mirror_iproute2/tipc
Richard Alpe ed81deabf2 tipc: add the ability to get UDP bearer options
In this patch we introduce the ability to get UDP specific bearer
options such as remoteip, remoteport, localip and localport.

After some discussions on tipc-discussion on how to handle media
specific options we agreed to pass them after the media.

For media generic bearer options we already do:
$ tipc bearer get OPTION media MEDIA name|device NAME|DEVICE

For the UDP media specific bearer options we introduce in this path:
$ tipc bearer get media udp name NAME OPTION
such as
$ tipc bearer get media udp name NAME remoteip

This allows bash-completion to tab complete only appropriate options,
it makes more logical sense and it scales better. Even though it might
look a little different to the user.

In order to use the existing option parsing framework to do this we
add a flag (OPT_KEY) to the option parsing function.

If the UDP bearer has multiple remoteip addresses associated with it
(replicast) we handle the TIPC_NLA_UDP_MULTI_REMOTEIP flag and send
a TIPC_NL_UDP_GET_REMOTEIP query transparently to the user.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
2016-09-01 08:34:35 -07:00
..
.gitignore tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
bearer.c tipc: add the ability to get UDP bearer options 2016-09-01 08:34:35 -07:00
bearer.h tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
cmdl.c tipc: add the ability to get UDP bearer options 2016-09-01 08:34:35 -07:00
cmdl.h tipc: add the ability to get UDP bearer options 2016-09-01 08:34:35 -07:00
link.c tipc: add the ability to get UDP bearer options 2016-09-01 08:34:35 -07:00
link.h tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
Makefile tipc: add peer remove functionality 2016-08-29 10:33:24 -07:00
media.c tipc: add the ability to get UDP bearer options 2016-09-01 08:34:35 -07:00
media.h tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
misc.c tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
misc.h tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
msg.c tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
msg.h tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
nametable.c tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
nametable.h tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
node.c tipc: fix help text spelling error in node.c 2016-01-06 09:24:25 -08:00
node.h tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
peer.c tipc: add peer remove functionality 2016-08-29 10:33:24 -07:00
peer.h tipc: add peer remove functionality 2016-08-29 10:33:24 -07:00
README tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
socket.c tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
socket.h tipc: add new TIPC configuration tool 2015-05-21 14:41:41 -07:00
tipc.c tipc: add peer remove functionality 2016-08-29 10:33:24 -07:00

DESIGN DECISIONS
----------------

HELP
~~~~
--help or -h is used for help. We do not reserve the bare word "help", which
for example the ip command does. Reserving a bare word like help quickly
becomes cumbersome to handle in the code. It might be simple to handle
when it's passed early in the command chain like "ip addr help". But when
the user tries to pass "help" further down this requires manual checks and
special treatment. For example, at the time of writing this tool, it's
possible to create a vlan named "help" with the ip tool, but it's impossible
to remove it, the command just shows help. This is an effect of treating
bare words specially.

Help texts are not dynamically generated. That is, we do not pass datastructures
like command list or option lists and print them dynamically. This is
intentional. There is always that exception and when it comes to help texts
these exceptions are normally neglected at the expence of usability.

KEY-VALUE
~~~~~~~~~
All options are key-values. There are both drawbacks and benefits to this.
The main drawback is that it becomes more to write for the user and
information might seem redundant. The main benefits is scalability and code
simplification. Consistency is important.

Consider this.
1. tipc link set priority PRIO link LINK
2. tipc link set LINK priority PRIO

Link might seem redundant in (1). However, if the command should live for many
years and be able to evolve example (2) limits the set command to only work on a
single link with no ability to extend. As an example, lets say we introduce
grouping on the kernel side.

1. tipc link set priority PRIO group GROUP
2. tipc link set ??? priority PRIO group GROUP

2. breaks, we can't extend the command to cover a group.

PARSING
~~~~~~~
Commands are single words. As an example, all words in "tipc link list" are
commands. Options are key-values that can be given in any order. In
"tipc link set priority PRIO link LINK" "tipc link set" are commands while
priority and link are options. Meaning that they can be given like
"tipc link set link LINK priority PRIO".

Abbreviation matching works for both command and options. Meaning that
"tipc link set priority PRIO link LINK" could be given as
"tipc l s p PRIO l LINK" and "tipc link list" as "tipc l l".

MEMORY
~~~~~~
The tool strives to avoid allocating memory on the heap. Most (if not all)
memory allocations are on the stack.

RETURNING
~~~~~~~~~
The tool could throw exit() deep down in functions but doing so always seems
to limit the program in the long run. So we output the error and return an
appropriate error code upon failure.