Extend the NSH network initialization logic. There is now an option that will create a network monitor thread that will monitor the state of the link. When the link goes down, the code will attempt to gracefully put the Ethernet driver in a down state; When the link comes back, the code will attempt to bring the network back up.

3 files changed, 352 insertions, 9 deletions

diff --git a/apps/nshlib/Kconfig b/apps/nshlib/Kconfig
index 36839a736..cae3a7dca 100644
--- a/apps/nshlib/Kconfig
+++ b/apps/nshlib/Kconfig
@@ -810,6 +810,43 @@ config NSH_NETINIT_THREAD
 
 if NSH_NETINIT_THREAD
 
+config NSH_NETINIT_MONITOR
+	bool "Monitor link state"
+	default n
+	depends on ARCH_PHY_INTERRUPT && NET_UDP && !DISABLE_SIGNALS && EXPERIMENTAL
+	---help---
+		By default the net initialization thread will bring-up the network
+		then exit, freeing all of the resources that it required.  This is a
+		good behavior for systems with limited memory.
+
+		If this option is selected, however, then the network initialization
+		thread will persist forever; it will monitor the network status.  In
+		the event that the network goes down (for example, if a cable is
+		removed), then the the thread will monitor the link status and
+		attempt to bring the network back up.  In this case the resources
+		required for network initialization are never released.
+
+config NSH_NETINIT_SIGNO
+	int "Notification signal number"
+	default 18
+	---help---
+		The network monitor logic will receive signals when there is any
+		change in the link status.  This setting may be used to customize
+		that signal number in order to avoid conflicts.
+
+if NSH_NETINIT_MONITOR
+
+config NSH_NETINIT_RETRYMSEC
+	int "Network bring-up retry period (msec)"
+	default 2000
+	---help---
+		When the network is down, the initialization thread will periodically
+		try to bring the network up.  This can be a time consuming operation
+		so is done only periodically with that period specified by this
+		selection in milliseconds.
+
+endif # NSH_NETINIT_MONITOR
+
 config NSH_NETINIT_THREAD_STACKSIZE
 	int "Network initialization thread stack size"
 	default 1568
@@ -820,6 +857,18 @@ config NSH_NETINIT_THREAD_PRIORITY
 
 endif # NSH_NETINIT_THREAD
 
+config NSH_NETINIT_DEBUG
+	bool "Network init debug"
+	default n
+	depends on DEBUG
+	---help---
+		Normally debug output is controlled by DEBUG_NET.  However, that
+		will generate a LOT of debug output, especially if DEBUG_VERBOSE is
+		also selected.  This option is intended to force VERVOSE debug
+		output from the NSH network initialization logic even if DEBUG_NET
+		or DEBUG_VERBOSE are not selected.  This allows for focused, unit-
+		level debug of the NSH network initialization logic.
+
 config NSH_DHCPC
 	bool "Use DHCP to get IP address"
 	default n
diff --git a/apps/nshlib/nsh.h b/apps/nshlib/nsh.h
index bff96dc1c..625d10b35 100644
--- a/apps/nshlib/nsh.h
+++ b/apps/nshlib/nsh.h
@@ -128,16 +128,29 @@
 #  define CONFIG_NSH_MACADDR   0x00e0deadbeef
 #endif
 
+#ifndef CONFIG_NET
+#  undef CONFIG_NSH_ARCHMAC
+#endif
+
+#if !defined(CONFIG_NSH_NETINIT_THREAD) || !defined(CONFIG_ARCH_PHY_INTERRUPT) || \
+    !defined(CONFIG_NET_UDP) || defined(CONFIG_DISABLE_SIGNALS)
+#  undef CONFIG_NSH_NETINIT_MONITOR
+#endif
+
+#ifndef CONFIG_NSH_NETINIT_RETRYMSEC
+#  define CONFIG_NSH_NETINIT_RETRYMSEC 2000
+#endif
+
+#ifndef CONFIG_NSH_NETINIT_SIGNO
+#  define CONFIG_NSH_NETINIT_SIGNO 18
+#endif
+
 #ifndef CONFIG_NSH_NETINIT_THREAD_STACKSIZE
 #  define CONFIG_NSH_NETINIT_THREAD_STACKSIZE 1568
 #endif
 
 #ifndef CONFIG_NSH_NETINIT_THREAD_PRIORITY
-#  define CONFIG_NSH_NETINIT_THREAD_PRIORITY   100
-#endif
-
-#ifndef CONFIG_NET
-#  undef CONFIG_NSH_ARCHMAC
+#  define CONFIG_NSH_NETINIT_THREAD_PRIORITY 100
 #endif
 
 /* Telnetd requires networking support */
diff --git a/apps/nshlib/nsh_netinit.c b/apps/nshlib/nsh_netinit.c
index 647d0eebd..e04591f7b 100644
--- a/apps/nshlib/nsh_netinit.c
+++ b/apps/nshlib/nsh_netinit.c
@@ -42,13 +42,30 @@
 
