/*      $NetBSD: swapctl.c,v 1.44 2026/02/16 23:14:32 kre Exp $ */

/*
 * Copyright (c) 1996, 1997, 1999, 2015 Matthew R. Green
 * 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.
 *
 * 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.
 */

/*
 * swapctl command:
 *      -A              add all devices listed as `sw' in /etc/fstab (also
 *                      (sets the dump device, if listed in fstab)
 *      -D [<dev>|none] set dumpdev to <dev> or disable dumps
 *      -z              show dumpdev
 *      -U              remove all devices listed as `sw' in /etc/fstab.
 *      -t [blk|noblk|auto]
 *                      if -A or -U , add (remove) either all block device
 *                      or all non-block devices, or all swap partitions
 *      -q              check if any swap or dump devices are defined in
 *                      /etc/fstab
 *      -a <dev>        add this device
 *      -d <dev>        remove this swap device
 *      -f              with -A -t auto, use the first swap as dump device
 *      -g              use gigabytes
 *      -h              use humanize_number(3) for listing
 *      -l              list swap devices
 *      -m              use megabytes
 *      -n              print actions, but do not add/remove swap or
 *                      with -A/-U
 *      -o              with -A -t auto only configure the first swap as dump,
 *                      (similar to -f), but do not add any further swap devs
 *      -s              short listing of swap devices
 *      -k              use kilobytes
 *      -p <pri>        use this priority
 *      -c              change priority
 *
 * or, if invoked as "swapon" (compatibility mode):
 *
 *      -a              all devices listed as `sw' in /etc/fstab
 *      -t              same as -t above (feature not present in old
 *                      swapon(8) command)
 *      <dev>           add this device
 */
#include <sys/cdefs.h>

#ifndef lint
__RCSID("$NetBSD: swapctl.c,v 1.44 2026/02/16 23:14:32 kre Exp $");
#endif


#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/swap.h>
#include <sys/sysctl.h>
#include <sys/disk.h>
#include <sys/disklabel.h>

#include <unistd.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fstab.h>
#include <fcntl.h>
#include <util.h>
#include <paths.h>

#include "swapctl.h"

static int      command;

/*
 * Commands for swapctl(8).  These are mutually exclusive.
 */
#define CMD_A           0x01    /* process /etc/fstab for adding */
#define CMD_D           0x02    /* set dumpdev */
#define CMD_U           0x04    /* process /etc/fstab for removing */
#define CMD_a           0x08    /* add a swap file/device */
#define CMD_c           0x10    /* change priority of a swap file/device */
#define CMD_d           0x20    /* delete a swap file/device */
#define CMD_l           0x40    /* list swap files/devices */
#define CMD_s           0x80    /* summary of swap files/devices */
#define CMD_z           0x100   /* show dump device */
#define CMD_q           0x200   /* check for dump/swap in /etc/fstab */

#define SET_COMMAND(cmd) \
do { \
        if (command) \
                usage(); \
        command = (cmd); \
} while (0)

/*
 * Commands that require a "path" argument at the end of the command
 * line, and the ones which require that none exist.
 */
#define REQUIRE_PATH    (CMD_D | CMD_a | CMD_c | CMD_d)
#define REQUIRE_NOPATH  (CMD_A | CMD_U | CMD_l | CMD_s | CMD_z | CMD_q)

/*
 * Option flags, and the commands with which they are valid.
 */
static int      kflag;          /* display in 1K^x blocks */
#define KFLAG_CMDS      (CMD_l | CMD_s)
#define MFLAG_CMDS      (CMD_l | CMD_s)
#define GFLAG_CMDS      (CMD_l | CMD_s)

static int      hflag;          /* display with humanize_number */
#define HFLAG_CMDS      (CMD_l | CMD_s)

static int      pflag;          /* priority was specified */
#define PFLAG_CMDS      (CMD_A | CMD_a | CMD_c)

static char     *tflag;         /* swap device type (blk, noblk, auto) */
static int      autoflag;       /* 1, if tflag is "auto" */
#define TFLAG_CMDS      (CMD_A | CMD_U)

static int      fflag;          /* first swap becomes dump */
#define FFLAG_CMDS      (CMD_A)

static int      oflag;          /* only autoset dump device */
#define OFLAG_CMDS      (CMD_A)

static int      nflag;          /* no execute, just print actions */
#define NFLAG_CMDS      (CMD_A | CMD_U)

static int      pri;            /* uses 0 as default pri */

static  void change_priority(char *);
static  int  add_swap(char *, int);
static  int  delete_swap(char *);
static  int set_dumpdev1(char *);
static  void set_dumpdev(char *);
static  int get_dumpdev(void);
__dead static   void do_fstab(int);
static  int check_fstab(void);
static  void do_localdevs(int);
static  void do_localdisk(const char *, int);
static  int do_wedgesofdisk(int fd, int);
static  int do_partitionsofdisk(const char *, int fd, int);
__dead static   void usage(void);
__dead static   void swapon_command(int, char **);
#if 0
static  void swapoff_command(int, char **);
#endif

int
main(int argc, char *argv[])
{
        int     c;

        if (strcmp(getprogname(), "swapon") == 0) {
                swapon_command(argc, argv);
                /* NOTREACHED */
        }

