diff options
Diffstat (limited to 'src/transports/smtp.c')
| -rw-r--r-- | src/transports/smtp.c | 5487 |
1 files changed, 5487 insertions, 0 deletions
diff --git a/src/transports/smtp.c b/src/transports/smtp.c new file mode 100644 index 0000000..a351da8 --- /dev/null +++ b/src/transports/smtp.c @@ -0,0 +1,5487 @@ +/************************************************* +* Exim - an Internet mail transport agent * +*************************************************/ + +/* Copyright (c) University of Cambridge 1995 - 2018 */ +/* See the file NOTICE for conditions of use and distribution. */ + +#include "../exim.h" +#include "smtp.h" + + +/* Options specific to the smtp transport. This transport also supports LMTP +over TCP/IP. The options must be in alphabetic order (note that "_" comes +before the lower case letters). Some live in the transport_instance block so as +to be publicly visible; these are flagged with opt_public. */ + +optionlist smtp_transport_options[] = { + { "*expand_multi_domain", opt_stringptr | opt_hidden | opt_public, + (void *)offsetof(transport_instance, expand_multi_domain) }, + { "*expand_retry_include_ip_address", opt_stringptr | opt_hidden, + (void *)(offsetof(smtp_transport_options_block, expand_retry_include_ip_address)) }, + + { "address_retry_include_sender", opt_bool, + (void *)offsetof(smtp_transport_options_block, address_retry_include_sender) }, + { "allow_localhost", opt_bool, + (void *)offsetof(smtp_transport_options_block, allow_localhost) }, +#ifdef EXPERIMENTAL_ARC + { "arc_sign", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, arc_sign) }, +#endif + { "authenticated_sender", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, authenticated_sender) }, + { "authenticated_sender_force", opt_bool, + (void *)offsetof(smtp_transport_options_block, authenticated_sender_force) }, + { "command_timeout", opt_time, + (void *)offsetof(smtp_transport_options_block, command_timeout) }, + { "connect_timeout", opt_time, + (void *)offsetof(smtp_transport_options_block, connect_timeout) }, + { "connection_max_messages", opt_int | opt_public, + (void *)offsetof(transport_instance, connection_max_messages) }, +# ifdef SUPPORT_DANE + { "dane_require_tls_ciphers", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, dane_require_tls_ciphers) }, +# endif + { "data_timeout", opt_time, + (void *)offsetof(smtp_transport_options_block, data_timeout) }, + { "delay_after_cutoff", opt_bool, + (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) }, +#ifndef DISABLE_DKIM + { "dkim_canon", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, dkim.dkim_canon) }, + { "dkim_domain", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, dkim.dkim_domain) }, + { "dkim_hash", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, dkim.dkim_hash) }, + { "dkim_identity", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, dkim.dkim_identity) }, + { "dkim_private_key", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, dkim.dkim_private_key) }, + { "dkim_selector", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, dkim.dkim_selector) }, + { "dkim_sign_headers", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, dkim.dkim_sign_headers) }, + { "dkim_strict", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, dkim.dkim_strict) }, + { "dkim_timestamps", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, dkim.dkim_timestamps) }, +#endif + { "dns_qualify_single", opt_bool, + (void *)offsetof(smtp_transport_options_block, dns_qualify_single) }, + { "dns_search_parents", opt_bool, + (void *)offsetof(smtp_transport_options_block, dns_search_parents) }, + { "dnssec_request_domains", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, dnssec.request) }, + { "dnssec_require_domains", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, dnssec.require) }, + { "dscp", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, dscp) }, + { "fallback_hosts", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, fallback_hosts) }, + { "final_timeout", opt_time, + (void *)offsetof(smtp_transport_options_block, final_timeout) }, + { "gethostbyname", opt_bool, + (void *)offsetof(smtp_transport_options_block, gethostbyname) }, + { "helo_data", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, helo_data) }, + { "hosts", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts) }, + { "hosts_avoid_esmtp", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) }, + { "hosts_avoid_pipelining", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_avoid_pipelining) }, +#ifdef SUPPORT_TLS + { "hosts_avoid_tls", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) }, +#endif + { "hosts_max_try", opt_int, + (void *)offsetof(smtp_transport_options_block, hosts_max_try) }, + { "hosts_max_try_hardlimit", opt_int, + (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) }, +#ifdef SUPPORT_TLS + { "hosts_nopass_tls", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) }, + { "hosts_noproxy_tls", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_noproxy_tls) }, +#endif + { "hosts_override", opt_bool, + (void *)offsetof(smtp_transport_options_block, hosts_override) }, +#ifdef EXPERIMENTAL_PIPE_CONNECT + { "hosts_pipe_connect", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_pipe_connect) }, +#endif + { "hosts_randomize", opt_bool, + (void *)offsetof(smtp_transport_options_block, hosts_randomize) }, +#if defined(SUPPORT_TLS) && !defined(DISABLE_OCSP) + { "hosts_request_ocsp", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_request_ocsp) }, +#endif + { "hosts_require_auth", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_require_auth) }, +#ifdef SUPPORT_TLS +# ifdef SUPPORT_DANE + { "hosts_require_dane", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_require_dane) }, +# endif +# ifndef DISABLE_OCSP + { "hosts_require_ocsp", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_require_ocsp) }, +# endif + { "hosts_require_tls", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_require_tls) }, +#endif + { "hosts_try_auth", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_try_auth) }, + { "hosts_try_chunking", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_try_chunking) }, +#if defined(SUPPORT_TLS) && defined(SUPPORT_DANE) + { "hosts_try_dane", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_try_dane) }, +#endif + { "hosts_try_fastopen", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_try_fastopen) }, +#ifndef DISABLE_PRDR + { "hosts_try_prdr", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_try_prdr) }, +#endif +#ifdef SUPPORT_TLS + { "hosts_verify_avoid_tls", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, hosts_verify_avoid_tls) }, +#endif + { "interface", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, interface) }, + { "keepalive", opt_bool, + (void *)offsetof(smtp_transport_options_block, keepalive) }, + { "lmtp_ignore_quota", opt_bool, + (void *)offsetof(smtp_transport_options_block, lmtp_ignore_quota) }, + { "max_rcpt", opt_int | opt_public, + (void *)offsetof(transport_instance, max_addresses) }, + { "multi_domain", opt_expand_bool | opt_public, + (void *)offsetof(transport_instance, multi_domain) }, + { "port", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, port) }, + { "protocol", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, protocol) }, + { "retry_include_ip_address", opt_expand_bool, + (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) }, + { "serialize_hosts", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, serialize_hosts) }, + { "size_addition", opt_int, + (void *)offsetof(smtp_transport_options_block, size_addition) }, +#ifdef SUPPORT_SOCKS + { "socks_proxy", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, socks_proxy) }, +#endif +#ifdef SUPPORT_TLS + { "tls_certificate", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, tls_certificate) }, + { "tls_crl", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, tls_crl) }, + { "tls_dh_min_bits", opt_int, + (void *)offsetof(smtp_transport_options_block, tls_dh_min_bits) }, + { "tls_privatekey", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, tls_privatekey) }, + { "tls_require_ciphers", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) }, + { "tls_sni", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, tls_sni) }, + { "tls_tempfail_tryclear", opt_bool, + (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) }, + { "tls_try_verify_hosts", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, tls_try_verify_hosts) }, + { "tls_verify_cert_hostnames", opt_stringptr, + (void *)offsetof(smtp_transport_options_block,tls_verify_cert_hostnames)}, + { "tls_verify_certificates", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }, + { "tls_verify_hosts", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, tls_verify_hosts) }, +#endif +#ifdef SUPPORT_I18N + { "utf8_downconvert", opt_stringptr, + (void *)offsetof(smtp_transport_options_block, utf8_downconvert) }, +#endif +}; + +/* Size of the options list. An extern variable has to be used so that its +address can appear in the tables drtables.c. */ + +int smtp_transport_options_count = nelem(smtp_transport_options); + + +#ifdef MACRO_PREDEF + +/* Dummy values */ +smtp_transport_options_block smtp_transport_option_defaults = {0}; +void smtp_transport_init(transport_instance *tblock) {} +BOOL smtp_transport_entry(transport_instance *tblock, address_item *addr) {return FALSE;} +void smtp_transport_closedown(transport_instance *tblock) {} + +#else /*!MACRO_PREDEF*/ + + +/* Default private options block for the smtp transport. */ + +smtp_transport_options_block smtp_transport_option_defaults = { + .hosts = NULL, + .fallback_hosts = NULL, + .hostlist = NULL, + .fallback_hostlist = NULL, + .helo_data = US"$primary_hostname", + .interface = NULL, + .port = NULL, + .protocol = US"smtp", + .dscp = NULL, + .serialize_hosts = NULL, + .hosts_try_auth = NULL, + .hosts_require_auth = NULL, + .hosts_try_chunking = US"*", +#ifdef SUPPORT_DANE + .hosts_try_dane = NULL, + .hosts_require_dane = NULL, + .dane_require_tls_ciphers = NULL, +#endif + .hosts_try_fastopen = NULL, +#ifndef DISABLE_PRDR + .hosts_try_prdr = US"*", +#endif +#ifndef DISABLE_OCSP + .hosts_request_ocsp = US"*", /* hosts_request_ocsp (except under DANE; tls_client_start()) */ + .hosts_require_ocsp = NULL, +#endif + .hosts_require_tls = NULL, + .hosts_avoid_tls = NULL, + .hosts_verify_avoid_tls = NULL, + .hosts_avoid_pipelining = NULL, +#ifdef EXPERIMENTAL_PIPE_CONNECT + .hosts_pipe_connect = NULL, +#endif + .hosts_avoid_esmtp = NULL, +#ifdef SUPPORT_TLS + .hosts_nopass_tls = NULL, + .hosts_noproxy_tls = US"*", +#endif + .command_timeout = 5*60, + .connect_timeout = 5*60, + .data_timeout = 5*60, + .final_timeout = 10*60, + .size_addition = 1024, + .hosts_max_try = 5, + .hosts_max_try_hardlimit = 50, + .address_retry_include_sender = TRUE, + .allow_localhost = FALSE, + .authenticated_sender_force = FALSE, + .gethostbyname = FALSE, + .dns_qualify_single = TRUE, + .dns_search_parents = FALSE, + .dnssec = { .request=NULL, .require=NULL }, + .delay_after_cutoff = TRUE, + .hosts_override = FALSE, + .hosts_randomize = FALSE, + .keepalive = TRUE, + .lmtp_ignore_quota = FALSE, + .expand_retry_include_ip_address = NULL, + .retry_include_ip_address = TRUE, +#ifdef SUPPORT_SOCKS + .socks_proxy = NULL, +#endif +#ifdef SUPPORT_TLS + .tls_certificate = NULL, + .tls_crl = NULL, + .tls_privatekey = NULL, + .tls_require_ciphers = NULL, + .tls_sni = NULL, + .tls_verify_certificates = US"system", + .tls_dh_min_bits = EXIM_CLIENT_DH_DEFAULT_MIN_BITS, + .tls_tempfail_tryclear = TRUE, + .tls_verify_hosts = NULL, + .tls_try_verify_hosts = US"*", + .tls_verify_cert_hostnames = US"*", +#endif +#ifdef SUPPORT_I18N + .utf8_downconvert = NULL, +#endif +#ifndef DISABLE_DKIM + .dkim = + {.dkim_domain = NULL, + .dkim_identity = NULL, + .dkim_private_key = NULL, + .dkim_selector = NULL, + .dkim_canon = NULL, + .dkim_sign_headers = NULL, + .dkim_strict = NULL, + .dkim_hash = US"sha256", + .dkim_timestamps = NULL, + .dot_stuffed = FALSE, + .force_bodyhash = FALSE, +# ifdef EXPERIMENTAL_ARC + .arc_signspec = NULL, +# endif + }, +# ifdef EXPERIMENTAL_ARC + .arc_sign = NULL, +# endif +#endif +}; + +/* some DSN flags for use later */ + +static int rf_list[] = {rf_notify_never, rf_notify_success, + rf_notify_failure, rf_notify_delay }; + +static uschar *rf_names[] = { US"NEVER", US"SUCCESS", US"FAILURE", US"DELAY" }; + + + +/* Local statics */ + +static uschar *smtp_command; /* Points to last cmd for error messages */ +static uschar *mail_command; /* Points to MAIL cmd for error messages */ +static uschar *data_command = US""; /* Points to DATA cmd for error messages */ +static BOOL update_waiting; /* TRUE to update the "wait" database */ + +/*XXX move to smtp_context */ +static BOOL pipelining_active; /* current transaction is in pipe mode */ + + +static unsigned ehlo_response(uschar * buf, unsigned checks); + + +/************************************************* +* Setup entry point * +*************************************************/ + +/* This function is called when the transport is about to be used, +but before running it in a sub-process. It is used for two things: + + (1) To set the fallback host list in addresses, when delivering. + (2) To pass back the interface, port, protocol, and other options, for use + during callout verification. + +Arguments: + tblock pointer to the transport instance block + addrlist list of addresses about to be transported + tf if not NULL, pointer to block in which to return options + uid the uid that will be set (not used) + gid the gid that will be set (not used) + errmsg place for error message (not used) + +Returns: OK always (FAIL, DEFER not used) +*/ + +static int +smtp_transport_setup(transport_instance *tblock, address_item *addrlist, + transport_feedback *tf, uid_t uid, gid_t gid, uschar **errmsg) +{ +smtp_transport_options_block *ob = SOB tblock->options_block; + +errmsg = errmsg; /* Keep picky compilers happy */ +uid = uid; +gid = gid; + +/* Pass back options if required. This interface is getting very messy. */ + +if (tf) + { + tf->interface = ob->interface; + tf->port = ob->port; + tf->protocol = ob->protocol; + tf->hosts = ob->hosts; + tf->hosts_override = ob->hosts_override; + tf->hosts_randomize = ob->hosts_randomize; + tf->gethostbyname = ob->gethostbyname; + tf->qualify_single = ob->dns_qualify_single; + tf->search_parents = ob->dns_search_parents; + tf->helo_data = ob->helo_data; + } + +/* Set the fallback host list for all the addresses that don't have fallback +host lists, provided that the local host wasn't present in the original host +list. */ + +if (!testflag(addrlist, af_local_host_removed)) + for (; addrlist; addrlist = addrlist->next) + if (!addrlist->fallback_hosts) addrlist->fallback_hosts = ob->fallback_hostlist; + +return OK; +} + + + +/************************************************* +* Initialization entry point * +*************************************************/ + +/* Called for each instance, after its options have been read, to +enable consistency checks to be done, or anything else that needs +to be set up. + +Argument: pointer to the transport instance block +Returns: nothing +*/ + +void +smtp_transport_init(transport_instance *tblock) +{ +smtp_transport_options_block *ob = SOB tblock->options_block; + +/* Retry_use_local_part defaults FALSE if unset */ + +if (tblock->retry_use_local_part == TRUE_UNSET) + tblock->retry_use_local_part = FALSE; + +/* Set the default port according to the protocol */ + +if (!ob->port) + ob->port = strcmpic(ob->protocol, US"lmtp") == 0 + ? US"lmtp" + : strcmpic(ob->protocol, US"smtps") == 0 + ? US"smtps" : US"smtp"; + +/* Set up the setup entry point, to be called before subprocesses for this +transport. */ + +tblock->setup = smtp_transport_setup; + +/* Complain if any of the timeouts are zero. */ + +if (ob->command_timeout <= 0 || ob->data_timeout <= 0 || + ob->final_timeout <= 0) + log_write(0, LOG_PANIC_DIE|LOG_CONFIG, + "command, data, or final timeout value is zero for %s transport", + tblock->name); + +/* If hosts_override is set and there are local hosts, set the global +flag that stops verify from showing router hosts. */ + +if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE; + +/* If there are any fallback hosts listed, build a chain of host items +for them, but do not do any lookups at this time. */ + +host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE); +} + + + + + +/************************************************* +* Set delivery info into all active addresses * +*************************************************/ + +/* Only addresses whose status is >= PENDING are relevant. A lesser +status means that an address is not currently being processed. + +Arguments: + addrlist points to a chain of addresses + errno_value to put in each address's errno field + msg to put in each address's message field + rc to put in each address's transport_return field + pass_message if TRUE, set the "pass message" flag in the address + host if set, mark addrs as having used this host + smtp_greeting from peer + helo_response from peer + +If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in +the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate +this particular type of timeout. + +Returns: nothing +*/ + +static void +set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc, + BOOL pass_message, host_item * host +#ifdef EXPERIMENTAL_DSN_INFO + , const uschar * smtp_greeting, const uschar * helo_response +#endif + ) +{ +address_item *addr; +int orvalue = 0; +if (errno_value == ERRNO_CONNECTTIMEOUT) + { + errno_value = ETIMEDOUT; + orvalue = RTEF_CTOUT; + } +for (addr = addrlist; addr; addr = addr->next) + if (addr->transport_return >= PENDING) + { + addr->basic_errno = errno_value; + addr->more_errno |= orvalue; + if (msg) + { + addr->message = msg; + if (pass_message) setflag(addr, af_pass_message); + } + addr->transport_return = rc; + if (host) + { + addr->host_used = host; +#ifdef EXPERIMENTAL_DSN_INFO + if (smtp_greeting) + {uschar * s = Ustrchr(smtp_greeting, '\n'); if (s) *s = '\0';} + addr->smtp_greeting = smtp_greeting; + + if (helo_response) + {uschar * s = Ustrchr(helo_response, '\n'); if (s) *s = '\0';} + addr->helo_response = helo_response; +#endif + } + } +} + +static void +set_errno_nohost(address_item *addrlist, int errno_value, uschar *msg, int rc, + BOOL pass_message) +{ +set_errno(addrlist, errno_value, msg, rc, pass_message, NULL +#ifdef EXPERIMENTAL_DSN_INFO + , NULL, NULL +#endif + ); +} + + +/************************************************* +* Check an SMTP response * +*************************************************/ + +/* This function is given an errno code and the SMTP response buffer +to analyse, together with the host identification for generating messages. It +sets an appropriate message and puts the first digit of the response code into +the yield variable. If no response was actually read, a suitable digit is +chosen. + +Arguments: + host the current host, to get its name for messages + errno_value pointer to the errno value + more_errno from the top address for use with ERRNO_FILTER_FAIL + buffer the SMTP response buffer + yield where to put a one-digit SMTP response code + message where to put an error message + pass_message set TRUE if message is an SMTP response + +Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE +*/ + +static BOOL +check_response(host_item *host, int *errno_value, int more_errno, + uschar *buffer, int *yield, uschar **message, BOOL *pass_message) +{ +uschar * pl = pipelining_active ? US"pipelined " : US""; +const uschar * s; + +*yield = '4'; /* Default setting is to give a temporary error */ + +switch(*errno_value) + { + case ETIMEDOUT: /* Handle response timeout */ + *message = US string_sprintf("SMTP timeout after %s%s", + pl, smtp_command); + if (transport_count > 0) + *message = US string_sprintf("%s (%d bytes written)", *message, + transport_count); + return FALSE; + + case ERRNO_SMTPFORMAT: /* Handle malformed SMTP response */ + s = string_printing(buffer); + while (isspace(*s)) s++; + *message = *s == 0 + ? string_sprintf("Malformed SMTP reply (an empty line) " + "in response to %s%s", pl, smtp_command) + : string_sprintf("Malformed SMTP reply in response to %s%s: %s", + pl, smtp_command, s); + return FALSE; + + case ERRNO_FILTER_FAIL: /* Handle a failed filter process error; + can't send QUIT as we mustn't end the DATA. */ + *message = string_sprintf("transport filter process failed (%d)%s", + more_errno, + more_errno == EX_EXECFAILED ? ": unable to execute command" : ""); + return FALSE; + + case ERRNO_CHHEADER_FAIL: /* Handle a failed add_headers expansion; + can't send QUIT as we mustn't end the DATA. */ + *message = + string_sprintf("failed to expand headers_add or headers_remove: %s", + expand_string_message); + return FALSE; + + case ERRNO_WRITEINCOMPLETE: /* failure to write a complete data block */ + *message = string_sprintf("failed to write a data block"); + return FALSE; + +#ifdef SUPPORT_I18N + case ERRNO_UTF8_FWD: /* no advertised SMTPUTF8, for international message */ + *message = US"utf8 support required but not offered for forwarding"; + DEBUG(D_deliver|D_transport) debug_printf("%s\n", *message); + return TRUE; +#endif + } + +/* Handle error responses from the remote mailer. */ + +if (buffer[0] != 0) + { + *message = string_sprintf("SMTP error from remote mail server after %s%s: " + "%s", pl, smtp_command, s = string_printing(buffer)); + *pass_message = TRUE; + *yield = buffer[0]; + return TRUE; + } + +/* No data was read. If there is no errno, this must be the EOF (i.e. +connection closed) case, which causes deferral. An explicit connection reset +error has the same effect. Otherwise, put the host's identity in the message, +leaving the errno value to be interpreted as well. In all cases, we have to +assume the connection is now dead. */ + +if (*errno_value == 0 || *errno_value == ECONNRESET) + { + *errno_value = ERRNO_SMTPCLOSED; + *message = US string_sprintf("Remote host closed connection " + "in response to %s%s", pl, smtp_command); + } +else + *message = US string_sprintf("%s [%s]", host->name, host->address); + +return FALSE; +} + + + +/************************************************* +* Write error message to logs * +*************************************************/ + +/* This writes to the main log and to the message log. + +Arguments: + host the current host + detail the current message (addr_item->message) + basic_errno the errno (addr_item->basic_errno) + +Returns: nothing +*/ + +static void +write_logs(const host_item *host, const uschar *suffix, int basic_errno) +{ +gstring * message = LOGGING(outgoing_port) + ? string_fmt_append(NULL, "H=%s [%s]:%d", host->name, host->address, + host->port == PORT_NONE ? 