 #include <nuttx/config.h>
 
+/* Is network initialization debug forced on? */
+
+#ifdef CONFIG_NSH_NETINIT_DEBUG
+#  undef  CONFIG_DEBUG_VERBOSE
+#  define CONFIG_DEBUG_VERBOSE 1
+#  undef  CONFIG_DEBUG_NET
+#  define CONFIG_DEBUG_NET 1
+#endif
+
+#include <sys/ioctl.h>
+
+#include <stdint.h>
+#include <unistd.h>
+#include <string.h>
 #include <pthread.h>
+#include <signal.h>
 #include <debug.h>
 
 #include <net/if.h>
 #include <arpa/inet.h>
 #include <netinet/in.h>
 
+#include <nuttx/net/mii.h>
+
 #include <apps/netutils/netlib.h>
 #if defined(CONFIG_NSH_DHCPC) || defined(CONFIG_NSH_DNS)
 #  include <apps/netutils/dnsclient.h>
@@ -83,6 +100,14 @@
 #  define NET_DEVNAME "eth0"
 #endif
 
+/* While the network is up, the network monitor really does nothing.  It
+ * will wait for a very long time while waiting, it can be awakened by a
+ * signal indicating a change in network status.
+ */
+
+#define A_REALLY_LONG_TIME  (60*60) /* One hour in seconds */
+#define A_SHORT_TIME        (2)     /* 2 seconds */
+
 /****************************************************************************
  * Private Types
  ****************************************************************************/
@@ -96,14 +121,14 @@
  ****************************************************************************/
 
 /****************************************************************************
- * Name: nsh_netinit_thread
+ * Name: nsh_netinit_configure
  *
  * Description:
  *   Initialize the network per the selected NuttX configuration
  *
  ****************************************************************************/
 
-pthread_addr_t nsh_netinit_thread(pthread_addr_t arg)
+static void nsh_netinit_configure(void)
 {
   struct in_addr addr;
 #if defined(CONFIG_NSH_DHCPC)
@@ -207,7 +232,263 @@ pthread_addr_t nsh_netinit_thread(pthread_addr_t arg)
 #endif
 
