diff options
| author | kamil <kamil@NetBSD.org> | 2018-04-13 01:20:27 +0000 |
|---|---|---|
| committer | kamil <kamil@NetBSD.org> | 2018-04-13 01:20:27 +0000 |
| commit | d0077632400ff866eb19b79a587c4251774d0b0d (patch) | |
| tree | 0decd323e2c18c0c67e12848d3d5f533241a749f /sys/modules/examples/sysctl | |
| parent | 76ea748cef29af6e037ba4c92c03433e51210f54 (diff) | |
Add new example kernel module: sysctl
sysctl - demonstrates adding a sysctl handle dynamically.
Patch by <Siddharth Muralee>
Polishing by myself.
Diffstat (limited to 'sys/modules/examples/sysctl')
| -rw-r--r-- | sys/modules/examples/sysctl/Makefile | 10 | ||||
| -rw-r--r-- | sys/modules/examples/sysctl/sysctl.c | 118 |
2 files changed, 128 insertions, 0 deletions
diff --git a/sys/modules/examples/sysctl/Makefile b/sys/modules/examples/sysctl/Makefile new file mode 100644 index 00000000000..677cc839ed7 --- /dev/null +++ b/sys/modules/examples/sysctl/Makefile @@ -0,0 +1,10 @@ +# $NetBSD: Makefile,v 1.1 2018/04/13 01:20:28 kamil Exp $ + +.include "../Makefile.inc" + +#S?= /usr/src/sys + +KMOD= sysctl +SRCS= sysctl.c + +.include <bsd.kmodule.mk> diff --git a/sys/modules/examples/sysctl/sysctl.c b/sys/modules/examples/sysctl/sysctl.c new file mode 100644 index 00000000000..2fced29f6c1 --- /dev/null +++ b/sys/modules/examples/sysctl/sysctl.c @@ -0,0 +1,118 @@ +/* $NetBSD: sysctl.c,v 1.1 2018/04/13 01:20:28 kamil Exp $ */ + +/*- + * Copyright (c) 2018 The NetBSD Foundation, Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS + * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED + * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__KERNEL_RCSID(0, "$NetBSD: sysctl.c,v 1.1 2018/04/13 01:20:28 kamil Exp $"); + +#include <sys/param.h> +#include <sys/module.h> +#include <sys/sysctl.h> + +/* + * Check if sysctl -A contains an entry + * example_subroot1.sysctl_example=0 + * to test this module + * + */ + +MODULE(MODULE_CLASS_MISC, sysctl, NULL); + +static int sysctl_example; + +static struct sysctllog *example_sysctl_log; + +static void sysctl_example_setup(struct sysctllog **); + + +/* + * sysctl_example_setup : + * It first creates a subtree by adding a node to the tree. + * This node is named as example_subroot1. + * + * It then creates a node in subtree for the example variable which + * is an integer and is defined in this file itself. + * + * ROOT + * | + * ------- + * | + * examples_subroot1 + * | + * | + * sysctl_example (INT) + * + */ + +static void +sysctl_example_setup(struct sysctllog **clog) +{ + const struct sysctlnode *rnode; + + sysctl_createv(clog, 0, NULL, &rnode, + CTLFLAG_PERMANENT, + CTLTYPE_NODE, "example_subroot1", + NULL, + NULL, 0, + NULL, 0, + CTL_CREATE, CTL_EOL); + + sysctl_createv(clog, 0, &rnode, NULL, + CTLFLAG_PERMANENT|CTLFLAG_READWRITE, + CTLTYPE_INT, "sysctl_example", + SYSCTL_DESCR("An example for sysctl_example"), + NULL, 0, + &sysctl_example, 0, + CTL_CREATE, CTL_EOL); +} + +/* + * The sysctl_example modcmd has two functions. + * 1. Call the sysctl_example_setup function to create a sysctl + * handle when the module is loaded in the kernel. + * 2. Remove the sysctl entry from the kernel once the module + * is unloaded. + */ + + +static int +sysctl_modcmd(modcmd_t cmd, void *arg) +{ + switch(cmd) { + case MODULE_CMD_INIT: + printf("sysctl module inserted"); + sysctl_example_setup(&example_sysctl_log); + break; + case MODULE_CMD_FINI: + printf("sysctl module unloaded"); + sysctl_teardown(&example_sysctl_log); + break; + default: + return ENOTTY; + } + return 0; +} |
