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2008-01-28sysctl: Add register_sysctl_paths functionEric W. Biederman
There are a number of modules that register a sysctl table somewhere deeply nested in the sysctl hierarchy, such as fs/nfs, fs/xfs, dev/cdrom, etc. They all specify several dummy ctl_tables for the path name. This patch implements register_sysctl_path that takes an additional path name, and makes up dummy sysctl nodes for each component. This patch was originally written by Olaf Kirch and brought to my attention and reworked some by Olaf Hering. I have changed a few additional things so the bugs are mine. After converting all of the easy callers Olaf Hering observed allyesconfig ARCH=i386, the patch reduces the final binary size by 9369 bytes. .text +897 .data -7008 text data bss dec hex filename 26959310 4045899 4718592 35723801 2211a19 ../vmlinux-vanilla 26960207 4038891 4718592 35717690 221023a ../O-allyesconfig/vmlinux So this change is both a space savings and a code simplification. CC: Olaf Kirch <okir@suse.de> CC: Olaf Hering <olaf@aepfle.de> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Daniel Lezcano <dlezcano@fr.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NETFILTER]: Convert old checksum helper namesPatrick McHardy
Kill the defines again, convert to the new checksum helper names and remove the dependency of NET_ACT_NAT on NETFILTER. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NET]: Move netfilter checksum helpers to net/core/utils.cPatrick McHardy
This allows to get rid of the CONFIG_NETFILTER dependency of NET_ACT_NAT. This patch redefines the old names to keep the noise low, the next patch converts all users. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[DCCP]: Remove duplicate test for CloseReqGerrit Renker
This removes a redundant test for unexpected packet types. In dccp_rcv_state_process it is tested twice whether a DCCP-server has received a CloseReq (Step 7): * first in the combined if-statement, * then in the call to dccp_rcv_closereq(). The latter is necesssary since dccp_rcv_closereq() is also called from __dccp_rcv_established(). This patch removes the duplicate test. 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[DCCP]: Integrate state transitions for passive-closeGerrit Renker
This adds the necessary state transitions for the two forms of passive-close * PASSIVE_CLOSE - which is entered when a host receives a Close; * PASSIVE_CLOSEREQ - which is entered when a client receives a CloseReq. Here is a detailed account of what the patch does in each state. 1) Receiving CloseReq The pseudo-code in 8.5 says: Step 13: Process CloseReq If P.type == CloseReq and S.state < CLOSEREQ, Generate Close S.state := CLOSING Set CLOSING timer. This means we need to address what to do in CLOSED, LISTEN, REQUEST, RESPOND, PARTOPEN, and OPEN. * CLOSED: silently ignore - it may be a late or duplicate CloseReq; * LISTEN/RESPOND: will not appear, since Step 7 is performed first (we know we are the client); * REQUEST: perform Step 13 directly (no need to enqueue packet); * OPEN/PARTOPEN: enter PASSIVE_CLOSEREQ so that the application has a chance to process unread data. When already in PASSIVE_CLOSEREQ, no second CloseReq is enqueued. In any other state, the CloseReq is ignored. I think that this offers some robustness against rare and pathological cases: e.g. a simultaneous close where the client sends a Close and the server a CloseReq. The client will then be retransmitting its Close until it gets the Reset, so ignoring the CloseReq while in state CLOSING is sane. 2) Receiving Close The code below from 8.5 is unconditional. Step 14: Process Close If P.type == Close, Generate Reset(Closed) Tear down connection Drop packet and return Thus we need to consider all states: * CLOSED: silently ignore, since this can happen when a retransmitted or late Close arrives; * LISTEN: dccp_rcv_state_process() will generate a Reset ("No Connection"); * REQUEST: perform Step 14 directly (no need to enqueue packet); * RESPOND: dccp_check_req() will generate a Reset ("Packet Error") -- left it at that; * OPEN/PARTOPEN: enter PASSIVE_CLOSE so that application has a chance to process unread data; * CLOSEREQ: server performed active-close -- perform Step 14; * CLOSING: simultaneous-close: use a tie-breaker to avoid message ping-pong (see comment); * PASSIVE_CLOSEREQ: ignore - the peer has a bug (sending first a CloseReq and now a Close); * TIMEWAIT: packet is ignored. Note that the condition of receiving a packet in state CLOSED here is different from the condition "there is no socket for such a connection": the socket still exists, but its state indicates it is unusable. Last, dccp_finish_passive_close sets either DCCP_CLOSED or DCCP_CLOSING = TCP_CLOSING, so that sk_stream_wait_close() will wait for the final Reset (which will trigger CLOSING => CLOSED). 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[DCCP]: Dedicated auxiliary states to support passive-closeGerrit Renker
