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-rw-r--r--src/basic/io-util.c5
-rw-r--r--src/basic/socket-util.c40
-rw-r--r--src/basic/socket-util.h2
-rw-r--r--src/core/socket.c172
4 files changed, 161 insertions, 58 deletions
diff --git a/src/basic/io-util.c b/src/basic/io-util.c
index 0037a37f2a..cc6dfa8c1b 100644
--- a/src/basic/io-util.c
+++ b/src/basic/io-util.c
@@ -33,6 +33,11 @@ int flush_fd(int fd) {
.events = POLLIN,
};
+ /* Read from the specified file descriptor, until POLLIN is not set anymore, throwing away everything
+ * read. Note that some file descriptors (notable IP sockets) will trigger POLLIN even when no data can be read
+ * (due to IP packet checksum mismatches), hence this function is only safe to be non-blocking if the fd used
+ * was set to non-blocking too. */
+
for (;;) {
char buf[LINE_MAX];
ssize_t l;
diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c
index 0f38f9a0f3..c634f1d564 100644
--- a/src/basic/socket-util.c
+++ b/src/basic/socket-util.c
@@ -23,6 +23,7 @@
#include <net/if.h>
#include <netdb.h>
#include <netinet/ip.h>
+#include <poll.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
@@ -970,3 +971,42 @@ fallback:
return (ssize_t) k;
}
+
+int flush_accept(int fd) {
+
+ struct pollfd pollfd = {
+ .fd = fd,
+ .events = POLLIN,
+ };
+ int r;
+
+
+ /* Similar to flush_fd() but flushes all incoming connection by accepting them and immediately closing them. */
+
+ for (;;) {
+ int cfd;
+
+ r = poll(&pollfd, 1, 0);
+ if (r < 0) {
+ if (errno == EINTR)
+ continue;
+
+ return -errno;
+
+ } else if (r == 0)
+ return 0;
+
+ cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);
+ if (cfd < 0) {
+ if (errno == EINTR)
+ continue;
+
+ if (errno == EAGAIN)
+ return 0;
+
+ return -errno;
+ }
+
+ close(cfd);
+ }
+}
diff --git a/src/basic/socket-util.h b/src/basic/socket-util.h
index daa4b24a37..160f7c484b 100644
--- a/src/basic/socket-util.h
+++ b/src/basic/socket-util.h
@@ -135,6 +135,8 @@ int receive_one_fd(int transport_fd, int flags);
ssize_t next_datagram_size_fd(int fd);
+int flush_accept(int fd);
+
#define CMSG_FOREACH(cmsg, mh) \
for ((cmsg) = CMSG_FIRSTHDR(mh); (cmsg); (cmsg) = CMSG_NXTHDR((mh), (cmsg)))
diff --git a/src/core/socket.c b/src/core/socket.c
index d4b409ef53..f6204d04bf 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -28,7 +28,6 @@
#include <unistd.h>
#include <linux/sctp.h>
-#include "sd-event.h"
#include "alloc-util.h"
#include "bus-error.h"
#include "bus-util.h"
@@ -38,6 +37,7 @@
#include "exit-status.h"
#include "fd-util.h"
#include "formats-util.h"
+#include "io-util.h"
#include "label.h"
#include "log.h"
#include "missing.h"
@@ -1247,6 +1247,45 @@ fail:
return r;
}
+static int socket_determine_selinux_label(Socket *s, char **ret) {
+ ExecCommand *c;
+ int r;
+
+ assert(s);
+ assert(ret);
+
+ if (s->selinux_context_from_net) {
+ /* If this is requested, get label from the network label */
+
+ r = mac_selinux_get_our_label(ret);
+ if (r == -EOPNOTSUPP)
+ goto no_label;
+
+ } else {
+ /* Otherwise, get it from the executable we are about to start */
+ r = socket_instantiate_service(s);
+ if (r < 0)
+ return r;
+
+ if (!UNIT_ISSET(s->service))
+ goto no_label;
+
+ c = SERVICE(UNIT_DEREF(s->service))->exec_command[SERVICE_EXEC_START];
+ if (!c)
+ goto no_label;
+
+ r = mac_selinux_get_create_label_from_exe(c->path, ret);
+ if (r == -EPERM || r == -EOPNOTSUPP)
+ goto no_label;
+ }
+
+ return r;
+
+no_label:
+ *ret = NULL;
+ return 0;
+}
+
static int socket_open_fds(Socket *s) {
_cleanup_(mac_selinux_freep) char *label = NULL;
bool know_label = false;
@@ -1265,48 +1304,28 @@ static int socket_open_fds(Socket *s) {
case SOCKET_SOCKET:
if (!know_label) {
- /* Figure out label, if we don't it know
- * yet. We do it once, for the first
- * socket where we need this and
- * remember it for the rest. */
-
- if (s->selinux_context_from_net) {
- /* Get it from the network label */
-
- r = mac_selinux_get_our_label(&label);
- if (r < 0 && r != -EOPNOTSUPP)
- goto rollback;
-
- } else {
- /* Get it from the executable we are about to start */
-
- r = socket_instantiate_service(s);
- if (r < 0)
- goto rollback;
+ /* Figure out label, if we don't it know yet. We do it once, for the first socket where
