Terry Lambert's loadable kernel module support - modload & modunload

utilities w/improvements from the NetBSD group.

4 files changed, 495 insertions, 0 deletions

diff --git a/sbin/modload/Makefile b/sbin/modload/Makefile
new file mode 100644
index 0000000..265869f
--- /dev/null
+++ b/sbin/modload/Makefile
@@ -0,0 +1,42 @@
+#
+# Makefile for modload
+#
+# 25 May 93	Terry Lambert		Original
+#
+# 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.
+#
+#	$Id: Makefile,v 1.4 1994/02/09 15:00:32 deraadt Exp $
+#
+
+PROG=	modload
+MAN8=	modload.8
+
+.include <bsd.prog.mk>
diff --git a/sbin/modload/modload.8 b/sbin/modload/modload.8
new file mode 100644
index 0000000..e9e9315
--- /dev/null
+++ b/sbin/modload/modload.8
@@ -0,0 +1,115 @@
+.\" Copyright (c) 1993 Christopher G. Demetriou
+.\" 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. The name of the author may not be used to endorse or promote products
+.\"    derived from this software without specific prior written permission
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
+.\"
+.\"	$Id: modload.8,v 1.3 1994/01/29 01:43:30 jtc Exp $
+.\"
+.Dd June 7, 1993
+.Dt MODLOAD 8
+.Os NetBSD 0.8a
+.Sh NAME
+.Nm modload
+.Nd load a kernel module
+.Sh SYNOPSIS
+.Nm modload
+.Op Fl dv
+.Op Fl A Ar kernel
+.Op Fl e Ar entry
+.Op Fl p Ar postinstall
+.Op Fl o Ar output_file
+.Ar input_file
+.Sh DESCRIPTION
+The
+.Nm
+utility loads a loadable kernel module into a running system.
+The input file is an object file (.o file).
+.Pp
+The options to
+.Nm
+are as follows:
+.Bl -tag -width indent
+.It Fl d
+Debug.  Used to debug
+.Nm
+itself.
+.It Fl v
+Print comments about the loading process.
+.It Fl A Ar kernel
+Specify the file that is passed to the linker
+to resolve module references to external symbols. 
+The symbol file must be for the currently running
+kernel or the module is likely to crash the system.
+.It Fl e Ar entry
+Specify the module entry point.
+This is passed by
+.Nm
+to
+.Xr ld 1
+when the module is linked.
+The default module entry point name is `xxxinit'.
+.It Fl p Ar postinstall
+Specify the name of a shell script or program that will
+be executed if the module is successfully loaded. It
+is always passed the module id (in decimal) and module
+type (in hexadecimal) as the first two arguments.
+For loadable drivers, the third and fourth arguments are
+the block major and character major numbers respectively.
+For a loadable system call, the third argument is the system
+call number.
+.It Fl o Ar output_file
+Specify the name of the output file that is produced by
+the linker.
+.El
+.Sh FILES
+.Bl -tag -width /usr/include/sys/lkm.h -compact
+.It Pa /netbsd
+default file passed to the linker to resolve external
+references in the module
+.It Pa /usr/include/sys/lkm.h
+file containing definitions of module types
+.\" .It Pa output file.
+.\" default output file name
+.Sh DIAGNOSTICS
+The
+.Nm
+utility exits with a status of 0 on success
+and with a nonzero status if an error occurs.
+.Sh SEE ALSO
+.Xr ld 1 ,
+.Xr lkm 4 ,
+.Xr modunload 8 ,
+.Xr modstat 8
+.Sh HISTORY
+The
+.Nm
+command was designed to be similar in functionality
+to the corresponding command in
+.Tn "SunOS 4.1.3" .
+.Sh AUTHOR
+.Bl -tag
+Terrence R. Lambert, terry@cs.weber.edu
+.El
+.Sh BUGS
+Loadable streams modules and loadable execution interpreters
+are not currently supported.
diff --git a/sbin/modload/modload.c b/sbin/modload/modload.c
new file mode 100644
index 0000000..256d1f3
--- /dev/null
+++ b/sbin/modload/modload.c
@@ -0,0 +1,335 @@
+/*
+ * 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.
