New plugin API and porting of the plugins (+ several changes in the DNS plugin)

SRC/PLUGINS

@@ -1,22 +1,42 @@
-If you want to write your own plugins, they will have to provide three
-functions:
+If you want to write your own plugins, you will first have to decide
+wether your plugin uses a "cooked" hostname or a "raw" one.
 
-char * init (const int argc, const char **argv)
-  Accepts remaining arguments (you have to use popt to parse them, or
-do it by hand, getopt does not allow you to resume the parsing) and
-returns a string identifying the port name. If it makes no sense, you
-can safely return NULL.
+In the first case, the cooked hostname, your plugin will receive from
+echoping a struct addrinfo. All the DNS stuff, including IDN, is
+performed by echoping. You can immediately start using the struct
+addrinfo.
+
+But some libraries (typically, the one used by the DBMS) do not work
+on struct addrinfo but on strings such as "dbname=test
+hostname=foo.bar". Plugins using these libraries will have to use the
+raw interface.
+
+You indicate to echoping wether you use the raw interface or the
+cooked one by returning a port name or NULL from the init() function.
+
+You will have to provide three functions:
+
+char * init (const int argc, const char **argv) Accepts remaining
+  arguments (you have to use popt to parse them, or do it by hand,
+  getopt does not allow you to resume the parsing) and returns a
+  string identifying the port name (cooked interface) or NULL (raw
+  interface).
+
+For the cooked interface:
 
 void start (struct addrinfo *res)
   Typically just stores the res structure for later use.
 
-TODO: two start() routines, one which takes a struct addrinfo and one
-which does not (PostgreSQL or MySQL does not use struct addrinfo but a
-string)?
+For the raw interface:
+
+void start_raw ()
+  Typically connects to the server.
 
 int execute ()
   Connects and do whatever the protocol requires. It is called once
-  per iteration. It returns >=0 if it succeeds and -1 if it failed.
+  per iteration. It returns >=0 if it succeeds, -1 if it failed
+  temporarily (so echoping will continue its loop) and -2 if it failes
+  permanently (so echoping will stop the iteration).
 
 void terminate ()
   Cleans everything. It is called after all iterations.
@@ -24,11 +44,12 @@ void terminate ()
 Start your plugin source code with:
 
 #define IN_PLUGIN
-#include "../echoping.h"
+#include "/wherever/echoping/is/installed/echoping.h"
 
 You can look at random.c, the simplest plugin, and whois.c, the
 simplest which still does something useful.
 
-TODO: documentation of the plugin. A man page echoping_PLUGINNAME?
+The documentation of the plugin should be in a manual page named
+echoping_PLUGINNAME. See the above plugins for examples.
 
 $Id$

SRC/configure

@@ -18940,6 +18940,7 @@ _ACEOF
  fi
 fi;
 
+
 # Check whether --with-popt or --without-popt was given.
 if test "${with_popt+set}" = set; then
   withval="$with_popt"

SRC/configure.ac

@@ -98,8 +98,15 @@ AC_ARG_WITH(gnutls,
         CPPFLAGS="${CPPFLAGS} -I$GNUTLSROOT/include"  
    fi
  fi],
- dnl Default: disable it
-)
+ dnl Default: disable it 
+) 
+
+dnl TODO: test if the getopt variable optreset exists and, if it
+dnl does, we can use getopt (Free BSDs and MacOS X). This implies to
+dnl maintain the two versions, popt and getopt, while echoping has 
+dnl many options. It probably means a high-level language to describe
+dnl the options and to produce the two versions. gengetopt is an obvious
+dnl candidate.
 AC_ARG_WITH(popt,
  [  --with-popt[=DIR]  popt command-line parsing library],dnl
  [if test "$withval" != "no"; then

SRC/echoping.c

@@ -87,6 +87,7 @@ main (argc, argv)
   char *plugin_name, *complete_plugin_name = NULL;
   char *ext;
   void *plugin;
+  int plugin_result;
   char *dl_result;
 
   void to_alarm ();		/* our alarm() signal handler */
@@ -100,6 +101,7 @@ main (argc, argv)
 #endif
 
