/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Tony Nardo of the Johns Hopkins University/Applied Physics Lab.
 *
 * 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.
 */

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <ctype.h>
#include <db.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <utmpx.h>
#include "finger.h"
#include "pathnames.h"

static void      find_idle_and_ttywrite(WHERE *);
static void      userinfo(PERSON *, struct passwd *);
static WHERE    *walloc(PERSON *);

int
match(struct passwd *pw, const char *user)
{
        char *p, *t;
        char name[1024];

        if (!strcasecmp(pw->pw_name, user))
                return(1);

        /*
         * XXX
         * Why do we skip asterisks!?!?
         */
        (void)strncpy(p = tbuf, pw->pw_gecos, sizeof(tbuf));
        tbuf[sizeof(tbuf) - 1] = '\0';
        if (*p == '*')
                ++p;

        /* Ampersands get replaced by the login name. */
        if ((p = strtok(p, ",")) == NULL)
                return(0);

        for (t = name; t < &name[sizeof(name) - 1] && (*t = *p) != '\0'; ++p) {
                if (*t == '&') { 
                        (void)strncpy(t, pw->pw_name, 
                            sizeof(name) - (t - name));
                        name[sizeof(name) - 1] = '\0';
                        while (t < &name[sizeof(name) - 1] && *++t)
                                continue;
                } else {
                        ++t;
                }
        }
        *t = '\0';
        for (t = name; (p = strtok(t, "\t ")) != NULL; t = NULL)
                if (!strcasecmp(p, user))
                        return(1);
        return(0);
}

void
enter_lastlog(PERSON *pn)
{
        WHERE *w;
        struct utmpx *ut = NULL;
        char doit = 0;

        if (setutxdb(UTXDB_LASTLOGIN, NULL) == 0)
                ut = getutxuser(pn->name);
        if ((w = pn->whead) == NULL)
                doit = 1;
        else if (ut != NULL && ut->ut_type == USER_PROCESS) {
                /* if last login is earlier than some current login */
                for (; !doit && w != NULL; w = w->next)
                        if (w->info == LOGGEDIN &&
                            w->loginat < ut->ut_tv.tv_sec)
                                doit = 1;
                /*
                 * and if it's not any of the current logins
                 * can't use time comparison because there may be a small
                 * discrepancy since login calls time() twice
                 */
                for (w = pn->whead; doit && w != NULL; w = w->next)
                        if (w->info == LOGGEDIN &&
                            strcmp(w->tty, ut->ut_line) == 0)
                                doit = 0;
        }
        if (ut != NULL && doit) {
                w = walloc(pn);
                w->info = LASTLOG;
                strcpy(w->tty, ut->ut_line);
                strcpy(w->host, ut->ut_host);
                w->loginat = ut->ut_tv.tv_sec;
        }
        endutxent();
}

void
enter_where(struct utmpx *ut, PERSON *pn)
{
        WHERE *w;

        w = walloc(pn);
        w->info = LOGGEDIN;
        strcpy(w->tty, ut->ut_line);
        strcpy(w->host, ut->ut_host);
        w->loginat = ut->ut_tv.tv_sec;
        find_idle_and_ttywrite(w);
}

PERSON *
enter_person(struct passwd *pw)
{
        DBT data, key;
        PERSON *pn;

        if (db == NULL &&
            (db = dbopen(NULL, O_RDWR, 0, DB_BTREE, NULL)) == NULL)
                err(1, NULL);

        key.data = pw->pw_name;
        key.size = strlen(pw->pw_name);

        switch ((*db->get)(db, &key, &data, 0)) {
        case 0:
                memmove(&pn, data.data, sizeof pn);
                return (pn);
        default:
        case -1:
                err(1, "db get");
                /* NOTREACHED */
        case 1:
                ++entries;
                pn = palloc();
                userinfo(pn, pw);
                pn->whead = NULL;

                data.size = sizeof(PERSON *);
                data.data = &pn;
                if ((*db->put)(db, &key, &data, 0))
                        err(1, "db put");
                return (pn);
        }
}

PERSON *
find_person(char *name)
{
        struct passwd *pw;

        DBT data, key;
        PERSON *p;

        if (!db)
                return(NULL);

        if ((pw = getpwnam(name)) && hide(pw))
                return(NULL);

        key.data = name;
        key.size = strlen(name);

        if ((*db->get)(db, &key, &data, 0))
                return (NULL);
        memmove(&p, data.data, sizeof p);
        return (p);
}

PERSON *
palloc(void)
{
        PERSON *p;

        if ((p = malloc(sizeof(PERSON))) == NULL)
                err(1, NULL);
        return(p);
}

static WHERE *
walloc(PERSON *pn)
{
        WHERE *w;

        if ((w = malloc(sizeof(WHERE))) == NULL)
                err(1, NULL);
        if (pn->whead == NULL)
                pn->whead = pn->wtail = w;
        else {
                pn->wtail->next = w;
                pn->wtail = w;
        }
        w->next = NULL;
        return(w);
}

char *
prphone(char *num)
{
        char *p;
        int len;
        static char pbuf[20];

