Import of Linux 2.2.12 subset (ipv4 stack and related)

1 files changed, 1191 insertions, 0 deletions

diff --git a/pfinet/linux-src/net/ipv4/udp.c b/pfinet/linux-src/net/ipv4/udp.c
new file mode 100644
index 00000000..909e858f
--- /dev/null
+++ b/pfinet/linux-src/net/ipv4/udp.c
@@ -0,0 +1,1191 @@
+/*
+ * 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 User Datagram Protocol (UDP).
+ *
+ * Version:	$Id: udp.c,v 1.66.2.3 1999/08/07 10:56:36 davem Exp $
+ *
+ * Authors:	Ross Biro, <bir7@leland.Stanford.Edu>
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Alan Cox, <Alan.Cox@linux.org>
+ *
+ * Fixes:
+ *		Alan Cox	:	verify_area() calls
+ *		Alan Cox	: 	stopped close while in use off icmp
+ *					messages. Not a fix but a botch that
+ *					for udp at least is 'valid'.
+ *		Alan Cox	:	Fixed icmp handling properly
+ *		Alan Cox	: 	Correct error for oversized datagrams
+ *		Alan Cox	:	Tidied select() semantics. 
+ *		Alan Cox	:	udp_err() fixed properly, also now 
+ *					select and read wake correctly on errors
+ *		Alan Cox	:	udp_send verify_area moved to avoid mem leak
+ *		Alan Cox	:	UDP can count its memory
+ *		Alan Cox	:	send to an unknown connection causes
+ *					an ECONNREFUSED off the icmp, but
+ *					does NOT close.
+ *		Alan Cox	:	Switched to new sk_buff handlers. No more backlog!
+ *		Alan Cox	:	Using generic datagram code. Even smaller and the PEEK
+ *					bug no longer crashes it.
+ *		Fred Van Kempen	: 	Net2e support for sk->broadcast.
+ *		Alan Cox	:	Uses skb_free_datagram
+ *		Alan Cox	:	Added get/set sockopt support.
+ *		Alan Cox	:	Broadcasting without option set returns EACCES.
+ *		Alan Cox	:	No wakeup calls. Instead we now use the callbacks.
+ *		Alan Cox	:	Use ip_tos and ip_ttl
+ *		Alan Cox	:	SNMP Mibs
+ *		Alan Cox	:	MSG_DONTROUTE, and 0.0.0.0 support.
+ *		Matt Dillon	:	UDP length checks.
+ *		Alan Cox	:	Smarter af_inet used properly.
+ *		Alan Cox	:	Use new kernel side addressing.
+ *		Alan Cox	:	Incorrect return on truncated datagram receive.
+ *	Arnt Gulbrandsen 	:	New udp_send and stuff
+ *		Alan Cox	:	Cache last socket
+ *		Alan Cox	:	Route cache
+ *		Jon Peatfield	:	Minor efficiency fix to sendto().
+ *		Mike Shaver	:	RFC1122 checks.
+ *		Alan Cox	:	Nonblocking error fix.
+ *	Willy Konynenberg	:	Transparent proxying support.
+ *		Mike McLagan	:	Routing by source
+ *		David S. Miller	:	New socket lookup architecture.
+ *					Last socket cache retained as it
+ *					does have a high hit rate.
+ *		Olaf Kirch	:	Don't linearise iovec on sendmsg.
+ *		Andi Kleen	:	Some cleanups, cache destination entry
+ *					for connect. 
+ *	Vitaly E. Lavrov	:	Transparent proxy revived after year coma.
+ *		Melvin Smith	:	Check msg_name not msg_namelen in sendto(),
+ *					return ENOTCONN for unconnected sockets (POSIX)
+ *		Janos Farkas	:	don't deliver multi/broadcasts to a different
+ *					bound-to-device socket
+ *
+ *
+ *		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.
