/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1992 Keith Muller.
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Keith Muller of the University of California, San Diego.
 *
 * 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/time.h>
#include <sys/stat.h>

#include <ctype.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>

#include "pax.h"
#include "sel_subs.h"
#include "extern.h"

static int str_sec(const char *, time_t *);
static int usr_match(ARCHD *);
static int grp_match(ARCHD *);
static int trng_match(ARCHD *);

static TIME_RNG *trhead = NULL;         /* time range list head */
static TIME_RNG *trtail = NULL;         /* time range list tail */
static USRT **usrtb = NULL;             /* user selection table */
static GRPT **grptb = NULL;             /* group selection table */

/*
 * Routines for selection of archive members
 */

/*
 * sel_chk()
 *      check if this file matches a specified uid, gid or time range
 * Return:
 *      0 if this archive member should be processed, 1 if it should be skipped
 */

int
sel_chk(ARCHD *arcn)
{
        if (((usrtb != NULL) && usr_match(arcn)) ||
            ((grptb != NULL) && grp_match(arcn)) ||
            ((trhead != NULL) && trng_match(arcn)))
                return(1);
        return(0);
}

/*
 * User/group selection routines
 *
 * Routines to handle user selection of files based on the file uid/gid. To
 * add an entry, the user supplies either the name or the uid/gid starting with
 * a # on the command line. A \# will escape the #.
 */

/*
 * usr_add()
 *      add a user match to the user match hash table
 * Return:
 *      0 if added ok, -1 otherwise;
 */

int
usr_add(char *str)
{
        u_int indx;
        USRT *pt;
        struct passwd *pw;
        uid_t uid;

        /*
         * create the table if it doesn't exist
         */
        if ((str == NULL) || (*str == '\0'))
                return(-1);
        if ((usrtb == NULL) &&
            ((usrtb = (USRT **)calloc(USR_TB_SZ, sizeof(USRT *))) == NULL)) {
                paxwarn(1, "Unable to allocate memory for user selection table");
                return(-1);
        }

        /*
         * figure out user spec
         */
        if (str[0] != '#') {
                /*
                 * it is a user name, \# escapes # as first char in user name
                 */
                if ((str[0] == '\\') && (str[1] == '#'))
                        ++str;
                if ((pw = getpwnam(str)) == NULL) {
                        paxwarn(1, "Unable to find uid for user: %s", str);
                        return(-1);
                }
                uid = (uid_t)pw->pw_uid;
        } else
                uid = (uid_t)strtoul(str+1, NULL, 10);
        endpwent();

        /*
         * hash it and go down the hash chain (if any) looking for it
         */
        indx = ((unsigned)uid) % USR_TB_SZ;
        if ((pt = usrtb[indx]) != NULL) {
                while (pt != NULL) {
                        if (pt->uid == uid)
                                return(0);
                        pt = pt->fow;
                }
        }

        /*
         * uid is not yet in the table, add it to the front of the chain
         */
        if ((pt = (USRT *)malloc(sizeof(USRT))) != NULL) {
                pt->uid = uid;
                pt->fow = usrtb[indx];
                usrtb[indx] = pt;
                return(0);
        }
        paxwarn(1, "User selection table out of memory");
        return(-1);
}

/*
 * usr_match()
 *      check if this files uid matches a selected uid.
 * Return:
 *      0 if this archive member should be processed, 1 if it should be skipped
 */

static int
usr_match(ARCHD *arcn)
{
        USRT *pt;

        /*
         * hash and look for it in the table
         */
        pt = usrtb[((unsigned)arcn->sb.st_uid) % USR_TB_SZ];
        while (pt != NULL) {
                if (pt->uid == arcn->sb.st_uid)
                        return(0);
                pt = pt->fow;
        }

        /*
         * not found
         */
        return(1);
}

/*
 * grp_add()
 *      add a group match to the group match hash table
 * Return:
 *      0 if added ok, -1 otherwise;
 */

int
grp_add(char *str)
{
        u_int indx;
        GRPT *pt;
        struct group *gr;
        gid_t gid;

        /*
         * create the table if it doesn't exist
         */
        if ((str == NULL) || (*str == '\0'))
                return(-1);
        if ((grptb == NULL) &&
            ((grptb = (GRPT **)calloc(GRP_TB_SZ, sizeof(GRPT *))) == NULL)) {
                paxwarn(1, "Unable to allocate memory fo group selection table");
                return(-1);
        }

        /*
         * figure out user spec
         */
        if (str[0] != '#') {
                /*
                 * it is a group name, \# escapes # as first char in group name
                 */
                if ((str[0] == '\\') && (str[1] == '#'))
                        ++str;
                if ((gr = getgrnam(str)) == NULL) {
                        paxwarn(1,"Cannot determine gid for group name: %s", str);
                        return(-1);
                }
                gid = gr->gr_gid;
        } else
                gid = (gid_t)strtoul(str+1, NULL, 10);
        endgrent();

        /*
         * hash it and go down the hash chain (if any) looking for it
         */
        indx = ((unsigned)gid) % GRP_TB_SZ;
        if ((pt = grptb[indx]) != NULL) {
                while (pt != NULL) {
                        if (pt->gid == gid)
                                return(0);
                        pt = pt->fow;
                }
        }

