ucx: src/string.c@2def28b65328 (annotated)

src/string.c@2def28b65328 (annotated)

src/string.c

Sun, 21 Jan 2018 10:57:32 +0100

author: Olaf Wintermann <olaf.wintermann@gmail.com>
date: Sun, 21 Jan 2018 10:57:32 +0100
changeset 272: 2def28b65328
parent 270: 3d80d425543b
child 275: 96f643d30ff1
permissions: -rw-r--r--

adds integer overflow checks to sstrlen and sstrcat

 /*
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
  *
  * Copyright 2017 Mike Becker, Olaf Wintermann 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 COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 "ucx/string.h"
 #include "ucx/allocator.h"
 #include <stdlib.h>
 #include <string.h>
 #include <stdarg.h>
 #include <stdint.h>
 #include <ctype.h>
 sstr_t sstr(char *cstring) {
     sstr_t string;
     string.ptr = cstring;
     string.length = strlen(cstring);
     return string;
 }
 sstr_t sstrn(char *cstring, size_t length) {
     sstr_t string;
     string.ptr = cstring;
     string.length = length;
     return string;
 }
 size_t sstrnlen(size_t n, sstr_t s, ...) {
     va_list ap;
     size_t size = s.length;
     va_start(ap, s);
     for (size_t i = 1 ; i < n ; i++) {
         sstr_t str = va_arg(ap, sstr_t);
         if(((size_t)-1) - str.length < size) {
             size = 0;
             break;
         }
         size += str.length;
     }
     va_end(ap);
     return size;
 }
 static sstr_t sstrvcat_a(
         UcxAllocator *a,
         size_t count,
         sstr_t s1,
         sstr_t s2,
         va_list ap) {
     sstr_t str;
     str.ptr = NULL;
     str.length = 0;
     if(count < 2) {
         return str;
     }
     if(((size_t)-1) - s1.length < s2.length) {
         return str;
     }
     sstr_t *strings = (sstr_t*) calloc(count, sizeof(sstr_t));
     if(!strings) {
         return str;
     }
     // get all args and overall length
     strings[0] = s1;
     strings[1] = s2;
     size_t slen = s1.length + s2.length;
     int error = 0;
     for (size_t i=2;i<count;i++) {
         sstr_t s = va_arg (ap, sstr_t);
         strings[i] = s;
         if(((size_t)-1) - s.length < slen) {
             error = 1;
             break;
         }
         slen += s.length;
     }
     if(error) {
         free(strings);
         return str;
     }
     // create new string
     str.ptr = (char*) almalloc(a, slen + 1);
     str.length = slen;
     if(!str.ptr) {
         free(strings);
         str.length = 0;
         return str;
     }
     // concatenate strings
     size_t pos = 0;
     for (size_t i=0;i<count;i++) {
         sstr_t s = strings[i];
         memcpy(str.ptr + pos, s.ptr, s.length);
         pos += s.length;
     }
     str.ptr[str.length] = '\0';
     free(strings);
     return str;
 }
 sstr_t sstrcat(size_t count, sstr_t s1, sstr_t s2, ...) {
     va_list ap;
     va_start(ap, s2);
     sstr_t s = sstrvcat_a(ucx_default_allocator(), count, s1, s2, ap);
     va_end(ap);
     return s;
 }
 sstr_t sstrcat_a(UcxAllocator *a, size_t count, sstr_t s1, sstr_t s2, ...) {
     va_list ap;
     va_start(ap, s2);
     sstr_t s = sstrvcat_a(a, count, s1, s2, ap);
     va_end(ap);
     return s;
 }
 sstr_t sstrsubs(sstr_t s, size_t start) {
     return sstrsubsl (s, start, s.length-start);
 }
 sstr_t sstrsubsl(sstr_t s, size_t start, size_t length) {
     sstr_t new_sstr;
     if (start >= s.length) {
         new_sstr.ptr = NULL;
         new_sstr.length = 0;
     } else {
         if (length > s.length-start) {
             length = s.length-start;
         }
         new_sstr.ptr = &s.ptr[start];
         new_sstr.length = length;
     }
     return new_sstr;
 }
 sstr_t sstrchr(sstr_t s, int c) {
     for(size_t i=0;i<s.length;i++) {
         if(s.ptr[i] == c) {
             return sstrsubs(s, i);
         }
     }
     sstr_t n;
     n.ptr = NULL;
     n.length = 0;
     return n;
 }
 sstr_t sstrrchr(sstr_t s, int c) {
     if (s.length > 0) {
         for(size_t i=s.length;i>0;i--) {
             if(s.ptr[i-1] == c) {
                 return sstrsubs(s, i-1);
             }
         }
     }
     sstr_t n;
     n.ptr = NULL;
     n.length = 0;
     return n;
 }
 #define ptable_r(dest, useheap, ptable, index) (dest = useheap ? \
