[IPv4]: More output path work.

- Change {udp,raw}_sendmsg to ip_append_data, work done
by Maxim Giryaev <gem@asplinux.ru>
- Get rid of ip_build_xmit() and helper functions.
Nobody uses it anymore.

include/net/ip.h

@@ -98,17 +98,6 @@ extern int		ip_do_nat(struct sk_buff *skb);
 extern void		ip_send_check(struct iphdr *ip);
 extern int		ip_queue_xmit(struct sk_buff *skb);
 extern void		ip_init(void);
-extern int		ip_build_xmit(struct sock *sk,
-				      int getfrag (const void *,
-						   char *,
-						   unsigned int,
-						   unsigned int,
-						   struct sk_buff *),
-				      const void *frag,
-				      unsigned length,
-				      struct ipcm_cookie *ipc,
-				      struct rtable *rt,
-				      int flags);
 extern int		ip_append_data(struct sock *sk,
 				       int getfrag(void *from, char *to, int offset, int len,
 						   int odd, struct sk_buff *skb),

net/ipv4/ip_output.c

@@ -375,361 +375,6 @@ int ip_queue_xmit(struct sk_buff *skb)
 	return -EHOSTUNREACH;
 }
 
-/* _Dead beaf_
- *
- *	Build and send a packet, with as little as one copy
- *
- *	Doesn't care much about ip options... option length can be
- *	different for fragment at 0 and other fragments.
- *
- *	Note that the fragment at the highest offset is sent first,
- *	so the getfrag routine can fill in the TCP/UDP checksum header
- *	field in the last fragment it sends... actually it also helps
- * 	the reassemblers, they can put most packets in at the head of
- *	the fragment queue, and they know the total size in advance. This
- *	last feature will measurably improve the Linux fragment handler one
- *	day.
- *
- *	The callback has five args, an arbitrary pointer (copy of frag),
- *	the source IP address (may depend on the routing table), the 
- *	destination address (char *), the offset to copy from, and the
- *	length to be copied.
- */
-
-static int ip_build_xmit_slow(struct sock *sk,
-		  int getfrag (const void *,
-			       char *,
-			       unsigned int,	
-			       unsigned int,
-			       struct sk_buff *),
-		  const void *frag,
-		  unsigned length,
-		  struct ipcm_cookie *ipc,
-		  struct rtable *rt,
-		  int flags)
-{
-	struct inet_opt *inet = inet_sk(sk);
-	unsigned int fraglen, maxfraglen, fragheaderlen;
-	int err;
-	int offset, mf;
-	int mtu;
-	u16 id;
-
-	int hh_len = (rt->u.dst.dev->hard_header_len&~15) + 16;
-	int nfrags=0;
-	struct ip_options *opt = ipc->opt;
-	int df = 0;
-	int csumselect = CHECKSUM_NONE;
-
-	mtu = rt->u.dst.pmtu;
-	if (ip_dont_fragment(sk, &rt->u.dst))
-		df = htons(IP_DF);
-
-	length -= sizeof(struct iphdr);
-
-	if (opt) {
-		fragheaderlen = sizeof(struct iphdr) + opt->optlen;
-		maxfraglen = ((mtu-sizeof(struct iphdr)-opt->optlen) & ~7) + fragheaderlen;
-	} else {
-		fragheaderlen = sizeof(struct iphdr);
-
-		/*
-		 *	Fragheaderlen is the size of 'overhead' on each buffer. Now work
-		 *	out the size of the frames to send.
-		 */
-
-		maxfraglen = ((mtu-sizeof(struct iphdr)) & ~7) + fragheaderlen;
-	}
-
-	if (length + fragheaderlen > 0xFFFF) {
-		ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu);
-		return -EMSGSIZE;
-	}
-
-	/*
-	 *	Start at the end of the frame by handling the remainder.
