patch-2.1.30 linux/net/ipv4/ip_masq_quake.c

• Lines: 317
• Date: Thu Mar 20 18:17:14 1997
• Orig file: v2.1.29/linux/net/ipv4/ip_masq_quake.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.29/linux/net/ipv4/ip_masq_quake.c linux/net/ipv4/ip_masq_quake.c
@@ -0,0 +1,316 @@
+/*
+ *		IP_MASQ_QUAKE quake masquerading module
+ *
+ *
+ * Version:	@(#)ip_masq_quake.c 0.02   22/02/97
+ *
+ * Author:	Harald Hoyer mailto:HarryH@Royal.Net
+ *		
+ *
+ * Fixes: 
+ *      Harald Hoyer            :       Unofficial Quake Specs found at 
+ *                                 http://www.gamers.org/dEngine/quake/spec/ 
+ *      Harald Hoyer            :       Check for QUAKE-STRING
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *  
+ *  
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <asm/system.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <net/protocol.h>
+#include <net/udp.h>
+#include <net/ip_masq.h>
+
+#define DEBUG_CONFIG_IP_MASQ_QUAKE 0
+
+typedef struct
+{ 
+        __u16 type;     // (Little Endian) Type of message.
+	__u16 length;   // (Little Endian) Length of message, header included. 
+	char  message[0];  // The contents of the message.
+} QUAKEHEADER;
+
+struct quake_priv_data {
+	/* Have we seen a client connect message */
+	char	cl_connect;
+};
+
+static int
+masq_quake_init_1 (struct ip_masq_app *mapp, struct ip_masq *ms)
+{
+        MOD_INC_USE_COUNT;
+	if ((ms->app_data = kmalloc(sizeof(struct quake_priv_data),
+				    GFP_ATOMIC)) == NULL) 
+		printk(KERN_INFO "Quake: No memory for application data\n");
+	else 
+	{
+		struct quake_priv_data *priv = 
+			(struct quake_priv_data *)ms->app_data;
+		priv->cl_connect = 0;
+	}
+        return 0;
+}
+
+static int
+masq_quake_done_1 (struct ip_masq_app *mapp, struct ip_masq *ms)
+{
+	MOD_DEC_USE_COUNT;
+	if (ms->app_data)
+		kfree_s(ms->app_data, sizeof(struct quake_priv_data));
+	return 0;
+}
+
+int
+masq_quake_in (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, struct device *dev)
+{
+	struct sk_buff *skb;
+	struct iphdr *iph;
+	struct udphdr *uh;
+	QUAKEHEADER *qh;
+	__u16 udp_port;
+	char *data;
+	unsigned char code;
+	struct quake_priv_data *priv = (struct quake_priv_data *)ms->app_data;
+        
+	if(priv->cl_connect == -1)
+	  return 0;
+
+	skb = *skb_p;
+
+	iph = skb->nh.iph;
+	uh = (struct udphdr *)&(((char *)iph)[iph->ihl*4]);
+
+	/* Check for lenght */
+	if(ntohs(uh->len) < 5)
+	  return 0;
+	
+	qh = (QUAKEHEADER *)&uh[1];
+
+	if(qh->type != 0x0080)
+	  return 0;
+
+	
+	code = qh->message[0];
+
+#if DEBUG_CONFIG_IP_MASQ_QUAKE
+	  printk("Quake_in: code = %d \n", (int)code);
+#endif
+
+	switch(code) {
+	case 0x01:
+	  /* Connection Request */
+
+	  if(ntohs(qh->length) < 0x0c) {
+#if DEBUG_CONFIG_IP_MASQ_QUAKE
+	    printk("Quake_in: length < 0xc \n");
+#endif
+	    return 0;
+	  }
+
+	  data = &qh->message[1];
+
+	  /* Check for stomping string */
+	  if(memcmp(data,"QUAKE\0\3",7)) {
+#if DEBUG_CONFIG_IP_MASQ_QUAKE
+	    printk("Quake_out: memcmp failed \n");
+#endif
+	    return 0;
+	  }
+	  else {
+	    priv->cl_connect = 1;
+#if DEBUG_CONFIG_IP_MASQ_QUAKE
+	    printk("Quake_out: memcmp ok \n");
+#endif
+	  }
+	  break;
+
+	case 0x81:
+	  /* Accept Connection */
+	  if((ntohs(qh->length) < 0x09) || (priv->cl_connect == 0))
+	    return 0;
+	  data = &qh->message[1];
+
+	  memcpy(&udp_port, data, 2);
+
+	  ms->dport = htons(udp_port);
+
+#if DEBUG_CONFIG_IP_MASQ_QUAKE
+	  printk("Quake_in: in_rewrote UDP port %d \n", udp_port);
+#endif
+	  priv->cl_connect = -1;
+
+	  break;
+	}
+	 
+	return 0;
