/*
   * 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.

   *

   * 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/module.h>
  #include <linux/types.h>
  #include <linux/mm.h>

  #include <linux/skbuff.h>
  #include <linux/ip.h>
  #include <linux/icmp.h>

  #include <linux/inetdevice.h>

  #include <linux/netdevice.h>

  #include <linux/slab.h>

  #include <net/sock.h>
  #include <net/ip.h>
  #include <net/icmp.h>

  #include <net/tcp_states.h>

  #include <linux/udp.h>
  #include <linux/igmp.h>
  #include <linux/netfilter.h>
  #include <linux/route.h>
  #include <linux/mroute.h>

  #include <net/inet_ecn.h>

  #include <net/route.h>
  #include <net/xfrm.h>

  #include <net/compat.h>

  #if IS_ENABLED(CONFIG_IPV6)

  #include <net/transp_v6.h>
  #endif
  
  #include <linux/errqueue.h>
  #include <asm/uaccess.h>
  
  #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

  #define IP_CMSG_PASSSEC		32

  #define IP_CMSG_ORIGDSTADDR     64

  
  /*
   *	SOL_IP control messages.
   */

  #define PKTINFO_SKB_CB(__skb) ((struct in_pktinfo *)((__skb)->cb))

  
  static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
  {

  	struct in_pktinfo info = *PKTINFO_SKB_CB(skb);

  	info.ipi_addr.s_addr = ip_hdr(skb)->daddr;

  
  	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 = ip_hdr(skb)->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, &ip_hdr(skb)->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,
  		 ip_hdr(skb) + 1);

  }
  
  
  static 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);
  }

  static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
  {
  	char *secdata;

  	u32 seclen, secid;

  	int err;

  	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
  	if (err)
  		return;
  
  	err = security_secid_to_secctx(secid, &secdata, &seclen);

  	if (err)
  		return;
  
  	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);

  	security_release_secctx(secdata, seclen);

  }

  static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)

  {
  	struct sockaddr_in sin;

  	const struct iphdr *iph = ip_hdr(skb);

  	__be16 *ports = (__be16 *)skb_transport_header(skb);

  
  	if (skb_transport_offset(skb) + 4 > skb->len)
  		return;
  
  	/* All current transport protocols have the port numbers in the
  	 * first four bytes of the transport header and this function is
  	 * written with this assumption in mind.
  	 */
  
  	sin.sin_family = AF_INET;
  	sin.sin_addr.s_addr = iph->daddr;
  	sin.sin_port = ports[1];
  	memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
  
  	put_cmsg(msg, SOL_IP, IP_ORIGDSTADDR, sizeof(sin), &sin);
  }

  
  void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
  {
  	struct inet_sock *inet = inet_sk(skb->sk);
  	unsigned flags = inet->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);

  	if ((flags >>= 1) == 0)

  		return;
  
  	if (flags & 1)
  		ip_cmsg_recv_security(msg, skb);

  	if ((flags >>= 1) == 0)

  		return;
  	if (flags & 1)
  		ip_cmsg_recv_dstaddr(msg, skb);

  }

  EXPORT_SYMBOL(ip_cmsg_recv);

  int ip_cmsg_send(struct net *net, 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_OK(msg, cmsg))
  			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(net, &ipc->opt, CMSG_DATA(cmsg),
  					     err < 40 ? err : 40);

  			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 caught 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 __rcu *ip_ra_chain;

  static DEFINE_SPINLOCK(ip_ra_lock);

  
  static void ip_ra_destroy_rcu(struct rcu_head *head)

  {

  	struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu);
  
  	sock_put(ra->saved_sk);
  	kfree(ra);

  }

  int ip_ra_control(struct sock *sk, unsigned char on,
  		  void (*destructor)(struct sock *))

  {

  	struct ip_ra_chain *ra, *new_ra;
  	struct ip_ra_chain __rcu **rap;

  	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)

  		return -EINVAL;
  
  	new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;

  	spin_lock_bh(&ip_ra_lock);

  	for (rap = &ip_ra_chain;
  	     (ra = rcu_dereference_protected(*rap,
  			lockdep_is_held(&ip_ra_lock))) != NULL;
  	     rap = &ra->next) {

  		if (ra->sk == sk) {
  			if (on) {

  				spin_unlock_bh(&ip_ra_lock);

  				kfree(new_ra);

  				return -EADDRINUSE;
  			}

  			/* dont let ip_call_ra_chain() use sk again */
  			ra->sk = NULL;

  			rcu_assign_pointer(*rap, ra->next);
  			spin_unlock_bh(&ip_ra_lock);

  
  			if (ra->destructor)
  				ra->destructor(sk);

