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2020-09-08rxrpc: Rewrite the client connection managerDavid Howells
Rewrite the rxrpc client connection manager so that it can support multiple connections for a given security key to a peer. The following changes are made: (1) For each open socket, the code currently maintains an rbtree with the connections placed into it, keyed by communications parameters. This is tricky to maintain as connections can be culled from the tree or replaced within it. Connections can require replacement for a number of reasons, e.g. their IDs span too great a range for the IDR data type to represent efficiently, the call ID numbers on that conn would overflow or the conn got aborted. This is changed so that there's now a connection bundle object placed in the tree, keyed on the same parameters. The bundle, however, does not need to be replaced. (2) An rxrpc_bundle object can now manage the available channels for a set of parallel connections. The lock that manages this is moved there from the rxrpc_connection struct (channel_lock). (3) There'a a dummy bundle for all incoming connections to share so that they have a channel_lock too. It might be better to give each incoming connection its own bundle. This bundle is not needed to manage which channels incoming calls are made on because that's the solely at whim of the client. (4) The restrictions on how many client connections are around are removed. Instead, a previous patch limits the number of client calls that can be allocated. Ordinarily, client connections are reaped after 2 minutes on the idle queue, but when more than a certain number of connections are in existence, the reaper starts reaping them after 2s of idleness instead to get the numbers back down. It could also be made such that new call allocations are forced to wait until the number of outstanding connections subsides. Signed-off-by: David Howells <dhowells@redhat.com>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-05-28ipv6: add ip6_sock_set_recverrChristoph Hellwig
Add a helper to directly set the IPV6_RECVERR sockopt from kernel space without going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28ipv4: add ip_sock_set_mtu_discoverChristoph Hellwig
Add a helper to directly set the IP_MTU_DISCOVER sockopt from kernel space without going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> [rxrpc bits] Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28ipv4: add ip_sock_set_recverrChristoph Hellwig
Add a helper to directly set the IP_RECVERR sockopt from kernel space without going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-28net: add sock_enable_timestampsChristoph Hellwig
Add a helper to directly enable timestamps instead of setting the SO_TIMESTAMP* sockopts from kernel space and going through a fake uaccess. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-14rxrpc: Fix DATA Tx to disable nofrag for UDP on AF_INET6 socketDavid Howells
Fix the DATA packet transmission to disable nofrag for UDPv4 on an AF_INET6 socket as well as UDPv6 when trying to transmit fragmentably. Without this, packets filled to the normal size used by the kernel AFS client of 1412 bytes be rejected by udp_sendmsg() with EMSGSIZE immediately. The ->sk_error_report() notification hook is called, but rxrpc doesn't generate a trace for it. This is a temporary fix; a more permanent solution needs to involve changing the size of the packets being filled in accordance with the MTU, which isn't currently done in AF_RXRPC. The reason for not doing so was that, barring the last packet in an rx jumbo packet, jumbos can only be assembled out of 1412-byte packets - and the plan was to construct jumbos on the fly at transmission time. Also, there's no point turning on IPV6_MTU_DISCOVER, since IPv6 has to engage in this anyway since fragmentation is only done by the sender. We can then condense the switch-statement in rxrpc_send_data_packet(). Fixes: 75b54cb57ca3 ("rxrpc: Add IPv6 support") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-30rxrpc: Fix missing active use pinning of rxrpc_local objectDavid Howells
The introduction of a split between the reference count on rxrpc_local objects and the usage count didn't quite go far enough. A number of kernel work items need to make use of the socket to perform transmission. These also need to get an active count on the local object to prevent the socket from being closed. Fix this by getting the active count in those places. Also split out the raw active count get/put functions as these places tend to hold refs on the rxrpc_local object already, so getting and putting an extra object ref is just a waste of time. The problem can lead to symptoms like: BUG: kernel NULL pointer dereference, address: 0000000000000018 .. CPU: 2 PID: 818 Comm: kworker/u9:0 Not tainted 5.5.0-fscache+ #51 ... RIP: 0010:selinux_socket_sendmsg+0x5/0x13 ... Call Trace: security_socket_sendmsg+0x2c/0x3e sock_sendmsg+0x1a/0x46 rxrpc_send_keepalive+0x131/0x1ae rxrpc_peer_keepalive_worker+0x219/0x34b process_one_work+0x18e/0x271 worker_thread+0x1a3/0x247 kthread+0xe6/0xeb ret_from_fork+0x1f/0x30 Fixes: 730c5fd42c1e ("rxrpc: Fix local endpoint refcounting") Signed-off-by: David Howells <dhowells@redhat.com>
