/*      $NetBSD: aout2elf.c,v 1.2 2019/06/12 06:20:17 martin Exp $
 *
 * Copyright 1997 Piermont Information Systems Inc.
 * All rights reserved.
 *
 * Written by Philip A. Nelson for Piermont Information Systems Inc.
 *
 * 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. The name of Piermont Information Systems Inc. may not be used to endorse
 *    or promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY PIERMONT INFORMATION SYSTEMS INC. ``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 PIERMONT INFORMATION SYSTEMS INC. 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.
 *
 */

/* aout2elf.c -- routines for upgrading an a.out system to ELF */

#include <sys/param.h>
#include <sys/exec.h>
#include <sys/exec_aout.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <dirent.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>

#include "defs.h"
#include "md.h"
#include "msg_defs.h"
#include "menu_defs.h"

/* Local prototypes */
static int is_aout_shared_lib(const char *name);
static void handle_aout_x_libs(const char *srcdir, const char *tgtdir);
static int handle_aout_libs(const char *dir, int op, const void *arg);
static char *target_realpath(const char *, char *);

#define LIB_COUNT       0
#define LIB_MOVE        1

/* XXX NAH. This probably needs moving to arch/<foo>/md.h
 *
 * a.out X libraries to move. These have not changed since 1.3.x
 */
const char *x_libs[] = {
        "libICE.so.6.3",
        "libPEX5.so.6.0",
        "libSM.so.6.0",
        "libX11.so.6.1",
        "libXIE.so.6.0",
        "libXaw.so.6.1",
        "libXext.so.6.3",
        "libXi.so.6.0",
        "libXmu.so.6.0",
        "libXp.so.6.2",
        "libXt.so.6.0",
        "libXtst.so.6.1",
        "liboldX.so.6.0",
};

static int
is_aout_shared_lib(const char *name)
{
        struct exec ex;
        struct stat st;
        int fd;

        if (stat(name, &st) < 0)
                return 0;
        if ((st.st_mode & (S_IFREG|S_IFLNK)) == 0)
                return 0;

        fd = open(name, O_RDONLY);
        if (fd < 0) {
                return 0;
        }
        if (read(fd, &ex, sizeof ex) - sizeof ex != 0) {
                close(fd);
                return 0;
        }
        close(fd);
        if (N_GETMAGIC(ex) != ZMAGIC ||
            (N_GETFLAG(ex) & EX_DYNAMIC) == 0)
                return 0;

        return 1;
}

static void
handle_aout_x_libs(const char *srcdir, const char *tgtdir)
{
        char src[MAXPATHLEN];
        unsigned int i;

        for (i = 0; i < (sizeof x_libs / sizeof (const char *)); i++) {
                snprintf(src, MAXPATHLEN, "%s/%s", srcdir, x_libs[i]);
                if (!is_aout_shared_lib(src))
                        continue;
                run_program(0, "mv -f %s %s", src, tgtdir);
        }

        /*
         * Don't care if it fails; X may not have been installed.
         */
}

/*
 * Function to count or move a.out shared libraries.
 */
static int
handle_aout_libs(const char *dir, int op, const void *arg)
{
        DIR *dd;
        struct dirent *dp;
        char *full_name;
        const char *destdir = NULL; /* XXX -Wuninitialized [many] */
        int n;

        destdir = NULL; /* XXX gcc */

        dd = opendir(dir);
        if (dd == NULL)
                return -1;

        n = 0;

        switch (op) {
        case LIB_COUNT:
                break;
        case LIB_MOVE:
                destdir = (const char *)arg;
                break;
        default:
                return -1;
        }

        while ((dp = readdir(dd)) != NULL) {
                /*
                 * strlen("libX.so")
                 */
                if (dp->d_namlen < 7)
                        continue;
                if (strncmp(dp->d_name, "lib", 3) != 0)
                        continue;

                if (asprintf(&full_name, "%s/%s", dir, dp->d_name) == -1)  {
                        warn("Out of memory");
                        continue;
                }

                if (!is_aout_shared_lib(full_name))
                        goto endloop;

                switch (op) {
                case LIB_COUNT:
                        n++;
                        break;
                case LIB_MOVE:
                        run_program(0, "mv -f %s %s/%s",
                            full_name, destdir, dp->d_name);
                        break;
                }

endloop:
                free(full_name);
        }

        closedir(dd);

        return n;
}

__dead static void
abort_libupdate(void)
{
        hit_enter_to_continue(MSG_aoutfail, NULL);
        exit(1);
}

int
move_aout_libs(void)
{
        int n, backedup = 0;
        char prefix[MAXPATHLEN], src[MAXPATHLEN];
        struct stat st;

        n = handle_aout_libs(target_expand("/usr/lib"), LIB_COUNT, NULL);
        if (n <= 0)
                return n;

