+
+#ifdef EXPERIMENTAL_PROXY
+/*************************************************
+* Restore socket timeout to previous value *
+*************************************************/
+/* If the previous value was successfully retrieved, restore
+it before returning control to the non-proxy routines
+
+Arguments: fd - File descriptor for input
+ get_ok - Successfully retrieved previous values
+ tvtmp - Time struct with previous values
+ vslen - Length of time struct
+Returns: none
+*/
+static void
+restore_socket_timeout(int fd, int get_ok, struct timeval tvtmp, socklen_t vslen)
+{
+if (get_ok == 0)
+ setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tvtmp, vslen);
+}
+
+/*************************************************
+* Check if host is required proxy host *
+*************************************************/
+/* The function determines if inbound host will be a regular smtp host
+or if it is configured that it must use Proxy Protocol.
+
+Arguments: none
+Returns: bool
+*/
+
+static BOOL
+check_proxy_protocol_host()
+{
+int rc;
+/* Cannot configure local connection as a proxy inbound */
+if (sender_host_address == NULL) return proxy_session;
+
+rc = verify_check_this_host(&proxy_required_hosts, NULL, NULL,
+ sender_host_address, NULL);
+if (rc == OK)
+ {
+ DEBUG(D_receive)
+ debug_printf("Detected proxy protocol configured host\n");
+ proxy_session = TRUE;
+ }
+return proxy_session;
+}
+
+
+/*************************************************
+* Setup host for proxy protocol *
+*************************************************/
+/* The function configures the connection based on a header from the
+inbound host to use Proxy Protocol. The specification is very exact
+so exit with an error if do not find the exact required pieces. This
+includes an incorrect number of spaces separating args.
+
+Arguments: none
+Returns: int
+*/
+
+static BOOL
+setup_proxy_protocol_host()
+{
+union {
+ struct {
+ uschar line[108];
+ } v1;
+ struct {
+ uschar sig[12];
+ uint8_t ver_cmd;
+ uint8_t fam;
+ uint16_t len;
+ union {
+ struct { /* TCP/UDP over IPv4, len = 12 */
+ uint32_t src_addr;
+ uint32_t dst_addr;
+ uint16_t src_port;
+ uint16_t dst_port;
+ } ip4;
+ struct { /* TCP/UDP over IPv6, len = 36 */
+ uint8_t src_addr[16];
+ uint8_t dst_addr[16];
+ uint16_t src_port;
+ uint16_t dst_port;
+ } ip6;
+ struct { /* AF_UNIX sockets, len = 216 */
+ uschar src_addr[108];
+ uschar dst_addr[108];
+ } unx;
+ } addr;
+ } v2;
+} hdr;
+
+/* Temp variables used in PPv2 address:port parsing */
+uint16_t tmpport;
+char tmpip[INET_ADDRSTRLEN];
+struct sockaddr_in tmpaddr;
+char tmpip6[INET6_ADDRSTRLEN];
+struct sockaddr_in6 tmpaddr6;
+
+int get_ok = 0;
+int size, ret, fd;
+const char v2sig[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
+uschar *iptype; /* To display debug info */
+struct timeval tv;
+socklen_t vslen = 0;
+struct timeval tvtmp;
+
+vslen = sizeof(struct timeval);
+
+fd = fileno(smtp_in);
+
+/* Save current socket timeout values */
+get_ok = getsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tvtmp,
+ &vslen);
+
+/* Proxy Protocol host must send header within a short time
+(default 3 seconds) or it's considered invalid */
+tv.tv_sec = PROXY_NEGOTIATION_TIMEOUT_SEC;
+tv.tv_usec = PROXY_NEGOTIATION_TIMEOUT_USEC;
+setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tv,
+ sizeof(struct timeval));
+
+do
+ {
+ /* The inbound host was declared to be a Proxy Protocol host, so
