X_ip_mrouter_done might sleep, which triggers INVARIANTS to
print additional errors on the screen.
Move it outside the lock, but provide some basic synchronization
to avoid race condition during module uninit/unload.
Obtained from: Semihalf
Sponsored by: Stormshield
mrouter_done is called with RAW IP lock taken. Some annoying
printfs are visible on the console if INVARIANTS option is enabled.
Provide atomic-based mechanism which counts enters and exits from/to
critical section in ip_input and ip_output.
Before de-initialization of function pointers ensure (with busy-wait)
that mrouter de-initialization is visible to all readers and that we don't
remove pointers (like ip_mforward etc.) in the middle of packet processing.
Provide structure inpcbstorage, that holds zones and lock names for
a protocol. Initialize it with global protocol init using macro
INPCBSTORAGE_DEFINE(). Then, at VNET protocol init supply it as
the main argument to the in_pcbinfo_init(). Each VNET pcbinfo uses
its private hash, but they all use same zone to allocate and SMR
section to synchronize.
Note: there is kern.ipc.maxsockets sysctl, which controls UMA limit
on the socket zone, which was always global. Historically same
maxsockets value is applied also to every PCB zone. Important fact:
you can't create a pcb without a socket! A pcb may outlive its socket,
however. Given that there are multiple protocols, and only one socket
zone, the per pcb zone limits seem to have little value. Under very
special conditions it may trigger a little bit earlier than socket zone
limit, but in most setups the socket zone limit will be triggered
earlier. When VIMAGE was added to the kernel PCB zones became per-VNET.
This magnified existing disbalance further: now we have multiple pcb
zones in multiple vnets limited to maxsockets, but every pcb requires a
socket allocated from the global zone also limited by maxsockets.
IMHO, this per pcb zone limit doesn't bring any value, so this patch
drops it. If anybody explains value of this limit, it can be restored
very easy - just 2 lines change to in_pcbstorage_init().
Differential revision: https://reviews.freebsd.org/D33542
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
This reverts commit 266f97b5e9, reversing
changes made to a10253cffe.
A mismerge of a merge to catch up to main resulted in files being
committed which should not have been.
With introduction of epoch(9) synchronization to network stack the
inpcb database became protected by the network epoch together with
static network data (interfaces, addresses, etc). However, inpcb
aren't static in nature, they are created and destroyed all the
time, which creates some traffic on the epoch(9) garbage collector.
Fairly new feature of uma(9) - Safe Memory Reclamation allows to
safely free memory in page-sized batches, with virtually zero
overhead compared to uma_zfree(). However, unlike epoch(9), it
puts stricter requirement on the access to the protected memory,
needing the critical(9) section to access it. Details:
- The database is already build on CK lists, thanks to epoch(9).
- For write access nothing is changed.
- For a lookup in the database SMR section is now required.
Once the desired inpcb is found we need to transition from SMR
section to r/w lock on the inpcb itself, with a check that inpcb
isn't yet freed. This requires some compexity, since SMR section
itself is a critical(9) section. The complexity is hidden from
KPI users in inp_smr_lock().
- For a inpcb list traversal (a pcblist sysctl, or broadcast
notification) also a new KPI is provided, that hides internals of
the database - inp_next(struct inp_iterator *).
Reviewed by: rrs
Differential revision: https://reviews.freebsd.org/D33022
An IPv4 address is embedded into an ifaddr which is freed
via epoch. And the in_ifaddrhead is already a CK list. Use
the network epoch to protect against use after free.
Next step would be to CK-ify the in_addr hash and get rid of the...
Reviewed by: melifaro
Differential Revision: https://reviews.freebsd.org/D32434
SO_RERROR indicates that receive buffer overflows should be handled as
errors. Historically receive buffer overflows have been ignored and
programs could not tell if they missed messages or messages had been
truncated because of overflows. Since programs historically do not
expect to get receive overflow errors, this behavior is not the
default.
This is really really important for programs that use route(4) to keep
in sync with the system. If we loose a message then we need to reload
the full system state, otherwise the behaviour from that point is
undefined and can lead to chasing bogus bug reports.
Reviewed by: philip (network), kbowling (transport), gbe (manpages)
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D26652
If the socket is configured such that the sender is expected to supply
the IP header, then we need to verify that it actually did so.
Reported by: syzkaller+KMSAN
Reviewed by: donner
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D31302
The various protocol implementations are not very consistent about
freeing mbufs in error paths. In general, all protocols must free both
"m" and "control" upon an error, except if PRUS_NOTREADY is specified
(this is only implemented by TCP and unix(4) and requires further work
not handled in this diff), in which case "control" still must be freed.
This diff plugs various leaks in the pru_send implementations.
Reviewed by: tuexen
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D30151
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
Historically receive buffer overflows have been ignored and programs
could not tell if they missed messages or messages had been truncated
because of overflows. Since programs historically do not expect to get
receive overflow errors, this behavior is not the default.
This is really really important for programs that use route(4) to keep in sync
with the system. If we loose a message then we need to reload the full system
state, otherwise the behaviour from that point is undefined and can lead
to chasing bogus bug reports.
rtinit[1]() is a function used to add or remove interface address prefix routes,
similar to ifa_maintain_loopback_route().
It was intended to be family-agnostic. There is a problem with this approach
in reality.
1) IPv6 code does not use it for the ifa routes. There is a separate layer,
nd6_prelist_(), providing interface for maintaining interface routes. Its part,
responsible for the actual route table interaction, mimics rtenty() code.