This adds two auxiliary states to deal with passive closes: * PASSIVE_CLOSE (reached from OPEN via reception of Close) and * PASSIVE_CLOSEREQ (reached from OPEN via reception of CloseReq) as internal intermediate states. These states are used to allow a receiver to process unread data before acknowledging the received connection-termination-request (the Close/CloseReq). Without such support, it will happen that passively-closed sockets enter CLOSED state while there is still unprocessed data in the queue; leading to unexpected and erratic API behaviour. PASSIVE_CLOSE has been mapped into TCPF_CLOSE_WAIT, so that the code will seamlessly work with inet_accept() (which tests for this state). The state names are thanks to Arnaldo, who suggested this naming scheme following an earlier revision of this patch. 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[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[TFRC]: Migrate TX history to singly-linked lisArnaldo Carvalho de Melo
This patch was based on another made by Gerrit Renker, his changelog was: ------------------------------------------------------ The patch set migrates TFRC TX history to a singly-linked list. The details are: * use of a consistent naming scheme (all TFRC functions now begin with `tfrc_'); * allocation and cleanup are taken care of internally; * provision of a lookup function, which is used by the CCID TX infrastructure to determine the time a packet was sent (in turn used for RTT sampling); * integration of the new interface with the present use in CCID3. ------------------------------------------------------ Simplifications I did: . removing the tfrc_tx_hist_head that had a pointer to the list head and another for the slabcache. . No need for creating a slabcache for each CCID that wants to use the TFRC tx history routines, create a single slabcache when the dccp_tfrc_lib module init routine is called. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Two fixes to new sacktag codeIlpo Järvinen
1) Skip condition used to be wrong way around which made SACK processing very broken, missed many blocks because of that. 2) Use highest_sack advancement only if some skbs are already sacked because otherwise tcp_write_queue_next may move things too far (occurs mainly with GSO). The other similar advancement is not problem because highest_sack was previosly put to point a sacked skb. These problems were located because of problem report from Matt Mathis <mathis@psc.edu>. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NET]: Nicer WARN_ON in netstat_showPavel Emelyanov
The if (statement) WARN_ON(1); looks much better as WARN_ON(statement); 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>
2008-01-28[IPV6]: Add RFC4214 supportFred L. Templin
This patch includes support for the Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) per RFC4214. It uses the SIT module, and is configured using extensions to the "iproute2" utility. The diffs are specific to the Linux 2.6.24-rc2 kernel distribution. This version includes the diff for ./include/linux/if.h which was missing in the v2.4 submission and is needed to make the patch compile. The patch has been installed, compiled and tested in a clean 2.6.24-rc2 kernel build area. Signed-off-by: Fred L. Templin <fred.l.templin@boeing.com> Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NET]: Eliminate unused argument from sk_stream_alloc_pskbPavel Emelyanov
The 3rd argument is always zero (according to grep :) Eliminate it and merge the function with sk_stream_alloc_skb. This saves 44 more bytes, and together with the previous patch we have: add/remove: 1/0 grow/shrink: 0/8 up/down: 183/-751 (-568) function old new delta sk_stream_alloc_skb - 183 +183 ip_rt_init 529 525 -4 arp_ignore 112 107 -5 __inet_lookup_listener 284 274 -10 tcp_sendmsg 2583 2481 -102 tcp_sendpage 1449 1300 -149 tso_fragment 417 258 -159 tcp_fragment 1149 988 -161 __tcp_push_pending_frames 1998 1837 -161 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>
2008-01-28[NET]: Uninline the sk_stream_alloc_pskbPavel Emelyanov
This function seems too big for inlining. Indeed, it saves half-a-kilo when uninlined: add/remove: 1/0 grow/shrink: 0/7 up/down: 195/-719 (-524) function old new delta sk_stream_alloc_pskb - 195 +195 ip_rt_init 529 525 -4 __inet_lookup_listener 284 274 -10 tcp_sendmsg 2583 2486 -97 tcp_sendpage 1449 1305 -144 tso_fragment 417 267 -150 tcp_fragment 1149 992 -157 __tcp_push_pending_frames 1998 1841 -157 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>
2008-01-28[IPV4] fib_hash: kmalloc + memset conversion to kzallocJoonwoo Park
