* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2009 */
+/* 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"
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
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;
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)
{
break;
}
-if (iface != NULL) *interface = string_copy(iface);
+if (iface) *interface = string_copy(iface);
return TRUE;
}
{
uschar *pstring = expand_string(rstring);
-if (pstring == NULL)
+if (!pstring)
{
addr->transport_return = PANIC;
addr->message = string_sprintf("failed to expand \"%s\" (\"port\" option) "
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",
-/*************************************************
-* 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 or elsewhere). In other cases, the default passed as an argument is
-used, and the host item is updated with its value.
+ }
+# 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
- dscp DSCP value to assign to socket
+
+/* 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, const uschar *dscp)
+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;
- }
-else host->port = port; /* Set the port actually used */
-
-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("DSCP \"%s\"=%x ", dscp, dscp_value);
+ 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("failed to set DSCP: %s ", strerror(errno));
+ 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 */
{
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");
{
union sockaddr_46 interface_sock;
EXIM_SOCKLEN_T size = sizeof(interface_sock);
- HDEBUG(D_transport|D_acl|D_v) debug_printf("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 (keepalive) ip_keepalive(sock, host->address, TRUE);
+ 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 *
*************************************************/
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_out.active == outblock->sock)
- rc = tls_write(FALSE, outblock->buffer, outblock->ptr - outblock->buffer);
+ 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;
}
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
*/
int
-smtp_write_command(smtp_outblock *outblock, BOOL noflush, const 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;
/* 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
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
*/
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 (;;)
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
}
/* End of smtp_out.c */
+/* vi: aw ai sw=2
+*/
git://git.exim.org / exim.git / blobdiff