+ */
+ 
+/* RFC1122 Status:
+   4.1.3.1 (Ports):
+     SHOULD send ICMP_PORT_UNREACHABLE in response to datagrams to 
+       an un-listened port. (OK)
+   4.1.3.2 (IP Options)
+     MUST pass IP options from IP -> application (OK)
+     MUST allow application to specify IP options (OK)
+   4.1.3.3 (ICMP Messages)
+     MUST pass ICMP error messages to application (OK -- except when SO_BSDCOMPAT is set)
+   4.1.3.4 (UDP Checksums)
+     MUST provide facility for checksumming (OK)
+     MAY allow application to control checksumming (OK)
+     MUST default to checksumming on (OK)
+     MUST discard silently datagrams with bad csums (OK, except during debugging)
+   4.1.3.5 (UDP Multihoming)
+     MUST allow application to specify source address (OK)
+     SHOULD be able to communicate the chosen src addr up to application
+       when application doesn't choose (DOES - use recvmsg cmsgs)
+   4.1.3.6 (Invalid Addresses)
+     MUST discard invalid source addresses (OK -- done in the new routing code)
+     MUST only send datagrams with one of our addresses (OK)
+*/
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/config.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <net/snmp.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/udp.h>
+#include <net/icmp.h>
+#include <net/route.h>
+#include <net/checksum.h>
+
+/*
+ *	Snmp MIB for the UDP layer
+ */
+
+struct udp_mib		udp_statistics;
+
+struct sock *udp_hash[UDP_HTABLE_SIZE];
+
+/* Shared by v4/v6 udp. */
+int udp_port_rover = 0;
+
+static int udp_v4_get_port(struct sock *sk, unsigned short snum)
+{
+	SOCKHASH_LOCK();
+	if (snum == 0) {
+		int best_size_so_far, best, result, i;
+
+		if (udp_port_rover > sysctl_local_port_range[1] ||
+		    udp_port_rover < sysctl_local_port_range[0])
+			udp_port_rover = sysctl_local_port_range[0];
+		best_size_so_far = 32767;
+		best = result = udp_port_rover;
+		for (i = 0; i < UDP_HTABLE_SIZE; i++, result++) {
+			struct sock *sk;
+			int size;
+
+			sk = udp_hash[result & (UDP_HTABLE_SIZE - 1)];
+			if (!sk) {
+				if (result > sysctl_local_port_range[1])
+					result = sysctl_local_port_range[0] +
+						((result - sysctl_local_port_range[0]) &
+						 (UDP_HTABLE_SIZE - 1));
+				goto gotit;
+			}
+			size = 0;
+			do {
+				if (++size >= best_size_so_far)
+					goto next;
+			} while ((sk = sk->next) != NULL);
+			best_size_so_far = size;
+			best = result;
+		next:
+		}
+		result = best;
+		for(;; result += UDP_HTABLE_SIZE) {
+			if (result > sysctl_local_port_range[1])
+				result = sysctl_local_port_range[0]
+					+ ((result - sysctl_local_port_range[0]) &
+					   (UDP_HTABLE_SIZE - 1));
+			if (!udp_lport_inuse(result))
+				break;
+		}
+gotit:
+		udp_port_rover = snum = result;
+	} else {
+		struct sock *sk2;
+
+		for (sk2 = udp_hash[snum & (UDP_HTABLE_SIZE - 1)];
+		     sk2 != NULL;
+		     sk2 = sk2->next) {
+			if (sk2->num == snum &&
+			    sk2 != sk &&
+			    sk2->bound_dev_if == sk->bound_dev_if &&
+			    (!sk2->rcv_saddr ||
+			     !sk->rcv_saddr ||
+			     sk2->rcv_saddr == sk->rcv_saddr) &&
+			    (!sk2->reuse || !sk->reuse))
+				goto fail;
+		}
+	}
+	sk->num = snum;
+	SOCKHASH_UNLOCK();
+	return 0;
+
+fail:
+	SOCKHASH_UNLOCK();
+	return 1;
+}
+
+/* Last hit UDP socket cache, this is ipv4 specific so make it static. */
+static u32 uh_cache_saddr, uh_cache_daddr;
+static u16 uh_cache_dport, uh_cache_sport;
+static struct sock *uh_cache_sk = NULL;
+
+static void udp_v4_hash(struct sock *sk)
+{
+	struct sock **skp = &udp_hash[sk->num & (UDP_HTABLE_SIZE - 1)];
+
+	SOCKHASH_LOCK();
+	if ((sk->next = *skp) != NULL)
+		(*skp)->pprev = &sk->next;
+	*skp = sk;
+	sk->pprev = skp;
+	SOCKHASH_UNLOCK();
+}
+
+static void udp_v4_unhash(struct sock *sk)
+{
+	SOCKHASH_LOCK();
+	if (sk->pprev) {
+		if (sk->next)
+			sk->next->pprev = sk->pprev;
+		*sk->pprev = sk->next;
+		sk->pprev = NULL;
+		if(uh_cache_sk == sk)
+			uh_cache_sk = NULL;
+	}
+	SOCKHASH_UNLOCK();
+}
+
+/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
+ * harder than this here plus the last hit cache. -DaveM
+ */
+struct sock *udp_v4_lookup_longway(u32 saddr, u16 sport, u32 daddr, u16 dport, int dif)
+{
+	struct sock *sk, *result = NULL;
+	unsigned short hnum = ntohs(dport);
+	int badness = -1;
+
