Not sure what I was thinking: Have SLT_SessOpen log the fd#, not

the xid, we already have that.

bin/varnishd/cache/cache_session.c

@@ -197,8 +197,8 @@ ses_vsl_socket(struct sess *sp, const char *lsockname)
 		strcpy(laddr, "-");
 		strcpy(lport, "-");
 	}
-	VSL(SLT_SessOpen, sp->vxid, "%u %s %s %s %s %s %.6f",
-	    sp->vxid, sp->addr, sp->port, lsockname, laddr, lport, sp->t_open);
+	VSL(SLT_SessOpen, sp->vxid, "%s %s %s %s %s %.6f %d",
+	    sp->addr, sp->port, lsockname, laddr, lport, sp->t_open, sp->fd);
 }
 
 /*--------------------------------------------------------------------

include/tbl/vsl_tags.h

@@ -73,6 +73,7 @@ SLTM(SessOpen, "Client connection opened",
 	"lsock\n    Listen socket\n\n"
 	"laddr\n    Local IPv4/6 address ('-' if !$log_local_addr)\n\n"
 	"lport\n    Local TCP port ('-' if !$log_local_addr)\n\n"
+	"fd\n    File descriptor number"
 )
 
 /*