diff --git a/src/tuntap_freebsd.c b/src/tuntap_freebsd.c
index d871e89..ebc5d56 100644
--- a/src/tuntap_freebsd.c
+++ b/src/tuntap_freebsd.c
@@ -16,118 +16,121 @@
  *
  */
 
+
 #include "n2n.h"
 
+
 #ifdef __FreeBSD__
 
-void tuntap_close(tuntap_dev *device);
-
-/* ********************************** */
 
 #define N2N_FREEBSD_TAPDEVICE_SIZE 32
-int tuntap_open(tuntap_dev *device /* ignored */, 
-                char *dev, 
-                const char *address_mode, /* static or dhcp */
-                char *device_ip, 
-                char *device_mask,
-                const char * device_mac,
-		int mtu) {
-  int i;
-  char tap_device[N2N_FREEBSD_TAPDEVICE_SIZE];
 
-  for (i = 0; i < 255; i++) {
-    snprintf(tap_device, sizeof(tap_device), "/dev/tap%d", i);
 
-    device->fd = open(tap_device, O_RDWR);
-    if(device->fd > 0) {
-      traceEvent(TRACE_NORMAL, "Succesfully open %s", tap_device);
-      break;
-    }
-  }
-  
-  if(device->fd < 0) {
-    traceEvent(TRACE_ERROR, "Unable to open tap device");
-    return(-1);
-  } else {
-    char buf[256];
-    FILE *fd;
+void tuntap_close (tuntap_dev *device);
 
-    device->ip_addr = inet_addr(device_ip);
 
-    if ( device_mac && device_mac[0] != '\0' )
-    {
-        /* FIXME - This is not tested. Might be wrong syntax for OS X */
+int tuntap_open (tuntap_dev *device /* ignored */,
+                 char *dev,
+                 const char *address_mode, /* static or dhcp */
+                 char *device_ip,
+                 char *device_mask,
+                 const char * device_mac,
+                 int mtu) {
 
-        /* Set the hw address before bringing the if up. */
-        snprintf(buf, sizeof(buf), "ifconfig tap%d ether %s",
-                 i, device_mac);
-        system(buf);
+    int i;
+    char tap_device[N2N_FREEBSD_TAPDEVICE_SIZE];
+
+    for(i = 0; i < 255; i++) {
+        snprintf(tap_device, sizeof(tap_device), "/dev/tap%d", i);
+
+        device->fd = open(tap_device, O_RDWR);
+        if(device->fd > 0) {
+            traceEvent(TRACE_NORMAL, "Succesfully open %s", tap_device);
+            break;
+        }
     }
 
-    snprintf(buf, sizeof(buf), "ifconfig tap%d %s netmask %s mtu %d up",
-             i, device_ip, device_mask, mtu);
-    system(buf);
-
-    traceEvent(TRACE_NORMAL, "Interface tap%d up and running (%s/%s)",
-               i, device_ip, device_mask);
-
-  /* Read MAC address */
-
-    snprintf(buf, sizeof(buf), "ifconfig tap%d |grep ether|cut -c 8-24", i);
-    /* traceEvent(TRACE_INFO, "%s", buf); */
-
-    fd = popen(buf, "r");
-    if(fd < 0) {
-      tuntap_close(device);
-      return(-1);
+    if(device->fd < 0) {
+        traceEvent(TRACE_ERROR, "Unable to open tap device");
+        return -1;
     } else {
-      int a, b, c, d, e, f;
+        char buf[256];
+        FILE *fd;
 
-      buf[0] = 0;
-      fgets(buf, sizeof(buf), fd);
-      pclose(fd);
-      
-      if(buf[0] == '\0') {
-	traceEvent(TRACE_ERROR, "Unable to read tap%d interface MAC address");
-	exit(0);
-      }
+        device->ip_addr = inet_addr(device_ip);
 
-      traceEvent(TRACE_NORMAL, "Interface tap%d mac %s", i, buf);
-      if(sscanf(buf, "%02x:%02x:%02x:%02x:%02x:%02x", &a, &b, &c, &d, &e, &f) == 6) {
-	device->mac_addr[0] = a, device->mac_addr[1] = b;
-	device->mac_addr[2] = c, device->mac_addr[3] = d;
-	device->mac_addr[4] = e, device->mac_addr[5] = f;
-      }
+        if(device_mac && device_mac[0] != '\0') {
+            // FIXME - this is not tested, might be wrong syntax for OS X
+
+            // set the hw address before bringing the if up
+            snprintf(buf, sizeof(buf), "ifconfig tap%d ether %s", i, device_mac);
+            system(buf);
+        }
+
+        snprintf(buf, sizeof(buf), "ifconfig tap%d %s netmask %s mtu %d up", i, device_ip, device_mask, mtu);
+        system(buf);
+
+        traceEvent(TRACE_NORMAL, "Interface tap%d up and running (%s/%s)", i, device_ip, device_mask);
+
+        // read MAC address
+        snprintf(buf, sizeof(buf), "ifconfig tap%d |grep ether|cut -c 8-24", i);
+        // traceEvent(TRACE_INFO, "%s", buf);
+
+        fd = popen(buf, "r");
+        if(fd < 0) {
+            tuntap_close(device);
+            return -1;
+        } else {
+            int a, b, c, d, e, f;
+
+            buf[0] = 0;
+            fgets(buf, sizeof(buf), fd);
+            pclose(fd);
+
+            if(buf[0] == '\0') {
+                traceEvent(TRACE_ERROR, "Unable to read tap%d interface MAC address");
+                exit(0);
+            }
+
+            traceEvent(TRACE_NORMAL, "Interface tap%d mac %s", i, buf);
+            if(sscanf(buf, "%02x:%02x:%02x:%02x:%02x:%02x", &a, &b, &c, &d, &e, &f) == 6) {
+                device->mac_addr[0] = a, device->mac_addr[1] = b;
+                device->mac_addr[2] = c, device->mac_addr[3] = d;
+                device->mac_addr[4] = e, device->mac_addr[5] = f;
+            }
+        }
     }
-  }
 
