was: attach route domain if found from domains link set
now: attach any domain which is found from domains link set
No functional change to monolithic kernel. In a rump kernel, which
attaches networking domains "modularly", prevents domains from
accidentally leaking in via the link set in static linked scenarios.
Problem reported by cube, Tom Bousso, and the voices in my head.
addresses. Make the kernel support SIOC[SG]IFADDRPREF for IPv6
interface addresses.
In in6ifa_ifpforlinklocal(), consult preference numbers before
making an otherwise arbitrary choice of in6_ifaddr. Otherwise,
preference numbers are *not* consulted by the kernel, but that will
be rather easy for somebody with a little bit of free time to fix.
Please note that setting the preference number for a link-local
IPv6 address does not work right, yet, but that ought to be fixed
soon.
In support of the changes above,
1 Add a method to struct domain for "externalizing" a sockaddr, and
provide an implementation for IPv6. Expect more work in this area: it
may be more proper to say that the IPv6 implementation "internalizes"
a sockaddr. Add sockaddr_externalize().
2 Add a subroutine, sofamily(), that returns a struct socket's address
family or AF_UNSPEC.
3 Make a lot of IPv4-specific code generic, and move it from
sys/netinet/ to sys/net/ for re-use by IPv6 parts of the kernel and
ifconfig(8).
- Socket layer becomes MP safe.
- Unix protocols become MP safe.
- Allows protocol processing interrupts to safely block on locks.
- Fixes a number of race conditions.
With much feedback from matt@ and plunky@.
- Lock processes, credentials, filehead etc correctly.
- Acquire a read hold on sysctl_treelock if only doing a query.
- Don't wire down the output buffer. It doesn't work correctly and the code
regularly does long term sleeps with it held - it's not worth it.
- Don't hold locks other than sysctl_lock while doing copyout().
- Drop sysctl_lock while doing copyout / allocating memory in a few places.
- Don't take kernel_lock for sysctl.
- Fix a number of bugs spotted along the way
tells a socket that it should both add a protocol header to tx'd
datagrams and remove the header from rx'd datagrams:
int onoff = 1, s = socket(...);
setsockopt(s, SOL_SOCKET, SO_NOHEADER, &onoff);
2) Add an implementation of (SOL_SOCKET, SO_NOHEADER) for raw IPv4
sockets.
3) Reorganize the protocols' pr_ctloutput implementations a bit.
Consistently return ENOPROTOOPT when an option is unsupported,
and EINVAL if a supported option's arguments are incorrect.
Reorganize the flow of code so that it's more clear how/when
options are passed down the stack until they are handled.
Shorten some pr_ctloutput staircases for readability.
4) Extract common mbuf code into subroutines, add new sockaddr
methods, and introduce a new subroutine, fsocreate(), for reuse
later; use it first in sys_socket():
struct mbuf *m_getsombuf(struct socket *so)
Create an mbuf and make its owner the socket `so'.
struct mbuf *m_intopt(struct socket *so, int val)
Create an mbuf, make its owner the socket `so', put the
int `val' into it, and set its length to sizeof(int).
int fsocreate(..., int *fd)
Create a socket, a la socreate(9), put the socket into the
given LWP's descriptor table, return the descriptor at `fd'
on success.
void *sockaddr_addr(struct sockaddr *sa, socklen_t *slenp)
const void *sockaddr_const_addr(const struct sockaddr *sa, socklen_t *slenp)
Extract a pointer to the address part of a sockaddr. Write
the length of the address part at `slenp', if `slenp' is
not NULL.
socklen_t sockaddr_getlen(const struct sockaddr *sa)
Return the length of a sockaddr. This just evaluates to
sa->sa_len. I only add this for consistency with code that
appears in a portable userland library that I am going to
import.
const struct sockaddr *sockaddr_any(const struct sockaddr *sa)
Return the "don't care" sockaddr in the same family as
`sa'. This is the address a client should sobind(9) if it
does not care the source address and, if applicable, the
port et cetera that it uses.
const void *sockaddr_anyaddr(const struct sockaddr *sa, socklen_t *slenp)
Return the "don't care" sockaddr in the same family as
`sa'. This is the address a client should sobind(9) if it
does not care the source address and, if applicable, the
port et cetera that it uses.
and dom_sa_len members from struct domain. Pools of fixed-size
objects are too rigid for sockaddr_dls, whose size can vary over
a wide range.
Return sockaddr_dl to its "historical" size. Now that I'm using
malloc(9) instead of pool(9) to allocate sockaddr_dl, I can create
a sockaddr_dl of any size in the kernel, so expanding sockaddr_dl
is useless.
Avoid using sizeof(struct sockaddr_dl) in the kernel.
Introduce sockaddr_dl_alloc() for allocating & initializing an
arbitrary sockaddr_dl on the heap.
Add an argument, the sockaddr length, to sockaddr_alloc(),
sockaddr_copy(), and sockaddr_dl_setaddr().
Constify: LLADDR() -> CLLADDR().
Where the kernel overwrites LLADDR(), use sockaddr_dl_setaddr(),
instead. Used properly, sockaddr_dl_setaddr() will not overrun
the end of the sockaddr.
into sdl_data[].
Move the macro satocsdl() to net/if_dl.h, and introduce satosdl().
Add some helpers for initializing sockaddr_dl (sockaddr_dl_init),
for finding out the length to put in a sockaddr_dl's sdl_len member
(sockaddr_dl_measure), and for setting the link-layer address in
a sockaddr_dl to a new value (sockaddr_dl_setaddr).
Make sockaddr_copy() panic if the caller tries to copy a sockaddr
to a destination where it will not fit.
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.
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.
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.
net.local.stream.pcblist
net.local.dgram.pcblist
net.inet.tcp.pcblist
net.inet.udp.pcblist
net.inet.raw.pcblist
net.inet6.tcp6.pcblist
net.inet6.udp6.pcblist
net.inet6.raw6.pcblist
which allow retrieval of the pcbs in use for those protocols. The
struct involved is 32/64 bit clean and incorporates parts of struct
inpcb, struct unpcb, a bit of struct tcpcb, and two socket addresses.
