1 files changed, 739 insertions, 0 deletions

diff --git a/pfinet/linux-src/net/ipv4/ip_sockglue.c b/pfinet/linux-src/net/ipv4/ip_sockglue.c
new file mode 100644
index 00000000..369a6770
--- /dev/null
+++ b/pfinet/linux-src/net/ipv4/ip_sockglue.c
@@ -0,0 +1,739 @@
+/*
+ * 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 IP to API glue.
+ *		
+ * Version:	$Id: ip_sockglue.c,v 1.42 1999/04/22 10:07:34 davem Exp $
+ *
+ * Authors:	see ip.c
+ *
+ * Fixes:
+ *		Many		:	Split from ip.c , see ip.c for history.
+ *		Martin Mares	:	TOS setting fixed.
+ *		Alan Cox	:	Fixed a couple of oopses in Martin's 
+ *					TOS tweaks.
+ *		Mike McLagan	:	Routing by source
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/icmp.h>
+#include <linux/netdevice.h>
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/tcp.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/igmp.h>
+#include <linux/firewall.h>
+#include <linux/ip_fw.h>
+#include <linux/route.h>
+#include <linux/mroute.h>
+#include <net/route.h>
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+#include <net/transp_v6.h>
+#endif
+
+#ifdef CONFIG_IP_MASQUERADE
+#include <linux/ip_masq.h>
+#endif
+
+#include <linux/errqueue.h>
+#include <asm/uaccess.h>
+
+#define MAX(a,b) ((a)>(b)?(a):(b))
+
+#define IP_CMSG_PKTINFO		1
+#define IP_CMSG_TTL		2
+#define IP_CMSG_TOS		4
+#define IP_CMSG_RECVOPTS	8
+#define IP_CMSG_RETOPTS		16
+
+/*
+ *	SOL_IP control messages.
+ */
+
+static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
+{
+	struct in_pktinfo info;
+	struct rtable *rt = (struct rtable *)skb->dst;
+
+	info.ipi_addr.s_addr = skb->nh.iph->daddr;
+	if (rt) {
+		info.ipi_ifindex = rt->rt_iif;
+		info.ipi_spec_dst.s_addr = rt->rt_spec_dst;
+	} else {
+		info.ipi_ifindex = 0;
+		info.ipi_spec_dst.s_addr = 0;
+	}
+
+	put_cmsg(msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
+}
+
+static void ip_cmsg_recv_ttl(struct msghdr *msg, struct sk_buff *skb)
+{
+	int ttl = skb->nh.iph->ttl;
+	put_cmsg(msg, SOL_IP, IP_TTL, sizeof(int), &ttl);
+}
+
+static void ip_cmsg_recv_tos(struct msghdr *msg, struct sk_buff *skb)
+{
+	put_cmsg(msg, SOL_IP, IP_TOS, 1, &skb->nh.iph->tos);
+}
+
+static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb)
+{
+	if (IPCB(skb)->opt.optlen == 0)
+		return;
+
+	put_cmsg(msg, SOL_IP, IP_RECVOPTS, IPCB(skb)->opt.optlen, skb->nh.iph+1);
+}
+
+
+void ip_cmsg_recv_retopts(struct msghdr *msg, struct sk_buff *skb)
+{
+	unsigned char optbuf[sizeof(struct ip_options) + 40];
+	struct ip_options * opt = (struct ip_options*)optbuf;
+
+	if (IPCB(skb)->opt.optlen == 0)
+		return;
+
+	if (ip_options_echo(opt, skb)) {
+		msg->msg_flags |= MSG_CTRUNC;
+		return;
+	}
+	ip_options_undo(opt);
+
+	put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
+}
+
+
+void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
+{
+	unsigned flags = skb->sk->ip_cmsg_flags;
+
+	/* Ordered by supposed usage frequency */
+	if (flags & 1)
+		ip_cmsg_recv_pktinfo(msg, skb);
