Grrr...add the Skinny alias code forgotten in the last commit.

1 files changed, 338 insertions, 0 deletions

diff --git a/lib/libalias/alias_skinny.c b/lib/libalias/alias_skinny.c
new file mode 100644
index 0000000..055c05b
--- /dev/null
+++ b/lib/libalias/alias_skinny.c
@@ -0,0 +1,338 @@
+/*-
+ * alias_skinny.c
+ *
+ * Copyright (c) 2002, 2003 MarcusCom, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * Author: Joe Marcus Clarke <marcus@FreeBSD.org>
+ *
+ * $FreeBSD$
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in_systm.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netinet/ip.h>
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+#include <unistd.h>
+
+#include "alias_local.h"
+
+/*
+ * alias_skinny.c handles the translation for the Cisco Skinny Station
+ * protocol.  Skinny typically uses TCP port 2000 to set up calls between
+ * a Cisco Call Manager and a Cisco IP phone.  When a phone comes on line,
+ * it first needs to register with the Call Manager.  To do this it sends
+ * a registration message.  This message contains the IP address of the
+ * IP phone.  This message must then be translated to reflect our global
+ * IP address.  Along with the registration message (and usually in the
+ * same packet), the phone sends an IP port message.  This message indicates
+ * the TCP port over which it will communicate.
+ *
+ * When a call is placed from the phone, the Call Manager will send an
+ * Open Receive Channel message to the phone to let the caller know someone
+ * has answered.  The phone then sends back an Open Receive Channel
+ * Acknowledgement.  In this packet, the phone sends its IP address again,
+ * and the UDP port over which the voice traffic should flow.  These values
+ * need translation.  Right after the Open Receive Channel Acknowledgement, 
+ * the Call Manager sends a Start Media Transmission message indicating the
+ * call is connected.  This message contains the IP address and UDP port 
+ * number of the remote (called) party.  Once this message is translated, the 
+ * call can commence.  The called part sends the first UDP packet to the
+ * calling phone at the pre-arranged UDP port in the Open Receive Channel
+ * Acknowledgement.
+ *
+ * Skinny is a Cisco-proprietary protocol and is a trademark of Cisco Systems,
+ * Inc.  All rights reserved.
+*/
+
+/* #define DEBUG 1 */
+
+/* Message types that need translating */
+#define REG_MSG         0x00000001
+#define IP_PORT_MSG     0x00000002
+#define OPNRCVCH_ACK    0x00000022
+#define START_MEDIATX   0x0000008a
+
+struct skinny_header {
+    u_int32_t       len;
+    u_int32_t       reserved;
+    u_int32_t       msgId;
+};
+
+struct RegisterMessage {
+    u_int32_t       msgId;
+    char            devName[16];
+    u_int32_t       uid;
+    u_int32_t       instance;
+    u_int32_t       ipAddr;
+    u_char          devType;
+    u_int32_t       maxStreams;
+};
+
+struct IpPortMessage {
+    u_int32_t       msgId;
+    u_int32_t       stationIpPort;  /* Note: Skinny uses 32-bit port
+                                     * numbers */
+};
+
+struct OpenReceiveChannelAck {
+    u_int32_t       msgId;
+    u_int32_t       status;
+    u_int32_t       ipAddr;
+    u_int32_t       port;
+    u_int32_t       passThruPartyID;
+};
+
+struct StartMediaTransmission {
+    u_int32_t       msgId;
+    u_int32_t       conferenceID;
+    u_int32_t       passThruPartyID;
+    u_int32_t       remoteIpAddr;
+    u_int32_t       remotePort;
+    u_int32_t       MSPacket;
+    u_int32_t       payloadCap;
+    u_int32_t       precedence;
+    u_int32_t       silenceSuppression;
+    u_short         maxFramesPerPacket;
+    u_int32_t       G723BitRate;
+};
+
+typedef enum {
+    ClientToServer = 0,
+    ServerToClient = 1
+} ConvDirection;
+
+
+static int
+alias_skinny_reg_msg(struct RegisterMessage *reg_msg, struct ip *pip,
+                     struct tcphdr *tc, struct alias_link *link,
+                     ConvDirection direction)
+{
+  reg_msg->ipAddr = (u_int32_t) GetAliasAddress(link).s_addr;
+
+  tc->th_sum = 0;
+  tc->th_sum = TcpChecksum(pip);
+
+  return 0;
+}
+
+static int
+alias_skinny_startmedia(struct StartMediaTransmission *start_media,
+                        struct ip *pip, struct tcphdr *tc,
+                        struct alias_link *link, u_int32_t localIpAddr,
+                        ConvDirection direction)
+{
+  struct in_addr  dst, src;
+
+  dst.s_addr = start_media->remoteIpAddr;
+  src.s_addr = localIpAddr;
+
+  /* XXX I should probably handle in bound global translations as well. */
+
+  return 0;
+}
+
+static int
+alias_skinny_port_msg(struct IpPortMessage *port_msg, struct ip *pip,
+                      struct tcphdr *tc, struct alias_link *link,
+                      ConvDirection direction)
+{
+  port_msg->stationIpPort = (u_int32_t) ntohs(GetAliasPort(link));
+
+  tc->th_sum = 0;
+  tc->th_sum = TcpChecksum(pip);
+
+  return 0;
+}
+
+static int
+alias_skinny_opnrcvch_ack(struct OpenReceiveChannelAck *opnrcvch_ack,
+                          struct ip * pip, struct tcphdr *tc,
+                          struct alias_link *link, u_int32_t *localIpAddr,
+                          ConvDirection direction)
+{
+  struct in_addr  null_addr;
+  struct alias_link *opnrcv_link;
+  u_int32_t localPort;
+
+  *localIpAddr = (u_int32_t) opnrcvch_ack->ipAddr;
+  localPort = opnrcvch_ack->port;
+
+  null_addr.s_addr = INADDR_ANY;
+  opnrcv_link = FindUdpTcpOut(pip->ip_src, null_addr,
+                              htons((u_short) opnrcvch_ack->port), 0,
+                              IPPROTO_UDP, 1);
+  opnrcvch_ack->ipAddr = (u_int32_t) GetAliasAddress(opnrcv_link).s_addr;
+  opnrcvch_ack->port = (u_int32_t) ntohs(GetAliasPort(opnrcv_link));
+
+  tc->th_sum = 0;
+  tc->th_sum = TcpChecksum(pip);
+
+  return 0;
+}
+
+void
+AliasHandleSkinny(struct ip *pip, struct alias_link *link)
+{
+  int             hlen, tlen, dlen;
+  struct tcphdr  *tc;
+  u_int32_t       msgId, len, t, lip;
+  struct skinny_header *sd;
+  int             orig_len, skinny_hdr_len = sizeof(struct skinny_header);
+  ConvDirection   direction;
+
+  tc = (struct tcphdr *) ((char *)pip + (pip->ip_hl << 2));
+  hlen = (pip->ip_hl + tc->th_off) << 2;
+  tlen = ntohs(pip->ip_len);
+  dlen = tlen - hlen;
+
+  sd = (struct skinny_header *) ((char *)pip + hlen);
+
+  /*
+   * XXX This direction is reserved for future use.  I still need to
+   * handle the scenario where the call manager is on the inside, and
+   * the calling phone is on the global outside.
