X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/829dd84217ed9c32fda88a4ca2cb20b41c950f1e..4c2471caf34b901ee481cd1e742b3620e734b16b:/src/src/transports/smtp.c diff --git a/src/src/transports/smtp.c b/src/src/transports/smtp.c index e177ee9c3..997281901 100644 --- a/src/src/transports/smtp.c +++ b/src/src/transports/smtp.c @@ -87,6 +87,8 @@ optionlist smtp_transport_options[] = { #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) }, @@ -218,7 +220,10 @@ smtp_transport_options_block smtp_transport_option_defaults = { NULL, /* hosts_verify_avoid_tls */ NULL, /* hosts_avoid_pipelining */ NULL, /* hosts_avoid_esmtp */ +#ifdef SUPPORT_TLS NULL, /* hosts_nopass_tls */ + US"*", /* hosts_noproxy_tls */ +#endif 5*60, /* command_timeout */ 5*60, /* connect_timeout; shorter system default overrides */ 5*60, /* data timeout */ @@ -283,6 +288,8 @@ 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 */ @@ -789,7 +796,9 @@ with an address by scanning for the next address whose status is PENDING_DEFER. while (count-- > 0) { - while (addr->transport_return != PENDING_DEFER) addr = addr->next; + while (addr->transport_return != PENDING_DEFER) + if (!(addr = addr->next)) + return -2; /* The address was accepted */ addr->host_used = sx->host; @@ -1340,15 +1349,22 @@ return checks; If given a nonzero size, first flush any buffered SMTP commands then emit the command. -Reap previous SMTP command responses if requested. -Reap one SMTP command response if requested. +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(int fd, transport_ctx * tctx, - unsigned chunk_size, unsigned flags) +smtp_chunk_cmd_callback(transport_ctx * tctx, unsigned chunk_size, + unsigned flags) { smtp_transport_options_block * ob = (smtp_transport_options_block *)(tctx->tblock->options_block); @@ -1409,7 +1425,7 @@ if (sx->pending_BDAT) if (errno == 0 && sx->buffer[0] == '4') { errno = ERRNO_DATA4XX; /*XXX does this actually get used? */ - sx->first_addr->more_errno |= + sx->addrlist->more_errno |= ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8; } return ERROR; @@ -1551,7 +1567,7 @@ if (continue_hostname == NULL) uschar * msg = NULL; if (sx->verify) { - msg = strerror(errno); + msg = US strerror(errno); HDEBUG(D_verify) debug_printf("connect: %s\n", msg); } set_errno_nohost(sx->addrlist, @@ -1796,9 +1812,11 @@ goto SEND_QUIT; } } -/* For continuing deliveries down the same channel, the socket is the standard -input, and 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 +/* 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. */ @@ -1810,10 +1828,33 @@ separate - we could match up by host ip+port as a bodge. */ else { - sx->inblock.sock = sx->outblock.sock = fileno(stdin); + if (cutthrough.fd >= 0 && cutthrough.callout_hold_only) + { + sx->inblock.sock = sx->outblock.sock = cutthrough.fd; + sx->host->port = sx->port = cutthrough.host.port; + } + else + { + sx->inblock.sock = sx->outblock.sock = 0; /* stdin */ + sx->host->port = sx->port; /* Record the port that was used */ + } smtp_command = big_buffer; - sx->host->port = sx->port; /* Record the port that was used */ 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.fd >= 0 && cutthrough.callout_hold_only && cutthrough.is_tls) + ) + { + sx->peer_offered = smtp_peer_options; + pipelining_active = !!