summaryrefslogtreecommitdiff
path: root/net/netlink/diag.c
AgeCommit message (Collapse)AuthorFilesLines
2017-12-11rhashtable: Change rhashtable_walk_start to return voidTom Herbert1-6/+2
Most callers of rhashtable_walk_start don't care about a resize event which is indicated by a return value of -EAGAIN. So calls to rhashtable_walk_start are wrapped wih code to ignore -EAGAIN. Something like this is common: ret = rhashtable_walk_start(rhiter); if (ret && ret != -EAGAIN) goto out; Since zero and -EAGAIN are the only possible return values from the function this check is pointless. The condition never evaluates to true. This patch changes rhashtable_walk_start to return void. This simplifies code for the callers that ignore -EAGAIN. For the few cases where the caller cares about the resize event, particularly where the table can be walked in mulitple parts for netlink or seq file dump, the function rhashtable_walk_start_check has been added that returns -EAGAIN on a resize event. Signed-off-by: Tom Herbert <tom@quantonium.net> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-05netlink/diag: report flags for netlink socketsAndrey Vagin1-0/+25
cb_running is reported in /proc/self/net/netlink and it is reported by the ss tool, when it gets information from the proc files. sock_diag is a new interface which is used instead of proc files, so it looks reasonable that this interface has to report no less information about sockets than proc files. We use these flags to dump and restore netlink sockets. Signed-off-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-03netlink: netlink_diag_dump() runs without locksEric Dumazet1-4/+1
A recent commit removed locking from netlink_diag_dump() but forgot one error case. ===================================== [ BUG: bad unlock balance detected! ] 4.9.0-rc3+ #336 Not tainted ------------------------------------- syz-executor/4018 is trying to release lock ([ 36.220068] nl_table_lock ) at: [<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182 but there are no more locks to release! other info that might help us debug this: 3 locks held by syz-executor/4018: #0: [ 36.220068] ( sock_diag_mutex[ 36.220068] ){+.+.+.} , at: [ 36.220068] [<ffffffff82c3873b>] sock_diag_rcv+0x1b/0x40 #1: [ 36.220068] ( sock_diag_table_mutex[ 36.220068] ){+.+.+.} , at: [ 36.220068] [<ffffffff82c38e00>] sock_diag_rcv_msg+0x140/0x3a0 #2: [ 36.220068] ( nlk->cb_mutex[ 36.220068] ){+.+.+.} , at: [ 36.220068] [<ffffffff82db6600>] netlink_dump+0x50/0xac0 stack backtrace: CPU: 1 PID: 4018 Comm: syz-executor Not tainted 4.9.0-rc3+ #336 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 ffff8800645df688 ffffffff81b46934 ffffffff84eb3e78 ffff88006ad85800 ffffffff82dc8683 ffffffff84eb3e78 ffff8800645df6b8 ffffffff812043ca dffffc0000000000 ffff88006ad85ff8 ffff88006ad85fd0 00000000ffffffff Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51 [<ffffffff812043ca>] print_unlock_imbalance_bug+0x17a/0x1a0 kernel/locking/lockdep.c:3388 [< inline >] __lock_release kernel/locking/lockdep.c:3512 [<ffffffff8120cfd8>] lock_release+0x8e8/0xc60 kernel/locking/lockdep.c:3765 [< inline >] __raw_read_unlock ./include/linux/rwlock_api_smp.h:225 [<ffffffff83fc001a>] _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:255 [<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182 [<ffffffff82db6947>] netlink_dump+0x397/0xac0 net/netlink/af_netlink.c:2110 Fixes: ad202074320c ("netlink: Use rhashtable walk interface in diag dump") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-08netlink: don't forget to release a rhashtable_iter structureAndrey Vagin1-1/+0
This bug was detected by kmemleak: unreferenced object 0xffff8804269cc3c0 (size 64): comm "criu", pid 1042, jiffies 4294907360 (age 13.713s) hex dump (first 32 bytes): a0 32 cc 2c 04 88 ff ff 00 00 00 00 00 00 00 00 .2.,............ 00 01 00 00 00 00 ad de 00 02 00 00 00 00 ad de ................ backtrace: [<ffffffff8184dffa>] kmemleak_alloc+0x4a/0xa0 [<ffffffff8124720f>] kmem_cache_alloc_trace+0x10f/0x280 [<ffffffffa02864cc>] __netlink_diag_dump+0x26c/0x290 [netlink_diag] v2: don't remove a reference on a rhashtable_iter structure to release it from netlink_diag_dump_done Cc: Herbert Xu <herbert@gondor.apana.org.au> Fixes: ad202074320c ("netlink: Use rhashtable walk interface in diag dump") Signed-off-by: Andrei Vagin <avagin@openvz.org> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-20netlink: Use rhashtable walk interface in diag dumpHerbert Xu1-30/+73
This patch converts the diag dumping code to use the rhashtable walk code instead of going through rhashtable by hand. The lock nl_table_lock is now only taken while we process the multicast list as it's not needed for the rhashtable walk. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-18netlink: remove mmapped netlink supportFlorian Westphal1-39/+0