        /*
         * See if /emul/aout already exists, taking symlinks into
         * account. If so, no need to create it, just use it.
         */
        if (target_realpath("/emul/aout", prefix) != NULL && stat(prefix, &st) == 0)
                goto domove;

        /*
         * See if /emul exists. If not, create it.
         */
        if (target_realpath("/emul", prefix) == NULL || stat(prefix, &st) < 0) {
                strlcpy(prefix, target_expand("/emul"), sizeof(prefix));
                if (lstat(prefix, &st) == 0) {
                        run_program(0, "mv -f %s %s", prefix,
                            target_expand("/emul.old"));
                        backedup = 1;
                }
                scripting_fprintf(NULL, "mkdir %s\n", prefix);
                mkdir(prefix, 0755);
        }

        /*
         * Can use strcpy, target_expand has made sure it fits into
         * MAXPATHLEN. XXX all this copying is because concat_paths
         * returns a pointer to a static buffer.
         *
         * If an old aout link exists (apparently pointing to nowhere),
         * move it out of the way.
         */
        strlcpy(src, concat_paths(prefix, "aout"), sizeof(src));
        if (lstat(src, &st) == 0) {
                run_program(0, "mv -f %s %s", src,
                    concat_paths(prefix, "aout.old"));
                backedup = 1;
        }

        /*
         * We have created /emul if needed. Since no previous /emul/aout
         * existed, we'll use a symbolic link in /emul to /usr/aout, to
         * avoid overflowing the root partition.
         */
        strlcpy(prefix, target_expand("/usr/aout"), sizeof(prefix));
        if (run_program(0, "mkdir -p %s", prefix))
                abort_libupdate();
        if (run_program(0, "ln -s %s %s", "/usr/aout", src))
                abort_libupdate();

domove:
        /*
         * Rename etc and usr/lib if they already existed, so that we
         * do not overwrite old files.
         *
         * Then, move /etc/ld.so.conf to /emul/aout/etc/ld.so.conf,
         * and all a.out dynamic libraries from /usr/lib to
         * /emul/aout/usr/lib. This is where the a.out code in ldconfig
         * and ld.so respectively will find them.
         */
        strlcpy(src, concat_paths(prefix, "usr/lib"), sizeof(src));
        run_program(0, "mv -f %s %s", src, concat_paths(prefix, "usr/lib.old"));
        strlcpy(src, concat_paths(prefix, "etc/ld.so.conf"), sizeof(src));
        run_program(0, "mv -f %s %s",
            src, concat_paths(prefix, "etc/ld.so.conf.old"));
        if (run_program(0, "mkdir -p %s ", concat_paths(prefix, "usr/lib")))
                abort_libupdate();
        if (run_program(0, "mkdir -p %s ", concat_paths(prefix, "etc")))
                abort_libupdate();

        strlcpy(src, target_expand("/etc/ld.so.conf"), sizeof(src));
        if (run_program(0, "mv -f %s %s",
            src, concat_paths(prefix, "etc/ld.so.conf")))
                abort_libupdate();

        strlcpy(src, target_expand("/usr/lib"), sizeof(src));
        n = handle_aout_libs(src, LIB_MOVE, concat_paths(prefix, "usr/lib"));

        if (run_program(0, "mkdir -p %s ",
            concat_paths(prefix, "usr/X11R6/lib")))
                abort_libupdate();

        strlcpy(src, target_expand("/usr/X11R6/lib"), sizeof(src));
        handle_aout_x_libs(src, concat_paths(prefix, "usr/X11R6/lib"));

        if (backedup) {
                hit_enter_to_continue(MSG_emulbackup, NULL);
        }

