Sample modules for KLD.

PR: misc/8621
Submitted by: Rajesh Vaidheeswarran <rv@fore.com>

1 files changed, 197 insertions, 0 deletions

diff --git a/share/examples/kld/misc/module/miscmod.c b/share/examples/kld/misc/module/miscmod.c
new file mode 100644
index 0000000..07be90f
--- /dev/null
+++ b/share/examples/kld/misc/module/miscmod.c
@@ -0,0 +1,197 @@
+/* 08 Nov 1998*/
+/*
+ * miscmod.c
+ *
+ * 08 Nov 1998  Rajesh Vaidheeswarran  - adapted from the lkm miscmod.c
+ *
+ * Copyright (c) 1998 Rajesh Vaidheeswarran
+ * 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed by Rajesh Vaidheeswarran.
+ * 4. The name Rajesh Vaidheeswarran may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY RAJESH VAIDHEESWARRAN ``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 RAJESH VAIDHEESWARRAN 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.
+ *
+ *
+ * Copyright (c) 1993 Terrence R. Lambert.
+ * 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed by Terrence R. Lambert.
+ * 4. The name Terrence R. Lambert may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY TERRENCE R. LAMBERT ``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 TERRENCE R. LAMBERT 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/param.h>
+#include <sys/systm.h>
+#include <sys/sysproto.h>
+#include <sys/exec.h>
+#include <sys/sysent.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/conf.h>
+
+#include "misccall.h"
+
+/*
+ * These two entries define our system call and module information.  We
+ * have 0 arguments to our system call.
+ */
+static struct sysent newent = {
+	0,	misccall		/* # of args, function pointer*/
+};
+
+/*
+ * Miscellaneous modules must have their own save areas...
+ */
+static struct sysent	oldent;		/* save area for old callslot entry*/
+
+/*
+ * Number of syscall entries for a.out executables
+ */
+#define nsysent (aout_sysvec.sv_size)
+
+/*
+ * If you have a data structure to pass ...
+ */
+
+typedef struct misc_data {
+    char name[20];
+    struct sysent * nent;
+    struct sysent * oent;
+    int offset;
+} misc_data_t;
+
+static misc_data_t misc_arg = {
+    "misccall",
+    &newent,
+    &oldent,
+    -1
+};
+
+static int misc_load(module_t,   modeventtype_t, void *);
+
+static moduledata_t misc_mod = {
+    "misc_mod",
+    misc_load,
+    (void *)&misc_arg /* This is our real data */
+};
+
+/*
+ * This function is called each time the module is loaded or unloaded.
+ *
+ * For the system call table, we duplicate the code in the kern_lkm.c
+ * file for patching into the system call table.  We can tell what
+ * has been allocated, etc. by virtue of the fact that we know the
+ * criteria used by the system call loader interface.  We still
+ * kick out the copyright to the console here (to give an example).
+ */
+static int
+misc_load(mod, cmd, arg)
+    module_t	mod;
+    modeventtype_t cmd;
+    void * arg;
+{
+    int i, err = 0;
+
+    misc_data_t * args = (misc_data_t *)arg;
+
+    switch (cmd) {
+    case MOD_LOAD:
+	
+	/*
+	 * Search the table looking for a slot...
+	 */
+	for(i = 1; i < nsysent; i++)
+	    if(sysent[i].sy_call == (sy_call_t *)nosys)
+		break;		/* found it!*/
+	/* out of allocable slots?*/
+	if(i == nsysent) {
+	    err = ENFILE;
+	    break;
+	}
+
+	/* save old -- we must provide our own data area*/
+	bcopy(&sysent[i], args->oent, sizeof(struct sysent));
+
+	/* replace with new*/
+	bcopy(args->nent, &sysent[i], sizeof(struct sysent));
+
+	/* done!*/
+	args->offset = i;	/* slot in sysent[]*/
+
+
+	/* if we make it to here, print copyright on console*/
+	printf("\nSample Loaded kld module (system call)\n");
+	printf("Copyright (c) 1998\n");
+	printf("Rajesh Vaidheeswarran\n");
+	printf("All rights reserved\n");
+	printf("System call %s loaded into slot %d\n", args->name, 
+	       args->offset);
+	break;		/* Success*/
+
+    case MOD_UNLOAD:
+	/* current slot...*/
+	i = args->offset;
+
+	/* replace current slot contents with old contents*/
+	bcopy(args->oent, &sysent[ i], sizeof( struct sysent));
+
+	printf("Unloaded kld module (system call)\n");
+
+	break;		/* Success*/
+
+    default:	/* we only understand load/unload*/
+	err = EINVAL;
+	break;
+    }
+
+    return(err);
+}
+
+/* Now declare the module to the system */
+
+DECLARE_MODULE(misc, misc_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);