25 : host->port) + : string_fmt_append(NULL, "H=%s [%s]", host->name, host->address); + +if (suffix) + { + message = string_fmt_append(message, ": %s", suffix); + if (basic_errno > 0) + message = string_fmt_append(message, ": %s", strerror(basic_errno)); + } +else + message = string_fmt_append(message, " %s", exim_errstr(basic_errno)); + +log_write(0, LOG_MAIN, "%s", string_from_gstring(message)); +deliver_msglog("%s %s\n", tod_stamp(tod_log), message->s); +} + +static void +msglog_line(host_item * host, uschar * message) +{ +deliver_msglog("%s H=%s [%s] %s\n", tod_stamp(tod_log), + host->name, host->address, message); +} + + + +#ifndef DISABLE_EVENT +/************************************************* +* Post-defer action * +*************************************************/ + +/* This expands an arbitrary per-transport string. + It might, for example, be used to write to the database log. + +Arguments: + addr the address item containing error information + host the current host + +Returns: nothing +*/ + +static void +deferred_event_raise(address_item *addr, host_item *host) +{ +uschar * action = addr->transport->event_action; +const uschar * save_domain; +uschar * save_local; + +if (!action) + return; + +save_domain = deliver_domain; +save_local = deliver_localpart; + +/*XXX would ip & port already be set up? */ +deliver_host_address = string_copy(host->address); +deliver_host_port = host->port == PORT_NONE ? 25 : host->port; +event_defer_errno = addr->basic_errno; + +router_name = addr->router->name; +transport_name = addr->transport->name; +deliver_domain = addr->domain; +deliver_localpart = addr->local_part; + +(void) event_raise(action, US"msg:host:defer", + addr->message + ? addr->basic_errno > 0 + ? string_sprintf("%s: %s", addr->message, strerror(addr->basic_errno)) + : string_copy(addr->message) + : addr->basic_errno > 0 + ? string_copy(US strerror(addr->basic_errno)) + : NULL); + +deliver_localpart = save_local; +deliver_domain = save_domain; +router_name = transport_name = NULL; +} +#endif + +/************************************************* +* Reap SMTP specific responses * +*************************************************/ +static int +smtp_discard_responses(smtp_context * sx, smtp_transport_options_block * ob, + int count) +{ +uschar flushbuffer[4096]; + +while (count-- > 0) + { + if (!smtp_read_response(sx, flushbuffer, sizeof(flushbuffer), + '2', ob->command_timeout) + && (errno != 0 || flushbuffer[0] == 0)) + break; + } +return count; +} + + +/* Return boolean success */ + +static BOOL +smtp_reap_banner(smtp_context * sx) +{ +BOOL good_response = smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), + '2', (SOB sx->conn_args.ob)->command_timeout); +#ifdef EXPERIMENTAL_DSN_INFO +sx->smtp_greeting = string_copy(sx->buffer); +#endif +return good_response; +} + +static BOOL +smtp_reap_ehlo(smtp_context * sx) +{ +if (!smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), '2', + (SOB sx->conn_args.ob)->command_timeout)) + { + if (errno != 0 || sx->buffer[0] == 0 || sx->lmtp) + { +#ifdef EXPERIMENTAL_DSN_INFO + sx->helo_response = string_copy(sx->buffer); +#endif + return FALSE; + } + sx->esmtp = FALSE; + } +#ifdef EXPERIMENTAL_DSN_INFO +sx->helo_response = string_copy(sx->buffer); +#endif +return TRUE; +} + + + +#ifdef EXPERIMENTAL_PIPE_CONNECT +static uschar * +ehlo_cache_key(const smtp_context * sx) +{ +host_item * host = sx->conn_args.host; +return Ustrchr(host->address, ':') + ? string_sprintf("[%s]:%d.EHLO", host->address, + host->port == PORT_NONE ? sx->port : host->port) + : string_sprintf("%s:%d.EHLO", host->address, + host->port == PORT_NONE ? sx->port : host->port); +} + +static void +write_ehlo_cache_entry(const smtp_context * sx) +{ +open_db dbblock, * dbm_file; + +if ((dbm_file = dbfn_open(US"misc", O_RDWR, &dbblock, TRUE))) + { + uschar * ehlo_resp_key = ehlo_cache_key(sx); + dbdata_ehlo_resp er = { .data = sx->ehlo_resp }; + + HDEBUG(D_transport) debug_printf("writing clr %04x/%04x cry %04x/%04x\n", + sx->ehlo_resp.cleartext_features, sx->ehlo_resp.cleartext_auths, + sx->ehlo_resp.crypted_features, sx->ehlo_resp.crypted_auths); + + dbfn_write(dbm_file, ehlo_resp_key, &er, (int)sizeof(er)); + dbfn_close(dbm_file); + } +} + +static void +invalidate_ehlo_cache_entry(smtp_context * sx) +{ +open_db dbblock, * dbm_file; + +if ( sx->early_pipe_active + && (dbm_file = dbfn_open(US"misc", O_RDWR, &dbblock, TRUE))) + { + uschar * ehlo_resp_key = ehlo_cache_key(sx); + dbfn_delete(dbm_file, ehlo_resp_key); + dbfn_close(dbm_file); + } +} + +static BOOL +read_ehlo_cache_entry(smtp_context * sx) +{ +open_db dbblock; +open_db * dbm_file; + +if (!(dbm_file = dbfn_open(US"misc", O_RDONLY, &dbblock, FALSE))) + { DEBUG(D_transport) debug_printf("ehlo-cache: no misc DB\n"); } +else + { + uschar * ehlo_resp_key = ehlo_cache_key(sx); + dbdata_ehlo_resp * er; + + if (!(er = dbfn_read(dbm_file, ehlo_resp_key))) + { DEBUG(D_transport) debug_printf("no ehlo-resp record\n"); } + else if (time(NULL) - er->time_stamp > retry_data_expire) + { + DEBUG(D_transport) debug_printf("ehlo-resp record too old\n"); + dbfn_close(dbm_file); + if ((dbm_file = dbfn_open(US"misc", O_RDWR, &dbblock, TRUE))) + dbfn_delete(dbm_file, ehlo_resp_key); + } + else + { + sx->ehlo_resp = er->data; + dbfn_close(dbm_file); + DEBUG(D_transport) debug_printf( + "EHLO response bits from cache: cleartext 0x%04x crypted 0x%04x\n", + er->data.cleartext_features, er->data.crypted_features); + return TRUE; + } + dbfn_close(dbm_file); + } +return FALSE; +} + + + +/* Return an auths bitmap for the set of AUTH methods offered by the server +which match our authenticators. */ + +static unsigned short +study_ehlo_auths(smtp_context * sx) +{ +uschar * names; +auth_instance * au; +uschar authnum; +unsigned short authbits = 0; + +if (!sx->esmtp) return 0; +if (!regex_AUTH) regex_AUTH = regex_must_compile(AUTHS_REGEX, FALSE, TRUE); +if (!regex_match_and_setup(regex_AUTH, sx->buffer, 0, -1)) return 0; +expand_nmax = -1; /* reset */ +names = string_copyn(expand_nstring[1], expand_nlength[1]); + +for (au = auths, authnum = 0; au; au = au->next, authnum++) if (au->client) + { + const uschar * list = names; + int sep = ' '; + uschar name[32]; + + while (string_nextinlist(&list, &sep, name, sizeof(name))) + if (strcmpic(au->public_name, name) == 0) + { authbits |= BIT(authnum); break; } + } + +DEBUG(D_transport) + debug_printf("server offers %s AUTH, methods '%s', bitmap 0x%04x\n", + tls_out.active.sock >= 0 ? "crypted" : "plaintext", names, authbits); + +if (tls_out.active.sock >= 0) + sx->ehlo_resp.crypted_auths = authbits; +else + sx->ehlo_resp.cleartext_auths = authbits; +return authbits; +} + + + + +/* Wait for and check responses for early-pipelining. + +Called from the lower-level smtp_read_response() function +used for general code that assume synchronisation, if context +flags indicate outstanding early-pipelining commands. Also +called fom sync_responses() which handles pipelined commands. + +Arguments: + sx smtp connection context + countp number of outstanding responses, adjusted on return + +Return: + OK all well + FAIL SMTP error in response +*/ +int +smtp_reap_early_pipe(smtp_context * sx, int * countp) +{ +BOOL pending_BANNER = sx->pending_BANNER; +BOOL pending_EHLO = sx->pending_EHLO; + +sx->pending_BANNER = FALSE; /* clear early to avoid recursion */ +sx->pending_EHLO = FALSE; + +if (pending_BANNER) + { + DEBUG(D_transport) debug_printf("%s expect banner\n", __FUNCTION__); + (*countp)--; + if (!smtp_reap_banner(sx)) + { + DEBUG(D_transport) debug_printf("bad banner\n"); + goto fail; + } + } + +if (pending_EHLO) + { + unsigned peer_offered; + unsigned short authbits = 0, * ap; + + DEBUG(D_transport) debug_printf("%s expect ehlo\n", __FUNCTION__); + (*countp)--; + if (!smtp_reap_ehlo(sx)) + { + DEBUG(D_transport) debug_printf("bad response for EHLO\n"); + goto fail; + } + + /* Compare the actual EHLO response to the cached value we assumed; + on difference, dump or rewrite the cache and arrange for a retry. */ + + ap = tls_out.active.sock < 0 + ? &sx->ehlo_resp.cleartext_auths : &sx->ehlo_resp.crypted_auths; + + peer_offered = ehlo_response(sx->buffer, + (tls_out.active.sock < 0 ? OPTION_TLS : OPTION_REQUIRETLS) + | OPTION_CHUNKING | OPTION_PRDR | OPTION_DSN | OPTION_PIPE | OPTION_SIZE + | OPTION_UTF8 | OPTION_EARLY_PIPE + ); + if ( peer_offered != sx->peer_offered + || (authbits = study_ehlo_auths(sx)) != *ap) + { + HDEBUG(D_transport) + debug_printf("EHLO %s extensions changed, 0x%04x/0x%04x -> 0x%04x/0x%04x\n", + tls_out.active.sock < 0 ? "cleartext" : "crypted", + sx->peer_offered, *ap, peer_offered, authbits); + *(tls_out.active.sock < 0 + ? &sx->ehlo_resp.cleartext_features : &sx->ehlo_resp.crypted_features) = peer_offered; + *ap = authbits; + if (peer_offered & OPTION_EARLY_PIPE) + write_ehlo_cache_entry(sx); + else + invalidate_ehlo_cache_entry(sx); + + return OK; /* just carry on */ + } + } +return OK; + +fail: + invalidate_ehlo_cache_entry(sx); + (void) smtp_discard_responses(sx, sx->conn_args.ob, *countp); + return FAIL; +} +#endif + + +/************************************************* +* Synchronize SMTP responses * +*************************************************/ + +/* This function is called from smtp_deliver() to receive SMTP responses from +the server, and match them up with the commands to which they relate. When +PIPELINING is not in use, this function is called after every command, and is +therefore somewhat over-engineered, but it is simpler to use a single scheme +that works both with and without PIPELINING instead of having two separate sets +of code. + +The set of commands that are buffered up with pipelining may start with MAIL +and may end with DATA; in between are RCPT commands that correspond to the +addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH, +etc.) are never buffered. + +Errors after MAIL or DATA abort the whole process leaving the response in the +buffer. After MAIL, pending responses are flushed, and the original command is +re-instated in big_buffer for error messages. For RCPT commands, the remote is +permitted to reject some recipient addresses while accepting others. However +certain errors clearly abort the whole process. Set the value in +transport_return to PENDING_OK if the address is accepted. If there is a +subsequent general error, it will get reset accordingly. If not, it will get +converted to OK at the end. + +Arguments: + sx smtp connection context + count the number of responses to read + pending_DATA 0 if last command sent was not DATA + +1 if previously had a good recipient + -1 if not previously had a good recipient + +Returns: 3 if at least one address had 2xx and one had 5xx + 2 if at least one address had 5xx but none had 2xx + 1 if at least one host had a 2xx response, but none had 5xx + 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA) + -1 timeout while reading RCPT response + -2 I/O or other non-response error for RCPT + -3 DATA or MAIL failed - errno and buffer set + -4 banner or EHLO failed (early-pipelining) +*/ + +static int +sync_responses(smtp_context * sx, int count, int pending_DATA) +{ +address_item * addr = sx->sync_addr; +smtp_transport_options_block * ob = sx->conn_args.ob; +int yield = 0; + +#ifdef EXPERIMENTAL_PIPE_CONNECT +if (smtp_reap_early_pipe(sx, &count) != OK) + return -4; +#endif + +/* Handle the response for a MAIL command. On error, reinstate the original +command in big_buffer for error message use, and flush any further pending +responses before returning, except after I/O errors and timeouts. */ + +if (sx->pending_MAIL) + { + DEBUG(D_transport) debug_printf("%s expect mail\n", __FUNCTION__); + count--; + if (!smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), + '2', ob->command_timeout)) + { + DEBUG(D_transport) debug_printf("bad response for MAIL\n"); + Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */ + if (errno == 0 && sx->buffer[0] != 0) + { + int save_errno = 0; + if (sx->buffer[0] == '4') + { + save_errno = ERRNO_MAIL4XX; + addr->more_errno |= ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8; + } + count = smtp_discard_responses(sx, ob, count); + errno = save_errno; + } + + if (pending_DATA) count--; /* Number of RCPT responses to come */ + while (count-- > 0) /* Mark any pending addrs with the host used */ + { + while (addr->transport_return != PENDING_DEFER) addr = addr->next; + addr->host_used = sx->conn_args.host; + addr = addr->next; + } + return -3; + } + } + +if (pending_DATA) count--; /* Number of RCPT responses to come */ + +/* Read and handle the required number of RCPT responses, matching each one up +with an address by scanning for the next address whose status is PENDING_DEFER. +*/ + +while (count-- > 0) + { + while (addr->transport_return != PENDING_DEFER) + if (!(addr = addr->next)) + return -2; + + /* The address was accepted */ + addr->host_used = sx->conn_args.host; + + DEBUG(D_transport) debug_printf("%s expect rcpt\n", __FUNCTION__); + if (smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), + '2', ob->command_timeout)) + { + yield |= 1; + addr->transport_return = PENDING_OK; + + /* If af_dr_retry_exists is set, there was a routing delay on this address; + ensure that any address-specific retry record is expunged. We do this both + for the basic key and for the version that also includes the sender. */ + + if (testflag(addr, af_dr_retry_exists)) + { + uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key, + sender_address); + retry_add_item(addr, altkey, rf_delete); + retry_add_item(addr, addr->address_retry_key, rf_delete); + } + } + + /* Timeout while reading the response */ + + else if (errno == ETIMEDOUT) + { + uschar *message = string_sprintf("SMTP timeout after RCPT TO:<%s>", + transport_rcpt_address(addr, sx->conn_args.tblock->rcpt_include_affixes)); + set_errno_nohost(sx->first_addr, ETIMEDOUT, message, DEFER, FALSE); + retry_add_item(addr, addr->address_retry_key, 0); + update_waiting = FALSE; + return -1; + } + + /* Handle other errors in obtaining an SMTP response by returning -1. This + will cause all the addresses to be deferred. Restore the SMTP command in + big_buffer for which we are checking the response, so the error message + makes sense. */ + + else if (errno != 0 || sx->buffer[0] == 0) + { + string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>", + transport_rcpt_address(addr, sx->conn_args.tblock->rcpt_include_affixes)); + return -2; + } + + /* Handle SMTP permanent and temporary response codes. */ + + else + { + addr->message = + string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: " + "%s", transport_rcpt_address(addr, sx->conn_args.tblock->rcpt_include_affixes), + string_printing(sx->buffer)); + setflag(addr, af_pass_message); + if (!sx->verify) + msglog_line(sx->conn_args.host, addr->message); + + /* The response was 5xx */ + + if (sx->buffer[0] == '5') + { + addr->transport_return = FAIL; + yield |= 2; + } + + /* The response was 4xx */ + + else + { + addr->transport_return = DEFER; + addr->basic_errno = ERRNO_RCPT4XX; + addr->more_errno |= ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8; + + if (!sx->verify) + { +#ifndef DISABLE_EVENT + event_defer_errno = addr->more_errno; + msg_event_raise(US"msg:rcpt:host:defer", addr); +#endif + + /* Log temporary errors if there are more hosts to be tried. + If not, log this last one in the == line. */ + + if (sx->conn_args.host->next) + if (LOGGING(outgoing_port)) + log_write(0, LOG_MAIN, "H=%s [%s]:%d %s", sx->conn_args.host->name, + sx->conn_args.host->address, + sx->port == PORT_NONE ? 25 : sx->port, addr->message); + else + log_write(0, LOG_MAIN, "H=%s [%s]: %s", sx->conn_args.host->name, + sx->conn_args.host->address, addr->message); + +#ifndef DISABLE_EVENT + else + msg_event_raise(US"msg:rcpt:defer", addr); +#endif + + /* Do not put this message on the list of those waiting for specific + hosts, as otherwise it is likely to be tried too often. */ + + update_waiting = FALSE; + + /* Add a retry item for the address so that it doesn't get tried again + too soon. If address_retry_include_sender is true, add the sender address + to the retry key. */ + + retry_add_item(addr, + ob->address_retry_include_sender + ? string_sprintf("%s:<%s>", addr->address_retry_key, sender_address) + : addr->address_retry_key, + 0); + } + } + } + } /* Loop for next RCPT response */ + +/* Update where to start at for the next block of responses, unless we +have already handled all the addresses. */ + +if (addr) sx->sync_addr = addr->next; + +/* Handle a response to DATA. If we have not had any good recipients, either +previously or in this block, the response is ignored. */ + +if (pending_DATA != 0) + { + DEBUG(D_transport) debug_printf("%s expect data\n", __FUNCTION__); + if (!smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), + '3', ob->command_timeout)) + { + int code; + uschar *msg; + BOOL pass_message; + if (pending_DATA > 0 || (yield & 1) != 0) + { + if (errno == 0 && sx->buffer[0] == '4') + { + errno = ERRNO_DATA4XX; + sx->first_addr->more_errno |= ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8; + } + return -3; + } + (void)check_response(sx->conn_args.host, &errno, 0, sx->buffer, &code, &msg, &pass_message); + DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining " + "is in use and there were no good recipients\n", msg); + } + } + +/* All responses read and handled; MAIL (if present) received 2xx and DATA (if +present) received 3xx. If any RCPTs were handled and yielded anything other +than 4xx, yield will be set non-zero. */ + +return yield; +} + + + + + +/* Try an authenticator's client entry */ + +static int +try_authenticator(smtp_context * sx, auth_instance * au) +{ +smtp_transport_options_block * ob = sx->conn_args.ob; /* transport options */ +host_item * host = sx->conn_args.host; /* host to deliver to */ +int rc; + +sx->outblock.authenticating = TRUE; +rc = (au->info->clientcode)(au, sx, ob->command_timeout, + sx->buffer, sizeof(sx->buffer)); +sx->outblock.authenticating = FALSE; +DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n", au->name, rc); + +/* A temporary authentication failure must hold up delivery to +this host. After a permanent authentication failure, we carry on +to try other authentication methods. If all fail hard, try to +deliver the message unauthenticated unless require_auth was set. */ + +switch(rc) + { + case OK: + f.smtp_authenticated = TRUE; /* stops the outer loop */ + client_authenticator = au->name; + if (au->set_client_id) + client_authenticated_id = expand_string(au->set_client_id); + break; + + /* Failure after writing a command */ + + case FAIL_SEND: + return FAIL_SEND; + + /* Failure after reading a response */ + + case FAIL: + if (errno != 0 || sx->buffer[0] != '5') return FAIL; + log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s", + au->name, host->name, host->address, sx->buffer); + break; + + /* Failure by some other means. In effect, the authenticator + decided it wasn't prepared to handle this case. Typically this + is the result of "fail" in an expansion string. Do we need to + log anything here? Feb 2006: a message is now put in the buffer + if logging is required. */ + + case CANCELLED: + if (*sx->buffer != 0) + log_write(0, LOG_MAIN, "%s authenticator cancelled " + "authentication H=%s [%s] %s", au->name, host->name, + host->address, sx->buffer); + break; + + /* Internal problem, message in buffer. */ + + case ERROR: + set_errno_nohost(sx->addrlist, ERRNO_AUTHPROB, string_copy(sx->buffer), + DEFER, FALSE); + return ERROR; + } +return OK; +} + + + + +/* Do the client side of smtp-level authentication. + +Arguments: + sx smtp connection context + +sx->buffer should have the EHLO response from server (gets overwritten) + +Returns: + OK Success, or failed (but not required): global "smtp_authenticated" set + DEFER Failed authentication (and was required) + ERROR Internal problem + + FAIL_SEND Failed communications - transmit + FAIL - response +*/ + +static int +smtp_auth(smtp_context * sx) +{ +host_item * host = sx->conn_args.host; /* host to deliver to */ +smtp_transport_options_block * ob = sx->conn_args.ob; /* transport options */ +int require_auth = verify_check_given_host(CUSS &ob->hosts_require_auth, host); +#ifdef EXPERIMENTAL_PIPE_CONNECT +unsigned short authbits = tls_out.active.sock >= 0 + ? sx->ehlo_resp.crypted_auths : sx->ehlo_resp.cleartext_auths; +#endif +uschar * fail_reason = US"server did not advertise AUTH support"; + +f.smtp_authenticated = FALSE; +client_authenticator = client_authenticated_id = client_authenticated_sender = NULL; + +if (!regex_AUTH) + regex_AUTH = regex_must_compile(AUTHS_REGEX, FALSE, TRUE); + +/* Is