The initial commit adding netlink callback handling also introduced
memory leak issue. The python callback info was stored in an allocated
structure, but that was never freed.
Only exposing nl_cb_alloc() as is. nl_cb_get() is removed as it is
not very useful to use reference counting mechanism. Python uses
that itself internally. To deal properly with Python callback info
the function nl_cb_put() and nl_cb_clone() have a custom wrapper
taking care of Python reference counting.
This commit also adds a Callback python class using the netlink
callback functions.
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
The application could use the same handler for multiple
nl_cb_type events. This patch stores the nl_cb_type in
the nl_cb struct during the callback. This allows the
application to obtain that information using the new
nl_cb_active_type() function. This way the callback
signature remains as is so existing applications are
not affected.
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
using the nl80211 family to show use of generic netlink api and
attribute parsing.
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Newer kernels support conntrack zones, which help to partition the
conntrack table into virtual conntrack tables.
This patch is for adding support for the optional attribute, adds
setters and getters, and adds support for the zone ID in the conntrack
dumper.
An example entry in NL_DUMP_LINE format looks like:
tcp SYN_SENT 10.128.128.99:43354 <-> 10.128.129.20:22 zone 1
Signed-off-by: Holger Eitzenberger <holger@eitzenberger.org>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Recent kernels support conntrack time stamping, which is a helpful
feature to determine the duration of a flow without building a flow
cache in your user space application, just to keep the 'start' time of
your flow.
Timestamps are recorded with nanosecond resolution once this feature
is enabled.
This patch adds optional support for the CTA_TIMESTAMP, then
modifies the dump routine to write that info in a format similar
to /proc/net/nf_conntrack. This is an example output when using
NL_DUMP_LINE:
udp 10.128.128.28:56836 <-> 10.128.129.255:8612 delta-time 30
Signed-off-by: Holger Eitzenberger <holger@eitzenberger.org>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Introduced by commit 8026fe2e3a ("link:
Free and realloc af specific data upon rtnl_link_set_family()")
link->l_af_data[link->l_af_ops->ao_family] is freed here but not set to
zero. That leads to double free made by link_free_data->do_foreach_af.
Fix this by setting link->l_af_data[link->l_af_ops->ao_family] to zero
rigth after free.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
This small program lists all sockets on the system seen by netlink and serves
as a simple example showing how to alloc an idiag msg cache and dump the
objects in it.
- Inet diag allows users to gather low-level socket information.
- This library provides a higher-level API for creating inetdiag requests (via
idiagnl_connect and idiagnl_send_simple) and parsing the replies (via
idiagnl_msg_parse). A cache is also provided (via idiagnl_msg_alloc_cache).
- Request and message objects provide APIs for accessing and setting the
various properties of each.
- This library also allows the user to parse the inetdiag response attributes
which contain information about traffic class, TOS, congestion, socket
memory info, and more depending on the kernel version used.
- Includes doxygen documentation.
Provide wrapper function for generic netlink library functions. The
genlmsg_parse() function is handled similar to nla_parse_nested() so
it returns tuple with error code and dictionary of parsed attributes.
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
This commit adds creation of the netlink.genl package. The actual
capi.i will be filled in upcoming commits so the module is rather
dumb for now.
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
added support functions to access the netlink attributes and use
custom callback handlers. Most is wrapped as is, but there are
a couple of special cases handled.
1) void *nla_data(struct nlattr *);
The return value is changed to a Python byte array so it includes
the lenght of the data stream.
2) int nla_parse_nested(...);
This returns a tuple (err, dict). 'err' is the error code and 'dict'
is a dictionary with attribute identifier as key and value represents
a struct nlattr object.
3) macro nla_for_each_nested()
Provide nla_get_nested() which returns a Python list of struct nlattr
objects that is iterable.
4) allocate struct nla_policy array
Provide nla_policy_array() function that allocates consecutive space
in memory for struct nla_policy array entries. Each entry is put in
a Python list so the entry fields can be modified in Python. This
array object can be passed to the nla_parse_nested() function.
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
If a hdrlen was provided that was greather than the actual
message length, a negative attributes length would result.
This was typically happening for RTM_GETLINK requests where
we can get a away with a 4 bytes header on the request side
but the response would use a 16 bytes header.
This resulted in strange -8 bytes leftover debug messages.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
The batched verdict implicitely ACKs all queue packet IDs up to the
one send back, which reduces the number of verdict messages send
to the kernel.
Signed-off-by: Holger Eitzenberger <holger@eitzenberger.org>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Since commit "nl: Return -NLE_AGAIN if non-blocking socket would block",
nl_cache_mngr_data_ready returns -NLE_AGAIN to callers on non-blocking sockets.
Change it to consider -NLE_AGAIN as a non-error case as it is expected behavior
with the nl_recv changes.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Since commit: "cache pickup: Avoid duplicates during cache pickup",
nfnl_ct_alloc_cache no longer properly fills the cache, as it doesn't
define oo_id_attrs so all items are considered duplicates.
Instead of adding a ~0 oo_id_attrs to ct_obj, this changes
nl_object_identical to default to comparing all attributes if
neither oo_id_attrs_get or oo_id_attrs are provided.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Assuming that the kernel does not send more than a page is no longer valid,
and enabling MSG_PEEK'ing by default to figure out the exact message buffer
requirements can have a negative influence on the performance of existing
applications. Bumping the default receive buffer space to 4 pages seems
a sane default.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
rtnl_link_af_unregister() attempts to write-lock info_lock twice
instead of releasing it before returning. It also will return with
info_lock write-locked if passed a NULL ops.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
There seams to be an error in the calculation of needed space for the message in nla_reserve. The current size of the message is counted twice: Once in NLMSG_ALIGN, once in the condition below.
This causes nla_put_* calls to be rejected if the allocation size of the message has been strictly calculated by the caller.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
- each *_get() should have corresponding *_put(). That rule was broken in nl_socket_alloc()
- Also, check if cb is NULL in nl_socket_set_cb (calls BUG())
Passing a NULL pointer would cause a NULL pointer dereference within
nl_object_free().
Returning early on NULL pointer is the behavior free(3) and other
nl*_free() functions.
Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
Previously 0 was returned which gave the caller no chance of detecting
when a non-blocking socket would block. If a caller intends to never
see an error message it should utilize poll()/select() to only read
when the socket has pending data or information.
Reported-by: Holger Eitzenberger <holger@eitzenberger.org>
Signed-off-by: Thomas Graf <tgraf@suug.ch>
