patch-2.1.73 linux/net/ipv4/ip_masq_autofw.c

• Lines: 428
• Date: Wed Dec 10 09:45:16 1997
• Orig file: v2.1.72/linux/net/ipv4/ip_masq_autofw.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.72/linux/net/ipv4/ip_masq_autofw.c linux/net/ipv4/ip_masq_autofw.c
@@ -0,0 +1,427 @@
+/*
+ *		IP_MASQ_AUTOFW auto forwarding module
+ *
+ *
+ * Version:	@(#)ip_masq_autofw.c  0.02      97/10/22
+ *
+ * Author:	Richard Lynch
+ *
+ *	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.
+ *
+ *
+ * Fixes:
+ *	Juan Jose Ciarlante	: created this new file from ip_masq.c and ip_fw.c
+ *	Juan Jose Ciarlante	: modularized 
+ *	Juan Jose Ciarlante	: use GFP_KERNEL when creating entries
+ *	Juan Jose Ciarlante	: call del_timer() when freeing entries (!)
+ *  FIXME:
+ *	- implement refcnt
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <asm/system.h>
+#include <linux/stat.h>
+#include <linux/proc_fs.h>
+#include <linux/if.h>
+#include <linux/init.h>
+#include <linux/ip_fw.h>
+#include <net/ip_masq.h>
+#include <net/ip_masq_mod.h>
+#include <net/ip_autofw.h>
+
+/*
+ *	Debug level
+ */
+static int debug=0;
+
+MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_MASQ_APP_PORTS) "i");
+MODULE_PARM(debug, "i");
+
+/*
+ *	Auto-forwarding table
+ */
+
+static struct ip_autofw * ip_autofw_hosts = NULL;
+static struct ip_masq_mod * mmod_self = NULL;
+
+/*
+ *	Check if a masq entry should be created for a packet
+ */
+
+static __inline__ struct ip_autofw * ip_autofw_check_range (__u32 where, __u16 port, __u16 protocol, int reqact)
+{
+	struct ip_autofw *af;
+	af=ip_autofw_hosts;
+	port=ntohs(port);
+	while (af) {
+		if (af->type==IP_FWD_RANGE && 
+		     port>=af->low && 
+		     port<=af->high && 
+		     protocol==af->protocol && 
+
+		     /*
+		      *		It's ok to create masq entries after 
+		      *		the timeout if we're in insecure mode 
+		      */
+		     (af->flags & IP_AUTOFW_ACTIVE || !reqact || !(af->flags & IP_AUTOFW_SECURE)) &&  
+		     (!(af->flags & IP_AUTOFW_SECURE) || af->lastcontact==where || !reqact))
+			return(af);
+		af=af->next;
+	}
+	return(NULL);
+}
+
+static __inline__ struct ip_autofw * ip_autofw_check_port (__u16 port, __u16 protocol)
+{
+	struct ip_autofw *af;
+	af=ip_autofw_hosts;
+	port=ntohs(port);
+	while (af)
+	{
+		if (af->type==IP_FWD_PORT && port==af->visible && protocol==af->protocol)
+			return(af);
+		af=af->next;
+	}
+	return(NULL);
+}
+
+static __inline__ struct ip_autofw * ip_autofw_check_direct (__u16 port, __u16 protocol)
+{
+	struct ip_autofw *af;
+	af=ip_autofw_hosts;
+	port=ntohs(port);
+	while (af)
+	{
+		if (af->type==IP_FWD_DIRECT && af->low<=port && af->high>=port)
+			return(af);
+		af=af->next;
+	}
+	return(NULL);
+}
+
+static __inline__ void ip_autofw_update_out (__u32 who, __u32 where, __u16 port, __u16 protocol)
+{
+	struct ip_autofw *af;
+	af=ip_autofw_hosts;
+	port=ntohs(port);
+	while (af)
+	{
+		if (af->type==IP_FWD_RANGE && af->ctlport==port && af->ctlproto==protocol)
+		{
+			if (af->flags & IP_AUTOFW_USETIME)
+			{
+				if (af->timer.expires)
+					del_timer(&af->timer);
+				af->timer.expires=jiffies+IP_AUTOFW_EXPIRE;
