From 7d43d1a0f2cf535167ec7247f110a1f85cecac43 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Tue, 4 Nov 2008 23:43:47 -0800 Subject: dccp: Implement lookup table for feature-negotiation information A lookup table for feature-negotiation information, extracted from RFC 4340/42, is provided by this patch. All currently known features can be found in this table, along with their feature location, their default value, and type. Signed-off-by: Gerrit Renker Acked-by: Ian McDonald Acked-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- include/linux/dccp.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'include/linux/dccp.h') diff --git a/include/linux/dccp.h b/include/linux/dccp.h index 6080449fbec..3978aff197d 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -176,19 +176,20 @@ enum { }; /* DCCP features (RFC 4340 section 6.4) */ -enum { +enum dccp_feature_numbers { DCCPF_RESERVED = 0, DCCPF_CCID = 1, - DCCPF_SHORT_SEQNOS = 2, /* XXX: not yet implemented */ + DCCPF_SHORT_SEQNOS = 2, DCCPF_SEQUENCE_WINDOW = 3, - DCCPF_ECN_INCAPABLE = 4, /* XXX: not yet implemented */ + DCCPF_ECN_INCAPABLE = 4, DCCPF_ACK_RATIO = 5, DCCPF_SEND_ACK_VECTOR = 6, DCCPF_SEND_NDP_COUNT = 7, DCCPF_MIN_CSUM_COVER = 8, - DCCPF_DATA_CHECKSUM = 9, /* XXX: not yet implemented */ + DCCPF_DATA_CHECKSUM = 9, /* 10-127 reserved */ DCCPF_MIN_CCID_SPECIFIC = 128, + DCCPF_SEND_LEV_RATE = 192, /* RFC 4342, sec. 8.4 */ DCCPF_MAX_CCID_SPECIFIC = 255, }; -- cgit v1.2.3 From ac75773c2742d82cbcb078708df406e9017224b7 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Tue, 4 Nov 2008 23:55:49 -0800 Subject: dccp: Per-socket initialisation of feature negotiation 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. Thanks to Wei Yongjun for help with the IPv6 side of this patch. Signed-off-by: Gerrit Renker Acked-by: Ian McDonald Signed-off-by: David S. Miller --- include/linux/dccp.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/dccp.h') diff --git a/include/linux/dccp.h b/include/linux/dccp.h index 3978aff197d..484b8a1fb02 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -412,6 +412,7 @@ extern void dccp_minisock_init(struct dccp_minisock *dmsk); * @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 * The following two fields are analogous to the ones in dccp_sock: * @dreq_timestamp_echo: last received timestamp to echo (13.1) * @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo @@ -421,6 +422,7 @@ struct dccp_request_sock { __u64 dreq_iss; __u64 dreq_isr; __be32 dreq_service; + struct list_head dreq_featneg; __u32 dreq_timestamp_echo; __u32 dreq_timestamp_time; }; @@ -498,6 +500,7 @@ 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) @@ -535,6 +538,7 @@ struct dccp_sock { __u64 dccps_ndp_count:48; 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; -- cgit v1.2.3 From d90ebcbfa7f5a8b4e20518c9f94c5c4e4cd3c2e5 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Wed, 12 Nov 2008 00:47:26 -0800 Subject: dccp: Query supported CCIDs This provides a data structure to record which CCIDs are locally supported and three accessor functions: - a test function for internal use which is used to validate CCID requests made by the user; - a copy function so that the list can be used for feature-negotiation; - documented getsockopt() support so that the user can query capabilities. The data structure is a table which is filled in at compile-time with the list of available CCIDs (which in turn depends on the Kconfig choices). Using the copy function for cloning the list of supported CCIDs is useful for feature negotiation, since the negotiation is now with the full list of available CCIDs (e.g. {2, 3}) instead of the default value {2}. This means negotiation will not fail if the peer requests to use CCID3 instead of CCID2. Signed-off-by: Gerrit Renker Acked-by: Ian McDonald Signed-off-by: David S. Miller --- include/linux/dccp.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/dccp.h') diff --git a/include/linux/dccp.h b/include/linux/dccp.h index 484b8a1fb02..d3ac1bde60b 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -209,6 +209,7 @@ struct dccp_so_feat { #define DCCP_SOCKOPT_SERVER_TIMEWAIT 6 #define DCCP_SOCKOPT_SEND_CSCOV 10 #define DCCP_SOCKOPT_RECV_CSCOV 11 +#define DCCP_SOCKOPT_AVAILABLE_CCIDS 12 #define DCCP_SOCKOPT_CCID_RX_INFO 128 #define DCCP_SOCKOPT_CCID_TX_INFO 192 -- cgit v1.2.3 From 49aebc66d6b896f9c7c5739d85c4548c00015aa7 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Sun, 16 Nov 2008 22:51:23 -0800 Subject: dccp: Deprecate old setsockopt framework The previous setsockopt