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-rw-r--r--extensions/libipt_DNAT.c275
1 files changed, 261 insertions, 14 deletions
diff --git a/extensions/libipt_DNAT.c b/extensions/libipt_DNAT.c
index a14d16f7..b89d3ca5 100644
--- a/extensions/libipt_DNAT.c
+++ b/extensions/libipt_DNAT.c
@@ -35,6 +35,15 @@ static void DNAT_help(void)
"[--random] [--persistent]\n");
}
+static void DNAT_help_v2(void)
+{
+ printf(
+"DNAT target options:\n"
+" --to-destination [<ipaddr>[-<ipaddr>]][:port[-port[/port]]]\n"
+" Address to map destination to.\n"
+"[--random] [--persistent]\n");
+}
+
static const struct xt_option_entry DNAT_opts[] = {
{.name = "to-destination", .id = O_TO_DEST, .type = XTTYPE_STRING,
.flags = XTOPT_MAND | XTOPT_MULTI},
@@ -287,22 +296,260 @@ static int DNAT_xlate(struct xt_xlate *xl,
return 1;
}
-static struct xtables_target dnat_tg_reg = {
- .name = "DNAT",
- .version = XTABLES_VERSION,
- .family = NFPROTO_IPV4,
- .size = XT_ALIGN(sizeof(struct nf_nat_ipv4_multi_range_compat)),
- .userspacesize = XT_ALIGN(sizeof(struct nf_nat_ipv4_multi_range_compat)),
- .help = DNAT_help,
- .x6_parse = DNAT_parse,
- .x6_fcheck = DNAT_fcheck,
- .print = DNAT_print,
- .save = DNAT_save,
- .x6_options = DNAT_opts,
- .xlate = DNAT_xlate,
+static void
+parse_to_v2(const char *orig_arg, int portok, struct nf_nat_range2 *range)
+{
+ char *arg, *colon, *dash, *error;
+ const struct in_addr *ip;
+
+ arg = strdup(orig_arg);
+ if (arg == NULL)
+ xtables_error(RESOURCE_PROBLEM, "strdup");
+
+ colon = strchr(arg, ':');
+ if (colon) {
+ int port;
+
+ if (!portok)
+ xtables_error(PARAMETER_PROBLEM,
+ "Need TCP, UDP, SCTP or DCCP with port specification");
+
+ range->flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
+
+ port = atoi(colon+1);
+ if (port <= 0 || port > 65535)
+ xtables_error(PARAMETER_PROBLEM,
+ "Port `%s' not valid\n", colon+1);
+
+ error = strchr(colon+1, ':');
+ if (error)
+ xtables_error(PARAMETER_PROBLEM,
+ "Invalid port:port syntax - use dash\n");
+
+ dash = strchr(colon, '-');
+ if (!dash) {
+ range->min_proto.tcp.port
+ = range->max_proto.tcp.port
+ = htons(port);
+ } else {
+ int maxport;
+ char *slash;
+
+ maxport = atoi(dash + 1);
+ if (maxport <= 0 || maxport > 65535)
+ xtables_error(PARAMETER_PROBLEM,
+ "Port `%s' not valid\n", dash+1);
+ if (maxport < port)
+ /* People are stupid. */
+ xtables_error(PARAMETER_PROBLEM,
+ "Port range `%s' funky\n", colon+1);
+ range->min_proto.tcp.port = htons(port);
+ range->max_proto.tcp.port = htons(maxport);
+
+ slash = strchr(dash, '/');
+ if (slash) {
+ int baseport;
+
+ baseport = atoi(slash + 1);
+ if (baseport <= 0 || baseport > 65535)
+ xtables_error(PARAMETER_PROBLEM,
