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* netlink: Annotate RCU locking for seq_file walkerThomas Graf2014-08-141-0/+2
| | | | | | | | | Silences the following sparse warnings: net/netlink/af_netlink.c:2926:21: warning: context imbalance in 'netlink_seq_start' - wrong count at exit net/netlink/af_netlink.c:2972:13: warning: context imbalance in 'netlink_seq_stop' - unexpected unlock Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: reset network header before passing to tapsDaniel Borkmann2014-08-071-1/+1
| | | | | | | | | | | | | | | | | | | netlink doesn't set any network header offset thus when the skb is being passed to tap devices via dev_queue_xmit_nit(), it emits klog false positives due to it being unset like: ... [ 124.990397] protocol 0000 is buggy, dev nlmon0 [ 124.990411] protocol 0000 is buggy, dev nlmon0 ... So just reset the network header before passing to the device; for packet sockets that just means nothing will change - mac and net offset hold the same value just as before. Reported-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: hold nl_sock_hash_lock during diag dumpThomas Graf2014-08-061-0/+1
| | | | | | | | | | | | | | | | 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>
* netlink: fix lockdep splatsEric Dumazet2014-08-041-2/+2
| | | | | | | | | | With netlink_lookup() conversion to RCU, we need to use appropriate rcu dereference in netlink_seq_socket_idx() & netlink_seq_next() Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: e341694e3eb57fc ("netlink: Convert netlink_lookup() to use RCU protected hash table") Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: Convert netlink_lookup() to use RCU protected hash tableThomas Graf2014-08-021-178/+107
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* netlink: Use PAGE_ALIGNED macroTobias Klauser2014-07-311-1/+1
| | | | | | | Use PAGE_ALIGNED(...) instead of IS_ALIGNED(..., PAGE_SIZE). Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: remove bool varibleVarka Bhadram2014-07-161-4/+2
| | | | | | | | This patch removes the bool variable 'pass'. If the swith case exist return true or return false. Signed-off-by: Varka Bhadram <varkab@cdac.in> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2014-07-161-2/+2
|\ | | | | | | Signed-off-by: David S. Miller <davem@davemloft.net>
| * netlink: Fix handling of error from netlink_dump().Ben Pfaff2014-07-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | netlink_dump() returns a negative errno value on error. Until now, netlink_recvmsg() directly recorded that negative value in sk->sk_err, but that's wrong since sk_err takes positive errno values. (This manifests as userspace receiving a positive return value from the recv() system call, falsely indicating success.) This bug was introduced in the commit that started checking the netlink_dump() return value, commit b44d211 (netlink: handle errors from netlink_dump()). Multithreaded Netlink dumps are one way to trigger this behavior in practice, as described in the commit message for the userspace workaround posted here: http://openvswitch.org/pipermail/dev/2014-June/042339.html This commit also fixes the same bug in netlink_poll(), introduced in commit cd1df525d (netlink: add flow control for memory mapped I/O). Signed-off-by: Ben Pfaff <blp@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netlink: Fix do_one_broadcast() prototype.Rami Rosen2014-07-071-9/+6
|/ | | | | | | This patch changes the prototype of the do_one_broadcast() method so that it will return void. Signed-off-by: Rami Rosen <ramirose@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2014-06-031-1/+6
|\ | | | | | | | | | | | | | | | | | | Conflicts: include/net/inetpeer.h net/ipv6/output_core.c Changes in net were fixing bugs in code removed in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
| * netlink: Only check file credentials for implicit destinationsEric W. Biederman2014-06-021-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It was possible to get a setuid root or setcap executable to write to it's stdout or stderr (which has been set made a netlink socket) and inadvertently reconfigure the networking stack. To prevent this we check that both the creator of the socket and the currentl applications has permission to reconfigure the network stack. Unfortunately this breaks Zebra which always uses sendto/sendmsg and creates it's socket without any privileges. To keep Zebra working don't bother checking if the creator of the socket has privilege when a destination address is specified. Instead rely exclusively on the privileges of the sender of the socket. Note from Andy: This is exactly Eric's code except for some comment clarifications and formatting fixes. Neither I nor, I think, anyone else is thrilled with this approach, but I'm hesitant to wait on a better fix since 3.15 is almost here. Note to stable maintainers: This is a mess. An earlier series of patches in 3.15 fix a rather serious security issue (CVE-2014-0181), but they did so in a way that breaks Zebra. The offending series includes: commit aa4cf9452f469f16cea8c96283b641b4576d4a7b Author: Eric W. Biederman <ebiederm@xmission.com> Date: Wed Apr 23 14:28:03 2014 -0700 net: Add variants of capable for use on netlink messages If a given kernel version is missing that series of fixes, it's probably worth backporting it and this patch. if that series is present, then this fix is critical if you care about Zebra. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2014-05-121-5/+70
