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2016-04-27net: snmp: kill STATS_BH macrosEric Dumazet1-1/+1
There is nothing related to BH in SNMP counters anymore, since linux-3.0. Rename helpers to use __ prefix instead of _BH prefix, for contexts where preemption is disabled. This more closely matches convention used to update percpu variables. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-27dccp: rename DCCP_INC_STATS_BH()Eric Dumazet1-3/+3
Rename DCCP_INC_STATS_BH() to __DCCP_INC_STATS() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-23tcp/dccp: fix hashdance race for passive sessionsEric Dumazet1-1/+3
Multiple cpus can process duplicates of incoming ACK messages matching a SYN_RECV request socket. This is a rare event under normal operations, but definitely can happen. Only one must win the race, otherwise corruption would occur. To fix this without adding new atomic ops, we use logic in inet_ehash_nolisten() to detect the request was present in the same ehash bucket where we try to insert the new child. If request socket was not found, we have to undo the child creation. This actually removes a spin_lock()/spin_unlock() pair in reqsk_queue_unlink() for the fast path. Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets") Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-09net/dccp: dccp_bad_service_code can be booleanYaowei Bai1-2/+2
This patch makes dccp_bad_service_code return bool due to these particular functions only using either one or zero as their return value. dccp_list_has_service is also been made return bool in this patchset. No functional change. Signed-off-by: Yaowei Bai <bywxiaobai@163.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29tcp/dccp: constify syn_recv_sock() method sock argumentEric Dumazet1-1/+1
We'll soon no longer hold listener socket lock, these functions do not modify the socket in any way. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29dccp: constify dccp_create_openreq_child() sock argumentEric Dumazet1-1/+1
socket no longer needs to be read/write Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29tcp/dccp: constify send_synack and send_reset socket argumentEric Dumazet1-1/+1
None of these functions need to change the socket, make it const. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-25dccp: constify dccp_make_response() socket argumentEric Dumazet1-1/+1
Like tcp_make_synack() the only time we might change the socket is when calling sock_wmalloc(), which is using atomic operation to update sk->sk_wmem_alloc Also use MAX_DCCP_HEADER as both IPv4/IPv6 use this value for max_header. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-23ipv4: dccp: handle ICMP messages on DCCP_NEW_SYN_RECV request socketsEric Dumazet1-0/+1
dccp_v4_err() can restrict lookups to ehash table, and not to listeners. Note this patch creates the infrastructure, but this means that ICMP messages for request sockets are ignored until complete conversion. New dccp_req_err() helper is exported so that we can use it in IPv6 in following patch. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-20inet: drop prev pointer handling in request sockEric Dumazet1-2/+1
When request sock are put in ehash table, the whole notion of having a previous request to update dl_next is pointless. Also, following patch will get rid of big purge timer, so we want to delete a request sock without holding listener lock. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-02net: Remove iocb argument from sendmsg and recvmsgYing Xue1-5/+3
After TIPC doesn't depend on iocb argument in its internal implementations of sendmsg() and recvmsg() hooks defined in proto structure, no any user is using iocb argument in them at all now. Then we can drop the redundant iocb argument completely from kinds of implementations of both sendmsg() and recvmsg() in the entire networking stack. Cc: Christoph Hellwig <hch@lst.de> Suggested-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-11-08dccp: Convert DCCP_WARN to net_warn_ratelimitedJoe Perches1-2/+2
Remove the dependency on the "warning" sysctl (net_msg_warn) which is only used by the LIMIT_NETDEBUG macro. Convert the LIMIT_NETDEBUG use in DCCP_WARN to the more common net_warn_ratelimited mechanism. This still ratelimits based on the net_ratelimit() function, but removes the check for the sysctl. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-04dccp: remove obsolete codestephen hemminger1-1/+0
This function is defined but not used. Remove it now, can be resurrected if ever needed. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-19net: dccp: Remove extern from function prototypesJoe Perches1-96/+90
