avoid an indirect function call by comparing the family, length,
and bytes [dom->dom_sa_cmpofs, dom->dom_sa_cmpofs + dom->dom_sa_cmplen),
corresponding to the the sockaddrs' "address" members.
For ISO, actually use sockaddr_iso_cmp, for a change. Thanks to
yamt@ for pointing out my error.
While I am here, introduce an rtentry pointer, 'rt', and set it
equal to ip6_forward.ro_rt. Replace several occurrences of
'ip6_forward.ro_rt' with 'rt'.
> Revision 1.371
> Thu May 3 22:07:39 2007 UTC (47 hours, 7 minutes ago) by itojun
>
> drop packets with more than 1 routing headers.
> from claudio@openbsd
(and increment ifs6_in_hdrerr on ip6s_toomanyhdr.)
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.
socket. If we don't make an exact match, we may use a cached rule which
has lower priority than a rule that would otherwise have matched the
packet.
Code submitted by Karl Knutsson in PR/36051
is equal to one of the host's IPv6 addresses, do not stop at setting
the route's interface to lo0, but also clear the route's RTF_CLONED
flag, if it is present, so that ip6_input() will accept packets
sent to that destination. This is necessary because ip6_input()
will not accept a packet if it looks up the packet's destination
and finds a route with RTF_CLONED set.
I believe this will help IPv6 networking survive '/etc/rc.d/network
restart'. See the problem report, kern/33279.
If ip6_forward successfully forwards a packet, a cache, in this case a
ip6flow struct entry, will be created. ether_input and friends will
then be able to call ip6flow_fastforward with the packet which will then
be passed to if_output (unless an issue is found - in that case the packet
is passed back to ip6_input).
ok matt@ christos@ dyoung@ and joerg@
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.
