1 files changed, 40 insertions, 32 deletions

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 63ae94771b8e..32b94cf19f89 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -721,45 +721,23 @@ svc_write_space(struct sock *sk)
         }
 }
 
-static void svc_udp_get_sender_address(struct svc_rqst *rqstp,
-                                        struct sk_buff *skb)
+static inline void svc_udp_get_dest_address(struct svc_rqst *rqstp,
+                                            struct cmsghdr *cmh)
 {
         switch (rqstp->rq_sock->sk_sk->sk_family) {
         case AF_INET: {
-                /* this seems to come from net/ipv4/udp.c:udp_recvmsg */
-                        struct sockaddr_in *sin = svc_addr_in(rqstp);
-
-                        sin->sin_family = AF_INET;
-                        sin->sin_port = skb->h.uh->source;
-                        sin->sin_addr.s_addr = skb->nh.iph->saddr;
-                        rqstp->rq_addrlen = sizeof(struct sockaddr_in);
-                        /* Remember which interface received this request */
-                        rqstp->rq_daddr.addr.s_addr = skb->nh.iph->daddr;
-                }
+                struct in_pktinfo *pki = CMSG_DATA(cmh);
+                rqstp->rq_daddr.addr.s_addr = pki->ipi_spec_dst.s_addr;
                 break;
+                }
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
         case AF_INET6: {
-                /* this is derived from net/ipv6/udp.c:udpv6_recvmesg */
-                        struct sockaddr_in6 *sin6 = svc_addr_in6(rqstp);
-
-                        sin6->sin6_family = AF_INET6;
-                        sin6->sin6_port = skb->h.uh->source;
-                        sin6->sin6_flowinfo = 0;
-                        sin6->sin6_scope_id = 0;
-                        if (ipv6_addr_type(&sin6->sin6_addr) &
-                                                        IPV6_ADDR_LINKLOCAL)
-                                sin6->sin6_scope_id = IP6CB(skb)->iif;
-                        ipv6_addr_copy(&sin6->sin6_addr,
-                                                        &skb->nh.ipv6h->saddr);
-                        rqstp->rq_addrlen = sizeof(struct sockaddr_in);
-                        /* Remember which interface received this request */
-                        ipv6_addr_copy(&rqstp->rq_daddr.addr6,
-                                                        &skb->nh.ipv6h->saddr);
-                }
+                struct in6_pktinfo *pki = CMSG_DATA(cmh);
+                ipv6_addr_copy(&rqstp->rq_daddr.addr6, &pki->ipi6_addr);
                 break;
+                }
 #endif
         }
-        return;
 }
 
 /*
@@ -771,7 +749,15 @@ svc_udp_recvfrom(struct svc_rqst *rqstp)
         struct svc_sock *svsk = rqstp->rq_sock;
         struct svc_serv *serv = svsk->sk_server;
         struct sk_buff  *skb;
+        char            buffer[CMSG_SPACE(sizeof(union svc_pktinfo_u))];
+        struct cmsghdr *cmh = (struct cmsghdr *)buffer;
         int             err, len;
+        struct msghdr msg = {
+                .msg_name = svc_addr(rqstp),
+                .msg_control = cmh,
+                .msg_controllen = sizeof(buffer),
+                .msg_flags = MSG_DONTWAIT,
+        };
 
         if (test_and_clear_bit(SK_CHNGBUF, &svsk->sk_flags))
             /* udp sockets need large rcvbuf as all pending
@@ -797,7 +783,9 @@ svc_udp_recvfrom(struct svc_rqst *rqstp)
         }
 
         clear_bit(SK_DATA, &svsk->sk_flags);
-        while ((skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err)) == NULL) {
+        while ((err == kernel_recvmsg(svsk->sk_sock, &msg, NULL,
+                                      0, 0, MSG_PEEK | MSG_DONTWAIT)) < 0 ||
+               (skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err)) == NULL) {
                 if (err == -EAGAIN) {
                         svc_sock_received(svsk);
                         return err;
@@ -805,6 +793,7 @@ svc_udp_recvfrom(struct svc_rqst *rqstp)
                 /* possibly an icmp error */
                 dprintk("svc: recvfrom returned error %d\n", -err);
         }
+        rqstp->rq_addrlen = sizeof(rqstp->rq_addr);
         if (skb->tstamp.off_sec == 0) {
                 struct timeval tv;
 
@@ -827,7 +816,16 @@ svc_udp_recvfrom(struct svc_rqst *rqstp)
 
         rqstp->rq_prot = IPPROTO_UDP;
 
-        svc_udp_get_sender_address(rqstp, skb);
+        if (cmh->cmsg_level != IPPROTO_IP ||
+            cmh->cmsg_type != IP_PKTINFO) {
+                if (net_ratelimit())
+                        printk("rpcsvc: received unknown control message:"
+                               "%d/%d\n",
+                               cmh->cmsg_level, cmh->cmsg_type);
+                skb_free_datagram(svsk->sk_sk, skb);
+                return 0;
+        }
+        svc_udp_get_dest_address(rqstp, cmh);
 
         if (skb_is_nonlinear(skb)) {
                 /* we have to copy */
@@ -884,6 +882,9 @@ svc_udp_sendto(struct svc_rqst *rqstp)
 static void
 svc_udp_init(struct svc_sock *svsk)
 {
+        int one = 1;
+        mm_segment_t oldfs;
+
         svsk->sk_sk->sk_data_ready = svc_udp_data_ready;
         svsk->sk_sk->sk_write_space = svc_write_space;
         svsk->sk_recvfrom = svc_udp_recvfrom;
@@ -899,6 +900,13 @@ svc_udp_init(struct svc_sock *svsk)
 
         set_bit(SK_DATA, &svsk->sk_flags); /* might have come in before data_ready set up */
         set_bit(SK_CHNGBUF, &svsk->sk_flags);
+
+        oldfs = get_fs();
+        set_fs(KERNEL_DS);
+        /* make sure we get destination address info */
+        svsk->sk_sock->ops->setsockopt(svsk->sk_sock, IPPROTO_IP, IP_PKTINFO,
+                                       (char __user *)&one, sizeof(one));
+        set_fs(oldfs);
 }
 
 /*