This simplifies the code and allows to further split rtentry and nexthop,
removing one of the blockers for multipath code introduction, described in
D24141.
Reviewed by: ae
Differential Revision: https://reviews.freebsd.org/D25192
Currently the only reason of refcounting rtentries is the need to report
the rtable operation details immediately after the execution.
Delaying rtentry reclamation allows to stop refcounting and simplify the code.
Additionally, this change allows to reimplement rib_lookup_info(), which
is used by some of the customers to get the matching prefix along
with nexthops, in more efficient way.
The change keeps per-vnet rtzone uma zone. It adds nh_vnet field to
nhop_priv to be able to reliably set curvnet even during vnet teardown.
Rest of the reference counting code will be removed in the D24867 .
Differential Revision: https://reviews.freebsd.org/D24866
Currently each rtentry has dst&gateway allocated separately from another zone,
bloating cache accesses.
Current 'struct rtentry' has 12 "mandatory" radix pointers in the beginning,
leaving 4 usable pointers/32 bytes in the first 2 cache lines (amd64).
Fields needed for the datapath are destination sockaddr and rt_nhop.
So far it doesn't look like there is other routable addressing protocol other
than IPv4/IPv6/MPLS, which uses keys longer than 20 bytes.
With that in mind, embed dst into struct rtentry, making the first 24 bytes
of rtentry within 128 bytes. That is enough to make IPv6 address within first
128 bytes.
It is still pretty easy to add code for supporting separately-allocated dst,
however it doesn't make a lot of sense in having such code without a use case.
As rS359823 moved the gateway to the nexthop structure, the dst embedding change
removes the need for any additional allocations done by rt_setgate().
Lastly, as a part of cleanup, remove counter(9) allocation code, as this field
is not used in packet processing anymore.
Reviewed by: ae
Differential Revision: https://reviews.freebsd.org/D24669
Continue routing subsystem conversion to nhop objects defined in r359823.
Use fields from nhop structure instead of "struct rtentry" fields.
This is one of the last changes prior to removing rt_ifp, rt_ifa,
rt_gateway and rt_mtu from struct rtentry.
Differential Revision: https://reviews.freebsd.org/D24609
Currently functionality resides in rtsock.c, which is a controlling
interface, partially external to the routing subsystem.
Additionally, DDB-supporting functionality is > 100SLOC, which deserves
a separate file.
Given that, move this functionality to a newly-created net/route/ subdir.
Reviewed by: cem
Differential Revision: https://reviews.freebsd.org/D24561
Nexthop objects implementation, defined in r359823,
introduced sys/net/route directory intended to hold all
routing-related code. Move recently-introduced route_temporal.c and
private route_var.h header there.
Differential Revision: https://reviews.freebsd.org/D24597
One of the goals of the new routing KPI defined in r359823 is to entirely
hide`struct rtentry` from the consumers. It will allow to improve routing
subsystem internals and deliver more features much faster.
This commit is mostly mechanical change to eliminate direct struct rtentry
field accesses.
The only notable difference is AF_LINK gateway encoding.
AF_LINK gw is used in routing stack for operations with interface routes
and host loopback routes.
In the former case it indicates _some_ non-NULL gateway, as the interface
is the same as in rt_ifp in kernel and rtm_ifindex in rtsock reporting.
In the latter case the interface index inside gateway was used by the IPv6
datapath to verify address scope for link-local interfaces.
Kernel uses struct sockaddr_dl for this type of gateway. This structure
allows for specifying rich interface data, such as mac address and interface
name. However, this results in relatively large structure size - 52 bytes.
Routing stack fils in only 2 fields - sdl_index and sdl_type, which reside
in the first 8 bytes of the structure.
In the new KPI, struct nhop_object tries to be cache-efficient, hence
embodies gateway address inside the structure. In the AF_LINK case it
stores stortened version of the structure - struct sockaddr_dl_short,
which occupies 16 bytes. After D24340 changes, the data inside AF_LINK
gateway will not be used in the kernel at all, leaving rtsock as the only
potential concern.
The difference in rtsock reporting:
(old)
got message of size 240 on Thu Apr 16 03:12:13 2020
RTM_ADD: Add Route: len 240, pid: 0, seq 0, errno 0, flags:<UP,DONE,PINNED>
locks: inits:
sockaddrs: <DST,GATEWAY,NETMASK>
10.0.0.0 link#5 255.255.255.0
(new)
got message of size 200 on Sun Apr 19 09:46:32 2020
RTM_ADD: Add Route: len 200, pid: 0, seq 0, errno 0, flags:<UP,DONE,PINNED>
locks: inits:
sockaddrs: <DST,GATEWAY,NETMASK>
10.0.0.0 link#5 255.255.255.0
Note 40 bytes different (52-16 + alignment).
However, gateway is still a valid AF_LINK gateway with proper data filled in.