2020-01-30rxrpc: Fix use-after-free in rxrpc_put_local()David Howells
Fix rxrpc_put_local() to not access local->debug_id after calling atomic_dec_return() as, unless that returned n==0, we no longer have the right to access the object. Fixes: 06d9532fa6b3 ("rxrpc: Fix read-after-free in rxrpc_queue_local()") Signed-off-by: David Howells <dhowells@redhat.com>
2019-08-30rxrpc: Fix lack of conn cleanup when local endpoint is cleaned up [ver #2]David Howells
When a local endpoint is ceases to be in use, such as when the kafs module is unloaded, the kernel will emit an assertion failure if there are any outstanding client connections: rxrpc: Assertion failed ------------[ cut here ]------------ kernel BUG at net/rxrpc/local_object.c:433! and even beyond that, will evince other oopses if there are service connections still present. Fix this by: (1) Removing the triggering of connection reaping when an rxrpc socket is released. These don't actually clean up the connections anyway - and further, the local endpoint may still be in use through another socket. (2) Mark the local endpoint as dead when we start the process of tearing it down. (3) When destroying a local endpoint, strip all of its client connections from the idle list and discard the ref on each that the list was holding. (4) When destroying a local endpoint, call the service connection reaper directly (rather than through a workqueue) to immediately kill off all outstanding service connections. (5) Make the service connection reaper reap connections for which the local endpoint is marked dead. Only after destroying the connections can we close the socket lest we get an oops in a workqueue that's looking at a connection or a peer. Fixes: 3d18cbb7fd0c ("rxrpc: Fix conn expiry timers") Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-14rxrpc: Fix read-after-free in rxrpc_queue_local()David Howells
rxrpc_queue_local() attempts to queue the local endpoint it is given and then, if successful, prints a trace line. The trace line includes the current usage count - but we're not allowed to look at the local endpoint at this point as we passed our ref on it to the workqueue. Fix this by reading the usage count before queuing the work item. Also fix the reading of local->debug_id for trace lines, which must be done with the same consideration as reading the usage count. Fixes: 09d2bf595db4 ("rxrpc: Add a tracepoint to track rxrpc_local refcounting") Reported-by: syzbot+78e71c5bab4f76a6a719@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com>
2019-08-14rxrpc: Fix local endpoint replacementDavid Howells
When a local endpoint (struct rxrpc_local) ceases to be in use by any AF_RXRPC sockets, it starts the process of being destroyed, but this doesn't cause it to be removed from the namespace endpoint list immediately as tearing it down isn't trivial and can't be done in softirq context, so it gets deferred. If a new socket comes along that wants to bind to the same endpoint, a new rxrpc_local object will be allocated and rxrpc_lookup_local() will use list_replace() to substitute the new one for the old. Then, when the dying object gets to rxrpc_local_destroyer(), it is removed unconditionally from whatever list it is on by calling list_del_init(). However, list_replace() doesn't reset the pointers in the replaced list_head and so the list_del_init() will likely corrupt the local endpoints list. Fix this by using list_replace_init() instead. Fixes: 730c5fd42c1e ("rxrpc: Fix local endpoint refcounting") Reported-by: syzbot+193e29e9387ea5837f1d@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com>
2019-08-11rxrpc: Fix local refcountingDavid Howells
Fix rxrpc_unuse_local() to handle a NULL local pointer as it can be called on an unbound socket on which rx->local is not yet set. The following reproduced (includes omitted): int main(void) { socket(AF_RXRPC, SOCK_DGRAM, AF_INET); return 0; } causes the following oops to occur: BUG: kernel NULL pointer dereference, address: 0000000000000010 ... RIP: 0010:rxrpc_unuse_local+0x8/0x1b ... Call Trace: rxrpc_release+0x2b5/0x338 __sock_release+0x37/0xa1 sock_close+0x14/0x17 __fput+0x115/0x1e9 task_work_run+0x72/0x98 do_exit+0x51b/0xa7a ? __context_tracking_exit+0x4e/0x10e do_group_exit+0xab/0xab __x64_sys_exit_group+0x14/0x17 do_syscall_64+0x89/0x1d4 entry_SYSCALL_64_after_hwframe+0x49/0xbe Reported-by: syzbot+20dee719a2e090427b5f@syzkaller.appspotmail.com Fixes: 730c5fd42c1e ("rxrpc: Fix local endpoint refcounting") Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeffrey Altman <jaltman@auristor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-09rxrpc: Fix local endpoint refcountingDavid Howells