     ((size_t*)ptable)[index] : (size_t) ((uint8_t*)ptable)[index])
 #define ptable_w(useheap, ptable, index, src) do {\
     if (!useheap) ((uint8_t*)ptable)[index] = (uint8_t) src;\
     else ((size_t*)ptable)[index] = src;\
     } while (0);
 sstr_t sstrstr(sstr_t string, sstr_t match) {
     if (match.length == 0) {
         return string;
     }
     /* prepare default return value in case of no match */
     sstr_t result = sstrn(NULL, 0);
     /*
      * IMPORTANT:
      * our prefix table contains the prefix length PLUS ONE
      * this is our decision, because we want to use the full range of size_t
      * the original algorithm needs a (-1) at one single place
      * and we want to avoid that
      */
     /* static prefix table */
     static uint8_t s_prefix_table[256];
     /* check pattern length and use appropriate prefix table */
     /* if the pattern exceeds static prefix table, allocate on the heap */
     register int useheap = match.length > 255;
     register void* ptable = useheap ?
         calloc(match.length+1, sizeof(size_t)): s_prefix_table;
     /* keep counter in registers */
     register size_t i, j;
     /* fill prefix table */
     i = 0; j = 0;
     ptable_w(useheap, ptable, i, j);
     while (i < match.length) {
         while (j >= 1 && match.ptr[j-1] != match.ptr[i]) {
             ptable_r(j, useheap, ptable, j-1);
         }
         i++; j++;
         ptable_w(useheap, ptable, i, j);
     }
     /* search */
     i = 0; j = 1;
     while (i < string.length) {
         while (j >= 1 && string.ptr[i] != match.ptr[j-1]) {
             ptable_r(j, useheap, ptable, j-1);
         }
         i++; j++;
         if (j-1 == match.length) {
             size_t start = i - match.length;
             result.ptr = string.ptr + start;
             result.length = string.length - start;
             break;
         }
     }
     /* if prefix table was allocated on the heap, free it */
     if (ptable != s_prefix_table) {
         free(ptable);
     }
     return result;
 }
 #undef ptable_r
 #undef ptable_w
 sstr_t* sstrsplit(sstr_t s, sstr_t d, ssize_t *n) {
     return sstrsplit_a(ucx_default_allocator(), s, d, n);
 }
 sstr_t* sstrsplit_a(UcxAllocator *allocator, sstr_t s, sstr_t d, ssize_t *n) {
     if (s.length == 0 || d.length == 0) {
         *n = -1;
         return NULL;
     }
     /* special cases: delimiter is at least as large as the string */
     if (d.length >= s.length) {
         /* exact match */
         if (sstrcmp(s, d) == 0) {
             *n = 0;
             return NULL;
         } else /* no match possible */ {
             *n = 1;
             sstr_t *result = (sstr_t*) almalloc(allocator, sizeof(sstr_t));
             if(result) {
                 *result = sstrdup_a(allocator, s);
             } else {
                 *n = -2;
             }
             return result;
         }
     }
     ssize_t nmax = *n;
     size_t arrlen = 16;
     sstr_t* result = (sstr_t*) alcalloc(allocator, arrlen, sizeof(sstr_t));
     if (result) {
         sstr_t curpos = s;
         ssize_t j = 1;
         while (1) {
             sstr_t match;
             /* optimize for one byte delimiters */
             if (d.length == 1) {
                 match = curpos;
                 for (size_t i = 0 ; i < curpos.length ; i++) {
                     if (curpos.ptr[i] == *(d.ptr)) {
                         match.ptr = curpos.ptr + i;
                         break;
                     }
                     match.length--;
                 }
             } else {
                 match = sstrstr(curpos, d);
             }
             if (match.length > 0) {
                 /* is this our last try? */
                 if (nmax == 0 || j < nmax) {
                     /* copy the current string to the array */
                     sstr_t item = sstrn(curpos.ptr, match.ptr - curpos.ptr);
                     result[j-1] = sstrdup_a(allocator, item);
                     size_t processed = item.length + d.length;
                     curpos.ptr += processed;
                     curpos.length -= processed;
                     /* allocate memory for the next string */
                     j++;
                     if (j > arrlen) {
                         arrlen *= 2;
