extensions/libxt_cluster.c

   1 /*
   2  * (C) 2009 by Pablo Neira Ayuso <pablo@netfilter.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8 #include <stdio.h>
   9 #include <string.h>
  10 #include <stdlib.h>
  11 #include <getopt.h>
  12 #include <stddef.h>
  13
  14 #include <xtables.h>
  15 #include <linux/netfilter/x_tables.h>
  16 #include <linux/netfilter/xt_cluster.h>
  17
  18 /* hack to keep for check */
  19 static unsigned int total_nodes;
  20 static unsigned int node_mask;
  21
  22 static void
  23 cluster_help(void)
  24 {
  25         printf(
  26 "cluster match options:\n"
  27 "  --cluster-total-nodes <num>          Set number of total nodes in cluster\n"
  28 "  [!] --cluster-local-node <num>       Set the local node number\n"
  29 "  [!] --cluster-local-nodemask <num>   Set the local node mask\n"
  30 "  --cluster-hash-seed <num>            Set seed value of the Jenkins hash\n");
  31 }
  32
  33 enum {
  34         CLUSTER_OPT_TOTAL_NODES,
  35         CLUSTER_OPT_LOCAL_NODE,
  36         CLUSTER_OPT_NODE_MASK,
  37         CLUSTER_OPT_HASH_SEED,
  38 };
  39
  40 static const struct option cluster_opts[] = {
  41         { "cluster-total-nodes",        1, NULL, CLUSTER_OPT_TOTAL_NODES },
  42         { "cluster-local-node",         1, NULL, CLUSTER_OPT_LOCAL_NODE },
  43         { "cluster-local-nodemask",     1, NULL, CLUSTER_OPT_NODE_MASK },
  44         { "cluster-hash-seed",          1, NULL, CLUSTER_OPT_HASH_SEED },
  45         { .name = NULL }
  46 };
  47
  48 static int
  49 cluster_parse(int c, char **argv, int invert, unsigned int *flags,
  50               const void *entry, struct xt_entry_match **match)
  51 {
  52         struct xt_cluster_match_info *info = (void *)(*match)->data;
  53         unsigned int num;
  54
  55         switch (c) {
  56         case CLUSTER_OPT_TOTAL_NODES:
  57                 if (*flags & (1 << c)) {
  58                         xtables_error(PARAMETER_PROBLEM,
  59                                       "Can only specify "
  60                                       "`--cluster-total-nodes' once");
  61                 }
  62                 if (!xtables_strtoui(optarg, NULL, &num, 1,
  63                                      XT_CLUSTER_NODES_MAX)) {
  64                         xtables_error(PARAMETER_PROBLEM,
  65                                       "Unable to parse `%s' in "
  66                                       "`--cluster-total-nodes'", optarg);
  67                 }
  68                 total_nodes = num;
  69                 info->total_nodes = total_nodes = num;
  70                 *flags |= 1 << c;
  71                 break;
  72         case CLUSTER_OPT_LOCAL_NODE:
  73                 if (*flags & (1 << c)) {
  74                         xtables_error(PARAMETER_PROBLEM,
  75                                       "Can only specify "
  76                                       "`--cluster-local-node' once");
  77                 }
  78                 if (*flags & (1 << CLUSTER_OPT_NODE_MASK)) {
  79                         xtables_error(PARAMETER_PROBLEM, "You cannot use "
  80                                       "`--cluster-local-nodemask' and "
  81                                       "`--cluster-local-node'");
  82                 }
  83                 xtables_check_inverse(optarg, &invert, &optind, 0, argv);
  84
  85                 if (!xtables_strtoui(optarg, NULL, &num, 1,
  86                                      XT_CLUSTER_NODES_MAX)) {
  87                         xtables_error(PARAMETER_PROBLEM,
  88                                       "Unable to parse `%s' in "
  89                                       "`--cluster-local-node'", optarg);
  90                 }
  91                 if (invert)
  92                         info->flags |= (1 << XT_CLUSTER_F_INV);
  93
  94                 info->node_mask = node_mask = (1 << (num - 1));
  95                 *flags |= 1 << c;
  96                 break;
  97         case CLUSTER_OPT_NODE_MASK:
  98                 if (*flags & (1 << c)) {
  99                         xtables_error(PARAMETER_PROBLEM,
 100                                       "Can only specify "
 101                                       "`--cluster-local-node' once");
 102                 }
 103                 if (*flags & (1 << CLUSTER_OPT_LOCAL_NODE)) {
 104                         xtables_error(PARAMETER_PROBLEM, "You cannot use "
 105                                       "`--cluster-local-nodemask' and "
 106                                       "`--cluster-local-node'");
 107                 }
 108                 xtables_check_inverse(optarg, &invert, &optind, 0, argv);
 109
 110                 if (!xtables_strtoui(optarg, NULL, &num, 1,
 111                                      XT_CLUSTER_NODES_MAX)) {
 112                         xtables_error(PARAMETER_PROBLEM,
 113                                       "Unable to parse `%s' in "
 114                                       "`--cluster-local-node'", optarg);
 115                 }
 116                 if (invert)
 117                         info->flags |= (1 << XT_CLUSTER_F_INV);
 118
