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| * | IPVS: Convert procfs files for IPv6 entry outputVince Busam2008-09-052-18/+73
| | | | | | | | | | | | | | | | | | | | | Correctly output IPv6 connection/service/dest entries in procfs files. Signed-off-by: Vince Busam <vbusam@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Convert real server lookup functionsJulius Volz2008-09-055-37/+67
| | | | | | | | | | | | | | | | | | | | | | | | Convert functions for looking up destinations (real servers) to support IPv6 services/dests. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Add/adjust Netfilter hook functions and helpers for v6Julius Volz2008-09-051-36/+329
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add Netfilter hook functions or modify existing ones, if possible, to process IPv6 packets. Some support functions are also added/modified for this. ip_vs_nat_icmp_v6() was already added in the patch that added the v6 xmit functions, as it is called from one of them. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Extend scheduling functions for IPv6 supportJulius Volz2008-09-051-25/+31
| | | | | | | | | | | | | | | | | | | | | | | | Convert ip_vs_schedule() and ip_vs_sched_persist() to support scheduling of IPv6 connections. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Add and bind IPv6 xmit functionsJulius Volz2008-09-054-2/+472
| | | | | | | | | | | | | | | | | | | | | | | | Add xmit functions for IPv6. Also add the already needed __ip_vs_get_out_rt_v6() to ip_vs_core.c. Bind the new xmit functions to v6 connections. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Add IPv6 support to xmit() support functionsJulius Volz2008-09-051-7/+75
| | | | | | | | | | | | | | | | | | | | | | | | Add IPv6 support to IP_VS_XMIT() and to the xmit routing cache, introducing a new function __ip_vs_get_out_rt_v6(). Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Extend functions for getting/creating connectionsJulius Volz2008-09-058-163/+209
| | | | | | | | | | | | | | | | | | | | | | | | Extend functions for getting/creating connections and connection templates for IPv6 support and fix the callers. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Extend protocol DNAT/SNAT and state handlersJulius Volz2008-09-053-36/+142
| | | | | | | | | | | | | | | | | | | | | | | | Extend protocol DNAT/SNAT and state handlers to work with IPv6. Also change/introduce new checksumming helper functions for this. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Add protocol debug functions for IPv6Julius Volz2008-09-052-6/+93
| | | | | | | | | | | | | | | | | | | | | | | | Add protocol (TCP, UDP, AH, ESP) debug functions for IPv6 packet debug output. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Add 'af' args to protocol handler functionsJulius Volz2008-09-055-124/+171
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add 'af' arguments to conn_schedule(), conn_in_get(), conn_out_get() and csum_check() function pointers in struct ip_vs_protocol. Extend the respective functions for TCP, UDP, AH and ESP and adjust the callers. The changes in the callers need to be somewhat extensive, since they now need to pass a filled out struct ip_vs_iphdr * to the modified functions instead of a struct iphdr *. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Add IPv6 support flag to schedulersJulius Volz2008-09-0511-33/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add 'supports_ipv6' flag to struct ip_vs_scheduler to indicate whether a scheduler supports IPv6. Set the flag to 1 in schedulers that work with IPv6, 0 otherwise. This flag is checked in a later patch while trying to add a service with a specific scheduler. Adjust debug in v6-supporting schedulers to work with both address families. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Add v6 support to ip_vs_service_get()Julius Volz2008-09-054-19/+28
| | | | | | | | | | | | | | | | | | | | | | | | Add support for selecting services based on their address family to ip_vs_service_get() and adjust the callers. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Convert __ip_vs_svc_get() and __ip_vs_fwm_get()Julius Volz2008-09-051-32/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for getting services based on their address family to __ip_vs_service_get(), __ip_vs_fwm_get() and the helper hash function ip_vs_svc_hashkey(). Adjust the callers. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Add internal versions of sockopt interface structsJulius Volz2008-09-052-48/+129
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add extended internal versions of struct ip_vs_service_user and struct ip_vs_dest_user (the originals can't be modified as they are part of the old sockopt interface). Adjust ip_vs_ctl.c to work with the new data structures and add some minor AF-awareness. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Add debug macros for v4 and v6 address outputJulius Volz2008-09-051-0/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add some debugging macros that allow conditional output of either v4 or v6 addresses, depending on an 'af' parameter. This is done by creating a temporary string buffer in an outer debug macro and writing addresses' string representations into it from another macro which can only be used when inside the outer one. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Add general v4/v6 helper functions / data structuresJulius Volz2008-09-051-0/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a struct ip_vs_iphdr for easier handling of common v4 and v6 header fields in the same code path. ip_vs_fill_iphdr() helps to fill this struct from an IPv4 or IPv6 header. Add further helper functions for copying and comparing addresses. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Change IPVS data structures to support IPv6 addressesJulius Volz2008-09-0519-114/+121
| | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce new 'af' fields into IPVS data structures for specifying an entry's address family. Convert IP addresses to be of type union nf_inet_addr. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
| * | IPVS: Add CONFIG_IP_VS_IPV6 option for IPv6 supportJulius Volz2008-09-051-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add boolean config option CONFIG_IP_VS_IPV6 for enabling experimental IPv6 support in IPVS. Only visible if IPv6 support is set to 'y' or both IPv6 and IPVS are modules. Signed-off-by: Julius Volz <juliusv@google.com> Signed-off-by: Simon Horman <horms@verge.net.au>
* | | Merge branch 'master' of ↵David S. Miller2008-09-099-51/+89
|\ \ \ | |_|/ |/| | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
| * | ipv6: Fix OOPS in ip6_dst_lookup_tail().Neil Horman2008-09-091-32/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes kernel bugzilla 11469: "TUN with 1024 neighbours: ip6_dst_lookup_tail NULL crash" dst->neighbour is not necessarily hooked up at this point in the processing path, so blindly dereferencing it is the wrong thing to do. This NULL check exists in other similar paths and this case was just an oversight. Also fix the completely wrong and confusing indentation here while we're at it. Based upon a patch by Evgeniy Polyakov. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | ipsec: Restore larval states and socket policies in dumpHerbert Xu2008-09-092-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit commit 4c563f7669c10a12354b72b518c2287ffc6ebfb3 ("[XFRM]: Speed up xfrm_policy and xfrm_state walking") inadvertently removed larval states and socket policies from netlink dumps. This patch restores them. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | Merge branch 'master' of ↵David S. Miller2008-09-096-19/+54
| |\ \ | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/holtmann/bluetooth-2.6
| | * | [Bluetooth] Reject L2CAP connections on an insecure ACL linkMarcel Holtmann2008-09-094-5/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Security Mode 4 of the Bluetooth 2.1 specification has strict authentication and encryption requirements. It is the initiators job to create a secure ACL link. However in case of malicious devices, the acceptor has to make sure that the ACL is encrypted before allowing any kind of L2CAP connection. The only exception here is the PSM 1 for the service discovery protocol, because that is allowed to run on an insecure ACL link. Previously it was enough to reject a L2CAP connection during the connection setup phase, but with Bluetooth 2.1 it is forbidden to do any L2CAP protocol exchange on an insecure link (except SDP). The new hci_conn_check_link_mode() function can be used to check the integrity of an ACL link. This functions also takes care of the cases where Security Mode 4 is disabled or one of the devices is based on an older specification. Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
| | * | [Bluetooth] Enforce correct authentication requirementsMarcel Holtmann2008-09-094-7/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the introduction of Security Mode 4 and Simple Pairing from the Bluetooth 2.1 specification it became mandatory that the initiator requires authentication and encryption before any L2CAP channel can be established. The only exception here is PSM 1 for the service discovery protocol (SDP). It is meant to be used without any encryption since it contains only public information. This is how Bluetooth 2.0 and before handle connections on PSM 1. For Bluetooth 2.1 devices the pairing procedure differentiates between no bonding, general bonding and dedicated bonding. The L2CAP layer wrongly uses always general bonding when creating new connections, but it should not do this for SDP connections. In this case the authentication requirement should be no bonding and the just-works model should be used, but in case of non-SDP connection it is required to use general bonding. If the new connection requires man-in-the-middle (MITM) protection, it also first wrongly creates an unauthenticated link key and then later on requests an upgrade to an authenticated link key to provide full MITM protection. With Simple Pairing the link key generation is an expensive operation (compared to Bluetooth 2.0 and before) and doing this twice during a connection setup causes a noticeable delay when establishing a new connection. This should be avoided to not regress from the expected Bluetooth 2.0 connection times. The authentication requirements are known up-front and so enforce them. To fulfill these requirements the hci_connect() function has been extended with an authentication requirement parameter that will be stored inside the connection information and can be retrieved by userspace at any time. This allows the correct IO capabilities exchange and results in the expected behavior. Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
