Added insert tool and mail parsing

Signed-off-by: Tyrolyean <tyrolyean@tyrolyean.net>

include/attach.h

@@ -19,8 +19,22 @@
 #define ATTACH_H
 
 #include <stdint.h>
-#include <stdio.h>
+#include <stddef.h>
 
-char* attach_files(FILE* buffer);
+struct email_t{
+	char* message;
+	/* From the below values you can say pretty much anything about the 
+	 * message. The line delimiting body and header is left out. The header
+	 * len includes the last \r\n of the header. If header len is zero,
+	 * there was no clear distinction between header and body...
+	 */
+	size_t header_len, body_offset, message_length;
+};
+
+struct email_t mail_from_text(char* message, size_t length);
+void redetect_body_head(struct email_t* mail);
+
+
+char* attach_files(char* message, size_t len);
 
 #endif /* ATTACH_H */

include/tools.h

@@ -0,0 +1,26 @@
+/*
+ * tools.h - Utility functions
+ * The author licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#ifndef TOOLS_H
+#define TOOLS_H
+
+#include <stddef.h>
+
+const char* insert_string(char * destination, const char* source, 
+	size_t dest_orig_len, size_t offset);
+
+#endif /* TOOLS_H */

src/attach.c

@@ -18,23 +18,71 @@
 
 #include "attach.h"
 #include <string.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <ctype.h>
 #include <stdlib.h>
 
-char* attach_files(FILE* buffer){
-	fseek(buffer, 0, SEEK_END);
-	size_t len = ftell(buffer);
+struct email_t mail_from_text(char* message, size_t length){
+	
+	struct email_t mail;
+	memset(&mail, 0, sizeof(mail));
+	mail.message = message;
+	mail.message_length = length;
+	
+	redetect_body_head(&mail);
 
-	char* new_body = malloc(len + 1);
-	if(new_body == NULL){
-		return NULL;
-	}
-	memset(new_body,0, len + 1);
-	fseek(buffer, 0, SEEK_SET);
-	if(fread(new_body, 1, len, buffer) <= 0){
-		perror("Failed to read file buffer");
-		free(new_body);
-	}
-
-	return new_body;
+	return mail;
+}
+
+void redetect_body_head(struct email_t* mail){
+	
+	char* last_lf = NULL;
+	char* body_start = NULL;
+	bool found_alnum = false;
+	for(size_t i = 0; i < mail->message_length; i++){
+		if(mail->message[i] == '\n' && !found_alnum){
+			body_start = &(mail->message[i+1]);
+			break;
+			
+		}else if(mail->message[i] == '\n'){
+			last_lf = &(mail->message[i]);
+			found_alnum = false;
+		}else if(isalnum(mail->message[i])){
+			found_alnum = true;
+		}
+	}
+
+	/* In that case we only have a body and no header, or something along
+	 * those lines... In any case, if postfix delivers that to us, something
+	 * is probably wrong!
+	 */
+
+	if(body_start == NULL) {
+		fprintf(stderr, "Received message without header!");
+		mail->header_len = 0;
+		mail->body_offset = 0;
+		return;
+	}
+	
+	mail->body_offset = body_start - mail->message;
+	mail->header_len = last_lf - mail->message;
+	return;
+	
+	
+}
+
+char* attach_files(char* message, size_t len){
+
+	struct email_t email = mail_from_text(message,len);
+	
+	printf("Received message header: [%.*s]\n", email.header_len, 
+		email.message);
+	printf("Received message body: [%s]\n", 
+		email.message + email.body_offset);
+
+	/* Now we have a null terminated body which we can edit! */
+
+	return email.message;
 }
 

src/main.c

@@ -65,7 +65,7 @@ void* client_handle_async(void* params){
 	}
 
 	int n; /* message byte size */
-	char buf[10];
+	char buf[1000];
 	struct pollfd fds[2];
 	memset(fds, 0 , sizeof(fds));
 	fds[0].fd = cli->fd;
@@ -84,17 +84,17 @@ void* client_handle_async(void* params){
 
 	while(poll(fds, 2, timeout) > 0){
 		for(size_t i = 0; i < 2; i++){
+			
 			if(!(fds[i].revents & POLLIN)){
 				continue;
 
 			}
+
 			bzero(buf, sizeof(buf));
 			n = read(fds[i].fd, buf, sizeof(buf)-1);
 			if (n <= 0) {
 				goto closeup;
 			}
-			printf("%lu:[%s]", i, buf);
-			
 
 			if(i==0 && !in_body){
 				/* As long as we are outside the real mail body 
@@ -112,7 +112,7 @@ void* client_handle_async(void* params){
 					write((fds[!i].fd), 
 						input_buffer+(in_len-n), 
 						body_offs-(in_len-n));
-					printf("Beginning of body found! "
+					printf("Beginning of message found! "
 						"Awaiting end...\n");
 					
 				}else{
@@ -124,22 +124,35 @@ void* client_handle_async(void* params){
 				 */
 				in_len += n;
 				input_buffer = realloc(input_buffer, in_len);
-				strncat(input_buffer,buf, n);
+				strncat(input_buffer, buf, n);
 				body_p = detect_end_of_body(input_buffer+ 
 					body_offs);
 
 				if(body_p != NULL){
 					
-					printf("We found the body:\n%.*s\n",
-						body_p-(input_buffer+body_offs),
-						input_buffer+body_offs);
-
+					printf("Data found, interpreting...\n");
 					size_t body_len = body_p-
 						(input_buffer+body_offs);
-
-					write((fds[!i].fd), 
+					
+					char* new_body = attach_files(
 						input_buffer+body_offs, 
 						body_len);
+					
+					if(new_body != NULL){
+						/* Write the replacement */
+						write((fds[!i].fd), new_body, 
+							strlen(new_body));
+						free(new_body);
+					}else{
+						/* Write the original */
+						write((fds[!i].fd), 
+							input_buffer+body_offs, 
+							body_len);
+						
+					}
+
+					/* Rest of conversation after message */
+
 					write((fds[!i].fd), 
 						input_buffer+body_offs+body_len, 
 						in_len-(body_offs+body_len));

src/tools.c

@@ -0,0 +1,48 @@
+/*
+ * tools.c - Utility functions
+ * The author licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include "tools.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include <strings.h>
+
+/* Takes a string destination and inserts at the given point offset the string
+ * in source. Really more like a stringcat with shifting the end. 
+ * dest_orig_len is without '\0'*/
+const char* insert_string(char * destination, const char* source, 
+	size_t dest_orig_len, size_t offset){
+
+	if(source == NULL|| dest_orig_len < offset){
+		return destination;
+	}
+	
+	size_t src_len = strlen(source);
+	size_t new_len = dest_orig_len + src_len + 1;
+
+	char* result = realloc(destination, new_len);
+	if(result == NULL){
+		/* Out of memory... Failed me.. */
+		return NULL;
+	}
+	memmove(result+offset+src_len, result+offset, dest_orig_len - offset);
+	memcpy(result+offset, source, src_len);
+	return result;
+	
+	
+}
+