From d4e7c6876eed2733a2678668bdcabdd87659e826 Mon Sep 17 00:00:00 2001
From: Raymaekers Luca <raymaekers.luca@gmail.com>
Date: Mon, 21 Oct 2024 00:12:02 +0200
Subject: Added common code for messages

- add: send_message, receive_message functions
- change: use u8, u16, u32, where possible
- fix: use PORT in server.c
---
 common.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 60 insertions(+), 1 deletion(-)

(limited to 'common.c')

diff --git a/common.c b/common.c
index 232cf64..34bed33 100644
--- a/common.c
+++ b/common.c
@@ -3,8 +3,10 @@
 #include <stdarg.h>
 #include <stdint.h>
 #include <stdio.h>
-#include <strings.h>
+#include <string.h>
 #include <unistd.h>
+#include <sys/socket.h>
+
 
 void writef(char *format, ...)
 {
@@ -74,3 +76,60 @@ u8 load_message(struct message *msg, FILE *f)
 
     return 0;
 }
+
+u32 send_message(struct message msg, u32 serverfd)
+{
+    // stream length : message author : message timestamp : message text
+    u32 buf_len = sizeof(buf_len) + MESSAGE_AUTHOR_LEN + MESSAGE_TIMESTAMP_LEN + msg.len;
+    char buf[buf_len];
+    u32 offset;
+
+    memcpy(buf, &buf_len, sizeof(buf_len));
+    offset = sizeof(buf_len);
+    memcpy(buf + offset, msg.author, MESSAGE_AUTHOR_LEN);
+    offset += MESSAGE_AUTHOR_LEN;
+    memcpy(buf + offset, msg.timestamp, MESSAGE_TIMESTAMP_LEN);
+    offset += MESSAGE_TIMESTAMP_LEN;
+    memcpy(buf + offset, msg.text, msg.len);
+
+    u32 n = send(serverfd, &buf, buf_len, 0);
+    if (n == -1)
+        return n;
+
+    writef("%d bytes sent.\n", n);
+    return n;
+}
+
+u32 receive_message(struct message *msg, u32 clientfd)
+{
+    // must all be of the s
+    u32 nrecv, buf_len;
+    // limit on what can be received with recv()
+    u32 buf_size = 20;
+    // temporary buffer to receive message data over a stream
+    char recv_buf[BUF_MAX];
+
+    nrecv = recv(clientfd, recv_buf, buf_size, 0);
+    if (nrecv == 0 || nrecv == -1)
+        return nrecv;
+
+    memcpy(&buf_len, recv_buf, sizeof(buf_len));
+
+    u32 i = 0;
+    while (nrecv < buf_len) {
+        // advance the copying by the amounts of bytes received each time
+        i = recv(clientfd, recv_buf + nrecv, buf_size, 0);
+        if (i == 0 || i == -1)
+            return nrecv;
+        nrecv += i;
+    }
+
+    struct message received = {0};
+    memcpy(&received, recv_buf + sizeof(buf_len), MESSAGE_AUTHOR_LEN + MESSAGE_TIMESTAMP_LEN);
+    received.text = recv_buf + sizeof(buf_len) + MESSAGE_AUTHOR_LEN + MESSAGE_TIMESTAMP_LEN;
+    received.len  = buf_len - sizeof(buf_len) - MESSAGE_AUTHOR_LEN - MESSAGE_TIMESTAMP_LEN;
+
+    // assume clientfd is serverfd + 1;
+    writef("Received %d bytes from client(%d): %s [%s] %s\n", nrecv, clientfd - 3, received.timestamp, received.author, received.text);
+    return nrecv;
+}
-- 
cgit v1.2.3