Adding upstream version 1:2.3.19.1+dfsg1.upstream/1%2.3.19.1+dfsg1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 448 insertions, 0 deletions

diff --git a/src/submission/submission-backend.c b/src/submission/submission-backend.c
new file mode 100644
index 0000000..889a24b
--- /dev/null
+++ b/src/submission/submission-backend.c
@@ -0,0 +1,448 @@
+/* Copyright (c) 2018 Dovecot authors, see the included COPYING file */
+
+#include "submission-common.h"
+#include "llist.h"
+#include "istream.h"
+#include "istream-sized.h"
+
+#include "submission-recipient.h"
+#include "submission-client.h"
+#include "submission-commands.h"
+#include "submission-backend.h"
+
+struct submission_backend_module_register
+submission_backend_module_register = { 0 };
+
+void submission_backend_init(struct submission_backend *backend,
+			     pool_t pool, struct client *client,
+			     const struct submission_backend_vfuncs *vfunc)
+{
+	backend->pool = pool;
+	backend->client = client;
+	backend->v = *vfunc;
+
+	p_array_init(&backend->module_contexts, pool, 5);
+
+	client->backends_count++;
+	DLLIST_PREPEND(&client->backends, backend);
+}
+
+static void submission_backend_destroy(struct submission_backend *backend)
+{
+	struct client *client = backend->client;
+
+	i_stream_unref(&backend->data_input);
+
+	i_free(backend->fail_enh_code);
+	i_free(backend->fail_reason);
+
+	DLLIST_REMOVE(&client->backends, backend);
+	backend->v.destroy(backend);
+	pool_unref(&backend->pool);
+}
+
+void submission_backends_destroy_all(struct client *client)
+{
+	while (client->backends != NULL)
+		submission_backend_destroy(client->backends);
+	array_clear(&client->rcpt_backends);
+	client->state.backend = NULL;
+}
+
+void submission_backend_start(struct submission_backend *backend)
+{
+	if (backend->started)
+		return;
+	if (backend->fail_reason != NULL) {
+		/* Don't restart until failure is reset at transaction end */
+		return;
+	}
+	backend->started = TRUE;
+	backend->v.start(backend);
+}
+
+void submission_backend_started(struct submission_backend *backend,
+				enum smtp_capability caps)
+{
+	struct client *client = backend->client;
+
+	if (backend == client->backend_default)
+		client_default_backend_started(client, caps);
+	backend->ready = TRUE;
+	if (backend->v.ready != NULL)
+		backend->v.ready(backend, caps);
+}
+
+static void
+submission_backend_fail_rcpts(struct submission_backend *backend)
+{
+	struct client *client = backend->client;
+	struct submission_recipient *srcpt;
+	const char *enh_code = backend->fail_enh_code;
+	const char *reason = backend->fail_reason;
+
+	i_assert(array_count(&client->rcpt_to) > 0);
+
+	i_assert(reason != NULL);
+	if (enh_code == NULL)
+		enh_code = "4.0.0";
+
+	array_foreach_elem(&client->rcpt_to, srcpt) {
+		struct smtp_server_recipient *rcpt = srcpt->rcpt;
+
+		if (srcpt->backend != backend)
+			continue;
+		if (rcpt->cmd == NULL)
+			continue;
+
+		smtp_server_recipient_reply(rcpt, 451, enh_code, "%s", reason);
+	}
+}
+
+static inline void
+submission_backend_reply_failure(struct submission_backend *backend,
+				 struct smtp_server_cmd_ctx *cmd)
+{
+	const char *enh_code = backend->fail_enh_code;
+	const char *reason = backend->fail_reason;
+
+	if (enh_code == NULL)
+		enh_code = "4.0.0";
+
+	i_assert(smtp_server_command_get_reply_count(cmd->cmd) == 1);
+	smtp_server_reply(cmd, 451, enh_code, "%s", reason);
+}
+
+static inline bool
+submission_backend_handle_failure(struct submission_backend *backend,
+				  struct smtp_server_cmd_ctx *cmd)
+{
+	if (backend->fail_reason == NULL)
+		return TRUE;
+
+	/* already failed */
