In the original design of the network stack from the protocol control
input method pr_ctlinput was used notify the protocols about two very
different kinds of events: internal system events and receival of an
ICMP messages from outside. These events were coded with PRC_ codes.
Today these methods are removed from the protosw(9) and are isolated
to IPv4 and IPv6 stacks and are called only from icmp*_input(). The
PRC_ codes now just create a shim layer between ICMP codes and errors
or actions taken by protocols.
- Change ipproto_ctlinput_t to pass just pointer to ICMP header. This
allows protocols to not deduct it from the internal IP header.
- Change ip6proto_ctlinput_t to pass just struct ip6ctlparam pointer.
It has all the information needed to the protocols. In the structure,
change ip6c_finaldst fields to sockaddr_in6. The reason is that
icmp6_input() already has this address wrapped in sockaddr, and the
protocols want this address as sockaddr.
- For UDP tunneling control input, as well as for IPSEC control input,
change the prototypes to accept a transparent union of either ICMP
header pointer or struct ip6ctlparam pointer.
- In icmp_input() and icmp6_input() do only validation of ICMP header and
count bad packets. The translation of ICMP codes to errors/actions is
done by protocols.
- Provide icmp_errmap() and icmp6_errmap() as substitute to inetctlerrmap,
inet6ctlerrmap arrays.
- In protocol ctlinput methods either trust what icmp_errmap() recommend,
or do our own logic based on the ICMP header.
Differential revision: https://reviews.freebsd.org/D36731
Now these functions are called only from icmp*_input(). The pointer
to the ICMP data is never NULL and cmd has a limited set of values.
In the past the functions were demultiplexing control messages from
ICMP layer, as well as internally generated events. In the latter
case the the pointer to IP would be NULL.
Differential revision: https://reviews.freebsd.org/D36729
After decoupling of protosw(9) and IP wire protocols in 78b1fc05b205 for
IPv4 we got vector ip_ctlprotox[] that is executed only and only from
icmp_input() and respectively for IPv6 we got ip6_ctlprotox[] executed
only and only from icmp6_input(). This allows to use protocol specific
argument types in these methods instead of struct sockaddr and void.
Reviewed by: melifaro
Differential revision: https://reviews.freebsd.org/D36727
o Assert that every protosw has pr_attach. Now this structure is
only for socket protocols declarations and nothing else.
o Merge struct pr_usrreqs into struct protosw. This was suggested
in 1996 by wollman@ (see 7b187005d18ef), and later reiterated
in 2006 by rwatson@ (see 6fbb9cf860dcd).
o Make struct domain hold a variable sized array of protosw pointers.
For most protocols these pointers are initialized statically.
Those domains that may have loadable protocols have spacers. IPv4
and IPv6 have 8 spacers each (andre@ dff3237ee54ea).
o For inetsw and inet6sw leave a comment noting that many protosw
entries very likely are dead code.
o Refactor pf_proto_[un]register() into protosw_[un]register().
o Isolate pr_*_notsupp() methods into uipc_domain.c
Reviewed by: melifaro
Differential revision: https://reviews.freebsd.org/D36232
The historical BSD network stack loop that rolls over domains and
over protocols has no advantages over more modern SYSINIT(9).
While doing the sweep, split global and per-VNET initializers.
Getting rid of pr_init allows to achieve several things:
o Get rid of ifdef's that protect against double foo_init() when
both INET and INET6 are compiled in.
o Isolate initializers statically to the module they init.
o Makes code easier to understand and maintain.
Reviewed by: melifaro
Differential revision: https://reviews.freebsd.org/D33537
Allow the resending of DATA chunks to be controlled by the caller,
which allows retiring sctp_mtu_size_reset() in a separate commit.
Also improve the computaion of the overhead and use 32-bit integers
consistently.
Thanks to Timo Voelker for pointing me to the code.
MFC after: 3 days
This patch makes the handling of the SCTP_MAXSEG socket option
compliant with RFC 6458 (SCTP socket API) and fixes an issue
found by syzkaller.
Reported by: syzbot+a2791b89ab99121e3333@syzkaller.appspotmail.com
MFC after: 3 days
For socket options related to local and remote addresses providing
generic association ids does not make sense. Report EINVAL in this
case.
MFC after: 1 week
Callers are getting the stcb send lock, so just KASSERT that.
No need to signal this when calling stream scheduler functions.
No functional change intended.
MFC after: 1 week
All callers of sctp_aloc_assoc() mark the PCB as connected after a
successful call (for one-to-one-style sockets). In all cases this is
done without the PCB lock, so the PCB's flags can be corrupted. We also
do not atomically check whether a one-to-one-style socket is a listening
socket, which violates various assumptions in solisten_proto().
We need to hold the PCB lock across all of sctp_aloc_assoc() to fix
this. In order to do that without introducing lock order reversals, we
have to hold the global info lock as well.
So:
- Convert sctp_aloc_assoc() so that the inp and info locks are
consistently held. It returns with the association lock held, as
before.
