X-Git-Url: https://vcs.fsf.org/?a=blobdiff_plain;f=src%2Fsrc%2Fsmtp_out.c;h=12ed5bc612e3fd639056c97ebb479877c41ec5eb;hb=568092148bf6ade68174fa1ccf34b8c37d9064e9;hp=9221aa8680dd5985987574abf0d84424dbf7671d;hpb=0ab63f3dea522591218c0d65c78a686b7fa64db6;p=exim.git diff --git a/src/src/smtp_out.c b/src/src/smtp_out.c index 9221aa868..12ed5bc61 100644 --- a/src/src/smtp_out.c +++ b/src/src/smtp_out.c @@ -2,7 +2,7 @@ * Exim - an Internet mail transport agent * *************************************************/ -/* Copyright (c) University of Cambridge 1995 - 2016 */ +/* 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. */ @@ -45,13 +45,24 @@ if (!istring) return TRUE; if (!(expint = expand_string(istring))) { - if (expand_string_forcedfail) return TRUE; + if (f.expand_string_forcedfail) return TRUE; addr->transport_return = PANIC; addr->message = string_sprintf("failed to expand \"interface\" " "option for %s: %s", msg, expand_string_message); return FALSE; } +if (is_tainted(expint)) + { + log_write(0, LOG_MAIN|LOG_PANIC, + "attempt to use tainted value '%s' from '%s' for interface", + expint, istring); + addr->transport_return = PANIC; + addr->message = string_sprintf("failed to expand \"interface\" " + "option for %s: configuration error", msg); + return FALSE; + } + while (isspace(*expint)) expint++; if (*expint == 0) return TRUE; @@ -144,28 +155,86 @@ return TRUE; static void tfo_out_check(int sock) { -# if defined(TCP_INFO) && defined(EXIM_HAVE_TCPI_UNACKED) +# ifdef __FreeBSD__ +struct tcp_info tinfo; +int val; +socklen_t len = sizeof(val); + +/* The observability as of 12.1 is not useful as a client, only telling us that +a TFO option was used on SYN. It could have been a TFO-R, or ignored by the +server. */ + +/* +if (tcp_out_fastopen == TFO_ATTEMPTED_NODATA || tcp_out_fastopen == TFO_ATTEMPTED_DATA) + if (getsockopt(sock, IPPROTO_TCP, TCP_FASTOPEN, &val, &len) == 0 && val != 0) {} +*/ +switch (tcp_out_fastopen) + { + case TFO_ATTEMPTED_NODATA: tcp_out_fastopen = TFO_USED_NODATA; break; + case TFO_ATTEMPTED_DATA: tcp_out_fastopen = TFO_USED_DATA; break; + default: break; /* compiler quietening */ + } + +# else /* Linux & Apple */ +# if defined(TCP_INFO) && defined(EXIM_HAVE_TCPI_UNACKED) struct tcp_info tinfo; socklen_t len = sizeof(tinfo); -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. */ + /* 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 TFO_ATTEMPTED_NODATA: + if ( getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0 + && tinfo.tcpi_state == TCP_SYN_SENT + && tinfo.tcpi_unacked > 1 + ) + { + DEBUG(D_transport|D_v) + debug_printf("TCP_FASTOPEN tcpi_unacked %d\n", tinfo.tcpi_unacked); + tcp_out_fastopen = TFO_USED_NODATA; + } + break; - if (tinfo.tcpi_unacked > 1) - { - DEBUG(D_transport|D_v) debug_printf("TCP_FASTOPEN mode connection\n"); - tcp_out_fastopen = TRUE; - } + /* When called after waiting for received data we should be able + to tell if data we sent was accepted. */ + + case TFO_ATTEMPTED_DATA: + if ( getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0 + && tinfo.tcpi_state == TCP_ESTABLISHED + ) + if (tinfo.tcpi_options & TCPI_OPT_SYN_DATA) + { + DEBUG(D_transport|D_v) debug_printf("TFO: data was acked\n"); + tcp_out_fastopen = TFO_USED_DATA; + } + else + { + DEBUG(D_transport|D_v) debug_printf("TFO: had to retransmit\n"); + tcp_out_fastopen = TFO_NOT_USED; + } + break; + + default: break; /* compiler quietening */ } -# endif +# endif +# endif /* Linux & Apple */ } #endif /* Arguments as for smtp_connect(), plus - early_data if non-NULL, data to be sent - preferably in the TCP SYN segment + early_data if non-NULL, idenmpotent data to be sent - + preferably in the TCP SYN segment Returns: connected socket number, or -1 with errno set */ @@ -182,6 +251,8 @@ int dscp_level; int dscp_option; int sock; int save_errno = 0; +const blob * fastopen_blob = NULL; + #ifndef DISABLE_EVENT deliver_host_address = host->address; @@ -227,22 +298,29 @@ if (interface && ip_bind(sock, host_af, interface, 0) < 0) /* Connect to the remote host, and add keepalive to the socket before returning 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. */ +requested some early-data then include that in the TFO request. If there is +early-data but no TFO support, send it after connecting. */ else { - const blob * fastopen = NULL; - #ifdef TCP_FASTOPEN - if (verify_check_given_host(&ob->hosts_try_fastopen, host) == OK) - fastopen = early_data ? early_data : &tcp_fastopen_nodata; + if (verify_check_given_host(CUSS &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) < 0) + if (ip_connect(sock, host_af, host->address, port, timeout, fastopen_blob) < 