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dccp: Insert feature-negotiation options into skb 

This patch replaces the earlier insertion routine from options.c, so that
code specific to feature negotiation can remain in feat.c. This is possible
by calling a function already existing in options.c.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
This commit is contained in:
Gerrit Renker 2008-09-04 07:30:19 +02:00
parent cf9ddf73b9
commit 0ef118a017
2 changed files with 67 additions and 0 deletions
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2
net/dccp/dccp.h
View File

@ -443,6 +443,8 @@ static inline int dccp_ack_pending(const struct sock *sk)
extern int dccp_feat_finalise_settings(struct dccp_sock *dp);
extern int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq);
extern int dccp_feat_insert_opts(struct dccp_sock*, struct dccp_request_sock*,
struct sk_buff *skb);
extern void dccp_feat_list_purge(struct list_head *fn_list);
extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);

65
net/dccp/feat.c
View File

@ -300,6 +300,20 @@ int dccp_feat_clone_list(struct list_head const *from, struct list_head *to)
return -ENOMEM;
}
/**
* dccp_feat_valid_nn_length - Enforce length constraints on NN options
* Length is between 0 and %DCCP_OPTVAL_MAXLEN. Used for outgoing packets only,
* incoming options are accepted as long as their values are valid.
*/
static u8 dccp_feat_valid_nn_length(u8 feat_num)
{
if (feat_num == DCCPF_ACK_RATIO) /* RFC 4340, 11.3 and 6.6.8 */
return 2;
if (feat_num == DCCPF_SEQUENCE_WINDOW) /* RFC 4340, 7.5.2 and 6.5 */
return 6;
return 0;
}
static u8 dccp_feat_is_valid_nn_val(u8 feat_num, u64 val)
{
switch (feat_num) {
@ -341,6 +355,57 @@ static u8 dccp_feat_sp_list_ok(u8 feat_num, u8 const *sp_list, u8 sp_len)
return 1;
}
/**
* dccp_feat_insert_opts - Generate FN options from current list state
* @skb: next sk_buff to be sent to the peer
* @dp: for client during handshake and general negotiation
* @dreq: used by the server only (all Changes/Confirms in LISTEN/RESPOND)
*/
int dccp_feat_insert_opts(struct dccp_sock *dp, struct dccp_request_sock *dreq,
struct sk_buff *skb)
{
struct list_head *fn = dreq ? &dreq->dreq_featneg : &dp->dccps_featneg;
struct dccp_feat_entry *pos, *next;
u8 opt, type, len, *ptr, nn_in_nbo[DCCP_OPTVAL_MAXLEN];
bool rpt;
/* put entries into @skb in the order they appear in the list */
list_for_each_entry_safe_reverse(pos, next, fn, node) {
opt = dccp_feat_genopt(pos);
type = dccp_feat_type(pos->feat_num);
rpt = false;
if (pos->empty_confirm) {
len = 0;
ptr = NULL;
} else {
if (type == FEAT_SP) {
len = pos->val.sp.len;
ptr = pos->val.sp.vec;
rpt = pos->needs_confirm;
} else if (type == FEAT_NN) {
len = dccp_feat_valid_nn_length(pos->feat_num);
ptr = nn_in_nbo;
dccp_encode_value_var(pos->val.nn, ptr, len);
} else {
DCCP_BUG("unknown feature %u", pos->feat_num);
return -1;
}
}
if (dccp_insert_fn_opt(skb, opt, pos->feat_num, ptr, len, rpt))
return -1;
if (pos->needs_mandatory && dccp_insert_option_mandatory(skb))
return -1;
/*
* Enter CHANGING after transmitting the Change option (6.6.2).
*/
if (pos->state == FEAT_INITIALISING)
pos->state = FEAT_CHANGING;
}
return 0;
}
/**
* __feat_register_nn - Register new NN value on socket
* @fn: feature-negotiation list to register with