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* tcp: better retrans tracking for defer-acceptEric Dumazet2012-11-031-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For passive TCP connections using TCP_DEFER_ACCEPT facility, we incorrectly increment req->retrans each time timeout triggers while no SYNACK is sent. SYNACK are not sent for TCP_DEFER_ACCEPT that were established (for which we received the ACK from client). Only the last SYNACK is sent so that we can receive again an ACK from client, to move the req into accept queue. We plan to change this later to avoid the useless retransmit (and potential problem as this SYNACK could be lost) TCP_INFO later gives wrong information to user, claiming imaginary retransmits. Decouple req->retrans field into two independent fields : num_retrans : number of retransmit num_timeout : number of timeouts num_timeout is the counter that is incremented at each timeout, regardless of actual SYNACK being sent or not, and used to compute the exponential timeout. Introduce inet_rtx_syn_ack() helper to increment num_retrans only if ->rtx_syn_ack() succeeded. Use inet_rtx_syn_ack() from tcp_check_req() to increment num_retrans when we re-send a SYNACK in answer to a (retransmitted) SYN. Prior to this patch, we were not counting these retransmits. Change tcp_v[46]_rtx_synack() to increment TCP_MIB_RETRANSSEGS only if a synack packet was successfully queued. Reported-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Julian Anastasov <ja@ssi.bg> Cc: Vijay Subramanian <subramanian.vijay@gmail.com> Cc: Elliott Hughes <enh@google.com> Cc: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* dccp: fix info leak via getsockopt(DCCP_SOCKOPT_CCID_TX_INFO)Mathias Krause2012-08-151-0/+1
| | | | | | | | | | | | The CCID3 code fails to initialize the trailing padding bytes of struct tfrc_tx_info added for alignment on 64 bit architectures. It that for potentially leaks four bytes kernel stack via the getsockopt() syscall. Add an explicit memset(0) before filling the structure to avoid the info leak. Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* dccp: check ccid before dereferencingMathias Krause2012-08-151-2/+2
| | | | | | | | | | | | ccid_hc_rx_getsockopt() and ccid_hc_tx_getsockopt() might be called with a NULL ccid pointer leading to a NULL pointer dereference. This could lead to a privilege escalation if the attacker is able to map page 0 and prepare it with a fake ccid_ops pointer. Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk> Cc: stable@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Prepare for change of rt->rt_iif encoding.David S. Miller2012-07-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | Use inet_iif() consistently, and for TCP record the input interface of cached RX dst in inet sock. rt->rt_iif is going to be encoded differently, so that we can legitimately cache input routes in the FIB info more aggressively. When the input interface is "use SKB device index" the rt->rt_iif will be set to zero. This forces us to move the TCP RX dst cache installation into the ipv4 specific code, and as well it should since doing the route caching for ipv6 is pointless at the moment since it is not inspected in the ipv6 input paths yet. Also, remove the unlikely on dst->obsolete, all ipv4 dsts have obsolete set to a non-zero value to force invocation of the check callback. Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Kill FLOWI_FLAG_RT_NOCACHE and associated code.David S. Miller2012-07-201-1/+1
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Pass optional SKB and SK arguments to dst_ops->{update_pmtu,redirect}()David S. Miller2012-07-172-2/+2
| | | | | | | | | | | | | | | | This will be used so that we can compose a full flow key. Even though we have a route in this context, we need more. In the future the routes will be without destination address, source address, etc. keying. One ipv4 route will cover entire subnets, etc. In this environment we have to have a way to possess persistent storage for redirects and PMTU information. This persistent storage will exist in the FIB tables, and that's why we'll need to be able to rebuild a full lookup flow key here. Using that flow key will do a fib_lookup() and create/update the persistent entry. Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv6: Add helper inet6_csk_update_pmtu().David S. Miller2012-07-161-31/+4
| | | | | | This is the ipv6 version of inet_csk_update_pmtu(). Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Add helper inet_csk_update_pmtu().David S. Miller2012-07-161-9/+2
