Commit Graph

1753 Commits

Author SHA1 Message Date
Sean Bruno
06b479a6a7 Refactor ip6_getpcbopt() for better locking and memory management
Created GET_PKTOPT_EXT_HDR() and GET_PKTOPT_SOCKADDR() macros to
handle safely fetching options from in6p_outputopts, including
properly dealing with in6p locking and preparing memory for
sooptcopyout().

Changed the function signature of ip6_getpcbopt() to allow the
function to acquire and release locks on in6p as needed.

Submitted by:	Jason Eggleston <jason@eggnet.com>
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D14619
2018-03-22 23:34:48 +00:00
Sean Bruno
2a499acf59 Simple locking fixes in ip_ctloutput, ip6_ctloutput, rip_ctloutput.
Submitted by:	Jason Eggleston <jason@eggnet.com>
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D14624
2018-03-22 22:29:32 +00:00
Sean Bruno
5cbeca4497 Handle locking and memory safety for IPV6_PATHMTU in ip6_ctloutput().
Submitted by:	Jason Eggleston <jason@eggnet.com>
Reviewed by:	ae
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D14622
2018-03-22 21:18:34 +00:00
Sean Bruno
37d4fc1e70 Improve write locking in ip6_ctloutput() with macros.
Submitted by:	Jason Eggleston <jason@eggnet.com>
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D14620
2018-03-22 20:21:05 +00:00
Jonathan T. Looney
7fb2986ff6 If the INP lock is uncontested, avoid taking a reference and jumping
through the lock-switching hoops.

A few of the INP lookup operations that lock INPs after the lookup do
so using this mechanism (to maintain lock ordering):

1. Lock lookup structure.
2. Find INP.
3. Acquire reference on INP.
4. Drop lock on lookup structure.
5. Acquire INP lock.
6. Drop reference on INP.

This change provides a slightly shorter path for cases where the INP
lock is uncontested:

1. Lock lookup structure.
2. Find INP.
3. Try to acquire the INP lock.
4. If successful, drop lock on lookup structure.

Of course, if the INP lock is contested, the functions will need to
revert to the previous way of switching locks safely.

This saves a few atomic operations when the INP lock is uncontested.

Discussed with:	gallatin, rrs, rwatson
MFC after:	2 weeks
Sponsored by:	Netflix, Inc.
Differential Revision:	https://reviews.freebsd.org/D12911
2018-03-21 15:54:46 +00:00
Alexander V. Chernikov
1435dcd94f Fix outgoing TCP/UDP packet drop on arp/ndp entry expiration.
Current arp/nd code relies on the feedback from the datapath indicating
 that the entry is still used. This mechanism is incorporated into the
 arpresolve()/nd6_resolve() routines. After the inpcb route cache
 introduction, the packet path for the locally-originated packets changed,
 passing cached lle pointer to the ether_output() directly. This resulted
 in the arp/ndp entry expire each time exactly after the configured max_age
 interval. During the small window between the ARP/NDP request and reply
 from the router, most of the packets got lost.

Fix this behaviour by plugging datapath notification code to the packet
 path used by route cache. Unify the notification code by using single
 inlined function with the per-AF callbacks.

Reported by:	sthaug at nethelp.no
Reviewed by:	ae
MFC after:	2 weeks
2018-03-17 17:05:48 +00:00
Eric van Gyzen
0bbfb20fe5 Update the MTU in affected routes when IPv6 RA changes the MTU
ip6_calcmtu() only looks at the interface MTU if neither the TCP hostcache
nor the route provides an MTU.  Update the routes so they do not provide
stale MTUs.

This fixes UNH IPv6 conformance test cases v6LC_4_1_08 and v6LC_4_1_09,
which use a RA to reduce the link MTU from 1500 to 1280.

