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* rxrpc: Fix NULL pointer deref due to call->conn being cleared on disconnectDavid Howells2020-02-141-0/+1
| | | | | | | | | | | | | | | | | | | [ Upstream commit 5273a191dca65a675dc0bcf3909e59c6933e2831 ] When a call is disconnected, the connection pointer from the call is cleared to make sure it isn't used again and to prevent further attempted transmission for the call. Unfortunately, there might be a daemon trying to use it at the same time to transmit a packet. Fix this by keeping call->conn set, but setting a flag on the call to indicate disconnection instead. Remove also the bits in the transmission functions where the conn pointer is checked and a ref taken under spinlock as this is now redundant. Fixes: 8d94aa381dab ("rxrpc: Calls shouldn't hold socket refs") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* rxrpc: Fix connection-level abort handlingDavid Howells2018-11-041-2/+2
| | | | | | | | | | | | | | | [ Upstream commit 647530924f47c93db472ee3cf43b7ef1425581b6 ] Fix connection-level abort handling to cache the abort and error codes properly so that a new incoming call can be properly aborted if it races with the parent connection being aborted by another CPU. The abort_code and error parameters can then be dropped from rxrpc_abort_calls(). Fixes: f5c17aaeb2ae ("rxrpc: Calls should only have one terminal state") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
* rxrpc: Fix service endpoint expiryDavid Howells2018-02-031-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit f859ab61875978eeaa539740ff7f7d91f5d60006 ] RxRPC service endpoints expire like they're supposed to by the following means: (1) Mark dead rxrpc_net structs (with ->live) rather than twiddling the global service conn timeout, otherwise the first rxrpc_net struct to die will cause connections on all others to expire immediately from then on. (2) Mark local service endpoints for which the socket has been closed (->service_closed) so that the expiration timeout can be much shortened for service and client connections going through that endpoint. (3) rxrpc_put_service_conn() needs to schedule the reaper when the usage count reaches 1, not 0, as idle conns have a 1 count. (4) The accumulator for the earliest time we might want to schedule for should be initialised to jiffies + MAX_JIFFY_OFFSET, not ULONG_MAX as the comparison functions use signed arithmetic. (5) Simplify the expiration handling, adding the expiration value to the idle timestamp each time rather than keeping track of the time in the past before which the idle timestamp must go to be expired. This is much easier to read. (6) Ignore the timeouts if the net namespace is dead. (7) Restart the service reaper work item rather the client reaper. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* rxrpc: Provide a different lockdep key for call->user_mutex for kernel callsDavid Howells2018-02-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 9faaff593404a9c4e5abc6839a641635d7b9d0cd ] Provide a different lockdep key for rxrpc_call::user_mutex when the call is made on a kernel socket, such as by the AFS filesystem. The problem is that lockdep registers a false positive between userspace calling the sendmsg syscall on a user socket where call->user_mutex is held whilst userspace memory is accessed whereas the AFS filesystem may perform operations with mmap_sem held by the caller. In such a case, the following warning is produced. ====================================================== WARNING: possible circular locking dependency detected 4.14.0-fscache+ #243 Tainted: G E ------------------------------------------------------ modpost/16701 is trying to acquire lock: (&vnode->io_lock){+.+.}, at: [<ffffffffa000fc40>] afs_begin_vnode_operation+0x33/0x77 [kafs] but task is already holding lock: (&mm->mmap_sem){++++}, at: [<ffffffff8104376a>] __do_page_fault+0x1ef/0x486 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&mm->mmap_sem){++++}: __might_fault+0x61/0x89 _copy_from_iter_full+0x40/0x1fa rxrpc_send_data+0x8dc/0xff3 rxrpc_do_sendmsg+0x62f/0x6a1 rxrpc_sendmsg+0x166/0x1b7 sock_sendmsg+0x2d/0x39 ___sys_sendmsg+0x1ad/0x22b __sys_sendmsg+0x41/0x62 do_syscall_64+0x89/0x1be return_from_SYSCALL_64+0x0/0x75 -> #2 (&call->user_mutex){+.+.}: __mutex_lock+0x86/0x7d2 rxrpc_new_client_call+0x378/0x80e rxrpc_kernel_begin_call+0xf3/0x154 afs_make_call+0x195/0x454 [kafs] afs_vl_get_capabilities+0x193/0x198 [kafs] afs_vl_lookup_vldb+0x5f/0x151 [kafs] afs_create_volume+0x2e/0x2f4 [kafs] afs_mount+0x56a/0x8d7 [kafs] mount_fs+0x6a/0x109 vfs_kern_mount+0x67/0x135 do_mount+0x90b/0xb57 SyS_mount+0x72/0x98 do_syscall_64+0x89/0x1be return_from_SYSCALL_64+0x0/0x75 -> #1 (k-sk_lock-AF_RXRPC){+.+.}: lock_sock_nested+0x74/0x8a rxrpc_kernel_begin_call+0x8a/0x154 afs_make_call+0x195/0x454 [kafs] afs_fs_get_capabilities+0x17a/0x17f [kafs] afs_probe_fileserver+0xf7/0x2f0 [kafs] afs_select_fileserver+0x83f/0x903 [kafs] afs_fetch_status+0x89/0x11d [kafs] afs_iget+0x16f/0x4f8 [kafs] afs_mount+0x6c6/0x8d7 [kafs] mount_fs+0x6a/0x109 vfs_kern_mount+0x67/0x135 do_mount+0x90b/0xb57 SyS_mount+0x72/0x98 do_syscall_64+0x89/0x1be return_from_SYSCALL_64+0x0/0x75 -> #0 (&vnode->io_lock){+.