[DCCP] ccid3: Divide by zero fix

[safe/jmp/linux-2.6] / net / dccp / ccids / ccid3.c

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index e05f4f9..35d1d34 100644 (file)
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -2,7 +2,7 @@
  *  net/dccp/ccids/ccid3.c
  *
  *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
- *  Copyright (c) 2005 Ian McDonald <iam4@cs.waikato.ac.nz>
+ *  Copyright (c) 2005-6 Ian McDonald <imcdnzl@gmail.com>
  *
  *  An implementation of the DCCP protocol
  *
@@ -1033,9 +1033,13 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
        p_prev = hcrx->ccid3hcrx_p;
        
        /* Calculate loss event rate */
-       if (!list_empty(&hcrx->ccid3hcrx_li_hist))
+       if (!list_empty(&hcrx->ccid3hcrx_li_hist)) {
+               u32 i_mean = dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
+
                /* Scaling up by 1000000 as fixed decimal */
-               hcrx->ccid3hcrx_p = 1000000 / dccp_li_hist_calc_i_mean(&hcrx->ccid3hcrx_li_hist);
+               if (i_mean != 0)
+                       hcrx->ccid3hcrx_p = 1000000 / i_mean;
+       }
 
        if (hcrx->ccid3hcrx_p > p_prev) {
                ccid3_hc_rx_send_feedback(sk);
@@ -1095,6 +1099,10 @@ static void ccid3_hc_rx_get_info(struct sock *sk, struct tcp_info *info)
 {
        const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
 
+       /* Listen socks doesn't have a private CCID block */
+       if (sk->sk_state == DCCP_LISTEN)
+               return;
+
        BUG_ON(hcrx == NULL);
 
        info->tcpi_ca_state     = hcrx->ccid3hcrx_state;
@@ -1106,12 +1114,70 @@ static void ccid3_hc_tx_get_info(struct sock *sk, struct tcp_info *info)
 {
        const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
 
+       /* Listen socks doesn't have a private CCID block */
+       if (sk->sk_state == DCCP_LISTEN)
+               return;
+
        BUG_ON(hctx == NULL);
 
        info->tcpi_rto = hctx->ccid3hctx_t_rto;
        info->tcpi_rtt = hctx->ccid3hctx_rtt;
 }
 
+static int ccid3_hc_rx_getsockopt(struct sock *sk, const int optname, int len,
+                                 u32 __user *optval, int __user *optlen)
+{
+       const struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
+       const void *val;
+       
+       /* Listen socks doesn't have a private CCID block */
+       if (sk->sk_state == DCCP_LISTEN)
+               return -EINVAL;
+
+       switch (optname) {
+       case DCCP_SOCKOPT_CCID_RX_INFO:
+               if (len < sizeof(hcrx->ccid3hcrx_tfrc))
+                       return -EINVAL;
+               len = sizeof(hcrx->ccid3hcrx_tfrc);
+               val = &hcrx->ccid3hcrx_tfrc;
+               break;
+       default:
+               return -ENOPROTOOPT;
+       }
+
+       if (put_user(len, optlen) || copy_to_user(optval, val, len))
+               return -EFAULT;
+
+       return 0;
+}
+
+static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
+                                 u32 __user *optval, int __user *optlen)
+{
+       const struct ccid3_hc_tx_sock *hctx = ccid3_hc_tx_sk(sk);
+       const void *val;
+       
+       /* Listen socks doesn't have a private CCID block */
+       if (sk->sk_state == DCCP_LISTEN)
+               return -EINVAL;
+
+       switch (optname) {
+       case DCCP_SOCKOPT_CCID_TX_INFO:
+               if (len < sizeof(hctx->ccid3hctx_tfrc))
+                       return -EINVAL;
+               len = sizeof(hctx->ccid3hctx_tfrc);
+               val = &hctx->ccid3hctx_tfrc;
+               break;
+       default:
+               return -ENOPROTOOPT;
+       }
+
+       if (put_user(len, optlen) || copy_to_user(optval, val, len))
+               return -EFAULT;
+
+       return 0;
+}
+
 static struct ccid ccid3 = {
        .ccid_id                   = 3,
        .ccid_name                 = "ccid3",
@@ -1131,6 +1197,8 @@ static struct ccid ccid3 = {
        .ccid_hc_rx_packet_recv    = ccid3_hc_rx_packet_recv,
        .ccid_hc_rx_get_info       = ccid3_hc_rx_get_info,
        .ccid_hc_tx_get_info       = ccid3_hc_tx_get_info,
+       .ccid_hc_rx_getsockopt     = ccid3_hc_rx_getsockopt,
+       .ccid_hc_tx_getsockopt     = ccid3_hc_tx_getsockopt,
 };
  
 module_param(ccid3_debug, int, 0444);