Add support for capabilities added by plugins (unused)

NEWS

@@ -1,8 +1,13 @@
 -------------------------------------------------------------------------------
 Changes in version 2.00
 
-- This version updates the API to add new features.  Plugins compiled
-  for previous versions of mailfront will not work without recompiling.
+- This version updates the plugin API to add new features:
+
+  - Capabilities reported by the SMTP EHLO response can be added by
+    plugins.
+
+  Plugins compiled for previous versions of mailfront will not work
+  without recompiling.
 
 Development of this version has been sponsored by FutureQuest, Inc.
 [email protected]  http://www.FutureQuest.net/

TODO

@@ -14,6 +14,10 @@ Plugin: clamav
 
   - Add tests (not sure how to emulate the daemon properly)
 
+Plugin: lua
+
+  - Fix hooks that can modify strings to actually allow modification
+
 Plugin: patterns
 
   - Add better MIME attachment discrimination to patterns, instead of

mailfront.c

@@ -57,11 +57,13 @@ static const response* handle_init(void)
   return 0;
 }
 
-const response* handle_helo(str* host)
+const response* handle_helo(str* host, str* capabilities)
 {
   const response* resp;
-  MODULE_CALL(helo, (host), 0, 0);
+  MODULE_CALL(helo, (host, capabilities), 0, 0);
   session_setstr("helo_domain", host->s);
+  if (session.backend->helo != 0)
+    return session.backend->helo(host, capabilities);
   return 0;
 }
 
@@ -188,13 +190,20 @@ int respond_line(unsigned number, int final,
   return 1;
 }
 
-int respond(const response* resp)
+int respond_multiline(unsigned number, int final, const char* msg)
 {
-  const char* msg;
   const char* nl;
-  for (msg = resp->message; (nl = strchr(msg, '\n')) != 0; msg = nl + 1)
-    respond_line(resp->number, 0, msg, nl-msg);
-  return respond_line(resp->number, 1, msg, strlen(msg));
+  while ((nl = strchr(msg, '\n')) != 0) {
+    if (!respond_line(number, 0, msg, nl-msg))
+      return 0;
+    msg = nl + 1;
+  }
+  return respond_line(number, final, msg, strlen(msg));
+}
+
+int respond(const response* resp)
+{
+  return respond_multiline(resp->number, 1, resp->message);
 }
 
 const response* backend_data_block(const char* data, unsigned long len)

mailfront.h

@@ -17,7 +17,7 @@ struct plugin
   const char* name;
   unsigned flags;
   const response* (*init)(void);
-  const response* (*helo)(str*);
+  const response* (*helo)(str* hostname, str* capabilities);
   const response* (*reset)(void);
   const response* (*sender)(str*);
   const response* (*recipient)(str*);
@@ -43,7 +43,7 @@ extern const char* getprotoenv(const char*);
 
 /* From mailfront.c */
 extern const char UNKNOWN[];
-extern const response* handle_helo(str* host);
+extern const response* handle_helo(str* host, str* capabilities);
 extern const response* handle_reset(void);
 extern const response* handle_sender(str* sender);
 extern const response* handle_recipient(str* recip);
@@ -53,6 +53,7 @@ extern const response* handle_message_end(void);
 extern int respond(const response*);
 extern int respond_line(unsigned number, int final,
 			const char* msg, unsigned long len);
+extern int respond_multiline(unsigned number, int final, const char* msg);
 extern const response* backend_data_block(const char* data, unsigned long len);
 extern int scratchfile(void);
 

plugin-api.html

@@ -121,10 +121,12 @@ <h2>Hook Functions</h2>
 responses to the sender address or data, and after the SMTP
 <tt>HELO</tt> command.</dd>
 
-<dt><tt>const response* helo(str* hostname)</tt></dt> <dd>This hook is
-called when the SMTP <tt>HELO</tt> or <tt>EHLO</tt> commands are issued.
-As yet nothing actually uses the <tt>hostname</tt> string.  Other
-protocols will not call this hook.</dd>
+<dt><tt>const response* helo(str* hostname, str* capabilities)</tt></dt>
+<dd>This hook is called when the SMTP <tt>HELO</tt> or <tt>EHLO</tt>
+commands are issued.  As yet nothing actually uses the <tt>hostname</tt>
+string.  Other protocols will not call this hook.
+The <tt>capabilities</tt> variable contains a list of SMTP EHLO response
+capabilities, each followed by a newline.</dd>
 
