X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/8e669ac162fe3b1040297f1d021de10778dce9d9..fdfe718d5ed9f551120a29af214883d59ddb85d1:/src/src/smtp_out.c diff --git a/src/src/smtp_out.c b/src/src/smtp_out.c index 2caa775fc..c968f70e2 100644 --- a/src/src/smtp_out.c +++ b/src/src/smtp_out.c @@ -1,16 +1,15 @@ -/* $Cambridge: exim/src/src/smtp_out.c,v 1.4 2005/02/17 11:58:26 ph10 Exp $ */ - /************************************************* * Exim - an Internet mail transport agent * *************************************************/ -/* Copyright (c) University of Cambridge 1995 - 2005 */ +/* Copyright (c) University of Cambridge 1995 - 2018 */ /* See the file NOTICE for conditions of use and distribution. */ /* A number of functions for driving outgoing SMTP calls. */ #include "exim.h" +#include "transports/smtp.h" @@ -27,7 +26,6 @@ Arguments: which case the function does nothing host_af AF_INET or AF_INET6 for the outgoing IP address addr the mail address being handled (for setting errors) - changed if not NULL, set TRUE if expansion actually changed istring interface point this to the interface msg to add to any error message @@ -37,16 +35,15 @@ Returns: TRUE on success, FALSE on failure, with error message BOOL smtp_get_interface(uschar *istring, int host_af, address_item *addr, - BOOL *changed, uschar **interface, uschar *msg) + uschar **interface, uschar *msg) { -uschar *expint; +const uschar * expint; uschar *iface; int sep = 0; -if (istring == NULL) return TRUE; +if (!istring) return TRUE; -expint = expand_string(istring); -if (expint == NULL) +if (!(expint = expand_string(istring))) { if (expand_string_forcedfail) return TRUE; addr->transport_return = PANIC; @@ -55,13 +52,11 @@ if (expint == NULL) return FALSE; } -if (changed != NULL) *changed = expint != istring; - while (isspace(*expint)) expint++; if (*expint == 0) return TRUE; while ((iface = string_nextinlist(&expint, &sep, big_buffer, - big_buffer_size)) != NULL) + big_buffer_size))) { if (string_is_ip_address(iface, NULL) == 0) { @@ -76,7 +71,7 @@ while ((iface = string_nextinlist(&expint, &sep, big_buffer, break; } -if (iface != NULL) *interface = string_copy(iface); +if (iface) *interface = string_copy(iface); return TRUE; } @@ -105,7 +100,7 @@ smtp_get_port(uschar *rstring, address_item *addr, int *port, uschar *msg) { uschar *pstring = expand_string(rstring); -if (pstring == NULL) +if (!pstring) { addr->transport_return = PANIC; addr->message = string_sprintf("failed to expand \"%s\" (\"port\" option) " @@ -129,7 +124,7 @@ if (isdigit(*pstring)) else { struct servent *smtp_service = getservbyname(CS pstring, "tcp"); - if (smtp_service == NULL) + if (!smtp_service) { addr->transport_return = PANIC; addr->message = string_sprintf("TCP port \"%s\" is not defined for %s", @@ -145,79 +140,140 @@ return TRUE; -/************************************************* -* Connect to remote host * -*************************************************/ +#ifdef TCP_FASTOPEN +static void +tfo_out_check(int sock) +{ +# if defined(TCP_INFO) && defined(EXIM_HAVE_TCPI_UNACKED) +struct tcp_info tinfo; +socklen_t len = sizeof(tinfo); -/* Create a socket, and connect it to a remote host. IPv6 addresses are -detected by checking for a colon in the address. AF_INET6 is defined even on -non-IPv6 systems, to enable the code to be less messy. However, on such systems -host->address will always be an IPv4 address. +if (getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0) + { + switch (tcp_out_fastopen) + { + /* This is a somewhat dubious detection method; totally undocumented so likely + to fail in future kernels. There seems to be no documented way. What we really + want to know is if the server