Two new functions are provided, bit_ffs_at() and bit_ffc_at(), which allow
for efficient searching of set or cleared bits starting from any bit offset
within the bit string.
Performance is improved by operating on longs instead of bytes and using
ffsl() for searches within a long. ffsl() is a compiler builtin in both
clang and gcc for most architectures, converting what was a brute force
while loop search into a couple of instructions.
All of the bitstring(3) API continues to be contained in the header file.
Some of the functions are large enough that perhaps they should be uninlined
and moved to a library, but that is beyond the scope of this commit.
sys/sys/bitstring.h:
Convert the majority of the existing bit string implementation from
macros to inline functions.
Properly protect the implementation from inadvertant macro expansion
when included in a user's program by prefixing all private
macros/functions and local variables with '_'.
Add bit_ffs_at() and bit_ffc_at(). Implement bit_ffs() and
bit_ffc() in terms of their "at" counterparts.
Provide a kernel implementation of bit_alloc(), making the full API
usable in the kernel.
Improve code documenation.
share/man/man3/bitstring.3:
Add pre-exisiting API bit_ffc() to the synopsis.
Document new APIs.
Document the initialization state of the bit strings
allocated/declared by bit_alloc() and bit_decl().
Correct documentation for bitstr_size(). The original code comments
indicate the size is in bytes, not "elements of bitstr_t". The new
implementation follows this lead. Only hastd assumed "elements"
rather than bytes and it has been corrected.
etc/mtree/BSD.tests.dist:
tests/sys/Makefile:
tests/sys/sys/Makefile:
tests/sys/sys/bitstring.c:
Add tests for all existing and new functionality.
include/bitstring.h
Include all headers needed by sys/bitstring.h
lib/libbluetooth/bluetooth.h:
usr.sbin/bluetooth/hccontrol/le.c:
Include bitstring.h instead of sys/bitstring.h.
sbin/hastd/activemap.c:
Correct usage of bitstr_size().
sys/dev/xen/blkback/blkback.c
Use new bit_alloc.
sys/kern/subr_unit.c:
Remove hard-coded assumption that sizeof(bitstr_t) is 1. Get rid of
unrb.busy, which caches the number of bits set in unrb.map. When
INVARIANTS are disabled, nothing needs to know that information.
callapse_unr can be adapted to use bit_ffs and bit_ffc instead.
Eliminating unrb.busy saves memory, simplifies the code, and
provides a slight speedup when INVARIANTS are disabled.
sys/net/flowtable.c:
Use the new kernel implementation of bit-alloc, instead of hacking
the old libc-dependent macro.
sys/sys/param.h
Update __FreeBSD_version to indicate availability of new API
Submitted by: gibbs, asomers
Reviewed by: gibbs, ngie
MFC after: 4 weeks
Sponsored by: Spectra Logic Corp
Differential Revision: https://reviews.freebsd.org/D6004
interested in having tunneled UDP and finding out about the
ICMP (tested by Michael Tuexen with SCTP.. soon to be using
this feature).
Differential Revision: http://reviews.freebsd.org/D5875
It seems rn_dupedkey may be NULL, because of the NULL check inside the loop.
(Also, the rt gets assigned from rn_dupedkey and NULL checked at top of loop.)
However, the for-loop update condition happens before the top-of-loop check and
dereferences 'rt' unconditionally.
Instead, NULL-check before dereferencing.
If rn_dupedkey cannot in fact be NULL, or something else protects this, feel
free to revert this and add an ASSERT of some kind instead.
This was introduced in r191080 (2009) and moved around slightly in r293657.
Reported by: Coverity
CID: 1348482
Sponsored by: EMC / Isilon Storage Division
rounddown2 tends to produce longer lines than the original code
and when the code has a high indentation level it was not really
advantageous to do the replacement.
This tries to strike a balance between readability using the macros
and flexibility of having the expressions, so not everything is
converted.
R_Zalloc is essentially a malloc(M_NOWAIT) wrapper. It is possible that 'rnh'
failed to allocate, but 'rmh' succeeds. In that case, we bail out of
rn_inithead() but previously did not free 'rmh'.
