Subject: Re: [PATCH v3 net-next 4/4] bpftool: implement cgroup bpf operations
To: Jakub Kicinski <jakub.kicinski@netronome.com>,
        Roman Gushchin <guro@fb.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        kernel-team@fb.com, ast@kernel.org, daniel@iogearbox.net, kafai@fb.com,
        Quentin Monnet <quentin.monnet@netronome.com>
References: <20171208145236.12635-1-guro@fb.com>
 <20171208145236.12635-5-guro@fb.com>
 <20171208154629.20ace049@cakuba.netronome.com>
From: David Ahern <dsahern@gmail.com>
Message-ID: <f7cf4c91-7ba6-5771-7a1d-70bed1213dd9@gmail.com>
Date: Sat, 9 Dec 2017 09:28:17 -0700
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On 12/8/17 4:46 PM, Jakub Kicinski wrote:
>> +	argc -= 2;
>> +	argv = &argv[2];
>> +	prog_fd = prog_parse_fd(&argc, &argv);
>> +	if (prog_fd < 0)
>> +		goto exit_cgroup;
>> +
>> +	for (i = 0; i < argc; i++) {
>> +		if (strcmp(argv[i], "allow_multi") == 0) {
>> +			attach_flags |= BPF_F_ALLOW_MULTI;
>> +		} else if (strcmp(argv[i], "allow_override") == 0) {
>> +			attach_flags |= BPF_F_ALLOW_OVERRIDE;
> 
> I don't feel about this strongly but as I said I was trying to follow
> iproute2's conventions, and it allows aliasing.  So if you type "ip a"
> it will give you the first thing that starts with a, not necessarily
> alphabetically, more likely in order of usefulness or order in which
> things were added.  IOW if "allow_" selects "allow_mutli" that's what I
> would actually expect it to do..
> 
> Maybe others disagree?

The iproute2 syntax is very user friendly, and I agree with following
the conventions.

With respect to the attach flags, allow_yyyyy is a lot to type, but
having 'a .. allow_' mean one flag over the other is going to be
confusing. Perhaps dropping the 'allow_' prefix in favor of just 'multi'
and 'override' and doing prefix match on it? User commands do not need
to follow flag names precisely.