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2008-09-04dccp: Policy-based packet dequeueing infrastructureTomasz Grobelny
This patch adds a generic infrastructure for policy-based dequeueing of TX packets and provides two policies: * a simple FIFO policy (which is the default) and * a priority based policy (set via socket options). Both policies honour the tx_qlen sysctl for the maximum size of the write queue (can be overridden via socket options). The priority policy uses skb->priority internally to assign an u32 priority identifier, using the same ranking as SO_PRIORITY. The skb->priority field is set to 0 when the packet leaves DCCP. The priority is supplied as ancillary data using cmsg(3), the patch also provides the requisite parsing routines. Signed-off-by: Tomasz Grobelny <tomasz@grobelny.oswiecenia.net> Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-04dccp: Combine the functionality of enqeueing and cloningGerrit Renker
Realising the following call pattern, * first dccp_entail() is called to enqueue a new skb and * then skb_clone() is called to transmit a clone of that skb, this patch integrates both interrelated steps into dccp_entail(). Note: the return value of skb_clone is not checked. It may be an idea to add a warning if this occurs. In both instances, however, a timer is set for retransmission, so that cloning is re-tried via dccp_retransmit_skb(). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-04dccp: Refine the wait-for-ccid mechanismGerrit Renker
This extends the existing wait-for-ccid routine so that it may be used with different types of CCID. It further addresses the problems listed below. The code looks if the write queue is non-empty and grants the TX CCID up to `timeout' jiffies to drain the queue. It will instead purge that queue if * the delay suggested by the CCID exceeds the time budget; * a socket error occurred while waiting for the CCID; * there is a signal pending (eg. annoyed user pressed Control-C); * the CCID does not support delays (we don't know how long it will take). D e t a i l s [can be removed] ------------------------------- DCCP's sending mechanism functions a bit like non-blocking I/O: dccp_sendmsg() will enqueue up to net.dccp.default.tx_qlen packets (default=5), without waiting for them to be released to the network. Rate-based CCIDs, such as CCID3/4, can impose sending delays of up to maximally 64 seconds (t_mbi in RFC 3448). Hence the write queue may still contain packets when the application closes. Since the write queue is congestion-controlled by the CCID, draining the queue is also under control of the CCID. There are several problems that needed to be addressed: 1) The queue-drain mechanism only works with rate-based CCIDs. If CCID2 for example has a full TX queue and becomes network-limited just as the application wants to close, then waiting for CCID2 to become unblocked could lead to an indefinite delay (i.e., application "hangs"). 2) Since each TX CCID in turn uses a feedback mechanism, there may be changes in its sending policy while the queue is being drained. This can lead to further delays during which the application will not be able to terminate. 3) The minimum wait time for CCID3/4 can be expected to be the queue length times the current inter-packet delay. For example if tx_qlen=100 and a delay of 15 ms is used for each packet, then the application would have to wait for a minimum of 1.5 seconds before being allowed to exit. 4) There is no way for the user/application to control this behaviour. It would be good to use the timeout argument of dccp_close() as an upper bound. Then the maximum time that an application is willing to wait for its CCIDs to can be set via the SO_LINGER option. These problems are addressed by giving the CCID a grace period of up to the `timeout' value. The wait-for-ccid function is, as before, used when the application (a) has read all the data in its receive buffer and (b) if SO_LINGER was set with a non-zero linger time, or (c) the socket is either in the OPEN (active close) or in the PASSIVE_CLOSEREQ state (client application closes after receiving CloseReq). In addition, there is a catch-all case by calling __skb_queue_purge() after waiting for the CCID. This is necessary since the write queue may still have data when (a) the host has been passively-closed, (b) abnormal termination (unread data, zero linger time), (c) wait-for-ccid could not finish within the given time limit. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-04dccp: Extend CCID packet dequeueing interfaceGerrit Renker