the server offering AUTH? */ + +if ( sx->esmtp + && +#ifdef EXPERIMENTAL_PIPE_CONNECT + sx->early_pipe_active ? authbits + : +#endif + regex_match_and_setup(regex_AUTH, sx->buffer, 0, -1) + ) + { + uschar * names = NULL; + expand_nmax = -1; /* reset */ + +#ifdef EXPERIMENTAL_PIPE_CONNECT + if (!sx->early_pipe_active) +#endif + names = string_copyn(expand_nstring[1], expand_nlength[1]); + + /* Must not do this check until after we have saved the result of the + regex match above as the check could be another RE. */ + + if ( require_auth == OK + || verify_check_given_host(CUSS &ob->hosts_try_auth, host) == OK) + { + auth_instance * au; + + DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n"); + fail_reason = US"no common mechanisms were found"; + +#ifdef EXPERIMENTAL_PIPE_CONNECT + if (sx->early_pipe_active) + { + /* Scan our authenticators (which support use by a client and were offered + by the server (checked at cache-write time)), not suppressed by + client_condition. If one is found, attempt to authenticate by calling its + client function. We are limited to supporting up to 16 authenticator + public-names by the number of bits in a short. */ + + uschar bitnum; + int rc; + + for (bitnum = 0, au = auths; + !f.smtp_authenticated && au && bitnum < 16; + bitnum++, au = au->next) if (authbits & BIT(bitnum)) + { + if ( au->client_condition + && !expand_check_condition(au->client_condition, au->name, + US"client authenticator")) + { + DEBUG(D_transport) debug_printf("skipping %s authenticator: %s\n", + au->name, "client_condition is false"); + continue; + } + + /* Found data for a listed mechanism. Call its client entry. Set + a flag in the outblock so that data is overwritten after sending so + that reflections don't show it. */ + + fail_reason = US"authentication attempt(s) failed"; + + if ((rc = try_authenticator(sx, au)) != OK) + return rc; + } + } + else +#endif + + /* Scan the configured authenticators looking for one which is configured + for use as a client, which is not suppressed by client_condition, and + whose name matches an authentication mechanism supported by the server. + If one is found, attempt to authenticate by calling its client function. + */ + + for (au = auths; !f.smtp_authenticated && au; au = au->next) + { + uschar *p = names; + + if ( !au->client + || ( au->client_condition + && !expand_check_condition(au->client_condition, au->name, + US"client authenticator"))) + { + DEBUG(D_transport) debug_printf("skipping %s authenticator: %s\n", + au->name, + (au->client)? "client_condition is false" : + "not configured as a client"); + continue; + } + + /* Loop to scan supported server mechanisms */ + + while (*p) + { + int len = Ustrlen(au->public_name); + int rc; + + while (isspace(*p)) p++; + + if (strncmpic(au->public_name, p, len) != 0 || + (p[len] != 0 && !isspace(p[len]))) + { + while (*p != 0 && !isspace(*p)) p++; + continue; + } + + /* Found data for a listed mechanism. Call its client entry. Set + a flag in the outblock so that data is overwritten after sending so + that reflections don't show it. */ + + fail_reason = US"authentication attempt(s) failed"; + + if ((rc = try_authenticator(sx, au)) != OK) + return rc; + + break; /* If not authenticated, try next authenticator */ + } /* Loop for scanning supported server mechanisms */ + } /* Loop for further authenticators */ + } + } + +/* If we haven't authenticated, but are required to, give up. */ + +if (require_auth == OK && !f.smtp_authenticated) + { + set_errno_nohost(sx->addrlist, ERRNO_AUTHFAIL, + string_sprintf("authentication required but %s", fail_reason), DEFER, + FALSE); + return DEFER; + } + +return OK; +} + + +/* Construct AUTH appendix string for MAIL TO */ +/* +Arguments + buffer to build string + addrlist chain of potential addresses to deliver + ob transport options + +Globals f.smtp_authenticated + client_authenticated_sender +Return True on error, otherwise buffer has (possibly empty) terminated string +*/ + +BOOL +smtp_mail_auth_str(uschar *buffer, unsigned bufsize, address_item *addrlist, + smtp_transport_options_block *ob) +{ +uschar *local_authenticated_sender = authenticated_sender; + +#ifdef notdef + debug_printf("smtp_mail_auth_str: as<%s> os<%s> SA<%s>\n", authenticated_sender, ob->authenticated_sender, f.smtp_authenticated?"Y":"N"); +#endif + +if (ob->authenticated_sender != NULL) + { + uschar *new = expand_string(ob->authenticated_sender); + if (new == NULL) + { + if (!f.expand_string_forcedfail) + { + uschar *message = string_sprintf("failed to expand " + "authenticated_sender: %s", expand_string_message); + set_errno_nohost(addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE); + return TRUE; + } + } + else if (new[0] != 0) local_authenticated_sender = new; + } + +/* Add the authenticated sender address if present */ + +if ((f.smtp_authenticated || ob->authenticated_sender_force) && + local_authenticated_sender != NULL) + { + string_format(buffer, bufsize, " AUTH=%s", + auth_xtextencode(local_authenticated_sender, + Ustrlen(local_authenticated_sender))); + client_authenticated_sender = string_copy(local_authenticated_sender); + } +else + *buffer= 0; + +return FALSE; +} + + + +#ifdef SUPPORT_DANE +/* Lookup TLSA record for host/port. +Return: OK success with dnssec; DANE mode + DEFER Do not use this host now, may retry later + FAIL_FORCED No TLSA record; DANE not usable + FAIL Do not use this connection +*/ + +int +tlsa_lookup(const host_item * host, dns_answer * dnsa, BOOL dane_required) +{ +/* move this out to host.c given the similarity to dns_lookup() ? */ +uschar buffer[300]; +const uschar * fullname = buffer; +int rc; +BOOL sec; + +/* TLSA lookup string */ +(void)sprintf(CS buffer, "_%d._tcp.%.256s", host->port, host->name); + +rc = dns_lookup(dnsa, buffer, T_TLSA, &fullname); +sec = dns_is_secure(dnsa); +DEBUG(D_transport) + debug_printf("TLSA lookup ret %d %sDNSSEC\n", rc, sec ? "" : "not "); + +switch (rc) + { + case DNS_AGAIN: + return DEFER; /* just defer this TLS'd conn */ + + case DNS_SUCCEED: + if (sec) + { + DEBUG(D_transport) + { + dns_scan dnss; + dns_record * rr; + for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; + rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)) + if (rr->type == T_TLSA && rr->size > 3) + { + uint16_t payload_length = rr->size - 3; + uschar s[MAX_TLSA_EXPANDED_SIZE], * sp = s, * p = US rr->data; + + sp += sprintf(CS sp, "%d ", *p++); /* usage */ + sp += sprintf(CS sp, "%d ", *p++); /* selector */ + sp += sprintf(CS sp, "%d ", *p++); /* matchtype */ + while (payload_length-- > 0 && sp-s < (MAX_TLSA_EXPANDED_SIZE - 4)) + sp += sprintf(CS sp, "%02x", *p++); + + debug_printf(" %s\n", s); + } + } + return OK; + } + log_write(0, LOG_MAIN, + "DANE error: TLSA lookup for %s not DNSSEC", host->name); + /*FALLTRHOUGH*/ + + case DNS_NODATA: /* no TLSA RR for this lookup */ + case DNS_NOMATCH: /* no records at all for this lookup */ + return dane_required ? FAIL : FAIL_FORCED; + + default: + case DNS_FAIL: + return dane_required ? FAIL : DEFER; + } +} +#endif + + + +typedef struct smtp_compare_s +{ + uschar *current_sender_address; + struct transport_instance *tblock; +} smtp_compare_t; + + +/* Create a unique string that identifies this message, it is based on +sender_address, helo_data and tls_certificate if enabled. +*/ + +static uschar * +smtp_local_identity(uschar * sender, struct transport_instance * tblock) +{ +address_item * addr1; +uschar * if1 = US""; +uschar * helo1 = US""; +#ifdef SUPPORT_TLS +uschar * tlsc1 = US""; +#endif +uschar * save_sender_address = sender_address; +uschar * local_identity = NULL; +smtp_transport_options_block * ob = SOB tblock->options_block; + +sender_address = sender; + +addr1 = deliver_make_addr (sender, TRUE); +deliver_set_expansions(addr1); + +if (ob->interface) + if1 = expand_string(ob->interface); + +if (ob->helo_data) + helo1 = expand_string(ob->helo_data); + +#ifdef SUPPORT_TLS +if (ob->tls_certificate) + tlsc1 = expand_string(ob->tls_certificate); +local_identity = string_sprintf ("%s^%s^%s", if1, helo1, tlsc1); +#else +local_identity = string_sprintf ("%s^%s", if1, helo1); +#endif + +deliver_set_expansions(NULL); +sender_address = save_sender_address; + +return local_identity; +} + + + +/* This routine is a callback that is called from transport_check_waiting. +This function will evaluate the incoming message versus the previous +message. If the incoming message is using a different local identity then +we will veto this new message. */ + +static BOOL +smtp_are_same_identities(uschar * message_id, smtp_compare_t * s_compare) +{ +uschar * message_local_identity, + * current_local_identity, + * new_sender_address; + +current_local_identity = + smtp_local_identity(s_compare->current_sender_address, s_compare->tblock); + +if (!(new_sender_address = deliver_get_sender_address(message_id))) + return 0; + +message_local_identity = + smtp_local_identity(new_sender_address, s_compare->tblock); + +return Ustrcmp(current_local_identity, message_local_identity) == 0; +} + + + +static unsigned +ehlo_response(uschar * buf, unsigned checks) +{ +size_t bsize = Ustrlen(buf); + +/* debug_printf("%s: check for 0x%04x\n", __FUNCTION__, checks); */ + +#ifdef SUPPORT_TLS +# ifdef EXPERIMENTAL_REQUIRETLS +if ( checks & OPTION_REQUIRETLS + && pcre_exec(regex_REQUIRETLS, NULL, CS buf,bsize, 0, PCRE_EOPT, NULL,0) < 0) +# endif + checks &= ~OPTION_REQUIRETLS; + +if ( checks & OPTION_TLS + && pcre_exec(regex_STARTTLS, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0) +#endif + checks &= ~OPTION_TLS; + +if ( checks & OPTION_IGNQ + && pcre_exec(regex_IGNOREQUOTA, NULL, CS buf, bsize, 0, + PCRE_EOPT, NULL, 0) < 0) + checks &= ~OPTION_IGNQ; + +if ( checks & OPTION_CHUNKING + && pcre_exec(regex_CHUNKING, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0) + checks &= ~OPTION_CHUNKING; + +#ifndef DISABLE_PRDR +if ( checks & OPTION_PRDR + && pcre_exec(regex_PRDR, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0) +#endif + checks &= ~OPTION_PRDR; + +#ifdef SUPPORT_I18N +if ( checks & OPTION_UTF8 + && pcre_exec(regex_UTF8, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0) +#endif + checks &= ~OPTION_UTF8; + +if ( checks & OPTION_DSN + && pcre_exec(regex_DSN, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0) + checks &= ~OPTION_DSN; + +if ( checks & OPTION_PIPE + && pcre_exec(regex_PIPELINING, NULL, CS buf, bsize, 0, + PCRE_EOPT, NULL, 0) < 0) + checks &= ~OPTION_PIPE; + +if ( checks & OPTION_SIZE + && pcre_exec(regex_SIZE, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0) + checks &= ~OPTION_SIZE; + +#ifdef EXPERIMENTAL_PIPE_CONNECT +if ( checks & OPTION_EARLY_PIPE + && pcre_exec(regex_EARLY_PIPE, NULL, CS buf, bsize, 0, + PCRE_EOPT, NULL, 0) < 0) +#endif + checks &= ~OPTION_EARLY_PIPE; + +/* debug_printf("%s: found 0x%04x\n", __FUNCTION__, checks); */ +return checks; +} + + + +/* Callback for emitting a BDAT data chunk header. + +If given a nonzero size, first flush any buffered SMTP commands +then emit the command. + +Reap previous SMTP command responses if requested, and always reap +the response from a previous BDAT command. + +Args: + tctx transport context + chunk_size value for SMTP BDAT command + flags + tc_chunk_last add LAST option to SMTP BDAT command + tc_reap_prev reap response to previous SMTP commands + +Returns: OK or ERROR +*/ + +static int +smtp_chunk_cmd_callback(transport_ctx * tctx, unsigned chunk_size, + unsigned flags) +{ +smtp_transport_options_block * ob = SOB tctx->tblock->options_block; +smtp_context * sx = tctx->smtp_context; +int cmd_count = 0; +int prev_cmd_count; + +/* Write SMTP chunk header command. If not reaping responses, note that +there may be more writes (like, the chunk data) done soon. */ + +if (chunk_size > 0) + { +#ifdef EXPERIMENTAL_PIPE_CONNECT + BOOL new_conn = !!(sx->outblock.conn_args); +#endif + if((cmd_count = smtp_write_command(sx, + flags & tc_reap_prev ? SCMD_FLUSH : SCMD_MORE, + "BDAT %u%s\r\n", chunk_size, flags & tc_chunk_last ? " LAST" : "") + ) < 0) return ERROR; + if (flags & tc_chunk_last) + data_command = string_copy(big_buffer); /* Save for later error message */ +#ifdef EXPERIMENTAL_PIPE_CONNECT + /* That command write could have been the one that made the connection. + Copy the fd from the client conn ctx (smtp transport specific) to the + generic transport ctx. */ + + if (new_conn) + tctx->u.fd = sx->outblock.cctx->sock; +#endif + } + +prev_cmd_count = cmd_count += sx->cmd_count; + +/* Reap responses for any previous, but not one we just emitted */ + +if (chunk_size > 0) + prev_cmd_count--; +if (sx->pending_BDAT) + prev_cmd_count--; + +if (flags & tc_reap_prev && prev_cmd_count > 0) + { + DEBUG(D_transport) debug_printf("look for %d responses" + " for previous pipelined cmds\n", prev_cmd_count); + + switch(sync_responses(sx, prev_cmd_count, 0)) + { + case 1: /* 2xx (only) => OK */ + case 3: sx->good_RCPT = TRUE; /* 2xx & 5xx => OK & progress made */ + case 2: sx->completed_addr = TRUE; /* 5xx (only) => progress made */ + case 0: break; /* No 2xx or 5xx, but no probs */ + + case -1: /* Timeout on RCPT */ +#ifdef EXPERIMENTAL_PIPE_CONNECT + case -4: /* non-2xx for pipelined banner or EHLO */ +#endif + default: return ERROR; /* I/O error, or any MAIL/DATA error */ + } + cmd_count = 1; + if (!sx->pending_BDAT) + pipelining_active = FALSE; + } + +/* Reap response for an outstanding BDAT */ + +if (sx->pending_BDAT) + { + DEBUG(D_transport) debug_printf("look for one response for BDAT\n"); + + if (!smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), '2', + ob->command_timeout)) + { + if (errno == 0 && sx->buffer[0] == '4') + { + errno = ERRNO_DATA4XX; /*XXX does this actually get used? */ + sx->addrlist->more_errno |= + ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8; + } + return ERROR; + } + cmd_count--; + sx->pending_BDAT = FALSE; + pipelining_active = FALSE; + } +else if (chunk_size > 0) + sx->pending_BDAT = TRUE; + + +sx->cmd_count = cmd_count; +return OK; +} + + + + + +/************************************************* +* Make connection for given message * +*************************************************/ + +/* +Arguments: + ctx connection context + suppress_tls if TRUE, don't attempt a TLS connection - this is set for + a second attempt after TLS initialization fails + +Returns: OK - the connection was made and the delivery attempted; + fd is set in the conn context, tls_out set up. + DEFER - the connection could not be made, or something failed + while setting up the SMTP session, or there was a + non-message-specific error, such as a timeout. + ERROR - helo_data or add_headers or authenticated_sender is + specified for this transport, and the string failed + to expand +*/ +int +smtp_setup_conn(smtp_context * sx, BOOL suppress_tls) +{ +#if defined(SUPPORT_TLS) && defined(SUPPORT_DANE) +dns_answer tlsa_dnsa; +#endif +smtp_transport_options_block * ob = sx->conn_args.tblock->options_block; +BOOL pass_message = FALSE; +uschar * message = NULL; +int yield = OK; +int rc; + +sx->conn_args.ob = ob; + +sx->lmtp = strcmpic(ob->protocol, US"lmtp") == 0; +sx->smtps = strcmpic(ob->protocol, US"smtps") == 0; +sx->ok = FALSE; +sx->send_rset = TRUE; +sx->send_quit = TRUE; +sx->setting_up = TRUE; +sx->esmtp = TRUE; +sx->esmtp_sent = FALSE; +#ifdef SUPPORT_I18N +sx->utf8_needed = FALSE; +#endif +sx->dsn_all_lasthop = TRUE; +#if defined(SUPPORT_TLS) && defined(SUPPORT_DANE) +sx->dane = FALSE; +sx->dane_required = + verify_check_given_host(CUSS &ob->hosts_require_dane, sx->conn_args.host) == OK; +#endif +#ifdef EXPERIMENTAL_PIPE_CONNECT +sx->early_pipe_active = sx->early_pipe_ok = FALSE; +sx->ehlo_resp.cleartext_features = sx->ehlo_resp.crypted_features = 0; +sx->pending_BANNER = sx->pending_EHLO = FALSE; +#endif + +if ((sx->max_rcpt = sx->conn_args.tblock->max_addresses) == 0) sx->max_rcpt = 999999; +sx->peer_offered = 0; +sx->avoid_option = 0; +sx->igquotstr = US""; +if (!sx->helo_data) sx->helo_data = ob->helo_data; +#ifdef EXPERIMENTAL_DSN_INFO +sx->smtp_greeting = NULL; +sx->helo_response = NULL; +#endif + +smtp_command = US"initial connection"; +sx->buffer[0] = '\0'; + +/* Set up the buffer for reading SMTP response packets. */ + +sx->inblock.buffer = sx->inbuffer; +sx->inblock.buffersize = sizeof(sx->inbuffer); +sx->inblock.ptr = sx->inbuffer; +sx->inblock.ptrend = sx->inbuffer; + +/* Set up the buffer for holding SMTP commands while pipelining */ + +sx->outblock.buffer = sx->outbuffer; +sx->outblock.buffersize = sizeof(sx->outbuffer); +sx->outblock.ptr = sx->outbuffer; +sx->outblock.cmd_count = 0; +sx->outblock.authenticating = FALSE; +sx->outblock.conn_args = NULL; + +/* Reset the parameters of a TLS session. */ + +tls_out.bits = 0; +tls_out.cipher = NULL; /* the one we may use for this transport */ +tls_out.ourcert = NULL; +tls_out.peercert = NULL; +tls_out.peerdn = NULL; +#if defined(SUPPORT_TLS) && !defined(USE_GNUTLS) +tls_out.sni = NULL; +#endif +tls_out.ocsp = OCSP_NOT_REQ; + +/* Flip the legacy TLS-related variables over to the outbound set in case +they're used in the context of the transport. Don't bother resetting +afterward (when being used by a transport) as we're in a subprocess. +For verify, unflipped once the callout is dealt with */ + +tls_modify_variables(&tls_out); + +#ifndef SUPPORT_TLS +if (sx->smtps) + { + set_errno_nohost(sx->addrlist, ERRNO_TLSFAILURE, US"TLS support not available", + DEFER, FALSE); + return ERROR; + } +#endif + +/* Make a connection to the host if this isn't a continued delivery, and handle +the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled +specially so they can be identified for retries. */ + +if (!continue_hostname) + { + if (sx->verify) + HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", sx->conn_args.interface, sx->port); + + /* Get the actual port the connection will use, into sx->conn_args.host */ + + smtp_port_for_connect(sx->conn_args.host, sx->port); + +#if defined(SUPPORT_TLS) && defined(SUPPORT_DANE) + /* Do TLSA lookup for DANE */ + { + tls_out.dane_verified = FALSE; + tls_out.tlsa_usage = 0; + + if (sx->conn_args.host->dnssec == DS_YES) + { + if( sx->dane_required + || verify_check_given_host(CUSS &ob->hosts_try_dane, sx->conn_args.host) == OK + ) + switch (rc = tlsa_lookup(sx->conn_args.host, &tlsa_dnsa, sx->dane_required)) + { + case OK: sx->dane = TRUE; + ob->tls_tempfail_tryclear = FALSE; + break; + case FAIL_FORCED: break; + default: set_errno_nohost(sx->addrlist, ERRNO_DNSDEFER, + string_sprintf("DANE error: tlsa lookup %s", + rc == DEFER ? "DEFER" : "FAIL"), + rc, FALSE); +# ifndef DISABLE_EVENT + (void) event_raise(sx->conn_args.tblock->event_action, + US"dane:fail", sx->dane_required + ? US"dane-required" : US"dnssec-invalid"); +# endif + return rc; + } + } + else if (sx->dane_required) + { + set_errno_nohost(sx->addrlist, ERRNO_DNSDEFER, + string_sprintf("DANE error: %s lookup not DNSSEC", sx->conn_args.host->name), + FAIL, FALSE); +# ifndef DISABLE_EVENT + (void) event_raise(sx->conn_args.tblock->event_action, + US"dane:fail", US"dane-required"); +# endif + return FAIL; + } + } +#endif /*DANE*/ + + /* Make the TCP connection */ + + sx->cctx.tls_ctx = NULL; + sx->inblock.cctx = sx->outblock.cctx = &sx->cctx; + sx->avoid_option = sx->peer_offered = smtp_peer_options = 0; + +#ifdef EXPERIMENTAL_PIPE_CONNECT + if (verify_check_given_host(CUSS &ob->hosts_pipe_connect, sx->conn_args.host) == OK) + { + sx->early_pipe_ok = TRUE; + if ( read_ehlo_cache_entry(sx) + && sx->ehlo_resp.cleartext_features & OPTION_EARLY_PIPE) + { + DEBUG(D_transport) debug_printf("Using cached cleartext PIPE_CONNECT\n"); + sx->early_pipe_active = TRUE; + sx->peer_offered = sx->ehlo_resp.cleartext_features; + } + } + + if (sx->early_pipe_active) + sx->outblock.conn_args = &sx->conn_args; + else +#endif + { + if ((sx->cctx.sock = smtp_connect(&sx->conn_args, NULL)) < 0) + { + uschar * msg = NULL; + if (sx->verify) + { + msg = US strerror(errno); + HDEBUG(D_verify) debug_printf("connect: %s\n", msg); + } + set_errno_nohost(sx->addrlist, + errno == ETIMEDOUT ? ERRNO_CONNECTTIMEOUT : errno, + sx->verify ? string_sprintf("could not connect: %s", msg) + : NULL, + DEFER, FALSE); + sx->send_quit = FALSE; + return DEFER; + } + } + /* Expand the greeting message while waiting for the initial response. (Makes + sense if helo_data contains ${lookup dnsdb ...} stuff). The expansion is + delayed till here so that $sending_interface and $sending_port are set. */ +/*XXX early-pipe: they still will not be. Is there any way to find out what they +will be? Somehow I doubt it. */ + + if (sx->helo_data) + if (!