update_rtm_from_rc() calls update_rtm_from_info() internally.
The latter one may update provided prtm pointer with a new rtm.
Reassign rtm from prtm afeter calling update_rtm_from_info() to
avoid touching the freed rtm.
PR: 255871
Submitted by: lylgood@foxmail.com
MFC after: 3 days
b31fbebeb3 introduced alloc_sockaddr_aligned() which, in fact,
failed to produce aligned addresses.
Reported by: Oskar Holmlund <oskar.holmlund at yahoo.com>
MFC after: immediately
Traditionally we had 2 sources of information whether the
added/delete route request targets network or a host route:
netmask (RTA_NETMASK) and RTF_HOST flag.
The former one is tricky: netmask can be empty or can explicitly
specify the host netmask. Parsing netmask sockaddr requires per-family
parsing and that's what rtsock code traditionally avoided. As a result,
consistency was not enforced and it was possible to specify network with
the RTF_HOST flag and vice versa.
Continue normalization efforts from D29826 and D29826 and ensure that
RTF_HOST flag always reflects host/network data from netmask field.
Differential Revision: https://reviews.freebsd.org/D29958
MFC after: 2 days
Address multiple issues with strict rtsock message validation.
D28668 "normalisation" approach was based on the assumption that
we always have at least "standard" sockaddr len.
It turned out to be false - certain older applications like quagga
or routed abuse sin[6]_len field and set it to the offset to the
first fully-zero bit in the mask. It is impossible to normalise
such sockaddrs without reallocation.
With that in mind, change the approach to use a distinct memory
buffer for the altered sockaddrs. This allows supporting the older
software while maintaining the guarantee on the "standard" sockaddrs.
PR: 255273,255089
Differential Revision: https://reviews.freebsd.org/D29826
MFC after: 3 days
Slighly relax the gateway validation rules imposed by the
2fe5a79425, by requiring only first 8 bytes (everyhing
before sdl_data to be present in the AF_LINK gateway.
Reported by: olivier
rtsock message validation changes committed in 2fe5a79425
did not take llinfo messages into account.
Add a special validation case for RTA_GATEWAY llinfo messages.
MFC after: 2 days
Changes in the 2fe5a79425 moved dst sockaddr masking from the
routing control plane to the rtsock code.
It broke arp/ndp deletion.
It turns out, arp/ndp perform RTM_GET request first to get an
interface index necessary for the deletion.
Then they simply stamp the reply with RTF_LLDATA and set the
command to RTM_DELETE.
As a result, kernel receives request with non-empty RTA_NETMASK
and clears RTA_DST host bits before passing the message to the
lla code.
De facto, the only needed bits are RTA_DST, RTA_GATEWAY and the
subset of rtm_flags.
With that in mind, fix the interace by clearing RTA_NETMASK
for every messages with RTF_LLDATA.
While here, cleanup arp/ndp code a bit.
MFC after: 1 day
Reviewed by: gnn
Differential Revision: https://reviews.freebsd.org/D28804
Traditionally routing socket code did almost zero checks on
the input message except for the most basic size checks.
This resulted in the unclear KPI boundary for the routing system code
(`rtrequest*` and now `rib_action()`) w.r.t message validness.
Multiple potential problems and nuances exists:
* Host bits in RTAX_DST sockaddr. Existing applications do send prefixes
with hostbits uncleared. Even `route(8)` does this, as they hope the kernel
would do the job of fixing it. Code inside `rib_action()` needs to handle
it on its own (see `rt_maskedcopy()` ugly hack).
* There are multiple way of adding the host route: it can be DST without
netmask or DST with /32(/128) netmask. Also, RTF_HOST has to be set correspondingly.
Currently, these 2 options create 2 DIFFERENT routes in the kernel.
* no sockaddr length/content checking for the "secondary" fields exists: nothing
stops rtsock application to send sockaddr_in with length of 25 (instead of 16).
