patch-2.1.8 linux/net/ipv6/ipv6_input.c

• Lines: 438
• Date: Sun Nov 3 11:04:46 1996
• Orig file: v2.1.7/linux/net/ipv6/ipv6_input.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.1.7/linux/net/ipv6/ipv6_input.c linux/net/ipv6/ipv6_input.c
@@ -0,0 +1,437 @@
+/*
+ *	IPv6 input
+ *	Linux INET6 implementation 
+ *
+ *	Authors:
+ *	Pedro Roque		<roque@di.fc.ul.pt>
+ *	Ian P. Morris		<I.P.Morris@soton.ac.uk>
+ *
+ *	Based in linux/net/ipv4/ip_input.c
+ *
+ *	$Id: ipv6_input.c,v 1.13 1996/10/11 16:03:06 roque Exp $
+ *
+ *	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/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/sched.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/in6.h>
+#include <linux/icmpv6.h>
+
+#include <net/sock.h>
+#include <net/snmp.h>
+
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <net/transp_v6.h>
+#include <net/rawv6.h>
+#include <net/ndisc.h>
+#include <net/ipv6_route.h>
+#include <net/addrconf.h>
+
+/*
+ *	Header processing function list
+ *	We process headers in order (as per RFC)
+ *	If the processing function returns 0 the packet is considered 
+ *	delivered else it returns the value of the nexthdr.
+ *	The ptr field of the function points to the previous nexthdr field.
+ *	This is allows the processing function to change it if it's sematics
+ *	is: return a new packet without this header (like fragmentation).
+ *	When a next_header value is not within the list 
+ *	the inet protocol list is searched (i.e. to deliver to 
+ *	TCP for instance)
+ */
+
+static int ipv6_dest_opt(struct sk_buff **skb_ptr, struct device *dev, __u8 *nhptr,
+			 struct ipv6_options *opt);
+
+
+struct hdrtype_proc {
+	u8	type;
+	int	(*func) (struct sk_buff **, struct device *dev, __u8 *ptr,
+			 struct ipv6_options *opt);
+} hdrproc_lst[] = {
+  /*
+	TODO
+
+	{NEXTHDR_HOP,		ipv6_hop_by_hop}
+   */
+	{NEXTHDR_ROUTING,	ipv6_routing_header},
+	{NEXTHDR_FRAGMENT,	ipv6_reassembly},
+  
+	{NEXTHDR_DEST,		ipv6_dest_opt},
+   /*	
+	{NEXTHDR_AUTH,		ipv6_auth_hdr},
+	{NEXTHDR_ESP,		ipv6_esp_hdr},
+    */
+	{NEXTHDR_MAX,		NULL}
+};
+
+/* New header structures */
+
+
+struct ipv6_tlvtype {
+	u8 type;
+	u8 len;
+};
+
+struct ipv6_destopt_hdr {
+	u8 nexthdr;
+	u8 hdrlen;
+};
+
+
+struct tlvtype_proc {
+	u8	type;
+	int	(*func) (struct sk_buff *, struct device *dev, __u8 *ptr,
+			 struct ipv6_options *opt); 
+	
+	/* these functions do NOT  update skb->h.raw */
+			 
+} tlvprocdestopt_lst[] = {
+	{255,			NULL}
+};
+
+
+static int parse_tlv(struct tlvtype_proc *procs, struct sk_buff *skb,
+		     struct device *dev, __u8 *nhptr, struct ipv6_options *opt,
+		     void *lastopt)
+{
+	struct ipv6_tlvtype *hdr;
+	struct tlvtype_proc *curr;
+	int pos;
+
+	while ((hdr=(struct ipv6_tlvtype *)skb->h.raw) != lastopt)
+		switch (hdr->type & 0x3F)
+		{
+		case 0: /* TLV encoded Pad1 */
+			skb->h.raw++;
+			break;
+
+		case 1: /* TLV encoded PadN */
+			skb->h.raw += hdr->len+2;
+			break;
+
+		default: /* Other TLV code so scan list */
+			for (curr=procs; curr->type != 255; curr++)
+				if (curr->type == (hdr->type & 0x3F))
+				{
+					curr->func(skb, dev, nhptr, opt);
+					skb->h.raw += hdr->len+2;
+					break;
+				}
+		
+			if (curr->type==255)
+			{ 
+				/* unkown type */
+				pos= (__u8 *) skb->h.raw - (__u8 *) skb->ipv6_hdr;
+				/* I think this is correct please check - IPM */
+
+				switch ((hdr->type & 0xC0) >> 6) {
+					case 0: /* ignore */
+						skb->h.raw += hdr->len+2;
+						break;
+						
+					case 1: /* drop packet */
+						kfree_skb(skb, FREE_READ);
+						return 0;
+
+					case 2: /* send ICMP PARM PROB regardless and 