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/net/ethernet/altera/altera_sgdma.c net/netlink/af_netlink.c net/sched/cls_api.c net/sched/sch_api.c The netlink conflict dealt with moving to netlink_capable() and netlink_ns_capable() in the 'net' tree vs. supporting 'tc' operations in non-init namespaces. These were simple transformations from netlink_capable to netlink_ns_capable. The Altera driver conflict was simply code removal overlapping some void pointer cast cleanups in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
| * net: Add variants of capable for use on netlink messagesEric W. Biederman2014-04-241-0/+65
| | | | | | | | | | | | | | | | | | | | | | | | netlink_net_capable - The common case use, for operations that are safe on a network namespace netlink_capable - For operations that are only known to be safe for the global root netlink_ns_capable - The general case of capable used to handle special cases __netlink_ns_capable - Same as netlink_ns_capable except taking a netlink_skb_parms instead of the skbuff of a netlink message. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * netlink: Rename netlink_capable netlink_allowedEric W. Biederman2014-04-241-5/+5
| | | | | | | | | | | | | | | | netlink_capable is a static internal function in af_netlink.c and we have better uses for the name netlink_capable. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netlink: implement unbind to netlink_setsockopt NETLINK_DROP_MEMBERSHIPRichard Guy Briggs2014-04-221-1/+3
| | | | | | | | | | | | | | | | Call the per-protocol unbind function rather than bind function on NETLINK_DROP_MEMBERSHIP in netlink_setsockopt(). Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netlink: have netlink per-protocol bind function return an error code.Richard Guy Briggs2014-04-221-20/+48
|/ | | | | | | | | | | | | | | | | | | | | | | Have the netlink per-protocol optional bind function return an int error code rather than void to signal a failure. This will enable netlink protocols to perform extra checks including capabilities and permissions verifications when updating memberships in multicast groups. In netlink_bind() and netlink_setsockopt() the call to the per-protocol bind function was moved above the multicast group update to prevent any access to the multicast socket groups before checking with the per-protocol bind function. This will enable the per-protocol bind function to be used to check permissions which could be denied before making them available, and to avoid the messy job of undoing the addition should the per-protocol bind function fail. The netfilter subsystem seems to be the only one currently using the per-protocol bind function. Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Fix use after free by removing length arg from sk_data_ready callbacks.David S. Miller2014-04-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Several spots in the kernel perform a sequence like: skb_queue_tail(&sk->s_receive_queue, skb); sk->sk_data_ready(sk, skb->len); But at the moment we place the SKB onto the socket receive queue it can be consumed and freed up. So this skb->len access is potentially to freed up memory. Furthermore, the skb->len can be modified by the consumer so it is possible that the value isn't accurate. And finally, no actual implementation of this callback actually uses the length argument. And since nobody actually cared about it's value, lots of call sites pass arbitrary values in such as '0' and even '1'. So just remove the length argument from the callback, that way there is no confusion whatsoever and all of these use-after-free cases get fixed as a side effect. Based upon a patch by Eric Dumazet and his suggestion to audit this issue tree-wide. Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: autosize skb lengthesEric Dumazet2014-03-101-1/+26
| | | | | | | | | | | | | | | | | | | One known problem with netlink is the fact that NLMSG_GOODSIZE is really small on PAGE_SIZE==4096 architectures, and it is difficult to know in advance what buffer size is used by the application. This patch adds an automatic learning of the size. First netlink message will still be limited to ~4K, but if user used bigger buffers, then following messages will be able to use up to 16KB. This speedups dump() operations by a large factor and should be safe for legacy applications. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Thomas Graf <tgraf@suug.ch> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2014-03-051-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/net/wireless/ath/ath9k/recv.c drivers/net/wireless/mwifiex/pcie.c net/ipv6/sit.c The SIT driver conflict consists of a bug fix being done by hand in 'net' (missing u64_stats_init()) whilst in 'net-next' a helper was created (netdev_alloc_pcpu_stats()) which takes care of this. The two wireless conflicts were overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