interface, which passed socket options via struct dccp_so_feat, is complicated/difficult to use. Continuing to support it leads to ugly code since the old approach did not distinguish between NN and SP values. This patch removes the old setsockopt interface and replaces it with two new functions to register NN/SP values for feature negotiation. These are essentially wrappers around the internal __feat_register functions, with checking added to avoid * wrong usage (type); * changing values while the connection is in progress. Signed-off-by: Gerrit Renker Signed-off-by: David S. Miller --- include/linux/dccp.h | 7 ------- 1 file changed, 7 deletions(-) (limited to 'include/linux/dccp.h') diff --git a/include/linux/dccp.h b/include/linux/dccp.h index d3ac1bde60b..6eaaca9b037 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -193,13 +193,6 @@ enum dccp_feature_numbers { DCCPF_MAX_CCID_SPECIFIC = 255, }; -/* this structure is argument to DCCP_SOCKOPT_CHANGE_X */ -struct dccp_so_feat { - __u8 dccpsf_feat; - __u8 __user *dccpsf_val; - __u8 dccpsf_len; -}; - /* DCCP socket options */ #define DCCP_SOCKOPT_PACKET_SIZE 1 /* XXX deprecated, without effect */ #define DCCP_SOCKOPT_SERVICE 2 -- cgit v1.2.3 From 29450559849da7066813601effb7666966869853 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Sun, 16 Nov 2008 22:53:48 -0800 Subject: dccp: Feature negotiation for minimum-checksum-coverage This provides feature negotiation for server minimum checksum coverage which so far has been missing. Since sender/receiver coverage values range only from 0...15, their type has also been reduced in size from u16 to u4. Feature-negotiation options are now generated for both sender and receiver coverage, i.e. when the peer has `forgotten' to enable partial coverage then feature negotiation will automatically enable (negotiate) the partial coverage value for this connection. Signed-off-by: Gerrit Renker Acked-by: Ian McDonald Signed-off-by: David S. Miller --- include/linux/dccp.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/dccp.h') diff --git a/include/linux/dccp.h b/include/linux/dccp.h index 6eaaca9b037..5a5a89935db 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -527,8 +527,8 @@ struct dccp_sock { __u32 dccps_timestamp_time; __u16 dccps_l_ack_ratio; __u16 dccps_r_ack_ratio; - __u16 dccps_pcslen; - __u16 dccps_pcrlen; + __u8 dccps_pcslen:4; + __u8 dccps_pcrlen:4; __u64 dccps_ndp_count:48; unsigned long dccps_rate_last; struct dccp_minisock dccps_minisock; -- cgit v1.2.3 From dd9c0e363cef32b7d6f23d4c87e8dfe4f91fd1c5 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Sun, 16 Nov 2008 22:55:08 -0800 Subject: dccp: Deprecate Ack Ratio sysctl This patch deprecates the Ack Ratio sysctl, since * Ack Ratio is entirely ignored by CCID-3 and CCID-4, * Ack Ratio currently doesn't work in CCID-2 (i.e. is always set to 1); * even if it would work in CCID-2, there is no point for a user to change it: - Ack Ratio is constrained by cwnd (RFC 4341, 6.1.2), - if Ack Ratio > cwnd, the system resorts to spurious RTO timeouts (since waiting for Acks which will never arrive in this window), - cwnd is not a user-configurable value. The only reasonable place for Ack Ratio is to print it for debugging. It is planned to do this later on, as part of e.g. dccp_probe. With this patch Ack Ratio is now under full control of feature negotiation: * Ack Ratio is resolved as a dependency of the selected CCID; * if the chosen CCID supports it (i.e. CCID == CCID-2), Ack Ratio is set to the default of 2, following RFC 4340, 11.3 - "New connections start with Ack Ratio 2 for both endpoints"; * what happens then is part of another patch set, since it concerns the dynamic update of Ack Ratio while the connection is in full flight. Thanks to Tomasz Grobelny for discussion leading up to this patch. Signed-off-by: Gerrit Renker Acked-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- include/linux/dccp.