/*
 * Copyright (c) 1993 Paul Kranenburg
 * 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 Paul Kranenburg.
 * 4. 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.
 *
 * $FreeBSD: src/usr.bin/ldd/ldd.c,v 1.18.2.7 2002/02/27 18:35:53 sobomax Exp $
 */

#include <sys/param.h>
#include <sys/wait.h>

#include <machine/elf.h>
#include <dlfcn.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

static void     usage(void);

static void
usage(void)
{
        fprintf(stderr, "usage: ldd [-av] [-f format] program ...\n");
        exit(1);
}

int
main(int argc, char **argv)
{
        char            *fmt1 = NULL, *fmt2 = NULL;
        int             rval;
        int             c;
        int             aflag;

        aflag = 0;
        while ((c = getopt(argc, argv, "af:v")) != -1) {
                switch (c) {
                case 'a':
                        aflag++;
                        break;
                case 'f':
                        if (fmt1) {
                                if (fmt2)
                                        errx(1, "too many formats");
                                fmt2 = optarg;
                        } else
                                fmt1 = optarg;
                        break;
                case 'v':
                        break;
                default:
                        usage();
                        /* NOTREACHED */
                }
        }
        argc -= optind;
        argv += optind;

        if (argc <= 0) {
                usage();
                /* NOTREACHED */
        }

        /* ld.so magic */
        if (setenv("LD_TRACE_LOADED_OBJECTS", "yes", 1) == -1)
                err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS=1");
        if (fmt1) {
                if (setenv("LD_TRACE_LOADED_OBJECTS_FMT1", fmt1, 1) == -1)
                        err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS_FMT1=%s", fmt1);
        }
        if (fmt2) {
                if (setenv("LD_TRACE_LOADED_OBJECTS_FMT2", fmt2, 1) == -1)
                        err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS_FMT2=%s", fmt2);
        }

        rval = 0;
        for ( ;  argc > 0;  argc--, argv++) {
                int     fd;
                union {
                        Elf_Ehdr elf;
                } hdr;
                ssize_t n;
                int     status;
                int     file_ok;
                int     is_shlib;

                if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
                        warn("%s", *argv);
                        rval |= 1;
                        continue;
                }
                if ((n = read(fd, &hdr, sizeof hdr)) == -1) {
                        warn("%s: can't read program header", *argv);
                        close(fd);
                        rval |= 1;
                        continue;
                }

                file_ok = 1;
                is_shlib = 0;
                if ((size_t)n >= sizeof hdr.elf && IS_ELF(hdr.elf)) {
                        Elf_Ehdr ehdr;
                        Elf_Phdr phdr;
                        int dynamic = 0, i;

                        if (lseek(fd, 0, SEEK_SET) == -1 ||
                            read(fd, &ehdr, sizeof ehdr) != sizeof ehdr ||
                            lseek(fd, ehdr.e_phoff, SEEK_SET) == -1
                           ) {
                                warnx("%s: can't read program header", *argv);
                                file_ok = 0;
                        } else {
                                for (i = 0; i < ehdr.e_phnum; i++) {
                                        if (read(fd, &phdr, ehdr.e_phentsize)
                                           != sizeof phdr) {
                                                warnx("%s: can't read program header",
                                                    *argv);
                                                file_ok = 0;
                                                break;
                                        }
                                        if (phdr.p_type == PT_DYNAMIC)
                                                dynamic = 1;
                                }
                        }
                        if (!dynamic) {
                                warnx("%s: not a dynamic executable", *argv);
                                file_ok = 0;
                        } else if (hdr.elf.e_type == ET_DYN) {
                                is_shlib = 1;
                        }
                } else {
                        warnx("%s: not a dynamic executable", *argv);
                        file_ok = 0;
                }
                close(fd);
                if (!file_ok) {
                        rval |= 1;
                        continue;
                }

                if (setenv("LD_TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1) == -1)
                        err(1, "setenv: cannot set LD_TRACE_LOADED_OBJECTS_PROGNAME=%s", *argv);
                if (aflag) setenv("LD_TRACE_LOADED_OBJECTS_ALL", "1", 1);
                else if (fmt1 == NULL && fmt2 == NULL)
                        /* Default formats */
                        printf("%s:\n", *argv);
                fflush(stdout);

                switch (fork()) {
                case -1:
                        err(1, "fork");
                        break;
                default:
                        if (wait(&status) <= 0) {
                                warn("wait");
                                rval |= 1;
                        } else if (WIFSIGNALED(status)) {
                                fprintf(stderr, "%s: signal %d\n",
                                                *argv, WTERMSIG(status));
                                rval |= 1;
                        } else if (WIFEXITED(status) && WEXITSTATUS(status)) {
                                fprintf(stderr, "%s: exit status %d\n",
                                                *argv, WEXITSTATUS(status));
                                rval |= 1;
                        }
                        break;
                case 0:
                        if (is_shlib == 0) {
                                execl(*argv, *argv, NULL);
                                warn("%s", *argv);
                        } else {
                                dlopen(*argv, RTLD_TRACE);
                                warnx("%s: %s", *argv, dlerror());
                        }
                        _exit(1);
                }
        }

        return rval;
}