updated picoTCP to 1.4.0, lowered build optimization levels to -O2, improved selftest

ext/picotcp/modules/pico_dev_tap.c

@@ -1,6 +1,6 @@
 /*********************************************************************
-   PicoTCP. Copyright (c) 2012-2015 Altran Intelligent Systems. Some rights reserved.
-   See LICENSE and COPYING for usage.
+   PicoTCP. Copyright (c) 2012-2017 Altran Intelligent Systems. Some rights reserved.
+   See COPYING, LICENSE.GPLv2 and LICENSE.GPLv3 for usage.
 
    Authors: Daniele Lacamera
  *********************************************************************/
@@ -27,23 +27,26 @@ struct pico_device_tap {
 
 #define TUN_MTU 2048
 
-// We only support one global link state - we only have two USR signals, we
-// can't spread these out over an arbitrary amount of devices. When you unplug
-// one tap, you unplug all of them.
+/* We only support one global link state - we only have two USR signals, we */
+/* can't spread these out over an arbitrary amount of devices. When you unplug */
+/* one tap, you unplug all of them. */
 
-static int link_state = 0;
+static int tapdev_link_state = 0;
 
 static void sig_handler(int signo)
 {
-  if (signo == SIGUSR1)
-    link_state = 0;
-  if (signo == SIGUSR2)
-    link_state = 1;
+    if (signo == SIGUSR1) {
+        tapdev_link_state = 0;
+    }
+
+    if (signo == SIGUSR2) {
+        tapdev_link_state = 1;
+    }
 }
 
 static int tap_link_state(__attribute__((unused)) struct pico_device *self)
 {
-  return link_state;
+    return tapdev_link_state;
 }
 
 
@@ -62,8 +65,9 @@ static int pico_tap_poll(struct pico_device *dev, int loop_score)
     pfd.fd = tap->fd;
     pfd.events = POLLIN;
     do  {
-        if (poll(&pfd, 1, 0) <= 0)
+        if (poll(&pfd, 1, 0) <= 0) {
             return loop_score;
+        }
 
         len = (int)read(tap->fd, buf, TUN_MTU);
         if (len > 0) {
@@ -79,8 +83,9 @@ static int pico_tap_poll(struct pico_device *dev, int loop_score)
 void pico_tap_destroy(struct pico_device *dev)
 {
     struct pico_device_tap *tap = (struct pico_device_tap *) dev;
-    if(tap->fd > 0)
+    if(tap->fd > 0) {
         close(tap->fd);
+    }
 }
 
 #ifndef __FreeBSD__
@@ -89,14 +94,14 @@ static int tap_open(char *name)
     struct ifreq ifr;
     int tap_fd;
     if((tap_fd = open("/dev/net/tun", O_RDWR)) < 0) {
-        return(-1);
+        return -1;
     }
 
     memset(&ifr, 0, sizeof(ifr));
     ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
     strncpy(ifr.ifr_name, name, IFNAMSIZ);
     if(ioctl(tap_fd, TUNSETIFF, &ifr) < 0) {
-        return(-1);
+        return -1;
     }
 
     return tap_fd;
@@ -119,9 +124,6 @@ static int tap_get_mac(char *name, uint8_t *mac)
     struct ifreq eth;
     int retval = -1;
 
-
-
-
     sck = socket(AF_INET, SOCK_DGRAM, 0);
     if(sck < 0) {
         return retval;
@@ -133,12 +135,9 @@ static int tap_get_mac(char *name, uint8_t *mac)
     if (ioctl(sck, SIOCGIFHWADDR, &eth) < 0) {
         perror("ioctl(SIOCGIFHWADDR)");
         return -1;
-        ;
     }
 
     memcpy (mac, &eth.ifr_hwaddr.sa_data, 6);
-
-
     close(sck);
     return 0;
 
@@ -156,8 +155,9 @@ static int tap_get_mac(char *name, uint8_t *mac)
 
     root = ifap;
     while(ifap) {
-        if (strcmp(name, ifap->ifa_name) == 0)
+        if (strcmp(name, ifap->ifa_name) == 0) {
             sdl = (struct sockaddr_dl *) ifap->ifa_addr;
+        }
 
         if (sdl->sdl_type == IFT_ETHER) {
             memcpy(mac, LLADDR(sdl), 6);
@@ -178,16 +178,18 @@ struct pico_device *pico_tap_create(char *name)
     uint8_t mac[6] = {};
     struct sigaction sa;
 
-    if (!tap)
+    if (!tap) {
         return NULL;
+    }
 
     sa.sa_flags = 0;
     sigemptyset(&sa.sa_mask);
     sa.sa_handler = sig_handler;
 
     if ((sigaction(SIGUSR1, &sa, NULL) == 0) &&
-       (sigaction(SIGUSR2, &sa, NULL) == 0))
-      tap->dev.link_state = &tap_link_state;
+        (sigaction(SIGUSR2, &sa, NULL) == 0)) {
+        tap->dev.link_state = &tap_link_state;
+    }
 
     tap->dev.overhead = 0;
     tap->fd = tap_open(name);
@@ -197,12 +199,20 @@ struct pico_device *pico_tap_create(char *name)
         return NULL;
     }
 
+    /* Host's mac address is generated * by the host kernel and is
+     * retrieved via tap_get_mac().
+     */
     if (tap_get_mac(name, mac) < 0) {
         dbg("Tap mac query failed.\n");
         pico_tap_destroy((struct pico_device *)tap);
         return NULL;
     }
 
+    /* To act as a second endpoint in the same subnet, the picoTCP
+     * app using the tap device must have a different mac address.
+     * For simplicity, we just add 1 to the last byte of the linux
+     * endpoint so the two addresses are consecutive.
+     */
     mac[5]++;
 
     if( 0 != pico_device_init((struct pico_device *)tap, name, mac)) {