sent smtp-banner data before our ACK of his SYN,ACK + hit him. What this (possibly?) detects is whether we sent a TFO cookie with our + SYN, as distinct from a TFO request. This gets a false-positive when the server + key is rotated; we send the old one (which this test sees) but the server returns + the new one and does not send its SMTP banner before we ACK his SYN,ACK. + To force that rotation case: + '# echo -n "00000000-00000000-00000000-0000000" >/proc/sys/net/ipv4/tcp_fastopen_key' + The kernel seems to be counting unack'd packets. */ + + case 1: + if (tinfo.tcpi_unacked > 1) + { + DEBUG(D_transport|D_v) + debug_printf("TCP_FASTOPEN tcpi_unacked %d\n", tinfo.tcpi_unacked); + tcp_out_fastopen = 2; + } + break; + +#ifdef notdef /* This seems to always fire, meaning that we cannot tell + whether the server accepted data we sent. For now assume + that it did. */ + + /* If there was data-on-SYN but we had to retrasnmit it, declare no TFO */ + + case 2: + if (!(tinfo.tcpi_options & TCPI_OPT_SYN_DATA)) + { + DEBUG(D_transport|D_v) debug_printf("TFO: had to retransmit\n"); + tcp_out_fastopen = 0; + } + break; +#endif + } -The port field in the host item is used if it is set (usually router from SRV -records). In other cases, the default passed as an argument is used. + } +# endif +} +#endif -Arguments: - host host item containing name and address (and sometimes port) - host_af AF_INET or AF_INET6 - port default, remote port to connect to, in host byte order for those - hosts whose port setting is PORT_NONE - interface outgoing interface address or NULL - timeout timeout value or 0 - keepalive TRUE to use keepalive + +/* Arguments as for smtp_connect(), plus + early_data if non-NULL, data to be sent - preferably in the TCP SYN segment Returns: connected socket number, or -1 with errno set */ int -smtp_connect(host_item *host, int host_af, int port, uschar *interface, - int timeout, BOOL keepalive) +smtp_sock_connect(host_item * host, int host_af, int port, uschar * interface, + transport_instance * tb, int timeout, const blob * early_data) { -int on = 1; -int save_errno = 0; +smtp_transport_options_block * ob = + (smtp_transport_options_block *)tb->options_block; +const uschar * dscp = ob->dscp; +int dscp_value; +int dscp_level; +int dscp_option; int sock; +int save_errno = 0; +const blob * fastopen_blob = NULL; -if (host->port != PORT_NONE) - { - HDEBUG(D_transport|D_acl|D_v) - debug_printf("Transport port=%d replaced by host-specific port=%d\n", port, - host->port); - port = host->port; - } - -HDEBUG(D_transport|D_acl|D_v) - { - if (interface == NULL) - debug_printf("Connecting to %s [%s]:%d ... ",host->name,host->address,port); - else - debug_printf("Connecting to %s [%s]:%d from %s ... ", host->name, - host->address, port, interface); - } -/* Create the socket */ +#ifndef DISABLE_EVENT +deliver_host_address = host->address; +deliver_host_port = port; +if (event_raise(tb->event_action, US"tcp:connect", NULL)) return -1; +#endif if ((sock = ip_socket(SOCK_STREAM, host_af)) < 0) return -1; /* Set TCP_NODELAY; Exim does its own buffering. */ -setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (uschar *)(&on), sizeof(on)); +if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, US &on, sizeof(on))) + HDEBUG(D_transport|D_acl|D_v) + debug_printf_indent("failed to set NODELAY: %s ", strerror(errno)); + +/* Set DSCP value, if we can. For now, if we fail to set the value, we don't +bomb out, just log it and continue in default traffic class. */ + +if (dscp && dscp_lookup(dscp, host_af, &dscp_level, &dscp_option, &dscp_value)) + { + HDEBUG(D_transport|D_acl|D_v) + debug_printf_indent("DSCP \"%s\"=%x ", dscp, dscp_value); + if (setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value)) < 0) + HDEBUG(D_transport|D_acl|D_v) + debug_printf_indent("failed to set DSCP: %s ", strerror(errno)); + /* If the kernel supports IPv4 and IPv6 on an IPv6 socket, we need to set the + option for both; ignore failures here */ + if (host_af == AF_INET6 && + dscp_lookup(dscp, AF_INET, &dscp_level, &dscp_option, &dscp_value)) + (void) setsockopt(sock, dscp_level, dscp_option, &dscp_value, sizeof(dscp_value)); + } /* Bind to a specific interface if requested. Caller must ensure the interface is the same type (IPv4 or IPv6) as the outgoing address. */ -if (interface != NULL && ip_bind(sock, host_af, interface, 0) < 0) +if (interface && ip_bind(sock, host_af, interface, 0) < 0) { save_errno = errno; HDEBUG(D_transport|D_acl|D_v) - debug_printf("unable to bind outgoing SMTP call to %s: %s", interface, + debug_printf_indent("unable to bind outgoing SMTP call to %s: %s", interface, strerror(errno)); } /* Connect to the remote host, and add keepalive to the socket before returning -it, if requested. */ +it, if requested. If the build supports TFO, request it - and if the caller +requested some early-data then include that in the TFO request. */ -else if (ip_connect(sock, host_af, host->address, port, timeout) < 0) - save_errno = errno; +else + { +#ifdef TCP_FASTOPEN + if (verify_check_given_host(&ob->hosts_try_fastopen, host) == OK) + fastopen_blob = early_data ? early_data : &tcp_fastopen_nodata; +#endif + + if (ip_connect(sock, host_af, host->address, port, timeout, fastopen_blob) < 0) + save_errno = errno; + else if (early_data && !fastopen_blob && early_data->data && early_data->len) + if (send(sock, early_data->data, early_data->len, 0) < 0) + save_errno = errno; + } /* Either bind() or connect() failed */ @@ -225,12 +281,12 @@ if (save_errno != 0) { HDEBUG(D_transport|D_acl|D_v) { - debug_printf("failed: %s", CUstrerror(save_errno)); + debug_printf_indent("failed: %s", CUstrerror(save_errno)); if (save_errno == ETIMEDOUT) debug_printf(" (timeout=%s)", readconf_printtime(timeout)); debug_printf("\n"); } - close(sock); + (void)close(sock); errno = save_errno; return -1; } @@ -239,13 +295,96 @@ if (save_errno != 0) else { - HDEBUG(D_transport|D_acl|D_v) debug_printf("connected\n"); - if (keepalive) ip_keepalive(sock, host->address, TRUE); + union sockaddr_46 interface_sock; + EXIM_SOCKLEN_T size = sizeof(interface_sock); + HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("connected\n"); + if (getsockname(sock, (struct sockaddr *)(&interface_sock), &size) == 0) + sending_ip_address = host_ntoa(-1, &interface_sock, NULL, &sending_port); + else + { + log_write(0, LOG_MAIN | ((errno == ECONNRESET)? 0 : LOG_PANIC), + "getsockname() failed: %s", strerror(errno)); + close(sock); + return -1; + } + if (ob->keepalive) ip_keepalive(sock, host->address, TRUE); +#ifdef TCP_FASTOPEN + if (fastopen_blob) tfo_out_check(sock); +#endif return sock; } } + + + +void +smtp_port_for_connect(host_item * host, int port) +{ +if (host->port != PORT_NONE) + { + HDEBUG(D_transport|D_acl|D_v) + debug_printf_indent("Transport port=%d replaced by host-specific port=%d\n", port, + host->port); + port = host->port; + } +else host->port = port; /* Set the port actually used */ +} + + +/************************************************* +* Connect to remote host * +*************************************************/ + +/* Create a socket, and connect it to a remote host. IPv6 addresses are +detected by checking for a colon in the address. AF_INET6 is defined even on +non-IPv6 systems, to enable the code to be less messy. However, on such systems +host->address will always be an IPv4 address. + +Arguments: + host host item containing