baresip · sreimers · Mar 21, 2022 · Mar 20, 2022 · Mar 20, 2022 · Mar 20, 2022
diff --git a/.github/workflows/centos7.yml b/.github/workflows/centos7.yml
@@ -9,7 +9,7 @@ jobs:
 
     strategy:
       matrix:
-        compiler: [gcc, clang]
+        compiler: [clang]
         os: [ubuntu-latest]
 
     env:

diff --git a/README.md b/README.md
@@ -245,8 +245,8 @@ legend:
 
 ### Supported compilers:
 
-* gcc 4.x or later
-* ms vc2003 compiler
+* gcc 4.9 or later
+* MSVC 2019
 * clang 3.x or later
 
 

diff --git a/include/re.h b/include/re.h
@@ -25,6 +25,7 @@ extern "C" {
 #include "re_bfcp.h"
 #include "re_btrace.h"
 #include "re_conf.h"
+#include "re_convert.h"
 #include "re_crc32.h"
 #include "re_dns.h"
 #include "re_hash.h"

diff --git a/include/re_convert.h b/include/re_convert.h
@@ -0,0 +1,79 @@
+/**
+ * @file re_convert.h  Conversion helpers
+ *
+ * Copyright (C) 2022 Sebastian Reimers
+ */
+#include <limits.h>
+
+static inline int try_into_u16_from_size(uint16_t *dest, const size_t src)
+{
+	*dest = 0;
+
+	if (src > UINT16_MAX)
+		return ERANGE;
+
+	*dest = (uint16_t)src;
+
+	return 0;
+}
+
+
+static inline int try_into_u16_from_int(uint16_t *dest, const int src)
+{
+	*dest = 0;
+
+	if (src > UINT16_MAX)
+		return ERANGE;
+
+	if (src < 0)
+		return ERANGE;
+
+	*dest = (uint16_t)src;
+
+	return 0;
+}
+
+
+static inline int try_into_int_from_size(int *dest, const size_t src)
+{
+	*dest = 0;
+
+	if (src > INT_MAX)
+		return ERANGE;
+
+	*dest = (int)src;
+
+	return 0;
+}
+
+
+static inline int try_into_err(void *dest, ...)
+{
+	(void)dest;
+
+	return ENOTSUP;
+}
+
+
+/**
+ * Try to convert safely from one type (src) into another (dest).
+ * Types are auto detected.
+ *
+ * @param dest Destination
+ * @param src  Source value
+ *
+ * @return 0 if success, ERANGE if value overflow and ENOTSUP if not supported
+ */
+#define try_into(dest, src)						      \
+	_Generic((dest), 						      \
+		uint16_t: _Generic((src),				      \
+				size_t: try_into_u16_from_size, 	      \
+				int: try_into_u16_from_int,		      \
+				default: try_into_err			      \
+			),						      \
+		int: _Generic((src),					      \
+				size_t: try_into_int_from_size,		      \
+				default: try_into_err			      \
+			)						      \
+		)							      \
+	(&(dest), (src))
diff --git a/src/shim/shim.c b/src/shim/shim.c
@@ -11,6 +11,7 @@
 #include <re_tcp.h>
 #include <re_net.h>
 #include <re_shim.h>
+#include <re_convert.h>
 
 
 #define DEBUG_MODULE "shim"
@@ -36,7 +37,8 @@ struct shim {
 static bool shim_send_handler(int *err, struct mbuf *mb, void *arg)
 {
 	struct shim *shim = arg;
-	size_t len;
+	int err_len;
+	uint16_t len;
 	(void)shim;
 
 	if (mb->pos < SHIM_HDR_SIZE) {
@@ -45,7 +47,12 @@ static bool shim_send_handler(int *err, struct mbuf *mb, void *arg)
 		return true;
 	}
 
-	len = mbuf_get_left(mb);
+	err_len = try_into(len, mbuf_get_left(mb));
+	if (err_len) {
+		DEBUG_WARNING("send: mbuf to big\n");
+		*err = err_len;
+		return true;
+	}
 
 	mb->pos -= SHIM_HDR_SIZE;
 	*err = mbuf_write_u16(mb, htons(len));