from the forwarding table's users:
Introduce rt_walktree() for walking the routing table and
applying a function to each rtentry. Replace most
rn_walktree() calls with it.
Use rt_getkey()/rt_setkey() to get/set a route's destination.
Keep a pointer to the sockaddr key in the rtentry, so that
rtentry users do not have to grovel in the radix_node for
the key.
Add a RTM_GET method to rtrequest. Use that instead of
radix_node lookups in, e.g., carp(4).
Add sys/net/link_proto.c, which supplies sockaddr routines for
link-layer socket addresses (sockaddr_dl).
Cosmetic:
Constify. KNF. Stop open-coding LIST_FOREACH, TAILQ_FOREACH,
et cetera. Use NULL instead of 0 for null pointers. Use
__arraycount(). Reduce gratuitous parenthesization.
Stop using variadic arguments for rip6_output(), it is
unnecessary.
Remove the unnecessary rtentry member rt_genmask and the
code to maintain it, since nothing actually used it.
Make rt_maskedcopy() easier to read by using meaningful variable
names.
Extract a subroutine intern_netmask() for looking up a netmask in
the masks table.
Start converting backslash-ridden IPv6 macros in
sys/netinet6/in6_var.h into inline subroutines that one
can read without special eyeglasses.
One functional change: when the kernel serves an RTM_GET, RTM_LOCK,
or RTM_CHANGE request, it applies the netmask (if supplied) to a
destination before searching for it in the forwarding table.
I have changed sys/netinet/ip_carp.c, carp_setroute(), to remove
the unlawful radix_node knowledge.
Apart from the changes to carp(4), netiso, ATM, and strip(4), I
have run the changes on three nodes in my wireless routing testbed,
which involves IPv4 + IPv6 dynamic routing acrobatics, and it's
working beautifully so far.
set to rn_walktree.
Introduce rt_walktree(), which applies a subroutine to every route
in a particular address family. Use it instead of rn_walktree()
virtually everywhere. This helps to hide the routing table
implementation.
route_in6, struct route_iso), replacing all caches with a struct
route.
The principle benefit of this change is that all of the protocol
families can benefit from route cache-invalidation, which is
necessary for correct routing. Route-cache invalidation fixes an
ancient PR, kern/3508, at long last; it fixes various other PRs,
also.
Discussions with and ideas from Joerg Sonnenberger influenced this
work tremendously. Of course, all design oversights and bugs are
mine.
DETAILS
1 I added to each address family a pool of sockaddrs. I have
introduced routines for allocating, copying, and duplicating,
and freeing sockaddrs:
struct sockaddr *sockaddr_alloc(sa_family_t af, int flags);
struct sockaddr *sockaddr_copy(struct sockaddr *dst,
const struct sockaddr *src);
struct sockaddr *sockaddr_dup(const struct sockaddr *src, int flags);
void sockaddr_free(struct sockaddr *sa);
sockaddr_alloc() returns either a sockaddr from the pool belonging
to the specified family, or NULL if the pool is exhausted. The
returned sockaddr has the right size for that family; sa_family
and sa_len fields are initialized to the family and sockaddr
length---e.g., sa_family = AF_INET and sa_len = sizeof(struct
sockaddr_in). sockaddr_free() puts the given sockaddr back into
its family's pool.
sockaddr_dup() and sockaddr_copy() work analogously to strdup()
and strcpy(), respectively. sockaddr_copy() KASSERTs that the
family of the destination and source sockaddrs are alike.
The 'flags' argumet for sockaddr_alloc() and sockaddr_dup() is
passed directly to pool_get(9).
2 I added routines for initializing sockaddrs in each address
family, sockaddr_in_init(), sockaddr_in6_init(), sockaddr_iso_init(),
etc. They are fairly self-explanatory.
3 structs route_in6 and route_iso are no more. All protocol families
use struct route. I have changed the route cache, 'struct route',
so that it does not contain storage space for a sockaddr. Instead,
struct route points to a sockaddr coming from the pool the sockaddr
belongs to. I added a new method to struct route, rtcache_setdst(),
for setting the cache destination:
int rtcache_setdst(struct route *, const struct sockaddr *);
rtcache_setdst() returns 0 on success, or ENOMEM if no memory is
available to create the sockaddr storage.
It is now possible for rtcache_getdst() to return NULL if, say,
rtcache_setdst() failed. I check the return value for NULL
everywhere in the kernel.
