Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 431 insertions, 0 deletions

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
new file mode 100644
index 00000000000..a0d0833034b
--- /dev/null
+++ b/net/ipv4/ip_input.c
@@ -0,0 +1,431 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		The Internet Protocol (IP) module.
+ *
+ * Version:	$Id: ip_input.c,v 1.55 2002/01/12 07:39:45 davem Exp $
+ *
+ * Authors:	Ross Biro, <bir7@leland.Stanford.Edu>
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Donald Becker, <becker@super.org>
+ *		Alan Cox, <Alan.Cox@linux.org>
+ *		Richard Underwood
+ *		Stefan Becker, <stefanb@yello.ping.de>
+ *		Jorge Cwik, <jorge@laser.satlink.net>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		
+ *
+ * Fixes:
+ *		Alan Cox	:	Commented a couple of minor bits of surplus code
+ *		Alan Cox	:	Undefining IP_FORWARD doesn't include the code
+ *					(just stops a compiler warning).
+ *		Alan Cox	:	Frames with >=MAX_ROUTE record routes, strict routes or loose routes
+ *					are junked rather than corrupting things.
+ *		Alan Cox	:	Frames to bad broadcast subnets are dumped
+ *					We used to process them non broadcast and
+ *					boy could that cause havoc.
+ *		Alan Cox	:	ip_forward sets the free flag on the
+ *					new frame it queues. Still crap because
+ *					it copies the frame but at least it
+ *					doesn't eat memory too.
+ *		Alan Cox	:	Generic queue code and memory fixes.
+ *		Fred Van Kempen :	IP fragment support (borrowed from NET2E)
+ *		Gerhard Koerting:	Forward fragmented frames correctly.
+ *		Gerhard Koerting: 	Fixes to my fix of the above 8-).
+ *		Gerhard Koerting:	IP interface addressing fix.
+ *		Linus Torvalds	:	More robustness checks
+ *		Alan Cox	:	Even more checks: Still not as robust as it ought to be
+ *		Alan Cox	:	Save IP header pointer for later
+ *		Alan Cox	:	ip option setting
+ *		Alan Cox	:	Use ip_tos/ip_ttl settings
+ *		Alan Cox	:	Fragmentation bogosity removed
+ *					(Thanks to Mark.Bush@prg.ox.ac.uk)
+ *		Dmitry Gorodchanin :	Send of a raw packet crash fix.
+ *		Alan Cox	:	Silly ip bug when an overlength
+ *					fragment turns up. Now frees the
+ *					queue.
+ *		Linus Torvalds/ :	Memory leakage on fragmentation
+ *		Alan Cox	:	handling.
+ *		Gerhard Koerting:	Forwarding uses IP priority hints
+ *		Teemu Rantanen	:	Fragment problems.
+ *		Alan Cox	:	General cleanup, comments and reformat
+ *		Alan Cox	:	SNMP statistics
+ *		Alan Cox	:	BSD address rule semantics. Also see
+ *					UDP as there is a nasty checksum issue
+ *					if you do things the wrong way.
+ *		Alan Cox	:	Always defrag, moved IP_FORWARD to the config.in file
+ *		Alan Cox	: 	IP options adjust sk->priority.
+ *		Pedro Roque	:	Fix mtu/length error in ip_forward.
+ *		Alan Cox	:	Avoid ip_chk_addr when possible.
+ *	Richard Underwood	:	IP multicasting.
+ *		Alan Cox	:	Cleaned up multicast handlers.
+ *		Alan Cox	:	RAW sockets demultiplex in the BSD style.
+ *		Gunther Mayer	:	Fix the SNMP reporting typo
+ *		Alan Cox	:	Always in group 224.0.0.1
+ *	Pauline Middelink	:	Fast ip_checksum update when forwarding
+ *					Masquerading support.
+ *		Alan Cox	:	Multicast loopback error for 224.0.0.1
+ *		Alan Cox	:	IP_MULTICAST_LOOP option.
+ *		Alan Cox	:	Use notifiers.
+ *		Bjorn Ekwall	:	Removed ip_csum (from slhc.c too)
+ *		Bjorn Ekwall	:	Moved ip_fast_csum to ip.h (inline!)