#if 0
        if (strcmp(getprogname(), "swapoff") == 0) {
                swapoff_command(argc, argv);
                /* NOTREACHED */
        }
#endif

        while ((c = getopt(argc, argv, "ADUacdfghklmnop:qst:z")) != -1) {
                switch (c) {
                case 'A':
                        SET_COMMAND(CMD_A);
                        break;

                case 'D':
                        SET_COMMAND(CMD_D);
                        break;

                case 'U':
                        SET_COMMAND(CMD_U);
                        break;

                case 'a':
                        SET_COMMAND(CMD_a);
                        break;

                case 'c':
                        SET_COMMAND(CMD_c);
                        break;

                case 'd':
                        SET_COMMAND(CMD_d);
                        break;

                case 'f':
                        fflag = 1;
                        break;

                case 'g':
                        kflag = 3; /* 1k ^ 3 */
                        break;

                case 'h':
                        hflag = 1;
                        break;

                case 'k':
                        kflag = 1;
                        break;

                case 'l':
                        SET_COMMAND(CMD_l);
                        break;

                case 'm':
                        kflag = 2; /* 1k ^ 2 */
                        break;

                case 'n':
                        nflag = 1;
                        break;

                case 'o':
                        oflag = 1;
                        break;

                case 'p':
                        pflag = 1;
                        /* XXX strtol() */
                        pri = atoi(optarg);
                        break;

                case 'q':
                        SET_COMMAND(CMD_q);
                        break;

                case 's':
                        SET_COMMAND(CMD_s);
                        break;

                case 't':
                        if (tflag != NULL)
                                usage();
                        tflag = optarg;
                        if (strcmp(tflag, "auto") == 0)
                                autoflag = 1;
                        break;

                case 'z':
                        SET_COMMAND(CMD_z);
                        break;

                default:
                        usage();
                        /* NOTREACHED */
                }
        }

        /* Did the user specify a command? */
        if (command == 0)
                usage();

        argv += optind;
        argc -= optind;

        switch (argc) {
        case 0:
                if (command & REQUIRE_PATH)
                        usage();
                break;

        case 1:
                if (command & REQUIRE_NOPATH)
                        usage();
                break;

        default:
                usage();
        }

        /* To change priority, you have to specify one. */
        if ((command == CMD_c) && pflag == 0)
                usage();

        /* -f and -o are mutually exclusive */
        if (fflag && oflag)
                usage();
                
        /* Sanity-check -t */
        if (tflag != NULL) {
                if (command != CMD_A && command != CMD_U)
                        usage();
                if (strcmp(tflag, "blk") != 0 &&
                    strcmp(tflag, "noblk") != 0 &&
                    strcmp(tflag, "auto") != 0)
                        usage();
        }

        /* Dispatch the command. */
        switch (command) {
        case CMD_l:
                if (!list_swap(pri, kflag, pflag, 0, 1, hflag))
                        exit(1);
                break;

        case CMD_s:
                list_swap(pri, kflag, pflag, 0, 0, hflag);
                break;

        case CMD_c:
                change_priority(argv[0]);
                break;

        case CMD_a:
                if (! add_swap(argv[0], pri))
                        exit(1);
                break;

        case CMD_d:
                if (! delete_swap(argv[0]))
                        exit(1);
                break;

        case CMD_A:
                if (autoflag)
                        do_localdevs(1);
                else
                        do_fstab(1);
                break;

        case CMD_D:
                set_dumpdev(argv[0]);
                break;

        case CMD_z:
                if (!get_dumpdev())
                        exit(1);
                break;

        case CMD_U:
                if (autoflag)
                        do_localdevs(0);
                else
                        do_fstab(0);
                break;
        case CMD_q:
                if (check_fstab()) {
                        printf("%s: there are swap or dump devices defined in "
                            _PATH_FSTAB "\n", getprogname());
                        exit(0);
                } else {
                        printf("%s: no swap or dump devices in "
                            _PATH_FSTAB "\n", getprogname());
                        exit(1);
                }
        }

