From 316d434ea8c0e7de1359dd04644cdc9dc955c839 Mon Sep 17 00:00:00 2001
From: Max Christian Pohle
Date: Wed, 17 Nov 2021 21:54:56 +0100
Subject: That is much better now

---
 main.c | 178 +++++++++++++++++++++++++++++++++++------------------------------
 1 file changed, 95 insertions(+), 83 deletions(-)

diff --git a/main.c b/main.c
index 2bf2e14..7fef5f3 100644
--- a/main.c
+++ b/main.c
@@ -54,12 +54,16 @@ void read_everything(FILE * f_r, FILE * output) {
 		if(-2 == size || (-1 == size && EWOULDBLOCK == errno)) {
 			usleep(EWOULDBLOCK_DELAY); // try again a little later
 			continue;
-		} else if (1 != size) { // I expect one nmemb of data
-			break;
 		}
 
 		fwrite(read_buffer, read_buffer_length, 1, output);
+		fwrite(read_buffer, read_buffer_length, 1, stdout);
+
+		if (1 != size) { // I expect one nmemb of data
+			break;
+		}
 	}
+	fflush(stdout);
 	fflush(output);
 }
 
@@ -83,6 +87,14 @@ void header_next(const char * key, const char * value) {
 	}
 }
 
+typedef struct {
+	int newline_length; // lenght of one newline in bytes (\n has 1, CR/LF has 2)
+	char * method;
+	char * boundary;
+	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");
@@ -93,111 +105,111 @@ void * next_customer(size_t new_socket) {
 
 	verbose("\n\n########################################## Content Reader [%d]\n", f_r);
 	read_everything(f_r, output);
-	verbose("\n\n########################################## Content Parser");
+	verbose("\n\n########################################## Content Parser\n");
 
 
 	// token parser...
-	const char * boundary = NULL;
-	size_t boundary_length = 0;
-	char * search = NULL;
 	char * key = output_buffer;
 
 	char * saveptr = NULL;
 	char * content_start = NULL;
 	char * content_end = NULL;
 
-	while(key ? key[0] != '\0' : 1) {
-		verbose("> [!] Next iteration with search '%s'\n", search);
-		for(char *
-				token = strtok_r(NULL == saveptr ? output_buffer : saveptr, NULL == search ? "\n\r" : search, &saveptr);
-				token != NULL;
-				token = strtok_r(NULL, search, &saveptr))
-		{
-
-			if(!search) { // first round: HTTP status code
-				verbose("> First Iteration: HTTP sanity check of: %s\n", token);
-				search = ":";
-				continue;
-			}
+	char * start = output_buffer;
+	char * end;
+	char * search = "\r\n";
+
+	Http_Header http_header;
+	http_header.newline_length = 1;
+	http_header.method = NULL;
+	http_header.boundary = NULL;
+	http_header.content_disposition = NULL;
+	http_header.content_type = NULL;
+
+	char * name = NULL;
+	while(NULL != (end = strpbrk(start, search))) {
 
-			if(!key) {
-				search = "\r\n"; // we found a key and expect the value to be between here and EOL
-				key = &token[strspn(token, search)]; // also remove leading spaces
+		size_t matchlen = strspn(end, search);
+		switch(end[0]) {
+			case ':':
+				end[0] = '\0';
+				end++;
 
