This is important, because for most protocols, link level fragmentation is
used, but with different default effective MTUs. (e.g.: IPv4 default MTU
is 1500 octets, IPv6 default MTU is 9072 octets).
MSS advertisement must always be:
max(if mtu) - ip hdr siz - tcp hdr siz
We violated this in the previous code so it was fixed.
tcp_mss_to_advertise() now takes af (af on wire) as its argument,
to compute right ip hdr siz.
tcp_segsize() will take care of IPsec header size.
One thing I'm not really sure is how to handle IPsec header size in
*rxsegsizep (inbound segment size estimation).
The current code subtracts possible *outbound* IPsec size from *rxsegsizep,
hoping that the peer is using the same IPsec policy as me.
It may not be applicable, could TCP gulu please comment...
This situation happens on severe memory shortage. We may need more
improvements here and there.
- Grab IEEE802 address from IFT_ETHER card, even if the card is
inserted after bootup time. Is there any other card that can be
inserted afterwards? pcmcia fddi card? :-P
- RFC2373 u bit handling suggests that we SHOULD NOT copy interface id from
ethernet card to pseudo interface, when ethernet card has IEEE802/EUI64
with u bit != 0 (this means that IEEE802/EUI64 is not universally unique).
Do not use such address as, for example, interface id for gif interface.
(I have such an ethernet card myself)
This may change interface id for your gif interface. be careful upgrading
rc files.
(sync with recent KAME)
the member is used to pass struct socket to ip{,6}_output for ipsec decisions.
(i agree it is kind of ugly. we need to modify struct mbuf if we are
to do better - which seems to me a bit too much)
New Reno fast recovery code was being executed even when New Reno was
disabled, resulting in an unfortunate interaction with the traditional
fast recovery code, the end resulting being that the very condition
that would trigger the traditional fast recovery mechanism caused fast
recovery to be disabled!
Problem reported by Ted Lemon, and some analytical help from Charles Hannum.
Stale syn cache entries are useless because none of them will be used
if there is no listening socket, as tcp_input looks up listening socket by
in_pcblookup*() before looking into syn cache.
This fixes race condition due to dangling socket pointer from syn cache
entries to listening socket (this was introduced when ipsec is merged in).
This should preserve currently implemented behavior (but not 4.4BSD
behavior prior to syn cache).
Tested in KAME repository before commit, but we'd better run some
regression tests.
check that the packet if of the rigth protocol before giving it to the
proxy module, otherwise let the ipnat code handle it.
What happens in kern/7831 is that a router sends back a icmp message for
a TCP SYN, and ip_proxy.c forwards it to ip_ftp_pxy.c which can only
handle TCP packets. The icmp message is properly handled by ipnat, no need to
go to ip_ftp_pxy.c.
- Make sure that snd_recover is always at least snd_una. If we don't do
this, there can be confusion when sequence numbers wrap around on a
large loss-free data transfer.
- When doing a New Reno retransmit, snd_una hasn't been updated yet,
and the socket's send buffer has not yet dropped off ACK'd data, so
don't muddle with snd_una, so that tcp_output() gets the correct data
offset.
- When doing a New Reno retransmit, make sure the congestion window is
open one segment beyond the ACK'd data, so that we can actually perform
the retransmit.
Partially derived from, although more complete than, similar changes in
OpenBSD, which in turn originated from Tom Henderson <tomh@cs.berkeley.edu>.
is not the expected one.
I see PRC_REDIRECT_HOST with sa->sa_family == AF_UNIX coming to
{tcp,udp}_ctlinput() when I use dhclient, and I feel like adding
more sanity checks, without logging - if we log it it is too noisy.
when ip header and tcp header are not adjacent to each other
(i.e. when ip6 options are attached).
To test this, try
telnet @::1@::1 port
toward a port without responding server. Prior to the fix, the kernel will
generate broken RST packet.
for the protocol in the specified packet.
Fix statistic gathering to not make bogus increments of ips_delivered and
ips_noproto for cases where rip_input() is called by a protocol handler
(such as icmp_input or igmp_input) which has already processed the packet.
(Sorry for a big commit, I can't separate this into several pieces...)
Pls check sys/netinet6/TODO and sys/netinet6/IMPLEMENTATION for details.
- sys/kern: do not assume single mbuf, accept chained mbuf on passing
data from userland to kernel (or other way round).
- "midway" ATM card: ATM PVC pseudo device support, like those done in ALTQ
package (ftp://ftp.csl.sony.co.jp/pub/kjc/).
- sys/netinet/tcp*: IPv4/v6 dual stack tcp support.
- sys/netinet/{ip6,icmp6}.h, sys/net/pfkeyv2.h: IETF document assumes those
file to be there so we patch it up.
