net: Allow netconsole settings to change after nc_start

Refresh the netconsole settings from the env before each packet instead
of only on netconsole init.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index da82aa94ca4f87e592eafafee15f87b54e8ca2c6..63ce73c81891004594e4b1ff42e3ef935b8f671d 100644 (file)
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -69,8 +69,69 @@ static void nc_timeout(void)
        net_set_state(NETLOOP_SUCCESS);
 }
 
+static int is_broadcast(IPaddr_t ip)
+{
+       static IPaddr_t netmask;
+       static IPaddr_t our_ip;
+       static int env_changed_id;
+       int env_id = get_env_id();
+
+       /* update only when the environment has changed */
+       if (env_changed_id != env_id) {
+               netmask = getenv_IPaddr("netmask");
+               our_ip = getenv_IPaddr("ipaddr");
+
+               env_changed_id = env_id;
+       }
+
+       return (ip == ~0 ||                             /* 255.255.255.255 */
+           ((netmask & our_ip) == (netmask & ip) &&    /* on the same net */
+           (netmask | ip) == ~0));             /* broadcast to our net */
+}
+
+static int refresh_settings_from_env(void)
+{
+       const char *p;
+       static int env_changed_id;
+       int env_id = get_env_id();
+
+       /* update only when the environment has changed */
+       if (env_changed_id != env_id) {
+               if (getenv("ncip")) {
+                       nc_ip = getenv_IPaddr("ncip");
+                       if (!nc_ip)
+                               return -1;      /* ncip is 0.0.0.0 */
+                       p = strchr(getenv("ncip"), ':');
+                       if (p != NULL) {
+                               nc_out_port = simple_strtoul(p + 1, NULL, 10);
+                               nc_in_port = nc_out_port;
+                       }
+               } else
+                       nc_ip = ~0; /* ncip is not set, so broadcast */
+
+               p = getenv("ncoutport");
+               if (p != NULL)
+                       nc_out_port = simple_strtoul(p, NULL, 10);
+               p = getenv("ncinport");
+               if (p != NULL)
+                       nc_in_port = simple_strtoul(p, NULL, 10);
+
+               if (is_broadcast(nc_ip))
+                       /* broadcast MAC address */
+                       memset(nc_ether, 0xff, sizeof(nc_ether));
+               else
+                       /* force arp request */
+                       memset(nc_ether, 0, sizeof(nc_ether));
+       }
+       return 0;
+}
+
+/**
+ * Called from NetLoop in net/net.c before each packet
+ */
 void NcStart(void)
 {
+       refresh_settings_from_env();
        if (!output_packet_len || memcmp(nc_ether, NetEtherNullAddr, 6)) {
                /* going to check for input packet */
                net_set_udp_handler(nc_handler);
@@ -166,41 +227,14 @@ static void nc_send_packet(const char *buf, int len)
 
 static int nc_start(void)
 {
-       int netmask, our_ip;
-       char *p;
+       int retval;
 
        nc_out_port = 6666; /* default port */
        nc_in_port = nc_out_port;
 
-       if (getenv("ncip")) {
-
-               nc_ip = getenv_IPaddr("ncip");
-               if (!nc_ip)
-                       return -1;      /* ncip is 0.0.0.0 */
-               p = strchr(getenv("ncip"), ':');
-               if (p != NULL) {
-                       nc_out_port = simple_strtoul(p + 1, NULL, 10);
-                       nc_in_port = nc_out_port;
-               }
-       } else
-               nc_ip = ~0; /* ncip is not set, so broadcast */
-
-       p = getenv("ncoutport");
-       if (p != NULL)
-               nc_out_port = simple_strtoul(p, NULL, 10);
-       p = getenv("ncinport");
-       if (p != NULL)
-               nc_in_port = simple_strtoul(p, NULL, 10);
-
-       our_ip = getenv_IPaddr("ipaddr");
-       netmask = getenv_IPaddr("netmask");
-
-       if (nc_ip == ~0 ||                              /* 255.255.255.255 */
-           ((netmask & our_ip) == (netmask & nc_ip) && /* on the same net */
-           (netmask | nc_ip) == ~0))           /* broadcast to our net */
-               memset(nc_ether, 0xff, sizeof(nc_ether));
-       else
-               memset(nc_ether, 0, sizeof(nc_ether));  /* force arp request */
+       retval = refresh_settings_from_env();
+       if (retval != 0)
+               return retval;
 
        /*
         * Initialize the static IP settings and buffer pointers