19 Feb, 2016

1 commit


16 Dec, 2015

1 commit


25 Sep, 2015

1 commit

  • The genl_notify function has too many arguments for no real reason - all
    callers use genl_info to get them anyway. Just pass the genl_info down to
    genl_notify.

    Signed-off-by: Jiri Benc
    Signed-off-by: David S. Miller

    Jiri Benc
     

13 Mar, 2015

1 commit

  • Having to say
    > #ifdef CONFIG_NET_NS
    > struct net *net;
    > #endif

    in structures is a little bit wordy and a little bit error prone.

    Instead it is possible to say:
    > typedef struct {
    > #ifdef CONFIG_NET_NS
    > struct net *net;
    > #endif
    > } possible_net_t;

    And then in a header say:

    > possible_net_t net;

    Which is cleaner and easier to use and easier to test, as the
    possible_net_t is always there no matter what the compile options.

    Further this allows read_pnet and write_pnet to be functions in all
    cases which is better at catching typos.

    This change adds possible_net_t, updates the definitions of read_pnet
    and write_pnet, updates optional struct net * variables that
    write_pnet uses on to have the type possible_net_t, and finally fixes
    up the b0rked users of read_pnet and write_pnet.

    Signed-off-by: "Eric W. Biederman"
    Acked-by: Eric Dumazet
    Signed-off-by: David S. Miller

    Eric W. Biederman
     

28 Jan, 2015

1 commit


27 Jan, 2015

1 commit


18 Jan, 2015

1 commit

  • 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 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
    Signed-off-by: David S. Miller

    Johannes Berg
     

17 Jan, 2015

2 commits

  • In addition to the problem Jeff Layton reported, I looked at the code
    and reproduced the same warning by subscribing and removing the genl
    family with a socket still open. This is a fairly tricky race which
    originates in the fact that generic netlink allows the family to go
    away while sockets are still open - unlike regular netlink which has
    a module refcount for every open socket so in general this cannot be
    triggered.

    Trying to resolve this issue by the obvious locking isn't possible as
    it will result in deadlocks between unregistration and group unbind
    notification (which incidentally lockdep doesn't find due to the home
    grown locking in the netlink table.)

    To really resolve this, introduce a "closing socket" reference counter
    (for generic netlink only, as it's the only affected family) in the
    core netlink code and use that in generic netlink to wait for all the
    sockets that are being closed at the same time as a generic netlink
    family is removed.

    This fixes the race that when a socket is closed, it will should call
    the unbind, but if the family is removed at the same time the unbind
    will not find it, leading to the warning. The real problem though is
    that in this case the unbind could actually find a new family that is
    registered to have a multicast group with the same ID, and call its
    mcast_unbind() leading to confusing.

    Also remove the warning since it would still trigger, but is now no
    longer a problem.

    This also moves the code in af_netlink.c to before unreferencing the
    module to avoid having the same problem in the normal non-genl case.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     
  • The kernel-doc for the parallel_ops family struct member is
    missing, add it.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     

27 Dec, 2014

3 commits

  • Netlink families can exist in multiple namespaces, and for the most
    part multicast subscriptions are per network namespace. Thus it only
    makes sense to have bind/unbind notifications per network namespace.

    To achieve this, pass the network namespace of a given client socket
    to the bind/unbind functions.

    Also do this in generic netlink, and there also make sure that any
    bind for multicast groups that only exist in init_net is rejected.
    This isn't really a problem if it is accepted since a client in a
    different namespace will never receive any notifications from such
    a group, but it can confuse the family if not rejected (it's also
    possible to silently (without telling the family) accept it, but it
    would also have to be ignored on unbind so families that take any
    kind of action on bind/unbind won't do unnecessary work for invalid
    clients like that.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     
  • In order to make the newly fixed multicast bind/unbind
    functionality in generic netlink, pass them down to the
    appropriate family.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     
  • There's no point to force the caller to know about the internal
    genl_sock to use inside struct net, just have them pass the network
    namespace. This doesn't really change code generation since it's
    an inline, but makes the caller less magic - there's never any
    reason to pass another socket.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     

20 Sep, 2014

1 commit


07 Jan, 2014

1 commit

  • Allocates a new sk_buff large enough to cover the specified payload
    plus required Netlink headers. Will check receiving socket for
    memory mapped i/o capability and use it if enabled. Will fall back
    to non-mapped skb if message size exceeds the frame size of the ring.

