* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2009 */
+/* 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. */
*/
static void
-ip_addrinfo(uschar *address, struct sockaddr_in6 *saddr)
+ip_addrinfo(const uschar *address, struct sockaddr_in6 *saddr)
{
#ifdef IPV6_USE_INET_PTON
- if (inet_pton(AF_INET6, CS address, &saddr->sin6_addr) != 1)
+ if (inet_pton(AF_INET6, CCS address, &saddr->sin6_addr) != 1)
log_write(0, LOG_MAIN|LOG_PANIC_DIE, "unable to parse \"%s\" as an "
"IP address", address);
saddr->sin6_family = AF_INET6;
hints.ai_family = AF_INET6;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_NUMERICHOST;
- if ((rc = getaddrinfo(CS address, NULL, &hints, &res)) != 0 || res == NULL)
+ if ((rc = getaddrinfo(CCS address, NULL, &hints, &res)) != 0 || res == NULL)
log_write(0, LOG_MAIN|LOG_PANIC_DIE, "unable to parse \"%s\" as an "
"IP address: %s", address,
(rc == 0)? "NULL result returned" : gai_strerror(rc));
* Bind socket to interface and port *
*************************************************/
-/* This function binds a socket to a local interface address and port. For a
-wildcard IPv6 bind, the address is ":".
-
-Arguments:
- sock the socket
- af AF_INET or AF_INET6 - the socket type
- address the IP address, in text form
- port the IP port (host order)
-
-Returns: the result of bind()
-*/
-
int
-ip_bind(int sock, int af, uschar *address, int port)
+ip_addr(void * sin_, int af, const uschar * address, int port)
{
-int s_len;
-union sockaddr_46 sin;
-memset(&sin, 0, sizeof(sin));
+union sockaddr_46 * sin = sin_;
+memset(sin, 0, sizeof(*sin));
/* Setup code when using an IPv6 socket. The wildcard address is ":", to
ensure an IPv6 socket is used. */
{
if (address[0] == ':' && address[1] == 0)
{
- sin.v6.sin6_family = AF_INET6;
- sin.v6.sin6_addr = in6addr_any;
+ sin->v6.sin6_family = AF_INET6;
+ sin->v6.sin6_addr = in6addr_any;
}
else
- {
- ip_addrinfo(address, &sin.v6); /* Panic-dies on error */
- }
- sin.v6.sin6_port = htons(port);
- s_len = sizeof(sin.v6);
+ ip_addrinfo(address, &sin->v6); /* Panic-dies on error */
+ sin->v6.sin6_port = htons(port);
+ return sizeof(sin->v6);
}
else
#else /* HAVE_IPv6 */
/* Setup code when using IPv4 socket. The wildcard address is "". */
{
- sin.v4.sin_family = AF_INET;
- sin.v4.sin_port = htons(port);
- s_len = sizeof(sin.v4);
- if (address[0] == 0)
- sin.v4.sin_addr.s_addr = (S_ADDR_TYPE)INADDR_ANY;
- else
- sin.v4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(CS address);
+ sin->v4.sin_family = AF_INET;
+ sin->v4.sin_port = htons(port);
+ sin->v4.sin_addr.s_addr = address[0] == 0
+ ? (S_ADDR_TYPE)INADDR_ANY
+ : (S_ADDR_TYPE)inet_addr(CS address);
+ return sizeof(sin->v4);
}
+}
+
+
+
+/* This function binds a socket to a local interface address and port. For a
+wildcard IPv6 bind, the address is ":".
-/* Now we can call the bind() function */
+Arguments:
+ sock the socket
+ af AF_INET or AF_INET6 - the socket type
+ address the IP address, in text form
+ port the IP port (host order)
+Returns: the result of bind()
+*/
+
+int
+ip_bind(int sock, int af, uschar *address, int port)
+{
+union sockaddr_46 sin;
+int s_len = ip_addr(&sin, af, address, port);
return bind(sock, (struct sockaddr *)&sin, s_len);
}
af AF_INET6 or AF_INET for the socket type
address the remote address, in text form
port the remote port
- timeout a timeout
+ timeout a timeout (zero for indefinite timeout)
+ fastopen TRUE iff TCP_FASTOPEN can be used
Returns: 0 on success; -1 on failure, with errno set
*/
int
-ip_connect(int sock, int af, uschar *address, int port, int timeout)
+ip_connect(int sock, int af, const uschar *address, int port, int timeout,
+ BOOL fastopen)
{
struct sockaddr_in s_in4;
struct sockaddr *s_ptr;
memset(&s_in4, 0, sizeof(s_in4));
s_in4.sin_family = AF_INET;
s_in4.sin_port = htons(port);
- s_in4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(CS address);
+ s_in4.sin_addr.s_addr = (S_ADDR_TYPE)inet_addr(CCS address);
s_ptr = (struct sockaddr *)&s_in4;
s_len = sizeof(s_in4);
}
/* 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, NULL, 0, MSG_FASTOPEN, s_ptr, s_len)) < 0
+ && errno == EOPNOTSUPP
+ )
+ {
+ DEBUG(D_transport)
+ debug_printf("Tried TCP Fast Open but apparently not enabled by sysctl\n");
+ rc = connect(sock, s_ptr, s_len);
+ }
+ }
+else
+#endif
+ rc = connect(sock, s_ptr, s_len);
+
save_errno = errno;
alarm(0);
can't think of any other way of doing this. It converts a connection refused
into a timeout if the timeout is set to 999999. */
-if (running_in_test_harness)
+if (running_in_test_harness && save_errno == ECONNREFUSED && timeout == 999999)
{
- if (save_errno == ECONNREFUSED && timeout == 999999)
- {
- rc = -1;
- save_errno = EINTR;
- sigalrm_seen = TRUE;
- }
+ rc = -1;
+ save_errno = EINTR;
+ sigalrm_seen = TRUE;
}
/* 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. */
-errno = (save_errno == EINTR && sigalrm_seen)? ETIMEDOUT : save_errno;
+errno = save_errno == EINTR && sigalrm_seen ? ETIMEDOUT : save_errno;
return -1;
}
+/*************************************************
+* Create connected socket to remote host *
+*************************************************/
+
+/* Create a socket and connect to host (name or number, ipv6 ok)
+ at one of port-range.