+				add_timer(&af->timer);
+			}
+			af->flags|=IP_AUTOFW_ACTIVE;
+			af->lastcontact=where;
+			af->where=who;
+		}
+		af=af->next;
+	}
+}
+
+#if 0
+static __inline__ void ip_autofw_update_in (__u32 where, __u16 port, __u16 protocol)
+{
+	struct ip_autofw *af;
+	af=ip_autofw_check_range(where, port,protocol);
+	if (af)
+	{
+		del_timer(&af->timer);
+		af->timer.expires=jiffies+IP_AUTOFW_EXPIRE;
+		add_timer(&af->timer);
+	}
+}
+#endif
+
+
+static __inline__ void ip_autofw_expire(unsigned long data)
+{
+	struct ip_autofw * af;
+	af=(struct ip_autofw *) data;
+	af->flags &= ~IP_AUTOFW_ACTIVE;
+	af->timer.expires=0;
+	af->lastcontact=0;
+	if (af->flags & IP_AUTOFW_SECURE)
+		af->where=0;
+}
+
+
+
+static __inline__ int ip_autofw_add(struct ip_autofw * af)
+{
+	struct ip_autofw * newaf;
+	init_timer(&af->timer);
+	newaf = kmalloc( sizeof(struct ip_autofw), GFP_KERNEL );
+	if ( newaf == NULL ) 
+	{
+		printk("ip_autofw_add:  malloc said no\n");
+		return( ENOMEM );
+	}
+
+	MOD_INC_USE_COUNT;
+
+	memcpy(newaf, af, sizeof(struct ip_autofw));
+	newaf->timer.data = (unsigned long) newaf;
+	newaf->timer.function = ip_autofw_expire;
+	newaf->timer.expires = 0;
+	newaf->lastcontact=0;
+	newaf->next=ip_autofw_hosts;
+	ip_autofw_hosts=newaf;
+	ip_masq_mod_inc_nent(mmod_self);
+	return(0);
+}
+
+static __inline__ int ip_autofw_del(struct ip_autofw * af)
+{
+	struct ip_autofw ** af_p, *curr;
+
+	for (af_p=&ip_autofw_hosts, curr=*af_p; (curr=*af_p); af_p = &(*af_p)->next) {
+		if (af->type     == curr->type &&
+		    af->low      == curr->low &&
+		    af->high     == curr->high &&
+		    af->hidden   == curr->hidden &&
+		    af->visible  == curr->visible &&
+		    af->protocol == curr->protocol &&
+		    af->where    == curr->where &&
+		    af->ctlproto == curr->ctlproto &&
+		    af->ctlport  == curr->ctlport)
+		{
+			ip_masq_mod_dec_nent(mmod_self);
+			*af_p = curr->next;
+			if (af->flags&IP_AUTOFW_ACTIVE)
+				del_timer(&curr->timer);
+			kfree_s(curr,sizeof(struct ip_autofw));
+			MOD_DEC_USE_COUNT;
+			return 0;
+		}
+		curr=curr->next;
+	}
+	return EINVAL;
+}
+
+static __inline__ int ip_autofw_flush(void)
+{
+	struct ip_autofw * af;
+
+	while (ip_autofw_hosts)
+	{
+		af=ip_autofw_hosts;
+		ip_masq_mod_dec_nent(mmod_self);
+		ip_autofw_hosts=ip_autofw_hosts->next;
+		if (af->flags&IP_AUTOFW_ACTIVE)
+			del_timer(&af->timer);
+		kfree_s(af,sizeof(struct ip_autofw));
+		MOD_DEC_USE_COUNT;
+	}
+	return(0);
+}
+
+/*
+ *	Methods for registered object
+ */
+
+static int autofw_ctl(int optname, struct ip_fw_masqctl *mctl, int optlen)
+{
+	struct ip_autofw *af = (struct ip_autofw*) mctl->u.mod.data;
+
+	switch (optname) {
+		case IP_FW_MASQ_ADD:
+			if (optlen<sizeof(*af))
+				return EINVAL;
+			return ip_autofw_add(af);
+		case IP_FW_MASQ_DEL:
+			if (optlen<sizeof(*af))
+				return EINVAL;
+			return ip_autofw_del(af);
+		case IP_FW_MASQ_FLUSH:
+			return ip_autofw_flush();
+
+	}
+	return EINVAL;
+}
+
+
+static int autofw_out_update(struct iphdr *iph, __u16 *portp, struct ip_masq *ms)
+{
+	/* 
+	 *	Update any ipautofw entries ...