-	 */
-
-	offset = length - (length % (maxfraglen - fragheaderlen));
-
-	/*
-	 *	Amount of memory to allocate for final fragment.
-	 */
-
-	fraglen = length - offset + fragheaderlen;
-
-	if (length-offset==0) {
-		fraglen = maxfraglen;
-		offset -= maxfraglen-fragheaderlen;
-	}
-
-	/*
-	 *	The last fragment will not have MF (more fragments) set.
-	 */
-
-	mf = 0;
-
-	/*
-	 *	Don't fragment packets for path mtu discovery.
-	 */
-
-	if (offset > 0 && inet->pmtudisc == IP_PMTUDISC_DO) { 
-		ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu);
- 		return -EMSGSIZE;
-	}
-	if (flags&MSG_PROBE)
-		goto out;
-
-	/*
-	 *	Give the upper layer a chance to decide whether to use HW
-	 *	checksumming or not.
-	 */
-	if (offset == 0 && rt->u.dst.dev->features & (NETIF_F_IP_CSUM|NETIF_F_NO_CSUM|NETIF_F_HW_CSUM))
-		csumselect = CHECKSUM_HW;
-
-	/*
-	 *	Begin outputting the bytes.
-	 */
-
-	id = inet->id++;
-
-	do {
-		char *data;
-		struct sk_buff * skb;
-
-		/*
-		 *	Get the memory we require with some space left for alignment.
-		 */
-		if (!(flags & MSG_DONTWAIT) || nfrags == 0) {
-			skb = sock_alloc_send_skb(sk, fraglen + hh_len + 15,
-						  (flags & MSG_DONTWAIT), &err);
-		} else {
-			/* On a non-blocking write, we check for send buffer
-			 * usage on the first fragment only.
-			 */
-			skb = sock_wmalloc(sk, fraglen + hh_len + 15, 1,
-					   sk->allocation);
-			if (!skb)
-				err = -ENOBUFS;
-		}
-		if (skb == NULL)
-			goto error;
-
-		/*
-		 *	Fill in the control structures
-		 */
-
-		skb->priority = sk->priority;
-		skb->dst = dst_clone(&rt->u.dst);
-		skb->ip_summed = csumselect;
-		skb_reserve(skb, hh_len);
-
-		/*
-		 *	Find where to start putting bytes.
-		 */
-
-		data = skb_put(skb, fraglen);
-		skb->nh.iph = (struct iphdr *)data;
-
-		/*
-		 *	Only write IP header onto non-raw packets 
-		 */
-
-		{
-			struct iphdr *iph = (struct iphdr *)data;
-
-			iph->version = 4;
-			iph->ihl = 5;
-			if (opt) {
-				iph->ihl += opt->optlen>>2;
-				ip_options_build(skb, opt,
-						 ipc->addr, rt, offset);
-			}
-			iph->tos = inet->tos;
-			iph->tot_len = htons(fraglen - fragheaderlen + iph->ihl*4);
-			iph->frag_off = htons(offset>>3)|mf|df;
-			iph->id = id;
-			if (!mf) {
-				if (offset || !df) {
-					/* Select an unpredictable ident only
-					 * for packets without DF or having
-					 * been fragmented.
-					 */
-					__ip_select_ident(iph, &rt->u.dst, 0);
-					id = iph->id;
-				}
-
-				/*
-				 *	Any further fragments will have MF set.
-				 */
-				mf = htons(IP_MF);
-			}
-			if (rt->rt_type == RTN_MULTICAST)
-				iph->ttl = inet->mc_ttl;
-			else
-				iph->ttl = inet->ttl;
-			iph->protocol = sk->protocol;
-			iph->saddr = rt->rt_src;
-			iph->daddr = rt->rt_dst;
-			ip_send_check(iph);
-			data += iph->ihl*4;
-			skb->h.raw = data;
-		}
-
-		/*
-		 *	User data callback
-		 */
-
-		if (getfrag(frag, data, offset, fraglen-fragheaderlen, skb)) {
-			err = -EFAULT;
-			kfree_skb(skb);
-			goto error;
-		}
-
-		offset -= (maxfraglen-fragheaderlen);
-		fraglen = maxfraglen;
-
-		nfrags++;
-
-		err = NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, 
-			      skb->dst->dev, dst_output);