Introduced in r287073 (projects/routing) / MFP r294706.
Reported by: Coverity
CID: 1350258
Sponsored by: EMC / Isilon Storage Division
'lst' is allocated with 'n1' members. 'n' indexes 'lst'. So 'n == n1' is an
invalid 'lst' index. This is a follow-up to r296009.
Reported by: Coverity
CID: 1352743
Sponsored by: EMC / Isilon Storage Division
handler notifying about interface departure and one of the consumers will
detach if_bpf.
There is no way for us to re-attach this easily as the DLT and hdrlen are
only given on interface creation.
Add a function to allow us to query the DLT and hdrlen from a current
BPF attachment and after if_attach_internal() manually re-add the if_bpf
attachment using these values.
Found by panics triggered by nd6 packets running past BPF_MTAP() with no
proper if_bpf pointer on the interface.
Also add a basic DDB show function to investigate the if_bpf attachment
of an interface.
Reviewed by: gnn
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5896
- properly V_irtualise variable access unbreaking VIMAGE kernels.
- remove the volatile from the function return type to make architecture
using gcc happy [-Wreturn-type]
"type qualifiers ignored on function return type"
I am not entirely happy with this solution putting the u_int there
but it will do for now.
route caching for TCP, with some improvements. In particular, invalidate
the route cache if a new route is added, which might be a better match.
The cache is automatically invalidated if the old route is deleted.
Submitted by: Mike Karels
Reviewed by: gnn
Differential Revision: https://reviews.freebsd.org/D4306
Unlike buf_ring_peek, it only supports single consumer mode, and it
clears the cons_head if DEBUG_BUFRING/INVARIANTS is defined.
The normal use case of drbr_peek for network drivers is:
m = drbr_peek(br);
err = hw_spec_encap(&m); /* could m_defrag/m_collapse */
(*)
if (err) {
if (m == NULL)
drbr_advance(br);
else
drbr_putback(br, m);
/* break the loop */
}
drbr_advance(br);
The race is:
If hw_spec_encap() m_defrag or m_collapse the mbuf, i.e. the old mbuf
was freed, or like the Hyper-V's network driver, that transmission-
done does not even require the TX lock; then on the other CPU at the
(*) time, the freed mbuf could be recycled and being drbr_enqueue even
before the current CPU had the chance to call drbr_{advance,putback}.
This triggers a panic in drbr_enqueue duplicated element check, if
DEBUG_BUFRING/INVARIANTS is defined.
Use buf_ring_peek_clear_sc() in drbr_peek() to fix the above race.
This change is a NO-OP, if neither DEBUG_BUFRING nor INVARIANTS are
defined.
MFC after: 1 week
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D5416
Copy the data into temprorary malloced buffer and drop the lock for
copyout.
Reported, reviewed and tested by: cem
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Fix a panic that occurs when a vnet interface is unavailable at the time the
vnet jail referencing said interface is stopped.
Sponsored by: FIS Global, Inc.
There are number of radix consumers in kernel land (pf,ipfw,nfs,route)
with different requirements. In fact, first 3 don't have _any_ requirements
and first 2 does not use radix locking. On the other hand, routing
structure do have these requirements (rnh_gen, multipath, custom
to-be-added control plane functions, different locking).
Additionally, radix should not known anything about its consumers internals.
So, radix code now uses tiny 'struct radix_head' structure along with
internal 'struct radix_mask_head' instead of 'struct radix_node_head'.
Existing consumers still uses the same 'struct radix_node_head' with
slight modifications: they need to pass pointer to (embedded)
'struct radix_head' to all radix callbacks.
Routing code now uses new 'struct rib_head' with different locking macro:
RADIX_NODE_HEAD prefix was renamed to RIB_ (which stands for routing
information base).
New net/route_var.h header was added to hold routing subsystem internal
data. 'struct rib_head' was placed there. 'struct rtentry' will also
be moved there soon.
sent using roundrobin protocol and set a better granularity and distribution
among the interfaces. Tuning the number of packages sent by interface can
increase throughput and reduce unordered packets as well as reduce SACK.