The object lifetime management on the rxrpc_local struct is broken in that the rxrpc_local_processor() function is expected to clean up and remove an object - but it may get requeued by packets coming in on the backing UDP socket once it starts running. This may result in the assertion in rxrpc_local_rcu() firing because the memory has been scheduled for RCU destruction whilst still queued: rxrpc: Assertion failed ------------[ cut here ]------------ kernel BUG at net/rxrpc/local_object.c:468! Note that if the processor comes around before the RCU free function, it will just do nothing because ->dead is true. Fix this by adding a separate refcount to count active users of the endpoint that causes the endpoint to be destroyed when it reaches 0. The original refcount can then be used to refcount objects through the work processor and cause the memory to be rcu freed when that reaches 0. Fixes: 4f95dd78a77e ("rxrpc: Rework local endpoint management") Reported-by: syzbot+1e0edc4b8b7494c28450@syzkaller.appspotmail.com Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-24treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public licence as published by the free software foundation either version 2 of the licence or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 114 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Two easy cases of overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-24rxrpc: fix race condition in rxrpc_input_packet()Eric Dumazet
After commit 5271953cad31 ("rxrpc: Use the UDP encap_rcv hook"), rxrpc_input_packet() is directly called from lockless UDP receive path, under rcu_read_lock() protection. It must therefore use RCU rules : - udp_sk->sk_user_data can be cleared at any point in this function. rcu_dereference_sk_user_data() is what we need here. - Also, since sk_user_data might have been set in rxrpc_open_socket() we must observe a proper RCU grace period before kfree(local) in rxrpc_lookup_local() v4: @local can be NULL in xrpc_lookup_local() as reported by kbuild test robot <lkp@intel.com> and Julia Lawall <julia.lawall@lip6.fr>, thanks ! v3,v2 : addressed David Howells feedback, thanks ! syzbot reported : kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 19236 Comm: syz-executor703 Not tainted 5.1.0-rc6 #79 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0xbef/0x3fb0 kernel/locking/lockdep.c:3573 Code: 00 0f 85 a5 1f 00 00 48 81 c4 10 01 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f 85 4a 21 00 00 49 81 7d 00 20 54 9c 89 0f 84 cf f4 RSP: 0018:ffff88809d7aef58 EFLAGS: 00010002 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000026 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff88809d7af090 R08: 0000000000000001 R09: 0000000000000001 R10: ffffed1015d05bc7 R11: ffff888089428600 R12: 0000000000000000 R13: 0000000000000130 R14: 0000000000000001 R15: 0000000000000001 FS: 00007f059044d700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004b6040 CR3: 00000000955ca000 CR4: 00000000001406f0 Call Trace: lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:4211 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152 skb_queue_tail+0x26/0x150 net/core/skbuff.c:2972 rxrpc_reject_packet net/rxrpc/input.c:1126 [inline] rxrpc_input_packet+0x4a0/0x5536 net/rxrpc/input.c:1414 udp_queue_rcv_one_skb+0xaf2/0x1780 net/ipv4/udp.c:2011 udp_queue_rcv_skb+0x128/0x730 net/ipv4/udp.c:2085 udp_unicast_rcv_skb.isra.0+0xb9/0x360 net/ipv4/udp.c:2245 __udp4_lib_rcv+0x701/0x2ca0 net/ipv4/udp.c:2301 udp_rcv+0x22/0x30 net/ipv4/udp.c:2482 ip_protocol_deliver_rcu+0x60/0x8f0 net/ipv4/ip_input.c:208 ip_local_deliver_finish+0x23b/0x390 net/ipv4/ip_input.c:234 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ip_local_deliver+0x1e9/0x520 net/ipv4/ip_input.c:255 dst_input include/net/dst.h:450 [inline] ip_rcv_finish+0x1e1/0x300 net/ipv4/ip_input.c:413 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ip_rcv+0xe8/0x3f0 net/ipv4/ip_input.c:523 __netif_receive_skb_one_core+0x115/0x1a0 net/core/dev.c:4987 __netif_receive_skb+0x2c/0x1c0 net/core/dev.c:5099 netif_receive_skb_internal+0x117/0x660 net/core/dev.c:5202 napi_frags_finish net/core/dev.c:5769 [inline] napi_gro_frags+0xade/0xd10 net/core/dev.c:5843 tun_get_user+0x2f24/0x3fb0 drivers/net/tun.c:1981 tun_chr_write_iter+0xbd/0x156 drivers/net/tun.c:2027 call_write_iter include/linux/fs.h:1866 [inline] do_iter_readv_writev+0x5e1/0x8e0 fs/read_write.c:681 do_iter_write fs/read_write.c:957 [inline] do_iter_write+0x184/0x610 fs/read_write.c:938 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1002 do_writev+0x15e/0x370 fs/read_write.c:1037 __do_sys_writev fs/read_write.c:1110 [inline] __se_sys_writev fs/read_write.c:1107 [inline] __x64_sys_writev+0x75/0xb0 fs/read_write.c:1107 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: 5271953cad31 ("rxrpc: Use the UDP encap_rcv hook") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-03rxrpc: Mark expected switch fall-throughGustavo A. R. Silva
