Page MenuHomeFreeBSD
Files F103023150

D25998.diff
No OneTemporary
Actions

D25998.diff
View Options

Index: head/usr.sbin/crunch/crunchgen/crunched_main.c
===================================================================
--- head/usr.sbin/crunch/crunchgen/crunched_main.c
+++ head/usr.sbin/crunch/crunchgen/crunched_main.c
@@ -23,6 +23,38 @@
* Computer Science Department
* University of Maryland at College Park
*/
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright 2020 Alex Richardson <arichardson@FreeBSD.org>
+ *
+ * This software was developed by SRI International and the University of
+ * Cambridge Computer Laboratory (Department of Computer Science and
+ * Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the
+ * DARPA SSITH research programme.
+ *
+ * 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 AUTHOR 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 AUTHOR 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.
+ *
+ */
/*
* crunched_main.c - main program for crunched binaries, it branches to a
* particular subprogram based on the value of argv[0]. Also included
@@ -35,6 +67,11 @@
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
+#include <sys/param.h>
+#include <sys/auxv.h>
+#include <sys/sysctl.h>
+
+#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -44,30 +81,88 @@
int (*f)();
};
-extern char *__progname;
+extern const char *__progname;
extern struct stub entry_points[];
static void crunched_usage(void);
+static struct stub *
+find_entry_point(const char *basename)
+{
+ struct stub *ep = NULL;
+
+ for (ep = entry_points; ep->name != NULL; ep++)
+ if (!strcmp(basename, ep->name))
+ break;
+
+ return (ep);
+}
+
+static const char *
+get_basename(const char *exe_path)
+{
+ const char *slash = strrchr(exe_path, '/');
+ return (slash ? slash + 1 : exe_path);
+}
+
int
main(int argc, char **argv, char **envp)
{
- char *slash, *basename;
- struct stub *ep;
+ struct stub *ep = NULL;
+ const char *basename = NULL;
- if (argv[0] == NULL || *argv[0] == '\0')
- crunched_usage();
+ /*
+ * Look at __progname first (this will be set if the crunched binary is
+ * invoked directly).
+ */
+ if (__progname) {
+ basename = get_basename(__progname);
+ ep = find_entry_point(basename);
+ }
- slash = strrchr(argv[0], '/');
- basename = slash ? slash + 1 : argv[0];
+ /*
+ * Otherwise try to find entry point based on argv[0] (this works for
+ * both symlinks as well as hardlinks). However, it does not work when
+ * su invokes a crunched shell because it sets argv[0] to _su when
+ * invoking the shell. In that case we look at AT_EXECPATH as a
+ * fallback.
+ */
+ if (ep == NULL) {
+ basename = get_basename(argv[0]);
+ ep = find_entry_point(basename);
+ }
- for (ep = entry_points; ep->name != NULL; ep++)
- if (!strcmp(basename, ep->name))
- break;
+ /*
+ * If we didn't find the entry point based on __progname or argv[0],
+ * try AT_EXECPATH to get the actual binary that was executed.
+ */
+ if (ep == NULL) {
+ char buf[MAXPATHLEN];
+ int error = elf_aux_info(AT_EXECPATH, &buf, sizeof(buf));
- if (ep->name)
+ if (error == 0) {
+ const char *exe_name = get_basename(buf);
+ /*
+ * Keep using argv[0] if AT_EXECPATH is the crunched
+ * binary so that symlinks to the crunched binary report
+ * "not compiled in" instead of invoking
+ * crunched_main().
+ */
+ if (strcmp(exe_name, EXECNAME) != 0) {
+ basename = exe_name;
+ ep = find_entry_point(basename);
+ }
+ } else {
+ warnc(error, "elf_aux_info(AT_EXECPATH) failed");
+ }
+ }
+
+ if (basename == NULL || *basename == '\0')
+ crunched_usage();
+
+ if (ep != NULL) {
return ep->f(argc, argv, envp);
- else {
+ } else {
fprintf(stderr, "%s: %s not compiled in\n", EXECNAME, basename);
crunched_usage();
}
@@ -76,16 +171,10 @@
int
crunched_main(int argc, char **argv, char **envp)
{
- char *slash;
- struct stub *ep;
- int columns, len;
-
if (argc <= 1)
crunched_usage();
- slash = strrchr(argv[1], '/');
- __progname = slash ? slash + 1 : argv[1];
-
+ __progname = get_basename(argv[1]);
return main(--argc, ++argv, envp);
}

File Metadata

Mime Type
text/plain
Expires
Wed, Nov 20, 10:58 PM (20 h, 37 m)
Storage Engine
blob
Storage Format
Raw Data
Storage Handle
14749172
Default Alt Text
D25998.diff (5 KB)

Event Timeline