lib/curl_fnmatch.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

#include "curl_setup.h"

#include <curl/curl.h>

#include "curl_fnmatch.h"
#include "curl_memory.h"

/* The last #include file should be: */
#include "memdebug.h"

#define CURLFNM_CHARSET_LEN (sizeof(char) * 256)
#define CURLFNM_CHSET_SIZE (CURLFNM_CHARSET_LEN + 15)

#define CURLFNM_NEGATE  CURLFNM_CHARSET_LEN

#define CURLFNM_ALNUM   (CURLFNM_CHARSET_LEN + 1)
#define CURLFNM_DIGIT   (CURLFNM_CHARSET_LEN + 2)
#define CURLFNM_XDIGIT  (CURLFNM_CHARSET_LEN + 3)
#define CURLFNM_ALPHA   (CURLFNM_CHARSET_LEN + 4)
#define CURLFNM_PRINT   (CURLFNM_CHARSET_LEN + 5)
#define CURLFNM_BLANK   (CURLFNM_CHARSET_LEN + 6)
#define CURLFNM_LOWER   (CURLFNM_CHARSET_LEN + 7)
#define CURLFNM_GRAPH   (CURLFNM_CHARSET_LEN + 8)
#define CURLFNM_SPACE   (CURLFNM_CHARSET_LEN + 9)
#define CURLFNM_UPPER   (CURLFNM_CHARSET_LEN + 10)

typedef enum {
  CURLFNM_SCHS_DEFAULT = 0,
  CURLFNM_SCHS_RIGHTBR,
  CURLFNM_SCHS_RIGHTBRLEFTBR
} setcharset_state;

typedef enum {
  CURLFNM_PKW_INIT = 0,
  CURLFNM_PKW_DDOT
} parsekey_state;

typedef enum {
  CCLASS_OTHER = 0,
  CCLASS_DIGIT,
  CCLASS_UPPER,
  CCLASS_LOWER
} char_class;

#define SETCHARSET_OK     1
#define SETCHARSET_FAIL   0

static int parsekeyword(unsigned char **pattern, unsigned char *charset)
{
  parsekey_state state = CURLFNM_PKW_INIT;
#define KEYLEN 10
  char keyword[KEYLEN] = { 0 };
  int found = FALSE;
  int i;
  unsigned char *p = *pattern;
  for(i = 0; !found; i++) {
    char c = *p++;
    if(i >= KEYLEN)
      return SETCHARSET_FAIL;
    switch(state) {
    case CURLFNM_PKW_INIT:
      if(ISLOWER(c))
        keyword[i] = c;
      else if(c == ':')
        state = CURLFNM_PKW_DDOT;
      else
        return SETCHARSET_FAIL;
      break;
    case CURLFNM_PKW_DDOT:
      if(c == ']')
        found = TRUE;
      else
        return SETCHARSET_FAIL;
    }
  }
#undef KEYLEN

  *pattern = p; /* move caller's pattern pointer */
  if(strcmp(keyword, "digit") == 0)
    charset[CURLFNM_DIGIT] = 1;
  else if(strcmp(keyword, "alnum") == 0)
    charset[CURLFNM_ALNUM] = 1;
  else if(strcmp(keyword, "alpha") == 0)
    charset[CURLFNM_ALPHA] = 1;
  else if(strcmp(keyword, "xdigit") == 0)
    charset[CURLFNM_XDIGIT] = 1;
  else if(strcmp(keyword, "print") == 0)
    charset[CURLFNM_PRINT] = 1;
  else if(strcmp(keyword, "graph") == 0)
    charset[CURLFNM_GRAPH] = 1;
  else if(strcmp(keyword, "space") == 0)
    charset[CURLFNM_SPACE] = 1;
  else if(strcmp(keyword, "blank") == 0)
    charset[CURLFNM_BLANK] = 1;
  else if(strcmp(keyword, "upper") == 0)
    charset[CURLFNM_UPPER] = 1;
  else if(strcmp(keyword, "lower") == 0)
    charset[CURLFNM_LOWER] = 1;
  else
    return SETCHARSET_FAIL;
  return SETCHARSET_OK;
}

/* Return the character class. */
static char_class charclass(unsigned char c)
{
  if(ISUPPER(c))
    return CCLASS_UPPER;
  if(ISLOWER(c))
    return CCLASS_LOWER;
  if(ISDIGIT(c))
    return CCLASS_DIGIT;
  return CCLASS_OTHER;
}

/* Include a character or a range in set. */
static void setcharorrange(unsigned char **pp, unsigned char *charset)
{
  unsigned char *p = (*pp)++;
  unsigned char c = *p++;

  charset[c] = 1;
  if(ISALNUM(c) && *p++ == '-') {
    char_class cc = charclass(c);
    unsigned char endrange = *p++;

    if(endrange == '\\')
      endrange = *p++;
    if(endrange >= c && charclass(endrange) == cc) {
      while(c++ != endrange)
        if(charclass(c) == cc)  /* Chars in class may be not consecutive. */
          charset[c] = 1;
      *pp = p;
    }
  }
}