-				if(0 == strncmp(token, "\n\r\n", 3)
-				|| 0 == strncmp(token, "\n\n", 2)) {
+				name = start;
+
+				if (0 == strcasecmp("Content-Type", start)) {
+					search = "\r\n;";
+				} else {
 					search = "\r\n";
+				}
+				break;
+			case ';':
+				{
+					start += strspn(start, "; ");
+
+					const char s_multipart_form_data[] = "boundary=";
+					if(NULL == http_header.boundary && 0 < strcasecmp(start, s_multipart_form_data))
+					{
+						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);
+						search = "\r\n";
+						continue;
+					}
 					break;
 				}
-			} else { // value
-
-				token += strspn(token, ": ");
-				const char * value = token;
-
-				const char pattern[] = "multipart/form-data; boundary=";
-				if(!boundary && strstr(key, "Content-Type") && strncmp(value, pattern, sizeof(pattern))) {
-					boundary = &value[sizeof(pattern) + strspn(&value[sizeof(pattern)], "-")];
-					boundary_length = strlen(boundary);
-					verbose("> [!] boundary detected '%s' ", boundary);
+			case '\r': // fallthrough
+			case '\n':
+				end[0] = '\0';
+				search = ":"; // we will continue to search for headers
+
+
+				if(NULL == name) {
+					if(NULL == http_header.method) {
+						verbose("[%ld]> HTTP REQUEST LINE :: %s \n", matchlen, start);
+						http_header.method = start;
+						http_header.newline_length = matchlen;
+					} else {
+						verbose("[...]\n"); // if we want to intentially skip something, we land here by setting name = NUL;
+						break;
+					}
+				} else { // we know that name is not NULL and can work with it
+					if (0 == strcasecmp("Content-Disposition", name))
+					{ http_header.content_disposition = start; }
 				}
 
-				header_next(key, value);
-
-				verbose("> [%ld] \"%s\" :: \"%s\"\n", key - output_buffer, key, value); fflush(stdout);
+				verbose("\033[0;32m[%ld]> '% 20s' = '%s'\033[0m\n", matchlen, name, start);
 
-				search = ":";
-				key = NULL;
-			}
-		}
-
-		if(!key)
-			break;
-		// printf("We are now here: %ld\n", key - output_buffer);
-		verbose("We are now here: %s\n", key);
-
-		// jump over the content...
-		content_start = key;
-		while((key = memchr(key, '\n', output_buffer_length - (key - output_buffer)))) {
-			if(!key) {
-				verbose("out at %p\n", key);
+				if(matchlen > http_header.newline_length) {
+					verbose("END HEADERS, boundary='%s'\n", http_header.boundary);
+					// start = strstr(end, http_header.boundary);
+					search = "-";
+				}
 				break;
-			} else {
-				key++;
-			}
-
-			if(key[0] == '-') {
-				if(0 == strncmp(&key[strspn(key, "-")], boundary, boundary_length)) {
-					verbose("> boundary found.");
-
-					if(key[-1] == '\n') key--;
-					if(key[-1] == '\r') key--;
-
-					content_end = key;
-					key += strspn(key, "\r\n-");
-					key += boundary_length;
-					key += strspn(key, "\r\n");
-					saveptr = key;
-					key = NULL;
-					search = ":";
+			case '-':
+				{
+					char * content_start = end;
+					content_start += strspn(content_start, "-");
+					// verbose("CONTENT: %s\n", content_start);
+					if(0 <= strcmp(content_start, http_header.boundary)) {
+						verbose("MATCH\n");
+						search = "\r\n";
+						start = content_start + strlen(http_header.boundary);
+						name = NULL;
+						continue;
+					} else {
+						verbose("NO MATCH\n");
+					}
 					break;
 				}
-			}
 		}
 
-		verbose("content is %p - %p = %ld in size\n", content_end, content_start, content_end - content_start);
-		if(content_end - content_start > 1000) {
-			FILE * f_w = fopen("/tmp/test.gif", "w");
-			fwrite(content_start, content_end - content_start, 1, f_w);
-			fclose(f_w);
-			puts("FILE WRITTEN");
-		}
+		start = end + matchlen;
+	}
 
-		// printf("We have gone to %ld\n", key - output_buffer); fflush(stdout);
-		if(key && key[0] == '\0') // final boundary reached?
-			break;
+	if(http_header.boundary)
+		verbose("http-boundary: %s", http_header.boundary);
 
-		// usleep(100000);
-	}
 
 	verbose("> sending answer...");
 	send_answer(f_w);
-- 
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