+	for(sk = udp_hash[hnum & (UDP_HTABLE_SIZE - 1)]; sk != NULL; sk = sk->next) {
+		if((sk->num == hnum) && !(sk->dead && (sk->state == TCP_CLOSE))) {
+			int score = 0;
+			if(sk->rcv_saddr) {
+				if(sk->rcv_saddr != daddr)
+					continue;
+				score++;
+			}
+			if(sk->daddr) {
+				if(sk->daddr != saddr)
+					continue;
+				score++;
+			}
+			if(sk->dport) {
+				if(sk->dport != sport)
+					continue;
+				score++;
+			}
+			if(sk->bound_dev_if) {
+				if(sk->bound_dev_if != dif)
+					continue;
+				score++;
+			}
+			if(score == 4) {
+				result = sk;
+				break;
+			} else if(score > badness) {
+				result = sk;
+				badness = score;
+			}
+		}
+	}
+	return result;
+}
+
+__inline__ struct sock *udp_v4_lookup(u32 saddr, u16 sport, u32 daddr, u16 dport, int dif)
+{
+	struct sock *sk;
+
+	if(!dif && uh_cache_sk		&&
+	   uh_cache_saddr == saddr	&&
+	   uh_cache_sport == sport	&&
+	   uh_cache_dport == dport	&&
+	   uh_cache_daddr == daddr)
+		return uh_cache_sk;
+
+	sk = udp_v4_lookup_longway(saddr, sport, daddr, dport, dif);
+	if(!dif) {
+		uh_cache_sk	= sk;
+		uh_cache_saddr	= saddr;
+		uh_cache_daddr	= daddr;
+		uh_cache_sport	= sport;
+		uh_cache_dport	= dport;
+	}
+	return sk;
+}
+
+#ifdef CONFIG_IP_TRANSPARENT_PROXY
+#define secondlist(hpnum, sk, fpass) \
+({ struct sock *s1; if(!(sk) && (fpass)--) \
+	s1 = udp_hash[(hpnum) & (UDP_HTABLE_SIZE - 1)]; \
+   else \
+	s1 = (sk); \
+   s1; \
+})
+
+#define udp_v4_proxy_loop_init(hnum, hpnum, sk, fpass) \
+	secondlist((hpnum), udp_hash[(hnum)&(UDP_HTABLE_SIZE-1)],(fpass))
+
+#define udp_v4_proxy_loop_next(hnum, hpnum, sk, fpass) \
+	secondlist((hpnum),(sk)->next,(fpass))
+
+static struct sock *udp_v4_proxy_lookup(unsigned short num, unsigned long raddr,
+					unsigned short rnum, unsigned long laddr,
+					struct device *dev, unsigned short pnum,
+					int dif)
+{
+	struct sock *s, *result = NULL;
+	int badness = -1;
+	u32 paddr = 0;
+	unsigned short hnum = ntohs(num);
+	unsigned short hpnum = ntohs(pnum);
+	int firstpass = 1;
+
+	if(dev && dev->ip_ptr) {
+		struct in_device *idev = dev->ip_ptr;
+
+		if(idev->ifa_list)
+			paddr = idev->ifa_list->ifa_local;
+	}
+
+	SOCKHASH_LOCK();
+	for(s = udp_v4_proxy_loop_init(hnum, hpnum, s, firstpass);
+	    s != NULL;
+	    s = udp_v4_proxy_loop_next(hnum, hpnum, s, firstpass)) {
+		if(s->num == hnum || s->num == hpnum) {
+			int score = 0;
+			if(s->dead && (s->state == TCP_CLOSE))
+				continue;
+			if(s->rcv_saddr) {
+				if((s->num != hpnum || s->rcv_saddr != paddr) &&
+				   (s->num != hnum || s->rcv_saddr != laddr))
+					continue;
+				score++;
+			}
+			if(s->daddr) {
+				if(s->daddr != raddr)
+					continue;
+				score++;
+			}
+			if(s->dport) {
+				if(s->dport != rnum)
+					continue;
+				score++;
+			}
+			if(s->bound_dev_if) {
+				if(s->bound_dev_if != dif)
+					continue;
+				score++;
+			}
+			if(score == 4 && s->num == hnum) {
+				result = s;
+				break;
+			} else if(score > badness && (s->num == hpnum || s->rcv_saddr)) {
+					result = s;
+					badness = score;
+			}
+		}
+	}
+	SOCKHASH_UNLOCK();
+	return result;
+}
+
+#undef secondlist
+#undef udp_v4_proxy_loop_init
+#undef udp_v4_proxy_loop_next
+
+#endif
+
+static inline struct sock *udp_v4_mcast_next(struct sock *sk,
+					     unsigned short num,
+					     unsigned long raddr,
+					     unsigned short rnum,
+					     unsigned long laddr,
+					     int dif)
+{
+	struct sock *s = sk;
+	unsigned short hnum = ntohs(num);
+	for(; s; s = s->next) {
+		if ((s->num != hnum)					||
+		    (s->dead && (s->state == TCP_CLOSE))		||
+		    (s->daddr && s->daddr!=raddr)			||
+		    (s->dport != rnum && s->dport != 0)			||
+		    (s->rcv_saddr  && s->rcv_saddr != laddr)		||
+		    (s->bound_dev_if && s->bound_dev_if != dif))
+			continue;
+		break;
+  	}
+  	return s;
+}
+
+/*
+ * This routine is called by the ICMP module when it gets some
+ * sort of error condition.  If err < 0 then the socket should
+ * be closed and the error returned to the user.  If err > 0
+ * it's just the icmp type << 8 | icmp code.  
+ * Header points to the ip header of the error packet. We move
+ * on past this. Then (as it used to claim before adjustment)
+ * header points to the first 8 bytes of the udp header.  We need
+ * to find the appropriate port.