 
-  /* read_mac(dev, device->mac_addr); */
-  return(device->fd);
+    // read_mac(dev, device->mac_addr);
+
+    return device->fd;
 }
 
-/* ********************************** */
 
-int tuntap_read(struct tuntap_dev *tuntap, unsigned char *buf, int len) {
-  return(read(tuntap->fd, buf, len));
+int tuntap_read (struct tuntap_dev *tuntap, unsigned char *buf, int len) {
+
+    return read(tuntap->fd, buf, len);
 }
 
-/* ********************************** */
 
-int tuntap_write(struct tuntap_dev *tuntap, unsigned char *buf, int len) {
-  return(write(tuntap->fd, buf, len));
+int tuntap_write (struct tuntap_dev *tuntap, unsigned char *buf, int len) {
+
+    return write(tuntap->fd, buf, len);
 }
 
-/* ********************************** */
 
-void tuntap_close(struct tuntap_dev *tuntap) {
-  close(tuntap->fd);
+void tuntap_close (struct tuntap_dev *tuntap) {
+
+    close(tuntap->fd);
 }
 
-/* Fill out the ip_addr value from the interface. Called to pick up dynamic
- * address changes. */
-void tuntap_get_address(struct tuntap_dev *tuntap)
-{
+
+// fill out the ip_addr value from the interface, called to pick up dynamic address changes
+void tuntap_get_address (struct tuntap_dev *tuntap) {
+
+    // no action
 }
 
+
 #endif /* #ifdef __FreeBSD__ */
diff --git a/src/tuntap_linux.c b/src/tuntap_linux.c
index 94b3766..99c2620 100644
--- a/src/tuntap_linux.c
+++ b/src/tuntap_linux.c
@@ -16,71 +16,72 @@
  *
  */
 
+
 #ifdef __linux__
 
+
 #include "n2n.h"
 
-/* ********************************** */
 
-static int setup_ifname(int fd, const char *ifname, const char *ipaddr,
-          const char *netmask, uint8_t *mac, int mtu) {
-  struct ifreq ifr;
+static int setup_ifname (int fd, const char *ifname, const char *ipaddr,
+                         const char *netmask, uint8_t *mac, int mtu) {
 
-  memset(&ifr, 0, sizeof(ifr));
+    struct ifreq ifr;
 
-  strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
-  ifr.ifr_name[IFNAMSIZ-1] = '\0';
+    memset(&ifr, 0, sizeof(ifr));
 
-  ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER;
-  memcpy(ifr.ifr_hwaddr.sa_data, mac, 6);
+    strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
+    ifr.ifr_name[IFNAMSIZ-1] = '\0';
 
-  if(ioctl(fd, SIOCSIFHWADDR, &ifr) == -1) {
-    traceEvent(TRACE_ERROR, "ioctl(SIOCSIFHWADDR) failed [%d]: %s", errno, strerror(errno));
-    return(-1);
-  }
+    ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER;
+    memcpy(ifr.ifr_hwaddr.sa_data, mac, 6);
 
-  ifr.ifr_addr.sa_family = AF_INET;
-
-  /* Interface Address */
-  inet_pton(AF_INET, ipaddr, &((struct sockaddr_in*)&ifr.ifr_addr)->sin_addr);
-  if(ioctl(fd, SIOCSIFADDR, &ifr) == -1) {
-    traceEvent(TRACE_ERROR, "ioctl(SIOCSIFADDR) failed [%d]: %s", errno, strerror(errno));
-    return(-2);
-  }
-
-  /* Netmask */
-  if(netmask && (((struct sockaddr_in*)&ifr.ifr_addr)->sin_addr.s_addr != 0)) {
-    inet_pton(AF_INET, netmask, &((struct sockaddr_in*)&ifr.ifr_addr)->sin_addr);
-    if(ioctl(fd, SIOCSIFNETMASK, &ifr) == -1) {
-      traceEvent(TRACE_ERROR, "ioctl(SIOCSIFNETMASK, %s) failed [%d]: %s", netmask, errno, strerror(errno));
-      return(-3);
+    if(ioctl(fd, SIOCSIFHWADDR, &ifr) == -1) {
+        traceEvent(TRACE_ERROR, "ioctl(SIOCSIFHWADDR) failed [%d]: %s", errno, strerror(errno));
+        return -1;
     }
+
+    ifr.ifr_addr.sa_family = AF_INET;
+
+    // interface address
+    inet_pton(AF_INET, ipaddr, &((struct sockaddr_in*)&ifr.ifr_addr)->sin_addr);
+    if(ioctl(fd, SIOCSIFADDR, &ifr) == -1) {
+        traceEvent(TRACE_ERROR, "ioctl(SIOCSIFADDR) failed [%d]: %s", errno, strerror(errno));
+        return -2;
   }
 
