From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ozgur Akan Subject: Re: argv[optind-1] == optarg Date: Mon, 24 May 2004 08:26:17 +0300 Sender: netfilter-devel-admin@lists.netfilter.org Message-ID: <40B18779.8010606@aiqa.com> References: <40AF9F99.7070305@aiqa.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------040807000602020602030700" Return-path: To: "netfilter-devel@lists.netfilter.org" , Harald Welte In-Reply-To: <40AF9F99.7070305@aiqa.com> Errors-To: netfilter-devel-admin@lists.netfilter.org List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: List-Id: netfilter-devel.vger.kernel.org This is a multi-part message in MIME format. --------------040807000602020602030700 Content-Type: multipart/alternative; boundary="------------050407090102020108010203" --------------050407090102020108010203 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Hi, I attached the patch file for optarg. It includes patches for iptables.c and ip6tables.c. regards, Ozgur Akan Ozgur Akan wrote: > Hi, > > I think using optarg instead of argv[optind-1] will be better. In > iptables.c; while parsing iptables options with getopt_long, > argv[optind-1] is used in 8 places. > > optarg (option argument) gives us the value of the option we are > parsing. So when we do something with the argument of (for example) A > option the easiest way to get the value of A`s argument is using > optarg. optarg is designed to be used with getopt_long. > > Using optind (option index) is more tricky because optind starts from > 1 and when we are parsing an option with an index of value n of argv > array it shows n+2. That`s why we substract 1 from optind. > > best wishes, > Ozgur Akan --------------050407090102020108010203 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Hi,
I attached the patch file for optarg. It includes patches for iptables.c and ip6tables.c.

regards,
Ozgur Akan

Ozgur Akan wrote:

Hi,

I think using optarg instead of argv[optind-1] will be better. In iptables.c; while parsing iptables options with getopt_long, argv[optind-1] is used in 8 places.

optarg (option argument) gives us the value of the option we are parsing. So when we do something with the argument of (for example) A option the easiest way to get the value of A`s argument is using optarg. optarg is designed to be used with getopt_long.

Using optind (option index) is more tricky because optind starts from 1 and when we are parsing an option with an index of value n of argv array it shows n+2. That`s why we substract 1 from optind.

best wishes,
Ozgur Akan

--------------050407090102020108010203-- --------------040807000602020602030700 Content-Type: text/plain; name="optarg.PATCH" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="optarg.PATCH" diff -Naur iptables/ip6tables.c iptables_dev/ip6tables.c --- iptables/ip6tables.c 2004-05-24 08:07:59.782220912 +0300 +++ iptables_dev/ip6tables.c 2004-05-24 08:16:48.830793304 +0300 @@ -1853,10 +1853,10 @@ invert); /* Canonicalize into lower case */ - for (protocol = argv[optind-1]; *protocol; protocol++) + for (protocol = optarg; *protocol; protocol++) *protocol = tolower(*protocol); - protocol = argv[optind-1]; + protocol = optarg; if ( strcmp(protocol,"ipv6-icmp") == 0) protocol = icmp6p; fw.ipv6.proto = parse_protocol(protocol); @@ -1873,7 +1873,7 @@ check_inverse(optarg, &invert, &optind, argc); set_option(&options, OPT_SOURCE, &fw.ipv6.invflags, invert); - shostnetworkmask = argv[optind-1]; + shostnetworkmask = optarg; fw.nfcache |= NFC_IP6_SRC; break; @@ -1881,7 +1881,7 @@ check_inverse(optarg, &invert, &optind, argc); set_option(&options, OPT_DESTINATION, &fw.ipv6.invflags, invert); - dhostnetworkmask = argv[optind-1]; + dhostnetworkmask = optarg; fw.nfcache |= NFC_IP6_DST; break; @@ -1911,7 +1911,7 @@ check_inverse(optarg, &invert, &optind, argc); set_option(&options, OPT_VIANAMEIN, &fw.ipv6.invflags, invert); - parse_interface(argv[optind-1], + parse_interface(optarg, fw.ipv6.iniface, fw.ipv6.iniface_mask); fw.nfcache |= NFC_IP6_IF_IN; @@ -1921,7 +1921,7 @@ check_inverse(optarg, &invert, &optind, argc); set_option(&options, OPT_VIANAMEOUT, &fw.ipv6.invflags, invert); - parse_interface(argv[optind-1], + parse_interface(optarg, fw.ipv6.outiface, fw.ipv6.outiface_mask); fw.nfcache |= NFC_IP6_IF_OUT; @@ -1961,7 +1961,7 @@ if (invert) exit_error(PARAMETER_PROBLEM, "unexpected ! flag before --table"); - *table = argv[optind-1]; + *table = optarg; break; case 'x': @@ -2100,7 +2100,7 @@ if (!m) exit_error(PARAMETER_PROBLEM, "Unknown arg `%s'", - argv[optind-1]); + optarg); } } invert = FALSE; diff -Naur iptables/iptables.c iptables_dev/iptables.c --- iptables/iptables.c 2004-05-24 08:08:00.804065568 +0300 +++ iptables_dev/iptables.c 2004-05-24 08:11:02.797398376 +0300 @@ -1850,10 +1850,10 @@ invert); /* Canonicalize into lower case */ - for (protocol = argv[optind-1]; *protocol; protocol++) + for (protocol = optard; *protocol; protocol++) *protocol = tolower(*protocol); - protocol = argv[optind-1]; + protocol = optarg; fw.ip.proto = parse_protocol(protocol); if (fw.ip.proto == 0 @@ -1867,7 +1867,7 @@ check_inverse(optarg, &invert, &optind, argc); set_option(&options, OPT_SOURCE, &fw.ip.invflags, invert); - shostnetworkmask = argv[optind-1]; + shostnetworkmask = optarg; fw.nfcache |= NFC_IP_SRC; break; @@ -1875,7 +1875,7 @@ check_inverse(optarg, &invert, &optind, argc); set_option(&options, OPT_DESTINATION, &fw.ip.invflags, invert); - dhostnetworkmask = argv[optind-1]; + dhostnetworkmask = optarg; fw.nfcache |= NFC_IP_DST; break; @@ -1905,7 +1905,7 @@ check_inverse(optarg, &invert, &optind, argc); set_option(&options, OPT_VIANAMEIN, &fw.ip.invflags, invert); - parse_interface(argv[optind-1], + parse_interface(optarg, fw.ip.iniface, fw.ip.iniface_mask); fw.nfcache |= NFC_IP_IF_IN; @@ -1915,7 +1915,7 @@ check_inverse(optarg, &invert, &optind, argc); set_option(&options, OPT_VIANAMEOUT, &fw.ip.invflags, invert); - parse_interface(argv[optind-1], + parse_interface(optarg, fw.ip.outiface, fw.ip.outiface_mask); fw.nfcache |= NFC_IP_IF_OUT; @@ -1962,7 +1962,7 @@ if (invert) exit_error(PARAMETER_PROBLEM, "unexpected ! flag before --table"); - *table = argv[optind-1]; + *table = optarg; break; case 'x': @@ -2100,7 +2100,7 @@ if (!m) exit_error(PARAMETER_PROBLEM, "Unknown arg `%s'", - argv[optind-1]); + optarg); } } invert = FALSE; --------------040807000602020602030700--