(sx->helo_data = expand_string(sx->helo_data))) + if (sx->verify) + log_write(0, LOG_MAIN|LOG_PANIC, + "<%s>: failed to expand transport's helo_data value for callout: %s", + sx->addrlist->address, expand_string_message); + +#ifdef SUPPORT_I18N + if (sx->helo_data) + { + expand_string_message = NULL; + if ((sx->helo_data = string_domain_utf8_to_alabel(sx->helo_data, + &expand_string_message)), + expand_string_message) + if (sx->verify) + log_write(0, LOG_MAIN|LOG_PANIC, + "<%s>: failed to expand transport's helo_data value for callout: %s", + sx->addrlist->address, expand_string_message); + else + sx->helo_data = NULL; + } +#endif + + /* The first thing is to wait for an initial OK response. The dreaded "goto" + is nevertheless a reasonably clean way of programming this kind of logic, + where you want to escape on any error. */ + + if (!sx->smtps) + { +#ifdef EXPERIMENTAL_PIPE_CONNECT + if (sx->early_pipe_active) + { + sx->pending_BANNER = TRUE; /* sync_responses() must eventually handle */ + sx->outblock.cmd_count = 1; + } + else +#endif + { +#ifdef TCP_QUICKACK + (void) setsockopt(sx->cctx.sock, IPPROTO_TCP, TCP_QUICKACK, US &off, + sizeof(off)); +#endif + if (!smtp_reap_banner(sx)) + goto RESPONSE_FAILED; + } + +#ifndef DISABLE_EVENT + { + uschar * s; + lookup_dnssec_authenticated = sx->conn_args.host->dnssec==DS_YES ? US"yes" + : sx->conn_args.host->dnssec==DS_NO ? US"no" : NULL; + s = event_raise(sx->conn_args.tblock->event_action, US"smtp:connect", sx->buffer); + if (s) + { + set_errno_nohost(sx->addrlist, ERRNO_EXPANDFAIL, + string_sprintf("deferred by smtp:connect event expansion: %s", s), + DEFER, FALSE); + yield = DEFER; + goto SEND_QUIT; + } + } +#endif + + /* Now check if the helo_data expansion went well, and sign off cleanly if + it didn't. */ + + if (!sx->helo_data) + { + message = string_sprintf("failed to expand helo_data: %s", + expand_string_message); + set_errno_nohost(sx->addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE); + yield = DEFER; + goto SEND_QUIT; + } + } + +/** Debugging without sending a message +sx->addrlist->transport_return = DEFER; +goto SEND_QUIT; +**/ + + /* Errors that occur after this point follow an SMTP command, which is + left in big_buffer by smtp_write_command() for use in error messages. */ + + smtp_command = big_buffer; + + /* Tell the remote who we are... + + February 1998: A convention has evolved that ESMTP-speaking MTAs include the + string "ESMTP" in their greeting lines, so make Exim send EHLO if the + greeting is of this form. The assumption was that the far end supports it + properly... but experience shows that there are some that give 5xx responses, + even though the banner includes "ESMTP" (there's a bloody-minded one that + says "ESMTP not spoken here"). Cope with that case. + + September 2000: Time has passed, and it seems reasonable now to always send + EHLO at the start. It is also convenient to make the change while installing + the TLS stuff. + + July 2003: Joachim Wieland met a broken server that advertises "PIPELINING" + but times out after sending MAIL FROM, RCPT TO and DATA all together. There + would be no way to send out the mails, so there is now a host list + "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the + PIPELINING problem as well. Maybe it can also be useful to cure other + problems with broken servers. + + Exim originally sent "Helo" at this point and ran for nearly a year that way. + Then somebody tried it with a Microsoft mailer... It seems that all other + mailers use upper case for some reason (the RFC is quite clear about case + independence) so, for peace of mind, I gave in. */ + + sx->esmtp = verify_check_given_host(CUSS &ob->hosts_avoid_esmtp, sx->conn_args.host) != OK; + + /* Alas; be careful, since this goto is not an error-out, so conceivably + we might set data between here and the target which we assume to exist + and be usable. I can see this coming back to bite us. */ +#ifdef SUPPORT_TLS + if (sx->smtps) + { + smtp_peer_options |= OPTION_TLS; + suppress_tls = FALSE; + ob->tls_tempfail_tryclear = FALSE; + smtp_command = US"SSL-on-connect"; + goto TLS_NEGOTIATE; + } +#endif + + if (sx->esmtp) + { + if (smtp_write_command(sx, +#ifdef EXPERIMENTAL_PIPE_CONNECT + sx->early_pipe_active ? SCMD_BUFFER : +#endif + SCMD_FLUSH, + "%s %s\r\n", sx->lmtp ? "LHLO" : "EHLO", sx->helo_data) < 0) + goto SEND_FAILED; + sx->esmtp_sent = TRUE; + +#ifdef EXPERIMENTAL_PIPE_CONNECT + if (sx->early_pipe_active) + { + sx->pending_EHLO = TRUE; + + /* If we have too many authenticators to handle and might need to AUTH + for this transport, pipeline no further as we will need the + list of auth methods offered. Reap the banner and EHLO. */ + + if ( (ob->hosts_require_auth || ob->hosts_try_auth) + && f.smtp_in_early_pipe_no_auth) + { + DEBUG(D_transport) debug_printf("may need to auth, so pipeline no further\n"); + if (smtp_write_command(sx, SCMD_FLUSH, NULL) < 0) + goto SEND_FAILED; + if (sync_responses(sx, 2, 0) != 0) + { + HDEBUG(D_transport) + debug_printf("failed reaping pipelined cmd responses\n"); + goto RESPONSE_FAILED; + } + sx->early_pipe_active = FALSE; + } + } + else +#endif + if (!smtp_reap_ehlo(sx)) + goto RESPONSE_FAILED; + } + else + DEBUG(D_transport) + debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n"); + +#ifdef EXPERIMENTAL_PIPE_CONNECT + if (!sx->early_pipe_active) +#endif + if (!sx->esmtp) + { + BOOL good_response; + int n = sizeof(sx->buffer); + uschar * rsp = sx->buffer; + + if (sx->esmtp_sent && (n = Ustrlen(sx->buffer)) < sizeof(sx->buffer)/2) + { rsp = sx->buffer + n + 1; n = sizeof(sx->buffer) - n; } + + if (smtp_write_command(sx, SCMD_FLUSH, "HELO %s\r\n", sx->helo_data) < 0) + goto SEND_FAILED; + good_response = smtp_read_response(sx, rsp, n, '2', ob->command_timeout); +#ifdef EXPERIMENTAL_DSN_INFO + sx->helo_response = string_copy(rsp); +#endif + if (!good_response) + { + /* Handle special logging for a closed connection after HELO + when had previously sent EHLO */ + + if (rsp != sx->buffer && rsp[0] == 0 && (errno == 0 || errno == ECONNRESET)) + { + errno = ERRNO_SMTPCLOSED; + goto EHLOHELO_FAILED; + } + memmove(sx->buffer, rsp, Ustrlen(rsp)); + goto RESPONSE_FAILED; + } + } + + if (sx->esmtp || sx->lmtp) + { +#ifdef EXPERIMENTAL_PIPE_CONNECT + if (!sx->early_pipe_active) +#endif + { + sx->peer_offered = ehlo_response(sx->buffer, + OPTION_TLS /* others checked later */ +#ifdef EXPERIMENTAL_PIPE_CONNECT + | (sx->early_pipe_ok + ? OPTION_IGNQ + | OPTION_CHUNKING | OPTION_PRDR | OPTION_DSN | OPTION_PIPE | OPTION_SIZE +#ifdef SUPPORT_I18N + | OPTION_UTF8 +#endif + | OPTION_EARLY_PIPE + : 0 + ) +#endif + ); +#ifdef EXPERIMENTAL_PIPE_CONNECT + if (sx->early_pipe_ok) + { + sx->ehlo_resp.cleartext_features = sx->peer_offered; + + if ( (sx->peer_offered & (OPTION_PIPE | OPTION_EARLY_PIPE)) + == (OPTION_PIPE | OPTION_EARLY_PIPE)) + { + DEBUG(D_transport) debug_printf("PIPE_CONNECT usable in future for this IP\n"); + sx->ehlo_resp.cleartext_auths = study_ehlo_auths(sx); + write_ehlo_cache_entry(sx); + } + } +#endif + } + + /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */ + +#ifdef SUPPORT_TLS + smtp_peer_options |= sx->peer_offered & OPTION_TLS; +#endif + } + } + +/* For continuing deliveries down the same channel, having re-exec'd the socket +is the standard input; for a socket held open from verify it is recorded +in the cutthrough context block. Either way we don't need to redo EHLO here +(but may need to do so for TLS - see below). +Set up the pointer to where subsequent commands will be left, for +error messages. Note that smtp_peer_options will have been +set from the command line if they were set in the process that passed the +connection on. */ + +/*XXX continue case needs to propagate DSN_INFO, prob. in deliver.c +as the continue goes via transport_pass_socket() and doublefork and exec. +It does not wait. Unclear how we keep separate host's responses +separate - we could match up by host ip+port as a bodge. */ + +else + { + if (cutthrough.cctx.sock >= 0 && cutthrough.callout_hold_only) + { + sx->cctx = cutthrough.cctx; + sx->conn_args.host->port = sx->port = cutthrough.host.port; + } + else + { + sx->cctx.sock = 0; /* stdin */ + sx->cctx.tls_ctx = NULL; + smtp_port_for_connect(sx->conn_args.host, sx->port); /* Record the port that was used */ + } + sx->inblock.cctx = sx->outblock.cctx = &sx->cctx; + smtp_command = big_buffer; + sx->helo_data = NULL; /* ensure we re-expand ob->helo_data */ + + /* For a continued connection with TLS being proxied for us, or a + held-open verify connection with TLS, nothing more to do. */ + + if ( continue_proxy_cipher + || (cutthrough.cctx.sock >= 0 && cutthrough.callout_hold_only + && cutthrough.is_tls) + ) + { + sx->peer_offered = smtp_peer_options; + sx->pipelining_used = pipelining_active = !!(smtp_peer_options & OPTION_PIPE); + HDEBUG(D_transport) debug_printf("continued connection, %s TLS\n", + continue_proxy_cipher ? "proxied" : "verify conn with"); + return OK; + } + HDEBUG(D_transport) debug_printf("continued connection, no TLS\n"); + } + +/* If TLS is available on this connection, whether continued or not, attempt to +start up a TLS session, unless the host is in hosts_avoid_tls. If successful, +send another EHLO - the server may give a different answer in secure mode. We +use a separate buffer for reading the response to STARTTLS so that if it is +negative, the original EHLO data is available for subsequent analysis, should +the client not be required to use TLS. If the response is bad, copy the buffer +for error analysis. */ + +#ifdef SUPPORT_TLS +if ( smtp_peer_options & OPTION_TLS + && !suppress_tls + && verify_check_given_host(CUSS &ob->hosts_avoid_tls, sx->conn_args.host) != OK + && ( !sx->verify + || verify_check_given_host(CUSS &ob->hosts_verify_avoid_tls, sx->conn_args.host) != OK + ) ) + { + uschar buffer2[4096]; + + if (smtp_write_command(sx, SCMD_FLUSH, "STARTTLS\r\n") < 0) + goto SEND_FAILED; + +#ifdef EXPERIMENTAL_PIPE_CONNECT + /* If doing early-pipelining reap the banner and EHLO-response but leave + the response for the STARTTLS we just sent alone. */ + + if (sx->early_pipe_active && sync_responses(sx, 2, 0) != 0) + { + HDEBUG(D_transport) + debug_printf("failed reaping pipelined cmd responses\n"); + goto RESPONSE_FAILED; + } +#endif + + /* If there is an I/O error, transmission of this message is deferred. If + there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is + false, we also defer. However, if there is a temporary rejection of STARTTLS + and tls_tempfail_tryclear is true, or if there is an outright rejection of + STARTTLS, we carry on. This means we will try to send the message in clear, + unless the host is in hosts_require_tls (tested below). */ + + if (!smtp_read_response(sx, buffer2, sizeof(buffer2), '2', ob->command_timeout)) + { + if ( errno != 0 + || buffer2[0] == 0 + || (buffer2[0] == '4' && !ob->tls_tempfail_tryclear) + ) + { + Ustrncpy(sx->buffer, buffer2, sizeof(sx->buffer)); + sx->buffer[sizeof(sx->buffer)-1] = '\0'; + goto RESPONSE_FAILED; + } + } + + /* STARTTLS accepted: try to negotiate a TLS session. */ + + else + TLS_NEGOTIATE: + { + address_item * addr; + uschar * errstr; + sx->cctx.tls_ctx = tls_client_start(sx->cctx.sock, sx->conn_args.host, + sx->addrlist, sx->conn_args.tblock, +# ifdef SUPPORT_DANE + sx->dane ? &tlsa_dnsa : NULL, +# endif + &tls_out, &errstr); + + if (!sx->cctx.tls_ctx) + { + /* TLS negotiation failed; give an error. From outside, this function may + be called again to try in clear on a new connection, if the options permit + it for this host. */ + DEBUG(D_tls) debug_printf("TLS session fail: %s\n", errstr); + +# ifdef SUPPORT_DANE + if (sx->dane) + { + log_write(0, LOG_MAIN, + "DANE attempt failed; TLS connection to %s [%s]: %s", + sx->conn_args.host->name, sx->conn_args.host->address, errstr); +# ifndef DISABLE_EVENT + (void) event_raise(sx->conn_args.tblock->event_action, + US"dane:fail", US"validation-failure"); /* could do with better detail */ +# endif + } +# endif + + errno = ERRNO_TLSFAILURE; + message = string_sprintf("TLS session: %s", errstr); + sx->send_quit = FALSE; + goto TLS_FAILED; + } + + /* TLS session is set up */ + + smtp_peer_options_wrap = smtp_peer_options; + for (addr = sx->addrlist; addr; addr = addr->next) + if (addr->transport_return == PENDING_DEFER) + { + addr->cipher = tls_out.cipher; + addr->ourcert = tls_out.ourcert; + addr->peercert = tls_out.peercert; + addr->peerdn = tls_out.peerdn; + addr->ocsp = tls_out.ocsp; + } + } + } + +/* if smtps, we'll have smtp_command set to something else; always safe to +reset it here. */ +smtp_command = big_buffer; + +/* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. If +helo_data is null, we are dealing with a connection that was passed from +another process, and so we won't have expanded helo_data above. We have to +expand it here. $sending_ip_address and $sending_port are set up right at the +start of the Exim process (in exim.c). */ + +if (tls_out.active.sock >= 0) + { + uschar * greeting_cmd; + + if (!sx->helo_data && !(sx->helo_data = expand_string(ob->helo_data))) + { + uschar *message = string_sprintf("failed to expand helo_data: %s", + expand_string_message); + set_errno_nohost(sx->addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE); + yield = DEFER; + goto SEND_QUIT; + } + +#ifdef EXPERIMENTAL_PIPE_CONNECT + /* For SMTPS there is no cleartext early-pipe; use the crypted permission bit. + We're unlikely to get the group sent and delivered before the server sends its + banner, but it's still worth sending as a group. + For STARTTLS allow for cleartext early-pipe but no crypted early-pipe, but not + the reverse. */ + + if (sx->smtps ? sx->early_pipe_ok : sx->early_pipe_active) + { + sx->peer_offered = sx->ehlo_resp.crypted_features; + if ((sx->early_pipe_active = + !!(sx->ehlo_resp.crypted_features & OPTION_EARLY_PIPE))) + DEBUG(D_transport) debug_printf("Using cached crypted PIPE_CONNECT\n"); + } +#endif + + /* For SMTPS we need to wait for the initial OK response. */ + if (sx->smtps) +#ifdef EXPERIMENTAL_PIPE_CONNECT + if (sx->early_pipe_active) + { + sx->pending_BANNER = TRUE; + sx->outblock.cmd_count = 1; + } + else +#endif + if (!smtp_reap_banner(sx)) + goto RESPONSE_FAILED; + + if (sx->lmtp) + greeting_cmd = US"LHLO"; + else if (sx->esmtp) + greeting_cmd = US"EHLO"; + else + { + greeting_cmd = US"HELO"; + DEBUG(D_transport) + debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n"); + } + + if (smtp_write_command(sx, +#ifdef EXPERIMENTAL_PIPE_CONNECT + sx->early_pipe_active ? SCMD_BUFFER : +#endif + SCMD_FLUSH, + "%s %s\r\n", greeting_cmd, sx->helo_data) < 0) + goto SEND_FAILED; + +#ifdef EXPERIMENTAL_PIPE_CONNECT + if (sx->early_pipe_active) + sx->pending_EHLO = TRUE; + else +#endif + { + if (!smtp_reap_ehlo(sx)) + goto RESPONSE_FAILED; + smtp_peer_options = 0; + } + } + +/* If the host is required to use a secure channel, ensure that we +have one. */ + +else if ( sx->smtps +# ifdef SUPPORT_DANE + || sx->dane +# endif +# ifdef EXPERIMENTAL_REQUIRETLS + || tls_requiretls & REQUIRETLS_MSG +# endif + || verify_check_given_host(CUSS &ob->hosts_require_tls, sx->conn_args.host) == OK + ) + { + errno = +# ifdef EXPERIMENTAL_REQUIRETLS + tls_requiretls & REQUIRETLS_MSG ? ERRNO_REQUIRETLS : +# endif + ERRNO_TLSREQUIRED; + message = string_sprintf("a TLS session is required, but %s", + smtp_peer_options & OPTION_TLS + ? "an attempt to start TLS failed" : "the server did not offer TLS support"); +# if defined(SUPPORT_DANE) && !defined(DISABLE_EVENT) + if (sx->dane) + (void) event_raise(sx->conn_args.tblock->event_action, US"dane:fail", + smtp_peer_options & OPTION_TLS + ? US"validation-failure" /* could do with better detail */ + : US"starttls-not-supported"); +# endif + goto TLS_FAILED; + } +#endif /*SUPPORT_TLS*/ + +/* If TLS is active, we have just started it up and re-done the EHLO command, +so its response needs to be analyzed. If TLS is not active and this is a +continued session down a previously-used socket, we haven't just done EHLO, so +we skip this. */ + +if (continue_hostname == NULL +#ifdef SUPPORT_TLS + || tls_out.active.sock >= 0 +#endif + ) + { + if (sx->esmtp || sx->lmtp) + { +#ifdef EXPERIMENTAL_PIPE_CONNECT + if (!sx->early_pipe_active) +#endif + { + sx->peer_offered = ehlo_response(sx->buffer, + 0 /* no TLS */ +#ifdef EXPERIMENTAL_PIPE_CONNECT + | (sx->lmtp && ob->lmtp_ignore_quota ? OPTION_IGNQ : 0) + | OPTION_DSN | OPTION_PIPE | OPTION_SIZE + | OPTION_CHUNKING | OPTION_PRDR | OPTION_UTF8 | OPTION_REQUIRETLS + | (tls_out.active.sock >= 0 ? OPTION_EARLY_PIPE : 0) /* not for lmtp */ + +#else + + | (sx->lmtp && ob->lmtp_ignore_quota ? OPTION_IGNQ : 0) + | OPTION_CHUNKING + | OPTION_PRDR +# ifdef SUPPORT_I18N + | (sx->addrlist->prop.utf8_msg ? OPTION_UTF8 : 0) + /*XXX if we hand peercaps on to continued-conn processes, + must not depend on this addr */ +# endif + | OPTION_DSN + | OPTION_PIPE + | (ob->size_addition >= 0 ? OPTION_SIZE : 0) +# if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_REQUIRETLS) + | (tls_requiretls & REQUIRETLS_MSG ? OPTION_REQUIRETLS : 0) +# endif +#endif + ); +#ifdef EXPERIMENTAL_PIPE_CONNECT + if (tls_out.active.sock >= 0) + sx->ehlo_resp.crypted_features = sx->peer_offered; +#endif + } + + /* Set for IGNOREQUOTA if the response to LHLO specifies support and the + lmtp_ignore_quota option was set. */ + + sx->igquotstr = sx->peer_offered & OPTION_IGNQ ? US" IGNOREQUOTA" : US""; + + /* If the response to EHLO specified support for the SIZE parameter, note + this, provided size_addition is non-negative. */ + + smtp_peer_options |= sx->peer_offered & OPTION_SIZE; + + /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched + the current host, esmtp will be false, so PIPELINING can never be used. If + the current host matches hosts_avoid_pipelining, don't do it. */ + + if ( sx->peer_offered & OPTION_PIPE + && verify_check_given_host(CUSS &ob->hosts_avoid_pipelining, sx->conn_args.host) != OK) + smtp_peer_options |= OPTION_PIPE; + + DEBUG(D_transport) debug_printf("%susing PIPELINING\n", + smtp_peer_options & OPTION_PIPE ? "" : "not "); + + if ( sx->peer_offered & OPTION_CHUNKING + && verify_check_given_host(CUSS &ob->hosts_try_chunking, sx->conn_args.host) != OK) + sx->peer_offered &= ~OPTION_CHUNKING; + + if (sx->peer_offered & OPTION_CHUNKING) + DEBUG(D_transport) debug_printf("CHUNKING usable\n"); + +#ifndef DISABLE_PRDR + if ( sx->peer_offered & OPTION_PRDR + && verify_check_given_host(CUSS &ob->hosts_try_prdr, sx->conn_args.host) != OK) + sx->peer_offered &= ~OPTION_PRDR; + + if (sx->peer_offered & OPTION_PRDR) + DEBUG(D_transport) debug_printf("PRDR usable\n"); +#endif + + /* Note if the server supports DSN */ + smtp_peer_options |= sx->peer_offered & OPTION_DSN; + DEBUG(D_transport) debug_printf("%susing DSN\n", + sx->peer_offered & OPTION_DSN ? "" : "not "); + +#if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_REQUIRETLS) + if (sx->peer_offered & OPTION_REQUIRETLS) + { + smtp_peer_options |= OPTION_REQUIRETLS; + DEBUG(D_transport) debug_printf( + tls_requiretls & REQUIRETLS_MSG + ? "using REQUIRETLS\n" : "REQUIRETLS offered\n"); + } +#endif + +#ifdef EXPERIMENTAL_PIPE_CONNECT + if ( sx->early_pipe_ok + && !sx->early_pipe_active + && tls_out.active.sock >= 0 + && smtp_peer_options & OPTION_PIPE + && ( sx->ehlo_resp.cleartext_features | sx->ehlo_resp.crypted_features) + & OPTION_EARLY_PIPE) + { + DEBUG(D_transport) debug_printf("PIPE_CONNECT usable in future for this IP\n"); + sx->ehlo_resp.crypted_auths = study_ehlo_auths(sx); + write_ehlo_cache_entry(sx); + } +#endif + + /* Note if the response to EHLO specifies support for the AUTH extension. + If it has, check that this host is one we want to authenticate to, and do + the business. The host name and address must be available when the + authenticator's client driver is running. */ + + switch (yield = smtp_auth(sx)) + { + default: goto SEND_QUIT; + case OK: break; + case FAIL_SEND: goto SEND_FAILED; + case FAIL: goto RESPONSE_FAILED; + } + } + } +sx->pipelining_used = pipelining_active = !!(smtp_peer_options & OPTION_PIPE); + +/* The setting up of the SMTP call is now complete. Any subsequent errors are +message-specific. */ + +sx->setting_up = FALSE; + +#ifdef SUPPORT_I18N +if (sx->addrlist->prop.utf8_msg) + { + uschar * s; + + /* If the transport sets a downconversion mode it overrides any set by ACL + for the message. */ + + if ((s = ob->utf8_downconvert)) + { + if (!(s = expand_string(s))) + { + message = string_sprintf("failed to expand utf8_downconvert: %s", + expand_string_message); + set_errno_nohost(sx->addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE); + yield = DEFER; + goto SEND_QUIT; + } + switch (*s) + { + case '1': sx->addrlist->prop.utf8_downcvt = TRUE; + sx->addrlist->prop.utf8_downcvt_maybe = FALSE; + break; + case '0': sx->addrlist->prop.utf8_downcvt = FALSE; + sx->addrlist->prop.utf8_downcvt_maybe = FALSE; + break; + case '-': if (s[1] == '1') + { + sx->addrlist->prop.utf8_downcvt = FALSE; + sx->addrlist->prop.utf8_downcvt_maybe = TRUE; + } + break; + } + } + + sx->utf8_needed = !sx->addrlist->prop.utf8_downcvt + && !sx->addrlist->prop.utf8_downcvt_maybe; + DEBUG(D_transport) if (!sx->utf8_needed) + debug_printf("utf8: %s downconvert\n", + sx->addrlist->prop.utf8_downcvt ? "mandatory" : "optional"); + } + +/* If this is an international message we need the host to speak SMTPUTF8 */ +if (sx->utf8_needed && !(sx->peer_offered & OPTION_UTF8)) + { + errno = ERRNO_UTF8_FWD; + goto RESPONSE_FAILED; + } +#endif /*SUPPORT_I18N*/ + +#if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_REQUIRETLS) + /*XXX should tls_requiretls actually be per-addr? */ + +if ( tls_requiretls & REQUIRETLS_MSG + && !