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-rw-r--r--net/dccp/feat.h2
-rw-r--r--net/dccp/options.c91
2 files changed, 33 insertions, 60 deletions
diff --git a/net/dccp/feat.h b/net/dccp/feat.h
index 602e0a7294b..8e863839ed9 100644
--- a/net/dccp/feat.h
+++ b/net/dccp/feat.h
@@ -140,4 +140,6 @@ extern void dccp_encode_value_var(const u64 value, u8 *to, const u8 len);
extern u64 dccp_decode_value_var(const u8 *bf, const u8 len);
extern int dccp_insert_option_mandatory(struct sk_buff *skb);
+extern int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
+ u8 *val, u8 len, bool repeat_first);
#endif /* _DCCP_FEAT_H */
diff --git a/net/dccp/options.c b/net/dccp/options.c
index 676d53065de..bfa1cb8f3ef 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -482,23 +482,46 @@ int dccp_insert_option_mandatory(struct sk_buff *skb)
return 0;
}
-static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
- u8 *val, u8 len)
+/**
+ * dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb
+ * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R
+ * @feat: one out of %dccp_feature_numbers
+ * @val: NN value or SP array (preferred element first) to copy
+ * @len: true length of @val in bytes (excluding first element repetition)
+ * @repeat_first: whether to copy the first element of @val twice
+ * The last argument is used to construct Confirm options, where the preferred
+ * value and the preference list appear separately (RFC 4340, 6.3.1). Preference
+ * lists are kept such that the preferred entry is always first, so we only need
+ * to copy twice, and avoid the overhead of cloning into a bigger array.
+ */
+int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
+ u8 *val, u8 len, bool repeat_first)
{
- u8 *to;
+ u8 tot_len, *to;
- if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
- DCCP_WARN("packet too small for feature %d option!\n", feat);
+ /* take the `Feature' field and possible repetition into account */
+ if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) {
+ DCCP_WARN("length %u for feature %u too large\n", len, feat);
return -1;
}
- DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
+ if (unlikely(val == NULL || len == 0))
+ len = repeat_first = 0;
+ tot_len = 3 + repeat_first + len;
+
+ if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) {
+ DCCP_WARN("packet too small for feature %d option!\n", feat);
+ return -1;
+ }
+ DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len;
- to = skb_push(skb, len + 3);
+ to = skb_push(skb, tot_len);
*to++ = type;
- *to++ = len + 3;
+ *to++ = tot_len;
*to++ = feat;
+ if (repeat_first)
+ *to++ = *val;
if (len)
memcpy(to, val, len);
@@ -508,51 +531,6 @@ static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
return 0;
}
-static int dccp_insert_options_feat(struct sock *sk, struct sk_buff *skb)
-{
- struct dccp_minisock *dmsk = dccp_msk(sk);
- struct dccp_opt_pend *opt, *next;
- int change = 0;
-
- /* confirm any options [NN opts] */
- list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
- dccp_insert_feat_opt(skb, opt->dccpop_type,
- opt->dccpop_feat, opt->dccpop_val,
- opt->dccpop_len);
- /* fear empty confirms */
- if (opt->dccpop_val)
- kfree(opt->dccpop_val);
- kfree(opt);
- }
- INIT_LIST_HEAD(&dmsk->dccpms_conf);
-
- /* see which features we need to send */
- list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
- /* see if we need to send any confirm */
- if (opt->dccpop_sc) {
- dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
- opt->dccpop_feat,
- opt->dccpop_sc->dccpoc_val,
- opt->dccpop_sc->dccpoc_len);
-
- BUG_ON(!opt->dccpop_sc->dccpoc_val);
- kfree(opt->dccpop_sc->dccpoc_val);
- kfree(opt->dccpop_sc);
- opt->dccpop_sc = NULL;
- }
-
- /* any option not confirmed, re-send it */
- if (!opt->dccpop_conf) {
- dccp_insert_feat_opt(skb, opt->dccpop_type,
- opt->dccpop_feat, opt->dccpop_val,
- opt->dccpop_len);
- change++;
- }
- }
-
- return 0;
-}
-
/* The length of all options needs to be a multiple of 4 (5.8) */
static void dccp_insert_option_padding(struct sk_buff *skb)
{
@@ -589,13 +567,6 @@ int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
dp->dccps_hc_rx_insert_options = 0;
}
- /* Feature negotiation */
- /* Data packets can't do feat negotiation */
- if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA &&
- DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATAACK &&
- dccp_insert_options_feat(sk, skb))
- return -1;
-
/*
* Obtain RTT sample from Request/Response exchange.
* This is currently used in CCID 3 initialisation.