There are a mix of function prototypes with and without extern in the kernel sources. Standardize on not using extern for function prototypes. Function prototypes don't need to be written with extern. extern is assumed by the compiler. Its use is as unnecessary as using auto to declare automatic/local variables in a block. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10net: Fix (nearly-)kernel-doc comments for various functionsBen Hutchings1-0/+1
Fix incorrect start markers, wrapped summary lines, missing section breaks, incorrect separators, and some name mismatches. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15net: cleanup unsigned to unsigned intEric Dumazet1-4/+4
Use of "unsigned int" is preferred to bare "unsigned" in net tree. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-19module_param: make bool parameters really bool (net & drivers/net)Rusty Russell1-1/+1
module_param(bool) used to counter-intuitively take an int. In fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy trick. It's time to remove the int/unsigned int option. For this version it'll simply give a warning, but it'll break next kernel version. (Thanks to Joe Perches for suggesting coccinelle for 0/1 -> true/false). Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-11net: use IS_ENABLED(CONFIG_IPV6)Eric Dumazet1-1/+1
Instead of testing defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-01dccp: support for the exchange of NN options in established state 1/2Gerrit Renker1-0/+1
In contrast to static feature negotiation at the begin of a connection, this patch introduces support for exchange of dynamically changing options. Such an update/exchange is necessary in at least two cases: * CCID-2's Ack Ratio (RFC 4341, 6.1.2) which changes during the connection; * Sequence Window values that, as per RFC 4340, 7.5.2, should be sent "as the connection progresses". Both are non-negotiable (NN) features, which means that no new capabilities are negotiated, but rather that changes in known parameters are brought up-to-date at either end. Thse characteristics are reflected by the implementation: * only NN options can be exchanged after connection setup; * an ack is scheduled directly after activation to speed up the update; * CCIDs may request changes to an NN feature even if a negotiation for that feature is already underway: this is required by CCID-2, where changes in cwnd necessitate Ack Ratio changes, such that the previous Ack Ratio (which is still being negotiated) would cause irrecoverable RTO timeouts (thanks to work by Samuel Jero). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: Samuel Jero <sj323707@ohio.edu> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.uk>
2011-01-07dccp: fix bug in updating the GSRSamuel Jero1-1/+2
Currently dccp_check_seqno allows any valid packet to update the Greatest Sequence Number Received, even if that packet's sequence number is less than the current GSR. This patch adds a check to make sure that the new packet's sequence number is greater than GSR. Signed-off-by: Samuel Jero <sj323707@ohio.edu> Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-12-10dccp: remove unused macrosShan Wei1-8/+0
Remove macros which have been unused since the initial implementation (commit 7c657876b63cb1d8a2ec06f8fc6c37bb8412e66c, [DCCP]: Initial implementation from Tue Aug 9 20:14:34 2005 -0700). Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com> Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-12-07dccp qpolicy: Parameter checking of cmsg qpolicy parametersTomasz Grobelny1-0/+1
Ensure that cmsg->cmsg_type value is valid for qpolicy that is currently in use. Signed-off-by: Tomasz Grobelny <tomasz@grobelny.oswiecenia.net> Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-12-07dccp: Policy-based packet dequeueing infrastructureTomasz Grobelny1-0/+12
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>
2010-11-10dccp ccid-2: Implementation of circular Ack Vector buffer with overflow handlingGerrit Renker1-4/+7
This completes the implementation of a circular buffer for Ack Vectors, by extending the current (linear array-based) implementation. The changes are: (a) An `overflow' flag to deal with the case of overflow. As before, dynamic growth of the buffer will not be supported; but code will be added to deal robustly with overflowing Ack Vector buffers. (b) A `tail_seqno' field. When naively implementing the algorithm of Appendix A in RFC 4340, problems arise whenever subsequent Ack Vector records overlap, which can bring the entire run length calculation completely out of synch. (This is documented on http://www.erg.abdn.ac.uk/users/gerrit/dccp/notes/\ ack_vectors/tracking_tail_ackno/ .) (c) The buffer length is now computed dynamically (i.e. current fill level), as the span between head to tail. As a result, dccp_ackvec_pending() is now simpler - the #ifdef is no longer necessary since buf_empty is always true when IP_DCCP_ACKVEC is not configured. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-10-28dccp: Refine the wait-for-ccid mechanismGerrit Renker1-2/+3
