svn commit: r321790 - head/sbin/sysctl

[Andrew Gallatin]

On 07/31/17 13:20, John Baldwin wrote:
> On Monday, July 31, 2017 02:56:35 PM Andrew Gallatin wrote:
>> Author: gallatin
>> Date: Mon Jul 31 14:56:35 2017
>> New Revision: 321790
>> URL: https://urldefense.proofpoint.com/v2/url?u=https-3A__svnweb.freebsd.org_changeset_base_321790&d=DwICAg&c=imBPVzF25OnBgGmVOlcsiEgHoG1i6YHLR0Sj_gZ4adc&r=Ed-falealxPeqc22ehgAUCLh8zlZbibZLSMWJeZro4A&m=6pTZhALOHVMuNxvC0RsuEoG4j_dKwjmuXgxC_aZLwj4&s=iX60l0OLjrKSEAZM1J0IrtmCEX_ZvHr2sMgDd4SdHxg&e=
>>
>> Log:
>>    Don't request CTLTYPE_OPAQUE if we can't print them.
>>    
>>    The intent is to skip expensive opaque sysctls like tcp_pcblist unless
>>    they are explicitly requested. Sysctl nodes like this don't show up in
>>    sysctl -a, but they do generate output that winds up being dropped,
>>    unless the user specifically requested  binary/hex output or opaques.
>>    
>>    This reduces the runtime of sysctl in many circumstances on a loaded
>>    system.  It also reduces the likelihood that simply gathering
>>    diagnostics on a sick machine (stuck lock, etc) via sysctl -a might
>>    push it over the edge into a total lockup.
>>    
>>    Reviewed by:	jtl
>>    Sponsored by:	Netflix
>>    Differential Revision:	https://urldefense.proofpoint.com/v2/url?u=https-3A__reviews.freebsd.org_D11461&d=DwICAg&c=imBPVzF25OnBgGmVOlcsiEgHoG1i6YHLR0Sj_gZ4adc&r=Ed-falealxPeqc22ehgAUCLh8zlZbibZLSMWJeZro4A&m=6pTZhALOHVMuNxvC0RsuEoG4j_dKwjmuXgxC_aZLwj4&s=b-hXEv1EHJwVhKxSsmgugUz3RBcGHN7oxcMcI3Dbp_c&e=
>>
>> Modified:
>>    head/sbin/sysctl/sysctl.c
>>
>> Modified: head/sbin/sysctl/sysctl.c
>> ==============================================================================
>> --- head/sbin/sysctl/sysctl.c	Mon Jul 31 14:53:03 2017	(r321789)
>> +++ head/sbin/sysctl/sysctl.c	Mon Jul 31 14:56:35 2017	(r321790)
>> @@ -925,6 +925,32 @@ show_var(int *oid, int nlen)
>>   		printf("%s", buf);
>>   		return (0);
>>   	}
>> +
>> +	/* don't fetch opaques that we don't know how to print */
>> +	if (ctltype == CTLTYPE_OPAQUE) {
>> +		if (strcmp(fmt, "S,clockinfo") == 0)
>> +			func = S_clockinfo;
>> +		else if (strcmp(fmt, "S,timeval") == 0)
>> +			func = S_timeval;
>> +		else if (strcmp(fmt, "S,loadavg") == 0)
>> +			func = S_loadavg;
>> +		else if (strcmp(fmt, "S,vmtotal") == 0)
>> +			func = S_vmtotal;
>> +#ifdef __amd64__
>> +		else if (strcmp(fmt, "S,efi_map_header") == 0)
>> +			func = S_efi_map;
>> +#endif
>> +#if defined(__amd64__) || defined(__i386__)
>> +		else if (strcmp(fmt, "S,bios_smap_xattr") == 0)
>> +			func = S_bios_smap_xattr;
>> +#endif
>> +		else {
>> +			func = NULL;
>> +			if (!bflag && !oflag && !xflag)
>> +				return (1);
>> +		}
>> +	}
>> +
>>   	/* find an estimate of how much we need for this var */
>>   	if (Bflag)
>>   		j = Bflag;
>> @@ -1045,24 +1071,6 @@ show_var(int *oid, int nlen)
>>   
>>   	case CTLTYPE_OPAQUE:
>>   		i = 0;
>> -		if (strcmp(fmt, "S,clockinfo") == 0)
>> -			func = S_clockinfo;
>> -		else if (strcmp(fmt, "S,timeval") == 0)
>> -			func = S_timeval;
>> -		else if (strcmp(fmt, "S,loadavg") == 0)
>> -			func = S_loadavg;
>> -		else if (strcmp(fmt, "S,vmtotal") == 0)
>> -			func = S_vmtotal;
>> -#ifdef __amd64__
>> -		else if (strcmp(fmt, "S,efi_map_header") == 0)
>> -			func = S_efi_map;
>> -#endif
>> -#if defined(__amd64__) || defined(__i386__)
>> -		else if (strcmp(fmt, "S,bios_smap_xattr") == 0)
>> -			func = S_bios_smap_xattr;
>> -#endif
>> -		else
>> -			func = NULL;
>>   		if (func) {
> 
> func should always be true now?
> 

Not if you've set one of the flags to dump raw data.  Eg, try
sysctl -o net.inet.tcp.pcblist



Drew