* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2015 */
+/* Copyright (c) University of Cambridge 1995 - 2017 */
/* See the file NOTICE for conditions of use and distribution. */
/* Functions for doing things with sockets. With the advent of IPv6 this has
got messier, so that it's worth pulling out the code into separate functions
-that other parts of Exim can call, expecially as there are now several
+that other parts of Exim can call, especially as there are now several
different places in the code where sockets are used. */
address the remote address, in text form
port the remote port
timeout a timeout (zero for indefinite timeout)
+ fastopen non-null iff TCP_FASTOPEN can be used; may indicate early-data to
+ be sent in SYN segment
Returns: 0 on success; -1 on failure, with errno set
*/
int
-ip_connect(int sock, int af, const uschar *address, int port, int timeout)
+ip_connect(int sock, int af, const uschar *address, int port, int timeout,
+ const blob * fastopen)
{
struct sockaddr_in s_in4;
struct sockaddr *s_ptr;
callout_address = string_sprintf("[%s]:%d", address, port);
sigalrm_seen = FALSE;
if (timeout > 0) alarm(timeout);
-rc = connect(sock, s_ptr, s_len);
+
+#if defined(TCP_FASTOPEN) && defined(MSG_FASTOPEN)
+/* TCP Fast Open, if the system has a cookie from a previous call to
+this peer, can send data in the SYN packet. The peer can send data
+before it gets our ACK of its SYN,ACK - the latter is useful for
+the SMTP banner. Other (than SMTP) cases of TCP connections can
+possibly use the data-on-syn, so support that too. */
+
+if (fastopen)
+ {
+ if ((rc = sendto(sock, fastopen->data, fastopen->len,
+ MSG_FASTOPEN | MSG_DONTWAIT, s_ptr, s_len)) >= 0)
+ /* seen for with-data, experimental TFO option, with-cookie case */
+ {
+ DEBUG(D_transport|D_v) debug_printf("TFO mode connection attempt, %s data\n",
+ fastopen->len > 0 ? "with" : "no");
+ tcp_out_fastopen = fastopen->len > 0 ? 2 : 1;
+ }
+ else if (errno == EINPROGRESS) /* expected for nonready peer */
+ /* seen for no-data, proper TFO option, both cookie-request and with-cookie cases */
+ /* apparently no visibility of the diffference at this point */
+ /* with netwk delay, post-conn tcp_info sees unacked 1 for R, 2 for C; code in smtp_out.c */
+ /* ? older Experimental TFO option behaviour ? */
+ { /* queue unsent data */
+ if (!fastopen->data)
+ {
+ tcp_out_fastopen = 1; /* we tried; unknown if useful yet */
+ rc = 0;
+ }
+ else if ( (rc = send(sock, fastopen->data, fastopen->len, 0)) < 0
+ && errno == EINPROGRESS /* expected for nonready peer */
+ )
+ rc = 0;
+ }
+ else if(errno == EOPNOTSUPP)
+ {
+ DEBUG(D_transport)
+ debug_printf("Tried TCP Fast Open but apparently not enabled by sysctl\n");
+ goto legacy_connect;
+ }
+ }
+else
+#endif
+ {
+legacy_connect:
+ if ((rc = connect(sock, s_ptr, s_len)) >= 0)
+ if ( fastopen && fastopen->data && fastopen->len
+ && send(sock, fastopen->data, fastopen->len, 0) < 0)
+ rc = -1;
+ }
+
save_errno = errno;
alarm(0);
address the remote address, in text form
portlo,porthi the remote port range
timeout a timeout
- connhost if not NULL, host_item filled in with connection details
+ connhost if not NULL, host_item to be filled in with connection details
errstr pointer for allocated string on error
+ fastopen with SOCK_STREAM, if non-null, request TCP Fast Open.
+ Additionally, optional early-data to send
Return:
socket fd, or -1 on failure (having allocated an error string)
*/
int
ip_connectedsocket(int type, const uschar * hostname, int portlo, int porthi,
- int timeout, host_item * connhost, uschar ** errstr)
+ int timeout, host_item * connhost, uschar ** errstr, const blob * fastopen)
{
int namelen, port;
host_item shost;
/* Try to connect to the server - test each IP till one works */
-for (h = &shost; h != NULL; h = h->next)
+for (h = &shost; h; h = h->next)
{
fd = Ustrchr(h->address, ':') != 0
? fd6 < 0 ? (fd6 = ip_socket(type, af = AF_INET6)) : fd6
}
for(port = portlo; port <= porthi; port++)
- if (ip_connect(fd, af, h->address, port, timeout) == 0)
+ if (ip_connect(fd, af, h->address, port, timeout, fastopen) == 0)
{
if (fd != fd6) close(fd6);
if (fd != fd4) close(fd4);
}
+/*XXX TFO? */
int
ip_tcpsocket(const uschar * hostport, uschar ** errstr, int tmo)
{
}
return ip_connectedsocket(SOCK_STREAM, hostname, portlow, porthigh,
- tmo, NULL, errstr);
+ tmo, NULL, errstr, NULL);
}
int
{
int fodder = 1;
if (setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
- (uschar *)(&fodder), sizeof(fodder)) != 0)
+ US (&fodder), sizeof(fodder)) != 0)
log_write(0, LOG_MAIN, "setsockopt(SO_KEEPALIVE) on connection %s %s "
"failed: %s", torf? "to":"from", address, strerror(errno));
}
do
{
- struct timeval tv = { time_left, 0 };
+ struct timeval tv = { .tv_sec = time_left, .tv_usec = 0 };
FD_ZERO (&select_inset);
FD_SET (fd, &select_inset);
git://git.exim.org / exim.git / blobdiff