This extends the packet dequeuing interface of dccp_write_xmit() to allow 1. CCIDs to take care of timing when the next packet may be sent; 2. delayed sending (as before, with an inter-packet gap up to 65.535 seconds). The main purpose is to take CCID2 out of its polling mode (when it is network- limited, it tries every millisecond to send, without interruption). The interface can also be used to support other CCIDs. The mode of operation for (2) is as follows: * new packet is enqueued via dccp_sendmsg() => dccp_write_xmit(), * ccid_hc_tx_send_packet() detects that it may not send (e.g. window full), * it signals this condition via `CCID_PACKET_WILL_DEQUEUE_LATER', * dccp_write_xmit() returns without further action; * after some time the wait-condition for CCID becomes true, * that CCID schedules the tasklet, * tasklet function calls ccid_hc_tx_send_packet() via dccp_write_xmit(), * since the wait-condition is now true, ccid_hc_tx_packet() returns "send now", * packet is sent, and possibly more (since dccp_write_xmit() loops). Code reuse: the taskled function calls dccp_write_xmit(), the timer function reduces to a wrapper around the same code. If the tasklet finds that the socket is locked, it re-schedules the tasklet function (not the tasklet) after one jiffy. Changed DCCP_BUG to dccp_pr_debug when transmit_skb returns an error (e.g. when a local qdisc is used, NET_XMIT_DROP=1 can be returned for many packets). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-04dccp ccid-2: Schedule Sync as out-of-band mechanismGerrit Renker
The problem with Ack Vectors is that i) their length is variable and can in principle grow quite large, ii) it is hard to predict exactly how large they will be. Due to the second point it seems not a good idea to reduce the MPS; in particular when on average there is enough room for the Ack Vector and an increase in length is momentarily due to some burst loss, after which the Ack Vector returns to its normal/average length. The solution taken by this patch is to subtract a minimum-expected Ack Vector length from the MPS (previous patch), and to defer any larger Ack Vectors onto a separate Sync - but only if indeed there is no space left on the skb. This patch provides the infrastructure to schedule Sync-packets for transporting (urgent) out-of-band data. Its signalling is quicker than scheduling an Ack, since it does not need to wait for new application data. It can thus serve other parts of the DCCP code as well. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-04dccp: Merge now-reduced connect_init() functionGerrit Renker
After moving the assignment of GAR/ISS from dccp_connect_init() to dccp_transmit_skb(), the former function becomes very small, so that a merger with dccp_connect() suggests itself. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-04dccp: Unused argument in CCID tx functionGerrit Renker
This removes the argument `more' from ccid_hc_tx_packet_sent, since it was nowhere used in the entire code. (Anecdotally, this argument was not even used in the original KAME code where the function originally came from; compare the variable moreToSend in the freebsd61-dccp-kame-28.08.2006.patch now maintained by Emmanuel Lochin.) Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-04dccp: Special case of the MPS for client-PARTOPEN with DataAcksGerrit Renker
To increase robustness, it is necessary to resend Confirm feature-negotiation options, even though the RFC does not mandate it. But feature negotiation options can take (much) more room than the options on common DataAck packets. Instead of reducing the MPS always for a case which only applies to the three messages send during initial handshake, this patch devises a special case: if the payload length of the DataAck in PARTOPEN is too large, an Ack is sent to carry the options, and the feature-negotiation list is then flushed. This means that the server gets two Acks for one Response. If both Acks get lost, it is probably better to restart the connection anyway and devising yet another special-case does not seem worth the extra complexity. The patch (over-)estimates the expected overhead to be 32*4 bytes -- commonly seen values were 20-90 bytes for initial feature-negotiation options. It uses sizeof(u32) to mean "aligned units of 4 bytes". For consistency, another use of sizeof is modified. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-04dccp: Leave headroom for options when calculating the MPSGerrit Renker
The Maximum Packet Size (MPS) is of interest for applications which want to transfer data, so it is only relevant to the data transfer phase of a connection (unless one wants to send data on the DCCP-Request, but that is not considered here). The strategy chosen to deal with this requirement is to leave room for only such options that may appear on data packets. A special consideration applies to Ack Vectors: this is purely guesswork, since these can have any length between 3 and 1020 bytes. The strategy chosen here is to subtract a configurable minimum, the value of 16 bytes (2 bytes for type/length plus 14 Ack Vector cells) has been found by experimentatation. If people experience this as too much or too little, this could later be turned into a Kconfig option. There are currently no CCID-specific header options which may appear on data packets, hence it is not necessary to define a corresponding CCID field. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
