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>
This commit is contained in:
Gerrit Renker 2008-11-04 23:43:47 -08:00 committed by David S. Miller
parent bd012f2e7b
commit 7d43d1a0f2
2 changed files with 44 additions and 4 deletions

View file

@ -176,19 +176,20 @@ enum {
}; };
/* DCCP features (RFC 4340 section 6.4) */ /* DCCP features (RFC 4340 section 6.4) */
enum { enum dccp_feature_numbers {
DCCPF_RESERVED = 0, DCCPF_RESERVED = 0,
DCCPF_CCID = 1, DCCPF_CCID = 1,
DCCPF_SHORT_SEQNOS = 2, /* XXX: not yet implemented */ DCCPF_SHORT_SEQNOS = 2,
DCCPF_SEQUENCE_WINDOW = 3, DCCPF_SEQUENCE_WINDOW = 3,
DCCPF_ECN_INCAPABLE = 4, /* XXX: not yet implemented */ DCCPF_ECN_INCAPABLE = 4,
DCCPF_ACK_RATIO = 5, DCCPF_ACK_RATIO = 5,
DCCPF_SEND_ACK_VECTOR = 6, DCCPF_SEND_ACK_VECTOR = 6,
DCCPF_SEND_NDP_COUNT = 7, DCCPF_SEND_NDP_COUNT = 7,
DCCPF_MIN_CSUM_COVER = 8, DCCPF_MIN_CSUM_COVER = 8,
DCCPF_DATA_CHECKSUM = 9, /* XXX: not yet implemented */ DCCPF_DATA_CHECKSUM = 9,
/* 10-127 reserved */ /* 10-127 reserved */
DCCPF_MIN_CCID_SPECIFIC = 128, DCCPF_MIN_CCID_SPECIFIC = 128,
DCCPF_SEND_LEV_RATE = 192, /* RFC 4342, sec. 8.4 */
DCCPF_MAX_CCID_SPECIFIC = 255, DCCPF_MAX_CCID_SPECIFIC = 255,
}; };

View file

@ -23,6 +23,43 @@
#define DCCP_FEAT_SP_NOAGREE (-123) #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, int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
u8 *val, u8 len, gfp_t gfp) u8 *val, u8 len, gfp_t gfp)
{ {
@ -639,6 +676,8 @@ const char *dccp_feat_name(const u8 feat)
if (feat > DCCPF_DATA_CHECKSUM && feat < DCCPF_MIN_CCID_SPECIFIC) if (feat > DCCPF_DATA_CHECKSUM && feat < DCCPF_MIN_CCID_SPECIFIC)
return feature_names[DCCPF_RESERVED]; return feature_names[DCCPF_RESERVED];
if (feat == DCCPF_SEND_LEV_RATE)
return "Send Loss Event Rate";
if (feat >= DCCPF_MIN_CCID_SPECIFIC) if (feat >= DCCPF_MIN_CCID_SPECIFIC)
return "CCID-specific"; return "CCID-specific";