| | * | [Bluetooth] Fix reference counting during ACL config stageMarcel Holtmann2008-09-091-7/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ACL config stage keeps holding a reference count on incoming connections when requesting the extended features. This results in keeping an ACL link up without any users. The problem here is that the Bluetooth specification doesn't define an ownership of the ACL link and thus it can happen that the implementation on the initiator side doesn't care about disconnecting unused links. In this case the acceptor needs to take care of this. Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
* | | | ipsec: Make xfrm_larval_drop default to 1.David S. Miller2008-09-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The previous default behavior is definitely the least user friendly. Hanging there forever just because the keying daemon is wedged or the refreshing of the policy can't move forward is anti-social to say the least. Signed-off-by: David S. Miller <davem@davemloft.net>
* | | | Merge branch 'master' of git://eden-feed.erg.abdn.ac.uk/net-next-2.6David S. Miller2008-09-0936-3971/+2884
|\ \ \ \
| * | | | This reverts "Merge branch 'dccp' of git://eden-feed.erg.abdn.ac.uk/dccp_exp"Gerrit Renker2008-09-0936-3971/+2884
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | as it accentally contained the wrong set of patches. These will be submitted separately. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* | | | | bnx2x: EEH recovery fixYitchak Gertner2008-09-091-12/+83
|/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When EEH detects an i/o error it resets the device thus it cannot be accessed. In this case the driver needs to unload its interface only with OS, kernel and network stack but not with the device. After successful recovery, the driver can load normally. Signed-off-by: Yitchak Gertner <gertner@broadcom.com> Signed-off-by: Eilon Greenstein <eilong@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | | | Merge branch 'dccp' of git://eden-feed.erg.abdn.ac.uk/dccp_expDavid S. Miller2008-09-0836-2884/+3971
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: net/dccp/input.c net/dccp/options.c
| * | | | dccp ccid-3: Preventing OscillationsGerrit Renker2008-09-043-2/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This implements [RFC 3448, 4.5], which performs congestion avoidance behaviour by reducing the transmit rate as the queueing delay (measured in terms of long-term RTT) increases. Oscillation can be turned on/off via a module option (do_osc_prev) and via sysfs (using mode 0644), the default is off. Overflow analysis: ------------------ * oscillation prevention is done after update_x(), so that t_ipi <= 64000; * hence the multiplication "t_ipi * sqrt(R_sample)" needs 64 bits; * done using u64 for sqrt_sample and explicit typecast of t_ipi; * the divisor, R_sqmean, is non-zero because oscillation prevention is first called when receiving the second feedback packet, and tfrc_scaled_rtt() > 0. A detailed discussion of the algorithm (with plots) is on http://www.erg.abdn.ac.uk/users/gerrit/dccp/notes/ccid3/sender_notes/oscillation_prevention/ The algorithm has negative side effects: * when allowing to decrease t_ipi (leads to a large RTT) and * when using it during slow-start; both uses are therefore disabled. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp ccid-3: Simplify computing and range-checking of t_ipiGerrit Renker2008-09-041-10/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch simplifies the computation of t_ipi, avoiding expensive computations to enforce the minimum sending rate. Both RFC 3448 and rfc3448bis (revision #06), as well as RFC 4342 sec 5., require at various stages that at least one packet must be sent per t_mbi = 64 seconds. This requires frequent divisions of the type X_min = s/t_mbi, which are later converted back into an inter-packet-interval t_ipi_max = s/X_min = t_mbi. The patch removes the expensive indirection; in the unlikely case of having a sending rate less than one packet per 64 seconds, it also re-adjusts X. The following cases document conformance with RFC 3448 / rfc3448bis-06: 1) Time until receiving the first feedback packet: * if the sender has no initial RTT sample then X = s/1 Bps > s/t_mbi; * if the sender has an initial RTT sample or when the first feedback packet is received, X = W_init/R > s/t_mbi. 2) Slow-start (p == 0 and feedback packets come in): * RFC 3448 (current code) enforces a minimum of s/R > s/t_mbi; * rfc3448bis (future code) enforces an even higher minimum of W_init/R. 3) Congestion avoidance with no absence of feedback (p > 0): * when X_calc or X_recv/2 are too low, the minimum of X_min = s/t_mbi is enforced in update_x() when calling update_send_interval(); * update_send_interval() is, as before, only called when X changes (i.e. either when increasing or decreasing, not when in equilibrium). 4) Reduction of X without prior feedback or during slow-start (p==0): * both RFC 3448 and rfc3448bis here halve X directly; * the associated constraint X >= s/t_mbi is nforced here by send_interval(). 