+}
+
+int
+masq_quake_out (struct ip_masq_app *mapp, struct ip_masq *ms, struct sk_buff **skb_p, struct device *dev)
+{
+	struct sk_buff *skb;
+	struct iphdr *iph;
+	struct udphdr *uh;
+	QUAKEHEADER *qh;
+	__u16 udp_port;
+	char *data;
+	unsigned char code;
+	struct ip_masq *n_ms;
+	struct quake_priv_data *priv = (struct quake_priv_data *)ms->app_data;
+
+	if(priv->cl_connect == -1)
+	  return 0;
+        
+	skb = *skb_p;
+
+	iph = skb->nh.iph;
+	uh = (struct udphdr *)&(((char *)iph)[iph->ihl*4]);
+
+	/* Check for lenght */
+	if(ntohs(uh->len) < 5)
+	  return 0;
+	
+	qh = (QUAKEHEADER *)&uh[1];
+
+#if DEBUG_CONFIG_IP_MASQ_QUAKE
+	  printk("Quake_out: qh->type = %d \n", (int)qh->type);
+#endif
+
+	if(qh->type != 0x0080)
+	  return 0;
+	
+	code = qh->message[0];
+
+#if DEBUG_CONFIG_IP_MASQ_QUAKE
+	  printk("Quake_out: code = %d \n", (int)code);
+#endif
+
+	switch(code) {
+	case 0x01:
+	  /* Connection Request */
+
+	  if(ntohs(qh->length) < 0x0c) {
+#if DEBUG_CONFIG_IP_MASQ_QUAKE
+	    printk("Quake_out: length < 0xc \n");
+#endif
+	    return 0;
+	  }
+
+	  data = &qh->message[1];
+
+	  /* Check for stomping string */
+	  if(memcmp(data,"QUAKE\0\3",7)) {
+#if DEBUG_CONFIG_IP_MASQ_QUAKE
+	    printk("Quake_out: memcmp failed \n");
+#endif
+	    return 0;
+	  }
+	  else {
+	    priv->cl_connect = 1;
+#if DEBUG_CONFIG_IP_MASQ_QUAKE
+	    printk("Quake_out: memcmp ok \n");
+#endif
+	  }
+	  break;
+
+	case 0x81:
+	  /* Accept Connection */
+	  if((ntohs(qh->length) < 0x09) || (priv->cl_connect == 0))
+	    return 0;
+
+	  data = &qh->message[1];
+
+	  memcpy(&udp_port, data, 2);
+	  
+	  n_ms = ip_masq_new(dev, IPPROTO_UDP,
+			     ms->saddr, htons(udp_port),
+			     ms->daddr, ms->dport,
+			     0);
+
+	  if (n_ms==NULL)
+	    return 0;
+
+#if DEBUG_CONFIG_IP_MASQ_QUAKE
+	  printk("Quake_out: out_rewrote UDP port %d -> %d\n",
+		 udp_port, ntohs(n_ms->mport));
+#endif
+	  udp_port = ntohs(n_ms->mport);
+	  memcpy(data, &udp_port, 2);
+
+	  break;
+	}
+	 
+	return 0;
+}
+
+struct ip_masq_app ip_masq_quake = {
+        NULL,			/* next */
+	"Quake_26",	       	/* name */
+        0,                      /* type */
+        0,                      /* n_attach */
+        masq_quake_init_1,      /* ip_masq_init_1 */
+        masq_quake_done_1,      /* ip_masq_done_1 */
+        masq_quake_out,         /* pkt_out */
+        masq_quake_in           /* pkt_in */
+};
+struct ip_masq_app ip_masq_quakenew = {
+        NULL,			/* next */
+	"Quake_27",	       	/* name */
+        0,                      /* type */
+        0,                      /* n_attach */
+        masq_quake_init_1,      /* ip_masq_init_1 */
+        masq_quake_done_1,      /* ip_masq_done_1 */
+        masq_quake_out,         /* pkt_out */
+        masq_quake_in           /* pkt_in */
+};
+
+/*
+ * 	ip_masq_quake initialization
+ */
+
+int ip_masq_quake_init(void)
+{
+        return (register_ip_masq_app(&ip_masq_quake, IPPROTO_UDP, 26000) +
+		register_ip_masq_app(&ip_masq_quakenew, IPPROTO_UDP, 27000));
+}
+
+/*
+ * 	ip_masq_quake fin.
+ */
+
+int ip_masq_quake_done(void)
+{
+        return (unregister_ip_masq_app(&ip_masq_quake) +
+                unregister_ip_masq_app(&ip_masq_quakenew));
+}
+
+#ifdef MODULE
+EXPORT_NO_SYMBOLS;
+
+int init_module(void)
+{
+        if (ip_masq_quake_init() != 0)
+                return -EIO;
+        return 0;
+}
+
+void cleanup_module(void)
+{
+        if (ip_masq_quake_done() != 0)
+                printk("ip_masq_quake: can't remove module");
+}
+
+#endif /* MODULE */
+
+