diff options
Diffstat (limited to 'src/backend/utils/mb/mbutils.c')
| -rw-r--r-- | src/backend/utils/mb/mbutils.c | 48 |
1 files changed, 39 insertions, 9 deletions
diff --git a/src/backend/utils/mb/mbutils.c b/src/backend/utils/mb/mbutils.c index cee6807d66c..a466073ca0a 100644 --- a/src/backend/utils/mb/mbutils.c +++ b/src/backend/utils/mb/mbutils.c @@ -4,7 +4,7 @@ * (currently mule internal code (mic) is used) * Tatsuo Ishii * - * $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.62 2007/02/27 23:48:09 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/utils/mb/mbutils.c,v 1.63 2007/05/28 16:43:24 tgl Exp $ */ #include "postgres.h" @@ -16,6 +16,17 @@ #include "utils/syscache.h" /* + * When converting strings between different encodings, we assume that space + * for converted result is 4-to-1 growth in the worst case. The rate for + * currently supported encoding pairs are within 3 (SJIS JIS X0201 half width + * kanna -> UTF8 is the worst case). So "4" should be enough for the moment. + * + * Note that this is not the same as the maximum character width in any + * particular encoding. + */ +#define MAX_CONVERSION_GROWTH 4 + +/* * We handle for actual FE and BE encoding setting encoding-identificator * and encoding-name too. It prevent searching and conversion from encoding * to encoding name in getdatabaseencoding() and other routines. @@ -207,15 +218,14 @@ pg_get_client_encoding_name(void) * conversion function is chosen from the pg_conversion system catalog * marked as "default". If it is not found in the schema search path, * it's taken from pg_catalog schema. If it even is not in the schema, - * warn and returns src. We cannot raise an error, since it will cause - * an infinit loop in error message sending. + * warn and return src. * * In the case of no conversion, src is returned. * - * XXX We assume that storage for converted result is 4-to-1 growth in - * the worst case. The rate for currently supported encoding pares are within 3 - * (SJIS JIS X0201 half width kanna -> UTF8 is the worst case). - * So "4" should be enough for the moment. + * Note: we try to avoid raising error, since that could get us into + * infinite recursion when this function is invoked during error message + * sending. It should be OK to raise error for overlength strings though, + * since the recursion will come with a shorter message. */ unsigned char * pg_do_encoding_conversion(unsigned char *src, int len, @@ -260,7 +270,17 @@ pg_do_encoding_conversion(unsigned char *src, int len, return src; } - result = palloc(len * 4 + 1); + /* + * Allocate space for conversion result, being wary of integer overflow + */ + if ((Size) len >= (MaxAllocSize / (Size) MAX_CONVERSION_GROWTH)) + ereport(ERROR, + (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), + errmsg("out of memory"), + errdetail("String of %d bytes is too long for encoding conversion.", + len))); + + result = palloc(len * MAX_CONVERSION_GROWTH + 1); OidFunctionCall5(proc, Int32GetDatum(src_encoding), @@ -458,7 +478,17 @@ perform_default_encoding_conversion(const char *src, int len, bool is_client_to_ if (flinfo == NULL) return (char *) src; - result = palloc(len * 4 + 1); + /* + * Allocate space for conversion result, being wary of integer overflow + */ + if ((Size) len >= (MaxAllocSize / (Size) MAX_CONVERSION_GROWTH)) + ereport(ERROR, + (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED), + errmsg("out of memory"), + errdetail("String of %d bytes is too long for encoding conversion.", + len))); + + result = palloc(len * MAX_CONVERSION_GROWTH + 1); FunctionCall5(flinfo, Int32GetDatum(src_encoding), |