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 "  --add-mark                   Add value of skb->mark to skb->priority (PlanetLab specific)\n"
  21 "\n",
  22 IPTABLES_VERSION);
  23 }
  24
  25 static struct option opts[] = {
  26         { "set-class", 1, 0, '1' },
  27         { "add-mark", 0, 0, '2' },
  28         { 0 }
  29 };
  30
  31 /* Initialize the target. */
  32 static void
  33 init(struct ipt_entry_target *t, unsigned int *nfcache)
  34 {
  35 }
  36
  37 int string_to_priority(const char *s, unsigned int *p)
  38 {
  39         unsigned int i, j;
  40
  41         if (sscanf(s, "%x:%x", &i, &j) != 2)
  42                 return 1;
  43
  44         *p = TC_H_MAKE(i<<16, j);
  45         return 0;
  46 }
  47
  48 /* Function which parses command options; returns true if it
  49    ate an option */
  50 static int
  51 parse(int c, char **argv, int invert, unsigned int *flags,
  52       const struct ipt_entry *entry,
  53       struct ipt_entry_target **target)
  54 {
  55         struct ipt_classify_target_info *clinfo
  56                 = (struct ipt_classify_target_info *)(*target)->data;
  57
  58         clinfo->add_mark = 0;
  59
  60         switch (c) {
  61         case '1':
  62                 if (string_to_priority(optarg, &clinfo->priority))
  63                         exit_error(PARAMETER_PROBLEM,
  64                                    "Bad class value `%s'", optarg);
  65                 if (*flags)
  66                         exit_error(PARAMETER_PROBLEM,
  67                                    "CLASSIFY: Can't specify --set-class twice");
  68                 *flags = 1;
  69                 break;
  70
  71         case '2':
  72                 clinfo->add_mark = 1;
  73                 break;
  74
  75         default:
  76                 return 0;
  77         }
  78
  79         return 1;
  80 }
  81
  82 static void
  83 final_check(unsigned int flags)
  84 {
  85         if (!flags)
  86                 exit_error(PARAMETER_PROBLEM,
  87                            "CLASSIFY: Parameter --set-class is required");
  88 }
  89
  90 static void
  91 print_class(unsigned int priority, int numeric)
  92 {
  93         printf("%x:%x ", TC_H_MAJ(priority)>>16, TC_H_MIN(priority));
  94 }
  95
  96 /* Prints out the targinfo. */
  97 static void
  98 print(const struct ipt_ip *ip,
  99       const struct ipt_entry_target *target,
 100       int numeric)
 101 {
 102         const struct ipt_classify_target_info *clinfo =
 103                 (const struct ipt_classify_target_info *)target->data;
 104         printf("CLASSIFY set ");
 105         print_class(clinfo->priority, numeric);
 106         if (clinfo->add_mark)
 107                printf ("add-mark ");
 108 }
 109
 110 /* Saves the union ipt_targinfo in parsable form to stdout. */
 111 static void
 112 save(const struct ipt_ip *ip, const struct ipt_entry_target *target)
 113 {
 114         const struct ipt_classify_target_info *clinfo =
 115                 (const struct ipt_classify_target_info *)target->data;
 116
 117         printf("--set-class %.4x:%.4x ",
 118                TC_H_MAJ(clinfo->priority)>>16, TC_H_MIN(clinfo->priority));
 119
 120         if (clinfo->add_mark)
 121                printf("--add-mark ");
 122 }
 123
 124 static struct iptables_target classify = {
 125         .next           = NULL,
 126         .name           = "CLASSIFY",
 127         .version        = IPTABLES_VERSION,
 128         .size           = IPT_ALIGN(sizeof(struct ipt_classify_target_info)),
 129         .userspacesize  = IPT_ALIGN(sizeof(struct ipt_classify_target_info)),
 130         .help           = &help,
 131         .init           = &init,
 132         .parse          = &parse,
 133         .final_check    = &final_check,
 134         .print          = &print,
 135         .save           = &save,
 136         .extra_opts     = opts
 137 };
 138
 139 void _init(void)
 140 {
 141         register_target(&classify);
 142 }