vis.c

/*      $NetBSD: vis.c,v 1.44 2011/03/12 19:52:48 christos Exp $        */

/*-
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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.
 */

/*-
 * Copyright (c) 1999, 2005 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 "config.h"

#if defined(LIBC_SCCS) && !defined(lint)
#endif /* LIBC_SCCS and not lint */

/* XXXMYSQL : Make compiler happy. */
#ifdef _LIBC
#include "namespace.h"
#endif

#include <sys/types.h>

#include <assert.h>
/*
  XXXMYSQL : Due to different versions of vis.h available,
             use the one bundled with libedit.
*/
#include "np/vis.h"
#include <errno.h>
#include <stdlib.h>

#ifdef __weak_alias
__weak_alias(strvisx,_strvisx)
#endif

#if !HAVE_VIS || !HAVE_SVIS
#include <ctype.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>

static char *do_svis(char *, size_t *, int, int, int, const char *);

#undef BELL
#define BELL '\a'

#ifndef isoctal
#define isoctal(c)      (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
#endif
#define iswhite(c)      (c == ' ' || c == '\t' || c == '\n')
#define issafe(c)       (c == '\b' || c == BELL || c == '\r')
#define xtoa(c)         "0123456789abcdef"[c]
#define XTOA(c)         "0123456789ABCDEF"[c]

#define MAXEXTRAS       5

#define MAKEEXTRALIST(flag, extra, orig_str)                                  \
do {                                                                          \
        const char *orig = orig_str;                                          \
        const char *o = orig;                                                 \
        char *e;                                                              \
        while (*o++)                                                          \
                continue;                                                     \
        extra = malloc((size_t)((o - orig) + MAXEXTRAS));                     \
        if (!extra) break;                                                    \
        for (o = orig, e = extra; (*e++ = *o++) != '\0';)                     \
                continue;                                                     \
        e--;                                                                  \
        if (flag & VIS_SP) *e++ = ' ';                                        \
        if (flag & VIS_TAB) *e++ = '\t';                                      \
        if (flag & VIS_NL) *e++ = '\n';                                       \
        if ((flag & VIS_NOSLASH) == 0) *e++ = '\\';                           \
        *e = '\0';                                                            \
} while (/*CONSTCOND*/0)

/*
 * This is do_hvis, for HTTP style (RFC 1808)
 */
static char *
do_hvis(char *dst, size_t *dlen, int c, int flag, int nextc, const char *extra)
{

        if ((isascii(c) && isalnum(c))
            /* safe */
            || c == '$' || c == '-' || c == '_' || c == '.' || c == '+'
            /* extra */
            || c == '!' || c == '*' || c == '\'' || c == '(' || c == ')'
            || c == ',') {
                dst = do_svis(dst, dlen, c, flag, nextc, extra);
        } else {
                if (dlen) {
                        if (*dlen < 3)
                                return NULL;
                        *dlen -= 3;
                }
                *dst++ = '%';
                *dst++ = xtoa(((unsigned int)c >> 4) & 0xf);
                *dst++ = xtoa((unsigned int)c & 0xf);
        }

        return dst;
}

/*
 * This is do_mvis, for Quoted-Printable MIME (RFC 2045)
 * NB: No handling of long lines or CRLF.
 */
static char *
do_mvis(char *dst, size_t *dlen, int c, int flag, int nextc, const char *extra)
{
        if ((c != '\n') &&
            /* Space at the end of the line */
            ((isspace(c) && (nextc == '\r' || nextc == '\n')) ||
            /* Out of range */
            (!isspace(c) && (c < 33 || (c > 60 && c < 62) || c > 126)) ||
            /* Specific char to be escaped */ 
            strchr("#$@[\\]^`{|}~", c) != NULL)) {
                if (dlen) {
                        if (*dlen < 3)
                                return NULL;
                        *dlen -= 3;
                }
                *dst++ = '=';
                *dst++ = XTOA(((unsigned int)c >> 4) & 0xf);
                *dst++ = XTOA((unsigned int)c & 0xf);
        } else {
                dst = do_svis(dst, dlen, c, flag, nextc, extra);
        }
        return dst;
}

