Merge pull request #431 from Logan007/ipSbnt

merged edge's subnet parameter into address parameter

doc/TapConfiguration.md

@@ -20,7 +20,7 @@ n2n supports several ways to assign an IPv4 address to the virtual ethernet devi
 
 The command line parameter `-a <static:IP address>` assigns a static IP address, e.g. `-a static:192.168.8.5` to the device. The optional `static` keyword (and the delimiting colon) can be omitted, so `-a 192.168.8.5` works as well.
 
-The netmask can optionally be provided using `-s <netmask>`, e.g. `-s 255.255.255.0` which also is the default should `-s` not be provided.
+The netmask in CIDR notation can optionally be appended to the address, e.g. `-a 192.168.8.5/24` for netmask `255.255.255.0` which also is the default should the netmask not be provided.
 
 ### Auto-IP Address
 

include/n2n.h

@@ -257,7 +257,6 @@ typedef struct n2n_tuntap_priv_config {
   dec_ip_str_t        netmask;
   char                device_mac[N2N_MACNAMSIZ];
   int                 mtu;
-  uint8_t             got_s;
   uint8_t             daemon;
 #ifndef WIN32
   uid_t               userid;

include/n2n_define.h

@@ -89,6 +89,10 @@
 #define N2N_MACNAMSIZ           18 /* AA:BB:CC:DD:EE:FF + NULL*/
 #define N2N_IF_MODE_SIZE        16 /* static | dhcp */
 
+#define N2N_EDGE_DEFAULT_DEV_NAME  "edge0"
+#define N2N_EDGE_DEFAULT_NETMASK   "255.255.255.0"  /* default netmask for edge ip address... */
+#define N2N_EDGE_DEFAULT_CIDR_NM   24               /* ... also in cidr format                */
+
 #define N2N_SN_LPORT_DEFAULT 7654
 #define N2N_SN_PKTBUF_SIZE   2048
 

src/edge.c

@@ -45,54 +45,65 @@ int num_cap = sizeof(cap_values)/sizeof(cap_value_t);
 
 /** Find the address and IP mode for the tuntap device.
  *
- *  s is one of these forms:
+ *  s is of the form:
  *
- *  <host> := <hostname> | A.B.C.D
+ * ["static"|"dhcp",":"] (<host>|<ip>) [/<cidr subnet mask>]
  *
- *  <host> | static:<host> | dhcp:<host>
+ * for example    static:192.168.8.5/24
  *
- *  If the mode is present (colon required) then fill ip_mode with that value
+ * Fill the parts of the string into the fileds, ip_mode only if
- *  otherwise do not change ip_mode. Fill ip_mode with everything after the
+ * present. All strings are NULL terminated.
- *  colon if it is present; or s if colon is not present.
- *
- *  ip_add and ip_mode are NULL terminated if modified.
  *
  *  return 0 on success and -1 on error
  */
 static int scan_address(char * ip_addr, size_t addr_size,
+			char * netmask, size_t netmask_size,
 			char * ip_mode, size_t mode_size,
-			const char * s) {
+			char * s) {
+
   int retval = -1;
-  char * p;
+  char * start;
+  char * end;
+  int bitlen = N2N_EDGE_DEFAULT_CIDR_NM;
 
-  if((NULL == s) || (NULL == ip_addr))
+  if((NULL == s) || (NULL == ip_addr) || (NULL == netmask)) {
-    {
     return -1;
   }
 
   memset(ip_addr, 0, addr_size);
+  memset(netmask, 0, netmask_size);
 
-  p = strpbrk(s, ":");
+  start = s;
-
+  end = strpbrk(s, ":");
-  if(p)
-    {
-      /* colon is present */
-      if(ip_mode)
-        {
-	  size_t end=0;
 
