diff options
Diffstat (limited to '')
| -rw-r--r-- | src/lmtp/lmtp-proxy.c | 860 |
1 files changed, 860 insertions, 0 deletions
diff --git a/src/lmtp/lmtp-proxy.c b/src/lmtp/lmtp-proxy.c new file mode 100644 index 0000000..bf03c75 --- /dev/null +++ b/src/lmtp/lmtp-proxy.c @@ -0,0 +1,860 @@ +/* Copyright (c) 2009-2018 Dovecot authors, see the included COPYING file */ + +#include "lmtp-common.h" +#include "istream.h" +#include "istream-sized.h" +#include "ostream.h" +#include "iostream-ssl.h" +#include "str.h" +#include "strescape.h" +#include "time-util.h" +#include "smtp-common.h" +#include "smtp-params.h" +#include "smtp-address.h" +#include "smtp-client.h" +#include "smtp-client-connection.h" +#include "smtp-client-transaction.h" +#include "auth-master.h" +#include "master-service-ssl-settings.h" +#include "mail-storage-service.h" +#include "lda-settings.h" +#include "lmtp-recipient.h" +#include "lmtp-proxy.h" + +#define LMTP_MAX_REPLY_SIZE 4096 +#define LMTP_PROXY_DEFAULT_TIMEOUT_MSECS (1000*125) + +enum lmtp_proxy_ssl_flags { + /* Use SSL/TLS enabled */ + PROXY_SSL_FLAG_YES = 0x01, + /* Don't do SSL handshake immediately after connected */ + PROXY_SSL_FLAG_STARTTLS = 0x02, + /* Don't require that the received certificate is valid */ + PROXY_SSL_FLAG_ANY_CERT = 0x04 +}; + +struct lmtp_proxy_rcpt_settings { + enum smtp_protocol protocol; + const char *host; + struct ip_addr hostip, source_ip; + in_port_t port; + enum lmtp_proxy_ssl_flags ssl_flags; + unsigned int timeout_msecs; + struct smtp_params_rcpt params; + + bool proxy_not_trusted:1; +}; + +struct lmtp_proxy_recipient { + struct lmtp_recipient *rcpt; + struct lmtp_proxy_connection *conn; + + struct smtp_address *address; + + const unsigned char *forward_fields; + size_t forward_fields_size; + + bool rcpt_to_failed:1; + bool data_reply_received:1; +}; + +struct lmtp_proxy_connection { + struct lmtp_proxy *proxy; + struct lmtp_proxy_rcpt_settings set; + char *host; + + struct smtp_client_connection *lmtp_conn; + struct smtp_client_transaction *lmtp_trans; + struct istream *data_input; + struct timeout *to; + + bool finished:1; + bool failed:1; +}; + +struct lmtp_proxy { + struct client *client; + + struct smtp_server_transaction *trans; + + struct smtp_client *lmtp_client; + + ARRAY(struct lmtp_proxy_connection *) connections; + ARRAY(struct lmtp_proxy_recipient *) rcpt_to; + unsigned int next_data_reply_idx; + + struct timeout *to_finish; + struct istream *data_input; + + unsigned int max_timeout_msecs; + unsigned int proxy_session_seq; + + bool finished:1; +}; + +static void +lmtp_proxy_data_cb(const struct smtp_reply *reply, + struct lmtp_proxy_recipient *lprcpt); + +/* + * LMTP proxy + */ + +static struct lmtp_proxy * +lmtp_proxy_init(struct client *client, + struct smtp_server_transaction *trans) +{ + const char *extra_capabilities[] = { + LMTP_RCPT_FORWARD_CAPABILITY, + NULL }; + struct smtp_client_settings lmtp_set; + struct lmtp_proxy *proxy; + + proxy = i_new(struct lmtp_proxy, 1); + proxy->client = client; + proxy->trans = trans; + i_array_init(&proxy->rcpt_to, 32); + i_array_init(&proxy->connections, 