linux.git/net/ipv4/raw.c, branch v2.6.32

AF_RAW: Augment raw_send_hdrinc to expand skb to fit iphdr->ihl (v2)

2009-10-29T08:09:58+00:00

Augment raw_send_hdrinc to correct for incorrect ip header length values

A series of oopses was reported to me recently.  Apparently when using AF_RAW
sockets to send data to peers that were reachable via ipsec encapsulation,
people could panic or BUG halt their systems.

I've tracked the problem down to user space sending an invalid ip header over an
AF_RAW socket with IP_HDRINCL set to 1.

Basically what happens is that userspace sends down an ip frame that includes
only the header (no data), but sets the ip header ihl value to a large number,
one that is larger than the total amount of data passed to the sendmsg call.  In
raw_send_hdrincl, we allocate an skb based on the size of the data in the msghdr
that was passed in, but assume the data is all valid.  Later during ipsec
encapsulation, xfrm4_tranport_output moves the entire frame back in the skbuff
to provide headroom for the ipsec headers.  During this operation, the
skb->transport_header is repointed to a spot computed by
skb->network_header + the ip header length (ihl).  Since so little data was
passed in relative to the value of ihl provided by the raw socket, we point
transport header to an unknown location, resulting in various crashes.

This fix for this is pretty straightforward, simply validate the value of of
iph->ihl when sending over a raw socket.  If (iph->ihl*4U) > user data buffer
size, drop the frame and return -EINVAL.  I just confirmed this fixes the
reported crashes.

Signed-off-by: Neil Horman 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: Make setsockopt() optlen be unsigned.

2009-09-30T23:12:20+00:00

This provides safety against negative optlen at the type
level instead of depending upon (sometimes non-trivial)
checks against this sprinkled all over the the place, in
each and every implementation.

Based upon work done by Arjan van de Ven and feedback
from Linus Torvalds.

Signed-off-by: David S. Miller

ip: Report qdisc packet drops

2009-09-03T01:05:33+00:00

Christoph Lameter pointed out that packet drops at qdisc level where not
accounted in SNMP counters. Only if application sets IP_RECVERR, drops
are reported to user (-ENOBUFS errors) and SNMP counters updated.

IP_RECVERR is used to enable extended reliable error message passing,
but these are not needed to update system wide SNMP stats.

This patch changes things a bit to allow SNMP counters to be updated,
regardless of IP_RECVERR being set or not on the socket.

Example after an UDP tx flood
# netstat -s 
...
IP:
    1487048 outgoing packets dropped
...
Udp:
...
    SndbufErrors: 1487048


send() syscalls, do however still return an OK status, to not
break applications.

Note : send() manual page explicitly says for -ENOBUFS error :

 "The output queue for a network interface was full.
  This generally indicates that the interface has stopped sending,
  but may be caused by transient congestion.
  (Normally, this does not occur in Linux. Packets are just silently
  dropped when a device queue overflows.) "

This is not true for IP_RECVERR enabled sockets : a send() syscall
that hit a qdisc drop returns an ENOBUFS error.

Many thanks to Christoph, David, and last but not least, Alexey !

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: correct off-by-one write allocations reports

2009-06-18T07:29:12+00:00

commit 2b85a34e911bf483c27cfdd124aeb1605145dc80
(net: No more expensive sock_hold()/sock_put() on each tx)
changed initial sk_wmem_alloc value.

We need to take into account this offset when reporting
sk_wmem_alloc to user, in PROC_FS files or various
ioctls (SIOCOUTQ/TIOCOUTQ)

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: skb->dst accessors

2009-06-03T09:51:04+00:00

Define three accessors to get/set dst attached to a skb

struct dst_entry *skb_dst(const struct sk_buff *skb)

void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)

void skb_dst_drop(struct sk_buff *skb)
This one should replace occurrences of :
dst_release(skb->dst)
skb->dst = NULL;

Delete skb->dst field

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

ip: support for TX timestamps on UDP and RAW sockets

2009-02-16T06:43:38+00:00

Instructions for time stamping outgoing packets are take from the
socket layer and later copied into the new skb.

Signed-off-by: Patrick Ohly 
Signed-off-by: David S. Miller

net: avoid a pair of dst_hold()/dst_release() in ip_append_data()

2008-11-24T23:52:46+00:00

We can reduce pressure on dst entry refcount that slowdown UDP transmit
path on SMP machines. This pressure is visible on RTP servers when
delivering content to mediagateways, especially big ones, handling
thousand of streams. Several cpus send UDP frames to the same
destination, hence use the same dst entry.

This patch makes ip_append_data() eventually steal the refcount its
callers had to take on the dst entry.

This doesnt avoid all refcounting, but still gives speedups on SMP,
on UDP/RAW transmit path

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: clean up net/ipv4/ipip.c raw.c tcp.c tcp_minisocks.c tcp_yeah.c xfrm4_policy.c

2008-11-03T08:24:34+00:00

Signed-off-by: Jianjun Kong 
Signed-off-by: David S. Miller

mib: add net to IP_INC_STATS

2008-07-17T03:19:49+00:00

All the callers already have either the net itself, or the place
where to get it from.

Signed-off-by: Pavel Emelyanov 
Signed-off-by: David S. Miller

icmp: add struct net argument to icmp_out_count

2008-07-15T06:05:13+00:00

This routine deals with ICMP statistics, but doesn't have a
struct net at hands, so add one.

Signed-off-by: Pavel Emelyanov 
Signed-off-by: David S. Miller