requests which have a 0-length response (such as copyin 0/0).
This change makes links(1) work against a rump kernel which contains
rumpnet_local. The presence of unix domain sockets caused links
to select() with 0 fds and a timeout, and because copyin never woke
up in the kernel the application blocked indefinitely.
would have been much easier if up to and including 5.0 we wouldn't
silently cap the nfds argument to poll(!!!).
Makes things like socket(1) work out-of-the-box, and pretty much
every other decidedly prehistoric select() user.
(netcat is a slight exception since it sets FD_SETSIZE, a.k.a.
interface-of-the-year, to 16)
to convince non-rumped applications to communicate with a rump
kernel instead of the host kernel. The precision of what goes
where is not exactly surgical, but for example when wanting to
debug a web server's TCP/IP stack interaction, it might be enough.
When all you have is a hand grenade, all problems look like a ....
hmm?
There's still plenty to figure out. For example, I'm not sure what
the user interface will be like. Now it just attempts to hijack
network communication. It also needs to sync with symbol renaming
in libc, and maybe autogenerate the non-schizophrenic wrappers
where the communication is heading to exactly one destination, lest
I'll be a mummmy by the time I finish writing them all. As a fun
example of a non-non-schizophrenic one, consider poll().
Work in progress, but I managed to get two non-rumped netcats
talking to each other or fetching the index from a non-rumped
thttpd. telnet works in one direction (i can read the data from
netcat, but anything i send back is not printed). bozohttpd uses
dup2() which i haven't bothered to address yet, etcetc.
(not hooking this up the build for now)
dlsym(RTLD_NEXT) to lookup a host_syscall() function pointer which
is used instead of syscall() to communicate with the kernel server.
WARNING: popular opinion classifies this as "ugly code". if you
have a weak heart/mind/soul/sole meuniere, read max. 1 line of the
diff per day, preferably with food.
