/*-
 * Copyright (c) 1980, 1989, 1993, 1994
 *      The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 * @(#) Copyright (c) 1980, 1989, 1993, 1994 The Regents of the University of California.  All rights reserved.
 * @(#)mount.c  8.25 (Berkeley) 5/8/95
 * $FreeBSD: src/sbin/mount/mount.c,v 1.39.2.3 2001/08/01 08:26:23 obrien Exp $
 */

#include <sys/param.h>
#include <sys/mount.h>
#include <sys/mountctl.h>
#include <sys/stat.h>
#include <sys/wait.h>

#include <err.h>
#include <errno.h>
#include <fstab.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "extern.h"
#include "mntopts.h"
#include "pathnames.h"

/* `meta' options */
#define MOUNT_META_OPTION_FSTAB         "fstab"
#define MOUNT_META_OPTION_CURRENT       "current"

int debug, fstab_style, verbose;

static char  *catopt(char *, const char *);
static struct statfs
             *getmntpt(const char *);
static int    hasopt(const char *, const char *);
static int    ismounted(struct fstab *, struct statfs *, int);
static int    isremountable(const char *);
static void   mangle(char *, int *, const char **);
static char  *update_options(char *, char *, int);
static int    mountfs(const char *, const char *, const char *,
                      int, const char *, const char *);
static void   remopt(char *, const char *);
static void   printdefvals(const struct statfs *);
static void   prmount(struct statfs *);
static void   putfsent(const struct statfs *);
static void   usage(void);
static char  *flags2opts(int);
static char  *xstrdup(const char *str);

/* mount_ufs.c */
int mount_ufs(int, const char **);

/*
 * List of VFS types that can be remounted without becoming mounted on top
 * of each other.
 * XXX Is this list correct?
 */
static const char *
remountable_fs_names[] = {
        "ufs", "ffs", "ext2fs",
        0
};

int
main(int argc, char **argv)
{
        const char *mntfromname, **vfslist, *vfstype;
        struct fstab *fs;
        struct statfs *mntbuf;
        FILE *mountdfp;
        pid_t pid;
        int all, ch, i, init_flags, mntsize, rval, have_fstab;
        char *options;

        all = init_flags = 0;
        options = NULL;
        vfslist = NULL;
        vfstype = "ufs";
        while ((ch = getopt(argc, argv, "adF:fo:prwt:uv")) != -1)
                switch (ch) {
                case 'a':
                        all = 1;
                        break;
                case 'd':
                        debug = 1;
                        break;
                case 'F':
                        setfstab(optarg);
                        break;
                case 'f':
                        init_flags |= MNT_FORCE;
                        break;
                case 'o':
                        if (*optarg)
                                options = catopt(options, optarg);
                        break;
                case 'p':
                        fstab_style = 1;
                        verbose = 1;
                        break;
                case 'r':
                        options = catopt(options, "ro");
                        break;
                case 't':
                        if (vfslist != NULL)
                                errx(1, "only one -t option may be specified");
                        vfslist = makevfslist(optarg);
                        vfstype = optarg;
                        break;
                case 'u':
                        init_flags |= MNT_UPDATE;
                        break;
                case 'v':
                        verbose = 1;
                        break;
                case 'w':
                        options = catopt(options, "noro");
                        break;
                case '?':
                default:
                        usage();
                        /* NOTREACHED */
                }
        argc -= optind;
        argv += optind;

#define BADTYPE(type)                                                   \
        (strcmp(type, FSTAB_RO) &&                                      \
            strcmp(type, FSTAB_RW) && strcmp(type, FSTAB_RQ))