+
+Arguments:
+ type SOCK_DGRAM or SOCK_STREAM
+ af AF_INET6 or AF_INET for the socket type
+ 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
+ errstr pointer for allocated string on error
+
+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 namelen, port;
+host_item shost;
+host_item *h;
+int af = 0, fd, fd4 = -1, fd6 = -1;
+BOOL fastopen = tcp_fastopen_ok && type == SOCK_STREAM;
+
+shost.next = NULL;
+shost.address = NULL;
+shost.port = portlo;
+shost.mx = -1;
+
+namelen = Ustrlen(hostname);
+
+/* Anything enclosed in [] must be an IP address. */
+
+if (hostname[0] == '[' &&
+ hostname[namelen - 1] == ']')
+ {
+ uschar * host = string_copyn(hostname+1, namelen-2);
+ if (string_is_ip_address(host, NULL) == 0)
+ {
+ *errstr = string_sprintf("malformed IP address \"%s\"", hostname);
+ return -1;
+ }
+ shost.name = shost.address = host;
+ }
+
+/* Otherwise check for an unadorned IP address */
+
+else if (string_is_ip_address(hostname, NULL) != 0)
+ shost.name = shost.address = string_copyn(hostname, namelen);
+
+/* Otherwise lookup IP address(es) from the name */
+
+else
+ {
+ shost.name = string_copyn(hostname, namelen);
+ if (host_find_byname(&shost, NULL, HOST_FIND_QUALIFY_SINGLE,
+ NULL, FALSE) != HOST_FOUND)
+ {
+ *errstr = string_sprintf("no IP address found for host %s", shost.name);
+ return -1;
+ }
+ }
+
+/* Try to connect to the server - test each IP till one works */
+
+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;
+
+ if (fd < 0)
+ {
+ *errstr = string_sprintf("failed to create socket: %s", strerror(errno));
+ goto bad;
+ }
+
+ for(port = portlo; port <= porthi; port++)
+ if (ip_connect(fd, af, h->address, port, timeout, fastopen) == 0)
+ {
+ if (fd != fd6) close(fd6);
+ if (fd != fd4) close(fd4);
+ if (connhost)
+ {
+ h->port = port;
+ *connhost = *h;
+ connhost->next = NULL;
+ }
+ return fd;
+ }
+ }
+
+*errstr = string_sprintf("failed to connect to any address for %s: %s",
+ hostname, strerror(errno));
+
+bad:
+ close(fd4); close(fd6); return -1;
+}
+
+
+int
+ip_tcpsocket(const uschar * hostport, uschar ** errstr, int tmo)
+{
+int scan;
+uschar hostname[256];
+unsigned int portlow, porthigh;
+
+/* extract host and port part */
+scan = sscanf(CS hostport, "%255s %u-%u", hostname, &portlow, &porthigh);
+if (scan != 3)
+ {
+ if (scan != 2)
+ {
+ *errstr = string_sprintf("invalid socket '%s'", hostport);
+ return -1;
+ }
+ porthigh = portlow;
+ }
+
+return ip_connectedsocket(SOCK_STREAM, hostname, portlow, porthigh,
+ tmo, NULL, errstr);
+}
+
+int
+ip_unixsocket(const uschar * path, uschar ** errstr)
+{
+int sock;
+struct sockaddr_un server;
+
+if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
+ {
+ *errstr = US"can't open UNIX socket.";
+ 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';
+if (connect(sock, (struct sockaddr *) &server, sizeof(server)) < 0)
+ {
+ int err = errno;
+ (void)close(sock);
+ *errstr = string_sprintf("unable to connect to UNIX socket (%s): %s",
+ path, strerror(err));
+ return -1;
+ }
+return sock;
+}
+
+int
+ip_streamsocket(const uschar * spec, uschar ** errstr, int tmo)
+{
+return *spec == '/'
+ ? ip_unixsocket(spec, errstr) : ip_tcpsocket(spec, errstr, tmo);
+}
+
/*************************************************
* Set keepalive on a socket *
*************************************************/
*/
void
-ip_keepalive(int sock, uschar *address, BOOL torf)
+ip_keepalive(int sock, const uschar *address, BOOL torf)
{
int fodder = 1;
if (setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
* Receive from a socket with timeout *
*************************************************/
-/* The timeout is implemented using select(), and we loop to cover select()
-getting interrupted, and the possibility of select() returning with a positive
-result but no ready descriptor. Is this in fact possible?