-  /* MTU */
-  ifr.ifr_mtu = mtu;
-  if(ioctl(fd, SIOCSIFMTU, &ifr) == -1) {
-    traceEvent(TRACE_ERROR, "ioctl(SIOCSIFMTU) failed [%d]: %s", errno, strerror(errno));
-    return(-4);
-  }
+    // netmask
+    if(netmask && (((struct sockaddr_in*)&ifr.ifr_addr)->sin_addr.s_addr != 0)) {
+        inet_pton(AF_INET, netmask, &((struct sockaddr_in*)&ifr.ifr_addr)->sin_addr);
+        if(ioctl(fd, SIOCSIFNETMASK, &ifr) == -1) {
+            traceEvent(TRACE_ERROR, "ioctl(SIOCSIFNETMASK, %s) failed [%d]: %s", netmask, errno, strerror(errno));
+            return -3;
+        }
+    }
 
-  /* Set up and running */
-  if(ioctl(fd, SIOCGIFFLAGS, &ifr) == -1) {
-    traceEvent(TRACE_ERROR, "ioctl(SIOCGIFFLAGS) failed [%d]: %s", errno, strerror(errno));
-    return(-5);
-  }
+    // MTU
+    ifr.ifr_mtu = mtu;
+    if(ioctl(fd, SIOCSIFMTU, &ifr) == -1) {
+        traceEvent(TRACE_ERROR, "ioctl(SIOCSIFMTU) failed [%d]: %s", errno, strerror(errno));
+        return -4;
+    }
 
-  ifr.ifr_flags |= (IFF_UP | IFF_RUNNING);
+    // set up and running
+    if(ioctl(fd, SIOCGIFFLAGS, &ifr) == -1) {
+        traceEvent(TRACE_ERROR, "ioctl(SIOCGIFFLAGS) failed [%d]: %s", errno, strerror(errno));
+        return -5;
+    }
 
-  if(ioctl(fd, SIOCSIFFLAGS, &ifr) == -1) {
-    traceEvent(TRACE_ERROR, "ioctl(SIOCSIFFLAGS) failed [%d]: %s", errno, strerror(errno));
-    return(-6);
-  }
+    ifr.ifr_flags |= (IFF_UP | IFF_RUNNING);
 
-  return(0);
+    if(ioctl(fd, SIOCSIFFLAGS, &ifr) == -1) {
+        traceEvent(TRACE_ERROR, "ioctl(SIOCSIFFLAGS) failed [%d]: %s", errno, strerror(errno));
+        return -6;
+    }
+
+    return 0;
 }
 
-/* ********************************** */
 
 /** @brief  Open and configure the TAP device for packet read/write.
  *
@@ -88,7 +89,7 @@ static int setup_ifname(int fd, const char *ifname, const char *ipaddr,
  *  configures it.
  *
  *  @param device      - [inout] a device info holder object
- *  @param dev         - user-defined name for the new iface, 
+ *  @param dev         - user-defined name for the new iface,
  *                       if NULL system will assign a name
  *  @param device_ip   - address of iface
  *  @param device_mask - netmask for device_ip
@@ -97,179 +98,186 @@ static int setup_ifname(int fd, const char *ifname, const char *ipaddr,
  *  @return - negative value on error
  *          - non-negative file-descriptor on success
  */
-int tuntap_open(tuntap_dev *device, 
-                char *dev, /* user-definable interface name, eg. edge0 */
-                const char *address_mode, /* static or dhcp */
-                char *device_ip, 
-                char *device_mask,
-                const char * device_mac,
-		int mtu) {
-  char *tuntap_device = "/dev/net/tun";
-  int ioctl_fd;
-  struct ifreq ifr;
-  int rc;
-  int nl_fd;
-  char nl_buf[8192]; /* >= 8192 to avoid truncation, see "man 7 netlink" */
-  struct iovec iov;
-  struct sockaddr_nl sa;
-  int up_and_running = 0;
-  struct msghdr msg;
+int tuntap_open (tuntap_dev *device,
+                 char *dev, /* user-definable interface name, eg. edge0 */
+                 const char *address_mode, /* static or dhcp */
+                 char *device_ip,
+                 char *device_mask,
+                 const char * device_mac,
+                 int mtu) {
 
-  device->fd = open(tuntap_device, O_RDWR);
-  if(device->fd < 0) {
-    traceEvent(TRACE_ERROR, "tuntap open() error: %s[%d]. Is the tun kernel module loaded?\n", strerror(errno), errno);
-    return -1;
-  }
+    char *tuntap_device = "/dev/net/tun";
+    int ioctl_fd;
+    struct ifreq ifr;
+    int rc;
+    int nl_fd;
+    char nl_buf[8192]; /* >= 8192 to avoid truncation, see "man 7 netlink" */
+    struct iovec iov;
+    struct sockaddr_nl sa;
+    int up_and_running = 0;
+    struct msghdr msg;
 