/* returns 1 (true) if pattern is OK, 0 if is bad ("p" is pattern pointer) */
static int setcharset(unsigned char **p, unsigned char *charset)
{
  setcharset_state state = CURLFNM_SCHS_DEFAULT;
  bool something_found = FALSE;
  unsigned char c;

  memset(charset, 0, CURLFNM_CHSET_SIZE);
  for(;;) {
    c = **p;
    if(!c)
      return SETCHARSET_FAIL;

    switch(state) {
    case CURLFNM_SCHS_DEFAULT:
      if(c == ']') {
        if(something_found)
          return SETCHARSET_OK;
        something_found = TRUE;
        state = CURLFNM_SCHS_RIGHTBR;
        charset[c] = 1;
        (*p)++;
      }
      else if(c == '[') {
        unsigned char *pp = *p + 1;

        if(*pp++ == ':' && parsekeyword(&pp, charset))
          *p = pp;
        else {
          charset[c] = 1;
          (*p)++;
        }
        something_found = TRUE;
      }
      else if(c == '^' || c == '!') {
        if(!something_found) {
          if(charset[CURLFNM_NEGATE]) {
            charset[c] = 1;
            something_found = TRUE;
          }
          else
            charset[CURLFNM_NEGATE] = 1; /* negate charset */
        }
        else
          charset[c] = 1;
        (*p)++;
      }
      else if(c == '\\') {
        c = *(++(*p));
        if(c)
          setcharorrange(p, charset);
        else
          charset['\\'] = 1;
        something_found = TRUE;
      }
      else {
        setcharorrange(p, charset);
        something_found = TRUE;
      }
      break;
    case CURLFNM_SCHS_RIGHTBR:
      if(c == '[') {
        state = CURLFNM_SCHS_RIGHTBRLEFTBR;
        charset[c] = 1;
        (*p)++;
      }
      else if(c == ']') {
        return SETCHARSET_OK;
      }
      else if(ISPRINT(c)) {
        charset[c] = 1;
        (*p)++;
        state = CURLFNM_SCHS_DEFAULT;
      }
      else
        /* used 'goto fail' instead of 'return SETCHARSET_FAIL' to avoid a
         * nonsense warning 'statement not reached' at end of the fnc when
         * compiling on Solaris */
        goto fail;
      break;
    case CURLFNM_SCHS_RIGHTBRLEFTBR:
      if(c == ']')
        return SETCHARSET_OK;
      state  = CURLFNM_SCHS_DEFAULT;
      charset[c] = 1;
      (*p)++;
      break;
    }
  }
fail:
  return SETCHARSET_FAIL;
}

static int loop(const unsigned char *pattern, const unsigned char *string,
                int maxstars)
{
  unsigned char *p = (unsigned char *)pattern;
  unsigned char *s = (unsigned char *)string;
  unsigned char charset[CURLFNM_CHSET_SIZE] = { 0 };

  for(;;) {
    unsigned char *pp;

    switch(*p) {
    case '*':
      if(!maxstars)
        return CURL_FNMATCH_NOMATCH;
      /* Regroup consecutive stars and question marks. This can be done because
         '*?*?*' can be expressed as '??*'. */
      for(;;) {
        if(*++p == '\0')
          return CURL_FNMATCH_MATCH;
        if(*p == '?') {
          if(!*s++)
            return CURL_FNMATCH_NOMATCH;
        }
        else if(*p != '*')
          break;
      }
      /* Skip string characters until we find a match with pattern suffix. */
      for(maxstars--; *s; s++) {
        if(loop(p, s, maxstars) == CURL_FNMATCH_MATCH)
          return CURL_FNMATCH_MATCH;
      }
      return CURL_FNMATCH_NOMATCH;
    case '?':
      if(!*s)
        return CURL_FNMATCH_NOMATCH;
      s++;
      p++;
      break;
    case '\0':
      return *s? CURL_FNMATCH_NOMATCH: CURL_FNMATCH_MATCH;
    case '\\':
      if(p[1])
        p++;
      if(*s++ != *p++)
        return CURL_FNMATCH_NOMATCH;
      break;
    case '[':
      pp = p + 1; /* Copy in case of syntax error in set. */
      if(setcharset(&pp, charset)) {
        int found = FALSE;
        if(!*s)
          return CURL_FNMATCH_NOMATCH;
        if(charset[(unsigned int)*s])
          found = TRUE;
        else if(charset[CURLFNM_ALNUM])
          found = ISALNUM(*s);
        else if(charset[CURLFNM_ALPHA])
          found = ISALPHA(*s);
        else if(charset[CURLFNM_DIGIT])
          found = ISDIGIT(*s);
        else if(charset[CURLFNM_XDIGIT])
          found = ISXDIGIT(*s);
        else if(charset[CURLFNM_PRINT])
          found = ISPRINT(*s);
        else if(charset[CURLFNM_SPACE])
          found = ISSPACE(*s);
        else if(charset[CURLFNM_UPPER])
          found = ISUPPER(*s);
        else if(charset[CURLFNM_LOWER])
          found = ISLOWER(*s);
        else if(charset[CURLFNM_BLANK])
          found = ISBLANK(*s);
        else if(charset[CURLFNM_GRAPH])
          found = ISGRAPH(*s);

        if(charset[CURLFNM_NEGATE])
          found = !found;

        if(!found)
          return CURL_FNMATCH_NOMATCH;
        p = pp + 1;
        s++;
        break;
      }

      /* Syntax error in set: this must be taken as a regular character. */
      /* FALLTHROUGH */
    default:
      if(*p++ != *s++)
        return CURL_FNMATCH_NOMATCH;
      break;
    }
  }
}

/*
 * @unittest: 1307
 */
int Curl_fnmatch(void *ptr, const char *pattern, const char *string)
{
  (void)ptr; /* the argument is specified by the curl_fnmatch_callback
                prototype, but not used by Curl_fnmatch() */
  if(!pattern || !string) {
    return CURL_FNMATCH_FAIL;
  }
  return loop((unsigned char *)pattern, (unsigned char *)string, 5);
}