that if we sort the incoming SACK blocks, we can update the scoreboard
in one pass of the scoreboard. The added overhead of sorting upto 4
sack blocks is much lower than traversing (potentially) large
scoreboards multiple times. The code was updating the scoreboard with
multiple passes over it (once for each sack option). The rewrite fixes
that, reducing the complexity of the main loop from O(n^2) to O(n).
Submitted by: Mohan Srinivasan, Noritoshi Demizu.
Reviewed by: Raja Mukerji.
real next hole to retransmit from the scoreboard, caused by a bug
which did not update the "nexthole" hint in one case in
tcp_sack_option().
Reported by: Daniel Eriksson
Submitted by: Mohan Srinivasan
or to compute the total retransmitted bytes in this sack recovery
episode, the scoreboard is traversed. While in sack recovery, this
traversal occurs on every call to tcp_output(), every dupack and
every partial ack. The scoreboard could potentially get quite large,
making this traversal expensive.
This change optimizes this by storing hints (for the next hole to
retransmit and the total retransmitted bytes in this sack recovery
episode) reducing the complexity to find these values from O(n) to
constant time.
The debug code that sanity checks the hints against the computed
value will be removed eventually.
Submitted by: Mohan Srinivasan, Noritoshi Demizu, Raja Mukerji.
1. Copy a NULL-terminated string into a fixed-length buffer, and
2. copyout that buffer to userland,
we really ought to
0. Zero the entire buffer
first.
Security: FreeBSD-SA-05:08.kmem
- kernel module declarations and handler.
- macros to map malloc(3) calls to malloc(9) ones.
- malloc(9) declarations.
- call finishoff() from module handler MOD_UNLOAD case
instead of atexit(3).
- use panic(9) instead of abort(3)
- take time from time_second instead of gettimeofday(2)
- define INADDR_NONE
look up the packet size of the packet that generated the
response, step down the MTU by one step through ip_next_mtu()
and try again.
Suggested by: dwmalone
needed only for implicit connect cases. Under load, especially on SMP,
this can greatly reduce contention on the tcbinfo lock.
NB: Ambiguities about the state of so_pcb need to be resolved so that
all use of the tcbinfo lock in non-implicit connection cases can be
eliminated.
Submited by: Kazuaki Oda <kaakun at highway dot ne dot jp>
fields of an ICMP packet.
Use this to allow ipfw to pullup only these values since it does not use
the rest of the packet and it was failed on ICMP packets because they
were not long enough.
struct icmp should probably be modified to use these at some point, but
that will break a fair bit of code so it can wait for another day.
On the off chance that adding this struct breaks something in ports,
bump __FreeBSD_version.
Reported by: Randy Bush <randy at psg dot com>
Tested by: Randy Bush <randy at psg dot com>
If TCP Signatures are enabled, the maximum allowed sack blocks aren't
going to fit. The fix is to compute how many sack blocks fit and tack
these on last. Also on SYNs, defer padding until after the SACK
PERMITTED option has been added.
Found by: Mohan Srinivasan.
Submitted by: Mohan Srinivasan, Noritoshi Demizu.
Reviewed by: Raja Mukerji.
code readability and facilitates some anticipated optimizations in
tcp_sack_option().
- Remove tcp_print_holes() and TCP_SACK_DEBUG.
Submitted by: Raja Mukerji.
Reviewed by: Mohan Srinivasan, Noritoshi Demizu.
- If the peer sends the Signature option in the SYN, use of Timestamps
and Window Scaling were disabled (even if the peer supports them).
- The sender must not disable signatures if the option is absent in
the received SYN. (See comment in syncache_add()).
Found, Submitted by: Noritoshi Demizu <demizu at dd dot ij4u dot or dot jp>.
Reviewed by: Mohan Srinivasan <mohans at yahoo-inc dot com>.
tcp_ctlinput() and subject it to active tcpcb and sequence
number checking. Previously any ICMP unreachable/needfrag
message would cause an update to the TCP hostcache. Now only
ICMP PMTU messages belonging to an active TCP session with
the correct src/dst/port and sequence number will update the
hostcache and complete the path MTU discovery process.