+ "Port `%s' not valid\n", slash+1);
+ range->flags |= NF_NAT_RANGE_PROTO_OFFSET;
+ range->base_proto.tcp.port = htons(baseport);
+ }
+ }
+ /* Starts with a colon? No IP info...*/
+ if (colon == arg) {
+ free(arg);
+ return;
+ }
+ *colon = '\0';
+ }
+
+ range->flags |= NF_NAT_RANGE_MAP_IPS;
+ dash = strchr(arg, '-');
+ if (colon && dash && dash > colon)
+ dash = NULL;
+
+ if (dash)
+ *dash = '\0';
+
+ ip = xtables_numeric_to_ipaddr(arg);
+ if (!ip)
+ xtables_error(PARAMETER_PROBLEM, "Bad IP address \"%s\"\n",
+ arg);
+ range->min_addr.in = *ip;
+ if (dash) {
+ ip = xtables_numeric_to_ipaddr(dash+1);
+ if (!ip)
+ xtables_error(PARAMETER_PROBLEM, "Bad IP address \"%s\"\n",
+ dash+1);
+ range->max_addr.in = *ip;
+ } else
+ range->max_addr = range->min_addr;
+
+ free(arg);
+ return;
+}
+
+static void DNAT_parse_v2(struct xt_option_call *cb)
+{
+ const struct ipt_entry *entry = cb->xt_entry;
+ struct nf_nat_range2 *range = cb->data;
+ int portok;
+
+ if (entry->ip.proto == IPPROTO_TCP
+ || entry->ip.proto == IPPROTO_UDP
+ || entry->ip.proto == IPPROTO_SCTP
+ || entry->ip.proto == IPPROTO_DCCP
+ || entry->ip.proto == IPPROTO_ICMP)
+ portok = 1;
+ else
+ portok = 0;
+
+ xtables_option_parse(cb);
+ switch (cb->entry->id) {
+ case O_TO_DEST:
+ if (cb->xflags & F_X_TO_DEST) {
+ xtables_error(PARAMETER_PROBLEM,
+ "DNAT: Multiple --to-destination not supported");
+ }
+ parse_to_v2(cb->arg, portok, range);
+ cb->xflags |= F_X_TO_DEST;
+ break;
+ case O_PERSISTENT:
+ range->flags |= NF_NAT_RANGE_PERSISTENT;
+ break;
+ }
+}
+
+static void DNAT_fcheck_v2(struct xt_fcheck_call *cb)
+{
+ static const unsigned int f = F_TO_DEST | F_RANDOM;
+ struct nf_nat_range2 *range = cb->data;
+
+ if ((cb->xflags & f) == f)
+ range->flags |= NF_NAT_RANGE_PROTO_RANDOM;
+}
+
+static void print_range_v2(const struct nf_nat_range2 *range)
+{
+ if (range->flags & NF_NAT_RANGE_MAP_IPS) {
+ printf("%s", xtables_ipaddr_to_numeric(&range->min_addr.in));
+ if (memcmp(&range->min_addr, &range->max_addr,
+ sizeof(range->min_addr)))
+ printf("-%s", xtables_ipaddr_to_numeric(&range->max_addr.in));
+ }
+ if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
+ printf(":");
+ printf("%hu", ntohs(range->min_proto.tcp.port));
+ if (range->max_proto.tcp.port != range->min_proto.tcp.port)
+ printf("-%hu", ntohs(range->max_proto.tcp.port));
+ if (range->flags & NF_NAT_RANGE_PROTO_OFFSET)
+ printf("/%hu", ntohs(range->base_proto.tcp.port));
+ }
+}
+
+static void DNAT_print_v2(const void *ip, const struct xt_entry_target *target,
+ int numeric)
+{
+ const struct nf_nat_range2 *range = (const void *)target->data;
+
+ printf(" to:");
+ print_range_v2(range);
+ if (range->flags & NF_NAT_RANGE_PROTO_RANDOM)
+ printf(" random");
