < 0) {
- union sockaddr_union sa = {
- .un.sun_family = AF_UNIX,
- .un.sun_path = "/run/systemd/journal/stdout",
- };
-
s->stdout_fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
if (s->stdout_fd < 0)
return log_error_errno(errno, "socket() failed: %m");
- unlink(sa.un.sun_path);
+ (void) unlink(sa.un.sun_path);
- r = bind(s->stdout_fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path));
+ r = bind(s->stdout_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
if (r < 0)
return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
.msg_iov = (struct iovec *) iovec,
.msg_iovlen = n_iovec,
.msg_name = (struct sockaddr*) &sa.sa,
- .msg_namelen = offsetof(union sockaddr_union, un.sun_path)
- + strlen("/run/systemd/journal/syslog"),
+ .msg_namelen = SOCKADDR_UN_LEN(sa.un),
};
struct cmsghdr *cmsg;
union {
}
int server_open_syslog_socket(Server *s) {
+
+ static const union sockaddr_union sa = {
+ .un.sun_family = AF_UNIX,
+ .un.sun_path = "/run/systemd/journal/dev-log",
+ };
static const int one = 1;
int r;
assert(s);
if (s->syslog_fd < 0) {
- static const union sockaddr_union sa = {
- .un.sun_family = AF_UNIX,
- .un.sun_path = "/run/systemd/journal/dev-log",
- };
-
s->syslog_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
if (s->syslog_fd < 0)
return log_error_errno(errno, "socket() failed: %m");
- unlink(sa.un.sun_path);
+ (void) unlink(sa.un.sun_path);
- r = bind(s->syslog_fd, &sa.sa, offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path));
+ r = bind(s->syslog_fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
if (r < 0)
return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);
void server_maybe_warn_forward_syslog_missed(Server *s) {
usec_t n;
+
assert(s);
if (s->n_forward_syslog_missed <= 0)
b->sockaddr.un.sun_family = AF_UNIX;
strncpy(b->sockaddr.un.sun_path, "/var/run/dbus/system_bus_socket", sizeof(b->sockaddr.un.sun_path));
- b->sockaddr_size = offsetof(struct sockaddr_un, sun_path) + strlen("/var/run/dbus/system_bus_socket");
+ b->sockaddr_size = SOCKADDR_UN_LEN(b->sockaddr.un);
return 0;
}
if (sockaddr.un.sun_path[0] == '@')
sockaddr.un.sun_path[0] = 0;
- msghdr.msg_namelen = offsetof(struct sockaddr_un, sun_path) + strlen(e);
- if (msghdr.msg_namelen > sizeof(struct sockaddr_un))
- msghdr.msg_namelen = sizeof(struct sockaddr_un);
+ msghdr.msg_namelen = SOCKADDR_UN_LEN(sockaddr.un);
have_pid = pid != 0 && pid != getpid();
if (fd < 0)
return -errno;
- if (connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0)
+ if (connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0)
return -errno;
r = getpeercred(fd, &ucred);
#include "fd-util.h"
#include "log.h"
#include "macro.h"
+#include "socket-util.h"
#include "string-util.h"
#include "util.h"
static int send_on_socket(int fd, const char *socket_name, const void *packet, size_t size) {
- union {
- struct sockaddr sa;
- struct sockaddr_un un;
- } sa = {
+ union sockaddr_union sa = {
.un.sun_family = AF_UNIX,
};
strncpy(sa.un.sun_path, socket_name, sizeof(sa.un.sun_path));
- if (sendto(fd, packet, size, MSG_NOSIGNAL, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(socket_name)) < 0)
+ if (sendto(fd, packet, size, MSG_NOSIGNAL, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0)
