for arg and gre because they cause a race condition by calling ioctl() during
interface initialization. To make this work correctly we would need to
synchronize all interface init routines.
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).
to an interface. This keeps the kernel from entering ifp->if_ioctl
recursively, which can deadlock if if_ioctl takes locks. This will
fix deadlocks & LOCKDEBUG errors in agr(4) (kern/39940) and in
gre(4).
When a link-layer address changes (e.g., ifconfig ex0 link
02🇩🇪ad:be:ef:02 active), send a gratuitous ARP and/or a Neighbor
Advertisement to update the network-/link-layer address bindings
on our LAN peers.
Refuse a change of ethernet address to the address 00:00:00:00:00:00
or to any multicast/broadcast address. (Thanks matt@.)
Reorder ifnet ioctl operations so that driver ioctls may inherit
the functions of their "class"---ether_ioctl(), fddi_ioctl(), et
cetera---and the class ioctls may inherit from the generic ioctl,
ifioctl_common(), but both driver- and class-ioctls may override
the generic behavior. Make network drivers share more code.
Distinguish a "factory" link-layer address from others for the
purposes of both protecting that address from deletion and computing
EUI64.
Return consistent, appropriate error codes from network drivers.
Improve readability. KNF.
*** Details ***
In if_attach(), always initialize the interface ioctl routine,
ifnet->if_ioctl, if the driver has not already initialized it.
Delete if_ioctl == NULL tests everywhere else, because it cannot
happen.
In the ioctl routines of network interfaces, inherit common ioctl
behaviors by calling either ifioctl_common() or whichever ioctl
routine is appropriate for the class of interface---e.g., ether_ioctl()
for ethernets.
Stop (ab)using SIOCSIFADDR and start to use SIOCINITIFADDR. In
the user->kernel interface, SIOCSIFADDR's argument was an ifreq,
but on the protocol->ifnet interface, SIOCSIFADDR's argument was
an ifaddr. That was confusing, and it would work against me as I
make it possible for a network interface to overload most ioctls.
On the protocol->ifnet interface, replace SIOCSIFADDR with
SIOCINITIFADDR. In ifioctl(), return EPERM if userland tries to
invoke SIOCINITIFADDR.
In ifioctl(), give the interface the first shot at handling most
interface ioctls, and give the protocol the second shot, instead
of the other way around. Finally, let compatibility code (COMPAT_OSOCK)
take a shot.
Pull device initialization out of switch statements under
SIOCINITIFADDR. For example, pull ..._init() out of any switch
statement that looks like this:
switch (...->sa_family) {
case ...:
..._init();
...
break;
...
default:
..._init();
...
break;
}
Rewrite many if-else clauses that handle all permutations of IFF_UP
and IFF_RUNNING to use a switch statement,
switch (x & (IFF_UP|IFF_RUNNING)) {
case 0:
...
break;
case IFF_RUNNING:
...
break;
case IFF_UP:
...
break;
case IFF_UP|IFF_RUNNING:
...
break;
}
unifdef lots of code containing #ifdef FreeBSD, #ifdef NetBSD, and
#ifdef SIOCSIFMTU, especially in fwip(4) and in ndis(4).
In ipw(4), remove an if_set_sadl() call that is out of place.
In nfe(4), reuse the jumbo MTU logic in ether_ioctl().
Let ethernets register a callback for setting h/w state such as
promiscuous mode and the multicast filter in accord with a change
in the if_flags: ether_set_ifflags_cb() registers a callback that
returns ENETRESET if the caller should reset the ethernet by calling
if_init(), 0 on success, != 0 on failure. Pull common code from
ex(4), gem(4), nfe(4), sip(4), tlp(4), vge(4) into ether_ioctl(),
and register if_flags callbacks for those drivers.
Return ENOTTY instead of EINVAL for inappropriate ioctls. In
zyd(4), use ENXIO instead of ENOTTY to indicate that the device is
not any longer attached.
Add to if_set_sadl() a boolean 'factory' argument that indicates
whether a link-layer address was assigned by the factory or some
other source. In a comment, recommend using the factory address
for generating an EUI64, and update in6_get_hw_ifid() to prefer a
factory address to any other link-layer address.
Add a routing message, RTM_LLINFO_UPD, that tells protocols to
update the binding of network-layer addresses to link-layer addresses.
Implement this message in IPv4 and IPv6 by sending a gratuitous
ARP or a neighbor advertisement, respectively. Generate RTM_LLINFO_UPD
messages on a change of an interface's link-layer address.
In ether_ioctl(), do not let SIOCALIFADDR set a link-layer address
that is broadcast/multicast or equal to 00:00:00:00:00:00.
Make ether_ioctl() call ifioctl_common() to handle ioctls that it
does not understand.
In gif(4), initialize if_softc and use it, instead of assuming that
the gif_softc and ifp overlap.
Let ifioctl_common() handle SIOCGIFADDR.
Sprinkle rtcache_invariants(), which checks on DIAGNOSTIC kernels
that certain invariants on a struct route are satisfied.
In agr(4), rewrite agr_ioctl_filter() to be a bit more explicit
about the ioctls that we do not allow on an agr(4) member interface.
bzero -> memset. Delete unnecessary casts to void *. Use
sockaddr_in_init() and sockaddr_in6_init(). Compare pointers with
NULL instead of "testing truth". Replace some instances of (type
*)0 with NULL. Change some K&R prototypes to ANSI C, and join
lines.
sa6_len, and sa6_add) with sockaddr_in6_init() calls.
De-__P(). Constify. KNF. Shorten a staircase. Change bcmp() to
memcmp().
Extract subroutine in6_setzoneid() from in6_setscope(), for re-use
soon.
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.
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.
in6_control() with splnet()/splx(). I was being a bit paranoid
here. Following a cursory analysis of the code, this still looked
necessary. We don't spend a lot of time in these calls, so it
should not be too harmful to suspend network interrupts.
In in6_unlink_ifa(), call in6_delmulti() just once on each multicast
address (in6_multi). Previously, in6_unlink_ifa() called in6_delmulti()
on each in6_multi until in6_delmulti() removed the in6_multi from
the list and freed its memory. That's not justified: the multicast
list holds *one* reference. All other references belong to other
entities. We must wait to free the memory until the other entities
release their references, to protect against dereferencing a freed
in6_multi.
XXX I need to revisit in6_delmulti(), in6_unlink_ifa(), and friends,
XXX to pry apart the conditions where an in6_multi is removed from
XXX its list and where it is freed. Following my change, above,
XXX we still risk dereferencing a freed in6_multi.
Prevent in6_update_ifa() and in6_addremloop() from creating dangling
pointers to interfaces in the routing table. Previously, my NetBSD
tunnel concentrator, which adds and deletes a lot of P2P interfaces
with the same local address, crashed in 8 hours or less when it
dereferenced a dangling pointer to a deleted ifnet. Now, its uptime
is greater than 3 days.
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.
- struct timeval time is gone
time.tv_sec -> time_second
- struct timeval mono_time is gone
mono_time.tv_sec -> time_uptime
- access to time via
{get,}{micro,nano,bin}time()
get* versions are fast but less precise
- support NTP nanokernel implementation (NTP API 4)
- further reading:
Timecounter Paper: http://phk.freebsd.dk/pubs/timecounter.pdf
NTP Nanokernel: http://www.eecis.udel.edu/~mills/ntp/html/kern.html
dyoung