cmd/lastcomm/lc_utils.c

	lc_utils.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 1999-2000 by Sun Microsystems, Inc.
 * All rights reserved.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include "lastcomm.h"

/*
 * lc_utils contains utility functions used by both the basic and extended
 * accounting components of lastcomm.  getdev(), on its first call, builds
 * the set of tty device name to dev_t mappings.
 */

#define N_DEVS      43      /* hash value for device names */
#define NDEVS       500     /* max number of file names in /dev */

#define HASH(d) (((int)d) % N_DEVS) /* hash function */

struct  devhash {
    dev_t   dev_dev;
    char    dev_name [PATHNAMLEN];
    struct  devhash *dev_nxt;
};

static struct devhash *dev_hash[N_DEVS];
static struct devhash *dev_chain;
static int ndevs = NDEVS;
static struct devhash *hashtab;

/*
 * Default search list, used if /etc/ttysrch unavailable or unparsable.
 */
static char *def_srch_dirs[] = {
    "/dev/term",
    "/dev/pts",
    "/dev/xt",
    NULL
};
static char *raw_sf;    /* buffer containing raw image of the search file */

#define SRCH_FILE_NAME  "/etc/ttysrch"
/*
 * /etc/ttysrch tokens.
 */
#define COMMENT_CHAR    '#'
#define EOLN        '\n'
/*
 * /etc/ttysrch parser states.
 */
#define START_STATE 1
#define COMMENT_STATE   2
#define DIRNAME_STATE   3

/*
 * The following 2 routines are modified version of get_pri_dirs
 * and srch_dir in ttyname.c.
 */
static char **
get_pri_dirs()
{
    int bcount = 0;
    int c;
    int sf_lines = 0;   /* number of lines in search file */
    int dirno = 0;
    int state;
    FILE *sf;
    char **pri_dirs;    /* priority search list */
    char *sfp;      /* pointer inside the raw image buffer */
    struct stat sfsb;   /* search file's stat structure buffer */


    if ((sf = fopen(SRCH_FILE_NAME, "r")) == NULL)
        return (def_srch_dirs);
    if (stat(SRCH_FILE_NAME, &sfsb) < 0) {
        (void) fclose(sf);
        return (def_srch_dirs);
    }
    raw_sf = malloc(sfsb.st_size + 1);
    sfp = raw_sf;
    while ((bcount++ < sfsb.st_size) && ((c = getc(sf)) != EOF)) {
        *sfp++ = (char)c;
        if (c == EOLN)
            sf_lines++;
    }
    (void) fclose(sf);
    *sfp = EOLN;
    pri_dirs = malloc(++sf_lines * sizeof (char *));

    sfp = raw_sf;
    state = START_STATE;
    while (--bcount) {
        switch (state) {
        case START_STATE:
            if (*sfp == COMMENT_CHAR) {
                state = COMMENT_STATE;
            } else if (!isspace(*sfp)) {
                state = DIRNAME_STATE;
                pri_dirs[dirno++] = sfp;
            }
            break;
        case COMMENT_STATE:
            if (*sfp == EOLN)
                state = START_STATE;
            break;
        case DIRNAME_STATE:
            if (*sfp == EOLN) {
                *sfp = '\0';
                state = START_STATE;
            } else if (isspace(*sfp)) {
                *sfp = '\0';
                state = COMMENT_STATE;
            }
            break;

        } /* switch */
        sfp++;
    }

    *sfp = '\0';
    pri_dirs[dirno] = NULL;
    return (pri_dirs);
}

/*
 * Build a chain of character devices in dev_chain, starting with the given
 * path.
 */
static int
srch_dir(char *path)
{
    DIR *dirp;
    struct dirent *direntp;
    struct stat st;
    char file_name[PATHNAMLEN];

    if ((dirp = opendir(path)) == NULL)
        return (0);

    if ((readdir(dirp) == NULL) || (readdir(dirp) == NULL))
        return (0);

    while ((direntp = readdir(dirp)) != NULL) {
        (void) strcpy(file_name, path);
        (void) strcat(file_name, "/");
        (void) strcat(file_name, direntp->d_name);
        if (stat((const char *)file_name, &st) < 0)
            continue;
        if ((st.st_mode & S_IFMT) == S_IFCHR) {
            (void) strcpy(hashtab->dev_name,
                file_name + strlen("/dev/"));
            hashtab->dev_nxt = dev_chain;
            dev_chain = hashtab;
            hashtab++;
            if (--ndevs < 0)
                return (-1);
        }
    }
    (void) closedir(dirp);
    return (1);
}


static void
setupdevs()
{
    int dirno = 0;
    char **srch_dirs;

    hashtab = malloc(NDEVS * sizeof (struct devhash));
    if (hashtab == NULL) {
        (void) fprintf(stderr, gettext("No memory for device table\n"));
        return;
    }

    srch_dirs = get_pri_dirs();

    while (srch_dirs[dirno] != NULL) {
        if (srch_dir(srch_dirs[dirno]) < 0)
            return;
        dirno++;
    }

    dirno = 0;
    while (srch_dirs[dirno] != NULL) {
        if (strcmp("/dev", srch_dirs[dirno]) == 0)
            /*
             * Don't search /dev twice.
             */
            return;
        dirno++;
    }
}

char *
getdev(dev_t dev)
{
    struct devhash *hp, *nhp;
    struct stat statb;
    char name[PATHNAMLEN];
    static dev_t lastdev = (dev_t)-1;
    static char *lastname;
    static int init = 0;

    if (dev == NODEV)
        return ("__");
    if (dev == lastdev)
        return (lastname);
    if (!init) {
        setupdevs();
        init++;
    }

    for (hp = dev_hash[HASH(dev)]; hp; hp = hp->dev_nxt)
        if (hp->dev_dev == dev) {
            lastdev = dev;
            return (lastname = hp->dev_name);
        }

    for (hp = dev_chain; hp; hp = nhp) {
        nhp = hp->dev_nxt;
        (void) strcpy(name, "/dev/");
        (void) strcat(name, hp->dev_name);
        if (stat(name, &statb) < 0) /* name truncated usually */
            continue;
        if ((statb.st_mode & S_IFMT) != S_IFCHR)
            continue;
        hp->dev_dev = statb.st_rdev;
        hp->dev_nxt = dev_hash[HASH(hp->dev_dev)];
        dev_hash[HASH(hp->dev_dev)] = hp;
        if (hp->dev_dev == dev) {
            dev_chain = nhp;
            lastdev = dev;
            return (lastname = hp->dev_name);
        }
    }
    dev_chain = NULL;
    return ("??");
}

char *
flagbits(int f)
{
    int i = 0;
    static char flags[20];

#define BIT(flag, ch)   flags[i++] = (f & flag) ? ch : ' '
    BIT(ASU, 'S');
    BIT(AFORK, 'F');
    flags[i] = '\0';
    return (flags);
#undef  BIT
}

char *
getname(uid_t uid)
{
    struct passwd *pw;
    static char uidname[NMAX];

    if ((pw = getpwuid(uid)) == NULL) {
        (void) sprintf(uidname, "%ld", uid);
        return (uidname);
    }
    return (pw->pw_name);
}