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-rw-r--r--net/dccp/dccp.h1
-rw-r--r--net/dccp/feat.c37
-rw-r--r--net/dccp/output.c13
3 files changed, 47 insertions, 4 deletions
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index 1881527bdcd7..e656dafb5d96 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -443,6 +443,7 @@ 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 void dccp_feat_list_purge(struct list_head *fn_list);
extern int dccp_insert_options(struct sock *sk, struct sk_buff *skb);
diff --git a/net/dccp/feat.c b/net/dccp/feat.c
index 4c4144147325..4f86a48723f6 100644
--- a/net/dccp/feat.c
+++ b/net/dccp/feat.c
@@ -166,6 +166,18 @@ static void dccp_feat_entry_destructor(struct dccp_feat_entry *entry)
* - SP values are always freshly allocated
* - list is sorted in increasing order of feature number (faster lookup)
*/
+static struct dccp_feat_entry *dccp_feat_list_lookup(struct list_head *fn_list,
+ u8 feat_num, bool is_local)
+{
+ struct dccp_feat_entry *entry;
+
+ list_for_each_entry(entry, fn_list, node)
+ if (entry->feat_num == feat_num && entry->is_local == is_local)
+ return entry;
+ else if (entry->feat_num > feat_num)
+ break;
+ return NULL;
+}
/**
* dccp_feat_entry_new - Central list update routine (called by all others)
@@ -560,6 +572,31 @@ int dccp_feat_finalise_settings(struct dccp_sock *dp)
return 0;
}
+/**
+ * dccp_feat_server_ccid_dependencies - Resolve CCID-dependent features
+ * It is the server which resolves the dependencies once the CCID has been
+ * fully negotiated. If no CCID has been negotiated, it uses the default CCID.
+ */
+int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq)
+{
+ struct list_head *fn = &dreq->dreq_featneg;
+ struct dccp_feat_entry *entry;
+ u8 is_local, ccid;
+
+ for (is_local = 0; is_local <= 1; is_local++) {
+ entry = dccp_feat_list_lookup(fn, DCCPF_CCID, is_local);
+
+ if (entry != NULL && !entry->empty_confirm)
+ ccid = entry->val.sp.vec[0];
+ else
+ ccid = dccp_feat_default_value(DCCPF_CCID);
+
+ if (dccp_feat_propagate_ccid(fn, ccid, is_local))
+ return -1;
+ }
+ return 0;
+}
+
static int dccp_feat_update_ccid(struct sock *sk, u8 type, u8 new_ccid_nr)
{
struct dccp_sock *dp = dccp_sk(sk);
diff --git a/net/dccp/output.c b/net/dccp/output.c
index 92f3f6f2ef51..fea30cdc0bee 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -339,10 +339,12 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE;
DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss;
- if (dccp_insert_options_rsk(dreq, skb)) {
- kfree_skb(skb);
- return NULL;
- }
+ /* Resolve feature dependencies resulting from choice of CCID */
+ if (dccp_feat_server_ccid_dependencies(dreq))
+ goto response_failed;
+
+ if (dccp_insert_options_rsk(dreq, skb))
+ goto response_failed;
/* Build and checksum header */
dh = dccp_zeroed_hdr(skb, dccp_header_size);
@@ -363,6 +365,9 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
inet_rsk(req)->acked = 1;
DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
return skb;
+response_failed:
+ kfree_skb(skb);
+ return NULL;
}
EXPORT_SYMBOL_GPL(dccp_make_response);