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      1 /* Shared library add-on to iptables to add CLASSIFY target support. */
      2 #include <stdio.h>
      3 #include <string.h>
      4 #include <stdlib.h>
      5 #include <getopt.h>
      6 
      7 #include <iptables.h>
      8 #include <linux/netfilter_ipv4/ip_tables.h>
      9 #include <linux/netfilter_ipv4/ipt_CLASSIFY.h>
     10 #include <linux/types.h>
     11 #include <linux/pkt_sched.h>
     12 
     13 /* Function which prints out usage message. */
     14 static void
     15 help(void)
     16 {
     17 	printf(
     18 "CLASSIFY target v%s options:\n"
     19 "  --set-class [MAJOR:MINOR]    Set skb->priority value\n"
     20 "\n",
     21 IPTABLES_VERSION);
     22 }
     23 
     24 static struct option opts[] = {
     25 	{ "set-class", 1, 0, '1' },
     26 	{ 0 }
     27 };
     28 
     29 /* Initialize the target. */
     30 static void
     31 init(struct ipt_entry_target *t, unsigned int *nfcache)
     32 {
     33 }
     34 
     35 int string_to_priority(const char *s, unsigned int *p)
     36 {
     37 	unsigned int i, j;
     38 
     39 	if (sscanf(s, "%x:%x", &i, &j) != 2)
     40 		return 1;
     41 
     42 	*p = TC_H_MAKE(i<<16, j);
     43 	return 0;
     44 }
     45 
     46 /* Function which parses command options; returns true if it
     47    ate an option */
     48 static int
     49 parse(int c, char **argv, int invert, unsigned int *flags,
     50       const struct ipt_entry *entry,
     51       struct ipt_entry_target **target)
     52 {
     53 	struct ipt_classify_target_info *clinfo
     54 		= (struct ipt_classify_target_info *)(*target)->data;
     55 
     56 	switch (c) {
     57 	case '1':
     58 		if (string_to_priority(optarg, &clinfo->priority))
     59 			exit_error(PARAMETER_PROBLEM,
     60 				   "Bad class value `%s'", optarg);
     61 		if (*flags)
     62 			exit_error(PARAMETER_PROBLEM,
     63 			           "CLASSIFY: Can't specify --set-class twice");
     64 		*flags = 1;
     65 		break;
     66 
     67 	default:
     68 		return 0;
     69 	}
     70 
     71 	return 1;
     72 }
     73 
     74 static void
     75 final_check(unsigned int flags)
     76 {
     77 	if (!flags)
     78 		exit_error(PARAMETER_PROBLEM,
     79 		           "CLASSIFY: Parameter --set-class is required");
     80 }
     81 
     82 static void
     83 print_class(unsigned int priority, int numeric)
     84 {
     85 	printf("%x:%x ", TC_H_MAJ(priority)>>16, TC_H_MIN(priority));
     86 }
     87 
     88 /* Prints out the targinfo. */
     89 static void
     90 print(const struct ipt_ip *ip,
     91       const struct ipt_entry_target *target,
     92       int numeric)
     93 {
     94 	const struct ipt_classify_target_info *clinfo =
     95 		(const struct ipt_classify_target_info *)target->data;
     96 	printf("CLASSIFY set ");
     97 	print_class(clinfo->priority, numeric);
     98 }
     99 
    100 /* Saves the union ipt_targinfo in parsable form to stdout. */
    101 static void
    102 save(const struct ipt_ip *ip, const struct ipt_entry_target *target)
    103 {
    104 	const struct ipt_classify_target_info *clinfo =
    105 		(const struct ipt_classify_target_info *)target->data;
    106 
    107 	printf("--set-class %.4x:%.4x ",
    108 	       TC_H_MAJ(clinfo->priority)>>16, TC_H_MIN(clinfo->priority));
    109 }
    110 
    111 static struct iptables_target classify = {
    112 	.next		= NULL,
    113 	.name		= "CLASSIFY",
    114 	.version	= IPTABLES_VERSION,
    115 	.size		= IPT_ALIGN(sizeof(struct ipt_classify_target_info)),
    116 	.userspacesize	= IPT_ALIGN(sizeof(struct ipt_classify_target_info)),
    117 	.help		= &help,
    118 	.init		= &init,
    119 	.parse		= &parse,
    120 	.final_check	= &final_check,
    121 	.print		= &print,
    122 	.save		= &save,
    123 	.extra_opts	= opts
    124 };
    125 
    126 void ipt_CLASSIFY_init(void)
    127 {
    128 	register_target(&classify);
    129 }
    130