It is worth noting that these particular messages (interface routes) are mostly
ignored by routing daemons:
* bird/quagga/frr uses RTM_NEWADDR and ignores prefix route addition messages.
* quagga/frr ignores routes without gateway
More detailed overview on how rtsock messages are used by the
routing daemons to reconstruct the kernel view, can be found in D22974.
Differential Revision: https://reviews.freebsd.org/D24519
This is the foundational change for the routing subsytem rearchitecture.
More details and goals are available in https://reviews.freebsd.org/D24141 .
This patch introduces concept of nexthop objects and new nexthop-based
routing KPI.
Nexthops are objects, containing all necessary information for performing
the packet output decision. Output interface, mtu, flags, gw address goes
there. For most of the cases, these objects will serve the same role as
the struct rtentry is currently serving.
Typically there will be low tens of such objects for the router even with
multiple BGP full-views, as these objects will be shared between routing
entries. This allows to store more information in the nexthop.
New KPI:
struct nhop_object *fib4_lookup(uint32_t fibnum, struct in_addr dst,
uint32_t scopeid, uint32_t flags, uint32_t flowid);
struct nhop_object *fib6_lookup(uint32_t fibnum, const struct in6_addr *dst6,
uint32_t scopeid, uint32_t flags, uint32_t flowid);
These 2 function are intended to replace all all flavours of
<in_|in6_>rtalloc[1]<_ign><_fib>, mpath functions and the previous
fib[46]-generation functions.
Upon successful lookup, they return nexthop object which is guaranteed to
exist within current NET_EPOCH. If longer lifetime is desired, one can
specify NHR_REF as a flag and get a referenced version of the nexthop.
Reference semantic closely resembles rtentry one, allowing sed-style conversion.
Additionally, another 2 functions are introduced to support uRPF functionality
inside variety of our firewalls. Their primary goal is to hide the multipath
implementation details inside the routing subsystem, greatly simplifying
firewalls implementation:
int fib4_lookup_urpf(uint32_t fibnum, struct in_addr dst, uint32_t scopeid,
uint32_t flags, const struct ifnet *src_if);
int fib6_lookup_urpf(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid,
uint32_t flags, const struct ifnet *src_if);
All functions have a separate scopeid argument, paving way to eliminating IPv6 scope
embedding and allowing to support IPv4 link-locals in the future.
Structure changes:
* rtentry gets new 'rt_nhop' pointer, slightly growing the overall size.
* rib_head gets new 'rnh_preadd' callback pointer, slightly growing overall sz.
Old KPI:
During the transition state old and new KPI will coexists. As there are another 4-5
decent-sized conversion patches, it will probably take a couple of weeks.
To support both KPIs, fields not required by the new KPI (most of rtentry) has to be
kept, resulting in the temporary size increase.
Once conversion is finished, rtentry will notably shrink.
More details:
* architectural overview: https://reviews.freebsd.org/D24141
* list of the next changes: https://reviews.freebsd.org/D24232
Reviewed by: ae,glebius(initial version)
Differential Revision: https://reviews.freebsd.org/D24232
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
Amount of changes to the original code has been intentionally minimised
to ease diffing.
The changes are mostly mechanical, with the following exceptions:
* lltable handler is now called directly based of RTF_LLINFO flag presense.
* "report" logic for updating rtm in RTM_GET/RTM_DELETE has been simplified,
fixing several potential use-after-free cases in rt_addrinfo.
* llable asserts has been replaced with error-returning, preventing kernel
crashes when lltable gw af family is invalid (root required).
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D22864
When epoch(9) was introduced to network stack, it was basically
dropped in place of existing locking, which was mutexes and
rwlocks. For the sake of performance mutex covered areas were
as small as possible, so became epoch covered areas.
However, epoch doesn't introduce any contention, it just delays
memory reclaim. So, there is no point to minimise epoch covered
areas in sense of performance. Meanwhile entering/exiting epoch
also has non-zero CPU usage, so doing this less often is a win.
Not the least is also code maintainability. In the new paradigm
we can assume that at any stage of processing a packet, we are
inside network epoch. This makes coding both input and output
path way easier.
On output path we already enter epoch quite early - in the
ip_output(), in the ip6_output().
This patch does the same for the input path. All ISR processing,
network related callouts, other ways of packet injection to the
network stack shall be performed in net_epoch. Any leaf function
that walks network configuration now asserts epoch.
Tricky part is configuration code paths - ioctls, sysctls. They
also call into leaf functions, so some need to be changed.
This patch would introduce more epoch recursions (see EPOCH_TRACE)
than we had before. They will be cleaned up separately, as several
of them aren't trivial. Note, that unlike a lock recursion the
epoch recursion is safe and just wastes a bit of resources.