        exit(0);
}

/*
 * swapon_command: emulate the old swapon(8) program.
 */
static void
swapon_command(int argc, char **argv)
{
        int ch, fiztab = 0;

        while ((ch = getopt(argc, argv, "at:")) != -1) {
                switch (ch) {
                case 'a':
                        fiztab = 1;
                        break;
                case 't':
                        if (tflag != NULL)
                                usage();
                        tflag = optarg;
                        break;
                default:
                        goto swapon_usage;
                }
        }
        argc -= optind;
        argv += optind;

        if (fiztab) {
                if (argc)
                        goto swapon_usage;
                /* Sanity-check -t */
                if (tflag != NULL) {
                        if (strcmp(tflag, "blk") != 0 &&
                            strcmp(tflag, "noblk") != 0)
                                usage();
                }
                do_fstab(1);
                exit(0);
        } else if (argc == 0 || tflag != NULL)
                goto swapon_usage;

        while (argc) {
                if (! add_swap(argv[0], pri))
                        exit(1);
                argc--;
                argv++;
        }
        exit(0);
        /* NOTREACHED */

 swapon_usage:
        fprintf(stderr, "usage: %s -a [-t blk|noblk]\n", getprogname());
        fprintf(stderr, "       %s <path> ...\n", getprogname());
        exit(1);
}

/*
 * change_priority:  change the priority of a swap device.
 */
static void
change_priority(char *path)
{

        if (swapctl(SWAP_CTL, path, pri) < 0)
                err(1, "%s", path);
}

/*
 * add_swap:  add the pathname to the list of swap devices.
 */
static int
add_swap(char *path, int priority)
{
        struct stat sb;
        char buf[MAXPATHLEN];
        char *spec;

        if (getfsspecname(buf, sizeof(buf), path) == NULL)
                goto oops;
        spec = buf;

        if (stat(spec, &sb) < 0)
                goto oops;

        if (sb.st_mode & S_IROTH) 
                warnx("WARNING: %s is readable by the world", path);
        if (sb.st_mode & S_IWOTH)
                warnx("WARNING: %s is writable by the world", path);

        if (fflag || oflag) {
                set_dumpdev1(spec);
                if (oflag)
                        exit(0);
                else
                        fflag = 0;
        }

        if (nflag)
                return 1;

        if (swapctl(SWAP_ON, spec, priority) < 0) {
oops:
                warn("%s", path);
                return 0;
        }
        return 1;
}

/*
 * delete_swap:  remove the pathname to the list of swap devices.
 */
static int
delete_swap(char *path)
{
        char buf[MAXPATHLEN];
        char *spec;

        if (getfsspecname(buf, sizeof(buf), path) == NULL) {
                warn("%s", path);
                return 0;
        }
        spec = buf;

        if (nflag)
                return 1;

        if (swapctl(SWAP_OFF, spec, pri) < 0) {
                warn("%s", path);
                return 0;
        }
        return 1;
}

static int
set_dumpdev1(char *spec)
{
        int rv = 0;

        if (!nflag) {
                if (strcmp(spec, "none") == 0) 
                        rv = swapctl(SWAP_DUMPOFF, NULL, 0);
                else
                        rv = swapctl(SWAP_DUMPDEV, spec, 0);
        }

        if (rv == -1)
                warn("could not set dump device to %s", spec);
        else
                printf("%s: setting dump device to %s\n", getprogname(), spec);

        return rv == -1 ? 0 : 1;
}

static void
set_dumpdev(char *path)
{
        char buf[MAXPATHLEN];
        char *spec;

        if (getfsspecname(buf, sizeof(buf), path) == NULL)
                err(1, "%s", path);
        spec = buf;

        if (! set_dumpdev1(spec))
                exit(1);
}

static int
get_dumpdev(void)
{
        dev_t   dev;
        char    *name;

        if (swapctl(SWAP_GETDUMPDEV, &dev, 0) == -1) {
                warn("could not get dump device");
                return 0;
        } else if (dev == NODEV) {
                printf("no dump device set\n");
                return 0;
        } else {
                name = devname(dev, S_IFBLK);
                printf("dump device is ");
                if (name)
                        printf("%s\n", name);
                else
                        printf("major %llu minor %llu\n",
                            (unsigned long long)major(dev),
                            (unsigned long long)minor(dev));
        }
        return 1;
}

static void
do_localdevs(int add)
{
        size_t ressize;
        char *disknames, *disk;
        static const char mibname[] = "hw.disknames";

