init. Otherwise powerpc dlsym() DTWT and returns NULL.
(now i have no idea why dlsym() it works from rcinit(), but i'll
opt to not care)
Hah, only took 15min to debug that crap this time around. I'm
quickly approaching zero-time with it.
now possible to use unmodified userspace binaries (rpcbind, mountd,
nfsd) to start a rump nfs service and mount file systems from it.
pain-rustique:42:~> mount
rumpfs on / type rumpfs (local)
10.1.1.1:/export on /mnt type nfs
_not_ get removed if the call goes to the rump namespace.
So, now it's possible to use e.g. tcpdump (and most other utilities
which hardcore a /dev pathname) on a rump kernel:
golem> setenv RUMPHIJACK blanket=/dev/bpf
golem> tcpdump -n -i virt0
tcpdump: WARNING: SIOCGIFADDR: virt0: Device not configured
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on virt0, link-type EN10MB (Ethernet), capture size 96 bytes
21:55:38.925596 IP 192.168.2.101 > 204.152.190.12: ICMP echo request, id 47811, seq 0, length 64
21:55:39.095596 IP 204.152.190.12 > 192.168.2.101: ICMP echo reply, id 47811, seq 0, length 64
(if you additionally set socket=all in RUMPHIJACK, tcpdump doesn't
whine about the "not configured" interface)
dealing with dup2() from a rump kernel fd to a host kernel fd.
Consider:
s1 = socket();
s2 = socket();
dup2(s2, 0);
Instead, maintain a real mapping table (and get on my knees and
pray i don't have to touch this hair-splitting code ever again).
Apparently bourne shell scripts from a rump kernel fs work now
(sh script.sh; ./script.sh doesn't work for obvious "IT'S THE WRONG
FS NAMESPACE" reasons). No test regressions either, so I'm a
happy camper.
yesterday on powerpc broke overnight. Apparently adding one more
function before the call to dlsym() fixes things again. I hope
I don't have to add another one tomorrow ....
function call instead of a call through a function pointer.
Apparently powerpc ld.elf_so gets __hackish_return_address() wrong
if the call is done through a function pointer (digging deeper into
that stuff is beyond my interest).
Thanks to riz for providing access to a macppc for debugging.
Unthanks to the broken toolchain in the default installation which
wasted approximately 4 hours of time last night.
module which is compiled -fno-optimize-sibling-calls instead of
trying to fool the optimizer in various ways in the trampoline.
thanks to yamt for the tip
be hijacked. If it's not specified, the default is
"path=/rump,socket=all:nolocal".
So, if you're moof and want to relive your domain/os days (??),
you can do this:
pain-rustique:51:~> setenv RUMPHIJACK 'path=//'
pain-rustique:52:~> df //dev
Filesystem 1K-blocks Used Avail %Cap Mounted on
rumpfs 1 1 0 100% /
pain-rustique:53:~> df /dev
Filesystem 1K-blocks Used Avail %Cap Mounted on
/dev/wd0a 1019864 280640 688232 28% /
where you can mount a file system with a userspace server *without*
it having to go through puffs.
Say, you first start a server with ffs capability and map a host
ffs image into it:
rump_server -lrumpvfs -lrumpfs_ffs \
-d key=/ffsimg,hostpath=ffs2.img,size=e unix:///tmp/ffsserv
Then, configure your shell to talk to the rump server:
setenv RUMP_SERVER unix:///tmp/ffsserv
setenv LD_PRELOAD /usr/lib/librumphijack.so
Create a mountpoint and mount the file system:
pain-rustique:60:~> sh
$ cd /rump
$ ls
dev
$ ls -l
total 1
drwxr-xr-x 2 root wheel 512 Feb 17 18:00 dev
$ mkdir mnt
$ mount_ffs /ffsimg /rump/mnt
mount_ffs: Warning: realpath /ffsimg: No such file or directory
$ df -h mnt
Filesystem Size Used Avail %Cap Mounted on
/ffsimg 496M 380M 91M 80% /mnt
$ du -sckh *
192K dev
380M mnt
381M total
$ umount -R mnt
$ df -h mnt
Filesystem Size Used Avail %Cap Mounted on
rumpfs 1.0K 1.0K 0B 100% /
$
(note, you need -R to umount due to various degrees of unsuccesful
magic it attempts to perform without it)
distinct file descriptors, but the rump kernel thinks they are both
the same. Now, if either one is closed by the application, "both"
will be closed in the rump kernel. To fix this, maintain an
alias-mask. It's not a perfect solution, though (consider e.g.
F_SETFL). Maybe we should actually dup the fd and maintain a
mapping table?
Also, prevent the host from opening file descriptors onto the places
in the fd namespace that have been dupped.
These together fix "cat < /rump/foo" in a hijacked /bin/sh.
(the first one makes sure stdin is open in cat and the second one
makes sure it doesn't try to cat something from /usr/share/locale
instead of stdin)
pooka