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authorGerrit Renker <gerrit@erg.abdn.ac.uk>2008-09-04 07:30:19 +0200
committerGerrit Renker <gerrit@erg.abdn.ac.uk>2008-09-04 07:45:37 +0200
commitc8bf462bc567c3dcb083ff95cc13060dd06f138c (patch)
treec612129b23db7bb8613fff4c6e2d51301bc77f65 /net/dccp/options.c
parent5a577b488f687f339dea62e7bb4f4c5793ad523f (diff)
dccp ccid-2: Separate option parsing from CCID processing
This patch replaces an almost identical replication of code: large parts of dccp_parse_options() re-appeared as ccid2_ackvector() in ccid2.c. Apart from the duplication, this caused two more problems: 1. CCIDs should not need to be concerned with parsing header options; 2. one can not assume that Ack Vectors appear as a contiguous area within an skb, it is legal to insert other options and/or padding in between. The current code would throw an error and stop reading in such a case. The patch provides a new data structure and associated list housekeeping. Only small changes were necessary to integrate with CCID-2: data structure initialisation, adapt list traversal routine, and add call to the provided cleanup routine. The latter also lead to fixing the following BUG: CCID-2 so far ignored Ack Vectors on all packets other than Ack/DataAck, which is incorrect, since Ack Vectors can be present on any packet that has an Ack field. Details: -------- * received Ack Vectors are parsed by dccp_parse_options() alone, which passes the result on to the CCID-specific routine ccid_hc_tx_parse_options(); * CCIDs interested in using/decoding Ack Vector information will add code to fetch parsed Ack Vectors via this interface; * a data structure, `struct dccp_ackvec_parsed' is provided as interface; * this structure arranges Ack Vectors of the same skb into a FIFO order; * a doubly-linked list is used to keep the required FIFO code small. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Diffstat (limited to 'net/dccp/options.c')
-rw-r--r--net/dccp/options.c17
1 files changed, 10 insertions, 7 deletions
diff --git a/net/dccp/options.c b/net/dccp/options.c
index 791e07853a7..e5a32979d7d 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -128,13 +128,6 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
if (rc)
goto out_featneg_failed;
break;
- case DCCPO_ACK_VECTOR_0:
- case DCCPO_ACK_VECTOR_1:
- if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */
- break;
- dccp_pr_debug("%s Ack Vector (len=%u)\n", dccp_role(sk),
- len);
- break;
case DCCPO_TIMESTAMP:
if (len != 4)
goto out_invalid_option;
@@ -224,6 +217,16 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
pkt_type, opt, value, len))
goto out_invalid_option;
break;
+ case DCCPO_ACK_VECTOR_0:
+ case DCCPO_ACK_VECTOR_1:
+ if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */
+ break;
+ /*
+ * Ack vectors are processed by the TX CCID if it is
+ * interested. The RX CCID need not parse Ack Vectors,
+ * since it is only interested in clearing old state.
+ * Fall through.
+ */
case DCCPO_MIN_TX_CCID_SPECIFIC ... DCCPO_MAX_TX_CCID_SPECIFIC:
if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
pkt_type, opt, value, len))