diff options
| -rw-r--r-- | net/dccp/feat.c | 77 |
1 files changed, 75 insertions, 2 deletions
diff --git a/net/dccp/feat.c b/net/dccp/feat.c index da686464462d..d53077bd40bf 100644 --- a/net/dccp/feat.c +++ b/net/dccp/feat.c @@ -718,6 +718,76 @@ static int dccp_feat_update(struct sock *sk, u8 type, u8 feat, u8 val) return 0; } +/* Select the first entry in @servlist that also occurs in @clilist (6.3.1) */ +static int dccp_feat_preflist_match(u8 *servlist, u8 slen, u8 *clilist, u8 clen) +{ + u8 c, s; + + for (s = 0; s < slen; s++) + for (c = 0; c < clen; c++) + if (servlist[s] == clilist[c]) + return servlist[s]; + return -1; +} + +/** + * dccp_feat_prefer - Move preferred entry to the start of array + * Reorder the @array_len elements in @array so that @preferred_value comes + * first. Returns >0 to indicate that @preferred_value does occur in @array. + */ +static u8 dccp_feat_prefer(u8 preferred_value, u8 *array, u8 array_len) +{ + u8 i, does_occur = 0; + + if (array != NULL) { + for (i = 0; i < array_len; i++) + if (array[i] == preferred_value) { + array[i] = array[0]; + does_occur++; + } + if (does_occur) + array[0] = preferred_value; + } + return does_occur; +} + +/** + * dccp_feat_reconcile - Reconcile SP preference lists + * @fval: SP list to reconcile into + * @arr: received SP preference list + * @len: length of @arr in bytes + * @is_server: whether this side is the server (and @fv is the server's list) + * @reorder: whether to reorder the list in @fv after reconciling with @arr + * When successful, > 0 is returned and the reconciled list is in @fval. + * A value of 0 means that negotiation failed (no shared entry). + */ +static int dccp_feat_reconcile(dccp_feat_val *fv, u8 *arr, u8 len, + bool is_server, bool reorder) +{ + int rc; + + if (!fv->sp.vec || !arr) { + DCCP_CRIT("NULL feature value or array"); + return 0; + } + + if (is_server) + rc = dccp_feat_preflist_match(fv->sp.vec, fv->sp.len, arr, len); + else + rc = dccp_feat_preflist_match(arr, len, fv->sp.vec, fv->sp.len); + + if (!reorder) + return rc; + if (rc < 0) + return 0; + + /* + * Reorder list: used for activating features and in dccp_insert_fn_opt. + */ + return dccp_feat_prefer(rc, fv->sp.vec, fv->sp.len); +} + +#ifdef __this_is_the_old_framework_and_will_be_removed_later_in_a_subsequent_patch static int dccp_feat_reconcile(struct sock *sk, struct dccp_opt_pend *opt, u8 *rpref, u8 rlen) { @@ -913,6 +983,7 @@ static int dccp_feat_nn(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len) return 0; } +#endif /* (later) */ static void dccp_feat_empty_confirm(struct dccp_minisock *dmsk, u8 type, u8 feature) @@ -988,12 +1059,14 @@ int dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len) switch (feature) { /* deal with SP features */ case DCCPF_CCID: - rc = dccp_feat_sp(sk, type, feature, val, len); + /* XXX Obsoleted by next patch + rc = dccp_feat_sp(sk, type, feature, val, len); */ break; /* deal with NN features */ case DCCPF_ACK_RATIO: - rc = dccp_feat_nn(sk, type, feature, val, len); + /* XXX Obsoleted by next patch + rc = dccp_feat_nn(sk, type, feature, val, len); */ break; /* XXX implement other features */ |