Re: [Crash-utility] [RFC patch crash 0/2] namespace support for net command
----- Original Message -----
Dear Dave,
I would like to ask you to take a look and comment this patch set.
I would like to add namespace support to net command.
Currently crash already have ipcs and mount commands that supports namespaces,
however it still had no command to look at list network devices and IP addresses,
related to non-default network namespace. In OpenVZ we have separate network
namespaces for each containers, and we would like to have ability to quickly
get list of netdevices and IPs in container related to crashed process.
Also I believe it should be useful for LXC/Docker containers too.
Mount and ipcs have used -n key to point at according namespace,
however this key was in use in net command. With some doubts I've decided to move
existing -n command to -N, and use -n key as namespace pointer, as in other commands.
Please let me know if it is unacceptable or you have some better ideas.
Typically I prefer to keep traditional option letters in place, but
in this case, I agree with you.
Vasily Averin (2):
net -n option renamed to -N
namespace support for net command
defs.h | 1 +
help.c | 9 ++++++---
net.c | 48 ++++++++++++++++++++++++++++++++++--------------
symbols.c | 2 ++
4 files changed, 43 insertions(+), 17 deletions(-)
I guess this version hasn't been built/tested:
$ make warn
... [ cut ] ...
cc -c -g -DX86_64 -DLZO -DSNAPPY -DGDB_7_6 net.c -Wall -O2 -Wstrict-prototypes
-Wmissing-prototypes -fstack-protector -Wformat-security
net.c: In function 'show_net_devices_v3':
net.c:541:135: error: 'nsproxy_p' undeclared (first use in this function)
net.c:541:135: note: each undeclared identifier is reported only once for each function
it appears in
net.c:543:135: error: 'net_ns_p' undeclared (first use in this function)
make[4]: *** [net.o] Error 1
make[3]: *** [gdb] Error 2
make[2]: *** [rebuild] Error 2
make[1]: *** [gdb_merge] Error 2
make: *** [warn] Error 2
$
But I have no problem with the concept, it's definitely a good idea.
A couple other points/suggestions:
(1) When adding items to the offset_table[], please append them to
the end of the list. This maintains compatibility with extension
modules that were built with an older version of defs.h.
(2) While the location of the new offset_table[] entry is not adjacent
to nsproxy_ipc_ns, it make sense to display them together in
dump_offset_table() as you have done. And thanks for remembering
to put it there, as most patch-posters forget to do so.
(3) The help page is confusing. Since the existing [pid | task] options
are unique and unrelated to -n, it should be something like:
net [-a] [[-s | -S [-xd]] [-R ref] [pid | taskp] [-n pid | taskp]] [-N addr]
Thanks,
Dave