-  memset(&ifr, 0, sizeof(ifr));
-  ifr.ifr_flags = IFF_TAP|IFF_NO_PI; /* Want a TAP device for layer 2 frames. */
-  strncpy(ifr.ifr_name, dev, IFNAMSIZ-1);
-  ifr.ifr_name[IFNAMSIZ-1] = '\0';
-  rc = ioctl(device->fd, TUNSETIFF, (void *)&ifr);
-
-  if(rc < 0) {
-    traceEvent(TRACE_ERROR, "tuntap ioctl(TUNSETIFF, IFF_TAP) error: %s[%d]\n", strerror(errno), rc);
-    close(device->fd);
-    return -1;
-  }
-
-  /* Store the device name for later reuse */
-  strncpy(device->dev_name, ifr.ifr_name, MIN(IFNAMSIZ, N2N_IFNAMSIZ) );
-
-  if(device_mac && device_mac[0]) {
-    /* Use the user-provided MAC */
-    str2mac(device->mac_addr, device_mac);
-  } else {
-    /* Set an explicit random MAC to know the exact MAC in use. Manually
-     * reading the MAC address is not safe as it may change internally
-     * also after the TAP interface UP status has been notified. */
-    int i;
-
-    for(i = 0; i < 6; i++)
-      device->mac_addr[i] = n2n_rand();
-
-    device->mac_addr[0] &= ~0x01; /* Clear multicast bit */
-    device->mac_addr[0] |= 0x02;  /* Set locally-assigned bit */
-  }
-
-  /* Initialize Netlink socket */
-  if((nl_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) == -1) {
-    traceEvent(TRACE_ERROR, "netlink socket creation failed [%d]: %s", errno, strerror(errno));
-    return -1;
-  }
-
-  iov.iov_base = nl_buf;
-  iov.iov_len = sizeof(nl_buf);
-
-  memset(&sa, 0, sizeof(sa));
-  sa.nl_family = PF_NETLINK;
-  sa.nl_groups = RTMGRP_LINK;
-  sa.nl_pid = getpid();
-
-  memset(&msg, 0, sizeof(msg));
-  msg.msg_name = &sa;
-  msg.msg_namelen = sizeof(sa);
-  msg.msg_iov = &iov;
-  msg.msg_iovlen = 1;
-
-  /* Subscribe to interface events */
-  if(bind(nl_fd, (struct sockaddr*)&sa, sizeof(sa)) == -1) {
-    traceEvent(TRACE_ERROR, "netlink socket bind failed [%d]: %s", errno, strerror(errno));
-    return -1;
-  }
-
-  if((ioctl_fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP)) < 0) {
-    traceEvent(TRACE_ERROR, "socket creation failed [%d]: %s", errno, strerror(errno));
-    close(nl_fd);
-    return -1;
-  }
-
-  if(setup_ifname(ioctl_fd, device->dev_name, device_ip, device_mask, device->mac_addr, mtu) < 0) {
-    close(nl_fd);
-    close(ioctl_fd);
-    close(device->fd);
-    return -1;
-  }
-
-  close(ioctl_fd);
-
-  /* Wait for the up and running notification */
-  traceEvent(TRACE_INFO, "Waiting for TAP interface to be up and running...");
-
-  while(!up_and_running) {
-    ssize_t len = recvmsg(nl_fd, &msg, 0);
-    struct nlmsghdr *nh;
-
-    for(nh = (struct nlmsghdr *)nl_buf; NLMSG_OK(nh, len); nh = NLMSG_NEXT(nh, len)) {
-      if(nh->nlmsg_type == NLMSG_ERROR) {
-        traceEvent(TRACE_DEBUG, "nh->nlmsg_type == NLMSG_ERROR");
-        break;
-      }
-
-      if(nh->nlmsg_type == NLMSG_DONE)
-        break;
-
-      if(nh->nlmsg_type == NETLINK_GENERIC) {
-        struct ifinfomsg *ifi = NLMSG_DATA(nh);
-
-        /* NOTE: skipping interface name check, assuming it's our TAP */
-        if((ifi->ifi_flags & IFF_UP) && (ifi->ifi_flags & IFF_RUNNING)) {
-          up_and_running = 1;
-          traceEvent(TRACE_INFO, "Interface is up and running");
-          break;
-        }
-      }
+    device->fd = open(tuntap_device, O_RDWR);
+    if(device->fd < 0) {
+        traceEvent(TRACE_ERROR, "tuntap open() error: %s[%d]. Is the tun kernel module loaded?\n", strerror(errno), errno);
+        return -1;
     }
-  }
 
-  close(nl_fd);
+    memset(&ifr, 0, sizeof(ifr));
 
-  device->ip_addr = inet_addr(device_ip);
-  device->device_mask = inet_addr(device_mask);
-  device->if_idx = if_nametoindex(dev);
+    // want a TAP device for layer 2 frames
+    ifr.ifr_flags = IFF_TAP|IFF_NO_PI;
 