Note that we don't entirely implement the recommended counter
measures of Section 7.2 of the paper. However we close down
the possible degradation vector from trivially easy to really
complex and resource intensive. In addition we have limited
the smallest acceptable MTU with net.inet.tcp.minmss sysctl
for some time already, further reducing the effect of any
degradation due to an attack.
Security: draft-gont-tcpm-icmp-attacks-03.txt Section 7.2
MFC after: 3 days
ineffective, depreciated and can be abused to degrade the performance
of active TCP sessions if spoofed.
Replace a bogus call to tcp_quench() in tcp_output() with the direct
equivalent tcpcb variable assignment.
Security: draft-gont-tcpm-icmp-attacks-03.txt Section 7.1
MFC after: 3 days
IPv6 support. The header in IPv6 is more complex then in IPv4 so we
want to handle skipping over it in one location.
Submitted by: Mariano Tortoriello and Raffaele De Lorenzo (via luigi)
in flight in SACK recovery.
Found by: Noritoshi Demizu
Submitted by: Mohan Srinivasan <mohans at yahoo-inc dot com>
Noritoshi Demizu <demizu at dd dot ij4u dot or dot jp>
Raja Mukerji <raja at moselle dot com>
setting ts_recent to an arbitrary value, stopping further
communication between the two hosts.
- If the Echoed Timestamp is greater than the current time,
fall back to the non RFC 1323 RTT calculation.
Submitted by: Raja Mukerji (raja at moselle dot com)
Reviewed by: Noritoshi Demizu, Mohan Srinivasan
a reassembly queue state structure, don't update (receiver) sack
report.
- Similarly, if tcp_drain() is called, freeing up all items on the
reassembly queue, clean the sack report.
Found, Submitted by: Noritoshi Demizu <demizu at dd dot iij4u dot or dot jp>
Reviewed by: Mohan Srinivasan (mohans at yahoo-inc dot com),
Raja Mukerji (raja at moselle dot com).
(Fix for kern/78226).
Submitted by : Noritoshi Demizu <demizu at dd dot iij4u dot or dot jp>
Reviewed by : Mohan Srinivasan (mohans at yahoo-inc dot com),
Raja Mukerji (raja at moselle dot com).
try to reasseble the packet from the fragments queue with the only
fragment, finish with the first fragment as soon as we create a queue.
Spotted by: Vijay Singh
o Drop the fragment if maxfragsperpacket == 0, no chances we
will be able to reassemble the packet in future.
Reviewed by: silby
ip.portrange.last and there is the only port for that because:
a) it is not wise; b) it leads to a panic in the random ip port
allocation code. In general we need to disable ip port allocation
randomization if the last - first delta is ridiculous small.
PR: kern/79342
Spotted by: Anjali Kulkarni
Glanced at by: silby
MFC after: 2 weeks
we have a non-NULL args.rule. If the same packet later is subject to "tee"
rule, its original is sent again into ipfw_chk() and it reenters at the same
rule. This leads to infinite loop and frozen router.
Assign args.rule to NULL, any time we are going to send packet back to
ipfw_chk() after a tee rule. This is a temporary workaround, which we
will leave for RELENG_5. In HEAD we are going to make divert(4) save
next rule the same way as dummynet(4) does.
PR: kern/79546
Submitted by: Oleg Bulyzhin
Reviewed by: maxim, andre
MFC after: 3 days
libalias.
In /usr/src/lib/libalias/alias.c, the functions LibAliasIn and
LibAliasOutTry call the legacy PacketAliasIn/PacketAliasOut instead
of LibAliasIn/LibAliasOut when the PKT_ALIAS_REVERSE option is set.
In this case, the context variable "la" gets lost because the legacy
compatibility routines expect "la" to be global. This was obviously
an oversight when rewriting the PacketAlias* functions to the
LibAlias* functions.
The fix (as shown in the patch below) is to remove the legacy
subroutine calls and replace with the new ones using the "la" struct
as the first arg.
Submitted by: Gil Kloepfer <fgil@kloepfer.org>
Confirmed by: <nicolai@catpipe.net>
PR: 76839
MFC after: 3 days
carp_carpdev_state_locked() is called every time carp interface is attached.
The first call backs up flags of the first interface, and the second
call backs up them again, erasing correct values.
