Merge branch 'wip/client' into wip/i2c-communication

1 files changed, 118 insertions, 51 deletions

diff --git a/client/parse.cpp b/client/parse.cpp
index 223dc5d..16f0781 100644
--- a/client/parse.cpp
+++ b/client/parse.cpp
@@ -1,14 +1,12 @@
-#include <math.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
+#include <netinet/in.h>
 
 #include "parse.h"
 
-static int parse_str(const char* str, char* data, size_t* size) {
-	char closing = str[0];
+static int parse_string(const char * str, char * data, size_t * offset) {
 	char escape = false;
-	bool scan = data == NULL;
 	int i = 0;
 	size_t len = strlen(str);
 
@@ -22,34 +20,76 @@ static int parse_str(const char* str, char* data, size_t* size) {
 		default:
 			return -i;
 	}
+	char closing = str[i];
 
-	for (i = 1; i < len && str[i] != '\0'; i++) {
+	for (i = 1; i < len && str[i] != '\0'; i++, *offset += 1) {
 		char c = str[i];
 
-		if (c == closing) {
-			if (scan) printf("string%s of length %d\n", escape ? " (w/ escape)" : "", i - 1);
+		if (c == closing)
 			return i + 1; // +1 for closing quote
+
+		if (escape && c == '\\') {
+			char x = str[i + 1];
+			if      (x == '0')  c = '\0';
+			else if (x == 't')  c = '\t';
+			else if (x == 'n')  c = '\n';
+			else if (x == 'r')  c = '\r';
+			else if (x == '\\') c = '\\';
+			else if (x == '\"') c = '\"';
+			else if (x == '\'') c = '\'';
+			else break;
+			i++;
 		}
 
-		if (scan) *size += 1;
+		if (data != NULL)
+			data[*offset] = c;
 	}
 
 	return -i;
 }
 
-static int parse_num(const char* str, char* data, size_t* size) {
-	const char* ifs = IFS;
-	size_t len = strcspn(str, ifs);
-	bool scan = data == NULL;
+static int parse_hexstr(const char * str, char * data, size_t * offset) {
+	size_t len = strcspn(str, IFS);
+	int i = 0;
+
+	// check if token contains at least one colon
+	const char* colon = strchr(str, ':');
+	if (colon == NULL) return -i;
+	if (colon >= str + len) return -i;
+
+	// check if token only contains allowed characters [0-9a-fA-F:]
+	size_t len_ok = strspn(str + i, SET_HEX_STR) + i;
+	if (len != len_ok) return -len_ok;
+
+	size_t c = 0;
+	while (c < len) { // count bytes in bytestring
+		if (strspn(str + c, SET_HEX) != 2)
+			return -i -c;
+
+		if (data != NULL)
+			data[*offset] = strtol(str + c, NULL, 16) & 0xff;
+
+		c += 2;
+		*offset += 1;
+
+		if (str[c] == ':') {
+			c += 1;
+			continue;
+		}
+		break;
+	}
+
+	i += len;
+	return i;
+}
+
+static int parse_number(const char * str, char * data, size_t * offset) {
+	size_t len = strcspn(str, IFS);
 	int i = 0;
 	int base = 10;
 	bool bytestring = false;
 
-	const char* colon = strchr(str, ':');
-	if (colon != NULL && colon < str + len) { // byte string
-		base = 16;
-		bytestring = true;
-	} else if (len > 2 && strncmp(str, "0x", 2) == 0) { // hexadecimal prefix
+	if (len > 2 && strncmp(str, "0x", 2) == 0) { // hexadecimal prefix
 		base = 16;
 		i += 2;
 	}/* else if (len > 1 && strncmp(str, "0", 1) == 0) { // octal prefix
@@ -60,58 +100,85 @@ static int parse_num(const char* str, char* data, size_t* size) {
 	const char* set;
 	// if (base == 8) set = SET_OCT;
 	if (base == 10) set = SET_DEC;
-	if (base == 16) {
-		if (bytestring) set = SET_HEX_STR;
-		else set = SET_HEX;
-	}
+	if (base == 16) set = SET_HEX;
 	
 	size_t len_ok = strspn(str + i, set) + i;
 	if (len != len_ok) return -len_ok;
 
