[PATCH] Convert gre_sysctl to sysctl_bounded_arr

[Greg Steuck]

Hi David,

What do you think about this patch? I suspect the reference to the
variable is accidental. I changed it to a hardcoded 4 with a quote from
draft-wilson-wrec-wccp-v2-01, though I'm not entirely sure I found the
right reference.

And since I hope to get your attention, maybe you can also OK the
sysctl conversion? Tell me if one or two commits is preferable.

Thanks
Greg

>From 0759b51ee5c612d3f922a334f5eddf2bc1fa053a Mon Sep 17 00:00:00 2001
From: Greg Steuck <g...@nest.cx>
Date: Sat, 21 Nov 2020 14:48:12 -0800
Subject: [PATCH] Convert gre_sysctl to sysctl_bounded_arr

Fixed up a reference to gre_wccp where a fixed value from wwcp
standard was intended.
---
 sys/net/if_gre.c | 31 +++++++++++--------------------
 1 file changed, 11 insertions(+), 20 deletions(-)

diff --git sys/net/if_gre.c sys/net/if_gre.c
index cb5beeaad62..deacad9c755 100644
--- sys/net/if_gre.c
+++ sys/net/if_gre.c
@@ -1109,7 +1109,7 @@ gre_input_key(struct mbuf **mp, int *offp, int type, int 
af, uint8_t otos,
                if (n == NULL)
                        goto decline;
                if (n->m_data[off] >> 4 != IPVERSION)
-                       hlen += sizeof(gre_wccp);
+                       hlen += 4;  /* four-octet GRE header */
 
                /* FALLTHROUGH */
        }
@@ -4229,31 +4229,22 @@ drop:
        return (NULL);
 }
 
+const struct sysctl_bounded_args gre_vars[] = {
+       { GRECTL_ALLOW, &gre_allow, 0, 1 },
+       { GRECTL_WCCP, &gre_wccp, 0, 1 },
+};
+
 int
 gre_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
     size_t newlen)
 {
        int error;
 
-       /* All sysctl names at this level are terminal. */
-       if (namelen != 1)
-               return (ENOTDIR);
-
-       switch (name[0]) {
-       case GRECTL_ALLOW:
-               NET_LOCK();
-               error = sysctl_int(oldp, oldlenp, newp, newlen, &gre_allow);
-               NET_UNLOCK();
-               return (error);
-       case GRECTL_WCCP:
-               NET_LOCK();
-               error = sysctl_int(oldp, oldlenp, newp, newlen, &gre_wccp);
-               NET_UNLOCK();
-               return (error);
-       default:
-               return (ENOPROTOOPT);
-       }
-       /* NOTREACHED */
+       NET_LOCK();
+       error = sysctl_bounded_arr(gre_vars, nitems(gre_vars), name,
+           namelen, oldp, oldlenp, newp, newlen);
+       NET_UNLOCK();
+       return error;
 }
 
 static inline int
-- 
2.29.2