Send "FTP transfer complete" events to the DHCP lease script.

CHANGELOG

@@ -24,6 +24,24 @@ version 2.61
 	    Add --host-record. Thanks to Rob Zwissler for the
 	    suggestion.
 
+	    Invoke the DHCP script with action "tftp" when a TFTP file
+	    transfer completes. The size of the file, address to which
+	    it was sent and complete pathname are supplied. Note that
+	    version 2.60 introduced some script incompatibilties
+	    associated with DHCPv6, and this is a further change. To
+	    be safe, scripts should ignore unknown actions, and if
+	    not IPv6-aware, should exit if the environment
+	    variable DNSMASQ_IAID is set. The use-case for this is
+	    to track netboot/install.  Suggestion from Shantanu
+	    Gadgil.
+
+	    Update contrib/port-forward/dnsmasq-portforward to reflect
+	    the above.
+
+	    Set the environment variable DNSMASQ_LOG_DHCP when running
+	    the script id --log-dhcp is in effect, so that script can
+	    taylor their logging verbosity. Suggestion from Malte Forkel.
+
  
 version 2.60
             Fix compilation problem in Mac OS X Lion. Thanks to Olaf

contrib/port-forward/dnsmasq-portforward

@@ -34,11 +34,21 @@ if [ ${DNSMASQ_OLD_HOSTNAME} ] && [ ${action} = old ] ; then
     hostname=${DNSMASQ_OLD_HOSTNAME}
 fi
 
+# IPv6 leases are not our concern. no NAT there!
+if [ ${DNSMASQ_IAID} ] ; then
+   exit 0
+fi
+
 # action init is not relevant, and will only be seen when leasefile-ro is set.
 if [ ${action} = init ] ; then
     exit 0
 fi
 
+# action tftp is not relevant.
+if [ ${action} = tftp ] ; then
+    exit 0
+fi
+
 if [ ${hostname} ]; then
     ports=$(sed -n -e "/^${hostname}\ .*/ s/^.* //p" ${PORTSFILE})
 

man/dnsmasq.8

@@ -1069,7 +1069,8 @@ re-intialised. The enterprise-id is assigned by IANA, and the uid is a
 string of hex octets unique to a particular device.
 .TP
 .B \-6 --dhcp-script=<path>
-Whenever a new DHCP lease is created, or an old one destroyed, the
+Whenever a new DHCP lease is created, or an old one destroyed, or a
+TFTP file transfer completes, the
 executable specified by this option is run.  <path>
 must be an absolute pathname, no PATH search occurs. 
 The arguments to the process
@@ -1119,6 +1120,8 @@ is known.
 DNSMASQ_TAGS contains all the tags set during the
 DHCP transaction, separated by spaces.
 
+DNSMASQ_LOG_DHCP is set if --log-dhcp is in effect.
+
 For IPv4 only:
 
 DNSMASQ_CLIENT_ID if the host provided a client-id.
@@ -1145,6 +1148,8 @@ only  supplied for
 since these data are not held in dnsmasq's lease
 database.
 
+
+
 All file descriptors are
 closed except stdin, stdout and stderr which are open to /dev/null
 (except in debug mode).
@@ -1163,6 +1168,17 @@ all existing leases as they are read from the lease file. Expired
 leases will be called with "del" and others with "old". When dnsmasq
 receives a HUP signal, the script will be invoked for existing leases
 with an "old " event.
+
+
+There are two further actions which may appear as the first argument
+to the script, "init" and "tftp". More may be added in the future, so
+scripts should be written to ignore unknown actions. "init" is
+decsribed below in 
+.B --leasefile-ro
+The "tftp" action is invoked when a TFTP file transfer completes: the
+arguments are the file size in bytes, the address to which the file
+was sent, and the complete pathname of the file.
+ 
 .TP
 .B --dhcp-luascript=<path>
 Specify a script written in Lua, to be run when leases are created,
@@ -1176,11 +1192,13 @@ function, and may provide
 and
 .B shutdown
 functions, which are called, without arguments when dnsmasq starts up
-and terminates.
+and terminates. It may also provide a 
+.B tftp
+function.
 
 The 
 .B lease
-method receives the information detailed in 
+function receives the information detailed in 
 .B --dhcp-script. 
 It gets two arguments, firstly the action, which is a string
 containing, "add", "old" or "del", and secondly a table of tag value
@@ -1198,6 +1216,15 @@ for IPv4, and
 and 
 .B hostname
 for IPv6.
+
+The  
+.B tftp
+function is called in the same way as the lease function, and the
+table holds the tags 
+.B destination_address,
+.B file_name
+and 
+.B file_size.
 .TP
 .B --dhcp-scriptuser
 Specify the user as which to run the lease-change script or Lua script. This defaults to root, but can be changed to another user using this flag. 

src/dnsmasq.c

@@ -721,6 +721,10 @@ int main (int argc, char **argv)
 #  ifdef HAVE_SCRIPT
       while (helper_buf_empty() && do_script_run(now));
 