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/dccp.h') diff --git a/include/linux/dccp.h b/include/linux/dccp.h index 5a5a89935db..eda389ce04f 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -368,7 +368,6 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb) * @dccpms_ccid - Congestion Control Id (CCID) (section 10) * @dccpms_send_ack_vector - Send Ack Vector Feature (section 11.5) * @dccpms_send_ndp_count - Send NDP Count Feature (7.7.2) - * @dccpms_ack_ratio - Ack Ratio Feature (section 11.3) * @dccpms_pending - List of features being negotiated * @dccpms_conf - */ @@ -378,7 +377,6 @@ struct dccp_minisock { __u8 dccpms_tx_ccid; __u8 dccpms_send_ack_vector; __u8 dccpms_send_ndp_count; - __u8 dccpms_ack_ratio; struct list_head dccpms_pending; struct list_head dccpms_conf; }; -- cgit v1.2.3 From b20a9c24d5c5d466d7e4a25c6f1bedbd2d16ad4f Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Sun, 23 Nov 2008 16:02:31 -0800 Subject: dccp: Set per-connection CCIDs via socket options With this patch, TX/RX CCIDs can now be changed on a per-connection basis, which overrides the defaults set by the global sysctl variables for TX/RX CCIDs. To make full use of this facility, the remaining patches of this patch set are needed, which track dependencies and activate negotiated feature values. Signed-off-by: Gerrit Renker Signed-off-by: David S. Miller --- include/linux/dccp.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/dccp.h') diff --git a/include/linux/dccp.h b/include/linux/dccp.h index eda389ce04f..6a72ff52a8a 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -168,6 +168,8 @@ enum { DCCPO_MIN_CCID_SPECIFIC = 128, DCCPO_MAX_CCID_SPECIFIC = 255, }; +/* maximum size of a single TLV-encoded DCCP option (sans type/len bytes) */ +#define DCCP_SINGLE_OPT_MAXLEN 253 /* DCCP CCIDS */ enum { @@ -203,6 +205,9 @@ enum dccp_feature_numbers { #define DCCP_SOCKOPT_SEND_CSCOV 10 #define DCCP_SOCKOPT_RECV_CSCOV 11 #define DCCP_SOCKOPT_AVAILABLE_CCIDS 12 +#define DCCP_SOCKOPT_CCID 13 +#define DCCP_SOCKOPT_TX_CCID 14 +#define DCCP_SOCKOPT_RX_CCID 15 #define DCCP_SOCKOPT_CCID_RX_INFO 128 #define DCCP_SOCKOPT_CCID_TX_INFO 192 -- cgit v1.2.3 From 0049bab5e765aa74cf767a834fa336e19453fc5e Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Mon, 8 Dec 2008 01:18:05 -0800 Subject: dccp: Remove obsolete parts of the old CCID interface The TX/RX CCIDs of the minisock are now redundant: similar to the Ack Vector case, their value equals initially that of the sysctl, but at the end of feature negotiation may be something different. The old interface removed by this patch thus has been replaced by the newer interface to dynamically query the currently loaded CCIDs. Also removed are the constructors for the TX CCID and the RX CCID, since the switch "rx <-> non-rx" is done by the handler in minisocks.c (and the handler is the only place in the code where CCIDs are loaded). Signed-off-by: Gerrit Renker Acked-by: Ian McDonald Signed-off-by: David S. Miller --- include/linux/dccp.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'include/linux/dccp.h') diff --git a/include/linux/dccp.h b/include/linux/dccp.h index 6a72ff52a8a..46daea312d9 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -370,7 +370,6 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb) * Will be used to pass the state from dccp_request_sock to dccp_sock. * * @dccpms_sequence_window - Sequence Window Feature (section 7.5.2) - * @dccpms_ccid - Congestion Control Id (CCID) (section 10) * @dccpms_send_ack_vector - Send Ack Vector Feature (section 11.5) * @dccpms_send_ndp_count - Send NDP Count Feature (7.7.2) * @dccpms_pending - List of features being negotiated @@ -378,8 +377,6 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb) */ struct dccp_minisock { __u64 dccpms_sequence_window; - __u8 dccpms_rx_ccid; - __u8 dccpms_tx_ccid; __u8 dccpms_send_ack_vector; __u8 dccpms_send_ndp_count; struct list_head dccpms_pending; -- cgit v1.2.3 From 4098dce5be537a157eed4a326efd464109825b8b Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Mon, 8 Dec 2008 01:18:37 -0800 Subject: dccp: Remove manual influence on NDP Count feature Updating the NDP count feature is handled automatically now: * for CCID-2 it is disabled, since the code does not use NDP counts; * for CCID-3 it is enabled, as NDP counts are used to determine loss lengths. Allowing the user to change NDP values leads to unpredictable and failing behaviour, since it is then possible to disable NDP counts even when they are needed (e.g. in CCID-3). This means that only those user settings are sensible that agree with the values for Send NDP Count implied by the choice of CCID. But those settings are already activated by the feature negotiation (CCID dependency tracking), hence this form of support is redundant. At startup the initialisation of the NDP count feature uses the default value of 0, which is done implicitly by the zeroing-out of the socket when it is allocated. If the choice of CCID or feature negotiation enables NDP count, this will then be updated via the NDP activation handler. Signed-off-by: Gerrit Renker Acked-by: Ian McDonald Signed-off-by: David S. Miller --- include/linux/dccp.