  			/*
  			 * Delay sock_put(sk) and kfree(ra) after one rcu grace
  			 * period. This guarantee ip_call_ra_chain() dont need
  			 * to mess with socket refcounts.
  			 */
  			ra->saved_sk = sk;
  			call_rcu(&ra->rcu, ip_ra_destroy_rcu);

  			return 0;
  		}
  	}
  	if (new_ra == NULL) {

  		spin_unlock_bh(&ip_ra_lock);

  		return -ENOBUFS;
  	}
  	new_ra->sk = sk;
  	new_ra->destructor = destructor;
  
  	new_ra->next = ra;

  	rcu_assign_pointer(*rap, new_ra);

  	sock_hold(sk);

  	spin_unlock_bh(&ip_ra_lock);

  
  	return 0;
  }

  void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,

  		   __be16 port, u32 info, u8 *payload)

  {

  	struct sock_exterr_skb *serr;

  	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 = icmp_hdr(skb)->type;
  	serr->ee.ee_code = icmp_hdr(skb)->code;

  	serr->ee.ee_pad = 0;
  	serr->ee.ee_info = info;
  	serr->ee.ee_data = 0;

  	serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -

  				   skb_network_header(skb);

  	serr->port = port;

  	if (skb_pull(skb, payload - skb->data) != NULL) {
  		skb_reset_transport_header(skb);
  		if (sock_queue_err_skb(sk, skb) == 0)
  			return;
  	}
  	kfree_skb(skb);

  }

  void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)

  {
  	struct inet_sock *inet = inet_sk(sk);
  	struct sock_exterr_skb *serr;
  	struct iphdr *iph;
  	struct sk_buff *skb;
  
  	if (!inet->recverr)
  		return;
  
  	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
  	if (!skb)
  		return;

  	skb_put(skb, sizeof(struct iphdr));
  	skb_reset_network_header(skb);

  	iph = ip_hdr(skb);

  	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_network_header(skb);

  	serr->port = port;

  	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);

  	skb_reset_transport_header(skb);

  
  	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->sk_error_queue);
  	if (skb == NULL)
  		goto out;
  
  	copied = skb->len;
  	if (copied > len) {
  		msg->msg_flags |= MSG_TRUNC;
  		copied = len;
  	}
  	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
  	if (err)
  		goto out_free_skb;
  
  	sock_recv_timestamp(msg, sk, 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 = *(__be32 *)(skb_network_header(skb) +
  						   serr->addr_offset);

  		sin->sin_port = serr->port;
  		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
  	}
  
  	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) {
  		struct inet_sock *inet = inet_sk(sk);
  
  		sin->sin_family = AF_INET;

  		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;

  		sin->sin_port = 0;
  		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
  		if (inet->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 */

  	spin_lock_bh(&sk->sk_error_queue.lock);

  	sk->sk_err = 0;

  	skb2 = skb_peek(&sk->sk_error_queue);
  	if (skb2 != NULL) {

  		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;

  		spin_unlock_bh(&sk->sk_error_queue.lock);

  		sk->sk_error_report(sk);
  	} else

  		spin_unlock_bh(&sk->sk_error_queue.lock);

  out_free_skb:

  	kfree_skb(skb);
  out:
  	return err;
  }

  static void opt_kfree_rcu(struct rcu_head *head)
  {
  	kfree(container_of(head, struct ip_options_rcu, rcu));
  }

  /*

   *	Socket option code for IP. This is the end of the line after any
   *	TCP,UDP etc options on an IP socket.

   */

  static int do_ip_setsockopt(struct sock *sk, int level,

  			    int optname, char __user *optval, unsigned int optlen)

  {
  	struct inet_sock *inet = inet_sk(sk);

  	int val = 0, err;

  	if (((1<<optname) & ((1<<IP_PKTINFO) | (1<<IP_RECVTTL) |

  			     (1<<IP_RECVOPTS) | (1<<IP_RECVTOS) |
  			     (1<<IP_RETOPTS) | (1<<IP_TOS) |
  			     (1<<IP_TTL) | (1<<IP_HDRINCL) |
  			     (1<<IP_MTU_DISCOVER) | (1<<IP_RECVERR) |
  			     (1<<IP_ROUTER_ALERT) | (1<<IP_FREEBIND) |

