[Project] Allow to replace body in milter

src/libserver/milter.c

 	rspamd_fstring_t *reply = NULL;
 	gsize len;
 	GString *name, *value;
-	const char *reason;
+	const char *reason, *body_str;
 	struct rspamd_milter_outbuf *obuf;
 	struct rspamd_milter_private *priv = session->priv;
 
 		pos += name->len + 1;
 		memcpy (pos, value->str, value->len + 1);
 		break;
+	case RSPAMD_MILTER_REPLBODY:
+		len = va_arg (ap, gsize);
+		body_str = va_arg (ap, const char *);
+		msg_debug_milter ("want to change body; size = %uz",
+				len);
+		SET_COMMAND (cmd, len, reply, pos);
+		memcpy (pos, body_str, len + 1);
+		break;
 	case RSPAMD_MILTER_REPLYCODE:
 	case RSPAMD_MILTER_ADDRCPT:
 	case RSPAMD_MILTER_DELRCPT:

src/libserver/milter.h

 	RSPAMD_MILTER_ADDHEADER = 'h',
 	RSPAMD_MILTER_CHGHEADER = 'm',
 	RSPAMD_MILTER_INSHEADER = 'i',
+	RSPAMD_MILTER_REPLBODY = 'b',
 	RSPAMD_MILTER_REJECT = 'r',
 	RSPAMD_MILTER_TEMPFAIL = 't',
 	RSPAMD_MILTER_REPLYCODE = 'y',

src/libserver/milter_internal.h

 #define RSPAMD_MILTER_ACTIONS_MASK \
     (RSPAMD_MILTER_FLAG_ADDHDRS | RSPAMD_MILTER_FLAG_ADDRCPT | \
     RSPAMD_MILTER_FLAG_DELRCPT | RSPAMD_MILTER_FLAG_CHGHDRS | \
-    RSPAMD_MILTER_FLAG_QUARANTINE)
+    RSPAMD_MILTER_FLAG_CHGBODY | RSPAMD_MILTER_FLAG_QUARANTINE)
 
 enum rspamd_milter_connect_proto {
 	RSPAMD_MILTER_CONN_UNKNOWN = 'U',