* [PATCH] reduce parser size to 88 bytes on 64-bit
@ 2017-03-05 1:10 Eric Wong
0 siblings, 0 replies; only message in thread
From: Eric Wong @ 2017-03-05 1:10 UTC (permalink / raw)
To: kcar-public
The actual struct we manage is 48 bytes, along with
40 bytes for object overhead.
---
ext/kcar/kcar.rl | 42 ++++++++++++++++++++++++++++++++----------
1 file changed, 32 insertions(+), 10 deletions(-)
diff --git a/ext/kcar/kcar.rl b/ext/kcar/kcar.rl
index 4c66fb5..e015bdb 100644
--- a/ext/kcar/kcar.rl
+++ b/ext/kcar/kcar.rl
@@ -10,6 +10,7 @@
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
+#include <limits.h>
#include "c_util.h"
static VALUE eParserError;
@@ -47,15 +48,15 @@ DEF_MAX_LENGTH(HEADER, (1024 * (80 + 32)));
struct http_parser {
int cs; /* Ragel internal state */
unsigned int flags;
- size_t mark;
- size_t offset;
+ unsigned int mark;
+ unsigned int offset;
union { /* these 2 fields don't nest */
- size_t field;
- size_t query;
+ unsigned int field;
+ unsigned int query;
} start;
union {
- size_t field_len; /* only used during header processing */
- size_t dest_offset; /* only used during body processing */
+ unsigned int field_len; /* only used during header processing */
+ unsigned int dest_offset; /* only used during body processing */
} s;
VALUE cont; /* Qfalse: unset, Qnil: ignored header, T_STRING: append */
VALUE status; /* String or Qnil */
@@ -65,9 +66,21 @@ struct http_parser {
} len;
};
+static unsigned int ulong2uint(unsigned long n)
+{
+ unsigned int i = (unsigned int)n;
+
+ if (sizeof(unsigned int) != sizeof(unsigned long)) {
+ if ((unsigned long)i != n) {
+ rb_raise(rb_eRangeError, "too large to be 32-bit uint: %lu", n);
+ }
+ }
+ return i;
+}
+
#define REMAINING (unsigned long)(pe - p)
-#define LEN(AT, FPC) (FPC - buffer - hp->AT)
-#define MARK(M,FPC) (hp->M = (FPC) - buffer)
+#define LEN(AT, FPC) (ulong2uint(FPC - buffer) - hp->AT)
+#define MARK(M,FPC) (hp->M = ulong2uint((FPC) - buffer))
#define PTR_TO(F) (buffer + hp->F)
#define STR_NEW(M,FPC) rb_str_new(PTR_TO(M), LEN(M, FPC))
#define STRIPPED_STR_NEW(M,FPC) stripped_str_new(PTR_TO(M), LEN(M, FPC))
@@ -403,7 +416,7 @@ static void http_parser_execute(struct http_parser *hp,
post_exec: /* "_out:" also goes here */
if (hp->cs != http_parser_error)
hp->cs = cs;
- hp->offset = p - buffer;
+ hp->offset = ulong2uint(p - buffer);
assert(p <= pe && "buffer overflow after parsing execute");
assert(hp->offset <= len && "offset longer than length");
@@ -537,6 +550,12 @@ static VALUE chunked(VALUE self)
return HP_FL_TEST(hp, CHUNKED) ? Qtrue : Qfalse;
}
+static void check_buffer_size(long dlen)
+{
+ if (dlen > UINT_MAX)
+ rb_raise(rb_eRangeError, "headers too large to process (%ld bytes)", dlen);
+}
+
/**
* Document-method: headers
* call-seq:
@@ -552,8 +571,10 @@ static VALUE chunked(VALUE self)
static VALUE headers(VALUE self, VALUE hdr, VALUE data)
{
struct http_parser *hp = data_get(self);
+ long dlen = RSTRING_LEN(data);
- http_parser_execute(hp, hdr, RSTRING_PTR(data), RSTRING_LEN(data));
+ check_buffer_size(dlen);
+ http_parser_execute(hp, hdr, RSTRING_PTR(data), dlen);
VALIDATE_MAX_LENGTH(hp->offset, HEADER);
if (hp->cs == http_parser_first_final ||
@@ -653,6 +674,7 @@ static VALUE filter_body(VALUE self, VALUE buf, VALUE data)
dptr = RSTRING_PTR(data);
dlen = RSTRING_LEN(data);
+ check_buffer_size(dlen);
StringValue(buf);
rb_str_modify(buf);
--
EW
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