return log_error_errno(errno, "Failed to send: %m");
return 0;
snprintf(sa.un.sun_path, sizeof(sa.un.sun_path)-1, "/run/systemd/ask-password/sck.%" PRIx64, random_u64());
RUN_WITH_UMASK(0177) {
- if (bind(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + strlen(sa.un.sun_path)) < 0)
+ if (bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un)) < 0)
return -errno;
}
union sockaddr_union sa = {};
const char *node, *service;
- socklen_t salen;
int r;
if (path_is_absolute(arg_remote_host)) {
sa.un.sun_family = AF_UNIX;
- strncpy(sa.un.sun_path, arg_remote_host, sizeof(sa.un.sun_path)-1);
- sa.un.sun_path[sizeof(sa.un.sun_path)-1] = 0;
-
- salen = offsetof(union sockaddr_union, un.sun_path) + strlen(sa.un.sun_path);
-
- return connection_start(c, &sa.sa, salen);
+ strncpy(sa.un.sun_path, arg_remote_host, sizeof(sa.un.sun_path));
+ return connection_start(c, &sa.sa, SOCKADDR_UN_LEN(sa.un));
}
if (arg_remote_host[0] == '@') {
sa.un.sun_family = AF_UNIX;
sa.un.sun_path[0] = 0;
- strncpy(sa.un.sun_path+1, arg_remote_host+1, sizeof(sa.un.sun_path)-2);
- sa.un.sun_path[sizeof(sa.un.sun_path)-1] = 0;
-
- salen = offsetof(union sockaddr_union, un.sun_path) + 1 + strlen(sa.un.sun_path + 1);
-
- return connection_start(c, &sa.sa, salen);
+ strncpy(sa.un.sun_path+1, arg_remote_host+1, sizeof(sa.un.sun_path)-1);
+ return connection_start(c, &sa.sa, SOCKADDR_UN_LEN(sa.un));
}
service = strrchr(arg_remote_host, ':');
assert_se(!sockaddr_equal(&b, &c));
}
+static void test_sockaddr_un_len(void) {
+ static const struct sockaddr_un fs = {
+ .sun_family = AF_UNIX,
+ .sun_path = "/foo/bar/waldo",
+ };
+
+ static const struct sockaddr_un abstract = {
+ .sun_family = AF_UNIX,
+ .sun_path = "\0foobar",
+ };
+
+ assert_se(SOCKADDR_UN_LEN(fs) == offsetof(struct sockaddr_un, sun_path) + strlen(fs.sun_path));
+ assert_se(SOCKADDR_UN_LEN(abstract) == offsetof(struct sockaddr_un, sun_path) + 1 + strlen(abstract.sun_path + 1));
+}
+
int main(int argc, char *argv[]) {
log_set_max_level(LOG_DEBUG);
test_sockaddr_equal();
+ test_sockaddr_un_len();
+
return 0;
}
const char *flag_file,
char ***ret) {
+ static const union sockaddr_union sa = PLYMOUTH_SOCKET;
_cleanup_close_ int fd = -1, notify = -1;
- union sockaddr_union sa = PLYMOUTH_SOCKET;
_cleanup_free_ char *packet = NULL;
ssize_t k;
int r, n;
if (fd < 0)
return -errno;
- r = connect(fd, &sa.sa, offsetof(struct sockaddr_un, sun_path) + 1 + strlen(sa.un.sun_path+1));
+ r = connect(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
if (r < 0)
return -errno;
strncpy(sa.un.sun_path, socket_name, sizeof(sa.un.sun_path));
- r = sendto(socket_fd, packet, packet_length, MSG_NOSIGNAL, &sa.sa,
- offsetof(struct sockaddr_un, sun_path) + strlen(socket_name));
+ r = sendto(socket_fd, packet, packet_length, MSG_NOSIGNAL, &sa.sa, SOCKADDR_UN_LEN(sa.un));
if (r < 0)
r = log_debug_errno(errno, "sendto(): %m");
uctrl->saddr.un.sun_family = AF_LOCAL;
strscpy(uctrl->saddr.un.sun_path, sizeof(uctrl->saddr.un.sun_path), "/run/udev/control");
- uctrl->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(uctrl->saddr.un.sun_path);
+ uctrl->addrlen = SOCKADDR_UN_LEN(uctrl->saddr.un);
return uctrl;
}