Reported and tested by:	Farrell Woods <Farrell_Woods@Dell.com>
Reviewed by:	dab, melifaro
Discussed with:	ae
MFC after:	1 week
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D14257
2018-02-12 19:49:20 +00:00
Eric van Gyzen
43105e589a Fix ICMPv6 redirects
icmp6_redirect_input() validates that a redirect packet came from the
current gateway for the respective destination.  To do this, it compares
the source address, which has an embedded scope zone id, to the next-hop
address, which does not.  If the address is link-local, which should be
the case, the comparison fails and the redirect is ignored.

Insert the scope zone id into the next-hop address so the comparison
is accurate.

Unsurprisingly, this fixes 35 UNH IPv6 conformance test cases.

Submitted by:	Farrell Woods <Farrell_Woods@Dell.com> (initial revision)
Reviewed by:	ae melifaro dab
MFC after:	1 week
Relnotes:	yes
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D14254
2018-02-09 00:13:05 +00:00
Andrey V. Elsukov
68e0e5a673 Modify ip6_get_prevhdr() to be able use it safely.
Instead of returning pointer to the previous header, return its offset.
In frag6_input() use m_copyback() and determined offset to store next
header instead of accessing to it by pointer and assuming that the memory
is contiguous.

In rip6_input() use offset returned by ip6_get_prevhdr() instead of
calculating it from pointers arithmetic, because IP header can belong
to another mbuf in the chain.

Reported by:	Maxime Villard <max at m00nbsd dot net>
Reviewed by:	kp
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D14158
2018-02-05 09:22:07 +00:00
Andrey V. Elsukov
883cd89b05 Merge r1.120 from NetBSD:
Fix a pretty simple, yet pretty tragic typo: we should return IPPROTO_DONE,
  not IPPROTO_NONE. With IPPROTO_NONE we will keep parsing the header chain
  on an mbuf that was already freed.

Reported by:	Maxime Villard <max at m00nbsd dot net>
MFC after:	3 days
2018-02-02 07:39:34 +00:00
Eric van Gyzen
f8116f391a ND6: Set the correct state for new neighbor cache entries
Restore state 6.  Many of the UNH tests end up exercising this
state, where we have a new neighbor cache entry and a new link-layer
entry is being created for it.  The link-layer address is currently
unknown so the initial state of the "llentry" should remain initialized
to ND6_LLINFO_NOSTATE so that the ND code will send a solicitation.
Setting this to ND6_LLINFO_STALE implies that the link-level entry
is valid and can be used (but needs to be refreshed via the Neighbor
Unreachability state machine).

https://forums.freebsd.org/threads/64287/

Submitted by:	Farrell Woods <Farrell_Woods@Dell.com>
Reviewed by:	mjoras, dab, ae
MFC after:	1 week
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D14059
2018-01-29 16:12:26 +00:00
Andrey V. Elsukov
2164def67c Do not skip scope zone violation check, when mbuf has M_FASTFWD_OURS flag.
When mbuf has M_FASTFWD_OURS flag, this means that a destination address
is our local, but we still need to pass scope zone violation check,
because protocol level expects that IPv6 link-local addresses have
embedded scope zone indexes. This should fix the problem, when ipfw is
used to forward packets to local address and source address of a packet
is IPv6 LLA.

Reported by:	sbruno
MFC after:	3 weeks
2018-01-29 11:03:29 +00:00
Andrey V. Elsukov
efc284cb12 Assign IPv6 link-local address to loopback interfaces whith unit > 0.
When an interface has IFF_LOOPBACK flag in6_ifattach() tries to assing
IPv6 loopback address to this interface. It uses in6ifa_ifpwithaddr()
to check, that interface doesn't already have given address and then
uses in6_ifattach_loopback(). If in6_ifattach_loopback() fails, it just
exits and thus skips assignment of IPv6 LLA.
Fix this using in6ifa_ifwithaddr() function. If IPv6 loopback address is
already assigned in the system, do not call in6_ifattach_loopback().

PR:		138678
MFC after:	3 weeks
2018-01-29 10:33:55 +00:00
Navdeep Parhar
09b0b8c058 Do not generate illegal mbuf chains during IP fragment reassembly. Only
the first mbuf of the reassembled datagram should have a pkthdr.

