Commit Graph

159 Commits

Author SHA1 Message Date
des
66f807ed8b Retire the MALLOC and FREE macros. They are an abomination unto style(9).
MFC after:	3 months
2008-10-23 15:53:51 +00:00
rwatson
482bfeab47 Remove NETISR_MPSAFE, which allows specific netisr handlers to be directly
dispatched without Giant, and add NETISR_FORCEQUEUE, which allows specific
netisr handlers to always be dispatched via a queue (deferred).  Mark the
usb and if_ppp netisr handlers as NETISR_FORCEQUEUE, and explicitly
acquire Giant in those handlers.

Previously, any netisr handler not marked NETISR_MPSAFE would necessarily
run deferred and with Giant acquired.  This change removes Giant
scaffolding from the netisr infrastructure, but NETISR_FORCEQUEUE allows
non-MPSAFE handlers to continue to force deferred dispatch so as to avoid
lock order reversals between their acqusition of Giant and any calling
context.

It is likely we will be able to remove NETISR_FORCEQUEUE once
IFF_NEEDSGIANT is removed, as non-MPSAFE usb and if_ppp drivers will no
longer be supported.

Reviewed by:	bz
MFC after:	1 month
X-MFC note:	We can't remove NETISR_MPSAFE from stable/7 for KPI reasons,
		but the rest can go back.
2008-07-04 00:21:38 +00:00
julian
1dfc5c98a4 Add code to allow the system to handle multiple routing tables.
This particular implementation is designed to be fully backwards compatible
and to be MFC-able to 7.x (and 6.x)

Currently the only protocol that can make use of the multiple tables is IPv4
Similar functionality exists in OpenBSD and Linux.

From my notes:

-----

  One thing where FreeBSD has been falling behind, and which by chance I
  have some time to work on is "policy based routing", which allows
  different
  packet streams to be routed by more than just the destination address.

  Constraints:
  ------------

  I want to make some form of this available in the 6.x tree
  (and by extension 7.x) , but FreeBSD in general needs it so I might as
  well do it in -current and back port the portions I need.

  One of the ways that this can be done is to have the ability to
  instantiate multiple kernel routing tables (which I will now
  refer to as "Forwarding Information Bases" or "FIBs" for political
  correctness reasons). Which FIB a particular packet uses to make
  the next hop decision can be decided by a number of mechanisms.
  The policies these mechanisms implement are the "Policies" referred
  to in "Policy based routing".

  One of the constraints I have if I try to back port this work to
  6.x is that it must be implemented as a EXTENSION to the existing
  ABIs in 6.x so that third party applications do not need to be
  recompiled in timespan of the branch.

  This first version will not have some of the bells and whistles that
  will come with later versions. It will, for example, be limited to 16
  tables in the first commit.
  Implementation method, Compatible version. (part 1)
  -------------------------------
  For this reason I have implemented a "sufficient subset" of a
  multiple routing table solution in Perforce, and back-ported it
  to 6.x. (also in Perforce though not  always caught up with what I
  have done in -current/P4). The subset allows a number of FIBs
  to be defined at compile time (8 is sufficient for my purposes in 6.x)
  and implements the changes needed to allow IPV4 to use them. I have not
  done the changes for ipv6 simply because I do not need it, and I do not
  have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it.

  Other protocol families are left untouched and should there be
  users with proprietary protocol families, they should continue to work
  and be oblivious to the existence of the extra FIBs.

  To understand how this is done, one must know that the current FIB
  code starts everything off with a single dimensional array of
  pointers to FIB head structures (One per protocol family), each of
  which in turn points to the trie of routes available to that family.

  The basic change in the ABI compatible version of the change is to
  extent that array to be a 2 dimensional array, so that
  instead of protocol family X looking at rt_tables[X] for the
  table it needs, it looks at rt_tables[Y][X] when for all
  protocol families except ipv4 Y is always 0.
  Code that is unaware of the change always just sees the first row
  of the table, which of course looks just like the one dimensional
  array that existed before.

  The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign()
  are all maintained, but refer only to the first row of the array,
  so that existing callers in proprietary protocols can continue to
  do the "right thing".
  Some new entry points are added, for the exclusive use of ipv4 code
  called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(),
  which have an extra argument which refers the code to the correct row.

  In addition, there are some new entry points (currently called
  rtalloc_fib() and friends) that check the Address family being
  looked up and call either rtalloc() (and friends) if the protocol
  is not IPv4 forcing the action to row 0 or to the appropriate row
  if it IS IPv4 (and that info is available). These are for calling
  from code that is not specific to any particular protocol. The way
  these are implemented would change in the non ABI preserving code
  to be added later.

