reload: implement reload/reexec logic

1 files changed, 276 insertions, 55 deletions

diff --git a/socket.c b/socket.c
index 22658dcb00..63346a2bfc 100644
--- a/socket.c
+++ b/socket.c
@@ -52,20 +52,22 @@ static const UnitActiveState state_translation_table[_SOCKET_STATE_MAX] = {
         [SOCKET_MAINTAINANCE] = UNIT_INACTIVE,
 };
 
-static const char* const state_string_table[_SOCKET_STATE_MAX] = {
-        [SOCKET_DEAD] = "dead",
-        [SOCKET_START_PRE] = "start-pre",
-        [SOCKET_START_POST] = "start-post",
-        [SOCKET_LISTENING] = "listening",
-        [SOCKET_RUNNING] = "running",
-        [SOCKET_STOP_PRE] = "stop-pre",
-        [SOCKET_STOP_PRE_SIGTERM] = "stop-pre-sigterm",
-        [SOCKET_STOP_PRE_SIGKILL] = "stop-pre-sigkill",
-        [SOCKET_STOP_POST] = "stop-post",
-        [SOCKET_FINAL_SIGTERM] = "final-sigterm",
-        [SOCKET_FINAL_SIGKILL] = "final-sigkill",
-        [SOCKET_MAINTAINANCE] = "maintainance"
-};
+static void socket_init(Unit *u) {
+        Socket *s = SOCKET(u);
+
+        assert(u);
+        assert(u->meta.load_state == UNIT_STUB);
+
+        s->timer_watch.type = WATCH_INVALID;
+        s->backlog = SOMAXCONN;
+        s->timeout_usec = DEFAULT_TIMEOUT_USEC;
+        s->directory_mode = 0755;
+        s->socket_mode = 0666;
+
+        exec_context_init(&s->exec_context);
+
+        s->control_command_id = _SOCKET_EXEC_COMMAND_INVALID;
+}
 
 static void socket_unwatch_control_pid(Socket *s) {
         assert(s);
@@ -86,8 +88,11 @@ static void socket_done(Unit *u) {
         while ((p = s->ports)) {
                 LIST_REMOVE(SocketPort, port, s->ports, p);
 
-                if (p->fd >= 0)
-                        close_nointr(p->fd);
+                if (p->fd >= 0) {
+                        unit_unwatch_fd(UNIT(s), &p->fd_watch);
+                        close_nointr_nofail(p->fd);
+                }
+
                 free(p->path);
                 free(p);
         }
@@ -106,21 +111,6 @@ static void socket_done(Unit *u) {
         unit_unwatch_timer(u, &s->timer_watch);
 }
 
-static void socket_init(Unit *u) {
-        Socket *s = SOCKET(u);
-
-        assert(u);
-        assert(u->meta.load_state == UNIT_STUB);
-
-        s->timer_watch.type = WATCH_INVALID;
-        s->backlog = SOMAXCONN;
-        s->timeout_usec = DEFAULT_TIMEOUT_USEC;
-        s->directory_mode = 0755;
-        s->socket_mode = 0666;
-
-        exec_context_init(&s->exec_context);
-}
-
 static bool have_non_accept_socket(Socket *s) {
         SocketPort *p;
 
@@ -196,13 +186,6 @@ static const char* listen_lookup(int type) {
 
 static void socket_dump(Unit *u, FILE *f, const char *prefix) {
 
-        static const char* const command_table[_SOCKET_EXEC_COMMAND_MAX] = {
-                [SOCKET_EXEC_START_PRE] = "StartPre",
-                [SOCKET_EXEC_START_POST] = "StartPost",
-                [SOCKET_EXEC_STOP_PRE] = "StopPre",
-                [SOCKET_EXEC_STOP_POST] = "StopPost"
-        };
-
         SocketExecCommand c;
         Socket *s = SOCKET(u);
         SocketPort *p;
@@ -222,7 +205,7 @@ static void socket_dump(Unit *u, FILE *f, const char *prefix) {
                 "%sKillMode: %s\n"
                 "%sSocketMode: %04o\n"
                 "%sDirectoryMode: %04o\n",
-                prefix, state_string_table[s->state],
+                prefix, socket_state_to_string(s->state),
                 prefix, yes_no(s->bind_ipv6_only),
                 prefix, s->backlog,
                 prefix, kill_mode_to_string(s->kill_mode),
@@ -269,7 +252,7 @@ static void socket_dump(Unit *u, FILE *f, const char *prefix) {
                         continue;
 