name and address and port + host_af AF_INET or AF_INET6 + interface outgoing interface address or NULL + timeout timeout value or 0 + tb transport + +Returns: connected socket number, or -1 with errno set +*/ + +int +smtp_connect(host_item *host, int host_af, uschar *interface, + int timeout, transport_instance * tb) +{ +int port = host->port; +#ifdef SUPPORT_SOCKS +smtp_transport_options_block * ob = + (smtp_transport_options_block *)tb->options_block; +#endif + +callout_address = string_sprintf("[%s]:%d", host->address, port); + +HDEBUG(D_transport|D_acl|D_v) + { + uschar * s = US" "; + if (interface) s = string_sprintf(" from %s ", interface); +#ifdef SUPPORT_SOCKS + if (ob->socks_proxy) s = string_sprintf("%svia proxy ", s); +#endif + debug_printf_indent("Connecting to %s %s%s... ", host->name, callout_address, s); + } + +/* Create and connect the socket */ + +#ifdef SUPPORT_SOCKS +if (ob->socks_proxy) + return socks_sock_connect(host, host_af, port, interface, tb, timeout); +#endif + +return smtp_sock_connect(host, host_af, port, interface, tb, timeout, NULL); +} + + /************************************************* * Flush outgoing command buffer * *************************************************/ @@ -256,25 +395,37 @@ pipelining. Argument: outblock the SMTP output block + mode further data expected, or plain Returns: TRUE if OK, FALSE on error, with errno set */ static BOOL -flush_buffer(smtp_outblock *outblock) +flush_buffer(smtp_outblock * outblock, int mode) { int rc; +int n = outblock->ptr - outblock->buffer; +BOOL more = mode == SCMD_MORE; + +HDEBUG(D_transport|D_acl) debug_printf_indent("cmd buf flush %d bytes%s\n", n, + more ? " (more expected)" : ""); #ifdef SUPPORT_TLS -if (tls_active == outblock->sock) - rc = tls_write(outblock->buffer, outblock->ptr - outblock->buffer); +if (tls_out.active == outblock->sock) + rc = tls_write(FALSE, outblock->buffer, n, more); else #endif + rc = send(outblock->sock, outblock->buffer, n, +#ifdef MSG_MORE + more ? MSG_MORE : 0 +#else + 0 +#endif + ); -rc = send(outblock->sock, outblock->buffer, outblock->ptr - outblock->buffer, 0); if (rc <= 0) { - HDEBUG(D_transport|D_acl) debug_printf("send failed: %s\n", strerror(errno)); + HDEBUG(D_transport|D_acl) debug_printf_indent("send failed: %s\n", strerror(errno)); return FALSE; } @@ -294,9 +445,10 @@ any error message. Arguments: outblock contains buffer for pipelining, and socket - noflush if TRUE, save the command in the output buffer, for pipelining + mode buffer, write-with-more-likely, write format a format, starting with one of of HELO, MAIL FROM, RCPT TO, DATA, ".", or QUIT. + If NULL, flush pipeline buffer only. ... data for the format Returns: 0 if command added to pipelining buffer, with nothing transmitted @@ -305,55 +457,62 @@ Returns: 0 if command added to pipelining buffer, with nothing transmitted */ int -smtp_write_command(smtp_outblock *outblock, BOOL noflush, char *format, ...) +smtp_write_command(smtp_outblock * outblock, int mode, const char *format, ...) { int count; int rc = 0; va_list ap; -va_start(ap, format); -if (!string_vformat(big_buffer, big_buffer_size, CS format, ap)) - log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " - "SMTP"); -va_end(ap); -count = Ustrlen(big_buffer); - -if (count > outblock->buffersize - (outblock->ptr - outblock->buffer)) +if (format) { - rc = outblock->cmd_count; /* flush resets */ - if (!flush_buffer(outblock)) return -1; - } + va_start(ap, format); + if (!string_vformat(big_buffer, big_buffer_size, CS format, ap)) + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " + "SMTP"); + va_end(ap); + count = Ustrlen(big_buffer); + + if (count > outblock->buffersize) + log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " + "SMTP"); + + if (count > outblock->buffersize - (outblock->ptr - outblock->buffer)) + { + rc = outblock->cmd_count; /* flush resets */ + if (!flush_buffer(outblock, SCMD_FLUSH)) return -1; + } -Ustrncpy(CS outblock->ptr, big_buffer, count); -outblock->ptr += count; -outblock->cmd_count++; -count -= 2; -big_buffer[count] = 0; /* remove \r\n for error message */ + Ustrncpy(CS outblock->ptr, big_buffer, count); + outblock->ptr += count; + outblock->cmd_count++; + count -= 2; + big_buffer[count] = 0; /* remove \r\n for error message */ -/* We want to hide the actual data sent in AUTH transactions from reflections -and logs. While authenticating, a flag is set in the outblock to enable this. -The AUTH command itself gets any data flattened. Other lines are flattened -completely. */ + /* We want to hide the actual data sent in AUTH transactions from reflections + and logs. While authenticating, a flag is set in the outblock to enable this. + The AUTH command itself gets any data flattened. Other lines are flattened + completely. */ -if (outblock->authenticating) - { - uschar *p = big_buffer; - if (Ustrncmp(big_buffer, "AUTH ", 5) == 0) + if (outblock->authenticating) { - p += 5; - while (isspace(*p)) p++; - while (!isspace(*p)) p++; - while (isspace(*p)) p++; + uschar *p = big_buffer; + if (Ustrncmp(big_buffer, "AUTH ", 5) == 0) + { + p += 5; + while (isspace(*p)) p++; + while (!isspace(*p)) p++; + while (isspace(*p)) p++; + } + while (*p != 0) *p++ = '*'; } - while (*p != 0) *p++ = '*'; - } -HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP>> %s\n", big_buffer); + HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> %s\n", big_buffer); + } -if (!noflush) +if (mode != SCMD_BUFFER) { rc += outblock->cmd_count; /* flush resets */ - if (!flush_buffer(outblock)) return -1; + if (!flush_buffer(outblock, mode)) return -1; } return rc; @@ -425,15 +584,20 @@ for (;;) /* Need to read a new input packet. */ - rc = ip_recv(sock, inblock->buffer, inblock->buffersize, timeout); - if (rc <= 0) break; + if((rc = ip_recv(sock, inblock->buffer, inblock->buffersize, timeout)) <= 0) + { + DEBUG(D_deliver|D_transport|D_acl) + debug_printf_indent(errno ? " SMTP(%s)<<\n" : " SMTP(closed)<<\n", + strerror(errno)); + break; + } /* Another block of data has been successfully read. Set up the pointers and let the loop continue. */ ptrend = inblock->ptrend = inblock->buffer + rc; ptr = inblock->buffer; - DEBUG(D_transport|D_acl) debug_printf("read response data: size=%d\n", rc); + DEBUG(D_transport|D_acl) debug_printf_indent("read response data: size=%d\n", rc); } /* Get here if there has been some kind of recv() error; errno is set, but we @@ -463,7 +627,7 @@ Arguments: buffer where to put the response size the size of the buffer okdigit the expected first digit of the response - timeout the timeout to use + timeout the timeout to use, in seconds Returns: TRUE if a valid, non-error response was received; else FALSE */ @@ -477,7 +641,7 @@ int count; errno = 0; /* Ensure errno starts out zero */ -/* This is a loop to read and concatentate the lines that make up a multi-line +/* This is a loop to read and concatenate the lines that make up a multi-line response. */ for (;;) @@ -486,7 +650,7 @@ for (;;) return FALSE; HDEBUG(D_transport|D_acl|D_v) - debug_printf(" %s %s\n", (ptr == buffer)? "SMTP<<" : " ", ptr); + debug_printf_indent(" %s %s\n", (ptr == buffer)? "SMTP<<" : " ", ptr); /* Check the format of the response: it must start with three digits; if these are followed by a space or end of line, the response is complete. If @@ -531,3 +695,5 @@ return buffer[0] == okdigit; } /* End of smtp_out.c */ +/* vi: aw ai sw=2 +*/