+	if ((flags>>=1) == 0)
+		return;
+
+	if (flags & 1)
+		ip_cmsg_recv_ttl(msg, skb);
+	if ((flags>>=1) == 0)
+		return;
+
+	if (flags & 1)
+		ip_cmsg_recv_tos(msg, skb);
+	if ((flags>>=1) == 0)
+		return;
+
+	if (flags & 1)
+		ip_cmsg_recv_opts(msg, skb);
+	if ((flags>>=1) == 0)
+		return;
+
+	if (flags & 1)
+		ip_cmsg_recv_retopts(msg, skb);
+}
+
+int ip_cmsg_send(struct msghdr *msg, struct ipcm_cookie *ipc)
+{
+	int err;
+	struct cmsghdr *cmsg;
+
+	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
+		if (cmsg->cmsg_len < sizeof(struct cmsghdr) ||
+		    (unsigned long)(((char*)cmsg - (char*)msg->msg_control)
+				    + cmsg->cmsg_len) > msg->msg_controllen) {
+			return -EINVAL;
+		}
+		if (cmsg->cmsg_level != SOL_IP)
+			continue;
+		switch (cmsg->cmsg_type) {
+		case IP_RETOPTS:
+			err = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
+			err = ip_options_get(&ipc->opt, CMSG_DATA(cmsg), err < 40 ? err : 40, 0);
+			if (err)
+				return err;
+			break;
+		case IP_PKTINFO:
+		{
+			struct in_pktinfo *info;
+			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
+				return -EINVAL;
+			info = (struct in_pktinfo *)CMSG_DATA(cmsg);
+			ipc->oif = info->ipi_ifindex;
+			ipc->addr = info->ipi_spec_dst.s_addr;
+			break;
+		}
+		default:
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+
+/* Special input handler for packets catched by router alert option.
+   They are selected only by protocol field, and then processed likely
+   local ones; but only if someone wants them! Otherwise, router
+   not running rsvpd will kill RSVP.
+
+   It is user level problem, what it will make with them.
+   I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
+   but receiver should be enough clever f.e. to forward mtrace requests,
+   sent to multicast group to reach destination designated router.
+ */
+struct ip_ra_chain *ip_ra_chain;
+
+int ip_ra_control(struct sock *sk, unsigned char on, void (*destructor)(struct sock *))
+{
+	struct ip_ra_chain *ra, *new_ra, **rap;
+
+	if (sk->type != SOCK_RAW || sk->num == IPPROTO_RAW)
+		return -EINVAL;
+
+	new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
+
+	for (rap = &ip_ra_chain; (ra=*rap) != NULL; rap = &ra->next) {
+		if (ra->sk == sk) {
+			if (on) {
+				if (new_ra)
+					kfree(new_ra);
+				return -EADDRINUSE;
+			}
+			*rap = ra->next;
+			synchronize_bh();
+
+			if (ra->destructor)
+				ra->destructor(sk);
+			kfree(ra);
+			return 0;
+		}
+	}
+	if (new_ra == NULL)
+		return -ENOBUFS;
+	new_ra->sk = sk;
+	new_ra->destructor = destructor;
+
+	new_ra->next = ra;
+	wmb();
+	*rap = new_ra;
+
+	return 0;
+}
+
+void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, 
+		   u16 port, u32 info, u8 *payload)
+{
+	struct sock_exterr_skb *serr;
+
+	if (!sk->ip_recverr)
+		return;
+
+	skb = skb_clone(skb, GFP_ATOMIC);
+	if (!skb)
+		return;
+
+	serr = SKB_EXT_ERR(skb);  
+	serr->ee.ee_errno = err;
+	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
