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path: root/net/l2tp/l2tp_core.h
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2014-03-06l2tp: fix manual sequencing (de)activation in L2TPv2Guillaume Nault
Commit e0d4435f "l2tp: Update PPP-over-L2TP driver to work over L2TPv3" broke the PPPOL2TP_SO_SENDSEQ setsockopt. The L2TP header length was previously computed by pppol2tp_l2t_header_len() before each call to l2tp_xmit_skb(). Now that header length is retrieved from the hdr_len session field, this field must be updated every time the L2TP header format is modified, or l2tp_xmit_skb() won't push the right amount of data for the L2TP header. This patch uses l2tp_session_set_header_len() to adjust hdr_len every time sequencing is (de)activated from userspace (either by the PPPOL2TP_SO_SENDSEQ setsockopt or the L2TP_ATTR_SEND_SEQ netlink attribute). Signed-off-by: Guillaume Nault <g.nault@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-13l2tp: make local functions staticstephen hemminger
Avoid needless export of local functions Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Acked-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-19net: misc: Remove extern from function prototypesJoe Perches
There are a mix of function prototypes with and without extern in the kernel sources. Standardize on not using extern for function prototypes. Function prototypes don't need to be written with extern. extern is assumed by the compiler. Its use is as unnecessary as using auto to declare automatic/local variables in a block. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-02l2tp: fix kernel panic when using IPv4-mapped IPv6 addressesFrançois Cachereul
IPv4 mapped addresses cause kernel panic. The patch juste check whether the IPv6 address is an IPv4 mapped address. If so, use IPv4 API instead of IPv6. [ 940.026915] general protection fault: 0000 [#1] [ 940.026915] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core pppox ppp_generic slhc loop psmouse [ 940.026915] CPU: 0 PID: 3184 Comm: memcheck-amd64- Not tainted 3.11.0+ #1 [ 940.026915] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 940.026915] task: ffff880007130e20 ti: ffff88000737e000 task.ti: ffff88000737e000 [ 940.026915] RIP: 0010:[<ffffffff81333780>] [<ffffffff81333780>] ip6_xmit+0x276/0x326 [ 940.026915] RSP: 0018:ffff88000737fd28 EFLAGS: 00010286 [ 940.026915] RAX: c748521a75ceff48 RBX: ffff880000c30800 RCX: 0000000000000000 [ 940.026915] RDX: ffff88000075cc4e RSI: 0000000000000028 RDI: ffff8800060e5a40 [ 940.026915] RBP: ffff8800060e5a40 R08: 0000000000000000 R09: ffff88000075cc90 [ 940.026915] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88000737fda0 [ 940.026915] R13: 0000000000000000 R14: 0000000000002000 R15: ffff880005d3b580 [ 940.026915] FS: 00007f163dc5e800(0000) GS:ffffffff81623000(0000) knlGS:0000000000000000 [ 940.026915] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 940.026915] CR2: 00000004032dc940 CR3: 0000000005c25000 CR4: 00000000000006f0 [ 940.026915] Stack: [ 940.026915] ffff88000075cc4e ffffffff81694e90 ffff880000c30b38 0000000000000020 [ 940.026915] 11000000523c4bac ffff88000737fdb4 0000000000000000 ffff880000c30800 [ 940.026915] ffff880005d3b580 ffff880000c30b38 ffff8800060e5a40 0000000000000020 [ 940.026915] Call Trace: [ 940.026915] [<ffffffff81356cc3>] ? inet6_csk_xmit+0xa4/0xc4 [ 940.026915] [<ffffffffa0038535>] ? l2tp_xmit_skb+0x503/0x55a [l2tp_core] [ 940.026915] [<ffffffff812b8d3b>] ? pskb_expand_head+0x161/0x214 [ 940.026915] [<ffffffffa003e91d>] ? pppol2tp_xmit+0xf2/0x143 [l2tp_ppp] [ 940.026915] [<ffffffffa00292e0>] ? ppp_channel_push+0x36/0x8b [ppp_generic] [ 940.026915] [<ffffffffa00293fe>] ? ppp_write+0xaf/0xc5 [ppp_generic] [ 940.026915] [<ffffffff8110ead4>] ? vfs_write+0xa2/0x106 [ 940.026915] [<ffffffff8110edd6>] ? SyS_write+0x56/0x8a [ 940.026915] [<ffffffff81378ac0>] ? system_call_fastpath+0x16/0x1b [ 940.026915] Code: 00 49 8b 8f d8 00 00 00 66 83 7c 11 02 00 74 60 49 8b 47 58 48 83 e0 fe 48 8b 80 18 01 00 00 48 85 c0 74 13 48 8b 80 78 02 00 00 <48> ff 40 28 41 8b 57 68 48 01 50 30 48 8b 54 24 08 49 c7 c1 51 [ 940.026915] RIP [<ffffffff81333780>] ip6_xmit+0x276/0x326 [ 940.026915] RSP <ffff88000737fd28> [ 940.057945] ---[ end trace be8aba9a61c8b7f3 ]--- [ 940.058583] Kernel panic - not syncing: Fatal exception in interrupt Signed-off-by: François CACHEREUL <f.cachereul@alphalink.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-02l2tp: make datapath resilient to packet loss when sequence numbers enabledJames Chapman
If L2TP data sequence numbers are enabled and reordering is not enabled, data reception stops if a packet is lost since the kernel waits for a sequence number that is never resent. (When reordering is enabled, data reception restarts when the reorder timeout expires.) If no reorder timeout is set, we should count the number of in-sequence packets after the out-of-sequence (OOS) condition is detected, and reset sequence number state after a number of such packets are received. For now, the number of in-sequence packets while in OOS state which cause the sequence number state to be reset is hard-coded to 5. This could be configurable later. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-02l2tp: make datapath sequence number support RFC-compliantJames Chapman