-		if (err) {
-			if (err > 0)
-				err = inet->recverr ? net_xmit_errno(err) : 0;
-			if (err)
-				goto error;
-		}
-	} while (offset >= 0);
-
-	if (nfrags>1)
-		ip_statistics[smp_processor_id()*2 + !in_softirq()].IpFragCreates += nfrags;
-out:
-	return 0;
-
-error:
-	IP_INC_STATS(IpOutDiscards);
-	if (nfrags>1)
-		ip_statistics[smp_processor_id()*2 + !in_softirq()].IpFragCreates += nfrags;
-	return err; 
-}
-
-/*
- *	Fast path for unfragmented packets.
- */
-int ip_build_xmit(struct sock *sk, 
-		  int getfrag (const void *,
-			       char *,
-			       unsigned int,	
-			       unsigned int,
-			       struct sk_buff *),
-		  const void *frag,
-		  unsigned length,
-		  struct ipcm_cookie *ipc,
-		  struct rtable *rt,
-		  int flags)
-{
-	struct inet_opt *inet = inet_sk(sk);
-	int err;
-	struct sk_buff *skb;
-	int df;
-	struct iphdr *iph;
-
-	/*
-	 *	Try the simple case first. This leaves fragmented frames, and by
-	 *	choice RAW frames within 20 bytes of maximum size(rare) to the long path
-	 */
-
-	if (!inet->hdrincl) {
-		length += sizeof(struct iphdr);
-
-		/*
-		 * 	Check for slow path.
-		 */
-		if (length > rt->u.dst.pmtu || ipc->opt != NULL)  
-			return ip_build_xmit_slow(sk,getfrag,frag,length,ipc,rt,flags); 
-	} else {
-		if (length > rt->u.dst.dev->mtu) {
-			ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport,
-				       rt->u.dst.dev->mtu);
-			return -EMSGSIZE;
-		}
-	}
-	if (flags&MSG_PROBE)
-		goto out;
-
-	/*
-	 *	Do path mtu discovery if needed.
-	 */
-	df = 0;
-	if (ip_dont_fragment(sk, &rt->u.dst))
-		df = htons(IP_DF);
-
-	/* 
-	 *	Fast path for unfragmented frames without options. 
-	 */ 
-	{
-	int hh_len = (rt->u.dst.dev->hard_header_len&~15) + 16;
-
-	skb = sock_alloc_send_skb(sk, length+hh_len+15,
-				  flags&MSG_DONTWAIT, &err);
-	if(skb==NULL)
-		goto error; 
-	skb_reserve(skb, hh_len);
-	}
-
-	skb->priority = sk->priority;
-	skb->dst = dst_clone(&rt->u.dst);
-
-	skb->nh.iph = iph = (struct iphdr *)skb_put(skb, length);
-
-	/*
-	 *	Give the upper layer a chance to decide whether to use HW
-	 *	checksumming or not.
-	 */
-	if (rt->u.dst.dev->features & (NETIF_F_IP_CSUM|NETIF_F_NO_CSUM|NETIF_F_HW_CSUM))
-		skb->ip_summed = CHECKSUM_HW;
-
-	if (!inet->hdrincl) {
-		iph->version=4;
-		iph->ihl=5;
-		iph->tos = inet->tos;
-		iph->tot_len = htons(length);
-		iph->frag_off = df;
-		iph->ttl = inet->mc_ttl;
-		ip_select_ident(iph, &rt->u.dst, sk);
-		if (rt->rt_type != RTN_MULTICAST)
-			iph->ttl = inet->ttl;
-		iph->protocol=sk->protocol;
-		iph->saddr=rt->rt_src;
-		iph->daddr=rt->rt_dst;
-		ip_send_check(iph);
-		skb->h.raw = skb->nh.raw + iph->ihl*4;
-		err = getfrag(frag, ((char *)iph)+iph->ihl*4,0, length-iph->ihl*4, skb);
-	}
-	else {
-		skb->h.raw = skb->nh.raw;
-		err = getfrag(frag, (void *)iph, 0, length, skb);
-	}
-
-	if (err)
-		goto error_fault;
-
-	err = NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
-		      dst_output);
-	if (err > 0)
-		err = inet->recverr ? net_xmit_errno(err) : 0;
-	if (err)
-		goto error;
-out:
-	return 0;
-
-error_fault:
-	err = -EFAULT;
-	kfree_skb(skb);
-error:
-	IP_INC_STATS(IpOutDiscards);
-	return err; 
-}
 