+	serr->ee.ee_type = skb->h.icmph->type; 
+	serr->ee.ee_code = skb->h.icmph->code;
+	serr->ee.ee_pad = 0;
+	serr->ee.ee_info = info;
+	serr->ee.ee_data = 0;
+	serr->addr_offset = (u8*)&(((struct iphdr*)(skb->h.icmph+1))->daddr) - skb->nh.raw;
+	serr->port = port;
+
+	skb->h.raw = payload;
+	skb_pull(skb, payload - skb->data);
+
+	if (sock_queue_err_skb(sk, skb))
+		kfree_skb(skb);
+}
+
+void ip_local_error(struct sock *sk, int err, u32 daddr, u16 port, u32 info)
+{
+	struct sock_exterr_skb *serr;
+	struct iphdr *iph;
+	struct sk_buff *skb;
+
+	if (!sk->ip_recverr)
+		return;
+
+	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
+	if (!skb)
+		return;
+
+	iph = (struct iphdr*)skb_put(skb, sizeof(struct iphdr));
+	skb->nh.iph = iph;
+	iph->daddr = daddr;
+
+	serr = SKB_EXT_ERR(skb);  
+	serr->ee.ee_errno = err;
+	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
+	serr->ee.ee_type = 0; 
+	serr->ee.ee_code = 0;
+	serr->ee.ee_pad = 0;
+	serr->ee.ee_info = info;
+	serr->ee.ee_data = 0;
+	serr->addr_offset = (u8*)&iph->daddr - skb->nh.raw;
+	serr->port = port;
+
+	skb->h.raw = skb->tail;
+	skb_pull(skb, skb->tail - skb->data);
+
+	if (sock_queue_err_skb(sk, skb))
+		kfree_skb(skb);
+}
+
+/* 
+ *	Handle MSG_ERRQUEUE
+ */
+int ip_recv_error(struct sock *sk, struct msghdr *msg, int len)
+{
+	struct sock_exterr_skb *serr;
+	struct sk_buff *skb, *skb2;
+	struct sockaddr_in *sin;
+	struct {
+		struct sock_extended_err ee;
+		struct sockaddr_in	 offender;
+	} errhdr;
+	int err;
+	int copied;
+
+	err = -EAGAIN;
+	skb = skb_dequeue(&sk->error_queue);
+	if (skb == NULL)
+		goto out;
+
+	copied = skb->len;
+	if (copied > len) {
+		msg->msg_flags |= MSG_TRUNC;
+		copied = len;
+	}
+	err = memcpy_toiovec(msg->msg_iov, skb->data, copied);
+	if (err)
+		goto out_free_skb;
+
+	serr = SKB_EXT_ERR(skb);
+
+	sin = (struct sockaddr_in *)msg->msg_name;
+	if (sin) {
+		sin->sin_family = AF_INET; 
+		sin->sin_addr.s_addr = *(u32*)(skb->nh.raw + serr->addr_offset);
+		sin->sin_port = serr->port; 
+	}
+
+	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
+	sin = &errhdr.offender;
+	sin->sin_family = AF_UNSPEC;
+	if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP) {
+		sin->sin_family = AF_INET;
+		sin->sin_addr.s_addr = skb->nh.iph->saddr;
+		if (sk->ip_cmsg_flags)
+			ip_cmsg_recv(msg, skb);
+	}
+
+	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
+
+	/* Now we could try to dump offended packet options */
+
+	msg->msg_flags |= MSG_ERRQUEUE;
+	err = copied;
+
+	/* Reset and regenerate socket error */
+	sk->err = 0;
+	if ((skb2 = skb_peek(&sk->error_queue)) != NULL) {
+		sk->err = SKB_EXT_ERR(skb2)->ee.ee_errno;
+		sk->error_report(sk);
+	}
+
+out_free_skb:	
+	kfree_skb(skb);
+out:
+	return err;
+}
+
+
+/*
+ *	Socket option code for IP. This is the end of the line after any TCP,UDP etc options on
+ *	an IP socket.
+ *
+ *	We implement IP_TOS (type of service), IP_TTL (time to live).
