[src/trunk]: src/sys/netinet6 more cleanup (don't allow oldlenp == NULL)

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/62e1a71f171c
branches:  trunk
changeset: 829413:62e1a71f171c
user:      christos <christos%NetBSD.org@localhost>
date:      Mon Jan 29 19:51:15 2018 +0000

description:
more cleanup (don't allow oldlenp == NULL)

diffstat:

 sys/netinet6/nd6.c |  53 +++++++++++++++++++++++++----------------------------
 1 files changed, 25 insertions(+), 28 deletions(-)

diffs (100 lines):

diff -r 37044d8d9c09 -r 62e1a71f171c sys/netinet6/nd6.c
--- a/sys/netinet6/nd6.c        Mon Jan 29 19:33:39 2018 +0000
+++ b/sys/netinet6/nd6.c        Mon Jan 29 19:51:15 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nd6.c,v 1.244 2018/01/29 03:42:53 pgoyette Exp $       */
+/*     $NetBSD: nd6.c,v 1.245 2018/01/29 19:51:15 christos Exp $       */
 /*     $KAME: nd6.c,v 1.279 2002/06/08 11:16:51 itojun Exp $   */
 
 /*
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.244 2018/01/29 03:42:53 pgoyette Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.245 2018/01/29 19:51:15 christos Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_net_mpsafe.h"
@@ -2487,21 +2487,10 @@
     size_t newlen
 )
 {
-       void *p;
-       size_t ol;
-       int error;
-       size_t bufsize = 0;
        int (*fill_func)(void *, size_t *);
 
-       error = 0;
-
        if (newp)
                return EPERM;
-       if (oldp && !oldlenp)
-               return EINVAL;
-       ol = oldlenp ? *oldlenp : 0;
-
-       p = NULL;
 
        switch (name) {
        case ICMPV6CTL_ND6_DRLIST:
@@ -2519,18 +2508,28 @@
                return ENOPROTOOPT;
        }
 
-       error = (*fill_func)(p, oldlenp);       /* calc len needed */
-       if (error == 0 && oldp && *oldlenp > 0 ) {
-               p = kmem_alloc(*oldlenp, KM_SLEEP);
-               bufsize = *oldlenp;
-               error = (*fill_func)(p, oldlenp);
-               if (!error && oldp != NULL)
-                       error = copyout(p, oldp, min(ol, *oldlenp));
-               if (*oldlenp > ol)
-                       error = ENOMEM;
+       if (oldlenp == NULL)
+               return EINVAL;
+
+       size_t ol;
+       int error = (*fill_func)(NULL, &ol);    /* calc len needed */
+       if (error)
+               return error;
+
+       if (oldp == NULL) {
+               *oldlenp = ol;
+               return 0;
        }
-       if (p)
-               kmem_free(p, bufsize);
+
+       ol = *oldlenp = min(ol, *oldlenp);
+       if (ol == 0)
+               return 0;
+
+       void *p = kmem_alloc(ol, KM_SLEEP);
+       error = (*fill_func)(p, oldlenp);
+       if (!error)
+               error = copyout(p, oldp, *oldlenp);
+       kmem_free(p, ol);
 
        return error;
 }
@@ -2575,8 +2574,7 @@
        }
        ND6_UNLOCK();
 
-       if (oldlenp)
-               *oldlenp = l;   /* (void *)d - (void *)oldp */
+       *oldlenp = l;   /* (void *)d - (void *)oldp */
 
        return error;
 }
@@ -2678,8 +2676,7 @@
        }
        ND6_UNLOCK();
 
-       if (oldlenp)
-               *oldlenp = l;
+       *oldlenp = l;
 
        return error;
 }