 119                 info->node_mask = node_mask = num;
 120                 *flags |= 1 << c;
 121                 break;
 122
 123         case CLUSTER_OPT_HASH_SEED:
 124                 if (*flags & (1 << c)) {
 125                         xtables_error(PARAMETER_PROBLEM,
 126                                       "Can only specify "
 127                                       "`--cluster-hash-seed' once");
 128                 }
 129                 if (!xtables_strtoui(optarg, NULL, &num, 0, UINT32_MAX)) {
 130                         xtables_error(PARAMETER_PROBLEM,
 131                                       "Unable to parse `%s'", optarg);
 132                 }
 133                 info->hash_seed = num;
 134                 *flags |= 1 << c;
 135                 break;
 136         default:
 137                 return 0;
 138         }
 139
 140         return 1;
 141 }
 142
 143 static void
 144 cluster_check(unsigned int flags)
 145 {
 146         if ((flags & ((1 << CLUSTER_OPT_TOTAL_NODES) |
 147                       (1 << CLUSTER_OPT_LOCAL_NODE) |
 148                       (1 << CLUSTER_OPT_HASH_SEED)))
 149                 == ((1 << CLUSTER_OPT_TOTAL_NODES) |
 150                     (1 << CLUSTER_OPT_LOCAL_NODE) |
 151                     (1 << CLUSTER_OPT_HASH_SEED))) {
 152                 if (node_mask >= (1ULL << total_nodes)) {
 153                         xtables_error(PARAMETER_PROBLEM,
 154                                       "cluster match: "
 155                                       "`--cluster-local-node' "
 156                                       "must be <= `--cluster-total-nodes'");
 157                 }
 158                 return;
 159         }
 160         if ((flags & ((1 << CLUSTER_OPT_TOTAL_NODES) |
 161                       (1 << CLUSTER_OPT_NODE_MASK) |
 162                       (1 << CLUSTER_OPT_HASH_SEED)))
 163                 == ((1 << CLUSTER_OPT_TOTAL_NODES) |
 164                     (1 << CLUSTER_OPT_NODE_MASK) |
 165                     (1 << CLUSTER_OPT_HASH_SEED))) {
 166                 if (node_mask >= (1ULL << total_nodes)) {
 167                         xtables_error(PARAMETER_PROBLEM,
 168                                       "cluster match: "
 169                                       "`--cluster-local-nodemask' too big "
 170                                       "for `--cluster-total-nodes'");
 171                 }
 172                 return;
 173         }
 174         if (!(flags & (1 << CLUSTER_OPT_TOTAL_NODES))) {
 175                 xtables_error(PARAMETER_PROBLEM,
 176                               "cluster match: `--cluster-total-nodes' "
 177                               "is missing");
 178         }
 179         if (!(flags & (1 << CLUSTER_OPT_HASH_SEED))) {
 180                 xtables_error(PARAMETER_PROBLEM,
 181                               "cluster match: `--cluster-hash-seed' "
 182                               "is missing");
 183         }
 184         if (!(flags & ((1 << (CLUSTER_OPT_LOCAL_NODE) |
 185                        (1 << (CLUSTER_OPT_NODE_MASK)))))) {
 186                 xtables_error(PARAMETER_PROBLEM,
 187                               "cluster match: `--cluster-local-node' or"
 188                               "`--cluster-local-nodemask' is missing");
 189         }
 190 }
 191
 192 static void
 193 cluster_print(const void *ip, const struct xt_entry_match *match, int numeric)
 194 {
 195         const struct xt_cluster_match_info *info = (void *)match->data;
 196
 197         printf("cluster ");
 198         if (info->flags & XT_CLUSTER_F_INV)
 199                 printf("!node_mask=0x%08x ", info->node_mask);
 200         else
 201                 printf("node_mask=0x%08x ", info->node_mask);
 202
 203         printf("total_nodes=%u hash_seed=0x%08x ",
 204                 info->total_nodes, info->hash_seed);
 205 }
 206
 207 static void
 208 cluster_save(const void *ip, const struct xt_entry_match *match)
 209 {
 210         const struct xt_cluster_match_info *info = (void *)match->data;
 211
 212         if (info->flags & XT_CLUSTER_F_INV)
 213                 printf("! --cluster-local-nodemask 0x%08x ", info->node_mask);
 214         else
 215                 printf("--cluster-local-nodemask 0x%08x ", info->node_mask);
 216
 217         printf("--cluster-total-nodes %u --cluster-hash-seed 0x%08x ",
 218                 info->total_nodes, info->hash_seed);
 219 }
 220
 221 static struct xtables_match cluster_mt_reg = {
 222         .family         = NFPROTO_UNSPEC,
 223         .name           = "cluster",
 224         .version        = XTABLES_VERSION,
 225         .size           = XT_ALIGN(sizeof(struct xt_cluster_match_info)),
 226         .userspacesize  = XT_ALIGN(sizeof(struct xt_cluster_match_info)),
 227         .help           = cluster_help,
 228         .parse          = cluster_parse,
 229         .final_check    = cluster_check,
 230         .print          = cluster_print,
 231         .save           = cluster_save,
 232         .extra_opts     = cluster_opts,
 233 };
 234
 235 void _init(void)
 236 {
 237         xtables_register_match(&cluster_mt_reg);
 238 }