dparrish/libcli

Libcli provides a shared library for including a Cisco-like command-line interface into other software. It's a telnet interface which supports command-line editing, history, authentication and callbacks for a user-definable function tree.

libcli's Issues

Make libcli 'case sensitive' for handling completors

Currently libcli is basically doing case insensitive checks for all command lookups and '' or '' actions, as well as for the completors. Specific to commands you cannot currently have a command "delete" and one "DELETE" within the same mode. If the commands were 'Delete' and 'declutter' for example, the command name will be correctly display and selected if enough case insensitive characters were entered to resolve one or the other.

For completors it appears to be a bit different. If your set of potential completors could contain entries that differ only in case (one example being a completor for selecting a single file from a Linux directory) if there are entries that differ only in case, then using tab completion you will only be able to get one or the other, depending on which one appears first in the completor entries.

A possible quick fix is to change the strncasecmp() command near line 1506 in libcli.c (1.10.7 version) to be a strncmp(). This makes the main 'see where entries differ' be case sensitive.

Initial testing this did not seem to break anything, and preserves the current 'commands are case insensitive' behavior.

Constant Memory leak found at this trace

Constant Memory leak found at this trace.
Every time we try to search in CLI,

==7781== LEAK SUMMARY:

==7781== definitely lost: 114 bytes in 20 blocks
==7781== 114 bytes in 20 blocks are definitely lost in loss record 85 of 90

Trace

==7781== at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==7781== by 0x4E3971F: cli_parse_line.constprop.5 (libcli.c:670)
==7781== by 0x4E3CD13: cli_loop (libcli.c:989)
==7781== by 0x4010A1: main (in /home/kalyan/cloutra/src/cli/a.out)

memory leak in _printf?

n = vasprintf(&p, format, ap);

p is leak in _printf in libcli.c.

Segfault on ambiguous optarg during tab/help parsing

Found a segfault condition during tab/help parsing. Suppose a command has two optional arguments 'opt1' and 'opt2'. If the command line is "command opt" this will segfault. Problem has been identified and will be fixed in 1.10.4, to be release very shortly.

Get all strings entered in a submode

I want to create a submode for the user to enter a sequence of strings. They are arbitrary strings and not predetermined keywords. The strings should be processed by a supplied function line by line. Can I do this with libcli ?

maintaining the telnet sessions

Hi... How to change the number of telnet(client) connections to CLI server.

Build failure on darwin: `error: implicit declaration of function 'strchrnul' is invalid in C99`

Noticed by @bobby285271 in NixOS/nixpkgs#147749 when we attempted to update libcli in NixOS.

Build fails on Darwin libc as:

libcli.c:2521:41: error: implicit declaration of function 'strchrnul' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
  if (help && !(c->help = strndup(help, strchrnul(help, '\v') - help))) {

Full build log: https://logs.nix.ci/?key=nixos/nixpkgs.147749&attempt_id=54ba70b3-6044-4233-ab14-a2ecea5c68e8

Looks like strchrnul() needs to be avoided on non-GNU systems.

Licence doubt

Can i copy the project to another project and use directly the .h and .c importing the .h file in a non-free software?
There are some limitations to do this?

help ? hangs cli

start cli using telnet 8000, provide username/password. now use command "help ?" or using "help ". This will hang the cli.

how to access global variable within the command function?

Hi. I have a question while testing the library. I would like to know how to access global variables within the command function registered through the cli_register_command().

If the value of the global variable changed inside main() is printed using cli_print() in the command function, it is not reflected, and on the contrary, the value of the global variable changed inside the command function is not properly displayed in main().
Also, is there a way to telnet output using cli_print() inside another function not registered through cli_register_command()?

Do you ever have a similar problem?

Tag 1.9.5 Release

Hi David,

Would you mind tagging the 1.9.5 release?

I'm submitting a patch for the FreeBSD port and I'd prefer to use the Github download URL.

Out of kindness to the portmaintainers, would you mind using the 'v1.9.5' format for tagging?

Thanks!

-Erik

does libcli support concatinated command+arg?

Say I have the following command under config term subtree:

interface eth0 ip 1.1.1.1 mask-len 24

where eth0, 1.1.1.1 and 24 are filtered results after I type the corresponding command.

