Commit Graph

24 Commits

Author SHA1 Message Date
Christian S.J. Peron
16d878cc99 Fix the following bpf(4) race condition which can result in a panic:
(1) bpf peer attaches to interface netif0
	(2) Packet is received by netif0
	(3) ifp->if_bpf pointer is checked and handed off to bpf
	(4) bpf peer detaches from netif0 resulting in ifp->if_bpf being
	    initialized to NULL.
	(5) ifp->if_bpf is dereferenced by bpf machinery
	(6) Kaboom

This race condition likely explains the various different kernel panics
reported around sending SIGINT to tcpdump or dhclient processes. But really
this race can result in kernel panics anywhere you have frequent bpf attach
and detach operations with high packet per second load.

Summary of changes:

- Remove the bpf interface's "driverp" member
- When we attach bpf interfaces, we now set the ifp->if_bpf member to the
  bpf interface structure. Once this is done, ifp->if_bpf should never be
  NULL. [1]
- Introduce bpf_peers_present function, an inline operation which will do
  a lockless read bpf peer list associated with the interface. It should
  be noted that the bpf code will pickup the bpf_interface lock before adding
  or removing bpf peers. This should serialize the access to the bpf descriptor
  list, removing the race.
- Expose the bpf_if structure in bpf.h so that the bpf_peers_present function
  can use it. This also removes the struct bpf_if; hack that was there.
- Adjust all consumers of the raw if_bpf structure to use bpf_peers_present

Now what happens is:

	(1) Packet is received by netif0
	(2) Check to see if bpf descriptor list is empty
	(3) Pickup the bpf interface lock
	(4) Hand packet off to process

From the attach/detach side:

	(1) Pickup the bpf interface lock
	(2) Add/remove from bpf descriptor list

Now that we are storing the bpf interface structure with the ifnet, there is
is no need to walk the bpf interface list to locate the correct bpf interface.
We now simply look up the interface, and initialize the pointer. This has a
nice side effect of changing a bpf interface attach operation from O(N) (where
N is the number of bpf interfaces), to O(1).

[1] From now on, we can no longer check ifp->if_bpf to tell us whether or
    not we have any bpf peers that might be interested in receiving packets.

In collaboration with:	sam@
MFC after:	1 month
2006-06-02 19:59:33 +00:00
Gleb Smirnoff
e5f88c4492 Since m_pullup() can return a new mbuf, change gre_input2() to
return mbuf back to gre_input(). If the former returns mbuf back
to the latter, then pass it to raw_input().

Coverity ID:	829
2006-05-16 11:15:22 +00:00
Robert Watson
d0c75d36b9 Convert last remaining function in ip_gre.c to ANSI C function
declaration.

MFC after:	1 week
2006-01-22 01:08:30 +00:00
Bjoern A. Zeeb
3f2e28fe9f Fix stack corruptions on amd64.
Vararg functions have a different calling convention than regular
functions on amd64. Casting a varag function to a regular one to
match the function pointer declaration will hide the varargs from
the caller and we will end up with an incorrectly setup stack.

Entirely remove the varargs from these functions and change the
functions to match the declaration of the function pointers.
Remove the now unnecessary casts.

Lots of explanations and help from:     peter
Reviewed by:                            peter
PR:                                     amd64/89261
MFC after:                              6 days
2006-01-21 10:44:34 +00:00
Bjoern A. Zeeb
9e669156d4 Add support for IPv6 over GRE [1]. PR kern/80340 includes the
FreeBSD specific ip_newid() changes NetBSD does not have.
Correct handling of non AF_INET packets passed to bpf [2].

PR:		kern/80340[1], NetBSD PRs 29150[1], 30844[2]
Obtained from:	NetBSD ip_gre.c rev. 1.34,1.35, if_gre.c rev. 1.56
Submitted by:	Gert Doering <gert at greenie.muc.de>[2]
MFC after:	4 days
2005-08-01 08:14:21 +00:00
Brooks Davis
fc74a9f93a Stop embedding struct ifnet at the top of driver softcs. Instead the
struct ifnet or the layer 2 common structure it was embedded in have
been replaced with a struct ifnet pointer to be filled by a call to the
new function, if_alloc(). The layer 2 common structure is also allocated
via if_alloc() based on the interface type. It is hung off the new
struct ifnet member, if_l2com.

This change removes the size of these structures from the kernel ABI and
will allow us to better manage them as interfaces come and go.

Other changes of note:
 - Struct arpcom is no longer referenced in normal interface code.
   Instead the Ethernet address is accessed via the IFP2ENADDR() macro.
   To enforce this ac_enaddr has been renamed to _ac_enaddr.
 - The second argument to ether_ifattach is now always the mac address
   from driver private storage rather than sometimes being ac_enaddr.

Reviewed by:	sobomax, sam
2005-06-10 16:49:24 +00:00
Warner Losh
c398230b64 /* -> /*- for license, minor formatting changes 2005-01-07 01:45:51 +00:00
Robert Watson
a4f757cd5d White space cleanup for netinet before branch:
- Trailing tab/space cleanup
- Remove spurious spaces between or before tabs

This change avoids touching files that Andre likely has in his working
set for PFIL hooks changes for IPFW/DUMMYNET.