                 fprintf(f, "%s→ %s:\n",
-                        prefix, command_table[c]);
+                        prefix, socket_exec_command_to_string(c));
 
                 exec_command_dump_list(s->exec_command[c], f, prefix2);
         }
@@ -307,7 +290,7 @@ static int instance_from_socket(int fd, unsigned nr, char **instance) {
                         b = ntohl(remote.in.sin_addr.s_addr);
 
                 if (asprintf(&r,
-                             "%u-%u.%u.%u.%u-%u-%u.%u.%u.%u-%u",
+                             "%u-%u.%u.%u.%u:%u-%u.%u.%u.%u:%u",
                              nr,
                              a >> 24, (a >> 16) & 0xFF, (a >> 8) & 0xFF, a & 0xFF,
                              ntohs(local.in.sin_port),
@@ -322,7 +305,7 @@ static int instance_from_socket(int fd, unsigned nr, char **instance) {
                 char a[INET6_ADDRSTRLEN], b[INET6_ADDRSTRLEN];
 
                 if (asprintf(&r,
-                             "%u-%s-%u-%s-%u",
+                             "%u-%s:%u-%s:%u",
                              nr,
                              inet_ntop(AF_INET6, &local.in6.sin6_addr, a, sizeof(a)),
                              ntohs(local.in6.sin6_port),
@@ -368,7 +351,15 @@ static void socket_close_fds(Socket *s) {
                         continue;
 
                 unit_unwatch_fd(UNIT(s), &p->fd_watch);
-                assert_se(close_nointr(p->fd) >= 0);
+                close_nointr_nofail(p->fd);
+
+                /* One little note: we should never delete any sockets
+                 * in the file system here! After all some other
+                 * process we spawned might still have a reference of
+                 * this fd and wants to continue to use it. Therefore
+                 * we delete sockets in the file system before we
+                 * create a new one, not after we stopped using
+                 * one! */
 
                 p->fd = -1;
         }
@@ -490,8 +481,12 @@ static void socket_set_state(Socket *s, SocketState state) {
                 unit_unwatch_timer(UNIT(s), &s->timer_watch);
                 socket_unwatch_control_pid(s);
                 s->control_command = NULL;
+                s->control_command_id = _SOCKET_EXEC_COMMAND_INVALID;
         }
 
+        if (state != SOCKET_LISTENING)
+                socket_unwatch_fds(s);
+
         if (state != SOCKET_START_POST &&
             state != SOCKET_LISTENING &&
             state != SOCKET_RUNNING &&
@@ -500,15 +495,62 @@ static void socket_set_state(Socket *s, SocketState state) {
             state != SOCKET_STOP_PRE_SIGKILL)
                 socket_close_fds(s);
 
-        if (state != SOCKET_LISTENING)
-                socket_unwatch_fds(s);
-
         if (state != old_state)
-                log_debug("%s changed %s → %s", s->meta.id, state_string_table[old_state], state_string_table[state]);
+                log_debug("%s changed %s → %s",
+                          s->meta.id,
+                          socket_state_to_string(old_state),
+                          socket_state_to_string(state));
 