Currently, if I create an "interface" command with an argument of interface name, then create an "ip" command with the "interface" command as its parent, when the cli runs it will skip the interface name parameter but goes directly to "ip", e.g.

"interface ?" will show "interface ip" as the only help string.

Thanks

Command processing displays confusing messages when an error detected during parsing

If I have a command with multiple 'levels' ( for example, from clitest 'show regular') that I typo I get this:

router> show reguaaa
Invalid command "show"

It should show the command up to and including the word with an error.
This has been be fixed in the 1.10.5 devel branch

I think it may be better to test lib without install.

So i try to change my makefile as:
clitest: clitest.o $(LIB_STATIC)
$(CC) $(CPPFLAGS) $(CFLAGS) -o $@ $^ $(LIBS)
And it need to export 'LD_LIBRARY_PATH=.' if i use the original makefile.

No version defines in libcli.h

Hi,

There are no version number defines in libcli.h

This makes it hard for consumers to work out what version of the command callback prototype to use.

The change between 0.9.5 and 0.9.6 for example broke the razorback builds.

For this release I guess I will have to implement version checks with compile tests in autoconf.

Please provide real distfiles

Hi,

I am maintaining a freebsd port for libcli. but in order to be able to provide it we need a real distfile.

github guys also think that the tags aren't clean distfiles:
http://support.github.com/discussions/repos/4017-tags-and-distfile-generation-issues

The main problem for us is the http redirection. With true distfiles we can access a directly link with no redirection: cloud.github.com with tags we can't plus the checksum changes each time the tarball associated to the tag is regenerated by github.

Thanks
Bapt

git clone checkout failure

I think somehow you messed up your repository..

git clone git://github.com/dparrish/libcli.git
Initialized empty Git repository in /home/karl/Work/libcli/.git/
remote: Counting objects: 494, done.
remote: Compressing objects: 100% (405/405), done.
remote: Total 494 (delta 51), reused 435 (delta 8)
Receiving objects: 100% (494/494), 576.42 KiB | 173 KiB/s, done.
Resolving deltas: 100% (51/51), done.
warning: remote HEAD refers to nonexistent ref, unable to checkout.

Symptom After you log in to port 8000 through Telnet, no response occurs after entering the password

1. libcli version:1.10.7
2. platform:Centos

As a reference version, 1.9.3 does not have this problem.

Visual Studio support

Please can someone clarify to me the state of Visual Studio support?

It seems that this library doesn't build out of the box with VS2019. There are many issues, the most blatant being the unguarded #include <unistd.h>. However, there's an awful lot of #ifndef WIN32 in the source code, as if at some point, some version of this library worked with some version of Visual Studio.

libcli with nc

Can we make libcli to work with 'nc - netcat ' ? I tried connecting with nc, it connects but output is not displayed.

Suggestion for SSH

Hi,

Any suggestion for SSH support?
Is this outside libcli?

Regards,

Bandu

Correct quote parsing and allow for 'escaping' quotes

Currently cli_parse_line() is not correctly several types of lines with quotes. For example (ignore quotes for the 'parsed' output):

• mixed double and single quotes
  show 'alpha"bravo" charlie'
  parsed as 3 words (1)"show" (2)"bravo" (3)<emptystring>
• lines with non-whitespace immediately before or after the quoted string
  show alpha,"bravo",charlie
  parsed as 3 words (1)"show" (2)"bravo" (3)",charlie"
• no way to 'escape' a quote within a quoted string
  show "alpha,"bravo",charlie"
  parsed as 3 words (1)"show" (2)"alpha," (3)",charlie"

Note that in all 3 cases text is lost. Ideally libcli should support:

• balanced quotes (accept all characters until next matching quote found)
• escaping a quote using the '\' character so it is treated as a literal (deal with escaping the escape as well)

Open question on how two properly quoted strings without whitespace separating them should be handled. Combined into a single string, or converted into two separate tokens?