  One feature of the first version of the code is that for ipv4,
  the interface routes show up automatically on all the FIBs, so
  that no matter what FIB you select you always have the basic
  direct attached hosts available to you. (rtinit() does this
  automatically).

  You CAN delete an interface route from one FIB should you want
  to but by default it's there. ARP information is also available
  in each FIB. It's assumed that the same machine would have the
  same MAC address, regardless of which FIB you are using to get
  to it.

  This brings us as to how the correct FIB is selected for an outgoing
  IPV4 packet.

  Firstly, all packets have a FIB associated with them. if nothing
  has been done to change it, it will be FIB 0. The FIB is changed
  in the following ways.

  Packets fall into one of a number of classes.

  1/ locally generated packets, coming from a socket/PCB.
     Such packets select a FIB from a number associated with the
     socket/PCB. This in turn is inherited from the process,
     but can be changed by a socket option. The process in turn
     inherits it on fork. I have written a utility call setfib
     that acts a bit like nice..

         setfib -3 ping target.example.com # will use fib 3 for ping.

     It is an obvious extension to make it a property of a jail
     but I have not done so. It can be achieved by combining the setfib and
     jail commands.

  2/ packets received on an interface for forwarding.
     By default these packets would use table 0,
     (or possibly a number settable in a sysctl(not yet)).
     but prior to routing the firewall can inspect them (see below).
     (possibly in the future you may be able to associate a FIB
     with packets received on an interface..  An ifconfig arg, but not yet.)

  3/ packets inspected by a packet classifier, which can arbitrarily
     associate a fib with it on a packet by packet basis.
     A fib assigned to a packet by a packet classifier
     (such as ipfw) would over-ride a fib associated by
     a more default source. (such as cases 1 or 2).

  4/ a tcp listen socket associated with a fib will generate
     accept sockets that are associated with that same fib.

  5/ Packets generated in response to some other packet (e.g. reset
     or icmp packets). These should use the FIB associated with the
     packet being reponded to.

  6/ Packets generated during encapsulation.
     gif, tun and other tunnel interfaces will encapsulate using the FIB
     that was in effect withthe proces that set up the tunnel.
     thus setfib 1 ifconfig gif0 [tunnel instructions]
     will set the fib for the tunnel to use to be fib 1.

  Routing messages would be associated with their
  process, and thus select one FIB or another.
  messages from the kernel would be associated with the fib they
  refer to and would only be received by a routing socket associated
  with that fib. (not yet implemented)

  In addition Netstat has been edited to be able to cope with the
  fact that the array is now 2 dimensional. (It looks in system
  memory using libkvm (!)). Old versions of netstat see only the first FIB.

  In addition two sysctls are added to give:
  a) the number of FIBs compiled in (active)
  b) the default FIB of the calling process.

  Early testing experience:
  -------------------------

  Basically our (IronPort's) appliance does this functionality already
  using ipfw fwd but that method has some drawbacks.

  For example,
  It can't fully simulate a routing table because it can't influence the
  socket's choice of local address when a connect() is done.

  Testing during the generating of these changes has been
  remarkably smooth so far. Multiple tables have co-existed
  with no notable side effects, and packets have been routes
  accordingly.

  ipfw has grown 2 new keywords:

  setfib N ip from anay to any
  count ip from any to any fib N

  In pf there seems to be a requirement to be able to give symbolic names to the
  fibs but I do not have that capacity. I am not sure if it is required.

  SCTP has interestingly enough built in support for this, called VRFs
  in Cisco parlance. it will be interesting to see how that handles it
  when it suddenly actually does something.

  Where to next:
  --------------------

  After committing the ABI compatible version and MFCing it, I'd
  like to proceed in a forward direction in -current. this will
  result in some roto-tilling in the routing code.

  Firstly: the current code's idea of having a separate tree per
  protocol family, all of the same format, and pointed to by the
  1 dimensional array is a bit silly. Especially when one considers that
  there is code that makes assumptions about every protocol having the
  same internal structures there. Some protocols don't WANT that
  sort of structure. (for example the whole idea of a netmask is foreign
  to appletalk). This needs to be made opaque to the external code.

  My suggested first change is to add routing method pointers to the
  'domain' structure, along with information pointing the data.
  instead of having an array of pointers to uniform structures,
  there would be an array pointing to the 'domain' structures
  for each protocol address domain (protocol family),
  and the methods this reached would be called. The methods would have
  an argument that gives FIB number, but the protocol would be free
  to ignore it.

