/*      $OpenBSD: ukc.c,v 1.25 2019/08/13 21:36:18 deraadt Exp $ */

/*
 * Copyright (c) 1999-2001 Mats O Jansson.  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.
 */

#include <sys/types.h>
#include <sys/device.h>

#include <err.h>
#include <fcntl.h>
#include <kvm.h>
#include <limits.h>
#include <nlist.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define UKC_MAIN
#include "ukc.h"
#include "exec.h"
#include "config.h"

void            init(void);
__dead void     usage(void);

int     ukc_mod_kernel = 0;

static void
check_int(int idx, const char *name)
{
        if (nl[idx].n_type == 0)
                printf("WARNING this kernel doesn't support modification "
                    "of %s.\n", name);
}

int
ukc(char *file, char *outfile, int uflag, int force)
{
        int i;
        kvm_t *kd;
        char errbuf[_POSIX2_LINE_MAX];
        int histlen = 0, ok = 1;
        char history[1024], kversion[1024];

        if (file == NULL) {
                warnx("no file specified");
                usage();
        }

        loadkernel(file);

        if (nlist(file, nl) == -1)
                errx(1, "nlist: %s", file);

        if (uflag) {
                struct nlist *knl;

                knl = emalloc(sizeof(nl));
                memcpy(knl, &nl, sizeof nl);

                if ((kd = kvm_openfiles(NULL,NULL,NULL,O_RDONLY, errbuf)) == 0)
                        errx(1, "kvm_openfiles: %s", errbuf);

                if (kvm_nlist(kd, knl) == -1)
                        errx(1, "kvm_nlist: %s", kvm_geterr(kd));

                i = 0;
                while (i < NLENTRIES) {
                        if (nl[i].n_type != knl[i].n_type ||
                            nl[i].n_desc != knl[i].n_desc ||
                            nl[i].n_value != knl[i].n_value)
                                ok = 0;
                        i++;
                }

                if (knl[I_HISTLEN].n_type != 0 && ok) {
                        if (kvm_read(kd, knl[I_HISTLEN].n_value, &histlen,
                            sizeof(histlen)) != sizeof(histlen))
                                warnx("cannot read %s: %s",
                                    knl[I_HISTLEN].n_name,
                                    kvm_geterr(kd));
                }
                if (knl[CA_HISTORY].n_type != 0 && ok) {
                        if (kvm_read(kd, knl[CA_HISTORY].n_value, history,
                            sizeof(history)) != sizeof(history))
                                warnx("cannot read %s: %s",
                                    knl[CA_HISTORY].n_name,
                                    kvm_geterr(kd));
                }
                if (knl[P_VERSION].n_type != 0 && ok) {
                        if (kvm_read(kd, knl[P_VERSION].n_value, kversion,
                            sizeof(kversion)) != sizeof(kversion))
                                warnx("cannot read %s: %s",
                                    knl[P_VERSION].n_name,
                                    kvm_geterr(kd));
                }
        }

        if (force == 0 && outfile == NULL)
                printf("WARNING no output file specified\n");

        if (nl[IA_EXTRALOC].n_type == 0 || nl[I_REXTRALOC].n_type == 0 ||
            nl[I_TEXTRALOC].n_type == 0 ||
            nl[I_HISTLEN].n_type == 0 || nl[CA_HISTORY].n_type == 0) {
                printf("\
WARNING this kernel doesn't contain all information needed!\n\
WARNING the commands add and change might not work.\n");
                oldkernel = 1;
        }

        if (nl[P_PDEVNAMES].n_type == 0 ||
            nl[I_PDEVSIZE].n_type == 0 ||
            nl[S_PDEVINIT].n_type == 0) {
                printf("\
WARNING this kernel doesn't support pseudo devices.\n");
                nopdev = 1;
        }

        check_int(I_NKMEMPG, "NKMEMPAGES");

        init();

        if (uflag) {
                if (ok) {
                        if (strcmp(adjust((caddr_t)nl[P_VERSION].n_value),
                            kversion) != 0)
                                ok = 1;
                }
                if (!ok) {
                        printf("WARNING kernel mismatch. -u ignored.\n");
                        printf("WARNING the running kernel version:\n");
                        printf("%s", kversion);
                } else
                        process_history(histlen, history);
        }

        printf("%s", adjust((caddr_t)nl[P_VERSION].n_value));

        if (config()) {
                if (force == 0 && outfile == NULL) {
                        fprintf(stderr, "not forced\n");
                        return (1);
                }
                if (outfile == NULL)
                        outfile = file;
                if (ukc_mod_kernel == 0) {
                        fprintf(stderr, "Kernel not modified\n");
                        return (1);
                } else {
                        printf ("Saving modified kernel.\n");
                        savekernel(outfile);
                }
        }
        return(0);
}

void
init(void)
{
        int i = 0;
        struct cfdata *cd;
        short   *ln;
        int     *p;

        if ((cd = get_cfdata(0)) == NULL)       /* get first item */
                errx(1, "failed to get first cfdata");

        while (cd->cf_attach != 0) {
                maxdev = i;
                totdev = i;

                ln = get_locnamp(cd->cf_locnames);
                while (*ln != -1) {
                        if (*ln > maxlocnames)
                                maxlocnames = *ln;
                        ln++;
                }
                i++;
                cd++;
        }

        while (cd->cf_attach == 0) {
                totdev = i;
                i++;
                cd++;
        }

        totdev = totdev - 1;

        if (nopdev == 0) {
                p = (int *)adjust((caddr_t)nl[I_PDEVSIZE].n_value);
                maxpseudo = *p;
        }
}