| | | | | | | | | | | | | | | This abstracts away the call to dst_ops->update_pmtu() so that we can transparently handle the fact that, in the future, the dst itself can be invalidated by the PMTU update (when we have non-host routes cached in sockets). So we try to rebuild the socket cached route after the method invocation if necessary. This isn't used by SCTP because it needs to cache dsts per-transport, and thus will need it's own local version of this helper. Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Remove checks for dst_ops->redirect being NULL.David S. Miller2012-07-122-2/+2
| | | | | | No longer necessary. Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv6: Add redirect support to all protocol icmp error handlers.David S. Miller2012-07-121-0/+7
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Add redirect support to all protocol icmp error handlers.David S. Miller2012-07-111-0/+11
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Fix (nearly-)kernel-doc comments for various functionsBen Hutchings2012-07-1011-5/+31
| | | | | | | | 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>
* dccp: remove unnecessary codes in ipv6.cRongQing.Li2012-07-051-16/+5
| | | | | | | | | opt always equals np->opts, so it is meaningless to define opt, and check if opt does not equal np->opts and then try to free opt. Signed-off-by: RongQing.Li <roy.qing.li@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: tcp: dont cache output dst for syncookiesEric Dumazet2012-06-221-1/+1
| | | | | | | | | | Don't cache output dst for syncookies, as this adds pressure on IP route cache and rcu subsystem for no gain. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Hans Schillstrom <hans.schillstrom@ericsson.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv6: Handle PMTU in ICMP error handlers.David S. Miller2012-06-151-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One tricky issue on the ipv6 side vs. ipv4 is that the ICMP callouts to handle the error pass the 32-bit info cookie in network byte order whereas ipv4 passes it around in host byte order. Like the ipv4 side, we have two helper functions. One for when we have a socket context and one for when we do not. ip6ip6 tunnels are not handled here, because they handle PMTU events by essentially relaying another ICMP packet-too-big message back to the original sender. This patch allows us to get rid of rt6_do_pmtu_disc(). It handles all kinds of situations that simply cannot happen when we do the PMTU update directly using a fully resolved route. In fact, the "plen == 128" check in ip6_rt_update_pmtu() can very likely be removed or changed into a BUG_ON() check. We should never have a prefixed ipv6 route when we get there. Another piece of strange history here is that TCP and DCCP, unlike in ipv4, never invoke the update_pmtu() method from their ICMP error handlers. This is incredibly astonishing since this is the context where we have the most accurate context in which to make a PMTU update, namely we have a fully connected socket and associated cached socket route. Signed-off-by: David S. Miller <davem@davemloft.net>
* net: include/net/sock.h cleanupEric Dumazet2012-05-171-2/+2
| | | | | | | | | | | bool/const conversions where possible __inline__ -> inline space cleanups Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Convert all sysctl registrations to register_net_sysctlEric W. Biederman2012-04-201-8/+1
| | | | | | | | | | | | This results in code with less boiler plate that is a bit easier to read. Additionally stops us from using compatibility code in the sysctl core, hastening the day when the compatibility code can be removed. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Move all of the network sysctls without a namespace into init_net.Eric W. Biederman2012-04-201-2/+2
| | | | | | | | | | | | | | | | This makes it clearer which sysctls are relative to your current network namespace. This makes it a little less error prone by not exposing sysctls for the initial network namespace in other namespaces. This is the same way we handle all of our other network interfaces to userspace and I can't honestly remember why we didn't do this for sysctls right from the start. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv6: dccp: dont drop packet but consume itEric Dumazet2012-04-191-1/+1
| | | | | | | | When we need to clone skb, we dont drop a packet. Call consume_skb() to not confuse dropwatch. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: cleanup unsigned to unsigned intEric Dumazet2012-04-153-15/+15
| | | | | | | 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>
* inet: makes syn_ack_timeout mandatoryEric Dumazet2012-04-142-0/+7