+.}: lock_acquire+0x174/0x19f __mutex_lock+0x86/0x7d2 afs_begin_vnode_operation+0x33/0x77 [kafs] afs_fetch_data+0x80/0x12a [kafs] afs_readpages+0x314/0x405 [kafs] __do_page_cache_readahead+0x203/0x2ba filemap_fault+0x179/0x54d __do_fault+0x17/0x60 __handle_mm_fault+0x6d7/0x95c handle_mm_fault+0x24e/0x2a3 __do_page_fault+0x301/0x486 do_page_fault+0x236/0x259 page_fault+0x22/0x30 __clear_user+0x3d/0x60 padzero+0x1c/0x2b load_elf_binary+0x785/0xdc7 search_binary_handler+0x81/0x1ff do_execveat_common.isra.14+0x600/0x888 do_execve+0x1f/0x21 SyS_execve+0x28/0x2f do_syscall_64+0x89/0x1be return_from_SYSCALL_64+0x0/0x75 other info that might help us debug this: Chain exists of: &vnode->io_lock --> &call->user_mutex --> &mm->mmap_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem); lock(&call->user_mutex); lock(&mm->mmap_sem); lock(&vnode->io_lock); *** DEADLOCK *** 1 lock held by modpost/16701: #0: (&mm->mmap_sem){++++}, at: [<ffffffff8104376a>] __do_page_fault+0x1ef/0x486 stack backtrace: CPU: 0 PID: 16701 Comm: modpost Tainted: G E 4.14.0-fscache+ #243 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 Call Trace: dump_stack+0x67/0x8e print_circular_bug+0x341/0x34f check_prev_add+0x11f/0x5d4 ? add_lock_to_list.isra.12+0x8b/0x8b ? add_lock_to_list.isra.12+0x8b/0x8b ? __lock_acquire+0xf77/0x10b4 __lock_acquire+0xf77/0x10b4 lock_acquire+0x174/0x19f ? afs_begin_vnode_operation+0x33/0x77 [kafs] __mutex_lock+0x86/0x7d2 ? afs_begin_vnode_operation+0x33/0x77 [kafs] ? afs_begin_vnode_operation+0x33/0x77 [kafs] ? afs_begin_vnode_operation+0x33/0x77 [kafs] afs_begin_vnode_operation+0x33/0x77 [kafs] afs_fetch_data+0x80/0x12a [kafs] afs_readpages+0x314/0x405 [kafs] __do_page_cache_readahead+0x203/0x2ba ? filemap_fault+0x179/0x54d filemap_fault+0x179/0x54d __do_fault+0x17/0x60 __handle_mm_fault+0x6d7/0x95c handle_mm_fault+0x24e/0x2a3 __do_page_fault+0x301/0x486 do_page_fault+0x236/0x259 page_fault+0x22/0x30 RIP: 0010:__clear_user+0x3d/0x60 RSP: 0018:ffff880071e93da0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000011c RCX: 000000000000011c RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000060f720 RBP: 000000000060f720 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffff8800b5459b68 R12: ffff8800ce150e00 R13: 000000000060f720 R14: 00000000006127a8 R15: 0000000000000000 padzero+0x1c/0x2b load_elf_binary+0x785/0xdc7 search_binary_handler+0x81/0x1ff do_execveat_common.isra.14+0x600/0x888 do_execve+0x1f/0x21 SyS_execve+0x28/0x2f do_syscall_64+0x89/0x1be entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x7fdb6009ee07 RSP: 002b:00007fff566d9728 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 000055ba57280900 RCX: 00007fdb6009ee07 RDX: 000055ba5727f270 RSI: 000055ba5727cac0 RDI: 000055ba57280900 RBP: 000055ba57280900 R08: 00007fff566d9700 R09: 0000000000000000 R10: 000055ba5727cac0 R11: 0000000000000246 R12: 0000000000000000 R13: 000055ba5727cac0 R14: 000055ba5727f270 R15: 0000000000000000 Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* rxrpc: Allow failed client calls to be retriedDavid Howells2017-08-291-12/+7
| | | | | | | | | | | | | | | | | | | | | | | | Allow a client call that failed on network error to be retried, provided that the Tx queue still holds DATA packet 1. This allows an operation to be submitted to another server or another address for the same server without having to repackage and re-encrypt the data so far processed. Two new functions are provided: (1) rxrpc_kernel_check_call() - This is used to find out the completion state of a call to guess whether it can be retried and whether it should be retried. (2) rxrpc_kernel_retry_call() - Disconnect the call from its current connection, reset the state and submit it as a new client call to a new address. The new address need not match the previous address. A call may be retried even if all the data hasn't been loaded into it yet; a partially constructed will be retained at the same point it was at when an error condition was detected. msg_data_left() can be used to find out how much data was packaged before the error occurred. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix IPv6 supportDavid Howells2017-08-291-2/+2
| | | | | | | | | | | | | | | | | | Fix IPv6 support in AF_RXRPC in the following ways: (1) When extracting the address from a received IPv4 packet, if the local transport socket is open for IPv6 then fill out the sockaddr_rxrpc struct for an IPv4-mapped-to-IPv6 AF_INET6 transport address instead of an AF_INET one. (2) When sending CHALLENGE or RESPONSE packets, the transport length needs to be set from the sockaddr_rxrpc::transport_len field rather than sizeof() on the IPv4 transport address. (3) When processing an IPv4 ICMP packet received by an IPv6 socket, set up the address correctly before searching for the affected peer. Signed-off-by: David Howells <dhowells@redhat.com>
