bin/57393: wgconfig add peer accepts anything for options

[oster%netbsd.org@localhost]

>Number:         57393
>Category:       bin
>Synopsis:       wgconfig add peer accepts anything for command-line options
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat May 06 03:20:00 +0000 2023
>Originator:     Greg Oster
>Release:        NetBSD 10.0_BETA
>Organization:
>Environment:
System: NetBSD test1.fween.ca 10.0_BETA NetBSD 10.0_BETA (GENERIC) #0: Sat Apr 29 13:22:34 CST 2023  oster%buildbot.fween.ca@localhost:/u1/builds/build2/src/obj/amd64/u1/builds/build2/src/sys/arch/amd64/compile/GENERIC amd64

Architecture: x86_64
Machine: amd64
>Description:
When running "wgconfig add peer <peer name> <base64 public key>" one can add, 
via options, a preshared key path, an endpoint, or allowed IPs.  Unfortunately, 
the following:

wgconfig add peer somepeer UNAzPLq7HDvg6P7ezD3v+S0jE+KxcFCKb/zv3Msa9AA= --allowed-ip=192.168.0.1/32

looks valid, returns no error, but is equivalent to:

wgconfig add peer somepeer UNAzPLq7HDvg6P7ezD3v+S0jE+KxcFCKb/zv3Msa9AA=

which would definitely not be what is expected, nor desired.  In fact, 

wgconfig add peer somepeer UNAzPLq7HDvg6P7ezD3v+S0jE+KxcFCKb/zv3Msa9AA= random text

is also equivalent to:

wgconfig add peer somepeer UNAzPLq7HDvg6P7ezD3v+S0jE+KxcFCKb/zv3Msa9AA= 

(again, without any error).

Not erroring out on invalid options is not good, as one ends up with a
configuration that does not match the desired intent, even though the 
command appears to have been 'successful'.

>How-To-Repeat:

ifconfig wg0 create 192.168.200.2/24
wgconfig wg0 set private-key /etc/wireguard/wg0
wgconfig wg0 set listen-port 51820
wgconfig wg0 add peer other UNAzPLq7HDvg6P7ezD3v+S0jE+KxcFCKb/zv3Msa9AA= --allowed-ip=192.168.100.1/32
wgconfig wg0 show peer other

scratch head wondering why there is no 'allowed-ips' mentioned in the output:

peer: other
        public-key: UNAzPLq7HDvg6P7ezD3v+S0jE+KxcFCKb/zv3Msa9AA=
        endpoint: (none)
        preshared-key: (hidden)
        latest-handshake: (never)

Realize that 'allowed-ip' is not the same as 'allowed-ips'. 

>Fix:

Perhaps something like this?

*** wgconfig.c.orig	2023-05-04 16:35:04.400335580 -0600
--- wgconfig.c	2023-05-05 19:27:42.055900579 -0600
***************
*** 680,693 ****
--- 680,697 ----
  {
  
  	while (argc > 0) {
+ 		int found = 0;
  		for (size_t i = 0; i < __arraycount(options); i++) {
  			const struct option *opt = &options[i];
  			size_t optlen = strlen(opt->option);
  			if (strncmp(argv[0], opt->option, optlen) == 0) {
  				opt->func(argv[0] + optlen, prop_dict);
+ 				found = 1;
  				break;
  			}
  		}
+ 		if (found == 0)
+ 			errx(EXIT_FAILURE, "invalid option: %s", argv[0]);
  		argc -= 1;
  		argv += 1;
  	}