+ */
+
+void udp_err(struct sk_buff *skb, unsigned char *dp, int len)
+{
+	struct iphdr *iph = (struct iphdr*)dp;
+	struct udphdr *uh = (struct udphdr*)(dp+(iph->ihl<<2));
+	int type = skb->h.icmph->type;
+	int code = skb->h.icmph->code;
+	struct sock *sk;
+	int harderr;
+	u32 info;
+	int err;
+
+	if (len < (iph->ihl<<2)+sizeof(struct udphdr)) {
+		icmp_statistics.IcmpInErrors++;
+		return;
+	}
+
+	sk = udp_v4_lookup(iph->daddr, uh->dest, iph->saddr, uh->source, skb->dev->ifindex);
+	if (sk == NULL) {
+		icmp_statistics.IcmpInErrors++;
+    	  	return;	/* No socket for error */
+	}
+
+	err = 0;
+	info = 0;
+	harderr = 0;
+
+	switch (type) {
+	default:
+	case ICMP_TIME_EXCEEDED:
+		err = EHOSTUNREACH;
+		break;
+	case ICMP_SOURCE_QUENCH:
+		return;
+	case ICMP_PARAMETERPROB:
+		err = EPROTO;
+		info = ntohl(skb->h.icmph->un.gateway)>>24;
+		harderr = 1;
+		break;
+	case ICMP_DEST_UNREACH:
+		if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
+			if (sk->ip_pmtudisc != IP_PMTUDISC_DONT) {
+				err = EMSGSIZE;
+				info = ntohs(skb->h.icmph->un.frag.mtu);
+				harderr = 1;
+				break;
+			}
+			return;
+		}
+		err = EHOSTUNREACH;
+		if (code <= NR_ICMP_UNREACH) {
+			harderr = icmp_err_convert[code].fatal;
+			err = icmp_err_convert[code].errno;
+		}
+		break;
+	}
+
+	/*
+	 *	Various people wanted BSD UDP semantics. Well they've come 
+	 *	back out because they slow down response to stuff like dead
+	 *	or unreachable name servers and they screw term users something
+	 *	chronic. Oh and it violates RFC1122. So basically fix your 
+	 *	client code people.
+	 */
+	 
+	/*
+	 *      RFC1122: OK.  Passes ICMP errors back to application, as per 
+	 *	4.1.3.3. After the comment above, that should be no surprise. 
+	 */
+
+	if (!harderr && !sk->ip_recverr)
+		return;
+
+	/*
+	 *	4.x BSD compatibility item. Break RFC1122 to
+	 *	get BSD socket semantics.
+	 */
+	if(sk->bsdism && sk->state!=TCP_ESTABLISHED)
+		return;
+
+	if (sk->ip_recverr)
+		ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1));
+	sk->err = err;
+	sk->error_report(sk);
+}
+
+
+static unsigned short udp_check(struct udphdr *uh, int len, unsigned long saddr, unsigned long daddr, unsigned long base)
+{
+	return(csum_tcpudp_magic(saddr, daddr, len, IPPROTO_UDP, base));
+}
+
+struct udpfakehdr 
+{
+	struct udphdr uh;
+	u32 saddr;
+	u32 daddr;
+	struct iovec *iov;
+	u32 wcheck;
+};
+
+/*
+ *	Copy and checksum a UDP packet from user space into a buffer. We still have
+ *	to do the planning to get ip_build_xmit to spot direct transfer to network
+ *	card and provide an additional callback mode for direct user->board I/O
+ *	transfers. That one will be fun.
+ */
+ 
+static int udp_getfrag(const void *p, char * to, unsigned int offset, unsigned int fraglen) 
+{
+	struct udpfakehdr *ufh = (struct udpfakehdr *)p;
+	if (offset==0) {
+		if (csum_partial_copy_fromiovecend(to+sizeof(struct udphdr), ufh->iov, offset,
+						   fraglen-sizeof(struct udphdr), &ufh->wcheck))
+			return -EFAULT;
+ 		ufh->wcheck = csum_partial((char *)ufh, sizeof(struct udphdr),
+					   ufh->wcheck);
+		ufh->uh.check = csum_tcpudp_magic(ufh->saddr, ufh->daddr, 
+					  ntohs(ufh->uh.len),
+					  IPPROTO_UDP, ufh->wcheck);
+		if (ufh->uh.check == 0)
+			ufh->uh.check = -1;
+		memcpy(to, ufh, sizeof(struct udphdr));
+		return 0;
+	}
+	if (csum_partial_copy_fromiovecend(to, ufh->iov, offset-sizeof(struct udphdr),
+					   fraglen, &ufh->wcheck))
+		return -EFAULT;
+	return 0;
+}
+
+/*
+ *	Unchecksummed UDP is sufficiently critical to stuff like ATM video conferencing
+ *	that we use two routines for this for speed. Probably we ought to have a
+ *	CONFIG_FAST_NET set for >10Mb/second boards to activate this sort of coding.
+ *	Timing needed to verify if this is a valid decision.
+ */
+ 
+static int udp_getfrag_nosum(const void *p, char * to, unsigned int offset, unsigned int fraglen) 
+{
+	struct udpfakehdr *ufh = (struct udpfakehdr *)p;
+
+	if (offset==0) {
+		memcpy(to, ufh, sizeof(struct udphdr));
+		return memcpy_fromiovecend(to+sizeof(struct udphdr), ufh->iov, offset,
+					   fraglen-sizeof(struct udphdr));
+	}
+	return memcpy_fromiovecend(to, ufh->iov, offset-sizeof(struct udphdr),
+				   fraglen);
+}
+
+int udp_sendmsg(struct sock *sk, struct msghdr *msg, int len)
+{
+	int ulen = len + sizeof(struct udphdr);
+	struct ipcm_cookie ipc;
+	struct udpfakehdr ufh;
+	struct rtable *rt = NULL;
+	int free = 0;
+	int connected = 0;
+	u32 daddr;
+	u8  tos;
+	int err;
+
+	/* This check is ONLY to check for arithmetic overflow
+	   on integer(!) len. Not more! Real check will be made
+	   in ip_build_xmit --ANK
+
+	   BTW socket.c -> af_*.c -> ... make multiple
+	   invalid conversions size_t -> int. We MUST repair it f.e.
