From cd0f707c7377cae33a379a5f38ae95411b7748c5 Mon Sep 17 00:00:00 2001
From: oshogbo <oshogbo@FreeBSD.org>
Date: Sun, 18 Nov 2018 12:23:03 +0000
Subject: [PATCH] brandelf: capsicumize it

---
 usr.bin/brandelf/Makefile   |  8 ++++++++
 usr.bin/brandelf/brandelf.c | 25 +++++++++++++++++++++++--
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/usr.bin/brandelf/Makefile b/usr.bin/brandelf/Makefile
index 2c4859fcd959..9d3efde974d6 100644
--- a/usr.bin/brandelf/Makefile
+++ b/usr.bin/brandelf/Makefile
@@ -1,5 +1,13 @@
 # $FreeBSD$
 
+.include <src.opts.mk>
+
 PROG=	brandelf
 
+.if ${MK_CASPER} != "no"
+LIBADD+=	casper
+LIBADD+=	cap_fileargs
+CFLAGS+=	-DWITH_CASPER
+.endif
+
 .include <bsd.prog.mk>
diff --git a/usr.bin/brandelf/brandelf.c b/usr.bin/brandelf/brandelf.c
index 2dc84796c836..c7ce94112365 100644
--- a/usr.bin/brandelf/brandelf.c
+++ b/usr.bin/brandelf/brandelf.c
@@ -33,9 +33,11 @@
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
+#include <sys/capsicum.h>
 #include <sys/elf_common.h>
 #include <sys/errno.h>
 
+#include <capsicum_helpers.h>
 #include <err.h>
 #include <fcntl.h>
 #include <stdbool.h>
@@ -44,6 +46,9 @@ __FBSDID("$FreeBSD$");
 #include <string.h>
 #include <unistd.h>
 
+#include <libcasper.h>
+#include <casper/cap_fileargs.h>
+
 static int elftype(const char *);
 static const char *iselftype(int);
 static void printelftypes(void);
@@ -66,8 +71,10 @@ main(int argc, char **argv)
 {
 
 	const char *strtype = "FreeBSD";
-	int ch, retval, type;
+	int ch, flags, retval, type;
 	bool change, force, listed;
+	fileargs_t *fa;
+	cap_rights_t rights;
 
 	type = ELFOSABI_FREEBSD;
 	retval = 0;
@@ -121,11 +128,24 @@ main(int argc, char **argv)
 		usage();
 	}
 
+	flags = change || force ? O_RDWR : O_RDONLY;
+	cap_rights_init(&rights, CAP_READ, CAP_SEEK);
+	if (flags == O_RDWR)
+		cap_rights_set(&rights, CAP_WRITE);
+
+	fa = fileargs_init(argc, argv, flags, 0, &rights);
+	if (fa == NULL)
+		errx(1, "unable to init casper");
+
+	caph_cache_catpages();
+	if (caph_limit_stdio() < 0 || caph_enter_casper() < 0)
+		err(1, "unable to enter capability mode");
+
 	while (argc != 0) {
 		int fd;
 		char buffer[EI_NIDENT];
 
-		if ((fd = open(argv[0], change || force ? O_RDWR : O_RDONLY, 0)) < 0) {
+		if ((fd = fileargs_open(fa, argv[0])) < 0) {
 			warn("error opening file %s", argv[0]);
 			retval = 1;
 			goto fail;
@@ -167,6 +187,7 @@ main(int argc, char **argv)
 		argv++;
 	}
 
+	fileargs_free(fa);
 	return (retval);
 }