(smtp_peer_options & PEER_OFFERED_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 @@ -1863,11 +1904,12 @@ if ( smtp_peer_options & PEER_OFFERED_TLS TLS_NEGOTIATE: { address_item * addr; - int rc = tls_client_start(sx->inblock.sock, sx->host, sx->addrlist, sx->tblock + uschar * errstr; + int rc = tls_client_start(sx->inblock.sock, sx->host, sx->addrlist, sx->tblock, # ifdef EXPERIMENTAL_DANE - , sx->dane ? &tlsa_dnsa : NULL + sx->dane ? &tlsa_dnsa : NULL, # endif - ); + &errstr); /* 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 @@ -1877,12 +1919,12 @@ if ( smtp_peer_options & PEER_OFFERED_TLS { # ifdef EXPERIMENTAL_DANE if (sx->dane) log_write(0, LOG_MAIN, - "DANE attempt failed; no TLS connection to %s [%s]", - sx->host->name, sx->host->address); + "DANE attempt failed; TLS connection to %s [%s]: %s", + sx->host->name, sx->host->address, errstr); # endif errno = ERRNO_TLSFAILURE; - message = US"failure while setting up TLS session"; + message = string_sprintf("TLS session: %s", errstr); sx->send_quit = FALSE; goto TLS_FAILED; } @@ -2166,7 +2208,7 @@ 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(" SMTP(close)>>\n"); +HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n"); if (sx->send_quit) { shutdown(sx->outblock.sock, SHUT_WR); @@ -2435,7 +2477,8 @@ for (addr = sx->first_addr, address_count = 0; ? dsn_support_yes : dsn_support_no; address_count++; - no_flush = pipelining_active && !sx->verify && (!mua_wrapper || addr->next); + no_flush = pipelining_active && !sx->verify + && (!mua_wrapper || addr->next && address_count < sx->max_rcpt); build_rcptcmd_options(sx, addr); @@ -2488,6 +2531,94 @@ return 0; } +#ifdef SUPPORT_TLS +/***************************************************** +* Proxy TLS connection for another transport process * +******************************************************/ +/* +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. + +Arguments: + buf space to use for buffering + bufsiz size of buffer + proxy_fd comms to proxied process + timeout per-read timeout, seconds +*/ + +void +smtp_proxy_tls(uschar * buf, size_t bsize, int proxy_fd, int timeout) +{ +fd_set fds; +int max_fd = MAX(proxy_fd, tls_out.active) + 1; +int rc, i, fd_bits, nbytes; + +set_process_info("proxying TLS connection for continued transport"); +FD_ZERO(&fds); +FD_SET(tls_out.active, &fds); +FD_SET(proxy_fd, &fds); + +for (fd_bits = 3; fd_bits; ) + { + time_t time_left = timeout; + time_t time_start = time(NULL); + + /* wait for data */ + do + { + struct timeval tv = { time_left, 0 }; + + rc = select(max_fd, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &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__); + return; + } + } + while (rc < 0 || !(FD_ISSET(tls_out.active, &fds) || FD_ISSET(proxy_fd, &fds))); + + /* handle inbound data */ + if (FD_ISSET(tls_out.active, &fds)) + if ((rc = tls_read(FALSE, buf, bsize)) <= 0) + { + fd_bits &= ~1; + FD_CLR(tls_out.active, &fds); + shutdown(proxy_fd, SHUT_WR); + } + else + { + for (nbytes = 0; rc - nbytes > 0; nbytes += i) + if ((i = write(proxy_fd, buf + nbytes, rc - nbytes)) < 0) return; + } + else if (fd_bits & 1) + FD_SET(tls_out.active, &fds); + + /* handle outbound data */ + if (FD_ISSET(proxy_fd, &fds)) + if ((rc = read(proxy_fd, buf, bsize)) <= 0) + { + fd_bits &= ~2; + FD_CLR(proxy_fd, &fds); + shutdown(tls_out.active, SHUT_WR); + } + else + { + for (nbytes = 0; rc - nbytes > 0; nbytes += i) + if ((i = tls_write(FALSE, buf + nbytes, rc - nbytes)) < 0) return; + } + else if (fd_bits & 2) + FD_SET(proxy_fd, &fds); + } +} +#endif + + /************************************************* * Deliver address list to given host * *************************************************/ @@ -2573,17 +2704,14 @@ set it up. This cannot be done until the identify of the host is known. */ if (tblock->filter_command) { - BOOL rc; - uschar fbuf[64]; - sprintf(CS fbuf, "%.50s transport", tblock->name); - rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command, - TRUE, DEFER, addrlist, fbuf, NULL); transport_filter_timeout = tblock->filter_timeout; /* On failure, copy the error to all addresses, abandon the SMTP call, and yield ERROR. */ - if (!rc) + 