1 files changed, 55 insertions, 17 deletions

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 465abf0a9869..43c05854d752 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -48,6 +48,7 @@
 #define IP_CMSG_RECVOPTS        8
 #define IP_CMSG_RETOPTS         16
 #define IP_CMSG_PASSSEC         32
+#define IP_CMSG_ORIGDSTADDR     64
 
 /*
  *      SOL_IP control messages.
@@ -94,7 +95,7 @@ static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb)
 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;
+        struct ip_options * opt = (struct ip_options *)optbuf;
 
         if (IPCB(skb)->opt.optlen == 0)
                 return;
@@ -126,6 +127,27 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
         security_release_secctx(secdata, seclen);
 }
 
+static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
+{
+        struct sockaddr_in sin;
+        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)
 {
@@ -160,6 +182,12 @@ void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
 
         if (flags & 1)
                 ip_cmsg_recv_security(msg, skb);
+
+        if ((flags>>=1) == 0)
+                return;
+        if (flags & 1)
+                ip_cmsg_recv_dstaddr(msg, skb);
+
 }
 
 int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc)
@@ -411,7 +439,7 @@ static int do_ip_setsockopt(struct sock *sk, int level,
                             int optname, char __user *optval, int optlen)
 {
         struct inet_sock *inet = inet_sk(sk);
-        int val=0,err;
+        int val = 0, err;
 
         if (((1<<optname) & ((1<<IP_PKTINFO) | (1<<IP_RECVTTL) |
                              (1<<IP_RECVOPTS) | (1<<IP_RECVTOS) |
@@ -421,7 +449,8 @@ static int do_ip_setsockopt(struct sock *sk, int level,
                              (1<<IP_ROUTER_ALERT) | (1<<IP_FREEBIND) |
                              (1<<IP_PASSSEC) | (1<<IP_TRANSPARENT))) ||
             optname == IP_MULTICAST_TTL ||
-            optname == IP_MULTICAST_LOOP) {
+            optname == IP_MULTICAST_LOOP ||
+            optname == IP_RECVORIGDSTADDR) {
                 if (optlen >= sizeof(int)) {
                         if (get_user(val, (int __user *) optval))
                                 return -EFAULT;
@@ -437,7 +466,7 @@ static int do_ip_setsockopt(struct sock *sk, int level,
         /* If optlen==0, it is equivalent to val == 0 */
 
         if (ip_mroute_opt(optname))
-                return ip_mroute_setsockopt(sk,optname,optval,optlen);
+                return ip_mroute_setsockopt(sk, optname, optval, optlen);
 
         err = 0;
         lock_sock(sk);
@@ -509,6 +538,12 @@ static int do_ip_setsockopt(struct sock *sk, int level,
                 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 &= ~3;
@@ -549,7 +584,7 @@ static int do_ip_setsockopt(struct sock *sk, int level,
                         goto e_inval;
                 if (optlen<1)
                         goto e_inval;
-                if (val==-1)
+                if (val == -1)
                         val = 1;
                 if (val < 0 || val > 255)
                         goto e_inval;
@@ -573,12 +608,12 @@ static int do_ip_setsockopt(struct sock *sk, int level,
 
                 err = -EFAULT;
                 if (optlen >= sizeof(struct ip_mreqn)) {
-                        if (copy_from_user(&mreq,optval,sizeof(mreq)))
+                        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)))
+                            copy_from_user(&mreq.imr_address, optval, sizeof(struct in_addr)))
                                 break;
                 }
 
@@ -626,11 +661,11 @@ static int do_ip_setsockopt(struct sock *sk, int level,
                         goto e_inval;
                 err = -EFAULT;
                 if (optlen >= sizeof(struct ip_mreqn)) {
-                        if (copy_from_user(&mreq,optval,sizeof(mreq)))
+                        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)))
+                        if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
                                 break;
                 }
 
@@ -808,7 +843,7 @@ static int do_ip_setsockopt(struct sock *sk, int level,
                         err = -ENOBUFS;
                         break;
                 }
-                gsf = kmalloc(optlen,GFP_KERNEL);
+                gsf = kmalloc(optlen, GFP_KERNEL);
                 if (!gsf) {
                         err = -ENOBUFS;
                         break;
@@ -828,7 +863,7 @@ static int do_ip_setsockopt(struct sock *sk, int level,
                         goto mc_msf_out;
                 }
                 msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
-                msf = kmalloc(msize,GFP_KERNEL);
+                msf = kmalloc(msize, GFP_KERNEL);
                 if (!msf) {
                         err = -ENOBUFS;
                         goto mc_msf_out;
@@ -971,9 +1006,9 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
                 return -EOPNOTSUPP;
 
         if (ip_mroute_opt(optname))
-                return ip_mroute_getsockopt(sk,optname,optval,optlen);
+                return ip_mroute_getsockopt(sk, optname, optval, optlen);
 
-        if (get_user(len,optlen))
+        if (get_user(len, optlen))
                 return -EFAULT;
         if (len < 0)
                 return -EINVAL;
@@ -984,7 +1019,7 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
         case IP_OPTIONS:
         {
                 unsigned char optbuf[sizeof(struct ip_options)+40];
-                struct ip_options * opt = (struct ip_options*)optbuf;
+                struct ip_options * opt = (struct ip_options *)optbuf;
                 opt->optlen = 0;
                 if (inet->opt)
                         memcpy(optbuf, inet->opt,
@@ -1022,6 +1057,9 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
         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;
@@ -1154,13 +1192,13 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname,
                 len = 1;
                 if (put_user(len, optlen))
                         return -EFAULT;
-                if (copy_to_user(optval,&ucval,1))
+                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))
+                if (copy_to_user(optval, &val, len))
                         return -EFAULT;
         }
         return 0;
@@ -1178,7 +1216,7 @@ int ip_getsockopt(struct sock *sk, int level,
                         !ip_mroute_opt(optname)) {
                 int len;
 
-                if (get_user(len,optlen))
+                if (get_user(len, optlen))
                         return -EFAULT;
 
                 lock_sock(sk);