fib_hash: kmalloc + memset conversion to kzalloc fix to avoid memset entirely. Signed-off-by: Joonwoo Park <joonwpark81@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[IPV4] fib_semantics: kmalloc + memset conversion to kzallocJoonwoo Park
fib_semantics: kmalloc + memset conversion to kzalloc fix to avoid memset entirely. Signed-off-by: Joonwoo Park <joonwpark81@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[IPSEC]: kmalloc + memset conversion to kzallocJoonwoo Park
2007/11/26, Patrick McHardy <kaber@trash.net>: > How about also switching vmalloc/get_free_pages to GFP_ZERO > and getting rid of the memset entirely while you're at it? > xfrm_hash: kmalloc + memset conversion to kzalloc fix to avoid memset entirely. Signed-off-by: Joonwoo Park <joonwpark81@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[TCP]: Move FRTO checks out from write queue abstraction funcsIlpo Järvinen
Better place exists in update_send_head (other non-queue related adjustments are done there as well) which is the only caller of tcp_advance_send_head (now that the bogus call from mtu_probe is gone). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[NET]: Make macro to specify the ptype_base sizePavel Emelyanov
Currently this size is 16, but as the comment says this is so only because all the chains (except one) has the length 1. I think, that some day this may change, so growing this hash will be much easier. Besides, symbolic names are read better than magic constants. 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>
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>
2008-01-28[DCCP]: Add support for abortive releaseGerrit Renker
This continues from the previous patch and adds support for actively aborting a DCCP connection, using a Reset Code 2, "Aborted" to inform the peer of an abortive release. I have tried this in various client/server settings and it works as expected. 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]: Check for unread data on closeGerrit Renker
This removes one FIXME with regard to close when there is still unread data. The mechanism is implemented similar to TCP: with regard to DCCP-specifics, a Reset with Code 2, "Aborted" is sent to the peer. This corresponds in part to RFC 4340, 8.1.1 and 8.1.5. 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[CCID2]: Remove misleading commentGerrit Renker
This removes a comment which identifies an `issue' with dccp_write_xmit() where there is none. The comment assumes it is possible that a packet is sent between the calls to ccid_hc_tx_send_packet(), dccp_transmit_skb(), ccid_hc_tx_packet_sent() (in the above order) in dccp_write_xmit(). I think that this is impossible, since dccp_write_xmit() is always called under lock: * when called as dccp_write_xmit(sk, 1) from dccp_send_close(), the socket is locked (see code comment above dccp_send_close()); * when called as dccp_write_xmit(sk, 0) from dccp_send_msg(), it is after lock_sock() has been called; * when called as dccp_write_xmit(sk, 0) from dccp_write_xmit_timer(), bh_lock_sock() has been called and the if/else statement has made sure that sk_lock.owner is not set; * there are no other places where dccp_write_xmit() is called. Furthermore, the debug statement for printing the sequence number of the packet just sent has been removed, since the entire list is being printed anyway and so the entry of that number appears last. 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@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[CCID2]: Remove redundant ack-counting variableGerrit Renker
The code used two different variables to count Acks, one of them redundant. This patch reduces the number of Ack counters to one. The type of the Ack counter has also been changed to u32 (twice the range of int); and the variable has been renamed into `packets_acked' - for consistency with RFC 3465 (and similarly named variables are used by TCP and SCTP). Lastly, a slightly less aggressive `maxincr' increment is used (for even Ack Ratios, maxincr was Ack Ratio/2 + 1 instead of Ack Ratio/2). 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@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[CCID2]: Remove redundant synchronisation variableGerrit Renker
This removes the synchronisation variable `ccid2hctx_sendwait', which is set to 1 when the CCID2 sender may send a new packet, and which is set to 0 otherwise The variable is redundant, since it is only used in combination with the hc_tx_send_packet/ hc_tx_packet_sent function pair. Both functions are called under socket lock, so the following happens when the CCID2 may send a new packet: * it sets sendwait = 1 in tx_send_packet and returns 0; * the subsequent call to tx_packet_sent clears the sendwait flag; * since tx_send_packet returns 0 if and only if sendwait == 1, the BUG_ON condition in tx_packet_sent is never satisfied, since that function is never called when tx_send_packet returns a value different from 0 (cf. dccp_write_xmit); * the call to tx_packet_sent clears the flag so that the condition "!sendwait" is true the next time tx_packet_sent is called. In other words, it is sufficient to just return 0 / not-0 to synchronise tx_send_packet and tx_packet_sent -- which is what the patch does. 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@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[CCID2]: Redundant debugging outputGerrit Renker