+	submission_backend_reply_failure(backend, cmd);
+	return TRUE;
+}
+
+void submission_backend_fail(struct submission_backend *backend,
+			     struct smtp_server_cmd_ctx *cmd,
+			     const char *enh_code, const char *reason)
+{
+	struct client *client = backend->client;
+	bool failed_before = (backend->fail_reason != NULL);
+
+	/* Can be called several times */
+
+	if (backend == client->backend_default) {
+		/* default backend: fail the whole client */
+		client_destroy(&client, enh_code, reason);
+		return;
+	}
+
+	/* Non-default backend for this transaction (maybe even for only
+	   some of the approved recipients): fail only the affected
+	   transaction and/or specific recipients. */
+
+	/* Remember the failure only once */
+	if (!failed_before) {
+		backend->fail_enh_code = i_strdup(enh_code);
+		backend->fail_reason = i_strdup(reason);
+	}
+	if (cmd == NULL) {
+		/* Called outside command context: just remember the failure */
+	} else if (smtp_server_command_get_reply_count(cmd->cmd) > 1) {
+		/* Fail DATA/BDAT/BURL command expecting several replies */
+		submission_backend_fail_rcpts(backend);
+	} else {
+		/* Single command */
+		submission_backend_reply_failure(backend, cmd);
+	}
+
+	/* Call the fail vfunc only once */
+	if (!failed_before && backend->v.fail != NULL)
+		backend->v.fail(backend, enh_code, reason);
+	backend->started = FALSE;
+	backend->ready = FALSE;
+}
+
+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;
+}
+
+void submission_backend_trans_start(struct submission_backend *backend,
+				    struct smtp_server_transaction *trans)
+{
+	submission_backend_start(backend);
+
+	if (backend->trans_started)
+		return;
+	backend->trans_started = TRUE;
+
+	if (backend->v.trans_start != NULL) {
+		backend->v.trans_start(backend, trans,
+				       trans->mail_from, &trans->params);
+	}
+}
+
+static void
+submission_backend_trans_free(struct submission_backend *backend,
+			      struct smtp_server_transaction *trans)
+{
+	i_stream_unref(&backend->data_input);
+	if (backend->v.trans_free != NULL)
+		backend->v.trans_free(backend, trans);
+	backend->trans_started = FALSE;
+
+	i_free(backend->fail_enh_code);
+	i_free(backend->fail_reason);
+}
+
+void submission_backends_trans_start(struct client *client,
+				     struct smtp_server_transaction *trans)
+{
+	struct submission_backend *backend;
+
+	i_assert(client->state.backend != NULL);
+	submission_backend_trans_start(client->state.backend, trans);
+
+	array_foreach_elem(&client->pending_backends, backend)
+		submission_backend_trans_start(backend, trans);
+	array_clear(&client->pending_backends);
+}
+
+void submission_backends_trans_free(struct client *client,
+				     struct smtp_server_transaction *trans)
+{
+	struct submission_backend *backend;
+
+	i_assert(client->state.backend != NULL ||
+		 array_count(&client->rcpt_backends) == 0);
+
+	array_foreach_elem(&client->rcpt_backends, backend)
+		submission_backend_trans_free(backend, trans);
+	array_clear(&client->pending_backends);
+	array_clear(&client->rcpt_backends);
+	client->state.backend = NULL;
+}
+
+int submission_backend_cmd_helo(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd,
+				struct smtp_server_cmd_helo *data)
+{
+	/* failure on default backend closes the client connection */
+	i_assert(backend->fail_reason == NULL);
+
+	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)
+{
+	if (!submission_backend_handle_failure(backend, cmd))
+		return -1;
+
+	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);
+}
+
+static void
+submission_backend_add_pending(struct submission_backend *backend)
