2 files changed, 58 insertions, 0 deletions
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index 94ae6d41d724..0a07b2e24e62 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -436,6 +436,7 @@ static inline int dccp_ack_pending(const struct sock *sk)
               inet_csk_ack_scheduled(sk);
 }
+extern int  dccp_feat_signal_nn_change(struct sock *sk, u8 feat, u64 nn_val);
 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*,
diff --git a/net/dccp/feat.c b/net/dccp/feat.c
index 3abacad0b224..5be8b85ac74b 100644
--- a/net/dccp/feat.c
+++ b/net/dccp/feat.c
@@ -13,6 +13,7 @@
 *  -----------
 *  o Feature negotiation is coordinated with connection setup (as in TCP), wild
 *    changes of parameters of an established connection are not supported.
+ *  o Changing NN values (Ack Ratio only) is supported in state OPEN/PARTOPEN.
 *  o All currently known SP features have 1-byte quantities. If in the future
 *    extensions of RFCs 4340..42 define features with item lengths larger than
 *    one byte, a feature-specific extension of the code will be required.
@@ -337,6 +338,20 @@ static int __dccp_feat_activate(struct sock *sk, const int idx,
        return dccp_feat_table[idx].activation_hdlr(sk, val, rx);
 }
+/**
+ * dccp_feat_activate  -  Activate feature value on socket
+ * @sk: fully connected DCCP socket (after handshake is complete)
+ * @feat_num: feature to activate, one of %dccp_feature_numbers
+ * @local: whether local (1) or remote (0) @feat_num is meant
+ * @fval: the value (SP or NN) to activate, or NULL to use the default value
+ * For general use this function is preferable over __dccp_feat_activate().
+ */
+static int dccp_feat_activate(struct sock *sk, u8 feat_num, bool local,
+                              dccp_feat_val const *fval)
+{
+        return __dccp_feat_activate(sk, dccp_feat_index(feat_num), local, fval);
+}
 /* Test for "Req'd" feature (RFC 4340, 6.4) */
 static inline int dccp_feat_must_be_understood(u8 feat_num)
 {
@@ -734,6 +749,48 @@ int dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val)
        return __feat_register_nn(&dccp_sk(sk)->dccps_featneg, feat, 0, val);
 }
+/**
+ * dccp_feat_signal_nn_change  -  Update NN values for an established connection
+ * @sk: DCCP socket of an established connection
+ * @feat: NN feature number from %dccp_feature_numbers
+ * @nn_val: the new value to use
+ * This function is used to communicate NN updates out-of-band. The difference
+ * to feature negotiation during connection setup is that values are activated
+ * immediately after validation, i.e. we don't wait for the Confirm: either the
+ * value is accepted by the peer (and then the waiting is futile), or it is not
+ * (Reset or empty Confirm). We don't accept empty Confirms - transmitted values
+ * are validated, and the peer "MUST accept any valid value" (RFC 4340, 6.3.2).
+ */
+int dccp_feat_signal_nn_change(struct sock *sk, u8 feat, u64 nn_val)
+{
+        struct list_head *fn = &dccp_sk(sk)->dccps_featneg;
+        dccp_feat_val fval = { .nn = nn_val };
+        struct dccp_feat_entry *entry;
+        if (sk->sk_state != DCCP_OPEN && sk->sk_state != DCCP_PARTOPEN)
+                return 0;
+        if (dccp_feat_type(feat) != FEAT_NN ||
+            !dccp_feat_is_valid_nn_val(feat, nn_val))
+                return -EINVAL;
+        entry = dccp_feat_list_lookup(fn, feat, 1);
+        if (entry != NULL) {
+                dccp_pr_debug("Ignoring %llu, entry %llu exists in state %s\n",
+                              (unsigned long long)nn_val,
+                              (unsigned long long)entry->val.nn,
+                              dccp_feat_sname[entry->state]);
+                return 0;
+        }
+        if (dccp_feat_activate(sk, feat, 1, &fval))
+                return -EADV;
+        inet_csk_schedule_ack(sk);
+        return dccp_feat_push_change(fn, feat, 1, 0, &fval);
+}
+EXPORT_SYMBOL_GPL(dccp_feat_signal_nn_change);
 /*
 *      Tracking features whose value depend on the choice of CCID
 *

diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h index 94ae6d41d724..0a07b2e24e62 100644 --- a/net/dccp/dccp.h +++ b/net/dccp/dccp.h
@@ -436,6 +436,7 @@ static inline int dccp_ack_pending(const struct sock *sk)
436	inet_csk_ack_scheduled(sk);	436	inet_csk_ack_scheduled(sk);
437	}	437	}
438		438
		439	extern int dccp_feat_signal_nn_change(struct sock *sk, u8 feat, u64 nn_val);
439	extern int dccp_feat_finalise_settings(struct dccp_sock *dp);	440	extern int dccp_feat_finalise_settings(struct dccp_sock *dp);
440	extern int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq);	441	extern int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq);
441	extern int dccp_feat_insert_opts(struct dccp_sock, struct dccp_request_sock,	442	extern int dccp_feat_insert_opts(struct dccp_sock, struct dccp_request_sock,


diff --git a/net/dccp/feat.c b/net/dccp/feat.c index 3abacad0b224..5be8b85ac74b 100644 --- a/net/dccp/feat.c +++ b/net/dccp/feat.c
@@ -13,6 +13,7 @@
13	* -----------	13	* -----------
14	* o Feature negotiation is coordinated with connection setup (as in TCP), wild	14	* o Feature negotiation is coordinated with connection setup (as in TCP), wild
15	* changes of parameters of an established connection are not supported.	15	* changes of parameters of an established connection are not supported.