   nvdbg("Exit\n");
-  return OK;
+}
+
+/****************************************************************************
+ * Name: nsh_netinit_signal
+ *
+ * Description:
+ *   This signal handler responds to changes in PHY status.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_NSH_NETINIT_MONITOR
+static void nsh_netinit_signal(int signo, FAR siginfo_t *siginfo,
+                               FAR void * context)
+{
+  volatile bool *event = (volatile bool *)siginfo->si_value.sival_ptr;
+
+  nlldbg("Entry: event=%p\n", event);
+  DEBUGASSERT(event);
+  *event = true;
+  nllvdbg("Exit\n");
+}
+#endif
+
+/****************************************************************************
+ * Name: nsh_netinit_monitor
+ *
+ * Description:
+ *   Monitor link status, gracefully taking the link up and down as the
+ *   link becomes available or as the link is lost.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_NSH_NETINIT_MONITOR
+static int nsh_netinit_monitor(void)
+{
+  struct ifreq ifr;
+  struct sigaction act;
+  volatile bool event;
+  bool devup;
+  int ret;
+  int sd;
+
+  nvdbg("Entry\n");
+
+  /* Get a socket descriptor that we can use to communicate with the network
+   * interface driver.
+   */
+
+  sd = socket(AF_INET, SOCK_DGRAM, 0);
+  if (sd < 0)
+    {
+      ret = -errno;
+      DEBUGASSERT(ret < 0);
+
+      ndbg("ERROR: Failed to create a socket: %d\n", ret);
+      goto errout;
+    }
+
+  /* Attach a signal handler so that we do not lose PHY events */
+
+  act.sa_sigaction = nsh_netinit_signal;
+  act.sa_flags = SA_SIGINFO;
+
+  ret = sigaction(CONFIG_NSH_NETINIT_SIGNO, &act, NULL);
+  if (ret < 0)
+    {
+      ret = -errno;
+      DEBUGASSERT(ret < 0);
+
+      ndbg("ERROR: sigaction() failed: %d\n", ret);
+      goto errout_with_socket;
+    }
+
+  /* Configure to receive a signal on changes in link status */
+
+  strncpy(ifr.ifr_name, NET_DEVNAME, IFNAMSIZ);
+  ifr.ifr_mii_notify_pid   = 0; /* PID=0 means this task */
+  ifr.ifr_mii_notify_signo = CONFIG_NSH_NETINIT_SIGNO;
+  ifr.ifr_mii_notify_arg   = (FAR void *)&event;
+
+  ret = ioctl(sd, SIOCMIINOTIFY, (unsigned long)&ifr);
+  if (ret < 0)
+    {
+      ret = -errno;
+      DEBUGASSERT(ret < 0);
+
+      ndbg("ERROR: ioctl(SIOCMIINOTIFY) failed: %d\n", ret);
+      goto errout_with_sigaction;
+    }
+
+  /* Now loop, waiting for changes in link status */
+
+  for (;;)
+    {
+      /* This should catch any events that occur while we are not listening */
+
+      event = false;
+
+      /* Does the driver think that the link is up or down? */
+
+      strncpy(ifr.ifr_name, NET_DEVNAME, IFNAMSIZ);
+
+      ret = ioctl(sd, SIOCGIFFLAGS, (unsigned long)&ifr);
+      if (ret < 0)
+        {
+          ret = -errno;
+          DEBUGASSERT(ret < 0);
+
+          ndbg("ERROR: ioctl(SIOCGIFFLAGS) failed: %d\n", ret);
+          goto errout_with_notification;
+        }
+
+      devup = ((ifr.ifr_flags & IFF_UP) != 0);
+
+      /* Get the current PHY address in use.  This probably does not change,
+       * but just in case...
+       *
+       * NOTE: We are assuming that the network device name is preserved in
+       * the ifr structure.
+       */
+
+      ret = ioctl(sd, SIOCGMIIPHY, (unsigned long)&ifr);
+      if (ret < 0)
+        {
+          ret = -errno;
+          DEBUGASSERT(ret < 0);
+
+          ndbg("ERROR: ioctl(SIOCGMIIPHY) failed: %d\n", ret);
+          goto errout_with_notification;
+        }
+
+      /* Read the PHY status register */
+
+      ifr.ifr_mii_reg_num = MII_MSR;
+
+      ret = ioctl(sd, SIOCGMIIREG, (unsigned long)&ifr);
+      if (ret < 0)
+        {
+          ret = -errno;
+          DEBUGASSERT(ret < 0);
+
+          ndbg("ERROR: ioctl(SIOCGMIIREG) failed: %d\n", ret);
+          goto errout_with_notification;
+        }
+
+      nvdbg("%s: devup=%d PHY address=%02x MSR=%04x\n",
+            devup, ifr.ifr_name, ifr.ifr_mii_phy_id, ifr.ifr_mii_val_out);
+
+      /* Check for link up or down */
+
+      if ((ifr.ifr_mii_val_out & MII_MSR_LINKSTATUS) != 0)
+        {
+          /* Link up... does the drive think that the link is up? */
+
+          if (!devup)
+            {
+              /* No... We just transitioned from link down to link up.
+               * Bring the link up.
+               */
+
+              nvdbg("Bringing the link up\n");
+
+              ifr.ifr_flags = IFF_UP;
+              ret = ioctl(sd, SIOCSIFFLAGS, (unsigned long)&ifr);
+              if (ret < 0)
+                {
+                  ret = -errno;
+                  DEBUGASSERT(ret < 0);
+
+                  ndbg("ERROR: ioctl(SIOCSIFFLAGS) failed: %d\n", ret);
+                  goto errout_with_notification;
+                }
+
+              /* And wait for a short delay.  We will want to recheck the
+               * link status again soon.
+               */
+
+              sleep(A_SHORT_TIME);
+            }
+          else
+            {
+              /* The link is still up.  Take a long, well-deserved rest */
+
+              sleep(A_REALLY_LONG_TIME);
+            }
+        }
+      else
+        {
+          /* Link down... Was the driver link state already down? */
+
+          if (devup)
+            {
+              /* No... we just transitioned from link up to link down.  Take
+               * the link down.
+               */
+
+              nvdbg("Taking the link down\n");
+
+              ifr.ifr_flags = IFF_DOWN;
+              ret = ioctl(sd, SIOCSIFFLAGS, (unsigned long)&ifr);
+              if (ret < 0)
+                {
+                  ret = -errno;
+                  DEBUGASSERT(ret < 0);
+
+                  ndbg("ERROR: ioctl(SIOCSIFFLAGS) failed: %d\n", ret);
+                  goto errout_with_notification;
+                }
+            }
+
+          /* In either case, wait for the short, configurable delay */
+
+          usleep(1000*CONFIG_NSH_NETINIT_RETRYMSEC);
+        }
+    }
+
+  /* TODO: Stop the PHY notifications and remove the signal handler.  This
+   * is important because the 'event' value is on the stack it is about to
+   * disappear!
+   */
+
+errout_with_notification:
+#  warning Missing logic
+errout_with_sigaction:
+#  warning Missing logic
+errout_with_socket:
+  close(sd);
+errout:
+  ndbg("Aborting\n");
+  return ret;
+}
+#endif
+
+/****************************************************************************
+ * Name: nsh_netinit_thread
+ *
+ * Description:
+ *   Initialize the network per the selected NuttX configuration
+ *
+ ****************************************************************************/
+
+static pthread_addr_t nsh_netinit_thread(pthread_addr_t arg)
+{
+  nvdbg("Entry\n");
+
+  /* Configure the network */
+
+  nsh_netinit_configure();
+
+#ifdef CONFIG_NSH_NETINIT_MONITOR
+  /* Monitor the network status */
+
+  nsh_netinit_monitor();
+#endif
+
+  nvdbg("Exit\n");
+  return NULL;
 }
 
 /****************************************************************************
@@ -262,7 +543,7 @@ int nsh_netinit(void)
 #else
   /* Perform network initialization sequentially */
 
-  (void)nsh_netinit_thread(NULL);
+  nsh_netinit_configure();
 #endif
 }