+ * we need this and remember it for the rest. */
- if (UNIT_ISSET(s->service) &&
- SERVICE(UNIT_DEREF(s->service))->exec_command[SERVICE_EXEC_START]) {
- r = mac_selinux_get_create_label_from_exe(SERVICE(UNIT_DEREF(s->service))->exec_command[SERVICE_EXEC_START]->path, &label);
- if (r < 0 && r != -EPERM && r != -EOPNOTSUPP)
- goto rollback;
- }
- }
+ r = socket_determine_selinux_label(s, &label);
+ if (r < 0)
+ goto rollback;
know_label = true;
}
/* Apply the socket protocol */
- switch(p->address.type) {
+ switch (p->address.type) {
case SOCK_STREAM:
case SOCK_SEQPACKET:
- if (p->socket->socket_protocol == IPPROTO_SCTP)
- p->address.protocol = p->socket->socket_protocol;
+ if (s->socket_protocol == IPPROTO_SCTP)
+ p->address.protocol = s->socket_protocol;
break;
case SOCK_DGRAM:
- if (p->socket->socket_protocol == IPPROTO_UDPLITE)
- p->address.protocol = p->socket->socket_protocol;
+ if (s->socket_protocol == IPPROTO_UDPLITE)
+ p->address.protocol = s->socket_protocol;
break;
}
@@ -1450,6 +1469,34 @@ fail:
return r;
}
+enum {
+ SOCKET_OPEN_NONE,
+ SOCKET_OPEN_SOME,
+ SOCKET_OPEN_ALL,
+};
+
+static int socket_check_open(Socket *s) {
+ bool have_open = false, have_closed = false;
+ SocketPort *p;
+
+ assert(s);
+
+ LIST_FOREACH(port, p, s->ports) {
+ if (p->fd < 0)
+ have_closed = true;
+ else
+ have_open = true;
+
+ if (have_open && have_closed)
+ return SOCKET_OPEN_SOME;
+ }
+
+ if (have_open)
+ return SOCKET_OPEN_ALL;
+
+ return SOCKET_OPEN_NONE;
+}
+
static void socket_set_state(Socket *s, SocketState state) {
SocketState old_state;
assert(s);
@@ -1529,14 +1576,24 @@ static int socket_coldplug(Unit *u) {
SOCKET_START_CHOWN,
SOCKET_START_POST,
SOCKET_LISTENING,
- SOCKET_RUNNING,
- SOCKET_STOP_PRE,
- SOCKET_STOP_PRE_SIGTERM,
- SOCKET_STOP_PRE_SIGKILL)) {
-
- r = socket_open_fds(s);
- if (r < 0)
- return r;
+ SOCKET_RUNNING)) {
+
+ /* Originally, we used to simply reopen all sockets here that we didn't have file descriptors
+ * for. However, this is problematic, as we won't traverse throught the SOCKET_START_CHOWN state for
+ * them, and thus the UID/GID wouldn't be right. Hence, instead simply check if we have all fds open,
+ * and if there's a mismatch, warn loudly. */
+
+ r = socket_check_open(s);
+ if (r == SOCKET_OPEN_NONE)
+ log_unit_warning(UNIT(s),
+ "Socket unit configuration has changed while unit has been running, "
+ "no open socket file descriptor left. "
+ "The socket unit is not functional until restarted.");
+ else if (r == SOCKET_OPEN_SOME)
+ log_unit_warning(UNIT(s),
+ "Socket unit configuration has changed while unit has been running, "
+ "and some socket file descriptors have not been opened yet. "
+ "The socket unit is not fully functional until restarted.");
}
if (s->deserialized_state == SOCKET_LISTENING) {
@@ -1909,6 +1966,21 @@ fail:
socket_enter_dead(s, SOCKET_FAILURE_RESOURCES);
}
+static void flush_ports(Socket *s) {
+ SocketPort *p;
+
+ /* Flush all incoming traffic, regardless if actual bytes or new connections, so that this socket isn't busy
+ * anymore */
+
+ LIST_FOREACH(port, p, s->ports) {
+ if (p->fd < 0)
+ continue;
+
+ (void) flush_accept(p->fd);
+ (void) flush_fd(p->fd);
+ }
+}
+
static void socket_enter_running(Socket *s, int cfd) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
int r;
@@ -1918,31 +1990,15 @@ static void socket_enter_running(Socket *s, int cfd) {
assert(s);
- /* We don't take connections anymore if we are supposed to
- * shut down anyway */
+ /* We don't take connections anymore if we are supposed to shut down anyway */
if (unit_stop_pending(UNIT(s))) {
log_unit_debug(UNIT(s), "Suppressing connection request since unit stop is scheduled.");
if (cfd >= 0)
cfd = safe_close(cfd);
- else {
- /* Flush all sockets by closing and reopening them */
- socket_close_fds(s);
-
- r = socket_open_fds(s);
- if (r < 0) {
- log_unit_warning_errno(UNIT(s), r, "Failed to listen on sockets: %m");
- socket_enter_stop_pre(s, SOCKET_FAILURE_RESOURCES);
- return;
- }
-
- r = socket_watch_fds(s);
- if (r < 0) {
- log_unit_warning_errno(UNIT(s), r, "Failed to watch sockets: %m");
- socket_enter_stop_pre(s, SOCKET_FAILURE_RESOURCES);
- }
- }
+ else
+ flush_ports(s);
return;
}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-12-15 20:40:04 +0000