This reduces the amount of redundant debugging messages: * pipe/cwnd are printed in both tx_send_packet() and tx_packet_sent(). Both functions are called immediately after one another, so one occurrence is sufficient. * Since tx_packet_sent() prints pipe/cwnd already, the second printk for pipe is redundant. * In tx_packet_sent() the check_sanity function is called twice (at the begin and at the end). 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@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[CCID2]: Replace pipe assignment-function with assignmentGerrit Renker
The function ccid2_change_pipe only does an assignment. This patch simplifies the code by replacing the function with the assignment it performs. Furthermore, the type of pipe is promoted from `signed' to unsigned (increasing the range). As a result, a BUG_ON test for negative values now becomes obsolete (for safety not removed, but replaced with a less annoying `DCCP_BUG'). 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[CCID2]: Replace cwnd assignment-function with assignmentGerrit Renker
The current function ccid2_change_cwnd in effect makes only an assignment, as the test whether cwnd has reached 0 is only required when cwnd is halved. This patch simplifies the code by replacing the function with the assignment it performs. Furthermore, since ssthresh derives from cwnd and appears in many assignments and comparisons, the type of ssthresh has also been changed to match that of cwnd. 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[CCID2]: Replace read-only variable with constantGerrit Renker
This replaces the field member `numdupack', which was used as a read-only constant in the code, with a #define. 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[CCID2]: Remove unused variableGerrit Renker
This removes a variable `ccid2hctx_sent' which is incremented but never referenced/read (i.e., dead code). 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[CCID2]: Disable broken Ack Ratio adaptation algorithmGerrit Renker
This comments out a problematic section comprising a half-finished algorithm: - The variable `ccid2hctx_ackloss' is never initialised to a value different from 0 and hence in fact is a read-only constant. - The `arsent' variable counts packets other than Acks (it is incremented for every packet), and there is no test for Ack Loss. - The concept of counting Acks as such leads to a complex calculation, and the calculation at the moment is inconsistent with this concept. The problem is that the number of Acks - rather than the number of windows - is counted, which leads to a complex (cubic/quadratic) expression - this is not even implemented. In its current state, the commented-out algorithm interfers with normal processing by changing Ack Ratio incorrectly, and at the wrong times. A new algorithm is necessary, which will not necessarily use the same variables as used by the unfinished one; hence the old variables have been removed. 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@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[CCID2]: Larger initial windows also for CCID2Gerrit Renker
RFC 4341, sec. 5 states that "The cwnd parameter is initialized to at most four packets for new connections, following the rules from [RFC3390]", which is implemented by this patch. 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@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[DCCP]: Initialize dccp_sock before calling the ccid constructorsArnaldo Carvalho de Melo
This is because in the next patch CCID2 will assume that dccps_mss_cache is non-zero. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[CCID2]: Deadlock and spurious timeouts when Ack Ratio > cwndGerrit Renker
This patch removes a bug in the current code. I agree with Andrea's comment that there is a problem here but the way it is treated does not fix it. The problem is that whenever Ack Ratio > cwnd, starvation/deadlock occurs: * the receiver will not send an Ack until (Ack Ratio - cwnd) data packets have arrived; * the sender will not send any data packet before the receipt of an Ack advances the send window. The only way that the connection then progresses was via RTO timeout. In one extreme case (bulk transfer), it was observed that this happened for every single packet; i.e. hundreds of packets, each a RTO timeout of 1..3 seconds apart: a transfer which normally would take a fraction of a second thus grew to several minutes. The solution taken by this approach is to observe the relation "Ack Ratio <= cwnd" by using the constraint (1) from RFC 4341, 6.1.2; i.e. set Ack Ratio = ceil(cwnd / 2) and update it whenever either Ack Ratio or cwnd change. This ensures that the deadlock problem can not arise. 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@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[CCID2]: Don't assign negative values to Ack RatioGerrit Renker
