dccp: Add packet type information to CCID-specific option parsing

This
 1. adds packet type information to ccid_hc_{rx,tx}_parse_options(). This is
    necessary, since table 3 in RFC 4340, 5.8 leaves it to the CCIDs to state
    which options may (not) appear on what packet type.

 2. adds such a check for CCID-3's {Loss Event, Receive} Rate as specified in
    RFC 4340 8.3 ("Receive Rate options MUST NOT be sent on DCCP-Data packets")
    and 8.5 ("Loss Event Rate options MUST NOT be sent on DCCP-Data packets").

 3. removes an unused argument `idx' from ccid_hc_{rx,tx}_parse_options(). This
    is also no longer necessary, since the CCID-specific option-parsing routines
    are passed every single parameter of the type-length-value option encoding.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

1 files changed, 4 insertions, 12 deletions

diff --git a/net/dccp/options.c b/net/dccp/options.c
index bfda087bd90d..e4983e3d2616 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -226,23 +226,15 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
                         dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
                                       dccp_role(sk), elapsed_time);
                         break;
-                case 128 ... 191: {
-                        const u16 idx = value - options;
-
+                case 128 ... 191:
                         if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
-                                                     opt, len, idx,
-                                                     value) != 0)
+                                                     pkt_type, opt, value, len))
                                 goto out_invalid_option;
-                }
                         break;
-                case 192 ... 255: {
-                        const u16 idx = value - options;
-
+                case 192 ... 255:
                         if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
-                                                     opt, len, idx,
-                                                     value) != 0)
+                                                     pkt_type, opt, value, len))
                                 goto out_invalid_option;
-                }
                         break;
                 default:
                         DCCP_CRIT("DCCP(%p): option %d(len=%d) not "