Implement dynamic32 framing function

1 files changed, 74 insertions, 0 deletions

diff --git a/plugins/framing_dynamic32.c b/plugins/framing_dynamic32.c
new file mode 100644
index 0000000..3b66588
--- /dev/null
+++ b/plugins/framing_dynamic32.c
@@ -0,0 +1,74 @@
+#include <stdio.h>
+#include <string.h>
+#include <endian.h>
+
+#include "../websocksy.h"
+
+typedef struct /*_framing_config*/ {
+	uint32_t offset;
+	int32_t fixed;
+	uint8_t endian;
+} dynamic32_config_t;
+
+static int64_t framing_dynamic32(uint8_t* data, size_t length, size_t last_read, ws_operation* opcode, void** framing_data, const char* config){
+	size_t u;
+	uint32_t* size_p, size = 0;
+	//get the current config if set
+	dynamic32_config_t* conncfg = (*framing_data) ? ((dynamic32_config_t*) (*framing_data)) : NULL;
+
+	//configure framing for this connection
+	if(data && !conncfg){
+		conncfg = calloc(1, sizeof(dynamic32_config_t));
+		if(!conncfg){
+			fprintf(stderr, "Failed to allocate memory\n");
+			return -1;
+		}
+
+		//parse config string
+		for(u = 0; config[u];){
+			if(!strncmp(config + u, "offset=", 7)){
+				conncfg->offset = strtoul(config + u + 7, NULL, 0);
+			}
+			else if(!strncmp(config + u, "static=", 7)){
+				conncfg->fixed = strtoul(config + u + 7, NULL, 0);
+			}
+			else if(!strncmp(config + u, "endian=", 7)){
+				conncfg->endian = 0;
+				if(!strncmp(config + u + 7, "big", 3)){
+					conncfg->endian = 1;
+				}
+			}
+
+			//skip to next item
+			for(; config[u] && config[u] != ','; u++){
+			}
+		}
+
+		//store configuration
+		*framing_data = conncfg;
+	}
+	//clean up configuration
+	else if(!data && conncfg){
+		free(*framing_data);
+		*framing_data = NULL;
+	}
+
+	if(length > conncfg->offset + 4){
+		//read size field
+		size_p = (uint32_t*) (data + conncfg->offset);
+		size = le32toh(*size_p);
+		if(conncfg->endian){
+			size = be32toh(*size_p);
+		}
+
+		if(length >= conncfg->offset + 4 + conncfg->fixed + size){
+			return conncfg->offset + 4 + conncfg->fixed + size;
+		}
+	}
+
+	return 0;
+}
+
+static void __attribute__((constructor)) init(){
+	core_register_framing("dynamic32", framing_dynamic32);
+}