 static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)
 {
@@ -1082,9 +727,6 @@ int ip_append_data(struct sock *sk,
 	unsigned int maxfraglen, fragheaderlen;
 	int csummode = CHECKSUM_NONE;
 
-	if (inet->hdrincl)
-		return -EPERM;
-
 	if (flags&MSG_PROBE)
 		return 0;
 

net/ipv4/raw.c

@@ -64,6 +64,7 @@
 #include <net/raw.h>
 #include <net/inet_common.h>
 #include <net/checksum.h>
+#include <linux/netfilter.h>
 
 struct sock *raw_v4_htable[RAWV4_HTABLE_SIZE];
 rwlock_t raw_v4_lock = RW_LOCK_UNLOCKED;
@@ -243,59 +244,71 @@ int raw_rcv(struct sock *sk, struct sk_buff *skb)
 	return 0;
 }
 
-struct rawfakehdr 
+static int raw_send_hdrinc(struct sock *sk, void *from, int length,
+			struct rtable *rt, 
+			unsigned int flags)
 {
-	struct	iovec *iov;
-	u32	saddr;
-	struct	dst_entry *dst;
-};
+	struct inet_opt *inet = inet_sk(sk);
+	int hh_len;
+	struct iphdr *iph;
+	struct sk_buff *skb;
+	int err;
 
-/*
- *	Send a RAW IP packet.
- */
+	if (length > rt->u.dst.dev->mtu) {
+		ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport,
+			       rt->u.dst.dev->mtu);
+		return -EMSGSIZE;
+	}
+	if (flags&MSG_PROBE)
+		goto out;
 
-/*
- *	Callback support is trivial for SOCK_RAW
- */
+	hh_len = (rt->u.dst.dev->hard_header_len&~15) + 16;
 
-static int raw_getfrag(const void *p, char *to, unsigned int offset,
-			unsigned int fraglen, struct sk_buff *skb)
-{
-	struct rawfakehdr *rfh = (struct rawfakehdr *) p;
-	skb->ip_summed = CHECKSUM_NONE; /* Is there any good place to set it? */
-	return memcpy_fromiovecend(to, rfh->iov, offset, fraglen);
-}
+	skb = sock_alloc_send_skb(sk, length+hh_len+15,
+				  flags&MSG_DONTWAIT, &err);
+	if (skb == NULL)
+		goto error; 
+	skb_reserve(skb, hh_len);
 
-/*
- *	IPPROTO_RAW needs extra work.
- */
+	skb->priority = sk->priority;
+	skb->dst = dst_clone(&rt->u.dst);
 
-static int raw_getrawfrag(const void *p, char *to, unsigned int offset,
-				unsigned int fraglen, struct sk_buff *skb)
-{
-	struct rawfakehdr *rfh = (struct rawfakehdr *) p;
+	skb->nh.iph = iph = (struct iphdr *)skb_put(skb, length);
 
-	skb->ip_summed = CHECKSUM_NONE; /* Is there any good place to set it? */
+	skb->ip_summed = CHECKSUM_NONE;
 
-	if (memcpy_fromiovecend(to, rfh->iov, offset, fraglen))
-		return -EFAULT;
+	skb->h.raw = skb->nh.raw;
+	err = memcpy_fromiovecend((void *)iph, from, 0, length);
+	if (err)
+		goto error_fault;
 
-	if (!offset) {
-		struct iphdr *iph = (struct iphdr *)to;
+	/* We don't modify invalid header */
+	if (length >= sizeof(*iph) && iph->ihl * 4 <= length) {
 		if (!iph->saddr)
-			iph->saddr = rfh->saddr;
+			iph->saddr = rt->rt_src;
 		iph->check   = 0;
-		iph->tot_len = htons(fraglen); /* This is right as you can't
-						  frag RAW packets */
-		/*
-	 	 *	Deliberate breach of modularity to keep 
-	 	 *	ip_build_xmit clean (well less messy).
-		 */
+		iph->tot_len = htons(length);
 		if (!iph->id)
-			ip_select_ident(iph, rfh->dst, NULL);
+			ip_select_ident(iph, &rt->u.dst, NULL);
+
 		iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
 	}
+
+	err = NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
+		      dst_output);
+	if (err > 0)
+		err = inet->recverr ? net_xmit_errno(err) : 0;
+	if (err)
+		goto error;
+out:
 	return 0;
+
+error_fault:
+	err = -EFAULT;
+	kfree_skb(skb);
+error:
+	IP_INC_STATS(IpOutDiscards);
+	return err; 
 }
 
 static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
@@ -303,10 +316,10 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 {
 	struct inet_opt *inet = inet_sk(sk);
 	struct ipcm_cookie ipc;
-	struct rawfakehdr rfh;
 	struct rtable *rt = NULL;
 	int free = 0;
 	u32 daddr;
+	u32 saddr;
 	u8  tos;
 	int err;
 
@@ -376,7 +389,7 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 			free = 1;
 	}
 