        /*
         * gid not in the table, add it to the front of the chain
         */
        if ((pt = (GRPT *)malloc(sizeof(GRPT))) != NULL) {
                pt->gid = gid;
                pt->fow = grptb[indx];
                grptb[indx] = pt;
                return(0);
        }
        paxwarn(1, "Group selection table out of memory");
        return(-1);
}

/*
 * grp_match()
 *      check if this files gid matches a selected gid.
 * Return:
 *      0 if this archive member should be processed, 1 if it should be skipped
 */

static int
grp_match(ARCHD *arcn)
{
        GRPT *pt;

        /*
         * hash and look for it in the table
         */
        pt = grptb[((unsigned)arcn->sb.st_gid) % GRP_TB_SZ];
        while (pt != NULL) {
                if (pt->gid == arcn->sb.st_gid)
                        return(0);
                pt = pt->fow;
        }

        /*
         * not found
         */
        return(1);
}

/*
 * Time range selection routines
 *
 * Routines to handle user selection of files based on the modification and/or
 * inode change time falling within a specified time range (the non-standard
 * -T flag). The user may specify any number of different file time ranges.
 * Time ranges are checked one at a time until a match is found (if at all).
 * If the file has a mtime (and/or ctime) which lies within one of the time
 * ranges, the file is selected. Time ranges may have a lower and/or an upper
 * value. These ranges are inclusive. When no time ranges are supplied to pax
 * with the -T option, all members in the archive will be selected by the time
 * range routines. When only a lower range is supplied, only files with a
 * mtime (and/or ctime) equal to or younger are selected. When only an upper
 * range is supplied, only files with a mtime (and/or ctime) equal to or older
 * are selected. When the lower time range is equal to the upper time range,
 * only files with a mtime (or ctime) of exactly that time are selected.
 */

/*
 * trng_add()
 *      add a time range match to the time range list.
 *      This is a non-standard pax option. Lower and upper ranges are in the
 *      format: [[[[[cc]yy]mm]dd]HH]MM[.SS] and are comma separated.
 *      Time ranges are based on current time, so 1234 would specify a time of
 *      12:34 today.
 * Return:
 *      0 if the time range was added to the list, -1 otherwise
 */

int
trng_add(char *str)
{
        TIME_RNG *pt;
        char *up_pt = NULL;
        char *stpt;
        char *flgpt;
        int dot = 0;

        /*
         * throw out the badly formed time ranges
         */
        if ((str == NULL) || (*str == '\0')) {
                paxwarn(1, "Empty time range string");
                return(-1);
        }

        /*
         * locate optional flags suffix /{cm}.
         */
        if ((flgpt = strrchr(str, '/')) != NULL)
                *flgpt++ = '\0';

        for (stpt = str; *stpt != '\0'; ++stpt) {
                if ((*stpt >= '0') && (*stpt <= '9'))
                        continue;
                if ((*stpt == ',') && (up_pt == NULL)) {
                        *stpt = '\0';
                        up_pt = stpt + 1;
                        dot = 0;
                        continue;
                }

                /*
                 * allow only one dot per range (secs)
                 */
                if ((*stpt == '.') && (!dot)) {
                        ++dot;
                        continue;
                }
                paxwarn(1, "Improperly specified time range: %s", str);
                goto out;
        }

        /*
         * allocate space for the time range and store the limits
         */
        if ((pt = (TIME_RNG *)malloc(sizeof(TIME_RNG))) == NULL) {
                paxwarn(1, "Unable to allocate memory for time range");
                return(-1);
        }

        /*
         * by default we only will check file mtime, but the user can specify
         * mtime, ctime (inode change time) or both.
         */
        if ((flgpt == NULL) || (*flgpt == '\0'))
                pt->flgs = CMPMTME;
        else {
                pt->flgs = 0;
                while (*flgpt != '\0') {
                        switch(*flgpt) {
                        case 'M':
                        case 'm':
                                pt->flgs |= CMPMTME;
                                break;
                        case 'C':
                        case 'c':
                                pt->flgs |= CMPCTME;
                                break;
                        default:
                                paxwarn(1, "Bad option %c with time range %s",
                                    *flgpt, str);
                                free(pt);
                                goto out;
                        }
                        ++flgpt;
                }
        }

        /*
         * start off with the current time
         */
        pt->low_time = pt->high_time = time(NULL);
        if (*str != '\0') {
                /*
                 * add lower limit
                 */
                if (str_sec(str, &(pt->low_time)) < 0) {
                        paxwarn(1, "Illegal lower time range %s", str);
                        free(pt);
                        goto out;
                }
                pt->flgs |= HASLOW;
        }

        if ((up_pt != NULL) && (*up_pt != '\0')) {
                /*
                 * add upper limit
                 */
                if (str_sec(up_pt, &(pt->high_time)) < 0) {
                        paxwarn(1, "Illegal upper time range %s", up_pt);
                        free(pt);
                        goto out;
                }
                pt->flgs |= HASHIGH;