0) save_errno = errno; - else if (early_data && !fastopen && early_data->data && early_data->len) + else if (early_data && !fastopen_blob && early_data->data && early_data->len) + { + HDEBUG(D_transport|D_acl|D_v) + debug_printf("sending %ld nonTFO early-data\n", (long)early_data->len); + +#ifdef TCP_QUICKACK + (void) setsockopt(sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off)); +#endif if (send(sock, early_data->data, early_data->len, 0) < 0) save_errno = errno; + } } /* Either bind() or connect() failed */ @@ -251,7 +329,7 @@ if (save_errno != 0) { HDEBUG(D_transport|D_acl|D_v) { - debug_printf_indent("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"); @@ -261,13 +339,14 @@ if (save_errno != 0) return -1; } -/* Both bind() and connect() succeeded */ +/* Both bind() and connect() succeeded, and any early-data */ else { union sockaddr_46 interface_sock; EXIM_SOCKLEN_T size = sizeof(interface_sock); - HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("connected\n"); + + 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 @@ -277,6 +356,7 @@ else close(sock); return -1; } + if (ob->keepalive) ip_keepalive(sock, host->address, TRUE); #ifdef TCP_FASTOPEN tfo_out_check(sock); @@ -313,45 +393,62 @@ 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 + sc details for making connection: host, af, interface, transport + 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, uschar *interface, - int timeout, transport_instance * tb) +smtp_connect(smtp_connect_args * sc, const blob * early_data) { -int port = host->port; -#ifdef SUPPORT_SOCKS -smtp_transport_options_block * ob = - (smtp_transport_options_block *)tb->options_block; -#endif +int port = sc->host->port; +smtp_transport_options_block * ob = sc->ob; -callout_address = string_sprintf("[%s]:%d", host->address, port); +callout_address = string_sprintf("[%s]:%d", sc->host->address, port); HDEBUG(D_transport|D_acl|D_v) { uschar * s = US" "; - if (interface) s = string_sprintf(" from %s ", interface); + if (sc->interface) s = string_sprintf(" from %s ", sc->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); + debug_printf_indent("Connecting to %s %s%s... ", sc->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); + { + int sock = socks_sock_connect(sc->host, sc->host_af, port, sc->interface, + sc->tblock, ob->connect_timeout); + + if (sock >= 0) + { + if (early_data && early_data->data && early_data->len) + if (send(sock, early_data->data, early_data->len, 0) < 0) + { + int save_errno = errno; + HDEBUG(D_transport|D_acl|D_v) + { + debug_printf_indent("failed: %s", CUstrerror(save_errno)); + if (save_errno == ETIMEDOUT) + debug_printf(" (timeout=%s)", readconf_printtime(ob->connect_timeout)); + debug_printf("\n"); + } + (void)close(sock); + sock = -1; + errno = save_errno; + } + } + return sock; + } #endif -return smtp_sock_connect(host, host_af, port, interface, tb, timeout, NULL); +return smtp_sock_connect(sc->host, sc->host_af, port, sc->interface, + sc->tblock, ob->connect_timeout, early_data); } @@ -380,18 +477,39 @@ 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_out.active == outblock->sock) - rc = tls_write(FALSE, outblock->buffer, n, more); +#ifndef DISABLE_TLS +if (outblock->cctx->tls_ctx) + rc = tls_write(outblock->cctx->tls_ctx, outblock->buffer, n, more); else #endif - rc = send(outblock->sock, outblock->buffer, n, + + { + if (outblock->conn_args) + { + blob early_data = { .data = outblock->buffer, .len = n }; + + /* We ignore the more-flag if we're doing a connect with early-data, which + means we won't get BDAT+data. A pity, but wise due to the idempotency + requirement: TFO with data can, in rare cases, replay the data to the + receiver. */ + + if ( (outblock->cctx->sock = smtp_connect(outblock->conn_args, &early_data)) + < 0) + return FALSE; + outblock->conn_args = NULL; + rc = n; + } + else + { + rc = send(outblock->cctx->sock, outblock->buffer, n, #ifdef MSG_MORE - more ? MSG_MORE : 0 + more ? MSG_MORE : 0 #else - 0 + 0 #endif - ); + ); + } + } if (rc <= 0) { @@ -414,7 +532,7 @@ return TRUE; any error message. Arguments: - outblock contains buffer for pipelining, and socket + sx SMTP connection, contains buffer for pipelining, and socket mode buffer, write-with-more-likely, write format a format, starting with one of of HELO, MAIL FROM, RCPT TO, DATA, ".", or QUIT. @@ -427,36 +545,43 @@ Returns: 0 if command added to pipelining buffer, with nothing transmitted */ int -smtp_write_command(smtp_outblock * outblock, int mode, const char *format, ...) +smtp_write_command(void * sx, int mode, const char *format, ...) { -int count; +smtp_outblock * outblock = &((smtp_context *)sx)->outblock; int rc = 0; -va_list ap; if (format) { + gstring gs = { .size = big_buffer_size, .ptr = 0, .s = big_buffer }; + va_list ap; + + /* Use taint-unchecked routines for writing into big_buffer, trusting that + we'll never expand the results. Actually, the error-message use - leaving + the results in big_buffer for potential later use - is uncomfortably distant. + XXX Would be better to assume all smtp commands are short, use normal pool + alloc rather than big_buffer, and another global for the data-for-error. */ + va_start(ap, format); - if (!string_vformat(big_buffer, big_buffer_size, CS format, ap)) + if (!string_vformat(&gs, SVFMT_TAINT_NOCHK, CS format, ap)) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " "SMTP"); va_end(ap); - count = Ustrlen(big_buffer); + string_from_gstring(&gs); - if (count > outblock->buffersize) + if (gs.ptr > outblock->buffersize) log_write(0, LOG_MAIN|LOG_PANIC_DIE, "overlong write_command in outgoing " "SMTP"); - if (count > outblock->buffersize - (outblock->ptr - outblock->buffer)) + if (gs.ptr > 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; + Ustrncpy(outblock->ptr, gs.s, gs.ptr); + outblock->ptr += gs.ptr; outblock->cmd_count++; - count -= 2; - big_buffer[count] = 0; /* remove \r\n for error message */ + gs.ptr -= 2; string_from_gstring(&gs); /* 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. @@ -504,19 +629,19 @@ Arguments: inblock the SMTP input block (contains holding buffer, socket, etc.) buffer where to put the line size space available for the line - timeout the timeout to use when reading a packet + timelimit deadline for reading the lime, seconds past epoch Returns: length of a line that has been put in the buffer -1 otherwise, with errno set */ static int -read_response_line(smtp_inblock *inblock, uschar *buffer, int size, int timeout) +read_response_line(smtp_inblock *inblock, uschar *buffer, int size, time_t timelimit) { uschar *p = buffer; uschar *ptr = inblock->ptr; uschar *ptrend = inblock->ptrend; -int sock = inblock->sock; +client_conn_ctx * cctx = inblock->cctx; /* Loop for reading multiple packets or reading another packet after emptying a previously-read one. */ @@ -554,9 +679,9 @@ for (;;) /* Need to read a new input packet. */ - if((rc = ip_recv(sock, inblock->buffer, inblock->buffersize, timeout)) <= 0) + if((rc = ip_recv(cctx, inblock->buffer, inblock->buffersize, timelimit)) <= 0) { - DEBUG(D_deliver|D_transport|D_acl) + DEBUG(D_deliver|D_transport|D_acl|D_v) debug_printf_indent(errno ? " SMTP(%s)<<\n" : " SMTP(closed)<<\n", strerror(errno)); break; @@ -593,7 +718,8 @@ also returned after a reading error. In this case buffer[0] will be zero, and the error code will be in errno. Arguments: - inblock the SMTP input block (contains holding buffer, socket, etc.) + sx the SMTP connection (contains input block with holding buffer, + socket, etc.) buffer where to put the response size the size of the buffer okdigit the expected first digit of the response @@ -601,26 +727,43 @@ Arguments: Returns: TRUE if a valid, non-error response was received; else FALSE */ +/*XXX could move to smtp transport; no other users */ BOOL -smtp_read_response(smtp_inblock *inblock, uschar *buffer, int size, int okdigit, +smtp_read_response(void * sx0, uschar * buffer, int size, int okdigit, int timeout) { -uschar *ptr = buffer; -int count; +smtp_context * sx = sx0; +uschar * ptr = buffer; +int count = 0; +time_t timelimit = time(NULL) + timeout; errno = 0; /* Ensure errno starts out zero */ +#ifndef DISABLE_PIPE_CONNECT +if (sx->pending_BANNER || sx->pending_EHLO) + { + int rc; + if ((rc = smtp_reap_early_pipe(sx, &count)) != OK) + { + DEBUG(D_transport) debug_printf("failed reaping pipelined cmd responsess\n"); + buffer[0] = '\0'; + if (rc == DEFER) errno = ERRNO_TLSFAILURE; + return FALSE; + } + } +#endif + /* This is a loop to read and concatenate the lines that make up a multi-line response. */ for (;;) { - if ((count = read_response_line(inblock, ptr, size, timeout)) < 0) + if ((count = read_response_line(&sx->inblock, ptr, size, timelimit)) < 0) return FALSE; HDEBUG(D_transport|D_acl|D_v) - debug_printf_indent(" %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 @@ -654,6 +797,10 @@ for (;;) size -= count + 1; } +#ifdef TCP_FASTOPEN + tfo_out_check(sx->cctx.sock); +#endif + /* Return a value that depends on the SMTP return code. On some systems a non-zero value of errno has been seen at this point, so ensure it is zero, because the caller of this function looks at errno when FALSE is returned, to