* net: rxrpc: Replace time_t type with time64_t typeBaolin Wang2017-08-291-1/+1
| | | | | | | | | | | | | | | | Since the 'expiry' variable of 'struct key_preparsed_payload' has been changed to 'time64_t' type, which is year 2038 safe on 32bits system. In net/rxrpc subsystem, we need convert 'u32' type to 'time64_t' type when copying ticket expires time to 'prep->expiry', then this patch introduces two helper functions to help convert 'u32' to 'time64_t' type. This patch also uses ktime_get_real_seconds() to get current time instead of get_seconds() which is not year 2038 safe on 32bits system. Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Move the packet.h include file into net/rxrpc/David Howells2017-07-211-1/+1
| | | | | | | | | | | Move the protocol description header file into net/rxrpc/ and rename it to protocol.h. It's no longer necessary to expose it as packets are no longer exposed to kernel services (such as AFS) that use the facility. The abort codes are transferred to the UAPI header instead as we pass these back to userspace and also to kernel services. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Cache the congestion window settingDavid Howells2017-06-141-0/+2
| | | | | | | | | | | | | Cache the congestion window setting that was determined during a call's transmission phase when it finishes so that it can be used by the next call to the same peer, thereby shortcutting the slow-start algorithm. The value is stored in the rxrpc_peer struct and is accessed without locking. Each call takes the value that happens to be there when it starts and just overwrites the value when it finishes. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* rxrpc: Provide a cmsg to specify the amount of Tx data for a callDavid Howells2017-06-071-1/+2
| | | | | | | | | | | | | | | | | | | Provide a control message that can be specified on the first sendmsg() of a client call or the first sendmsg() of a service response to indicate the total length of the data to be transmitted for that call. Currently, because the length of the payload of an encrypted DATA packet is encrypted in front of the data, the packet cannot be encrypted until we know how much data it will hold. By specifying the length at the beginning of the transmit phase, each DATA packet length can be set before we start loading data from userspace (where several sendmsg() calls may contribute to a particular packet). An error will be returned if too little or too much data is presented in the Tx phase. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add service upgrade support for client connectionsDavid Howells2017-06-051-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make it possible for a client to use AuriStor's service upgrade facility. The client does this by adding an RXRPC_UPGRADE_SERVICE control message to the first sendmsg() of a call. This takes no parameters. When recvmsg() starts returning data from the call, the service ID field in the returned msg_name will reflect the result of the upgrade attempt. If the upgrade was ignored, srx_service will match what was set in the sendmsg(); if the upgrade happened the srx_service will be altered to indicate the service the server upgraded to. Note that: (1) The choice of upgrade service is up to the server (2) Further client calls to the same server that would share a connection are blocked if an upgrade probe is in progress. (3) This should only be used to probe the service. Clients should then use the returned service ID in all subsequent communications with that server (and not set the upgrade). Note that the kernel will not retain this information should the connection expire from its cache. (4) If a server that supports upgrading is replaced by one that doesn't, whilst a connection is live, and if the replacement is running, say, OpenAFS 1.6.4 or older or an older IBM AFS, then the replacement server will not respond to packets sent to the upgraded connection. At this point, calls will time out and the server must be reprobed. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Implement service upgradeDavid Howells2017-06-051-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement AuriStor's service upgrade facility. There are three problems that this is meant to deal with: (1) Various of the standard AFS RPC calls have IPv4 addresses in their requests and/or replies - but there's no room for including IPv6 addresses. (2) Definition of IPv6-specific RPC operations in the standard operation sets has not yet been achieved. (3) One could envision the creation a new service on the same port that as the original service. The new service could implement improved operations - and the client could try this first, falling back to the original service if it's not there. Unfortunately, certain servers ignore packets addressed to a service they don't implement and don't respond in any way - not even with an