2008-09-04dccp: Mechanism to resolve CCID dependenciesGerrit Renker
This adds a hook to resolve features whose value depends on the choice of CCID. It is done at the server since it can only be done after the CCID values have been negotiated; i.e. the client will add its CCID preference list on the Change options sent in the Request, which will be reconciled with the local preference list of the server. The concept is documented on http://www.erg.abdn.ac.uk/users/gerrit/dccp/notes/feature_negotiation/\ implementation_notes.html#ccid_dependencies Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
2008-09-04dccp: Resolve dependencies of features on choice of CCIDGerrit Renker
This provides a missing link in the code chain, as several features implicitly depend and/or rely on the choice of CCID. Most notably, this is the Send Ack Vector feature, but also Ack Ratio and Send Loss Event Rate (also taken care of). For Send Ack Vector, the situation is as follows: * since CCID2 mandates the use of Ack Vectors, there is no point in allowing endpoints which use CCID2 to disable Ack Vector features such a connection; * a peer with a TX CCID of CCID2 will always expect Ack Vectors, and a peer with a RX CCID of CCID2 must always send Ack Vectors (RFC 4341, sec. 4); * for all other CCIDs, the use of (Send) Ack Vector is optional and thus negotiable. However, this implies that the code negotiating the use of Ack Vectors also supports it (i.e. is able to supply and to either parse or ignore received Ack Vectors). Since this is not the case (CCID-3 has no Ack Vector support), the use of Ack Vectors is here disabled, with a comment in the source code. An analogous consideration arises for the Send Loss Event Rate feature, since the CCID-3 implementation does not support the loss interval options of RFC 4342. To make such use explicit, corresponding feature-negotiation options are inserted which signal the use of the loss event rate option, as it is used by the CCID3 code. Lastly, the values of the Ack Ratio feature are matched to the choice of CCID. The patch implements this as a function which is called after the user has made all other registrations for changing default values of features. The table is variable-length, the reserved (and hence for feature-negotiation invalid, confirmed by considering section 19.4 of RFC 4340) feature number `0' is used to mark the end of the table. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
2008-07-26dccp: Bug-Fix - AWL was never updatedGerrit Renker
The AWL lower Ack validity window advances in proportion to GSS, the greatest sequence number sent. Updating AWL other than at connection setup (in the DCCP-Request sent by dccp_v{4,6}_connect()) was missing in the DCCP code. This bug lead to syslog messages such as "kernel: dccp_check_seqno: DCCP: Step 6 failed for DATAACK packet, [...] P.ackno exists or LAWL(82947089) <= P.ackno(82948208) <= S.AWH(82948728), sending SYNC..." The difference between AWL/AWH here is 1639 packets, while the expected value (the Sequence Window) would have been 100 (the default). A closer look showed that LAWL = AWL = 82947089 equalled the ISS on the Response. The patch now updates AWL with each increase of GSS. Further changes: ---------------- The patch also enforces more stringent checks on the ISS sequence number: * AWL is initialised to ISS at connection setup and remains at this value; * AWH is then always set to GSS (via dccp_update_gss()); * so on the first Request: AWL = AWH = ISS, and on the n-th Request: AWL = ISS, AWH = ISS + n. As a consequence, only Response packets that refer to Requests sent by this host will pass, all others are discarded. This is the intention and in effect implements the initial adjustments for AWL as specified in RFC 4340, 7.5.1. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
2008-07-26dccp: Allow to distinguish original and retransmitted packetsGerrit Renker
