could modify the struct mbuf and calling functions (udp_input() and
udp4_realinput()) would have used a garbled local copy of the pointer.
The fix is not perfect. udp4_espinudp() should use m_pulldown()...
pass it to in_pcbbind() so that can allocate a low numbered port
if setsockopt() has been used to set IP_PORTRANGE to IP_PORTRANGE_LOW.
While there, fail in_pcbconnect() if the in_pcbbind() fails - rather
than sending the request out from a port of zero.
This has been largely broken since the socket option was added in 1998.
the decapsulator dispatch changes in 2001. Problems found and fixed
by Christine Jones of BBN. Specifically:
Check for a packet's protocol to be ENCAP_PROTO, not AF_INET.
Remove one-back cache for last vif, because vif_encapcheck is called
for each vif, rather than being expected to find the appropriate vif.
The cache usage caused packets to be input on the wrong vif and hence
usually dropped.
In vif_encapcheck, verify the local source as well. While mrouted
endeavors not to create multiple tunnels with a peer, a packet
arriving with the wrong local address is still wrong and should not be
accepted. (This is a correctness nit, not a security issue.) Order
checks to fail quickly for packets being checked to see if they match
a vif other than the one they belong on (essentially, check peer
source address in outer header first).
Claim 69 bits of match (32 each from outer src/dst and 5 from checking
that inner dst is within 224/5). This should result in the vif having
a higher priority for multicast packets compared to a parallel gif(4)
tunnel, and that both seems appropriate if both are configured and
seems to match the semantics expected by the decapsulator dispatch
machinery.
(These changes were made in 2.99.15 and about a dozen nodes are
running them with many vifs. ip_mroute.c has not changed
significantly since then (February 2005) and the changes applied
cleanly to current and compile cleanly.)
http://www.gont.com.ar/drafts/icmp-attacks-against-tcp.html
1. Don't act on ICMP-need-frag immediately if adhoc checks on the
advertised MTU fail. The MTU update is delayed until a TCP retransmit
happens.
2. Ignore ICMP Source Quench messages meant for TCP connections.
From OpenBSD.
store a struct ifnet *, and define it for udp/tcp/rawip for INET and
INET6. When deleting a struct ifnet, invoke PRU_PURGEIF on all
protocols marked with PR_PURGEIF. Closes PR kern/29580 (mine).
The __UNCONST macro is now used only where necessary and the RW macros
are gone. Most of the changes here are consumers of the
sysctl_createv(9) interface that now takes a pair of const pointers
which used not to be.
"const struct mbuf *" to "struct mbuf *". Without this change the
actual implementation cannot even use m_copydata() on the mbuf chain
which is broken.