Reviewed by: gallatin, hselasky, cy, adrian, kristof
Differential Revision: https://reviews.freebsd.org/D19111
These commands show the route resolved for a specified destination, or
print out the entire routing table for a given address family (or all
families, if none is explicitly provided).
Discussed with: emaste
Differential Revision: https://reviews.freebsd.org/D21510
- Remove macros that covertly create epoch_tracker on thread stack. Such
macros a quite unsafe, e.g. will produce a buggy code if same macro is
used in embedded scopes. Explicitly declare epoch_tracker always.
- Unmask interface list IFNET_RLOCK_NOSLEEP(), interface address list
IF_ADDR_RLOCK() and interface AF specific data IF_AFDATA_RLOCK() read
locking macros to what they actually are - the net_epoch.
Keeping them as is is very misleading. They all are named FOO_RLOCK(),
while they no longer have lock semantics. Now they allow recursion and
what's more important they now no longer guarantee protection against
their companion WLOCK macros.
Note: INP_HASH_RLOCK() has same problems, but not touched by this commit.
This is non functional mechanical change. The only functionally changed
functions are ni6_addrs() and ni6_store_addrs(), where we no longer enter
epoch recursively.
Discussed with: jtl, gallatin
The panic can happen, when some application does dump of routing table
using sysctl interface. To prevent this, set IFF_DYING flag in
if_detach_internal() function, when ifnet under lock is removed from
the chain. In sysctl_rtsock() take IFNET_RLOCK_NOSLEEP() to prevent
ifnet detach during routes enumeration. In case, if some interface was
detached in the time before we take the lock, add the check, that ifnet
is not DYING. This prevents access to memory that could be freed after
ifnet is unlinked.
PR: 227720, 230498, 233306
Reviewed by: bz, eugen
MFC after: 1 week
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D18338
Various structures exported by sysctl_rtsock() contain padding fields
which were not being zeroed.
Reported by: Thomas Barabosch, Fraunhofer FKIE
Reviewed by: ae
MFC after: 3 days
Security: kernel memory disclosure
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18333
- 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
Using of rwlock with multiqueue NICs for IP forwarding on high pps
produces high lock contention and inefficient. Rmlock fits better for
such workloads.
Reviewed by: melifaro, olivier
Obtained from: Yandex LLC
Sponsored by: Yandex LLC
Differential Revision: https://reviews.freebsd.org/D15789
opt_compat.h is mentioned in nearly 180 files. In-progress network
driver compabibility improvements may add over 100 more so this is
closer to "just about everywhere" than "only some files" per the
guidance in sys/conf/options.
Keep COMPAT_LINUX32 in opt_compat.h as it is confined to a subset of
sys/compat/linux/*.c. A fake _COMPAT_LINUX option ensure opt_compat.h
is created on all architectures.
Move COMPAT_LINUXKPI to opt_dontuse.h as it is only used to control the
set of compiled files.
Reviewed by: kib, cem, jhb, jtl
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D14941
Only require a gateway to be specified on a route add request. On
a route change request that does not specify the gateway, the
gateway will remain the same. This allows changing other route
parameters without having to re-specifying the gateway, like in
"route change 10.0.0.0/8 -mtu 9000".
Update the route(8) manpage to explicitly call out this usage
as being supported.
MFC after: 2 weeks
Sponsored by: Dell EMC Isilon
Reviewed By: eugen (rtsock.c change), rgrimes
Differential Revision: https://reviews.freebsd.org/D14291
Route messages are aligned to the host long type alignment, which
breaks 32bit.
Reported and tested by: lwhsu
Diagnosed by: Yuri Pankov <yuripv@icloud.com>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
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.
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
Calling into an ifnet implementation with the if_addr_lock already
held can cause a LOR and potentially a deadlock, as ifnet
implementations typically can take the if_addr_lock after their
own locks during configuration. Refactor a sysctl handler that
was violating this to read if_counter data in a temporary buffer
before the if_addr_lock is taken, and then copying the data
in its final location later, when the if_addr_lock is held.
PR: 194109
Reported by: Jean-Sebastien Pedron
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D8498
Reviewed by: sbruno
Add accessor functions to toggle the state per VNET.
The base system (vnet0) will always enable itself with the normal
registration. We will share the registered protocol handlers in all
VNETs minimising duplication and management.
Upon disabling netisr processing for a VNET drain the netisr queue from
packets for that VNET.
Update netisr consumers to (de)register on a per-VNET start/teardown using
VNET_SYS(UN)INIT functionality.
The change should be transparent for non-VIMAGE kernels.
Reviewed by: gnn (, hiren)
Obtained from: projects/vnet
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D6691
There are number of radix consumers in kernel land (pf,ipfw,nfs,route)
with different requirements. In fact, first 3 don't have _any_ requirements
and first 2 does not use radix locking. On the other hand, routing
structure do have these requirements (rnh_gen, multipath, custom
to-be-added control plane functions, different locking).