+ *		Stefan Becker   :       Send out ICMP HOST REDIRECT
+ *	Arnt Gulbrandsen	:	ip_build_xmit
+ *		Alan Cox	:	Per socket routing cache
+ *		Alan Cox	:	Fixed routing cache, added header cache.
+ *		Alan Cox	:	Loopback didn't work right in original ip_build_xmit - fixed it.
+ *		Alan Cox	:	Only send ICMP_REDIRECT if src/dest are the same net.
+ *		Alan Cox	:	Incoming IP option handling.
+ *		Alan Cox	:	Set saddr on raw output frames as per BSD.
+ *		Alan Cox	:	Stopped broadcast source route explosions.
+ *		Alan Cox	:	Can disable source routing
+ *		Takeshi Sone    :	Masquerading didn't work.
+ *	Dave Bonn,Alan Cox	:	Faster IP forwarding whenever possible.
+ *		Alan Cox	:	Memory leaks, tramples, misc debugging.
+ *		Alan Cox	:	Fixed multicast (by popular demand 8))
+ *		Alan Cox	:	Fixed forwarding (by even more popular demand 8))
+ *		Alan Cox	:	Fixed SNMP statistics [I think]
+ *	Gerhard Koerting	:	IP fragmentation forwarding fix
+ *		Alan Cox	:	Device lock against page fault.
+ *		Alan Cox	:	IP_HDRINCL facility.
+ *	Werner Almesberger	:	Zero fragment bug
+ *		Alan Cox	:	RAW IP frame length bug
+ *		Alan Cox	:	Outgoing firewall on build_xmit
+ *		A.N.Kuznetsov	:	IP_OPTIONS support throughout the kernel
+ *		Alan Cox	:	Multicast routing hooks
+ *		Jos Vos		:	Do accounting *before* call_in_firewall
+ *	Willy Konynenberg	:	Transparent proxying support
+ *
+ *  
+ *
+ * To Fix:
+ *		IP fragmentation wants rewriting cleanly. The RFC815 algorithm is much more efficient
+ *		and could be made very efficient with the addition of some virtual memory hacks to permit
+ *		the allocation of a buffer that can then be 'grown' by twiddling page tables.
+ *		Output fragmentation wants updating along with the buffer management to use a single 
+ *		interleaved copy algorithm so that fragmenting has a one copy overhead. Actual packet
+ *		output should probably do its own fragmentation at the UDP/RAW layer. TCP shouldn't cause
+ *		fragmentation anyway.
+ *
+ *		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 <asm/system.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/config.h>
+
+#include <linux/net.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+
+#include <net/snmp.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/arp.h>
+#include <net/icmp.h>
+#include <net/raw.h>
+#include <net/checksum.h>
+#include <linux/netfilter_ipv4.h>
+#include <net/xfrm.h>
+#include <linux/mroute.h>
+#include <linux/netlink.h>
+
+/*
+ *	SNMP management statistics
+ */
+
+DEFINE_SNMP_STAT(struct ipstats_mib, ip_statistics);
+
+/*
+ *	Process Router Attention IP option
+ */ 
+int ip_call_ra_chain(struct sk_buff *skb)
+{
+	struct ip_ra_chain *ra;
+	u8 protocol = skb->nh.iph->protocol;
+	struct sock *last = NULL;
+
+	read_lock(&ip_ra_lock);
+	for (ra = ip_ra_chain; ra; ra = ra->next) {
+		struct sock *sk = ra->sk;
+
+		/* If socket is bound to an interface, only report
+		 * the packet if it came  from that interface.
