diff options
Diffstat (limited to 'net/dccp/options.c')
| -rw-r--r-- | net/dccp/options.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/net/dccp/options.c b/net/dccp/options.c index 7743df00f5b1..dabd6ee34d45 100644 --- a/net/dccp/options.c +++ b/net/dccp/options.c @@ -427,6 +427,7 @@ 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; + struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); 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); @@ -435,10 +436,25 @@ static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) const unsigned char *tail, *from; unsigned char *to; - if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) + if (dcb->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) { + DCCP_WARN("Lacking space for %u bytes on %s packet\n", len, + dccp_packet_name(dcb->dccpd_type)); return -1; - - DCCP_SKB_CB(skb)->dccpd_opt_len += len; + } + /* + * Since Ack Vectors are variable-length, we can not always predict + * their size. To catch exception cases where the space is running out + * on the skb, a separate Sync is scheduled to carry the Ack Vector. + */ + if (len > DCCPAV_MIN_OPTLEN && + len + dcb->dccpd_opt_len + skb->len > dp->dccps_mss_cache) { + DCCP_WARN("No space left for Ack Vector (%u) on skb (%u+%u), " + "MPS=%u ==> reduce payload size?\n", len, skb->len, + dcb->dccpd_opt_len, dp->dccps_mss_cache); + dp->dccps_sync_scheduled = 1; + return 0; + } + dcb->dccpd_opt_len += len; to = skb_push(skb, len); len = buflen; @@ -479,7 +495,7 @@ static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb) /* * 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)) + if (dccp_ackvec_update_records(av, dcb->dccpd_seq, nonce)) return -ENOBUFS; return 0; } |