-	rfh.saddr = ipc.addr;
+	saddr = ipc.addr;
 	ipc.addr = daddr;
 
 	if (!ipc.opt)
@@ -402,14 +415,14 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	if (MULTICAST(daddr)) {
 		if (!ipc.oif)
 			ipc.oif = inet->mc_index;
-		if (!rfh.saddr)
-			rfh.saddr = inet->mc_addr;
+		if (!saddr)
+			saddr = inet->mc_addr;
 	}
 
 	{
 		struct flowi fl = { .nl_u = { .ip4_u =
 					      { .daddr = daddr,
-						.saddr = rfh.saddr,
+						.saddr = saddr,
 						.tos = tos } },
 				    .oif = ipc.oif };
 		err = ip_route_output_key(&rt, &fl);
@@ -425,14 +438,22 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 		goto do_confirm;
 back_from_confirm:
 
-	rfh.iov		= msg->msg_iov;
-	rfh.saddr	= rt->rt_src;
-	rfh.dst		= &rt->u.dst;
+	if (inet->hdrincl)
+		err = raw_send_hdrinc(sk, msg->msg_iov, len, 
+					rt, msg->msg_flags);
+	
+	 else {
 		if (!ipc.addr)
 			ipc.addr = rt->rt_dst;
-	err = ip_build_xmit(sk, inet->hdrincl ? raw_getrawfrag :
-		       	    raw_getfrag, &rfh, len, &ipc, rt, msg->msg_flags);
-
+		lock_sock(sk);
+		err = ip_append_data(sk, ip_generic_getfrag, msg->msg_iov, len, 0,
+					&ipc, rt, msg->msg_flags);
+		if (err)
+			ip_flush_pending_frames(sk);
+		else if (!(msg->msg_flags & MSG_MORE))
+			err = ip_push_pending_frames(sk);
+		release_sock(sk);
+	}
 done:
 	if (free)
 		kfree(ipc.opt);

net/ipv4/udp.c

@@ -464,69 +464,6 @@ static unsigned short udp_check(struct udphdr *uh, int len, unsigned long saddr,
 	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.
- */
- 
-static int udp_getfrag(const void *p, char * to, unsigned int offset, unsigned int fraglen, struct sk_buff *skb) 
-{
-	struct udpfakehdr *ufh = (struct udpfakehdr *)p;
-	if (offset==0) {
-		if (skb->ip_summed == CHECKSUM_HW) {
-			skb->csum = offsetof(struct udphdr, check);
-			ufh->uh.check = ~csum_tcpudp_magic(ufh->saddr, ufh->daddr, 
-					  ntohs(ufh->uh.len), IPPROTO_UDP, 0);
-			memcpy(to, ufh, sizeof(struct udphdr));
-			return memcpy_fromiovecend(to+sizeof(struct udphdr), ufh->iov, offset,
-					   fraglen-sizeof(struct udphdr));
-		}
-
-		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;
-}
-
-/*
- *	Copy a UDP packet from user space into a buffer without checksumming.
- */
- 
-static int udp_getfrag_nosum(const void *p, char * to, unsigned int offset, unsigned int fraglen, struct sk_buff *skb) 
-{
-	struct udpfakehdr *ufh = (struct udpfakehdr *)p;
-
-	skb->ip_summed = CHECKSUM_NONE;
-	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 kiocb *iocb, struct sock *sk, struct msghdr *msg,
 		int len)
 {
@@ -534,18 +471,18 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	struct udp_opt *up = udp_sk(sk);
 	int ulen = len;
 	struct ipcm_cookie ipc;
-	struct udpfakehdr ufh;
 	struct rtable *rt = NULL;
 	int free = 0;
 	int connected = 0;
-	u32 daddr;
+	u32 daddr, faddr, saddr;
+	u16 dport;
 	u8  tos;
 	int err;
 	int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
 
 	/* This check is ONLY to check for arithmetic overflow
 	   on integer(!) len. Not more! Real check will be made
-	   in ip_build_xmit --ANK
+	   in ip_append_* --ANK
 
 	   BTW socket.c -> af_*.c -> ... make multiple
 	   invalid conversions size_t -> int. We MUST repair it f.e.
@@ -593,22 +530,21 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 				return -EINVAL;
 		}
 