/*
 * This is do_vis, the central code of vis.
 * dst:       Pointer to the destination buffer
 * c:         Character to encode
 * flag:      Flag word
 * nextc:     The character following 'c'
 * extra:     Pointer to the list of extra characters to be
 *            backslash-protected.
 */
static char *
do_svis(char *dst, size_t *dlen, int c, int flag, int nextc, const char *extra)
{
        int isextra;
        size_t odlen = dlen ? *dlen : 0;

        isextra = strchr(extra, c) != NULL;
#define HAVE(x) \
        do { \
                if (dlen) { \
                        if (*dlen < (x)) \
                                goto out; \
                        *dlen -= (x); \
                } \
        } while (/*CONSTCOND*/0)
        if (!isextra && isascii(c) && (isgraph(c) || iswhite(c) ||
            ((flag & VIS_SAFE) && issafe(c)))) {
                HAVE(1);
                *dst++ = c;
                return dst;
        }
        if (flag & VIS_CSTYLE) {
                HAVE(2);
                switch (c) {
                case '\n':
                        *dst++ = '\\'; *dst++ = 'n';
                        return dst;
                case '\r':
                        *dst++ = '\\'; *dst++ = 'r';
                        return dst;
                case '\b':
                        *dst++ = '\\'; *dst++ = 'b';
                        return dst;
                case BELL:
                        *dst++ = '\\'; *dst++ = 'a';
                        return dst;
                case '\v':
                        *dst++ = '\\'; *dst++ = 'v';
                        return dst;
                case '\t':
                        *dst++ = '\\'; *dst++ = 't';
                        return dst;
                case '\f':
                        *dst++ = '\\'; *dst++ = 'f';
                        return dst;
                case ' ':
                        *dst++ = '\\'; *dst++ = 's';
                        return dst;
                case '\0':
                        *dst++ = '\\'; *dst++ = '0';
                        if (isoctal(nextc)) {
                                HAVE(2);
                                *dst++ = '0';
                                *dst++ = '0';
                        }
                        return dst;
                default:
                        if (isgraph(c)) {
                                *dst++ = '\\'; *dst++ = c;
                                return dst;
                        }
                        if (dlen)
                                *dlen = odlen;
                }
        }
        if (isextra || ((c & 0177) == ' ') || (flag & VIS_OCTAL)) {
                HAVE(4);
                *dst++ = '\\';
                *dst++ = (u_char)(((u_int32_t)(u_char)c >> 6) & 03) + '0';
                *dst++ = (u_char)(((u_int32_t)(u_char)c >> 3) & 07) + '0';
                *dst++ =                             (c       & 07) + '0';
        } else {
                if ((flag & VIS_NOSLASH) == 0) {
                        HAVE(1);
                        *dst++ = '\\';
                }

                if (c & 0200) {
                        HAVE(1);
                        c &= 0177; *dst++ = 'M';
                }

                if (iscntrl(c)) {
                        HAVE(2);
                        *dst++ = '^';
                        if (c == 0177)
                                *dst++ = '?';
                        else
                                *dst++ = c + '@';
                } else {
                        HAVE(2);
                        *dst++ = '-'; *dst++ = c;
                }
        }
        return dst;
out:
        *dlen = odlen;
        return NULL;
}

typedef char *(*visfun_t)(char *, size_t *, int, int, int, const char *);

/*
 * Return the appropriate encoding function depending on the flags given.
 */
static visfun_t
getvisfun(int flag)
{
        if (flag & VIS_HTTPSTYLE)
                return do_hvis;
        if (flag & VIS_MIMESTYLE)
                return do_mvis;
        return do_svis;
}