+   */
+  if (ntohs(tc->th_dport) == skinnyPort) {
+    direction = ClientToServer;
+  } else if (ntohs(tc->th_sport) == skinnyPort) {
+    direction = ServerToClient;
+  } else {
+#ifdef DEBUG
+    fprintf(stderr,
+            "PacketAlias/Skinny: Invalid port number, not a Skinny packet\n");
+#endif
+    return;
+  }
+
+  orig_len = dlen;
+  /*
+   * Skinny packets can contain many messages.  We need to loop through
+   * the packet using len to determine message boundaries.  This comes
+   * into play big time with port messages being in the same packet as
+   * register messages.  Also, open receive channel acks are
+   * usually buried in a pakcet some 400 bytes long.
+   */
+  while (dlen >= skinny_hdr_len) {
+    len = (sd->len);
+    msgId = (sd->msgId);
+    t = len;
+
+    if (t < 0 || t > orig_len || t > dlen) {
+#ifdef DEBUG
+      fprintf(stderr,
+              "PacketAlias/Skinny: Not a skinny packet, invalid length \n");
+#endif
+      return;
+    }
+    switch (msgId) {
+      case REG_MSG:
+        {
+          struct RegisterMessage *reg_mesg;
+
+          if (len < sizeof(struct RegisterMessage)) {
+#ifdef DEBUG
+            fprintf(stderr,
+                    "PacketAlias/Skinny: Not a skinny packet, bad registration message\n");
+#endif
+            return;
+          }
+          reg_mesg = (struct RegisterMessage *) & sd->msgId;
+#ifdef DEBUG
+          fprintf(stderr,
+                  "PacketAlias/Skinny: Received a register message");
+#endif
+	  alias_skinny_reg_msg(reg_mesg, pip, tc, link, direction);
+        }
+        break;
+      case IP_PORT_MSG:
+        {
+          struct IpPortMessage *port_mesg;
+          if (len < sizeof(struct IpPortMessage)) {
+#ifdef DEBUG
+            fprintf(stderr,
+                    "PacketAlias/Skinny: Not a skinny packet, port message\n");
+#endif
+            return;
+          }
+#ifdef DEBUG
+          fprintf(stderr
+                  "PacketAlias/Skinny: Received ipport message\n");
+#endif
+          port_mesg = (struct IpPortMessage *) & sd->msgId;
+          alias_skinny_port_msg(port_mesg, pip, tc, link, direction);
+        }
+        break;
+      case OPNRCVCH_ACK:
+        {
+          struct OpenReceiveChannelAck *opnrcvchn_ack;
+
+          if (len < sizeof(struct OpenReceiveChannelAck)) {
+#ifdef DEBUG
+            fprintf(stderr,
+                    "PacketAlias/Skinny: Not a skinny packet, packet,OpnRcvChnAckMsg\n");
+#endif
+            return;
+          }
+#ifdef DEBUG
+          fprintf(stderr,
+                  "PacketAlias/Skinny: Received open rcv channel msg\n");
+#endif
+          opnrcvchn_ack = (struct OpenReceiveChannelAck *) & sd->msgId;
+          alias_skinny_opnrcvch_ack(opnrcvchn_ack, pip, tc, link, &lip, direction);
+        }
+        break;
+      case START_MEDIATX:
+        {
+          struct StartMediaTransmission *startmedia_tx;
+
+          if (len < sizeof(struct StartMediaTransmission)) {
+#ifdef DEBUG
+            fprintf(stderr,
+                    "PacketAlias/Skinny: Not a skinny packet,StartMediaTx Message\n");
+#endif
+            return;
+          }
+#ifdef DEBUG
+          fprintf(stderr,
+                  "PacketAlias/Skinny: Received start media trans msg\n");
+#endif
+           startmedia_tx = (struct StartMediaTransmission *) & sd->msgId;
+           alias_skinny_startmedia(startmedia_tx, pip, tc, link, lip, direction);
+         }
+         break;
+       default:
+         break;
+     }
+     /* Place the pointer at the next message in the packet. */
+     dlen -= len + (skinny_hdr_len - sizeof(msgId));
+     sd = (struct skinny_header *) (((char *)&sd->msgId) + len);
+   }
+}