+ */
+
+int ip_setsockopt(struct sock *sk, int level, int optname, char *optval, int optlen)
+{
+	int val=0,err;
+#if defined(CONFIG_IP_FIREWALL)
+	char tmp_fw[MAX(sizeof(struct ip_fwtest),sizeof(struct ip_fwnew))];
+#endif
+	if(optlen>=sizeof(int)) {
+		if(get_user(val, (int *) optval))
+			return -EFAULT;
+	} else if(optlen>=sizeof(char)) {
+		unsigned char ucval;
+		if(get_user(ucval, (unsigned char *) optval))
+			return -EFAULT;
+		val = (int)ucval;
+	}
+	/* If optlen==0, it is equivalent to val == 0 */
+	
+	if(level!=SOL_IP)
+		return -ENOPROTOOPT;
+#ifdef CONFIG_IP_MROUTE
+	if(optname>=MRT_BASE && optname <=MRT_BASE+10)
+	{
+		return ip_mroute_setsockopt(sk,optname,optval,optlen);
+	}
+#endif
+	
+	switch(optname)
+	{
+		case IP_OPTIONS:
+		{
+			struct ip_options * opt = NULL;
+			if (optlen > 40 || optlen < 0)
+				return -EINVAL;
+			err = ip_options_get(&opt, optval, optlen, 1);
+			if (err)
+				return err;
+			lock_sock(sk);
+			if (sk->type == SOCK_STREAM) {
+				struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+				if (sk->family == PF_INET ||
+				    ((tcp_connected(sk->state) || sk->state == TCP_SYN_SENT)
+				     && sk->daddr != LOOPBACK4_IPV6)) {
+#endif
+					if (opt)
+						tp->ext_header_len = opt->optlen;
+					tcp_sync_mss(sk, tp->pmtu_cookie);
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+				}
+#endif
+			}
+			opt = xchg(&sk->opt, opt);
+			release_sock(sk);
+			if (opt)
+				kfree_s(opt, sizeof(struct ip_options) + opt->optlen);
+			return 0;
+		}
+		case IP_PKTINFO:
+			if (val)
+				sk->ip_cmsg_flags |= IP_CMSG_PKTINFO;
+			else
+				sk->ip_cmsg_flags &= ~IP_CMSG_PKTINFO;
+			return 0;
+		case IP_RECVTTL:
+			if (val)
+				sk->ip_cmsg_flags |=  IP_CMSG_TTL;
+			else
+				sk->ip_cmsg_flags &= ~IP_CMSG_TTL;
+			return 0;
+		case IP_RECVTOS:
+			if (val)
+				sk->ip_cmsg_flags |=  IP_CMSG_TOS;
+			else
+				sk->ip_cmsg_flags &= ~IP_CMSG_TOS;
+			return 0;
+		case IP_RECVOPTS:
+			if (val)
+				sk->ip_cmsg_flags |=  IP_CMSG_RECVOPTS;
+			else
+				sk->ip_cmsg_flags &= ~IP_CMSG_RECVOPTS;
+			return 0;
+		case IP_RETOPTS:
+			if (val)
+				sk->ip_cmsg_flags |= IP_CMSG_RETOPTS;
+			else
+				sk->ip_cmsg_flags &= ~IP_CMSG_RETOPTS;
+			return 0;
+		case IP_TOS:	/* This sets both TOS and Precedence */
+			  /* Reject setting of unused bits */
+			if (val & ~(IPTOS_TOS_MASK|IPTOS_PREC_MASK))
+				return -EINVAL;
+			if (IPTOS_PREC(val) >= IPTOS_PREC_CRITIC_ECP && 
+			    !capable(CAP_NET_ADMIN))
+				return -EPERM;
+			if (sk->ip_tos != val) {
+				lock_sock(sk);
+				sk->ip_tos=val;
+				sk->priority = rt_tos2priority(val);
+				dst_release(xchg(&sk->dst_cache, NULL)); 
+				release_sock(sk);
+			}
+			return 0;
+		case IP_TTL:
+			if (optlen<1)
+				return -EINVAL;
+			if(val==-1)
+				val = ip_statistics.IpDefaultTTL;
+			if(val<1||val>255)
+				return -EINVAL;
+			sk->ip_ttl=val;
+			return 0;
+		case IP_HDRINCL:
+			if(sk->type!=SOCK_RAW)
+				return -ENOPROTOOPT;
+			sk->ip_hdrincl=val?1:0;
+			return 0;
+		case IP_MTU_DISCOVER:
+			if (val<0 || val>2)
+				return -EINVAL;
