X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/53c7b3a70978c2748f46d1d99211530750b1de22..86ddd98d63910f57b5aaacc6d77e09aa65b10b32:/src/src/smtp_out.c diff --git a/src/src/smtp_out.c b/src/src/smtp_out.c index 96ee15282..2a4497488 100644 --- a/src/src/smtp_out.c +++ b/src/src/smtp_out.c @@ -3,6 +3,7 @@ *************************************************/ /* Copyright (c) University of Cambridge 1995 - 2018 */ +/* Copyright (c) The Exim Maintainers 2020 */ /* See the file NOTICE for conditions of use and distribution. */ /* A number of functions for driving outgoing SMTP calls. */ @@ -63,9 +64,10 @@ if (is_tainted(expint)) return FALSE; } -while (isspace(*expint)) expint++; -if (*expint == 0) return TRUE; +Uskip_whitespace(&expint); +if (!*expint) return TRUE; +/* we just tested to ensure no taint, so big_buffer is ok */ while ((iface = string_nextinlist(&expint, &sep, big_buffer, big_buffer_size))) { @@ -157,20 +159,32 @@ tfo_out_check(int sock) { # ifdef __FreeBSD__ struct tcp_info tinfo; -int val; -socklen_t len = sizeof(val); +socklen_t len = sizeof(tinfo); -/* 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. */ +/* A getsockopt TCP_FASTOPEN unfortunately returns "was-used" for a TFO/R as +well as a TFO/C. Use what we can of the Linux hack below; reliability issues ditto. */ +switch (tcp_out_fastopen) + { + case TFO_ATTEMPTED_NODATA: + if ( getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0 + && tinfo.tcpi_state == TCPS_SYN_SENT + && tinfo.__tcpi_unacked > 0 + ) + { + DEBUG(D_transport|D_v) + debug_printf("TCP_FASTOPEN tcpi_unacked %d\n", tinfo.__tcpi_unacked); + tcp_out_fastopen = TFO_USED_NODATA; + } + break; + /* + case TFO_ATTEMPTED_DATA: + case TFO_ATTEMPTED_DATA: + if (tinfo.tcpi_options & TCPI_OPT_SYN_DATA) XXX no equvalent as of 12.2 + */ + } -/* -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 */ } @@ -232,9 +246,18 @@ switch (tcp_out_fastopen) #endif -/* Arguments as for smtp_connect(), plus - early_data if non-NULL, idenmpotent data to be sent - +/* Arguments: + host host item containing name and address and port + host_af AF_INET or AF_INET6 + port TCP port number + interface outgoing interface address or NULL + tb transport + timeout timeout value or 0 + early_data if non-NULL, idempotent data to be sent - preferably in the TCP SYN segment + Special case: non-NULL but with NULL blob.data - caller is + client-data-first (eg. TLS-on-connect) and a lazy-TCP-connect is + acceptable. Returns: connected socket number, or -1 with errno set */ @@ -304,23 +327,45 @@ early-data but no TFO support, send it after connecting. */ else { #ifdef TCP_FASTOPEN + /* See if TCP Fast Open usable. Default is a traditional 3WHS connect */ if (verify_check_given_host(CUSS &ob->hosts_try_fastopen, host) == OK) - fastopen_blob = early_data ? early_data : &tcp_fastopen_nodata; + { + if (!early_data) + fastopen_blob = &tcp_fastopen_nodata; /* TFO, with no data */ + else if (early_data->data) + fastopen_blob = early_data; /* TFO, with data */ +# ifdef TCP_FASTOPEN_CONNECT + else + { /* expecting client data */ + debug_printf(" set up lazy-connect\n"); + setsockopt(sock, IPPROTO_TCP, TCP_FASTOPEN_CONNECT, US &on, sizeof(on)); + /* fastopen_blob = NULL; lazy TFO, triggered by data write */ + } +# endif + } #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) { + /* We had some early-data to send, but couldn't do TFO */ HDEBUG(D_transport|D_acl|D_v) debug_printf("sending %ld nonTFO early-data\n", (long)early_data->len); -#ifdef TCP_QUICKACK +#ifdef TCP_QUICKACK_notdef (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; } +#ifdef TCP_QUICKACK_notdef + /* Under TFO (with openssl & pipe-conn; testcase 4069, as of + 5.10.8-100.fc32.x86_64) this seems to be inop. + Perhaps overwritten when we (client) go -> ESTABLISHED on seeing the 3rd-ACK? + For that case, added at smtp_reap_banner(). */ + (void) setsockopt(sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off)); +#endif } /* Either bind() or connect() failed */ @@ -374,7 +419,7 @@ smtp_port_for_connect(host_item * host, int port) { if (host->port != PORT_NONE) { - HDEBUG(D_transport|D_acl|D_v) + HDEBUG(D_transport|D_acl|D_v) if (port != host->port) debug_printf_indent("Transport port=%d replaced by host-specific port=%d\n", port, host->port); port = host->port; @@ -395,6 +440,9 @@ host->address will always be an IPv4 address. Arguments: sc details for making connection: host, af, interface, transport early_data if non-NULL, data to be sent - preferably in the TCP SYN segment + Special case: non-NULL but with NULL blob.data - caller is + client-data-first (eg. TLS-on-connect) and a lazy-TCP-connect is + acceptable. Returns: connected socket number, or -1 with errno set */ @@ -500,7 +548,7 @@ else rc = n; } else - + { rc = send(outblock->cctx->sock, outblock->buffer, n, #ifdef MSG_MORE more ? MSG_MORE : 0 @@ -508,6 +556,17 @@ else 0 #endif ); + +#if defined(__linux__) + /* This is a workaround for a current linux kernel bug: as of + 5.6.8-200.fc31.x86_64 small (cctx->sock, IPPROTO_TCP, TCP_CORK, &off, sizeof(off)); +#endif + } } if (rc <= 0) @@ -597,10 +656,12 @@ if (format) while (!isspace(*p)) p++; while (isspace(*p)) p++; } - while (*p != 0) *p++ = '*'; + while (*p) *p++ = '*'; } - HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP>> %s\n", big_buffer); + HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP%c> %s\n", + mode == SCMD_BUFFER ? '|' : mode == SCMD_MORE ? '+' : '>', + big_buffer); } if (mode != SCMD_BUFFER)