svn commit: r285782 - head/usr.bin/netstat

[Gleb Smirnoff]

  Mark, Jason,

On Tue, Jul 21, 2015 at 11:57:39PM +0000, Mark Johnston wrote:
M>   Fix counter reads on platforms where sizeof(uint64_t) != sizeof(uint64_t *).
M>   
M>   In the kernel, structs such as tcpstat are manipulated as an array of
M>   counter_u64_t (uint64_t *), but made visible to userland as an array of
M>   uint64_t. kread_counters() was previously copying the counter array into
M>   user space and sequentially overwriting each counter with its value. This
M>   mostly affects IPsec counters, as other counters are exported via sysctl.
M>   
M>   PR:		201700
M>   Tested by:	Jason Unovitch

Thanks for fixing the bug after me.

One question, though: why do you use sizeof(u_long) instead of size of a
pointer?

M> ==============================================================================
M> --- head/usr.bin/netstat/main.c	Tue Jul 21 23:44:36 2015	(r285781)
M> +++ head/usr.bin/netstat/main.c	Tue Jul 21 23:57:38 2015	(r285782)
M> @@ -776,19 +776,31 @@ kread_counter(u_long addr)
M>  int
M>  kread_counters(u_long addr, void *buf, size_t size)
M>  {
M> -	uint64_t *c = buf;
M> +	uint64_t *c;
M> +	u_long *counters;
M> +	size_t i, n;
M>  
M>  	if (kvmd_init() < 0)
M>  		return (-1);
M>  
M> -	if (kread(addr, buf, size) < 0)
M> +	if (size % sizeof(uint64_t) != 0) {
M> +		xo_warnx("kread_counters: invalid counter set size");
M>  		return (-1);
M> +	}
M>  
M> -	while (size != 0) {
M> -		*c = kvm_counter_u64_fetch(kvmd, *c);
M> -		size -= sizeof(*c);
M> -		c++;
M> +	n = size / sizeof(uint64_t);
M> +	if ((counters = malloc(n * sizeof(u_long))) == NULL)
M> +		xo_err(-1, "malloc");
M> +	if (kread(addr, counters, n * sizeof(u_long)) < 0) {
M> +		free(counters);
M> +		return (-1);
M>  	}
M> +
M> +	c = buf;
M> +	for (i = 0; i < n; i++)
M> +		c[i] = kvm_counter_u64_fetch(kvmd, counters[i]);
M> +
M> +	free(counters);
M>  	return (0);
M>  }

-- 
Totus tuus, Glebius.