diff options
Diffstat (limited to 'extensions/libipt_DNAT.c')
-rw-r--r-- | extensions/libipt_DNAT.c | 275 |
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)); } |