| * net: Fix permission check in netlink_connect()Mike Pecovnik2014-02-251-2/+2
| | | | | | | | | | | | | | | | | | | | netlink_sendmsg() was changed to prevent non-root processes from sending messages with dst_pid != 0. netlink_connect() however still only checks if nladdr->nl_groups is set. This patch modifies netlink_connect() to check for the same condition. Signed-off-by: Mike Pecovnik <mike.pecovnik@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netlink: fix checkpatch errors space and "foo *bar"Wang Yufen2014-02-171-2/+2
|/ | | | | | | ERROR: spaces required and "(foo*)" should be "(foo *)" Signed-off-by: Wang Yufen <wangyufen@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: add build-time checks for msg->msg_name sizeSteffen Hurrle2014-01-181-2/+2
| | | | | | | | | | | | | | | This is a follow-up patch to f3d3342602f8bc ("net: rework recvmsg handler msg_name and msg_namelen logic"). DECLARE_SOCKADDR validates that the structure we use for writing the name information to is not larger than the buffer which is reserved for msg->msg_name (which is 128 bytes). Also use DECLARE_SOCKADDR consistently in sendmsg code paths. Signed-off-by: Steffen Hurrle <steffen@hurrle.net> Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of ↵David S. Miller2014-01-061-0/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jesse/openvswitch Jesse Gross says: ==================== [GIT net-next] Open vSwitch Open vSwitch changes for net-next/3.14. Highlights are: * Performance improvements in the mechanism to get packets to userspace using memory mapped netlink and skb zero copy where appropriate. * Per-cpu flow stats in situations where flows are likely to be shared across CPUs. Standard flow stats are used in other situations to save memory and allocation time. * A handful of code cleanups and rationalization. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * netlink: Avoid netlink mmap alloc if msg size exceeds frame sizeThomas Graf2014-01-061-0/+4
| | | | | | | | | | | | | | | | | | | | | | An insufficent ring frame size configuration can lead to an unnecessary skb allocation for every Netlink message. Check frame size before taking the queue lock and allocating the skb and re-check with lock to be safe. Signed-off-by: Thomas Graf <tgraf@suug.ch> Reviewed-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Jesse Gross <jesse@nicira.com>
* | netlink: cleanup tap related functionsstephen hemminger2014-01-011-17/+1
| | | | | | | | | | | | | | | | | | | | Cleanups in netlink_tap code * remove unused function netlink_clear_multicast_users * make local function static Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netlink: specify netlink packet direction for nlmonDaniel Borkmann2013-12-311-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to facilitate development for netlink protocol dissector, fill the unused field skb->pkt_type of the cloned skb with a hint of the address space of the new owner (receiver) socket in the notion of "to kernel" resp. "to user". At the time we invoke __netlink_deliver_tap_skb(), we already have set the new skb owner via netlink_skb_set_owner_r(), so we can use that for netlink_is_kernel() probing. In normal PF_PACKET network traffic, this field denotes if the packet is destined for us (PACKET_HOST), if it's broadcast (PACKET_BROADCAST), etc. As we only have 3 bit reserved, we can use the value (= 6) of PACKET_FASTROUTE as it's _not used_ anywhere in the whole kernel and not supported anywhere, and packets of such type were never exposed to user space, so there are no overlapping users of such kind. Thus, as wished, that seems the only way to make both PACKET_* values non-overlapping and therefore device agnostic. By using those two flags for netlink skbs on nlmon devices, they can be made available and picked up via sll_pkttype (previously unused in netlink context) in struct sockaddr_ll. We now have these two directions: - PACKET_USER (= 6) -> to user space - PACKET_KERNEL (= 7) -> to kernel space Partial `ip a` example strace for sa_family=AF_NETLINK with detected nl msg direction: syscall: direction: sendto(3, ...) = 40 /* to kernel */ recvmsg(3, ...) = 3404 /* to user */ recvmsg(3, ...) = 1120 /* to user */ recvmsg(3, ...) = 20 /* to user */ sendto(3, ...) = 40 /* to kernel */ recvmsg(3, ...) = 168 /* to user */ recvmsg(3, ...) = 144 /* to user */ recvmsg(3, ...) = 20 /* to user */ Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Jakub Zawadzki <darkjames-ws@darkjames.pl> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netlink: only do not deliver to tap when both sides are kernel sksDaniel Borkmann2013-12-311-5/+8