        ressize = 0;
        if (sysctlbyname(mibname, NULL, &ressize, NULL, 0))
                return;
        ressize += 200; /* add some arbitrary slope */
        disknames = malloc(ressize);
        if (sysctlbyname(mibname, disknames, &ressize, NULL, 0) == 0) {
                for (disk = strtok(disknames, " "); disk;
                    disk = strtok(NULL, " "))
                        do_localdisk(disk, add);
        }
        free(disknames);
}

static void
do_localdisk(const char *disk, int add)
{
        int fd;
        char dvname[MAXPATHLEN];

        if ((fd = opendisk(disk, O_RDONLY, dvname, sizeof(dvname), 0)) == -1)
                return;

        if (!do_wedgesofdisk(fd, add))
                do_partitionsofdisk(disk, fd, add);

        close(fd);
}

static int
do_wedgesofdisk(int fd, int add)
{
        char devicename[MAXPATHLEN];
        struct dkwedge_info *dkw;
        struct dkwedge_list dkwl;
        size_t bufsize;
        u_int i;

        dkw = NULL;
        dkwl.dkwl_buf = dkw;
        dkwl.dkwl_bufsize = 0;

        for (;;) {
                if (ioctl(fd, DIOCLWEDGES, &dkwl) == -1)
                        return 0;
                if (dkwl.dkwl_nwedges == dkwl.dkwl_ncopied)
                        break;
                bufsize = dkwl.dkwl_nwedges * sizeof(*dkw);
                if (dkwl.dkwl_bufsize < bufsize) {
                        dkw = realloc(dkwl.dkwl_buf, bufsize);
                        if (dkw == NULL)
                                return 0;
                        dkwl.dkwl_buf = dkw;
                        dkwl.dkwl_bufsize = bufsize;
                }
        }

        for (i = 0; i < dkwl.dkwl_ncopied; i++) {
                if (strcmp(dkw[i].dkw_ptype, DKW_PTYPE_SWAP) != 0)
                        continue;
                snprintf(devicename, sizeof(devicename), "%s%s", _PATH_DEV,
                    dkw[i].dkw_devname);
                devicename[sizeof(devicename)-1] = '\0';

                if (add) {
                        if (add_swap(devicename, pri)) {
                                printf(
                                "%s: adding %s as swap device at priority 0\n",
                                    getprogname(), devicename);
                        }
                } else {
                        if (delete_swap(devicename)) {
                                printf(
                                    "%s: removing %s as swap device\n",
                                    getprogname(), devicename);
                        }
                }

        }

        free(dkw);
        return dkwl.dkwl_nwedges != 0;
}

static int
do_partitionsofdisk(const char *prefix, int fd, int add)
{
        char devicename[MAXPATHLEN];
        struct disklabel lab;
        uint i;

        if (ioctl(fd, DIOCGDINFO, &lab) != 0)
                return 0;

        for (i = 0; i < lab.d_npartitions; i++) {
                if (lab.d_partitions[i].p_fstype != FS_SWAP)
                        continue;
                snprintf(devicename, sizeof(devicename), "%s%s%c", _PATH_DEV,
                    prefix, 'a'+i);
                devicename[sizeof(devicename)-1] = '\0';

                if (add) {
                        if (add_swap(devicename, pri)) {
                                printf(
                                "%s: adding %s as swap device at priority 0\n",
                                    getprogname(), devicename);
                        }
                } else {
                        if (delete_swap(devicename)) {
                                printf(
                                    "%s: removing %s as swap device\n",
                                    getprogname(), devicename);
                        }
                }
        }

        return 1;
}

static int
check_fstab(void)
{
        struct  fstab *fp;

        while ((fp = getfsent()) != NULL) {
                if (strcmp(fp->fs_type, "dp") == 0)
                        return 1;

                if (strcmp(fp->fs_type, "sw") == 0)
                        return 1;
        }

        return 0;
}

static void
do_fstab(int add)
{
        struct  fstab *fp;
        char    *s;
        long    priority;
        struct  stat st;
        int     isblk;
        int     success = 0;    /* set to 1 after a successful operation */
        int     error = 0;      /* set to 1 after an error */

#ifdef RESCUEDIR
#define PATH_MOUNT      RESCUEDIR "/mount_nfs"
#define PATH_UMOUNT     RESCUEDIR "/umount"
#else
#define PATH_MOUNT      "/sbin/mount_nfs"
#define PATH_UMOUNT     "/sbin/umount"
#endif

        char    cmd[2*PATH_MAX+sizeof(PATH_MOUNT)+2];

