KAME_IPSEC, and make IPSEC define it so that existing kernel
config files work as before
Now the default can be easily be changed to FAST_IPSEC just by
setting the IPSEC alias to FAST_IPSEC.
implementation. Rewrite pseudodevice code to use cprng_strong(9).
The new pseudodevice is cloning, so each caller gets bits from a stream
generated with its own key. Users of /dev/urandom get their generators
keyed on a "best effort" basis -- the kernel will rekey generators
whenever the entropy pool hits the high water mark -- while users of
/dev/random get their generators rekeyed every time key-length bits
are output.
The underlying cprng_strong API can use AES-256 or AES-128, but we use
AES-128 because of concerns about related-key attacks on AES-256. This
improves performance (and reduces entropy pool depletion) significantly
for users of /dev/urandom but does cause users of /dev/random to rekey
twice as often.
Also fixes various bugs (including some missing locking and a reseed-counter
overflow in the CTR_DRBG code) found while testing this.
For long reads, this generator is approximately 20 times as fast as the
old generator (dd with bs=64K yields 53MB/sec on 2Ghz Core2 instead of
2.5MB/sec) and also uses a separate mutex per instance so concurrency
is greatly improved. For reads of typical key sizes for modern
cryptosystems (16-32 bytes) performance is about the same as the old
code: a little better for 32 bytes, a little worse for 16 bytes.
prefix does not have IFA_ROUTE.
Don't scrub the interface in SIOCAIFADDR if the new address does't
have IFA_ROUTE. If more functions are added to in_ifscrub then this logic
might need to be revisited.
Fixes PR/26450.
<20111022023242.BA26F14A158@mail.netbsd.org>. This change includes
the following:
An initial cleanup and minor reorganization of the entropy pool
code in sys/dev/rnd.c and sys/dev/rndpool.c. Several bugs are
fixed. Some effort is made to accumulate entropy more quickly at
boot time.
A generic interface, "rndsink", is added, for stream generators to
request that they be re-keyed with good quality entropy from the pool
as soon as it is available.
The arc4random()/arc4randbytes() implementation in libkern is
adjusted to use the rndsink interface for rekeying, which helps
address the problem of low-quality keys at boot time.
An implementation of the FIPS 140-2 statistical tests for random
number generator quality is provided (libkern/rngtest.c). This
is based on Greg Rose's implementation from Qualcomm.
A new random stream generator, nist_ctr_drbg, is provided. It is
based on an implementation of the NIST SP800-90 CTR_DRBG by
Henric Jungheim. This generator users AES in a modified counter
mode to generate a backtracking-resistant random stream.
An abstraction layer, "cprng", is provided for in-kernel consumers
of randomness. The arc4random/arc4randbytes API is deprecated for
in-kernel use. It is replaced by "cprng_strong". The current
cprng_fast implementation wraps the existing arc4random
implementation. The current cprng_strong implementation wraps the
new CTR_DRBG implementation. Both interfaces are rekeyed from
the entropy pool automatically at intervals justifiable from best
current cryptographic practice.
In some quick tests, cprng_fast() is about the same speed as
the old arc4randbytes(), and cprng_strong() is about 20% faster
than rnd_extract_data(). Performance is expected to improve.
The AES code in src/crypto/rijndael is no longer an optional
kernel component, as it is required by cprng_strong, which is
not an optional kernel component.
The entropy pool output is subjected to the rngtest tests at
startup time; if it fails, the system will reboot. There is
approximately a 3/10000 chance of a false positive from these
tests. Entropy pool _input_ from hardware random numbers is
subjected to the rngtest tests at attach time, as well as the
FIPS continuous-output test, to detect bad or stuck hardware
RNGs; if any are detected, they are detached, but the system
continues to run.
A problem with rndctl(8) is fixed -- datastructures with
pointers in arrays are no longer passed to userspace (this
was not a security problem, but rather a major issue for
compat32). A new kernel will require a new rndctl.
The sysctl kern.arandom() and kern.urandom() nodes are hooked
up to the new generators, but the /dev/*random pseudodevices
are not, yet.
Manual pages for the new kernel interfaces are forthcoming.
RTF_ANNOUNCE was defined as RTF_PROTO2. The flag is used to indicated
that host should act as a proxy for a link level arp or ndp request.
(If RTF_PROTO2 is used as an experimental flag (as advertised),
various problems can occur.)
This commit provides a first-class definition with its own bit for
RTF_ANNOUNCE, removes the old aliasing definitions, and adds support
for the new RTF_ANNOUNCE flag to netstat(8) and route(8).,
Also, remove unused RTF_ flags that collide with RTF_PROTO1:
netinet/icmp6.h defined RTF_PROBEMTU as RTF_PROTO1
netinet/if_inarp.h defined RTF_USETRAILERS as RTF_PROTO1
(Neither of these flags are used anywhere. Both have been removed
to reduce chances of collision with RTF_PROTO1.)
Figuring this out and the diff are the work of Beverly Schwartz of
BBN.
(Passed release build, boot in VM, with no apparently related atf
failures.)
Approved for Public Release, Distribution Unlimited
This material is based upon work supported by the Defense Advanced
Research Projects Agency and Space and Naval Warfare Systems Center,
Pacific, under Contract No. N66001-09-C-2073.
