extensions/libipt_ULOG.c

   1 /* Shared library add-on to iptables to add ULOG support.
   2  *
   3  * (C) 2000 by Harald Welte <laforge@gnumonks.org>
   4  *
   5  * multipart netlink support based on ideas by Sebastian Zander
   6  *                                              <zander@fokus.gmd.de>
   7  *
   8  * This software is released under the terms of GNU GPL
   9  *
  10  * libipt_ULOG.c,v 1.7 2001/01/30 11:55:02 laforge Exp
  11  */
  12 #include <stdio.h>
  13 #include <netdb.h>
  14 #include <string.h>
  15 #include <stdlib.h>
  16 #include <syslog.h>
  17 #include <getopt.h>
  18 #include <iptables.h>
  19 #include <linux/netfilter_ipv4/ip_tables.h>
  20 /* For 64bit kernel / 32bit userspace */
  21 #include "../include/linux/netfilter_ipv4/ipt_ULOG.h"
  22
  23
  24 static void print_groups(unsigned int gmask)
  25 {
  26         int b;
  27         unsigned int test;
  28
  29         for (b = 31; b >= 0; b--) {
  30                 test = (1 << b);
  31                 if (gmask & test)
  32                         printf("%d ", b + 1);
  33         }
  34 }
  35
  36 /* Function which prints out usage message. */
  37 static void ULOG_help(void)
  38 {
  39         printf("ULOG target options:\n"
  40                " --ulog-nlgroup nlgroup         NETLINK group used for logging\n"
  41                " --ulog-cprange size            Bytes of each packet to be passed\n"
  42                " --ulog-qthreshold              Threshold of in-kernel queue\n"
  43                " --ulog-prefix prefix           Prefix log messages with this prefix.\n");
  44 }
  45
  46 static const struct option ULOG_opts[] = {
  47         {"ulog-nlgroup", 1, NULL, '!'},
  48         {"ulog-prefix", 1, NULL, '#'},
  49         {"ulog-cprange", 1, NULL, 'A'},
  50         {"ulog-qthreshold", 1, NULL, 'B'},
  51         { .name = NULL }
  52 };
  53
  54 /* Initialize the target. */
  55 static void ULOG_init(struct xt_entry_target *t)
  56 {
  57         struct ipt_ulog_info *loginfo = (struct ipt_ulog_info *) t->data;
  58
  59         loginfo->nl_group = ULOG_DEFAULT_NLGROUP;
  60         loginfo->qthreshold = ULOG_DEFAULT_QTHRESHOLD;
  61
  62 }
  63
  64 #define IPT_LOG_OPT_NLGROUP 0x01
  65 #define IPT_LOG_OPT_PREFIX 0x02
  66 #define IPT_LOG_OPT_CPRANGE 0x04
  67 #define IPT_LOG_OPT_QTHRESHOLD 0x08
  68
  69 /* Function which parses command options; returns true if it
  70    ate an option */
  71 static int ULOG_parse(int c, char **argv, int invert, unsigned int *flags,
  72                       const void *entry, struct xt_entry_target **target)
  73 {
  74         struct ipt_ulog_info *loginfo =
  75             (struct ipt_ulog_info *) (*target)->data;
  76         int group_d;
  77
  78         switch (c) {
  79         case '!':
  80                 if (*flags & IPT_LOG_OPT_NLGROUP)
  81                         exit_error(PARAMETER_PROBLEM,
  82                                    "Can't specify --ulog-nlgroup twice");
  83
  84                 if (check_inverse(optarg, &invert, NULL, 0))
  85                         exit_error(PARAMETER_PROBLEM,
  86                                    "Unexpected `!' after --ulog-nlgroup");
  87                 group_d = atoi(optarg);
  88                 if (group_d > 32 || group_d < 1)
  89                         exit_error(PARAMETER_PROBLEM,
  90                                    "--ulog-nlgroup has to be between 1 and 32");
  91
  92                 loginfo->nl_group = (1 << (group_d - 1));
  93
  94                 *flags |= IPT_LOG_OPT_NLGROUP;
  95                 break;
  96
  97         case '#':
  98                 if (*flags & IPT_LOG_OPT_PREFIX)
  99                         exit_error(PARAMETER_PROBLEM,
 100                                    "Can't specify --ulog-prefix twice");
 101
 102                 if (check_inverse(optarg, &invert, NULL, 0))
 103                         exit_error(PARAMETER_PROBLEM,
 104                                    "Unexpected `!' after --ulog-prefix");
 105
 106                 if (strlen(optarg) > sizeof(loginfo->prefix) - 1)
 107                         exit_error(PARAMETER_PROBLEM,
 108                                    "Maximum prefix length %u for --ulog-prefix",
