From 206440659f16511200d1b20f340d5250683b3af4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juhani=20Krekel=C3=A4?= <juhani@krekelä.fi>
Date: Wed, 10 Jul 2019 23:49:05 +0300
Subject: [PATCH] Allow sending messages

---
 ethermess-backend.c | 39 ++++++++++++++++++++++++++++++++-------
 ethermess.py        |  3 ++-
 2 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/ethermess-backend.c b/ethermess-backend.c
index 6bca040..a37825d 100644
--- a/ethermess-backend.c
+++ b/ethermess-backend.c
@@ -436,7 +436,7 @@ void read_status(void) {
 	unsigned char length;
 	readallx(0, &length, 1);
 
-	unsigned char nick[256];
+	unsigned char nick[length];
 	readallx(0, nick, length);
 
 	if (!check_utf8(nick, length, false)) {
@@ -447,6 +447,31 @@ void read_status(void) {
 	own_nick_length = length;
 }
 
+void read_message(void) {
+	unsigned char mac[6];
+	readallx(0, mac, sizeof(mac));
+
+	unsigned char length_raw[2];
+	readallx(0, length_raw, 2);
+	size_t length = (length_raw[0] << 8) | length_raw[1];
+
+	if (length > EM_MESSAGE_MAX_LENGTH) {
+		errx(1, "Frontend sent a message that is too long (%zuB, max is %uB)", length, EM_MESSAGE_MAX_LENGTH);
+	}
+
+	unsigned char message[length];
+	readallx(0, message, length);
+
+	if (!check_utf8(message, length, true)) {
+		errx(1, "Frontend sent a nick with malformed utf-8 or control characters other than newline");
+	}
+
+	memcpy(own_message_destination_mac, mac, sizeof(own_message_destination_mac));
+	memcpy(own_message, message, length);
+	own_message_length = length;
+	own_message_send_state = QUEUED;
+}
+
 void read_command(void) {
 	unsigned char cmd;
 	readallx(0, &cmd, 1);
@@ -457,17 +482,14 @@ void read_command(void) {
 		unsigned char mac[6];
 		readallx(0, mac, sizeof(mac));
 		send_status_request(mac);
+	} else if (cmd == 'S') {
+		read_status();
 	} else if (cmd == 'i') {
 		unsigned char mac[6];
 		readallx(0, mac, sizeof(mac));
 		send_msgid_request(mac);
 	} else if (cmd == 'm') {
-		readallx(0, own_message_destination_mac, sizeof(own_message_destination_mac));
-		memcpy(own_message, "Hello, world!", 13);
-		own_message_length = 13;
-		own_message_send_state = QUEUED;
-	} else if (cmd == '\n') {
-		// Ignore
+		read_message();
 	} else {
 		fprintf(stderr, "?"); //debg
 	}
@@ -1026,6 +1048,9 @@ void eventloop(void) {
 			if (pollfds[0].revents & POLLIN) {
 				// Read a command
 				read_command();
+			} else if (pollfds[0].revents & POLLHUP) {
+				// Quit
+				running = false;
 			} else {
 				errx(1, "Got poll event %hd on stdin\n", pollfds[0].revents);
 			}
diff --git a/ethermess.py b/ethermess.py
index 588c43b..1bf8383 100644
--- a/ethermess.py
+++ b/ethermess.py
@@ -44,7 +44,8 @@ try:
 
 		elif command == 'm':
 			mac = parse_mac(input('mac> '))
-			writeall(proc.stdin, b'm' + mac)
+			message = input('message> ').encode('utf-8')
+			writeall(proc.stdin, b'm' + mac + bytes([len(message) >> 8, len(message) & 0xff]) + message)
 
 		else:
 			print('s - request status, i - request msgid, m - send message, ^D - quit')