The L2TP datapath is not currently RFC-compliant when sequence numbers are used in L2TP data packets. According to the L2TP RFC, any received sequence number NR greater than or equal to the next expected NR is acceptable, where the "greater than or equal to" test is determined by the NR wrap point. This differs for L2TPv2 and L2TPv3, so add state in the session context to hold the max NR value and the NR window size in order to do the acceptable sequence number value check. These might be configurable later, but for now we derive it from the tunnel L2TP version, which determines the sequence number field size. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-20l2tp: unhash l2tp sessions on delete, not on freeTom Parkin
If we postpone unhashing of l2tp sessions until the structure is freed, we risk: 1. further packets arriving and getting queued while the pseudowire is being closed down 2. the recv path hitting "scheduling while atomic" errors in the case that recv drops the last reference to a session and calls l2tp_session_free while in atomic context As such, l2tp sessions should be unhashed from l2tp_core data structures early in the teardown process prior to calling pseudowire close. For pseudowires like l2tp_ppp which have multiple shutdown codepaths, provide an unhash hook. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-20l2tp: avoid deadlock in l2tp stats updateTom Parkin
l2tp's u64_stats writers were incorrectly synchronised, making it possible to deadlock a 64bit machine running a 32bit kernel simply by sending the l2tp code netlink commands while passing data through l2tp sessions. Previous discussion on netdev determined that alternative solutions such as spinlock writer synchronisation or per-cpu data would bring unjustified overhead, given that most users interested in high volume traffic will likely be running 64bit kernels on 64bit hardware. As such, this patch replaces l2tp's use of u64_stats with atomic_long_t, thereby avoiding the deadlock. Ref: http://marc.info/?l=linux-netdev&m=134029167910731&w=2 http://marc.info/?l=linux-netdev&m=134079868111131&w=2 Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-20l2tp: add session reorder queue purge function to coreTom Parkin
If an l2tp session is deleted, it is necessary to delete skbs in-flight on the session's reorder queue before taking it down. Rather than having each pseudowire implementation reaching into the l2tp_session struct to handle this itself, provide a function in l2tp_core to purge the session queue. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-20l2tp: export l2tp_tunnel_closeallTom Parkin
l2tp_core internally uses l2tp_tunnel_closeall to close all sessions in a tunnel when a UDP-encapsulation socket is destroyed. We need to do something similar for IP-encapsulation sockets. Export l2tp_tunnel_closeall as a GPL symbol to enable l2tp_ip and l2tp_ip6 to call it from their .destroy handlers. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-05l2tp: put tunnel socket release on a workqueueTom Parkin
To allow l2tp_tunnel_delete to be called from an atomic context, place the tunnel socket release calls on a workqueue for asynchronous execution. Tunnel memory is eventually freed in the tunnel socket destructor. Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-01-29l2tp: prevent l2tp_tunnel_delete racing with userspace closeTom Parkin
If a tunnel socket is created by userspace, l2tp hooks the socket destructor in order to clean up resources if userspace closes the socket or crashes. It also caches a pointer to the struct sock for use in the data path and in the netlink interface. While it is safe to use the cached sock pointer in the data path, where the skb references keep the socket alive, it is not safe to use it elsewhere as such access introduces a race with userspace closing the socket. In particular, l2tp_tunnel_delete is prone to oopsing if a multithreaded userspace application closes a socket at the same time as sending a netlink delete command for the tunnel. This patch fixes this oops by forcing l2tp_tunnel_delete to explicitly look up a tunnel socket held by userspace using sockfd_lookup(). Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-30l2tp: avoid to use synchronize_rcu in tunnel free functionxeb@mail.ru
Avoid to use synchronize_rcu in l2tp_tunnel_free because context may be atomic. Signed-off-by: Dmitry Kozlov <xeb@mail.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-17net: l2tp: Standardize logging stylesJoe Perches
Use more current logging styles. Add pr_fmt to prefix output appropriately. Convert printks to pr_<level>. Convert PRINTK macros to new l2tp_<level> macros. Neaten some <foo>_refcount debugging macros. Use print_hex_dump_bytes instead of hand-coded loops. Coalesce formats and align arguments. Some KERN_DEBUG output is not now emitted unless dynamic_debugging is enabled. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-10l2tp: fix reorder timeout recoveryJames Chapman
When L2TP data packet reordering is enabled, packets are held in a queue while waiting for out-of-sequence packets. If a packet gets lost, packets will be held until the reorder timeout expires, when we are supposed to then advance to the sequence number of the next packet but we don't currently do so. As a result, the data channel is stuck because we are waiting for a packet that will never arrive - all packets age out and none are passed. The fix is to add a flag to the session context, which is set when the reorder timeout expires and tells the receive code to reset the next expected sequence number to that of the next packet in the queue. Tested in a production L2TP network with Starent and Nortel L2TP gear. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01l2tp: netlink api for l2tpv3 ipv6 unmanaged tunnelsChris Elston