32); + + i_zero(&lmtp_set); + lmtp_set.my_hostname = client->my_domain; + lmtp_set.extra_capabilities = extra_capabilities; + lmtp_set.dns_client_socket_path = dns_client_socket_path; + lmtp_set.max_reply_size = LMTP_MAX_REPLY_SIZE; + lmtp_set.rawlog_dir = client->lmtp_set->lmtp_proxy_rawlog_dir; + + smtp_server_connection_get_proxy_data(client->conn, + &lmtp_set.proxy_data); + lmtp_set.proxy_data.source_ip = client->remote_ip; + lmtp_set.proxy_data.source_port = client->remote_port; + /* This initial session_id is used only locally by lib-smtp. Each LMTP + proxy connection gets a more specific updated session_id. */ + lmtp_set.proxy_data.session = trans->id; + if (lmtp_set.proxy_data.ttl_plus_1 == 0) + lmtp_set.proxy_data.ttl_plus_1 = LMTP_PROXY_DEFAULT_TTL + 1; + else + lmtp_set.proxy_data.ttl_plus_1--; + lmtp_set.event_parent = client->event; + + proxy->lmtp_client = smtp_client_init(&lmtp_set); + + return proxy; +} + +static void lmtp_proxy_connection_deinit(struct lmtp_proxy_connection *conn) +{ + if (conn->lmtp_trans != NULL) + smtp_client_transaction_destroy(&conn->lmtp_trans); + if (conn->lmtp_conn != NULL) + smtp_client_connection_close(&conn->lmtp_conn); + timeout_remove(&conn->to); + i_stream_unref(&conn->data_input); + i_free(conn->host); + i_free(conn); +} + +void lmtp_proxy_deinit(struct lmtp_proxy **_proxy) +{ + struct lmtp_proxy *proxy = *_proxy; + struct lmtp_proxy_connection *conn; + + *_proxy = NULL; + + array_foreach_elem(&proxy->connections, conn) + lmtp_proxy_connection_deinit(conn); + + smtp_client_deinit(&proxy->lmtp_client); + i_stream_unref(&proxy->data_input); + timeout_remove(&proxy->to_finish); + array_free(&proxy->rcpt_to); + array_free(&proxy->connections); + i_free(proxy); +} + +static void +lmtp_proxy_mail_cb(const struct smtp_reply *proxy_reply ATTR_UNUSED, + struct lmtp_proxy_connection *conn ATTR_UNUSED) +{ + /* nothing */ +} + +static void lmtp_proxy_connection_finish(struct lmtp_proxy_connection *conn) +{ + conn->finished = TRUE; + conn->lmtp_trans = NULL; +} + +static void +lmtp_proxy_connection_init_ssl(struct lmtp_proxy_connection *conn, + struct ssl_iostream_settings *ssl_set_r, + enum smtp_client_connection_ssl_mode *ssl_mode_r) +{ + const struct master_service_ssl_settings *master_ssl_set; + + *ssl_mode_r = SMTP_CLIENT_SSL_MODE_NONE; + + if ((conn->set.ssl_flags & PROXY_SSL_FLAG_YES) == 0) { + i_zero(ssl_set_r); + return; + } + + master_ssl_set = master_service_ssl_settings_get(master_service); + master_service_ssl_client_settings_to_iostream_set( + master_ssl_set, pool_datastack_create(), ssl_set_r); + if ((conn->set.ssl_flags & PROXY_SSL_FLAG_ANY_CERT) != 0) + ssl_set_r->allow_invalid_cert = TRUE; + + if ((conn->set.ssl_flags & PROXY_SSL_FLAG_STARTTLS) == 0) + *ssl_mode_r = SMTP_CLIENT_SSL_MODE_IMMEDIATE; + else + *ssl_mode_r = SMTP_CLIENT_SSL_MODE_STARTTLS; +} + +static bool +lmtp_proxy_connection_has_rcpt_forward(struct lmtp_proxy_connection *conn) +{ + const struct smtp_capability_extra *cap_extra = + smtp_client_connection_get_extra_capability( + conn->lmtp_conn, LMTP_RCPT_FORWARD_CAPABILITY); + + return (cap_extra != NULL); +} + +static struct lmtp_proxy_connection * +lmtp_proxy_get_connection(struct lmtp_proxy *proxy, + const struct lmtp_proxy_rcpt_settings *set) +{ + static const char *rcpt_param_extensions[] = + { LMTP_RCPT_FORWARD_PARAMETER, NULL }; + static const struct smtp_client_capability_extra cap_rcpt_forward = { + .name = LMTP_RCPT_FORWARD_CAPABILITY, + .rcpt_param_extensions = rcpt_param_extensions, + }; + struct smtp_client_settings lmtp_set; + struct smtp_server_transaction *trans = proxy->trans; + struct client *client = proxy->client; + struct lmtp_proxy_connection *conn; + enum smtp_client_connection_ssl_mode ssl_mode; + struct ssl_iostream_settings ssl_set; + + i_assert(set->timeout_msecs > 0); + + array_foreach_elem(&proxy->connections, conn) { + if (conn->set.protocol == set->protocol && + conn->set.port == set->port && + strcmp(conn->set.host, set->host) == 0 && + net_ip_compare(&conn->set.hostip, &set->hostip) && + net_ip_compare(&conn->set.source_ip, &set->source_ip) && + conn->set.ssl_flags == set->ssl_flags) + return conn; + } + + conn = i_new(struct lmtp_proxy_connection, 1); + conn->proxy = proxy; + conn->set.protocol = set->protocol; + conn->set.hostip = set->hostip; + conn->host = i_strdup(set->host); + conn->set.host = conn->host; + conn->set.source_ip = set->source_ip; + conn->set.port = set->port; + conn->set.ssl_flags = set->ssl_flags; + conn->set.timeout_msecs = set->timeout_msecs; + array_push_back(&proxy->connections, &conn); + + lmtp_proxy_connection_init_ssl(conn, &ssl_set, &ssl_mode); + + i_zero(&lmtp_set); + lmtp_set.my_ip = conn->set.source_ip; + lmtp_set.ssl = &ssl_set; + lmtp_set.peer_trusted = !conn->set.proxy_not_trusted; + lmtp_set.forced_capabilities = SMTP_CAPABILITY__ORCPT; + lmtp_set.mail_send_broken_path = TRUE; + lmtp_set.verbose_user_errors = client->lmtp_set->lmtp_verbose_replies; + + if (conn->set.hostip.family != 0) { + conn->lmtp_conn = smtp_client_connection_create_ip( + proxy->lmtp_client, set->protocol, + &conn->set.hostip, conn->set.port, + conn->set.host, ssl_mode, &lmtp_set); + } else { + conn->lmtp_conn = smtp_client_connection_create( + proxy->lmtp_client, set->protocol, + conn->set.host, conn->set.port, + ssl_mode, &lmtp_set); + } + struct smtp_proxy_data proxy_data = { + .session = t_strdup_printf("%s:P%u", proxy->trans->id, + ++proxy->proxy_session_seq), + }; + smtp_client_connection_update_proxy_data(conn->lmtp_conn, &proxy_data); + smtp_client_connection_accept_extra_capability(conn->lmtp_conn, + &cap_rcpt_forward); + smtp_client_connection_connect(conn->lmtp_conn, NULL, NULL); + + conn->lmtp_trans = smtp_client_transaction_create( + conn->lmtp_conn, trans->mail_from, &trans->params, 0, + lmtp_proxy_connection_finish, conn); + + smtp_client_transaction_start(conn->lmtp_trans, + lmtp_proxy_mail_cb, conn); + + if (proxy->max_timeout_msecs < set->timeout_msecs) + proxy->max_timeout_msecs = set->timeout_msecs; + return conn; +} + +static void +lmtp_proxy_handle_connection_error(struct lmtp_proxy_recipient *lprcpt, + const struct smtp_reply *reply) +{ + struct lmtp_recipient *lrcpt = lprcpt->rcpt; + struct client *client = lrcpt->client; + struct smtp_server_recipient *rcpt = lrcpt->rcpt; + const