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. This patch fixes the following warning: net/rxrpc/local_object.c: In function ‘rxrpc_open_socket’: net/rxrpc/local_object.c:175:6: warning: this statement may fall through [-Wimplicit-fallthrough=] if (ret < 0) { ^ net/rxrpc/local_object.c:184:2: note: here case AF_INET: ^~~~ Warning level 3 was used: -Wimplicit-fallthrough=3 Currently, GCC is expecting to find the fall-through annotations at the very bottom of the case and on its own line. That's why I had to add the annotation, although the intentional fall-through is already mentioned in a few lines above. This patch is part of the ongoing efforts to enable -Wimplicit-fallthrough. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-03sockopt: Rename SO_TIMESTAMP* to SO_TIMESTAMP*_OLDDeepa Dinamani
SO_TIMESTAMP, SO_TIMESTAMPNS and SO_TIMESTAMPING options, the way they are currently defined, are not y2038 safe. Subsequent patches in the series add new y2038 safe versions of these options which provide 64 bit timestamps on all architectures uniformly. Hence, rename existing options with OLD tag suffixes. Also note that kernel will not use the untagged SO_TIMESTAMP* and SCM_TIMESTAMP* options internally anymore. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Acked-by: Willem de Bruijn <willemb@google.com> Cc: deller@gmx.de Cc: dhowells@redhat.com Cc: jejb@parisc-linux.org Cc: ralf@linux-mips.org Cc: rth@twiddle.net Cc: linux-afs@lists.infradead.org Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-parisc@vger.kernel.org Cc: linux-rdma@vger.kernel.org Cc: sparclinux@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-15rxrpc: Fix incorrect conditional on IPV6David Howells
The udpv6_encap_enable() function is part of the ipv6 code, and if that is configured as a loadable module and rxrpc is built in then a build failure will occur because the conditional check is wrong: net/rxrpc/local_object.o: In function `rxrpc_lookup_local': local_object.c:(.text+0x2688): undefined reference to `udpv6_encap_enable' Use the correct config symbol (CONFIG_AF_RXRPC_IPV6) in the conditional check rather than CONFIG_IPV6 as that will do the right thing. Fixes: 5271953cad31 ("rxrpc: Use the UDP encap_rcv hook") Reported-by: kbuild-all@01.org Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-08rxrpc: Use the UDP encap_rcv hookDavid Howells
Use the UDP encap_rcv hook to cut the bit out of the rxrpc packet reception in which a packet is placed onto the UDP receive queue and then immediately removed again by rxrpc. Going via the queue in this manner seems like it should be unnecessary. This does, however, require the invention of a value to place in encap_type as that's one of the conditions to switch packets out to the encap_rcv hook. Possibly the value doesn't actually matter for anything other than sockopts on the UDP socket, which aren't accessible outside of rxrpc anyway. This seems to cut a bit of time out of the time elapsed between each sk_buff being timestamped and turning up in rxrpc (the final number in the following trace excerpts). I measured this by making the rxrpc_rx_packet trace point print the time elapsed between the skb being timestamped and the current time (in ns), e.g.: ... 424.278721: rxrpc_rx_packet: ... ACK 25026 So doing a 512MiB DIO read from my test server, with an unmodified kernel: N min max sum mean stddev 27605 2626 7581 7.83992e+07 2840.04 181.029 and with the patch applied: N min max sum mean stddev 27547 1895 12165 6.77461e+07 2459.29 255.02 Signed-off-by: David Howells <dhowells@redhat.com>
2018-10-05rxrpc: Fix the data_ready handlerDavid Howells
Fix the rxrpc_data_ready() function to pick up all packets and to not miss any. There are two problems: (1) The sk_data_ready pointer on the UDP socket is set *after* it is bound. This means that it's open for business before we're ready to dequeue packets and there's a tiny window exists in which a packet can sneak onto the receive queue, but we never know about it. Fix this by setting the pointers on the socket prior to binding it. (2) skb_recv_udp() will return an error (such as ENETUNREACH) if there was an error on the transmission side, even though we set the sk_error_report hook. Because rxrpc_data_ready() returns immediately in such a case, it never actually removes its packet from the receive queue. Fix this by abstracting out the UDP dequeuing and checksumming into a separate function that keeps hammering on skb_recv_udp() until it returns -EAGAIN, passing the packets extracted to the remainder of the function. and two potential problems: (3) It might be possible in some circumstances or in the future for packets to be being added to the UDP receive queue whilst rxrpc is running consuming them, so the data_ready() handler might get called less often than once per packet. Allow for this by fully draining the queue on each call as (2). (4) If a packet fails the checksum check, the code currently returns after discarding the packet without checking for more. Allow for this by fully draining the queue on each call as (2). Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Paolo Abeni <pabeni@redhat.com>
