Date: Wed, 3 Jun 2009 13:03:08 +1000 From: Benno Rice <benno@jeamland.net> To: current@freebsd.org Subject: CFR: sanity checking arguments to kldload(8) Message-ID: <B8E26963-4413-499B-A512-A5ECF997D11A@jeamland.net>
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The attached patch performs some sanity checking on arguments passed
to kldload(8). Specifically, if an argument looks like a filename but
lacks a path (eg, 'xfs.ko' as opposed to 'xfs' or './xfs.ko') it
checks to see if a file with that name is in the current directory.
If it is, it checks the current module path to see if a file with that
name also exists there (possibly in an earlier entry if the current
directory is in the module path), if so it warns the user that that
module will be loaded and not the one in the current directory. If
not, it tells the user how to use a path to load the module.
A -q option is added to quieten the output if desired.
Sample output:
# sysctl kern.module_path
kern.module_path: /boot/kernel;/boot/modules
# kldstat
Id Refs Address Size Name
1 1 0xc0400000 cc016c kernel
# pwd
/boot/kernel
# kldload xfs.ko
# kldstat
Id Refs Address Size Name
1 3 0xc0400000 cc016c kernel
2 1 0xc3a09000 b0000 xfs.ko
# kldunload xfs
# cd /boot/modules
# pwd
/boot/modules
# ls
xfs.ko* xfs.ko.symbols*
# kldload xfs.ko
kldload: xfs.ko will be loaded from /boot/kernel, not the current
directory
kldload: to load from the current directory use ./xfs.ko
# kldstat
Id Refs Address Size Name
1 3 0xc0400000 cc016c kernel
2 1 0xc3a09000 b0000 xfs.ko
# kldunload xfs
# kldload -q xfs.ko
# kldstat
Id Refs Address Size Name
1 3 0xc0400000 cc016c kernel
2 1 0xc3a09000 b0000 xfs.ko
# kldunload xfs
# kldstat
Id Refs Address Size Name
1 1 0xc0400000 cc016c kernel
# cd fnord
# pwd
/boot/modules/fnord
# ls
ibcs2.ko* ibcs2.ko.symbols*
# ls /boot/kernel/ibcs2.ko
ls: /boot/kernel/ibcs2.ko: No such file or directory
# ls /boot/modules/ibcs2.ko
ls: /boot/modules/ibcs2.ko: No such file or directory
# kldload ibcs2.ko
kldload: ibcs2.ko is not in the module path
kldload: to load from the current directory use ./ibcs2.ko
# kldstat
Id Refs Address Size Name
1 1 0xc0400000 cc016c kernel
# kldload -q ibcs2.ko
# kldstat
Id Refs Address Size Name
1 1 0xc0400000 cc016c kernel
# kldload ./ibcs2.ko
# kldstat
Id Refs Address Size Name
1 6 0xc0400000 cc016c kernel
2 1 0xc3a09000 b000 ibcs2.ko
# kldunload ibcs2
# kldstat
Id Refs Address Size Name
1 1 0xc0400000 cc016c kernel
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Index: sbin/kldload/kldload.c
===================================================================
--- sbin/kldload/kldload.c (revision 193292)
+++ sbin/kldload/kldload.c (working copy)
@@ -30,10 +30,103 @@
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
+#include <string.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/linker.h>
+#include <sys/sysctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#define PATHCTL "kern.module_path"
+
+/*
+ * Check to see if the requested module is specified as a filename with no
+ * path. If so and if a file by the same name exists in the module path,
+ * warn the user that the module in the path will be used in preference.
+ */
+static int
+path_check(const char *kldname, int quiet)
+{
+ int mib[5], found;
+ size_t miblen, pathlen;
+ char kldpath[MAXPATHLEN];
+ char *path, *tmppath, *element;
+ struct stat sb;
+ dev_t dev;
+ ino_t ino;
+
+ if (strchr(kldname, '/') != NULL) {
+ return (0);
+ }
+ if (strstr(kldname, ".ko") == NULL) {
+ return (0);
+ }
+ if (stat(kldname, &sb) != 0) {
+ return (0);
+ }
+
+ found = 0;
+ dev = sb.st_dev;
+ ino = sb.st_ino;
+
+ miblen = sizeof(mib) / sizeof(mib[0]);
+ if (sysctlnametomib(PATHCTL, mib, &miblen) != 0) {
+ err(1, "sysctlnametomib(%s)", PATHCTL);
+ }
+ if (sysctl(mib, miblen, NULL, &pathlen, NULL, 0) == -1) {
+ err(1, "getting path: sysctl(%s) - size only", PATHCTL);
+ }
+ path = malloc(pathlen + 1);
+ if (path == NULL) {
+ err(1, "allocating %lu bytes for the path",
+ (unsigned long)pathlen + 1);
+ }
+ if (sysctl(mib, miblen, path, &pathlen, NULL, 0) == -1) {
+ err(1, "getting path: sysctl(%s)", PATHCTL);
+ }
+ tmppath = path;
+
+ while ((element = strsep(&tmppath, ";")) != NULL) {
+ strlcpy(kldpath, element, MAXPATHLEN);
+ if (kldpath[strlen(kldpath) - 1] != '/') {
+ strlcat(kldpath, "/", MAXPATHLEN);
+ }
+ strlcat(kldpath, kldname, MAXPATHLEN);
+
+ if (stat(kldpath, &sb) == -1) {
+ continue;
+ }
+
+ found = 1;
+
+ if (sb.st_dev != dev || sb.st_ino != ino) {
+ if (!quiet) {
+ warnx("%s will be loaded from %s, not the "
+ "current directory", kldname, element);
+ warnx("to load from the current directory use "
+ "./%s", kldname);
+ }
+ break;
+ } else if (sb.st_dev == dev && sb.st_ino == ino) {
+ return (0);
+ }
+ }
+
+ free(path);
+
+ if (!found) {
+ if (!quiet) {
+ warnx("%s is not in the module path", kldname);
+ warnx("to load from the current directory use ./%s",
+ kldname);
+ }
+ return (-1);
+ }
+
+ return (0);
+}
+
static void
usage(void)
{
@@ -48,14 +141,21 @@
int errors;
int fileid;
int verbose;
+ int quiet;
errors = 0;
verbose = 0;
-
- while ((c = getopt(argc, argv, "v")) != -1)
+ quiet = 0;
+
+ while ((c = getopt(argc, argv, "qv")) != -1)
switch (c) {
+ case 'q':
+ quiet = 1;
+ verbose = 0;
+ break;
case 'v':
verbose = 1;
+ quiet = 0;
break;
default:
usage();
@@ -67,13 +167,17 @@
usage();
while (argc-- != 0) {
- fileid = kldload(argv[0]);
- if (fileid < 0) {
- warn("can't load %s", argv[0]);
- errors++;
- } else
- if (verbose)
- printf("Loaded %s, id=%d\n", argv[0], fileid);
+ if (path_check(argv[0], quiet) == 0) {
+ fileid = kldload(argv[0]);
+ if (fileid < 0) {
+ warn("can't load %s", argv[0]);
+ errors++;
+ } else
+ if (verbose)
+ printf("Loaded %s, id=%d\n", argv[0], fileid);
+ } else {
+ errors++;
+ }
argv++;
}
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--
Benno Rice
benno@jeamland.net
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