+#    ifdef HAVE_TFTP
+      while (helper_buf_empty() && do_tftp_script_run());
+#    endif
+
       if (!helper_buf_empty())
 	{
 	  FD_SET(daemon->helperfd, &wset);
@@ -729,6 +733,11 @@ int main (int argc, char **argv)
 #  else
       /* need this for other side-effects */
       while (do_script_run(now));
+
+#    ifdef HAVE_TFTP 
+      while (do_tftp_script_run());
+#    endif
+
 #  endif
 #endif
    

src/dnsmasq.h

@@ -458,6 +458,7 @@ struct frec {
 #define ACTION_OLD_HOSTNAME  2
 #define ACTION_OLD           3
 #define ACTION_ADD           4
+#define ACTION_TFTP          5
 
 #define LEASE_NEW            1  /* newly created */
 #define LEASE_CHANGED        2  /* modified */
@@ -803,7 +804,7 @@ extern struct daemon {
 #endif
 
   /* TFTP stuff */
-  struct tftp_transfer *tftp_trans;
+  struct tftp_transfer *tftp_trans, *tftp_done_trans;
 
   /* utility string buffer, hold max sized IP address as string */
   char *addrbuff;
@@ -1040,6 +1041,9 @@ int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd);
 void helper_write(void);
 void queue_script(int action, struct dhcp_lease *lease, 
 		  char *hostname, time_t now);
+#ifdef HAVE_TFTP
+void queue_tftp(off_t file_len, char *filename, union mysockaddr *peer);
+#endif
 int helper_buf_empty(void);
 #endif
 
@@ -1047,6 +1051,7 @@ int helper_buf_empty(void);
 #ifdef HAVE_TFTP
 void tftp_request(struct listener *listen, time_t now);
 void check_tftp_listeners(fd_set *rset, time_t now);
+int do_tftp_script_run(void);
 #endif
 
 /* conntrack.c */

src/helper.c

@@ -193,16 +193,22 @@ int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd)
 	  _exit(0);
 	}
  
+      is6 = !!(data.flags & (LEASE_TA | LEASE_NA));
+      
       if (data.action == ACTION_DEL)
 	action_str = "del";
       else if (data.action == ACTION_ADD)
 	action_str = "add";
       else if (data.action == ACTION_OLD || data.action == ACTION_OLD_HOSTNAME)
 	action_str = "old";
+      else if (data.action == ACTION_TFTP)
+	{
+	  action_str = "tftp";
+	  is6 = (data.flags != AF_INET);
+	}
       else
 	continue;
 
-      is6 = !!(data.flags & (LEASE_TA | LEASE_NA));
       	
       if (!is6)
 	{
@@ -271,6 +277,8 @@ int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd)
 	  char *dot;
 	  hostname = (char *)buf;
 	  hostname[data.hostname_len - 1] = 0;
+	  if (data.action != ACTION_TFTP)
+	    {
 	      if (!legal_hostname(hostname))
 		hostname = NULL;
 	      else if ((dot = strchr(hostname, '.')))
@@ -279,6 +287,7 @@ int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd)
 		  *dot = 0;
 		} 
 	    }
+	}
     
       extradata = buf + data.hostname_len;
     
@@ -289,8 +298,32 @@ int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd)
 	inet_ntop(AF_INET6, &data.hwaddr, daemon->addrbuff, ADDRSTRLEN);
 #endif
 
+      /* file length */
+      if (data.action == ACTION_TFTP)
+	sprintf(daemon->dhcp_buff, "%u", data.hwaddr_len);
+      
 #ifdef HAVE_LUASCRIPT
       if (daemon->luascript)
+	{
+	  if (data.action == ACTION_TFTP)
+	    {
+	      lua_getglobal(lua, "tftp"); 
+	      if (lua_type(lua, -1) != LUA_TFUNCTION)
+		lua_pop(lua, 1); /* tftp function optional */
+	      else
+		{
+		  lua_pushstring(lua, action_str); /* arg1 - action */
+		  lua_newtable(lua);               /* arg2 - data table */
+		  lua_pushstring(lua, daemon->addrbuff);
+		  lua_setfield(lua, -2, "destination_address");
+		  lua_pushstring(lua, hostname);
+		  lua_setfield(lua, -2, "file_name"); 
+		  lua_pushstring(lua, daemon->dhcp_buff);
+		  lua_setfield(lua, -2, "file_size");
+		  lua_call(lua, 2, 0);	/* pass 2 values, expect 0 */
+		}
+	    }
+	  else
 	    {
 	      lua_getglobal(lua, "lease");     /* function to call */
 	      lua_pushstring(lua, action_str); /* arg1 - action */
@@ -400,6 +433,7 @@ int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd)
 	    
 	      lua_call(lua, 2, 0);	/* pass 2 values, expect 0 */
 	    }
+	}
 #endif
 
       /* no script, just lua */
@@ -439,6 +473,8 @@ int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd)
 	  continue;
 	}
       
