Change the logic around rounding up the needed memory for sysctls since

the network state can change between the two sysctl calls. Adding 10%
extra works for larger routing tables but can be too little on smaller
tables to hold even a single extra message. Instead of that add at least
1024 bytes or 10% (whichever is bigger) and round the size up to the next
page. With this there are no more sporadic errors in the bgpd integration
tests.
OK sthen@

diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index da157d4..bf0f9c0 100644 (file)
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: rtsock.c,v 1.326 2022/02/25 23:51:03 guenther Exp $   */
+/*     $OpenBSD: rtsock.c,v 1.327 2022/03/09 17:29:52 claudio Exp $    */
 /*     $NetBSD: rtsock.c,v 1.18 1996/03/29 00:32:10 cgd Exp $  */
 
 /*
@@ -2218,9 +2218,12 @@ sysctl_rtable(int *name, u_int namelen, void *where, size_t *given, void *new,
                *given = w.w_where - (caddr_t)where;
                if (*given < w.w_needed)
                        return (ENOMEM);
-       } else
-               *given = w.w_needed + w.w_needed / 10;
-
+       } else if (w.w_needed == 0) {
+               *given = 0;
+       } else {
+               *given = roundup(w.w_needed + MAX(w.w_needed / 10, 1024),
+                   PAGE_SIZE);
+       }
        return (error);
 }