        return n;
}

/*
 * XXXX had to include this to deal with symlinks in some places.
 * When the target * disk is mounted under /targetroot, absolute symlinks
 * on it don't work right.
 * This function will resolve them using the mountpoint as prefix.
 * Copied verbatim from libc, with added prefix handling.
 *
 * char *realpath(const char *path, char resolved_path[MAXPATHLEN]);
 *
 * Find the real name of path, by removing all ".", ".." and symlink
 * components.  Returns (resolved) on success, or (NULL) on failure,
 * in which case the path which caused trouble is left in (resolved).
 */
static char *
target_realpath(const char *path, char *resolved)
{
        struct stat sb;
        int fd, n, rootd, serrno, nlnk = 0;
        char *p, *q, wbuf[MAXPATHLEN];
        char solidus[2], empty[1];
        solidus[0] = '/';
        solidus[1] = '\0';
        empty[0] = '\0';

        /* Save the starting point. */
        if ((fd = open(".", O_RDONLY)) < 0) {
                (void)strlcpy(resolved, ".", MAXPATHLEN);
                return (NULL);
        }

        /*
         * Find the dirname and basename from the path to be resolved.
         * Change directory to the dirname component.
         * lstat the basename part.
         *     if it is a symlink, read in the value and loop.
         *     if it is a directory, then change to that directory.
         * get the current directory name and append the basename.
         */
        if (target_prefix() != NULL && strcmp(target_prefix(), "") != 0)
                snprintf(resolved, MAXPATHLEN, "%s/%s", target_prefix(), path);
        else
                if (strlcpy(resolved, path, MAXPATHLEN) >= MAXPATHLEN) {
                        errno = ENAMETOOLONG;
                        goto err1;
                }
loop:
        q = strrchr(resolved, '/');
        if (q != NULL) {
                p = q + 1;
                if (q == resolved)
                        q = solidus;
                else {
                        do {
                                --q;
                        } while (q > resolved && *q == '/');
                        q[1] = '\0';
                        q = resolved;
                }
                if (chdir(q) < 0)
                        goto err1;
        } else
                p = resolved;

        /* Deal with the last component. */
        if (lstat(p, &sb) == 0) {
                if (S_ISLNK(sb.st_mode)) {
                        if (nlnk++ >= MAXSYMLINKS) {
                                errno = ELOOP;
                                goto err1;
                        }
                        n = readlink(p, wbuf, MAXPATHLEN - 1);
                        if (n < 0)
                                goto err1;
                        wbuf[n] = '\0';
                        if (wbuf[0] == '/')
                                snprintf(resolved, MAXPATHLEN, "%s%s",
                                    target_prefix(), wbuf);
                        else
                                strlcpy(resolved, wbuf, MAXPATHLEN);
                        goto loop;
                }
                if (S_ISDIR(sb.st_mode)) {
                        if (chdir(p) < 0)
                                goto err1;
                        p = empty;
                }
        }

        /*
         * Save the last component name and get the full pathname of
         * the current directory.
         */
        if (strlcpy(wbuf, p, sizeof(wbuf)) >= sizeof(wbuf)) {
                errno = ENAMETOOLONG;
                goto err1;
        }

        /*
         * Call the internal internal version of getcwd which
         * does a physical search rather than using the $PWD short-cut
         */
        if (getcwd(resolved, MAXPATHLEN) == 0)
                goto err1;

        /*
         * Join the two strings together, ensuring that the right thing
         * happens if the last component is empty, or the dirname is root.
         */
        if (resolved[0] == '/' && resolved[1] == '\0')
                rootd = 1;
        else
                rootd = 0;

        if (*wbuf) {
                if (strlen(resolved) + strlen(wbuf) + (rootd ? 0 : 1) + 1 >
                    MAXPATHLEN) {
                        errno = ENAMETOOLONG;
                        goto err1;
                }
                if (rootd == 0)
                        if (strlcat(resolved, "/", MAXPATHLEN) >= MAXPATHLEN) {
                                errno = ENAMETOOLONG;
                                goto err1;
                        }
                if (strlcat(resolved, wbuf, MAXPATHLEN) >= MAXPATHLEN) {
                        errno = ENAMETOOLONG;
                        goto err1;
                }
        }

        /* Go back to where we came from. */
        if (fchdir(fd) < 0) {
                serrno = errno;
                goto err2;
        }

        /* It's okay if the close fails, what's an fd more or less? */
        (void)close(fd);
        return (resolved);

err1:   serrno = errno;
        (void)fchdir(fd);
err2:   (void)close(fd);
        errno = serrno;
        return (NULL);
}