  			     (1<<IP_PASSSEC) | (1<<IP_TRANSPARENT) |

  			     (1<<IP_MINTTL) | (1<<IP_NODEFRAG))) ||

  	    optname == IP_MULTICAST_TTL ||

  	    optname == IP_MULTICAST_ALL ||

  	    optname == IP_MULTICAST_LOOP ||
  	    optname == IP_RECVORIGDSTADDR) {

  		if (optlen >= sizeof(int)) {
  			if (get_user(val, (int __user *) optval))
  				return -EFAULT;
  		} else if (optlen >= sizeof(char)) {
  			unsigned char ucval;
  
  			if (get_user(ucval, (unsigned char __user *) optval))
  				return -EFAULT;
  			val = (int) ucval;
  		}
  	}
  
  	/* If optlen==0, it is equivalent to val == 0 */

  	if (ip_mroute_opt(optname))

  		return ip_mroute_setsockopt(sk, optname, optval, optlen);

  
  	err = 0;
  	lock_sock(sk);
  
  	switch (optname) {

  	case IP_OPTIONS:
  	{

  		struct ip_options_rcu *old, *opt = NULL;

  		if (optlen > 40)

  			goto e_inval;

  		err = ip_options_get_from_user(sock_net(sk), &opt,

  					       optval, optlen);

  		if (err)
  			break;

  		old = rcu_dereference_protected(inet->inet_opt,
  						sock_owned_by_user(sk));

  		if (inet->is_icsk) {
  			struct inet_connection_sock *icsk = inet_csk(sk);

  #if IS_ENABLED(CONFIG_IPV6)

  			if (sk->sk_family == PF_INET ||
  			    (!((1 << sk->sk_state) &
  			       (TCPF_LISTEN | TCPF_CLOSE)) &&

  			     inet->inet_daddr != LOOPBACK4_IPV6)) {

  #endif

  				if (old)
  					icsk->icsk_ext_hdr_len -= old->opt.optlen;

  				if (opt)

  					icsk->icsk_ext_hdr_len += opt->opt.optlen;

  				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);

  #if IS_ENABLED(CONFIG_IPV6)

  			}

  #endif

  		}

  		rcu_assign_pointer(inet->inet_opt, opt);
  		if (old)
  			call_rcu(&old->rcu, opt_kfree_rcu);

  		break;
  	}
  	case IP_PKTINFO:
  		if (val)
  			inet->cmsg_flags |= IP_CMSG_PKTINFO;
  		else
  			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
  		break;
  	case IP_RECVTTL:
  		if (val)
  			inet->cmsg_flags |=  IP_CMSG_TTL;
  		else
  			inet->cmsg_flags &= ~IP_CMSG_TTL;
  		break;
  	case IP_RECVTOS:
  		if (val)
  			inet->cmsg_flags |=  IP_CMSG_TOS;
  		else
  			inet->cmsg_flags &= ~IP_CMSG_TOS;
  		break;
  	case IP_RECVOPTS:
  		if (val)
  			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
  		else
  			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
  		break;
  	case IP_RETOPTS:
  		if (val)
  			inet->cmsg_flags |= IP_CMSG_RETOPTS;
  		else
  			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
  		break;
  	case IP_PASSSEC:
  		if (val)
  			inet->cmsg_flags |= IP_CMSG_PASSSEC;
  		else
  			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
  		break;

  	case IP_RECVORIGDSTADDR:
  		if (val)
  			inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
  		else
  			inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
  		break;

  	case IP_TOS:	/* This sets both TOS and Precedence */
  		if (sk->sk_type == SOCK_STREAM) {

  			val &= ~INET_ECN_MASK;
  			val |= inet->tos & INET_ECN_MASK;

  		}

  		if (inet->tos != val) {
  			inet->tos = val;
  			sk->sk_priority = rt_tos2priority(val);
  			sk_dst_reset(sk);
  		}
  		break;
  	case IP_TTL:

  		if (optlen < 1)

  			goto e_inval;

  		if (val != -1 && (val < 0 || val > 255))

  			goto e_inval;
  		inet->uc_ttl = val;
  		break;
  	case IP_HDRINCL:
  		if (sk->sk_type != SOCK_RAW) {
  			err = -ENOPROTOOPT;

  			break;

  		}
  		inet->hdrincl = val ? 1 : 0;
  		break;

  	case IP_NODEFRAG:
  		if (sk->sk_type != SOCK_RAW) {
  			err = -ENOPROTOOPT;
  			break;
  		}
  		inet->nodefrag = val ? 1 : 0;
  		break;

  	case IP_MTU_DISCOVER:

  		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_PROBE)

  			goto e_inval;
  		inet->pmtudisc = val;
  		break;
  	case IP_RECVERR:
  		inet->recverr = !!val;
  		if (!val)
  			skb_queue_purge(&sk->sk_error_queue);
  		break;
  	case IP_MULTICAST_TTL:
  		if (sk->sk_type == SOCK_STREAM)
  			goto e_inval;

  		if (optlen < 1)

  			goto e_inval;

  		if (val == -1)

  			val = 1;
  		if (val < 0 || val > 255)
  			goto e_inval;
  		inet->mc_ttl = val;
  		break;
  	case IP_MULTICAST_LOOP:

  		if (optlen < 1)

  			goto e_inval;
  		inet->mc_loop = !!val;
  		break;
  	case IP_MULTICAST_IF:
  	{
  		struct ip_mreqn mreq;
  		struct net_device *dev = NULL;
  
  		if (sk->sk_type == SOCK_STREAM)
  			goto e_inval;
  		/*
  		 *	Check the arguments are allowable
  		 */

  		if (optlen < sizeof(struct in_addr))
  			goto e_inval;

  		err = -EFAULT;
  		if (optlen >= sizeof(struct ip_mreqn)) {

  			if (copy_from_user(&mreq, optval, sizeof(mreq)))

  				break;

  		} else {
  			memset(&mreq, 0, sizeof(mreq));
  			if (optlen >= sizeof(struct in_addr) &&

  			    copy_from_user(&mreq.imr_address, optval,
  					   sizeof(struct in_addr)))

  				break;
  		}
  
  		if (!mreq.imr_ifindex) {

  			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {

  				inet->mc_index = 0;
  				inet->mc_addr  = 0;
  				err = 0;

  				break;
  			}

  			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);

  			if (dev)

  				mreq.imr_ifindex = dev->ifindex;

  		} else

  			dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);

  		err = -EADDRNOTAVAIL;
  		if (!dev)
  			break;

  		dev_put(dev);

  
  		err = -EINVAL;
  		if (sk->sk_bound_dev_if &&
  		    mreq.imr_ifindex != sk->sk_bound_dev_if)
  			break;

  		inet->mc_index = mreq.imr_ifindex;
  		inet->mc_addr  = mreq.imr_address.s_addr;
  		err = 0;
  		break;
  	}

  	case IP_ADD_MEMBERSHIP:
  	case IP_DROP_MEMBERSHIP:
  	{
  		struct ip_mreqn mreq;

  		err = -EPROTO;
  		if (inet_sk(sk)->is_icsk)
  			break;

  		if (optlen < sizeof(struct ip_mreq))
  			goto e_inval;
  		err = -EFAULT;
  		if (optlen >= sizeof(struct ip_mreqn)) {

  			if (copy_from_user(&mreq, optval, sizeof(mreq)))

  				break;

  		} else {
  			memset(&mreq, 0, sizeof(mreq));

  			if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))

  				break;

  		}

  		if (optname == IP_ADD_MEMBERSHIP)
  			err = ip_mc_join_group(sk, &mreq);
  		else
  			err = ip_mc_leave_group(sk, &mreq);
  		break;
  	}
  	case IP_MSFILTER:
  	{

  		struct ip_msfilter *msf;
  
  		if (optlen < IP_MSFILTER_SIZE(0))
  			goto e_inval;
  		if (optlen > sysctl_optmem_max) {
  			err = -ENOBUFS;

  			break;
  		}

  		msf = kmalloc(optlen, GFP_KERNEL);

  		if (!msf) {

  			err = -ENOBUFS;
  			break;
  		}
  		err = -EFAULT;
  		if (copy_from_user(msf, optval, optlen)) {
  			kfree(msf);
  			break;
  		}
  		/* numsrc >= (1G-4) overflow in 32 bits */
  		if (msf->imsf_numsrc >= 0x3ffffffcU ||
  		    msf->imsf_numsrc > sysctl_igmp_max_msf) {
  			kfree(msf);
  			err = -ENOBUFS;
  			break;
  		}
  		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
  			kfree(msf);
  			err = -EINVAL;
  			break;
  		}
  		err = ip_mc_msfilter(sk, msf, 0);
  		kfree(msf);
  		break;
  	}
  	case IP_BLOCK_SOURCE:
  	case IP_UNBLOCK_SOURCE:
  	case IP_ADD_SOURCE_MEMBERSHIP:
  	case IP_DROP_SOURCE_MEMBERSHIP:
  	{
  		struct ip_mreq_source mreqs;
  		int omode, add;

  		if (optlen != sizeof(struct ip_mreq_source))
  			goto e_inval;
  		if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {

  			err = -EFAULT;

  			break;
  		}

  		if (optname == IP_BLOCK_SOURCE) {
  			omode = MCAST_EXCLUDE;
  			add = 1;
  		} else if (optname == IP_UNBLOCK_SOURCE) {
  			omode = MCAST_EXCLUDE;
  			add = 0;
  		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
  			struct ip_mreqn mreq;