+ *
+ *	$Id: modload.c,v 1.9 1994/05/23 05:42:41 cgd Exp $
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <err.h>
+#include <a.out.h>
+#include <sys/param.h>
+#include <sys/ioctl.h>
+#include <sys/conf.h>
+#include <sys/mount.h>
+#include <sys/lkm.h>
+#include <sys/file.h>
+#include <sys/errno.h>
+#include "pathnames.h"
+
+#ifndef DFLT_ENTRY
+#define	DFLT_ENTRY	"xxxinit"
+#endif	/* !DFLT_ENTRY */
+
+#define	min(a, b)	((a) < (b) ? (a) : (b))
+
+/*
+ * Expected linker options:
+ *
+ * -A		executable to link against
+ * -e		entry point
+ * -o		output file
+ * -T		address to link to in hex (assumes it's a page boundry)
+ * <target>	object file
+ */
+#define	LINKCMD		"ld -A %s -e _%s -o %s -T %x %s"
+
+int debug = 0;
+int verbose = 0;
+
+int
+linkcmd(kernel, entry, outfile, address, object)
+	char *kernel, *entry, *outfile;
+	u_int address;	/* XXX */
+	char *object;
+{
+	char cmdbuf[1024];
+	int error = 0;
+
+	sprintf(cmdbuf, LINKCMD, kernel, entry, outfile, address, object);
+
+	if (debug)
+		printf("%s\n", cmdbuf);
+
+	switch (system(cmdbuf)) {
+	case 0:				/* SUCCESS! */
+		break;
+	case 1:				/* uninformitive error */
+		/*
+		 * Someone needs to fix the return values from the NetBSD
+		 * ld program -- it's totally uninformative.
+		 *
+		 * No such file		(4 on SunOS)
+		 * Can't write output	(2 on SunOS)
+		 * Undefined symbol	(1 on SunOS)
+		 * etc.
+		 */
+	case 127:			/* can't load shell */
+	case 32512:
+	default:
+		error = 1;
+		break;
+	}
+
+	return error;
+}
+
+void
+usage()
+{
+
+	fprintf(stderr, "usage:\n");
+	fprintf(stderr, "modload [-d] [-v] [-A <kernel>] [-e <entry]\n");
+	fprintf(stderr,
+	    "[-p <postinstall>] [-o <output file>] <input file>\n");
+	exit(1);
+}
+
+int fileopen = 0;
+#define	DEV_OPEN	0x01
+#define	MOD_OPEN	0x02
+#define	PART_RESRV	0x04
+int devfd, modfd;
+struct lmc_resrv resrv;
+
+void
+cleanup()
+{
+	if (fileopen & PART_RESRV) {
+		/*
+		 * Free up kernel memory
+		 */
+		if (ioctl(devfd, LMUNRESRV, 0) == -1)
+			warn("can't release slot 0x%08x memory", resrv.slot);
+	}
+
+	if (fileopen & DEV_OPEN)
+		close(devfd);
+
+	if (fileopen & MOD_OPEN)
+		close(modfd);
+}
+
+int
+main(argc, argv)
+	int argc;
+	char *argv[];
+{
+	int c;
+	char *kname = _PATH_UNIX;
+	char *entry = DFLT_ENTRY;
+	char *post = NULL;
+	char *out = NULL;
+	char *modobj;
+	char modout[80], *p;
+	struct exec info_buf;
+	u_int modsize;	/* XXX */
+	u_int modentry;	/* XXX */
+
+	struct lmc_loadbuf ldbuf;
+	int sz, bytesleft;
+	char buf[MODIOBUF];
+
+	while ((c = getopt(argc, argv, "dvA:e:p:o:")) != EOF) {
+		switch (c) {
+		case 'd':
+			debug = 1;
+			break;	/* debug */
+		case 'v':
+			verbose = 1;
+			break;	/* verbose */
+		case 'A':
+			kname = optarg;
+			break;	/* kernel */
+		case 'e':
+			entry = optarg;
+			break;	/* entry point */
+		case 'p':
+			post = optarg;
+			break;	/* postinstall */
+		case 'o':
+			out = optarg;
+			break;	/* output file */
+		case '?':
+			usage();
+		default:
+			printf("default!\n");
+			break;
+		}
+	}
+	argc -= optind;
+	argv += optind;
+
+	if (argc != 1)
+		usage();
+
+	modobj = argv[0];
+
+	atexit(cleanup);
+
+	/*
+	 * Open the virtual device device driver for exclusive use (needed
+	 * to write the new module to it as our means of getting it in the
+	 * kernel).