Approved by:	re (scottl)
Submitted by:	Xin LI <delphij@frontfree.net>
2004-08-16 18:32:07 +00:00
Robert Watson
bdae44a844 Lock down global variables in if_gre:
- Add gre_mtx to protect global softc list.
- Hold gre_mtx over various list operations (insert, delete).
- Centralize if_gre interface teardown in gre_destroy(), and call this
  from modevent unload and gre_clone_destroy().
- Export gre_mtx to ip_gre.c, which walks the gre list to look up gre
  interfaces during encapsulation.  Add a wonking comment on how we need
  some sort of drain/reference count mechanism to keep gre references
  alive while in use and simultaneous destroy.

This commit does not lockdown softc data, which follows in a future
commit.
2004-03-22 16:04:43 +00:00
Maxim Sobolev
4c83789253 Remove NetBSD'isms (add FreeBSD'isms?), which makes gre(4) working again. 2004-01-30 09:03:01 +00:00
Maxim Sobolev
7735aeb9bb Add support for WCCPv2. It should be enablem manually using link2
ifconfig(8) flag since header for version 2 is the same but IP payload
is prepended with additional 4-bytes field.

Inspired by:	Roman Synyuk <roman@univ.kiev.ua>
MFC after:	2 weeks
2004-01-26 12:33:56 +00:00
Maxim Sobolev
6e628b8187 (whilespace-only)
Kill trailing spaces.
2004-01-26 12:21:59 +00:00
Maxim Sobolev
73d7ddbc56 Sync with NetBSD:
if_gre.c rev.1.41-1.49

 o Spell output with two ts.
 o Remove assigned-to but not used variable.
 o fix grammatical error in a diagnostic message.
 o u_short -> u_int16_t.
 o gi_len is ip_len, so it has to be network byteorder.

if_gre.h rev.1.11-1.13

 o prototype must not have variable name.
 o u_short -> u_int16_t.
 o Spell address with two d's.

ip_gre.c rev.1.22-1.29

 o KNF - return is not a function.
 o The "osrc" variable in gre_mobile_input() is only ever set but not
   referenced; remove it.
 o correct (false) assumptions on mbuf chain.  not sure if it really helps, but
   anyways, it is necessary to perform m_pullup.
 o correct arg to m_pullup (need to count IP header size as well).
 o remove redundant adjustment of m->m_pkthdr.len.
 o clear m_flags just for safety.
 o tabify.
 o u_short -> u_int16_t.

MFC after:	2 weeks
2003-12-30 11:41:43 +00:00
Sam Leffler
437ffe1823 o eliminate widespread on-stack mbuf use for bpf by introducing
a new bpf_mtap2 routine that does the right thing for an mbuf
  and a variable-length chunk of data that should be prepended.
o while we're sweeping the drivers, use u_int32_t uniformly when
  when prepending the address family (several places were assuming
  sizeof(int) was 4)
o return M_ASSERTVALID to BPF_MTAP* now that all stack-allocated
  mbufs have been eliminated; this may better be moved to the bpf
  routines

Reviewed by:	arch@ and several others
2003-12-28 03:56:00 +00:00
Peter Wemm
3c6b084e96 Finish driving a stake through the heart of netns and the associated
ifdefs scattered around the place - its dead Jim!

The SMB stuff had stolen AF_NS, make it official.
2003-03-05 19:24:24 +00:00
Jonathan Lemon
1cafed3941 Update netisr handling; Each SWI now registers its queue, and all queue
drain routines are done by swi_net, which allows for better queue control
at some future point.  Packets may also be directly dispatched to a netisr
instead of queued, this may be of interest at some installations, but
currently defaults to off.

Reviewed by: hsu, silby, jayanth, sam
Sponsored by: DARPA, NAI Labs
2003-03-04 23:19:55 +00:00
Maxim Sobolev
16199bf2d3 MFS: recognize gre packets used in the WCCP protocol.
Approved by:	re
2002-12-07 14:22:05 +00:00
Sam Leffler
ccb2acfe1b track bpf changes
Reviewed by:	many
Approved by:	re
2002-11-14 23:45:13 +00:00
Alfred Perlstein
dde2897f82 de-__P(). 2002-10-16 22:27:27 +00:00
Maxim Sobolev
748bb23dcc Since bpf is no longer an optional component, remove associated ifdef's.
Submitted by:	don't quite remember - the name of the sender disappeared
		with the rest of my inbox. :(
2002-10-02 09:38:17 +00:00
Maxim Sobolev
563a9b6ecb Remove __RCSID().
Submitted by:	bde
2002-09-17 11:31:41 +00:00
Maxim Sobolev
2b82e3b367 Remove superfluous break. 2002-09-10 09:18:33 +00:00
Maxim Sobolev
c23d234cce Reduce namespace pollution by staticizing everything, which doesn't need to
be visible from outside of the module.
2002-09-06 18:16:03 +00:00
Maxim Sobolev
8e96e13e6a Add a new gre(4) driver, which could be used to create GRE (RFC1701)
and MOBILE (RFC2004) IP tunnels.

Obrained from:  NetBSD
2002-09-06 17:12:50 +00:00