If a command is longer than 20 characters long it runs into the help message w/o any spaces

As mentioned, if a command is longer than 20 characters it runs in to the help message text w/o space, and is hard to understand.

ssh support

Hello
What do you think about different telnet, ssh support depending on the compilation options?
Is there an additional plan for ssh support?

conflict for c++ keyword

the word 'try' is keyword of c++, i modify it and now compile ok:

static int pass_matches(const char _pass, const char _try)
{
int des;
if ((des = !strncasecmp(pass, DES_PREFIX, sizeof(DES_PREFIX)-1)))
pass += sizeof(DES_PREFIX)-1;

ifndef WIN32

/*
 * TODO - find a small crypt(3) function for use on windows
 */
if (des || !strncmp(pass, MD5_PREFIX, sizeof(MD5_PREFIX)-1))
    **try** = crypt(**try**, pass);

endif

return !strcmp(pass, **try**);

}

Ubuntu repositories

When will version 1.10 be available on ubuntu repositories?

filter abbreviations gives unexpected results

If as a a filter I give "| e" egrep is chosen although the e also could match exclude
I had expected an error or autocompletion hint.
I suspect I got egrep because it is alphabetically first.

Example:

router> show counters | e call
called cmd_test with "show counters"

router> show counters | eg call
called cmd_test with "show counters"

router> show counters | ex call
0 arguments:

I suspect something similar will happen with "b" as it can match begin and between

Extra blank lines when displaying help on options/args

If you are requesting help on options and arguments the line formatting is inserting a extra blank line for each entry

invalid command message not extremely appropriate

Example with clitest

router> show something
Invalid command "show"

Actually the invalid command is not "show", it is the "something" part that causes the problem.
Better error message would be:
Invalid command "show something"
or maybe
Invalid command "something"

Endless Loop During Command Search

Hi all,

I found the following issue with the libcli. Entering a mode and issuing the same command by mistake, causes the main loop to hang forever. This can be simply reproduced with the test program, as shown below:

$ telnet 127.0.0.1 8000
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
libcli test environment

Username: fred
Password:  

router> enable
Password: 
router# configure terminal 

router(config)# interface test0/0

router(config-test)# interface

At this point, the CLI hangs and won't return a prompt.

I did some research by myself and think there's something wrong here:

libcli/libcli.c

Line 2913 in b6ff35c

if (again_config) {

As a workaround, I removed this check and it works for me so far.

Best regards,
Stefan Mächler

command completion does not work on filters

command completion for filters does not work as expected

E.g. build clitest, run it, telnet to it then do
show counters |
followed by tab -> no completion, no alternatives (also not after pressing tab a second time
show counters | g
followed by tab -> as above
show counters |
followed by ? -> gives a list of all options (as expected)
show counters | g
followed by ? -> again gist a list of all alternatives. I had expected only filters starting with g (just like happens with commands)

libcli without telnet

Hi
Is there any way I can use libcli without using telnet?
I'm wondering it is possible that run a program like clitest and it displays login screen directly without using telnet session and access cli commands.

Thanks,

How to display continuous date and time on cli console

How to display continuous date and time on cli console just below the banner

CLI_CMD_OPTIONAL_FLAG does not honor user supplied completor callback

As initially coded a CLI_CMD_OPTIONAL_FLAG item will only tab complete the name of the optional flag. This works for some arguments 'as-is', such as for a optarg named 'verbose'. However if there there are multiple acceptable 'answers' (true, True, yes, 1, verbose for example), the tab completion will not recognized them and this can impact parsing.

error - remove me

Add option to not send telnet negotiation

When using libcli as a backend for a libssh based console server the telnet negotiation sequence causes junk to be printed on the terminal at the beginning of the cli_loop. It would be nice to have an option to say that we a not a real telnet session.

backspace works only in one line

on linux centos or redhat 7, run ./testcli and telnet 127.0.0.1 8000 locally. under
Uername: or router> prompt, type very long chars more than 1 line and then hit Backspace, it can't go back to previous line and stuck at the beginning of second line.

New user

Hello, how I can add the new user? Should I use cli_allow_user and cli_allow_enable?
Best regards.

? leads to execution of command

With clitest I did enter "show counters ?"
This could e.g. happen if a user is entering show counters and assumes there is an actual argument.
However instead of some help the command is immediately executed (no return pressed).
It seems not correct that the command is executed just by pressing ?

from the log:

router> show counters
called cmd_test with "show counters"
1 arguments:
?

Incorrect error message when the validator for an optional argument fails

An incorrect error message is being display during command processing if a validator for an optional argument fails. Instead of showing the name of the argument and the actual value that failed, the name of the argument is shown twice.
This issue is fixed in the 1.10.5 devel branch.