Assuming that the kernel does not send more than a page is no longer valid,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>
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>
Up to now only calls to nl_send_auto() could be overwritten with
nl_cb_overwrite_send(). This patch extends the capability to
nl_send()
Signed-off-by: Thomas Graf <tgraf@redhat.com>
Make nl_sendto() return NLE_INVAL if provided buffer is NULL
and make it return NLE_BAD_SOCK if the socket is not connected.
Add note in docs about lack of NL_CB_MSG_OUT invokation
1. all cleanup actions (like free()) now located at the end of function
2. in case of error or EOF, *buf and *creds (if given) set to NULL
This protect from invalid code at user's side, like:
char *buf;
x = nl_recv(..., &buf, ...);
if (x<=0)
goto cleanup;
cleanup:
free(buf);
3. all intermediate buffers are stored into local variables, and user's
variables only touches at the end.
Based on clang diagnostics:
1. lib/nl.c: recvmsgs(): nla filling with zeros commented.
2. lib/route/classid.c: & lib/route/pktloc.c:
remove zero-filling of struct stat
3. lib/route/qdisc/htb.c: Fix htb_qdisc_msg_fill(): fix zero-filling
4. ematch/container.c: container_parse:
commented why only 4 bytes are copied
len marked as unused to eliminate compiler warning
This may happen when passing connected socket to nl_cache_mngr_alloc().
Now, nl_connect() will return error trying to connect already connected socket.
Also, dont call close(-1) if socket() fails.
1. Fix some places where unsigned value compared < 0
2. Fix obsolete %Z specifier to more portable %z
3. Some erroneous types substitution
4. nl_msec2str() - 64-bit msec is now properly used,
Only safe changes. I mean int <--> uint32_t and signed/unsigned fixes.
Some functinos require size_t argument instead of int, but changes of
signatures of that functions is terrible thing.
Also, I do not pretend for a full list of fixes.
Just to shut up clang -Wall -Wextra
One more thing. ifindex. I don't change that because changes will
be too big for simple fix.
- changes the modules hierarchy to better represent the set of libaries
- list the header file that needs to be included
- remove examples/doc from api ref that is included in the guide
- add references to the guide
- fix doxygen api linking for version 1.8.0
- readd doxygen mainpage to config file
- fix a couple of doxygen doc bugs
Apparently the change to have nl_recvmsgs() return the number of
parsed messages broke nl_wait_for_ack() among other applications.
This patch reverts to the old behaviour and provides a new function
nl_recvmsgs_report() which provides the additional information for
use by the cache manager and possibly other applications.
Reported-by: Scott Bonar <sbonar@cradlepoint.com>
Signed-off-by: Thomas Graf <tgraf@redhat.com>
Provide nl_pickup() to pick up an answer from a netlink request and parse
it using the supplied parser.
Add rtnl_link_get_kernel() which sends an RTM_GETLINK to the kernel to
fetch a single link directly from the kernel. This can be faster than
dumping the whole table, especially if lots of links are configured.
I have a patch against commit d378220c96
extending libnl with a facility to receive generic netlink messages sent
to multicast groups.
Essentially it add one new function genl_ctrl_resolve_grp which
prototype looks like this
int genl_ctrl_resolve_grp(struct nl_sock *sk, const char *family_name,
const char *grp_name)
It resolves the family name and the group name to group id. Then
the returned id can be used in nl_socket_add_membership to subscribe
to multicast messages.
Besides that it adds two more functions
uint32_t nl_socket_get_peer_groups(struct nl_sock *sk)
void nl_socket_set_peer_groups(struct nl_sock *sk, uint32_t groups)
allowing to modify the socket peer groups field. So it's possible to
multicast messages from the user space using the legacy interface.
Looks like there is no way (or I was not able to find one?) to modify
the netlink socket destination group from the user space, when the
group id is greater then 32.
Create new function nl_send_iovec() to be used to send multiple 'struct iovec'
through the netlink socket. This will be used for NF_QUEUE, to send
packet payload of a modified packet.
Refactor nl_send() to use nl_send_iovec() sending a single struct iovec.
Create new function nl_auto_complete() by refactoring nl_send_auto_complete(),
so other functions that call nl_send may also use nl_auto_complete()
Signed-off-by: Karl Hiramoto <karl@hiramoto.org>
The idea of a common handle is long revised and only misleading,
nl_handle really represents a socket with some additional
action handlers assigned to it.
Alias for nl_handle is kept for backwards compatibility.
In order for the interface to become more thread safe, the error
handling was revised to no longer depend on a static errno and
error string buffer.
This patch converts all error paths to return a libnl specific
error code which can be translated to a error message using
nl_geterror(int error). The functions nl_error() and
nl_get_errno() are therefore obsolete.
This change required various sets of function prototypes to be
changed in order to return an error code, the most prominent
are:
struct nl_cache *foo_alloc_cache(...);
changed to:
int foo_alloc_cache(..., struct nl_cache **);
struct nl_msg *foo_build_request(...);
changed to:
int foo_build_request(..., struct nl_msg **);
struct foo *foo_parse(...);
changed to:
int foo_parse(..., struct foo **);
This pretty much only leaves trivial allocation functions to
still return a pointer object which can still return NULL to
signal out of memory.
This change is a serious API and ABI breaker, sorry!
As pointed out by Regis Hanna, a considerable performance gain can be
achieved by using malloc() over calloc() when allocating netlink message
buffers. This is likely due to the fact that we use a complete page for
each message.
Thomas Graf