  			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
  			mreq.imr_address.s_addr = mreqs.imr_interface;
  			mreq.imr_ifindex = 0;
  			err = ip_mc_join_group(sk, &mreq);
  			if (err && err != -EADDRINUSE)

  				break;

  			omode = MCAST_INCLUDE;
  			add = 1;
  		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
  			omode = MCAST_INCLUDE;
  			add = 0;
  		}
  		err = ip_mc_source(add, omode, sk, &mreqs, 0);
  		break;
  	}
  	case MCAST_JOIN_GROUP:
  	case MCAST_LEAVE_GROUP:
  	{
  		struct group_req greq;
  		struct sockaddr_in *psin;
  		struct ip_mreqn mreq;
  
  		if (optlen < sizeof(struct group_req))
  			goto e_inval;
  		err = -EFAULT;
  		if (copy_from_user(&greq, optval, sizeof(greq)))
  			break;
  		psin = (struct sockaddr_in *)&greq.gr_group;
  		if (psin->sin_family != AF_INET)
  			goto e_inval;
  		memset(&mreq, 0, sizeof(mreq));
  		mreq.imr_multiaddr = psin->sin_addr;
  		mreq.imr_ifindex = greq.gr_interface;
  
  		if (optname == MCAST_JOIN_GROUP)
  			err = ip_mc_join_group(sk, &mreq);
  		else
  			err = ip_mc_leave_group(sk, &mreq);
  		break;
  	}
  	case MCAST_JOIN_SOURCE_GROUP:
  	case MCAST_LEAVE_SOURCE_GROUP:
  	case MCAST_BLOCK_SOURCE:
  	case MCAST_UNBLOCK_SOURCE:
  	{
  		struct group_source_req greqs;
  		struct ip_mreq_source mreqs;
  		struct sockaddr_in *psin;
  		int omode, add;
  
  		if (optlen != sizeof(struct group_source_req))
  			goto e_inval;
  		if (copy_from_user(&greqs, optval, sizeof(greqs))) {

  			err = -EFAULT;

  			break;
  		}

  		if (greqs.gsr_group.ss_family != AF_INET ||
  		    greqs.gsr_source.ss_family != AF_INET) {
  			err = -EADDRNOTAVAIL;

  			break;
  		}

  		psin = (struct sockaddr_in *)&greqs.gsr_group;
  		mreqs.imr_multiaddr = psin->sin_addr.s_addr;
  		psin = (struct sockaddr_in *)&greqs.gsr_source;
  		mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
  		mreqs.imr_interface = 0; /* use index for mc_source */
  
  		if (optname == MCAST_BLOCK_SOURCE) {
  			omode = MCAST_EXCLUDE;
  			add = 1;
  		} else if (optname == MCAST_UNBLOCK_SOURCE) {
  			omode = MCAST_EXCLUDE;
  			add = 0;
  		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {

  			struct ip_mreqn mreq;

  			psin = (struct sockaddr_in *)&greqs.gsr_group;

  			mreq.imr_multiaddr = psin->sin_addr;

  			mreq.imr_address.s_addr = 0;
  			mreq.imr_ifindex = greqs.gsr_interface;
  			err = ip_mc_join_group(sk, &mreq);
  			if (err && err != -EADDRINUSE)
  				break;
  			greqs.gsr_interface = mreq.imr_ifindex;
  			omode = MCAST_INCLUDE;
  			add = 1;
  		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
  			omode = MCAST_INCLUDE;
  			add = 0;
  		}
  		err = ip_mc_source(add, omode, sk, &mreqs,
  				   greqs.gsr_interface);
  		break;
  	}
  	case MCAST_MSFILTER:
  	{

  		struct sockaddr_in *psin;
  		struct ip_msfilter *msf = NULL;
  		struct group_filter *gsf = NULL;
  		int msize, i, ifindex;
  
  		if (optlen < GROUP_FILTER_SIZE(0))
  			goto e_inval;
  		if (optlen > sysctl_optmem_max) {
  			err = -ENOBUFS;

  			break;
  		}

  		gsf = kmalloc(optlen, GFP_KERNEL);

  		if (!gsf) {

  			err = -ENOBUFS;

  			break;
  		}

  		err = -EFAULT;

  		if (copy_from_user(gsf, optval, optlen))

  			goto mc_msf_out;