+	   by replacing all of them with size_t and revise all
+	   the places sort of len += sizeof(struct iphdr)
+	   If len was ULONG_MAX-10 it would be cathastrophe  --ANK
+	 */
+
+	if (len < 0 || len > 0xFFFF)
+		return -EMSGSIZE;
+
+	/* 
+	 *	Check the flags.
+	 */
+
+	if (msg->msg_flags&MSG_OOB)	/* Mirror BSD error message compatibility */
+		return -EOPNOTSUPP;
+
+#ifdef CONFIG_IP_TRANSPARENT_PROXY
+	if (msg->msg_flags&~(MSG_DONTROUTE|MSG_DONTWAIT|MSG_PROXY|MSG_NOSIGNAL))
+	  	return -EINVAL;
+	if ((msg->msg_flags&MSG_PROXY) && !capable(CAP_NET_ADMIN))
+	  	return -EPERM;
+#else
+	if (msg->msg_flags&~(MSG_DONTROUTE|MSG_DONTWAIT|MSG_NOSIGNAL))
+	  	return -EINVAL;
+#endif
+
+	/*
+	 *	Get and verify the address. 
+	 */
+	 
+	if (msg->msg_name) {
+		struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name;
+		if (msg->msg_namelen < sizeof(*usin))
+			return(-EINVAL);
+		if (usin->sin_family != AF_INET) {
+			static int complained;
+			if (!complained++)
+				printk(KERN_WARNING "%s forgot to set AF_INET in udp sendmsg. Fix it!\n", current->comm);
+			if (usin->sin_family)
+				return -EINVAL;
+		}
+		ufh.daddr = usin->sin_addr.s_addr;
+		ufh.uh.dest = usin->sin_port;
+		if (ufh.uh.dest == 0)
+			return -EINVAL;
+	} else {
+		if (sk->state != TCP_ESTABLISHED)
+			return -ENOTCONN;
+		ufh.daddr = sk->daddr;
+		ufh.uh.dest = sk->dport;
+		/* Open fast path for connected socket.
+		   Route will not be used, if at least one option is set.
+		 */
+		connected = 1;
+  	}
+#ifdef CONFIG_IP_TRANSPARENT_PROXY
+	if (msg->msg_flags&MSG_PROXY) {
+		/*
+		 * We map the first 8 bytes of a second sockaddr_in
+		 * into the last 8 (unused) bytes of a sockaddr_in.
+		 */
+		struct sockaddr_in *from = (struct sockaddr_in *)msg->msg_name;
+		from = (struct sockaddr_in *)&from->sin_zero;
+		if (from->sin_family != AF_INET)
+			return -EINVAL;
+		ipc.addr = from->sin_addr.s_addr;
+		ufh.uh.source = from->sin_port;
+		if (ipc.addr == 0)
+			ipc.addr = sk->saddr;
+		connected = 0;
+	} else
+#endif
+	{
+		ipc.addr = sk->saddr;
+		ufh.uh.source = sk->sport;
+	}
+
+	ipc.opt = NULL;
+	ipc.oif = sk->bound_dev_if;
+	if (msg->msg_controllen) {
+		err = ip_cmsg_send(msg, &ipc);
+		if (err)
+			return err;
+		if (ipc.opt)
+			free = 1;
+		connected = 0;
+	}
+	if (!ipc.opt)
+		ipc.opt = sk->opt;
+
+	ufh.saddr = ipc.addr;
+	ipc.addr = daddr = ufh.daddr;
+
+	if (ipc.opt && ipc.opt->srr) {
+		if (!daddr)
+			return -EINVAL;
+		daddr = ipc.opt->faddr;
+		connected = 0;
+	}
+	tos = RT_TOS(sk->ip_tos);
+	if (sk->localroute || (msg->msg_flags&MSG_DONTROUTE) || 
+	    (ipc.opt && ipc.opt->is_strictroute)) {
+		tos |= RTO_ONLINK;
+		connected = 0;
+	}
+
+	if (MULTICAST(daddr)) {
+		if (!ipc.oif)
+			ipc.oif = sk->ip_mc_index;
+		if (!ufh.saddr)
+			ufh.saddr = sk->ip_mc_addr;
+		connected = 0;
+	}
+
+	if (connected && sk->dst_cache) {
+		rt = (struct rtable*)sk->dst_cache;
+		if (rt->u.dst.obsolete) {
+			sk->dst_cache = NULL;
+			dst_release(&rt->u.dst);
+			rt = NULL;
+		} else
+			dst_clone(&rt->u.dst);
+	}
+
+	if (rt == NULL) {
+		err = ip_route_output(&rt, daddr, ufh.saddr,
+#ifdef CONFIG_IP_TRANSPARENT_PROXY
+			(msg->msg_flags&MSG_PROXY ? RTO_TPROXY : 0) |
+#endif
+			 tos, ipc.oif);
+		if (err) 
+			goto out;
+
+		err = -EACCES;
+		if (rt->rt_flags&RTCF_BROADCAST && !sk->broadcast) 
+			goto out;
+		if (connected && sk->dst_cache == NULL)
+			sk->dst_cache = dst_clone(&rt->u.dst);
+	}
+
+	ufh.saddr = rt->rt_src;
+	if (!ipc.addr)
+		ufh.daddr = ipc.addr = rt->rt_dst;
+	ufh.uh.len = htons(ulen);
+	ufh.uh.check = 0;
+	ufh.iov = msg->msg_iov;
+	ufh.wcheck = 0;
+
+	/* RFC1122: OK.  Provides the checksumming facility (MUST) as per */
+	/* 4.1.3.4. It's configurable by the application via setsockopt() */
+	/* (MAY) and it defaults to on (MUST). */
+
+	err = ip_build_xmit(sk,sk->no_check ? udp_getfrag_nosum : udp_getfrag,
+			    &ufh, ulen, &ipc, rt, msg->msg_flags);
+
+out:
+	ip_rt_put(rt);
+	if (free)
+		kfree(ipc.opt);
+	if (!err) {
+		udp_statistics.UdpOutDatagrams++;
+		return len;
+	}
+	return err;
+}
+
+/*
+ *	IOCTL requests applicable to the UDP protocol
+ */
+ 
+int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
+{
+	switch(cmd) 
+	{
+		case TIOCOUTQ:
+		{
+			unsigned long amount;
+
+			amount = sock_wspace(sk);
+			return put_user(amount, (int *)arg);
+		}
+
+		case TIOCINQ:
+		{
+			struct sk_buff *skb;
+			unsigned long amount;
+
+			amount = 0;
+			/* N.B. Is this interrupt safe??