This was discovered with cxgbe(4) + IPSEC + ping with payload more than
interface MTU.  cxgbe can generate !M_WRITEABLE mbufs and this results
in m_unshare being called on the reassembled datagram, and it complains:

panic: m_unshare: m0 0xfffff80020f82600, m 0xfffff8005d054100 has M_PKTHDR

PR:		224922
Reviewed by:	ae@
MFC after:	1 week
Sponsored by:	Chelsio Communications
Differential Revision:	https://reviews.freebsd.org/D14009
2018-01-24 05:09:21 +00:00
Alan Somers
81e04458b8 sys/netinet6: fix typos in comments. No functional change.
MFC after:	3 weeks
Sponsored by:	Spectra Logic Corp
2018-01-23 19:40:05 +00:00
Pedro F. Giffuni
ac2fffa4b7 Revert r327828, r327949, r327953, r328016-r328026, r328041:
Uses of mallocarray(9).

The use of mallocarray(9) has rocketed the required swap to build FreeBSD.
This is likely caused by the allocation size attributes which put extra pressure
on the compiler.

Given that most of these checks are superfluous we have to choose better
where to use mallocarray(9). We still have more uses of mallocarray(9) but
hopefully this is enough to bring swap usage to a reasonable level.

Reported by:	wosch
PR:		225197
2018-01-21 15:42:36 +00:00
Pedro F. Giffuni
443133416b net*: make some use of mallocarray(9).
Focus on code where we are doing multiplications within malloc(9). None of
these ire likely to overflow, however the change is still useful as some
static checkers can benefit from the allocation attributes we use for
mallocarray.

This initial sweep only covers malloc(9) calls with M_NOWAIT. No good
reason but I started doing the changes before r327796 and at that time it
was convenient to make sure the sorrounding code could handle NULL values.

X-Differential revision: https://reviews.freebsd.org/D13837
2018-01-15 21:21:51 +00:00
Pedro F. Giffuni
3760a9ac78 Fix some typos.
Obtained from:	OpenBSD (CVS v1.5)
2017-12-28 20:40:56 +00:00
Pedro F. Giffuni
a8e6714356 netinet6/ip6_id.c: niels kindly dropped clause 3/4 from the license.
This bring back r327293 from OpenBSD, with the important difference that
we are now getting it from their ip6_id.c file.

Obtained from:	OpenBSD (CVS v1.3)
2017-12-28 20:35:21 +00:00
Pedro F. Giffuni
b3c64c30fa Start syncing changes from OpenBSD's ip6_id.c instead of ip_id.c.
correct non-repetitive ID code, based on comments from niels provos.
- seed2 is necessary, but use it as "seed2 + x" not "seed2 ^ x".
- skipping number is not needed, so disable it for 16bit generator (makes
  the repetition period to 30000)

Obtained from:	OpenBSD (CVS rev. 1.2)
MFC after:	1 week
2017-12-28 20:26:51 +00:00
Pedro F. Giffuni
d82751000f Revert r327293
netinet6/ip6_id.c: niels kindly dropped clause 3/4 from the license.

I was looking at the wrong file. There is an important merge that must be
done before I can bring this change.
2017-12-28 20:10:10 +00:00
Pedro F. Giffuni
e9738d25c1 netinet6/ip6_id.c: niels kindly dropped clause 3/4 from the license.
This file is supposed to be based on the OpenBSD CVS v1.6 but checking
the OpenBSD repository the license had already dropped the 2&3 clasues by
then. Catch up with the licensing.

Obtained from:	OpenBSD (CVS 1.2)
2017-12-28 19:42:53 +00:00
Alexander Kabaev
151ba7933a Do pass removing some write-only variables from the kernel.
This reduces noise when kernel is compiled by newer GCC versions,
such as one used by external toolchain ports.