  When the ABI can be changed it raises the possibilty of the
  addition of a fib entry into the "struct route". Currently,
  the structure contains the sockaddr of the desination, and the resulting
  fib entry. To make this work fully, one could add a fib number
  so that given an address and a fib, one can find the third element, the
  fib entry.

  Interaction with the ARP layer/ LL layer would need to be
  revisited as well. Qing Li has been working on this already.

  This work was sponsored by Ironport Systems/Cisco

Reviewed by:    several including rwatson, bz and mlair (parts each)
Obtained from:  Ironport systems/Cisco
2008-05-09 23:03:00 +00:00
ru
3b1bf8c2e9 Replaced the misleading uses of a historical artefact M_TRYWAIT with M_WAIT.
Removed dead code that assumed that M_TRYWAIT can return NULL; it's not true
since the advent of MBUMA.

Reviewed by:	arch

There are ongoing disputes as to whether we want to switch to directly using
UMA flags M_WAITOK/M_NOWAIT for mbuf(9) allocation.
2008-03-25 09:39:02 +00:00
rwatson
2fce7b68b1 Annotate two possible bugs in a comment: (1) we allocate and explicitly
prepend a data mbuf in front of a header mbuf without moving the header
to the new mbuf, and (2) a possible alignment problem on architectures
with strict alignment as reported in kern/4184.

PR:	kern/4184 (1)
2007-11-20 18:50:54 +00:00
rwatson
261a3b571d Add additional robustness to at_aarpinput() by testing for broadcast
addresses as the source of an AARP request.  While this PR was submitted
in the context of work in OpenBSD to port netatalk (in 1997), I've
synchronized the code more to our ARP input routine, which had similar
requirements.

Submitted by:	Denton Gentry
PR:		kern/4184
MFC after:	1 week
2007-11-20 18:35:57 +00:00
rwatson
2bca3d4001 Move towards more explicit support for various network protocol stacks
in the TrustedBSD MAC Framework:

- Add mac_atalk.c and add explicit entry point mac_netatalk_aarp_send()
  for AARP packet labeling, rather than using a generic link layer
  entry point.

- Add mac_inet6.c and add explicit entry point mac_netinet6_nd6_send()
  for ND6 packet labeling, rather than using a generic link layer entry
  point.

- Add expliict entry point mac_netinet_arp_send() for ARP packet
  labeling, and mac_netinet_igmp_send() for IGMP packet labeling,
  rather than using a generic link layer entry point.

- Remove previous genering link layer entry point,
  mac_mbuf_create_linklayer() as it is no longer used.

- Add implementations of new entry points to various policies, largely
  by replicating the existing link layer entry point for them; remove
  old link layer entry point implementation.

- Make MAC_IFNET_LOCK(), MAC_IFNET_UNLOCK(), and mac_ifnet_mtx global
  to the MAC Framework rather than static to mac_net.c as it is now
  needed outside of mac_net.c.

Obtained from:	TrustedBSD Project
2007-10-28 15:55:23 +00:00
rwatson
a3b8fc4866 Rename 'mac_mbuf_create_from_firewall' to 'mac_netinet_firewall_send' as
we move towards netinet as a pseudo-object for the MAC Framework.

Rename 'mac_create_mbuf_linklayer' to 'mac_mbuf_create_linklayer' to
reflect general object-first ordering preference.

Sponsored by:	SPARTA (original patches against Mac OS X)
Obtained from:	TrustedBSD Project, Apple Computer
2007-10-26 13:18:38 +00:00
rwatson
60570a92bf Merge first in a series of TrustedBSD MAC Framework KPI changes
from Mac OS X Leopard--rationalize naming for entry points to
the following general forms:

  mac_<object>_<method/action>
  mac_<object>_check_<method/action>

The previous naming scheme was inconsistent and mostly
reversed from the new scheme.  Also, make object types more
consistent and remove spaces from object types that contain
multiple parts ("posix_sem" -> "posixsem") to make mechanical
parsing easier.  Introduce a new "netinet" object type for
certain IPv4/IPv6-related methods.  Also simplify, slightly,
some entry point names.

All MAC policy modules will need to be recompiled, and modules
not updates as part of this commit will need to be modified to
conform to the new KPI.