+			   -> Yes. Interrupts do not remove skbs. --ANK (980725)
+			 */
+			skb = skb_peek(&sk->receive_queue);
+			if (skb != NULL) {
+				/*
+				 * We will only return the amount
+				 * of this packet since that is all
+				 * that will be read.
+				 */
+				amount = skb->len - sizeof(struct udphdr);
+			}
+			return put_user(amount, (int *)arg);
+		}
+
+		default:
+			return(-ENOIOCTLCMD);
+	}
+	return(0);
+}
+
+#ifndef HAVE_CSUM_COPY_USER
+#undef CONFIG_UDP_DELAY_CSUM
+#endif
+
+/*
+ * 	This should be easy, if there is something there we
+ * 	return it, otherwise we block.
+ */
+
+int udp_recvmsg(struct sock *sk, struct msghdr *msg, int len,
+		int noblock, int flags, int *addr_len)
+{
+  	struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
+  	struct sk_buff *skb;
+  	int copied, err;
+
+	if (flags & MSG_ERRQUEUE)
+		return ip_recv_error(sk, msg, len);
+
+	/*
+	 *	From here the generic datagram does a lot of the work. Come
+	 *	the finished NET3, it will do _ALL_ the work!
+	 */
+
+	skb = skb_recv_datagram(sk, flags, noblock, &err);
+	if (!skb)
+		goto out;
+  
+  	copied = skb->len - sizeof(struct udphdr);
+	if (copied > len) {
+		copied = len;
+		msg->msg_flags |= MSG_TRUNC;
+	}
+
+#ifndef CONFIG_UDP_DELAY_CSUM
+	err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
+					copied);
+#else
+	if (skb->ip_summed==CHECKSUM_UNNECESSARY) {
+		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
+					      copied);
+	} else if (copied > msg->msg_iov[0].iov_len || (msg->msg_flags&MSG_TRUNC)) {
+		if ((unsigned short)csum_fold(csum_partial(skb->h.raw, skb->len, skb->csum))) 
+			goto csum_copy_err;
+		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
+					      copied);
+	} else {
+		unsigned int csum;
+
+		err = 0;
+		csum = csum_partial(skb->h.raw, sizeof(struct udphdr), skb->csum);
+		csum = csum_and_copy_to_user((char*)&skb->h.uh[1], msg->msg_iov[0].iov_base, 
+					     copied, csum, &err);
+		if (err)
+			goto out_free;
+		if ((unsigned short)csum_fold(csum)) 
+			goto csum_copy_err;
+	}
+#endif
+	if (err)
+		goto out_free;
+	sk->stamp=skb->stamp;
+
+	/* Copy the address. */
+	if (sin)
+	{
+		/*
+		 *	Check any passed addresses
+		 */
+		if (addr_len) 
+			*addr_len=sizeof(*sin);
+
+		sin->sin_family = AF_INET;
+		sin->sin_port = skb->h.uh->source;
+		sin->sin_addr.s_addr = skb->nh.iph->saddr;
+#ifdef CONFIG_IP_TRANSPARENT_PROXY
+		if (flags&MSG_PROXY)
+		{
+			/*
+			 * We map the first 8 bytes of a second sockaddr_in
+			 * into the last 8 (unused) bytes of a sockaddr_in.
+			 * This _is_ ugly, but it's the only way to do it
+			 * easily,  without adding system calls.
+			 */
+			struct sockaddr_in *sinto =
+				(struct sockaddr_in *) sin->sin_zero;
+
+			sinto->sin_family = AF_INET;
+			sinto->sin_port = skb->h.uh->dest;
+			sinto->sin_addr.s_addr = skb->nh.iph->daddr;
+		}
+#endif
+  	}
+	if (sk->ip_cmsg_flags)
+		ip_cmsg_recv(msg, skb);
+	err = copied;
+  
+out_free:
+  	skb_free_datagram(sk, skb);
+out:
+  	return err;
+
+#ifdef CONFIG_UDP_DELAY_CSUM
+csum_copy_err:
+	udp_statistics.UdpInErrors++;
+	skb_free_datagram(sk, skb);
+
+	/* 
+	 * Error for blocking case is chosen to masquerade
+   	 * as some normal condition.