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); @@ -2602,6 +2730,7 @@ if (tblock->filter_command) } } +sx.first_addr = addrlist; /* For messages that have more than the maximum number of envelope recipients, we want to send several transactions down the same SMTP connection. (See @@ -2613,39 +2742,61 @@ transaction to handle. */ SEND_MESSAGE: sx.from_addr = return_path; -sx.first_addr = sx.sync_addr = addrlist; +sx.sync_addr = sx.first_addr; sx.ok = FALSE; sx.send_rset = TRUE; sx.completed_addr = FALSE; -/* Initiate a message transfer. */ +/* 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. */ -switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield)) +if (continue_hostname && continue_sequence == 1) { - case 0: break; - case -1: case -2: goto RESPONSE_FAILED; - case -3: goto END_OFF; - case -4: goto SEND_QUIT; - default: goto SEND_FAILED; - } + address_item * addr; -/* 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. */ + sx.peer_offered = smtp_peer_options; + sx.pending_MAIL = FALSE; + sx.ok = TRUE; + sx.next_addr = NULL; -if (mua_wrapper) + for (addr = addrlist; addr; addr = addr->next) + addr->transport_return = PENDING_OK; + } +else { - address_item *badaddr; - for (badaddr = sx.first_addr; badaddr; badaddr = badaddr->next) - if (badaddr->transport_return != PENDING_OK) - { - /*XXX could we find a better errno than 0 here? */ - set_errno_nohost(addrlist, 0, badaddr->message, FAIL, - testflag(badaddr, af_pass_message)); - sx.ok = FALSE; - break; - } + /* 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 @@ -2744,7 +2895,8 @@ else transport_count = 0; #ifndef DISABLE_DKIM - sx.ok = dkim_transport_write_message(sx.inblock.sock, &tctx, &sx.ob->dkim); + sx.ok = dkim_transport_write_message(sx.inblock.sock, &tctx, &sx.ob->dkim, + CUSS &message); #else sx.ok = transport_write_message(sx.inblock.sock, &tctx, 0); #endif @@ -2761,7 +2913,8 @@ else Or, when CHUNKING, it can be a protocol-detected failure. */ if (!sx.ok) - goto RESPONSE_FAILED; + 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 @@ -2943,7 +3096,7 @@ else else sprintf(CS sx.buffer, "%.500s\n", addr->unique); - DEBUG(D_deliver) debug_printf("journalling %s\n", sx.buffer); + 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 " @@ -3026,8 +3179,8 @@ if (!sx.ok) { save_errno = errno; code = '4'; - message = US string_sprintf("send() to %s [%s] failed: %s", - host->name, host->address, strerror(save_errno)); + 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; } @@ -3168,10 +3321,13 @@ if (sx.completed_addr && sx.ok && sx.send_quit) if ( sx.first_addr != NULL || continue_more - || ( ( tls_out.active < 0 + || ( +#ifdef SUPPORT_TLS + ( tls_out.active < 0 && !continue_proxy_cipher || verify_check_given_host(&sx.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) @@ -3204,29 +3360,51 @@ if (sx.completed_addr && sx.ok && sx.send_quit) if (sx.ok) { - if (sx.first_addr != NULL) /* More addresses still to be sent */ + int pfd[2]; + int socket_fd = sx.inblock.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; } if (continue_more) return yield; /* More addresses for another run */ - /* Pass the socket to a new Exim process. Before doing so, 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. */ - + /* Pass the connection on to a new Exim process. */ #ifdef SUPPORT_TLS if (tls_out.active >= 0) - { - tls_close(FALSE, TRUE); - smtp_peer_options = smtp_peer_options_wrap; - sx.ok = !sx.smtps - && smtp_write_command(&sx.outblock, FALSE, - "EHLO %s\r\n", sx.helo_data) >= 0 - && smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer), - '2', sx.ob->command_timeout); - } + if (verify_check_given_host(&sx.ob->hosts_noproxy_tls, host) == OK) + { + /* Pass the socket, for direct use, to a new Exim process. Before + doing so, 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(FALSE, TRUE); + smtp_peer_options = smtp_peer_options_wrap; + sx.ok = !sx.smtps + && smtp_write_command(&sx.outblock, FALSE, + "EHLO %s\r\n", sx.helo_data) >= 0 + && smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer), + '2', sx.ob->command_timeout); + } + else + { + /* Set up a pipe for proxying TLS for the new transport process */ + + smtp_peer_options |= PEER_OFFERED_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 + ); + } #endif /* If the socket is successfully passed, we mustn't send QUIT (or @@ -3236,13 +3414,42 @@ if (sx.completed_addr && sx.ok && sx.send_quit) propagate it from the initial */ if (sx.ok && transport_pass_socket(tblock->name, host->name, - host->address, new_message_id, sx.inblock.sock)) + host->address, new_message_id, socket_fd)) + { sx.send_quit = FALSE; + + /* 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 >= 0) + { + int pid = fork(); + if (pid > 0) /* parent */ + { + waitpid(pid, NULL, 0); + tls_close(FALSE, FALSE); + (void)close(sx.inblock.sock); + continue_transport = NULL; + continue_hostname = NULL; + return yield; + } + else if (pid == 0) /* child; fork again to disconnect totally */ + { + if ((pid = fork())) + _exit(pid ? EXIT_FAILURE : EXIT_SUCCESS); + smtp_proxy_tls(sx.buffer, sizeof(sx.buffer), pfd[0], sx.ob->command_timeout); + exim_exit(0); + } + } +#endif + } } /* If RSET failed and there are addresses left, they get deferred. */ - - else set_errno(sx.first_addr, errno, msg, DEFER, FALSE, host + else + set_errno(sx.first_addr, errno, msg, DEFER, FALSE, host #ifdef EXPERIMENTAL_DSN_INFO , sx.smtp_greeting, sx.helo_response #endif @@ -3287,7 +3494,7 @@ 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(" SMTP(close)>>\n"); +HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n"); if (sx.send_quit) { shutdown(sx.outblock.sock, SHUT_WR); @@ -3451,8 +3658,10 @@ DEBUG(D_transport) for (host = hostlist; host; host = host->next) debug_printf(" %s:%d\n", host->name, host->port); } - if (continue_hostname) debug_printf("already connected to %s [%s]\n", - continue_hostname, continue_host_address); + if (continue_hostname) + debug_printf("already connected to %s [%s] (on fd %d)\n", + continue_hostname, continue_host_address, + cutthrough.fd >= 0 ? cutthrough.fd : 0); } /* Set the flag requesting that these hosts be added to the waiting @@ -3717,7 +3926,7 @@ for (cutoff_retry = 0; 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_FAILED) + 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; @@ -3730,8 +3939,11 @@ for (cutoff_retry = 0; { if (addr->transport_return != DEFER) continue; addr->basic_errno = ERRNO_UNKNOWNHOST; - addr->message = - string_sprintf("failed to lookup IP address for %s", host->name); + 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; } @@ -3849,7 +4061,7 @@ for (cutoff_retry = 0; 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 status = %s\n", host->name, + DEBUG(D_transport) debug_printf("%s [%s]%s retry-status = %s\n", host->name, (host->address == NULL)? US"" : host->address, pistring, (host->status == hstatus_usable)? "usable" : (host->status == hstatus_unusable)? "unusable" : @@ -3870,6 +4082,7 @@ for (cutoff_retry = 0; { case hwhy_retry: hosts_retry++; break; case hwhy_failed: hosts_fail++; break; + case hwhy_insecure: case hwhy_deferred: hosts_defer++; break; } @@ -4053,8 +4266,9 @@ for (cutoff_retry = 0; && verify_check_given_host(&ob->hosts_require_tls, host) != OK ) { - log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted " - "to %s [%s] (not in hosts_require_tls)", host->name, host->address); + 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, port, interface, tblock, &message_defer, TRUE);