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/dccp.h') diff --git a/include/linux/dccp.h b/include/linux/dccp.h index 46daea312d9..60e94438ead 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -371,14 +371,12 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb) * * @dccpms_sequence_window - Sequence Window Feature (section 7.5.2) * @dccpms_send_ack_vector - Send Ack Vector Feature (section 11.5) - * @dccpms_send_ndp_count - Send NDP Count Feature (7.7.2) * @dccpms_pending - List of features being negotiated * @dccpms_conf - */ struct dccp_minisock { __u64 dccpms_sequence_window; __u8 dccpms_send_ack_vector; - __u8 dccpms_send_ndp_count; struct list_head dccpms_pending; struct list_head dccpms_conf; }; @@ -490,6 +488,7 @@ struct dccp_ackvec; * @dccps_r_ack_ratio - feature-remote Ack Ratio * @dccps_pcslen - sender partial checksum coverage (via sockopt) * @dccps_pcrlen - receiver partial checksum coverage (via sockopt) + * @dccps_send_ndp_count - local Send NDP Count feature (7.7.2) * @dccps_ndp_count - number of Non Data Packets since last data packet * @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) @@ -529,6 +528,7 @@ struct dccp_sock { __u16 dccps_r_ack_ratio; __u8 dccps_pcslen:4; __u8 dccps_pcrlen:4; + __u8 dccps_send_ndp_count:1; __u64 dccps_ndp_count:48; unsigned long dccps_rate_last; struct dccp_minisock dccps_minisock; -- cgit v1.2.3 From 6fdd34d43bff8be9bb925b49d87a0ee144d2ab07 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Mon, 8 Dec 2008 01:19:06 -0800 Subject: dccp ccid-2: Phase out the use of boolean Ack Vector sysctl This removes the use of the sysctl and the minisock variable for the Send Ack Vector feature, as it now is handled fully dynamically via feature negotiation (i.e. when CCID-2 is enabled, Ack Vectors are automatically enabled as per RFC 4341, 4.). Using a sysctl in parallel to this implementation would open the door to crashes, since much of the code relies on tests of the boolean minisock / sysctl variable. Thus, this patch replaces all tests of type if (dccp_msk(sk)->dccpms_send_ack_vector) /* ... */ with if (dp->dccps_hc_rx_ackvec != NULL) /* ... */ The dccps_hc_rx_ackvec is allocated by the dccp_hdlr_ackvec() when feature negotiation concluded that Ack Vectors are to be used on the half-connection. Otherwise, it is NULL (due to dccp_init_sock/dccp_create_openreq_child), so that the test is a valid one. The activation handler for Ack Vectors is called as soon as the feature negotiation has concluded at the * server when the Ack marking the transition RESPOND => OPEN arrives; * client after it has sent its ACK, marking the transition REQUEST => PARTOPEN. Adding the sequence number of the Response packet to the Ack Vector has been removed, since (a) connection establishment implies that the Response has been received; (b) the CCIDs only look at packets received in the (PART)OPEN state, i.e. this entry will always be ignored; (c) it can not be used for anything useful - to detect loss for instance, only packets received after the loss can serve as pseudo-dupacks. There was a FIXME to change the error code when dccp_ackvec_add() fails. I removed this after finding out that: * the check whether ackno < ISN is already made earlier, * this Response is likely the 1st packet with an Ackno that the client gets, * so when dccp_ackvec_add() fails, the reason is likely not a packet error. Signed-off-by: Gerrit Renker Acked-by: Ian McDonald Signed-off-by: David S. Miller --- include/linux/dccp.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'include/linux/dccp.h') diff --git a/include/linux/dccp.h b/include/linux/dccp.h index 60e94438ead..61734e27abb 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -360,7 +360,6 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb) #define DCCPF_INITIAL_SEQUENCE_WINDOW 100 #define DCCPF_INITIAL_ACK_RATIO 2 #define DCCPF_INITIAL_CCID DCCPC_CCID2 -#define DCCPF_INITIAL_SEND_ACK_VECTOR 1 /* FIXME: for now we're default to 1 but it should really be 0 */ #define DCCPF_INITIAL_SEND_NDP_COUNT 1 @@ -370,13 +369,11 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb) * Will be used to pass the state from dccp_request_sock to dccp_sock. * * @dccpms_sequence_window - Sequence Window Feature (section 7.5.2) - * @dccpms_send_ack_vector - Send Ack Vector Feature (section 11.5) * @dccpms_pending - List of features being negotiated * @dccpms_conf - */ struct dccp_minisock { __u64 dccpms_sequence_window; - __u8 dccpms_send_ack_vector; struct list_head dccpms_pending; struct list_head dccpms_conf; }; -- cgit v1.2.3