                         size_t reallocsz;
                         sstr_t* reallocated = NULL;
                         if(!ucx_szmul(arrlen, sizeof(sstr_t), &reallocsz)) {
                             reallocated = (sstr_t*) alrealloc(
                                     allocator, result, reallocsz);
                         }
                         if (reallocated) {
                             result = reallocated;
                         } else {
                             for (ssize_t i = 0 ; i < j-1 ; i++) {
                                 alfree(allocator, result[i].ptr);
                             }
                             alfree(allocator, result);
                             *n = -2;
                             return NULL;
                         }
                     }
                 } else {
                     /* nmax reached, copy the _full_ remaining string */
                     result[j-1] = sstrdup_a(allocator, curpos);
                     break;
                 }
             } else {
                 /* no more matches, copy last string */
                 result[j-1] = sstrdup_a(allocator, curpos);
                 break;
             }
         }
         *n = j;
     } else {
         *n = -2;
     }
     return result;
 }
 int sstrcmp(sstr_t s1, sstr_t s2) {
     if (s1.length == s2.length) {
         return memcmp(s1.ptr, s2.ptr, s1.length);
     } else if (s1.length > s2.length) {
         return 1;
     } else {
         return -1;
     }
 }
 int sstrcasecmp(sstr_t s1, sstr_t s2) {
     if (s1.length == s2.length) {
 #ifdef _WIN32
         return _strnicmp(s1.ptr, s2.ptr, s1.length);
 #else
         return strncasecmp(s1.ptr, s2.ptr, s1.length);
 #endif
     } else if (s1.length > s2.length) {
         return 1;
     } else {
         return -1;
     }
 }
 sstr_t sstrdup(sstr_t s) {
     return sstrdup_a(ucx_default_allocator(), s);
 }
 sstr_t sstrdup_a(UcxAllocator *allocator, sstr_t s) {
     sstr_t newstring;
     newstring.ptr = (char*)almalloc(allocator, s.length + 1);
     if (newstring.ptr) {
         newstring.length = s.length;
         newstring.ptr[newstring.length] = 0;
         memcpy(newstring.ptr, s.ptr, s.length);
     } else {
         newstring.length = 0;
     }
     return newstring;
 }
 sstr_t sstrtrim(sstr_t string) {
     sstr_t newstr = string;
     while (newstr.length > 0 && isspace(*newstr.ptr)) {
         newstr.ptr++;
         newstr.length--;
     }
     while (newstr.length > 0 && isspace(newstr.ptr[newstr.length-1])) {
         newstr.length--;
     }
     return newstr;
 }
 int sstrprefix(sstr_t string, sstr_t prefix) {
     if (string.length == 0) {
         return prefix.length == 0;
     }
     if (prefix.length == 0) {
         return 1;
     }
     if (prefix.length > string.length) {
         return 0;
     } else {
         return memcmp(string.ptr, prefix.ptr, prefix.length) == 0;
     }
 }
 int sstrsuffix(sstr_t string, sstr_t suffix) {
     if (string.length == 0) {
         return suffix.length == 0;
     }
     if (suffix.length == 0) {
         return 1;
     }
     if (suffix.length > string.length) {
         return 0;
     } else {
         return memcmp(string.ptr+string.length-suffix.length,
             suffix.ptr, suffix.length) == 0;
     }
 }
 sstr_t sstrlower(sstr_t string) {
     sstr_t ret = sstrdup(string);
     for (size_t i = 0; i < ret.length ; i++) {
         ret.ptr[i] = tolower(ret.ptr[i]);
     }
     return ret;
 }
 sstr_t sstrlower_a(UcxAllocator *allocator, sstr_t string) {
     sstr_t ret = sstrdup_a(allocator, string);
     for (size_t i = 0; i < ret.length ; i++) {
         ret.ptr[i] = tolower(ret.ptr[i]);
     }
     return ret;
 }
 sstr_t sstrupper(sstr_t string) {
     sstr_t ret = sstrdup(string);
     for (size_t i = 0; i < ret.length ; i++) {
         ret.ptr[i] = toupper(ret.ptr[i]);
     }
     return ret;
 }
 sstr_t sstrupper_a(UcxAllocator *allocator, sstr_t string) {
     sstr_t ret = sstrdup_a(allocator, string);
     for (size_t i = 0; i < ret.length ; i++) {
         ret.ptr[i] = toupper(ret.ptr[i]);
     }
     return ret;
 }

Mercurial > hg > ucx / annotate

src/string.c@2def28b65328 (annotated)

src/string.c