|/ | | | | | | | | | | | We should also deliver packets to nlmon devices when we are in netlink_unicast_kernel(), and only one of the {src,dst} sockets is user sk and the other one kernel sk. That's e.g. the case in netlink diag, netlink route, etc. Still, forbid to deliver messages from kernel to kernel sks. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Jakub Zawadzki <darkjames-ws@darkjames.pl> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: rework recvmsg handler msg_name and msg_namelen logicHannes Frederic Sowa2013-11-201-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch now always passes msg->msg_namelen as 0. recvmsg handlers must set msg_namelen to the proper size <= sizeof(struct sockaddr_storage) to return msg_name to the user. This prevents numerous uninitialized memory leaks we had in the recvmsg handlers and makes it harder for new code to accidentally leak uninitialized memory. Optimize for the case recvfrom is called with NULL as address. We don't need to copy the address at all, so set it to NULL before invoking the recvmsg handler. We can do so, because all the recvmsg handlers must cope with the case a plain read() is called on them. read() also sets msg_name to NULL. Also document these changes in include/linux/net.h as suggested by David Miller. Changes since RFC: Set msg->msg_name = NULL if user specified a NULL in msg_name but had a non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't affect sendto as it would bail out earlier while trying to copy-in the address. It also more naturally reflects the logic by the callers of verify_iovec. With this change in place I could remove " if (!uaddr || msg_sys->msg_namelen == 0) msg->msg_name = NULL ". This change does not alter the user visible error logic as we ignore msg_namelen as long as msg_name is NULL. Also remove two unnecessary curly brackets in ___sys_recvmsg and change comments to netdev style. Cc: David Miller <davem@davemloft.net> Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: fix documentation typo in netlink_set_err()Johannes Berg2013-11-191-1/+1
| | | | | | | The parameter is just 'group', not 'groups', fix the documentation typo. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: netlink: filter particular protocols from analyzersDaniel Borkmann2013-09-061-0/+30
| | | | | | | | | | | | Fix finer-grained control and let only a whitelist of allowed netlink protocols pass, in our case related to networking. If later on, other subsystems decide they want to add their protocol as well to the list of allowed protocols they shall simply add it. While at it, we also need to tell what protocol is in use otherwise BPF_S_ANC_PROTOCOL can not pick it up (as it's not filled out). Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: Eliminate kmalloc in netlink dump operation.Pravin B Shelar2013-08-151-55/+42
| | | | | | | | | | | Following patch stores struct netlink_callback in netlink_sock to avoid allocating and freeing it on every netlink dump msg. Only one dump operation is allowed for a given socket at a time therefore we can safely convert cb pointer to cb struct inside netlink_sock. Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: netlink: minor: remove unused pointer in alloc_pg_vecDaniel Borkmann2013-08-021-2/+2
| | | | | | | Variable ptr is being assigned, but never used, so just remove it. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: fix splat in skb_clone with large messagesPablo Neira2013-06-271-17/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since (c05cdb1 netlink: allow large data transfers from user-space), netlink splats if it invokes skb_clone on large netlink skbs since: * skb_shared_info was not correctly initialized. * skb->destructor is not set in the cloned skb. This was spotted by trinity: [ 894.990671] BUG: unable to handle kernel paging request at ffffc9000047b001 [ 894.991034] IP: [<ffffffff81a212c4>] skb_clone+0x24/0xc0 [...] [ 894.991034] Call Trace: [ 894.991034] [<ffffffff81ad299a>] nl_fib_input+0x6a/0x240 [ 894.991034] [<ffffffff81c3b7e6>] ? _raw_read_unlock+0x26/0x40 [ 894.991034] [<ffffffff81a5f189>] netlink_unicast+0x169/0x1e0 [ 894.991034] [<ffffffff81a601e1>] netlink_sendmsg+0x251/0x3d0 Fix it by: 1) introducing a new netlink_skb_clone function that is used in nl_fib_input, that sets our special skb->destructor in the cloned skb. Moreover, handle the release of the large cloned skb head area in the destructor path. 2) not allowing large skbuffs in the netlink broadcast path. I cannot find any reasonable use of the large data transfer using netlink in that path, moreover this helps to skip extra skb_clone handling. I found two more netlink clients that are cloning the skbs, but they are not in the sendmsg path. Therefore, the sole client cloning that I found seems to be the fib frontend. Thanks to Eric Dumazet for helping to address this issue. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: netlink: virtual tap device managementDaniel Borkmann2013-06-241-0/+107