This patch allows the sender to distinguish original and retransmitted packets, which is in particular needed for the retransmission of DCCP-Requests: * the first Request uses ISS (generated in net/dccp/ip*.c), and sets GSS = ISS; * all retransmitted Requests use GSS' = GSS + 1, so that the n-th retransmitted Request has sequence number ISS + n (mod 48). To add generic support, the patch reorganises existing code so that: * icsk_retransmits == 0 for the original packet and * icsk_retransmits = n > 0 for the n-th retransmitted packet at the time dccp_transmit_skb() is called, via dccp_retransmit_skb(). Thanks to Wei Yongjun for pointing this problem out. Further changes: ---------------- * removed the `skb' argument from dccp_retransmit_skb(), since sk_send_head is used for all retransmissions (the exception is client-Acks in PARTOPEN state, but these do not use sk_send_head); * since sk_send_head always contains the original skb (via dccp_entail()), skb_cloned() never evaluated to true and thus pskb_copy() was never used. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-06-11dccp: Fix sparse warningsGerrit Renker
This patch fixes the following sparse warnings: * nested min(max()) expression: net/dccp/ccids/ccid3.c:91:21: warning: symbol '__x' shadows an earlier one net/dccp/ccids/ccid3.c:91:21: warning: symbol '__y' shadows an earlier one * Declaration of function prototypes in .c instead of .h file, resulting in "should it be static?" warnings. * Declared "struct dccpw" static (local to dccp_probe). * Disabled dccp_delayed_ack() - not fully removed due to RFC 4340, 11.3 ("Receivers SHOULD implement delayed acknowledgement timers ..."). * Used a different local variable name to avoid net/dccp/ackvec.c:293:13: warning: symbol 'state' shadows an earlier one net/dccp/ackvec.c:238:33: originally declared here * Removed unused functions `dccp_ackvector_print' and `dccp_ackvec_print'. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-04-14Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/ehea/ehea_main.c drivers/net/wireless/iwlwifi/Kconfig drivers/net/wireless/rt2x00/rt61pci.c net/ipv4/inet_timewait_sock.c net/ipv6/raw.c net/mac80211/ieee80211_sta.c
2008-04-12[DCCP]: Fix skb->cb conflicts with IPPatrick McHardy
dev_queue_xmit() and the other IP output functions expect to get a skb with clear or properly initialized skb->cb. Unlike TCP and UDP, the dccp_skb_cb doesn't contain a struct inet_skb_parm at the beginning, so the DCCP-specific data is interpreted by the IP output functions. This can cause false negatives for the conditional POST_ROUTING hook invocation, making the packet bypass the hook. Add a inet_skb_parm/inet6_skb_parm union to the beginning of dccp_skb_cb to avoid clashes. Also add a BUILD_BUG_ON to make sure it fits in the cb. [ Combined with patch from Gerrit Renker to remove two now unnecessary memsets of IPCB(skb)->opt ] Signed-off-by: Patrick McHardy <kaber@trash.net> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-04-03[DCCP]: Replace socket with sock for reset sending.Denis V. Lunev
Replace dccp_v(4|6)_ctl_socket with sock to unify a code with TCP/ICMP. Signed-off-by: Denis V. Lunev <den@openvz.org> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[DCCP]: Introducing CCMPSGerrit Renker
This introduces a CCMPS field for setting a CCID-specific upper bound on the application payload size, as is defined in RFC 4340, section 14. Only the TX CCID is considered in setting this limit, since the RX CCID generates comparatively small (DCCP-Ack) feedback packets. The CCMPS field includes network and transport layer header lengths. The only current CCMPS customer is CCID4 (via RFC 4828). A wrapper is used to allow querying the CCMPS even at times where the CCID modules may not have been fully negotiated yet. In dccp_sync_mss() the variable `mss_now' has been renamed into `cur_mps', to reflect that we are dealing with an MPS, but not an MSS. Since the DCCP code closely follows the TCP code, the identifiers `dccp_sync_mss' and `dccps_mss_cache' have been kept, as they have direct TCP counterparts. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[DCCP]: Support inserting options during the 3-way handshakeGerrit Renker
This provides a separate routine to insert options during the initial handshake. The main purpose is to conduct feature negotiation, for the moment the only user is the timestamp echo needed for the (CCID3) handshake RTT sample. Padding of options has been put into a small separate routine, to be shared among the two functions. This could also be used as a generic routine to finish inserting options. Also removed an `XXX' comment since its content was obvious. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[DCCP]: Support for server holding timewait stateGerrit Renker
This adds a socket option and signalling support for the case where the server holds timewait state on closing the connection, as described in RFC 4340, 8.3. Since holding timewait state at the server is the non-usual case, it is enabled via a socket option. Documentation for this socket option has been added. The setsockopt statement has been made resilient against different possible cases of expressing boolean `true' values using a suggestion by Ian McDonald. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[DCCP]: Shift the retransmit timer for active-close into output.cGerrit Renker