(sx->peer_offered & OPTION_REQUIRETLS) + ) + { + sx->setting_up = TRUE; + errno = ERRNO_REQUIRETLS; + message = US"REQUIRETLS support is required from the server" + " but it was not offered"; + DEBUG(D_transport) debug_printf("%s\n", message); + goto TLS_FAILED; + } +#endif + +return OK; + + + { + int code; + + RESPONSE_FAILED: + message = NULL; + sx->send_quit = check_response(sx->conn_args.host, &errno, sx->addrlist->more_errno, + sx->buffer, &code, &message, &pass_message); + yield = DEFER; + goto FAILED; + + SEND_FAILED: + code = '4'; + message = US string_sprintf("send() to %s [%s] failed: %s", + sx->conn_args.host->name, sx->conn_args.host->address, strerror(errno)); + sx->send_quit = FALSE; + yield = DEFER; + goto FAILED; + + EHLOHELO_FAILED: + code = '4'; + message = string_sprintf("Remote host closed connection in response to %s" + " (EHLO response was: %s)", smtp_command, sx->buffer); + sx->send_quit = FALSE; + yield = DEFER; + goto FAILED; + + /* This label is jumped to directly when a TLS negotiation has failed, + or was not done for a host for which it is required. Values will be set + in message and errno, and setting_up will always be true. Treat as + a temporary error. */ + +#ifdef SUPPORT_TLS + TLS_FAILED: +# ifdef EXPERIMENTAL_REQUIRETLS + if (errno == ERRNO_REQUIRETLS) + code = '5', yield = FAIL; + /*XXX DSN will be labelled 500; prefer 530 5.7.4 */ + else +# endif + code = '4', yield = DEFER; + goto FAILED; +#endif + + /* The failure happened while setting up the call; see if the failure was + a 5xx response (this will either be on connection, or following HELO - a 5xx + after EHLO causes it to try HELO). If so, and there are no more hosts to try, + fail all addresses, as this host is never going to accept them. For other + errors during setting up (timeouts or whatever), defer all addresses, and + yield DEFER, so that the host is not tried again for a while. + + XXX This peeking for another host feels like a layering violation. We want + to note the host as unusable, but down here we shouldn't know if this was + the last host to try for the addr(list). Perhaps the upper layer should be + the one to do set_errno() ? The problem is that currently the addr is where + errno etc. are stashed, but until we run out of hosts to try the errors are + host-specific. Maybe we should enhance the host_item definition? */ + +FAILED: + sx->ok = FALSE; /* For when reached by GOTO */ + set_errno(sx->addrlist, errno, message, + sx->conn_args.host->next + ? DEFER + : code == '5' +#ifdef SUPPORT_I18N + || errno == ERRNO_UTF8_FWD +#endif + ? FAIL : DEFER, + pass_message, sx->conn_args.host +#ifdef EXPERIMENTAL_DSN_INFO + , sx->smtp_greeting, sx->helo_response +#endif + ); + } + + +SEND_QUIT: + +if (sx->send_quit) + (void)smtp_write_command(sx, SCMD_FLUSH, "QUIT\r\n"); + +#ifdef SUPPORT_TLS +if (sx->cctx.tls_ctx) + { + tls_close(sx->cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT); + sx->cctx.tls_ctx = NULL; + } +#endif + +/* Close the socket, and return the appropriate value, first setting +works because the NULL setting is passed back to the calling process, and +remote_max_parallel is forced to 1 when delivering over an existing connection, +*/ + +HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n"); +if (sx->send_quit) + { + shutdown(sx->cctx.sock, SHUT_WR); + if (fcntl(sx->cctx.sock, F_SETFL, O_NONBLOCK) == 0) + for (rc = 16; read(sx->cctx.sock, sx->inbuffer, sizeof(sx->inbuffer)) > 0 && rc > 0;) + rc--; /* drain socket */ + sx->send_quit = FALSE; + } +(void)close(sx->cctx.sock); +sx->cctx.sock = -1; + +#ifndef DISABLE_EVENT +(void) event_raise(sx->conn_args.tblock->event_action, US"tcp:close", NULL); +#endif + +continue_transport = NULL; +continue_hostname = NULL; +return yield; +} + + + + +/* Create the string of options that will be appended to the MAIL FROM: +in the connection context buffer */ + +static int +build_mailcmd_options(smtp_context * sx, address_item * addrlist) +{ +uschar * p = sx->buffer; +address_item * addr; +int address_count; + +*p = 0; + +/* If we know the receiving MTA supports the SIZE qualification, and we know it, +send it, adding something to the message size to allow for imprecision +and things that get added en route. Exim keeps the number of lines +in a message, so we can give an accurate value for the original message, but we +need some additional to handle added headers. (Double "." characters don't get +included in the count.) */ + +if ( message_size > 0 + && sx->peer_offered & OPTION_SIZE && !(sx->avoid_option & OPTION_SIZE)) + { +/*XXX problem here under spool_files_wireformat? +Or just forget about lines? Or inflate by a fixed proportion? */ + + sprintf(CS p, " SIZE=%d", message_size+message_linecount+(SOB sx->conn_args.ob)->size_addition); + while (*p) p++; + } + +#ifndef DISABLE_PRDR +/* If it supports Per-Recipient Data Responses, and we have more than one recipient, +request that */ + +sx->prdr_active = FALSE; +if (sx->peer_offered & OPTION_PRDR) + for (addr = addrlist; addr; addr = addr->next) + if (addr->transport_return == PENDING_DEFER) + { + for (addr = addr->next; addr; addr = addr->next) + if (addr->transport_return == PENDING_DEFER) + { /* at least two recipients to send */ + sx->prdr_active = TRUE; + sprintf(CS p, " PRDR"); p += 5; + break; + } + break; + } +#endif + +#ifdef SUPPORT_I18N +/* If it supports internationalised messages, and this meesage need that, +request it */ + +if ( sx->peer_offered & OPTION_UTF8 + && addrlist->prop.utf8_msg + && !addrlist->prop.utf8_downcvt + ) + Ustrcpy(p, " SMTPUTF8"), p += 9; +#endif + +#if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_REQUIRETLS) +if (tls_requiretls & REQUIRETLS_MSG) + Ustrcpy(p, " REQUIRETLS") , p += 11; +#endif + +/* check if all addresses have DSN-lasthop flag; do not send RET and ENVID if so */ +for (sx->dsn_all_lasthop = TRUE, addr = addrlist, address_count = 0; + addr && address_count < sx->max_rcpt; + addr = addr->next) if (addr->transport_return == PENDING_DEFER) + { + address_count++; + if (!(addr->dsn_flags & rf_dsnlasthop)) + { + sx->dsn_all_lasthop = FALSE; + break; + } + } + +/* Add any DSN flags to the mail command */ + +if (sx->peer_offered & OPTION_DSN && !sx->dsn_all_lasthop) + { + if (dsn_ret == dsn_ret_hdrs) + { Ustrcpy(p, " RET=HDRS"); p += 9; } + else if (dsn_ret == dsn_ret_full) + { Ustrcpy(p, " RET=FULL"); p += 9; } + + if (dsn_envid) + { + string_format(p, sizeof(sx->buffer) - (p-sx->buffer), " ENVID=%s", dsn_envid); + while (*p) p++; + } + } + +/* If an authenticated_sender override has been specified for this transport +instance, expand it. If the expansion is forced to fail, and there was already +an authenticated_sender for this message, the original value will be used. +Other expansion failures are serious. An empty result is ignored, but there is +otherwise no check - this feature is expected to be used with LMTP and other +cases where non-standard addresses (e.g. without domains) might be required. */ + +if (smtp_mail_auth_str(p, sizeof(sx->buffer) - (p-sx->buffer), addrlist, sx->conn_args.ob)) + return ERROR; + +return OK; +} + + +static void +build_rcptcmd_options(smtp_context * sx, const address_item * addr) +{ +uschar * p = sx->buffer; +*p = 0; + +/* Add any DSN flags to the rcpt command */ + +if (sx->peer_offered & OPTION_DSN && !(addr->dsn_flags & rf_dsnlasthop)) + { + if (addr->dsn_flags & rf_dsnflags) + { + int i; + BOOL first = TRUE; + + Ustrcpy(p, " NOTIFY="); + while (*p) p++; + for (i = 0; i < nelem(rf_list); i++) if (addr->dsn_flags & rf_list[i]) + { + if (!first) *p++ = ','; + first = FALSE; + Ustrcpy(p, rf_names[i]); + while (*p) p++; + } + } + + if (addr->dsn_orcpt) + { + string_format(p, sizeof(sx->buffer) - (p-sx->buffer), " ORCPT=%s", + addr->dsn_orcpt); + while (*p) p++; + } + } +} + + + +/* +Return: + 0 good, rcpt results in addr->transport_return (PENDING_OK, DEFER, FAIL) + -1 MAIL response error + -2 any non-MAIL read i/o error + -3 non-MAIL response timeout + -4 internal error; channel still usable + -5 transmit failed + */ + +int +smtp_write_mail_and_rcpt_cmds(smtp_context * sx, int * yield) +{ +address_item * addr; +int address_count; +int rc; + +if (build_mailcmd_options(sx, sx->first_addr) != OK) + { + *yield = ERROR; + return -4; + } + +/* From here until we send the DATA command, we can make use of PIPELINING +if the server host supports it. The code has to be able to check the responses +at any point, for when the buffer fills up, so we write it totally generally. +When PIPELINING is off, each command written reports that it has flushed the +buffer. */ + +sx->pending_MAIL = TRUE; /* The block starts with MAIL */ + + { + uschar * s = sx->from_addr; +#ifdef SUPPORT_I18N + uschar * errstr = NULL; + + /* If we must downconvert, do the from-address here. Remember we had to + for the to-addresses (done below), and also (ugly) for re-doing when building + the delivery log line. */ + + if ( sx->addrlist->prop.utf8_msg + && (sx->addrlist->prop.utf8_downcvt || !(sx->peer_offered & OPTION_UTF8)) + ) + { + if (s = string_address_utf8_to_alabel(s, &errstr), errstr) + { + set_errno_nohost(sx->addrlist, ERRNO_EXPANDFAIL, errstr, DEFER, FALSE); + *yield = ERROR; + return -4; + } + setflag(sx->addrlist, af_utf8_downcvt); + } +#endif + + rc = smtp_write_command(sx, pipelining_active ? SCMD_BUFFER : SCMD_FLUSH, + "MAIL FROM:<%s>%s\r\n", s, sx->buffer); + } + +mail_command = string_copy(big_buffer); /* Save for later error message */ + +switch(rc) + { + case -1: /* Transmission error */ + return -5; + + case +1: /* Cmd was sent */ + if (!smtp_read_response(sx, sx->buffer, sizeof(sx->buffer), '2', + (SOB sx->conn_args.ob)->command_timeout)) + { + if (errno == 0 && sx->buffer[0] == '4') + { + errno = ERRNO_MAIL4XX; + sx->addrlist->more_errno |= ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8; + } + return -1; + } + sx->pending_MAIL = FALSE; + break; + + /* otherwise zero: command queued for pipeline */ + } + +/* Pass over all the relevant recipient addresses for this host, which are the +ones that have status PENDING_DEFER. If we are using PIPELINING, we can send +several before we have to read the responses for those seen so far. This +checking is done by a subroutine because it also needs to be done at the end. +Send only up to max_rcpt addresses at a time, leaving next_addr pointing to +the next one if not all are sent. + +In the MUA wrapper situation, we want to flush the PIPELINING buffer for the +last address because we want to abort if any recipients have any kind of +problem, temporary or permanent. We know that all recipient addresses will have +the PENDING_DEFER status, because only one attempt is ever made, and we know +that max_rcpt will be large, so all addresses will be done at once. + +For verify we flush the pipeline after any (the only) rcpt address. */ + +for (addr = sx->first_addr, address_count = 0; + addr && address_count < sx->max_rcpt; + addr = addr->next) if (addr->transport_return == PENDING_DEFER) + { + int count; + BOOL no_flush; + uschar * rcpt_addr; + + addr->dsn_aware = sx->peer_offered & OPTION_DSN + ? dsn_support_yes : dsn_support_no; + + address_count++; + no_flush = pipelining_active && !sx->verify + && (!mua_wrapper || addr->next && address_count < sx->max_rcpt); + + build_rcptcmd_options(sx, addr); + + /* Now send the RCPT command, and process outstanding responses when + necessary. After a timeout on RCPT, we just end the function, leaving the + yield as OK, because this error can often mean that there is a problem with + just one address, so we don't want to delay the host. */ + + rcpt_addr = transport_rcpt_address(addr, sx->conn_args.tblock->rcpt_include_affixes); + +#ifdef SUPPORT_I18N + if ( testflag(sx->addrlist, af_utf8_downcvt) + && !(rcpt_addr = string_address_utf8_to_alabel(rcpt_addr, NULL)) + ) + { + /*XXX could we use a per-address errstr here? Not fail the whole send? */ + errno = ERRNO_EXPANDFAIL; + return -5; /*XXX too harsh? */ + } +#endif + + count = smtp_write_command(sx, no_flush ? SCMD_BUFFER : SCMD_FLUSH, + "RCPT TO:<%s>%s%s\r\n", rcpt_addr, sx->igquotstr, sx->buffer); + + if (count < 0) return -5; + if (count > 0) + { + switch(sync_responses(sx, count, 0)) + { + case 3: sx->ok = TRUE; /* 2xx & 5xx => OK & progress made */ + case 2: sx->completed_addr = TRUE; /* 5xx (only) => progress made */ + break; + + case 1: sx->ok = TRUE; /* 2xx (only) => OK, but if LMTP, */ + if (!sx->lmtp) /* can't tell about progress yet */ + sx->completed_addr = TRUE; + case 0: /* No 2xx or 5xx, but no probs */ + break; + + case -1: return -3; /* Timeout on RCPT */ + case -2: return -2; /* non-MAIL read i/o error */ + default: return -1; /* any MAIL error */ + +#ifdef EXPERIMENTAL_PIPE_CONNECT + case -4: return -1; /* non-2xx for pipelined banner or EHLO */ +#endif + } + sx->pending_MAIL = FALSE; /* Dealt with MAIL */ + } + } /* Loop for next address */ + +sx->next_addr = addr; +return 0; +} + + +#ifdef SUPPORT_TLS +/***************************************************** +* Proxy TLS connection for another transport process * +******************************************************/ +/* +Close the unused end of the pipe, fork once more, then use the given buffer +as a staging area, and select on both the given fd and the TLS'd client-fd for +data to read (per the coding in ip_recv() and fd_ready() this is legitimate). +Do blocking full-size writes, and reads under a timeout. Once both input +channels are closed, exit the process. + +Arguments: + ct_ctx tls context + buf space to use for buffering + bufsiz size of buffer + pfd pipe filedescriptor array; [0] is comms to proxied process + timeout per-read timeout, seconds +*/ + +void +smtp_proxy_tls(void * ct_ctx, uschar * buf, size_t bsize, int * pfd, + int timeout) +{ +fd_set rfds, efds; +int max_fd = MAX(pfd[0], tls_out.active.sock) + 1; +int rc, i, fd_bits, nbytes; + +close(pfd[1]); +if ((rc = fork())) + { + DEBUG(D_transport) debug_printf("proxy-proc final-pid %d\n", rc); + _exit(rc < 0 ? EXIT_FAILURE : EXIT_SUCCESS); + } + +if (f.running_in_test_harness) millisleep(100); /* let parent debug out */ +set_process_info("proxying TLS connection for continued transport"); +FD_ZERO(&rfds); +FD_SET(tls_out.active.sock, &rfds); +FD_SET(pfd[0], &rfds); + +for (fd_bits = 3; fd_bits; ) + { + time_t time_left = timeout; + time_t time_start = time(NULL); + + /* wait for data */ + efds = rfds; + do + { + struct timeval tv = { time_left, 0 }; + + rc = select(max_fd, + (SELECT_ARG2_TYPE *)&rfds, NULL, (SELECT_ARG2_TYPE *)&efds, &tv); + + if (rc < 0 && errno == EINTR) + if ((time_left -= time(NULL) - time_start) > 0) continue; + + if (rc <= 0) + { + DEBUG(D_transport) if (rc == 0) debug_printf("%s: timed out\n", __FUNCTION__); + goto done; + } + + if (FD_ISSET(tls_out.active.sock, &efds) || FD_ISSET(pfd[0], &efds)) + { + DEBUG(D_transport) debug_printf("select: exceptional cond on %s fd\n", + FD_ISSET(pfd[0], &efds) ? "proxy" : "tls"); + goto done; + } + } + while (rc < 0 || !(FD_ISSET(tls_out.active.sock, &rfds) || FD_ISSET(pfd[0], &rfds))); + + /* handle inbound data */ + if (FD_ISSET(tls_out.active.sock, &rfds)) + if ((rc = tls_read(ct_ctx, buf, bsize)) <= 0) + { + fd_bits &= ~1; + FD_CLR(tls_out.active.sock, &rfds); + shutdown(pfd[0], SHUT_WR); + timeout = 5; + } + else + { + for (nbytes = 0; rc - nbytes > 0; nbytes += i) + if ((i = write(pfd[0], buf + nbytes, rc - nbytes)) < 0) goto done; + } + else if (fd_bits & 1) + FD_SET(tls_out.active.sock, &rfds); + + /* handle outbound data */ + if (FD_ISSET(pfd[0], &rfds)) + if ((rc = read(pfd[0], buf, bsize)) <= 0) + { + fd_bits = 0; + tls_close(ct_ctx, TLS_SHUTDOWN_NOWAIT); + ct_ctx = NULL; + } + else + { + for (nbytes = 0; rc - nbytes > 0; nbytes += i) + if ((i = tls_write(ct_ctx, buf + nbytes, rc - nbytes, FALSE)) < 0) + goto done; + } + else if (fd_bits & 2) + FD_SET(pfd[0], &rfds); + } + +done: + if (f.running_in_test_harness) millisleep(100); /* let logging complete */ + exim_exit(0, US"TLS proxy"); +} +#endif + + +/************************************************* +* Deliver address list to given host * +*************************************************/ + +/* If continue_hostname is not null, we get here only when continuing to +deliver down an existing channel. The channel was passed as the standard +input. TLS is never active on a passed channel; the previous process always +closes it down before passing the connection on. + +Otherwise, we have to make a connection to the remote host, and do the +initial protocol exchange. + +When running as an MUA wrapper, if the sender or any recipient is rejected, +temporarily or permanently, we force failure for all recipients. + +Arguments: + addrlist chain of potential addresses to deliver; only those whose + transport_return field is set to PENDING_DEFER are currently + being processed; others should be skipped - they have either + been delivered to an earlier host or IP address, or been + failed by one of them. + host host to deliver to + host_af AF_INET or AF_INET6 + defport default TCP/IP port to use if host does not specify, in host + byte order + interface interface to bind to, or NULL + tblock transport instance block + message_defer set TRUE if yield is OK, but all addresses were deferred + because of a non-recipient, non-host failure, that is, a + 4xx response to MAIL FROM, DATA, or ".". This is a defer + that is specific to the message. + suppress_tls if TRUE, don't attempt a TLS connection - this is set for + a second attempt after TLS initialization fails + +Returns: OK - the connection was made and the delivery attempted; + the result for each address is in its data block. + DEFER - the connection could not be made, or something failed + while setting up the SMTP session, or there was a + non-message-specific error, such as a timeout. + ERROR - a filter command is specified for this transport, + and there was a problem setting it up; OR helo_data + or add_headers or authenticated_sender is specified + for this transport, and the string failed to expand +*/ + +static int +smtp_deliver(address_item *addrlist, host_item *host, int host_af, int defport, + uschar *interface, transport_instance *tblock, + BOOL *message_defer, BOOL suppress_tls) +{ +address_item *addr; +smtp_transport_options_block * ob = SOB tblock->options_block; +int yield = OK; +int save_errno; +int rc; +struct timeval start_delivery_time; + +BOOL pass_message = FALSE; +uschar *message = NULL; +uschar new_message_id[MESSAGE_ID_LENGTH + 1]; + +smtp_context sx; + +gettimeofday(&start_delivery_time, NULL); +suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */ +*message_defer = FALSE; + +sx.addrlist = addrlist; +sx.conn_args.host = host; +sx.conn_args.host_af = host_af, +sx.port = defport; +sx.conn_args.interface = interface; +sx.helo_data = NULL; +sx.conn_args.tblock = tblock; +sx.verify = FALSE; +sx.sync_addr = sx.first_addr = addrlist; + +/* Get the channel set up ready for a message (MAIL FROM being the next +SMTP command to send */ + +if ((rc = smtp_setup_conn(&sx, suppress_tls)) != OK) + return rc; + +/* If there is a filter command specified for this transport, we can now +set it up. This cannot be done until the identify of the host is known. */ + +if (tblock->filter_command) + { + transport_filter_timeout = tblock->filter_timeout; + + /* On failure, copy the error to all addresses, abandon the SMTP call, and + yield ERROR. */ + + if (!transport_set_up_command(&transport_filter_argv, + tblock->filter_command, TRUE, DEFER, addrlist, + string_sprintf("%.50s transport", tblock->name), NULL)) + { + set_errno_nohost(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER, + FALSE); + yield = ERROR; + goto SEND_QUIT; + } + + if ( transport_filter_argv + && *transport_filter_argv + && **transport_filter_argv + && sx.peer_offered & OPTION_CHUNKING + ) + { + sx.peer_offered &= ~OPTION_CHUNKING; + DEBUG(D_transport) debug_printf("CHUNKING not usable due to transport filter\n"); + } + } + +/* For messages that have more than the maximum number of envelope recipients, +we want to send several transactions down the same SMTP connection. (See +comments in deliver.c as to how this reconciles, heuristically, with +remote_max_parallel.) This optimization was added to Exim after the following +code was already working. The simplest way to put it in without disturbing the +code was to use a goto to jump back to this point when there is another +transaction to handle. */ + +SEND_MESSAGE: +sx.from_addr = return_path; +sx.sync_addr = sx.first_addr; +sx.ok = FALSE; +sx.send_rset = TRUE; +sx.completed_addr = FALSE; + + +/* If we are a continued-connection-after-verify the MAIL and RCPT +commands were already sent; do not re-send but do mark the addrs as +having been accepted up to RCPT stage. A traditional cont-conn +always has a sequence number greater than one. */ + +if (continue_hostname && continue_sequence == 1) + { + address_item * addr; + + sx.peer_offered = smtp_peer_options; + sx.pending_MAIL = FALSE; + sx.ok = TRUE; + sx.next_addr = NULL; + + for (addr = addrlist; addr; addr = addr->next) + addr->transport_return = PENDING_OK; + } +else + { + /* Initiate a message transfer. */ + + switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield)) + { + case 0: break; + case -1: case -2: goto RESPONSE_FAILED; + case -3: goto END_OFF; + case -4: goto SEND_QUIT; + default: goto SEND_FAILED; + } + + /* If we are an MUA wrapper, abort if any RCPTs were rejected, either + permanently or temporarily. We should have flushed and synced after the last + RCPT. */ + + if (mua_wrapper) + { + address_item * a; + unsigned cnt; + + for (a = sx.first_addr, cnt = 0; a && cnt < sx.max_rcpt; a = a->next, cnt++) + if (a->transport_return != PENDING_OK) + { + /*XXX could we find a better errno than 0 here? */ + set_errno_nohost(addrlist, 0, a->message, FAIL, + testflag(a, af_pass_message)); + sx.ok = FALSE; + break; + } + } + } + +/* If ok is TRUE, we know we have got at least one good recipient, and must now +send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still +have a good recipient buffered up if we are pipelining. We don't want to waste +time sending DATA needlessly, so we only send it if either ok is TRUE or if we +are pipelining. The responses are all handled by sync_responses(). +If using CHUNKING, do not send a BDAT until we know how big a chunk we want +to send is. */ + +if ( !