-  return(device->fd);
+    strncpy(ifr.ifr_name, dev, IFNAMSIZ-1);
+    ifr.ifr_name[IFNAMSIZ-1] = '\0';
+    rc = ioctl(device->fd, TUNSETIFF, (void *)&ifr);
+
+    if(rc < 0) {
+        traceEvent(TRACE_ERROR, "tuntap ioctl(TUNSETIFF, IFF_TAP) error: %s[%d]\n", strerror(errno), rc);
+        close(device->fd);
+        return -1;
+    }
+
+    // store the device name for later reuse
+    strncpy(device->dev_name, ifr.ifr_name, MIN(IFNAMSIZ, N2N_IFNAMSIZ));
+
+    if(device_mac && device_mac[0]) {
+        // use the user-provided MAC
+        str2mac(device->mac_addr, device_mac);
+    } else {
+        // set an explicit random MAC to know the exact MAC in use, manually
+        // reading the MAC address is not safe as it may change internally
+        // also after the TAP interface UP status has been notified
+        int i;
+
+        for(i = 0; i < 6; i++)
+            device->mac_addr[i] = n2n_rand();
+
+        // clear multicast bit
+        device->mac_addr[0] &= ~0x01;
+
+        // set locally-assigned bit
+        device->mac_addr[0] |= 0x02;
+    }
+
+    // initialize netlink socket
+    if((nl_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) == -1) {
+        traceEvent(TRACE_ERROR, "netlink socket creation failed [%d]: %s", errno, strerror(errno));
+        return -1;
+    }
+
+    iov.iov_base = nl_buf;
+    iov.iov_len = sizeof(nl_buf);
+
+    memset(&sa, 0, sizeof(sa));
+    sa.nl_family = PF_NETLINK;
+    sa.nl_groups = RTMGRP_LINK;
+    sa.nl_pid = getpid();
+
+    memset(&msg, 0, sizeof(msg));
+    msg.msg_name = &sa;
+    msg.msg_namelen = sizeof(sa);
+    msg.msg_iov = &iov;
+    msg.msg_iovlen = 1;
+
+    // subscribe to interface events
+    if(bind(nl_fd, (struct sockaddr*)&sa, sizeof(sa)) == -1) {
+        traceEvent(TRACE_ERROR, "netlink socket bind failed [%d]: %s", errno, strerror(errno));
+        return -1;
+    }
+
+    if((ioctl_fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP)) < 0) {
+        traceEvent(TRACE_ERROR, "socket creation failed [%d]: %s", errno, strerror(errno));
+        close(nl_fd);
+        return -1;
+    }
+
+    if(setup_ifname(ioctl_fd, device->dev_name, device_ip, device_mask, device->mac_addr, mtu) < 0) {
+        close(nl_fd);
+        close(ioctl_fd);
+        close(device->fd);
+        return -1;
+    }
+
+    close(ioctl_fd);
+
+    // wait for the up and running notification
+    traceEvent(TRACE_INFO, "Waiting for TAP interface to be up and running...");
+
+    while(!up_and_running) {
+        ssize_t len = recvmsg(nl_fd, &msg, 0);
+        struct nlmsghdr *nh;
+
+        for(nh = (struct nlmsghdr *)nl_buf; NLMSG_OK(nh, len); nh = NLMSG_NEXT(nh, len)) {
+            if(nh->nlmsg_type == NLMSG_ERROR) {
+                traceEvent(TRACE_DEBUG, "nh->nlmsg_type == NLMSG_ERROR");
+                break;
+            }
+
+            if(nh->nlmsg_type == NLMSG_DONE)
+                break;
+
+            if(nh->nlmsg_type == NETLINK_GENERIC) {
+                struct ifinfomsg *ifi = NLMSG_DATA(nh);
+
+                // NOTE: skipping interface name check, assuming it's our TAP
+                if((ifi->ifi_flags & IFF_UP) && (ifi->ifi_flags & IFF_RUNNING)) {
+                    up_and_running = 1;
+                    traceEvent(TRACE_INFO, "Interface is up and running");
+                    break;
+                }
+            }
+        }
+    }
+
+    close(nl_fd);
+
+    device->ip_addr = inet_addr(device_ip);
+    device->device_mask = inet_addr(device_mask);
+    device->if_idx = if_nametoindex(dev);
+
+    return device->fd;
 }
 
-/* *************************************************** */
 
-int tuntap_read(struct tuntap_dev *tuntap, unsigned char *buf, int len) {
-  return(read(tuntap->fd, buf, len));
+int tuntap_read (struct tuntap_dev *tuntap, unsigned char *buf, int len) {
+
+    return read(tuntap->fd, buf, len);
 }
 
-/* *************************************************** */
 
-int tuntap_write(struct tuntap_dev *tuntap, unsigned char *buf, int len) {
-  return(write(tuntap->fd, buf, len));
+int tuntap_write (struct tuntap_dev *tuntap, unsigned char *buf, int len) {
+
+    return write(tuntap->fd, buf, len);
 }
 
-/* *************************************************** */
 
-void tuntap_close(struct tuntap_dev *tuntap) {
-  close(tuntap->fd);
+void tuntap_close (struct tuntap_dev *tuntap) {
+
+    close(tuntap->fd);
 }
 
-/* *************************************************** */
 
-/* Fill out the ip_addr value from the interface. Called to pick up dynamic
- * address changes. */
-void tuntap_get_address(struct tuntap_dev *tuntap) {
-  struct ifreq ifr;
-  int fd;
+// fill out the ip_addr value from the interface, called to pick up dynamic address changes
+void tuntap_get_address (struct tuntap_dev *tuntap) {
 
-  if((fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP)) < 0) {
-    traceEvent(TRACE_ERROR, "socket creation failed [%d]: %s", errno, strerror(errno));
-    return;
-  }
+    struct ifreq ifr;
+    int fd;
 
-  ifr.ifr_addr.sa_family = AF_INET;
-  strncpy(ifr.ifr_name, tuntap->dev_name, IFNAMSIZ);
-  ifr.ifr_name[IFNAMSIZ-1] = '\0';
+    if((fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP)) < 0) {
+        traceEvent(TRACE_ERROR, "socket creation failed [%d]: %s", errno, strerror(errno));
+        return;
+    }
 
-  if(ioctl(fd, SIOCGIFADDR, &ifr) != -1)
-    tuntap->ip_addr = ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr;
+    ifr.ifr_addr.sa_family = AF_INET;
+    strncpy(ifr.ifr_name, tuntap->dev_name, IFNAMSIZ);
+    ifr.ifr_name[IFNAMSIZ-1] = '\0';
 
-  close(fd);
+    if(ioctl(fd, SIOCGIFADDR, &ifr) != -1)
+        tuntap->ip_addr = ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr;
+
+    close(fd);
 }
 