char *detail = ""; + + if (client->lmtp_set->lmtp_verbose_replies) { + smtp_server_command_fail(rcpt->cmd->cmd, 451, "4.4.0", + "Proxy failed: %s (session=%s)", + smtp_reply_log(reply), + lrcpt->session_id); + return; + } + + switch (reply->status) { + case SMTP_CLIENT_COMMAND_ERROR_ABORTED: + break; + case SMTP_CLIENT_COMMAND_ERROR_HOST_LOOKUP_FAILED: + detail = "DNS lookup, "; + break; + case SMTP_CLIENT_COMMAND_ERROR_CONNECT_FAILED: + case SMTP_CLIENT_COMMAND_ERROR_AUTH_FAILED: + detail = "connect, "; + break; + case SMTP_CLIENT_COMMAND_ERROR_CONNECTION_LOST: + case SMTP_CLIENT_COMMAND_ERROR_CONNECTION_CLOSED: + detail = "connection lost, "; + break; + case SMTP_CLIENT_COMMAND_ERROR_BAD_REPLY: + detail = "bad reply, "; + break; + case SMTP_CLIENT_COMMAND_ERROR_TIMED_OUT: + detail = "timed out, "; + break; + default: + break; + } + + smtp_server_command_fail(rcpt->cmd->cmd, 451, "4.4.0", + "Proxy failed (%ssession=%s)", + detail, lrcpt->session_id); +} + +static bool +lmtp_proxy_handle_reply(struct lmtp_proxy_recipient *lprcpt, + const struct smtp_reply *reply, + struct smtp_reply *reply_r) +{ + *reply_r = *reply; + + if (!smtp_reply_is_remote(reply) || + reply->status == SMTP_CLIENT_COMMAND_ERROR_CONNECTION_CLOSED) { + lmtp_proxy_handle_connection_error(lprcpt, reply); + return FALSE; + } + + if (!smtp_reply_has_enhanced_code(reply)) { + reply_r->enhanced_code = + SMTP_REPLY_ENH_CODE(reply->status / 100, 0, 0); + } + return TRUE; +} + +/* + * RCPT command + */ + +static bool +lmtp_proxy_rcpt_parse_fields(struct lmtp_recipient *lrcpt, + struct lmtp_proxy_rcpt_settings *set, + const char *const *args, const char **address) +{ + struct smtp_server_recipient *rcpt = lrcpt->rcpt; + const char *p, *key, *value; + bool proxying = FALSE, port_set = FALSE; + + for (; *args != NULL; args++) { + p = strchr(*args, '='); + if (p == NULL) { + key = *args; + value = ""; + } else { + key = t_strdup_until(*args, p); + value = p + 1; + } + + if (strcmp(key, "proxy") == 0) + proxying = TRUE; + else if (strcmp(key, "host") == 0) + set->host = value; + else if (strcmp(key, "hostip") == 0) { + if (net_addr2ip(value, &set->hostip) < 0) { + e_error(rcpt->event, + "proxy: Invalid hostip %s", value); + return FALSE; + } + } else if (strcmp(key, "source_ip") == 0) { + if (net_addr2ip(value, &set->source_ip) < 0) { + e_error(rcpt->event, + "proxy: Invalid source_ip %s", value); + return FALSE; + } + } else if (strcmp(key, "port") == 0) { + if (net_str2port(value, &set->port) < 0) { + e_error(rcpt->event, + "proxy: Invalid port number %s", value); + return FALSE; + } + port_set = TRUE; + } else if (strcmp(key, "proxy_timeout") == 0) { + if (str_to_uint(value, &set->timeout_msecs) < 0) { + e_error(rcpt->event,"proxy: " + "Invalid proxy_timeout value %s", value); + return FALSE; + } + set->timeout_msecs *= 1000; + } else if (strcmp(key, "proxy_not_trusted") == 0) { + set->proxy_not_trusted = TRUE; + } else if (strcmp(key, "protocol") == 0) { + if (strcmp(value, "lmtp") == 0) { + set->protocol = SMTP_PROTOCOL_LMTP; + if (!port_set) + set->port = 24; + } else if (strcmp(value, "smtp") == 0) { + set->protocol = SMTP_PROTOCOL_SMTP; + if (!port_set) + set->port = 25; + } else { + e_error(rcpt->event, + "proxy: Unknown protocol %s", value); + return FALSE; + } + } else if (strcmp(key, "ssl") == 0) { + set->ssl_flags |= PROXY_SSL_FLAG_YES; + if (strcmp(value, "any-cert") == 0) + set->ssl_flags |= PROXY_SSL_FLAG_ANY_CERT; + } else if (strcmp(key, "starttls") == 0) { + set->ssl_flags |= PROXY_SSL_FLAG_YES | + PROXY_SSL_FLAG_STARTTLS; + if (strcmp(value, "any-cert") == 0) + set->ssl_flags |= PROXY_SSL_FLAG_ANY_CERT; + } else if (strcmp(key, "user") == 0 || + strcmp(key, "destuser") == 0) { + /* Changing the username */ + *address = value; + } else { + /* Just ignore it */ + } + } + if (proxying && set->host == NULL) { + e_error(rcpt->event, "proxy: host not given"); + return FALSE; + } + return proxying; +} + +static bool +lmtp_proxy_is_ourself(const struct client *client, + const struct lmtp_proxy_rcpt_settings *set) +{ + struct ip_addr ip; + + if (set->port != client->local_port) + return FALSE; + + if (set->hostip.family != 0) + ip = set->hostip; + else { + if (net_addr2ip(set->host, &ip) < 0) + return FALSE; + } + if (!net_ip_compare(&ip, &client->local_ip)) + return FALSE; + return TRUE; +} + +static void +lmtp_proxy_rcpt_approved(struct smtp_server_recipient *rcpt ATTR_UNUSED, + struct lmtp_proxy_recipient *lprcpt) +{ + struct client *client = lprcpt->rcpt->client; + + /* Add to proxy recipients */ + array_push_back(&client->proxy->rcpt_to, &lprcpt); +} + +static void +lmtp_proxy_rcpt_cb(const struct smtp_reply *proxy_reply, + struct lmtp_proxy_recipient *lprcpt) +{ + struct smtp_server_recipient *rcpt = lprcpt->rcpt->rcpt; + struct smtp_reply reply; + + if (!lmtp_proxy_handle_reply(lprcpt, proxy_reply, &reply)) + return; + + if (smtp_reply_is_success(proxy_reply)) { + /* If backend accepts it, we accept it too */ + + /* The default 2.0.0 code won't do */ + if (!smtp_reply_has_enhanced_code(proxy_reply)) + reply.enhanced_code = SMTP_REPLY_ENH_CODE(2, 1, 0); + } + + /* Forward reply */ + smtp_server_recipient_reply_forward(rcpt, &reply); +} + +static void +lmtp_proxy_rcpt_login_cb(const struct smtp_reply *proxy_reply, void *context) +{ + struct lmtp_proxy_recipient *lprcpt = context; + struct lmtp_recipient *lrcpt = lprcpt->rcpt; + struct lmtp_proxy_connection *conn = lprcpt->conn; + struct smtp_server_recipient *rcpt = lrcpt->rcpt; + struct smtp_reply reply; + struct smtp_client_transaction_rcpt *relay_rcpt; + struct smtp_params_rcpt *rcpt_params = &rcpt->params; + bool add_orcpt_param = FALSE, add_xrcptforward_param = FALSE; + pool_t param_pool; + + if (!lmtp_proxy_handle_reply(lprcpt, proxy_reply, &reply)) + return; + if (!smtp_reply_is_success(proxy_reply)) { + smtp_server_recipient_reply_forward(rcpt, &reply); + return; + } + + /* Add an ORCPT parameter when passdb changed the username (and + therefore the RCPT address changed) and there is no ORCPT parameter + yet. */ + if (!smtp_params_rcpt_has_orcpt(rcpt_params) && + !smtp_address_equals(lprcpt->address, rcpt->path)) + add_orcpt_param = TRUE; + + /* Add forward fields parameter when passdb returned forward_* fields */ + if (lprcpt->forward_fields != NULL && + lmtp_proxy_connection_has_rcpt_forward(conn)) + add_xrcptforward_param = TRUE; + + /* Copy params when changes are pending */ + param_pool = NULL; + if (add_orcpt_param || add_xrcptforward_param) { + param_pool = pool_datastack_create(); + rcpt_params = p_new(param_pool, struct smtp_params_rcpt, 1); + smtp_params_rcpt_copy(param_pool, rcpt_params, &rcpt->params); + } + + /* Add ORCPT */ + if (add_orcpt_param) { + smtp_params_rcpt_set_orcpt(rcpt_params, param_pool, + rcpt->path); + } + /* Add forward fields parameter */ + if (add_xrcptforward_param) { + smtp_params_rcpt_encode_extra( + rcpt_params, param_pool, LMTP_RCPT_FORWARD_PARAMETER, + lprcpt->forward_fields, lprcpt->forward_fields_size); + } + + smtp_server_recipient_add_hook( + rcpt, SMTP_SERVER_RECIPIENT_HOOK_APPROVED, + lmtp_proxy_rcpt_approved, lprcpt); + + relay_rcpt = smtp_client_transaction_add_pool_rcpt( + conn->lmtp_trans, rcpt->pool, lprcpt->address, rcpt_params, + lmtp_proxy_rcpt_cb, lprcpt); + smtp_client_transaction_rcpt_set_data_callback( + relay_rcpt, lmtp_proxy_data_cb, lprcpt); +} + +int lmtp_proxy_rcpt(struct client *client, + struct smtp_server_cmd_ctx *cmd, + struct lmtp_recipient *lrcpt, + const char *username, const char *detail, + char delim) +{ + struct auth_master_connection *auth_conn; + struct lmtp_proxy_rcpt_settings set; + struct lmtp_proxy_connection *conn; + struct smtp_server_recipient *rcpt = lrcpt->rcpt; + struct lmtp_proxy_recipient *lprcpt; + struct smtp_server_transaction *trans; + struct smtp_address *address = rcpt->path; + struct auth_user_info info; + struct mail_storage_service_input input; + const char *const *fields, *errstr, *orig_username = username; + struct smtp_proxy_data proxy_data; + struct smtp_address *user; + string_t *fwfields; + pool_t auth_pool; + int ret; + + trans = smtp_server_connection_get_transaction(cmd->conn); + i_assert(trans != NULL); /* MAIL command is synchronous */ + + i_zero(&input); + input.module = input.service = "lmtp"; + mail_storage_service_init_settings(storage_service, &input); + + i_zero(&info); + info.service = master_service_get_name(master_service); + info.local_ip = client->local_ip; + info.real_local_ip = client->real_local_ip; + info.remote_ip = client->remote_ip; + info.real_remote_ip = client->real_remote_ip; + info.local_port = client->local_port; + info.real_local_port = client->real_local_port; + info.remote_port = client->remote_port; + info.real_remote_port = client->real_remote_port; + info.forward_fields = lrcpt->forward_fields; + + // FIXME: make this async + auth_pool = pool_alloconly_create("auth lookup", 1024); + auth_conn = mail_storage_service_get_auth_conn(storage_service); + ret = auth_master_pass_lookup(auth_conn, username, &info, + auth_pool, &fields); + if (ret <= 0) { + errstr = (ret < 0 && fields[0] != NULL ? + t_strdup(fields[0]) : + "Temporary user lookup failure"); + pool_unref(&auth_pool); + if (ret < 0) { + smtp_server_recipient_reply(rcpt, 451, "4.3.0", "%s", + errstr); + return -1; + } else { + /* User not found from passdb: revert to local delivery. + */ + return 0; + } + } + + i_zero(&set); + set.port = client->local_port; + set.protocol = SMTP_PROTOCOL_LMTP; + set.timeout_msecs = LMTP_PROXY_DEFAULT_TIMEOUT_MSECS; + + if (!lmtp_proxy_rcpt_parse_fields(lrcpt, &set, fields, &username)) { + /* Not proxying this user */ + pool_unref(&auth_pool); + return 0; + } + if (strcmp(username, orig_username) != 0) { + /* The existing "user" event field is overridden with the new + user name, while old username is available as "orig_user" */ + event_add_str(rcpt->event, "user", username); + event_add_str(rcpt->event, "original_user", orig_username); + + if (smtp_address_parse_username(pool_datastack_create(), + username, &user, &errstr) < 0) { + e_error(rcpt->event, "%s: " + "Username `%s' returned by passdb lookup is not a valid SMTP address", + orig_username, username); + smtp_server_recipient_reply( + rcpt, 550, "5.3.5", + "Internal user lookup failure"); + pool_unref(&auth_pool); + return -1; + } + /* Username changed. change the address as well */ + if (*detail == '\0') { + address = user; + } else { + address = smtp_address_add_detail_temp( + user, detail, delim); + } + } else if (lmtp_proxy_is_ourself(client, &set)) { + e_error(rcpt->event, "Proxying to <%s> loops to itself", + username); + smtp_server_recipient_reply(rcpt, 554, "5.4.6", + "Proxying loops to itself"); + pool_unref(&auth_pool); + return -1; + } + + smtp_server_connection_get_proxy_data(cmd->conn, &proxy_data); + if (proxy_data.ttl_plus_1 == 1) { + e_error(rcpt->event, + "Proxying to <%s> appears to be looping (TTL=0)", + username); + smtp_server_recipient_reply(rcpt, 554, "5.4.6", + "Proxying appears to be looping " + "(TTL=0)"); + pool_unref(&auth_pool); + return -1; + } + + if (client->proxy == NULL) + client->proxy = lmtp_proxy_init(client, trans); + + conn = lmtp_proxy_get_connection(client->proxy, &set); + + lprcpt = p_new(rcpt->pool, struct lmtp_proxy_recipient, 1); + lprcpt->rcpt = lrcpt; + lprcpt->address = smtp_address_clone(rcpt->pool, address); + lprcpt->conn = conn; + + lrcpt->type = LMTP_RECIPIENT_TYPE_PROXY; + lrcpt->backend_context = lprcpt; + + /* Copy forward fields returned from passdb */ + fwfields = NULL; + for (const char *const *ptr = fields; *ptr != NULL; ptr++) { + if (strncasecmp(*ptr, "forward_", 8) != 0) + continue; + + if (fwfields == NULL) + fwfields = t_str_new(128); + else + str_append_c(fwfields, '\t'); + + str_append_tabescaped(fwfields, (*ptr) + 8); + } + if (fwfields != NULL) { + lprcpt->forward_fields = p_memdup( + rcpt->pool, str_data(fwfields), str_len(fwfields)); + lprcpt->forward_fields_size = str_len(fwfields); + } + + pool_unref(&auth_pool); + + smtp_client_connection_connect(conn->lmtp_conn, + lmtp_proxy_rcpt_login_cb, lprcpt); + return 1; +} + +/* + * DATA command + */ + +static void +lmtp_proxy_data_cb(const struct smtp_reply *proxy_reply, + struct lmtp_proxy_recipient *lprcpt) +{ + struct lmtp_proxy_connection *conn = lprcpt->conn; + struct lmtp_recipient *lrcpt = lprcpt->rcpt; + struct smtp_server_recipient *rcpt = lrcpt->rcpt; + struct lmtp_proxy *proxy = conn->proxy; + struct smtp_server_transaction *trans = proxy->trans; + struct smtp_address *address = lprcpt->address; + const struct