- sys/netinet: IPsec additions are here and there.
- sys/netinet6/*: most of IPv6 code sits here.
- sys/netkey: IPsec key management code
- dev/pci/pcidevs: regen
In my understanding no code here is subject to export control so it
should be safe.
address zero of each net/subnet is a broadcast address.
(The default value is nonzero, which preserves the current behavior).
This can be set using sysctl; the boot-time default can also be
configured using the HOSTZEROBROADCAST kernel config option.
While we're here, defopt HOSTZEROBROADCAST and SUBNETSARELOCAL
after various m_adj()s have been done. Kludge around this with a cheesy
macro that knows where the drivers put the mac header in the first mbuf.
XXX There should be a better way to do this.
where one side can think a connection exists, where the other side thinks
the connection was never established.
The original problem was first reported by Ty Sarna in PR #5909. The
original fix I made to the code didn't cover all cases. The problem this
fix addresses was reported by Christoph Badura via private e-mail.
Many thanks to Bill Sommerfeld for helping me to test this code, and
for finding a subtle bug.
remote of the tunnel can be found.
XXX If you manually mark the interface as "UP" and set the MTU later
XXX sending a packet will still cause a kernel panic.
passing SIOCSIFADDR/SIOIFDSTADDR, but by passing the addresses in
the appropriate structs.
One of the mysteries of ifconfig IMHO...
Should fix kern/6899.
and netinet, currently only tested under netinet.
Disabled by default, enabled by compiling the kernel with option
IFA_STATS. Enabling this feature seems to make the ip_output function
take 13% longer than before, which should be OK for people that need
this feature.
same uid or by root.
This code is from FreeBSD. (Whilst it was originally obtained from OpenBSD,
FreeBSD fixed it to work with multicast. To quote the commit message:
- Don't bother checking for conflicting sockets if we're binding to a
multicast address.
- Don't return an error if we're binding to INADDR_ANY, the conflicting
socket is bound to INADDR_ANY, and the conflicting socket has
SO_REUSEPORT set.
)
- Don't use tcp_respond(), instead create the tcp/ip header from scratch,
and send it ourself.
- Reuse the mbuf that carried the SYN, or allocate one if that is not
available.
- Cache the route we look up to do the Path MTU Discovery check, and
transfer the reference to that route to the inpcb when the connection
completes.
* Macro'ize a small, but often repeated code fragment.
SYN,ACK packets during Path MTU Discovery. Fix tcp_respond() to do the
appropriate route lookup and set DF as appropriate.
Also, fixup similar code in tcp_output() to relookup the route if it
is down.
ipip_input(), and returns non-zero if mrt_ipip_input() handled the
packet.
XXX Eventually, the multicast code should probably use regular IP-IP
XXX `interfaces', but mrouted knows about the VIF table, etc.
up the interface to ip_mroute.c somewhat, and properly separates IP-IP
from GRE. (They are similar, but they are different protocols, and should
not be implemented in the same place.)
where the user issued a write with a length greater than MLEN but less
than MINCLSIZE, thus causing two mbufs to be used. The loop in sosend()
would then call PRU_SEND twice, causing TCP to transmit 2 packets when
it could have transmitted one.
Suggested by Justin Walker <justin@apple.com> on the freebsd-net
mailing list.
((so->so_proto->pr_flags & PR_CONNREQUIRED) == 0 ||
(so->so_options & SO_ACCEPTCONN) == 0)
since the latter is always true, so the former test in unnecessary.
from `TCP/IP Illustrated, Volume 2', W. Richard Stevens, p 730.
Our other constants also use "ATALK".
Added many new ETHERTYPE constants to sys/net/ethertypes.h, including the
ones from libpcap and tcpdump "ethertype.h" files.
of a lookup_wildcard arg; simplifies the logic a bit.
* when assigning ephemeral ports in in_pcbbind(), always call
in_pcblookup_port() with lookup_wildcard=1, so that ephemeral port
allocation on sockets with SO_REUSEADDR set won't potentially bind to a
port in use by something else (principle of least surprise).
syn_cache_unreach() should remove the entry, or just continue on.
Algorithm is to only remove the entry if we've had more than one unreach
error and have retransmitted 3 or more times. This prevents the following
scenario, as noted in PR #5909 (PR from Ty Sarna, scenario from
Charles Hannum):
* Host A sends a SYN.
* Host A retransmits the SYN.
* Host B gets the first SYN and sends a SYN-ACK.
* Host B gets the second SYN and sends a SYN-ACK.
* One of the SYN-ACK bounces with an
ICMP unreachable, causing the `SYN cache' entry to be
removed with no notification.
* Host A receives the other SYN-ACK, sends an ACK, and goes to
ESTABLISHED state.
Should fix PR #5909.