Kernel will accept it, install to RIB as is and propagate to all rtsock consumers,
potentially triggering bugs in their code. Same goes for sin_port, sin_zero, etc.
The goal of this change is to make rtsock verify all sockaddr and prefix consistency.
Said differently, `rib_action()` or internals should NOT require to change any of the
sockaddrs supplied by `rt_addrinfo` structure due to incorrectness.
To be more specific, this change implements the following:
* sockaddr cleanup/validation check is added immediately after getting sockaddrs from rtm.
* Per-family dst/netmask checks clears host bits in dst and zeros all dst/netmask "secondary" fields.
* The same netmask checking code converts /32(/128) netmasks to "host" route case
(NULL netmask, RTF_HOST), removing the dualism.
* Instead of allowing ANY "known" sockaddr families (0<..<AF_MAX), allow only actually
supported ones (inet, inet6, link).
* Automatically convert `sockaddr_sdl` (AF_LINK) gateways to
`sockaddr_sdl_short`.
Reported by: Guy Yur <guyyur at gmail.com>
Reviewed By: donner
Differential Revision: https://reviews.freebsd.org/D28668
MFC after: 3 days
Traditionally *BSD routing stack required to supply some
interface data for blackhole/reject routes. This lead to
varieties of hacks in routing daemons when inserting such routes.
With the recent routeing stack changes, gateway sockaddr without
RTF_GATEWAY started to be treated differently, purely as link
identifier.
This change broke net/bird, which installs blackhole routes with
127.0.0.1 gateway without RTF_GATEWAY flags.
Fix this by automatically constructing necessary gateway data at
rtsock level if RTF_REJECT/RTF_BLACKHOLE is set.
Reported by: Marek Zarychta <zarychtam at plan-b.pwste.edu.pl>
Reviewed by: donner
MFC after: 1 week
When copying sockaddrs out to userspace, we pad them to a multiple of
the platform alignment (sizeof(long)). However, some sockaddr sizes,
such as struct sockaddr_dl, are not an integer multiple of the
alignment, so we may end up copying out uninitialized bytes.
Fix this by always bouncing through a pre-zeroed sockaddr_storage.
Reported by: KASAN
Reviewed by: melifaro
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D27729
rtsock code was build around the assumption that each rtentry record
in the system radix tree is a ready-to-use sockaddr. This assumptions
turned out to be not quite true:
* masks have their length tweaked, so we have rtsock_fix_netmask() hack
* IPv6 addresses have their scope embedded, so we have another explicit
deembedding hack.
Change the code to decouple rtentry internals from rtsock code using
newly-created rtentry accessors. This will allow to eventually eliminate
both of the hacks and change rtentry dst/mask format.
Differential Revision: https://reviews.freebsd.org/D27451
ROUTE_MPATH is the new config option controlling new multipath routing
implementation. Remove the last pieces of RADIX_MPATH-related code and
the config option.
Reviewed by: glebius
Differential Revision: https://reviews.freebsd.org/D27244
Nexthop lookup was not consireding rt_flags when doing
structure comparison, which lead to an original nexthop
selection when changing flags. Fix the case by adding
rt_flags field into comparison and rearranging nhop_priv
fields to allow for efficient matching.
Fix `route change X/Y flags` case - recent changes
disallowed specifying RTF_GATEWAY flag without actual gateway.
It turns out, route(8) fills in RTF_GATEWAY by default, unless
-interface flag is specified. Fix regression by clearing
RTF_GATEWAY flag instead of failing.
Fix route flag reporting in RTM_CHANGE messages by explicitly
updating rtm_flags after operation competion.
Add IPv4/IPv6 tests for flag-only route changes.
This change is based on the nexthop objects landed in D24232.
The change introduces the concept of nexthop groups.
Each group contains the collection of nexthops with their
relative weights and a dataplane-optimized structure to enable
efficient nexthop selection.
Simular to the nexthops, nexthop groups are immutable. Dataplane part
gets compiled during group creation and is basically an array of
nexthop pointers, compiled w.r.t their weights.