+	 */
+
+	ip_autofw_update_out(iph->saddr, iph->daddr, portp[1], iph->protocol);
+	return IP_MASQ_MOD_NOP;
+}
+
+static struct ip_masq * autofw_out_create(struct iphdr *iph, __u16 * portp, __u32 maddr)
+{
+	/*
+	 *	If the source port is supposed to match the masq port, then
+	 *  	make it so 
+	 */
+
+	if (ip_autofw_check_direct(portp[1],iph->protocol)) {
+		return ip_masq_new(iph->protocol,
+					maddr, portp[0],
+					iph->saddr, portp[0],
+					iph->daddr, portp[1],
+					0);
+	}
+	return NULL;
+}
+
+#if 0
+static int autofw_in_update(struct iphdr *iph, __u16 *portp, struct ip_masq *ms)
+{
+	ip_autofw_update_in(iph->saddr, portp[1], iph->protocol);
+	return IP_MASQ_MOD_NOP;
+}
+#endif
+
+static int autofw_in_rule(struct iphdr *iph, __u16 *portp)
+{
+	return (ip_autofw_check_range(iph->saddr, portp[1], iph->protocol, 0)
+		|| ip_autofw_check_direct(portp[1], iph->protocol)
+		|| ip_autofw_check_port(portp[1], iph->protocol));
+}
+
+static struct ip_masq * autofw_in_create(struct iphdr *iph, __u16 *portp, __u32 maddr)
+{
+	struct ip_autofw *af;
+
+        if ((af=ip_autofw_check_range(iph->saddr, portp[1], iph->protocol, 0))) {
+		IP_MASQ_DEBUG(1-debug, "autofw_check_range HIT\n");
+		return ip_masq_new(iph->protocol,
+					maddr, portp[1],
+					af->where, portp[1],
+					iph->saddr, portp[0],
+					0);
+        } 
+        if ((af=ip_autofw_check_port(portp[1], iph->protocol)) ) {
+		IP_MASQ_DEBUG(1-debug, "autofw_check_port HIT\n");
+		return ip_masq_new(iph->protocol,
+					maddr, htons(af->visible),
+					af->where, htons(af->hidden),
+					iph->saddr, portp[0],
+					0);
+        }
+	return NULL;
+}
+
+#ifdef CONFIG_PROC_FS
+static int autofw_procinfo(char *buffer, char **start, off_t offset,
+			      int length, int unused)
+{
+	off_t pos=0, begin=0;
+	struct ip_autofw * af;
+	int len=0;
+	
+	len=sprintf(buffer,"Type Prot Low  High Vis  Hid  Where    Last     CPto CPrt Timer Flags\n"); 
+        
+        for(af = ip_autofw_hosts; af ; af = af->next)
+	{
+		len+=sprintf(buffer+len,"%4X %4X %04X-%04X/%04X %04X %08lX %08lX %04X %04X %6lu %4X\n",
+					af->type,
+					af->protocol,
+					af->low,
+					af->high,
+					af->visible,
+					af->hidden,
+					ntohl(af->where),
+					ntohl(af->lastcontact),
+					af->ctlproto,
+					af->ctlport,
+					(af->timer.expires<jiffies ? 0 : af->timer.expires-jiffies), 
+					af->flags);
+
+		pos=begin+len;
+		if(pos<offset) 
+		{
+ 			len=0;
+			begin=pos;
+		}
+		if(pos>offset+length)
+			break;
+        }
+	*start=buffer+(offset-begin);
+	len-=(offset-begin);
+	if(len>length)
+		len=length;
+	return len;
+}
+
+static struct proc_dir_entry autofw_proc_entry = {
+		0, 0, NULL,
+		S_IFREG | S_IRUGO, 1, 0, 0,
+		0, &proc_net_inode_operations,
+		autofw_procinfo
+};
+
+#define proc_ent &autofw_proc_entry
+#else /* !CONFIG_PROC_FS */
+
+#define proc_ent NULL
+#endif
+
+
+#define	autofw_in_update NULL
+#define autofw_out_rule NULL
+#define autofw_mod_init NULL
+#define autofw_mod_done NULL
+
+static struct ip_masq_mod autofw_mod = {
+	NULL,			/* next */
+	NULL,			/* next_reg */
+	"autofw",		/* name */
+	ATOMIC_INIT(0),		/* nent */
+	ATOMIC_INIT(0),		/* refcnt */
+	proc_ent,
+	autofw_ctl,
+	autofw_mod_init,
+	autofw_mod_done,
+	autofw_in_rule,
+	autofw_in_update,
+	autofw_in_create,
+	autofw_out_rule,
+	autofw_out_update,
+	autofw_out_create,
+};
+
+__initfunc(int ip_autofw_init(void))
+{
+	return register_ip_masq_mod ((mmod_self=&autofw_mod));
+}
+
+int ip_autofw_done(void)
+{
+	return unregister_ip_masq_mod(&autofw_mod);
+}
+
+#ifdef MODULE
+EXPORT_NO_SYMBOLS;
+
+int init_module(void)
+{
+	if (ip_autofw_init() != 0)
+		return -EIO;
+	return 0;
+}
+
+void cleanup_module(void)
+{
+	if (ip_autofw_done() != 0)
+		printk(KERN_INFO "ip_autofw_done(): can't remove module");
+}
+
+#endif /* MODULE */