When performing active close, RFC 4340, 8.3. requires to retransmit the Close/CloseReq with a backoff-retransmit timer starting at intially 2 RTTs. This patch shifts the existing code for active-close retransmit timer into output.c, so that the retransmit timer is started when the first Close/CloseReq is sent. Previously, the timer was started when, after releasing the socket in dccp_close(), the actively-closing side had not yet reached the CLOSED/TIMEWAIT state. The patch further reduces the initial timeout from 3 seconds to the required 2 RTTs, where - in absence of a known RTT - the fallback value specified in RFC 4340, 3.4 is used. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[DCCP]: Use AF-independent rebuild_header routineGerrit Renker
This fixes a nasty bug: dccp_send_reset() is called by both DCCPv4 and DCCPv6, but uses inet_sk_rebuild_header() in each case. This leads to unpredictable and weird behaviour: under some conditions, DCCPv6 Resets were sent, in other not. The fix is to use the AF-independent rebuild_header routine. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NET]: Name magic constants in sock_wake_async()Pavel Emelyanov
The sock_wake_async() performs a bit different actions depending on "how" argument. Unfortunately this argument ony has numerical magic values. I propose to give names to their constants to help people reading this function callers understand what's going on without looking into this function all the time. I suppose this is 2.6.25 material, but if it's not (or the naming seems poor/bad/awful), I can rework it against the current net-2.6 tree. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[DCCP]: Wait for CCIDGerrit Renker
This performs a minor optimisation: when ccid_hc_tx_send_packet returns a value greater zero, then the same call previously was done again at the begin of the while loop in dccp_wait_for_ccid. This patch exploits the available information and schedule-timeouts directly instead. Documentation also added. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10[DCCP]: Factor out common code for generating ResetsGerrit Renker
This factors code common to dccp_v{4,6}_ctl_send_reset into a separate function, and adds support for filling in the Data 1 ... Data 3 fields from RFC 4340, 5.6. It is useful to have this separate, since the following Reset codes will always be generated from the control socket rather than via dccp_send_reset: * Code 3, "No Connection", cf. 8.3.1; * Code 4, "Packet Error" (identification for Data 1 added); * Code 5, "Option Error" (identification for Data 1..3 added, will be used later); * Code 6, "Mandatory Error" (same as Option Error); * Code 7, "Connection Refused" (what on Earth is the difference to "No Connection"?); * Code 8, "Bad Service Code"; * Code 9, "Too Busy"; * Code 10, "Bad Init Cookie" (not used). Code 0 is not recommended by the RFC, the following codes would be used in dccp_send_reset() instead, since they all relate to an established DCCP connection: * Code 1, "Closed"; * Code 2, "Aborted"; * Code 11, "Aggression Penalty" (12.3). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
2007-10-10[DCCP]: Remove duplicate code for Reset from connected socketGerrit Renker
In this patch, duplicated code is removed for the case when a Reset packet is sent from a connected socket. This code duplication is between dccp_make_reset and dccp_transmit_skb, which already contained an (up to now entirely unused) switch statement to fill in the reset code from the DCCP_SKB_CB. The only thing that has been removed is the call to dst_clone(dst), since the queue_xmit functions use sk_dst_cache anyway. I wasn't sure which purpose inet_sk_rebuild_header served, so I left it in. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
2007-10-10[DCCP]: Add FIXME for send_delayed_ackGerrit Renker
This adds a FIXME to signal that the function dccp_send_delayed_ack is nowhere used in the entire DCCP/CCID code. Using a delayed Ack timer is suggested in 11.3 of RFC 4340, but it has also rather subtle implications for the Ack-Ratio-accounting. CCID2 does not use this (maybe it should). I think leaving the function in is good, in case someone wants to implement this. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
2007-10-10[DCCP]: Parameter renamingGerrit Renker
The parameter `seq' of dccp_send_sync() is in fact an acknowledgement number and not a sequence number - thus renamed by this patch into `ackno'. Secondly, a `critical' warning is added when a Sync/SyncAck could not be sent. Sanity: I have checked all other functions that are called in dccp_transmit_skb, there are no clashes with the use of dccpd_ack_seq; no other function is using this slot at the same time. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25[DCCP]: More debug information for dccp_wait_for_ccidGerrit Renker