| | | | | | | | | | | | | Similarly to the networking receive path with ptype_all taps, we add the possibility to register netdevices that are for ARPHRD_NETLINK to the netlink subsystem, so that those can be used for netlink analyzers resp. debuggers. We do not offer a direct callback function as out-of-tree modules could do crap with it. Instead, a netdevice must be registered properly and only receives a clone, managed by the netlink layer. Symbols are exported as GPL-only. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2013-06-191-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/net/wireless/ath/ath9k/Kconfig drivers/net/xen-netback/netback.c net/batman-adv/bat_iv_ogm.c net/wireless/nl80211.c The ath9k Kconfig conflict was a change of a Kconfig option name right next to the deletion of another option. The xen-netback conflict was overlapping changes involving the handling of the notify list in xen_netbk_rx_action(). Batman conflict resolution provided by Antonio Quartulli, basically keep everything in both conflict hunks. The nl80211 conflict is a little more involved. In 'net' we added a dynamic memory allocation to nl80211_dump_wiphy() to fix a race that Linus reported. Meanwhile in 'net-next' the handlers were converted to use pre and post doit handlers which use a flag to determine whether to hold the RTNL mutex around the operation. However, the dump handlers to not use this logic. Instead they have to explicitly do the locking. There were apparent bugs in the conversion of nl80211_dump_wiphy() in that we were not dropping the RTNL mutex in all the return paths, and it seems we very much should be doing so. So I fixed that whilst handling the overlapping changes. To simplify the initial returns, I take the RTNL mutex after we try to allocate 'tb'. Signed-off-by: David S. Miller <davem@davemloft.net>
| * netlink: fix error propagation in netlink_mmap()Patrick McHardy2013-06-111-1/+1
| | | | | | | | | | | | | | | | Return the error if something went wrong instead of unconditionally returning 0. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netlink: make compare exist all the timeGao feng2013-06-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit da12c90e099789a63073fc82a19542ce54d4efb9 "netlink: Add compare function for netlink_table" only set compare at the time we create kernel netlink, and reset compare to NULL at the time we finially release netlink socket, but netlink_lookup wants the compare exist always. So we should set compare after we allocate nl_table, and never reset it. make comapre exist all the time. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netlink: Add compare function for netlink_tableGao feng2013-06-111-8/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As we know, netlink sockets are private resource of net namespace, they can communicate with each other only when they in the same net namespace. this works well until we try to add namespace support for other subsystems which use netlink. Don't like ipv4 and route table.., it is not suited to make these subsytems belong to net namespace, Such as audit and crypto subsystems,they are more suitable to user namespace. So we must have the ability to make the netlink sockets in same user namespace can communicate with each other. This patch adds a new function pointer "compare" for netlink_table, we can decide if the netlink sockets can communicate with each other through this netlink_table self-defined compare function. The behavior isn't changed if we don't provide the compare function for netlink_table. Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | netlink: allow large data transfers from user-spacePablo Neira Ayuso2013-06-071-2/+35
|/ | | | | | | | | | | | | | | | | | | | | | I can hit ENOBUFS in the sendmsg() path with a large batch that is composed of many netlink messages. Here that limit is 8 MBytes of skbuff data area as kmalloc does not manage to get more than that. While discussing atomic rule-set for nftables with Patrick McHardy, we decided to put all rule-set updates that need to be applied atomically in one single batch to simplify the existing approach. However, as explained above, the existing netlink code limits us to a maximum of ~20000 rules that fit in one single batch without hitting ENOBUFS. iptables does not have such limitation as it is using vmalloc. This patch adds netlink_alloc_large_skb() which is only used in the netlink_sendmsg() path. It uses alloc_skb if the memory requested is <= one memory page, that should be the common case for most subsystems, else vmalloc for higher memory allocations. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: fix sk_buff head without data areaPablo Neira2013-06-041-1/+1