To solve this, a carp_sc_state_locked() function is introduced. It is
called when interface is attached to parent, instead of calling
carp_carpdev_state_locked. carp_carpdev_state_locked() calls
carp_sc_state_locked() for each sc in chain.
Reported by: Yuriy N. Shkandybin, sem
returns error. In this case mbuf has already been freed. [1]
- Remove redundant declaration.
PR: kern/78893 [1]
Submitted by: Liang Yi [1]
Reviewed by: sam
MFC after: 1 day
Add two another workarounds for carp(4) interfaces:
- do not add connected route when address is assigned to carp(4) interface
- do not add connected route when other interface goes down
Embrace workarounds with #ifdef DEV_CARP
per-connection and globally. This eliminates potential DoS attacks
where SACK scoreboard elements tie up too much memory.
Submitted by: Raja Mukerji (raja at moselle dot com).
Reviewed by: Mohan Srinivasan (mohans at yahoo-inc dot com).
a libalias application (e.g. natd, ppp, etc.) to crash. Note: Skinny support
is not enabled in natd or ppp by default.
Approved by: secteam (nectar)
MFC after: 1 day
Secuiryt: This fixes a remote DoS exploit
attached to a parent interface we use its mutex to lock the softc. This
means that in several places like carp_ioctl() we lock softc conditionaly.
This should be redesigned.
To avoid LORs when MII announces us a link state change, we schedule
a quick callout and call carp_carpdev_state_locked() from it.
Initialize callouts using NET_CALLOUT_MPSAFE.
Sponsored by: Rambler
Reviewed by: mlaier
- In carp_send_ad_all() walk through list of all carp interfaces
instead of walking through list of all interfaces.
Sponsored by: Rambler
Reviewed by: mlaier
- Use our loop DLT type, not OpenBSD. [1]
- The fields that are converted to network byte order are not 32-bit
fields but 16-bit fields, so htons should be used in htonl. [1]
- Secondly, ip_input changes ip->ip_len into its value without
the ip-header length. So, restore the length to make bpf happy. [1]
- Use bpf_mtap2(), use temporary af1, since bpf_mtap2 doesn't
understand uint8_t af identifier.
Submitted by: Frank Volf [1]
ignore the sack options in that segment. Else we'd end up
corrupting the scoreboard.
Found by: Raja Mukerji (raja at moselle dot com)
Submitted by: Mohan Srinivasan
- Simplify CARP_LOG() and making it working (we don't have addlog in FreeBSD).
- Introduce CARP_DEBUG() which logs with LOG_DEBUG severity when
net.inet.carp.log > 1
- Use CARP_DEBUG to log state changes of carp interfaces.
After CARP_LOG() cleanup it appeared that carp_input_c() does not need sc
argument. Remove it.
Sponsored by: Rambler
mastering on all other interfaces:
- call carp_carpdev_state() on initialize instead of just setting to INIT
- in carp_carpdev_state() check that interface is UP, instead of checking
that it is not DOWN, because a rebooted machine may have interface in
UNKNOWN state.
Sponsored by: Rambler
Obtained from: OpenBSD (partially)
with the kernel compile time option:
options IPFIREWALL_FORWARD_EXTENDED
This option has to be specified in addition to IPFIRWALL_FORWARD.
With this option even packets targeted for an IP address local
to the host can be redirected. All restrictions to ensure proper
behaviour for locally generated packets are turned off. Firewall
rules have to be carefully crafted to make sure that things like
PMTU discovery do not break.
Document the two kernel options.
PR: kern/71910
PR: kern/73129
MFC after: 1 week
so that parent interface is not left in promiscous mode after carp
interface is destroyed.
This is not perfect, since promisc counter is added when carp
interface is assigned an IP address. However, when address is removed
parent interface is still in promiscuous mode. Only removal of
carp interface removes promisc from parent. Same way in OpenBSD.
Sponsored by: Rambler
hosts to share an IP address, providing high availability and load
balancing.
Original work on CARP done by Michael Shalayeff, with many
additions by Marco Pfatschbacher and Ryan McBride.
FreeBSD port done solely by Max Laier.
Patch by: mlaier
Obtained from: OpenBSD (mickey, mcbride)