/*
 * isnvis - visually encode characters, also encoding the characters
 *        pointed to by `extra'
 */
static char *
isnvis(char *dst, size_t *dlen, int c, int flag, int nextc, const char *extra)
{
        char *nextra = NULL;
        visfun_t f;

        _DIAGASSERT(dst != NULL);
        _DIAGASSERT(extra != NULL);
        MAKEEXTRALIST(flag, nextra, extra);
        if (!nextra) {
                if (dlen && *dlen == 0) {
                        errno = ENOSPC;
                        return NULL;
                }
                *dst = '\0';            /* can't create nextra, return "" */
                return dst;
        }
        f = getvisfun(flag);
        dst = (*f)(dst, dlen, c, flag, nextc, nextra);
        free(nextra);
        if (dst == NULL || (dlen && *dlen == 0)) {
                errno = ENOSPC;
                return NULL;
        }
        *dst = '\0';
        return dst;
}

char *
svis(char *dst, int c, int flag, int nextc, const char *extra)
{
        return isnvis(dst, NULL, c, flag, nextc, extra);
}

char *
snvis(char *dst, size_t dlen, int c, int flag, int nextc, const char *extra)
{
        return isnvis(dst, &dlen, c, flag, nextc, extra);
}


/*
 * strsvis, strsvisx - visually encode characters from src into dst
 *
 *      Extra is a pointer to a \0-terminated list of characters to
 *      be encoded, too. These functions are useful e. g. to
 *      encode strings in such a way so that they are not interpreted
 *      by a shell.
 *
 *      Dst must be 4 times the size of src to account for possible
 *      expansion.  The length of dst, not including the trailing NULL,
 *      is returned.
 *
 *      Strsvisx encodes exactly len bytes from src into dst.
 *      This is useful for encoding a block of data.
 */
static int
istrsnvis(char *dst, size_t *dlen, const char *csrc, int flag, const char *extra)
{
        int c;
        char *start;
        char *nextra = NULL;
        const unsigned char *src = (const unsigned char *)csrc;
        visfun_t f;

        _DIAGASSERT(dst != NULL);
        _DIAGASSERT(src != NULL);
        _DIAGASSERT(extra != NULL);
        MAKEEXTRALIST(flag, nextra, extra);
        if (!nextra) {
                *dst = '\0';            /* can't create nextra, return "" */
                return 0;
        }
        f = getvisfun(flag);
        for (start = dst; (c = *src++) != '\0'; /* empty */) {
                dst = (*f)(dst, dlen, c, flag, *src, nextra);
                if (dst == NULL) {
                        errno = ENOSPC;
                        return -1;
                }
        }
        free(nextra);
        if (dlen && *dlen == 0) {
                errno = ENOSPC;
                return -1;
        }
        *dst = '\0';
        return (int)(dst - start);
}

int
strsvis(char *dst, const char *csrc, int flag, const char *extra)
{
        return istrsnvis(dst, NULL, csrc, flag, extra);
}

int
strsnvis(char *dst, size_t dlen, const char *csrc, int flag, const char *extra)
{
        return istrsnvis(dst, &dlen, csrc, flag, extra);
}

static int
istrsnvisx(char *dst, size_t *dlen, const char *csrc, size_t len, int flag,
    const char *extra)
{
        unsigned char c;
        char *start;
        char *nextra = NULL;
        const unsigned char *src = (const unsigned char *)csrc;
        visfun_t f;

