Send int over socket in C/C++

When you send the bmp_info_buff array as char array, the size of bmp_info_buff is not 3 but is 3 * sizeof(int)

The same for recv

Replace

send(my_socket, (char*)bmp_info_buff, 3, 0);
recv(my_connection, bmp_info_buff, 3, NULL);

by

send(my_socket, (char*)bmp_info_buff, 3*sizeof(int), 0);
recv(my_connection, bmp_info_buff, 3*sizeof(int), NULL);

The size argument to send() and recv() is in bytes, not ints. You're sending/receiving too little data.

You need:

send(my_socket, bmp_info_buff, sizeof bmp_info_buff, 0);

and

recv(my_connection, bmp_info_buff, sizeof bmp_info_buff, 0);

Also note:

• This makes your code sensitive to byte endianness issues.
• The size of int is not the same on all platforms, you need to consider this, too.
• No need to cast the pointer argument, it's void *.
• You should also add code to check the return values, I/O can fail!
• The last argument to recv() shouldn't be NULL as in your code, it's a flags integer just as in send().