   char *plugin_port_name, *port_name;
+  unsigned short plugin_raw;
   unsigned short port_to_use = USE_ECHO;
   unsigned short http = 0;
   unsigned short smtp = 0;
@@ -143,6 +145,7 @@ main (argc, argv)
   /* popt variables */
   const struct poptOption options[] = {
     {"verbose", 'v', POPT_ARG_NONE, &verbose, 'v'},
+    {"help", '?', POPT_ARG_NONE, NULL, '?'},
     {"size", 's', POPT_ARG_INT, &size, 's'},
     {"number", 'n', POPT_ARG_INT, &number, 'n'},
 #ifdef HAVE_USLEEP
@@ -167,7 +170,7 @@ main (argc, argv)
     {"ipv4", '4', POPT_ARG_NONE, NULL, '4'},
     {"ipv6", '6', POPT_ARG_NONE, NULL, '6'},
     {"module", 'm', POPT_ARG_STRING, &plugin_name, 'm'},
-    {NULL, 0, 0, NULL, 0, NULL, NULL}
+    POPT_TABLEEND
   };
   poptContext poptcon;
 
@@ -192,20 +195,25 @@ main (argc, argv)
     }
   progname = (char *) argv[0];
 
-  poptcon = poptGetContext (NULL, argc, argv, options, 0);
+  poptcon =
+    poptGetContext (NULL, argc, argv, options, POPT_CONTEXT_POSIXMEHARDER);
 
-  while ((!module_find) && (result = poptGetNextOpt (poptcon)) != -1)
+  while ((result = poptGetNextOpt (poptcon)) != -1)
     {
       if (result < -1)
 	{
-	  printf ("%s: %s",
-		  poptBadOption (poptcon, POPT_BADOPTION_NOALIAS),
-		  poptStrerror (result));
-	  usage ();
+	  fprintf (stderr, "%s: %s\n",
+		   poptBadOption (poptcon, POPT_BADOPTION_NOALIAS),
+		   poptStrerror (result));
+	  usage (poptcon);
 	}
       remaining--;
       switch ((char) result)
 	{
+	case '?':
+	  poptPrintHelp (poptcon, stdout, 0);
+	  fprintf (stdout, " hostname [plugin-options...]\n");
+	  exit (0);
 	case 'v':
 	  break;
 	case 'r':
@@ -324,7 +332,7 @@ main (argc, argv)
 	  break;
 	default:
 	  printf ("Unknown character option %d (%c)", result, (char) result);
-	  usage ();
+	  usage (poptcon);
 	}
     }
   if (udp && ((port_to_use == USE_CHARGEN) ||
@@ -445,29 +453,43 @@ main (argc, argv)
 	     plugin_name, PLUGINS_DIR, dlerror ());
 	}
       plugin_init = dlsym (plugin, "init");
-      if (! plugin_init)
+      if (!plugin_init)
 	{
-	  err_sys ("Cannot find init in %s: %s", plugin_name, dlerror());
+	  err_sys ("Cannot find init in %s: %s", plugin_name, dlerror ());
 	}
       plugin_port_name = plugin_init (remaining, (const char **) leftover);
       if (plugin_port_name != NULL)
-	strcpy (port_name, plugin_port_name);
+	{
+	  strcpy (port_name, plugin_port_name);
+	  plugin_raw = FALSE;
+	  plugin_start = dlsym (plugin, "start");
+	  if (!plugin_start)
+	    {
+	      err_sys ("Cannot find start in %s: %s", plugin_name,
+		       dlerror ());
+	    }
+	}
       else
-	port_name = 0;
-      plugin_start = dlsym (plugin, "start");
-      if (! plugin_start)
 	{
-	  err_sys ("Cannot find start in %s: %s", plugin_name, dlerror());
+	  port_name = 0;
+	  plugin_raw = TRUE;
+	  plugin_raw_start = dlsym (plugin, "start_raw");
+	  if (!plugin_raw_start)
+	    {
+	      err_sys ("Cannot find start_raw in %s: %s", plugin_name,
+		       dlerror ());
+	    }
 	}
       plugin_execute = dlsym (plugin, "execute");
       if (!plugin_execute)
 	{
-	  err_sys ("Cannot find execute in %s: %s", plugin_name, dlerror());
+	  err_sys ("Cannot find execute in %s: %s", plugin_name, dlerror ());
 	}
       plugin_terminate = dlsym (plugin, "terminate");
-      if (! plugin_terminate)
+      if (!plugin_terminate)
 	{
-	  err_sys ("Cannot find terminate in %s: %s", plugin_name, dlerror());
+	  err_sys ("Cannot find terminate in %s: %s", plugin_name,
+		   dlerror ());
 	}
     }
   if (!udp && !ttcp)
@@ -475,11 +497,11 @@ main (argc, argv)
       tcp = 1;
     }
   if (remaining == 0)
-    usage ();
+    usage (poptcon);
   if (!module_find && remaining != 1)
     {
-      printf ("%d args remaning, should be 1\n", remaining);
-      usage ();
+      printf ("%d args remaining, should be 1\n", remaining);
+      usage (poptcon);
     }
   if (verbose)
     {
@@ -613,18 +635,21 @@ main (argc, argv)
 	}
     }				/* Else it is an address, do not IDNize it */
 #endif
-  error = getaddrinfo (server, port_name, &hints, &res);
-  if (error)
+  if (!plugin || !plugin_raw)
     {
-      err_quit ("getaddrinfo error for host: %s %s",
-		server, gai_strerror (error));
-    }
+      error = getaddrinfo (server, port_name, &hints, &res);
+      if (error)
+	{
+	  err_quit ("getaddrinfo error for host: %s %s",
+		    server, gai_strerror (error));
+	}
 