-	if (scan) {
-		if (base == 10) *size += 1;
-		else if (base == 16) {
-			if (!bytestring) {
-				*size += (len - i + 1) / 2;
-			} else {
-				for (; colon != NULL && colon < str + len; colon = strchr(str, ':')) {
-					*size += 1;
-				}
-			}
+	size_t size = 1; // default integer size in bytes
+	if (base == 16) {
+		size_t prefixless = len - i;
+		switch (prefixless) {
+			case 2:  //  8-bit (2 hex characters)
+			case 4:  // 16-bit
+			case 8:  // 32-bit
+			case 16: // 64-bit
+				break;
+			default:
+				return -i;
+		}
+		size = prefixless / 2;
+	}
+
+	if (data != NULL) {
+		unsigned long number = strtol(str + i, NULL, base);
+		long long mask = (1 << 8 * size) - 1;
+		number &= mask;
+		// NOTE: the hton? functions are used to convert host endianness to network
+		// endianness (big), and are required
+		switch (size) {
+			case 1:
+				data[*offset] = number & 0xff;
+				break;
+			case 2:
+				number = htons(number);
+				// TODO: check if the endianness is OK, or reverse these *offset indices*
+				data[*offset + 1] = (number)       & 0xff;
+				data[*offset + 0] = (number >>= 8) & 0xff;
+				break;
+			case 4:
+				number = htonl(number);
+				data[*offset + 3] = (number)       & 0xff;
+				data[*offset + 2] = (number >>= 8) & 0xff;
+				data[*offset + 1] = (number >>= 8) & 0xff;
+				data[*offset + 0] = (number >>= 8) & 0xff;
+				break;
 		}
 	}
 
-	if (scan) printf("number (base %d%s) of length %lu\n", base, bytestring ? " as bytestring" : "", len - i);
+	*offset += size;
 	return len;
 }
 
-int strtodata(const char* str, char** data, size_t* size) {
-	const char* ifs = IFS;
-	*size = 0;
-	size_t i;
+static int _strtodata_main(const char * str, char* data, size_t * offset) {
 	size_t len = strlen(str);
 
-	for (i = 0; i < len;) {
-		// skip whitespace
-		int run;
-		run = strspn(&str[i], ifs);
-		if (run > 0) printf("skipping whitespace for %d bytes...\n", run);
-		i += run;
-		// end of string
-		if (str[i] == '\0') break;
+	int i, run;
+	for (i = 0; i < len; i += run) {
+		i += strspn(&str[i], IFS); // skip whitespace
+		if (str[i] == '\0') break; // end of string
 
-		if ((run = parse_str(str + i, NULL, size)) > 0) { i += run; continue; }
-		if ((run = parse_num(str + i, NULL, size)) > 0) { i += run; continue; }
+		if ((run = parse_string(str + i, data, offset)) > 0) continue;
+		if ((run = parse_hexstr(str + i, data, offset)) > 0) continue;
+		if ((run = parse_number(str + i, data, offset)) > 0) continue;
 
 		// no format detected
 		return -i + run;
 	}
-	printf("end of string w/o parse errors\n");
-	printf("buffer size is now %lu\n", *size);
-	exit(0);
 
-	*data = (char*) malloc(*size);
+	return i;
+}
 
-	return 0;
+int strtodata(const char * str, char ** data, size_t * size) {
+	*size = 0;
+
+	// 1st pass: check data format
+	int ret = _strtodata_main(str, NULL, size);
+	if (ret <= 0) return ret; // on error
+
+	// 2nd pass: convert string literals into binary data
+	*data = (char*) malloc(*size);
+	size_t written = 0;
+	return _strtodata_main(str, *data, &written);
 }