5) Reduction of X when p > 0: * X is modified indirectly via X_recv (RFC 3448) or X_recv_set (rfc3448bis); * in both cases, control goes back to section 4.3 (in both documents); * since p > 0, both documents use X = max(min(...), s/t_mbi), which is enforced in this patch by calling send_interval() from update_x(). I think that this analysis is exhaustive. Should I have forgotten a case, the worst-case consideration arises when X sinks below s/t_mbi, and is then increased back up to this minimum value. Even under this assumption, the behaviour is correct, since all lower limits of X in RFC 3448 / rfc3448bis are either equal to or greater than s/t_mbi. Note on the condition X >= s/t_mbi <==> t_ipi = s/X <= t_mbi: since X is scaled by 64, and all time units are in microseconds, the coded condition is: t_ipi = s * 64 * 10^6 usec / X <= 64 * 10^6 usec This simplifies to s / X <= 1 second <==> X * 1 second >= s > 0. (A zero `s' is not allowed by the CCID-3 code). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp ccid-3: Measuring the packet size s with regard to rfc3448bis-06Gerrit Renker2008-09-042-12/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rfc3448bis allows three different ways of tracking the packet size `s': 1. using the MSS/MPS (at initialisation, 4.2, and in 4.1 (1)); 2. using the average of `s' (in 4.1); 3. using the maximum of `s' (in 4.2). Instead of hard-coding a single interpretation of rfc3448bis, this implements a choice of all three alternatives and suggests the first as default, since it is the option which is most consistent with other parts of the specification. The patch further deprecates the update of t_ipi whenever `s' changes. The gains of doing this are only small since a change of s takes effect at the next instant X is updated: * when the next feedback comes in (within one RTT or less); * when the nofeedback timer expires (within at most 4 RTTs). Further, there are complications caused by updating t_ipi whenever s changes: * if t_ipi had previously been updated to effect oscillation prevention (4.5), then it is impossible to make the same adjustment to t_ipi again, thus counter-acting the algorithm; * s may be updated any time and a modification of t_ipi depends on the current state (e.g. no oscillation prevention is done in the absence of feedback); * in rev-06 of rfc3448bis, there are more possible cases, depending on whether the sender is in slow-start (t_ipi <= R/W_init), or in congestion-avoidance, limited by X_recv or the throughput equation (t_ipi <= t_mbi). Thus there are side effects of always updating t_ipi as s changes. These may not be desirable. The only case I can think of where such an update makes sense is to recompute X_calc when p > 0 and when s changes (not done by this patch). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp ccid-3: Tidy up CCID-Kconfig dependenciesGerrit Renker2008-09-041-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The per-CCID menu has several dependencies on EXPERIMENTAL. These are redundant, since net/dccp/ccids/Kconfig is sourced by net/dccp/Kconfig and since the latter menu in turn asserts a dependency on EXPERIMENTAL. The patch removes the redundant dependencies as well as the repeated reference within the sub-menu. Further changes: ---------------- Two single dependencies on CCID-3 are replaced with a single enclosing `if'. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp ccid-3: Implement rfc3448bis change to initial-rate computationGerrit Renker2008-09-041-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patch updates CCID-3 with regard to the latest rfc3448bis-06: * in the first revisions of the draft, MSS was used for the RFC 3390 window; * then (from revision #1 to revision #2), it used the packet size `s'; * now, in this revision (and apparently final), the value is back to MSS. This change has an implication for the case when no RTT sample is available, at the time of sending the first packet: * with RTT sample, 2*MSS/RTT <= initial_rate <= 4*MSS/RTT; * without RTT sample, the initial rate is one packet (s bytes) per second (sec. 4.2), but using s instead of MSS here creates an imbalance, since this would further reduce the initial sending rate. Hence the patch uses MSS (called MPS in RFC 4340) in all places. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp ccid-3: Update the RX history records in one placeGerrit Renker2008-09-045-56/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is a requirement for enabling ECN support later on. With that change in mind, the following preparations are done: * renamed handle_loss() into congestion_event() since it returns true when a congestion event happens (it will eventually also take care of ECN packets); * lets tfrc_rx_congestion_event() always update the RX history records, since this routine needs to be called for each non-duplicate packet anyway; * made all involved boolean-type functions to have return type `bool'; Updating the RX history records is now only necessary for the packets received up to sending the first feedback. The receiver code becomes again simpler. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp ccid-3: Update the computation of X_recvGerrit Renker2008-09-043-41/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This updates the computation of X_recv with regard to Errata 610/611 for RFC 4342 and draft rfc3448bis-06, ensuring that at least an interval of 1 RTT is used to compute X_recv. The change is wrapped into a new function ccid3_hc_rx_x_recv(). Further changes: ---------------- * feedback is not sent when no data packets arrived (bytes_recv == 0), as per rfc3448bis-06, 6.2; * take the timestamp for the feedback /after/ dccp_send_ack() returns, to avoid taking the transmission time into account (in case layer-2 is busy); * clearer handling of failure in ccid3_first_li(). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp tfrc: Increase number of RTT samplesGerrit Renker2008-09-041-59/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This improves the receiver RTT sampling algorithm so that it tries harder to get as many RTT samples as possible. The algorithm is based the concepts presented in RFC 4340, 8.1, using timestamps and the CCVal window counter. There exist 4 cases for the CCVal difference: * == 0: less than RTT/4 passed since last packet -- unusable; * > 4: (much) more than 1 RTT has passed since last packet -- also unusable; * == 4: perfect sample (exactly one RTT has passed since last packet); * 1..3: sub-optimal sample (between RTT/4 and 3*RTT/4 has passed). In the last case the algorithm tried to optimise by storing away the candidate and then re-trying next time. The problem is that * a large number of samples is needed to smooth out the inaccuracies of the algorithm; * the sender may not be sending enough packets to warrant a "next time"; * hence it is better to use suboptimal samples whenever possible. The algorithm now stores away the current sample only if the difference is 0. Applicability and background ---------------------------- A realistic example is MP3 streaming where packets are sent at a rate of less than one packet per RTT, which means that suitable samples are absent for a very long time. The effectiveness of using suboptimal samples (with a delta between 1 and 4) was confirmed by instrumenting the algorithm with counters. The results of two 20 second test runs were: * With the old algorithm and a total of 38442 function calls, only 394 of these calls resulted in usable RTT samples (about 1%), and 378 out of these were "perfect" samples and 28013 (unused) samples had a delta of 1..3. * With the new algorithm and a total of 37057 function calls, 1702 usable RTT samples were retrieved (about 4.6%), 5 out of these were "perfect" samples. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp: Clamping RTT valuesGerrit Renker2008-09-042-11/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This extracts the clamping part of dccp_sample_rtt() and makes it available to other parts of the code (as e.g. used in the next patch). Note: The function dccp_sample_rtt() now reduces to subtracting the elapsed time. This could be eliminated but would require shorter prefixes and thus is not done by this patch - maybe an idea for later. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp ccid-3: Always perform receiver RTT samplingGerrit Renker2008-09-044-49/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This updates the CCID-3 receiver in part with regard to errata 610 and 611 (http://www.rfc-editor.org/errata_list.php), which change RFC 4342 to use the Receive Rate as specified in rfc3448bis, requiring to constantly sample the RTT (or use a sender RTT). Doing this requires reusing the RX history structure after dealing with a loss. The patch does not resolve how to compute X_recv if the interval is less than 1 RTT. A FIXME has been added (and is resolved in subsequent patch). Furthermore, since this is all TFRC-based functionality, the RTT estimation is now also performed by the dccp_tfrc_lib module. This further simplifies the CCID-3 code. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp ccid-3: Remove duplicate RX statesGerrit Renker2008-09-042-48/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only state information that the CCID-3 receiver keeps is whether initial feedback has been sent or not. Further, this overlaps with use of feedback: * state == TFRC_RSTATE_NO_DATA as long as no feedback has been sent; * state == TFRC_RSTATE_DATA as soon as the first feedback has been sent. This patch reduces the duplication, by memorising the type of the last feedback. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp tfrc: Let dccp_tfrc_lib do the sampling workGerrit Renker2008-09-045-35/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This migrates more TFRC-related code into the dccp_tfrc_lib: * sampling of the packet size `s' (which is only needed until the first loss interval is computed (ccid3_first_li)); * updating the byte-counter `bytes_recvd' in between sending feedbacks. The result is a better separation of CCID-3 specific and TFRC specific code, which aids future integration with ECN and e.g. CCID-4. Further changes: ---------------- * replaced magic number of 536 with equivalent constant TCP_MIN_RCVMSS; (this constant is also used when no estimate for `s' is available). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp tfrc: Return type of update_i_mean is voidGerrit Renker2008-09-044-18/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This changes the return type of tfrc_lh_update_i_mean() to void, since that function returns always `false'. This is due to len = dccp_delta_seqno(cur->li_seqno, DCCP_SKB_CB(skb)->dccpd_seq) + 1; if (len - (s64)cur->li_length <= 0) /* duplicate or reordered */ return 0; which means that update_i_mean can only increase the length of the open loss interval I_0, and hence the value of I_tot0 (RFC 3448, 5.4). Consequently the test `i_mean < old_i_mean' at the end of the function always evaluates to false. There is no known way by which a loss interval can suddenly become shorter, therefore the return type of the function is changed to void. (That is, under the given circumstances step (3) in RFC 3448, 6.1 will not occur.) Further changes: ---------------- * the function is now called from tfrc_rx_handle_loss, which is equivalent to the previous way of calling from rx_packet_recv (it was called whenever there was no new or pending loss, now it is also updated when there is a pending loss - this increases the accuracy a bit); * added a FIXME to possibly consider NDP counting as per RFC 4342 (this is not implemented yet). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp tfrc: Perform early loss detectionGerrit Renker2008-09-042-9/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This enables the TFRC code to begin loss detection (as soon as the module is loaded), using the latest updates from rfc3448bis-06, 6.3.1: * when the first data packet(s) are lost or marked, set * X_target = s/(2*R) => f(p) = s/(R * X_target) = 2, * corresponding to a loss rate of ~ 20.64%. The handle_loss() function is now called right at the begin of rx_packet_recv() and thus no longer protected against duplicates: hence a call to rx_duplicate() has been added. Such a call makes sense now, as the previous patch initialises the first entry with a sequence number of GSR. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp tfrc: Receiver history initialisation routineGerrit Renker2008-09-043-24/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch 1) separates history allocation and initialisation, to facilitate early loss detection (implemented by a subsequent patch); 2) removes duplication by using the existing tfrc_rx_hist_purge() if the allocation fails. This is now possible, since the initialisation routine 3) zeroes out the entire history before using it. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp tfrc: Suppress unavoidable "below resolution" warningGerrit Renker2008-09-041-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the congestion-avoidance phase a decay of p towards 0 is natural once fewer losses are encountered. Hence the warning message "p is below resolution" is not necessary, and thus turned into a debug message by this patch. The TFRC_SMALLEST_P is needed since in theory p never actually reaches 0. When no further losses are encountered, the loss interval I_0 grows in length, causing p to decrease towards 0, causing X_calc = s/(RTT * f(p)) to increase. With the given minimum-resolution this congestion avoidance phase stops at some fixed value, an approximation formula has been added to the documentation. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp ccid-3: Simplified handling of TX statesGerrit Renker2008-09-042-44/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since CCIDs are only used during the established phase of a connection, they have very little internal state; this specifically reduces to: * "no packet sent" if and only if s == 0, for the TX packet size s; * when the first packet has been sent (i.e. `s' > 0), the question is whether or not feedback has been received: - if a feedback packet is received, "feedback = yes" is set, - if the nofeedback timer expires, "feedback = no" is set. Thus the CCID only needs to remember state about whether or not feedback has been received. This is now implemented using a boolean flag, which is toggled when a feedback packet arrives or the nofeedback timer expires. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp ccid-3: Runtime verification of timer resolutionGerrit Renker2008-09-043-3/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The DCCP base time resolution is 10 microseconds (RFC 4340, 13.1 ... 13.3). Using a timer with a lower resolution was found to trigger the following bug warnings/problems on high-speed networks (e.g. local loopback): * RTT samples are rounded down to 0 if below resolution; * in some cases, negative RTT samples were observed; * the CCID-3 feedback timer complains that the feedback interval is 0, since the feedback interval is in the order of 1 RTT or less and RTT measurement rounded this down to 0; On an Intel computer this will for instance happen when using a boot-time parameter of "clocksource=jiffies". The following system log messages were observed: 11:24:00 kernel: BUG: delta (0) <= 0 at ccid3_hc_rx_send_feedback() 11:26:12 kernel: BUG: delta (0) <= 0 at ccid3_hc_rx_send_feedback() 11:26:30 kernel: dccp_sample_rtt: unusable RTT sample 0, using min 11:26:30 last message repeated 5 times This patch defines a global constant for the time resolution, adds this in timer.c, and checks the available clock resolution at CCID-3 module load time. When the resolution is worse than 10 microseconds, module loading exits with a message "socket type not supported". Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
| * | | | dccp qpolicy: Parameter checking of cmsg qpolicy parametersTomasz Grobelny2008-09-043-6/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | | | dccp: Policy-based packet dequeueing infrastructureTomasz Grobelny2008-09-047-8/+246
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>