/* 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. Is there any usage where the former might be?
-We might extend the ip_connect() args for data if so. For now,
-connect in FASTOPEN mode but with zero data.
-*/
+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)
- if (errno == EINPROGRESS) /* expected for nonready peer */
- { /* queue the data */
- if ( (rc = send(sock, fastopen->data, fastopen->len, 0)) < 0
- && errno == EINPROGRESS) /* expected for nonready peer */
- rc = 0;
- }
- else if(errno == EOPNOTSUPP)
+ 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)
{
- DEBUG(D_transport)
- debug_printf("Tried TCP Fast Open but apparently not enabled by sysctl\n");
- goto legacy_connect;
+ 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
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
-XXX could add early-data support
+ 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;
host_item *h;
int af = 0, fd, fd4 = -1, fd6 = -1;
-blob * fastopen = tcp_fastopen_ok && type == SOCK_STREAM
- ? &tcp_fastopen_nodata : NULL;
shost.next = NULL;
shost.address = NULL;
}
+/*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