Since it makes not sense to assign negative values to Ack Ratio, this patch disallows this possibility. As a consequence, a Bug test for negative Ack Ratio values becomes obsolete. Furthermore, a check against overflow (as Ack Ratio may not exceed 2 bytes, due to RFC 4340, 11.3) has been added. 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@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[CCID2]: Fix sequence number arithmetic/comparisonsGerrit Renker
This replaces use of normal subtraction with modulo-48 subtraction. 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@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[CCID2]: Bug in reading Ack VectorsGerrit Renker
In CCID2 the receiver-history is sorted in ascending order of sequence number, but the processing of received Ack Vectors requires the list traversal in the opposite direction. The current code has a bug in this regard: the list traversal is upwards. As a consequence, only Ack Vectors with a run length of 1 will pass, in all other Ack Vectors the remaining (acked) sequence numbers are missed, and may later falsely be identified as lost. Note: This bug is only visible when Ack Ratio > 1, since otherwise the run lengths of Ack Vectors are 0. 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[ACKVEC]: Reduce length of identifiersGerrit Renker
This is reduces the length of the struct ackvec/ackvec_record fields. It is a purely text-based replacement: s#dccpavr_#avr_#g; s#dccpav_#av_#g; and increases readability somewhat. 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[PCOUNTER] Fix build error without CONFIG_SMPIlpo Järvinen
I keep getting this build error and couldn't find anyone fixing it in archives. ...Maybe all net developers except me build just SMP kernels :-). In file included from include/net/sock.h:50, from ipc/mqueue.c:35: include/linux/pcounter.h: In function 'pcounter_add': include/linux/pcounter.h:87: error: 'struct pcounter' has no member named 'value' make[1]: *** [ipc/mqueue.o] Error 1 make: *** [ipc] Error 2 Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[IPV6]: Correct the comment concerning inetsw6 tablePavel Emelyanov
It seems that net/ipv6/af_inet6.c was copied from net/ipv4/af_inet.c, but one comment was not fixed. 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>
2008-01-28[UNIX] Move the unix sock iterators in to proper placePavel Emelyanov
The first_unix_socket() and next_unix_sockets() are now used in proc file and in forall_unix_socets macro only. The forall_unix_sockets is not used in this file at all so remove it. After this move the helpers to where they really belong, i.e. closer to proc code under the #ifdef CONFIG_PROC_FS option. 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>
2008-01-28[DCCP]: Update documentation on ioctlsGerrit Renker
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@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[DCCP]: Ignore Ack Vectors / Elapsed Time on DCCP-Request alsoGerrit Renker
Small update with regard to RFC 4340 (references added as documentation): on Requests, Ack Vectors / Elapsed Time should be ignored. Length handling of Elapsed Time also simplified. 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]: Remove redundant dependency on IP_DCCPGerrit Renker
This cleans up the consequences of an earlier patch which introduced the `if IP_DCCP' clause into net/dccp/Kconfig. The CCID Kconfig menu is sourced within this clause; as a consequence, all tests of type `depends on IP_DCCP' are now redundant. 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]: Promote CCID2 as default CCIDGerrit Renker