- Fix an apparent bug where we failed to remove an association from a
global hash if sctp_add_remote_addr() fails.
- sctp_select_a_tag() is called when initializing an association, and it
acquires the global info lock. To avoid lock recursion, push locking
into its callers.
- Introduce sctp_aloc_assoc_connected(), which atomically checks for a
listening socket and sets SCTP_PCB_FLAGS_CONNECTED.
There is still one edge case in sctp_process_cookie_new() where we do
not update PCB/socket state correctly.
Reviewed by: tuexen
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31908
When port reuse is enabled in a one-to-one-style socket, sctp_listen()
may call sctp_swap_inpcb_for_listen() to move the PCB out of the "TCP
pool". In so doing it will drop the PCB lock, yielding an LOR since we
now hold several socket locks. Reorder sctp_listen() so that it
performs this operation before beginning the conversion to a listening
socket. Also modify sctp_swap_inpcb_for_listen() to return with PCB
write-locked, since that's what sctp_listen() expects now.
Reviewed by: tuexen
Fixes: bd4a39cc93d9 ("socket: Properly interlock when transitioning to a listening socket")
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31879
... when applied to one-to-one-style sockets. sctp_listen() cannot be
used to toggle the listening state of such a socket. See RFC 6458's
description of expected listen(2) semantics for one-to-one- and
one-to-many-style sockets.
Reviewed by: tuexen
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31774
Currently, most protocols implement pru_listen with something like the
following:
SOCK_LOCK(so);
error = solisten_proto_check(so);
if (error) {
SOCK_UNLOCK(so);
return (error);
}
solisten_proto(so);
SOCK_UNLOCK(so);
solisten_proto_check() fails if the socket is connected or connecting.
However, the socket lock is not used during I/O, so this pattern is
racy.
The change modifies solisten_proto_check() to additionally acquire
socket buffer locks, and the calling thread holds them until
solisten_proto() or solisten_proto_abort() is called. Now that the
socket buffer locks are preserved across a listen(2), this change allows
socket I/O paths to properly interlock with listen(2).
This fixes a large number of syzbot reports, only one is listed below
and the rest will be dup'ed to it.
Reported by: syzbot+9fece8a63c0e27273821@syzkaller.appspotmail.com
Reviewed by: tuexen, gallatin
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31659
sctp_close() and sctp_abort() disassociate the PCB from its socket.
As a part of this, they attempt to free the PCB, which may end up
lingering. Fix some bugs in this area:
- For some reason, sctp_close() and sctp_abort() set
SCTP_PCB_FLAGS_SOCKET_GONE using an atomic compare-and-set without the
PCB lock held. This is racy since sctp_flags is normally updated
without atomics, using the PCB lock to synchronize. So, the update
can be lost, which can cause all sort of races with other SCTP
components which look for the _GONE flag. Fix the problem simply by
acquiring the PCB lock in order to set the flag. Note that we have to
drop and re-acquire the lock again in sctp_inpcb_free(), but I don't
see a good way around that for now. If it's a real problem, the _GONE
flag could be split out of sctp_flags and into a dedicated sctp_inpcb
field.
- In sctp_inpcb_free(), load sctp_socket after acquiring the PCB lock,
to avoid possible races with parallel sctp_inpcb_free() calls.
- Add an assertion sctp_inpcb_free() to verify that _ALLGONE is not set.
Reviewed by: tuexen
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31811
Several protocol methods take a sockaddr as input. In some cases the
sockaddr lengths were not being validated, or were validated after some
out-of-bounds accesses could occur. Add requisite checking to various
protocol entry points, and convert some existing checks to assertions
where appropriate.
Reported by: syzkaller+KASAN
Reviewed by: tuexen, melifaro
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D29519
The staleness reported in an error cause is in us, not ms.
Enforce limits on the life time via sysct; and socket options
consistently. Update the description of the sysctl variable to
use the right unit. Also do some minor cleanups.
This also fixes an interger overflow issue if the peer can
modify the cookie. This was reported by Felix Weinrank by fuzz testing
the userland stack and in
https://oss-fuzz.com/testcase-detail/4800394024452096
MFC after: 3 days
With this change, a kernel compiled with "options SCTP_SUPPORT" and
without "options SCTP" supports dynamic loading of the SCTP stack.
Currently sctp.ko cannot be unloaded since some prerequisite teardown
logic is not yet implemented. Attempts to unload the module will return
EOPNOTSUPP.
Discussed with: tuexen
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21997
is used by the IPPROTO_SCTP level socket options SCTP_GET_PEER_ADDRESSES
and SCTP_GET_LOCAL_ADDRESSES, which are used by libc to implement
sctp_getladdrs() and sctp_getpaddrs().
These changes allow an old libc to work on a newer kernel.
for the IPPROTO_SCTP level socket options SCTP_BINDX_ADD_ADDR and
SCTP_BINDX_REM_ADDR. These socket option are intended for internal
use only to implement sctp_bindx().
This is one user of struct sctp_getaddresses less.
struct sctp_getaddresses is strange and will be changed shortly.
