6 files changed, 135 insertions, 58 deletions

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index e92f1fd28aa5..5df2f6a0b0f0 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1077,12 +1077,16 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
                 ip_mc_up(in_dev);
                 /* fall through */
         case NETDEV_CHANGEADDR:
-                if (IN_DEV_ARP_NOTIFY(in_dev))
-                        arp_send(ARPOP_REQUEST, ETH_P_ARP,
-                                 in_dev->ifa_list->ifa_address,
-                                 dev,
-                                 in_dev->ifa_list->ifa_address,
-                                 NULL, dev->dev_addr, NULL);
+                /* Send gratuitous ARP to notify of link change */
+                if (IN_DEV_ARP_NOTIFY(in_dev)) {
+                        struct in_ifaddr *ifa = in_dev->ifa_list;
+
+                        if (ifa)
+                                arp_send(ARPOP_REQUEST, ETH_P_ARP,
+                                         ifa->ifa_address, dev,
+                                         ifa->ifa_address, NULL,
+                                         dev->dev_addr, NULL);
+                }
                 break;
         case NETDEV_DOWN:
                 ip_mc_down(in_dev);
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 4351ca2cf0b8..537731b3bcb3 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -446,6 +446,28 @@ extern int sysctl_tcp_synack_retries;
 
 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add);
 
+/* Decide when to expire the request and when to resend SYN-ACK */
+static inline void syn_ack_recalc(struct request_sock *req, const int thresh,
+                                  const int max_retries,
+                                  const u8 rskq_defer_accept,
+                                  int *expire, int *resend)
+{
+        if (!rskq_defer_accept) {
+                *expire = req->retrans >= thresh;
+                *resend = 1;
+                return;
+        }
+        *expire = req->retrans >= thresh &&
+                  (!inet_rsk(req)->acked || req->retrans >= max_retries);
+        /*
+         * Do not resend while waiting for data after ACK,
+         * start to resend on end of deferring period to give
+         * last chance for data or ACK to create established socket.
+         */
+        *resend = !inet_rsk(req)->acked ||
+                  req->retrans >= rskq_defer_accept - 1;
+}
+
 void inet_csk_reqsk_queue_prune(struct sock *parent,
                                 const unsigned long interval,
                                 const unsigned long timeout,
@@ -501,9 +523,15 @@ void inet_csk_reqsk_queue_prune(struct sock *parent,
                 reqp=&lopt->syn_table[i];
                 while ((req = *reqp) != NULL) {
                         if (time_after_eq(now, req->expires)) {
-                                if ((req->retrans < thresh ||
-                                     (inet_rsk(req)->acked && req->retrans < max_retries))
-                                    && !req->rsk_ops->rtx_syn_ack(parent, req)) {
+                                int expire = 0, resend = 0;
+
+                                syn_ack_recalc(req, thresh, max_retries,
+                                               queue->rskq_defer_accept,
+                                               &expire, &resend);
+                                if (!expire &&
+                                    (!resend ||
+                                     !req->rsk_ops->rtx_syn_ack(parent, req) ||
+                                     inet_rsk(req)->acked)) {
                                         unsigned long timeo;
 
                                         if (req->retrans++ == 0)
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 0c0b6e363a20..e982b5c1ee17 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -634,17 +634,16 @@ static int do_ip_setsockopt(struct sock *sk, int level,
                                 break;
                         }
                         dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
-                        if (dev) {
+                        if (dev)
                                 mreq.imr_ifindex = dev->ifindex;
-                                dev_put(dev);
-                        }
                 } else
-                        dev = __dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
+                        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 &&
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 64d0af675823..90b2e0649bfb 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -326,6 +326,43 @@ void tcp_enter_memory_pressure(struct sock *sk)
 
 EXPORT_SYMBOL(tcp_enter_memory_pressure);
 
+/* Convert seconds to retransmits based on initial and max timeout */
+static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
+{
+        u8 res = 0;
+
+        if (seconds > 0) {
+                int period = timeout;
+
+                res = 1;
+                while (seconds > period && res < 255) {
+                        res++;
+                        timeout <<= 1;
+                        if (timeout > rto_max)
+                                timeout = rto_max;
+                        period += timeout;
+                }
+        }
+        return res;
+}
+
+/* Convert retransmits to seconds based on initial and max timeout */
+static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
+{
+        int period = 0;
+
+        if (retrans > 0) {
+                period = timeout;
+                while (--retrans) {
+                        timeout <<= 1;
+                        if (timeout > rto_max)
+                                timeout = rto_max;
+                        period += timeout;
+                }
+        }
+        return period;
+}
+
 /*
  *      Wait for a TCP event.
  *
@@ -1405,7 +1442,9 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                                 goto found_ok_skb;
                         if (tcp_hdr(skb)->fin)
                                 goto found_fin_ok;
-                        WARN_ON(!(flags & MSG_PEEK));
+                        if (WARN_ON(!(flags & MSG_PEEK)))
+                                printk(KERN_INFO "recvmsg bug 2: copied %X "
+                                       "seq %X\n", *seq, TCP_SKB_CB(skb)->seq);
                 }
 