        /* don't touch anything if the user has their own formatting */
        for (p = num; *p; ++p)
                if (!isdigit(*p))
                        return(num);
        len = p - num;
        p = pbuf;
        switch(len) {
        case 11:                        /* +0-123-456-7890 */
                *p++ = '+';
                *p++ = *num++;
                *p++ = '-';
                /* FALLTHROUGH */
        case 10:                        /* 012-345-6789 */
                *p++ = *num++;
                *p++ = *num++;
                *p++ = *num++;
                *p++ = '-';
                /* FALLTHROUGH */
        case 7:                         /* 012-3456 */
                *p++ = *num++;
                *p++ = *num++;
                *p++ = *num++;
                break;
        case 5:                         /* x0-1234 */
        case 4:                         /* x1234 */
                *p++ = 'x';
                *p++ = *num++;
                break;
        default:
                return(num);
        }
        if (len != 4) {
            *p++ = '-';
            *p++ = *num++;
        }
        *p++ = *num++;
        *p++ = *num++;
        *p++ = *num++;
        *p = '\0';
        return(pbuf);
}

static void
find_idle_and_ttywrite(WHERE *w)
{
        struct stat sb;
        time_t touched;
        int error;

        (void)snprintf(tbuf, sizeof(tbuf), "%s/%s", _PATH_DEV, w->tty);

        error = stat(tbuf, &sb);
        if (error < 0 && errno == ENOENT) {
                /*
                 * The terminal listed is not actually a terminal (i.e.,
                 * ":0").  This is a failure, so we'll skip printing
                 * out the idle time, which is non-ideal but better
                 * than a bogus warning and idle time.
                 */
                w->idletime = -1;
                return;
        } else if (error < 0) {
                warn("%s", tbuf);
                w->idletime = -1;
                return;
        }
        touched = sb.st_atime;
        if (touched < w->loginat) {
                /* tty untouched since before login */
                touched = w->loginat;
        }
        w->idletime = now < touched ? 0 : now - touched;

#define TALKABLE        0220            /* tty is writable if 220 mode */
        w->writable = ((sb.st_mode & TALKABLE) == TALKABLE);
}

static void
userinfo(PERSON *pn, struct passwd *pw)
{
        char *p, *t;
        char *bp, name[1024];
        struct stat sb;

        pn->realname = pn->office = pn->officephone = pn->homephone = NULL;

        pn->uid = pw->pw_uid;
        if ((pn->name = strdup(pw->pw_name)) == NULL)
                err(1, "strdup failed");
        if ((pn->dir = strdup(pw->pw_dir)) == NULL)
                err(1, "strdup failed");
        if ((pn->shell = strdup(pw->pw_shell)) == NULL)
                err(1, "strdup failed");

        /* why do we skip asterisks!?!? */
        (void)strncpy(bp = tbuf, pw->pw_gecos, sizeof(tbuf));
        tbuf[sizeof(tbuf) - 1] = '\0';
        if (*bp == '*')
                ++bp;

        /* ampersands get replaced by the login name */
        if (!(p = strsep(&bp, ",")))
                return;
        for (t = name; t < &name[sizeof(name) - 1] && (*t = *p) != '\0'; ++p) {
                if (*t == '&') {
                        (void)strncpy(t, pw->pw_name, 
                            sizeof(name) - (t - name));
                        name[sizeof(name) - 1] = '\0';
                        if (islower(*t))
                                *t = toupper(*t);
                        while (t < &name[sizeof(name) - 1] && *++t)
                                continue;
                } else {
                        ++t;
                }
        }
        *t = '\0';
        if ((pn->realname = strdup(name)) == NULL)
                err(1, "strdup failed");
        pn->office = ((p = strsep(&bp, ",")) && *p) ?
            strdup(p) : NULL;
        pn->officephone = ((p = strsep(&bp, ",")) && *p) ?
            strdup(p) : NULL;
        pn->homephone = ((p = strsep(&bp, ",")) && *p) ?
            strdup(p) : NULL;
        (void)snprintf(tbuf, sizeof(tbuf), "%s/%s", _PATH_MAILDIR, pw->pw_name);
        pn->mailrecv = -1;              /* -1 == not_valid */
        if (stat(tbuf, &sb) < 0) {
                if (errno != ENOENT) {
                        warn("%s", tbuf);
                        return;
                }
        } else if (sb.st_size != 0) {
                pn->mailrecv = sb.st_mtime;
                pn->mailread = sb.st_atime;
        }
}

/*
 * Is this user hiding from finger?
 * If ~<user>/.nofinger exists, return 1 (hide), else return 0 (nohide).
 * Nobody can hide from root.
 */

int
hide(struct passwd *pw)
{
        struct stat st;
        char buf[MAXPATHLEN];

        if (invoker_root || !pw->pw_dir)
                return 0;

        snprintf(buf, sizeof(buf), "%s/%s", pw->pw_dir, _PATH_NOFINGER);

        if (stat(buf, &st) == 0)
                return 1;

        return 0;
}