release/src/router/ebtables/extensions/ebt_nflog.c

   1 /* ebt_nflog
   2  *
   3  * Authors:
   4  * Peter Warasin <peter@endian.com>
   5  *
   6  *  February, 2008
   7  *
   8  * Based on:
   9  *  ebt_ulog.c, (C) 2004, Bart De Schuymer <bdschuym@pandora.be>
  10  *  libxt_NFLOG.c
  11  */
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <getopt.h>
  17 #include "../include/ebtables_u.h"
  18 #include <linux/netfilter_bridge/ebt_nflog.h>
  19
  20 enum {
  21         NFLOG_GROUP = 0x1,
  22         NFLOG_PREFIX = 0x2,
  23         NFLOG_RANGE = 0x4,
  24         NFLOG_THRESHOLD = 0x8,
  25         NFLOG_NFLOG = 0x16,
  26 };
  27
  28 static struct option nflog_opts[] = {
  29         {"nflog-group", required_argument, NULL, NFLOG_GROUP},
  30         {"nflog-prefix", required_argument, NULL, NFLOG_PREFIX},
  31         {"nflog-range", required_argument, NULL, NFLOG_RANGE},
  32         {"nflog-threshold", required_argument, NULL, NFLOG_THRESHOLD},
  33         {"nflog", no_argument, NULL, NFLOG_NFLOG},
  34         {.name = NULL}
  35 };
  36
  37 static void nflog_help()
  38 {
  39         printf("nflog options:\n"
  40                "--nflog               : use the default nflog parameters\n"
  41                "--nflog-prefix prefix : Prefix string for log message\n"
  42                "--nflog-group group   : NETLINK group used for logging\n"
  43                "--nflog-range range   : Number of byte to copy\n"
  44                "--nflog-threshold     : Message threshold of"
  45                "in-kernel queue\n");
  46 }
  47
  48 static void init(struct ebt_entry_watcher *watcher)
  49 {
  50         struct ebt_nflog_info *info = (struct ebt_nflog_info *)watcher->data;
  51
  52         info->prefix[0] = '\0';
  53         info->group = EBT_NFLOG_DEFAULT_GROUP;
  54         info->threshold = EBT_NFLOG_DEFAULT_THRESHOLD;
  55 }
  56
  57 static int nflog_parse(int c, char **argv, int argc,
  58                        const struct ebt_u_entry *entry, unsigned int *flags,
  59                        struct ebt_entry_watcher **watcher)
  60 {
  61         struct ebt_nflog_info *info;
  62         unsigned int i;
  63         char *end;
  64
  65         info = (struct ebt_nflog_info *)(*watcher)->data;
  66         switch (c) {
  67         case NFLOG_PREFIX:
  68                 if (ebt_check_inverse2(optarg))
  69                         goto inverse_invalid;
  70                 ebt_check_option2(flags, NFLOG_PREFIX);
  71                 if (strlen(optarg) > EBT_NFLOG_PREFIX_SIZE - 1)
  72                         ebt_print_error("Prefix too long for nflog-prefix");
  73                 strcpy(info->prefix, optarg);
  74                 break;
  75
  76         case NFLOG_GROUP:
  77                 if (ebt_check_inverse2(optarg))
  78                         goto inverse_invalid;
  79                 ebt_check_option2(flags, NFLOG_GROUP);
  80                 i = strtoul(optarg, &end, 10);
  81                 if (*end != '\0')
  82                         ebt_print_error2("--nflog-group must be a number!");
  83                 info->group = i;
  84                 break;
  85
  86         case NFLOG_RANGE:
  87                 if (ebt_check_inverse2(optarg))
  88                         goto inverse_invalid;
  89                 ebt_check_option2(flags, NFLOG_RANGE);
  90                 i = strtoul(optarg, &end, 10);
  91                 if (*end != '\0')
  92                         ebt_print_error2("--nflog-range must be a number!");
  93                 info->len = i;
  94                 break;
  95
  96         case NFLOG_THRESHOLD:
  97                 if (ebt_check_inverse2(optarg))
  98                         goto inverse_invalid;
  99                 ebt_check_option2(flags, NFLOG_THRESHOLD);
 100                 i = strtoul(optarg, &end, 10);
 101                 if (*end != '\0')
 102                         ebt_print_error2("--nflog-threshold must be a number!");
 103                 info->threshold = i;
 104                 break;
 105         case NFLOG_NFLOG:
 106                 if (ebt_check_inverse(optarg))
 107                         goto inverse_invalid;
 108                 ebt_check_option2(flags, NFLOG_NFLOG);
 109                 break;
 110
 111         default:
 112                 return 0;
 113         }
 114         return 1;
 115
 116  inverse_invalid:
 117         ebt_print_error("The use of '!' makes no sense for the nflog watcher");
 118         return 1;
 119 }
 120
 121 static void nflog_final_check(const struct ebt_u_entry *entry,
 122                               const struct ebt_entry_watcher *watcher,
 123                               const char *name, unsigned int hookmask,
 124                               unsigned int time)
 125 {
 126 }
 127
 128 static void nflog_print(const struct ebt_u_entry *entry,
 129                         const struct ebt_entry_watcher *watcher)
 130 {
 131         struct ebt_nflog_info *info = (struct ebt_nflog_info *)watcher->data;
 132
 133         if (info->prefix[0] != '\0')
 134                 printf("--nflog-prefix \"%s\"", info->prefix);
 135         if (info->group)
 136                 printf("--nflog-group %d ", info->group);
 137         if (info->len)
 138                 printf("--nflog-range %d", info->len);
 139         if (info->threshold != EBT_NFLOG_DEFAULT_THRESHOLD)
 140                 printf(" --nflog-threshold %d ", info->threshold);
 141 }
 142
 143 static int nflog_compare(const struct ebt_entry_watcher *w1,
 144                          const struct ebt_entry_watcher *w2)
 145 {
 146         struct ebt_nflog_info *info1 = (struct ebt_nflog_info *)w1->data;
 147         struct ebt_nflog_info *info2 = (struct ebt_nflog_info *)w2->data;
 148
 149         if (info1->group != info2->group ||
 150             info1->len != info2->len ||
 151             info1->threshold != info2->threshold ||
 152             strcmp(info1->prefix, info2->prefix))
 153                 return 0;
 154         return 1;
 155 }
 156
 157 static struct ebt_u_watcher nflog_watcher = {
 158         .name = "nflog",
 159         .size = sizeof(struct ebt_nflog_info),
 160         .help = nflog_help,
 161         .init = init,
 162         .parse = nflog_parse,
 163         .final_check = nflog_final_check,
 164         .print = nflog_print,
 165         .compare = nflog_compare,
 166         .extra_ops = nflog_opts,
 167 };
 168
 169 void _init(void)
 170 {
 171         ebt_register_watcher(&nflog_watcher);
 172 }