+						   drop packet */
+						icmpv6_send(skb, ICMPV6_PARAMETER_PROB, 
+							    2, pos, dev);
+						kfree_skb(skb, FREE_READ);
+						return 0;
+
+					case 3: /* Send ICMP if not a multicast address 
+						   and drop packet */
+						if (!(ipv6_addr_type(&(skb->ipv6_hdr->daddr)) & IPV6_ADDR_MULTICAST) )
+							icmpv6_send(skb, ICMPV6_PARAMETER_PROB, 2, pos, dev);
+						kfree_skb(skb, FREE_READ);
+						return 0;
+					}
+			}
+			break;
+		}
+	
+	return 1;
+}
+ 
+
+
+static int ipv6_dest_opt(struct sk_buff **skb_ptr, struct device *dev, __u8 *nhptr,
+			 struct ipv6_options *opt)
+{
+	struct sk_buff *skb=*skb_ptr;
+	struct ipv6_destopt_hdr *hdr = (struct ipv6_destopt_hdr *) skb->h.raw;
+	
+	if (parse_tlv(tlvprocdestopt_lst, skb, dev, nhptr, opt,skb->h.raw+hdr->hdrlen))
+		return hdr->nexthdr;
+	else
+		return 0;
+}
+
+
+
+/*
+ *	0 - deliver
+ *	1 - block
+ */
+static __inline__ int icmpv6_filter(struct sock *sk, struct sk_buff *skb)
+{
+	struct icmpv6hdr *icmph;
+	struct raw6_opt *opt;
+
+	opt = &sk->tp_pinfo.tp_raw;
+	icmph = (struct icmpv6hdr *) (skb->ipv6_hdr + 1);
+	return test_bit(icmph->type, &opt->filter);
+}
+
+/*
+ *	demultiplex raw sockets.
+ *	(should consider queueing the skb in the sock receive_queue
+ *	without calling rawv6.c)
+ */
+static struct sock * ipv6_raw_deliver(struct sk_buff *skb,
+				      struct device *dev,
+				      struct ipv6_options *opt,
+				      __u16 nexthdr,
+				      __u16 len,
+				      struct in6_addr *saddr,
+				      struct in6_addr *daddr)
+{
+	struct sock *sk, *sk2;
+	__u8 hash;
+
+	hash = nexthdr & (SOCK_ARRAY_SIZE-1);
+
+	sk = rawv6_prot.sock_array[hash];
+	
+
+	/*
+	 *	The first socket found will be delivered after
+	 *	delivery to transport protocols.
+	 */
+
+	if (sk == NULL)
+		return NULL;
+	
+	sk = inet6_get_sock_raw(sk, nexthdr, daddr, saddr);
+
+	if (sk)
+	{
+		sk2 = sk;
+
+		while ((sk2 = inet6_get_sock_raw(sk2->next, nexthdr, 
+						 daddr, saddr)))
+		{
+			struct sk_buff *buff;
+
+			if (nexthdr == IPPROTO_ICMPV6 &&
+			    icmpv6_filter(sk2, skb))
+			{
+				continue;
+			}
+			buff = skb_clone(skb, GFP_ATOMIC);
+			buff->sk = sk2;
+			rawv6_rcv(buff, dev, saddr, daddr, opt, len);
+		}
+	}
+
+	if (sk && nexthdr == IPPROTO_ICMPV6 && icmpv6_filter(sk, skb))
+	{
+		sk = NULL;
+	}   
+	
+	return sk;
+}
+
+int ipv6_rcv(struct sk_buff *skb, struct device *dev, struct packet_type *pt)
+{
+	struct inet6_ifaddr	*ifp;
+	struct ipv6_options	*opt = (struct ipv6_options *) skb->proto_priv;
+	struct ipv6hdr		*hdr;
+	u8			hash;
+	u8			addr_type;
+	struct inet6_protocol	*ipprot;
+	struct sock		*raw_sk;
+	int			found = 0;
+	int			nexthdr = 0;
+	__u8			*nhptr;
+	int			pkt_len;
+
+	hdr = skb->ipv6_hdr = (struct ipv6hdr *) skb->h.raw;
+
+	if (skb->len < sizeof(struct ipv6hdr) || hdr->version != 6)
+	{
+		ipv6_statistics.Ip6InHdrErrors++;
+		printk(KERN_DEBUG "ipv6_rcv: broken header\n");
+		kfree_skb(skb, FREE_READ);
+		return 0;
+	}
+
+	pkt_len = ntohs(hdr->payload_len);
+
+	if (pkt_len + sizeof(struct ipv6hdr) > skb->len)
+	{
+		printk(KERN_DEBUG "ipv6_rcv: invalid payload length\n");
+		kfree_skb(skb, FREE_READ);
+		return 0;
+	}
+
+	skb_trim(skb, pkt_len + sizeof(struct ipv6hdr));
+
+	/* check daddr */
+
+	/* Accounting & Firewall check */
+
+	addr_type = ipv6_addr_type(&hdr->daddr);
+
+	if (addr_type & IPV6_ADDR_MULTICAST)
+	{
+		/* 
+		 * if mcast address is not for one of our groups
+		 * either pass it to mcast router or discard it 
+		 */
+
+		if (ipv6_chk_mcast_addr(dev, &hdr->daddr) == 0)
+		{
+			/* something like:
+			   if (acting_as_router)
+				ipv6_mcast_route(skb, ...)