-  if (getnameinfo (res->ai_addr, res->ai_addrlen, hbuf, sizeof (hbuf),
-		   pbuf, sizeof (pbuf), niflags) != 0)
-    {
-      strcpy (hbuf, "?");
-      strcpy (pbuf, "?");
+      if (getnameinfo (res->ai_addr, res->ai_addrlen, hbuf, sizeof (hbuf),
+		       pbuf, sizeof (pbuf), niflags) != 0)
+	{
+	  strcpy (hbuf, "?");
+	  strcpy (pbuf, "?");
+	}
     }
   if (plugin)
     {
@@ -632,7 +657,10 @@ main (argc, argv)
 	{
 	  printf ("Running start() for the plugin %s...\n", plugin_name);
 	}
-      plugin_start (res);
+      if (plugin_raw)
+	plugin_raw_start ();
+      else
+	plugin_start (res);
     }
 #ifdef HTTP
   if (http)
@@ -823,9 +851,12 @@ main (argc, argv)
 	    }
 	  else
 	    {
-	      printf
-		("Trying to call plugin %s for internet address %s %s...\n",
-		 plugin_name, hbuf, pbuf);
+	      if (plugin_raw)
+		printf ("Trying to call plugin %s...\n", plugin_name);
+	      else
+		printf
+		  ("Trying to call plugin %s for internet address %s %s...\n",
+		   plugin_name, hbuf, pbuf);
 	    }
 	}
 #ifdef FLUSH_OUTPUT
@@ -856,8 +887,9 @@ main (argc, argv)
       (void) gettimeofday (&oldtv, (struct timezone *) NULL);
       if (plugin)
 	{
-	  plugin_execute ();
-	  /* TODO: do something with the return code */
+	  plugin_result = plugin_execute ();
+	  if (plugin_result == -2)
+	    err_quit("");
 	}
       else
 	{

SRC/echoping.h

@@ -127,6 +127,8 @@ typedef char * (*init_f) (const int argc, const char **argv);
 init_f plugin_init;
 typedef void (*start_f) (struct addrinfo *);
 start_f plugin_start;
+typedef void (*start_raw_f) ();
+start_raw_f plugin_raw_start;
 typedef int (*execute_f) ();
 execute_f plugin_execute;
 typedef void (*terminate_f) ();

SRC/error.c

@@ -85,11 +85,10 @@ err_sys (char *str, ...)
 }
 
 void
-usage ()
+usage (poptContext context)
 {
-  fprintf (stderr,
-	   "Usage: %s [-4] [-6] [-v] [-r] [-f fill] [-t timeout] [-c] [-d] [-u] [-s size] [-n number] [-w delay] [-h url] [-i url] [-p priority] [-P tos] [-C] [-S] [-m plugin] hostname[:port]\n",
-	   progname);
+  poptPrintUsage (context, stderr, 0);
+  fprintf (stderr, " hostname [plugin-options...]\n");
   exit (1);
 }
 
@@ -110,11 +109,11 @@ sys_err_str ()
 
   if (errno != 0)
     {
-      sprintf (msgstr, "(%s)", strerror(errno));
+      sprintf (msgstr, "(%s)", strerror (errno));
     }
   else
     {
       msgstr[0] = '\0';
-	}
+    }
   return (msgstr);
 }