With this change, `rt_nhop` field of `struct rtentry` contains either
nexthop or nexthop group. They are distinguished by the presense of
NHF_MULTIPATH flag.
All dataplane lookup functions returns pointer to the nexthop object,
leaving nexhop groups details inside routing subsystem.
User-visible changes:
The change is intended to be backward-compatible: all non-mpath operations
should work as before with ROUTE_MPATH and net.route.multipath=1.
All routes now comes with weight, default weight is 1, maximum is 2^24-1.
Current maximum multipath group width is statically set to 64.
This will become sysctl-tunable in the followup changes.
Using functionality:
* Recompile kernel with ROUTE_MPATH
* set net.route.multipath to 1
route add -6 2001:db8::/32 2001:db8::2 -weight 10
route add -6 2001:db8::/32 2001:db8::3 -weight 20
netstat -6On
Nexthop groups data
Internet6:
GrpIdx NhIdx Weight Slots Gateway Netif Refcnt
1 ------- ------- ------- --------------------------------------- --------- 1
13 10 1 2001:db8::2 vlan2
14 20 2 2001:db8::3 vlan2
Next steps:
* Land outbound hashing for locally-originated routes ( D26523 ).
* Fix net/bird multipath (net/frr seems to work fine)
* Add ROUTE_MPATH to GENERIC
* Set net.route.multipath=1 by default
Tested by: olivier
Reviewed by: glebius
Relnotes: yes
Differential Revision: https://reviews.freebsd.org/D26449
* Split rt_setmetrics into get_info_weight() and rt_set_expire_info(),
as these two can be applied at different entities and at different times.
* Start filling route weight in route change notifications
* Pass flowid to UDP/raw IP route lookups
* Rework nd6_subscription_cb() and sysctl_dumpentry() to prepare for the fact
that rtentry can contain multiple nexthops.
Differential Revision: https://reviews.freebsd.org/D26497
No functional changes.
net/route/shared.h was created in the inital phases of nexthop conversion.
It was intended to serve the same purpose as route_var.h - share definitions
of functions and structures between the routing subsystem components. At
that time route_var.h was included by many files external to the routing
subsystem, which largerly defeats its purpose.
As currently this is not the case anymore and amount of route_var.h includes
is roughly the same as shared.h, retire the latter in favour of the former.
rtentry lock traditionally served 2 purposed: first was protecting refcounts,
the second was assuring consistent field access/changes.
Since route nexthop introduction, the need for the former disappeared and
the need for the latter reduced.
To be more precise, the following rte field are mutable:
rt_nhop (nexthop pointer, updated with RIB_WLOCK, passed in rib_cmd_info)
rte_flags (only RTF_HOST and RTF_UP, where RTF_UP gets changed at rte removal)
rt_weight (relative weight, updated with RIB_WLOCK, passed in rib_cmd_info)
rt_expire (time when rte deletion is scheduled, updated with RIB_WLOCK)
rt_chain (deletion chain pointer, updated with RIB_WLOCK)
All of them are updated under RIB_WLOCK, so the only remaining concern is the reading.
rt_nhop and rt_weight (addressed in this review) are read under rib lock and
stored in the rib_cmd_info, so the caller has no problem with consitency.
rte_flags is currently read unlocked in rtsock reporting (however the scope
is only RTF_UP flag, which is pretty static).
rt_expire is currently read unlocked in rtsock reporting.
rt_chain accesses are safe, as this is only used at route deletion.
rt_expire and rte_flags reads will be dealt in a separate reviews soon.
Differential Revision: https://reviews.freebsd.org/D26162
No functional changes.
Most of the routing flags are stored in the netxtop instead of rtentry.
Rename rt->rt_flags to rt->rte_flags to simplify reading/modifying code
checking routing flags.
In the new multipath code, rt->rt_nhop may actually point to nexthop group
instead of nhop. To ease transition, reduce the amount of rt->rt_nhop->...
accesses.
Differential Revision: https://reviews.freebsd.org/D26156
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