 109                                    (unsigned int)sizeof(loginfo->prefix) - 1);
 110
 111                 if (strlen(optarg) == 0)
 112                         exit_error(PARAMETER_PROBLEM,
 113                                    "No prefix specified for --ulog-prefix");
 114
 115                 if (strlen(optarg) != strlen(strtok(optarg, "\n")))
 116                         exit_error(PARAMETER_PROBLEM,
 117                                    "Newlines not allowed in --ulog-prefix");
 118
 119                 strcpy(loginfo->prefix, optarg);
 120                 *flags |= IPT_LOG_OPT_PREFIX;
 121                 break;
 122         case 'A':
 123                 if (*flags & IPT_LOG_OPT_CPRANGE)
 124                         exit_error(PARAMETER_PROBLEM,
 125                                    "Can't specify --ulog-cprange twice");
 126                 if (atoi(optarg) < 0)
 127                         exit_error(PARAMETER_PROBLEM,
 128                                    "Negative copy range?");
 129                 loginfo->copy_range = atoi(optarg);
 130                 *flags |= IPT_LOG_OPT_CPRANGE;
 131                 break;
 132         case 'B':
 133                 if (*flags & IPT_LOG_OPT_QTHRESHOLD)
 134                         exit_error(PARAMETER_PROBLEM,
 135                                    "Can't specify --ulog-qthreshold twice");
 136                 if (atoi(optarg) < 1)
 137                         exit_error(PARAMETER_PROBLEM,
 138                                    "Negative or zero queue threshold ?");
 139                 if (atoi(optarg) > ULOG_MAX_QLEN)
 140                         exit_error(PARAMETER_PROBLEM,
 141                                    "Maximum queue length exceeded");
 142                 loginfo->qthreshold = atoi(optarg);
 143                 *flags |= IPT_LOG_OPT_QTHRESHOLD;
 144                 break;
 145         default:
 146                 return 0;
 147         }
 148         return 1;
 149 }
 150
 151 /* Saves the union ipt_targinfo in parsable form to stdout. */
 152 static void ULOG_save(const void *ip, const struct xt_entry_target *target)
 153 {
 154         const struct ipt_ulog_info *loginfo
 155             = (const struct ipt_ulog_info *) target->data;
 156
 157         if (strcmp(loginfo->prefix, "") != 0) {
 158                 fputs("--ulog-prefix ", stdout);
 159                 save_string(loginfo->prefix);
 160         }
 161
 162         if (loginfo->nl_group != ULOG_DEFAULT_NLGROUP) {
 163                 printf("--ulog-nlgroup ");
 164                 print_groups(loginfo->nl_group);
 165         }
 166         if (loginfo->copy_range)
 167                 printf("--ulog-cprange %u ", (unsigned int)loginfo->copy_range);
 168
 169         if (loginfo->qthreshold != ULOG_DEFAULT_QTHRESHOLD)
 170                 printf("--ulog-qthreshold %u ", (unsigned int)loginfo->qthreshold);
 171 }
 172
 173 /* Prints out the targinfo. */
 174 static void ULOG_print(const void *ip, const struct xt_entry_target *target,
 175                        int numeric)
 176 {
 177         const struct ipt_ulog_info *loginfo
 178             = (const struct ipt_ulog_info *) target->data;
 179
 180         printf("ULOG ");
 181         printf("copy_range %u nlgroup ", (unsigned int)loginfo->copy_range);
 182         print_groups(loginfo->nl_group);
 183         if (strcmp(loginfo->prefix, "") != 0)
 184                 printf("prefix `%s' ", loginfo->prefix);
 185         printf("queue_threshold %u ", (unsigned int)loginfo->qthreshold);
 186 }
 187
 188 static struct xtables_target ulog_tg_reg = {
 189         .name           = "ULOG",
 190         .version        = XTABLES_VERSION,
 191         .family         = PF_INET,
 192         .size           = XT_ALIGN(sizeof(struct ipt_ulog_info)),
 193         .userspacesize  = XT_ALIGN(sizeof(struct ipt_ulog_info)),
 194         .help           = ULOG_help,
 195         .init           = ULOG_init,
 196         .parse          = ULOG_parse,
 197         .print          = ULOG_print,
 198         .save           = ULOG_save,
 199         .extra_opts     = ULOG_opts,
 200 };
 201
 202 void _init(void)
 203 {
 204         xtables_register_target(&ulog_tg_reg);
 205 }