+
 #endif /* #ifdef __linux__ */
diff --git a/src/tuntap_netbsd.c b/src/tuntap_netbsd.c
index 617e2b2..9a1277f 100644
--- a/src/tuntap_netbsd.c
+++ b/src/tuntap_netbsd.c
@@ -16,130 +16,133 @@
  *
  */
 
+
 #include "n2n.h"
 
+
 #ifdef __NetBSD__
 
+
 #include <errno.h>
 #include <string.h>
 #include <net/if_tap.h>
 
-void tun_close(tuntap_dev *device);
-
-/* ********************************** */
 
 #define N2N_NETBSD_TAPDEVICE_SIZE 32
-int tuntap_open(tuntap_dev *device /* ignored */,
-                char *dev,
-                const char *address_mode, /* static or dhcp */
-                char *device_ip,
-                char *device_mask,
-                const char * device_mac,
-		int mtu) {
-  char tap_device[N2N_NETBSD_TAPDEVICE_SIZE];
-  struct ifreq req;
 
-  if(dev) {
-     snprintf(tap_device, sizeof(tap_device), "/dev/%s", dev);
-     device->fd = open(tap_device, O_RDWR);
-     snprintf(tap_device, sizeof(tap_device), "%s", dev);
-  }
-  else {
-     device->fd = open("/dev/tap", O_RDWR);
-     if(device->fd >= 0) {
-        if(ioctl(device->fd, TAPGIFNAME, &req) == -1) {
-           traceEvent(TRACE_ERROR, "Unable to obtain name of tap device (%s)", strerror(errno));
-           close(device->fd);
-           return(-1);
-        }
-        else {
-           snprintf(tap_device, sizeof(tap_device), req.ifr_name);
-        }
-     }
-  }
 
-  if(device->fd < 0) {
-    traceEvent(TRACE_ERROR, "Unable to open tap device (%s)", strerror(errno));
-    return(-1);
-  } else {
-    char cmd[256];
-    FILE *fd;
+void tun_close (tuntap_dev *device);
 
-    traceEvent(TRACE_NORMAL, "Succesfully open %s", tap_device);
 
-    device->ip_addr = inet_addr(device_ip);
+int tuntap_open (tuntap_dev *device /* ignored */,
+                 char *dev,
+                 const char *address_mode, /* static or dhcp */
+                 char *device_ip,
+                 char *device_mask,
+                 const char * device_mac,
+                 int mtu) {
 
-    if( device_mac && device_mac[0] != '\0') {
-        /* Set the hw address before bringing the if up. */
-        snprintf(cmd, sizeof(cmd), "ifconfig %s link %s active",
-                 tap_device, device_mac);
-        system(cmd);
-    }
+    char tap_device[N2N_NETBSD_TAPDEVICE_SIZE];
+    struct ifreq req;
 
-    snprintf(cmd, sizeof(cmd), "ifconfig %s %s netmask %s mtu %d up",
-             tap_device, device_ip, device_mask, mtu);
-    system(cmd);
-
-    traceEvent(TRACE_NORMAL, "Interface %s up and running (%s/%s)",
-               tap_device, device_ip, device_mask);
-
-    /* Read MAC address */
-    snprintf(cmd, sizeof(cmd), "ifconfig %s |grep address|cut -c 11-28", tap_device);
-    /* traceEvent(TRACE_INFO, "%s", cmd); */
-
-    fd = popen(cmd, "r");
-    if(fd < 0) {
-      tun_close(device);
-      return(-1);
+    if(dev) {
+        snprintf(tap_device, sizeof(tap_device), "/dev/%s", dev);
+        device->fd = open(tap_device, O_RDWR);
+        snprintf(tap_device, sizeof(tap_device), "%s", dev);
     } else {
-      int a, b, c, d, e, f;
-      char buf[256];
-	
-      buf[0] = 0;
-      fgets(buf, sizeof(buf), fd);
-      pclose(fd);
-
-      if(buf[0] == '\0') {
-	traceEvent(TRACE_ERROR, "Unable to read %s interface MAC address [%s]", tap_device, cmd);
-	exit(0);
-      }
-
-      traceEvent(TRACE_NORMAL, "Interface %s mac %s", tap_device, buf);
-      if(sscanf(buf, "%02x:%02x:%02x:%02x:%02x:%02x", &a, &b, &c, &d, &e, &f) == 6) {
-	device->mac_addr[0] = a, device->mac_addr[1] = b;
-	device->mac_addr[2] = c, device->mac_addr[3] = d;
-	device->mac_addr[4] = e, device->mac_addr[5] = f;
-      }
+        device->fd = open("/dev/tap", O_RDWR);
+        if(device->fd >= 0) {
+            if(ioctl(device->fd, TAPGIFNAME, &req) == -1) {
+                traceEvent(TRACE_ERROR, "Unable to obtain name of tap device (%s)", strerror(errno));
+                close(device->fd);
+                return -1;
+            } else {
+                snprintf(tap_device, sizeof(tap_device), req.ifr_name);
+            }
+        }
     }
-  }
 
+    if(device->fd < 0) {
+        traceEvent(TRACE_ERROR, "Unable to open tap device (%s)", strerror(errno));
+        return -1;
+    } else {
+        char cmd[256];
+        FILE *fd;
 
