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* dccp: fix info leak via getsockopt(DCCP_SOCKOPT_CCID_TX_INFO)Mathias Krause2012-10-021-0/+1
| | | | | | | | | | | | | | | [ Upstream commit 7b07f8eb75aa3097cdfd4f6eac3da49db787381d ] 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dccp: check ccid before dereferencingMathias Krause2012-09-141-2/+2
| | | | | | | | | | | | | | | commit 276bdb82dedb290511467a5a4fdbe9f0b52dce6f upstream. 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> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* net: Compute protocol sequence numbers and fragment IDs using MD5.David S. Miller2011-08-152-7/+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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* ipv4: Make caller provide flowi4 key to inet_csk_route_req().David S. Miller2011-05-181-1/+2
| | | | | | | This way the caller can get at the fully resolved fl4->{daddr,saddr} etc. Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of ↵David S. Miller2011-05-111-0/+2
|\ | | | | | | | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-3.6 Conflicts: drivers/net/benet/be_main.c
| * dccp: handle invalid feature options lengthDan Rosenberg2011-05-061-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | A length of zero (after subtracting two for the type and len fields) for the DCCPO_{CHANGE,CONFIRM}_{L,R} options will cause an underflow due to the subtraction. The subsequent code may read past the end of the options value buffer when parsing. I'm unsure of what the consequences of this might be, but it's probably not good. Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> Cc: stable@kernel.org Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* | inet: Pass flowi to ->queue_xmit().David S. Miller2011-05-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | This allows us to acquire the exact route keying information from the protocol, however that might be managed. It handles all of the possibilities, from the simplest case of storing the key in inet->cork.fl to the more complex setup SCTP has where individual transports determine the flow. Signed-off-by: David S. Miller <davem@davemloft.net>
* | ipv4: Use inet_csk_route_child_sock() in DCCP and TCP.David S. Miller2011-05-081-9/+10
| | | | | | | | | | | | | | Operation order is now transposed, we first create the child socket then we try to hook up the route. Signed-off-by: David S. Miller <davem@davemloft.net>
* | dccp: Use cork flow in dccp_v4_connect()David S. Miller2011-05-081-5/+6
| | | | | | | | | | | | | | Since this is invoked from inet_stream_connect() the socket is locked and therefore this usage is safe. Signed-off-by: David S. Miller <davem@davemloft.net>
* | dccp: Use flowi4->saddr in dccp_v4_connect()David S. Miller2011-05-031-1/+1
| | | | | | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* | ipv4: Get route daddr from flow key in dccp_v4_connect().David S. Miller2011-04-281-1/+1
| | | | | | | | | | | | | | | | Now that output route lookups update the flow with destination address selection, we can fetch it from fl4->daddr instead of rt->rt_dst Signed-off-by: David S. Miller <davem@davemloft.net>
* | inet: add RCU protection to inet->optEric Dumazet2011-04-282-7/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We lack proper synchronization to manipulate inet->opt ip_options Problem is ip_make_skb() calls ip_setup_cork() and ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options), without any protection against another thread manipulating inet->opt. Another thread can change inet->opt pointer and free old one under us. Use RCU to protect inet->opt (changed to inet->inet_opt). Instead of handling atomic refcounts, just copy ip_options when necessary, to avoid cache line dirtying. We cant insert an rcu_head in struct ip_options since its included in skb->cb[], so this patch is large because I had to introduce a new ip_options_rcu structure. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* | ipv4: Sanitize and simplify ip_route_{connect,newports}()David S. Miller2011-04-271-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These functions are used together as a unit for route resolution during connect(). They address the chicken-and-egg problem that exists when ports need to be allocated during connect() processing, yet such port allocations require addressing information from the routing code. It's currently more heavy handed than it needs to be, and in particular we allocate and initialize a flow object twice. Let the callers provide the on-stack flow object. That way we only need to initialize it once in the ip_route_connect() call. Later, if ip_route_newports() needs to do anything, it re-uses that flow object as-is except for the ports which it updates before the route re-lookup. Also, describe why this set of facilities are needed and how it works in a big comment. Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
* | inet: constify ip headers and in6_addrEric Dumazet2011-04-221-4/+4
|/ | | | | | | | Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers where possible, to make code intention more obvious. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Fix common misspellingsLucas De Marchi2011-03-311-1/+1
| | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* net: Put fl6_* macros to struct flowi6 and use them again.David S. Miller2011-03-121-10/+10
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv6: Convert to use flowi6 where applicable.David S. Miller2011-03-121-66/+66
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Put fl4_* macros to struct flowi4 and use them again.David S. Miller2011-03-121-2/+2
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Use flowi4 in public route lookup interfaces.David S. Miller2011-03-121-10/+10
| | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Make flowi ports AF dependent.David S. Miller2011-03-122-12/+12
| | | | | | | | | | | | Create two sets of port member accessors, one set prefixed by fl4_* and the other prefixed by fl6_* This will let us to create AF optimal flow instances. It will work because every context in which we access the ports, we have to be fully aware of which AF the flowi is anyways. Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Put flowi_* prefix on AF independent members of struct flowiDavid S. Miller2011-03-122-18/+19
| | | | | | | | | | I intend to turn struct flowi into a union of AF specific flowi structs. There will be a common structure that each variant includes first, much like struct sock_common. This is the first step to move in that direction. Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of ↵David S. Miller2011-03-031-4/+3
|\ | | | | | | | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/bnx2x/bnx2x.h
| * dccp: fix oops on Reset after closeGerrit Renker2011-03-011-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes a bug in the order of dccp_rcv_state_process() that still permitted reception even after closing the socket. A Reset after close thus causes a NULL pointer dereference by not preventing operations on an already torn-down socket. dccp_v4_do_rcv() | | state other than OPEN v dccp_rcv_state_process() | | DCCP_PKT_RESET v dccp_rcv_reset() | v dccp_time_wait() WARNING: at net/ipv4/inet_timewait_sock.c:141 __inet_twsk_hashdance+0x48/0x128() Modules linked in: arc4 ecb carl9170 rt2870sta(C) mac80211 r8712u(C) crc_ccitt ah [<c0038850>] (unwind_backtrace+0x0/0xec) from [<c0055364>] (warn_slowpath_common) [<c0055364>] (warn_slowpath_common+0x4c/0x64) from [<c0055398>] (warn_slowpath_n) [<c0055398>] (warn_slowpath_null+0x1c/0x24) from [<c02b72d0>] (__inet_twsk_hashd) [<c02b72d0>] (__inet_twsk_hashdance+0x48/0x128) from [<c031caa0>] (dccp_time_wai) [<c031caa0>] (dccp_time_wait+0x40/0xc8) from [<c031c15c>] (dccp_rcv_state_proces) [<c031c15c>] (dccp_rcv_state_process+0x120/0x538) from [<c032609c>] (dccp_v4_do_) [<c032609c>] (dccp_v4_do_rcv+0x11c/0x14c) from [<c0286594>] (release_sock+0xac/0) [<c0286594>] (release_sock+0xac/0x110) from [<c031fd34>] (dccp_close+0x28c/0x380) [<c031fd34>] (dccp_close+0x28c/0x380) from [<c02d9a78>] (inet_release+0x64/0x70) The fix is by testing the socket state first. Receiving a packet in Closed state now also produces the required "No connection" Reset reply of RFC 4340, 8.3.1. Reported-and-tested-by: Johan Hovold <jhovold@gmail.com> Cc: stable@kernel.org Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* | ipv4: Make output route lookup return rtable directly.David S. Miller2011-03-021-13/+14