2018-09-28rxrpc: Fix transport sockopts to get IPv4 errors on an IPv6 socketDavid Howells
It seems that enabling IPV6_RECVERR on an IPv6 socket doesn't also turn on IP_RECVERR, so neither local errors nor ICMP-transported remote errors from IPv4 peer addresses are returned to the AF_RXRPC protocol. Make the sockopt setting code in rxrpc_open_socket() fall through from the AF_INET6 case to the AF_INET case to turn on all the AF_INET options too in the AF_INET6 case. Fixes: f2aeed3a591f ("rxrpc: Fix error reception on AF_INET6 sockets") Signed-off-by: David Howells <dhowells@redhat.com>
2018-09-28rxrpc: Fix RTT gatheringDavid Howells
Fix RTT information gathering in AF_RXRPC by the following means: (1) Enable Rx timestamping on the transport socket with SO_TIMESTAMPNS. (2) If the sk_buff doesn't have a timestamp set when rxrpc_data_ready() collects it, set it at that point. (3) Allow ACKs to be requested on the last packet of a client call, but not a service call. We need to be careful lest we undo: bf7d620abf22c321208a4da4f435e7af52551a21 Author: David Howells <dhowells@redhat.com> Date: Thu Oct 6 08:11:51 2016 +0100 rxrpc: Don't request an ACK on the last DATA packet of a call's Tx phase but that only really applies to service calls that we're handling, since the client side gets to send the final ACK (or not). (4) When about to transmit an ACK or DATA packet, record the Tx timestamp before only; don't update the timestamp afterwards. (5) Switch the ordering between recording the serial and recording the timestamp to always set the serial number first. The serial number shouldn't be seen referenced by an ACK packet until we've transmitted the packet bearing it - so in the Rx path, we don't need the timestamp until we've checked the serial number. Fixes: cf1a6474f807 ("rxrpc: Add per-peer RTT tracker") Signed-off-by: David Howells <dhowells@redhat.com>
2018-06-21atomics/treewide: Rename __atomic_add_unless() => atomic_fetch_add_unless()Mark Rutland
While __atomic_add_unless() was originally intended as a building-block for atomic_add_unless(), it's now used in a number of places around the kernel. It's the only common atomic operation named __atomic*(), rather than atomic_*(), and for consistency it would be better named atomic_fetch_add_unless(). This lack of consistency is slightly confusing, and gets in the way of scripting atomics. Given that, let's clean things up and promote it to an official part of the atomics API, in the form of atomic_fetch_add_unless(). This patch converts definitions and invocations over to the new name, including the instrumented version, using the following script: ---- git grep -w __atomic_add_unless | while read line; do sed -i '{s/\<__atomic_add_unless\>/atomic_fetch_add_unless/}' "${line%%:*}"; done git grep -w __arch_atomic_add_unless | while read line; do sed -i '{s/\<__arch_atomic_add_unless\>/arch_atomic_fetch_add_unless/}' "${line%%:*}"; done ---- Note that we do not have atomic{64,_long}_fetch_add_unless(), which will be introduced by later patches. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Palmer Dabbelt <palmer@sifive.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/lkml/20180621121321.4761-2-mark.rutland@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-10rxrpc: Fix error reception on AF_INET6 socketsDavid Howells
AF_RXRPC tries to turn on IP_RECVERR and IP_MTU_DISCOVER on the UDP socket it just opened for communications with the outside world, regardless of the type of socket. Unfortunately, this doesn't work with an AF_INET6 socket. Fix this by turning on IPV6_RECVERR and IPV6_MTU_DISCOVER instead if the socket is of the AF_INET6 family. Without this, kAFS server and address rotation doesn't work correctly because the algorithm doesn't detect received network errors. Fixes: 75b54cb57ca3 ("rxrpc: Add IPv6 support") Signed-off-by: David Howells <dhowells@redhat.com>
2018-03-30rxrpc: Add a tracepoint to track rxrpc_local refcountingDavid Howells
Add a tracepoint to track reference counting on the rxrpc_local struct. Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-05rxrpc: Permit multiple service bindingDavid Howells
