dccp: Implement lookup table for feature-negotiation information
A lookup table for feature-negotiation information, extracted from RFC
4340/42, is provided by this patch. All currently known features can
be found in this table, along with their feature location, their
default value, and type.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/feat.c b/net/dccp/feat.c
index 933a0ec..45e36fc 100644
--- a/net/dccp/feat.c
+++ b/net/dccp/feat.c
@@ -23,6 +23,43 @@
#define DCCP_FEAT_SP_NOAGREE (-123)
+static const struct {
+ u8 feat_num; /* DCCPF_xxx */
+ enum dccp_feat_type rxtx; /* RX or TX */
+ enum dccp_feat_type reconciliation; /* SP or NN */
+ u8 default_value; /* as in 6.4 */
+/*
+ * Lookup table for location and type of features (from RFC 4340/4342)
+ * +--------------------------+----+-----+----+----+---------+-----------+
+ * | Feature | Location | Reconc. | Initial | Section |
+ * | | RX | TX | SP | NN | Value | Reference |
+ * +--------------------------+----+-----+----+----+---------+-----------+
+ * | DCCPF_CCID | | X | X | | 2 | 10 |
+ * | DCCPF_SHORT_SEQNOS | | X | X | | 0 | 7.6.1 |
+ * | DCCPF_SEQUENCE_WINDOW | | X | | X | 100 | 7.5.2 |
+ * | DCCPF_ECN_INCAPABLE | X | | X | | 0 | 12.1 |
+ * | DCCPF_ACK_RATIO | | X | | X | 2 | 11.3 |
+ * | DCCPF_SEND_ACK_VECTOR | X | | X | | 0 | 11.5 |
+ * | DCCPF_SEND_NDP_COUNT | | X | X | | 0 | 7.7.2 |
+ * | DCCPF_MIN_CSUM_COVER | X | | X | | 0 | 9.2.1 |
+ * | DCCPF_DATA_CHECKSUM | X | | X | | 0 | 9.3.1 |
+ * | DCCPF_SEND_LEV_RATE | X | | X | | 0 | 4342/8.4 |
+ * +--------------------------+----+-----+----+----+---------+-----------+
+ */
+} dccp_feat_table[] = {
+ { DCCPF_CCID, FEAT_AT_TX, FEAT_SP, 2 },
+ { DCCPF_SHORT_SEQNOS, FEAT_AT_TX, FEAT_SP, 0 },
+ { DCCPF_SEQUENCE_WINDOW, FEAT_AT_TX, FEAT_NN, 100 },
+ { DCCPF_ECN_INCAPABLE, FEAT_AT_RX, FEAT_SP, 0 },
+ { DCCPF_ACK_RATIO, FEAT_AT_TX, FEAT_NN, 2 },
+ { DCCPF_SEND_ACK_VECTOR, FEAT_AT_RX, FEAT_SP, 0 },
+ { DCCPF_SEND_NDP_COUNT, FEAT_AT_TX, FEAT_SP, 0 },
+ { DCCPF_MIN_CSUM_COVER, FEAT_AT_RX, FEAT_SP, 0 },
+ { DCCPF_DATA_CHECKSUM, FEAT_AT_RX, FEAT_SP, 0 },
+ { DCCPF_SEND_LEV_RATE, FEAT_AT_RX, FEAT_SP, 0 },
+};
+#define DCCP_FEAT_SUPPORTED_MAX ARRAY_SIZE(dccp_feat_table)
+
int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
u8 *val, u8 len, gfp_t gfp)
{
@@ -639,6 +676,8 @@
if (feat > DCCPF_DATA_CHECKSUM && feat < DCCPF_MIN_CCID_SPECIFIC)
return feature_names[DCCPF_RESERVED];
+ if (feat == DCCPF_SEND_LEV_RATE)
+ return "Send Loss Event Rate";
if (feat >= DCCPF_MIN_CCID_SPECIFIC)
return "CCID-specific";