  		/* numsrc >= (4G-140)/128 overflow in 32 bits */
  		if (gsf->gf_numsrc >= 0x1ffffff ||
  		    gsf->gf_numsrc > sysctl_igmp_max_msf) {
  			err = -ENOBUFS;
  			goto mc_msf_out;
  		}
  		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
  			err = -EINVAL;
  			goto mc_msf_out;
  		}
  		msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);

  		msf = kmalloc(msize, GFP_KERNEL);

  		if (!msf) {

  			err = -ENOBUFS;
  			goto mc_msf_out;
  		}
  		ifindex = gsf->gf_interface;
  		psin = (struct sockaddr_in *)&gsf->gf_group;
  		if (psin->sin_family != AF_INET) {

  			err = -EADDRNOTAVAIL;

  			goto mc_msf_out;

  		}

  		msf->imsf_multiaddr = psin->sin_addr.s_addr;
  		msf->imsf_interface = 0;
  		msf->imsf_fmode = gsf->gf_fmode;
  		msf->imsf_numsrc = gsf->gf_numsrc;
  		err = -EADDRNOTAVAIL;

  		for (i = 0; i < gsf->gf_numsrc; ++i) {

  			psin = (struct sockaddr_in *)&gsf->gf_slist[i];

  			if (psin->sin_family != AF_INET)
  				goto mc_msf_out;
  			msf->imsf_slist[i] = psin->sin_addr.s_addr;
  		}
  		kfree(gsf);
  		gsf = NULL;
  
  		err = ip_mc_msfilter(sk, msf, ifindex);

  mc_msf_out:

  		kfree(msf);
  		kfree(gsf);
  		break;
  	}

  	case IP_MULTICAST_ALL:
  		if (optlen < 1)
  			goto e_inval;
  		if (val != 0 && val != 1)
  			goto e_inval;
  		inet->mc_all = val;
  		break;

  	case IP_ROUTER_ALERT:
  		err = ip_ra_control(sk, val ? 1 : 0, NULL);
  		break;
  
  	case IP_FREEBIND:

  		if (optlen < 1)

  			goto e_inval;
  		inet->freebind = !!val;
  		break;
  
  	case IP_IPSEC_POLICY:
  	case IP_XFRM_POLICY:
  		err = -EPERM;
  		if (!capable(CAP_NET_ADMIN))

  			break;

  		err = xfrm_user_policy(sk, optname, optval, optlen);
  		break;

  	case IP_TRANSPARENT:

  		if (!!val && !capable(CAP_NET_RAW) && !capable(CAP_NET_ADMIN)) {

  			err = -EPERM;
  			break;
  		}
  		if (optlen < 1)
  			goto e_inval;
  		inet->transparent = !!val;
  		break;

  	case IP_MINTTL:
  		if (optlen < 1)
  			goto e_inval;
  		if (val < 0 || val > 255)
  			goto e_inval;
  		inet->min_ttl = val;
  		break;

  	default:
  		err = -ENOPROTOOPT;
  		break;

  	}
  	release_sock(sk);
  	return err;
  
  e_inval:
  	release_sock(sk);
  	return -EINVAL;
  }

  /**

   * ipv4_pktinfo_prepare - transfert some info from rtable to skb

   * @sk: socket
   * @skb: buffer
   *

   * To support IP_CMSG_PKTINFO option, we store rt_iif and rt_spec_dst
   * in skb->cb[] before dst drop.
   * This way, receiver doesnt make cache line misses to read rtable.