4 Each routing domain (struct domain) has a list of live route
caches, dom_rtcache. rtflushall(sa_family_t af) looks up the
domain indicated by 'af', walks the domain's list of route caches
and invalidates each one.
parentheses in return statements.
Cosmetic: don't open-code TAILQ_FOREACH().
Cosmetic: change types of variables to avoid oodles of casts: in
in6_src.c, avoid casts by changing several route_in6 pointers
to struct route pointers. Remove unnecessary casts to caddr_t
elsewhere.
Pave the way for eliminating address family-specific route caches:
soon, struct route will not embed a sockaddr, but it will hold
a reference to an external sockaddr, instead. We will set the
destination sockaddr using rtcache_setdst(). (I created a stub
for it, but it isn't used anywhere, yet.) rtcache_free() will
free the sockaddr. I have extracted from rtcache_free() a helper
subroutine, rtcache_clear(). rtcache_clear() will "forget" a
cached route, but it will not forget the destination by releasing
the sockaddr. I use rtcache_clear() instead of rtcache_free()
in rtcache_update(), because rtcache_update() is not supposed
to forget the destination.
Constify:
1 Introduce const accessor for route->ro_dst, rtcache_getdst().
2 Constify the 'dst' argument to ifnet->if_output(). This
led me to constify a lot of code called by output routines.
3 Constify the sockaddr argument to protosw->pr_ctlinput. This
led me to constify a lot of code called by ctlinput routines.
4 Introduce const macros for converting from a generic sockaddr
to family-specific sockaddrs, e.g., sockaddr_in: satocsin6,
satocsin, et cetera.
like PR 35272 and 35318. When the kernel is compiled with
-DRTCACHE_DEBUG, all rtcache entries are logged to a list with the place
they got initialised. This allows overwrites, double inits and other
manual messing to be detected.
rtcache_init and rtcache_init_noclone lookup ro_dst and store
the result in ro_rt, taking care of the reference counting and
calling the domain specific route cache.
rtcache_free checks if a route was cashed and frees the reference.
rtcache_copy copies ro_dst of the given struct route, checking that
enough space is available and incrementing the reference count of the
cached rtentry if necessary.
rtcache_check validates that the cached route is still up. If it isn't,
it tries to look it up again. Afterwards ro_rt is either a valid again
or NULL.
rtcache_copy is used internally.
Adjust to callers of rtalloc/rtflush in the tree to check the sanity of
ro_dst first (if necessary). If it doesn't fit the expectations, free
the cache, otherwise check if the cached route is still valid. After
that combination, a single check for ro_rt == NULL is enough to decide
whether a new lookup needs to be done with a different ro_dst.
Make the route checking in gre stricter by repeating the loop check
after revalidation.
Remove some unused RADIX_MPATH code in in6_src.c. The logic is slightly
changed here to first validate the route and check RTF_GATEWAY
afterwards. This is sementically equivalent though.
etherip doesn't need sc_route_expire similiar to the gif changes from
dyoung@ earlier.
Based on the earlier patch from dyoung@, reviewed and discussed with
him.
routing caused by stale route caches (struct route). Route caches
are sprinkled throughout PCBs, the IP fast-forwarding table, and
IP tunnel interfaces (gre, gif, stf).
Stale IPv6 and ISO route caches will be treated by separate patches.
Thank you to Christoph Badura for suggesting the general approach
to invalidating route caches that I take here.
Here are the details:
Add hooks to struct domain for tracking and for invalidating each
domain's route caches: dom_rtcache, dom_rtflush, and dom_rtflushall.
Introduce helper subroutines, rtflush(ro) for invalidating a route
cache, rtflushall(family) for invalidating all route caches in a
routing domain, and rtcache(ro) for notifying the domain of a new
cached route.
Chain together all IPv4 route caches where ro_rt != NULL. Provide
in_rtcache() for adding a route to the chain. Provide in_rtflush()
and in_rtflushall() for invalidating IPv4 route caches. In
in_rtflush(), set ro_rt to NULL, and remove the route from the
chain. In in_rtflushall(), walk the chain and remove every route
cache.
In rtrequest1(), call rtflushall() to invalidate route caches when
a route is added.
In gif(4), discard the workaround for stale caches that involves
expiring them every so often.
Replace the pattern 'RTFREE(ro->ro_rt); ro->ro_rt = NULL;' with a
call to rtflush(ro).
Update ipflow_fastforward() and all other users of route caches so
that they expect a cached route, ro->ro_rt, to turn to NULL.