-  /* read_mac(dev, device->mac_addr); */
-  return(device->fd);
+        traceEvent(TRACE_NORMAL, "Succesfully open %s", tap_device);
+
+        device->ip_addr = inet_addr(device_ip);
+
+        if(device_mac && device_mac[0] != '\0') {
+            // set the hw address before bringing the if up
+            snprintf(cmd, sizeof(cmd), "ifconfig %s link %s active", tap_device, device_mac);
+            system(cmd);
+        }
+
+        snprintf(cmd, sizeof(cmd), "ifconfig %s %s netmask %s mtu %d up", tap_device, device_ip, device_mask, mtu);
+        system(cmd);
+
+        traceEvent(TRACE_NORMAL, "Interface %s up and running (%s/%s)", tap_device, device_ip, device_mask);
+
+        // read MAC address
+        snprintf(cmd, sizeof(cmd), "ifconfig %s |grep address|cut -c 11-28", tap_device);
+        // traceEvent(TRACE_INFO, "%s", cmd);
+
+        fd = popen(cmd, "r");
+        if(fd < 0) {
+            tun_close(device);
+            return -1;
+        } else {
+            int a, b, c, d, e, f;
+            char buf[256];
+
+            buf[0] = 0;
+            fgets(buf, sizeof(buf), fd);
+            pclose(fd);
+
+            if(buf[0] == '\0') {
+                traceEvent(TRACE_ERROR, "Unable to read %s interface MAC address [%s]", tap_device, cmd);
+                exit(0);
+            }
+
+            traceEvent(TRACE_NORMAL, "Interface %s mac %s", tap_device, buf);
+            if(sscanf(buf, "%02x:%02x:%02x:%02x:%02x:%02x", &a, &b, &c, &d, &e, &f) == 6) {
+                device->mac_addr[0] = a, device->mac_addr[1] = b;
+                device->mac_addr[2] = c, device->mac_addr[3] = d;
+                device->mac_addr[4] = e, device->mac_addr[5] = f;
+            }
+        }
+    }
+
+    // read_mac(dev, device->mac_addr);
+
+    return(device->fd);
 }
 
-/* ********************************** */
 
-int tuntap_read(struct tuntap_dev *tuntap, unsigned char *buf, int len) {
-  return(read(tuntap->fd, buf, len));
+int tuntap_read (struct tuntap_dev *tuntap, unsigned char *buf, int len) {
+
+    return(read(tuntap->fd, buf, len));
 }
 
-/* ********************************** */
 
-int tuntap_write(struct tuntap_dev *tuntap, unsigned char *buf, int len) {
-  return(write(tuntap->fd, buf, len));
+int tuntap_write (struct tuntap_dev *tuntap, unsigned char *buf, int len) {
+
+    return(write(tuntap->fd, buf, len));
 }
 
-/* ********************************** */
 
-void tuntap_close(struct tuntap_dev *tuntap) {
-  close(tuntap->fd);
+void tuntap_close (struct tuntap_dev *tuntap) {
+
+    close(tuntap->fd);
 }
 
-/* Fill out the ip_addr value from the interface. Called to pick up dynamic
- * address changes. */
-void tuntap_get_address(struct tuntap_dev *tuntap)
-{
+
+// fill out the ip_addr value from the interface, called to pick up dynamic address changes
+void tuntap_get_address (struct tuntap_dev *tuntap) {
+
+    // no action
 }
 
+
 #endif /* #ifdef __NetBSD__ */
diff --git a/src/tuntap_osx.c b/src/tuntap_osx.c
index ef166ff..00cc9fd 100644
--- a/src/tuntap_osx.c
+++ b/src/tuntap_osx.c
@@ -16,119 +16,119 @@
  *
  */
 
+
 #include "n2n.h"
 
+
 #ifdef __APPLE__
 
-void tun_close(tuntap_dev *device);
-
-/* ********************************** */
 
 #define N2N_OSX_TAPDEVICE_SIZE 32
-int tuntap_open(tuntap_dev *device /* ignored */, 
-                char *dev, 
-                const char *address_mode, /* static or dhcp */
-                char *device_ip, 
-                char *device_mask,
-                const char * device_mac,
-		int mtu) {
-  int i;
-  char tap_device[N2N_OSX_TAPDEVICE_SIZE];
 
-  for (i = 0; i < 255; i++) {
-    snprintf(tap_device, sizeof(tap_device), "/dev/tap%d", i);
 
-    device->fd = open(tap_device, O_RDWR);
-    if(device->fd > 0) {
-      traceEvent(TRACE_NORMAL, "Succesfully open %s", tap_device);
-      break;
-    }
-  }
-  
-  if(device->fd < 0) {
-    traceEvent(TRACE_ERROR, "Unable to open any tap devices /dev/tap0 through /dev/tap254. Is this user properly authorized to access those descriptors?");
-    traceEvent(TRACE_ERROR, "Please read https://github.com/ntop/n2n/blob/dev/doc/macOS.md");
-    return(-1);
-  } else {
-    char buf[256];
-    FILE *fd;
+void tun_close (tuntap_dev *device);
 
-    device->ip_addr = inet_addr(device_ip);
 
-    if ( device_mac && device_mac[0] != '\0' )
-    {
-        /* FIXME - This is not tested. Might be wrong syntax for OS X */
+int tuntap_open (tuntap_dev *device /* ignored */,
+                 char *dev,
+                 const char *address_mode, /* static or dhcp */
+                 char *device_ip,
+                 char *device_mask,
+                 const char * device_mac,
+                 int mtu) {
 
-        /* Set the hw address before bringing the if up. */
-        snprintf(buf, sizeof(buf), "ifconfig tap%d ether %s",
-                 i, device_mac);
-        system(buf);
+    int i;
+    char tap_device[N2N_OSX_TAPDEVICE_SIZE];
+
+    for(i = 0; i < 255; i++) {
+        snprintf(tap_device, sizeof(tap_device), "/dev/tap%d", i);
+
+        device->fd = open(tap_device, O_RDWR);
+        if(device->fd > 0) {
+            traceEvent(TRACE_NORMAL, "Succesfully open %s", tap_device);
+            break;
+        }
     }
 
