* 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. */
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;
static void
tfo_out_check(int sock)
{
-# if defined(TCP_INFO) && defined(EXIM_HAVE_TCPI_UNACKED)
+# ifdef __FreeBSD__
struct tcp_info tinfo;
-socklen_t len = sizeof(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 (getsockopt(sock, IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0)
+/*
+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)
{
- 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;
+ 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);
-#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. */
+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 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 there was data-on-SYN but we had to retrasnmit it, declare no TFO */
+ /* When called after waiting for received data we should be able
+ to tell if data we sent was accepted. */
- case 2:
- if (!(tinfo.tcpi_options & TCPI_OPT_SYN_DATA))
+ 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 = 0;
+ tcp_out_fastopen = TFO_NOT_USED;
}
- break;
-#endif
- }
+ 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
*/
int dscp_option;
int sock;
int save_errno = 0;
-const blob * fastopen = NULL;
+const blob * fastopen_blob = NULL;
#ifndef DISABLE_EVENT
/* 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
{
#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 */
{
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");
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
close(sock);
return -1;
}
+
if (ob->keepalive) ip_keepalive(sock, host->address, TRUE);
#ifdef TCP_FASTOPEN
- if (fastopen) tfo_out_check(sock);
+ tfo_out_check(sock);
#endif
return sock;
}
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);
}
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)
{
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.
*/
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.
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. */
/* 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;
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
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
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
git://git.exim.org / users / jgh / exim.git / blobdiff