| | | | | | | | | | | | Instead of on the stack. Signed-off-by: David S. Miller <davem@davemloft.net>
* | ipv4: Kill can_sleep arg to ip_route_output_flow()David S. Miller2011-03-011-1/+1
| | | | | | | | | | | | This boolean state is now available in the flow flags. Signed-off-by: David S. Miller <davem@davemloft.net>
* | ipv4: Make final arg to ip_route_output_flow to be boolean "can_sleep"David S. Miller2011-03-011-1/+1
| | | | | | | | | | | | Since that is what the current vague "flags" argument means. Signed-off-by: David S. Miller <davem@davemloft.net>
* | ipv4: Can final ip_route_connect() arg to boolean "can_sleep".David S. Miller2011-03-011-1/+1
| | | | | | | | | | | | Since that's what the current vague "flags" thing means. Signed-off-by: David S. Miller <davem@davemloft.net>
* | ipv6: Consolidate route lookup sequences.David S. Miller2011-03-011-45/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Route lookups follow a general pattern in the ipv6 code wherein we first find the non-IPSEC route, potentially override the flow destination address due to ipv6 options settings, and then finally make an IPSEC search using either xfrm_lookup() or __xfrm_lookup(). __xfrm_lookup() is used when we want to generate a blackhole route if the key manager needs to resolve the IPSEC rules (in this case -EREMOTE is returned and the original 'dst' is left unchanged). Otherwise plain xfrm_lookup() is used and when asynchronous IPSEC resolution is necessary, we simply fail the lookup completely. All of these cases are encapsulated into two routines, ip6_dst_lookup_flow and ip6_sk_dst_lookup_flow. The latter of which handles unconnected UDP datagram sockets. Signed-off-by: David S. Miller <davem@davemloft.net>
* | dccp: newdp is declared/assigned but never be usedHagen Paul Pfeifer2011-02-251-3/+0
| | | | | | | | | | | | | | | | Declaration and assignment of newdp is removed. Usage of dccp_sk() exhibit no side effects. Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* | ipv4: Rearrange how ip_route_newports() gets port keys.David S. Miller2011-02-241-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ip_route_newports() is the only place in the entire kernel that cares about the port members in the routing cache entry's lookup flow key. Therefore the only reason we store an entire flow inside of the struct rtentry is for this one special case. Rewrite ip_route_newports() such that: 1) The caller passes in the original port values, so we don't need to use the rth->fl.fl_ip_{s,d}port values to remember them. 2) The lookup flow is constructed by hand instead of being copied from the routing cache entry's flow. Signed-off-by: David S. Miller <davem@davemloft.net>
* | tcp: Increase the initial congestion window to 10.David S. Miller2011-02-021-0/+9
|/ | | | | Signed-off-by: David S. Miller <davem@davemloft.net> Acked-by: Nandita Dukkipati <nanditad@google.com>
* Merge branch 'for-next' of ↵Linus Torvalds2011-01-131-1/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits) Documentation/trace/events.txt: Remove obsolete sched_signal_send. writeback: fix global_dirty_limits comment runtime -> real-time ppc: fix comment typo singal -> signal drivers: fix comment typo diable -> disable. m68k: fix comment typo diable -> disable. wireless: comment typo fix diable -> disable. media: comment typo fix diable -> disable. remove doc for obsolete dynamic-printk kernel-parameter remove extraneous 'is' from Documentation/iostats.txt Fix spelling milisec -> ms in snd_ps3 module parameter description Fix spelling mistakes in comments Revert conflicting V4L changes i7core_edac: fix typos in comments mm/rmap.c: fix comment sound, ca0106: Fix assignment to 'channel'. hrtimer: fix a typo in comment init/Kconfig: fix typo anon_inodes: fix wrong function name in comment fix comment typos concerning "consistent" poll: fix a typo in comment ... Fix up trivial conflicts in: - drivers/net/wireless/iwlwifi/iwl-core.c (moved to iwl-legacy.c) - fs/ext4/ext4.h Also fix missed 'diabled' typo in drivers/net/bnx2x/bnx2x.h while at it.