| | | | | | | | | | | | | | | | | Eric Dumazet spotted that we have to check skb->head instead of skb->data as skb->head points to the beginning of the data area of the skbuff. Similarly, we have to initialize the skb->head pointer, not skb->data in __alloc_skb_head. After this fix, netlink crashes in the release path of the sk_buff, so let's fix that as well. This bug was introduced in (0ebd0ac net: add function to allocate sk_buff head without data area). Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: Fix skb ref counting.Pravin B Shelar2013-05-011-1/+0
| | | | | | | | | | | | Commit f9c2288837ba072b21dba955f04a4c97eaa77b1e (netlink: implement memory mapped recvmsg) increamented skb->users ref count twice for a dump op which does not look right. Following patch fixes that. CC: Patrick McHardy <kaber@trash.net> Signed-off-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: fix compilation after memory mapped patchesNicolas Dichtel2013-04-241-4/+4
| | | | | | | | | | | | | | | | | | | Depending of the kernel configuration (CONFIG_UIDGID_STRICT_TYPE_CHECKS), we can get the following errors: net/netlink/af_netlink.c: In function ‘netlink_queue_mmaped_skb’: net/netlink/af_netlink.c:663:14: error: incompatible types when assigning to type ‘__u32’ from type ‘kuid_t’ net/netlink/af_netlink.c:664:14: error: incompatible types when assigning to type ‘__u32’ from type ‘kgid_t’ net/netlink/af_netlink.c: In function ‘netlink_ring_set_copied’: net/netlink/af_netlink.c:693:14: error: incompatible types when assigning to type ‘__u32’ from type ‘kuid_t’ net/netlink/af_netlink.c:694:14: error: incompatible types when assigning to type ‘__u32’ from type ‘kgid_t’ We must use the helpers to get the uid and gid, and also take care of user_ns. Fix suggested by Eric W. Biederman <ebiederm@xmission.com>. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: fix typo in net/netlink/af_netlink.cStephen Rothwell2013-04-231-1/+1
| | | | | Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: add flow control for memory mapped I/OPatrick McHardy2013-04-191-27/+61
| | | | | | | | | | Add flow control for memory mapped RX. Since user-space usually doesn't invoke recvmsg() when using memory mapped I/O, flow control is performed in netlink_poll(). Dumps are allowed to continue if at least half of the ring frames are unused. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: implement memory mapped recvmsg()Patrick McHardy2013-04-191-3/+141
| | | | | | | | | | | | | | | | | Add support for mmap'ed recvmsg(). To allow the kernel to construct messages into the mapped area, a dataless skb is allocated and the data pointer is set to point into the ring frame. This means frames will be delivered to userspace in order of allocation instead of order of transmission. This usually doesn't matter since the order is either not determinable by userspace or message creation/transmission is serialized. The only case where this can have a visible difference is nfnetlink_queue. Userspace can't assume mmap'ed messages have ordered IDs anymore and needs to check this if using batched verdicts. For non-mapped sockets, nothing changes. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: implement memory mapped sendmsg()Patrick McHardy2013-04-191-6/+129
| | | | | | | | | | | | Add support for mmap'ed sendmsg() to netlink. Since the kernel validates received messages before processing them, the code makes sure userspace can't modify the message contents after invoking sendmsg(). To do that only a single mapping of the TX ring is allowed to exist and the socket must not be shared. If either of these two conditions does not hold, it falls back to copying. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: add mmap'ed netlink helper functionsPatrick McHardy2013-04-191-2/+183
| | | | | | | | | Add helper functions for looking up mmap'ed frame headers, reading and writing their status, allocating skbs with mmap'ed data areas and a poll function. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: mmaped netlink: ring setupPatrick McHardy2013-04-191-2/+266
| | | | | | | | | Add support for mmap'ed RX and TX ring setup and teardown based on the af_packet.c code. The following patches will use this to add the real mmap'ed receive and transmit functionality. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: add netlink_skb_set_owner_r()Patrick McHardy2013-04-191-3/+17
| | | | | | | | | | | | | | | | For mmap'ed I/O a netlink specific skb destructor needs to be invoked after the final kfree_skb() to clean up state. This doesn't work currently since the skb's ownership is transfered to the receiving socket using skb_set_owner_r(), which orphans the skb, thereby invoking the destructor prematurely. Since netlink doesn't account skbs to the originating socket, there's no need to orphan the skb. Add a netlink specific skb_set_owner_r() variant that does not orphan the skb and use a netlink specific destructor to call sock_rfree(). Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
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