#define PRIORITYEQ      "priority="
#define NFSMNTPT        "nfsmntpt="
        while ((fp = getfsent()) != NULL) {
                char buf[MAXPATHLEN];
                char *spec, *fsspec;

                /*
                 * Ignore any entries which are not related to swapping
                 */
                if (strcmp(fp->fs_type, "sw") != 0 &&
                    strcmp(fp->fs_type, "dp") != 0)
                        continue;

                if (getfsspecname(buf, sizeof(buf), fp->fs_spec) == NULL) {
                        warn("%s", buf);
                        continue;
                }
                fsspec = spec = buf;
                cmd[0] = '\0';

                if (strcmp(fp->fs_type, "dp") == 0 && add) {
                        set_dumpdev1(spec);
                        continue;
                }

                /* handle dp as mnt option */
                if (strstr(fp->fs_mntops, "dp") && add)
                        set_dumpdev1(spec);

                isblk = 0;

                if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
                        s += sizeof(PRIORITYEQ) - 1;
                        priority = atol(s);
                } else
                        priority = pri;

                if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
                        char *t;

                        /*
                         * Skip this song and dance if we're only
                         * doing block devices.
                         */
                        if (tflag != NULL && strcmp(tflag, "blk") == 0)
                                continue;

                        t = strpbrk(s, ",");
                        if (t != 0)
                                *t = '\0';
                        spec = strdup(s + strlen(NFSMNTPT));
                        if (t != 0)
                                *t = ',';

                        if (spec == NULL)
                                errx(1, "Out of memory");

                        if (strlen(spec) == 0) {
                                warnx("empty mountpoint");
                                free(spec);
                                continue;
                        }
                        if (add) {
                                snprintf(cmd, sizeof(cmd), "%s %s %s",
                                        PATH_MOUNT, fsspec, spec);
                                if (system(cmd) != 0) {
                                        warnx("%s: mount failed", fsspec);
                                        continue;
                                }
                        } else {
                                snprintf(cmd, sizeof(cmd), "%s %s",
                                        PATH_UMOUNT, fsspec);
                        }
                } else {
                        /*
                         * Determine blk-ness.
                         */
                        if (stat(spec, &st) < 0) {
                                warn("%s", spec);
                                continue;
                        }
                        if (S_ISBLK(st.st_mode))
                                isblk = 1;
                }

                /*
                 * Skip this type if we're told to.
                 */
                if (tflag != NULL) {
                        if (strcmp(tflag, "blk") == 0 && isblk == 0)
                                continue;
                        if (strcmp(tflag, "noblk") == 0 && isblk == 1)
                                continue;
                }

                if (add) {
                        if (add_swap(spec, (int)priority)) {
                                success = 1;
                                printf(
                                "%s: adding %s as swap device at priority %d\n",
                                    getprogname(), fsspec, (int)priority);
                        } else {
                                error = 1;
                                fprintf(stderr,
                                    "%s: failed to add %s as swap device\n",
                                    getprogname(), fsspec);
                        }
                } else {
                        if (delete_swap(spec)) {
                                success = 1;
                                printf(
                                    "%s: removing %s as swap device\n",
                                    getprogname(), fsspec);
                        } else {
                                error = 1;
                                fprintf(stderr,
                                    "%s: failed to remove %s as swap device\n",
                                    getprogname(), fsspec);
                        }
                        if (cmd[0]) {
                                if (system(cmd) != 0) {
                                        warnx("%s: umount failed", fsspec);
                                        error = 1;
                                        continue;
                                }
                        }
                }

                if (spec != fsspec)
                        free(spec);
        }
        if (error)
                exit(1);
        else if (success)
                exit(0);
        else
                exit(2); /* not really an error, but no swap devices found */
}

static void
usage(void)
{
        const char *progname = getprogname();

        fprintf(stderr, "usage: %s -A [-f|-o] [-n] [-p priority] "
            "[-t blk|noblk|auto]\n", progname);
        fprintf(stderr, "       %s -a [-p priority] path\n", progname);
        fprintf(stderr, "       %s -c -p priority path\n", progname);
        fprintf(stderr, "       %s -D dumpdev|none\n", progname);
        fprintf(stderr, "       %s -d path\n", progname);
        fprintf(stderr, "       %s -l|-s [-k|-m|-g|-h] [-p priority]\n",
            progname);
        fprintf(stderr, "       %s -q\n", progname);
        fprintf(stderr, "       %s -U [-n] [-t blk|noblk|auto]\n", progname);
        fprintf(stderr, "       %s -z\n", progname);
        exit(1);
}