From e60aa0c5779bce199020236c0ac3a4beace571cb Mon Sep 17 00:00:00 2001
From: cbdev <cb@cbcdn.com>
Date: Thu, 20 Jun 2019 08:19:29 +0200
Subject: Implement additional framing functions (Fixes #3)

---
 builtins.c | 125 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 118 insertions(+), 7 deletions(-)

(limited to 'builtins.c')

diff --git a/builtins.c b/builtins.c
index 5c1dfb8..41d76d4 100644
--- a/builtins.c
+++ b/builtins.c
@@ -1,4 +1,6 @@
 #include <string.h>
+#include <ctype.h>
+#include <stdio.h>
 
 #include "websocksy.h"
 #include "builtins.h"
@@ -151,7 +153,7 @@ int64_t framing_auto(uint8_t* data, size_t length, size_t last_read, ws_operatio
 	}
 
 	//if valid utf8, send as text frame
-	if(valid){
+	if(valid && opcode){
 		*opcode = ws_frame_text;
 	}
 
@@ -165,12 +167,121 @@ int64_t framing_binary(uint8_t* data, size_t length, size_t last_read, ws_operat
 	return length;
 }
 
-int64_t framing_separator(uint8_t* data, size_t length, size_t last_read, ws_operation* opcode, void** framing_data, const char* config){
-	//TODO implement separator framer
-	return length;
+/*
+ * The `separator` framing function waits until a variable-length separator is found in the stream and sends all 
+ * data up to and including that separator as binary frame. The configuration string is used as the separator, with
+ * the escape sequences \r, \t, \n, \0, \f, \\ being recognized as their ASCII expressions. Arbitrary bytes can be
+ * specified hexadecimally using the syntax \x<hexbyte>
+ */
+typedef struct /*_separator_framing_config*/ {
+	size_t length;
+	uint8_t* separator;
+} framing_separator_config;
+
+int64_t framing_separator(uint8_t* data, size_t length, size_t last_read, ws_operation* opcode, void** framing_data, const char* framing_config){
+	size_t u, p = 0;
+	unsigned hex;
+	framing_separator_config* config = framing_data ? *framing_data : NULL;
+
+	if(data && !config){
+		//parse configuration
+		config = calloc(1, sizeof(framing_separator_config));
+		config->separator = (uint8_t*) strdup(framing_config);
+		for(u = 0; config->separator[u]; u++){
+			config->separator[p] = config->separator[u];
+			if(config->separator[u] == '\\'){
+				switch(config->separator[u + 1]){
+					case 0:
+						u--;
+						//fall through
+					case '0':
+						config->separator[p] = 0;
+						break;
+					case 't':
+						config->separator[p] = '\t';
+						break;
+					case 'n':
+						config->separator[p] = '\n';
+						break;
+					case 'f':
+						config->separator[p] = '\f';
+						break;
+					case 'r':
+						config->separator[p] = '\r';
+						break;
+					case '\\':
+						config->separator[p] = '\\';
+						break;
+					case 'x':
+						if(!isxdigit(config->separator[u + 2])
+								|| !isxdigit(config->separator[u + 3])){
+							fprintf(stderr, "Prematurely terminated hex byte sequence in separator framing function\n");
+							return -1;
+						}
+						sscanf((char*) (config->separator + u + 3), "%02x", &hex);
+						config->separator[p] = hex;
+						u += 2;
+				}
+				u++;
+			}
+			p++;
+		}
+		config->length = p;
+		*framing_data = config;
+	}
+	else if(!data && config){
+		//free parsed configuration
+		free(config->separator);
+		config->separator = NULL;
+		config->length = 0;
+		free(config);
+		return 0;
+	}
+
+	if(config->length){
+		for(u = 0; u < last_read && (last_read - u) >= config->length; u++){
+			if(!memcmp(data + (length - last_read) + u, config->separator, config->length)){
+				return (length - last_read) + u + config->length;
+			}
+		}
+	}
+	else{
+		return length;
+	}
+	return 0;
 }
 
-int64_t framing_newline(uint8_t* data, size_t length, size_t last_read, ws_operation* opcode, void** framing_data, const char* config){
-	//TODO implement separator framer
-	return length;
+/*
+ * The `newline` framing function waits until a newline sequence is found in the buffer and sends all data up to and
+ * including the newline as text frame, if the data is detected as valid UTF-8. Otherwise, a binary frame is used.
+ * The configuration string may be one of
+ * 	* crlf
+ * 	* lfcr
+ * 	* lf
+ * 	* cr
+ */
+int64_t framing_newline(uint8_t* data, size_t length, size_t last_read, ws_operation* opcode, void** framing_data, const char* framing_config){
+	int64_t bytes = 0;
+	char* expression = "\\r\\n";
+	
+	if(data && (!framing_data || !(*framing_data))){
+		if(!strcmp(framing_config, "crlf")){
+			expression = "\\r\\n";
+		}
+		if(!strcmp(framing_config, "lfcr")){
+			expression = "\\n\\r";
+		}
+		if(!strcmp(framing_config, "lf")){
+			expression = "\\n";
+		}
+		if(!strcmp(framing_config, "cr")){
+			expression = "\\r";
+		}
+		bytes = framing_separator(data, length, last_read, opcode, framing_data, expression);
+	}
+	else{
+		bytes = framing_separator(data, length, last_read, opcode, framing_data, NULL);
+	}
+
+	return framing_auto(data, bytes, 0, opcode, NULL, NULL);
 }
-- 
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