+			sk->ip_pmtudisc = val;
+			return 0;
+		case IP_RECVERR:
+			sk->ip_recverr = !!val;
+			if (!val)
+				skb_queue_purge(&sk->error_queue);
+			return 0;
+		case IP_MULTICAST_TTL: 
+			if (optlen<1)
+				return -EINVAL;
+			if (val==-1)
+				val = 1;
+			if (val < 0 || val > 255)
+				return -EINVAL;
+			sk->ip_mc_ttl=val;
+	                return 0;
+		case IP_MULTICAST_LOOP: 
+			if (optlen<1)
+				return -EINVAL;
+			sk->ip_mc_loop = val ? 1 : 0;
+			return 0;
+		case IP_MULTICAST_IF: 
+		{
+			struct ip_mreqn mreq;
+			struct device *dev = NULL;
+			
+			/*
+			 *	Check the arguments are allowable
+			 */
+
+			if (optlen >= sizeof(struct ip_mreqn)) {
+				if (copy_from_user(&mreq,optval,sizeof(mreq)))
+					return -EFAULT;
+			} else {
+				memset(&mreq, 0, sizeof(mreq));
+				if (optlen >= sizeof(struct in_addr) &&
+				    copy_from_user(&mreq.imr_address,optval,sizeof(struct in_addr)))
+					return -EFAULT;
+			}
+
+			if (!mreq.imr_ifindex) {
+				if (mreq.imr_address.s_addr == INADDR_ANY) {
+					sk->ip_mc_index = 0;
+					sk->ip_mc_addr  = 0;
+					return 0;
+				}
+				dev = ip_dev_find(mreq.imr_address.s_addr);
+			} else
+				dev = dev_get_by_index(mreq.imr_ifindex);
+
+			if (!dev)
+				return -EADDRNOTAVAIL;
+
+			if (sk->bound_dev_if && dev->ifindex != sk->bound_dev_if)
+				return -EINVAL;
+
+			sk->ip_mc_index = mreq.imr_ifindex;
+			sk->ip_mc_addr  = mreq.imr_address.s_addr;
+			return 0;
+		}
+
+		case IP_ADD_MEMBERSHIP:
+		case IP_DROP_MEMBERSHIP: 
+		{
+			struct ip_mreqn mreq;
+			
+			if (optlen < sizeof(struct ip_mreq))
+				return -EINVAL;
+			if (optlen >= sizeof(struct ip_mreqn)) {
+				if(copy_from_user(&mreq,optval,sizeof(mreq)))
+					return -EFAULT;
+			} else {
+				memset(&mreq, 0, sizeof(mreq));
+				if (copy_from_user(&mreq,optval,sizeof(struct ip_mreq)))
+					return -EFAULT; 
+			}
+
+			if (optname == IP_ADD_MEMBERSHIP)
+				return ip_mc_join_group(sk,&mreq);
+			else
+				return ip_mc_leave_group(sk,&mreq);
+		}
+		case IP_ROUTER_ALERT:	
+			return ip_ra_control(sk, val ? 1 : 0, NULL);
+		
+#ifdef CONFIG_IP_FIREWALL
+		case IP_FW_MASQ_TIMEOUTS:
+		case IP_FW_APPEND:
+		case IP_FW_REPLACE:
+		case IP_FW_DELETE:
+		case IP_FW_DELETE_NUM:
+		case IP_FW_INSERT:
+		case IP_FW_FLUSH:
+		case IP_FW_ZERO:
+		case IP_FW_CHECK:
+		case IP_FW_CREATECHAIN:
+		case IP_FW_DELETECHAIN:
+		case IP_FW_POLICY:
+			if(!capable(CAP_NET_ADMIN))
+				return -EACCES;
+			if(optlen>sizeof(tmp_fw) || optlen<1)
+				return -EINVAL;
+			if(copy_from_user(&tmp_fw,optval,optlen))
+				return -EFAULT;
+			err=ip_fw_ctl(optname, &tmp_fw,optlen);
+			return -err;	/* -0 is 0 after all */
+#endif /* CONFIG_IP_FIREWALL */
+#ifdef CONFIG_IP_MASQUERADE
+		case IP_FW_MASQ_CTL:
+			if(!capable(CAP_NET_ADMIN))
+				return -EPERM;
+			if(optlen<1)
+				return -EINVAL;
+			err=ip_masq_uctl(optname, optval ,optlen);
+			return err;
+			
+#endif
+		default:
+			return(-ENOPROTOOPT);
+	}
+}
+
+/*
+ *	Get the options. Note for future reference. The GET of IP options gets the
+ *	_received_ ones. The set sets the _sent_ ones.
