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2009-07-09net: adding memory barrier to the poll and receive callbacksJiri Olsa
Adding memory barrier after the poll_wait function, paired with receive callbacks. Adding fuctions sock_poll_wait and sk_has_sleeper to wrap the memory barrier. Without the memory barrier, following race can happen. The race fires, when following code paths meet, and the tp->rcv_nxt and __add_wait_queue updates stay in CPU caches. CPU1 CPU2 sys_select receive packet ... ... __add_wait_queue update tp->rcv_nxt ... ... tp->rcv_nxt check sock_def_readable ... { schedule ... if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) wake_up_interruptible(sk->sk_sleep) ... } If there was no cache the code would work ok, since the wait_queue and rcv_nxt are opposit to each other. Meaning that once tp->rcv_nxt is updated by CPU2, the CPU1 either already passed the tp->rcv_nxt check and sleeps, or will get the new value for tp->rcv_nxt and will return with new data mask. In both cases the process (CPU1) is being added to the wait queue, so the waitqueue_active (CPU2) call cannot miss and will wake up CPU1. The bad case is when the __add_wait_queue changes done by CPU1 stay in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 will then endup calling schedule and sleep forever if there are no more data on the socket. Calls to poll_wait in following modules were ommited: net/bluetooth/af_bluetooth.c net/irda/af_irda.c net/irda/irnet/irnet_ppp.c net/mac80211/rc80211_pid_debugfs.c net/phonet/socket.c net/rds/af_rds.c net/rfkill/core.c net/sunrpc/cache.c net/sunrpc/rpc_pipe.c net/tipc/socket.c Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-03net: skb->dst accessorsEric Dumazet
Define three accessors to get/set dst attached to a skb struct dst_entry *skb_dst(const struct sk_buff *skb) void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) void skb_dst_drop(struct sk_buff *skb) This one should replace occurrences of : dst_release(skb->dst) skb->dst = NULL; Delete skb->dst field Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02dccp: Do not let initial option overhead shrink the MPSGerrit Renker
This fixes a problem caused by the overlap of the connection-setup and established-state phases of DCCP connections. During connection setup, the client retransmits Confirm Feature-Negotiation options until a response from the server signals that it can move from the half-established PARTOPEN into the OPEN state, whereupon the connection is fully established on both ends (RFC 4340, 8.1.5). However, since the client may already send data while it is in the PARTOPEN state, consequences arise for the Maximum Packet Size: the problem is that the initial option overhead is much higher than for the subsequent established phase, as it involves potentially many variable-length list-type options (server-priority options, RFC 4340, 6.4). Applying the standard MPS is insufficient here: especially with larger payloads this can lead to annoying, counter-intuitive EMSGSIZE errors. On the other hand, reducing the MPS available for the established phase by the added initial overhead is highly wasteful and inefficient. The solution chosen therefore is a two-phase strategy: 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 result is a higher utilisation of the available packet space for the data transmission phase (established state) of a connection. The patch (over-)estimates the initial overhead to be 32*4 bytes -- commonly seen values were around 90 bytes for initial feature-negotiation options. It uses sizeof(u32) to mean "aligned units of 4 bytes". For consistency, another use of 4-byte alignment is adapted. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02dccp: Minimise header option overhead in setting the MPSGerrit Renker
This patch resolves a long-standing FIXME to dynamically update the Maximum Packet Size depending on actual options usage. It uses the flags set by the feature-negotiation infrastructure to compute the required header option size. Most options are fixed-size, a notable exception are Ack Vectors (required currently only by CCID-2). These can have any length between 3 and 1020 bytes. As a result of testing, 16 bytes (2 bytes for type/length plus 14 Ack Vector cells) have been found to be sufficient for loss-free situations. There are currently no CCID-specific header options which may appear on data packets, thus it is not necessary to define a corresponding CCID field as suggested in the old comment. Further changes: ---------------- Adjusted the type of 'cur_mps' to match the unsigned return type of the function. 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>
2008-12-05dccp: use roundup instead of opencodingIlpo Järvinen
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-16dccp: 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> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-12dccp: 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> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-19dccp: Port redirection support for DCCPGerrit Renker
Commit a3116ac5c216fc3c145906a46df9ce542ff7dcf2 from 1st October ("tcp: Port redirection support for TCP") broke DCCP skb lookup by changing inet_csk_clone, which is used by DCCP to generate the child socket after the handshake. This patch updates DCCP to use 'loc_port' instead of 'sport', which fixes the problem, and thus inheriting port redirection support via the new interface. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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>
2006-03-20[DCCP]: Uninline some functionsArnaldo Carvalho de Melo
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[DCCP]: Move the IPv4 specific bits from proto.c to ipv4.cArnaldo Carvalho de Melo
With this patch in place we can break down the complexity by better compartmentalizing the code that is common to ipv6 and ipv4. Now we have these modules: Module Size Used by dccp_diag 1344 0 inet_diag 9448 1 dccp_diag dccp_ccid3 15856 0 dccp_tfrc_lib 12320 1 dccp_ccid3 dccp_ccid2 5764 0 dccp_ipv4 16996 2 dccp 48208 4 dccp_diag,dccp_ccid3,dccp_ccid2,dccp_ipv4 dccp_ipv6 still requires dccp_ipv4 due to dccp_ipv6_mapped, that is the next target to work on the "hey, ipv4 is legacy, I only want ipv6 dude!" direction. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[DCCP]: Dont use dccp_v4_checksum in dccp_make_responseArnaldo Carvalho de Melo
dccp_make_response is shared by ipv4/6 and the ipv6 code was recalculating the checksum, not good, so move the dccp_v4_checksum call to dccp_v4_send_response. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>