mariadb/mysys/my_memmem.c
unknown 3010890e58 SECURITY FIX
Bug#17667: An attacker has the opportunity to bypass query logging.

This adds a new, local-only printf format specifier to our *printf functions
that allows us to print known-size buffers that must not be interpreted as 
NUL-terminated "strings."

It uses this format-specifier to print to the log, thus fixing this 
problem.


include/my_sys.h:
  Add prototype for my_memmem() .
mysys/Makefile.am:
  Add reference to new file, my_memmem.c
mysys/mf_iocache2.c:
  Add a "%.1234b" and "%.*b" percent-code.  It takes a width, just like "%s", 
  but unlike the string-indicator, it requires the width and doesn't stop printing
  at NUL characters.
  
  Also, simplify the code a bit.
  
  TODO:  This code should be unified with the strings/my_vnsprintf.c code in 
  the future.
sql/sql_parse.cc:
  The query is not a C-string, but is a sized buffer, containing any character 
  at all, which may include NUL characters.
strings/my_vsnprintf.c:
  Add a "%.1234b" and "%.*b" percent-code.  It takes a width, just like "%s", 
  but unlike the string-indicator, it requires the width and doesn't stop printing
  at NUL characters.
tests/Makefile.am:
  We may need some of our local functions.
tests/mysql_client_test.c:
  Add a "%.1234b" and "%.*b" percent-code.  It takes a width, just like "%s", 
  but unlike the string-indicator, it requires the width and doesn't stop printing
  at NUL characters.
mysql-test/t/mysql_client_test.opt:
  New BitKeeper file ``mysql-test/t/mysql_client_test.opt''
  
  Add '--log' server parameter.
mysys/my_memmem.c:
  New BitKeeper file ``mysys/my_memmem.c''
  
  Implement memmem, a black-box work-alike of the GNU memmem(), which functions
  like strstr() but for arbitrary blocks of memory.
2006-05-01 22:10:50 -04:00

65 lines
1.6 KiB
C

#include "my_base.h"
/*
my_memmem, port of a GNU extension.
Returns a pointer to the beginning of the substring, needle, or NULL if the
substring is not found in haystack.
*/
void *my_memmem(const void *haystack, size_t haystacklen,
const void *needle, size_t needlelen)
{
const void *cursor;
const void *last_possible_needle_location = haystack + haystacklen - needlelen;
/* Easy answers */
if (needlelen > haystacklen) return(NULL);
if (needle == NULL) return(NULL);
if (haystack == NULL) return(NULL);
if (needlelen == 0) return(NULL);
if (haystacklen == 0) return(NULL);
for (cursor = haystack; cursor <= last_possible_needle_location; cursor++) {
if (memcmp(needle, cursor, needlelen) == 0) {
return((void *) cursor);
}
}
return(NULL);
}
#ifdef MAIN
#include <assert.h>
int main(int argc, char *argv[]) {
char haystack[10], needle[3];
memmove(haystack, "0123456789", 10);
memmove(needle, "no", 2);
assert(my_memmem(haystack, 10, needle, 2) == NULL);
memmove(needle, "345", 3);
assert(my_memmem(haystack, 10, needle, 3) != NULL);
memmove(needle, "789", 3);
assert(my_memmem(haystack, 10, needle, 3) != NULL);
assert(my_memmem(haystack, 9, needle, 3) == NULL);
memmove(needle, "012", 3);
assert(my_memmem(haystack, 10, needle, 3) != NULL);
assert(my_memmem(NULL, 10, needle, 3) == NULL);
assert(my_memmem(NULL, 10, needle, 3) == NULL);
assert(my_memmem(haystack, 0, needle, 3) == NULL);
assert(my_memmem(haystack, 10, NULL, 3) == NULL);
assert(my_memmem(haystack, 10, needle, 0) == NULL);
assert(my_memmem(haystack, 1, needle, 3) == NULL);
printf("success\n");
return(0);
}
#endif