Add CUSEEME support. This has *not* been tested, nor

could I find anyone to test it, so please report any
problems to me.

4 files changed, 131 insertions, 2 deletions

diff --git a/lib/libalias/Makefile b/lib/libalias/Makefile
index 8147665..cf92606 100644
--- a/lib/libalias/Makefile
+++ b/lib/libalias/Makefile
@@ -2,8 +2,8 @@ LIB=	alias
 SHLIB_MAJOR= 2
 SHLIB_MINOR= 5
 CFLAGS+=-Wall -I${.CURDIR}
-SRCS=	alias.c alias_db.c alias_ftp.c alias_irc.c alias_util.c alias_old.c \
-		alias_nbt.c
+SRCS=	alias.c alias_cuseeme.c alias_db.c alias_ftp.c alias_irc.c \
+	alias_nbt.c alias_old.c alias_util.c
 
 MAN3=libalias.3 
 
diff --git a/lib/libalias/alias.c b/lib/libalias/alias.c
index f0c0804..48a852a 100644
--- a/lib/libalias/alias.c
+++ b/lib/libalias/alias.c
@@ -99,6 +99,7 @@
 #define FTP_CONTROL_PORT_NUMBER 21
 #define IRC_CONTROL_PORT_NUMBER_1 6667
 #define IRC_CONTROL_PORT_NUMBER_2 6668
+#define CUSEEME_PORT_NUMBER 7648
 
 /*
    The following macro is used to update an
@@ -623,6 +624,9 @@ UdpAliasIn(struct ip *pip)
 								&ud->uh_dport );
 		}
 
+        if (ntohs(ud->uh_dport) == CUSEEME_PORT_NUMBER)
+            AliasHandleCUSeeMeIn(pip, original_address);
+
 /* If UDP checksum is not zero, then adjust since destination port */
 /* is being unaliased and destination port is being altered.       */
         if (ud->uh_sum != 0)
@@ -668,6 +672,9 @@ UdpAliasOut(struct ip *pip)
         alias_address = GetAliasAddress(link);
         alias_port = GetAliasPort(link);
 
+        if (ntohs(ud->uh_dport) == CUSEEME_PORT_NUMBER)
+            AliasHandleCUSeeMeOut(pip, link);
+
 /* If NETBIOS Datagram, It should be alias address in UDP Data, too */
 		if (ntohs(ud->uh_dport) == NETBIOS_DGM_PORT_NUMBER
          || ntohs(ud->uh_sport) == NETBIOS_DGM_PORT_NUMBER )
diff --git a/lib/libalias/alias_cuseeme.c b/lib/libalias/alias_cuseeme.c
new file mode 100644
index 0000000..7cb6d4e
--- /dev/null
+++ b/lib/libalias/alias_cuseeme.c
@@ -0,0 +1,120 @@
+/*-
+ * Copyright (c) 1998 Brian Somers <brian@Awfulhak.org>
+ *                    with the aid of code written by
+ *                    Junichi SATOH <junichi@astec.co.jp> 1996, 1997.
+ * 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.
+ *
+ *	$Id$
+ */
+
+#include <sys/types.h>
+#include <netinet/in_systm.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/udp.h>
+
+#include "alias_local.h"
+
+/* CU-SeeMe Data Header */
+struct cu_header {
+    u_int16_t dest_family;
+    u_int16_t dest_port;
+    u_int32_t  dest_addr;
+    int16_t family;
+    u_int16_t port;
+    u_int32_t addr;
+    u_int32_t seq;
+    u_int16_t msg;
+    u_int16_t data_type;
+    u_int16_t packet_len;
+};
+
+/* Open Continue Header */
+struct oc_header {
+    u_int16_t client_count;    /* Number of client info structs */
+    u_int32_t seq_no;
+    char user_name[20];
+    char reserved[4];        /* flags, version stuff, etc */
+};
+
+/* client info structures */
+struct client_info {
+    u_int32_t address;          /* Client address */
+    char reserved[8];        /* Flags, pruning bitfield, packet counts etc */
+};
+
+void
+AliasHandleCUSeeMeOut(struct ip *pip, struct alias_link *link)
+{
+  struct udphdr *ud;
+
+  ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2));
+  if(ud->uh_ulen >= sizeof(struct cu_header)) {
+    struct cu_header *cu;
+    struct alias_link *cu_link;
+
+    cu = (struct cu_header *)(ud + 1);
+    if (cu->addr)
+      cu->addr = (u_int32_t)GetAliasAddress(link).s_addr;
+
+    cu_link = FindUdpTcpOut(pip->ip_src, GetDestAddress(link),
+                            ud->uh_dport, 0, IPPROTO_UDP);
+                         
+#ifndef NO_FW_PUNCH
+    if (cu_link)
+        PunchFWHole(cu_link);
+#endif
+  }
+}
+
+void
+AliasHandleCUSeeMeIn(struct ip *pip, struct in_addr original_addr)
+{
+  struct in_addr alias_addr;
+  struct udphdr *ud;
+  struct cu_header *cu;
+  struct oc_header *oc;
+  struct client_info *ci;
+  char *end;
+  int i;
+
+  alias_addr.s_addr = pip->ip_dst.s_addr;
+  ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2));
+  cu = (struct cu_header *)(ud + 1);
+  oc = (struct oc_header *)(cu + 1);
+  ci = (struct client_info *)(oc + 1);
+  end = (char *)cu + ud->uh_ulen;
+
+  if ((char *)oc <= end) {
+    if(cu->dest_addr)
+      cu->dest_addr = (u_int32_t)original_addr.s_addr;
+    if(ntohs(cu->data_type) == 101)
+      /* Find and change our address */
+      for(i = 0; (char *)(ci + 1) <= end && i < oc->client_count; i++, ci++)
+        if(ci->address == (u_int32_t)alias_addr.s_addr) {
+          ci->address = (u_int32_t)original_addr.s_addr;
+          break;
+        }
+  }
+}
diff --git a/lib/libalias/alias_local.h b/lib/libalias/alias_local.h
index 16d0aaa..0e94a64 100644
--- a/lib/libalias/alias_local.h
+++ b/lib/libalias/alias_local.h
@@ -92,6 +92,8 @@ void AliasHandleFtpOut(struct ip *, struct alias_link *, int);
 void AliasHandleIrcOut(struct ip *pip, struct alias_link *link, int maxsize );
 void AliasHandleUdpNbt(struct ip *, struct alias_link *, struct in_addr *, u_short);
 void AliasHandleUdpNbtNS(struct ip *, struct alias_link *, struct in_addr *, u_short *, struct in_addr *, u_short *);
+void AliasHandleCUSeeMeOut(struct ip *, struct alias_link *);
+void AliasHandleCUSeeMeIn(struct ip *, struct in_addr);