From: Timo Sirainen <timo.sirainen@open-xchange.com>
Date: Sat, 14 Nov 2020 18:30:39 +0000 (+0200)
Subject: master: Support %{pid} in unix_listener paths
X-Git-Tag: 2.4.0~4556
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=56cfb459a63bfd3da0cc19e00239e3ff549869e1;p=thirdparty%2Fdovecot%2Fcore.git

master: Support %{pid} in unix_listener paths

This allows each process to have their own private UNIX socket listener.
---

diff --git a/src/master/service-process.c b/src/master/service-process.c
index 34d23ff55d..a9a9e8ee37 100644
--- a/src/master/service-process.c
+++ b/src/master/service-process.c
@@ -17,6 +17,7 @@
 #include "restrict-access.h"
 #include "restrict-process-size.h"
 #include "eacces-error.h"
+#include "var-expand.h"
 #include "master-service.h"
 #include "master-service-settings.h"
 #include "dup2-array.h"
@@ -51,6 +52,19 @@ static void service_reopen_inet_listeners(struct service *service)
 	}
 }
 
+static int
+service_unix_pid_listener_get_path(struct service_listener *l, pid_t pid,
+				   string_t *path, const char **error_r)
+{
+	struct var_expand_table var_table[] = {
+		{ '\0', dec2str(pid), "pid" },
+		{ '\0', NULL, NULL },
+	};
+
+	str_truncate(path, 0);
+	return var_expand(path, l->set.fileset.set->path, var_table, error_r);
+}
+
 static void
 service_dup_fds(struct service *service)
 {
@@ -113,6 +127,36 @@ service_dup_fds(struct service *service)
 			socket_listener_count++;
 		}
 	}
+	if (array_is_created(&service->unix_pid_listeners)) {
+		struct service_listener *const *listenerp, *l;
+		string_t *path = t_str_new(128);
+		const char *error;
+		int ret;
+		pid_t pid = getpid();
+
+		array_foreach(&service->unix_pid_listeners, listenerp) {
+			l = *listenerp;
+			ret = service_unix_pid_listener_get_path(l, pid, path, &error);
+			if (ret > 0) {
+				ret = service_unix_listener_listen(l,
+					str_c(path), FALSE, &error);
+			}
+			if (ret <= 0) {
+				i_fatal("Failed to create per-PID unix_listener %s: %s",
+					l->name, error);
+			}
+
+			str_truncate(listener_settings, 0);
+			str_append_tabescaped(listener_settings, l->name);
+			str_append(listener_settings, "\tpid");
+			dup2_append(&dups, l->fd, fd++);
+
+			env_put(t_strdup_printf("SOCKET%d_SETTINGS",
+						socket_listener_count),
+				str_c(listener_settings));
+			socket_listener_count++;
+		}
+	}
 
 	if (service->login_notify_fd != -1) {
 		dup2_append(&dups, service->login_notify_fd,
@@ -388,6 +432,19 @@ void service_process_destroy(struct service_process *process)
 	struct service *service = process->service;
 	struct service_list *service_list = service->list;
 
+	if (array_is_created(&service->unix_pid_listeners)) {
+		struct service_listener *const *listenerp;
+		string_t *path = t_str_new(128);
+		const char *error;
+
+		array_foreach(&service->unix_pid_listeners, listenerp) {
+			str_truncate(path, 0);
+			if (service_unix_pid_listener_get_path(*listenerp,
+					process->pid, path, &error) > 0)
+				i_unlink_if_exists(str_c(path));
+		}
+	}
+
 	DLLIST_REMOVE(&service->processes, process);
 	hash_table_remove(service_pids, POINTER_CAST(process->pid));
 
diff --git a/src/master/service.c b/src/master/service.c
index 74e6fa5bb7..0064c5b66a 100644
--- a/src/master/service.c
+++ b/src/master/service.c
@@ -319,7 +319,9 @@ service_create(pool_t pool, const struct service_settings *set,
 
 	p_array_init(&service->listeners, pool,
 		     unix_count + fifo_count + inet_count);
-		     
+	if (unix_count > 0)
+		p_array_init(&service->unix_pid_listeners, pool, 1);
+
 	for (i = 0; i < unix_count; i++) {
 		if (unix_listeners[i]->mode == 0) {
 			/* disabled */
@@ -330,7 +332,11 @@ service_create(pool_t pool, const struct service_settings *set,
 						 unix_listeners[i], error_r);
 		if (l == NULL)
 			return NULL;
-		array_push_back(&service->listeners, &l);
+
+		if (strstr(unix_listeners[i]->path, "%{pid}") == NULL)
+			array_push_back(&service->listeners, &l);
+		else
+			array_push_back(&service->unix_pid_listeners, &l);
 	}
 	for (i = 0; i < fifo_count; i++) {
 		if (fifo_listeners[i]->mode == 0) {
diff --git a/src/master/service.h b/src/master/service.h
index 441264185e..834324a040 100644
--- a/src/master/service.h
+++ b/src/master/service.h
@@ -58,6 +58,8 @@ struct service {
 
 	/* all listeners, even those that aren't currently listening */
 	ARRAY(struct service_listener *) listeners;
+	/* per-process unix_listeners */
+	ARRAY(struct service_listener *) unix_pid_listeners;
 	/* linked list of all processes belonging to this service */
 	struct service_process *processes;