Take care when moving a 'struct route' to rtflush() the source and
to rtcache() the destination.
In domain initializers, use .dom_xxx tags.
KNF here and there.
Also, add ioctls SIOCGIFADDRPREF/SIOCSIFADDRPREF to get/set preference
numbers for addresses. Make ifconfig(8) set/display preference
numbers.
To activate source-address selection policies in your kernel, add
'options IPSELSRC' to your kernel configuration.
Miscellaneous changes in support of source-address selection:
1 Factor out some common code, producing rt_replace_ifa().
2 Abbreviate a for-loop with TAILQ_FOREACH().
3 Add the predicates on IPv4 addresses IN_LINKLOCAL() and
IN_PRIVATE(), that are true for link-local unicast
(169.254/16) and RFC1918 private addresses, respectively.
Add the predicate IN_ANY_LOCAL() that is true for link-local
unicast and multicast.
4 Add IPv4-specific interface attach/detach routines,
in_domifattach and in_domifdetach, which build #ifdef
IPSELSRC.
See in_getifa(9) for a more thorough description of source-address
selection policy.
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.
Bump the kernel rev up to 1.6V
adds rt_parent to link parent from child (like NRL did, ours do refcnt
rt_refcnt properly).
bsdi rt_walkbranch would speedup the processing, but since the code will not
be visited too frequently, the current code (with rt_walktree) should be okay.
let static routes overwrite cloned routes, as cloned routes can come back again
if necessary. behavior same as freebsd/bsdi, code partially from bsdi42.
(NRL rt->rt_parent was not added)
should fix PR 11916 and maybe some other PRs with ARP behavior.
recompilation of usr.sbin/route6d is suggested.
have sys/net/route.c:rtrequest1(), which takes rt_addrinfo * as the argument.
pass rt_addrinfo all the way down to rtrequest, and ifa->ifa_rtrequest.
3rd arg of ifa->ifa_rtrequest is now rt_addrinfo * instead of sockaddr *
(almost noone is using it anyways).
benefit: the follwoing command now works. previously we need two route(8)
invocations, "add" then "change".
# route add -inet6 default ::1 -ifp gif0
remove unsafe typecast in rtrequest(), from rtentry * to sockaddr *. it was
introduced by 4.3BSD-reno and never corrected.
XXX is eon_rtrequest() change correct regarding to 3rd arg?
eon_rtrequest() and rtrequest() were incorrect since 4.3BSD-reno,
so i do not have correct answer in the source code.
someone with more clue about netiso-over-ip, please help.
mandatory for IPv6 (so we can't just validate by using connected pcb - we need
to allow traffic from unconnected pcb to do pmtud).
- if the traffic is validated by xx_ctlinput, allow up to "hiwat" pmtud
route entries.
- if the traffic was not validated by xx_ctlinput, allow up to "lowat" pmtud
route entries (there's upper limit, so bad guys cannot blow up our routing
table).
sync with kame
XXX need to think again about default hiwat/lowat value.
XXX victim selection to help starvation case
parties can easily know the state of a link.
- Define an interface announcement message for the routing socket so that
routing daemons and other interested parties know when an interface
is attached/detached.
RTM_IFINFO is now 0xf, 0xe is RTM_OIFINFO which returns the old (if_msghdr14)
struct with 32bit counters (binary compat, conditioned on COMPAT_14).
Same for sysctl: node 3 is renamed NET_RT_OIFLIST, NET_RT_IFLIST is now node 4.
Change rt_msg1() to add an mbuf to the mbuf chain instead of just panic()
when the message is larger than MHLEN.
(Sorry for a big commit, I can't separate this into several pieces...)
Pls check sys/netinet6/TODO and sys/netinet6/IMPLEMENTATION for details.
- sys/kern: do not assume single mbuf, accept chained mbuf on passing
data from userland to kernel (or other way round).
- "midway" ATM card: ATM PVC pseudo device support, like those done in ALTQ
package (ftp://ftp.csl.sony.co.jp/pub/kjc/).
- sys/netinet/tcp*: IPv4/v6 dual stack tcp support.
- sys/netinet/{ip6,icmp6}.h, sys/net/pfkeyv2.h: IETF document assumes those
file to be there so we patch it up.
- sys/netinet: IPsec additions are here and there.
- sys/netinet6/*: most of IPv6 code sits here.
- sys/netkey: IPsec key management code
- dev/pci/pcidevs: regen
In my understanding no code here is subject to export control so it
should be safe.