Additionally, radix should not known anything about its consumers internals.
So, radix code now uses tiny 'struct radix_head' structure along with
internal 'struct radix_mask_head' instead of 'struct radix_node_head'.
Existing consumers still uses the same 'struct radix_node_head' with
slight modifications: they need to pass pointer to (embedded)
'struct radix_head' to all radix callbacks.
Routing code now uses new 'struct rib_head' with different locking macro:
RADIX_NODE_HEAD prefix was renamed to RIB_ (which stands for routing
information base).
New net/route_var.h header was added to hold routing subsystem internal
data. 'struct rib_head' was placed there. 'struct rtentry' will also
be moved there soon.
entries data in unified format.
There are control plane functions that require information other than
just next-hop data (e.g. individual rtentry fields like flags or
prefix/mask). Given that the goal is to avoid rte reference/refcounting,
re-use rt_addrinfo structure to store most rte fields. If caller wants
to retrieve key/mask or gateway (which are sockaddrs and are allocated
separately), it needs to provide sufficient-sized sockaddrs structures
w/ ther pointers saved in passed rt_addrinfo.
Convert:
* lltable new records checks (in_lltable_rtcheck(),
nd6_is_new_addr_neighbor().
* rtsock pre-add/change route check.
* IPv6 NS ND-proxy check (RADIX_MPATH code was eliminated because
1) we don't support RTF_ANNOUNCE ND-proxy for networks and there should
not be multiple host routes for such hosts 2) if we have multiple
routes we should inspect them (which is not done). 3) the entire idea
of abusing KRT as storage for ND proxy seems odd. Userland programs
should be used for that purpose).
struct ifnet if_oqdrops.
Some netgraph modules used ifqueue w/o ifnet. Accounting of queue drops
is simply removed from them. There were no API to read this statistic.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
ifa_ifwithdstaddr. For the sake of backwards compatibility, the new
arguments were added to new functions named ifa_ifwithnet_fib and
ifa_ifwithdstaddr_fib, while the old functions became wrappers around the
new ones that passed RT_ALL_FIBS for the fib argument. However, the
backwards compatibility is not desired for FreeBSD 11, because there are
numerous other incompatible changes to the ifnet(9) API. We therefore
decided to remove it from head but leave it in place for stable/9 and
stable/10. In addition, this commit adds the fib argument to
ifa_ifwithbroadaddr for consistency's sake.
sys/sys/param.h
Increment __FreeBSD_version
sys/net/if.c
sys/net/if_var.h
sys/net/route.c
Add fibnum argument to ifa_ifwithbroadaddr, and remove the _fib
versions of ifa_ifwithdstaddr, ifa_ifwithnet, and ifa_ifwithroute.
sys/net/route.c
sys/net/rtsock.c
sys/netinet/in_pcb.c
sys/netinet/ip_options.c
sys/netinet/ip_output.c
sys/netinet6/nd6.c
Fixup calls of modified functions.
share/man/man9/ifnet.9
Document changed API.
CR: https://reviews.freebsd.org/D458
MFC after: Never
Sponsored by: Spectra Logic
for route(4) socket and ifmib(4) sysctl.
o Move fields from if_data to ifnet, but keep all statistic counters
separate, since they should disappear later.
o Provide function if_data_copy() to fill if_data, utilize it in routing
socket and ifmib handler.
o Provide overridable ifnet(9) method to fetch counters. If no provided,
if_get_counters_compat() would be used, that returns old counters.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
ifa_ifwithnet() and ifa_ifwithdstaddr() The legacy functions will call the
_fib() versions with RT_ALL_FIBS, preserving legacy behavior.
sys/net/if_var.h
sys/net/if.c
Add legacy-compatible functions as described above. Ensure legacy
behavior when RT_ALL_FIBS is passed as fibnum.
sys/netinet/in_pcb.c
sys/netinet/ip_output.c
sys/netinet/ip_options.c
sys/net/route.c
sys/net/rtsock.c
sys/netinet6/nd6.c
Call with _fib() functions if we must use a specific fib, or the
legacy functions otherwise.
tests/sys/netinet/fibs_test.sh
tests/sys/netinet/udp_dontroute.c
Improve the udp_dontroute test. The bug that this test exercises is
that ifa_ifwithnet() will return the wrong address, if multiple
interfaces have addresses on the same subnet but with different
fibs. The previous version of the test only considered one possible
failure mode: that ifa_ifwithnet_fib() might fail to find any
suitable address at all. The new version also checks whether
ifa_ifwithnet_fib() finds the correct address by checking where the
ARP request goes.
Reported by: bz, hrs
Reviewed by: hrs
MFC after: 1 week
X-MFC-with: 264905
Sponsored by: Spectra Logic
