From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91383C43603 for ; Fri, 13 Dec 2019 10:40:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6CFE8206B7 for ; Fri, 13 Dec 2019 10:40:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726674AbfLMKkc (ORCPT ); Fri, 13 Dec 2019 05:40:32 -0500 Received: from orbyte.nwl.cc ([151.80.46.58]:51180 "EHLO orbyte.nwl.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726016AbfLMKkb (ORCPT ); Fri, 13 Dec 2019 05:40:31 -0500 Received: from n0-1 by orbyte.nwl.cc with local (Exim 4.91) (envelope-from ) id 1ifiN4-0007Lh-Nn; Fri, 13 Dec 2019 11:40:30 +0100 Date: Fri, 13 Dec 2019 11:40:30 +0100 From: Phil Sutter To: Pablo Neira Ayuso Cc: netfilter-devel@vger.kernel.org, Jan Engelhardt Subject: Re: [PATCH nft] main: allow for getopt parser from top-level scope only Message-ID: <20191213104030.GB14465@orbyte.nwl.cc> Mail-Followup-To: Phil Sutter , Pablo Neira Ayuso , netfilter-devel@vger.kernel.org, Jan Engelhardt References: <20191212171455.83382-1-pablo@netfilter.org> <20191212174535.GI20005@orbyte.nwl.cc> <20191212182811.ufw4vxtjfs42zvc7@salvia> <20191213103345.GJ20005@orbyte.nwl.cc> <20191213103624.xhioyre6ckoar6y2@salvia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191213103624.xhioyre6ckoar6y2@salvia> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org On Fri, Dec 13, 2019 at 11:36:24AM +0100, Pablo Neira Ayuso wrote: > On Fri, Dec 13, 2019 at 11:33:45AM +0100, Phil Sutter wrote: > > Hi, > > > > On Thu, Dec 12, 2019 at 07:28:11PM +0100, Pablo Neira Ayuso wrote: > > > On Thu, Dec 12, 2019 at 06:45:35PM +0100, Phil Sutter wrote: > > > > On Thu, Dec 12, 2019 at 06:14:55PM +0100, Pablo Neira Ayuso wrote: > > > > [...] > > > > > diff --git a/src/main.c b/src/main.c > > > > > index fde8b15c5870..c96953e3cd2f 100644 > > > > > --- a/src/main.c > > > > > +++ b/src/main.c > > > > > @@ -202,29 +202,107 @@ static const struct { > > > > > }, > > > > > }; > > > > > > > > > > +struct nft_opts { > > > > > + char **argv; > > > > > + int argc; > > > > > +}; > > > > > + > > > > > +static int nft_opts_init(int argc, char * const argv[], struct nft_opts *opts) > > > > > +{ > > > > > + uint32_t scope = 0; > > > > > + char *new_argv; > > > > > + int i; > > > > > + > > > > > + opts->argv = calloc(argc + 1, sizeof(char *)); > > > > > + if (!opts->argv) > > > > > + return -1; > > > > > + > > > > > + for (i = 0; i < argc; i++) { > > > > > + if (scope > 0) { > > > > > + if (argv[i][0] == '-') { > > > > > + new_argv = malloc(strlen(argv[i]) + 2); > > > > > + if (!new_argv) > > > > > + return -1; > > > > > + > > > > > + sprintf(new_argv, "\\-%s", &argv[i][1]); > > > > > + opts->argv[opts->argc++] = new_argv; > > > > > + continue; > > > > > + } > > > > > + } else if (argv[i][0] == '{') { > > > > > + scope++; > > > > > + } else if (argv[i][0] == '}') { > > > > > + scope--; > > > > > + } > > > > > > > > This first char check is not reliable, bison accepts commands which lack > > > > spaces in the relevant places: > > > > > > > > | # nft add chain inet t c{ type filter hook input priority filter\; } > > > > | # echo $? > > > > | 0 > > > > > > Yes, it won't catch that case. Do you think it is worth going further > > > in this preprocessing? > > > > What about a different approach, namely to iterate over argv in reverse, > > reordering those *argv until **argv != '-'? One would have to make sure > > not to mess ordering, but that should be the only requirement to get > > expected results in any situation. > > That's another possibility, yes: > > argv[i][strlen(argv[i]) - 1] == '{' Bison doesn't allow for easy cheats: | # nft add chain inet t c{type filter hook input priority filter\; } | # echo $? | 0 Let me quickly hack my reordering idea to see how much of a mess it will become. Cheers, Phil