extensions/libxt_SECMARK.c

   1 /*
   2  * Shared library add-on to iptables to add SECMARK target support.
   3  *
   4  * Based on the MARK target.
   5  *
   6  * Copyright (C) 2006 Red Hat, Inc., James Morris <jmorris@redhat.com>
   7  */
   8 #include <stdio.h>
   9 #include <string.h>
  10 #include <stdlib.h>
  11 #include <getopt.h>
  12 #include <xtables.h>
  13 #include <linux/netfilter/xt_SECMARK.h>
  14
  15 #define PFX "SECMARK target: "
  16
  17 static void SECMARK_help(void)
  18 {
  19         printf(
  20 "SECMARK target options:\n"
  21 "  --selctx value                     Set the SELinux security context\n");
  22 }
  23
  24 static const struct option SECMARK_opts[] = {
  25         { "selctx", 1, NULL, '1' },
  26         { .name = NULL }
  27 };
  28
  29 static int SECMARK_parse(int c, char **argv, int invert, unsigned int *flags,
  30                          const void *entry, struct xt_entry_target **target)
  31 {
  32         struct xt_secmark_target_info *info =
  33                 (struct xt_secmark_target_info*)(*target)->data;
  34
  35         switch (c) {
  36         case '1':
  37                 if (*flags & SECMARK_MODE_SEL)
  38                         xtables_error(PARAMETER_PROBLEM, PFX
  39                                    "Can't specify --selctx twice");
  40                 info->mode = SECMARK_MODE_SEL;
  41
  42                 if (strlen(optarg) > SECMARK_SELCTX_MAX-1)
  43                         xtables_error(PARAMETER_PROBLEM, PFX
  44                                    "Maximum length %u exceeded by --selctx"
  45                                    " parameter (%zu)",
  46                                    SECMARK_SELCTX_MAX-1, strlen(optarg));
  47
  48                 strcpy(info->u.sel.selctx, optarg);
  49                 *flags |= SECMARK_MODE_SEL;
  50                 break;
  51         default:
  52                 return 0;
  53         }
  54
  55         return 1;
  56 }
  57
  58 static void SECMARK_check(unsigned int flags)
  59 {
  60         if (!flags)
  61                 xtables_error(PARAMETER_PROBLEM, PFX "parameter required");
  62 }
  63
  64 static void print_secmark(const struct xt_secmark_target_info *info)
  65 {
  66         switch (info->mode) {
  67         case SECMARK_MODE_SEL:
  68                 printf("selctx %s ", info->u.sel.selctx);\
  69                 break;
  70
  71         default:
  72                 xtables_error(OTHER_PROBLEM, PFX "invalid mode %hhu\n", info->mode);
  73         }
  74 }
  75
  76 static void SECMARK_print(const void *ip, const struct xt_entry_target *target,
  77                           int numeric)
  78 {
  79         const struct xt_secmark_target_info *info =
  80                 (struct xt_secmark_target_info*)(target)->data;
  81
  82         printf("SECMARK ");
  83         print_secmark(info);
  84 }
  85
  86 static void SECMARK_save(const void *ip, const struct xt_entry_target *target)
  87 {
  88         const struct xt_secmark_target_info *info =
  89                 (struct xt_secmark_target_info*)target->data;
  90
  91         printf("--");
  92         print_secmark(info);
  93 }
  94
  95 static struct xtables_target secmark_target = {
  96         .family         = AF_UNSPEC,
  97         .name           = "SECMARK",
  98         .version        = XTABLES_VERSION,
  99         .revision       = 0,
 100         .size           = XT_ALIGN(sizeof(struct xt_secmark_target_info)),
 101         .userspacesize  = XT_ALIGN(sizeof(struct xt_secmark_target_info)),
 102         .help           = SECMARK_help,
 103         .parse          = SECMARK_parse,
 104         .final_check    = SECMARK_check,
 105         .print          = SECMARK_print,
 106         .save           = SECMARK_save,
 107         .extra_opts     = SECMARK_opts,
 108 };
 109
 110 void _init(void)
 111 {
 112         xtables_register_target(&secmark_target);
 113 }