   */

  void ipv4_pktinfo_prepare(struct sk_buff *skb)

  {

  	struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
  	const struct rtable *rt = skb_rtable(skb);
  
  	if (rt) {
  		pktinfo->ipi_ifindex = rt->rt_iif;
  		pktinfo->ipi_spec_dst.s_addr = rt->rt_spec_dst;
  	} else {
  		pktinfo->ipi_ifindex = 0;
  		pktinfo->ipi_spec_dst.s_addr = 0;
  	}
  	skb_dst_drop(skb);

  }

  int ip_setsockopt(struct sock *sk, int level,

  		int optname, char __user *optval, unsigned int optlen)

  {
  	int err;
  
  	if (level != SOL_IP)
  		return -ENOPROTOOPT;
  
  	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
  #ifdef CONFIG_NETFILTER
  	/* we need to exclude all possible ENOPROTOOPTs except default case */
  	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&

  			optname != IP_IPSEC_POLICY &&
  			optname != IP_XFRM_POLICY &&
  			!ip_mroute_opt(optname)) {

  		lock_sock(sk);
  		err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
  		release_sock(sk);
  	}
  #endif
  	return err;
  }

  EXPORT_SYMBOL(ip_setsockopt);

  
  #ifdef CONFIG_COMPAT

  int compat_ip_setsockopt(struct sock *sk, int level, int optname,

  			 char __user *optval, unsigned int optlen)

  {
  	int err;
  
  	if (level != SOL_IP)
  		return -ENOPROTOOPT;

  	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
  		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
  			ip_setsockopt);

  	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
  #ifdef CONFIG_NETFILTER
  	/* we need to exclude all possible ENOPROTOOPTs except default case */
  	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&

  			optname != IP_IPSEC_POLICY &&
  			optname != IP_XFRM_POLICY &&
  			!ip_mroute_opt(optname)) {

  		lock_sock(sk);

  		err = compat_nf_setsockopt(sk, PF_INET, optname,
  					   optval, optlen);

  		release_sock(sk);
  	}
  #endif
  	return err;
  }

  EXPORT_SYMBOL(compat_ip_setsockopt);

  #endif

  /*

   *	Get the options. Note for future reference. The GET of IP options gets
   *	the _received_ ones. The set sets the _sent_ ones.

   */

  static int do_ip_getsockopt(struct sock *sk, int level, int optname,

  			    char __user *optval, int __user *optlen, unsigned flags)

  {
  	struct inet_sock *inet = inet_sk(sk);
  	int val;
  	int len;

  	if (level != SOL_IP)

  		return -EOPNOTSUPP;

  	if (ip_mroute_opt(optname))

  		return ip_mroute_getsockopt(sk, optname, optval, optlen);

  	if (get_user(len, optlen))

  		return -EFAULT;

  	if (len < 0)

  		return -EINVAL;

  	lock_sock(sk);

  	switch (optname) {
  	case IP_OPTIONS:
  	{
  		unsigned char optbuf[sizeof(struct ip_options)+40];

  		struct ip_options *opt = (struct ip_options *)optbuf;
  		struct ip_options_rcu *inet_opt;
  
  		inet_opt = rcu_dereference_protected(inet->inet_opt,
  						     sock_owned_by_user(sk));

  		opt->optlen = 0;

  		if (inet_opt)
  			memcpy(optbuf, &inet_opt->opt,
  			       sizeof(struct ip_options) +
  			       inet_opt->opt.optlen);

  		release_sock(sk);
  
  		if (opt->optlen == 0)
  			return put_user(0, optlen);
  
  		ip_options_undo(opt);
  
  		len = min_t(unsigned int, 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 = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
  		break;
  	case IP_RECVTTL:
  		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
  		break;
  	case IP_RECVTOS:
  		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
  		break;
  	case IP_RECVOPTS:
  		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
  		break;
  	case IP_RETOPTS:
  		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
  		break;
  	case IP_PASSSEC:
  		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
  		break;

  	case IP_RECVORIGDSTADDR:
  		val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
  		break;

  	case IP_TOS:
  		val = inet->tos;
  		break;
  	case IP_TTL:
  		val = (inet->uc_ttl == -1 ?
  		       sysctl_ip_default_ttl :
  		       inet->uc_ttl);
  		break;
  	case IP_HDRINCL:
  		val = inet->hdrincl;
  		break;

  	case IP_NODEFRAG:
  		val = inet->nodefrag;
  		break;

  	case IP_MTU_DISCOVER:
  		val = inet->pmtudisc;
  		break;
  	case IP_MTU:
  	{
  		struct dst_entry *dst;
  		val = 0;
  		dst = sk_dst_get(sk);
  		if (dst) {
  			val = dst_mtu(dst);
  			dst_release(dst);

  		}

  		if (!val) {

  			release_sock(sk);

  			return -ENOTCONN;

