[DCCP]: Socket support for feature negotiation and its initialisation
This provides feature-negotiation initialisation for both DCCP sockets and
DCCP request_sockets, to support feature negotiation during connection setup.
It also resolves a FIXME regarding the congestion control initialisation.
Signed-off-by: Gerrit Renker <gerrit@xxxxxxxxxxxxxx>
---
include/linux/dccp.h | 4 ++++
net/dccp/dccp.h | 3 ++-
net/dccp/feat.c | 19 +++++++++++++++++++
net/dccp/feat.h | 1 +
net/dccp/input.c | 2 --
net/dccp/ipv4.c | 3 ++-
net/dccp/ipv6.c | 3 ++-
net/dccp/minisocks.c | 7 ++++++-
net/dccp/proto.c | 1 +
9 files changed, 37 insertions(+), 6 deletions(-)
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -424,6 +424,7 @@ struct dccp_ts_echo {
* @dreq_iss: initial sequence number sent on the Response (RFC 4340, 7.1)
* @dreq_isr: initial sequence number received on the Request
* @dreq_service: service code present on the Request (there is just one)
+ * @dreq_featneg: feature negotiation options for this connection
* @dreq_tstamp: most recent timestamp received during connection setup
*/
struct dccp_request_sock {
@@ -431,6 +432,7 @@ struct dccp_request_sock {
__u64 dreq_iss;
__u64 dreq_isr;
__be32 dreq_service;
+ struct list_head dreq_featneg;
struct dccp_ts_echo *dreq_tstamp;
};
@@ -506,6 +508,7 @@ struct dccp_ackvec;
* @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
* @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
* @dccps_minisock - associated minisock (accessed via dccp_msk)
+ * @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
* @dccps_hc_rx_ackvec - rx half connection ack vector
* @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
* @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
@@ -542,6 +545,7 @@ struct dccp_sock {
__u32 dccps_mss_cache;
unsigned long dccps_rate_last;
struct dccp_minisock dccps_minisock;
+ struct list_head dccps_featneg;
struct dccp_ackvec *dccps_hc_rx_ackvec;
struct ccid *dccps_hc_rx_ccid;
struct ccid *dccps_hc_tx_ccid;
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -177,6 +177,7 @@ int dccp_init_sock(struct sock *sk, cons
dccp_minisock_init(&dp->dccps_minisock);
+ INIT_LIST_HEAD(&dp->dccps_featneg);
/*
* FIXME: We're hardcoding the CCID, and doing this at this point makes
* the listening (master) sock get CCID control blocks, which is not
--- a/net/dccp/feat.h
+++ b/net/dccp/feat.h
@@ -95,6 +95,7 @@ extern int dccp_feat_confirm_recv(struc
u8 *val, u8 len);
extern void dccp_feat_clean(struct dccp_minisock *dmsk);
extern int dccp_feat_clone(struct sock *oldsk, struct sock *newsk);
+extern int dccp_feat_clone_list(struct list_head const *, struct list_head *);
extern int dccp_feat_init(struct dccp_minisock *dmsk);
#endif /* _DCCP_FEAT_H */
--- a/net/dccp/feat.c
+++ b/net/dccp/feat.c
@@ -273,6 +273,25 @@ void dccp_feat_list_purge(struct list_he
EXPORT_SYMBOL_GPL(dccp_feat_list_purge);
+/* generate @to as full clone of @from - @to must not contain any nodes */
+int dccp_feat_clone_list(struct list_head const *from, struct list_head *to)
+{
+ struct dccp_feat_entry *entry, *new;
+
+ INIT_LIST_HEAD(to);
+ list_for_each_entry(entry, from, node) {
+ new = dccp_feat_clone_entry(entry);
+ if (new == NULL)
+ goto cloning_failed;
+ list_add_tail(&new->node, to);
+ }
+ return 0;
+
+cloning_failed:
+ dccp_feat_list_purge(to);
+ return -ENOMEM;
+}
+
int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
u8 *val, u8 len, gfp_t gfp)
{
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -236,7 +236,8 @@ extern const char *dccp_state_name(const
extern void dccp_set_state(struct sock *sk, const int state);
extern void dccp_done(struct sock *sk);
-extern void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb);
+extern int dccp_reqsk_init(struct request_sock *rq, struct dccp_sock const *dp,
+ struct sk_buff const *skb);
extern int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -124,6 +124,7 @@ struct sock *dccp_create_openreq_child(s
newdp->dccps_service = dreq->dreq_service;
newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
+ INIT_LIST_HEAD(&newdp->dccps_featneg);
if (dccp_feat_clone(sk, newsk))
goto out_free;
@@ -302,7 +303,8 @@ void dccp_reqsk_send_ack(struct sk_buff
EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack);
-void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb)
+int dccp_reqsk_init(struct request_sock *req,
+ struct dccp_sock const *dp, struct sk_buff const *skb)
{
struct dccp_request_sock *dreq = dccp_rsk(req);
@@ -310,6 +312,9 @@ void dccp_reqsk_init(struct request_sock
inet_rsk(req)->acked = 0;
req->rcv_wnd = sysctl_dccp_feat_sequence_window;
dreq->dreq_tstamp = NULL;
+
+ /* inherit feature negotiation options from listening socket */
+ return dccp_feat_clone_list(&dp->dccps_featneg, &dreq->dreq_featneg);
}
EXPORT_SYMBOL_GPL(dccp_reqsk_init);
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -606,7 +606,8 @@ int dccp_v4_conn_request(struct sock *sk
if (req == NULL)
goto drop;
- dccp_reqsk_init(req, skb);
+ if (dccp_reqsk_init(req, dccp_sk(sk), skb))
+ goto drop_and_free;
dreq = dccp_rsk(req);
if (dccp_parse_options(sk, dreq, skb))
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -419,7 +419,8 @@ static int dccp_v6_conn_request(struct s
if (req == NULL)
goto drop;
- dccp_reqsk_init(req, skb);
+ if (dccp_reqsk_init(req, dccp_sk(sk), skb))
+ goto drop_and_free;
dreq = dccp_rsk(req);
if (dccp_parse_options(sk, dreq, skb))
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -511,8 +511,6 @@ int dccp_rcv_state_process(struct sock *
if (inet_csk(sk)->icsk_af_ops->conn_request(sk,
skb) < 0)
return 1;
-
- /* FIXME: do congestion control initialization */
goto discard;
}
if (dh->dccph_type == DCCP_PKT_RESET)
-
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