| | | | | | | | | | | | There are two struct request_sock_ops providers, tcp and dccp. inet_csk_reqsk_queue_prune() can avoid testing syn_ack_timeout being NULL if we make it non NULL like syn_ack_timeout Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk> Cc: dccp@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
* dccp: fix bug in sequence number validation during connection setupSamuel Jero2012-03-034-18/+26
| | | | | | | | | | | | | | This fixes a bug in the sequence number validation during the initial handshake. The code did not treat the initial sequence numbers ISS and ISR as read-only and did not keep state for GSR and GSS as required by the specification. This causes problems with retransmissions during the initial handshake, causing the budding connection to be reset. This patch now treats ISS/ISR as read-only and tracks GSS/GSR as required. Signed-off-by: Samuel Jero <sj323707@ohio.edu> Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* dccp ccid-3: replace incorrect BUG_ONGerrit Renker2012-03-031-2/+1
| | | | | | | | | | | This replaces an unjustified BUG_ON(), which could get triggered under normal conditions: X_calc can be 0 when p > 0. X would in this case be set to the minimum, s/t_mbi. Its replacement avoids t_ipi = 0 (unbounded sending rate). Thanks to Jordi, Victor and Xavier who reported this. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.uk>
* inet_diag: Rename inet_diag_req into inet_diag_req_v2Pavel Emelyanov2012-01-111-2/+2
| | | | | Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* module_param: make bool parameters really bool (net & drivers/net)Rusty Russell2011-12-196-7/+7
| | | | | | | | | | | | | | | | 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>
* net: fix assignment of 0/1 to bool variables.Rusty Russell2011-12-192-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | DaveM said: Please, this kind of stuff rots forever and not using bool properly drives me crazy. Joe Perches <joe@perches.com> gave me the spatch script: @@ bool b; @@ -b = 0 +b = false @@ bool b; @@ -b = 1 +b = true I merely installed coccinelle, read the documentation and took credit. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* sock_diag: Fix module netlink aliasesPavel Emelyanov2011-12-161-1/+1
| | | | | | | | | | | | | | I've made a mistake when fixing the sock_/inet_diag aliases :( 1. The sock_diag layer should request the family-based alias, not just the IPPROTO_IP one; 2. The inet_diag layer should request for AF_INET+protocol alias, not just the protocol one. Thus fix this. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: use IS_ENABLED(CONFIG_IPV6)Eric Dumazet2011-12-112-2/+2
| | | | | | | 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>
* inet_diag: Generalize inet_diag dump and get_exact callsPavel Emelyanov2011-12-091-1/+14
| | | | | | | | | | | | | | | Introduce two callbacks in inet_diag_handler -- one for dumping all sockets (with filters) and the other one for dumping a single sk. Replace direct calls to icsk handlers with indirect calls to callbacks provided by handlers. Make existing TCP and DCCP handlers use provided helpers for icsk-s. The UDP diag module will provide its own. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet_diag: Remove indirect sizeof from inet diag handlersPavel Emelyanov2011-12-091-1/+0
| | | | | | | | | There's an info_size value stored on inet_diag_handler, but for existing code this value is effectively constant, so just use sizeof(struct tcp_info) where required. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet_diag: Switch from _GETSOCK to IPPROTO_ numbersPavel Emelyanov2011-12-061-2/+2
| | | | | | | | | | | Sorry, but the vger didn't let this message go to the list. Re-sending it with less spam-filter-prone subject. When dumping the AF_INET/AF_INET6 sockets user will also specify the protocol, so prepare the protocol diag handlers to work with IPPROTO_ constants. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* inet_diag: Partly rename inet_ to sock_Pavel Emelyanov2011-12-061-1/+1
| | | | | | | | | | The ultimate goal is to get the sock_diag module, that works in family+protocol terms. Currently this is suitable to do on the inet_diag basis, so rename parts of the code. It will be moved to sock_diag.c later. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* dccp: Fix compile warning in probe code.David S. Miller2011-12-011-2/+12