         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state]);
 }
 
+static int socket_coldplug(Unit *u) {
+        Socket *s = SOCKET(u);
+        int r;
+
+        assert(s);
+        assert(s->state == SOCKET_DEAD);
+
+        if (s->deserialized_state != s->state) {
+
+                if (s->deserialized_state == SOCKET_START_PRE ||
+                    s->deserialized_state == SOCKET_START_POST ||
+                    s->deserialized_state == SOCKET_STOP_PRE ||
+                    s->deserialized_state == SOCKET_STOP_PRE_SIGTERM ||
+                    s->deserialized_state == SOCKET_STOP_PRE_SIGKILL ||
+                    s->deserialized_state == SOCKET_STOP_POST ||
+                    s->deserialized_state == SOCKET_FINAL_SIGTERM ||
+                    s->deserialized_state == SOCKET_FINAL_SIGKILL) {
+
+                        if (s->control_pid <= 0)
+                                return -EBADMSG;
+
+                        if ((r = unit_watch_pid(UNIT(s), s->control_pid)) < 0)
+                                return r;
+
+                        if ((r = unit_watch_timer(UNIT(s), s->timeout_usec, &s->timer_watch)) < 0)
+                                return r;
+                }
+
+                if (s->deserialized_state == SOCKET_START_POST ||
+                    s->deserialized_state == SOCKET_LISTENING ||
+                    s->deserialized_state == SOCKET_RUNNING ||
+                    s->deserialized_state == SOCKET_STOP_PRE ||
+                    s->deserialized_state == SOCKET_STOP_PRE_SIGTERM ||
+                    s->deserialized_state == SOCKET_STOP_PRE_SIGKILL)
+                        if ((r = socket_open_fds(s)) < 0)
+                                return r;
+
+                if (s->deserialized_state == SOCKET_LISTENING)
+                        if ((r = socket_watch_fds(s)) < 0)
+                                return r;
+
+                socket_set_state(s, s->deserialized_state);
+        }
+
+        return 0;
+}
+
 static int socket_spawn(Socket *s, ExecCommand *c, pid_t *_pid) {
         pid_t pid;
         int r;
@@ -574,6 +616,8 @@ static void socket_enter_stop_post(Socket *s, bool success) {
 
         socket_unwatch_control_pid(s);
 
+        s->control_command_id = SOCKET_EXEC_STOP_POST;
+
         if ((s->control_command = s->exec_command[SOCKET_EXEC_STOP_POST])) {
                 if ((r = socket_spawn(s, s->control_command, &s->control_pid)) < 0)
                         goto fail;
@@ -647,6 +691,8 @@ static void socket_enter_stop_pre(Socket *s, bool success) {
 
         socket_unwatch_control_pid(s);
 
+        s->control_command_id = SOCKET_EXEC_STOP_PRE;
+
         if ((s->control_command = s->exec_command[SOCKET_EXEC_STOP_PRE])) {
                 if ((r = socket_spawn(s, s->control_command, &s->control_pid)) < 0)
                         goto fail;
@@ -689,6 +735,8 @@ static void socket_enter_start_post(Socket *s) {
 
         socket_unwatch_control_pid(s);
 
+        s->control_command_id = SOCKET_EXEC_START_POST;
+
         if ((s->control_command = s->exec_command[SOCKET_EXEC_START_POST])) {
                 if ((r = socket_spawn(s, s->control_command, &s->control_pid)) < 0) {
                         log_warning("%s failed to run start-post executable: %s", s->meta.id, strerror(-r));
@@ -711,6 +759,8 @@ static void socket_enter_start_pre(Socket *s) {
 
         socket_unwatch_control_pid(s);
 
+        s->control_command_id = SOCKET_EXEC_START_PRE;
+
         if ((s->control_command = s->exec_command[SOCKET_EXEC_START_PRE])) {
                 if ((r = socket_spawn(s, s->control_command, &s->control_pid)) < 0)
                         goto fail;
@@ -876,6 +926,142 @@ static int socket_stop(Unit *u) {
         return 0;
 }
 
