/*      $OpenBSD: util.c,v 1.37 2022/12/26 19:16:01 jmc Exp $   */

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 * Portions Copyright (c) 1983, 1995, 1996 Eric P. Allman (woof!)
 *
 * 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/types.h>
#include <sys/uio.h>
#include <sys/stat.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <paths.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <vis.h>
#include "finger.h"
#include "extern.h"

char    *estrdup(char *);
WHERE   *walloc(PERSON *pn);
void    find_idle_and_ttywrite(WHERE *);
void    userinfo(PERSON *, struct passwd *);

void
find_idle_and_ttywrite(WHERE *w)
{
        struct stat sb;

        (void)snprintf(tbuf, sizeof(tbuf), "%s%s", _PATH_DEV, w->tty);
        if (stat(tbuf, &sb) == -1) {
                /* Don't bitch about it, just handle it... */
                w->idletime = 0;
                w->writable = 0;

                return;
        }
        w->idletime = now < sb.st_atime ? 0 : now - sb.st_atime;

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

char *
estrdup(char *s)
{
        char *p = strdup(s);
        if (!p)
                err(1, "strdup");
        return (p);
}

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

        pn->realname = pn->office = pn->officephone = pn->homephone = NULL;
        pn->mailrecv = -1;              /* -1 == not_valid */

        pn->uid = pw->pw_uid;
        pn->name = estrdup(pw->pw_name);
        pn->dir = estrdup(pw->pw_dir);
        pn->shell = estrdup(pw->pw_shell);

        (void)strlcpy(bp = tbuf, pw->pw_gecos, sizeof(tbuf));

        /* ampersands get replaced by the login name */
        if (!(p = strsep(&bp, ",")))
                return;
        expandusername(p, pw->pw_name, name, sizeof(name));
        if (stravis(&pn->realname, name, VIS_SAFE|VIS_NOSLASH) == -1)
                err(1, "stravis");
        if ((p = strsep(&bp, ",")) && *p) {
                if (stravis(&pn->office, p, VIS_SAFE|VIS_NOSLASH) == -1)
                        err(1, "stravis");
        }
        if ((p = strsep(&bp, ",")) && *p) {
                if (stravis(&pn->officephone, p, VIS_SAFE|VIS_NOSLASH) == -1)
                        err(1, "stravis");
        }
        if ((p = strsep(&bp, ",")) && *p) {
                if (stravis(&pn->homephone, p, VIS_SAFE|VIS_NOSLASH) == -1)
                        err(1, "stravis");
        }
        len = snprintf(tbuf, sizeof(tbuf), "%s/%s", _PATH_MAILSPOOL,
            pw->pw_name);
        if (len >= 0 && len < sizeof(tbuf)) {
                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;
                }
        }
}

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

        (void)strlcpy(p = tbuf, pw->pw_gecos, sizeof(tbuf));

        /* ampersands get replaced by the login name */
        if (!(p = strtok(p, ",")))
                return (0);
        expandusername(p, pw->pw_name, name, sizeof(name));
        for (t = name; (p = strtok(t, "\t ")) != NULL; t = NULL)
                if (!strcasecmp(p, user))
                        return (1);
        return (0);
}

/* inspired by usr.sbin/sendmail/util.c::buildfname */
void
expandusername(char *gecos, char *login, char *buf, size_t buflen)
{
        char *p, *bp;

        /* why do we skip asterisks!?!? */
        if (*gecos == '*')
                gecos++;
        bp = buf;

        /* copy gecos, interpolating & to be full name */
        for (p = gecos; *p != '\0'; p++) {
                if (bp >= &buf[buflen - 1]) {
                        /* buffer overflow - just use login name */
                        strlcpy(buf, login, buflen);
                        buf[buflen - 1] = '\0';
                        return;
                }
                if (*p == '&') {
                        /* interpolate full name */
                        strlcpy(bp, login, buflen - (bp - buf));
                        *bp = toupper((unsigned char)*bp);
                        bp += strlen(bp);
                }
                else
                        *bp++ = *p;
        }
        *bp = '\0';
}

void
enter_lastlog(PERSON *pn)
{
        WHERE *w;
        static int opened, fd;
        struct lastlog ll;
        char doit = 0;

        /* some systems may not maintain lastlog, don't report errors. */
        if (!opened) {
                fd = open(_PATH_LASTLOG, O_RDONLY);
                opened = 1;
        }
        if (fd == -1 ||
            pread(fd, &ll, sizeof(ll), (off_t)pn->uid * sizeof(ll)) !=
            sizeof(ll)) {
                /* as if never logged in */
                ll.ll_line[0] = ll.ll_host[0] = '\0';
                ll.ll_time = 0;
        }
        if ((w = pn->whead) == NULL)
                doit = 1;
        else if (ll.ll_time != 0) {
                /* if last login is earlier than some current login */
                for (; !doit && w != NULL; w = w->next)
                        if (w->info == LOGGEDIN && w->loginat < ll.ll_time)
                                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 &&
                            strncmp(w->tty, ll.ll_line, UT_LINESIZE) == 0)
                                doit = 0;
        }
        if (doit) {
                w = walloc(pn);
                w->info = LASTLOG;
                bcopy(ll.ll_line, w->tty, UT_LINESIZE);
                w->tty[UT_LINESIZE] = 0;
                bcopy(ll.ll_host, w->host, UT_HOSTSIZE);
                w->host[UT_HOSTSIZE] = 0;
                w->loginat = ll.ll_time;
        }
}

void
enter_where(struct utmp *ut, PERSON *pn)
{
        WHERE *w = walloc(pn);

        w->info = LOGGEDIN;
        bcopy(ut->ut_line, w->tty, UT_LINESIZE);
        w->tty[UT_LINESIZE] = 0;
        bcopy(ut->ut_host, w->host, UT_HOSTSIZE);
        w->host[UT_HOSTSIZE] = 0;
        w->loginat = (time_t)ut->ut_time;
        find_idle_and_ttywrite(w);
}

PERSON *
enter_person(struct passwd *pw)
{
        PERSON *pn, **pp;

        for (pp = htab + hash(pw->pw_name);
            *pp != NULL && strcmp((*pp)->name, pw->pw_name) != 0;
            pp = &(*pp)->hlink)
                ;
        if ((pn = *pp) == NULL) {
                pn = palloc();
                entries++;
                if (phead == NULL)
                        phead = ptail = pn;
                else {
                        ptail->next = pn;
                        ptail = pn;
                }
                pn->next = NULL;
                pn->hlink = NULL;
                *pp = pn;
                userinfo(pn, pw);
                pn->whead = NULL;
        }
        return (pn);
}

PERSON *
find_person(char *name)
{
        PERSON *pn;

        /* name may be only UT_NAMESIZE long and not terminated */
        for (pn = htab[hash(name)];
            pn != NULL && strncmp(pn->name, name, UT_NAMESIZE) != 0;
            pn = pn->hlink)
                ;
        return (pn);
}

int
hash(char *name)
{
        int h, i;

        h = 0;
        /* name may be only UT_NAMESIZE long and not terminated */
        for (i = UT_NAMESIZE; --i >= 0 && *name;)
                h = ((h << 2 | h >> (HBITS - 2)) ^ *name++) & HMASK;
        return (h);
}

PERSON *
palloc(void)
{
        PERSON *p;

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

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

        if ((w = malloc((u_int) sizeof(WHERE))) == NULL)
                err(1, "malloc");
        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[15];

        /* don't touch anything if the user has their own formatting */
        for (p = num; *p; ++p)
                if (!isdigit((unsigned char)*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);
}