| * Merge branch 'master' into for-nextJiri Kosina2010-12-221-1/+2
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: MAINTAINERS arch/arm/mach-omap2/pm24xx.c drivers/scsi/bfa/bfa_fcpim.c Needed to update to apply fixes for which the old branch was too outdated.
| * | Docs/Kconfig: Update: osdl.org -> linuxfoundation.orgMichael Witten2010-11-151-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some of the documentation refers to web pages under the domain `osdl.org'. However, `osdl.org' now redirects to `linuxfoundation.org'. Rather than rely on redirections, this patch updates the addresses appropriately; for the most part, only documentation that is meant to be current has been updated. The patch should be pretty quick to scan and check; each new web-page url was gotten by trying out the original URL in a browser and then simply copying the the redirected URL (formatting as necessary). There is some conflict as to which one of these domain names is preferred: linuxfoundation.org linux-foundation.org So, I wrote: info@linuxfoundation.org and got this reply: Message-ID: <4CE17EE6.9040807@linuxfoundation.org> Date: Mon, 15 Nov 2010 10:41:42 -0800 From: David Ames <david@linuxfoundation.org> ... linuxfoundation.org is preferred. The canonical name for our web site is www.linuxfoundation.org. Our list site is actually lists.linux-foundation.org. Regarding email linuxfoundation.org is preferred there are a few people who choose to use linux-foundation.org for their own reasons. Consequently, I used `linuxfoundation.org' for web pages and `lists.linux-foundation.org' for mailing-list web pages and email addresses; the only personal email address I updated from `@osdl.org' was that of Andrew Morton, who prefers `linux-foundation.org' according `git log'. Signed-off-by: Michael Witten <mfwitten@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | | dccp: make upper bound for seq_window consistent on 32/64 bitGerrit Renker2011-01-071-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'seq_window' sysctl sets the initial value for the DCCP Sequence Window, which may range from 32..2^46-1 (RFC 4340, 7.5.2). The patch sets the upper bound consistently to 2^32-1 on both 32 and 64 bit systems, which should be sufficient - with a RTT of 1sec and 1-byte packets, a seq_window of 2^32-1 corresponds to a link speed of 34 Gbps. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* | | dccp: fix bug in updating the GSRSamuel Jero2011-01-071-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently dccp_check_seqno allows any valid packet to update the Greatest Sequence Number Received, even if that packet's sequence number is less than the current GSR. This patch adds a check to make sure that the new packet's sequence number is greater than GSR. Signed-off-by: Samuel Jero <sj323707@ohio.edu> Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* | | dccp: fix return value for sequence-invalid packetsSamuel Jero2011-01-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently dccp_check_seqno returns 0 (indicating a valid packet) if the acknowledgment number is out of bounds and the sync that RFC 4340 mandates at this point is currently being rate-limited. This function should return -1, indicating an invalid packet. Signed-off-by: Samuel Jero <sj323707@ohio.edu> Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* | | dccp: remove unused macrosShan Wei2010-12-101-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | Remove macros which have been unused since the initial implementation (commit 7c657876b63cb1d8a2ec06f8fc6c37bb8412e66c, [DCCP]: Initial implementation from Tue Aug 9 20:14:34 2005 -0700). Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com> Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* | | Merge branch 'master' of ↵David S. Miller2010-12-081-1/+2
|\ \ \ | | |/ | |/| | | | | | | | | | | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/wireless/ath/ath9k/ar9003_eeprom.c net/llc/af_llc.c
| * | dccp: fix error in updating the GARGerrit Renker2010-11-281-1/+2
| |/ | | | | | | | | | | | | | | | | This fixes a bug in updating the Greatest Acknowledgment number Received (GAR): the current implementation does not track the greatest received value - lower values in the range AWL..AWH (RFC 4340, 7.5.1) erase higher ones. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* | dccp qpolicy: Parameter checking of cmsg qpolicy parametersTomasz Grobelny2010-12-073-6/+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 Grobelny2010-12-075-9/+207
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | dccp ccid-2: whitespace fix-upGerrit Renker2010-11-181-1/+1