2) rtinit tries to combine multiple actions in the same function: constructing
proper route attributes and handling iterations over multiple fibs, for the
non-zero net.add_addr_allfibs use case. It notably increases the code complexity.
3) dstaddr handling. flags parameter re-uses RTF_ flags. As there is no special flag
for p2p connections, host routes and p2p routes are handled in the same way.
Additionally, mapping IFA flags to RTF flags makes the interface pretty messy.
It make rtinit() to clash with ifa_mainain_loopback_route() for IPV4 interface
aliases.
4) rtinit() is the last customer passing non-masked prefixes to rib_action(),
complicating rib_action() implementation.
5) rtinit() coupled ifa announce/withdrawal notifications, producing "false positive"
ifa messages in certain corner cases.
To address all these points, the following has been done:
* rtinit() has been split into multiple functions:
- Route attribute construction were moved to the per-address-family functions,
dealing with (2), (3) and (4).
- funnction providing net.add_addr_allfibs handling and route rtsock notificaions
is the new routing table inteface.
- rtsock ifa notificaion has been moved out as well. resulting set of funcion are only
responsible for the actual route notifications.
Side effects:
* /32 alias does not result in interface routes (/32 route and "host" route)
* RTF_PINNED is now set for IPv6 prefixes corresponding to the interface addresses
Differential revision: https://reviews.freebsd.org/D28186
connections over multiple paths.
Multipath routing relies on mbuf flowid data for both transit
and outbound traffic. Current code fills mbuf flowid from inp_flowid
for connection-oriented sockets. However, inp_flowid is currently
not calculated for outbound connections.
This change creates simple hashing functions and starts calculating hashes
for TCP,UDP/UDP-Lite and raw IP if multipath routes are present in the
system.
Reviewed by: glebius (previous version),ae
Differential Revision: https://reviews.freebsd.org/D26523
r357614 added CTLFLAG_NEEDGIANT to make it easier to find nodes that are
still not MPSAFE (or already are but aren’t properly marked).
Use it in preparation for a general review of all nodes.
This is non-functional change that adds annotations to SYSCTL_NODE and
SYSCTL_PROC nodes using one of the soon-to-be-required flags.
Mark all obvious cases as MPSAFE. All entries that haven't been marked
as MPSAFE before are by default marked as NEEDGIANT
Approved by: kib (mentor, blanket)
Commented by: kib, gallatin, melifaro
Differential Revision: https://reviews.freebsd.org/D23718
with this widen network epoch coverage up to tcp_connect() and udp_connect().
Revisions from r356974 and up to this revision cover D23187.
Differential Revision: https://reviews.freebsd.org/D23187
handlers can be greatly simplified. All the previous double
cycling and complex locking was added to avoid these functions
holding global PCB locks for extended period of time, preventing
addition of new entries.
ensure that the ip_hl field is valid. Furthermore, ensure that the complete
IPv4 header is contained in the first mbuf. Finally, move the length checks
before relying on them when accessing fields of the IPv4 header.
Reported by: jtl@
Reviewed by: jtl@
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D19181
option.
This issue was found by running syzkaller on OpenBSD.
Greg Steuck made me aware that the problem might also exist on FreeBSD.
Reported by: Greg Steuck
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D18834
Various network protocol sysctl handlers were not zero-filling their
output buffers and thus would export uninitialized stack memory to
userland. Fix a number of such handlers.
Reported by: Thomas Barabosch, Fraunhofer FKIE
Reviewed by: tuexen
MFC after: 3 days
Security: kernel memory disclosure
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18301
- Add tracker argument to preemptible epochs
- Inline epoch read path in kernel and tied modules
- Change in_epoch to take an epoch as argument
- Simplify tfb_tcp_do_segment to not take a ti_locked argument,
there's no longer any benefit to dropping the pcbinfo lock
and trying to do so just adds an error prone branchfest to
these functions
- Remove cases of same function recursion on the epoch as
recursing is no longer free.
- Remove the the TAILQ_ENTRY and epoch_section from struct
thread as the tracker field is now stack or heap allocated
as appropriate.
Tested by: pho and Limelight Networks
Reviewed by: kbowling at llnw dot com
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D16066
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.
function (they used to say UMA_ZONE_NOFREE), so flag parameter goes away.
The zone_fini parameter also goes away. Previously no protocols (except
divert) supplied zone_fini function, so inpcb locks were leaked with slabs.
This was okay while zones were allocated with UMA_ZONE_NOFREE flag, but now
this is a leak. Fix that by suppling inpcb_fini() function as fini method
for all inpcb zones.
This is a painful change, but it is needed. On the one hand, we avoid
modifying them, and this slows down some ideas, on the other hand we still
eventually modify them and tools like netstat(1) never work on next version of
FreeBSD. We maintain a ton of spares in them, and we already got some ifdef
hell at the end of tcpcb.
Details:
- Hide struct inpcb, struct tcpcb under _KERNEL || _WANT_FOO.
- Make struct xinpcb, struct xtcpcb pure API structures, not including
kernel structures inpcb and tcpcb inside. Export into these structures
the fields from inpcb and tcpcb that are known to be used, and put there
a ton of spare space.
- Make kernel and userland utilities compilable after these changes.
- Bump __FreeBSD_version.
Reviewed by: rrs, gnn
Differential Revision: D10018
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.
Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96