This patch addresses the following problems: 1. DCCP relies for its proper functioning on having at least one CCID module enabled (as in TCP plugable congestion control). Currently it is possible to disable both CCIDs and thus leave the DCCP module in a compiled, but entirely non-functional state: no sockets can be created when no CCID is available. Furthermore, the protocol is (again like TCP) not intended to be used without CCIDs. Last, a non-empty CCID list is needed for doing CCID feature negotiation. 2. Internally the default CCID that is advertised by the Linux host is set to CCID2 (DCCPF_INITIAL_CCID in include/linux/dccp.h). Disabling CCID2 in the Kconfig menu without changing the defaults leads to a failure `module not found' when trying to load the dccp module (which internally tries to load the default CCID). 3. The specification (RFC 4340, sec. 10) treats CCID2 somewhat like a `minimum common denominator'; the specification says that: * "New connections start with CCID 2 for both endpoints" * "A DCCP implementation intended for general use, such as an implementation in a general-purpose operating system kernel, SHOULD implement at least CCID 2. The intent is to make CCID 2 broadly available for interoperability [...]" Providing CCID2 as minimum-required CCID (like Reno/Cubic in TCP) thus seems reasonable. Hence this patch automatically selects CCID2 when DCCP is enabled. Documentation also added. Discussions with Ian McDonald on this subject are gratefully acknowledged. 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]: Update documentationGerrit Renker
This updates the DCCP documentation, following input from Ian McDonald, clarifiying the status of DCCP, and adding a note about the test tree. 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]: Honour and make use of shutdown option set by userGerrit Renker
This extends the DCCP socket API by honouring any shutdown(2) option set by the user. The behaviour is, as much as possible, made consistent with the API for TCP's shutdown. This patch exploits the information provided by the user via the socket API to reduce processing costs: * if the read end is closed (SHUT_RD), it is not necessary to deliver to input CCID; * if the write end is closed (SHUT_WR), the same idea applies, but with a difference - as long as the TX queue has not been drained, we need to receive feedback to keep congestion-control rates up to date. Hence SHUT_WR is honoured only after the last packet (under congestion control) has been sent; * although SHUT_RDWR seems nonsensical, it is nevertheless supported in the same manner as for TCP (and agrees with test for SHUTDOWN_MASK in dccp_poll() in net/dccp/proto.c). Furthermore, most of the code already honours the sk_shutdown flags (dccp_recvmsg() for instance sets the read length to 0 if SHUT_RD had been called); CCID handling is now added to this by the present patch. There will also no longer be any delivery when the socket is in the final stages, i.e. when one of dccp_close(), dccp_fin(), or dccp_done() has been called - which is fine since at that stage the connection is its final stages. Motivation and background are on http://www.erg.abdn.ac.uk/users/gerrit/dccp/notes/shutdown A FIXME has been added to notify the other end if SHUT_RD has been set (RFC 4340, 11.7). Note: There is a comment in inet_shutdown() in net/ipv4/af_inet.c which asks to "make sure the socket is a TCP socket". This should probably be extended to mean `TCP or DCCP socket' (the code is also used by UDP and raw sockets). 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]: Make PARTOPEN an autonomous stateGerrit Renker
This decouples PARTOPEN from TCP-specific stream-states. It thus addresses the FIXME. The code has been checked with regard to dependency on PARTOPEN and FIN_WAIT1 states (to which PARTOPEN previously was mapped): there is no difference, as PARTOPEN is always referred to directly (i.e. not via the mapping to TCP state). 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[CCID3]: Inline for moving averageGerrit Renker
The moving average computation occurs so frequently in the CCID 3 code that it merits an inline function of its own. This is uses a suggestion by Arnaldo as per http://www.mail-archive.com/dccp@vger.kernel.org/msg01662.html 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[CCID3]: Accurately determine idle & application-limited periodsGerrit Renker
This fixes/updates the handling of idle and application-limited periods in CCID3, which currently is broken: there is no detection as to how long a sender has been idle - there is only one flag which is toggled in between function calls. Being obsolete now, the `idle' flag is removed. 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[CCID3]: Ignore trivial amounts of elapsed timeGerrit Renker
This patch fixes a previously undiscovered bug; the problem is in computing the elapsed time as the time between `receiving' the packet (i.e. skb enters CCID module) and sending feedback: - there is no layer-processing, queueing, or delay involved, - hence the elapsed time is in the order of 1 function call - this is in the dimension of maximally 50..100usec - which renders the use of elapsed time almost entirely useless. The fix is simply to ignore such trivial amounts of elapsed time. As a further advantage, the now useless elapsed_time field can be removed from the socket, which reduces the socket structure by another four bytes. 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>