-    snprintf(buf, sizeof(buf), "ifconfig tap%d %s netmask %s mtu %d up",
-             i, device_ip, device_mask, mtu);
-    system(buf);
-
-    traceEvent(TRACE_NORMAL, "Interface tap%d up and running (%s/%s)",
-               i, device_ip, device_mask);
-
-  /* Read MAC address */
-
-    snprintf(buf, sizeof(buf), "ifconfig tap%d |grep ether|cut -c 8-24", i);
-    /* traceEvent(TRACE_INFO, "%s", buf); */
-
-    fd = popen(buf, "r");
-    if(fd < 0) {
-      tuntap_close(device);
-      return(-1);
+    if(device->fd < 0) {
+        traceEvent(TRACE_ERROR, "Unable to open any tap devices /dev/tap0 through /dev/tap254. Is this user properly authorized to access those descriptors?");
+        traceEvent(TRACE_ERROR, "Please read https://github.com/ntop/n2n/blob/dev/doc/Building.md");
+        return -1;
     } else {
-      int a, b, c, d, e, f;
+        char buf[256];
+        FILE *fd;
 
-      buf[0] = 0;
-      fgets(buf, sizeof(buf), fd);
-      pclose(fd);
-      
-      if(buf[0] == '\0') {
-	traceEvent(TRACE_ERROR, "Unable to read tap%d interface MAC address");
-	exit(0);
-      }
+        device->ip_addr = inet_addr(device_ip);
 
-      traceEvent(TRACE_NORMAL, "Interface tap%d [MTU %d] mac %s", i, mtu, buf);
-      if(sscanf(buf, "%02x:%02x:%02x:%02x:%02x:%02x", &a, &b, &c, &d, &e, &f) == 6) {
-	device->mac_addr[0] = a, device->mac_addr[1] = b;
-	device->mac_addr[2] = c, device->mac_addr[3] = d;
-	device->mac_addr[4] = e, device->mac_addr[5] = f;
-      }
+        if(device_mac && device_mac[0] != '\0') {
+            // FIXME - this is not tested. might be wrong syntax for OS X
+            // set the hw address before bringing the if up
+            snprintf(buf, sizeof(buf), "ifconfig tap%d ether %s", i, device_mac);
+            system(buf);
+        }
+
+        snprintf(buf, sizeof(buf), "ifconfig tap%d %s netmask %s mtu %d up", i, device_ip, device_mask, mtu);
+        system(buf);
+
+        traceEvent(TRACE_NORMAL, "Interface tap%d up and running (%s/%s)", i, device_ip, device_mask);
+
+        // read MAC address
+        snprintf(buf, sizeof(buf), "ifconfig tap%d |grep ether|cut -c 8-24", i);
+        // traceEvent(TRACE_INFO, "%s", buf);
+
+        fd = popen(buf, "r");
+        if(fd < 0) {
+            tuntap_close(device);
+            return -1;
+        } else {
+            int a, b, c, d, e, f;
+
+            buf[0] = 0;
+            fgets(buf, sizeof(buf), fd);
+            pclose(fd);
+
+            if(buf[0] == '\0') {
+                traceEvent(TRACE_ERROR, "Unable to read tap%d interface MAC address");
+                exit(0);
+            }
+
+            traceEvent(TRACE_NORMAL, "Interface tap%d [MTU %d] mac %s", i, mtu, buf);
+            if(sscanf(buf, "%02x:%02x:%02x:%02x:%02x:%02x", &a, &b, &c, &d, &e, &f) == 6) {
+                device->mac_addr[0] = a, device->mac_addr[1] = b;
+                device->mac_addr[2] = c, device->mac_addr[3] = d;
+                device->mac_addr[4] = e, device->mac_addr[5] = f;
+            }
+        }
     }
-  }
 
+    // read_mac(dev, device->mac_addr);
 
-  /* read_mac(dev, device->mac_addr); */
-  return(device->fd);
+    return(device->fd);
 }
 
-/* ********************************** */
 
-int tuntap_read(struct tuntap_dev *tuntap, unsigned char *buf, int len) {
-  return(read(tuntap->fd, buf, len));
+int tuntap_read (struct tuntap_dev *tuntap, unsigned char *buf, int len) {
+
+    return(read(tuntap->fd, buf, len));
 }
 
-/* ********************************** */
 
-int tuntap_write(struct tuntap_dev *tuntap, unsigned char *buf, int len) {
-  return(write(tuntap->fd, buf, len));
+int tuntap_write (struct tuntap_dev *tuntap, unsigned char *buf, int len) {
+
+    return(write(tuntap->fd, buf, len));
 }
 
-/* ********************************** */
 
-void tuntap_close(struct tuntap_dev *tuntap) {
-  close(tuntap->fd);
+void tuntap_close (struct tuntap_dev *tuntap) {
+
+    close(tuntap->fd);
 }
 
-/* Fill out the ip_addr value from the interface. Called to pick up dynamic
- * address changes. */
-void tuntap_get_address(struct tuntap_dev *tuntap)
-{
+// fill out the ip_addr value from the interface, called to pick up dynamic address changes
+void tuntap_get_address (struct tuntap_dev *tuntap) {
+
+    // no action
 }
 
+
 #endif /* __APPLE__ */