This extends the existing wait-for-ccid routine so that it may be used with different types of CCID, addressing the following problems: 1) The queue-drain mechanism only works with rate-based CCIDs. If CCID-2 for example has a full TX queue and becomes network-limited just as the application wants to close, then waiting for CCID-2 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 CCID-3/4 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 of __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> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-12dccp: schedule an Ack when receiving timestampsGerrit Renker1-2/+1
This schedules an Ack when receiving a timestamp, exploiting the existing inet_csk_schedule_ack() function, saving one case in the `dccp_ack_pending()' function. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-10-12dccp: generalise data-loss conditionIvo Calado1-6/+15
This patch generalises the task of determining data loss from RFC 4340, 7.7.1. Let S_A, S_B be sequence numbers such that S_B is "after" S_A, and let N_B be the NDP count of packet S_B. Then, using modulo-2^48 arithmetic, D = S_B - S_A - 1 is an upper bound of the number of lost data packets, D - N_B is an approximation of the number of lost data packets (there are cases where this is not exact). The patch implements this as dccp_loss_count(S_A, S_B, N_B) := max(S_B - S_A - 1 - N_B, 0) Signed-off-by: Ivo Calado <ivocalado@embedded.ufcg.edu.br> Signed-off-by: Erivaldo Xavier <desadoc@gmail.com> Signed-off-by: Leandro Sales <leandroal@gmail.com> Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-10-12dccp: fix the adjustments to AWL and SWLGerrit Renker1-0/+20
This fixes a problem and a potential loophole with regard to seqno/ackno validity: currently the initial adjustments to AWL/SWL are only performed once at the begin of the connection, during the handshake. Since the Sequence Window feature is always greater than Wmin=32 (7.5.2), it is however necessary to perform these adjustments at least for the first W/W' (variables as per 7.5.1) packets in the lifetime of a connection. This requirement is complicated by the fact that W/W' can change at any time during the lifetime of a connection. Therefore it is better to perform that safety check each time SWL/AWL are updated, as implemented by the patch. A second problem solved by this patch is that the remote/local Sequence Window feature values (which set the bounds for AWL/SWL/SWH) are undefined until the feature negotiation has completed. During the initial handshake we have more stringent sequence number protection; the changes added by this patch effect that {A,S}W{L,H} are within the correct bounds at the instant that feature negotiation completes (since the SeqWin feature activation handlers call dccp_update_gsr/gss()). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2010-10-06dccp: Kill dead code and add static markers.stephen hemminger1-2/+0
Remove dead code and make some functions static. Compile tested only. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-25dccp: remove unused function argumentGerrit Renker1-8/+4
This removes an unused 'sk' argument from several option-inserting functions. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-11inet: Remove unused send_check length argumentHerbert Xu1-1/+1
inet: Remove unused send_check length argument This patch removes the unused length argument from the send_check function in struct inet_connection_sock_af_ops. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Yinghai <yinghai.lu@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-21net: snmp mib cleanupEric Dumazet1-1/+1
There is no point to align or pad mibs to cache lines, they are per cpu allocated with a 8 bytes alignment anyway. This wastes space for no gain. This patch removes __SNMP_MIB_ALIGN__ Since SNMP mibs contain "unsigned long" fields only, we can relax the allocation alignment from "unsigned long long" to "unsigned long" Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-30net: Make setsockopt() optlen be unsigned.David S. Miller1-2/+2
This provides safety against negative optlen at the type level instead of depending upon (sometimes non-trivial) checks against this sprinkled all over the the place, in each and every implementation. Based upon work done by Arjan van de Ven and feedback from Linus Torvalds. Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-02dccp: Do not let initial option overhead shrink the MPSGerrit Renker1-1/+4
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>
2009-01-21dccp: Debugging functions for feature negotiationGerrit Renker1-0/+2