(sx.peer_offered & OPTION_CHUNKING) + && (sx.ok || (pipelining_active && !mua_wrapper))) + { + int count = smtp_write_command(&sx, SCMD_FLUSH, "DATA\r\n"); + + if (count < 0) goto SEND_FAILED; + switch(sync_responses(&sx, count, sx.ok ? +1 : -1)) + { + case 3: sx.ok = TRUE; /* 2xx & 5xx => OK & progress made */ + case 2: sx.completed_addr = TRUE; /* 5xx (only) => progress made */ + break; + + case 1: sx.ok = TRUE; /* 2xx (only) => OK, but if LMTP, */ + if (!sx.lmtp) sx.completed_addr = TRUE; /* can't tell about progress yet */ + case 0: break; /* No 2xx or 5xx, but no probs */ + + case -1: goto END_OFF; /* Timeout on RCPT */ + +#ifdef EXPERIMENTAL_PIPE_CONNECT + case -4: HDEBUG(D_transport) + debug_printf("failed reaping pipelined cmd responses\n"); +#endif + default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */ + } + pipelining_active = FALSE; + data_command = string_copy(big_buffer); /* Save for later error message */ + } + +/* If there were no good recipients (but otherwise there have been no +problems), just set ok TRUE, since we have handled address-specific errors +already. Otherwise, it's OK to send the message. Use the check/escape mechanism +for handling the SMTP dot-handling protocol, flagging to apply to headers as +well as body. Set the appropriate timeout value to be used for each chunk. +(Haven't been able to make it work using select() for writing yet.) */ + +if (!(sx.peer_offered & OPTION_CHUNKING) && !sx.ok) + { + /* Save the first address of the next batch. */ + sx.first_addr = sx.next_addr; + + sx.ok = TRUE; + } +else + { + transport_ctx tctx = { + .u = {.fd = sx.cctx.sock}, /*XXX will this need TLS info? */ + .tblock = tblock, + .addr = addrlist, + .check_string = US".", + .escape_string = US"..", /* Escaping strings */ + .options = + topt_use_crlf | topt_escape_headers + | (tblock->body_only ? topt_no_headers : 0) + | (tblock->headers_only ? topt_no_body : 0) + | (tblock->return_path_add ? topt_add_return_path : 0) + | (tblock->delivery_date_add ? topt_add_delivery_date : 0) + | (tblock->envelope_to_add ? topt_add_envelope_to : 0) + }; + + /* If using CHUNKING we need a callback from the generic transport + support to us, for the sending of BDAT smtp commands and the reaping + of responses. The callback needs a whole bunch of state so set up + a transport-context structure to be passed around. */ + + if (sx.peer_offered & OPTION_CHUNKING) + { + tctx.check_string = tctx.escape_string = NULL; + tctx.options |= topt_use_bdat; + tctx.chunk_cb = smtp_chunk_cmd_callback; + sx.pending_BDAT = FALSE; + sx.good_RCPT = sx.ok; + sx.cmd_count = 0; + tctx.smtp_context = &sx; + } + else + tctx.options |= topt_end_dot; + + /* Save the first address of the next batch. */ + sx.first_addr = sx.next_addr; + + /* Responses from CHUNKING commands go in buffer. Otherwise, + there has not been a response. */ + + sx.buffer[0] = 0; + + sigalrm_seen = FALSE; + transport_write_timeout = ob->data_timeout; + smtp_command = US"sending data block"; /* For error messages */ + DEBUG(D_transport|D_v) + if (sx.peer_offered & OPTION_CHUNKING) + debug_printf(" will write message using CHUNKING\n"); + else + debug_printf(" SMTP>> writing message and terminating \".\"\n"); + transport_count = 0; + +#ifndef DISABLE_DKIM + dkim_exim_sign_init(); +# ifdef EXPERIMENTAL_ARC + { + uschar * s = ob->arc_sign; + if (s) + { + if (!(ob->dkim.arc_signspec = s = expand_string(s))) + { + if (!f.expand_string_forcedfail) + { + message = US"failed to expand arc_sign"; + sx.ok = FALSE; + goto SEND_FAILED; + } + } + else if (*s) + { + /* Ask dkim code to hash the body for ARC */ + (void) arc_ams_setup_sign_bodyhash(); + ob->dkim.force_bodyhash = TRUE; + } + } + } +# endif + sx.ok = dkim_transport_write_message(&tctx, &ob->dkim, CUSS &message); +#else + sx.ok = transport_write_message(&tctx, 0); +#endif + + /* transport_write_message() uses write() because it is called from other + places to write to non-sockets. This means that under some OS (e.g. Solaris) + it can exit with "Broken pipe" as its error. This really means that the + socket got closed at the far end. */ + + transport_write_timeout = 0; /* for subsequent transports */ + + /* Failure can either be some kind of I/O disaster (including timeout), + or the failure of a transport filter or the expansion of added headers. + Or, when CHUNKING, it can be a protocol-detected failure. */ + + if (!sx.ok) + if (message) goto SEND_FAILED; + else goto RESPONSE_FAILED; + + /* We used to send the terminating "." explicitly here, but because of + buffering effects at both ends of TCP/IP connections, you don't gain + anything by keeping it separate, so it might as well go in the final + data buffer for efficiency. This is now done by setting the topt_end_dot + flag above. */ + + smtp_command = US"end of data"; + + if (sx.peer_offered & OPTION_CHUNKING && sx.cmd_count > 1) + { + /* Reap any outstanding MAIL & RCPT commands, but not a DATA-go-ahead */ + switch(sync_responses(&sx, sx.cmd_count-1, 0)) + { + case 3: sx.ok = TRUE; /* 2xx & 5xx => OK & progress made */ + case 2: sx.completed_addr = TRUE; /* 5xx (only) => progress made */ + break; + + case 1: sx.ok = TRUE; /* 2xx (only) => OK, but if LMTP, */ + if (!sx.lmtp) sx.completed_addr = TRUE; /* can't tell about progress yet */ + case 0: break; /* No 2xx or 5xx, but no probs */ + + case -1: goto END_OFF; /* Timeout on RCPT */ + +#ifdef EXPERIMENTAL_PIPE_CONNECT + case -4: HDEBUG(D_transport) + debug_printf("failed reaping pipelined cmd responses\n"); +#endif + default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */ + } + } + +#ifndef DISABLE_PRDR + /* For PRDR we optionally get a partial-responses warning followed by the + individual responses, before going on with the overall response. If we don't + get the warning then deal with per non-PRDR. */ + + if(sx.prdr_active) + { + sx.ok = smtp_read_response(&sx, sx.buffer, sizeof(sx.buffer), '3', ob->final_timeout); + if (!sx.ok && errno == 0) switch(sx.buffer[0]) + { + case '2': sx.prdr_active = FALSE; + sx.ok = TRUE; + break; + case '4': errno = ERRNO_DATA4XX; + addrlist->more_errno |= + ((sx.buffer[1] - '0')*10 + sx.buffer[2] - '0') << 8; + break; + } + } + else +#endif + + /* For non-PRDR SMTP, we now read a single response that applies to the + whole message. If it is OK, then all the addresses have been delivered. */ + + if (!sx.lmtp) + { + sx.ok = smtp_read_response(&sx, sx.buffer, sizeof(sx.buffer), '2', + ob->final_timeout); + if (!sx.ok && errno == 0 && sx.buffer[0] == '4') + { + errno = ERRNO_DATA4XX; + addrlist->more_errno |= ((sx.buffer[1] - '0')*10 + sx.buffer[2] - '0') << 8; + } + } + + /* For LMTP, we get back a response for every RCPT command that we sent; + some may be accepted and some rejected. For those that get a response, their + status is fixed; any that are accepted have been handed over, even if later + responses crash - at least, that's how I read RFC 2033. + + If all went well, mark the recipient addresses as completed, record which + host/IPaddress they were delivered to, and cut out RSET when sending another + message down the same channel. Write the completed addresses to the journal + now so that they are recorded in case there is a crash of hardware or + software before the spool gets updated. Also record the final SMTP + confirmation if needed (for SMTP only). */ + + if (sx.ok) + { + int flag = '='; + struct timeval delivery_time; + int len; + uschar * conf = NULL; + + timesince(&delivery_time, &start_delivery_time); + sx.send_rset = FALSE; + pipelining_active = FALSE; + + /* Set up confirmation if needed - applies only to SMTP */ + + if ( +#ifdef DISABLE_EVENT + LOGGING(smtp_confirmation) && +#endif + !sx.lmtp + ) + { + const uschar *s = string_printing(sx.buffer); + /* deconst cast ok here as string_printing was checked to have alloc'n'copied */ + conf = (s == sx.buffer)? US string_copy(s) : US s; + } + + /* Process all transported addresses - for LMTP or PRDR, read a status for + each one. */ + + for (addr = addrlist; addr != sx.first_addr; addr = addr->next) + { + if (addr->transport_return != PENDING_OK) continue; + + /* LMTP - if the response fails badly (e.g. timeout), use it for all the + remaining addresses. Otherwise, it's a return code for just the one + address. For temporary errors, add a retry item for the address so that + it doesn't get tried again too soon. */ + +#ifndef DISABLE_PRDR + if (sx.lmtp || sx.prdr_active) +#else + if (sx.lmtp) +#endif + { + if (!smtp_read_response(&sx, sx.buffer, sizeof(sx.buffer), '2', + ob->final_timeout)) + { + if (errno != 0 || sx.buffer[0] == 0) goto RESPONSE_FAILED; + addr->message = string_sprintf( +#ifndef DISABLE_PRDR + "%s error after %s: %s", sx.prdr_active ? "PRDR":"LMTP", +#else + "LMTP error after %s: %s", +#endif + data_command, string_printing(sx.buffer)); + setflag(addr, af_pass_message); /* Allow message to go to user */ + if (sx.buffer[0] == '5') + addr->transport_return = FAIL; + else + { + errno = ERRNO_DATA4XX; + addr->more_errno |= ((sx.buffer[1] - '0')*10 + sx.buffer[2] - '0') << 8; + addr->transport_return = DEFER; +#ifndef DISABLE_PRDR + if (!sx.prdr_active) +#endif + retry_add_item(addr, addr->address_retry_key, 0); + } + continue; + } + sx.completed_addr = TRUE; /* NOW we can set this flag */ + if (LOGGING(smtp_confirmation)) + { + const uschar *s = string_printing(sx.buffer); + /* deconst cast ok here as string_printing was checked to have alloc'n'copied */ + conf = (s == sx.buffer) ? US string_copy(s) : US s; + } + } + + /* SMTP, or success return from LMTP for this address. Pass back the + actual host that was used. */ + + addr->transport_return = OK; + addr->more_errno = delivery_time.tv_sec; + addr->delivery_usec = delivery_time.tv_usec; + addr->host_used = host; + addr->special_action = flag; + addr->message = conf; + + if (tcp_out_fastopen) + { + setflag(addr, af_tcp_fastopen_conn); + if (tcp_out_fastopen >= TFO_USED_NODATA) setflag(addr, af_tcp_fastopen); + if (tcp_out_fastopen >= TFO_USED_DATA) setflag(addr, af_tcp_fastopen_data); + } + if (sx.pipelining_used) setflag(addr, af_pipelining); +#ifdef EXPERIMENTAL_PIPE_CONNECT + if (sx.early_pipe_active) setflag(addr, af_early_pipe); +#endif +#ifndef DISABLE_PRDR + if (sx.prdr_active) setflag(addr, af_prdr_used); +#endif + if (sx.peer_offered & OPTION_CHUNKING) setflag(addr, af_chunking_used); + flag = '-'; + +#ifndef DISABLE_PRDR + if (!sx.prdr_active) +#endif + { + /* Update the journal. For homonymic addresses, use the base address plus + the transport name. See lots of comments in deliver.c about the reasons + for the complications when homonyms are involved. Just carry on after + write error, as it may prove possible to update the spool file later. */ + + if (testflag(addr, af_homonym)) + sprintf(CS sx.buffer, "%.500s/%s\n", addr->unique + 3, tblock->name); + else + sprintf(CS sx.buffer, "%.500s\n", addr->unique); + + DEBUG(D_deliver) debug_printf("S:journalling %s\n", sx.buffer); + len = Ustrlen(CS sx.buffer); + if (write(journal_fd, sx.buffer, len) != len) + log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for " + "%s: %s", sx.buffer, strerror(errno)); + } + } + +#ifndef DISABLE_PRDR + if (sx.prdr_active) + { + const uschar * overall_message; + + /* PRDR - get the final, overall response. For any non-success + upgrade all the address statuses. */ + + sx.ok = smtp_read_response(&sx, sx.buffer, sizeof(sx.buffer), '2', + ob->final_timeout); + if (!sx.ok) + { + if(errno == 0 && sx.buffer[0] == '4') + { + errno = ERRNO_DATA4XX; + addrlist->more_errno |= ((sx.buffer[1] - '0')*10 + sx.buffer[2] - '0') << 8; + } + for (addr = addrlist; addr != sx.first_addr; addr = addr->next) + if (sx.buffer[0] == '5' || addr->transport_return == OK) + addr->transport_return = PENDING_OK; /* allow set_errno action */ + goto RESPONSE_FAILED; + } + + /* Append the overall response to the individual PRDR response for logging + and update the journal, or setup retry. */ + + overall_message = string_printing(sx.buffer); + for (addr = addrlist; addr != sx.first_addr; addr = addr->next) + if (addr->transport_return == OK) + addr->message = string_sprintf("%s\\n%s", addr->message, overall_message); + + for (addr = addrlist; addr != sx.first_addr; addr = addr->next) + if (addr->transport_return == OK) + { + if (testflag(addr, af_homonym)) + sprintf(CS sx.buffer, "%.500s/%s\n", addr->unique + 3, tblock->name); + else + sprintf(CS sx.buffer, "%.500s\n", addr->unique); + + DEBUG(D_deliver) debug_printf("journalling(PRDR) %s\n", sx.buffer); + len = Ustrlen(CS sx.buffer); + if (write(journal_fd, sx.buffer, len) != len) + log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for " + "%s: %s", sx.buffer, strerror(errno)); + } + else if (addr->transport_return == DEFER) + retry_add_item(addr, addr->address_retry_key, -2); + } +#endif + + /* Ensure the journal file is pushed out to disk. */ + + if (EXIMfsync(journal_fd) < 0) + log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s", + strerror(errno)); + } + } + + +/* Handle general (not specific to one address) failures here. The value of ok +is used to skip over this code on the falling through case. A timeout causes a +deferral. Other errors may defer or fail according to the response code, and +may set up a special errno value, e.g. after connection chopped, which is +assumed if errno == 0 and there is no text in the buffer. If control reaches +here during the setting up phase (i.e. before MAIL FROM) then always defer, as +the problem is not related to this specific message. */ + +if (!sx.ok) + { + int code, set_rc; + uschar * set_message; + + RESPONSE_FAILED: + { + save_errno = errno; + message = NULL; + sx.send_quit = check_response(host, &save_errno, addrlist->more_errno, + sx.buffer, &code, &message, &pass_message); + goto FAILED; + } + + SEND_FAILED: + { + save_errno = errno; + code = '4'; + message = string_sprintf("send() to %s [%s] failed: %s", + host->name, host->address, message ? message : US strerror(save_errno)); + sx.send_quit = FALSE; + goto FAILED; + } + + FAILED: + { + BOOL message_error; + + sx.ok = FALSE; /* For when reached by GOTO */ + set_message = message; + + /* We want to handle timeouts after MAIL or "." and loss of connection after + "." specially. They can indicate a problem with the sender address or with + the contents of the message rather than a real error on the connection. These + cases are treated in the same way as a 4xx response. This next bit of code + does the classification. */ + + switch(save_errno) + { + case 0: + case ERRNO_MAIL4XX: + case ERRNO_DATA4XX: + message_error = TRUE; + break; + + case ETIMEDOUT: + message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 || + Ustrncmp(smtp_command,"end ",4) == 0; + break; + + case ERRNO_SMTPCLOSED: + message_error = Ustrncmp(smtp_command,"end ",4) == 0; + break; + + default: + message_error = FALSE; + break; + } + + /* Handle the cases that are treated as message errors. These are: + + (a) negative response or timeout after MAIL + (b) negative response after DATA + (c) negative response or timeout or dropped connection after "." + (d) utf8 support required and not offered + + It won't be a negative response or timeout after RCPT, as that is dealt + with separately above. The action in all cases is to set an appropriate + error code for all the addresses, but to leave yield set to OK because the + host itself has not failed. Of course, it might in practice have failed + when we've had a timeout, but if so, we'll discover that at the next + delivery attempt. For a temporary error, set the message_defer flag, and + write to the logs for information if this is not the last host. The error + for the last host will be logged as part of the address's log line. */ + + if (message_error) + { + if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */ + + /* If there's an errno, the message contains just the identity of + the host. */ + + if (code == '5') + set_rc = FAIL; + else /* Anything other than 5 is treated as temporary */ + { + set_rc = DEFER; + if (save_errno > 0) + message = US string_sprintf("%s: %s", message, strerror(save_errno)); + + write_logs(host, message, sx.first_addr ? sx.first_addr->basic_errno : 0); + + *message_defer = TRUE; + } + } + + /* Otherwise, we have an I/O error or a timeout other than after MAIL or + ".", or some other transportation error. We defer all addresses and yield + DEFER, except for the case of failed add_headers expansion, or a transport + filter failure, when the yield should be ERROR, to stop it trying other + hosts. */ + + else + { +#ifdef EXPERIMENTAL_PIPE_CONNECT + /* If we were early-pipelinng and the actual EHLO response did not match + the cached value we assumed, we could have detected it and passed a + custom errno through to here. It would be nice to RSET and retry right + away, but to reliably do that we eould need an extra synch point before + we committed to data and that would discard half the gained roundrips. + Or we could summarily drop the TCP connection. but that is also ugly. + Instead, we ignore the possibility (having freshened the cache) and rely + on the server telling us with a nonmessage error if we have tried to + do something it no longer supports. */ +#endif + set_rc = DEFER; + yield = (save_errno == ERRNO_CHHEADER_FAIL || + save_errno == ERRNO_FILTER_FAIL) ? ERROR : DEFER; + } + } + + set_errno(addrlist, save_errno, set_message, set_rc, pass_message, host +#ifdef EXPERIMENTAL_DSN_INFO + , sx.smtp_greeting, sx.helo_response +#endif + ); + } + + +/* If all has gone well, send_quit will be set TRUE, implying we can end the +SMTP session tidily. However, if there were too many addresses to send in one +message (indicated by first_addr being non-NULL) we want to carry on with the +rest of them. Also, it is desirable to send more than one message down the SMTP +connection if there are several waiting, provided we haven't already sent so +many as to hit the configured limit. The function transport_check_waiting looks +for a waiting message and returns its id. Then transport_pass_socket tries to +set up a continued delivery by passing the socket on to another process. The +variable send_rset is FALSE if a message has just been successfully transferred. + +If we are already sending down a continued channel, there may be further +addresses not yet delivered that are aimed at the same host, but which have not +been passed in this run of the transport. In this case, continue_more will be +true, and all we should do is send RSET if necessary, and return, leaving the +channel open. + +However, if no address was disposed of, i.e. all addresses got 4xx errors, we +do not want to continue with other messages down the same channel, because that +can lead to looping between two or more messages, all with the same, +temporarily failing address(es). [The retry information isn't updated yet, so +new processes keep on trying.] We probably also don't want to try more of this +message's addresses either. + +If we have started a TLS session, we have to end it before passing the +connection to a new process. However, not all servers can handle this (Exim +can), so we do not pass such a connection on if the host matches +hosts_nopass_tls. */ + +DEBUG(D_transport) + debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d " + "yield=%d first_address is %sNULL\n", sx.ok, sx.send_quit, + sx.send_rset, f.continue_more, yield, sx.first_addr ? "not " : ""); + +if (sx.completed_addr && sx.ok && sx.send_quit) + { + BOOL more; + smtp_compare_t t_compare; + + t_compare.tblock = tblock; + t_compare.current_sender_address = sender_address; + + if ( sx.first_addr != NULL + || f.continue_more + || ( +#ifdef SUPPORT_TLS + ( tls_out.active.sock < 0 && !continue_proxy_cipher + || verify_check_given_host(CUSS &ob->hosts_nopass_tls, host) != OK + ) + && +#endif + transport_check_waiting(tblock->name, host->name, + tblock->connection_max_messages, new_message_id, &more, + (oicf)smtp_are_same_identities, (void*)&t_compare) + ) ) + { + uschar *msg; + BOOL pass_message; + + if (sx.send_rset) + if (! (sx.ok = smtp_write_command(&sx, SCMD_FLUSH, "RSET\r\n") >= 0)) + { + msg = US string_sprintf("send() to %s [%s] failed: %s", host->name, + host->address, strerror(errno)); + sx.send_quit = FALSE; + } + else if (! (sx.ok = smtp_read_response(&sx, sx.buffer, sizeof(sx.buffer), + '2', ob->command_timeout))) + { + int code; + sx.send_quit = check_response(host, &errno, 0, sx.buffer, &code, &msg, + &pass_message); + if (!sx.send_quit) + { + DEBUG(D_transport) debug_printf("H=%s [%s] %s\n", + host->name, host->address, msg); + } + } + + /* Either RSET was not needed, or it succeeded */ + + if (sx.ok) + { +#ifdef SUPPORT_TLS + int pfd[2]; +#endif + int socket_fd = sx.cctx.sock; + + + if (sx.first_addr != NULL) /* More addresses still to be sent */ + { /* in this run of the transport */ + continue_sequence++; /* Causes * in logging */ + goto SEND_MESSAGE; + } + + /* Unless caller said it already has more messages listed for this host, + pass the connection on to a new Exim process (below, the call to + transport_pass_socket). If the caller has more ready, just return with + the connection still open. */ + +#ifdef SUPPORT_TLS + if (tls_out.active.sock >= 0) + if ( f.continue_more + || verify_check_given_host(CUSS &ob->hosts_noproxy_tls, host) == OK) + { + /* Before passing the socket on, or returning to caller with it still + open, we must shut down TLS. Not all MTAs allow for the continuation + of the SMTP session when TLS is shut down. We test for this by sending + a new EHLO. If we don't get a good response, we don't attempt to pass + the socket on. */ + + tls_close(sx.cctx.tls_ctx, TLS_SHUTDOWN_WAIT); + sx.cctx.tls_ctx = NULL; + smtp_peer_options = smtp_peer_options_wrap; + sx.ok = !sx.smtps + && smtp_write_command(&sx, SCMD_FLUSH, "EHLO %s\r\n", sx.helo_data) + >= 0 + && smtp_read_response(&sx, sx.buffer, sizeof(sx.buffer), + '2', ob->command_timeout); + + if (sx.ok && f.continue_more) + return yield; /* More addresses for another run */ + } + else + { + /* Set up a pipe for proxying TLS for the new transport process */ + + smtp_peer_options |= OPTION_TLS; + if (sx.ok = (socketpair(AF_UNIX, SOCK_STREAM, 0, pfd) == 0)) + socket_fd = pfd[1]; + else + set_errno(sx.first_addr, errno, US"internal allocation problem", + DEFER, FALSE, host +# ifdef EXPERIMENTAL_DSN_INFO + , sx.smtp_greeting, sx.helo_response +# endif + ); + } + else +#endif + if (f.continue_more) + return yield; /* More addresses for another run */ + + /* If the socket is successfully passed, we mustn't send QUIT (or + indeed anything!) from here. */ + +/*XXX DSN_INFO: assume likely to do new HELO; but for greet we'll want to +propagate it from the initial +*/ + if (sx.ok && transport_pass_socket(tblock->name, host->name, + host->address, new_message_id, socket_fd)) + { + sx.send_quit = FALSE; + + /* We have passed the client socket to a fresh transport process. + If TLS is still active, we need to proxy it for the transport we + just passed the baton to. Fork a child to to do it, and return to + get logging done asap. Which way to place the work makes assumptions + about post-fork prioritisation which may not hold on all platforms. */ +#ifdef SUPPORT_TLS + if (tls_out.active.sock >= 0) + { + int pid = fork(); + if (pid == 0) /* child; fork again to disconnect totally */ + { + if (f.running_in_test_harness) millisleep(100); /* let parent debug out */ + /* does not return */ + smtp_proxy_tls(sx.cctx.tls_ctx, sx.buffer, sizeof(sx.buffer), pfd, + ob->command_timeout); + } + + if (pid > 0) /* parent */ + { + DEBUG(D_transport) debug_printf("proxy-proc inter-pid %d\n", pid); + close(pfd[0]); + /* tidy the inter-proc to disconn the proxy proc */ + waitpid(pid, NULL, 0); + tls_close(sx.cctx.tls_ctx, TLS_NO_SHUTDOWN); + sx.cctx.tls_ctx = NULL; + (void)close(sx.cctx.sock); + sx.cctx.sock = -1; + continue_transport = NULL; + continue_hostname = NULL; + return yield; + } + log_write(0, LOG_PANIC_DIE, "fork failed"); + } +#endif + } + } + + /* If RSET failed and there are addresses left, they get deferred. */ + else + set_errno(sx.first_addr, errno, msg, DEFER, FALSE, host +#ifdef EXPERIMENTAL_DSN_INFO + , sx.smtp_greeting, sx.helo_response +#endif + ); + } + } + +/* End off tidily with QUIT unless the connection has died or the socket has +been passed to another process. There has been discussion on the net about what +to do after sending QUIT. The wording of the RFC suggests that it is necessary +to wait for a response, but on the other hand, there isn't anything one can do +with an error response, other than log it. Exim used to do that. However, +further discussion suggested that it is positively advantageous not to wait for +the response, but to close the session immediately. This is supposed to move +the TCP/IP TIME_WAIT state from the server to the client, thereby removing some +load from the server. (Hosts that are both servers and clients may not see much +difference, of course.) Further discussion indicated that this was safe to do +on Unix systems which have decent implementations of TCP/IP that leave the +connection around for a while (TIME_WAIT) after the application has gone away. +This enables the response sent by the server to be properly ACKed rather than +timed out, as can happen on broken TCP/IP implementations on other OS. + +This change is being made on 31-Jul-98. After over a year of trouble-free +operation, the old commented-out code was removed on 17-Sep-99. */ + +SEND_QUIT: +if (sx.send_quit) (void)smtp_write_command(&sx, SCMD_FLUSH, "QUIT\r\n"); + +END_OFF: + +#ifdef SUPPORT_TLS +tls_close(sx.cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT); +sx.cctx.tls_ctx = NULL; +#endif + +/* Close the socket, and return the appropriate value, first setting +works because the NULL setting is passed back to the calling process, and +remote_max_parallel is forced to 1 when delivering over an existing connection, + +If all went well and continue_more is set, we shouldn't actually get here if +there are further addresses, as the return above will be taken. However, +writing RSET might have failed, or there may be other addresses whose hosts are +specified in the transports, and therefore not visible at top level, in which +case continue_more won't get set. */ + +HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n"); +if (sx.send_quit) + { + shutdown(sx.cctx.sock, SHUT_WR); + millisleep(f.running_in_test_harness ? 200 : 20); + if (fcntl(sx.cctx.sock, F_SETFL, O_NONBLOCK) == 0) + for (rc = 16; read(sx.cctx.sock, sx.inbuffer, sizeof(sx.inbuffer)) > 0 && rc > 0;) + rc--; /* drain socket */ + } +(void)close(sx.cctx.sock); + +#ifndef DISABLE_EVENT +(void) event_raise(tblock->event_action, US"tcp:close", NULL); +#endif + +continue_transport = NULL; +continue_hostname = NULL; +return yield; +} + + + + +/************************************************* +* Closedown entry point * +*************************************************/ + +/* This function is called when exim is passed an open smtp channel +from another incarnation, but the message which it has been asked +to deliver no longer exists. The channel is on stdin. + +We might do fancy things like looking for another message to send down +the channel, but if the one we sought has gone, it has probably been +delivered by some other process that itself will seek further messages, +so just close down our connection. + +Argument: pointer to the transport instance block +Returns: nothing +*/ + +void +smtp_transport_closedown(transport_instance *tblock) +{ +smtp_transport_options_block * ob = SOB tblock->options_block; +client_conn_ctx cctx; +smtp_context sx; +uschar buffer[256]; +uschar inbuffer[4096]; +uschar outbuffer[16]; + +/*XXX really we need an active-smtp-client ctx, rather than assuming stdout */ +cctx.sock = fileno(stdin); +cctx.tls_ctx = cctx.sock == tls_out.active.sock ? tls_out.active.tls_ctx : NULL; + +sx.inblock.cctx = &cctx; +sx.inblock.buffer = inbuffer; +sx.inblock.buffersize = sizeof(inbuffer); +sx.inblock.ptr = inbuffer; +sx.inblock.ptrend = inbuffer; + +sx.outblock.cctx = &cctx; +sx.outblock.buffersize = sizeof(outbuffer); +sx.outblock.buffer = outbuffer; +sx.outblock.ptr = outbuffer; +sx.outblock.cmd_count = 0; +sx.outblock.authenticating = FALSE; + +(void)smtp_write_command(&sx, SCMD_FLUSH, "QUIT\r\n"); +(void)smtp_read_response(&sx, buffer, sizeof(buffer), '2', ob->command_timeout); +(void)close(cctx.sock); +} + + + +/************************************************* +* Prepare addresses for delivery * +*************************************************/ + +/* This function is called to flush out error settings from previous delivery +attempts to other hosts. It also records whether we got here via an MX record +or not in the more_errno field of the address. We are interested only in +addresses that are still marked DEFER - others may have got delivered to a +previously considered IP address. Set their status to PENDING_DEFER to indicate +which ones are relevant this time. + +Arguments: + addrlist the list of addresses + host the host we are delivering to + +Returns: the first address for this delivery +*/ + +static address_item * +prepare_addresses(address_item *addrlist, host_item *host) +{ +address_item *first_addr = NULL; +address_item *addr; +for (addr = addrlist; addr; addr = addr->next) + if (addr->transport_return == DEFER) + { + if (!first_addr) first_addr = addr; + addr->transport_return = PENDING_DEFER; + addr->basic_errno = 0; + addr->more_errno = (host->mx >= 0)? 'M' : 'A'; + addr->message = NULL; +#ifdef SUPPORT_TLS + addr->cipher = NULL; + addr->ourcert = NULL; + addr->peercert = NULL; + addr->peerdn = NULL; + addr->ocsp = OCSP_NOT_REQ; +#endif +#ifdef EXPERIMENTAL_DSN_INFO + addr->smtp_greeting = NULL; + addr->helo_response = NULL; +#endif + } +return first_addr; +} + + + +/************************************************* +* Main entry point * +*************************************************/ + +/* See local README for interface details. As this is a remote transport, it is +given a chain of addresses to be delivered in one connection, if possible. It +always returns TRUE, indicating that each address has its own independent +status set, except if there is a setting up problem, in which case it returns +FALSE. */ + +BOOL +smtp_transport_entry( + transport_instance *tblock, /* data for this instantiation */ + address_item *addrlist) /* addresses we are working on */ +{ +int cutoff_retry; +int defport; +int hosts_defer = 0; +int hosts_fail = 0; +int hosts_looked_up = 0; +int hosts_retry = 0; +int hosts_serial = 0; +int hosts_total = 0; +int total_hosts_tried = 0; +address_item *addr; +BOOL expired = TRUE; +uschar *expanded_hosts = NULL; +uschar *pistring; +uschar *tid = string_sprintf("%s transport", tblock->name); +smtp_transport_options_block *ob = SOB tblock->options_block; +host_item *hostlist = addrlist->host_list; +host_item *host; + +DEBUG(D_transport) + { + debug_printf("%s transport entered\n", tblock->name); + for (addr = addrlist; addr; addr = addr->next) + debug_printf(" %s\n", addr->address); + if (hostlist) + { + debug_printf("hostlist:\n"); + for (host = hostlist; host; host = host->next) + debug_printf(" '%s' IP %s port %d\n", host->name, host->address, host->port); + } + if (continue_hostname) + debug_printf("already connected to %s [%s] (on fd %d)\n", + continue_hostname, continue_host_address, + cutthrough.cctx.sock >= 0 ? cutthrough.cctx.sock : 0); + } + +/* Set the flag requesting that these hosts be added to the waiting +database if the delivery fails temporarily or if we are running with +queue_smtp or a 2-stage queue run. This gets unset for certain +kinds of error, typically those that are specific to the message. */ + +update_waiting = TRUE; + +/* If a host list is not defined for the addresses - they must all have the +same one in order to be passed to a single transport - or if the transport has +a host list with hosts_override set, use the host list supplied with the +transport. It is an error for this not to exist. */ + +#if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_REQUIRETLS) +if (tls_requiretls & REQUIRETLS_MSG) + ob->tls_tempfail_tryclear = FALSE; /*XXX surely we should have a local for this + rather than modifying the transport? */ +#endif + +if (!hostlist || (ob->hosts_override && ob->hosts)) + { + if (!ob->hosts) + { + addrlist->message = string_sprintf("%s transport called with no hosts set", + tblock->name); + addrlist->transport_return = PANIC; + return FALSE; /* Only top address has status */ + } + + DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n", + ob->hosts); + + /* If the transport's host list contains no '$' characters, and we are not + randomizing, it is fixed and therefore a chain of hosts can be built once + and for all, and remembered for subsequent use by other calls to this + transport. If, on the other hand, the host list does contain '$', or we are + randomizing its order, we have to rebuild it each time. In the fixed case, + as the hosts string will never be used again, it doesn't matter that we + replace all the : characters with zeros. */ + + if (!ob->hostlist) + { + uschar *s = ob->hosts; + + if (Ustrchr(s, '$') != NULL) + { + if (!(expanded_hosts = expand_string(s))) + { + addrlist->message = string_sprintf("failed to expand list of hosts " + "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message); + addrlist->transport_return = f.search_find_defer ? DEFER : PANIC; + return FALSE; /* Only top address has status */ + } + DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to " + "\"%s\"\n", s, expanded_hosts); + s = expanded_hosts; + } + else + if (ob->hosts_randomize) s = expanded_hosts = string_copy(s); + + host_build_hostlist(&hostlist, s, ob->hosts_randomize); + + /* Check that the expansion yielded something useful. */ + if (!hostlist) + { + addrlist->message = + string_sprintf("%s transport has empty hosts setting", tblock->name); + addrlist->transport_return = PANIC; + return FALSE; /* Only top address has status */ + } + + /* If there was no expansion of hosts, save the host list for + next time. */ + + if (!expanded_hosts) ob->hostlist = hostlist; + } + + /* This is not the first time this transport has been run in this delivery; + the host list was built previously. */ + + else + hostlist = ob->hostlist; + } + +/* The host list was supplied with the address. If hosts_randomize is set, we +must sort it into a random order if it did not come from MX records and has not +already been randomized (but don't bother if continuing down an existing +connection). */ + +else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continue_hostname) + { + host_item *newlist = NULL; + while (hostlist) + { + host_item *h = hostlist; + hostlist = hostlist->next; + + h->sort_key = random_number(100); + + if (!newlist) + { + h->next = NULL; + newlist = h; + } + else if (h->sort_key < newlist->sort_key) + { + h->next = newlist; + newlist = h; + } + else + { + host_item *hh = newlist; + while (hh->next) + { + if (h->sort_key < hh->next->sort_key) break; + hh = hh->next; + } + h->next = hh->next; + hh->next = h; + } + } + + hostlist = addrlist->host_list = newlist; + } + +/* Sort out the default port. */ + +if (!smtp_get_port(ob->port, addrlist, &defport, tid)) return FALSE; + +/* For each host-plus-IP-address on the list: + +. If this is a continued delivery and the host isn't the one with the + current connection, skip. + +. If the status is unusable (i.e. previously failed or retry checked), skip. + +. If no IP address set, get the address, either by turning the name into + an address, calling gethostbyname if gethostbyname is on, or by calling + the DNS. The DNS may yield multiple addresses, in which case insert the + extra ones into the list. + +. Get the retry data if not previously obtained for this address and set the + field which remembers the state of this address. Skip if the retry time is + not reached. If not, remember whether retry data was found. The retry string + contains both the name and the IP address. + +. Scan the list of addresses and mark those whose status is DEFER as + PENDING_DEFER. These are the only ones that will be processed in this cycle + of the hosts loop. + +. Make a delivery attempt - addresses marked PENDING_DEFER will be tried. + Some addresses may be successfully delivered, others may fail, and yet + others may get temporary errors and so get marked DEFER. + +. The return from the delivery attempt is OK if a connection was made and a + valid SMTP dialogue was completed. Otherwise it is DEFER. + +. If OK, add a "remove" retry item for this host/IPaddress, if any. + +. If fail to connect, or other defer state, add a retry item. + +. If there are any addresses whose status is still DEFER, carry on to the + next host/IPaddress, unless we have tried the number of hosts given + by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that + there is some fancy logic for hosts_max_try that means its limit can be + overstepped in some circumstances. + +If we get to the end of the list, all hosts have deferred at least one address, +or not reached their retry times. If delay_after_cutoff is unset, it requests a +delivery attempt to those hosts whose last try was before the arrival time of +the current message. To cope with this, we have to go round the loop a second +time. After that, set the status and error data for any addresses that haven't +had it set already. */ + +for (cutoff_retry = 0; + expired && cutoff_retry < (ob->delay_after_cutoff ? 1 : 2); + cutoff_retry++) + { + host_item *nexthost = NULL; + int unexpired_hosts_tried = 0; + BOOL continue_host_tried = FALSE; + +retry_non_continued: + for (host = hostlist; + host + && unexpired_hosts_tried < ob->hosts_max_try + && total_hosts_tried < ob->hosts_max_try_hardlimit; + host = nexthost) + { + int rc; + int host_af; + uschar *rs; + BOOL host_is_expired = FALSE; + BOOL message_defer = FALSE; + BOOL some_deferred = FALSE; + address_item *first_addr = NULL; + uschar *interface = NULL; + uschar *retry_host_key = NULL; + uschar *retry_message_key = NULL; + uschar *serialize_key = NULL; + + /* Default next host is next host. :-) But this can vary if the + hosts_max_try limit is hit (see below). It may also be reset if a host + address is looked up here (in case the host was multihomed). */ + + nexthost = host->next; + + /* If the address hasn't yet been obtained from the host name, look it up + now, unless the host is already marked as unusable. If it is marked as + unusable, it means that the router was unable to find its IP address (in + the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and + the lookup failed last time. We don't get this far if *all* MX records + point to non-existent hosts; that is treated as a hard error. + + We can just skip this host entirely. When the hosts came from the router, + the address will timeout based on the other host(s); when the address is + looked up below, there is an explicit retry record added. + + Note that we mustn't skip unusable hosts if the address is not unset; they + may be needed as expired hosts on the 2nd time round the cutoff loop. */ + + if (!host->address) + { + int new_port, flags; + host_item *hh; + + if (host->status >= hstatus_unusable) + { + DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n", + host->name); + continue; + } + + DEBUG(D_transport) debug_printf("getting address for %s\n", host->name); + + /* The host name is permitted to have an attached port. Find it, and + strip it from the name. Just remember it for now. */ + + new_port = host_item_get_port(host); + + /* Count hosts looked up */ + + hosts_looked_up++; + + /* Find by name if so configured, or if it's an IP address. We don't + just copy the IP address, because we need the test-for-local to happen. */ + + flags = HOST_FIND_BY_A | HOST_FIND_BY_AAAA; + if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE; + if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS; + + if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0) + rc = host_find_byname(host, NULL, flags, NULL, TRUE); + else + rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL, + &ob->dnssec, /* domains for request/require */ + NULL, NULL); + + /* Update the host (and any additional blocks, resulting from + multihoming) with a host-specific port, if any. */ + + for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port; + + /* Failure to find the host at this time (usually DNS temporary failure) + is really a kind of routing failure rather than a transport failure. + Therefore we add a retry item of the routing kind, not to stop us trying + to look this name up here again, but to ensure the address gets timed + out if the failures go on long enough. A complete failure at this point + commonly points to a configuration error, but the best action is still + to carry on for the next host. */ + + if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_SECURITY || rc == HOST_FIND_FAILED) + { + retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0); + expired = FALSE; + if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++; + DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)? + "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name); + host->status = hstatus_unusable; + + for (addr = addrlist; addr; addr = addr->next) + { + if (addr->transport_return != DEFER) continue; + addr->basic_errno = ERRNO_UNKNOWNHOST; + addr->message = string_sprintf( + rc == HOST_FIND_SECURITY + ? "lookup of IP address for %s was insecure" + : "failed to lookup IP address for %s", + host->name); + } + continue; + } + + /* If the host is actually the local host, we may have a problem, or + there may be some cunning configuration going on. In the problem case, + log things and give up. The default transport status is already DEFER. */ + + if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost) + { + for (addr = addrlist; addr; addr = addr->next) + { + addr->basic_errno = 0; + addr->message = string_sprintf("%s transport found host %s to be " + "local", tblock->name, host->name); + } + goto END_TRANSPORT; + } + } /* End of block for IP address lookup */ + + /* If this is a continued delivery, we are interested only in the host + which matches the name of the existing open channel. The check is put + here after the local host lookup, in case the name gets expanded as a + result of the lookup. Set expired FALSE, to save the outer loop executing + twice. */ + + if (continue_hostname) + if ( Ustrcmp(continue_hostname, host->name) != 0 + || Ustrcmp(continue_host_address, host->address) != 0 + ) + { + expired = FALSE; + continue; /* With next host */ + } + else + continue_host_tried = TRUE; + + /* Reset the default next host in case a multihomed host whose addresses + are not looked up till just above added to the host list. */ + + nexthost = host->next; + + /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the + domain is in queue_smtp_domains, we don't actually want to attempt any + deliveries. When doing a queue run, queue_smtp_domains is always unset. If + there is a lookup defer in queue_smtp_domains, proceed as if the domain + were not in it. We don't want to hold up all SMTP deliveries! Except when + doing a two-stage queue run, don't do this if forcing. */ + + if ((!f.deliver_force || f.queue_2stage) && (f.queue_smtp || + match_isinlist(addrlist->domain, + (const uschar **)&queue_smtp_domains, 0, + &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK)) + { + expired = FALSE; + for (addr = addrlist; addr; addr = addr->next) + if (addr->transport_return == DEFER) + addr->message = US"domain matches queue_smtp_domains, or -odqs set"; + continue; /* With next host */ + } + + /* Count hosts being considered - purely for an intelligent comment + if none are usable. */ + + hosts_total++; + + /* Set $host and $host address now in case they are needed for the + interface expansion or the serialize_hosts check; they remain set if an + actual delivery happens. */ + + deliver_host = host->name; + deliver_host_address = host->address; + lookup_dnssec_authenticated = host->dnssec == DS_YES ? US"yes" + : host->dnssec == DS_NO ? US"no" + : US""; + + /* Set up a string for adding to the retry key if the port number is not + the standard SMTP port. A host may have its own port setting that overrides + the default. */ + + pistring = string_sprintf(":%d", host->port == PORT_NONE + ? defport : host->port); + if (Ustrcmp(pistring, ":25") == 0) pistring = US""; + + /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface + string is set, even if constant (as different transports can have different + constant settings), we must add it to the key that is used for retries, + because connections to the same host from a different interface should be + treated separately. */ + + host_af = Ustrchr(host->address, ':') == NULL ? AF_INET : AF_INET6; + if ((rs = ob->interface) && *rs) + { + if (!smtp_get_interface(rs, host_af, addrlist, &interface, tid)) + return FALSE; + pistring = string_sprintf("%s/%s", pistring, interface); + } + + /* The first time round the outer loop, check the status of the host by + inspecting the retry data. The second time round, we are interested only + in expired hosts that haven't been tried since this message arrived. */ + + if (cutoff_retry == 0) + { + BOOL incl_ip; + /* Ensure the status of the address is set by checking retry data if + necessary. There may be host-specific retry data (applicable to all + messages) and also data for retries of a specific message at this host. + If either of these retry records are actually read, the keys used are + returned to save recomputing them later. */ + + if (exp_bool(addrlist, US"transport", tblock->name, D_transport, + US"retry_include_ip_address", ob->retry_include_ip_address, + ob->expand_retry_include_ip_address, &incl_ip) != OK) + continue; /* with next host */ + + host_is_expired = retry_check_address(addrlist->domain, host, pistring, + incl_ip, &retry_host_key, &retry_message_key); + + DEBUG(D_transport) debug_printf("%s [%s]%s retry-status = %s\n", host->name, + host->address ? host->address : US"", pistring, + host->status == hstatus_usable ? "usable" + : host->status == hstatus_unusable ? "unusable" + : host->status == hstatus_unusable_expired ? "unusable (expired)" : "?"); + + /* Skip this address if not usable at this time, noting if it wasn't + actually expired, both locally and in the address. */ + + switch (host->status) + { + case hstatus_unusable: + expired = FALSE; + setflag(addrlist, af_retry_skipped); + /* Fall through */ + + case hstatus_unusable_expired: + switch (host->why) + { + case hwhy_retry: hosts_retry++; break; + case hwhy_failed: hosts_fail++; break; + case hwhy_insecure: + case hwhy_deferred: hosts_defer++; break; + } + + /* If there was a retry message key, implying that previously there + was a message-specific defer, we don't want to update the list of + messages waiting for these hosts. */ + + if (retry_message_key) update_waiting = FALSE; + continue; /* With the next host or IP address */ + } + } + + /* Second time round the loop: if the address is set but expired, and + the message is newer than the last try, let it through. */ + + else + { + if ( !host->address + || host->status != hstatus_unusable_expired + || host->last_try > received_time.tv_sec) + continue; + DEBUG(D_transport) debug_printf("trying expired host %s [%s]%s\n", + host->name, host->address, pistring); + host_is_expired = TRUE; + } + + /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired; + it remains TRUE only if all hosts are expired and none are actually tried. + */ + + expired = FALSE; + + /* If this host is listed as one to which access must be serialized, + see if another Exim process has a connection to it, and if so, skip + this host. If not, update the database to record our connection to it + and remember this for later deletion. Do not do any of this if we are + sending the message down a pre-existing connection. */ + + if ( !continue_hostname + && verify_check_given_host(CUSS &ob->serialize_hosts, host) == OK) + { + serialize_key = string_sprintf("host-serialize-%s", host->name); + if (!enq_start(serialize_key, 1)) + { + DEBUG(D_transport) + debug_printf("skipping host %s because another Exim process " + "is connected to it\n", host->name); + hosts_serial++; + continue; + } + } + + /* OK, we have an IP address that is not waiting for its retry time to + arrive (it might be expired) OR (second time round the loop) we have an + expired host that hasn't been tried since the message arrived. Have a go + at delivering the message to it. First prepare the addresses by flushing + out the result of previous attempts, and finding the first address that + is still to be delivered. */ + + first_addr = prepare_addresses(addrlist, host); + + DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n", + message_id, host->name, host->address, addrlist->address, + addrlist->next ? ", ..." : ""); + + set_process_info("delivering %s to %s [%s]%s (%s%s)", + message_id, host->name, host->address, pistring, addrlist->address, + addrlist->next ? ", ..." : ""); + + /* This is not for real; don't do the delivery. If there are + any remaining hosts, list them. */ + + if (f.dont_deliver) + { + host_item *host2; + set_errno_nohost(addrlist, 0, NULL, OK, FALSE); + for (addr = addrlist; addr; addr = addr->next) + { + addr->host_used = host; + addr->special_action = '*'; + addr->message = US"delivery bypassed by -N option"; + } + DEBUG(D_transport) + { + debug_printf("*** delivery by %s transport bypassed by -N option\n" + "*** host and remaining hosts:\n", tblock->name); + for (host2 = host; host2; host2 = host2->next) + debug_printf(" %s [%s]\n", host2->name, + host2->address ? host2->address : US"unset"); + } + rc = OK; + } + + /* This is for real. If the host is expired, we don't count it for + hosts_max_retry. This ensures that all hosts must expire before an address + is timed out, unless hosts_max_try_hardlimit (which protects against + lunatic DNS configurations) is reached. + + If the host is not expired and we are about to hit the hosts_max_retry + limit, check to see if there is a subsequent hosts with a different MX + value. If so, make that the next host, and don't count this one. This is a + heuristic to make sure that different MXs do get tried. With a normal kind + of retry rule, they would get tried anyway when the earlier hosts were + delayed, but if the domain has a "retry every time" type of rule - as is + often used for the the very large ISPs, that won't happen. */ + + else + { + host_item * thost; + /* Make a copy of the host if it is local to this invocation + of the transport. */ + + if (expanded_hosts) + { + thost = store_get(sizeof(host_item)); + *thost = *host; + thost->name = string_copy(host->name); + thost->address = string_copy(host->address); + } + else + thost = host; + + if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try) + { + host_item *h; + DEBUG(D_transport) + debug_printf("hosts_max_try limit reached with this host\n"); + for (h = host; h; h = h->next) if (h->mx != host->mx) + { + nexthost = h; + unexpired_hosts_tried--; + DEBUG(D_transport) debug_printf("however, a higher MX host exists " + "and will be tried\n"); + break; + } + } + + /* Attempt the delivery. */ + + total_hosts_tried++; + rc = smtp_deliver(addrlist, thost, host_af, defport, interface, tblock, + &message_defer, FALSE); + + /* Yield is one of: + OK => connection made, each address contains its result; + message_defer is set for message-specific defers (when all + recipients are marked defer) + DEFER => there was a non-message-specific delivery problem; + ERROR => there was a problem setting up the arguments for a filter, + or there was a problem with expanding added headers + */ + + /* If the result is not OK, there was a non-message-specific problem. + If the result is DEFER, we need to write to the logs saying what happened + for this particular host, except in the case of authentication and TLS + failures, where the log has already been written. If all hosts defer a + general message is written at the end. */ + + if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL + && first_addr->basic_errno != ERRNO_TLSFAILURE) + write_logs(host, first_addr->message, first_addr->basic_errno); + +#ifndef DISABLE_EVENT + if (rc == DEFER) + deferred_event_raise(first_addr, host); +#endif + + /* If STARTTLS was accepted, but there was a failure in setting up the + TLS session (usually a certificate screwup), and the host is not in + hosts_require_tls, and tls_tempfail_tryclear is true, try again, with + TLS forcibly turned off. We have to start from scratch with a new SMTP + connection. That's why the retry is done from here, not from within + smtp_deliver(). [Rejections of STARTTLS itself don't screw up the + session, so the in-clear transmission after those errors, if permitted, + happens inside smtp_deliver().] */ + +#ifdef SUPPORT_TLS + if ( rc == DEFER + && first_addr->basic_errno == ERRNO_TLSFAILURE + && ob->tls_tempfail_tryclear + && verify_check_given_host(CUSS &ob->hosts_require_tls, host) != OK + ) + { + log_write(0, LOG_MAIN, + "%s: delivering unencrypted to H=%s [%s] (not in hosts_require_tls)", + first_addr->message, host->name, host->address); + first_addr = prepare_addresses(addrlist, host); + rc = smtp_deliver(addrlist, thost, host_af, defport, interface, tblock, + &message_defer, TRUE); + if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL) + write_logs(host, first_addr->message, first_addr->basic_errno); +# ifndef DISABLE_EVENT + if (rc == DEFER) + deferred_event_raise(first_addr, host); +# endif + } +#endif /*SUPPORT_TLS*/ + } + + /* Delivery attempt finished */ + + rs = rc == OK ? US"OK" + : rc == DEFER ? US"DEFER" + : rc == ERROR ? US"ERROR" + : US"?"; + + set_process_info("delivering %s: just tried %s [%s]%s for %s%s: result %s", + message_id, host->name, host->address, pistring, addrlist->address, + addrlist->next ? " (& others)" : "", rs); + + /* Release serialization if set up */ + + if (serialize_key) enq_end(serialize_key); + + /* If the result is DEFER, or if a host retry record is known to exist, we + need to add an item to the retry chain for updating the retry database + at the end of delivery. We only need to add the item to the top address, + of course. Also, if DEFER, we mark the IP address unusable so as to skip it + for any other delivery attempts using the same address. (It is copied into + the unusable tree at the outer level, so even if different address blocks + contain the same address, it still won't get tried again.) */ + + if (rc == DEFER || retry_host_key) + { + int delete_flag = rc != DEFER ? rf_delete : 0; + if (!retry_host_key) + { + BOOL incl_ip; + if (exp_bool(addrlist, US"transport", tblock->name, D_transport, + US"retry_include_ip_address", ob->retry_include_ip_address, + ob->expand_retry_include_ip_address, &incl_ip) != OK) + incl_ip = TRUE; /* error; use most-specific retry record */ + + retry_host_key = incl_ip + ? string_sprintf("T:%S:%s%s", host->name, host->address, pistring) + : string_sprintf("T:%S%s", host->name, pistring); + } + + /* If a delivery of another message over an existing SMTP connection + yields DEFER, we do NOT set up retry data for the host. This covers the + case when there are delays in routing the addresses in the second message + that are so long that the server times out. This is alleviated by not + routing addresses that previously had routing defers when handling an + existing connection, but even so, this case may occur (e.g. if a + previously happily routed address starts giving routing defers). If the + host is genuinely down, another non-continued message delivery will + notice it soon enough. */ + + if (delete_flag != 0 || !continue_hostname) + retry_add_item(first_addr, retry_host_key, rf_host | delete_flag); + + /* We may have tried an expired host, if its retry time has come; ensure + the status reflects the expiry for the benefit of any other addresses. */ + + if (rc == DEFER) + { + host->status = host_is_expired + ? hstatus_unusable_expired : hstatus_unusable; + host->why = hwhy_deferred; + } + } + + /* If message_defer is set (host was OK, but every recipient got deferred + because of some message-specific problem), or if that had happened + previously so that a message retry key exists, add an appropriate item + to the retry chain. Note that if there was a message defer but now there is + a host defer, the message defer record gets deleted. That seems perfectly + reasonable. Also, stop the message from being remembered as waiting + for specific hosts. */ + + if (message_defer || retry_message_key) + { + int delete_flag = message_defer ? 0 : rf_delete; + if (!retry_message_key) + { + BOOL incl_ip; + if (exp_bool(addrlist, US"transport", tblock->name, D_transport, + US"retry_include_ip_address", ob->retry_include_ip_address, + ob->expand_retry_include_ip_address, &incl_ip) != OK) + incl_ip = TRUE; /* error; use most-specific retry record */ + + retry_message_key = incl_ip + ? string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring, + message_id) + : string_sprintf("T:%S%s:%s", host->name, pistring, message_id); + } + retry_add_item(addrlist, retry_message_key, + rf_message | rf_host | delete_flag); + update_waiting = FALSE; + } + + /* Any return other than DEFER (that is, OK or ERROR) means that the + addresses have got their final statuses filled in for this host. In the OK + case, see if any of them are deferred. */ + + if (rc == OK) + for (addr = addrlist; addr; addr = addr->next) + if (addr->transport_return == DEFER) + { + some_deferred = TRUE; + break; + } + + /* If no addresses deferred or the result was ERROR, return. We do this for + ERROR because a failing filter set-up or add_headers expansion is likely to + fail for any host we try. */ + + if (rc == ERROR || (rc == OK && !some_deferred)) + { + DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name); + return TRUE; /* Each address has its status */ + } + + /* If the result was DEFER or some individual addresses deferred, let + the loop run to try other hosts with the deferred addresses, except for the + case when we were trying to deliver down an existing channel and failed. + Don't try any other hosts in this case. */ + + if (continue_hostname) break; + + /* If the whole delivery, or some individual addresses, were deferred and + there are more hosts that could be tried, do not count this host towards + the hosts_max_try limit if the age of the message is greater than the + maximum retry time for this host. This means we may try try all hosts, + ignoring the limit, when messages have been around for some time. This is + important because if we don't try all hosts, the address will never time + out. NOTE: this does not apply to hosts_max_try_hardlimit. */ + + if ((rc == DEFER || some_deferred) && nexthost) + { + BOOL timedout; + retry_config *retry = retry_find_config(host->name, NULL, 0, 0); + + if (retry && retry->rules) + { + retry_rule *last_rule; + for (last_rule = retry->rules; + last_rule->next; + last_rule = last_rule->next); + timedout = time(NULL) - received_time.tv_sec > last_rule->timeout; + } + else timedout = TRUE; /* No rule => timed out */ + + if (timedout) + { + unexpired_hosts_tried--; + DEBUG(D_transport) debug_printf("temporary delivery error(s) override " + "hosts_max_try (message older than host's retry time)\n"); + } + } + + DEBUG(D_transport) + { + if (unexpired_hosts_tried >= ob->hosts_max_try) + debug_printf("reached transport hosts_max_try limit %d\n", + ob->hosts_max_try); + if (total_hosts_tried >= ob->hosts_max_try_hardlimit) + debug_printf("reached transport hosts_max_try_hardlimit limit %d\n", + ob->hosts_max_try_hardlimit); + } + + if (f.running_in_test_harness) millisleep(500); /* let server debug out */ + } /* End of loop for trying multiple hosts. */ + + /* If we failed to find a matching host in the list, for an already-open + connection, just close it and start over with the list. This can happen + for routing that changes from run to run, or big multi-IP sites with + round-robin DNS. */ + + if (continue_hostname && !continue_host_tried) + { + int fd = cutthrough.cctx.sock >= 0 ? cutthrough.cctx.sock : 0; + + DEBUG(D_transport) debug_printf("no hosts match already-open connection\n"); +#ifdef SUPPORT_TLS + /* A TLS conn could be open for a cutthrough, but not for a plain continued- + transport */ +/*XXX doublecheck that! */ + + if (cutthrough.cctx.sock >= 0 && cutthrough.is_tls) + { + (void) tls_write(cutthrough.cctx.tls_ctx, US"QUIT\r\n", 6, FALSE); + tls_close(cutthrough.cctx.tls_ctx, TLS_SHUTDOWN_NOWAIT); + cutthrough.cctx.tls_ctx = NULL; + cutthrough.is_tls = FALSE; + } + else +#else + (void) write(fd, US"QUIT\r\n", 6); +#endif + (void) close(fd); + cutthrough.cctx.sock = -1; + continue_hostname = NULL; + goto retry_non_continued; + } + + /* This is the end of the loop that repeats iff expired is TRUE and + ob->delay_after_cutoff is FALSE. The second time round we will + try those hosts that haven't been tried since the message arrived. */ + + DEBUG(D_transport) + { + debug_printf("all IP addresses skipped or deferred at least one address\n"); + if (expired && !ob->delay_after_cutoff && cutoff_retry == 0) + debug_printf("retrying IP addresses not tried since message arrived\n"); + } + } + + +/* Get here if all IP addresses are skipped or defer at least one address. In +MUA wrapper mode, this will happen only for connection or other non-message- +specific failures. Force the delivery status for all addresses to FAIL. */ + +if (mua_wrapper) + { + for (addr = addrlist; addr; addr = addr->next) + addr->transport_return = FAIL; + goto END_TRANSPORT; + } + +/* In the normal, non-wrapper case, add a standard message to each deferred +address if there hasn't been an error, that is, if it hasn't actually been +tried this time. The variable "expired" will be FALSE if any deliveries were +actually tried, or if there was at least one host that was not expired. That +is, it is TRUE only if no deliveries were tried and all hosts were expired. If +a delivery has been tried, an error code will be set, and the failing of the +message is handled by the retry code later. + +If queue_smtp is set, or this transport was called to send a subsequent message +down an existing TCP/IP connection, and something caused the host not to be +found, we end up here, but can detect these cases and handle them specially. */ + +for (addr = addrlist; addr; addr = addr->next) + { + /* If host is not NULL, it means that we stopped processing the host list + because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this + means we need to behave as if some hosts were skipped because their retry + time had not come. Specifically, this prevents the address from timing out. + However, if we have hit hosts_max_try_hardlimit, we want to behave as if all + hosts were tried. */ + + if (host) + if (total_hosts_tried >= ob->hosts_max_try_hardlimit) + { + DEBUG(D_transport) + debug_printf("hosts_max_try_hardlimit reached: behave as if all " + "hosts were tried\n"); + } + else + { + DEBUG(D_transport) + debug_printf("hosts_max_try limit caused some hosts to be skipped\n"); + setflag(addr, af_retry_skipped); + } + + if (f.queue_smtp) /* no deliveries attempted */ + { + addr->transport_return = DEFER; + addr->basic_errno = 0; + addr->message = US"SMTP delivery explicitly queued"; + } + + else if ( addr->transport_return == DEFER + && (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) + && !addr->message + ) + { + addr->basic_errno = ERRNO_HRETRY; + if (continue_hostname) + addr->message = US"no host found for existing SMTP connection"; + else if (expired) + { + setflag(addr, af_pass_message); /* This is not a security risk */ + addr->message = string_sprintf( + "all hosts%s have been failing for a long time %s", + addr->domain ? string_sprintf(" for '%s'", addr->domain) : US"", + ob->delay_after_cutoff + ? US"(and retry time not reached)" + : US"and were last tried after this message arrived"); + + /* If we are already using fallback hosts, or there are no fallback hosts + defined, convert the result to FAIL to cause a bounce. */ + + if (addr->host_list == addr->fallback_hosts || !addr->fallback_hosts) + addr->transport_return = FAIL; + } + else + { + const char * s; + if (hosts_retry == hosts_total) + s = "retry time not reached for any host%s"; + else if (hosts_fail == hosts_total) + s = "all host address lookups%s failed permanently"; + else if (hosts_defer == hosts_total) + s = "all host address lookups%s failed temporarily"; + else if (hosts_serial == hosts_total) + s = "connection limit reached for all hosts%s"; + else if (hosts_fail+hosts_defer == hosts_total) + s = "all host address lookups%s failed"; + else + s = "some host address lookups failed and retry time " + "not reached for other hosts or connection limit reached%s"; + + addr->message = string_sprintf(s, + addr->domain ? string_sprintf(" for '%s'", addr->domain) : US""); + } + } + } + +/* Update the database which keeps information about which messages are waiting +for which hosts to become available. For some message-specific errors, the +update_waiting flag is turned off because we don't want follow-on deliveries in +those cases. If this transport instance is explicitly limited to one message +per connection then follow-on deliveries are not possible and there's no need +to create/update the per-transport wait-<transport_name> database. */ + +if (update_waiting && tblock->connection_max_messages != 1) + transport_update_waiting(hostlist, tblock->name); + +END_TRANSPORT: + +DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name); + +return TRUE; /* Each address has its status */ +} + +#endif /*!MACRO_PREDEF*/ +/* vi: aw ai sw=2 +*/ +/* End of transport/smtp.c */ |