Example of usage:
# ifconfig bge0 up
# ifconfig bge1 up
# ifconfig lagg0 create
# ifconfig lagg0 laggproto roundrobin laggport bge0 laggport bge1 \
192.168.1.1 netmask 255.255.255.0
# ifconfig lagg0 rr_limit 500
Reviewed by: thompsa, glebius, adrian (old patch)
Approved by: bapt (mentor)
Relnotes: Yes
Differential Revision: https://reviews.freebsd.org/D540
Move actual rte selection process from rtalloc_mpath_fib()
to the rt_path_selectrte() function. Add public
rt_mpath_select() to use in fibX_lookup_ functions.
The only piece of information that is required is rt_flags subset.
In particular, if_loop() requires RTF_REJECT and RTF_BLACKHOLE flags
to check if this particular mbuf needs to be dropped (and what
error should be returned).
Note that if_loop() will always return EHOSTUNREACH for "reject" routes
regardless of RTF_HOST flag existence. This is due to upcoming routing
changes where RTF_HOST value won't be available as lookup result.
All other functions require RTF_GATEWAY flag to check if they need
to return EHOSTUNREACH instead of EHOSTDOWN error.
There are 11 places where non-zero 'struct route' is passed to if_output().
For most of the callers (forwarding, bpf, arp) does not care about exact
error value. In fact, the only place where this result is propagated
is ip_output(). (ip6_output() passes NULL route to nd6_output_ifp()).
Given that, add 3 new 'struct route' flags (RT_REJECT, RT_BLACKHOLE and
RT_IS_GW) and inline function (rt_update_ro_flags()) to copy necessary
rte flags to ro_flags. Call this function in ip_output() after looking up/
verifying rte.
Reviewed by: ae
Such handler should pass different set of variables, instead
of directly providing 2 locked route entries.
Given that it hasn't been really used since at least 2012, remove
current code.
Will re-add it after finishing most major routing-related changes.
Discussed with: np
Last consumer using RTF_RNH_LOCKED flag was eliminated in r291643.
Restrict passing RTF_RNH_LOCKED to rtrequest1_fib() and do better
locking for RTM_ADD / RTM_DELETE cases.
entries data in unified format.
There are control plane functions that require information other than
just next-hop data (e.g. individual rtentry fields like flags or
prefix/mask). Given that the goal is to avoid rte reference/refcounting,
re-use rt_addrinfo structure to store most rte fields. If caller wants
to retrieve key/mask or gateway (which are sockaddrs and are allocated
separately), it needs to provide sufficient-sized sockaddrs structures
w/ ther pointers saved in passed rt_addrinfo.
Convert:
* lltable new records checks (in_lltable_rtcheck(),
nd6_is_new_addr_neighbor().
* rtsock pre-add/change route check.
* IPv6 NS ND-proxy check (RADIX_MPATH code was eliminated because
1) we don't support RTF_ANNOUNCE ND-proxy for networks and there should
not be multiple host routes for such hosts 2) if we have multiple
routes we should inspect them (which is not done). 3) the entire idea
of abusing KRT as storage for ND proxy seems odd. Userland programs
should be used for that purpose).
Add ro_mtu field to 'struct route' to be able to pass lookup MTU back to
the caller.
Currently, ip6_getpmtu() has 2 totally different use cases:
1) control plane (IPV6_PATHMTU req), where we just need to calculate MTU
and return it, w/o any reusability.
2) Actual ip6_output() data path where we (nearly) always use the provided
route lookup data. If this data is not 'valid' we need to perform another
lookup and save the result (which cannot be re-used by ip6_output()).
Given that, handle 1) by calling separate function doing rte lookup itself.
Resulting MTU is calculated by (newly-added) ip6_calcmtu() used by both
ip6_getpmtu_ctl() and ip6_getpmtu().
For 2) instead of storing ref'ed rte, store mtu (the only needed data
from the lookup result) inside newly-added ro_mtu field.
'struct route' was shrinked by 8(or 4 bytes) in r292978. Grow it again
by 4 bytes. New ro_mtu field will be used in other places like
ip/tcp_output (EMSGSIZE handling from output routines).
Reviewed by: ae