+	 */
+	return (flags&MSG_DONTWAIT) ? -EAGAIN : -EHOSTUNREACH;	
+#endif
+}
+
+int udp_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+{
+	struct sockaddr_in *usin = (struct sockaddr_in *) uaddr;
+	struct rtable *rt;
+	int err;
+
+	
+	if (addr_len < sizeof(*usin)) 
+	  	return(-EINVAL);
+
+	/*
+	 *	1003.1g - break association.
+	 */
+	 
+	if (usin->sin_family==AF_UNSPEC)
+	{
+		sk->saddr=INADDR_ANY;
+		sk->rcv_saddr=INADDR_ANY;
+		sk->daddr=INADDR_ANY;
+		sk->state = TCP_CLOSE;
+		if(uh_cache_sk == sk)
+			uh_cache_sk = NULL;
+		return 0;
+	}
+
+	if (usin->sin_family && usin->sin_family != AF_INET) 
+	  	return(-EAFNOSUPPORT);
+
+	dst_release(xchg(&sk->dst_cache, NULL));
+
+	err = ip_route_connect(&rt, usin->sin_addr.s_addr, sk->saddr,
+			       sk->ip_tos|sk->localroute, sk->bound_dev_if);
+	if (err)
+		return err;
+	if ((rt->rt_flags&RTCF_BROADCAST) && !sk->broadcast) {
+		ip_rt_put(rt);
+		return -EACCES;
+	}
+  	if(!sk->saddr)
+	  	sk->saddr = rt->rt_src;		/* Update source address */
+	if(!sk->rcv_saddr)
+		sk->rcv_saddr = rt->rt_src;
+	sk->daddr = rt->rt_dst;
+	sk->dport = usin->sin_port;
+	sk->state = TCP_ESTABLISHED;
+
+	if(uh_cache_sk == sk)
+		uh_cache_sk = NULL;
+
+	sk->dst_cache = &rt->u.dst;
+	return(0);
+}
+
+
+static void udp_close(struct sock *sk, long timeout)
+{
+	/* See for explanation: raw_close in ipv4/raw.c */
+	sk->state = TCP_CLOSE;
+	udp_v4_unhash(sk);
+	sk->dead = 1;
+	destroy_sock(sk);
+}
+
+static int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
+{
+	/*
+	 *	Charge it to the socket, dropping if the queue is full.
+	 */
+
+#if defined(CONFIG_FILTER) && defined(CONFIG_UDP_DELAY_CSUM)
+	if (sk->filter && skb->ip_summed != CHECKSUM_UNNECESSARY) {
+		if ((unsigned short)csum_fold(csum_partial(skb->h.raw, skb->len, skb->csum))) {
+			udp_statistics.UdpInErrors++;
+			ip_statistics.IpInDiscards++;
+			ip_statistics.IpInDelivers--;
+			kfree_skb(skb);
+			return -1;
+		}
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+	}
+#endif
+
+	if (sock_queue_rcv_skb(sk,skb)<0) {
+		udp_statistics.UdpInErrors++;
+		ip_statistics.IpInDiscards++;
+		ip_statistics.IpInDelivers--;
+		kfree_skb(skb);
+		return -1;
+	}
+	udp_statistics.UdpInDatagrams++;
+	return 0;
+}
+
+
+static inline void udp_deliver(struct sock *sk, struct sk_buff *skb)
+{
+	udp_queue_rcv_skb(sk, skb);
+}
+
+/*
+ *	Multicasts and broadcasts go to each listener.
+ *
+ *	Note: called only from the BH handler context,
+ *	so we don't need to lock the hashes.
+ */
+static int udp_v4_mcast_deliver(struct sk_buff *skb, struct udphdr *uh,
+				 u32 saddr, u32 daddr)
+{
+	struct sock *sk;
+	int dif;
+
+	sk = udp_hash[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)];
+	dif = skb->dev->ifindex;
+	sk = udp_v4_mcast_next(sk, uh->dest, saddr, uh->source, daddr, dif);
+	if (sk) {
+		struct sock *sknext = NULL;
+
+		do {
+			struct sk_buff *skb1 = skb;
+
+			sknext = udp_v4_mcast_next(sk->next, uh->dest, saddr,
+						   uh->source, daddr, dif);
+			if(sknext)
+				skb1 = skb_clone(skb, GFP_ATOMIC);
+
+			if(skb1)
+				udp_deliver(sk, skb1);
+			sk = sknext;
+		} while(sknext);
+	} else
+		kfree_skb(skb);
+	return 0;
+}
+
+#ifdef CONFIG_IP_TRANSPARENT_PROXY
+/*
+ *	Check whether a received UDP packet might be for one of our
+ *	sockets.
