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

• Lines: 554
• Date: Sun Nov 3 11:04:46 1996
• Orig file: v2.1.7/linux/net/ipv6/icmp.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v2.1.7/linux/net/ipv6/icmp.c linux/net/ipv6/icmp.c
@@ -0,0 +1,553 @@
+/*
+ *	Internet Control Message Protocol (ICMPv6)
+ *	Linux INET6 implementation
+ *
+ *	Authors:
+ *	Pedro Roque		<roque@di.fc.ul.pt>
+ *
+ *	Based on net/ipv4/icmp.c
+ *
+ *	RFC 1885
+ *
+ *	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.
+ */
+
+#define __NO_VERSION__
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/stat.h>
+#include <linux/skbuff.h>
+
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/icmpv6.h>
+
+#include <net/ip.h>
+#include <net/sock.h>
+
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/ndisc.h>
+#include <net/raw.h>
+#include <net/inet_common.h>
+#include <net/transp_v6.h>
+#include <net/ipv6_route.h>
+#include <net/addrconf.h>
+#include <net/rawv6.h>
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+/*
+ *	ICMP socket for flow control.
+ */
+
+static struct socket icmpv6_socket;
+
+int icmpv6_rcv(struct sk_buff *skb, struct device *dev,
+	       struct in6_addr *saddr, struct in6_addr *daddr,
+	       struct ipv6_options *opt, unsigned short len,
+	       int redo, struct inet6_protocol *protocol);
+
+static struct inet6_protocol icmpv6_protocol = 
+{
+	icmpv6_rcv,		/* handler		*/
+	NULL,			/* error control	*/
+	NULL,			/* next			*/
+	IPPROTO_ICMPV6,		/* protocol ID		*/
+	0,			/* copy			*/
+	NULL,			/* data			*/
+	"ICMPv6"	       	/* name			*/
+};
+
+
+
+struct icmpv6_msg {
+	struct icmpv6hdr	icmph;
+	__u8 			*data;
+	struct in6_addr		*daddr;
+	int			len;
+	__u32			csum;
+};
+
+
+
+/*
+ *	getfrag callback
+ *	not static because it's needed in ndisc.c
+ */
+
+static void icmpv6_getfrag(const void *data, struct in6_addr *saddr, 
+			   char *buff, unsigned int offset, unsigned int len)
+{
+	struct icmpv6_msg *msg = (struct icmpv6_msg *) data;
+	struct icmpv6hdr *icmph;
+	__u32 csum;
+
+	/* 
+	 *	in theory offset must be 0 since we never send more 
+	 *	than 576 bytes on an error or more than the path mtu
+	 *	on an echo reply. (those are the rules on RFC 1883)
+	 */
+
+	if (offset)
+	{
+		csum = csum_partial_copy((void *) msg->data +
+					 offset - sizeof(struct icmpv6hdr), 
+					 buff, len, msg->csum);
+		msg->csum = csum;
+		return;
+	}
+
+	csum = csum_partial_copy((void *) &msg->icmph, buff,
+				 sizeof(struct icmpv6hdr), msg->csum);
+
+	csum = csum_partial_copy((void *) msg->data, 
+				 buff + sizeof(struct icmpv6hdr),
+				 len - sizeof(struct icmpv6hdr), csum);
+
+	icmph = (struct icmpv6hdr *) buff;
+
+	icmph->checksum = csum_ipv6_magic(saddr, msg->daddr, msg->len,
+					  IPPROTO_ICMPV6, csum);
+}
+
+/*
+ *	an inline helper for the "simple" if statement bellow
+ *	checks if parameter problem report is caused by an
+ *	unrecognized IPv6 option that has the Option Type 
+ *	highest-order two bits set to 10
+ */
+static __inline__ int opt_unrec(struct sk_buff *skb, __u32 offset)
+{
+	char *buff = (char *) skb->ipv6_hdr;
+
+	return ( ( *(buff + offset) & 0xC0 ) == 0x80 );
+}
+
+/*
+ *	Send an ICMP message in response to a packet in error
+ */
+
+void icmpv6_send(struct sk_buff *skb, int type, int code, __u32 info, 
+		 struct device *dev)
+{
+	struct ipv6hdr *hdr = skb->ipv6_hdr;
+	struct sock *sk = (struct sock *) icmpv6_socket.data;
+	struct in6_addr *saddr = NULL;
+	struct device *src_dev = NULL;
+	struct icmpv6_msg msg;
+	int addr_type = 0;
+	int optlen;
+	int len;
+
+	/*
+	 *	sanity check pointer in case of parameter problem
+	 */
+
+	if (type == ICMPV6_PARAMETER_PROB && 
+	    (info > (skb->tail - ((unsigned char *) hdr))))
+	{
+		printk(KERN_DEBUG "icmpv6_send: bug! pointer > skb\n");
+		return;
+	}
+
+	/*
+	 *	Make sure we respect the rules 
+	 *	i.e. RFC 1885 2.4(e)
+	 *	Rule (e.1) is enforced by not using icmpv6_send
+	 *	in any code that processes icmp errors.