This adds more detail in the wait_for_ccid packet scheduling loop. In particular, it informs about (i) when delay is used and (ii) why a packet is discarded. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-03-09[DCCP]: Initialise write_xmit_timer also on passive socketsGerrit Renker
The TX CCID needs the write_xmit_timer for delaying packet sends. Previously this timer was only activated on active (connecting) sockets. This patch initialises the write_xmit_timer in sync with the other timers, i.e. the timer will be ready on any socket. This is used by applications with a listening socket which start to stream after receiving an initiation by the client. The write_xmit_timer is stopped when the application closes, as before. Was tested to work and to remove the timer bug reported on dccp@vger. Also moved timer initialisation into timer.c (static). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-28[NET]: Fix kfree(skb)Patrick McHardy
Signed-off-by: Patrick McHardy <kaber@trash.net> Acked-by: Paul Moore <paul.moore@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-10[NET] DCCP: Fix whitespace errors.YOSHIFUJI Hideaki
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-01-26[TCP]: Restore SKB socket owner setting in tcp_transmit_skb().David S. Miller
Revert 931731123a103cfb3f70ac4b7abfc71d94ba1f03 We can't elide the skb_set_owner_w() here because things like certain netfilter targets (such as owner MATCH) need a socket to be set on the SKB for correct operation. Thanks to Jan Engelhardt and other netfilter list members for pointing this out. Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-11[DCCP]: Whitespace cleanupsArnaldo Carvalho de Melo
That accumulated over the last months hackaton, shame on me for not using git-apply whitespace helping hand, will do that from now on. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-11[DCCP]: Warn when discarding packet due to internal errorsGerrit Renker
This adds a (debug) warning message which is triggered whenever a packet is discarded due to send failure. It also adds a conditional, so that an interruption during dccp_wait_for_ccid is not treated as a `BUG': the rationale is that interruptions are external, whereas bug warnings are concerned with the internals. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-11[DCCP]: Remove timeo from output.cIan McDonald
It simplifies waiting for the CCID module to signal that a packet is ready to be sent. Other simplifications flow on from this such as removing constants. As a result of this EAGAIN is not returned any more by dccp_wait_for_ccid (which would otherwise lead to unnecessarily discarding the packet in dccp_write_xmit). Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02[DCCP]: Use `unsigned' for packet lengthsGerrit Renker
This patch implements a suggestion by Ian McDonald and 1) Avoids tests against negative packet lengths by using unsigned int for packet payload lengths in the CCID send_packet()/packet_sent() routines 2) As a consequence, it removes an now unnecessary test with regard to `len > 0' in ccid3_hc_tx_packet_sent: that condition is always true, since * negative packet lengths are avoided * ccid3_hc_tx_send_packet flags an error whenever the payload length is 0. As a consequence, ccid3_hc_tx_packet_sent is never called as all errors returned by ccid_hc_tx_send_packet are caught in dccp_write_xmit 3) Removes the third argument of ccid_hc_tx_send_packet (the `len' parameter), since it is currently always set to skb->len. The code is updated with regard to this parameter change. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02[DCCP]: Simplified conditions due to use of enum:8 statesGerrit Renker
This reaps the benefit of the earlier patch, which changed the type of CCID 3 states to use enums, in that many conditions are now simplified and the number of possible (unexpected) values is greatly reduced. In a few instances, this also allowed to simplify pre-conditions; where care has been taken to retain logical equivalence. [DCCP]: Introduce a consistent BUG/WARN message scheme This refines the existing set of DCCP messages so that * BUG(), BUG_ON(), WARN_ON() have meaningful DCCP-specific counterparts * DCCP_CRIT (for severe warnings) is not rate-limited * DCCP_WARN() is introduced as rate-limited wrapper Using these allows a faster and cleaner transition to their original counterparts once the code has matured into a full DCCP implementation. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02[DCCP]: Miscellaneous code tidy-upsGerrit Renker