| | | | | | | | | | | | | | | | | | | | | Commit 1386be55e32a3c5d8ef4a2b243c530a7b664c02c ("dccp: fix auto-loading of dccp(_probe)") fixed a bug but created a new compiler warning: net/dccp/probe.c: In function ‘dccpprobe_init’: net/dccp/probe.c:166:2: warning: the omitted middle operand in ?: will always be ‘true’, suggest explicit middle operand [-Wparentheses] try_then_request_module() is built for situations where the "existence" test is some lookup function that returns a non-NULL object on success, and with a reference count of some kind held. Here we're looking for a success return of zero from the jprobe registry. Instead of fighting the way try_then_request_module() works, simply open code what we want to happen in a local helper function. Signed-off-by: David S. Miller <davem@davemloft.net>
* dccp: Evaluate ip_hdr() only once in dccp_v4_route_skb().David S. Miller2011-12-011-2/+3
| | | | | | | | This also works around a bogus gcc warning generated by an upcoming patch from Eric Dumazet that rearranges the layout of struct flowi4. Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2011-11-261-0/+1
|\ | | | | | | | | Conflicts: net/ipv4/inet_diag.c
| * dccp: fix error propagation in dccp_v4_connectRongQing.Li2011-11-211-0/+1
| | | | | | | | | | | | | | The errcode is not updated when ip_route_newports() fails. Signed-off-by: RongQing.Li <roy.qing.li@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: remove ipv6_addr_copy()Alexey Dobriyan2011-11-222-23/+23
| | | | | | | | | | | | | | C assignment can handle struct in6_addr copying. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: rename sk_clone to sk_clone_lockEric Dumazet2011-11-081-1/+1
|/ | | | | | | | | | Make clear that sk_clone() and inet_csk_clone() return a locked socket. Add _lock() prefix and kerneldoc. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds2011-11-063-0/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h
| * net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modulesPaul Gortmaker2011-10-312-0/+2
| | | | | | | | | | | | | | | | | | These files are non modular, but need to export symbols using the macros now living in export.h -- call out the include so that things won't break when we remove the implicit presence of module.h from everywhere. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
| * net: add moduleparam.h for users of module_param/MODULE_PARM_DESCPaul Gortmaker2011-10-311-0/+1
| | | | | | | | | | | | | | | | These files were getting access to these two via the implicit presence of module.h everywhere. They aren't modules, so they don't need the full module.h inclusion though. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* | net: add missing bh_unlock_sock() callsEric Dumazet2011-11-031-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Simon Kirby reported lockdep warnings and following messages : [104661.897577] huh, entered softirq 3 NET_RX ffffffff81613740 preempt_count 00000101, exited with 00000102? [104661.923653] huh, entered softirq 3 NET_RX ffffffff81613740 preempt_count 00000101, exited with 00000102? Problem comes from commit 0e734419 (ipv4: Use inet_csk_route_child_sock() in DCCP and TCP.) If inet_csk_route_child_sock() returns NULL, we should release socket lock before freeing it. Another lock imbalance exists if __inet_inherit_port() returns an error since commit 093d282321da ( tproxy: fix hash locking issue when using port redirection in __inet_inherit_port()) a backport is also needed for >= 2.6.37 kernels. Reported-by: Simon Kirby <sim@hostway.ca> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Tested-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Balazs Scheidler <bazsi@balabit.hu> CC: KOVACS Krisztian <hidden@balabit.hu> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Simon Kirby <sim@hostway.ca> Signed-off-by: David S. Miller <davem@davemloft.net>
* | ipv6: tcp: fix TCLASS value in ACK messages sent from TIME_WAITEric Dumazet2011-10-271-2/+2
|/ | | | | | | | | | | | | | | commit 66b13d99d96a (ipv4: tcp: fix TOS value in ACK messages sent from TIME_WAIT) fixed IPv4 only. This part is for the IPv6 side, adding a tclass param to ip6_xmit() We alias tw_tclass and tw_tos, if socket family is INET6. [ if sockets is ipv4-mapped, only IP_TOS socket option is used to fill TOS field, TCLASS is not taken into account ] Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/netDavid S. Miller2011-08-072-7/+3