+	 */
+	
+	addr_type = ipv6_addr_type(&hdr->daddr);
+
+	if (ipv6_chk_addr(&hdr->daddr))
+	{
+		saddr = &hdr->daddr;
+	}
+
+	/*
+	 *	Dest addr check
+	 */
+
+	if ((addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST))
+	{
+		if (type != ICMPV6_PKT_TOOBIG &&
+		    !(type == ICMPV6_PARAMETER_PROB && 
+		      code == ICMPV6_UNK_OPTION && 
+		      (opt_unrec(skb, info))))
+		{
+			return;
+		}
+
+		saddr = NULL;
+	}
+
+	addr_type = ipv6_addr_type(&hdr->saddr);
+
+	/*
+	 *	Source addr check
+	 */
+
+	if (addr_type & IPV6_ADDR_LINKLOCAL)
+	{
+		src_dev = skb->dev;
+	}
+
+	/*
+	 *	Must not send if we know that source is Anycast also.
+	 *	for now we don't know that.
+	 */
+	if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST))
+	{
+		printk(KERN_DEBUG "icmpv6_send: addr_any/mcast source\n");
+		return;
+	}
+
+	/*
+	 *	ok. kick it. checksum will be provided by the 
+	 *	getfrag_t callback.
+	 */
+
+	msg.icmph.type = type;
+	msg.icmph.code = code;
+	msg.icmph.checksum = 0;
+	msg.icmph.icmp6_pointer = htonl(info);
+
+	msg.data = (__u8 *) skb->ipv6_hdr;
+	msg.csum = 0;
+	msg.daddr = &hdr->saddr;
+        /*
+	if (skb->opt)
+		optlen = skb->opt->optlen;
+	else
+	*/
+
+	optlen = 0;
+
+	len = min(skb->tail - ((unsigned char *) hdr), 
+		  576 - sizeof(struct ipv6hdr) - sizeof(struct icmpv6hdr)
+		  - optlen);
+
+	if (len < 0)
+	{
+		printk(KERN_DEBUG "icmp: len problem\n");
+		return;
+	}
+
+	len += sizeof(struct icmpv6hdr);
+
+	msg.len = len;
+
+
+	ipv6_build_xmit(sk, icmpv6_getfrag, &msg, &hdr->saddr, len,
+			saddr, src_dev, NULL, IPPROTO_ICMPV6, 1);
+}
+
+static void icmpv6_echo_reply(struct sk_buff *skb)
+{
+	struct sock *sk = (struct sock *) icmpv6_socket.data;
+	struct ipv6hdr *hdr = skb->ipv6_hdr;
+	struct icmpv6hdr *icmph = (struct icmpv6hdr *) skb->h.raw;
+	struct in6_addr *saddr;
+	struct icmpv6_msg msg;
+	unsigned char *data;
+	int len;
+
+	data = (char *) (icmph + 1);
+
+	saddr = &hdr->daddr;
+
+	if (ipv6_addr_type(saddr) & IPV6_ADDR_MULTICAST)
+		saddr = NULL;
+
+	len = skb->tail - data;
+	len += sizeof(struct icmpv6hdr);
+
+	msg.icmph.type = ICMPV6_ECHO_REPLY;
+	msg.icmph.code = 0;
+	msg.icmph.checksum = 0;
+	msg.icmph.icmp6_identifier = icmph->icmp6_identifier;
+	msg.icmph.icmp6_sequence = icmph->icmp6_sequence;
+
+	msg.data = data;
+	msg.csum = 0;
+	msg.len = len;
+	msg.daddr = &hdr->saddr;
+       
+	ipv6_build_xmit(sk, icmpv6_getfrag, &msg, &hdr->saddr, len, saddr,
+			skb->dev, NULL, IPPROTO_ICMPV6, 1);
+}
+
+static __inline__ int ipv6_ext_hdr(u8 nexthdr)
+{
+	/* 
+	 * find out if nexthdr is an extension header or a protocol
+	 */
+	return ( (nexthdr == NEXTHDR_HOP)	||