Reviewed by: kib, andrew(sys/arm and sys/arm64), emaste(partial), erj(partial)
Reviewed by: jhb (sys/dev/pci/* sys/kern/vfs_aio.c and sys/kern/kern_synch.c)
Differential Revision: https://reviews.freebsd.org/D10385
2017-12-25 04:48:39 +00:00
Alexander Kabaev
bf51c9665d Silence clang analyzer false positive.
clang does not know that two lookup calls will return the same
pointer, so it assumes correctly that using the old pointer
after dropping the reference to it is a bit risky.
2017-12-23 16:45:26 +00:00
Andrey V. Elsukov
a406128960 Follow the RFC6980 and silently ignore following IPv6 NDP messages
that had the IPv6 fragmentation header:
 o  Neighbor Solicitation
 o  Neighbor Advertisement
 o  Router Solicitation
 o  Router Advertisement
 o  Redirect

Introduce M_FRAGMENTED mbuf flag, and set it after IPv6 fragment reassembly
is completed. Then check the presence of this flag in correspondig ND6
handling routines.

PR:		224247
MFC after:	2 weeks
2017-12-15 12:37:32 +00:00
Michael Tuexen
9f0abda051 Retire SCTP_WITH_NO_CSUM option.
This option was used in the early days to allow performance measurements
extrapolating the use of SCTP checksum offloading. Since this feature
is now available, get rid of this option.
This also un-breaks the LINT kernel. Thanks to markj@ for making me
aware of the problem.
2017-12-07 22:19:08 +00:00
Pedro F. Giffuni
fe267a5590 sys: general adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.
2017-11-27 15:23:17 +00:00
Pedro F. Giffuni
51369649b0 sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00
Pedro F. Giffuni
df57947f08 spdx: initial adoption of licensing ID tags.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Initially, only tag files that use BSD 4-Clause "Original" license.

RelNotes:	yes
Differential Revision:	https://reviews.freebsd.org/D13133
2017-11-18 14:26:50 +00:00
Konstantin Belousov
06193f0be0 Use hardware timestamps to report packet timestamps for SO_TIMESTAMP
and other similar socket options.

Provide new control message SCM_TIME_INFO to supply information about
timestamp.  Currently it indicates that the timestamp was
hardware-assisted and high-precision, for software timestamps the
message is not returned.  Reserved fields are added to ABI to report
additional info about it, it is expected that raw hardware clock value
might be useful for some applications.

Reviewed by:	gallatin (previous version), hselasky
Sponsored by:	Mellanox Technologies
MFC after:	2 weeks
X-Differential revision:	https://reviews.freebsd.org/D12638
2017-11-07 09:46:26 +00:00
Michael Tuexen
28a6adde1d Allow the setting of the MTU for future paths using an SCTP socket option.
This functionality was missing.

MFC after:	1 week
2017-11-03 20:46:12 +00:00
Kristof Provost
a0bf3ee425 Evaluate packet size after the firewall had its chance in the ip6 fast path
Defer the packet size check until after the firewall has had a look at it. This
means that the firewall now has the opportunity to (re-)fragment an oversized
packet.
This mirrors what the slow path does.

Reviewed by:	ae
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D12779
2017-10-25 19:21:48 +00:00
Gleb Smirnoff
0e229f343f Hide struct socket and struct unpcb from the userland.
Violators may define _WANT_SOCKET and _WANT_UNPCB respectively and
are not guaranteed for stability of the structures.  The violators
list is the the usual one: libprocstat(3) and netstat(1) internally
and lsof in ports.

In struct xunpcb remove the inclusion of kernel structure and add
a bunch of spare fields.  The xsocket already has socket not included,
but add there spares as well.  Embed xsockbuf into xsocket.

Sort declarations in sys/socketvar.h to separate kernel only from
userland available ones.

PR:		221820 (exp-run)
2017-10-02 23:29:56 +00:00
Michael Tuexen
2e8bb5ddf4 Fix a locking issue found by Coverity scanning the usrsctp library.
MFC after:	3 days
2017-09-09 20:51:54 +00:00
Bjoern A. Zeeb
ae69ad884d After inpcb route caching was put back in place there is no need for
flowtable anymore (as flowtable was never considered to be useful in
the forwarding path).