Permit bind() to be called on an AF_RXRPC socket more than once (currently maximum twice) to bind multiple listening services to it. There are some restrictions: (1) All bind() calls involved must have a non-zero service ID. (2) The service IDs must all be different. (3) The rest of the address (notably the transport part) must be the same in all (a single UDP socket is shared). (4) This must be done before listen() or sendmsg() is called. This allows someone to connect to the service socket with different service IDs and lays the foundation for service upgrading. The service ID used by an incoming call can be extracted from the msg_name returned by recvmsg(). Signed-off-by: David Howells <dhowells@redhat.com>
2017-05-25rxrpc: Support network namespacingDavid Howells
Support network namespacing in AF_RXRPC with the following changes: (1) All the local endpoint, peer and call lists, locks, counters, etc. are moved into the per-namespace record. (2) All the connection tracking is moved into the per-namespace record with the exception of the client connection ID tree, which is kept global so that connection IDs are kept unique per-machine. (3) Each namespace gets its own epoch. This allows each network namespace to pretend to be a separate client machine. (4) The /proc/net/rxrpc_xxx files are now called /proc/net/rxrpc/xxx and the contents reflect the namespace. fs/afs/ should be okay with this patch as it explicitly requires the current net namespace to be init_net to permit a mount to proceed at the moment. It will, however, need updating so that cells, IP addresses and DNS records are per-namespace also. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-29rxrpc: Reduce the rxrpc_local::services list to a pointerDavid Howells
Reduce the rxrpc_local::services list to just a pointer as we don't permit multiple service endpoints to bind to a single transport endpoints (this is excluded by rxrpc_lookup_local()). The reason we don't allow this is that if you send a request to an AFS filesystem service, it will try to talk back to your cache manager on the port you sent from (this is how file change notifications are handled). To prevent someone from stealing your CM callbacks, we don't let AF_RXRPC sockets share a UDP socket if at least one of them has a service bound. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17rxrpc: Make IPv6 support conditional on CONFIG_IPV6David Howells
Add CONFIG_AF_RXRPC_IPV6 and make the IPv6 support code conditional on it. This is then made conditional on CONFIG_IPV6. Without this, the following can be seen: net/built-in.o: In function `rxrpc_init_peer': >> peer_object.c:(.text+0x18c3c8): undefined reference to `ip6_route_output_flags' Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-13rxrpc: Add IPv6 supportDavid Howells
Add IPv6 support to AF_RXRPC. With this, AF_RXRPC sockets can be created: service = socket(AF_RXRPC, SOCK_DGRAM, PF_INET6); instead of: service = socket(AF_RXRPC, SOCK_DGRAM, PF_INET); The AFS filesystem doesn't support IPv6 at the moment, though, since that requires upgrades to some of the RPC calls. Note that a good portion of this patch is replacing "%pI4:%u" in print statements with "%pISpc" which is able to handle both protocols and print the port. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13rxrpc: Don't specify protocol to when creating transport socketDavid Howells
Pass 0 as the protocol argument when creating the transport socket rather than IPPROTO_UDP. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08rxrpc: Rewrite the data and ack handling codeDavid Howells
Rewrite the data and ack handling code such that: (1) Parsing of received ACK and ABORT packets and the distribution and the filing of DATA packets happens entirely within the data_ready context called from the UDP socket. This allows us to process and discard ACK and ABORT packets much more quickly (they're no longer stashed on a queue for a background thread to process). (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim(). We instead keep track of the offset and length of the content of each packet in the sk_buff metadata. This means we don't do any allocation in the receive path. (3) Jumbo DATA packet parsing is now done in data_ready context. Rather than cloning the packet once for each subpacket and pulling/trimming it, we file the packet multiple times with an annotation for each indicating which subpacket is there. From that we can directly calculate the offset and length. (4) A call's receive queue can be accessed without taking locks (memory barriers do have to be used, though). (5) Incoming calls are set up from preallocated resources and immediately made live. They can than have packets queued upon them and ACKs generated. If insufficient resources exist, DATA packet #1 is given a BUSY reply and other DATA packets are discarded). (6) sk_buffs no longer take a ref on their parent call. To make this work, the following changes are made: (1) Each call's receive buffer is now a circular buffer of sk_buff pointers (rxtx_buffer) rather than a number of sk_buff_heads spread between the