ABORT. This means that the client must then wait for the call timeout to occur. What service upgrade does is to see if the connection is marked as being 'upgradeable' and if so, change the service ID in the server and thus the request and reply formats. Note that the upgrade isn't mandatory - a server that supports only the original call set will ignore the upgrade request. In the protocol, the procedure is then as follows: (1) To request an upgrade, the first DATA packet in a new connection must have the userStatus set to 1 (this is normally 0). The userStatus value is normally ignored by the server. (2) If the server doesn't support upgrading, the reply packets will contain the same service ID as for the first request packet. (3) If the server does support upgrading, all future reply packets on that connection will contain the new service ID and the new service ID will be applied to *all* further calls on that connection as well. (4) The RPC op used to probe the upgrade must take the same request data as the shadow call in the upgrade set (but may return a different reply). GetCapability RPC ops were added to all standard sets for just this purpose. Ops where the request formats differ cannot be used for probing. (5) The client must wait for completion of the probe before sending any further RPC ops to the same destination. It should then use the service ID that recvmsg() reported back in all future calls. (6) The shadow service must have call definitions for all the operation IDs defined by the original service. To support service upgrading, a server should: (1) Call bind() twice on its AF_RXRPC socket before calling listen(). Each bind() should supply a different service ID, but the transport addresses must be the same. This allows the server to receive requests with either service ID. (2) Enable automatic upgrading by calling setsockopt(), specifying RXRPC_UPGRADEABLE_SERVICE and passing in a two-member array of unsigned shorts as the argument: unsigned short optval[2]; This specifies a pair of service IDs. They must be different and must match the service IDs bound to the socket. Member 0 is the service ID to upgrade from and member 1 is the service ID to upgrade to. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Permit multiple service bindingDavid Howells2017-06-051-0/+2
| | | | | | | | | | | | | | | | | | | | | | | 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>
* rxrpc: Separate the connection's protocol service ID from the lookup IDDavid Howells2017-06-051-1/+1
| | | | | | | | | | | | | | | | | | Keep the rxrpc_connection struct's idea of the service ID that is exposed in the protocol separate from the service ID that's used as a lookup key. This allows the protocol service ID on a client connection to get upgraded without making the connection unfindable for other client calls that also would like to use the upgraded connection. The connection's actual service ID is then returned through recvmsg() by way of msg_name. Whilst we're at it, we get rid of the last_service_id field from each channel. The service ID is per-connection, not per-call and an entire connection is upgraded in one go. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Support network namespacingDavid Howells2017-05-251-12/+53
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* rxrpc: Trace protocol errors in received packetsDavid Howells2017-04-061-0/+19
| | | | | | | | | | | | | | | | | | | | | Add a tracepoint (rxrpc_rx_proto) to record protocol errors in received packets. The following changes are made: (1) Add a function, __rxrpc_abort_eproto(), to note a protocol error on a call and mark the call aborted. This is wrapped by rxrpc_abort_eproto() that makes the why string usable in trace. (2) Add trace_rxrpc_rx_proto() or rxrpc_abort_eproto() to protocol error generation points, replacing rxrpc_abort_call() with the latter. (3) Only send an abort packet in rxkad_verify_packet*() if we actually managed to abort the call. Note that a trace event is also emitted if a kernel user (e.g. afs) tries to send data through a call when it's not in the transmission phase, though it's not technically a receive event. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix deadlock between call creation and sendmsg/recvmsgDavid Howells2017-03-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All the routines by which rxrpc is accessed from the outside are serialised by means of the socket lock (sendmsg, recvmsg, bind, rxrpc_kernel_begin_call(), ...) and this presents a problem: (1) If a number of calls on the same socket are in the process of connection to the same peer, a maximum of four concurrent live calls are permitted before further calls need to wait for a slot. (2) If a call is waiting for a slot, it is deep inside sendmsg() or rxrpc_kernel_begin_call() and the entry function is holding the socket lock. (3) sendmsg() and recvmsg() or the in-kernel equivalents are prevented from servicing the other calls as they need to take