+			   else	
+			   */
+			kfree_skb(skb, FREE_READ);
+			return 0;
+		}
+	}
+
+	if (addr_type & IPV6_ADDR_MULTICAST ||
+	    (ifp = ipv6_chk_addr(&hdr->daddr)))	    
+	{
+
+		/* loop in a cicle parsing nexthdrs */
+
+		skb->h.raw   += sizeof(struct ipv6hdr);
+ 
+		/* extension header processing must update skb->h.raw */
+
+		nexthdr = hdr->nexthdr;
+		nhptr = &hdr->nexthdr;
+
+
+		while(1)
+		{
+			struct hdrtype_proc *hdrt;
+
+			/* check for extension header */
+
+			for (hdrt=hdrproc_lst; hdrt->type != NEXTHDR_MAX; hdrt++)
+			{
+				if (hdrt->type == nexthdr)
+				{
+					if ((nexthdr = hdrt->func(&skb, dev, nhptr, opt)))
+					{
+						nhptr = skb->h.raw;
+						hdr = skb->ipv6_hdr;
+						continue;
+					}
+					return 0;
+				}
+			}
+			break;
+
+		}
+
+		/* 
+		 * deliver to raw sockets
+		 * should we deliver raw after or before parsing 
+		 * extension headers ?
+		 * delivering after means we do reassembly of datagrams
+		 * in ip.
+		 */
+
+		pkt_len = skb->tail - skb->h.raw;
+
+		raw_sk = ipv6_raw_deliver(skb, dev, opt, nexthdr, pkt_len,
+					  &hdr->saddr, &hdr->daddr);
+
+		/* check inet6_protocol list */
+
+		hash = nexthdr & (MAX_INET_PROTOS -1);
+		for (ipprot = (struct inet6_protocol *) inet6_protos[hash]; 
+		     ipprot != NULL; 
+		     ipprot = (struct inet6_protocol *) ipprot->next)
+		{
+			struct sk_buff *buff = skb;
+
+			if (ipprot->protocol != nexthdr)
+				continue;
+
+			if (ipprot->copy || raw_sk)
+				buff = skb_clone(skb, GFP_ATOMIC);
+
+
+			ipprot->handler(buff, dev, 
+					&hdr->saddr, &hdr->daddr,
+					opt, pkt_len,
+					0, ipprot);
+			found = 1;
+		}
+
+		if (raw_sk)
+		{
+			skb->sk = raw_sk;
+			rawv6_rcv(skb, dev, &hdr->saddr, &hdr->daddr, opt,
+				  htons(hdr->payload_len));
+			found = 1;
+		}
+ 	       
+		/* not found: send ICMP parameter problem back */
+
+		if (!found)
+		{
+			printk(KERN_DEBUG "proto not found %d\n", nexthdr);
+			skb->sk = NULL;
+			kfree_skb(skb, FREE_READ);
+		}
+			
+	}
+	else
+	{
+		if (ipv6_forwarding)
+		{
+			if (addr_type & IPV6_ADDR_LINKLOCAL)
+			{
+				printk(KERN_DEBUG
+				       "link local pkt to forward\n");
+				kfree_skb(skb, FREE_READ);
+				return 0;
+			}
+			ipv6_forward(skb, dev, 0);
+		}
+		else
+		{
+			printk(KERN_WARNING "IPV6: packet to forward -"
+			       "host not configured as router\n");
+			kfree_skb(skb, FREE_READ);
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * Local variables:
+ * c-file-style: "Linux"
+ * End:
+ */