1. log_movements: do you want to log the arp overwritten message or not?
2. log_wrong_iface: do you want to log when an arp arrives at the wrong
interface?
3. log_permanent_modify: do you want to log when an arp message attempts
to overwrite a static entry?
I did not call the sysctls log_arp like FreeBSD does, because we already
have an arp sysctl level. The default is on for all three of them.
sys/stdarg.h and expect compiler to provide proper builtins, defaulting
to the GCC interface. lint still has a special fallback.
Reduce abuse of _BSD_VA_LIST_ by defining __va_list by default and
derive va_list as required by standards.
Use kmem_zalloc() instead of kmem_alloc() + bzero().
During initialization, try to get all of the memory we need for the
vestigial time-wait structures before we set any of the structures up,
and if any single allocation fails, release all of the memory.
This should help low-memory hosts. A much better fix postpones
allocating any memory until vtw is enabled through the sysctl.
vtw_control() is called. In this way, vtw_tick() will be re-scheduled
repeatedly while vtw is in use.
Pay tcp_vtw_was_enabled no attention in vtw_earlyinit(), since it's
always going to be 0 during initialization.
ts_rtt is 1 plus the RTT, so that 0 can mean invalid measurement.
However, the code failed to subtract the 1 back out before use. With
this change, TCP from Massachusetts to France now typically has 1s RTO
values, rather than 1.5s.
This bug was found and fixed by Bev Schwartz of BBN. This material is
based upon work supported by the Defense Advanced Research Projects
Agency and Space and Naval Warfare Systems Center, Pacific, under
Contract No. N66001-09-C-2073. Approved for Public Release,
Distribution Unlimited
- introduce a limit for the routes accepted via IPv6 Router Advertisement:
a common 2 interface client will have 6, the default limit is 100 and
can be adjusted via sysctl
- report the current number of routes installed via RA via sysctl
- count discarded route additions. Note that one RA message is two routes.
This is at present only across all interfaces even though per-interface
would be more useful, since the per-interface structure complies to RFC2466
- bump kernel version due to the previous change
- adjust netstat to use the new value (with netstat -p icmp6)
methods called Vestigial Time-Wait (VTW) and Maximum Segment Lifetime
Truncation (MSLT).
MSLT and VTW were contributed by Coyote Point Systems, Inc.
Even after a TCP session enters the TIME_WAIT state, its corresponding
socket and protocol control blocks (PCBs) stick around until the TCP
Maximum Segment Lifetime (MSL) expires. On a host whose workload
necessarily creates and closes down many TCP sockets, the sockets & PCBs
for TCP sessions in TIME_WAIT state amount to many megabytes of dead
weight in RAM.
Maximum Segment Lifetimes Truncation (MSLT) assigns each TCP session to
a class based on the nearness of the peer. Corresponding to each class
is an MSL, and a session uses the MSL of its class. The classes are
loopback (local host equals remote host), local (local host and remote
host are on the same link/subnet), and remote (local host and remote
host communicate via one or more gateways). Classes corresponding to
nearer peers have lower MSLs by default: 2 seconds for loopback, 10
seconds for local, 60 seconds for remote. Loopback and local sessions
expire more quickly when MSLT is used.
Vestigial Time-Wait (VTW) replaces a TIME_WAIT session's PCB/socket
dead weight with a compact representation of the session, called a
"vestigial PCB". VTW data structures are designed to be very fast and
memory-efficient: for fast insertion and lookup of vestigial PCBs,
the PCBs are stored in a hash table that is designed to minimize the
number of cacheline visits per lookup/insertion. The memory both
for vestigial PCBs and for elements of the PCB hashtable come from
fixed-size pools, and linked data structures exploit this to conserve
memory by representing references with a narrow index/offset from the
start of a pool instead of a pointer. When space for new vestigial PCBs
runs out, VTW makes room by discarding old vestigial PCBs, oldest first.
VTW cooperates with MSLT.
It may help to think of VTW as a "FIN cache" by analogy to the SYN
cache.
A 2.8-GHz Pentium 4 running a test workload that creates TIME_WAIT
sessions as fast as it can is approximately 17% idle when VTW is active
versus 0% idle when VTW is inactive. It has 103 megabytes more free RAM
when VTW is active (approximately 64k vestigial PCBs are created) than
when it is inactive.
- don't forget ntohs.
- don't add hdrlen twice for l4 header offset.
- use M_CSUM_DATA_IPv4_IPHL instead of extracting it from ip header.
- simplify code.
- KNF.
Long ago, the storage representations of srtt and rttvar were changed
from the 4.4BSD scheme, and the comments are out of sync with the
code. This commit rewrites most of the comments that explain the RTO
calculations, and points out some issues in the code.
Joint work with Bev Schwartz of BBN (original analysis and comments),
but I have rewritten and extended them, so errors are mine.
This material is based upon work supported by the Defense Advanced
Research Projects Agency and Space and Naval Warfare Systems Center,
Pacific, under Contract No. N66001-09-C-2073. Approved for Public
Release, Distribution Unlimited
Initialize ipintrq.ifq_maxlen using IFQ_MAXLEN directly instead of using
the global ipqmaxlen. Get rid of the global ipqmaxlen.
Now it works again to override the maximum IP queue length with, for
example, sysctl -w net.inet.ip.ifq.maxlen=5.