the socket lock to do so. (4) The socket is stuck until a call is aborted and makes its slot available to the waiter. Fix this by: (1) Provide each call with a mutex ('user_mutex') that arbitrates access by the users of rxrpc separately for each specific call. (2) Make rxrpc_sendmsg() and rxrpc_recvmsg() unlock the socket as soon as they've got a call and taken its mutex. Note that I'm returning EWOULDBLOCK from recvmsg() if MSG_DONTWAIT is set but someone else has the lock. Should I instead only return EWOULDBLOCK if there's nothing currently to be done on a socket, and sleep in this particular instance because there is something to be done, but we appear to be blocked by the interrupt handler doing its ping? (3) Make rxrpc_new_client_call() unlock the socket after allocating a new call, locking its user mutex and adding it to the socket's call tree. The call is returned locked so that sendmsg() can add data to it immediately. From the moment the call is in the socket tree, it is subject to access by sendmsg() and recvmsg() - even if it isn't connected yet. (4) Lock new service calls in the UDP data_ready handler (in rxrpc_new_incoming_call()) because they may already be in the socket's tree and the data_ready handler makes them live immediately if a user ID has already been preassigned. Note that the new call is locked before any notifications are sent that it is live, so doing mutex_trylock() *ought* to always succeed. Userspace is prevented from doing sendmsg() on calls that are in a too-early state in rxrpc_do_sendmsg(). (5) Make rxrpc_new_incoming_call() return the call with the user mutex held so that a ping can be scheduled immediately under it. Note that it might be worth moving the ping call into rxrpc_new_incoming_call() and then we can drop the mutex there. (6) Make rxrpc_accept_call() take the lock on the call it is accepting and release the socket after adding the call to the socket's tree. This is slightly tricky as we've dequeued the call by that point and have to requeue it. Note that requeuing emits a trace event. (7) Make rxrpc_kernel_send_data() and rxrpc_kernel_recv_data() take the new mutex immediately and don't bother with the socket mutex at all. This patch has the nice bonus that calls on the same socket are now to some extent parallelisable. Note that we might want to move rxrpc_service_prealloc() calls out from the socket lock and give it its own lock, so that we don't hang progress in other calls because we're waiting for the allocator. We probably also want to avoid calling rxrpc_notify_socket() from within the socket lock (rxrpc_accept_call()). Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Marc Dionne <marc.c.dionne@auristor.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* rxrpc: Allow listen(sock, 0) to be used to disable listeningDavid Howells2017-01-091-0/+1
| | | | | | | | | | | | Allow listen() with a backlog of 0 to be used to disable listening on an AF_RXRPC socket. This also releases any preallocation, thereby making it easier for a kernel service to account for all allocated call structures when shutting down the service. The socket cannot thereafter have listening reenabled, but must rather be closed and reopened. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix handling of enums-to-string translation in tracingDavid Howells2017-01-051-194/+0
| | | | | | | | | | | | | | | | | Fix the way enum values are translated into strings in AF_RXRPC tracepoints. The problem with just doing a lookup in a normal flat array of strings or chars is that external tracing infrastructure can't find it. Rather, TRACE_DEFINE_ENUM must be used. Also sort the enums and string tables to make it easier to keep them in order so that a future patch to __print_symbolic() can be optimised to try a direct lookup into the table first before iterating over it. A couple of _proto() macro calls are removed because they refered to tables that got moved to the tracing infrastructure. The relevant data can be found by way of tracing. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Need to produce an ACK for service op if op takes a long timeDavid Howells2016-10-061-0/+3
| | | | | | | | | | | | | | | | | | | | | | We need to generate a DELAY ACK from the service end of an operation if we start doing the actual operation work and it takes longer than expected. This will hard-ACK the request data and allow the client to release its resources. To make this work: (1) We have to set the ack timer and propose an ACK when the call moves to the RXRPC_CALL_SERVER_ACK_REQUEST and clear the pending ACK and cancel the timer when we start transmitting the reply (the first DATA packet of the reply implicitly ACKs the request phase). (2) It must be possible to set the timer when the caller is holding call->state_lock, so split the lock-getting part of the timer function out. (3) Add trace notes for the ACK we're requesting and the timer we clear. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix loss of PING RESPONSE ACK production due to PING ACKsDavid Howells2016-10-061-3/+9