call and the socket. This permits each sk_buff to be in the buffer multiple times. The receive buffer is reused for the transmit buffer. (2) A circular buffer of annotations (rxtx_annotations) is kept parallel to the data buffer. Transmission phase annotations indicate whether a buffered packet has been ACK'd or not and whether it needs retransmission. Receive phase annotations indicate whether a slot holds a whole packet or a jumbo subpacket and, if the latter, which subpacket. They also note whether the packet has been decrypted in place. (3) DATA packet window tracking is much simplified. Each phase has just two numbers representing the window (rx_hard_ack/rx_top and tx_hard_ack/tx_top). The hard_ack number is the sequence number before base of the window, representing the last packet the other side says it has consumed. hard_ack starts from 0 and the first packet is sequence number 1. The top number is the sequence number of the highest-numbered packet residing in the buffer. Packets between hard_ack+1 and top are soft-ACK'd to indicate they've been received, but not yet consumed. Four macros, before(), before_eq(), after() and after_eq() are added to compare sequence numbers within the window. This allows for the top of the window to wrap when the hard-ack sequence number gets close to the limit. Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also to indicate when rx_top and tx_top point at the packets with the LAST_PACKET bit set, indicating the end of the phase. (4) Calls are queued on the socket 'receive queue' rather than packets. This means that we don't need have to invent dummy packets to queue to indicate abnormal/terminal states and we don't have to keep metadata packets (such as ABORTs) around (5) The offset and length of a (sub)packet's content are now passed to the verify_packet security op. This is currently expected to decrypt the packet in place and validate it. However, there's now nowhere to store the revised offset and length of the actual data within the decrypted blob (there may be a header and padding to skip) because an sk_buff may represent multiple packets, so a locate_data security op is added to retrieve these details from the sk_buff content when needed. (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is individually secured and needs to be individually decrypted. The code to do this is broken out into rxrpc_recvmsg_data() and shared with the kernel API. It now iterates over the call's receive buffer rather than walking the socket receive queue. Additional changes: (1) The timers are condensed to a single timer that is set for the soonest of three timeouts (delayed ACK generation, DATA retransmission and call lifespan). (2) Transmission of ACK and ABORT packets is effected immediately from process-context socket ops/kernel API calls that cause them instead of them being punted off to a background work item. The data_ready handler still has to defer to the background, though. (3) A shutdown op is added to the AF_RXRPC socket so that the AFS filesystem can shut down the socket and flush its own work items before closing the socket to deal with any in-progress service calls. Future additional changes that will need to be considered: (1) Make sure that a call doesn't hog the front of the queue by receiving data from the network as fast as userspace is consuming it to the exclusion of other calls. (2) Transmit delayed ACKs from within recvmsg() when we've consumed sufficiently more packets to avoid the background work item needing to run. Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08rxrpc: Convert rxrpc_local::services to an hlistDavid Howells
Convert the rxrpc_local::services list to an hlist so that it can be accessed under RCU conditions more readily. Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06rxrpc: Add RCU destruction for connections and callsDavid Howells
Add RCU destruction for connections and calls as the RCU lookup from the transport socket data_ready handler is going to come along shortly. Whilst we're at it, move the cleanup workqueue flushing and RCU barrierage into the destruction code for the objects that need it (locals and connections) and add the extra RCU barrier required for connection cleanup. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: Kill the client connection bundle conceptDavid Howells
Kill off the concept of maintaining a bundle of connections to a particular target service to increase the number of call slots available for any beyond four for that service (there are four call slots per connection). This will make cleaning up the connection handling code easier and facilitate removal of the rxrpc_transport struct. Bundling can be reintroduced later if necessary. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22rxrpc: Provide more refcount helper functionsDavid Howells