SRC/plugins/dns/dns.c

@@ -1,7 +1,5 @@
 /*
  * DNS plugin. 
- * TODO: return errors to echoping (name server not existing, for instance)
- * TODO: allow options like TCP
  * $Id$
  */
 
@@ -16,6 +14,8 @@ struct addrinfo name_server;
 poptContext dns_poptcon;
 char *request;
 int type;
+short use_tcp = FALSE;
+short no_recurse = FALSE;
 
 /* nsError stolen from Liu & Albitz check_soa (in their book "DNS and BIND") */
 
@@ -78,6 +78,12 @@ init (const int argc, const char **argv)
     {"type", 't', POPT_ARG_STRING, &type_name, 0,
      "Type of resources queried (A, MX, SOA, etc)",
      "type"},
+    {"tcp", NULL, POPT_ARG_NONE, &use_tcp, 0,
+     "Use TCP for the request (virtual circuit)",
+     "tcp"},
+    {"no-recurse", NULL, POPT_ARG_NONE, &no_recurse, 0,
+     "Do not ask recursion",
+     "no-recurse"},
     POPT_AUTOHELP POPT_TABLEEND
   };
   dns_poptcon = poptGetContext (NULL, argc,
@@ -100,14 +106,18 @@ init (const int argc, const char **argv)
     {				/* TODO: a better algorithm. Use dns_rdatatype_fromtext in BIND ? */
       if (!strcmp (type_name, "A"))
 	type = T_A;
+      else if (!strcmp (type_name, "AAAA"))
+	type = T_AAAA;
       else if (!strcmp (type_name, "NS"))
 	type = T_NS;
       else if (!strcmp (type_name, "SOA"))
 	type = T_SOA;
       else if (!strcmp (type_name, "MX"))
 	type = T_MX;
-      else if (!strcmp (type_name, "AAAA"))
-	type = T_AAAA;
+      else if (!strcmp (type_name, "SRV"))
+	type = T_SRV;
+      else if (!strcmp (type_name, "TXT"))
+	type = T_TXT;
       else
 	dns_usage ("Unknown type");
     }
@@ -129,6 +139,14 @@ start (struct addrinfo *res)
   _res.nsaddr_list[0] = name_server_sockaddr_in;	/* TODO: and IPv6? Detect _resext with autoconf (*BSD) and use it */
   _res.nscount = 1;
   _res.options &= ~(RES_DNSRCH | RES_DEFNAMES | RES_NOALIASES);
+  if (use_tcp)
+    {
+      _res.options &= RES_USEVC;
+    }
+  if (no_recurse)
+    {
+      _res.options &= ~RES_RECURSE;
+    }
 }
 
 int
@@ -142,13 +160,15 @@ execute ()
   int response_length;		/* buffer length */
   if ((response_length = res_query (request,	/* the domain we care about   */
 				    C_IN,	/* Internet class records     */
-				    type,	
-				    (u_char *) & response,	/*response buffer */
+				    type, (u_char *) & response,	/*response buffer */
 				    sizeof (response)))	/*buffer size    */
       < 0)
     {				/*If negative    */
       nsError (h_errno, request);	/* report the error           */
-      return -1;		/* and quit                   */
+      if (h_errno == TRY_AGAIN)
+	return -1;		/* More luck next time? */
+      else
+	return -2;		/* Give in */
     }
   /* TODO: better analysis of the replies. For instance, replies can be in the authority section (delegation info) */
   return 0;

SRC/plugins/postgresql/postgresql.c

@@ -58,7 +58,7 @@ init (const int argc, const char **argv)
 	  postgresql_usage (msg);
 	}
     }
-  if (request == NULL) /* TODO: a default like SELECT now()? */
+  if (request == NULL)		/* TODO: a default like SELECT now()? */
     postgresql_usage ("Mandatory request missing");
   if (conninfo == NULL)
     postgresql_usage ("Mandatory connection information missing");
@@ -66,18 +66,16 @@ init (const int argc, const char **argv)
 }
 
 void
-start (struct addrinfo *res)
+start_raw ()
 {
   conn = PQconnectdb (conninfo);
   if (conn == NULL)
     {
-      printf ("Cannot create connection\n");
-      exit (1);
+      err_quit ("Cannot create connection\n");
     }
   if (PQstatus (conn) == CONNECTION_BAD)
     {
-      printf ("Connection failed: %s\n", PQerrorMessage (conn));
-      exit (1);
+      err_quit ("Connection failed: %s\n", PQerrorMessage (conn));
     }
 }