+{
+	struct client *client = backend->client;
+	struct submission_backend *pending_backend;
+
+	array_foreach_elem(&client->pending_backends, pending_backend) {
+		if (backend == pending_backend)
+			return;
+	}
+
+	array_push_back(&client->pending_backends, &backend);
+}
+
+int submission_backend_cmd_rcpt(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd,
+				struct submission_recipient *srcpt)
+{
+	struct smtp_server_transaction *trans;
+
+	if (!submission_backend_handle_failure(backend, cmd))
+		return -1;
+
+	i_assert(backend->started);
+
+	if (backend->v.cmd_rcpt == NULL) {
+		/* backend is not interested, respond right away */
+		return 1;
+	}
+
+	trans = smtp_server_connection_get_transaction(cmd->conn);
+	if (trans != NULL)
+		submission_backend_trans_start(srcpt->backend, trans);
+	else
+		submission_backend_add_pending(srcpt->backend);
+
+	return backend->v.cmd_rcpt(backend, cmd, srcpt);
+}
+
+int submission_backend_cmd_rset(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd)
+{
+	if (!submission_backend_handle_failure(backend, cmd))
+		return -1;
+
+	submission_backend_start(backend);
+
+	if (backend->v.cmd_rset == NULL) {
+		/* backend is not interested, respond right away */
+		return 1;
+	}
+	return backend->v.cmd_rset(backend, cmd);
+}
+
+static int
+submission_backend_cmd_data(struct submission_backend *backend,
+			    struct smtp_server_cmd_ctx *cmd,
+			    struct smtp_server_transaction *trans)
+{
+	if (backend->fail_reason != NULL) {
+		submission_backend_fail_rcpts(backend);
+		return 0;
+	}
+
+	i_assert(backend->started);
+
+	return backend->v.cmd_data(backend, cmd, trans,
+				   backend->data_input, backend->data_size);
+}
+
+int submission_backends_cmd_data(struct client *client,
+				 struct smtp_server_cmd_ctx *cmd,
+				 struct smtp_server_transaction *trans,
+				 struct istream *data_input, uoff_t data_size)
+{
+	struct submission_backend *backend;
+	int ret = 0;
+
+	i_assert(array_count(&client->rcpt_backends) > 0);
+
+	/* Make sure data input stream is at the beginning (plugins may have
+	   messed with it. */
+	i_stream_seek(data_input, 0);
+
+	/* create the data_input streams first */
+	array_foreach_elem(&client->rcpt_backends, backend) {
+		backend->data_input =
+			i_stream_create_sized(data_input, data_size);
+		backend->data_size = data_size;
+	}
+
+	/* now that all the streams are created, start reading them
+	   (reading them earlier could have caused the data_input parent's
+	   offset to change) */
+	array_foreach_elem(&client->rcpt_backends, backend) {
+		ret = submission_backend_cmd_data(backend, cmd, trans);
+		if (ret < 0)
+			break;
+	}
+
+	return ret;
+}
+
+int submission_backend_cmd_vrfy(struct submission_backend *backend,
+				struct smtp_server_cmd_ctx *cmd,
+				const char *param)
+{
+	/* failure on default backend closes the client connection */
+	i_assert(backend->fail_reason == NULL);
+
+	submission_backend_start(backend);
+
+	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)
+{
+	/* failure on default backend closes the client connection */
+	i_assert(backend->fail_reason == NULL);
+
+	submission_backend_start(backend);
+
+	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)
+{
+	/* failure on default backend closes the client connection */
+	i_assert(backend->fail_reason == NULL);
+
+	if (!backend->started) {
+		/* quit before backend even started */
+		return 1;
+	}
+	if (backend->v.cmd_quit == NULL) {
+		/* backend is not interested, respond right away */
+		return 1;
+	}
+	return backend->v.cmd_quit(backend, cmd);
+}