Since all feature-negotiation processing now takes place in feat.c, functions for producing verbose debugging output are concentrated there. New functions to print out values, entry records, and options are provided, and also a macro is defined to not always have the function name in the output line. Thanks a lot to Wei Yongjun and Giuseppe Galeota for help and discussion with an earlier revision of this patch. 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>
2009-01-21dccp: Initialisation and type-checking of feature sysctlsGerrit Renker1-3/+0
This patch takes care of initialising and type-checking sysctls related to feature negotiation. Type checking is important since some of the sysctls now directly impact the feature-negotiation process. The sysctls are initialised with the known default values for each feature. For the type-checking the value constraints from RFC 4340 are used: * Sequence Window uses the specified Wmin=32, the maximum is ulong (4 bytes), tested and confirmed that it works up to 4294967295 - for Gbps speed; * Ack Ratio is between 0 .. 0xffff (2-byte unsigned integer); * CCIDs are between 0 .. 255; * request_retries, retries1, retries2 also between 0..255 for good measure; * tx_qlen is checked to be non-negative; * sync_ratelimit remains as before. Notes: ------ 1. Die s@sysctl_dccp_feat@sysctl_dccp@g since the sysctls are now in feat.c. 2. As pointed out by Arnaldo, the pattern of type-checking repeats itself in other places, sometimes with exactly the same kind of definitions (e.g. "static int zero;"). It may be a good idea (kernel janitors?) to consolidate type checking. For the sake of keeping the changeset small and in order not to affect other subsystems, I have not strived to generalise here. 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>
2009-01-21dccp: Implement both feature-local and feature-remote Sequence Window featureGerrit Renker1-9/+7
This adds full support for local/remote Sequence Window feature, from which the * sequence-number-validity (W) and * acknowledgment-number-validity (W') windows derive as specified in RFC 4340, 7.5.3. Specifically, the following is contained in this patch: * integrated new socket fields into dccp_sk; * updated the update_gsr/gss routines with regard to these fields; * updated handler code: the Sequence Window feature is located at the TX side, so the local feature is meant if the handler-rx flag is false; * the initialisation of `rcv_wnd' in reqsk is removed, since - rcv_wnd is not used by the code anywhere; - sequence number checks are not done in the LISTEN state (cf. 7.5.3); - dccp_check_req checks the Ack number validity more rigorously; * the `struct dccp_minisock' became empty and is now removed. 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>
2009-01-04dccp: Lockless integration of CCID congestion-control pluginsGerrit Renker1-2/+0
Based on Arnaldo's earlier patch, this patch integrates the standardised CCID congestion control plugins (CCID-2 and CCID-3) of DCCP with dccp.ko: * enables a faster connection path by eliminating the need to always go through the CCID registration lock; * updates the implementation to use only a single array whose size equals the number of configured CCIDs instead of the maximum (256); * since the CCIDs are now fixed array elements, synchronization is no longer needed, simplifying use and implementation. CCID-2 is suggested as minimum for a basic DCCP implementation (RFC 4340, 10); CCID-3 is a standards-track CCID supported by RFC 4342 and RFC 5348. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-08dccp ccid-2: Phase out the use of boolean Ack Vector sysctlGerrit Renker1-2/+1
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 <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-08dccp: Remove manual influence on NDP Count featureGerrit Renker1-1/+0
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 <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-01dccp: Feature activation handlersGerrit Renker1-0/+1
This patch provides the post-processing of feature negotiation state, after the negotiation has completed. To this purpose, handlers are used and added to the dccp_feat_table. Each handler is passed a boolean flag whether the RX or TX side of the feature is meant. Several handlers are provided already, new handlers can easily be added. The initialisation is now fully dynamic, i.e. CCIDs are activated only after the feature negotiation. The integration of this dynamic activation is done in the subsequent patches. Thanks to Wei Yongjun for pointing out the necessity of skipping over empty Confirm options while copying the negotiated feature values. 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>
2008-12-01dccp: Insert feature-negotiation options into skbGerrit Renker1-0/+2
