dccp: Processing Confirm options (b1ad0042) · Commits · 戴 / test

net/dccp/feat.c

+99 −1

Original line number	Diff line number	Diff line
		@@ -104,6 +104,13 @@ static int dccp_feat_default_value(u8 feat_num)
		return idx < 0 ? 0 : dccp_feat_table[idx].default_value;
		}

		/* Test for "Req'd" feature (RFC 4340, 6.4) */
		static inline int dccp_feat_must_be_understood(u8 feat_num)
		{
		return feat_num == DCCPF_CCID \|\| feat_num == DCCPF_SHORT_SEQNOS \|\|
		feat_num == DCCPF_SEQUENCE_WINDOW;
		}

		/* copy constructor, fval must not already contain allocated memory */
		static int dccp_feat_clone_sp_val(dccp_feat_val fval, u8 const val, u8 len)
		{
		@@ -1099,7 +1106,6 @@ int dccp_feat_change_recv(struct sock sk, u8 type, u8 feature, u8 val, u8 len)
		}

		EXPORT_SYMBOL_GPL(dccp_feat_change_recv);
		#endif /* (later) */

		int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
		u8 *val, u8 len)
		@@ -1154,6 +1160,7 @@ int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
		}

		EXPORT_SYMBOL_GPL(dccp_feat_confirm_recv);
		#endif /* (later) */

		void dccp_feat_clean(struct dccp_minisock *dmsk)
		{
		@@ -1349,6 +1356,93 @@ not_valid_or_not_known:
		: DCCP_RESET_CODE_OPTION_ERROR;
		}

		/**
		* dccp_feat_confirm_recv - Process received Confirm options
		* @fn: feature-negotiation list to update
		* @is_mandatory: whether @opt was preceded by a Mandatory option
		* @opt: %DCCPO_CONFIRM_L or %DCCPO_CONFIRM_R
		* @feat: one of %dccp_feature_numbers
		* @val: NN value or SP value/preference list
		* @len: length of @val in bytes
		* @server: whether this node is server (1) or client (0)
		*/
		static u8 dccp_feat_confirm_recv(struct list_head *fn, u8 is_mandatory, u8 opt,
		u8 feat, u8 *val, u8 len, const bool server)
		{
		u8 *plist, plen, type = dccp_feat_type(feat);
		const bool local = (opt == DCCPO_CONFIRM_R);
		struct dccp_feat_entry *entry = dccp_feat_list_lookup(fn, feat, local);

		if (entry == NULL) { /* nothing queued: ignore or handle error */
		if (is_mandatory && type == FEAT_UNKNOWN)
		return DCCP_RESET_CODE_MANDATORY_ERROR;

		if (!local && type == FEAT_NN) /* 6.3.2 */
		goto confirmation_failed;
		return 0;
		}

		if (entry->state != FEAT_CHANGING) /* 6.6.2 */
		return 0;

		if (len == 0) {
		if (dccp_feat_must_be_understood(feat)) /* 6.6.7 */
		goto confirmation_failed;
		/*
		* Empty Confirm during connection setup: this means reverting
		* to the `old' value, which in this case is the default. Since
		* we handle default values automatically when no other values
		* have been set, we revert to the old value by removing this
		* entry from the list.
		*/
		dccp_feat_list_pop(entry);
		return 0;
		}

		if (type == FEAT_NN) {
		if (len > sizeof(entry->val.nn))
		goto confirmation_failed;

		if (entry->val.nn == dccp_decode_value_var(val, len))
		goto confirmation_succeeded;

		DCCP_WARN("Bogus Confirm for non-existing value\n");
		goto confirmation_failed;
		}

		/*
		* Parsing SP Confirms: the first element of @val is the preferred
		* SP value which the peer confirms, the remainder depends on @len.
		* Note that only the confirmed value need to be a valid SP value.
		*/
		if (!dccp_feat_is_valid_sp_val(feat, *val))
		goto confirmation_failed;

		if (len == 1) { /* peer didn't supply a preference list */
		plist = val;
		plen = len;
		} else { /* preferred value + preference list */
		plist = val + 1;
		plen = len - 1;
		}

		/* Check whether the peer got the reconciliation right (6.6.8) */
		if (dccp_feat_reconcile(&entry->val, plist, plen, server, 0) != *val) {
		DCCP_WARN("Confirm selected the wrong value %u\n", *val);
		return DCCP_RESET_CODE_OPTION_ERROR;
		}
		entry->val.sp.vec[0] = *val;

		confirmation_succeeded:
		entry->state = FEAT_STABLE;
		return 0;

		confirmation_failed:
		DCCP_WARN("Confirmation failed\n");
		return is_mandatory ? DCCP_RESET_CODE_MANDATORY_ERROR
		: DCCP_RESET_CODE_OPTION_ERROR;
		}

		/**
		* dccp_feat_parse_options - Process Feature-Negotiation Options
		* @sk: for general use and used by the client during connection setup
		@@ -1379,6 +1473,10 @@ int dccp_feat_parse_options(struct sock sk, struct dccp_request_sock dreq,
		case DCCPO_CHANGE_R:
		return dccp_feat_change_recv(fn, mandatory, opt, feat,
		val, len, server);
		case DCCPO_CONFIRM_R:
		case DCCPO_CONFIRM_L:
		return dccp_feat_confirm_recv(fn, mandatory, opt, feat,
		val, len, server);
		}
		}
		return 0; /* ignore FN options in all other states */

net/dccp/feat.h

+0 −2

Original line number	Diff line number	Diff line
		@@ -118,8 +118,6 @@ extern int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local,
		extern int dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val);
		extern int dccp_feat_parse_options(struct sock , struct dccp_request_sock ,
		u8 mand, u8 opt, u8 feat, u8 *val, u8 len);
		extern int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
		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 );

net/dccp/options.c

+2 −14

Original line number	Diff line number	Diff line
		@@ -134,26 +134,14 @@ int dccp_parse_options(struct sock sk, struct dccp_request_sock dreq,
		dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk),
		(unsigned long long)opt_recv->dccpor_ndp);
		break;
		case DCCPO_CHANGE_L:
		case DCCPO_CHANGE_R:
		if (pkt_type == DCCP_PKT_DATA)
		case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R:
		if (pkt_type == DCCP_PKT_DATA) /* RFC 4340, 6 */
		break;
		rc = dccp_feat_parse_options(sk, dreq, mandatory, opt,
		*value, value + 1, len - 1);
		if (rc)
		goto out_featneg_failed;
		break;
		case DCCPO_CONFIRM_L:
		/* fall through */
		case DCCPO_CONFIRM_R:
		if (pkt_type == DCCP_PKT_DATA)
		break;
		if (len < 2) /* FIXME this disallows empty confirm */
		goto out_invalid_option;
		if (dccp_feat_confirm_recv(sk, opt, *value,
		value + 1, len - 1))
		goto out_invalid_option;
		break;
		case DCCPO_ACK_VECTOR_0:
		case DCCPO_ACK_VECTOR_1:
		if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */

Admin message