| | | | | | | | | | | | Separate the output of PING ACKs from the output of other sorts of ACK so that if we receive a PING ACK and schedule transmission of a PING RESPONSE ACK, the response doesn't get cancelled by a PING ACK we happen to be scheduling transmission of at the same time. If a PING RESPONSE gets lost, the other side might just sit there waiting for it and refuse to proceed otherwise. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix warning by splitting rxrpc_send_call_packet()David Howells2016-10-061-1/+2
| | | | | | | | | | | | | | | Split rxrpc_send_data_packet() to separate ACK generation (which is more complicated) from ABORT generation. This simplifies the code a bit and fixes the following warning: In file included from ../net/rxrpc/output.c:20:0: net/rxrpc/output.c: In function 'rxrpc_send_call_packet': net/rxrpc/ar-internal.h:1187:27: error: 'top' may be used uninitialized in this function [-Werror=maybe-uninitialized] net/rxrpc/output.c:103:24: note: 'top' was declared here net/rxrpc/output.c:225:25: error: 'hard_ack' may be used uninitialized in this function [-Werror=maybe-uninitialized] Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Fix duplicate constDavid Howells2016-10-061-1/+1
| | | | | | Remove a duplicate const keyword. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Keep the call timeouts as ktimes rather than jiffiesDavid Howells2016-09-301-4/+4
| | | | | | | Keep that call timeouts as ktimes rather than jiffies so that they can be expressed as functions of RTT. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Remove error from struct rxrpc_skb_priv as it is unusedDavid Howells2016-09-301-1/+0
| | | | | | Remove error from struct rxrpc_skb_priv as it is no longer used. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: The offset field in struct rxrpc_skb_priv is unnecessaryDavid Howells2016-09-301-1/+0
| | | | | | | The offset field in struct rxrpc_skb_priv is unnecessary as the value can always be calculated. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Reduce the rxrpc_local::services list to a pointerDavid Howells2016-09-291-2/+1
| | | | | | | | | | | | | | 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>
* rxrpc: Make Tx loss-injection go through normal return and adjust tracingDavid Howells2016-09-291-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | In rxrpc_send_data_packet() make the loss-injection path return through the same code as the transmission path so that the RTT determination is initiated and any future timer shuffling will be done, despite the packet having been binned. Whilst we're at it: (1) Add to the tx_data tracepoint an indication of whether or not we're retransmitting a data packet. (2) When we're deciding whether or not to request an ACK, rather than checking if we're in fast-retransmit mode check instead if we're retransmitting. (3) Don't invoke the lose_skb tracepoint when losing a Tx packet as we're not altering the sk_buff refcount nor are we just seeing it after getting it off the Tx list. (4) The rxrpc_skb_tx_lost note is then no longer used so remove it. (5) rxrpc_lose_skb() no longer needs to deal with rxrpc_skb_tx_lost. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Implement slow-startDavid Howells2016-09-241-1/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | Implement RxRPC slow-start, which is similar to RFC 5681 for TCP. A tracepoint is added to log the state of the congestion management algorithm and the decisions it makes. Notes: (1) Since we send fixed-size DATA packets (apart from the final packet in each phase), counters and calculations are in terms of packets rather than bytes. (2) The ACK packet carries the equivalent of TCP SACK. (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly suited to SACK of a small number of packets. It seems that, almost inevitably, by the time three 'duplicate' ACKs have been seen, we have narrowed the loss down to one or two missing packets, and the FLIGHT_SIZE calculation ends up as 2. (4) In rxrpc_resend(), if there was no data that apparently needed retransmission, we transmit a PING ACK to ask the peer to tell us what its Rx window state is. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Schedule an ACK if the reply to a client call appears overdueDavid Howells2016-09-241-0/+2
| | | | | | | | | | | | | | | | | | If we've sent all the request data in a client call but haven't seen any sign of the reply data yet, schedule an ACK to be sent to the server to find out if the reply data got lost. If the server hasn't yet hard-ACK'd the request data, we send a PING ACK to demand a response to find out whether we need to retransmit. If the server says it has received all of the data, we send an IDLE ACK to tell the server that we haven't received anything in the receive phase as yet. To make this work, a non-immediate PING ACK must carry a delay. I've chosen the same as the IDLE ACK for the moment. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Generate a summary of the ACK state for later useDavid Howells2016-09-241-0/+14
