From: Stephan Bosch <stephan.bosch@dovecot.fi>
Date: Sat, 15 Sep 2018 11:02:50 +0000 (+0200)
Subject: submission: Define generic backend API.
X-Git-Tag: 2.3.5~214
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=543b5df06e8c02702316e80020e30f0683def6b6;p=thirdparty%2Fdovecot%2Fcore.git

submission: Define generic backend API.
---

diff --git a/src/submission/Makefile.am b/src/submission/Makefile.am
index 08635bee34..2ccb1e16d9 100644
--- a/src/submission/Makefile.am
+++ b/src/submission/Makefile.am
@@ -35,6 +35,7 @@ submission_DEPENDENCIES = \
 
 submission_SOURCES = \
 	main.c \
+	submission-backend.c \
 	submission-backend-relay.c \
 	submission-recipient.c \
 	submission-client.c \
diff --git a/src/submission/submission-backend.c b/src/submission/submission-backend.c
new file mode 100644
index 0000000000..6588e0cb91
--- /dev/null
+++ b/src/submission/submission-backend.c
@@ -0,0 +1,178 @@
+/* Copyright (c) 2018 Dovecot authors, see the included COPYING file */
+
+#include "submission-common.h"
+#include "llist.h"
+
+#include "submission-client.h"
+#include "submission-commands.h"
+#include "submission-backend.h"
+
+void submission_backend_init(struct submission_backend *backend,
+			     struct client *client,
+			     const struct submission_backend_vfuncs *vfunc)
+{
+	backend->client = client;
+	backend->v = *vfunc;
+
+	client->backends_count++;
+	DLLIST_PREPEND(&client->backends, backend);
+}
+
+static void submission_backend_destroy(struct submission_backend *backend)
+{
+	struct client *client = backend->client;
+
+	DLLIST_REMOVE(&client->backends, backend);
+	backend->v.destroy(backend);
+}
+
+void submission_backends_destroy_all(struct client *client)
+{
+	while (client->backends != NULL)
+		submission_backend_destroy(client->backends);
+}
+
+void submission_backend_start(struct submission_backend *backend)
+{
+	if (backend->started)
+		return;
+	backend->v.start(backend);
+	backend->started = TRUE;
+}
+
+void submission_backend_started(struct submission_backend *backend,
+				enum smtp_capability caps)
+{
+	struct client *client = backend->client;
+
+	client_default_backend_started(client, caps);
+}
+
+void submission_backends_client_input_pre(struct client *client)
+{
+	struct submission_backend *backend;
+
+	for (backend = client->backends; backend != NULL;
+	     backend = backend->next) {
+		if (!backend->started)
+			continue;
+		if (backend->v.client_input_pre != NULL)
+			backend->v.client_input_pre(backend);
+
+	}
+}
+
+void submission_backends_client_input_post(struct client *client)
+{
+	struct submission_backend *backend;
+
+	for (backend = client->backends; backend != NULL;
+	     backend = backend->next) {
+		if (!backend->started)
+			continue;
+		if (backend->v.client_input_post != NULL)
+			backend->v.client_input_post(backend);
+	}
+}
+
+uoff_t submission_backend_get_max_mail_size(struct submission_backend *backend)
+{
+	if (backend->v.get_max_mail_size != NULL)
+		return backend->v.get_max_mail_size(backend);
+	return UOFF_T_MAX;
+}
+
+int submission_backend_cmd_helo(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd,
+				struct smtp_server_cmd_helo *data)
+{
+	if (!backend->started || backend->v.cmd_helo == NULL) {
+		/* default backend is not interested, respond right away */
+		submission_helo_reply_submit(cmd, data);
+		return 1;
+	}
+
+	return backend->v.cmd_helo(backend, cmd, data);
+}
+
+void submission_backend_helo_reply_submit(
+	struct submission_backend *backend ATTR_UNUSED,
+	struct smtp_server_cmd_ctx *cmd, struct smtp_server_cmd_helo *data)
+{
+	submission_helo_reply_submit(cmd, data);
+}
+
+int submission_backend_cmd_mail(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd,
+				struct smtp_server_cmd_mail *data)
+{
+	submission_backend_start(backend);
+
+	if (backend->v.cmd_mail == NULL) {
+		/* mail backend is not interested, respond right away */
+		return 1;
+	}
+
+	return backend->v.cmd_mail(backend, cmd, data);
+}
+
+int submission_backend_cmd_rcpt(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd,
+				struct smtp_server_cmd_rcpt *data)
+{
+	if (backend->v.cmd_rcpt == NULL) {
+		/* backend is not interested, respond right away */
+		return 1;
+	}
+
+	return backend->v.cmd_rcpt(backend, cmd, data);
+}
+
+int submission_backend_cmd_rset(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd)
+{
+	if (backend->v.cmd_rset == NULL) {
+		/* backend is not interested, respond right away */
+		return 1;
+	}
+	return backend->v.cmd_rset(backend, cmd);
+}
+
+int submission_backend_cmd_data(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd,
+				struct smtp_server_transaction *trans,
+				struct istream *data_input)
+{
+	return backend->v.cmd_data(backend, cmd, trans, data_input);
+}
+
+int submission_backend_cmd_vrfy(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd,
+				const char *param)
+{
+	if (backend->v.cmd_vrfy == NULL) {
+		/* backend is not interested, respond right away */
+		return 1;
+	}
+	return backend->v.cmd_vrfy(backend, cmd, param);
+}
+
+int submission_backend_cmd_noop(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd)
+{
+	if (backend->v.cmd_noop == NULL) {
+		/* backend is not interested, respond right away */
+		return 1;
+	}
+	return backend->v.cmd_noop(backend, cmd);
+}
+
+int submission_backend_cmd_quit(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd)
+{
+	if (backend->v.cmd_quit == NULL) {
+		/* backend is not interested, respond right away */
+		return 1;
+	}
+	return backend->v.cmd_quit(backend, cmd);
+}
diff --git a/src/submission/submission-backend.h b/src/submission/submission-backend.h
index 0a3e6ea9e6..12ad93bbee 100644
--- a/src/submission/submission-backend.h
+++ b/src/submission/submission-backend.h
@@ -1,8 +1,96 @@
 #ifndef SUBMISSION_BACKEND_H
 #define SUBMISSION_BACKEND_H
 