Reviewed by:		np
Differential Revision:	https://reviews.freebsd.org/D11448
2017-07-27 13:03:36 +00:00
Michael Tuexen
5ba7f91f9d Use memset/memcpy instead of bzero/bcopy.
Just use one variant instead of both. Use the memset/memcpy
ones since they cause less problems in crossplatform deployment.

MFC after:	1 week
2017-07-19 14:28:58 +00:00
Jonathan T. Looney
8b07e00e99 Fix an unnecessary/incorrect check in the PKTOPT_EXTHDRCPY macro.
This macro allocates memory and, if malloc does not return NULL, copies
data into the new memory. However, it doesn't just check whether malloc
returns NULL. It also checks whether we called malloc with M_NOWAIT. That
is not necessary.

While it may be that malloc() will only return NULL when the M_NOWAIT flag
is set, we don't need to check for this when checking malloc's return
value. Further, in this case, the check was not completely accurate,
because it checked for flags == M_NOWAIT, rather than treating it as a bit
field and checking for (flags & M_NOWAIT).

Reviewed by:	ae
MFC after:	2 weeks
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D10942
2017-05-30 14:50:28 +00:00
Jonathan T. Looney
fb04394554 Fix two places in the ICMP6 code where we could dereference a NULL pointer
in the icmp6_input() function.

When processing an ICMP6_ECHO_REQUEST, if IP6_EXTHDR_GET fails, it will
set nicmp6 and n to NULL. Therefore, we should condition our modification
to nicmp6 on n being not NULL.

And, when processing an ICMP6_WRUREQUEST in the (mode != FQDN) case, if
m_dup_pkthdr() fails, the code will set n to NULL. However, the very next
line dereferences n. Therefore, when m_dup_pkthdr() fails, we should
discontinue further processing and follow the same path as when m_gethdr()
fails.

Reported by:	clang static analyzer
Reviewed by:	ae
MFC after:	2 weeks
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D10941
2017-05-30 14:41:31 +00:00
Jonathan T. Looney
382a6bbcf1 Enforce the limit on ICMP messages before doing work to formulate the
response.

Delete an unneeded rate limit for UDP under IPv6. Because ICMP6
messages have their own rate limit, it is unnecessary to apply a
second rate limit to UDP messages.

Reviewed by:	glebius
MFC after:	2 weeks
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D10387
2017-05-30 14:32:44 +00:00
Michael Tuexen
5dba6ada91 The connect() system call should return -1 and set errno to EAFNOSUPPORT
if it is called on a TCP socket
 * with an IPv6 address and the socket is bound to an
    IPv4-mapped IPv6 address.
 * with an IPv4-mapped IPv6 address and the socket is bound to an
   IPv6 address.
Thanks to Jonathan T. Leighton for reporting this issue.

Reviewed by:		bz gnn
MFC after:		3 days
Differential Revision:	https://reviews.freebsd.org/D9163
2017-05-22 15:29:10 +00:00
Ed Maste
3e85b721d6 Remove register keyword from sys/ and ANSIfy prototypes
A long long time ago the register keyword told the compiler to store
the corresponding variable in a CPU register, but it is not relevant
for any compiler used in the FreeBSD world today.

ANSIfy related prototypes while here.

Reviewed by:	cem, jhb
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D10193
2017-05-17 00:34:34 +00:00
Enji Cooper
bd7459366e Add missing braces around MCAST_EXCLUDE check when KTR support is
compiled into the kernel

This ensures that .iss_asm (the number of ASM listeners) isn't incorrectly
decremented for MLD-layer source datagrams when inspecting im*s_st[1]
(the second state in the structure).

