/*
 * 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) 1994 by Sun Microsystems, Inc.
 * Copyright (c) 2018, Joyent, Inc.
 */

/*
 * Copyright 1991, 1992 by Mortice Kern Systems Inc.  All rights reserved.
 *
 * Standards Conformance :
 *      P1003.2/D11.2
 *
 */
/*
 * Original ident string for reference
 * ident        "$Id: pathchk.c,v 1.29 1994/05/24 15:51:19 mark Exp $"
 */

#include <locale.h>
#include <libintl.h>
#include <limits.h>
#include <sys/stat.h>
#include <fcntl.h>              /* for creat() prototype */
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <unistd.h>
#include <stdlib.h>

/*
 * These are the characters in the portable filename character set defined
 * in POSIX P1003.2.
 */
static  char    portfsset[] = \
        "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789._-";


#ifndef M_FSDELIM
#define M_FSDELIM(c)    ((c) == '/')
#endif

static char *nametoolong = "%s: component too long.\n";
static char *pathtoolong = "%s: pathname too long.\n";
static char *notsrch = "%s: Not searchable.\n";
static char *badchar = "%s: Nonportable character '%c' (%#02X) found.\n";
static char *badbyte = "%s: Nonportable byte %#02X found.\n";

static char *pathconfprob = "pathchk: warning: \
                            pathconf(\"%s\", %s) returns '%s'. Using %s = %d\n";


static int printWarnings = 1;

static int checkpathname(char *, int);
static void usage(void);

/*
 * mainline for pathchk
 */
int
main(int argc, char **argv)
{
        int c;
        int errors;
        int pflag = 0;

        (void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)
#define TEXT_DOMAIN "SYS_TEST"
#endif
        (void) textdomain(TEXT_DOMAIN);


        while ((c = getopt(argc, argv, "pw")) != EOF) {
                switch (c) {
                case 'p':
                        pflag = 1;
                        break;

                case 'w':
                        /* turn off warning messages */
                        printWarnings = 0;
                        break;

                default:
                        usage();
                }
        }

        argv += optind;

        if (*argv == 0) {
                usage();
                /* NOTREACHED */
        }

        errors = 0;
        while (*argv) {
                errors += checkpathname(*argv, pflag);
                argv += 1;
        }

        return (errors);
}

/*
 * checkPathConf(const char *, int, long *)
 *
 * Calls pathconf(), and returns 1 if pathconf failed, zero
 * otherwise.  If pathconf() succeeded, then *valp contains the
 * value returned
 */
static int
checkPathConf(const char *path, int type, long *valp)
{
        errno = 0;
        *valp = pathconf(path, type);
        if ((*valp == -1) && (errno != 0) && (errno != EACCES)) {
                /*
                 * pathconf() is not supported on some mounted filesystems
                 * (e.g NFS mounts) and pathconf() is known to fail.
                 * So, we print a warning and use the POSIX default values.
                 */
                if (type == _PC_PATH_MAX)
                        *valp = _POSIX_PATH_MAX;
                else
                        *valp = _POSIX_NAME_MAX;

                if (printWarnings) {
                        (void) fprintf(stderr, gettext(pathconfprob), path,
                                type == _PC_PATH_MAX?"_PC_PATH_MAX" :
                                    "_PC_NAME_MAX", strerror(errno),
                                type == _PC_PATH_MAX ? "PATH_MAX" : "NAME_MAX",
                                    *valp);
                }
        }
        return ((*valp == -1) && (errno != 0));
}


#define UPDATE_LIMITS(buf)\
{\
        if (pflag) {\
                nameMax = _POSIX_NAME_MAX;\
                pathMax = _POSIX_PATH_MAX;\
        } else if (checkPathConf((buf), _PC_PATH_MAX, &pathMax) || \
            checkPathConf((buf), _PC_NAME_MAX, &nameMax)) {\
                (void) fprintf(stderr, gettext(notsrch), buf);\
                return (1);\
        }\
}