mmapped netlink has a number of unresolved issues: - TX zerocopy support had to be disabled more than a year ago via commit 4682a0358639b29cf ("netlink: Always copy on mmap TX.") because the content of the mmapped area can change after netlink attribute validation but before message processing. - RX support was implemented mainly to speed up nfqueue dumping packet payload to userspace. However, since commit ae08ce0021087a5d812d2 ("netfilter: nfnetlink_queue: zero copy support") we avoid one copy with the socket-based interface too (via the skb_zerocopy helper). The other problem is that skbs attached to mmaped netlink socket behave different from normal skbs: - they don't have a shinfo area, so all functions that use skb_shinfo() (e.g. skb_clone) cannot be used. - reserving headroom prevents userspace from seeing the content as it expects message to start at skb->head. See for instance commit aa3a022094fa ("netlink: not trim skb for mmaped socket when dump"). - skbs handed e.g. to netlink_ack must have non-NULL skb->sk, else we crash because it needs the sk to check if a tx ring is attached. Also not obvious, leads to non-intuitive bug fixes such as 7c7bdf359 ("netfilter: nfnetlink: use original skbuff when acking batches"). mmaped netlink also didn't play nicely with the skb_zerocopy helper used by nfqueue and openvswitch. Daniel Borkmann fixed this via commit 6bb0fef489f6 ("netlink, mmap: fix edge-case leakages in nf queue zero-copy")' but at the cost of also needing to provide remaining length to the allocation function. nfqueue also has problems when used with mmaped rx netlink: - mmaped netlink doesn't allow use of nfqueue batch verdict messages. Problem is that in the mmap case, the allocation time also determines the ordering in which the frame will be seen by userspace (A allocating before B means that A is located in earlier ring slot, but this also means that B might get a lower sequence number then A since seqno is decided later. To fix this we would need to extend the spinlocked region to also cover the allocation and message setup which isn't desirable. - nfqueue can now be configured to queue large (GSO) skbs to userspace. Queing GSO packets is faster than having to force a software segmentation in the kernel, so this is a desirable option. However, with a mmap based ring one has to use 64kb per ring slot element, else mmap has to fall back to the socket path (NL_MMAP_STATUS_COPY) for all large packets. To use the mmap interface, userspace not only has to probe for mmap netlink support, it also has to implement a recv/socket receive path in order to handle messages that exceed the size of an rx ring element. Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Ken-ichirou MATSUZAWA <chamaken@gmail.com> Cc: Pablo Neira Ayuso <pablo@netfilter.org> Cc: Patrick McHardy <kaber@trash.net> Cc: Thomas Graf <tgraf@suug.ch> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-18netlink: make nlmsg_end() and genlmsg_end() voidJohannes Berg1-1/+2
Contrary to common expectations for an "int" return, these functions return only a positive value -- if used correctly they cannot even return 0 because the message header will necessarily be in the skb. This makes the very common pattern of if (genlmsg_end(...) < 0) { ... } be a whole bunch of dead code. Many places also simply do return nlmsg_end(...); and the caller is expected to deal with it. This also commonly (at least for me) causes errors, because it is very common to write if (my_function(...)) /* error condition */ and if my_function() does "return nlmsg_end()" this is of course wrong. Additionally, there's not a single place in the kernel that actually needs the message length returned, and if anyone needs it later then it'll be very easy to just use skb->len there. Remove this, and make the functions void. This removes a bunch of dead code as described above. The patch adds lines because I did - return nlmsg_end(...); + nlmsg_end(...); + return 0; I could have preserved all the function's return values by returning skb->len, but instead I've audited all the places calling the affected functions and found that none cared. A few places actually compared the return value with <= 0 in dump functionality, but that could just be changed to < 0 with no change in behaviour, so I opted for the more efficient version. One instance of the error I've made numerous times now is also present in net/phonet/pn_netlink.c in the route_dumpit() function - it didn't check for <0 or <=0 and thus broke out of the loop every single time. I've preserved this since it will (I think) have caused the messages to userspace to be formatted differently with just a single message for every SKB returned to userspace. It's possible that this isn't needed for the tools that actually use this, but I don't even know what they are so couldn't test that changing this behaviour would be acceptable. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-13netlink: eliminate nl_sk_hash_lockYing Xue1-5/+5