                /*
                 * check that the upper and lower do not overlap
                 */
                if (pt->flgs & HASLOW) {
                        if (pt->low_time > pt->high_time) {
                                paxwarn(1, "Upper %s and lower %s time overlap",
                                        up_pt, str);
                                free(pt);
                                return(-1);
                        }
                }
        }

        pt->fow = NULL;
        if (trhead == NULL) {
                trtail = trhead = pt;
                return(0);
        }
        trtail->fow = pt;
        trtail = pt;
        return(0);

    out:
        paxwarn(1, "Time range format is: [[[[[cc]yy]mm]dd]HH]MM[.SS][/[c][m]]");
        return(-1);
}

/*
 * trng_match()
 *      check if this files mtime/ctime falls within any supplied time range.
 * Return:
 *      0 if this archive member should be processed, 1 if it should be skipped
 */

static int
trng_match(ARCHD *arcn)
{
        TIME_RNG *pt;

        /*
         * have to search down the list one at a time looking for a match.
         * remember time range limits are inclusive.
         */
        pt = trhead;
        while (pt != NULL) {
                switch(pt->flgs & CMPBOTH) {
                case CMPBOTH:
                        /*
                         * user wants both mtime and ctime checked for this
                         * time range
                         */
                        if (((pt->flgs & HASLOW) &&
                            (arcn->sb.st_mtime < pt->low_time) &&
                            (arcn->sb.st_ctime < pt->low_time)) ||
                            ((pt->flgs & HASHIGH) &&
                            (arcn->sb.st_mtime > pt->high_time) &&
                            (arcn->sb.st_ctime > pt->high_time))) {
                                pt = pt->fow;
                                continue;
                        }
                        break;
                case CMPCTME:
                        /*
                         * user wants only ctime checked for this time range
                         */
                        if (((pt->flgs & HASLOW) &&
                            (arcn->sb.st_ctime < pt->low_time)) ||
                            ((pt->flgs & HASHIGH) &&
                            (arcn->sb.st_ctime > pt->high_time))) {
                                pt = pt->fow;
                                continue;
                        }
                        break;
                case CMPMTME:
                default:
                        /*
                         * user wants only mtime checked for this time range
                         */
                        if (((pt->flgs & HASLOW) &&
                            (arcn->sb.st_mtime < pt->low_time)) ||
                            ((pt->flgs & HASHIGH) &&
                            (arcn->sb.st_mtime > pt->high_time))) {
                                pt = pt->fow;
                                continue;
                        }
                        break;
                }
                break;
        }

        if (pt == NULL)
                return(1);
        return(0);
}

/*
 * str_sec()
 *      Convert a time string in the format of [[[[[cc]yy]mm]dd]HH]MM[.SS] to
 *      seconds UTC. Tval already has current time loaded into it at entry.
 * Return:
 *      0 if converted ok, -1 otherwise
 */

static int
str_sec(const char *p, time_t *tval)
{
        struct tm *lt;
        const char *dot, *t;
        size_t len;
        int bigyear;
        int yearset;

        yearset = 0;
        len = strlen(p);

        for (t = p, dot = NULL; *t; ++t) {
                if (isdigit((unsigned char)*t))
                        continue;
                if (*t == '.' && dot == NULL) {
                        dot = t;
                        continue;
                }
                return(-1);
        }

        lt = localtime(tval);

        if (dot != NULL) {                      /* .SS */
                if (strlen(++dot) != 2)
                        return(-1);
                lt->tm_sec = ATOI2(dot);
                if (lt->tm_sec > 61)
                        return(-1);
                len -= 3;
        } else
                lt->tm_sec = 0;

        switch (len) {
        case 12:                                /* cc */
                bigyear = ATOI2(p);
                lt->tm_year = (bigyear * 100) - 1900;
                yearset = 1;
                /* FALLTHROUGH */
        case 10:                                /* yy */
                if (yearset) {
                        lt->tm_year += ATOI2(p);
                } else {
                        lt->tm_year = ATOI2(p);
                        if (lt->tm_year < 69)           /* hack for 2000 ;-} */
                                lt->tm_year += (2000 - 1900);
                }
                /* FALLTHROUGH */
        case 8:                                 /* mm */
                lt->tm_mon = ATOI2(p);
                if ((lt->tm_mon > 12) || !lt->tm_mon)
                        return(-1);
                --lt->tm_mon;                   /* time struct is 0 - 11 */
                /* FALLTHROUGH */
        case 6:                                 /* dd */
                lt->tm_mday = ATOI2(p);
                if ((lt->tm_mday > 31) || !lt->tm_mday)
                        return(-1);
                /* FALLTHROUGH */
        case 4:                                 /* HH */
                lt->tm_hour = ATOI2(p);
                if (lt->tm_hour > 23)
                        return(-1);
                /* FALLTHROUGH */
        case 2:                                 /* MM */
                lt->tm_min = ATOI2(p);
                if (lt->tm_min > 59)
                        return(-1);
                break;
        default:
                return(-1);
        }

        /* convert broken-down time to UTC clock time seconds */
        if ((*tval = mktime(lt)) == -1)
                return(-1);
        return(0);
}