Sponsored by:	SPARTA (original patches against Mac OS X)
Obtained from:	TrustedBSD Project, Apple Computer
2007-10-24 19:04:04 +00:00
rwatson
4b7d057bea Mark wire data structures in netatalk as __packed so that they are
properly (un)padded on the arm platform.  With this change, FreeBSD/arm
boxes are able to route AppleTalk properly.

Submitted/tested by:	Nathan Whitehorn <nathanw at uchicago dot edu>
Tested on:		arm, i386, amd64
Approved by:		re (kensmith)
2007-06-28 12:54:58 +00:00
rwatson
47d37a80be Reduce network stack oddness: implement .pru_sockaddr and .pru_peeraddr
protocol entry points using functions named proto_getsockaddr and
proto_getpeeraddr rather than proto_setsockaddr and proto_setpeeraddr.
While it's true that sockaddrs are allocated and set, the net effect is
to retrieve (get) the socket address or peer address from a socket, not
set it, so align names to that intent.
2007-05-11 10:20:51 +00:00
rwatson
f191f06add Use privilege PRIV_NET_ADDIFADDR rather than suser() to authorize
adding a netatalk address to an interface.
2007-02-19 22:40:02 +00:00
rwatson
3f89da1440 Clean up DDP layer netatalk code:
- General style(9) cleanup -- white space, braces, line wraps, etc.

- Annotate a lack of synchronization the global route cache if the input
  routine is invoked with parallelism.

- Remove unused debugging code.
2007-01-12 15:07:51 +00:00
rwatson
751716e050 Cleanup of netatalk atalk layer includes, protocol definitions, and
routing:

- style(9) cleanup -- white space, braces, etc.

- Make include guards consistent with our more general naming
  convention.

- Rearrange and complete forward structure declarations in at_extern.h,
  remove testing of guards of various other include files to protect
  function declarations.

This leaves an ifdef _KERNEL in at_var.h, but from inspection it seems
likely that this file is not actually safe for inclusion in user space
still.  However, since it's not included from within src/ so this does
not appear to be an issue (ifconfig, etc, have migrated to the generic
cross-protocol ioctls for address operations).
2007-01-12 13:18:08 +00:00
rwatson
ccc086813d Re-style aarp with style(9): normal plethora of white space, brace,
etc, changes.

Remove a small amount of #if !defined(__FreeBSD__) code.

Add missing include guard for _NETATALK_AARP_H_.

Remove unneeded (and conflicting) extern prototype for aarptfree().
2007-01-12 12:25:12 +00:00
rwatson
c4c1a3359a Break out my copyrights with our 2-clause BSD license from the UMich
copyright, which while similar, is different.

MFC after:	3 days
2007-01-08 17:58:27 +00:00
rwatson
10d0d9cf47 Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges.  These may
require some future tweaking.

Sponsored by:           nCircle Network Security, Inc.
Obtained from:          TrustedBSD Project
Discussed on:           arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
                        Alex Lyashkov <umka at sevcity dot net>,
                        Skip Ford <skip dot ford at verizon dot net>,
                        Antoine Brodin <antoine dot brodin at laposte dot net>
2006-11-06 13:42:10 +00:00
rwatson
7beaaf5cd2 Complete break-out of sys/sys/mac.h into sys/security/mac/mac_framework.h
begun with a repo-copy of mac.h to mac_framework.h.  sys/mac.h now
contains the userspace and user<->kernel API and definitions, with all
in-kernel interfaces moved to mac_framework.h, which is now included
across most of the kernel instead.

This change is the first step in a larger cleanup and sweep of MAC
Framework interfaces in the kernel, and will not be MFC'd.

Obtained from:	TrustedBSD Project
Sponsored by:	SPARTA
2006-10-22 11:52:19 +00:00
rwatson
e3e9398c06 Since soisdisconnected() is no longer called in pru_detach(), call it
near consumers of at_pcbdisconnect() (_close, _abort).
2006-08-05 14:14:34 +00:00
rwatson
317b36ad9a Remove call to soisdisconnected() in at_pcbdetach(): by the time the
socket is being detached, there are no consumers left worth notifying
about the disconnect.
2006-08-02 16:22:34 +00:00
rwatson
720efebbba Change semantics of socket close and detach. Add a new protocol switch
function, pru_close, to notify protocols that the file descriptor or
other consumer of a socket is closing the socket.  pru_abort is now a
notification of close also, and no longer detaches.  pru_detach is no
longer used to notify of close, and will be called during socket
tear-down by sofree() when all references to a socket evaporate after
an earlier call to abort or close the socket.  This means detach is now
an unconditional teardown of a socket, whereas previously sockets could
persist after detach of the protocol retained a reference.