/*
 * checkpathname(char *pname)
 * pathchk a single pathname.
 */
int
checkpathname(char *path, int pflag)
{
        int             checkStat;
        long            nameMax;
        long            pathMax;
        char            *scomp;
        char            *ecomp;
        register char   *p;

        p = path;
        checkStat = 1;

        /*
         * Get the initial NAME_MAX and PATH_MAX values
         */
        if (M_FSDELIM(*p)) {
                char buf[2];

                buf[0] = *p;
                buf[1] = '\0';

                UPDATE_LIMITS(buf);
        } else {
                /*
                 * This is a relative pathname, initial values
                 * are relative to the current directory
                 */
                UPDATE_LIMITS(".");
        }

        /*
         * Check to make sure that the pathname doesn't exceed the
         * current PATH_MAX
         */
        if (pathMax != -1 && strlen(p) > (size_t)pathMax) {
                (void) fprintf(stderr, gettext(pathtoolong), path);
                return (1);
        }


        /*
         * Now spin around checking all the prefixes of
         * the pathname, until we hit the end of the
         * argument
         */
        while (*p != '\0') {
                /*
                 * Find the beginning of the next
                 * component.  Assume that
                 * M_FSDELIM('\0') == 0
                 */
                while (M_FSDELIM(*p))
                        p += 1;

                if (*p == '\0') {
                        /*
                         * There were trailing fsdelim chars on
                         * the path provided, so we were
                         * finished, we just didn't know it.
                         */
                        return (0);
                }

                scomp = p;

                /*
                 * Find the end of the current component
                 * and check for valid characters in the component
                 */
                while (*p != '\0' && !M_FSDELIM(*p)) {
                        /*
                         * for pflag: check for PFCS characters
                         * otherwise assume all characters are valid
                         */
                        if (pflag && (strchr(portfsset, *p) == 0)) {
                                if (isprint(*p)) {
                                        (void) fprintf(stderr,
                                            gettext(badchar), path, *p, *p);
                                } else {
                                        (void) fprintf(stderr,
                                            gettext(badbyte), path, *p);
                                }
                                return (1);
                        }
                        p += 1;
                 }

                ecomp = p;

                /*
                 * Make sure that this component does not exceed
                 * NAME_MAX in the current prefix directory
                 */
                if ((nameMax != -1) && (ecomp - scomp > nameMax)) {
                        (void) fprintf(stderr, gettext(nametoolong), scomp);
                        return (1);
                } else if (!pflag && checkStat) {
                        /*
                         * Perform the extra checks that
                         * are required when not just
                         * checking for portability.
                         */
                        struct stat sb;
                        char fsdelim;

                        fsdelim = *ecomp;
                        *ecomp = '\0';

                        if (stat(path, &sb) == -1) {
                                /*
                                 * We error out if an
                                 * intermediate component
                                 * is a file, when we
                                 * were expecting a
                                 * directory, or it is an
                                 * unsearchable directory.
                                 */
                                if ((errno == ENOTDIR && fsdelim != '\0') ||
                                    (errno == EACCES)) {
                                        (void) fprintf(stderr, gettext(notsrch),
                                                path);
                                        return (1);
                                } else if (errno == ENOENT) {
                                        checkStat = 0;
                                }
                        } else if (S_ISDIR(sb.st_mode)) {
                                /*
                                 * If the current prefix is a
                                 * directory, then we need to
                                 * update the limits for NAME_MAX
                                 * for the next component and the suffix.
                                 */
                                if (checkPathConf(path, _PC_NAME_MAX,
                                    &nameMax)) {
                                        (void) fprintf(stderr,
                                            gettext(notsrch), path);
                                        return (1);
                                }
                        }

                        /*
                         * restore the fsdelim char that we
                         * stomped to produce a prefix.
                         */
                        *ecomp = fsdelim;
                } /* if (we need to stat the path) */
        } /* while (more of this path to check) */

        /*
         * We successfully traversed the whole pathname
         */
        return (0);
}

void
usage()
{
        (void) fprintf(stderr, gettext("usage: pathchk [-p] pathname ..."));
        (void) fprintf(stderr, "\n");
        exit(2);
}