+      if (data.action != ACTION_TFTP)
+	{
 	  if (is6)
 	    {
 	      my_setenv("DNSMASQ_IAID", daemon->dhcp_buff3, &err);
@@ -513,6 +549,10 @@ int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd)
 	      my_setenv("DNSMASQ_OLD_HOSTNAME", hostname, &err);
 	      hostname = NULL;
 	    }
+	}
+
+      if (option_bool(OPT_LOG_OPTS))
+	my_setenv("DNSMASQ_LOG_DHCP", "1", &err);
 	 
       /* we need to have the event_fd around if exec fails */
       if ((i = fcntl(event_fd, F_GETFD)) != -1)
@@ -584,11 +624,29 @@ static unsigned char *grab_extradata_lua(unsigned char *buf, unsigned char *end,
 }
 #endif
 
+static void buff_alloc(size_t size)
+{
+  if (size > buf_size)
+    {
+      struct script_data *new;
+      
+      /* start with reasonable size, will almost never need extending. */
+      if (size < sizeof(struct script_data) + 200)
+	size = sizeof(struct script_data) + 200;
+
+      if (!(new = whine_malloc(size)))
+	return;
+      if (buf)
+	free(buf);
+      buf = new;
+      buf_size = size;
+    }
+}
+
 /* pack up lease data into a buffer */    
 void queue_script(int action, struct dhcp_lease *lease, char *hostname, time_t now)
 {
   unsigned char *p;
-  size_t size;
   unsigned int hostname_len = 0, clid_len = 0, ed_len = 0;
   int fd = daemon->dhcpfd;
 
@@ -608,23 +666,7 @@ void queue_script(int action, struct dhcp_lease *lease, char *hostname, time_t n
   if (hostname)
     hostname_len = strlen(hostname) + 1;
 
-  size = sizeof(struct script_data) +  clid_len + ed_len + hostname_len;
+  buff_alloc(sizeof(struct script_data) +  clid_len + ed_len + hostname_len);
-
-  if (size > buf_size)
-    {
-      struct script_data *new;
-      
-      /* start with reasonable size, will almost never need extending. */
-      if (size < sizeof(struct script_data) + 200)
-	size = sizeof(struct script_data) + 200;
-
-      if (!(new = whine_malloc(size)))
-	return;
-      if (buf)
-	free(buf);
-      buf = new;
-      buf_size = size;
-    }
 
   buf->action = action;
   buf->flags = lease->flags;
@@ -669,6 +711,37 @@ void queue_script(int action, struct dhcp_lease *lease, char *hostname, time_t n
   bytes_in_buf = p - (unsigned char *)buf;
 }
 
+#ifdef HAVE_TFTP
+/* This nastily re-uses DHCP-fields for TFTP stuff */
+void queue_tftp(off_t file_len, char *filename, union mysockaddr *peer)
+{
+  unsigned int filename_len;
+
+  /* no script */
+  if (daemon->helperfd == -1)
+    return;
+  
+  filename_len = strlen(filename) + 1;
+  buff_alloc(sizeof(struct script_data) +  filename_len);
+  memset(buf, 0, sizeof(struct script_data));
+
+  buf->action = ACTION_TFTP;
+  buf->hostname_len = filename_len;
+  buf->hwaddr_len = file_len;
+
+  if ((buf->flags = peer->sa.sa_family) == AF_INET)
+    buf->addr = peer->in.sin_addr;
+#ifdef HAVE_IPV6
+  else
+    memcpy(buf->hwaddr, &peer->in6.sin6_addr, IN6ADDRSZ);
+#endif
+
+  memcpy((unsigned char *)(buf+1), filename, filename_len);
+  
+  bytes_in_buf = sizeof(struct script_data) +  filename_len;
+}
+#endif
+
 int helper_buf_empty(void)
 {
   return bytes_in_buf == 0;

src/tftp.c

@@ -571,7 +571,9 @@ void check_tftp_listeners(fd_set *rset, time_t now)
 		my_syslog(MS_TFTP | LOG_INFO, _("sent %s to %s"), transfer->file->filename, daemon->addrbuff);
 	      /* unlink */
 	      *up = tmp;
-	      free_transfer(transfer);
+	      /* put on queue to be sent to script and deleted */
+	      transfer->next = daemon->tftp_done_trans;
+	      daemon->tftp_done_trans = transfer;
 	      continue;
 	    }
 	}
@@ -709,4 +711,21 @@ static ssize_t get_block(char *packet, struct tftp_transfer *transfer)
     }
 }
 
+
+int do_tftp_script_run(void)
+{
+  struct tftp_transfer *transfer;
+
+  if ((transfer = daemon->tftp_done_trans))
+    {
+      daemon->tftp_done_trans = transfer->next;
+#ifdef HAVE_SCRIPT
+      queue_tftp(transfer->file->size, transfer->file->filename, &transfer->peer);
+#endif
+      free_transfer(transfer);
+      return 1;
+    }
+
+  return 0;
+}
 #endif