This faciliates sharing mutexes between layers of the network stack as
the mutex is required during the checking and removal of references at
the head of sofree().  With this change, pru_detach can now assume that
the mutex will no longer be required by the socket layer after
completion, whereas before this was not necessarily true.

Reviewed by:	gnn
2006-07-21 17:11:15 +00:00
rwatson
6389ae9dfe Update global copyright statement for netatalk, as I claim copyright
on changes in a number of files in netatalk.

MFC after:	1 week
2006-06-08 22:13:52 +00:00
rwatson
9fa0587a55 White space consistency with kasserts. Minor style tweaks.
MFC after:	3 months
2006-04-01 16:54:37 +00:00
rwatson
5479e5d692 Chance protocol switch method pru_detach() so that it returns void
rather than an error.  Detaches do not "fail", they other occur or
the protocol flags SS_PROTOREF to take ownership of the socket.

soclose() no longer looks at so_pcb to see if it's NULL, relying
entirely on the protocol to decide whether it's time to free the
socket or not using SS_PROTOREF.  so_pcb is now entirely owned and
managed by the protocol code.  Likewise, no longer test so_pcb in
other socket functions, such as soreceive(), which have no business
digging into protocol internals.

Protocol detach routines no longer try to free the socket on detach,
this is performed in the socket code if the protocol permits it.

In rts_detach(), no longer test for rp != NULL in detach, and
likewise in other protocols that don't permit a NULL so_pcb, reduce
the incidence of testing for it during detach.

netinet and netinet6 are not fully updated to this change, which
will be in an upcoming commit.  In their current state they may leak
memory or panic.

MFC after:	3 months
2006-04-01 15:42:02 +00:00
rwatson
8622e776f9 Change protocol switch pru_abort() API so that it returns void rather
than an int, as an error here is not meaningful.  Modify soabort() to
unconditionally free the socket on the return of pru_abort(), and
modify most protocols to no longer conditionally free the socket,
since the caller will do this.

This commit likely leaves parts of netinet and netinet6 in a situation
where they may panic or leak memory, as they have not are not fully
updated by this commit.  This will be corrected shortly in followup
commits to these components.

MFC after:      3 months
2006-04-01 15:15:05 +00:00
rwatson
d1671df339 In at_setsockaddr(), assert that ddp != NULL, rather than returning an
error if it's NULL, as so_pcb != NULL is now an invariant.
2006-03-25 18:54:17 +00:00
rwatson
76be92c1fd Modify netatalk to ensure, and assert, that pcb's remain attached to
sockets as long as the sockets have not been aborted or detached.  Do
not try to free the socket in pru_detach(), since sofree() will do so,
if needed, once pru_detach() returns.

Annotate a bug in ddp_abort(), which fails to free the socket; this
is probably OK as ddp_abort() should never be called, so should
instead be deleted.
2006-03-17 20:40:17 +00:00
ru
f70f525b49 - Store pointer to the link-level address right in "struct ifnet"
rather than in ifindex_table[]; all (except one) accesses are
  through ifp anyway.  IF_LLADDR() works faster, and all (except
  one) ifaddr_byindex() users were converted to use ifp->if_addr.

- Stop storing a (pointer to) Ethernet address in "struct arpcom",
  and drop the IFP2ENADDR() macro; all users have been converted
  to use IF_LLADDR() instead.
2005-11-11 16:04:59 +00:00
ru
ec16970679 Catch up with IFP2ENADDR() type change (array -> pointer). 2005-11-11 12:17:31 +00:00
ru
dcace5669d Use sparse initializers for "struct domain" and "struct protosw",
so they are easier to follow for the human being.
2005-11-09 13:29:16 +00:00
rodrigc
0ccfef16a3 Forward declare atalkdomain with static linkage, not extern, since
it is defined with static linkage later in the file.  Eliminates
GCC 4.0 error.
2005-09-11 16:04:56 +00:00
andre
b31f736426 Use the correct mbuf type for MGET(). 2005-08-30 16:28:46 +00:00
rwatson
5e71112509 Eliminate MAC entry point mac_create_mbuf_from_mbuf(), which is
redundant with respect to existing mbuf copy label routines.  Expose
a new mac_copy_mbuf() routine at the top end of the Framework and
use that; use the existing mpo_copy_mbuf_label() routine on the
bottom end.