		16	* o Changing NN values (Ack Ratio only) is supported in state OPEN/PARTOPEN.
16	* o All currently known SP features have 1-byte quantities. If in the future	17	* o All currently known SP features have 1-byte quantities. If in the future
17	* extensions of RFCs 4340..42 define features with item lengths larger than	18	* extensions of RFCs 4340..42 define features with item lengths larger than
18	* one byte, a feature-specific extension of the code will be required.	19	* one byte, a feature-specific extension of the code will be required.
@@ -337,6 +338,20 @@ static int __dccp_feat_activate(struct sock *sk, const int idx,
337	return dccp_feat_table[idx].activation_hdlr(sk, val, rx);	338	return dccp_feat_table[idx].activation_hdlr(sk, val, rx);
338	}	339	}
339		340
		341	/**
		342	* dccp_feat_activate - Activate feature value on socket
		343	* @sk: fully connected DCCP socket (after handshake is complete)
		344	* @feat_num: feature to activate, one of %dccp_feature_numbers
		345	* @local: whether local (1) or remote (0) @feat_num is meant
		346	* @fval: the value (SP or NN) to activate, or NULL to use the default value
		347	* For general use this function is preferable over __dccp_feat_activate().
		348	*/
		349	static int dccp_feat_activate(struct sock *sk, u8 feat_num, bool local,
		350	dccp_feat_val const *fval)
		351	{
		352	return __dccp_feat_activate(sk, dccp_feat_index(feat_num), local, fval);
		353	}
		354
340	/* Test for "Req'd" feature (RFC 4340, 6.4) */	355	/* Test for "Req'd" feature (RFC 4340, 6.4) */
341	static inline int dccp_feat_must_be_understood(u8 feat_num)	356	static inline int dccp_feat_must_be_understood(u8 feat_num)
342	{	357	{
@@ -734,6 +749,48 @@ int dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val)
734	return __feat_register_nn(&dccp_sk(sk)->dccps_featneg, feat, 0, val);	749	return __feat_register_nn(&dccp_sk(sk)->dccps_featneg, feat, 0, val);
735	}	750	}
736		751
		752	/**
		753	* dccp_feat_signal_nn_change - Update NN values for an established connection
		754	* @sk: DCCP socket of an established connection
		755	* @feat: NN feature number from %dccp_feature_numbers
		756	* @nn_val: the new value to use
		757	* This function is used to communicate NN updates out-of-band. The difference
		758	* to feature negotiation during connection setup is that values are activated
		759	* immediately after validation, i.e. we don't wait for the Confirm: either the
		760	* value is accepted by the peer (and then the waiting is futile), or it is not
		761	* (Reset or empty Confirm). We don't accept empty Confirms - transmitted values
		762	* are validated, and the peer "MUST accept any valid value" (RFC 4340, 6.3.2).
		763	*/
		764	int dccp_feat_signal_nn_change(struct sock *sk, u8 feat, u64 nn_val)
		765	{
		766	struct list_head *fn = &dccp_sk(sk)->dccps_featneg;
		767	dccp_feat_val fval = { .nn = nn_val };
		768	struct dccp_feat_entry *entry;
		769
		770	if (sk->sk_state != DCCP_OPEN && sk->sk_state != DCCP_PARTOPEN)
		771	return 0;
		772
		773	if (dccp_feat_type(feat) != FEAT_NN \|\|
		774	!dccp_feat_is_valid_nn_val(feat, nn_val))
		775	return -EINVAL;
		776
		777	entry = dccp_feat_list_lookup(fn, feat, 1);
		778	if (entry != NULL) {
		779	dccp_pr_debug("Ignoring %llu, entry %llu exists in state %s\n",
		780	(unsigned long long)nn_val,
		781	(unsigned long long)entry->val.nn,
		782	dccp_feat_sname[entry->state]);
		783	return 0;
		784	}
		785
		786	if (dccp_feat_activate(sk, feat, 1, &fval))
		787	return -EADV;
		788
		789	inet_csk_schedule_ack(sk);
		790	return dccp_feat_push_change(fn, feat, 1, 0, &fval);
		791	}
		792	EXPORT_SYMBOL_GPL(dccp_feat_signal_nn_change);
		793
737	/*	794	/*
738	* Tracking features whose value depend on the choice of CCID	795	* Tracking features whose value depend on the choice of CCID
739	*	796	*