| | | | | | | | | | | | | | | | This fixes whitespace noise introduced in commit "dccp ccid-2: Algorithm to update buffer state", 5753fdfe8bd8e9a2ff9e5af19b0ffc78bfcd502a, 14 Nov 2010. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: use the macros defined for the members of flowiChangli Gao2010-11-171-8/+5
| | | | | | | | | | | | | | Use the macros defined for the members of flowi to clean the code up. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | dccp ccid-2: Separate option parsing from CCID processingGerrit Renker2010-11-155-100/+100
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch replaces an almost identical replication of code: large parts of dccp_parse_options() re-appeared as ccid2_ackvector() in ccid2.c. Apart from the duplication, this caused two more problems: 1. CCIDs should not need to be concerned with parsing header options; 2. one can not assume that Ack Vectors appear as a contiguous area within an skb, it is legal to insert other options and/or padding in between. The current code would throw an error and stop reading in such a case. Since Ack Vectors provide CCID-specific information, they are now processed by the CCID directly, separating this functionality from the main DCCP code. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* | dccp ccid-2: Remove old infrastructureGerrit Renker2010-11-152-265/+0
| | | | | | | | | | | | | | | | | | This removes * functions for which updates have been provided in the preceding patches and * the @av_vec_len field - it is no longer necessary since the buffer length is now always computed dynamically. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* | dccp ccid-2: Schedule Sync as out-of-band mechanismGerrit Renker2010-11-152-4/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The problem with Ack Vectors is that i) their length is variable and can in principle grow quite large, ii) it is hard to predict exactly how large they will be. Due to the second point it seems not a good idea to reduce the MPS; in particular when on average there is enough room for the Ack Vector and an increase in length is momentarily due to some burst loss, after which the Ack Vector returns to its normal/average length. The solution taken by this patch is to subtract a minimum-expected Ack Vector length from the MPS, and to defer any larger Ack Vectors onto a separate Sync - but only if indeed there is no space left on the skb. This patch provides the infrastructure to schedule Sync-packets for transporting (urgent) out-of-band data. Its signalling is quicker than scheduling an Ack, since it does not need to wait for new application data. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* | dccp ccid-2: Consolidate Ack-Vector processing within main DCCP moduleGerrit Renker2010-11-151-22/+9
| | | | | | | | | | | | | | | | | | | | | | | | This aggregates Ack Vector processing (handling input and clearing old state) into one function, for the following reasons and benefits: * all Ack Vector-specific processing is now in one place; * duplicated code is removed; * ensuring sanity: from an Ack Vector point of view, it is better to clear the old state first before entering new state; * Ack Event handling happens mostly within the CCIDs, not the main DCCP module. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* | dccp ccid-2: Update code for the Ack Vector input/registration routineGerrit Renker2010-11-152-0/+154
| | | | | | | | | | | | | | | | | | This patch updates the code which registers new packets as received, using the new circular buffer interface. It contributes a new algorithm which * supports both tail/head pointers and buffer wrap-around and * deals with overflow (head/tail move in lock-step). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
* | dccp ccid-2: Algorithm to update buffer stateGerrit Renker2010-11-154-6/+93
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This provides a routine to consistently update the buffer state when the peer acknowledges receipt of Ack Vectors; updating state in the list of Ack Vectors as well as in the circular buffer. While based on RFC 4340, several additional (and necessary) precautions were added to protect the consistency of the buffer state. These additions are essential, since analysis and experience showed that the basic algorithm was insufficient for this task (which lead to problems that were hard to debug). The algorithm now * deals with HC-sender acknowledging to HC-receiver and vice versa, * keeps track of the last unacknowledged but received seqno in tail_ackno, * has special cases to reset the overflow condition when appropriate, * is protected against receiving older information (would mess up buffer state). Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
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