 <dt><tt>const response* sender(str* address)</tt></dt> <dd>This hook is
 called after a sender email address is transmitted by the client, and is

plugin-lua.c

@@ -225,11 +225,12 @@ static const response* reset(void)
   return 0;
 }
 
-static const response* helo(str* hostname)
+static const response* helo(str* hostname, str* capabilities)
 {
   if (setup("helo")) {
     lua_pushlstring(L, hostname->s, hostname->len);
-    return callit(1);
+    lua_pushlstring(L, capabilities->s, capabilities->len);
+    return callit(2);
   }
   return 0;
 }

plugin-template.c

@@ -13,7 +13,7 @@ static const response* init(void)
 /* The helo function is called once by the SMTP protocol when either the
  * HELO or EHLO command is issued.  The parameter is the hostname given
  * in the command. */
-static const response* helo(str* hostname)
+static const response* helo(str* hostname, str* capabilities)
 {
   return 0;
 }

protocol-smtp.c

@@ -26,6 +26,7 @@ static str cmd;
 static str arg;
 static str addr;
 static str params;
+static str init_capabilities;
 
 static RESPONSE(no_mail, 503, "5.5.1 You must send MAIL FROM: first");
 static RESPONSE(vrfy, 252, "2.5.2 Send some mail, I'll try my best.");
@@ -42,7 +43,6 @@ static RESPONSE(toobig, 552, "5.2.3 The message would exceed the maximum message
 static RESPONSE(toomanyunimp, 503, "5.5.0 Too many unimplemented commands.\n5.5.0 Closing connection.");
 static RESPONSE(goodbye, 221, "2.0.0 Good bye.");
 static RESPONSE(authenticated, 235, "2.7.0 Authentication succeeded.");
-static RESPONSE(ehlo, 250, "8BITMIME\nENHANCEDSTATUSCODES\nPIPELINING");
 
 static int saw_mail = 0;
 static int saw_rcpt = 0;
@@ -126,32 +126,26 @@ static int HELO(void)
 {
   const response* resp;
   if (response_ok(resp = handle_reset()))
-    resp = handle_helo(&arg);
+    resp = handle_helo(&arg, &line);
   return (resp != 0) ? respond(resp)
     : respond_line(250, 1, domain_name.s, domain_name.len);
 }
 
 static int EHLO(void)
 {
-  static str auth_resp;
   const response* resp;
   protocol.name = "ESMTP";
+  line.len = 0;
   if (!response_ok(resp = handle_reset())
-      || !response_ok(resp = handle_helo(&arg)))
+      || !response_ok(resp = handle_helo(&arg, &line)))
     return respond(resp);
+  if (!str_cat(&line, &init_capabilities)) {
+    respond(&resp_oom);
+    return 0;
+  }
 
   if (!respond_line(250, 0, domain_name.s, domain_name.len)) return 0;
-  switch (sasl_auth_caps(&auth_resp)) {
-  case 0: break;
-  case 1:
-    if (!respond_line(250, 0, auth_resp.s, auth_resp.len)) return 0;
-    break;
-  default: return respond(&resp_internal);
-  }
-  if (!str_copys(&line, "SIZE ")) return 0;
-  if (!str_catu(&line, session_getnum("maxdatabytes", 0))) return 0;
-  if (!respond_line(250, 0, line.s, line.len)) return 0;
-  return respond(&resp_ehlo);
+  return respond_multiline(250, 1, line.s);
 }
 
 static void do_reset(void)
@@ -391,14 +385,31 @@ static int init(void)
   if ((tmp = getenv("MAXNOTIMPL")) != 0)
     maxnotimpl = strtoul(tmp, 0, 10);
 
+  if (!sasl_auth_init(&saslauth)) {
+    respond(&resp_authfail);
+    return 1;
+  }
+  switch (sasl_auth_caps(&init_capabilities)) {
+  case 0: break;
+  case 1: break;
+  default:
+    respond(&resp_authfail);
+    return 1;
+  }
+
+  if (!str_copys(&init_capabilities, "SIZE ")
+      || !str_catu(&init_capabilities, session_getnum("maxdatabytes", 0))
+      || !str_catc(&init_capabilities, '\n')
+      || !str_cats(&init_capabilities, "8BITMIME\nENHANCEDSTATUSCODES\nPIPELINING")) {
+    respond(&resp_oom);
+    return 1;
+  }
+
   return 0;
 }
 
 static int mainloop(void)
 {
-  if (!sasl_auth_init(&saslauth))
-    return respond(&resp_authfail);
-
   if (!respond_line(220, 1, str_welcome.s, str_welcome.len)) return 0;
   while (ibuf_getstr_crlf(&inbuf, &line))
     if (!smtp_dispatch()) {