As rhashtable_lookup_compare_insert() can guarantee the process of search and insertion is atomic, it's safe to eliminate the nl_sk_hash_lock. After this, object insertion or removal will be protected with per bucket lock on write side while object lookup is guarded with rcu read lock on read side. Signed-off-by: Ying Xue <ying.xue@windriver.com> Cc: Thomas Graf <tgraf@suug.ch> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-03rhashtable: Convert bucket iterators to take table and indexThomas Graf1-1/+3
This patch is in preparation to introduce per bucket spinlocks. It extends all iterator macros to take the bucket table and bucket index. It also introduces a new rht_dereference_bucket() to handle protected accesses to buckets. It introduces a barrier() to the RCU iterators to the prevent the compiler from caching the first element. The lockdep verifier is introduced as stub which always succeeds and properly implement in the next patch when the locks are introduced. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-07netlink: hold nl_sock_hash_lock during diag dumpThomas Graf1-0/+3
Although RCU protection would be possible during diag dump, doing so allows for concurrent table mutations which can render the in-table offset between individual Netlink messages invalid and thus cause legitimate sockets to be skipped in the dump. Since the diag dump is relatively low volume and consistency is more important than performance, the table mutex is held during dump. Reported-by: Andrey Wagin <avagin@gmail.com> Signed-off-by: Thomas Graf <tgraf@suug.ch> Fixes: e341694e3eb57fc ("netlink: Convert netlink_lookup() to use RCU protected hash table") Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-03netlink: Convert netlink_lookup() to use RCU protected hash tableThomas Graf1-3/+8
Heavy Netlink users such as Open vSwitch spend a considerable amount of time in netlink_lookup() due to the read-lock on nl_table_lock. Use of RCU relieves the lock contention. Makes use of the new resizable hash table to avoid locking on the lookup. The hash table will grow if entries exceeds 75% of table size up to a total table size of 64K. It will automatically shrink if usage falls below 30%. Also splits nl_table_lock into a separate mutex to protect hash table mutations and allow synchronize_rcu() to sleep while waiting for readers during expansion and shrinking. Before: 9.16% kpktgend_0 [openvswitch] [k] masked_flow_lookup 6.42% kpktgend_0 [pktgen] [k] mod_cur_headers 6.26% kpktgend_0 [pktgen] [k] pktgen_thread_worker 6.23% kpktgend_0 [kernel.kallsyms] [k] memset 4.79% kpktgend_0 [kernel.kallsyms] [k] netlink_lookup 4.37% kpktgend_0 [kernel.kallsyms] [k] memcpy 3.60% kpktgend_0 [openvswitch] [k] ovs_flow_extract 2.69% kpktgend_0 [kernel.kallsyms] [k] jhash2 After: 15.26% kpktgend_0 [openvswitch] [k] masked_flow_lookup 8.12% kpktgend_0 [pktgen] [k] pktgen_thread_worker 7.92% kpktgend_0 [pktgen] [k] mod_cur_headers 5.11% kpktgend_0 [kernel.kallsyms] [k] memset 4.11% kpktgend_0 [openvswitch] [k] ovs_flow_extract 4.06% kpktgend_0 [kernel.kallsyms] [k] _raw_spin_lock 3.90% kpktgend_0 [kernel.kallsyms] [k] jhash2 [...] 0.67% kpktgend_0 [kernel.kallsyms] [k] netlink_lookup Signed-off-by: Thomas Graf <tgraf@suug.ch> Reviewed-by: Nikolay Aleksandrov <nikolay@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-23netlink: Fix build with mmap disabled.David S. Miller1-0/+7
net/netlink/diag.c: In function 'sk_diag_put_rings_cfg': net/netlink/diag.c:28:17: error: 'struct netlink_sock' has no member named 'pg_vec_lock' net/netlink/diag.c:29:29: error: 'struct netlink_sock' has no member named 'rx_ring' net/netlink/diag.c:31:30: error: 'struct netlink_sock' has no member named 'tx_ring' net/netlink/diag.c:33:19: error: 'struct netlink_sock' has no member named 'pg_vec_lock' Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-19netlink: add RX/TX-ring support to netlink diagPatrick McHardy1-0/+32
Based on AF_PACKET. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-21netlink: Diag core and basic socket info dumping (v2)Andrey Vagin1-0/+188
The netlink_diag can be built as a module, just like it's done in unix sockets. The core dumping message carries the basic info about netlink sockets: family, type and protocol, portis, dst_group, dst_portid, state. Groups can be received as an optional parameter NETLINK_DIAG_GROUPS. Netlink sockets cab be filtered by protocols. The socket inode number and cookie is reserved for future per-socket info retrieving. The per-protocol filtering is also reserved for future by requiring the sdiag_protocol to be zero. The file /proc/net/netlink doesn't provide enough information for dumping netlink sockets. It doesn't provide dst_group, dst_portid, groups above 32. v2: fix NETLINK_DIAG_MAX. Now it's equal to the last constant. Acked-by: Pavel Emelyanov <xemul@parallels.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Pablo Neira Ayuso <pablo@netfilter.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Gao feng <gaofeng@cn.fujitsu.com> Cc: Thomas Graf <tgraf@suug.ch> Signed-off-by: Andrey Vagin <avagin@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>