        rval = 0;
        switch (argc) {
        case 0:
                if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0)
                        err(1, "getmntinfo");
                if (all) {
                        while ((fs = getfsent()) != NULL) {
                                if (BADTYPE(fs->fs_type))
                                        continue;
                                if (checkvfsname(fs->fs_vfstype, vfslist))
                                        continue;
                                if (hasopt(fs->fs_mntops, "noauto"))
                                        continue;
                                if (!(init_flags & MNT_UPDATE) &&
                                    ismounted(fs, mntbuf, mntsize))
                                        continue;
                                options = update_options(options,
                                    fs->fs_mntops, mntbuf->f_flags);
                                if (mountfs(fs->fs_vfstype, fs->fs_spec,
                                    fs->fs_file, init_flags, options,
                                    fs->fs_mntops))
                                        rval = 1;
                        }
                } else if (fstab_style) {
                        for (i = 0; i < mntsize; i++) {
                                if (checkvfsname(mntbuf[i].f_fstypename, vfslist))
                                        continue;
                                putfsent(&mntbuf[i]);
                        }
                } else {
                        for (i = 0; i < mntsize; i++) {
                                if (checkvfsname(mntbuf[i].f_fstypename,
                                    vfslist))
                                        continue;
                                prmount(&mntbuf[i]);
                        }
                }
                exit(rval);
        case 1:
                if (vfslist != NULL)
                        usage();

                rmslashes(*argv, *argv);

                if (init_flags & MNT_UPDATE) {
                        mntfromname = NULL;
                        have_fstab = 0;
                        if ((mntbuf = getmntpt(*argv)) == NULL)
                                errx(1, "not currently mounted %s", *argv);
                        /*
                         * Only get the mntflags from fstab if both mntpoint
                         * and mntspec are identical. Also handle the special
                         * case where just '/' is mounted and 'spec' is not
                         * identical with the one from fstab ('/dev' is missing
                         * in the spec-string at boot-time).
                         */
                        if ((fs = getfsfile(mntbuf->f_mntonname)) != NULL) {
                                if (strcmp(fs->fs_spec,
                                    mntbuf->f_mntfromname) == 0 &&
                                    strcmp(fs->fs_file,
                                    mntbuf->f_mntonname) == 0) {
                                        have_fstab = 1;
                                        mntfromname = mntbuf->f_mntfromname;
                                } else if (argv[0][0] == '/' &&
                                    argv[0][1] == '\0') {
                                        fs = getfsfile("/");
                                        have_fstab = 1;
                                        mntfromname = fs->fs_spec;
                                }
                        }
                        if (have_fstab) {
                                options = update_options(options, fs->fs_mntops,
                                    mntbuf->f_flags);
                        } else {
                                mntfromname = mntbuf->f_mntfromname;
                                options = update_options(options, NULL,
                                    mntbuf->f_flags);
                        }
                        rval = mountfs(mntbuf->f_fstypename, mntfromname,
                            mntbuf->f_mntonname, init_flags, options, 0);
                        break;
                }
                if ((fs = getfsfile(*argv)) == NULL &&
                    (fs = getfsspec(*argv)) == NULL)
                        errx(1, "%s: unknown special file or file system",
                            *argv);
                if (BADTYPE(fs->fs_type))
                        errx(1, "%s has unknown file system type",
                            *argv);
                rval = mountfs(fs->fs_vfstype, fs->fs_spec, fs->fs_file,
                    init_flags, options, fs->fs_mntops);
                break;
        case 2:
                /*
                 * If -t flag has not been specified, the path cannot be
                 * found, spec contains either a ':' or a '@', and the
                 * spec is not a file with those characters, then assume
                 * that an NFS filesystem is being specified ala Sun.
                 */
                if (vfslist == NULL && strpbrk(argv[0], ":@") != NULL &&
                    access(argv[0], 0) == -1)
                        vfstype = "nfs";
                rval = mountfs(vfstype, getdevpath(argv[0], 0), argv[1],
                               init_flags, options, NULL);
                break;
        default:
                usage();
                /* NOTREACHED */
        }

        /*
         * If the mount was successfully, and done by root, tell mountd the
         * good news.  Pid checks are probably unnecessary, but don't hurt.
         */
        if (rval == 0 && getuid() == 0 &&
            (mountdfp = fopen(_PATH_MOUNTDPID, "r")) != NULL) {
                if (fscanf(mountdfp, "%d", &pid) == 1 &&
                     pid > 0 && kill(pid, SIGHUP) == -1 && errno != ESRCH)
                        err(1, "signal mountd");
                fclose(mountdfp);
        }

        exit(rval);
}

static int
ismounted(struct fstab *fs, struct statfs *mntbuf, int mntsize)
{
        int i;

        if (fs->fs_file[0] == '/' && fs->fs_file[1] == '\0')
                /* the root file system can always be remounted */
                return (0);