+		 (nexthdr == NEXTHDR_ROUTING)	||
+		 (nexthdr == NEXTHDR_FRAGMENT)	||
+		 (nexthdr == NEXTHDR_ESP)	||
+		 (nexthdr == NEXTHDR_AUTH)	||
+		 (nexthdr == NEXTHDR_NONE)	||
+		 (nexthdr == NEXTHDR_DEST) );
+		 
+}
+
+static void icmpv6_notify(int type, int code, unsigned char *buff, int len,
+			  struct in6_addr *saddr, struct in6_addr *daddr, 
+			  struct inet6_protocol *protocol)
+{
+	struct ipv6hdr *hdr = (struct ipv6hdr *) buff;
+	struct inet6_protocol *ipprot;
+	struct sock *sk;
+	char * pbuff;
+	__u32 info = 0;
+	int hash;
+	u8 nexthdr;
+
+	/* now skip over extension headers */
+
+	nexthdr = hdr->nexthdr;
+
+	pbuff = (char *) (hdr + 1);
+	len -= sizeof(struct ipv6hdr);
+
+	while (ipv6_ext_hdr(nexthdr)) 
+	{
+		int hdrlen;
+
+		if (nexthdr == NEXTHDR_NONE)
+			return;
+
+		nexthdr = *pbuff;
+		hdrlen = *(pbuff+1);
+
+		if (((hdrlen + 1) << 3) > len)
+			return;
+		
+		pbuff += hdrlen;
+		len -= hdrlen;
+	}
+
+	hash = nexthdr & (MAX_INET_PROTOS -1);
+
+	for (ipprot = (struct inet6_protocol *) inet6_protos[hash]; 
+	     ipprot != NULL; 
+	     ipprot=(struct inet6_protocol *)ipprot->next)
+	{
+		if (ipprot->protocol != nexthdr)
+			continue;
+
+		if (ipprot->err_handler) 
+		{
+			ipprot->err_handler(type, code, pbuff, info,
+					    saddr, daddr, ipprot);
+		}
+		return;
+	}
+
+	/* delivery to upper layer protocols failed. try raw sockets */
+
+	sk = rawv6_prot.sock_array[hash];
+
+	if (sk == NULL)
+	{
+		return;
+	}
+
+	while ((sk = inet6_get_sock_raw(sk, nexthdr, daddr, saddr)))
+	{
+		rawv6_err(sk, type, code, pbuff, saddr, daddr);
+		sk = sk->next;
+	}
+
+	return;
+}
+  
+/*
+ *	Handle icmp messages
+ */
+
+int icmpv6_rcv(struct sk_buff *skb, struct device *dev,
+	       struct in6_addr *saddr, struct in6_addr *daddr,
+	       struct ipv6_options *opt, unsigned short len,
+	       int redo, struct inet6_protocol *protocol)
+{
+	struct ipv6hdr *orig_hdr;
+	struct icmpv6hdr *hdr = (struct icmpv6hdr *) skb->h.raw;
+	int ulen;
+
+	/* perform checksum */
+
+
+	switch (skb->ip_summed) {	
+	case CHECKSUM_NONE:
+		skb->csum = csum_partial((char *)hdr, len, 0);
+	case CHECKSUM_HW:
+		if (csum_ipv6_magic(saddr, daddr, len, IPPROTO_ICMPV6, 
+				    skb->csum))
+		{
+			printk(KERN_DEBUG "icmpv6 checksum failed\n");
+			goto discard_it;
+		}
+	default:
+		/* CHECKSUM_UNNECESSARY */
+	}
+
+	/*
+	 *	length of original packet carried in skb
+	 */
+	ulen = skb->tail - (unsigned char *) (hdr + 1);
+	
+	switch (hdr->type) {
+
+	case ICMPV6_ECHO_REQUEST:
+		icmpv6_echo_reply(skb);
+		break;
+
+	case ICMPV6_ECHO_REPLY:
+		/* we coulnd't care less */
+		break;
+
+	case ICMPV6_PKT_TOOBIG:
+		orig_hdr = (struct ipv6hdr *) (hdr + 1);
+		if (ulen >= sizeof(struct ipv6hdr))
+		{
+			rt6_handle_pmtu(&orig_hdr->daddr,
+					ntohl(hdr->icmp6_mtu));
+		}
+
+		/*
+		 * Drop through to notify
+		 */
+
+	case ICMPV6_DEST_UNREACH:
+	case ICMPV6_TIME_EXCEEDED:
+	case ICMPV6_PARAMETER_PROB:
+
+		icmpv6_notify(hdr->type, hdr->code, (char *) (hdr + 1), ulen,
+			      saddr, daddr, protocol);
+		break;
+
+	case NDISC_ROUTER_SOLICITATION:
+	case NDISC_ROUTER_ADVERTISEMENT:
+	case NDISC_NEIGHBOUR_SOLICITATION:
+	case NDISC_NEIGHBOUR_ADVERTISEMENT:
+	case NDISC_REDIRECT:
+		ndisc_rcv(skb, dev, saddr, daddr, opt, len);		
+		break;
+
+	case ICMPV6_MEMBERSHIP_QUERY:
+	case ICMPV6_MEMBERSHIP_REPORT:
+	case ICMPV6_MEMBERSHIP_REDUCTION:
+		/* forward the packet to the igmp module */
+		break;
+
+	default:
+		printk(KERN_DEBUG "icmpv6: msg of unkown type\n");
+		
+		/* informational */
+		if (hdr->type & 0x80)
+		{
+			goto discard_it;
+		}
+
+		/* 
+		 * error of unkown type. 
+		 * must pass to upper level 
+		 */
+
+		icmpv6_notify(hdr->type, hdr->code, (char *) (hdr + 1), ulen,
+			      saddr, daddr, protocol);	
+	}
+
+  discard_it:
+
+	kfree_skb(skb, FREE_READ);
+	return 0;
+}
+
+void icmpv6_init(struct proto_ops *ops)
+{
+	struct sock *sk;
+	int err;
+
+	icmpv6_socket.type=SOCK_RAW;
+	icmpv6_socket.ops=ops;
+
+	if((err=ops->create(&icmpv6_socket, IPPROTO_ICMPV6))<0)
+		printk(KERN_DEBUG 
+		       "Failed to create the ICMP control socket.\n");
+
+	MOD_DEC_USE_COUNT;
+
+	sk = icmpv6_socket.data;
+	sk->allocation = GFP_ATOMIC;
+	sk->num = 256;			/* Don't receive any data */
+
+	inet6_add_protocol(&icmpv6_protocol);
+}
+
+static struct icmp6_err {
+	int err;
+	int fatal;
+} tab_unreach[] = {
+	{ ENETUNREACH,	0},	/* NOROUTE		*/
+	{ EACCES,	1},	/* ADM_PROHIBITED	*/
+	{ EOPNOTSUPP,	1},	/* NOT_NEIGHBOUR	*/
+	{ EHOSTUNREACH,	0},	/* ADDR_UNREACH		*/
+	{ ECONNREFUSED,	1},	/* PORT_UNREACH		*/
+};
+
+int icmpv6_err_convert(int type, int code, int *err)
+{
+	int fatal = 0;
+
+	*err = 0;
+
+	switch (type) {
+	case ICMPV6_DEST_UNREACH:
+		if (code <= ICMPV6_PORT_UNREACH)
+		{
+			*err  = tab_unreach[code].err;
+			fatal = tab_unreach[code].fatal;
+		}
+		break;
+
+	case ICMPV6_PKT_TOOBIG:
+		*err = EMSGSIZE;
+		break;
+		
+	case ICMPV6_PARAMETER_PROB:
+		*err = EPROTO;
+		fatal = 1;
+		break;
+	};
+
+	return fatal;
+}
+
+/*
+ * Local variables:
+ *  compile-command: "gcc -D__KERNEL__ -I/usr/src/linux/include -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer -fno-strength-reduce -pipe -m486 -DCPU=486 -DMODULE -DMODVERSIONS -include /usr/src/linux/include/linux/modversions.h  -c -o icmp.o icmp.c"
+ * End:
+ */