This patch does not change code; it performs some trivial clean/tidy-ups: * removal of a `debug_prefix' string in favour of the already existing dccp_role(sk) * add documentation of structures and constants * separated out the cases for invalid packets (step 1 of the packet validation) * removing duplicate statements * combining declaration & initialisation Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02[TCP/DCCP]: Introduce net_xmit_evalGerrit Renker
Throughout the TCP/DCCP (and tunnelling) code, it often happens that the return code of a transmit function needs to be tested against NET_XMIT_CN which is a value that does not indicate a strict error condition. This patch uses a macro for these recurring situations which is consistent with the already existing macro net_xmit_errno, saving on duplicated code. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02[DCCPv6]: Choose a genuine initial sequence numberGerrit Renker
This * resolves a FIXME - DCCPv6 connections started all with an initial sequence number of 1; * provides a redirection `secure_dccpv6_sequence_number' in case the init_sequence_v6 code should be updated later; * concentrates the update of S.GAR into dccp_connect_init(); * removes a duplicate dccp_update_gss() in ipv4.c; * uses inet->dport instead of usin->sin_port, due to the following assignment in dccp_v4_connect(): inet->dport = usin->sin_port; Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02[DCCP]: Increment sequence numbers on retransmitted Response packetsGerrit Renker
Problem:
2006-12-02[DCCP]: Support for partial checksums (RFC 4340, sec. 9.2)Gerrit Renker
This patch does the following: a) introduces variable-length checksums as specified in [RFC 4340, sec. 9.2] b) provides necessary socket options and documentation as to how to use them c) basic support and infrastructure for the Minimum Checksum Coverage feature [RFC 4340, sec. 9.2.1]: acceptability tests, user notification and user interface In addition, it (1) fixes two bugs in the DCCPv4 checksum computation: * pseudo-header used checksum_len instead of skb->len * incorrect checksum coverage calculation based on dccph_x (2) removes dccp_v4_verify_checksum() since it reduplicates code of the checksum computation; code calling this function is updated accordingly. (3) now uses skb_checksum(), which is safer than checksum_partial() if the sk_buff has is a non-linear buffer (has pages attached to it). (4) fixes an outstanding TODO item: * If P.CsCov is too large for the packet size, drop packet and return. The code has been tested with applications, the latest version of tcpdump now comes with support for partial DCCP checksums. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02[DCCP]: Fix logfile overflowIan McDonald
This patch fixes data being spewed into the logs continually. As the code stood if there was a large queue and long delays timeo would go down to zero and never get reset. This fixes it by resetting timeo. Put constant into header as well. Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02[DCCP]: Combine allocating & zeroing header space on skbGerrit Renker
This is a code simplification: it combines three often recurring operations into one inline function, * allocate `len' bytes header space in skb * fill these `len' bytes with zeroes * cast the start of this header space as dccp_hdr Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2006-12-02[TCP]: Don't set SKB owner in tcp_transmit_skb().David S. Miller
The data itself is already charged to the SKB, doing the skb_set_owner_w() just generates a lot of noise and extra atomics we don't really need. Lmbench improvements on lat_tcp are minimal: before: TCP latency using localhost: 23.2701 microseconds TCP latency using localhost: 23.1994 microseconds TCP latency using localhost: 23.2257 microseconds after: TCP latency using localhost: 22.8380 microseconds TCP latency using localhost: 22.9465 microseconds TCP latency using localhost: 22.8462 microseconds Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-22[DCCP]: Introduce tx bufferingIan McDonald
This adds transmit buffering to DCCP. I have tested with CCID2/3 and with loss and rate limiting. Signed off by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-03-20[DCCP] options: Make dccp_insert_options & friends yell on errorArnaldo Carvalho de Melo
And not the silly LIMIT_NETDEBUG and silently return without inserting the option requested. Also drop some old debugging messages associated to option insertion. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[DCCP]: Use sk->sk_prot->max_header consistently for non-data packetsArnaldo Carvalho de Melo
Using this also provides opportunities for introducing inet_csk_alloc_skb that would call alloc_skb, account it to the sock and skb_reserve(max_header), but I'll leave this for later, for now using sk_prot->max_header consistently is enough. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>