+		 */
+		if (sk && inet_sk(sk)->num == protocol &&
+		    (!sk->sk_bound_dev_if ||
+		     sk->sk_bound_dev_if == skb->dev->ifindex)) {
+			if (skb->nh.iph->frag_off & htons(IP_MF|IP_OFFSET)) {
+				skb = ip_defrag(skb, IP_DEFRAG_CALL_RA_CHAIN);
+				if (skb == NULL) {
+					read_unlock(&ip_ra_lock);
+					return 1;
+				}
+			}
+			if (last) {
+				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
+				if (skb2)
+					raw_rcv(last, skb2);
+			}
+			last = sk;
+		}
+	}
+
+	if (last) {
+		raw_rcv(last, skb);
+		read_unlock(&ip_ra_lock);
+		return 1;
+	}
+	read_unlock(&ip_ra_lock);
+	return 0;
+}
+
+static inline int ip_local_deliver_finish(struct sk_buff *skb)
+{
+	int ihl = skb->nh.iph->ihl*4;
+
+#ifdef CONFIG_NETFILTER_DEBUG
+	nf_debug_ip_local_deliver(skb);
+#endif /*CONFIG_NETFILTER_DEBUG*/
+
+	__skb_pull(skb, ihl);
+
+	/* Free reference early: we don't need it any more, and it may
+           hold ip_conntrack module loaded indefinitely. */
+	nf_reset(skb);
+
+        /* Point into the IP datagram, just past the header. */
+        skb->h.raw = skb->data;
+
+	rcu_read_lock();
+	{
+		/* Note: See raw.c and net/raw.h, RAWV4_HTABLE_SIZE==MAX_INET_PROTOS */
+		int protocol = skb->nh.iph->protocol;
+		int hash;
+		struct sock *raw_sk;
+		struct net_protocol *ipprot;
+
+	resubmit:
+		hash = protocol & (MAX_INET_PROTOS - 1);
+		raw_sk = sk_head(&raw_v4_htable[hash]);
+
+		/* If there maybe a raw socket we must check - if not we
+		 * don't care less
+		 */
+		if (raw_sk)
+			raw_v4_input(skb, skb->nh.iph, hash);
+
+		if ((ipprot = rcu_dereference(inet_protos[hash])) != NULL) {
+			int ret;
+
+			if (!ipprot->no_policy &&
+			    !xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+				kfree_skb(skb);
+				goto out;
+			}
+			ret = ipprot->handler(skb);
+			if (ret < 0) {
+				protocol = -ret;
+				goto resubmit;
+			}
+			IP_INC_STATS_BH(IPSTATS_MIB_INDELIVERS);
+		} else {
+			if (!raw_sk) {
+				if (xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+					IP_INC_STATS_BH(IPSTATS_MIB_INUNKNOWNPROTOS);
+					icmp_send(skb, ICMP_DEST_UNREACH,
+						  ICMP_PROT_UNREACH, 0);
+				}
+			} else
+				IP_INC_STATS_BH(IPSTATS_MIB_INDELIVERS);
+			kfree_skb(skb);
+		}
+	}
+ out:
+	rcu_read_unlock();
+
+	return 0;
+}
+
+/*
+ * 	Deliver IP Packets to the higher protocol layers.
+ */ 
+int ip_local_deliver(struct sk_buff *skb)
+{
+	/*
+	 *	Reassemble IP fragments.
+	 */
+
+	if (skb->nh.iph->frag_off & htons(IP_MF|IP_OFFSET)) {
+		skb = ip_defrag(skb, IP_DEFRAG_LOCAL_DELIVER);
+		if (!skb)
+			return 0;
+	}
+
+	return NF_HOOK(PF_INET, NF_IP_LOCAL_IN, skb, skb->dev, NULL,
+		       ip_local_deliver_finish);
+}
+
+static inline int ip_rcv_finish(struct sk_buff *skb)
+{
+	struct net_device *dev = skb->dev;
+	struct iphdr *iph = skb->nh.iph;
+
+	/*
+	 *	Initialise the virtual path cache for the packet. It describes
+	 *	how the packet travels inside Linux networking.
+	 */ 
+	if (skb->dst == NULL) {
+		if (ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))
+			goto drop; 
+	}
+
+#ifdef CONFIG_NET_CLS_ROUTE
+	if (skb->dst->tclassid) {
+		struct ip_rt_acct *st = ip_rt_acct + 256*smp_processor_id();
+		u32 idx = skb->dst->tclassid;
+		st[idx&0xFF].o_packets++;
+		st[idx&0xFF].o_bytes+=skb->len;
+		st[(idx>>16)&0xFF].i_packets++;
+		st[(idx>>16)&0xFF].i_bytes+=skb->len;
+	}
+#endif
+
+	if (iph->ihl > 5) {
+		struct ip_options *opt;
+
+		/* It looks as overkill, because not all
+		   IP options require packet mangling.