This patch adds support for unmanaged L2TPv3 tunnels over IPv6 using the netlink API. We already support unmanaged L2TPv3 tunnels over IPv4. A patch to iproute2 to make use of this feature will be submitted separately. Signed-off-by: Chris Elston <celston@katalix.com> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01l2tp: fix locking of 64-bit counters for smpJames Chapman
L2TP uses 64-bit counters but since these are not updated atomically, we need to make them safe for smp. This patch addresses that. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15net: cleanup unsigned to unsigned intEric Dumazet
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>
2010-10-24l2tp: make local function staticstephen hemminger
Also moved the refcound inlines from l2tp_core.h to l2tp_core.c since only used in that one file. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Acked-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-04l2tp: unmanaged L2TPv3 tunnels fixesEric Dumazet
Followup to commit 789a4a2c (l2tp: Add support for static unmanaged L2TPv3 tunnels) One missing init in l2tp_tunnel_sock_create() could access random kernel memory, and a bit field should be unsigned. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03l2tp: Fix L2TP_DEBUGFS ifdef tests.David S. Miller
We have to check CONFIG_L2TP_DEBUGFS_MODULE as well as CONFIG_L2TP_DEBUGFS. Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03l2tp: Add support for static unmanaged L2TPv3 tunnelsJames Chapman
This patch adds support for static (unmanaged) L2TPv3 tunnels, where the tunnel socket is created by the kernel rather than being created by userspace. This means L2TP tunnels and sessions can be created manually, without needing an L2TP control protocol implemented in userspace. This might be useful where the user wants a simple ethernet over IP tunnel. A patch to iproute2 adds a new command set under "ip l2tp" to make use of this feature. This will be submitted separately. Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03l2tp: Add debugfs files for dumping l2tp debug infoJames Chapman
The existing pppol2tp driver exports debug info to /proc/net/pppol2tp. Rather than adding info to that file for the new functionality added in this patch series, we add new files in debugfs, leaving the old /proc file for backwards compatibility (L2TPv2 only). Currently only one file is provided: l2tp/tunnels, which lists internal debug info for all l2tp tunnels and sessions. More files may be added later. The info is for debug and problem analysis only - userspace apps should use netlink to obtain status about l2tp tunnels and sessions. Although debugfs does not support net namespaces, the tunnels and sessions dumped in l2tp/tunnels are only those in the net namespace of the process reading the file. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03l2tp: Add netlink control API for L2TPJames Chapman
In L2TPv3, we need to create/delete/modify/query L2TP tunnel and session contexts. The number of parameters is significant. So let's use netlink. Userspace uses this API to control L2TP tunnel/session contexts in the kernel. The previous pppol2tp driver was managed using [gs]etsockopt(). This API is retained for backwards compatibility. Unlike L2TPv2 which carries only PPP frames, L2TPv3 can carry raw ethernet frames or other frame types and these do not always have an associated socket family. Therefore, we need a way to use L2TP sessions that doesn't require a socket type for each supported frame type. Hence netlink is used. Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03l2tp: Add L2TPv3 IP encapsulation (no UDP) supportJames Chapman
This patch adds a new L2TPIP socket family and modifies the core to handle the case where there is no UDP header in the L2TP packet. L2TP/IP uses IP protocol 115. Since L2TP/UDP and L2TP/IP packets differ in layout, the datapath packet handling code needs changes too. Userspace uses an L2TPIP socket instead of a UDP socket when IP encapsulation is required. We can't use raw sockets for this because the semantics of raw sockets don't lend themselves to the socket-per-tunnel model - we need to Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03l2tp: Add L2TPv3 protocol supportJames Chapman
The L2TPv3 protocol changes the layout of the L2TP packet header. Tunnel and session ids change from 16-bit to 32-bit values, data sequence numbers change from 16-bit to 24-bit values and PPP-specific fields are moved into protocol-specific subheaders. Although this patch introduces L2TPv3 protocol support, there are no userspace interfaces to create L2TPv3 sessions yet. Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03l2tp: Split pppol2tp patch into separate l2tp and ppp partsJames Chapman
This patch splits the pppol2tp driver into separate L2TP and PPP parts to prepare for L2TPv3 support. In L2TPv3, protocols other than PPP can be carried, so this split creates a common L2TP core that will handle the common L2TP bits which protocol support modules such as PPP will use. Note that the existing pppol2tp module is split into l2tp_core and l2tp_ppp by this change. There are no feature changes here. Internally, however, there are significant changes, mostly to handle the separation of PPP-specific data from the L2TP session and to provide hooks in the core for modules like PPP to access. Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>