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| * net: Compute protocol sequence numbers and fragment IDs using MD5.David S. Miller2011-08-062-7/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Computers have become a lot faster since we compromised on the partial MD4 hash which we use currently for performance reasons. MD5 is a much safer choice, and is inline with both RFC1948 and other ISS generators (OpenBSD, Solaris, etc.) Furthermore, only having 24-bits of the sequence number be truly unpredictable is a very serious limitation. So the periodic regeneration and 8-bit counter have been removed. We compute and use a full 32-bit sequence number. For ipv6, DCCP was found to use a 32-bit truncated initial sequence number (it needs 43-bits) and that is fixed here as well. Reported-by: Dan Kaminsky <dan@doxpara.com> Tested-by: Willy Tarreau <w@1wt.eu> Signed-off-by: David S. Miller <davem@davemloft.net>
* | dccp ccid-2: check Ack Ratio when reducing cwndSamuel Jero2011-08-011-3/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch causes CCID-2 to check the Ack Ratio after reducing the congestion window. If the Ack Ratio is greater than the congestion window, it is reduced. This prevents timeouts caused by an Ack Ratio larger than the congestion window. In this situation, we choose to set the Ack Ratio to half the congestion window (or one if that's zero) so that if we loose one ack we don't trigger a timeout. Signed-off-by: Samuel Jero <sj323707@ohio.edu> Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* | dccp ccid-2: increment cwnd correctlySamuel Jero2011-08-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes an issue where CCID-2 will not increase the congestion window for numerous RTTs after an idle period, application-limited period, or a loss once the algorithm is in Congestion Avoidance. What happens is that, when CCID-2 is in Congestion Avoidance mode, it will increase hc->tx_packets_acked by one for every packet and will increment cwnd every cwnd packets. However, if there is now an idle period in the connection, cwnd will be reduced, possibly below the slow start threshold. This will cause the connection to go into Slow Start. However, in Slow Start CCID-2 performs this test to increment cwnd every second ack: ++hc->tx_packets_acked == 2 Unfortunately, this will be incorrect, if cwnd previous to the idle period was larger than 2 and if tx_packets_acked was close to cwnd. For example: cwnd=50 and tx_packets_acked=45. In this case, the current code, will increment tx_packets_acked until it equals two, which will only be once tx_packets_acked (an unsigned 32-bit integer) overflows. My fix is simply to change that test for tx_packets_acked greater than or equal to two in slow start. Signed-off-by: Samuel Jero <sj323707@ohio.edu> Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* | dccp ccid-2: prevent cwnd > Sequence WindowSamuel Jero2011-08-012-15/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a check to prevent CCID-2 from increasing the cwnd greater than the Sequence Window. When the congestion window becomes bigger than the Sequence Window, CCID-2 will attempt to keep more data in the network than the DCCP Sequence Window code considers possible. This results in the Sequence Window code issuing a Sync, thereby inducing needless overhead. Further, if this occurs at the sender, CCID-2 will never detect the problem because the Acks it receives will indicate no losses. I have seen this cause a drop of 1/3rd in throughput for a connection. Also add code to adjust the Sequence Window to be about 5 times the number of packets in the network (RFC 4340, 7.5.2) and to adjust the Ack Ratio so that the remote Sequence Window will hold about 5 times the number of packets in the network. This allows the congestion window to increase correctly without being limited by the Sequence Window. Signed-off-by: Samuel Jero <sj323707@ohio.edu> Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* | dccp ccid-2: use feature-negotiation to report Ack Ratio changesGerrit Renker2011-08-012-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | This uses the new feature-negotiation framework to signal Ack Ratio changes, as required by RFC 4341, sec. 6.1.2. That raises some problems with CCID-2, which at the moment can not cope gracefully with Ack Ratios > 1. Since these issues are not directly related to feature negotiation, they are marked by a FIXME. 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>
* | dccp: send Confirm options only onceSamuel Jero2011-08-011-5/+16
| | | | | | | | | | | | | | | | | | | | If a connection is in the OPEN state, remove feature negotiation Confirm options from the list of options after sending them once; as such options are NOT supposed to be retransmitted and are ONLY supposed to be sent in response to a Change option (RFC 4340 6.2). Signed-off-by: Samuel Jero <sj323707@ohio.edu> Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
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