smtp_client_transaction_times *times = + smtp_client_transaction_get_times(conn->lmtp_trans); + unsigned int rcpt_index = rcpt->index; + struct smtp_reply reply; + string_t *msg; + + /* Compose log message */ + msg = t_str_new(128); + str_printfa(msg, "<%s>: ", lrcpt->session_id); + if (smtp_reply_is_success(proxy_reply)) + str_append(msg, "Sent message to"); + else + str_append(msg, "Failed to send message to"); + str_printfa(msg, " <%s> at %s:%u: %s (%u/%u at %u ms)", + smtp_address_encode(address), + conn->set.host, conn->set.port, + smtp_reply_log(proxy_reply), + rcpt_index + 1, array_count(&trans->rcpt_to), + timeval_diff_msecs(&ioloop_timeval, ×->started)); + + /* Handle reply */ + if (smtp_reply_is_success(proxy_reply)) { + /* If backend accepts it, we accept it too */ + e_info(rcpt->event, "%s", str_c(msg)); + + /* Substitute our own success message */ + smtp_reply_printf(&reply, 250, "%s Saved", lrcpt->session_id); + /* Do let the enhanced code through */ + if (!smtp_reply_has_enhanced_code(proxy_reply)) + reply.enhanced_code = SMTP_REPLY_ENH_CODE(2, 0, 0); + else + reply.enhanced_code = proxy_reply->enhanced_code; + + } else { + if (smtp_reply_is_remote(proxy_reply)) { + /* The problem isn't with the proxy, it's with the + remote side. so the remote side will log an error, + while for us this is just an info event */ + e_info(rcpt->event, "%s", str_c(msg)); + } else { + e_error(rcpt->event, "%s", str_c(msg)); + } + + if (!lmtp_proxy_handle_reply(lprcpt, proxy_reply, &reply)) + return; + } + + /* Forward reply */ + smtp_server_recipient_reply_forward(rcpt, &reply); +} + +static void +lmtp_proxy_data_dummy_cb(const struct smtp_reply *proxy_reply ATTR_UNUSED, + struct lmtp_proxy_connection *conn ATTR_UNUSED) +{ + /* nothing */ +} + +void lmtp_proxy_data(struct client *client, + struct smtp_server_cmd_ctx *cmd ATTR_UNUSED, + struct smtp_server_transaction *trans ATTR_UNUSED, + struct istream *data_input) +{ + struct lmtp_proxy *proxy = client->proxy; + struct lmtp_proxy_connection *conn; + uoff_t size; + + i_assert(data_input->seekable); + i_assert(proxy->data_input == NULL); + + client_update_data_state(client, "proxying"); + + proxy->data_input = data_input; + i_stream_ref(proxy->data_input); + if (i_stream_get_size(proxy->data_input, TRUE, &size) < 0) { + e_error(client->event, + "i_stream_get_size(data_input) failed: %s", + i_stream_get_error(proxy->data_input)); + size = UOFF_T_MAX; + } + + /* Create the data_input streams first */ + array_foreach_elem(&proxy->connections, conn) { + if (conn->finished) { + /* This connection had already failed */ + continue; + } + + if (size == UOFF_T_MAX) { + conn->data_input = + i_stream_create_limit(data_input, UOFF_T_MAX); + } else { + conn->data_input = + i_stream_create_sized(data_input, 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(&proxy->connections, conn) { + if (conn->finished) { + /* This connection had already failed */ + continue; + } + + smtp_client_transaction_set_timeout(conn->lmtp_trans, + proxy->max_timeout_msecs); + smtp_client_transaction_send(conn->lmtp_trans, conn->data_input, + lmtp_proxy_data_dummy_cb, conn); + } +} |