+struct submission_backend;
+
+struct submission_backend_vfuncs {
+	void (*destroy)(struct submission_backend *backend);
+
+	void (*start)(struct submission_backend *backend);
+
+	void (*client_input_pre)(struct submission_backend *backend);
+	void (*client_input_post)(struct submission_backend *backend);
+
+	uoff_t (*get_max_mail_size)(struct submission_backend *backend);
+
+	int (*cmd_helo)(struct submission_backend *backend,
+			struct smtp_server_cmd_ctx *cmd,
+			struct smtp_server_cmd_helo *data);
+
+	int (*cmd_mail)(struct submission_backend *backend,
+			struct smtp_server_cmd_ctx *cmd,
+			struct smtp_server_cmd_mail *data);
+	int (*cmd_rcpt)(struct submission_backend *backend,
+			struct smtp_server_cmd_ctx *cmd,
+			struct smtp_server_cmd_rcpt *data);
+	int (*cmd_rset)(struct submission_backend *backend,
+			struct smtp_server_cmd_ctx *cmd);
+	int (*cmd_data)(struct submission_backend *backend,
+			struct smtp_server_cmd_ctx *cmd,
+			struct smtp_server_transaction *trans,
+			struct istream *data_input);
+
+	int (*cmd_vrfy)(struct submission_backend *backend,
+			struct smtp_server_cmd_ctx *cmd,
+			const char *param);
+	int (*cmd_noop)(struct submission_backend *backend,
+			struct smtp_server_cmd_ctx *cmd);
+
+	int (*cmd_quit)(struct submission_backend *backend,
+			struct smtp_server_cmd_ctx *cmd);
+};
+
 struct submission_backend {
 	struct client *client;
+
+	struct submission_backend *prev, *next;
+
+	struct submission_backend_vfuncs v;
+
+	bool started:1;
 };
 
