* 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;
/* If no connection timeout is set, just call connect() without setting a
timer, thereby allowing the inbuilt OS timeout to operate. */
+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. 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.
+*/
+
+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)
+ {
+ 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);
/* Success */
-if (rc >= 0) return 0;
+if (rc >= 0)
+ return 0;
/* A failure whose error code is "Interrupted system call" is in fact
an externally applied timeout if the signal handler has been run. */
timeout a timeout
connhost if not NULL, host_item filled in with connection details
errstr pointer for allocated string on error
+XXX could add early-data support
Return:
socket fd, or -1 on failure (having allocated an error string)
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;
if (hostname[0] == '[' &&
hostname[namelen - 1] == ']')
{
- uschar * host = string_copy(hostname);
- host[namelen - 1] = 0;
- host++;
+ uschar * host = string_copyn(hostname+1, namelen-2);
if (string_is_ip_address(host, NULL) == 0)
{
*errstr = string_sprintf("malformed IP address \"%s\"", hostname);
/* Otherwise check for an unadorned IP address */
else if (string_is_ip_address(hostname, NULL) != 0)
- shost.name = shost.address = string_copy(hostname);
+ shost.name = shost.address = string_copyn(hostname, namelen);
/* Otherwise lookup IP address(es) from the name */
else
{
- shost.name = string_copy(hostname);
+ shost.name = string_copyn(hostname, namelen);
if (host_find_byname(&shost, NULL, HOST_FIND_QUALIFY_SINGLE,
NULL, FALSE) != HOST_FOUND)
{
/* 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
- : (fd4 < 0) ? (fd4 = ip_socket(type, af = AF_INET )) : fd4;
+ fd = Ustrchr(h->address, ':') != 0
+ ? fd6 < 0 ? (fd6 = ip_socket(type, af = AF_INET6)) : fd6
+ : fd4 < 0 ? (fd4 = ip_socket(type, af = AF_INET )) : fd4;
if (fd < 0)
{
}
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);
return -1;
}
+callout_address = string_copy(path);
server.sun_family = AF_UNIX;
Ustrncpy(server.sun_path, path, sizeof(server.sun_path)-1);
server.sun_path[sizeof(server.sun_path)-1] = '\0';
{
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));
}
int time_left = timeout;
int rc;
-if (timeout <= 0)
+if (time_left <= 0)
{
errno = ETIMEDOUT;
return FALSE;
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);
if (rc < 0 && errno == EINTR)
{
DEBUG(D_transport) debug_printf("EINTR while waiting for socket data\n");
+
/* Watch out, 'continue' jumps to the condition, not to the loops top */
- if (time_left = timeout - (time(NULL) - start_recv)) continue;
+ time_left = timeout - (time(NULL) - start_recv);
+ if (time_left > 0) continue;
}
if (rc <= 0)
git://git.exim.org / users / jgh / exim.git / blobdiff