-
+/*
Arguments:
- sock the socket
- buffer to read into
- bufsize the buffer size
- timeout the timeout
-
-Returns: > 0 => that much data read
- <= 0 on error or EOF; errno set - zero for EOF
+ fd the file descriptor
+ timeout the timeout, seconds
+Returns: TRUE => ready for i/o
+ FALSE => timed out, or other error
*/
-
-int
-ip_recv(int sock, uschar *buffer, int buffsize, int timeout)
+BOOL
+fd_ready(int fd, int timeout)
{
fd_set select_inset;
-struct timeval tv;
-int start_recv = time(NULL);
+time_t start_recv = time(NULL);
+int time_left = timeout;
int rc;
+if (time_left <= 0)
+ {
+ errno = ETIMEDOUT;
+ return FALSE;
+ }
/* Wait until the socket is ready */
-for (;;)
+do
{
+ struct timeval tv = { time_left, 0 };
FD_ZERO (&select_inset);
- FD_SET (sock, &select_inset);
- tv.tv_sec = timeout;
- tv.tv_usec = 0;
+ FD_SET (fd, &select_inset);
- DEBUG(D_transport) debug_printf("waiting for data on socket\n");
- rc = select(sock + 1, (SELECT_ARG2_TYPE *)&select_inset, NULL, NULL, &tv);
+ /*DEBUG(D_transport) debug_printf("waiting for data on fd\n");*/
+ rc = select(fd + 1, (SELECT_ARG2_TYPE *)&select_inset, NULL, NULL, &tv);
/* If some interrupt arrived, just retry. We presume this to be rare,
but it can happen (e.g. the SIGUSR1 signal sent by exiwhat causes
Aug 2004: Somebody set up a cron job that ran exiwhat every 2 minutes, making
the interrupt not at all rare. Since the timeout is typically more than 2
minutes, the effect was to block the timeout completely. To prevent this
- happening again, we do an explicit time test. */
+ happening again, we do an explicit time test and adjust the timeout
+ accordingly */
if (rc < 0 && errno == EINTR)
{
DEBUG(D_transport) debug_printf("EINTR while waiting for socket data\n");
- if (time(NULL) - start_recv < timeout) continue;
- DEBUG(D_transport) debug_printf("total wait time exceeds timeout\n");
- }
- /* Handle a timeout, and treat any other select error as a timeout, including
- an EINTR when we have been in this loop for longer than timeout. */
+ /* Watch out, 'continue' jumps to the condition, not to the loops top */
+ time_left = timeout - (time(NULL) - start_recv);
+ if (time_left > 0) continue;
+ }
if (rc <= 0)
{
errno = ETIMEDOUT;
- return -1;
+ return FALSE;
}
- /* If the socket is ready, break out of the loop. */
-
- if (FD_ISSET(sock, &select_inset)) break;
+ /* Checking the FD_ISSET is not enough, if we're interrupted, the
+ select_inset may still contain the 'input'. */
}
+while (rc < 0 || !FD_ISSET(fd, &select_inset));
+return TRUE;
+}
+
+/* The timeout is implemented using select(), and we loop to cover select()
+getting interrupted, and the possibility of select() returning with a positive
+result but no ready descriptor. Is this in fact possible?
+
+Arguments:
+ sock the socket
+ buffer to read into
+ bufsize the buffer size
+ timeout the timeout
+
+Returns: > 0 => that much data read
+ <= 0 on error or EOF; errno set - zero for EOF
+*/
+
+int
+ip_recv(int sock, uschar *buffer, int buffsize, int timeout)
+{
+int rc;
+
+if (!fd_ready(sock, timeout))
+ return -1;
/* The socket is ready, read from it (via TLS if it's active). On EOF (i.e.
close down of the connection), set errno to zero; otherwise leave it alone. */
*level = IPPROTO_IP;
*optname = IP_TOS;
}
-#if HAVE_IPV6
+#if HAVE_IPV6 && defined(IPV6_TCLASS)
else if (af == AF_INET6)
{
*level = IPPROTO_IPV6;
return TRUE;
}
else if (c > 0)
- {
first = middle + 1;
- }
else
- {
last = middle;
- }
}
return FALSE;
}
/* End of ip.c */
+/* vi: aw ai sw=2
+*/
git://git.exim.org / exim.git / blobdiff