The recent exit-by-indent patch breaks a VTY case where a node is entered but
directly followed by a sibling or ancestor without listing any child nodes.
Regression introduced by I24cbb3f6de111f2d31110c3c484c066f1153aac9.
An example is a common usage in osmo-bts, where 'phy N' / 'instance N' is a
parent node that is commonly left empty:
phy 0
instance 0
bts 0
band 1800
Before this patch, this case produces the error:
There is no such command.
Error occurred during reading the below line:
bts 0
Fix indentation parsing logic in command.c to accomodate this case.
Add a unit test for empty parent node.
Change-Id: Ia0880a17ae55accb092ae8585cc3a1bec9986891
Note: This will break users' config files if they do not use consistent
indenting. (see below for a definition of "consistent".)
When reading VTY commands from a file, use indenting as means to implicitly
exit child nodes. Do not look for commands in the parent node implicitly.
The VTY so far implies 'exit' commands if a VTY line cannot be parsed on the
current node, but succeeds on the parent node. That is the mechanism by which
our VTY config files do not need 'exit' at the end of each child node.
We've hit problems with this in the following scenarios, which will show
improved user experience after this patch:
*) When both a parent and its child node have commands with identical names:
cs7 instace 0
point-code 1.2.3
sccp-address osmo-msc
point-code 0.0.1
If I put the parent's command below the child, it is still interpreted in the
context of the child node:
cs7 instace 0
sccp-address osmo-msc
point-code 0.0.1
point-code 1.2.3
Though the indenting lets me assume I am setting the cs7 instance's global PC
to 1.2.3, I'm actually overwriting osmo-msc's PC with 1.2.3 and discarding the
0.0.1.
*) When a software change moves a VTY command from a child to a parent. Say
'timezone' moved from 'bts' to 'network' level:
network
timezone 1 2
Say a user still has an old config file with 'timezone' on the child level:
network
bts 0
timezone 1 2
trx 0
The user would expect an error message that 'timezone' is invalid on the 'bts'
level. Instead, the VTY finds the parent node's 'timezone', steps out of 'bts'
to the 'network' level, and instead says that the 'trx' command does not exist.
Format:
Consistent means that two adjacent indenting lines have the exact
same indenting characters for the common length:
Weird mix if you ask me, but correct and consistent:
ROOT
<space>PARENT
<space><tab><space>CHILD
<space><tab><space><tab><tab>GRANDCHILD
<space><tab><space><tab><tab>GRANDCHILD2
<space>SIBLING
Inconsistent:
ROOT
<space>PARENT
<tab><space>CHILD
<space><space><tab>GRANDCHILD
<space><tab><tab>GRANDCHILD2
<tab>SIBLING
Also, when going back to a parent level, the exact same indenting must be used
as before in that node:
Incorrect:
ROOT
<tab>PARENT
<tab><tab><tab>CHILD
<tab><tab>SIBLING
As not really intended side effect, it is also permitted to indent the entire
file starting from the root level. We could guard against it but there's no
harm:
Correct and consistent:
<tab>ROOT
<tab><tab>PARENT
<tab><tab><tab><tab>CHILD
<tab><tab>SIBLING
Implementation:
Track parent nodes state: whenever a command enters a child node, push a parent
node onto an llist to remember the exact indentation characters used for that
level.
As soon as the first line on a child node is parsed, remember this new
indentation (which must have a longer strlen() than its parent level) to apply
to all remaining child siblings and grandchildren.
If the amount of spaces that indent a following VTY command are less than this
expected indentation, call vty_go_parent() until it matches up.
At any level, if the common length of indentation characters mismatch, abort
parsing in error.
Transitions to child node are spread across VTY implementations and are hard to
change. But transitions to the parent node are all handled by vty_go_parent().
By popping a parent from the list of parents in vty_go_parent(), we can also
detect that a command has changed the node without changing the parent, hence
it must have stepped into a child node, and we can push a parent frame.
The behavior on the interactive telnet VTY remains unchanged.
Change-Id: I24cbb3f6de111f2d31110c3c484c066f1153aac9
For interactive telnet VTY, remove the implicit move up to the parent node when
a command did not succeed on the current node level.
When reading config files, this behavior was useful to allow skipping explicit
'exit' commands. (A different patch deals with that.)
In the telnet VTY, this behavior was never necessary. Explicit 'exit' commands
can move to the parent node, and typically uninformed users expect to require
that.
On a telnet VTY, counting indents like for reading config files is not an
option: a user will always type from the first column or may paste some leading
spaces without intended meaning.
After this patch, it is thus no longer possible to paste a complete config
across several node levels directly to a telnet session, unless it contains
'exit' commands.
Change-Id: Id73cba2dd34676bad8a130e9c45e67a272f19588
This commit provides stats configuration similar to the log
configuration.
The following vty commands are added to the config node:
stats reporter statsd Create/Modify a statsd reporter
no stats reporter statsd Remove a statsd reporter
To actually configure a reporter, the config-stats node is entered
when the "stats reporter" command has succeeded. The following new
vty commands are available there:
local-ip ADDR Set the IP address to which we bind locally
no local-ip Do not bind to a certain IP address
remote-ip ADDR Set the remote IP address to which we connect
remote-port <1-65535> Set the remote port to which we connect
prefix PREFIX Set the item/counter name prefix
no prefix Do not use a prefix
enable Enable the reporter
disable Disable the reporter
Sponsored-by: On-Waves ehf
This adds the vty_install_default() function that is basically the
install_default() function plus the registration of the commands
'exit' and 'end'. The latter is only provided in subnodes of
ENABLED_NODE and CONFIG_NONE.
The VTY test program is extended to check these commands.
Ticket: OW#952
Compiled with ubuntu 1204 (precise), where -Wformat-security is enabled by
-Wall.
Test yields ok, but the current implementation doesn't properly support
multi-character separators and end strings. So the test output is truncated.
Addresses:
utils.c: In function 'vty_cmd_string_from_valstr':
utils.c:84:2: warning: format not a string literal and no format arguments [-Wformat-security]
utils.c:84:2: warning: format not a string literal and no format arguments [-Wformat-security]
utils.c:108:2: warning: format not a string literal and no format arguments [-Wformat-security]
utils.c:108:2: warning: format not a string literal and no format arguments [-Wformat-security]
Neels Hofmeyr