+static int socket_serialize(Unit *u, FILE *f, FDSet *fds) {
+        Socket *s = SOCKET(u);
+        SocketPort *p;
+        int r;
+
+        assert(u);
+        assert(f);
+        assert(fds);
+
+        unit_serialize_item(u, f, "state", socket_state_to_string(s->state));
+        unit_serialize_item(u, f, "failure", yes_no(s->failure));
+        unit_serialize_item_format(u, f, "n-accepted", "%u", s->n_accepted);
+
+        if (s->control_pid > 0)
+                unit_serialize_item_format(u, f, "control-pid", "%u", (unsigned) s->control_pid);
+
+        if (s->control_command_id >= 0)
+                unit_serialize_item(u, f, "control-command", socket_exec_command_to_string(s->control_command_id));
+
+        LIST_FOREACH(port, p, s->ports) {
+                int copy;
+
+                if (p->fd < 0)
+                        continue;
+
+                if ((copy = fdset_put_dup(fds, p->fd)) < 0)
+                        return copy;
+
+                if (p->type == SOCKET_SOCKET) {
+                        char *t;
+
+                        if ((r = socket_address_print(&p->address, &t)) < 0)
+                                return r;
+
+                        unit_serialize_item_format(u, f, "socket", "%i %s", copy, t);
+                        free(t);
+                } else {
+                        assert(p->type == SOCKET_FIFO);
+                        unit_serialize_item_format(u, f, "fifo", "%i %s", copy, p->path);
+                }
+        }
+
+        return 0;
+}
+
+static int socket_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
+        Socket *s = SOCKET(u);
+        int r;
+
+        assert(u);
+        assert(key);
+        assert(value);
+        assert(fds);
+
+        if (streq(key, "state")) {
+                SocketState state;
+
+                if ((state = socket_state_from_string(value)) < 0)
+                        log_debug("Failed to parse state value %s", value);
+                else
+                        s->deserialized_state = state;
+        } else if (streq(key, "failure")) {
+                int b;
+
+                if ((b = parse_boolean(value)) < 0)
+                        log_debug("Failed to parse failure value %s", value);
+                else
+                        s->failure = b || s->failure;
+
+        } else if (streq(key, "n-accepted")) {
+                unsigned k;
+
+                if ((r = safe_atou(value, &k)) < 0)
+                        log_debug("Failed to parse n-accepted value %s", value);
+                else
+                        s->n_accepted += k;
+        } else if (streq(key, "control-pid")) {
+                unsigned pid;
+
+                if ((r = safe_atou(value, &pid)) < 0 || pid <= 0)
+                        log_debug("Failed to parse control-pid value %s", value);
+                else
+                        s->control_pid = (pid_t) pid;
+        } else if (streq(key, "control-command")) {
+                SocketExecCommand id;
+
+                if ((id = socket_exec_command_from_string(value)) < 0)
+                        log_debug("Failed to parse exec-command value %s", value);
+                else {
+                        s->control_command_id = id;
+                        s->control_command = s->exec_command[id];
+                }
+        } else if (streq(key, "fifo")) {
+                int fd, skip = 0;
+                SocketPort *p;
+
+                if (sscanf(value, "%i %n", &fd, &skip) < 1 || fd < 0 || !fdset_contains(fds, fd))
+                        log_debug("Failed to parse fifo value %s", value);
+                else {
+
+                        LIST_FOREACH(port, p, s->ports)
+                                if (streq(p->path, value+skip))
+                                        break;
+
+                        if (p) {
+                                if (p->fd >= 0)
+                                        close_nointr_nofail(p->fd);
+                                p->fd = fdset_remove(fds, fd);
+                        }
+                }
+
+        } else if (streq(key, "socket")) {
+                int fd, skip = 0;
+                SocketPort *p;
+
+                if (sscanf(value, "%i %n", &fd, &skip) < 1 || fd < 0 || !fdset_contains(fds, fd))
+                        log_debug("Failed to parse socket value %s", value);
+                else {
+
+                        LIST_FOREACH(port, p, s->ports)
+                                if (socket_address_is(&p->address, value+skip))
+                                        break;
+
+                        if (p) {
+                                if (p->fd >= 0)
+                                        close_nointr_nofail(p->fd);
+                                p->fd = fdset_remove(fds, fd);
+                        }
+                }
+
+        } else
+                log_debug("Unknown serialization key '%s'", key);
+
+        return 0;
+}
+
 static UnitActiveState socket_active_state(Unit *u) {
         assert(u);
 