+ don't do a PEEK into the data, actually slurp it up. */
+ ret = recv(fd, &hdr, sizeof(hdr), 0);
+ }
+ while (ret == -1 && errno == EINTR);
+
+if (ret == -1)
+ {
+ restore_socket_timeout(fd, get_ok, tvtmp, vslen);
+ return (errno == EAGAIN) ? 0 : ERRNO_PROXYFAIL;
+ }
+
+if (ret >= 16 &&
+ memcmp(&hdr.v2, v2sig, 12) == 0)
+ {
+ uint8_t ver, cmd;
+
+ /* May 2014: haproxy combined the version and command into one byte to
+ allow two full bytes for the length field in order to proxy SSL
+ connections. SSL Proxy is not supported in this version of Exim, but
+ must still seperate values here. */
+ ver = (hdr.v2.ver_cmd & 0xf0) >> 4;
+ cmd = (hdr.v2.ver_cmd & 0x0f);
+
+ if (ver != 0x02)
+ {
+ DEBUG(D_receive) debug_printf("Invalid Proxy Protocol version: %d\n", ver);
+ goto proxyfail;
+ }
+ DEBUG(D_receive) debug_printf("Detected PROXYv2 header\n");
+ /* The v2 header will always be 16 bytes per the spec. */
+ size = 16 + hdr.v2.len;
+ if (ret < size)
+ {
+ DEBUG(D_receive) debug_printf("Truncated or too large PROXYv2 header (%d/%d)\n",
+ ret, size);
+ goto proxyfail;
+ }
+ switch (cmd)
+ {
+ case 0x01: /* PROXY command */
+ switch (hdr.v2.fam)
+ {
+ case 0x11: /* TCPv4 address type */
+ iptype = US"IPv4";
+ tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.src_addr;
+ inet_ntop(AF_INET, &(tmpaddr.sin_addr), (char *)&tmpip, sizeof(tmpip));
+ if (!string_is_ip_address(US tmpip,NULL))
+ {
+ DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
+ return ERRNO_PROXYFAIL;
+ }
+ proxy_host_address = sender_host_address;
+ sender_host_address = string_copy(US tmpip);
+ tmpport = ntohs(hdr.v2.addr.ip4.src_port);
+ proxy_host_port = sender_host_port;
+ sender_host_port = tmpport;
+ /* Save dest ip/port */
+ tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.dst_addr;
+ inet_ntop(AF_INET, &(tmpaddr.sin_addr), (char *)&tmpip, sizeof(tmpip));
+ if (!string_is_ip_address(US tmpip,NULL))
+ {
+ DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
+ return ERRNO_PROXYFAIL;
+ }
+ proxy_target_address = string_copy(US tmpip);
+ tmpport = ntohs(hdr.v2.addr.ip4.dst_port);
+ proxy_target_port = tmpport;
+ goto done;
+ case 0x21: /* TCPv6 address type */
+ iptype = US"IPv6";
+ memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.src_addr, 16);
+ inet_ntop(AF_INET6, &(tmpaddr6.sin6_addr), (char *)&tmpip6, sizeof(tmpip6));
+ if (!string_is_ip_address(US tmpip6,NULL))
+ {
+ DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
+ return ERRNO_PROXYFAIL;
+ }
+ proxy_host_address = sender_host_address;
+ sender_host_address = string_copy(US tmpip6);
+ tmpport = ntohs(hdr.v2.addr.ip6.src_port);
+ proxy_host_port = sender_host_port;
+ sender_host_port = tmpport;
+ /* Save dest ip/port */
+ memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.dst_addr, 16);
+ inet_ntop(AF_INET6, &(tmpaddr6.sin6_addr), (char *)&tmpip6, sizeof(tmpip6));
+ if (!string_is_ip_address(US tmpip6,NULL))
+ {
+ DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
+ return ERRNO_PROXYFAIL;
+ }
+ proxy_target_address = string_copy(US tmpip6);
+ tmpport = ntohs(hdr.v2.addr.ip6.dst_port);
+ proxy_target_port = tmpport;
+ goto done;
+ default:
+ DEBUG(D_receive)
+ debug_printf("Unsupported PROXYv2 connection type: 0x%02x\n",
+ hdr.v2.fam);
+ goto proxyfail;
+ }
+ /* Unsupported protocol, keep local connection address */
+ break;
+ case 0x00: /* LOCAL command */
+ /* Keep local connection address for LOCAL */
+ break;
+ default:
+ DEBUG(D_receive)
+ debug_printf("Unsupported PROXYv2 command: 0x%x\n", cmd);
+ goto proxyfail;
+ }
+ }
+else if (ret >= 8 &&
+ memcmp(hdr.v1.line, "PROXY", 5) == 0)
+ {
+ uschar *p = string_copy(hdr.v1.line);
+ uschar *end = memchr(p, '\r', ret - 1);
+ uschar *sp; /* Utility variables follow */
+ int tmp_port;
+ char *endc;
+
+ if (!end || end[1] != '\n')
+ {
+ DEBUG(D_receive) debug_printf("Partial or invalid PROXY header\n");
+ goto proxyfail;
+ }
+ *end = '\0'; /* Terminate the string */
+ size = end + 2 - hdr.v1.line; /* Skip header + CRLF */
+ DEBUG(D_receive) debug_printf("Detected PROXYv1 header\n");
+ /* Step through the string looking for the required fields. Ensure
+ strict adherance to required formatting, exit for any error. */
+ p += 5;
+ if (!isspace(*(p++)))
+ {
+ DEBUG(D_receive) debug_printf("Missing space after PROXY command\n");
+ goto proxyfail;
+ }
+ if (!Ustrncmp(p, CCS"TCP4", 4))
+ iptype = US"IPv4";
+ else if (!Ustrncmp(p,CCS"TCP6", 4))
+ iptype = US"IPv6";
+ else if (!Ustrncmp(p,CCS"UNKNOWN", 7))
+ {
+ iptype = US"Unknown";
+ goto done;
+ }
+ else
+ {
+ DEBUG(D_receive) debug_printf("Invalid TCP type\n");
+ goto proxyfail;
+ }
+
+ p += Ustrlen(iptype);
+ if (!isspace(*(p++)))
+ {
+ DEBUG(D_receive) debug_printf("Missing space after TCP4/6 command\n");
+ goto proxyfail;
+ }
+ /* Find the end of the arg */
+ if ((sp = Ustrchr(p, ' ')) == NULL)
+ {
+ DEBUG(D_receive)
+ debug_printf("Did not find proxied src %s\n", iptype);
+ goto proxyfail;
+ }
+ *sp = '\0';
+ if(!string_is_ip_address(p,NULL))
+ {
+ DEBUG(D_receive)
+ debug_printf("Proxied src arg is not an %s address\n", iptype);
+ goto proxyfail;
+ }
+ proxy_host_address = sender_host_address;
+ sender_host_address = p;
+ p = sp + 1;
+ if ((sp = Ustrchr(p, ' ')) == NULL)
+ {
+ DEBUG(D_receive)
+ debug_printf("Did not find proxy dest %s\n", iptype);
+ goto proxyfail;
+ }
+ *sp = '\0';
+ if(!string_is_ip_address(p,NULL))
+ {
+ DEBUG(D_receive)
+ debug_printf("Proxy dest arg is not an %s address\n", iptype);
+ goto proxyfail;
+ }
+ proxy_target_address = p;
+ p = sp + 1;
+ if ((sp = Ustrchr(p, ' ')) == NULL)
+ {
+ DEBUG(D_receive) debug_printf("Did not find proxied src port\n");
+ goto proxyfail;
+ }
+ *sp = '\0';
+ tmp_port = strtol(CCS p,&endc,10);
+ if (*endc || tmp_port == 0)
+ {
+ DEBUG(D_receive)
+ debug_printf("Proxied src port '%s' not an integer\n", p);
+ goto proxyfail;
+ }
+ proxy_host_port = sender_host_port;
+ sender_host_port = tmp_port;
+ p = sp + 1;
+ if ((sp = Ustrchr(p, '\0')) == NULL)
+ {
+ DEBUG(D_receive) debug_printf("Did not find proxy dest port\n");
+ goto proxyfail;
+ }
+ tmp_port = strtol(CCS p,&endc,10);
+ if (*endc || tmp_port == 0)
+ {
+ DEBUG(D_receive)
+ debug_printf("Proxy dest port '%s' not an integer\n", p);
+ goto proxyfail;
+ }
+ proxy_target_port = tmp_port;
+ /* Already checked for /r /n above. Good V1 header received. */
+ goto done;
+ }
+else
+ {
+ /* Wrong protocol */
+ DEBUG(D_receive) debug_printf("Invalid proxy protocol version negotiation\n");
+ goto proxyfail;
+ }
+
+proxyfail:
+restore_socket_timeout(fd, get_ok, tvtmp, vslen);
+/* Don't flush any potential buffer contents. Any input should cause a
+ synchronization failure */
+return FALSE;
+
+done:
+restore_socket_timeout(fd, get_ok, tvtmp, vslen);
+DEBUG(D_receive)
+ debug_printf("Valid %s sender from Proxy Protocol header\n", iptype);
+return proxy_session;
+}
+#endif
+
git://git.exim.org / exim.git / blobdiff