+	 */
+	if ((devfd = open(_PATH_LKM, O_RDWR, 0)) == -1)
+		err(3, _PATH_LKM);
+	fileopen |= DEV_OPEN;
+
+	strcpy(modout, modobj);
+
+	p = strchr(modout, '.');
+	if (!p || strcmp(p, ".o"))
+		errx(2, "module object must end in .o");
+	if (out == NULL) {
+		out = modout;
+		*p == 0;
+	}
+
+	/*
+	 * Prelink to get file size
+	 */
+	if (linkcmd(kname, entry, out, 0, modobj))
+		errx(1, "can't prelink `%s' creating `%s'", modobj, out);
+
+	/*
+	 * Pre-open the 0-linked module to get the size information
+	 */
+	if ((modfd = open(out, O_RDONLY, 0)) == -1)
+		err(4, out);
+	fileopen |= MOD_OPEN;
+
+	/*
+	 * Get the load module post load size... do this by reading the
+	 * header and doing page counts.
+	 */
+	if (read(modfd, &info_buf, sizeof(struct exec)) == -1)
+		err(3, "read `%s'", out);
+
+	/*
+	 * Close the dummy module -- we have our sizing information.
+	 */
+	close(modfd);
+	fileopen &= ~MOD_OPEN;
+
+	/*
+	 * Magic number...
+	 */
+	if (N_BADMAG(info_buf))
+		errx(4, "not an a.out format file");
+
+	/*
+	 * Calculate the size of the module
+	 */
+ 	modsize = info_buf.a_text + info_buf.a_data + info_buf.a_bss;
+
+	/*
+	 * Reserve the required amount of kernel memory -- this may fail
+	 * to be successful.
+	 */
+	resrv.size = modsize;	/* size in bytes */
+	resrv.name = modout;	/* objname w/o ".o" */
+	resrv.slot = -1;	/* returned */
+	resrv.addr = 0;		/* returned */
+	if (ioctl(devfd, LMRESERV, &resrv) == -1)
+		err(9, "can't reserve memory");
+	fileopen |= PART_RESRV;
+
+	/*
+	 * Relink at kernel load address
+	 */
+	if (linkcmd(kname, entry, out, resrv.addr, modobj))
+		errx(1, "can't link `%s' creating `%s' bound to 0x%08x",
+		    modobj, out, resrv.addr);
+
+	/*
+	 * Open the relinked module to load it...
+	 */
+	if ((modfd = open(out, O_RDONLY, 0)) == -1)
+		err(4, out);
+	fileopen |= MOD_OPEN;
+
+	/*
+	 * Reread the header to get the actual entry point *after* the
+	 * relink.
+	 */
+	if (read(modfd, &info_buf, sizeof(struct exec)) == -1)
+		err(3, "read `%s'", out);
+
+	/*
+	 * Get the entry point (for initialization)
+	 */
+	modentry = info_buf.a_entry;			/* place to call */
+
+	/*
+	 * Seek to the text offset to start loading...
+	 */
+	if (lseek(modfd, N_TXTOFF(info_buf), 0) == -1)
+		err(12, "lseek");
+
+	/*
+	 * Transfer the relinked module to kernel memory in chunks of
+	 * MODIOBUF size at a time.
+	 */
+	for (bytesleft = info_buf.a_text + info_buf.a_data;
+	    bytesleft > 0;
+	    bytesleft -= sz) {
+		sz = min(bytesleft, MODIOBUF);
+		read(modfd, buf, sz);
+		ldbuf.cnt = sz;
+		ldbuf.data = buf;
+		if (ioctl(devfd, LMLOADBUF, &ldbuf) == -1)
+			err(11, "error transferring buffer");
+	}
+
+	/*
+	 * Save ourselves before disaster (potentitally) strikes...
+	 */
+	sync();
+
+	/*
+	 * Trigger the module as loaded by calling the entry procedure;
+	 * this will do all necessary table fixup to ensure that state
+	 * is maintained on success, or blow everything back to ground
+	 * zero on failure.
+	 */
+	if (ioctl(devfd, LMREADY, &modentry) == -1)
+		err(14, "error initializing module");
+
+	/*
+	 * Success!
+	 */
+	fileopen &= ~PART_RESRV;	/* loaded */
+	printf("Module loaded as ID %d\n", resrv.slot);
+
+	return 0;
+}
diff --git a/sbin/modload/pathnames.h b/sbin/modload/pathnames.h
new file mode 100644
index 0000000..81f70f2
--- /dev/null
+++ b/sbin/modload/pathnames.h
@@ -0,0 +1,3 @@
+#include <paths.h>
+
+#define	_PATH_LKM	"/dev/lkm"