[src/trunk]: src/sbin/sysctl Apply patch from PR 43587, mostly from martin an...

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

details:   https://anonhg.NetBSD.org/src/rev/c4adc359ba09
branches:  trunk
changeset: 346753:c4adc359ba09
user:      dholland <dholland%NetBSD.org@localhost>
date:      Sun Jul 31 23:30:28 2016 +0000

description:
Apply patch from PR 43587, mostly from martin and kre. When writing a
sysctl variable using ?= fails with EPERM, don't print an error
message.

Ideally setting a sysctl to the same value it already has should also
not fail regardless of permissions, but this would need to be done in
the kernel.

diffstat:

 sbin/sysctl/sysctl.c |  27 +++++++++++++++++----------
 1 files changed, 17 insertions(+), 10 deletions(-)

diffs (85 lines):

diff -r f38964bb28e6 -r c4adc359ba09 sbin/sysctl/sysctl.c
--- a/sbin/sysctl/sysctl.c      Sun Jul 31 22:38:04 2016 +0000
+++ b/sbin/sysctl/sysctl.c      Sun Jul 31 23:30:28 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sysctl.c,v 1.157 2015/12/13 14:24:47 christos Exp $ */
+/*     $NetBSD: sysctl.c,v 1.158 2016/07/31 23:30:28 dholland Exp $ */
 
 /*-
  * Copyright (c) 2003 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
 #if 0
 static char sccsid[] = "@(#)sysctl.c   8.1 (Berkeley) 6/6/93";
 #else
-__RCSID("$NetBSD: sysctl.c,v 1.157 2015/12/13 14:24:47 christos Exp $");
+__RCSID("$NetBSD: sysctl.c,v 1.158 2016/07/31 23:30:28 dholland Exp $");
 #endif
 #endif /* not lint */
 
@@ -128,8 +128,8 @@
 static void purge_tree(struct sysctlnode *);
 static void print_tree(int *, u_int, struct sysctlnode *, u_int, int, regex_t *,
     size_t *);
-static void write_number(int *, u_int, struct sysctlnode *, char *);
-static void write_string(int *, u_int, struct sysctlnode *, char *);
+static void write_number(int *, u_int, struct sysctlnode *, char *, bool);
+static void write_string(int *, u_int, struct sysctlnode *, char *, bool);
 static void display_number(const struct sysctlnode *, const char *,
                           const void *, size_t, int);
 static void display_string(const struct sysctlnode *, const char *,
@@ -946,10 +946,10 @@
        case CTLTYPE_INT:
        case CTLTYPE_BOOL:
        case CTLTYPE_QUAD:
-               write_number(&name[0], namelen, node, value);
+               write_number(&name[0], namelen, node, value, optional);
                break;
        case CTLTYPE_STRING:
-               write_string(&name[0], namelen, node, value);
+               write_string(&name[0], namelen, node, value, optional);
                break;
        case CTLTYPE_STRUCT:
                /*
@@ -1754,7 +1754,8 @@
  * ********************************************************************
  */
 static void
-write_number(int *name, u_int namelen, struct sysctlnode *node, char *value)
+write_number(int *name, u_int namelen, struct sysctlnode *node, char *value,
+       bool optional)
 {
        u_int ii, io;
        u_quad_t qi, qo;
@@ -1811,7 +1812,9 @@
 
        rc = prog_sysctl(name, namelen, o, &so, i, si);
        if (rc == -1) {
-               sysctlerror(0);
+               if (!optional || errno != EPERM) {
+                       sysctlerror(0);
+               }
                return;
        }
 
@@ -1832,7 +1835,8 @@
 }
 
 static void
-write_string(int *name, u_int namelen, struct sysctlnode *node, char *value)
+write_string(int *name, u_int namelen, struct sysctlnode *node, char *value,
+       bool optional)
 {
        char *i, *o;
        size_t si, so;
@@ -1853,7 +1857,10 @@
 
        rc = prog_sysctl(name, namelen, o, &so, i, si);
        if (rc == -1) {
-               sysctlerror(0);
+               if (!optional || errno != EPERM) {
+                       sysctlerror(0);
+               }
+               free(o);
                return;
        }