Provide refcount helper functions for connections so that the code doesn't touch local or connection usage counts directly. Also make it such that local and peer put functions can take a NULL pointer. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15rxrpc: Rework local endpoint managementDavid Howells
Rework the local RxRPC endpoint management. Local endpoint objects are maintained in a flat list as before. This should be okay as there shouldn't be more than one per open AF_RXRPC socket (there can be fewer as local endpoints can be shared if their local service ID is 0 and they share the same local transport parameters). Changes: (1) Local endpoints may now only be shared if they have local service ID 0 (ie. they're not being used for listening). This prevents a scenario where process A is listening of the Cache Manager port and process B contacts a fileserver - which may then attempt to send CM requests back to B. But if A and B are sharing a local endpoint, A will get the CM requests meant for B. (2) We use a mutex to handle lookups and don't provide RCU-only lookups since we only expect to access the list when opening a socket or destroying an endpoint. The local endpoint object is pointed to by the transport socket's sk_user_data for the life of the transport socket - allowing us to refer to it directly from the sk_data_ready and sk_error_report callbacks. (3) atomic_inc_not_zero() now exists and can be used to only share a local endpoint if the last reference hasn't yet gone. (4) We can remove rxrpc_local_lock - a spinlock that had to be taken with BH processing disabled given that we assume sk_user_data won't change under us. (5) The transport socket is shut down before we clear the sk_user_data pointer so that we can be sure that the transport socket's callbacks won't be invoked once the RCU destruction is scheduled. (6) Local endpoints have a work item that handles both destruction and event processing. The means that destruction doesn't then need to wait for event processing. The event queues can then be cleared after the transport socket is shut down. (7) Local endpoints are no longer available for resurrection beyond the life of the sockets that had them open. As soon as their last ref goes, they are scheduled for destruction and may not have their usage count moved from 0. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15rxrpc: Separate local endpoint event handling out into its own fileDavid Howells
Separate local endpoint event handling out into its own file preparatory to overhauling the object management aspect (which remains in the original file). Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15rxrpc: Rename rxrpc_UDP_error_report() to rxrpc_error_report()David Howells
Rename rxrpc_UDP_error_report() to rxrpc_error_report() as it might get called for something other than UDP. Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-13rxrpc: Rename files matching ar-*.c to git rid of the "ar-" prefixDavid Howells
Rename files matching net/rxrpc/ar-*.c to get rid of the "ar-" prefix. This will aid splitting those files by making easier to come up with new names. Note that the not all files are simply renamed from ar-X.c to X.c. The following exceptions are made: (*) ar-call.c -> call_object.c ar-ack.c -> call_event.c call_object.c is going to contain the core of the call object handling. Call event handling is all going to be in call_event.c. (*) ar-accept.c -> call_accept.c Incoming call handling is going to be here. (*) ar-connection.c -> conn_object.c ar-connevent.c -> conn_event.c The former file is going to have the basic connection object handling, but there will likely be some differentiation between client connections and service connections in additional files later. The latter file will have all the connection-level event handling. (*) ar-local.c -> local_object.c This will have the local endpoint object handling code. The local endpoint event handling code will later be split out into local_event.c. (*) ar-peer.c -> peer_object.c This will have the peer endpoint object handling code. Peer event handling code will be placed in peer_event.c (for the moment, there is none). (*) ar-error.c -> peer_event.c This will become the peer event handling code, though for the moment it's actually driven from the local endpoint's perspective. Note that I haven't renamed ar-transport.c to transport_object.c as the intention is to delete it when the rxrpc_transport struct is excised. The only file that actually has its contents changed is net/rxrpc/Makefile. net/rxrpc/ar-internal.h will need its section marker comments updating, but I'll do that in a separate patch to make it easier for git to follow the history across the rename. I may also want to rename ar-internal.h at some point - but that would mean updating all the #includes and I'd rather do that in a separate step. Signed-off-by: David Howells <dhowells@redhat.com.