extensions/libxt_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 <xtables.h>
   8 #include <linux/netfilter/x_tables.h>
   9 #include <linux/netfilter/xt_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 CLASSIFY_help(void)
  16 {
  17         printf(
  18 "CLASSIFY target 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 }
  22
  23 static const struct option CLASSIFY_opts[] = {
  24         { "set-class", 1, NULL, '1' },
  25         { "add-mark", 0, 0, '2' },
  26         { .name = NULL }
  27 };
  28
  29 static int CLASSIFY_string_to_priority(const char *s, unsigned int *p)
  30 {
  31         unsigned int i, j;
  32
  33         if (sscanf(s, "%x:%x", &i, &j) != 2)
  34                 return 1;
  35
  36         *p = TC_H_MAKE(i<<16, j);
  37         return 0;
  38 }
  39
  40 /* Function which parses command options; returns true if it
  41    ate an option */
  42 static int
  43 CLASSIFY_parse(int c, char **argv, int invert, unsigned int *flags,
  44       const void *entry,
  45       struct xt_entry_target **target)
  46 {
  47         struct xt_classify_target_info *clinfo
  48                 = (struct xt_classify_target_info *)(*target)->data;
  49
  50         clinfo->add_mark = 0;
  51
  52         switch (c) {
  53         case '1':
  54                 if (CLASSIFY_string_to_priority(optarg, &clinfo->priority))
  55                         exit_error(PARAMETER_PROBLEM,
  56                                    "Bad class value `%s'", optarg);
  57                 if (*flags)
  58                         exit_error(PARAMETER_PROBLEM,
  59                                    "CLASSIFY: Can't specify --set-class twice");
  60                 *flags = 1;
  61                 break;
  62
  63         case '2':
  64                 clinfo->add_mark = 1;
  65                 break;
  66
  67         default:
  68                 return 0;
  69         }
  70
  71         return 1;
  72 }
  73
  74 static void
  75 CLASSIFY_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 CLASSIFY_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 CLASSIFY_print(const void *ip,
  91       const struct xt_entry_target *target,
  92       int numeric)
  93 {
  94         const struct xt_classify_target_info *clinfo =
  95                 (const struct xt_classify_target_info *)target->data;
  96         printf("CLASSIFY set ");
  97         CLASSIFY_print_class(clinfo->priority, numeric);
  98
  99         if (clinfo->add_mark)
 100                printf ("add-mark ");
 101 }
 102
 103 /* Saves the union ipt_targinfo in parsable form to stdout. */
 104 static void
 105 CLASSIFY_save(const void *ip, const struct xt_entry_target *target)
 106 {
 107         const struct xt_classify_target_info *clinfo =
 108                 (const struct xt_classify_target_info *)target->data;
 109
 110         printf("--set-class %.4x:%.4x ",
 111                TC_H_MAJ(clinfo->priority)>>16, TC_H_MIN(clinfo->priority));
 112
 113         if (clinfo->add_mark)
 114                printf("--add-mark ");
 115 }
 116
 117 static struct xtables_target classify_target = {
 118         .family         = AF_UNSPEC,
 119         .name           = "CLASSIFY",
 120         .version        = XTABLES_VERSION,
 121         .size           = XT_ALIGN(sizeof(struct xt_classify_target_info)),
 122         .userspacesize  = XT_ALIGN(sizeof(struct xt_classify_target_info)),
 123         .help           = CLASSIFY_help,
 124         .parse          = CLASSIFY_parse,
 125         .final_check    = CLASSIFY_final_check,
 126         .print          = CLASSIFY_print,
 127         .save           = CLASSIFY_save,
 128         .extra_opts     = CLASSIFY_opts,
 129 };
 130
 131 void _init(void)
 132 {
 133         xtables_register_target(&classify_target);
 134 }