5 files changed, 70 insertions, 7 deletions

diff --git a/INSTALL.md b/INSTALL.md
index 90563790..a0c4165d 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -58,7 +58,7 @@ make
 <a name="homebrew" />
 ####Homebrew:
 ```
-brew install libtool automake autoconf libconfig libsodium
+brew install libtool automake autoconf libconfig libsodium cmake
 cmake .
 make
 sudo make install
diff --git a/README.md b/README.md
index 55135d03..092fe2f6 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,8 @@ With the rise of governmental monitoring programs, Tox aims to be an easy to use
 **Qt GUI**: [see nurupo's repository](https://github.com/nurupo/ProjectTox-Qt-GUI)
 
 **How to build Tox on Linux**: [YouTube video](http://www.youtube.com/watch?v=M4WXE4VKmyg)<br />
-**How to use Tox on Windows**: [YouTube video](http://www.youtube.com/watch?v=qg_j_sDb6WQ)
+**How to use Tox on Windows**: [YouTube video](http://www.youtube.com/watch?v=qg_j_sDb6WQ)<br />
+**For Mac OSX read INSTALL.md**
 
 ### Objectives:
 
diff --git a/core/LAN_discovery.c b/core/LAN_discovery.c
index 0a23914d..6170f2fb 100644
--- a/core/LAN_discovery.c
+++ b/core/LAN_discovery.c
@@ -23,13 +23,67 @@
 
 #include "LAN_discovery.h"
 
+#define MAX_INTERFACES 16
+#define ERR_INTERFACES 0
+#define ERR_IOCTL 1
 
-/*Return the broadcast ip
-  TODO: make it return the real one, not the 255.255.255.255 one.*/
+#ifdef __linux
+/* get the first running interface's broadcast IP,
+ *  return is higher than 0 on success
+ *  ERR_IOCTL on an ioctl error
+ *  ERR_INTERFACES on general error */
+uint32_t get_broadcast(void)
+{
+    /* not sure how many platforms this will
+     *  run on, so it's wrapped in __linux for now */
+    struct ifconf ifconf;
+    struct ifreq i_faces[MAX_INTERFACES];
+    int count = 0;
+    int sock = 0;
+    int i = 0;
+    struct sockaddr_in *sock_holder = NULL;
+
+    /* configure ifconf for the ioctl call */
+    sock = socket(AF_INET, SOCK_STREAM, 0);
+    ifconf.ifc_buf = (char *)i_faces;
+    ifconf.ifc_len = sizeof(i_faces);
+    count = ifconf.ifc_len / sizeof(i_faces[0]);
+    
+    for(i = 0; i < count; i++) {
+        /* skip the loopback interface, as it's useless */
+        if(strcmp(i_faces[i].ifr_name, "lo") != 0) {
+            if(ioctl(sock, SIOCGIFBRDADDR, &i_faces[i]) < 0) {
+                perror("[!] get_broadcast: ioctl error");
+                return 0;
+            }
+
+            /* just to clarify where we're getting the values from */
+            sock_holder = (struct sockaddr_in *)&i_faces[i].ifr_broadaddr;
+            break;
+        }
+    }
+    close(sock);
+
+    if(sock_holder == NULL)
+        return ERR_INTERFACES;
+
+    return sock_holder->sin_addr.s_addr;
+}
+#endif
+
+/* Return the broadcast ip */
 IP broadcast_ip()
 {
     IP ip;
+    #ifdef __linux
+    ip.i = get_broadcast();
+    if(ip.i == ERR_INTERFACES)
+        ip.i = ~0;
+    else if(ip.i == ERR_IOCTL)
+        ip.i = 0;
+    #else
     ip.i = ~0;
+    #endif
     return ip;
 }
 
diff --git a/core/LAN_discovery.h b/core/LAN_discovery.h
index 4ca65c03..23391b90 100644
--- a/core/LAN_discovery.h
+++ b/core/LAN_discovery.h
@@ -28,6 +28,14 @@
 
 #include "DHT.h"
 
+/* used for get_broadcast() */
+#ifdef __linux
+#include <sys/ioctl.h>
+#include <arpa/inet.h>
+#include <linux/netdevice.h>
+#endif
+
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/start_guide.md b/start_guide.md
index 31d7ca8e..2f973a3e 100644
--- a/start_guide.md
+++ b/start_guide.md
@@ -2,7 +2,7 @@
 1. [Build Tox](/INSTALL.md)
 2. Fix errors
 3. Consult IRC for help
-4. Go on debugging journy for devs
+4. Go on debugging journey for devs
 5. Build Tox for real
 6. ???
 
@@ -22,9 +22,9 @@ Tox. Here's a user-friendly attempt at it.
     + Now that you're on the network, you need a friend. To get one of those,
        you need to to send or receive a request. What's a request, you ask?
        It's like a friend request, but we use really scary and cryptic numbers
-       instead of names. When `nTox` starts, it shows your _your_ long, scary number,
+       instead of names. When `nTox` starts, it shows _your_ long, scary number,
        called your *public key*. Give that to people, and they can add you as
-       as "friend". Or, you can add someone else, with the `/f` command, if you like.
+       a "friend". Or, you can add someone else, with the `/f` command, if you like.
 3. Chat it up!
     + Now use the `/m` command to send a message to someone. Wow, you're chatting!
 4. But something broke!