+ */
+
+int udp_chkaddr(struct sk_buff *skb)
+{
+	struct iphdr *iph = skb->nh.iph;
+	struct udphdr *uh = (struct udphdr *)(skb->nh.raw + iph->ihl*4);
+	struct sock *sk;
+
+	sk = udp_v4_lookup(iph->saddr, uh->source, iph->daddr, uh->dest, skb->dev->ifindex);
+	if (!sk)
+		return 0;
+
+	/* 0 means accept all LOCAL addresses here, not all the world... */
+	if (sk->rcv_saddr == 0)
+		return 0;
+
+	return 1;
+}
+#endif
+
+/*
+ *	All we need to do is get the socket, and then do a checksum. 
+ */
+ 
+int udp_rcv(struct sk_buff *skb, unsigned short len)
+{
+  	struct sock *sk;
+  	struct udphdr *uh;
+	unsigned short ulen;
+	struct rtable *rt = (struct rtable*)skb->dst;
+	u32 saddr = skb->nh.iph->saddr;
+	u32 daddr = skb->nh.iph->daddr;
+
+	/*
+	 * First time through the loop.. Do all the setup stuff
+	 * (including finding out the socket we go to etc)
+	 */
+
+	/*
+	 *	Get the header.
+	 */
+	 
+  	uh = skb->h.uh;
+	__skb_pull(skb, skb->h.raw - skb->data);
+
+  	ip_statistics.IpInDelivers++;
+
+	/*
+	 *	Validate the packet and the UDP length.
+	 */
+	 
+	ulen = ntohs(uh->len);
+
+	if (ulen > len || ulen < sizeof(*uh)) {
+		NETDEBUG(printk(KERN_DEBUG "UDP: short packet: %d/%d\n", ulen, len));
+		udp_statistics.UdpInErrors++;
+		kfree_skb(skb);
+		return(0);
+	}
+	skb_trim(skb, ulen);
+
+#ifndef CONFIG_UDP_DELAY_CSUM
+	if (uh->check &&
+	    (((skb->ip_summed==CHECKSUM_HW)&&udp_check(uh,ulen,saddr,daddr,skb->csum)) ||
+	     ((skb->ip_summed==CHECKSUM_NONE) &&
+	      (udp_check(uh,ulen,saddr,daddr, csum_partial((char*)uh, ulen, 0)))))) 
+		goto csum_error;
+#else
+	if (uh->check==0)
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+	else if (skb->ip_summed==CHECKSUM_HW) {
+		if (udp_check(uh,ulen,saddr,daddr,skb->csum)) 
+			goto csum_error;
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+	} else if (skb->ip_summed != CHECKSUM_UNNECESSARY)
+		skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
+#endif
+
+	if(rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
+		return udp_v4_mcast_deliver(skb, uh, saddr, daddr);
+
+#ifdef CONFIG_IP_TRANSPARENT_PROXY
+	if (IPCB(skb)->redirport)
+		sk = udp_v4_proxy_lookup(uh->dest, saddr, uh->source,
+					 daddr, skb->dev, IPCB(skb)->redirport,
+					 skb->dev->ifindex);
+	else
+#endif
+	sk = udp_v4_lookup(saddr, uh->source, daddr, uh->dest, skb->dev->ifindex);
+	
+	if (sk == NULL) {
+#ifdef CONFIG_UDP_DELAY_CSUM
+		if (skb->ip_summed != CHECKSUM_UNNECESSARY &&
+		    (unsigned short)csum_fold(csum_partial((char*)uh, ulen, skb->csum))) 
+			goto csum_error;
+#endif
+  		udp_statistics.UdpNoPorts++;
+		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+
+		/*
+		 * Hmm.  We got an UDP broadcast to a port to which we
+		 * don't wanna listen.  Ignore it.
+		 */
+		kfree_skb(skb);
+		return(0);
+  	}
+	udp_deliver(sk, skb);
+	return 0;
+
+csum_error:
+	/* 
+	 * RFC1122: OK.  Discards the bad packet silently (as far as 
+	 * the network is concerned, anyway) as per 4.1.3.4 (MUST). 
+	 */
+	NETDEBUG(printk(KERN_DEBUG "UDP: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
+			NIPQUAD(saddr),
+			ntohs(uh->source),
+			NIPQUAD(daddr),
+			ntohs(uh->dest),
+			ulen));
+	udp_statistics.UdpInErrors++;
+	kfree_skb(skb);
+	return(0);
+}
+
+struct proto udp_prot = {
+	(struct sock *)&udp_prot,	/* sklist_next */
+	(struct sock *)&udp_prot,	/* sklist_prev */
+	udp_close,			/* close */
+	udp_connect,			/* connect */
+	NULL,				/* accept */
+	NULL,				/* retransmit */
+	NULL,				/* write_wakeup */
+	NULL,				/* read_wakeup */
+	datagram_poll,			/* poll */
+	udp_ioctl,			/* ioctl */
+	NULL,				/* init */
+	NULL,				/* destroy */
+	NULL,				/* shutdown */
+	ip_setsockopt,			/* setsockopt */
+	ip_getsockopt,			/* getsockopt */
+	udp_sendmsg,			/* sendmsg */
+	udp_recvmsg,			/* recvmsg */
+	NULL,				/* bind */
+	udp_queue_rcv_skb,		/* backlog_rcv */
+	udp_v4_hash,			/* hash */
+	udp_v4_unhash,			/* unhash */
+	udp_v4_get_port,		/* good_socknum */
+	128,				/* max_header */
+	0,				/* retransmits */
+ 	"UDP",				/* name */
+	0,				/* inuse */
+	0				/* highestinuse */
+};