photosys: add idx for v6tab to mark its position

For linux kernel, it exposes almost 100 lines for /proc/net/snmp6
file. Considering multiple-netns situations, too many lines had to
be read and transferred, which is quite time consuming and space
consuming.

Let's optimize this by adding 'idx' to mark the needed indicators'
position in struct v6tab. During the first time reading, e.i. the
init_net namespace, we record the positions. Then in the following
other netns, we only need to store and transfer indicators' values
according to their positions.

Signed-off-by: Fei Li <[email protected]>

photosyst.c

@@ -116,6 +116,7 @@ static struct udpv6_stats	udpv6_tmp;
 struct v6tab {
 	char 	*nam;
 	count_t *val;
+	int	idx; /* the position of nam in /proc/snmp6 file */
 };
 
 static struct v6tab 		v6tab[] = {
@@ -1195,7 +1196,7 @@ photosyst(struct sstat *si)
 	if ( (fp = fopen("net/snmp6", "r")) != NULL)
 	{
 		count_t	countval;
-		int	cur = 0;
+		int	cur = 0, idx = 0;
 
 		/*
 		** one name-value pair per line
@@ -1210,19 +1211,24 @@ photosyst(struct sstat *si)
 		   	if (strcmp(v6tab[cur].nam, nam) == 0)
 		   	{
 		   		*(v6tab[cur].val) = countval;
+				v6tab[cur].idx = idx;
 		   	}
 		   	else
 		   	{
 		   		for (cur=0; cur < v6tab_entries; cur++)
 					if (strcmp(v6tab[cur].nam, nam) == 0)
 						break;
 
-				if (cur < v6tab_entries) /* found ? */
+				if (cur < v6tab_entries) {/* found ? */
 		   			*(v6tab[cur].val) = countval;
+					v6tab[cur].idx = idx;
+				}
 			}
 
 			if (++cur >= v6tab_entries)
 				cur = 0;
+
+			idx++;
 		}
 
 		memcpy(&si->net.netns[0].ipv6,   &ipv6_tmp,   sizeof ipv6_tmp);