This patch replaces the earlier insertion routine from options.c, so that code specific to feature negotiation can remain in feat.c. This is possible by calling a function already existing in options.c. 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>
2008-11-25net: Use a percpu_counter for orphan_countEric Dumazet1-1/+1
Instead of using one atomic_t per protocol, use a percpu_counter for "orphan_count", to reduce cache line contention on heavy duty network servers. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-16dccp: Deprecate Ack Ratio sysctlGerrit Renker1-1/+0
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 <gerrit@erg.abdn.ac.uk> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-16dccp: Mechanism to resolve CCID dependenciesGerrit Renker1-0/+1
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 Renker1-0/+1
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>
2008-11-04dccp: Per-socket initialisation of feature negotiationGerrit Renker1-1/+2
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 <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-04dccp: List management for new feature negotiationGerrit Renker1-0/+2
This adds list initial fields and list management functions for the new feature negotiation implementation. Thanks to Arnaldo for suggestions and improvements. 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>
2008-08-06tcp: Fix kernel panic when calling tcp_v(4/6)_md5_do_lookupGui Jianfeng1-1/+2
If the following packet flow happen, kernel will panic. MathineA MathineB SYN ----------------------> SYN+ACK <---------------------- ACK(bad seq) ----------------------> When a bad seq ACK is received, tcp_v4_md5_do_lookup(skb->sk, ip_hdr(skb)->daddr)) is finally called by tcp_v4_reqsk_send_ack(), but the first parameter(skb->sk) is NULL at that moment, so kernel panic happens. This patch fixes this bug. OOPS output is as following: [ 302.812793] IP: [<c05cfaa6>] tcp_v4_md5_do_lookup+0x12/0x42 [ 302.817075] Oops: 0000 [#1] SMP [ 302.819815] Modules linked in: ipv6 loop dm_multipath rtc_cmos rtc_core rtc_lib pcspkr pcnet32 mii i2c_piix4 parport_pc i2c_core parport ac button ata_piix libata dm_mod mptspi mptscsih mptbase scsi_transport_spi sd_mod scsi_mod crc_t10dif ext3 jbd mbcache uhci_hcd ohci_hcd ehci_hcd [last unloaded: scsi_wait_scan] [ 302.849946] [ 302.851198] Pid: 0, comm: swapper Not tainted (2.6.27-rc1-guijf #5) [ 302.855184] EIP: 0060:[<c05cfaa6>] EFLAGS: 00010296 CPU: 0 [ 302.858296] EIP is at tcp_v4_md5_do_lookup+0x12/0x42 [ 302.861027] EAX: 0000001e EBX: 00000000 ECX: 00000046 EDX: 00000046 [ 302.864867] ESI: ceb69e00 EDI: 1467a8c0 EBP: cf75f180 ESP: c0792e54 [ 302.868333] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 [ 302.871287] Process swapper (pid: 0, ti=c0792000 task=c0712340 task.ti=c0746000) [ 302.875592] Stack: c06f413a 00000000 cf75f180 ceb69e00 00000000 c05d0d86 000016d0 ceac5400 [ 302.883275] c05d28f8 000016d0 ceb69e00 ceb69e20 681bf6e3 00001000 00000000 0a67a8c0 [ 302.890971] ceac5400 c04250a3 c06f413a c0792eb0 c0792edc cf59a620 cf59a620 cf59a634 [ 302.900140] Call Trace: [ 302.902392] [<c05d0d86>] tcp_v4_reqsk_send_ack+0x17/0x35 [ 302.907060] [<c05d28f8>] tcp_check_req+0x156/0x372 [ 302.910082] [<c04250a3>] printk+0x14/0x18 [ 302.912868] [<c05d0aa1>] tcp_v4_do_rcv+0x1d3/0x2bf [ 302.917423] [<c05d26be>] tcp_v4_rcv+0x563/0x5b9 [ 302.920453] [<c05bb20f>] ip_local_deliver_finish+0xe8/0x183 [ 302.923865] [<c05bb10a>] ip_rcv_finish+0x286/0x2a3 [ 302.928569] [<c059e438>] dev_alloc_skb+0x11/0x25 [ 302.931563] [<c05a211f>] netif_receive_skb+0x2d6/0x33a [ 302.934914] [<d0917941>] pcnet32_poll+0x333/0x680 [pcnet32] [ 302.938735] [<c05a3b48>] net_rx_action+0x5c/0xfe [ 302.941792] [<c042856b>] __do_softirq+0x5d/0xc1 [ 302.944788] [<c042850e>] __do_softirq+0x0/0xc1 [ 302.948999] [<c040564b>] do_softirq+0x55/0x88 [ 302.951870] [<c04501b1>] handle_fasteoi_irq+0x0/0xa4 [ 302.954986] [<c04284da>] irq_exit+0x35/0x69 [ 302.959081] [<c0405717>] do_IRQ+0x99/0xae [ 302.961896] [<c040422b>] common_interrupt+0x23/0x28 [ 302.966279] [<c040819d>] default_idle+0x2a/0x3d [ 302.969212] [<c0402552>] cpu_idle+0xb2/0xd2 [ 302.972169] ======================= [ 302.974274] Code: fc ff 84 d2 0f 84 df fd ff ff e9 34 fe ff ff 83 c4 0c 5b 5e 5f 5d c3 90 90 57 89 d7 56 53 89 c3 50 68 3a 41 6f c0 e8 e9 55 e5 ff <8b> 93 9c 04 00 00 58 85 d2 59 74 1e 8b 72 10 31 db 31 c9 85 f6 [ 303.011610] EIP: [<c05cfaa6>] tcp_v4_md5_do_lookup+0x12/0x42 SS:ESP 0068:c0792e54 [ 303.018360] Kernel panic - not syncing: Fatal exception in interrupt Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-26dccp: Allow to distinguish original and retransmitted packetsGerrit Renker1-1/+1
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>
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