usr/src/sbin/savecore/savecore.c

#ifndef lint
static  char *sccsid = "@(#)savecore.c  4.15 (Berkeley) 85/06/03";
#endif

/*
 * savecore
 */

#include <stdio.h>
#include <nlist.h>
#include <sys/param.h>
#include <sys/dir.h>
#include <sys/stat.h>
#include <sys/time.h>

#define DAY     (60L*60L*24L)
#define LEEWAY  (3*DAY)

#define eq(a,b) (!strcmp(a,b))
#ifdef vax
#define ok(number) ((number)&0x7fffffff)
#else
#define ok(number) (number)
#endif

#define SHUTDOWNLOG "/usr/adm/shutdownlog"

struct nlist current_nl[] = {   /* namelist for currently running system */
#define X_DUMPDEV       0
        { "_dumpdev" },
#define X_DUMPLO        1
        { "_dumplo" },
#define X_TIME          2
        { "_time" },
#define X_DUMPSIZE      3
        { "_dumpsize" },
#define X_VERSION       4
        { "_version" },
#define X_PANICSTR      5
        { "_panicstr" },
#define X_DUMPMAG       6
        { "_dumpmag" },
        { "" },
};

struct nlist dump_nl[] = {      /* name list for dumped system */
        { "_dumpdev" },         /* entries MUST be the same as */
        { "_dumplo" },          /*      those in current_nl[]  */
        { "_time" },
        { "_dumpsize" },
        { "_version" },
        { "_panicstr" },
        { "_dumpmag" },
        { "" },
};

char    *system;
char    *dirname;                       /* directory to save dumps in */
char    *ddname;                        /* name of dump device */
char    *find_dev();
dev_t   dumpdev;                        /* dump device */
time_t  dumptime;                       /* time the dump was taken */
int     dumplo;                         /* where dump starts on dumpdev */
int     dumpsize;                       /* amount of memory dumped */
int     dumpmag;                        /* magic number in dump */
time_t  now;                            /* current date */
char    *path();
unsigned malloc();
char    *ctime();
char    vers[80];
char    core_vers[80];
char    panic_mesg[80];
int     panicstr;
off_t   lseek();
off_t   Lseek();
int     Verbose;

main(argc, argv)
        char **argv;
        int argc;
{

        while ((argc > 1) && (argv[1][0] == '-')) {
                switch (argv[1][1]) {
                case 'v':
                case 'd':
                        Verbose = 1;
                        break;
                default:
                        fprintf(stderr, "savecore: illegal flag -%c\n",
                                argv[1][1]);
                        fprintf(stderr,
                                "usage: savecore [-v] dirname [ system ]\n");
                        exit(1);
                }
                argc--;
                argv++;
        }

        if (argc != 2 && argc != 3) {
                fprintf(stderr, "usage: savecore [-v] dirname [ system ]\n");
                exit(1);
        }
        dirname = argv[1];
        if (argc == 3)
                system = argv[2];
        if (access(dirname, 2) < 0) {
                perror(dirname);
                exit(1);
        }
        read_kmem();
}

int
dump_exists()
{
        register int dumpfd;
        int word;

        dumpfd = Open(ddname, 0);
        Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), 0);
        Read(dumpfd, (char *)&word, sizeof word);
        close(dumpfd);
        if (Verbose && (word != dumpmag)) {
                printf("dumplo = %d (%d bytes)\n", dumplo/512, dumplo);
                printf("magic number mismatch: %x != %x\n", word, dumpmag);
        }
        return (word == dumpmag);
}

clear_dump()
{
        register int dumpfd;
        int zero = 0;

        dumpfd = Open(ddname, 1);
        Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_DUMPMAG].n_value)), 0);
        Write(dumpfd, (char *)&zero, sizeof zero);
        close(dumpfd);
}

char *
find_dev(dev, type)
        register dev_t dev;
        register int type;
{
        struct stat statb;
        char *dp;

        strcpy(devname, "/dev/");
                if (stat(devname, &statb)) {
                        perror(devname);
                        continue;
                }
                if ((statb.st_mode&S_IFMT) != type)
                        continue;
                if (dev == statb.st_rdev) {
                        dp = (char *)malloc(strlen(devname)+1);
                        strcpy(dp, devname);
                        return dp;
                }
        }
        fprintf(stderr, "savecore: Can't find device %d,%d\n",
                major(dev), minor(dev));
        exit(1);
        /*NOTREACHED*/
}

read_kmem()
{
        int kmem;
        FILE *fp;
        register char *cp;
        char *dump_sys;

        dump_sys = system ? system : "/vmunix";

        nlist("/vmunix", current_nl);
        nlist(dump_sys, dump_nl);