        _DIAGASSERT(dst != NULL);
        _DIAGASSERT(src != NULL);
        _DIAGASSERT(extra != NULL);
        MAKEEXTRALIST(flag, nextra, extra);
        if (! nextra) {
                if (dlen && *dlen == 0) {
                        errno = ENOSPC;
                        return -1;
                }
                *dst = '\0';            /* can't create nextra, return "" */
                return 0;
        }

        f = getvisfun(flag);
        for (start = dst; len > 0; len--) {
                c = *src++;
                dst = (*f)(dst, dlen, c, flag, len > 1 ? *src : '\0', nextra);
                if (dst == NULL) {
                        errno = ENOSPC;
                        return -1;
                }
        }
        free(nextra);
        if (dlen && *dlen == 0) {
                errno = ENOSPC;
                return -1;
        }
        *dst = '\0';
        return (int)(dst - start);
}

int
strsvisx(char *dst, const char *csrc, size_t len, int flag, const char *extra)
{
        return istrsnvisx(dst, NULL, csrc, len, flag, extra);
}

int
strsnvisx(char *dst, size_t dlen, const char *csrc, size_t len, int flag,
    const char *extra)
{
        return istrsnvisx(dst, &dlen, csrc, len, flag, extra);
}
#endif

#if !HAVE_VIS
/*
 * vis - visually encode characters
 */
static char *
invis(char *dst, size_t *dlen, int c, int flag, int nextc)
{
        char *extra = NULL;
        unsigned char uc = (unsigned char)c;
        visfun_t f;

        _DIAGASSERT(dst != NULL);

        MAKEEXTRALIST(flag, extra, "");
        if (! extra) {
                if (dlen && *dlen == 0) {
                        errno = ENOSPC;
                        return NULL;
                }
                *dst = '\0';            /* can't create extra, return "" */
                return dst;
        }
        f = getvisfun(flag);
        dst = (*f)(dst, dlen, uc, flag, nextc, extra);
        free(extra);
        if (dst == NULL || (dlen && *dlen == 0)) {
                errno = ENOSPC;
                return NULL;
        }
        *dst = '\0';
        return dst;
}

char *
vis(char *dst, int c, int flag, int nextc)
{
        return invis(dst, NULL, c, flag, nextc);
}

char *
nvis(char *dst, size_t dlen, int c, int flag, int nextc)
{
        return invis(dst, &dlen, c, flag, nextc);
}


/*
 * strvis, strvisx - visually encode characters from src into dst
 *
 *      Dst must be 4 times the size of src to account for possible
 *      expansion.  The length of dst, not including the trailing NULL,
 *      is returned.
 *
 *      Strvisx encodes exactly len bytes from src into dst.
 *      This is useful for encoding a block of data.
 */
static int
istrnvis(char *dst, size_t *dlen, const char *src, int flag)
{
        char *extra = NULL;
        int rv;

        MAKEEXTRALIST(flag, extra, "");
        if (!extra) {
                if (dlen && *dlen == 0) {
                        errno = ENOSPC;
                        return -1;
                }
                *dst = '\0';            /* can't create extra, return "" */
                return 0;
        }
        rv = istrsnvis(dst, dlen, src, flag, extra);
        free(extra);
        return rv;
}

int
strvis(char *dst, const char *src, int flag)
{
        return istrnvis(dst, NULL, src, flag);
}

int
strnvis(char *dst, size_t dlen, const char *src, int flag)
{
        return istrnvis(dst, &dlen, src, flag);
}

static int
istrnvisx(char *dst, size_t *dlen, const char *src, size_t len, int flag)
{
        char *extra = NULL;
        int rv;

        MAKEEXTRALIST(flag, extra, "");
        if (!extra) {
                if (dlen && *dlen == 0) {
                        errno = ENOSPC;
                        return -1;
                }
                *dst = '\0';            /* can't create extra, return "" */
                return 0;
        }
        rv = istrsnvisx(dst, dlen, src, len, flag, extra);
        free(extra);
        return rv;
}

int
strvisx(char *dst, const char *src, size_t len, int flag)
{
        return istrnvisx(dst, NULL, src, len, flag);
}

int
strnvisx(char *dst, size_t dlen, const char *src, size_t len, int flag)
{
        return istrnvisx(dst, &dlen, src, len, flag);
}

#endif