Obtained from:	TrustedBSD Project
Sponsored by:	SPARTA, SPAWAR
Approved by:	re (scottl)
2005-07-05 23:39:51 +00:00
brooks
567ba9b00a 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
rwatson
b09090425a When generating a phase II ARP lookup from aarpwhohas(), use a
non-sleeping mbuf allocation.

MFC after:	1 week
2005-02-22 14:37:22 +00:00
rwatson
1a0fc144d0 In the ddp_output() path, which can be called in a variety of threading
and locking contexts, use a non-sleeping allocation for mbufs.

MFC after:	1 week
2005-02-22 14:22:09 +00:00
rwatson
d552b6fe48 Convert the aa_ifaddr timeout to a callout, and run the aarprobe callout
MPSAFE.  Acquire the aarptab_mtx to make sure that the callout and msleep
in the ioctl thread don't race.

MFC after:	1 week
2005-02-22 14:20:29 +00:00
rwatson
0724e80aff Run the netatalk netisrs without Giant.
MFC after:	1 week
2005-02-18 10:53:00 +00:00
imp
2ecef44547 /* -> /*- for license, minor formatting changes, insert COPYRIGHT into files 2005-01-07 02:35:34 +00:00
rwatson
c146b8722a If MALLOC() fails in at_pcballoc(), return ENOBUFS rather than
potentially panicking.

MFC after:	1 week
2005-01-03 00:16:07 +00:00
rwatson
7679ddf408 Correct a misspelling in a comment. 2004-12-05 13:28:52 +00:00
rwatson
c39858036f Acquire socket receive buffer mutex before appending and then waking up
a receive socket in DDP.  This reduces the number of mutex operations
required to deliver to a socket by two, and is the model used in other
protocols.
2004-12-05 13:27:30 +00:00
phk
027fce30f5 Initialize struct pr_userreqs in new/sparse style and fill in common
default elements in net_init_domain().

This makes it possible to grep these structures and see any bogosities.
2004-11-08 14:44:54 +00:00
rwatson
4b81ce6dd2 Push acquisition of the accept mutex out of sofree() into the caller
(sorele()/sotryfree()):

- This permits the caller to acquire the accept mutex before the socket
  mutex, avoiding sofree() having to drop the socket mutex and re-order,
  which could lead to races permitting more than one thread to enter
  sofree() after a socket is ready to be free'd.

- This also covers clearing of the so_pcb weak socket reference from
  the protocol to the socket, preventing races in clearing and
  evaluation of the reference such that sofree() might be called more
  than once on the same socket.

This appears to close a race I was able to easily trigger by repeatedly
opening and resetting TCP connections to a host, in which the
tcp_close() code called as a result of the RST raced with the close()
of the accepted socket in the user process resulting in simultaneous
attempts to de-allocate the same socket.  The new locking increases
the overhead for operations that may potentially free the socket, so we
will want to revise the synchronization strategy here as we normalize
the reference counting model for sockets.  The use of the accept mutex
in freeing of sockets that are not listen sockets is primarily
motivated by the potential need to remove the socket from the
incomplete connection queue on its parent (listen) socket, so cleaning
up the reference model here may allow us to substantially weaken the
synchronization requirements.

RELENG_5_3 candidate.

MFC after:	3 days
Reviewed by:	dwhite
Discussed with:	gnn, dwhite, green
Reported by:	Marc UBM Bocklet <ubm at u-boot-man dot de>
Reported by:	Vlad <marchenko at gmail dot com>
2004-10-18 22:19:43 +00:00
rwatson
199b1160c6 Inline umich license from COPYRIGHT to make it clear what license the
umich copyright is asserting.

Clarify that the copyright I'm asserting is the standard Berkeley
license.

Remove Giant assertions from AARP and DDP input routines.
2004-08-10 03:23:05 +00:00
rwatson
7127c711e8 Further function forward declaration white space tweaks. 2004-07-19 17:18:58 +00:00
rwatson
dc1ff7aa46 Re-style at_control.c to bring it closer to style(9), primarily with
regard to function prototypes and indentation.  The lack of indentation
in if clauses and case statements made this code extremely difficult
to read.
2004-07-19 17:15:51 +00:00
rwatson
9183ed533a Procotol control block locking for netatalk DDP. 2004-07-12 18:39:59 +00:00
rwatson
d0f3949724 Imperfect synchronization solution to imperfect code: use a static 256
byte buffer in the stack for temporary printf results rather than a
global buffer without synchronization.
2004-07-12 18:37:31 +00:00
rwatson
de62cbb6dd Remove 'Not used' comment: at_org_code is used, just not in netatalk/. 2004-07-12 18:35:30 +00:00