+ if (range->flags & NF_NAT_RANGE_PERSISTENT)
+ printf(" persistent");
+}
+
+static void DNAT_save_v2(const void *ip, const struct xt_entry_target *target)
+{
+ const struct nf_nat_range2 *range = (const void *)target->data;
+
+ printf(" --to-destination ");
+ print_range_v2(range);
+ if (range->flags & NF_NAT_RANGE_PROTO_RANDOM)
+ printf(" --random");
+ if (range->flags & NF_NAT_RANGE_PERSISTENT)
+ printf(" --persistent");
+}
+
+static void print_range_xlate_v2(const struct nf_nat_range2 *range,
+ struct xt_xlate *xl)
+{
+ if (range->flags & NF_NAT_RANGE_MAP_IPS) {
+ xt_xlate_add(xl, "%s", xtables_ipaddr_to_numeric(&range->min_addr.in));
+ if (memcmp(&range->min_addr, &range->max_addr,
+ sizeof(range->min_addr))) {
+ xt_xlate_add(xl, "-%s", xtables_ipaddr_to_numeric(&range->max_addr.in));
+ }
+ }
+ if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
+ xt_xlate_add(xl, ":%hu", ntohs(range->min_proto.tcp.port));
+ if (range->max_proto.tcp.port != range->min_proto.tcp.port)
+ xt_xlate_add(xl, "-%hu", ntohs(range->max_proto.tcp.port));
+ if (range->flags & NF_NAT_RANGE_PROTO_OFFSET)
+ xt_xlate_add(xl, ";%hu", ntohs(range->base_proto.tcp.port));
+ }
+}
+
+static int DNAT_xlate_v2(struct xt_xlate *xl,
+ const struct xt_xlate_tg_params *params)
+{
+ const struct nf_nat_range2 *range = (const void *)params->target->data;
+ bool sep_need = false;
+ const char *sep = " ";
+
+ xt_xlate_add(xl, "dnat to ");
+ print_range_xlate_v2(range, xl);
+ if (range->flags & NF_NAT_RANGE_PROTO_RANDOM) {
+ xt_xlate_add(xl, " random");
+ sep_need = true;
+ }
+ if (range->flags & NF_NAT_RANGE_PERSISTENT) {
+ if (sep_need)
+ sep = ",";
+ xt_xlate_add(xl, "%spersistent", sep);
+ }
+
+ return 1;
+}
+
+static struct xtables_target dnat_tg_reg[] = {
+ {
+ .name = "DNAT",
+ .version = XTABLES_VERSION,
+ .family = NFPROTO_IPV4,
+ .revision = 0,
+ .size = XT_ALIGN(sizeof(struct nf_nat_ipv4_multi_range_compat)),
+ .userspacesize = XT_ALIGN(sizeof(struct nf_nat_ipv4_multi_range_compat)),
+ .help = DNAT_help,
+ .print = DNAT_print,
+ .save = DNAT_save,
+ .x6_parse = DNAT_parse,
+ .x6_fcheck = DNAT_fcheck,
+ .x6_options = DNAT_opts,
+ .xlate = DNAT_xlate,
+ },
+ {
+ .name = "DNAT",
+ .version = XTABLES_VERSION,
+ .family = NFPROTO_IPV4,
+ .revision = 2,
+ .size = XT_ALIGN(sizeof(struct nf_nat_range)),
+ .userspacesize = XT_ALIGN(sizeof(struct nf_nat_range)),
+ .help = DNAT_help_v2,
+ .print = DNAT_print_v2,
+ .save = DNAT_save_v2,
+ .x6_parse = DNAT_parse_v2,
+ .x6_fcheck = DNAT_fcheck_v2,
+ .x6_options = DNAT_opts,
+ .xlate = DNAT_xlate_v2,
+ },
};
void _init(void)
{
- xtables_register_target(&dnat_tg_reg);
+ xtables_register_targets(dnat_tg_reg, ARRAY_SIZE(dnat_tg_reg));
}