+ */
+
+int ip_getsockopt(struct sock *sk, int level, int optname, char *optval, int *optlen)
+{
+	int val;
+	int len;
+	
+	if(level!=SOL_IP)
+		return -EOPNOTSUPP;
+
+#ifdef CONFIG_IP_MROUTE
+	if(optname>=MRT_BASE && optname <=MRT_BASE+10)
+	{
+		return ip_mroute_getsockopt(sk,optname,optval,optlen);
+	}
+#endif
+
+	if(get_user(len,optlen))
+		return -EFAULT;
+
+	switch(optname)
+	{
+		case IP_OPTIONS:
+			{
+				unsigned char optbuf[sizeof(struct ip_options)+40];
+				struct ip_options * opt = (struct ip_options*)optbuf;
+				lock_sock(sk);
+				opt->optlen = 0;
+				if (sk->opt)
+					memcpy(optbuf, sk->opt, sizeof(struct ip_options)+sk->opt->optlen);
+				release_sock(sk);
+				if (opt->optlen == 0) 
+					return put_user(0, optlen);
+
+				ip_options_undo(opt);
+
+				len=min(len, opt->optlen);
+				if(put_user(len, optlen))
+					return -EFAULT;
+				if(copy_to_user(optval, opt->__data, len))
+					return -EFAULT;
+				return 0;
+			}
+		case IP_PKTINFO:
+			val = (sk->ip_cmsg_flags & IP_CMSG_PKTINFO) != 0;
+			break;
+		case IP_RECVTTL:
+			val = (sk->ip_cmsg_flags & IP_CMSG_TTL) != 0;
+			break;
+		case IP_RECVTOS:
+			val = (sk->ip_cmsg_flags & IP_CMSG_TOS) != 0;
+			break;
+		case IP_RECVOPTS:
+			val = (sk->ip_cmsg_flags & IP_CMSG_RECVOPTS) != 0;
+			break;
+		case IP_RETOPTS:
+			val = (sk->ip_cmsg_flags & IP_CMSG_RETOPTS) != 0;
+			break;
+		case IP_TOS:
+			val=sk->ip_tos;
+			break;
+		case IP_TTL:
+			val=sk->ip_ttl;
+			break;
+		case IP_HDRINCL:
+			val=sk->ip_hdrincl;
+			break;
+		case IP_MTU_DISCOVER:
+			val=sk->ip_pmtudisc;
+			break;
+		case IP_MTU:
+			val = 0;	
+			lock_sock(sk);
+			if (sk->dst_cache)		
+				val = sk->dst_cache->pmtu;
+			release_sock(sk);
+			if (!val)
+				return -ENOTCONN;
+			break;
+		case IP_RECVERR:
+			val=sk->ip_recverr;
+			break;
+		case IP_MULTICAST_TTL:
+			val=sk->ip_mc_ttl;
+			break;
+		case IP_MULTICAST_LOOP:
+			val=sk->ip_mc_loop;
+			break;
+		case IP_MULTICAST_IF:
+		{
+			struct ip_mreqn mreq;
+			len = min(len,sizeof(struct ip_mreqn));
+  			if(put_user(len, optlen))
+  				return -EFAULT;
+			mreq.imr_ifindex = sk->ip_mc_index;
+			mreq.imr_address.s_addr = sk->ip_mc_addr;
+			mreq.imr_multiaddr.s_addr = 0;
+			if(copy_to_user((void *)optval, &mreq, len))
+				return -EFAULT;
+			return 0;
+		}
+		default:
+			return(-ENOPROTOOPT);
+	}
+	
+	if (len < sizeof(int) && len > 0 && val>=0 && val<255) {
+		unsigned char ucval = (unsigned char)val;
+		len = 1;
+		if(put_user(len, optlen))
+			return -EFAULT;
+		if(copy_to_user(optval,&ucval,1))
+			return -EFAULT;
+	} else {
+		len=min(sizeof(int),len);
+		if(put_user(len, optlen))
+			return -EFAULT;
+		if(copy_to_user(optval,&val,len))
+			return -EFAULT;
+	}
+	return 0;
+}