  		}

  		break;
  	}
  	case IP_RECVERR:
  		val = inet->recverr;
  		break;
  	case IP_MULTICAST_TTL:
  		val = inet->mc_ttl;
  		break;
  	case IP_MULTICAST_LOOP:
  		val = inet->mc_loop;
  		break;
  	case IP_MULTICAST_IF:
  	{
  		struct in_addr addr;
  		len = min_t(unsigned int, len, sizeof(struct in_addr));
  		addr.s_addr = inet->mc_addr;
  		release_sock(sk);

  		if (put_user(len, optlen))
  			return -EFAULT;
  		if (copy_to_user(optval, &addr, len))
  			return -EFAULT;
  		return 0;
  	}
  	case IP_MSFILTER:
  	{
  		struct ip_msfilter msf;
  		int err;
  
  		if (len < IP_MSFILTER_SIZE(0)) {

  			release_sock(sk);

  			return -EINVAL;

  		}

  		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {

  			release_sock(sk);

  			return -EFAULT;

  		}

  		err = ip_mc_msfget(sk, &msf,
  				   (struct ip_msfilter __user *)optval, optlen);
  		release_sock(sk);
  		return err;
  	}
  	case MCAST_MSFILTER:
  	{
  		struct group_filter gsf;
  		int err;

  		if (len < GROUP_FILTER_SIZE(0)) {

  			release_sock(sk);

  			return -EINVAL;
  		}
  		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
  			release_sock(sk);
  			return -EFAULT;
  		}
  		err = ip_mc_gsfget(sk, &gsf,

  				   (struct group_filter __user *)optval,
  				   optlen);

  		release_sock(sk);
  		return err;
  	}

  	case IP_MULTICAST_ALL:
  		val = inet->mc_all;
  		break;

  	case IP_PKTOPTIONS:
  	{
  		struct msghdr msg;

  		release_sock(sk);

  		if (sk->sk_type != SOCK_STREAM)
  			return -ENOPROTOOPT;

  		msg.msg_control = optval;
  		msg.msg_controllen = len;

  		msg.msg_flags = flags;

  		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
  			struct in_pktinfo info;

  			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
  			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;

  			info.ipi_ifindex = inet->mc_index;
  			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);

  		}

  		if (inet->cmsg_flags & IP_CMSG_TTL) {
  			int hlim = inet->mc_ttl;
  			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
  		}
  		len -= msg.msg_controllen;
  		return put_user(len, optlen);
  	}
  	case IP_FREEBIND:
  		val = inet->freebind;
  		break;

  	case IP_TRANSPARENT:
  		val = inet->transparent;
  		break;

  	case IP_MINTTL:
  		val = inet->min_ttl;
  		break;

  	default:
  		release_sock(sk);
  		return -ENOPROTOOPT;

  	}
  	release_sock(sk);

  	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_t(unsigned int, sizeof(int), len);

  		if (put_user(len, optlen))

  			return -EFAULT;

  		if (copy_to_user(optval, &val, len))

  			return -EFAULT;
  	}
  	return 0;
  }

  int ip_getsockopt(struct sock *sk, int level,

  		  int optname, char __user *optval, int __user *optlen)

  {
  	int err;

  	err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);

  #ifdef CONFIG_NETFILTER
  	/* we need to exclude all possible ENOPROTOOPTs except default case */

  	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
  			!ip_mroute_opt(optname)) {

  		int len;

  		if (get_user(len, optlen))

  			return -EFAULT;
  
  		lock_sock(sk);
  		err = nf_getsockopt(sk, PF_INET, optname, optval,
  				&len);
  		release_sock(sk);
  		if (err >= 0)
  			err = put_user(len, optlen);
  		return err;
  	}
  #endif
  	return err;
  }

  EXPORT_SYMBOL(ip_getsockopt);

  
  #ifdef CONFIG_COMPAT

  int compat_ip_getsockopt(struct sock *sk, int level, int optname,
  			 char __user *optval, int __user *optlen)

  {

  	int err;
  
  	if (optname == MCAST_MSFILTER)
  		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
  			ip_getsockopt);

  	err = do_ip_getsockopt(sk, level, optname, optval, optlen,
  		MSG_CMSG_COMPAT);

  #ifdef CONFIG_NETFILTER
  	/* we need to exclude all possible ENOPROTOOPTs except default case */

  	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
  			!ip_mroute_opt(optname)) {

  		int len;

  		if (get_user(len, optlen))

  			return -EFAULT;
  
  		lock_sock(sk);

  		err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);

  		release_sock(sk);
  		if (err >= 0)
  			err = put_user(len, optlen);
  		return err;
  	}
  #endif
  	return err;
  }

  EXPORT_SYMBOL(compat_ip_getsockopt);

  #endif