+  if(end) {
+    // colon is present
+    if(ip_mode) {
       memset(ip_mode, 0, mode_size);
-	  end = MIN(p-s, (ssize_t)(mode_size-1)); /* ensure NULL term */
+      strncpy(ip_mode, start, (size_t)MIN(end - start, mode_size - 1));
-	  strncpy(ip_mode, s, end);
-	  strncpy(ip_addr, p+1, addr_size-1); /* ensure NULL term */
-	  retval = 0;
     }
+    start = end + 1;
+  } else {
+    // colon is not present
   }
-  else
+  // start now points to first address character
-    {
+  retval = 0; // we have got an address
-      /* colon is not present */
+
-      strncpy(ip_addr, s, addr_size-1);
+  end = strpbrk(start, "/");
-      ip_addr[addr_size-1] = '\0';
+
+  if(!end)
+    // no slash present -- default end
+    end = s + strlen(s);
+
+  strncpy(ip_addr, start, (size_t)MIN(end - start, addr_size - 1)); // ensure NULL term
+
+  if(end) {
+    // slash is present
+
+    // now, handle the sub-network address
+    sscanf(end + 1, "%u", &bitlen);
+    bitlen = htobe32(bitlen2mask(bitlen));
+    inet_ntop(AF_INET, &bitlen, netmask, netmask_size);
   }
 
   return retval;
@@ -110,11 +121,10 @@ static void help() {
 #if defined(N2N_CAN_NAME_IFACE)
 	 "-d <tap device> "
 #endif /* #if defined(N2N_CAN_NAME_IFACE) */
-	 "-a [static:|dhcp:]<tap IP address> "
+	 "-a [static:|dhcp:]<tap IP address>[/nn] "
 	 "-c <community> "
 	 "[-k <encrypt key>]\n"
 	 "    "
-	 "[-s <netmask>] "
 #ifndef WIN32
 	 "[-u <uid> -g <gid>]"
 #endif /* #ifndef WIN32 */
@@ -139,10 +149,9 @@ static void help() {
   printf("-d <tap device>          | tap device name\n");
 #endif
 
-  printf("-a <mode:address>        | Set interface address. For DHCP use '-r -a dhcp:0.0.0.0'\n");
+  printf("-a [mode:]<address>[/nn] | Interface address and optional subnet (cidr, default /24). For DHCP use '-r -a dhcp:0.0.0.0'\n");
   printf("-c <community>           | n2n community name the edge belongs to.\n");
   printf("-k <encrypt key>         | Encryption key (ASCII) - also N2N_KEY=<encrypt key>.\n");
-  printf("-s <netmask>             | Edge interface netmask in dotted decimal notation (255.255.255.0).\n");
   printf("-l <supernode host:port> | Supernode IP:port\n");
   printf("-i <reg_interval>        | Registration interval, for NAT hole punching (default 20 seconds)\n");
   printf("-L <reg_ttl>             | TTL for registration packet when UDP NAT hole punching through supernode (default 0 for not set )\n");
@@ -273,6 +282,7 @@ static int setOption(int optkey, char *optargument, n2n_tuntap_priv_config_t *ec
   case 'a': /* IP address and mode of TUNTAP interface */
     {
       scan_address(ec->ip_addr, N2N_NETMASK_STR_SIZE,
+		   ec->netmask, N2N_NETMASK_STR_SIZE,
 		   ec->ip_mode, N2N_IF_MODE_SIZE,
 		   optargument);
       break;
@@ -475,17 +485,6 @@ static int setOption(int optkey, char *optargument, n2n_tuntap_priv_config_t *ec
       break;
     }
 
-  case 's': /* Subnet Mask */
-    {
-      if(0 != ec->got_s) {
-        traceEvent(TRACE_WARNING, "Multiple subnet masks supplied");
-      }
-      strncpy(ec->netmask, optargument, N2N_NETMASK_STR_SIZE);
-      ec->netmask[N2N_NETMASK_STR_SIZE - 1] = '\0';
-      ec->got_s = 1;
-      break;
-    }
-
   case 'S':
     {
       conf->allow_p2p = 0;
@@ -809,9 +808,9 @@ int main(int argc, char* argv[]) {
 #ifdef WIN32
   ec.tuntap_dev_name[0] = '\0';
 #else
-  snprintf(ec.tuntap_dev_name, sizeof(ec.tuntap_dev_name), "edge0");
+  snprintf(ec.tuntap_dev_name, sizeof(ec.tuntap_dev_name), N2N_EDGE_DEFAULT_DEV_NAME);
 #endif
-  snprintf(ec.netmask, sizeof(ec.netmask), "255.255.255.0");
+  snprintf(ec.netmask, sizeof(ec.netmask), N2N_EDGE_DEFAULT_NETMASK);
 
   if((argc >= 2) && (argv[1][0] != '-')) {
     rc = loadFromFile(argv[1], &conf, &ec);