        for (i = mntsize - 1; i >= 0; --i)
                if (strcmp(fs->fs_file, mntbuf[i].f_mntonname) == 0 &&
                    (!isremountable(fs->fs_vfstype) ||
                     strcmp(fs->fs_spec, mntbuf[i].f_mntfromname) == 0))
                        return (1);
        return (0);
}

static int
isremountable(const char *vfsname)
{
        const char **cp;

        for (cp = remountable_fs_names; *cp; cp++)
                if (strcmp(*cp, vfsname) == 0)
                        return (1);
        return (0);
}

static int
hasopt(const char *mntopts, const char *option)
{
        int negative, found;
        char *opt, *optbuf;

        if (option[0] == 'n' && option[1] == 'o') {
                negative = 1;
                option += 2;
        } else
                negative = 0;
        optbuf = xstrdup(mntopts);
        found = 0;
        for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
                if (opt[0] == 'n' && opt[1] == 'o') {
                        if (!strcasecmp(opt + 2, option))
                                found = negative;
                } else if (!strcasecmp(opt, option))
                        found = !negative;
        }
        free(optbuf);
        return (found);
}

static int
mountfs(const char *vfstype, const char *spec, const char *name, int flags,
        const char *options, const char *mntopts)
{
        /* List of directories containing mount_xxx subcommands. */
        static const char *edirs[] = {
                _PATH_SBIN,
                _PATH_USRSBIN,
                NULL
        };
        const char *argv[100], **edir;
        struct statfs sf;
        pid_t pid;
        int argc, i, status;
        char *optbuf, execname[MAXPATHLEN + 1], mntpath[MAXPATHLEN];

        /* resolve the mountpoint with realpath(3) */
        checkpath(name, mntpath);
        name = mntpath;

        if (mntopts == NULL)
                mntopts = "";
        if (options == NULL) {
                if (*mntopts == '\0') {
                        options = "rw";
                } else {
                        options = mntopts;
                        mntopts = "";
                }
        }
        optbuf = catopt(xstrdup(mntopts), options);

        if (strcmp(name, "/") == 0)
                flags |= MNT_UPDATE;
        if (flags & MNT_FORCE)
                optbuf = catopt(optbuf, "force");
        if (flags & MNT_RDONLY)
                optbuf = catopt(optbuf, "ro");
        /*
         * XXX
         * The mount_mfs (newfs) command uses -o to select the
         * optimization mode.  We don't pass the default "-o rw"
         * for that reason.
         */
        if (flags & MNT_UPDATE)
                optbuf = catopt(optbuf, "update");

        argc = 0;
        argv[argc++] = vfstype;
        mangle(optbuf, &argc, argv);
        argv[argc++] = spec;
        argv[argc++] = name;
        argv[argc] = NULL;

        if (debug) {
                printf("exec: mount_%s", vfstype);
                for (i = 1; i < argc; i++)
                        printf(" %s", argv[i]);
                printf("\n");
                return (0);
        }

        switch (pid = fork()) {
        case -1:                                /* Error. */
                warn("fork");
                free(optbuf);
                return (1);
        case 0:                                 /* Child. */
                if (strcmp(vfstype, "ufs") == 0)
                        exit(mount_ufs(argc, argv));

                /* Go find an executable. */
                for (edir = edirs; *edir; edir++) {
                        snprintf(execname,
                            sizeof(execname), "%s/mount_%s", *edir, vfstype);
                        execv(execname, __DECONST(char * const *, argv));
                }
                if (errno == ENOENT) {
                        int len = 0;
                        char *cp;
                        for (edir = edirs; *edir; edir++)
                                len += strlen(*edir) + 2;       /* ", " */
                        if ((cp = malloc(len)) == NULL)
                                errx(1, "malloc failed");
                        cp[0] = '\0';
                        for (edir = edirs; *edir; edir++) {
                                strcat(cp, *edir);
                                if (edir[1] != NULL)
                                        strcat(cp, ", ");
                        }
                        warn("exec mount_%s not found in %s", vfstype, cp);
                }
                exit(1);
                /* NOTREACHED */
        default:                                /* Parent. */
                free(optbuf);

                if (waitpid(pid, &status, 0) < 0) {
                        warn("waitpid");
                        return (1);
                }