| | | | | | | Generate a summary of the Tx buffer packet state when an ACK is received for use in a later patch that does congestion management. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Reinitialise the call ACK and timer state for client reply phaseDavid Howells2016-09-241-0/+1
| | | | | | | | | | | Clear the ACK reason, ACK timer and resend timer when entering the client reply phase when the first DATA packet is received. New ACKs will be proposed once the data is queued. The resend timer is no longer relevant and we need to cancel ACKs scheduled to probe for a lost reply. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Send an ACK after every few DATA packets we receiveDavid Howells2016-09-241-0/+3
| | | | | | | | | | | | | Send an ACK if we haven't sent one for the last two packets we've received. This keeps the other end apprised of where we've got to - which is important if they're doing slow-start. We do this in recvmsg so that we can dispatch a packet directly without the need to wake up the background thread. This should possibly be made configurable in future. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add tracepoint for ACK proposalDavid Howells2016-09-231-2/+23
| | | | | | | | | | | | | Add a tracepoint to log proposed ACKs, including whether the proposal is used to update a pending ACK or is discarded in favour of an easlier, higher priority ACK. Whilst we're at it, get rid of the rxrpc_acks() function and access the name array directly. We do, however, need to validate the ACK reason number given to trace_rxrpc_rx_ack() to make sure we don't overrun the array. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add a tracepoint for the call timerDavid Howells2016-09-231-1/+12
| | | | | | Add a tracepoint to log call timer initiation, setting and expiry. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Pass the last Tx packet marker in the annotation bufferDavid Howells2016-09-231-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the last packet of data to be transmitted on a call is queued, tx_top is set and then the RXRPC_CALL_TX_LAST flag is set. Unfortunately, this leaves a race in the ACK processing side of things because the flag affects the interpretation of tx_top and also allows us to start receiving reply data before we've finished transmitting. To fix this, make the following changes: (1) rxrpc_queue_packet() now sets a marker in the annotation buffer instead of setting the RXRPC_CALL_TX_LAST flag. (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the same context as the routines that use it. (3) rxrpc_end_tx_phase() is simplified to just shift the call state. The Tx window must have been rotated before calling to discard the last packet. (4) rxrpc_receiving_reply() is added to handle the arrival of the first DATA packet of a reply to a client call (which is an implicit ACK of the Tx phase). (5) The last part of rxrpc_input_ack() is reordered to perform Tx rotation, then soft-ACK application and then to end the phase if we've rotated the last packet. In the event of a terminal ACK, the soft-ACK application will be skipped as nAcks should be 0. (6) rxrpc_input_ackall() now has to rotate as well as ending the phase. In addition: (7) Alter the transmit tracepoint to log the rotation of the last packet. (8) Remove the no-longer relevant queue_reqack tracepoint note. The ACK-REQUESTED packet header flag is now set as needed when we actually transmit the packet and may vary by retransmission. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Need to start the resend timer on initial transmissionDavid Howells2016-09-231-0/+1
| | | | | | | | When a DATA packet has its initial transmission, we may need to start or adjust the resend timer. Without this we end up relying on being sent a NACK to initiate the resend. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Make sure sendmsg() is woken on call completionDavid Howells2016-09-231-0/+1
| | | | | | | Make sure that sendmsg() gets woken up if the call it is waiting for completes abnormally. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Reduce the number of ACK-Requests sentDavid Howells2016-09-221-0/+1
| | | | | | | | | | | | | | | Reduce the number of ACK-Requests we set on DATA packets that we're sending to reduce network traffic. We set the flag on odd-numbered DATA packets to start off the RTT cache until we have at least three entries in it and then probe once per second thereafter to keep it topped up. This could be made tunable in future. Note that from this point, the RXRPC_REQUEST_ACK flag is set on DATA packets as we transmit them and not stored statically in the sk_buff. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Obtain RTT data by requesting ACKs on DATA packetsDavid Howells2016-09-221-4/+3