+		   But it is the easiest for now, especially taking
+		   into account that combination of IP options
+		   and running sniffer is extremely rare condition.
+		                                      --ANK (980813)
+		*/
+
+		if (skb_cow(skb, skb_headroom(skb))) {
+			IP_INC_STATS_BH(IPSTATS_MIB_INDISCARDS);
+			goto drop;
+		}
+		iph = skb->nh.iph;
+
+		if (ip_options_compile(NULL, skb))
+			goto inhdr_error;
+
+		opt = &(IPCB(skb)->opt);
+		if (opt->srr) {
+			struct in_device *in_dev = in_dev_get(dev);
+			if (in_dev) {
+				if (!IN_DEV_SOURCE_ROUTE(in_dev)) {
+					if (IN_DEV_LOG_MARTIANS(in_dev) && net_ratelimit())
+						printk(KERN_INFO "source route option %u.%u.%u.%u -> %u.%u.%u.%u\n",
+						       NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
+					in_dev_put(in_dev);
+					goto drop;
+				}
+				in_dev_put(in_dev);
+			}
+			if (ip_options_rcv_srr(skb))
+				goto drop;
+		}
+	}
+
+	return dst_input(skb);
+
+inhdr_error:
+	IP_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+drop:
+        kfree_skb(skb);
+        return NET_RX_DROP;
+}
+
+/*
+ * 	Main IP Receive routine.
+ */ 
+int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt)
+{
+	struct iphdr *iph;
+
+	/* When the interface is in promisc. mode, drop all the crap
+	 * that it receives, do not try to analyse it.
+	 */
+	if (skb->pkt_type == PACKET_OTHERHOST)
+		goto drop;
+
+	IP_INC_STATS_BH(IPSTATS_MIB_INRECEIVES);
+
+	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
+		IP_INC_STATS_BH(IPSTATS_MIB_INDISCARDS);
+		goto out;
+	}
+
+	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+		goto inhdr_error;
+
+	iph = skb->nh.iph;
+
+	/*
+	 *	RFC1122: 3.1.2.2 MUST silently discard any IP frame that fails the checksum.
+	 *
+	 *	Is the datagram acceptable?
+	 *
+	 *	1.	Length at least the size of an ip header
+	 *	2.	Version of 4
+	 *	3.	Checksums correctly. [Speed optimisation for later, skip loopback checksums]
+	 *	4.	Doesn't have a bogus length
+	 */
+
+	if (iph->ihl < 5 || iph->version != 4)
+		goto inhdr_error; 
+
+	if (!pskb_may_pull(skb, iph->ihl*4))
+		goto inhdr_error;
+
+	iph = skb->nh.iph;
+
+	if (ip_fast_csum((u8 *)iph, iph->ihl) != 0)
+		goto inhdr_error; 
+
+	{
+		__u32 len = ntohs(iph->tot_len); 
+		if (skb->len < len || len < (iph->ihl<<2))
+			goto inhdr_error;
+
+		/* Our transport medium may have padded the buffer out. Now we know it
+		 * is IP we can trim to the true length of the frame.
+		 * Note this now means skb->len holds ntohs(iph->tot_len).
+		 */
+		if (pskb_trim_rcsum(skb, len)) {
+			IP_INC_STATS_BH(IPSTATS_MIB_INDISCARDS);
+			goto drop;
+		}
+	}
+
+	return NF_HOOK(PF_INET, NF_IP_PRE_ROUTING, skb, dev, NULL,
+		       ip_rcv_finish);
+
+inhdr_error:
+	IP_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
+drop:
+        kfree_skb(skb);
+out:
+        return NET_RX_DROP;
+}
+
+EXPORT_SYMBOL(ip_rcv);
+EXPORT_SYMBOL(ip_statistics);