        /*
         * Some names we need for the currently running system,
         * others for the system that was running when the dump was made.
         * The values obtained from the current system are used
         * to look for things in /dev/kmem that cannot be found
         * in the dump_sys namelist, but are presumed to be the same
         * (since the disk partitions are probably the same!)
         */
        if (current_nl[X_DUMPDEV].n_value == 0) {
                fprintf(stderr, "savecore: /vmunix: dumpdev not in namelist\n");
                exit(1);
        }
        if (current_nl[X_DUMPLO].n_value == 0) {
                fprintf(stderr, "savecore: /vmunix: dumplo not in namelist\n");
                exit(1);
        }
        if (dump_nl[X_TIME].n_value == 0) {
                fprintf(stderr, "savecore: %s: time not in namelist\n",
                                dump_sys);
                exit(1);
        }
        if (dump_nl[X_DUMPSIZE].n_value == 0) {
                fprintf(stderr, "savecore: %s: dumpsize not in namelist\n",
                                dump_sys);
                exit(1);
        }
        /* we need VERSION in both images */
        if (current_nl[X_VERSION].n_value == 0) {
                fprintf(stderr, "savecore: /vmunix: version not in namelist\n",
                                dump_sys);
                exit(1);
        }
        if (dump_nl[X_VERSION].n_value == 0) {
                fprintf(stderr, "savecore: %s: version not in namelist\n",
                                dump_sys);
                exit(1);
        }
        if (dump_nl[X_PANICSTR].n_value == 0) {
                fprintf(stderr, "savecore: %s: panicstr not in namelist\n",
                                dump_sys);
                exit(1);
        }
        /* we need DUMPMAG in both images */
        if (current_nl[X_DUMPMAG].n_value == 0) {
                fprintf(stderr, "savecore: /vmunix: dumpmag not in namelist\n");
                exit(1);
        }
        if (dump_nl[X_DUMPMAG].n_value == 0) {
                fprintf(stderr, "savecore: %s: dumpmag not in namelist\n",
                                dump_sys);
                exit(1);
        }
        kmem = Open("/dev/kmem", 0);
        Lseek(kmem, (long)current_nl[X_DUMPDEV].n_value, 0);
        Read(kmem, (char *)&dumpdev, sizeof (dumpdev));
        Lseek(kmem, (long)current_nl[X_DUMPLO].n_value, 0);
        Read(kmem, (char *)&dumplo, sizeof (dumplo));
        Lseek(kmem, (long)current_nl[X_DUMPMAG].n_value, 0);
        Read(kmem, (char *)&dumpmag, sizeof (dumpmag));
        dumplo *= 512L;
        ddname = find_dev(dumpdev, S_IFBLK);
        if ((fp = fdopen(kmem, "r")) == NULL) {
                fprintf(stderr, "savecore: Couldn't fdopen kmem\n");
                exit(1);
        }
        if (system)
                return;
        fseek(fp, (long)current_nl[X_VERSION].n_value, 0);
        fgets(vers, sizeof vers, fp);
        fclose(fp);
}

check_kmem()
{
        FILE *fp;
        register char *cp;

        if ((fp = fopen(ddname, "r")) == NULL) {
                perror(ddname);
                exit(1);
        }
        fseek(fp, (off_t)(dumplo+ok(dump_nl[X_VERSION].n_value)), 0);
        fgets(core_vers, sizeof core_vers, fp);
        fclose(fp);
        if (!eq(vers, core_vers) && (system == 0))
                fprintf(stderr,
                   "savecore: Warning: vmunix version mismatch:\n\t%sand\n\t%s",
                   vers, core_vers);
        fp = fopen(ddname, "r");
        fseek(fp, (off_t)(dumplo + ok(dump_nl[X_PANICSTR].n_value)), 0);
        fread((char *)&panicstr, sizeof panicstr, 1, fp);
        if (panicstr) {
                fseek(fp, dumplo + ok(panicstr), 0);
                cp = panic_mesg;
                do
                        *cp = getc(fp);
                while (*cp++);
        }
        fclose(fp);
}

get_crashtime()
{
        int dumpfd;
        time_t clobber = (time_t)0;

        Lseek(dumpfd, (off_t)(dumplo + ok(dump_nl[X_TIME].n_value)), 0);
        Read(dumpfd, (char *)&dumptime, sizeof dumptime);
        close(dumpfd);
        if (dumptime == 0) {
                if (Verbose)
                        printf("dump time not found\n");
                return (0);
        }
        printf("System went down at %s", ctime(&dumptime));
        if (dumptime < now - LEEWAY || dumptime > now + LEEWAY) {
                printf("Dump time is unreasonable\n");
                return (0);
        }
        return (1);
}

char *
path(file)
        char *file;
{
        register char *cp = (char *)malloc(strlen(file) + strlen(dirname) + 2);