                if (WIFEXITED(status)) {
                        if (WEXITSTATUS(status) != 0)
                                return (WEXITSTATUS(status));
                } else if (WIFSIGNALED(status)) {
                        warnx("%s: %s", name, sys_siglist[WTERMSIG(status)]);
                        return (1);
                }

                if (verbose) {
                        if (statfs(name, &sf) < 0) {
                                warn("statfs %s", name);
                                return (1);
                        }
                        if (fstab_style)
                                putfsent(&sf);
                        else
                                prmount(&sf);
                }
                break;
        }

        return (0);
}

static void
prmount(struct statfs *sfp)
{
        struct passwd *pw;
        char *buf;
        int error;
        int len;

        error = 0;
        len = 256;

        if ((buf = malloc(len)) == NULL)
                errx(1, "malloc failed");

        printf("%s on %s (%s", sfp->f_mntfromname, sfp->f_mntonname,
            sfp->f_fstypename);

        /* Get a string buffer with all the used flags names */
        error = mountctl(sfp->f_mntonname, MOUNTCTL_MOUNTFLAGS,
                         -1, NULL, 0, buf, len);

        if (sfp->f_owner) {
                printf(", mounted by ");
                if ((pw = getpwuid(sfp->f_owner)) != NULL)
                        printf("%s", pw->pw_name);
                else
                        printf("%d", sfp->f_owner);
        }

        if (error != -1 && strlen(buf))
                printf(", %s", buf);

        if (verbose) {
                if (sfp->f_syncwrites != 0 || sfp->f_asyncwrites != 0)
                        printf(", writes: sync %ld async %ld",
                            sfp->f_syncwrites, sfp->f_asyncwrites);
                if (sfp->f_syncreads != 0 || sfp->f_asyncreads != 0)
                        printf(", reads: sync %ld async %ld",
                            sfp->f_syncreads, sfp->f_asyncreads);
        }
        printf(")\n");
}

static struct statfs *
getmntpt(const char *name)
{
        struct statfs *mntbuf;
        int i, mntsize;

        mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
        for (i = mntsize - 1; i >= 0; i--) {
                if (strcmp(mntbuf[i].f_mntfromname, name) == 0 ||
                    strcmp(mntbuf[i].f_mntonname, name) == 0)
                        return (&mntbuf[i]);
        }
        return (NULL);
}

static char *
catopt(char *s0, const char *s1)
{
        size_t i;
        char *cp;

        if (s1 == NULL || *s1 == '\0')
                return s0;

        if (s0 && *s0) {
                i = strlen(s0) + strlen(s1) + 1 + 1;
                if ((cp = malloc(i)) == NULL)
                        errx(1, "malloc failed");
                snprintf(cp, i, "%s,%s", s0, s1);
        } else
                cp = xstrdup(s1);

        if (s0)
                free(s0);
        return (cp);
}

static void
mangle(char *options, int *argcp, const char **argv)
{
        char *p, *s;
        int argc;

        argc = *argcp;
        for (s = options; (p = strsep(&s, ",")) != NULL;)
                if (*p != '\0') {
                        if (*p == '-') {
                                argv[argc++] = p;
                                p = strchr(p, '=');
                                if (p) {
                                        *p = '\0';
                                        argv[argc++] = p+1;
                                }
                        } else if (strcmp(p, "rw") != 0) {
                                argv[argc++] = "-o";
                                argv[argc++] = p;
                        }
                }

        *argcp = argc;
}


static char *
update_options(char *opts, char *fstab, int curflags)
{
        char *o, *p;
        char *cur;
        char *expopt, *newopt, *tmpopt;

        if (opts == NULL)
                return xstrdup("");

        /* remove meta options from list */
        remopt(fstab, MOUNT_META_OPTION_FSTAB);
        remopt(fstab, MOUNT_META_OPTION_CURRENT);
        cur = flags2opts(curflags);

        /*
         * Expand all meta-options passed to us first.
         */
        expopt = NULL;
        for (p = opts; (o = strsep(&p, ",")) != NULL;) {
                if (strcmp(MOUNT_META_OPTION_FSTAB, o) == 0)
                        expopt = catopt(expopt, fstab);
                else if (strcmp(MOUNT_META_OPTION_CURRENT, o) == 0)
                        expopt = catopt(expopt, cur);
                else
                        expopt = catopt(expopt, o);
        }
        free(cur);
        free(opts);

