extensions/libipt_CLASSIFY.c

   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 _init(void)
 127 {
 128         register_target(&classify);
 129 }