        (void) strcpy(cp, dirname);
        (void) strcat(cp, "/");
        (void) strcat(cp, file);
        return (cp);
}

check_space()
{
        struct stat dsb;
        register char *ddev;
        int dfd, spacefree;
        struct fs fs;

        if (stat(dirname, &dsb) < 0) {
                perror(dirname);
                exit(1);
        }
        ddev = find_dev(dsb.st_dev, S_IFBLK);
        dfd = Open(ddev, 0);
        Lseek(dfd, (long)(SBLOCK * DEV_BSIZE), 0);
        Read(dfd, (char *)&fs, sizeof fs);
        close(dfd);
        spacefree = fs.fs_cstotal.cs_nbfree * fs.fs_bsize / 1024;
        if (read_number("minfree") > spacefree) {
                fprintf(stderr,
                   "savecore: Dump omitted, not enough space on device\n");
                return (0);
        }
        if (fs.fs_cstotal.cs_nbfree * fs.fs_frag + fs.fs_cstotal.cs_nffree <
            fs.fs_dsize * fs.fs_minfree / 100)
                fprintf(stderr,
                        "Dump performed, but free space threshold crossed\n");
        return (1);
}

read_number(fn)
        char *fn;
{
        char lin[80];
        register FILE *fp;

        if ((fp = fopen(path(fn), "r")) == NULL)
                return (0);
        if (fgets(lin, 80, fp) == NULL) {
                fclose(fp);
                return (0);
        }
        fclose(fp);
        return (atoi(lin));
}

save_core()
{
        register int n;
        char buffer[32*NBPG];
        register char *cp = buffer;
        register int ifd, ofd, bounds;
        register FILE *fp;

        bounds = read_number("bounds");
        ifd = Open(system?system:"/vmunix", 0);
        while((n = Read(ifd, cp, BUFSIZ)) > 0)
                Write(ofd, cp, n);
        close(ifd);
        close(ofd);
        ifd = Open(ddname, 0);
        Lseek(ifd, (off_t)(dumplo + ok(dump_nl[X_DUMPSIZE].n_value)), 0);
        Read(ifd, (char *)&dumpsize, sizeof (dumpsize));
        sprintf(cp, "vmcore.%d", bounds);
        ofd = Create(path(cp), 0644);
        Lseek(ifd, (off_t)dumplo, 0);
        printf("Saving %d bytes of image in vmcore.%d\n", NBPG*dumpsize,
                bounds);
        while (dumpsize > 0) {
                n = Read(ifd, cp, (dumpsize > 32 ? 32 : dumpsize) * NBPG);
                Write(ofd, cp, n);
                dumpsize -= n/NBPG;
        }
        close(ifd);
        close(ofd);
        fp = fopen(path("bounds"), "w");
        fprintf(fp, "%d\n", bounds+1);
        fclose(fp);
}

char *days[] = {
        "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};

char *months[] = {
        "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep",
        "Oct", "Nov", "Dec"
};

log_entry()
{
        FILE *fp;
        struct tm *tm, *localtime();

        tm = localtime(&now);
        fp = fopen("/usr/adm/shutdownlog", "a");
        if (fp == 0)
                return;
        fseek(fp, 0L, 2);
        fprintf(fp, "%02d:%02d  %s %s %2d, %4d.  Reboot", tm->tm_hour,
                tm->tm_min, days[tm->tm_wday], months[tm->tm_mon],
                tm->tm_mday, tm->tm_year + 1900);
        if (panicstr)
                fprintf(fp, " after panic: %s\n", panic_mesg);
        else
                putc('\n', fp);
        fclose(fp);
}

/*
 * Versions of std routines that exit on error.
 */

Open(name, rw)
        char *name;
        int rw;
{
        int fd;

        if ((fd = open(name, rw)) < 0) {
                perror(name);
                exit(1);
        }
        return fd;
}

Read(fd, buff, size)
        int fd, size;
        char *buff;
{
        int ret;

        if ((ret = read(fd, buff, size)) < 0) {
                perror("read");
                exit(1);
        }
        return ret;
}

off_t
Lseek(fd, off, flag)
        int fd, flag;
        long off;
{
        long ret;

        if ((ret = lseek(fd, off, flag)) == -1L) {
                perror("lseek");
                exit(1);
        }
        return ret;
}

Create(file, mode)
        char *file;
        int mode;
{
        register int fd;

        if ((fd = creat(file, mode)) < 0) {
                perror(file);
                exit(1);
        }
        return fd;
}

Write(fd, buf, size)
        int fd, size;
        char *buf;
{

        if (write(fd, buf, size) < size) {
                perror("write");
                exit(1);
        }
}