@@ -885,7 +1071,7 @@ static UnitActiveState socket_active_state(Unit *u) {
 static const char *socket_sub_state_to_string(Unit *u) {
         assert(u);
 
-        return state_string_table[SOCKET(u)->state];
+        return socket_state_to_string(SOCKET(u)->state);
 }
 
 static void socket_fd_event(Unit *u, int fd, uint32_t events, Watch *w) {
@@ -918,6 +1104,7 @@ static void socket_fd_event(Unit *u, int fd, uint32_t events, Watch *w) {
                 }
         }
 
+        log_debug("cfd=%i", cfd);
         socket_enter_running(s, cfd);
         return;
 
@@ -936,21 +1123,24 @@ static void socket_sigchld_event(Unit *u, pid_t pid, int code, int status) {
         s->failure = s->failure || !success;
 
         assert(s->control_pid == pid);
-        assert(s->control_command);
-
-        exec_status_fill(&s->control_command->exec_status, pid, code, status);
         s->control_pid = 0;
 
+        if (s->control_command)
+                exec_status_fill(&s->control_command->exec_status, pid, code, status);
+
         log_debug("%s control process exited, code=%s status=%i", u->meta.id, sigchld_code_to_string(code), status);
 
-        if (s->control_command->command_next && success) {
-                log_debug("%s running next command for state %s", u->meta.id, state_string_table[s->state]);
+        if (s->control_command && s->control_command->command_next && success) {
+                log_debug("%s running next command for state %s", u->meta.id, socket_state_to_string(s->state));
                 socket_run_next(s, success);
         } else {
+                s->control_command = NULL;
+                s->control_command_id = _SOCKET_EXEC_COMMAND_INVALID;
+
                 /* No further commands for this step, so let's figure
                  * out what to do next */
 
-                log_debug("%s got final SIGCHLD for state %s", u->meta.id, state_string_table[s->state]);
+                log_debug("%s got final SIGCHLD for state %s", u->meta.id, socket_state_to_string(s->state));
 
                 switch (s->state) {
 
@@ -1082,18 +1272,49 @@ void socket_notify_service_dead(Socket *s) {
         }
 }
 
+static const char* const socket_state_table[_SOCKET_STATE_MAX] = {
+        [SOCKET_DEAD] = "dead",
+        [SOCKET_START_PRE] = "start-pre",
+        [SOCKET_START_POST] = "start-post",
+        [SOCKET_LISTENING] = "listening",
+        [SOCKET_RUNNING] = "running",
+        [SOCKET_STOP_PRE] = "stop-pre",
+        [SOCKET_STOP_PRE_SIGTERM] = "stop-pre-sigterm",
+        [SOCKET_STOP_PRE_SIGKILL] = "stop-pre-sigkill",
+        [SOCKET_STOP_POST] = "stop-post",
+        [SOCKET_FINAL_SIGTERM] = "final-sigterm",
+        [SOCKET_FINAL_SIGKILL] = "final-sigkill",
+        [SOCKET_MAINTAINANCE] = "maintainance"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(socket_state, SocketState);
+
+static const char* const socket_exec_command_table[_SOCKET_EXEC_COMMAND_MAX] = {
+        [SOCKET_EXEC_START_PRE] = "StartPre",
+        [SOCKET_EXEC_START_POST] = "StartPost",
+        [SOCKET_EXEC_STOP_PRE] = "StopPre",
+        [SOCKET_EXEC_STOP_POST] = "StopPost"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(socket_exec_command, SocketExecCommand);
+
 const UnitVTable socket_vtable = {
         .suffix = ".socket",
 
         .init = socket_init,
-        .load = socket_load,
         .done = socket_done,
+        .load = socket_load,
+
+        .coldplug = socket_coldplug,
 
         .dump = socket_dump,
 
         .start = socket_start,
         .stop = socket_stop,
 
+        .serialize = socket_serialize,
+        .deserialize_item = socket_deserialize_item,
+
         .active_state = socket_active_state,
         .sub_state_to_string = socket_sub_state_to_string,