From e6f9bc88a029bff63df9b029d986d5961a3ce021 Mon Sep 17 00:00:00 2001
From: Max Christian Pohle
Date: Thu, 18 Nov 2021 01:23:05 +0100
Subject: Looking for a good way to parse binary data

---
 main.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 47 insertions(+), 14 deletions(-)

diff --git a/main.c b/main.c
index 7fef5f3..5395ab2 100644
--- a/main.c
+++ b/main.c
@@ -91,13 +91,13 @@ typedef struct {
 	int newline_length; // lenght of one newline in bytes (\n has 1, CR/LF has 2)
 	char * method;
 	char * boundary;
+	size_t boundary_size;
 	char * content_type;
 	char * content_disposition;
 } Http_Header;
 
 void * next_customer(size_t new_socket) {
-	FILE * f_r = fdopen((size_t) new_socket, "r");
-	FILE * f_w = fdopen((size_t) new_socket, "w");
+	FILE * f_r = fdopen((size_t) new_socket, "rw");
 
 	char * output_buffer = NULL;
 	size_t output_buffer_length = 0;
@@ -105,9 +105,9 @@ void * next_customer(size_t new_socket) {
 
 	verbose("\n\n########################################## Content Reader [%d]\n", f_r);
 	read_everything(f_r, output);
+	shutdown(new_socket, SHUT_RD); // shutdown the reading half of the connection
 	verbose("\n\n########################################## Content Parser\n");
 
-
 	// token parser...
 	char * key = output_buffer;
 
@@ -116,10 +116,11 @@ void * next_customer(size_t new_socket) {
 	char * content_end = NULL;
 
 	char * start = output_buffer;
-	char * end;
+	char * end = NULL;
 	char * search = "\r\n";
 
 	Http_Header http_header;
+	http_header.boundary_size = 0;
 	http_header.newline_length = 1;
 	http_header.method = NULL;
 	http_header.boundary = NULL;
@@ -127,7 +128,9 @@ void * next_customer(size_t new_socket) {
 	http_header.content_type = NULL;
 
 	char * name = NULL;
+	// while(NULL != (end = strpbrk(start, search))) {
 	while(NULL != (end = strpbrk(start, search))) {
+		// verbose("\033[31m[%ld|%ld|%ld]\033[0m\n", start - output_buffer, end - start, end - output_buffer);
 
 		size_t matchlen = strspn(end, search);
 		switch(end[0]) {
@@ -152,7 +155,7 @@ void * next_customer(size_t new_socket) {
 					{
 						http_header.boundary = end + sizeof(s_multipart_form_data) + 1;
 						http_header.boundary += strspn(http_header.boundary, "-");
-						// verbose("GESCHAFFT %s QQQQ %s\n", http_header.boundary, end);
+						// verbose("GESCHAFFT %s [%ld] QQQQ %s\n", http_header.boundary, http_header.boundary_size, end);
 						search = "\r\n";
 						continue;
 					}
@@ -163,6 +166,9 @@ void * next_customer(size_t new_socket) {
 				end[0] = '\0';
 				search = ":"; // we will continue to search for headers
 
+				if(http_header.boundary && http_header.boundary_size == 0) {
+						http_header.boundary_size = strlen(http_header.boundary);
+				}
 
 				if(NULL == name) {
 					if(NULL == http_header.method) {
@@ -178,11 +184,10 @@ void * next_customer(size_t new_socket) {
 					{ http_header.content_disposition = start; }
 				}
 
-				verbose("\033[0;32m[%ld]> '% 20s' = '%s'\033[0m\n", matchlen, name, start);
+				verbose("\033[32m[%ld]> '% 20s' = '%s'\033[0m\n", matchlen, name, start);
 
 				if(matchlen > http_header.newline_length) {
-					verbose("END HEADERS, boundary='%s'\n", http_header.boundary);
-					// start = strstr(end, http_header.boundary);
+					verbose("END HEADERS, boundary='%s'[%ld]\n", http_header.boundary, http_header.boundary_size);
 					search = "-";
 				}
 				break;
@@ -192,11 +197,11 @@ void * next_customer(size_t new_socket) {
 					content_start += strspn(content_start, "-");
 					// verbose("CONTENT: %s\n", content_start);
 					if(0 <= strcmp(content_start, http_header.boundary)) {
-						verbose("MATCH\n");
+						verbose("MATCH for %s // %s\n", http_header.content_type, http_header.content_disposition);
+
 						search = "\r\n";
-						start = content_start + strlen(http_header.boundary);
+						matchlen = http_header.boundary_size;
 						name = NULL;
-						continue;
 					} else {
 						verbose("NO MATCH\n");
 					}
@@ -206,15 +211,43 @@ void * next_customer(size_t new_socket) {
 
 		start = end + matchlen;
 	}
+	printf("last known position: %p / %p with %s\n", start, end, search);
+
+
+	char * p;
+	if(NULL != (p = strstr(start, http_header.boundary))) {
+		puts("OKAY?");
+	}
+
+	p = start;
+	while(1) {
+		size_t size_remaining = (size_t)  output_buffer_length - (p - output_buffer) - 1;
+		printf("%ld remaining.\n", size_remaining); fflush(stdout);
+		if(size_remaining <= 0)
+			break;
+
+		p = (char *) memchr(
+				(void *) p, '-', size_remaining);
+
+		p += strspn(p, "-");
+
+		if(0 >= strcmp(p, http_header.boundary)) {
+			verbose("content ends here");
+			break;
+		} else {
+			printf("[%ld] kack: %c\n", size_remaining, p[0]); fflush(stdout);
+			p = p + 1;
+		}
+	}
+	start = p;
+	// exit(0);
 
 	if(http_header.boundary)
 		verbose("http-boundary: %s", http_header.boundary);
 
 
 	verbose("> sending answer...");
-	send_answer(f_w);
-
-	fclose(f_w);
+	send_answer(f_r);
 	fclose(f_r);
 
 	verbose("> answer sent.");
-- 
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