        /*
         * Remove previous contradictory arguments. Given option "foo" we
         * remove all the "nofoo" options. Given "nofoo" we remove "nonofoo"
         * and "foo" - so we can deal with possible options like "notice".
         */
        newopt = NULL;
        for (p = expopt; (o = strsep(&p, ",")) != NULL;) {
                if ((tmpopt = malloc( strlen(o) + 2 + 1 )) == NULL)
                        errx(1, "malloc failed");

                strcpy(tmpopt, "no");
                strcat(tmpopt, o);
                remopt(newopt, tmpopt);
                free(tmpopt);

                if (strncmp("no", o, 2) == 0)
                        remopt(newopt, o+2);

                newopt = catopt(newopt, o);
        }
        free(expopt);

        return newopt;
}

static void
remopt(char *string, const char *opt)
{
        char *o, *p, *r;

        if (string == NULL || *string == '\0' || opt == NULL || *opt == '\0')
                return;

        r = string;

        for (p = string; (o = strsep(&p, ",")) != NULL;) {
                if (strcmp(opt, o) != 0) {
                        if (*r == ',' && *o != '\0')
                                r++;
                        while ((*r++ = *o++) != '\0')
                            ;
                        *--r = ',';
                }
        }
        *r = '\0';
}

static void
usage(void)
{

        fprintf(stderr, "%s\n%s\n%s\n",
"usage: mount [-adfpruvw] [-F fstab] [-o options] [-t type]",
"       mount [-dfpruvw] {special | node}",
"       mount [-dfpruvw] [-o options] [-t type] special node");
        exit(1);
}

/*
 * Prints the default values for dump frequency and pass number of fsck.
 * This happens when mount(8) is called with -p and there is no fstab file
 * or there is but the values aren't specified.
 */
static void
printdefvals(const struct statfs *ent)
{
        if (strcmp(ent->f_fstypename, "ufs") == 0) {
                if (strcmp(ent->f_mntonname, "/") == 0)
                        printf("\t1 1\n");
                else
                        printf("\t2 2\n");
        } else {
                printf("\t0 0\n");
        }
}

static void
putfsent(const struct statfs *ent)
{
        struct stat sb;
        struct fstab *fst;
        char *opts;

        opts = flags2opts(ent->f_flags);
        printf("%s\t%s\t%s %s", ent->f_mntfromname, ent->f_mntonname,
            ent->f_fstypename, opts);
        free(opts);

        /*
         * If fstab file is missing don't call getfsspec() or getfsfile()
         * at all, because the same warning will be printed twice for every
         * mounted filesystem.
         */
        if (stat(_PATH_FSTAB, &sb) != -1) {
                if ((fst = getfsspec(ent->f_mntfromname)))
                        printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
                else if ((fst = getfsfile(ent->f_mntonname)))
                        printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
                else
                        printdefvals(ent);
        } else {
                printdefvals(ent);
        }
}


static char *
flags2opts(int flags)
{
        char *res;

        res = NULL;

        res = catopt(res, (flags & MNT_RDONLY) ? "ro" : "rw");

        if (flags & MNT_SYNCHRONOUS)    res = catopt(res, "sync");
        if (flags & MNT_NOEXEC)         res = catopt(res, "noexec");
        if (flags & MNT_NOSUID)         res = catopt(res, "nosuid");
        if (flags & MNT_NODEV)          res = catopt(res, "nodev");
        if (flags & MNT_ASYNC)          res = catopt(res, "async");
        if (flags & MNT_NOATIME)        res = catopt(res, "noatime");
        if (flags & MNT_NOCLUSTERR)     res = catopt(res, "noclusterr");
        if (flags & MNT_NOCLUSTERW)     res = catopt(res, "noclusterw");
        if (flags & MNT_NOSYMFOLLOW)    res = catopt(res, "nosymfollow");
        if (flags & MNT_SUIDDIR)        res = catopt(res, "suiddir");
        if (flags & MNT_IGNORE)         res = catopt(res, "ignore");

        return res;
}

static char*
xstrdup(const char *str)
{
        char* ret = strdup(str);
        if(ret == NULL) {
                errx(1, "strdup failed (could not allocate memory)");
        }
        return ret;
}