1 files changed, 63 insertions, 2 deletions

diff --git a/net/dccp/options.c b/net/dccp/options.c
index cd3061813009..5adeeed5e0d2 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -340,6 +340,7 @@ static inline int dccp_elapsed_time_len(const u32 elapsed_time)
         return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
 }
 
+/* FIXME: This function is currently not used anywhere */
 int dccp_insert_option_elapsed_time(struct sk_buff *skb, u32 elapsed_time)
 {
         const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
@@ -424,6 +425,67 @@ static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
         return 0;
 }
 
+static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
+{
+        struct dccp_sock *dp = dccp_sk(sk);
+        struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
+        const u16 buflen = dccp_ackvec_buflen(av);
+        /* Figure out how many options do we need to represent the ackvec */
+        const u8 nr_opts = DIV_ROUND_UP(buflen, DCCP_SINGLE_OPT_MAXLEN);
+        u16 len = buflen + 2 * nr_opts;
+        u8 i, nonce = 0;
+        const unsigned char *tail, *from;
+        unsigned char *to;
+
+        if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
+                return -1;
+
+        DCCP_SKB_CB(skb)->dccpd_opt_len += len;
+
+        to   = skb_push(skb, len);
+        len  = buflen;
+        from = av->av_buf + av->av_buf_head;
+        tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN;
+
+        for (i = 0; i < nr_opts; ++i) {
+                int copylen = len;
+
+                if (len > DCCP_SINGLE_OPT_MAXLEN)
+                        copylen = DCCP_SINGLE_OPT_MAXLEN;
+
+                /*
+                 * RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via
+                 * its type; ack_nonce is the sum of all individual buf_nonce's.
+                 */
+                nonce ^= av->av_buf_nonce[i];
+
+                *to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i];
+                *to++ = copylen + 2;
+
+                /* Check if buf_head wraps */
+                if (from + copylen > tail) {
+                        const u16 tailsize = tail - from;
+
+                        memcpy(to, from, tailsize);
+                        to      += tailsize;
+                        len     -= tailsize;
+                        copylen -= tailsize;
+                        from    = av->av_buf;
+                }
+
+                memcpy(to, from, copylen);
+                from += copylen;
+                to   += copylen;
+                len  -= copylen;
+        }
+        /*
+         * Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340.
+         */
+        if (dccp_ackvec_update_records(av, DCCP_SKB_CB(skb)->dccpd_seq, nonce))
+                return -ENOBUFS;
+        return 0;
+}
+
 /**
  * dccp_insert_option_mandatory  -  Mandatory option (5.8.2)
  * Note that since we are using skb_push, this function needs to be called
@@ -519,8 +581,7 @@ int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
                         if (dccp_insert_option_timestamp(skb))
                                 return -1;
 
-                } else if (dp->dccps_hc_rx_ackvec != NULL &&
-                           dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
+                } else if (dccp_ackvec_pending(sk) &&
                            dccp_insert_option_ackvec(sk, skb)) {
                                 return -1;
                 }