    Signed-of-by: Thomas Graf
    Reviewed-by: Daniel Borkmann
    Signed-off-by: Jesse Gross

    Thomas Graf
     

22 Nov, 2013

2 commits

  • Fix another really stupid bug - I introduced genl_set_err()
    precisely to be able to adjust the group and reject invalid
    ones, but then forgot to do so.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     
  • Unfortunately, I introduced a tremendously stupid bug into
    genlmsg_multicast() when doing all those multicast group
    changes: it adjusts the group number, but then passes it
    to genlmsg_multicast_netns() which does that again.

    Somehow, my tests failed to catch this, so add a warning
    into genlmsg_multicast_netns() and remove the offending
    group ID adjustment.

    Also add a warning to the similar code in other functions
    so people who misuse them are more loudly warned.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     

20 Nov, 2013

6 commits

  • Register generic netlink multicast groups as an array with
    the family and give them contiguous group IDs. Then instead
    of passing the global group ID to the various functions that
    send messages, pass the ID relative to the family - for most
    families that's just 0 because the only have one group.

    This avoids the list_head and ID in each group, adding a new
    field for the mcast group ID offset to the family.

    At the same time, this allows us to prevent abusing groups
    again like the quota and dropmon code did, since we can now
    check that a family only uses a group it owns.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     
  • This doesn't really change anything, but prepares for the
    next patch that will change the APIs to pass the group ID
    within the family, rather than the global group ID.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     
  • Add a static inline to generic netlink to wrap netlink_set_err()
    to make it easier to use here - use it in openvswitch (the only
    generic netlink user of netlink_set_err()).

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     
  • There's no reason to have the family pointer there since it
    can just be passed internally where needed, so remove it.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     
  • There are no users of this API remaining, and we'll soon
    change group registration to be static (like ops are now)

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     
  • As suggested by David Miller, make genl_register_family_with_ops()
    a macro and pass only the array, evaluating ARRAY_SIZE() in the
    macro, this is a little safer.

    The openvswitch has some indirection, assing ops/n_ops directly in
    that code. This might ultimately just assign the pointers in the
    family initializations, saving the struct genl_family_and_ops and
    code (once mcast groups are handled differently.)

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     

16 Nov, 2013

1 commit

  • Now that the ops assignment is just two variables rather than a
    long list iteration etc., there's no reason to separately export
    __genl_register_family() and __genl_register_family_with_ops().

    Unify the two functions into __genl_register_family() and make
    genl_register_family_with_ops() call it after assigning the ops.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     

15 Nov, 2013

4 commits

  • To save some space in the struct on 32-bit systems,
    make the flags a u8 (only 4 bits are used) and also
    move them to the end of the struct.

    This has no impact on 64-bit systems as alignment of
    the struct in an array uses up the space anyway.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     
  • Allow making the ops array const by not modifying the ops
    flags on registration but rather only when ops are sent
    out in the family information.

    No users are updated yet except for the pre_doit/post_doit
    calls in wireless (the only ones that exist now.)

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     
  • Instead of using a linked list, use an array. This reduces
    the data size needed by the users of genetlink, for example
    in wireless (net/wireless/nl80211.c) on 64-bit it frees up
    over 1K of data space.

    Remove the attempted sending of CTRL_CMD_NEWOPS ctrl event
    since genl_ctrl_event(CTRL_CMD_NEWOPS, ...) only returns
    -EINVAL anyway, therefore no such event could ever be sent.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     
  • genl_register_ops() is still needed for internal registration,
    but is no longer available to users of the API.

    Signed-off-by: Johannes Berg
    Signed-off-by: David S. Miller

    Johannes Berg
     

21 Sep, 2013

1 commit

  • There are a mix of function prototypes with and without extern
    in the kernel sources. Standardize on not using extern for
    function prototypes.

    Function prototypes don't need to be written with extern.
    extern is assumed by the compiler. Its use is as unnecessary as
    using auto to declare automatic/local variables in a block.

    Signed-off-by: Joe Perches
    Signed-off-by: David S. Miller

    Joe Perches
     

29 Aug, 2013

1 commit

  • netlink dump operations take module as parameter to hold
    reference for entire netlink dump duration.
    Currently it holds ref only on genl module which is not correct
    when we use ops registered to genl from another module.
    Following patch adds module pointer to genl_ops so that netlink
    can hold ref count on it.

    CC: Jesse Gross
    CC: Johannes Berg
    Signed-off-by: Pravin B Shelar
    Signed-off-by: David S. Miller

    Pravin B Shelar
     

25 Apr, 2013

1 commit

  • All genl callbacks are serialized by genl-mutex. This can become
    bottleneck in multi threaded case.
    Following patch adds an parameter to genl_family so that a
    particular family can get concurrent netlink callback without
    genl_lock held.
    New rw-sem is used to protect genl callback from genl family unregister.
    in case of parallel_ops genl-family read-lock is taken for callbacks and
    write lock is taken for register or unregistration for any family.
    In case of locked genl family semaphore and gel-mutex is locked for
    any openration.