-		ufh.daddr = usin->sin_addr.s_addr;
-		ufh.uh.dest = usin->sin_port;
-		if (ufh.uh.dest == 0)
+		daddr = usin->sin_addr.s_addr;
+		dport = usin->sin_port;
+		if (dport == 0)
 			return -EINVAL;
 	} else {
 		if (sk->state != TCP_ESTABLISHED)
 			return -ENOTCONN;
-		ufh.daddr   = inet->daddr;
-		ufh.uh.dest = inet->dport;
+		daddr = inet->daddr;
+		dport = inet->dport;
 		/* Open fast path for connected socket.
 		   Route will not be used, if at least one option is set.
 		 */
 		connected = 1;
   	}
 	ipc.addr = inet->saddr;
-	ufh.uh.source = inet->sport;
 
 	ipc.oif = sk->bound_dev_if;
 	if (msg->msg_controllen) {
@@ -622,13 +558,13 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	if (!ipc.opt)
 		ipc.opt = inet->opt;
 
-	ufh.saddr = ipc.addr;
-	ipc.addr = daddr = ufh.daddr;
+	saddr = ipc.addr;
+	ipc.addr = faddr = daddr;
 
 	if (ipc.opt && ipc.opt->srr) {
 		if (!daddr)
 			return -EINVAL;
-		daddr = ipc.opt->faddr;
+		faddr = ipc.opt->faddr;
 		connected = 0;
 	}
 	tos = RT_TOS(inet->tos);
@@ -641,8 +577,8 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	if (MULTICAST(daddr)) {
 		if (!ipc.oif)
 			ipc.oif = inet->mc_index;
-		if (!ufh.saddr)
-			ufh.saddr = inet->mc_addr;
+		if (!saddr)
+			saddr = inet->mc_addr;
 		connected = 0;
 	}
 
@@ -651,8 +587,8 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 
 	if (rt == NULL) {
 		struct flowi fl = { .nl_u = { .ip4_u =
-					      { .daddr = daddr,
-						.saddr = ufh.saddr,
+					      { .daddr = faddr,
+						.saddr = saddr,
 						.tos = tos } },
 				    .oif = ipc.oif };
 		err = ip_route_output_key(&rt, &fl);
@@ -670,16 +606,10 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 		goto do_confirm;
 back_from_confirm:
 
-	ufh.saddr = rt->rt_src;
+	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;
-
-	/* 0x80000000 is temporary hook for testing new output path */
-	if (corkreq || rt->u.dst.header_len || (msg->msg_flags&0x80000000)) {
+		daddr = ipc.addr = rt->rt_dst;
+
 	lock_sock(sk);
 	if (unlikely(up->pending)) {
 		/* The socket is already corked while preparing it. */
@@ -693,23 +623,22 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	/*
 	 *	Now cork the socket to pend data.
 	 */
-		up->daddr = ufh.daddr;
-		up->dport = ufh.uh.dest;
-		up->saddr = ufh.saddr;
-		up->sport = ufh.uh.source;
+	up->daddr = daddr;
+	up->dport = dport;
+	up->saddr = saddr;
+	up->sport = inet->sport;
 	up->pending = 1;
-		goto do_append_data;
-	}
-
-	/* 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_CSUM_NOXMIT ?
-			     udp_getfrag_nosum :
-			     udp_getfrag),
-			    &ufh, ulen, &ipc, rt, msg->msg_flags);
+do_append_data:
+	up->len += ulen;
+	err = ip_append_data(sk, ip_generic_getfrag, msg->msg_iov, ulen, 
+			sizeof(struct udphdr), &ipc, rt, 
+			corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
+	if (err)
+		udp_flush_pending_frames(sk);
+	else if (!corkreq)
+		err = udp_push_pending_frames(sk, up);
+	release_sock(sk);
 
 out:
 	ip_rt_put(rt);
@@ -727,18 +656,6 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 		goto back_from_confirm;
 	err = 0;
 	goto out;
-
-do_append_data:
-	up->len += ulen;
-	err = ip_append_data(sk, ip_generic_getfrag, msg->msg_iov, ulen, 
-			sizeof(struct udphdr), &ipc, rt, 
-			corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
-	if (err)
-		udp_flush_pending_frames(sk);
-	else if (!corkreq)
-		err = udp_push_pending_frames(sk, up);
-	release_sock(sk);
-	goto out;
 }
 
 int udp_sendpage(struct sock *sk, struct page *page, int offset, size_t size, int flags)