ping: fix parsing of options including '4' and '6'

[asomers]

Summary

ping uses a two-pass option parser. The first pass determines whether
ipv4 or ipv6 is desired, and the second parses the rest of the options.
But the first pass wrongly detects a '4' or '6' in an option's value as
a request to use ipv6 or ipv6 respectively, for example in an invocation
like "ping -c6 1.2.3.4".

Fix this confusion by including all options in the first round of
parsing, but ignoring those unrelated to ipv4/ipv6 selection.

PR: 258048
Reported by: [e-mail]
Submitted by: [e-mail]
MFC after: 2 weeks

Test Plan

tests added

[emaste]

should we add a test for exit:1 with -46 specified?

sbin/ping/tests/ping_test.sh

31

I wonder if we could cache this?

[asomers]

In D32344#735039, @emaste wrote:

should we add a test for exit:1 with -46 specified?

Yeah, sure.

sbin/ping/tests/ping_test.sh

31

No, because every ATF test case runs in its own process. And it only takes about 5ms on my system, anyway.

[asomers]

• add test cases suggested by @emaste

[emaste]

tests LGTM