| | | | | | | | | | | | | | | In addition to sending a PING ACK to gain RTT data, we can set the RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK. The ACK packet contains the serial number of the packet it is in response to, so we can look through the Tx buffer for a matching DATA packet. This requires that the data packets be stamped with the time of transmission as a ktime rather than having the resend_at time in jiffies. This further requires the resend code to do the resend determination in ktimes and convert to jiffies to set the timer. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Send pings to get RTT dataDavid Howells2016-09-221-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | Send a PING ACK packet to the peer when we get a new incoming call from a peer we don't have a record for. The PING RESPONSE ACK packet will tell us the following about the peer: (1) its receive window size (2) its MTU sizes (3) its support for jumbo DATA packets (4) if it supports slow start (similar to RFC 5681) (5) an estimate of the RTT This is necessary because the peer won't normally send us an ACK until it gets to the Rx phase and we send it a packet, but we would like to know some of this information before we start sending packets. A pair of tracepoints are added so that RTT determination can be observed. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add per-peer RTT trackerDavid Howells2016-09-221-4/+21
| | | | | | | | | | | | | | Add a function to track the average RTT for a peer. Sources of RTT data will be added in subsequent patches. The RTT data will be useful in the future for determining resend timeouts and for handling the slow-start part of the Rx protocol. Also add a pair of tracepoints, one to log transmissions to elicit a response for RTT purposes and one to log responses that contribute RTT data. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add re-sent Tx annotationDavid Howells2016-09-221-0/+2
| | | | | | | | | Add a Tx-phase annotation for packet buffers to indicate that a buffer has already been retransmitted. This will be used by future congestion management. Re-retransmissions of a packet don't affect the congestion window managment in the same way as initial retransmissions. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Don't store the rxrpc header in the Tx queue sk_buffsDavid Howells2016-09-221-3/+2
| | | | | | | | | | | Don't store the rxrpc protocol header in sk_buffs on the transmit queue, but rather generate it on the fly and pass it to kernel_sendmsg() as a separate iov. This reduces the amount of storage required. Note that the security header is still stored in the sk_buff as it may get encrypted along with the data (and doesn't change with each transmission). Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Improve skb tracingDavid Howells2016-09-171-5/+28
| | | | | | | | | | | | | | | | | | | | | | | Improve sk_buff tracing within AF_RXRPC by the following means: (1) Use an enum to note the event type rather than plain integers and use an array of event names rather than a big multi ?: list. (2) Distinguish Rx from Tx packets and account them separately. This requires the call phase to be tracked so that we know what we might find in rxtx_buffer[]. (3) Add a parameter to rxrpc_{new,see,get,free}_skb() to indicate the event type. (4) A pair of 'rotate' events are added to indicate packets that are about to be rotated out of the Rx and Tx windows. (5) A pair of 'lost' events are added, along with rxrpc_lose_skb() for packet loss injection recording. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add a tracepoint to follow what recvmsg doesDavid Howells2016-09-171-0/+17
| | | | | Add a tracepoint to follow what recvmsg does within AF_RXRPC. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add a tracepoint to follow packets in the Rx bufferDavid Howells2016-09-171-0/+12
| | | | | | | Add a tracepoint to follow the life of packets that get added to a call's receive buffer. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add a tracepoint to follow the life of a packet in the Tx bufferDavid Howells2016-09-171-0/+12
| | | | | | | Add a tracepoint to follow the insertion of a packet into the transmit buffer, its transmission and its rotation out of the buffer. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add connection tracepoint and client conn state tracepointDavid Howells2016-09-171-28/+48
| | | | | | | Add a pair of tracepoints, one to track rxrpc_connection struct ref counting and the other to track the client connection cache state. Signed-off-by: David Howells <dhowells@redhat.com>
* rxrpc: Add some additional call tracingDavid Howells2016-09-171-0/+3
| | | | | | | | | | Add additional call tracepoint points for noting call-connected, call-released and connection-failed events. Also fix one tracepoint that was using an integer instead of the corresponding enum value as the point type. Signed-off-by: David Howells <dhowells@redhat.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-04 02:31:12 +0000