MFC after:	2 months
PR:		217509 [1]
Reported by:	Coverity (Isilon)
Reviewed by:	ae ("This patch looks correct to me." [1])
Submitted by:	Miles Ohlrich <miles.ohlrich@isilon.com>
Sponsored by:	Dell EMC Isilon
2017-05-13 18:41:24 +00:00
Navdeep Parhar
ce9ac139d4 ip6_output runs with the inp lock held, just like ip_output. 2017-05-10 00:14:55 +00:00
Michael Tuexen
d274bcc661 Fix an issue with MTU calculation if an ICMP messaeg is received
for an SCTP/UDP packet.

MFC after:	1 week
2017-04-26 20:21:05 +00:00
Michael Tuexen
6ebfa5ee14 Use consistently uint32_t for mtu values.
This does not change functionality, but this cleanup is need for further
improvements of ICMP handling.

MFC after:	1 week
2017-04-26 19:26:40 +00:00
Kristof Provost
d78c0804fb Rename variable for clarity
Rename the mtu variable in ip6_fragment(), because mtu is misleading. The
variable actually holds the fragment length.
No functional change.

Suggested by: ae
2017-04-22 13:04:36 +00:00
Kristof Provost
00eab743ab pf: Fix possible incorrect IPv6 fragmentation
When forwarding pf tracks the size of the largest fragment in a fragmented
packet, and refragments based on this size.
It failed to ensure that this size was a multiple of 8 (as is required for all
but the last fragment), so it could end up generating incorrect fragments.

For example, if we received an 8 byte and 12 byte fragment pf would emit a first
fragment with 12 bytes of payload and the final fragment would claim to be at
offset 8 (not 12).

We now assert that the fragment size is a multiple of 8 in ip6_fragment(), so
other users won't make the same mistake.

Reported by:	Antonios Atlasis <aatlasis at secfu net>
MFC after:	3 days
2017-04-20 09:05:53 +00:00
Andrey V. Elsukov
c33a231337 Rework r316770 to make it protocol independent and general, like we
do for streaming sockets.

And do more cleanup in the sbappendaddr_locked_internal() to prevent
leak information from existing mbuf to the one, that will be possible
created later by netgraph.

Suggested by:	glebius
Tested by:	Irina Liakh <spell at itl ua>
MFC after:	1 week
2017-04-14 09:00:48 +00:00
Andrey V. Elsukov
8428914909 Clear h/w csum flags on mbuf handled by UDP.
When checksums of received IP and UDP header already checked, UDP uses
sbappendaddr_locked() to pass received data to the socket.
sbappendaddr_locked() uses given mbuf as is, and if NIC supports checksum
offloading, mbuf contains csum_data and csum_flags that were calculated
for already stripped headers. Some NICs support only limited checksums
offloading and do not use CSUM_PSEUDO_HDR flag, and csum_data contains
some value that UDP/TCP should use for pseudo header checksum calculation.

When L2TP is used for tunneling with mpd5, ng_ksocket receives mbuf with
filled csum_flags and csum_data, that were calculated for outer headers.
When L2TP header is stripped, a packet that was tunneled goes to the IP
layer and due to presence of csum_flags (without CSUM_PSEUDO_HDR) and
csum_data, the UDP/TCP checksum check fails for this packet.

Reported by:	Irina Liakh <spell at itl ua>
Tested by:	Irina Liakh <spell at itl ua>
MFC after:	1 week
2017-04-13 17:03:57 +00:00
Steven Hartland
4d806fc663 Allow explicitly assigned IPv6 loopback address to be used in jails
If a jail has an explicitly assigned IPv6 loopback address then allow it
to be used instead of remapping requests for the loopback adddress to the
first IPv6 address assigned to the jail.

This fixes issues where applications attempt to detect their bound port
where they requested a loopback address, which was available, but instead
the kernel remapped it to the jails first address.

This is the same fix applied to IPv4 fix by: r316313

Also:
* Correct the description of prison_check_ip6_locked to match the code.

MFC after:	2 weeks
Relnotes:	Yes
Sponsored by:	Multiplay
2017-03-31 09:10:05 +00:00