diff options
Diffstat (limited to 'usr.bin/brandelf/brandelf.c')
| -rw-r--r-- | usr.bin/brandelf/brandelf.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/usr.bin/brandelf/brandelf.c b/usr.bin/brandelf/brandelf.c new file mode 100644 index 000000000000..e99af06c428a --- /dev/null +++ b/usr.bin/brandelf/brandelf.c @@ -0,0 +1,231 @@ +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (c) 2000, 2001 David O'Brien + * Copyright (c) 1996 Søren Schmidt + * 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 + * in this position and unchanged. + * 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. + */ + +#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> +#include <stdio.h> +#include <stdlib.h> +#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); +static void usage(void) __dead2; + +struct ELFtypes { + const char *str; + int value; +}; +/* XXX - any more types? */ +static struct ELFtypes elftypes[] = { + { "FreeBSD", ELFOSABI_FREEBSD }, + { "Linux", ELFOSABI_LINUX }, + { "Solaris", ELFOSABI_SOLARIS }, + { "SVR4", ELFOSABI_SYSV } +}; + +int +main(int argc, char **argv) +{ + + const char *strtype = "FreeBSD"; + int ch, flags, retval, type; + bool change, force, listed; + fileargs_t *fa; + cap_rights_t rights; + + type = ELFOSABI_FREEBSD; + retval = 0; + change = false; + force = false; + listed = false; + + while ((ch = getopt(argc, argv, "f:lt:v")) != -1) + switch (ch) { + case 'f': + if (change) + errx(1, "f option incompatible with t option"); + force = true; + type = atoi(optarg); + if (errno == ERANGE || type < 0 || type > 255) { + warnx("invalid argument to option f: %s", + optarg); + usage(); + } + break; + case 'l': + printelftypes(); + listed = true; + break; + case 'v': + /* does nothing */ + break; + case 't': + if (force) + errx(1, "t option incompatible with f option"); + change = true; + strtype = optarg; + break; + default: + usage(); + } + argc -= optind; + argv += optind; + if (argc == 0) { + if (listed) + exit(0); + else { + warnx("no file(s) specified"); + usage(); + } + } + + if (!force && (type = elftype(strtype)) == -1) { + warnx("invalid ELF type '%s'", strtype); + printelftypes(); + 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, FA_OPEN); + if (fa == NULL) + err(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 = fileargs_open(fa, argv[0])) < 0) { + warn("error opening file %s", argv[0]); + retval = 1; + goto fail; + } + if (read(fd, buffer, EI_NIDENT) < EI_NIDENT) { + warnx("file '%s' too short", argv[0]); + retval = 1; + goto fail; + } + if (buffer[0] != ELFMAG0 || buffer[1] != ELFMAG1 || + buffer[2] != ELFMAG2 || buffer[3] != ELFMAG3) { + warnx("file '%s' is not ELF format", argv[0]); + retval = 1; + goto fail; + } + if (!change && !force) { + fprintf(stdout, + "File '%s' is of brand '%s' (%u).\n", + argv[0], iselftype(buffer[EI_OSABI]), + buffer[EI_OSABI]); + if (!iselftype(type)) { + warnx("ELF ABI Brand '%u' is unknown", + type); + printelftypes(); + } + } + else { + buffer[EI_OSABI] = type; + lseek(fd, 0, SEEK_SET); + if (write(fd, buffer, EI_NIDENT) != EI_NIDENT) { + warn("error writing %s %d", argv[0], fd); + retval = 1; + goto fail; + } + } +fail: + close(fd); + argc--; + argv++; + } + + fileargs_free(fa); + return (retval); +} + +static void +usage(void) +{ + (void)fprintf(stderr, + "usage: brandelf [-lv] [-f ELF_ABI_number] [-t string] file ...\n"); + exit(1); +} + +static const char * +iselftype(int etype) +{ + size_t elfwalk; + + for (elfwalk = 0; elfwalk < nitems(elftypes); elfwalk++) + if (etype == elftypes[elfwalk].value) + return (elftypes[elfwalk].str); + return (0); +} + +static int +elftype(const char *elfstrtype) +{ + size_t elfwalk; + + for (elfwalk = 0; elfwalk < nitems(elftypes); elfwalk++) + if (strcasecmp(elfstrtype, elftypes[elfwalk].str) == 0) + return (elftypes[elfwalk].value); + return (-1); +} + +static void +printelftypes(void) +{ + size_t elfwalk; + + fprintf(stderr, "known ELF types are: "); + for (elfwalk = 0; elfwalk < nitems(elftypes); elfwalk++) + fprintf(stderr, "%s(%u) ", elftypes[elfwalk].str, + elftypes[elfwalk].value); + fprintf(stderr, "\n"); +} |