+void submission_backend_init(struct submission_backend *backend,
+			     struct client *client,
+			     const struct submission_backend_vfuncs *vfunc);
+void submission_backends_destroy_all(struct client *client);
+
+void submission_backend_start(struct submission_backend *backend);
+void submission_backend_started(struct submission_backend *backend,
+				enum smtp_capability caps);
+
+void submission_backends_client_input_pre(struct client *client);
+void submission_backends_client_input_post(struct client *client);
+
+uoff_t submission_backend_get_max_mail_size(struct submission_backend *backend);
+
+void submission_backend_helo_reply_submit(struct submission_backend *backend,
+					  struct smtp_server_cmd_ctx *cmd,
+					  struct smtp_server_cmd_helo *data);
+int submission_backend_cmd_helo(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd,
+				struct smtp_server_cmd_helo *data);
+
+int submission_backend_cmd_mail(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd,
+				struct smtp_server_cmd_mail *data);
+int submission_backend_cmd_rcpt(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd,
+				struct smtp_server_cmd_rcpt *data);
+int submission_backend_cmd_rset(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd);
+int submission_backend_cmd_data(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd,
+				struct smtp_server_transaction *trans,
+				struct istream *data_input);
+
+int submission_backend_cmd_vrfy(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd,
+				const char *param);
+int submission_backend_cmd_noop(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd);
+
+int submission_backend_cmd_quit(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd);
+
 #endif
diff --git a/src/submission/submission-client.c b/src/submission/submission-client.c
index 976c8180a4..99a68d6c56 100644
--- a/src/submission/submission-client.c
+++ b/src/submission/submission-client.c
@@ -50,12 +50,14 @@ static void client_input_pre(void *context)
 	struct client *client = context;
 
 	client_proxy_input_pre(client);
+	submission_backends_client_input_pre(client);
 }
 static void client_input_post(void *context)
 {
 	struct client *client = context;
 
 	client_proxy_input_post(client);
+	submission_backends_client_input_post(client);
 }
 
 static const char *client_remote_id(struct client *client)
@@ -246,6 +248,7 @@ void client_destroy(struct client *client, const char *prefix,
 
 	client_disconnect(client, prefix, reason);
 
+	submission_backends_destroy_all(client);
 	array_free(&client->rcpt_to);
 
 	submission_client_count--;
@@ -371,6 +374,7 @@ void client_disconnect(struct client *client, const char *enh_code,
 
 	timeout_remove(&client->to_quit);
 	client_proxy_destroy(client);
+	submission_backends_destroy_all(client);
 
 	if (array_is_created(&client->rcpt_to)) {
 		array_foreach_modifiable(&client->rcpt_to, rcptp)
@@ -402,10 +406,11 @@ void client_disconnect(struct client *client, const char *enh_code,
 
 uoff_t client_get_max_mail_size(struct client *client)
 {
+	struct submission_backend *backend;
 	uoff_t max_size, limit;
 
-	/* Account for the backend server's SIZE limit and calculate our own
-	   relative to it. */
+	/* Account for backend SIZE limits and calculate our own relative to
+	   those. */
 	max_size = client->set->submission_max_mail_size;
 	if (max_size == 0)
 		max_size = UOFF_T_MAX;
@@ -415,6 +420,16 @@ uoff_t client_get_max_mail_size(struct client *client)
 		if (limit < max_size)
 			max_size = limit;
 	}
+	for (backend = client->backends; backend != NULL;
+	     backend = backend->next) {
+		limit = submission_backend_get_max_mail_size(backend);
+
+		if (limit <= SUBMISSION_MAX_ADDITIONAL_MAIL_SIZE)
+			continue;
+		limit -= SUBMISSION_MAX_ADDITIONAL_MAIL_SIZE;
+		if (limit < max_size)
+			max_size = limit;
+	}
 
 	return max_size;
 }
diff --git a/src/submission/submission-client.h b/src/submission/submission-client.h
index 71d73b4d17..9c219f5fa8 100644
--- a/src/submission/submission-client.h
+++ b/src/submission/submission-client.h
@@ -7,6 +7,7 @@
 struct smtp_reply;
 
 struct submission_recipient;
+struct submission_backend;
 struct client;
 
 struct client_state {
@@ -38,6 +39,8 @@ struct client {
 
 	enum smtp_capability backend_capabilities;
 	struct submission_backend_relay backend;
+	struct submission_backend *backends;
+	unsigned int backends_count;
 
 	bool standalone:1;
 	bool disconnected:1;