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