    Signed-off-by: Pravin B Shelar
    Signed-off-by: David S. Miller

    Pravin B Shelar
     

11 Sep, 2012

1 commit

  • It is a frequent mistake to confuse the netlink port identifier with a
    process identifier. Try to reduce this confusion by renaming fields
    that hold port identifiers portid instead of pid.

    I have carefully avoided changing the structures exported to
    userspace to avoid changing the userspace API.

    I have successfully built an allyesconfig kernel with this change.

    Signed-off-by: "Eric W. Biederman"
    Acked-by: Stephen Hemminger
    Signed-off-by: David S. Miller

    Eric W. Biederman
     

29 Jun, 2012

1 commit

  • Using NLMSG_GOODSIZE results in multiple pages being used as
    nlmsg_new() will automatically add the size of the netlink
    header to the payload thus exceeding the page limit.

    NLMSG_DEFAULT_SIZE takes this into account.

    Signed-off-by: Thomas Graf
    Cc: Jiri Pirko
    Cc: Dmitry Eremin-Solenikov
    Cc: Sergey Lapin
    Cc: Johannes Berg
    Cc: Lauro Ramos Venancio
    Cc: Aloisio Almeida Jr
    Cc: Samuel Ortiz
    Reviewed-by: Jiri Pirko
    Signed-off-by: David S. Miller

    Thomas Graf
     

31 Jan, 2012

1 commit

  • text data bss dec hex filename
    8455963 532732 1810804 10799499 a4c98b vmlinux.o.before
    8448899 532732 1810804 10792435 a4adf3 vmlinux.o

    This change also removes commented-out copy of __nlmsg_put
    which was last touched in 2005 with "Enable once all users
    have been converted" comment on top.

    Changes in v2: rediffed against net-next.

    Signed-off-by: Denys Vlasenko
    Signed-off-by: David S. Miller

    Denys Vlasenko
     

04 Dec, 2011

1 commit

  • Open vSwitch uses Generic Netlink interface for communication
    between userspace and kernel module. genl_notify() is used
    for sending notification back to userspace.

    genl_notify() is analogous to rtnl_notify() but uses genl_sock
    instead of rtnl.

    Signed-off-by: Pravin B Shelar
    Signed-off-by: Jesse Gross

    Pravin B Shelar
     

23 Jun, 2011

1 commit

  • Consider the following situation:
    * a dump that would show 8 entries, four in the first
    round, and four in the second
    * between the first and second rounds, 6 entries are
    removed
    * now the second round will not show any entry, and
    even if there is a sequence/generation counter the
    application will not know

    To solve this problem, add a new flag NLM_F_DUMP_INTR
    to the netlink header that indicates the dump wasn't
    consistent, this flag can also be set on the MSG_DONE
    message that terminates the dump, and as such above
    situation can be detected.

    To achieve this, add a sequence counter to the netlink
    callback struct. Of course, netlink code still needs
    to use this new functionality. The correct way to do
    that is to always set cb->seq when a dumpit callback
    is invoked and call nl_dump_check_consistent() for
    each new message. The core code will also call this
    function for the final MSG_DONE message.

    To make it usable with generic netlink, a new function
    genlmsg_nlhdr() is needed to obtain the netlink header
    from the genetlink user header.

    Signed-off-by: Johannes Berg
    Acked-by: David S. Miller
    Signed-off-by: John W. Linville

    Johannes Berg
     

10 May, 2011

1 commit


04 Feb, 2011

1 commit


06 Oct, 2010

1 commit

  • Each family may have some amount of boilerplate
    locking code that applies to most, or even all,
    commands.

    This allows a family to handle such things in
    a more generic way, by allowing it to
    a) include private flags in each operation
    b) specify a pre_doit hook that is called,
    before an operation's doit() callback and
    may return an error directly,
    c) specify a post_doit hook that can undo
    locking or similar things done by pre_doit,
    and finally
    d) include two private pointers in each info
    struct passed between all these operations
    including doit(). (It's two because I'll
    need two in nl80211 -- can be extended.)

    Signed-off-by: Johannes Berg
    Acked-by: David S. Miller
    Signed-off-by: John W. Linville

    Johannes Berg
     

02 Jun, 2010

1 commit


04 Nov, 2009

1 commit

  • This cleanup patch puts struct/union/enum opening braces,
    in first line to ease grep games.

    struct something
    {

    becomes :

    struct something {

    Signed-off-by: Eric Dumazet
    Signed-off-by: David S. Miller

    Eric Dumazet