                 /* Well, if we have backlog, try to process it now yet. */
@@ -2163,16 +2202,10 @@ static int do_tcp_setsockopt(struct sock *sk, int level,
                 break;
 
         case TCP_DEFER_ACCEPT:
-                icsk->icsk_accept_queue.rskq_defer_accept = 0;
-                if (val > 0) {
-                        /* Translate value in seconds to number of
-                         * retransmits */
-                        while (icsk->icsk_accept_queue.rskq_defer_accept < 32 &&
-                               val > ((TCP_TIMEOUT_INIT / HZ) <<
-                                       icsk->icsk_accept_queue.rskq_defer_accept))
-                                icsk->icsk_accept_queue.rskq_defer_accept++;
-                        icsk->icsk_accept_queue.rskq_defer_accept++;
-                }
+                /* Translate value in seconds to number of retransmits */
+                icsk->icsk_accept_queue.rskq_defer_accept =
+                        secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
+                                        TCP_RTO_MAX / HZ);
                 break;
 
         case TCP_WINDOW_CLAMP:
@@ -2353,8 +2386,8 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
                         val = (val ? : sysctl_tcp_fin_timeout) / HZ;
                 break;
         case TCP_DEFER_ACCEPT:
-                val = !icsk->icsk_accept_queue.rskq_defer_accept ? 0 :
-                        ((TCP_TIMEOUT_INIT / HZ) << (icsk->icsk_accept_queue.rskq_defer_accept - 1));
+                val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept,
+                                      TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ);
                 break;
         case TCP_WINDOW_CLAMP:
                 val = tp->window_clamp;
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 624c3c9b3c2b..4c03598ed924 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -641,8 +641,8 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
         if (!(flg & TCP_FLAG_ACK))
                 return NULL;
 
-        /* If TCP_DEFER_ACCEPT is set, drop bare ACK. */
-        if (inet_csk(sk)->icsk_accept_queue.rskq_defer_accept &&
+        /* While TCP_DEFER_ACCEPT is active, drop bare ACK. */
+        if (req->retrans < inet_csk(sk)->icsk_accept_queue.rskq_defer_accept &&
             TCP_SKB_CB(skb)->end_seq == tcp_rsk(req)->rcv_isn + 1) {
                 inet_rsk(req)->acked = 1;
                 return NULL;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 6ec6a8a4a224..d0d436d6216c 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -841,6 +841,42 @@ out:
         return ret;
 }
 
+
+/**
+ *      first_packet_length     - return length of first packet in receive queue
+ *      @sk: socket
+ *
+ *      Drops all bad checksum frames, until a valid one is found.
+ *      Returns the length of found skb, or 0 if none is found.
+ */
+static unsigned int first_packet_length(struct sock *sk)
+{
+        struct sk_buff_head list_kill, *rcvq = &sk->sk_receive_queue;
+        struct sk_buff *skb;
+        unsigned int res;
+
+        __skb_queue_head_init(&list_kill);
+
+        spin_lock_bh(&rcvq->lock);
+        while ((skb = skb_peek(rcvq)) != NULL &&
+                udp_lib_checksum_complete(skb)) {
+                UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS,
+                                 IS_UDPLITE(sk));
+                __skb_unlink(skb, rcvq);
+                __skb_queue_tail(&list_kill, skb);
+        }
+        res = skb ? skb->len : 0;
+        spin_unlock_bh(&rcvq->lock);
+
+        if (!skb_queue_empty(&list_kill)) {
+                lock_sock(sk);
+                __skb_queue_purge(&list_kill);
+                sk_mem_reclaim_partial(sk);
+                release_sock(sk);
+        }
+        return res;
+}
+
 /*
  *      IOCTL requests applicable to the UDP protocol
  */
@@ -857,21 +893,16 @@ int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 
         case SIOCINQ:
         {
-                struct sk_buff *skb;
-                unsigned long amount;
+                unsigned int amount = first_packet_length(sk);
 
-                amount = 0;
-                spin_lock_bh(&sk->sk_receive_queue.lock);
-                skb = skb_peek(&sk->sk_receive_queue);
-                if (skb != NULL) {
+                if (amount)
                         /*
                          * We will only return the amount
                          * of this packet since that is all
                          * that will be read.
                          */
-                        amount = skb->len - sizeof(struct udphdr);
-                }
-                spin_unlock_bh(&sk->sk_receive_queue.lock);
+                        amount -= sizeof(struct udphdr);
+
                 return put_user(amount, (int __user *)arg);
         }
 
@@ -1540,29 +1571,11 @@ unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
 {
         unsigned int mask = datagram_poll(file, sock, wait);
         struct sock *sk = sock->sk;
-        int     is_lite = IS_UDPLITE(sk);
 
         /* Check for false positives due to checksum errors */
-        if ((mask & POLLRDNORM) &&
-            !(file->f_flags & O_NONBLOCK) &&
-            !(sk->sk_shutdown & RCV_SHUTDOWN)) {
-                struct sk_buff_head *rcvq = &sk->sk_receive_queue;
-                struct sk_buff *skb;
-
-                spin_lock_bh(&rcvq->lock);
-                while ((skb = skb_peek(rcvq)) != NULL &&
-                       udp_lib_checksum_complete(skb)) {
-                        UDP_INC_STATS_BH(sock_net(sk),
-                                        UDP_MIB_INERRORS, is_lite);
-                        __skb_unlink(skb, rcvq);
-                        kfree_skb(skb);
-                }
-                spin_unlock_bh(&rcvq->lock);
-
-                /* nothing to see, move along */
-                if (skb == NULL)
-                        mask &= ~(POLLIN | POLLRDNORM);
-        }
+        if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
+            !(sk->sk_shutdown & RCV_SHUTDOWN) && !first_packet_length(sk))
+                mask &= ~(POLLIN | POLLRDNORM);
 
         return mask;