Ensure a minimum "slop" of 10 extra pcb structures when providing a

memory size estimate to userland for pcb list sysctls.  The previous
behavior of a "slop" of n/8 does not work well for small values of n
(e.g. no slop at all if you have less than 8 open UDP connections).

Reviewed by:	bz
MFC after:	1 week

sys/netinet/ip_divert.c

@@ -592,8 +592,8 @@ div_pcblist(SYSCTL_HANDLER_ARGS)
 	 */
 	if (req->oldptr == 0) {
 		n = V_divcbinfo.ipi_count;
-		req->oldidx = 2 * (sizeof xig)
-			+ (n + n/8) * sizeof(struct xinpcb);
+		n += imax(n / 8, 10);
+		req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
 		return 0;
 	}
 

sys/netinet/raw_ip.c

@@ -993,8 +993,8 @@ rip_pcblist(SYSCTL_HANDLER_ARGS)
 	 */
 	if (req->oldptr == 0) {
 		n = V_ripcbinfo.ipi_count;
-		req->oldidx = 2 * (sizeof xig)
-		    + (n + n/8) * sizeof(struct xinpcb);
+		n += imax(n / 8, 10);
+		req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
 		return (0);
 	}
 

sys/netinet/tcp_subr.c

@@ -1022,8 +1022,9 @@ tcp_pcblist(SYSCTL_HANDLER_ARGS)
 	if (req->oldptr == NULL) {
 		m = syncache_pcbcount();
 		n = V_tcbinfo.ipi_count;
-		req->oldidx = 2 * (sizeof xig)
-			+ ((m + n) + n/8) * sizeof(struct xtcpcb);
+		n += imax(n / 8, 10);
+		req->oldidx = 2 * (sizeof xig) +
+		    (m + n) * sizeof(struct xtcpcb);
 		return (0);
 	}
 

sys/netinet/udp_usrreq.c

@@ -707,8 +707,8 @@ udp_pcblist(SYSCTL_HANDLER_ARGS)
 	 */
 	if (req->oldptr == 0) {
 		n = V_udbinfo.ipi_count;
-		req->oldidx = 2 * (sizeof xig)
-			+ (n + n/8) * sizeof(struct xinpcb);
+		n += imax(n / 8, 10);
+		req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
 		return (0);
 	}