| /* |
| * Copyright (c) 2011 Patrick McHardy <kaber@trash.net> |
| * |
| * Based on Rusty Russell's IPv4 DNAT target. Development of IPv6 NAT |
| * funded by Astaro. |
| */ |
| |
| #include <stdio.h> |
| #include <netdb.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <xtables.h> |
| #include <iptables.h> |
| #include <limits.h> /* INT_MAX in ip_tables.h */ |
| #include <linux/netfilter_ipv6/ip6_tables.h> |
| #include <linux/netfilter/nf_nat.h> |
| |
| enum { |
| O_TO_DEST = 0, |
| O_RANDOM, |
| O_PERSISTENT, |
| O_X_TO_DEST, |
| F_TO_DEST = 1 << O_TO_DEST, |
| F_RANDOM = 1 << O_RANDOM, |
| F_X_TO_DEST = 1 << O_X_TO_DEST, |
| }; |
| |
| static void DNAT_help(void) |
| { |
| printf( |
| "DNAT target options:\n" |
| " --to-destination [<ipaddr>[-<ipaddr>]][:port[-port]]\n" |
| " Address to map destination to.\n" |
| "[--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}, |
| {.name = "random", .id = O_RANDOM, .type = XTTYPE_NONE}, |
| {.name = "persistent", .id = O_PERSISTENT, .type = XTTYPE_NONE}, |
| XTOPT_TABLEEND, |
| }; |
| |
| /* Ranges expected in network order. */ |
| static void |
| parse_to(const char *orig_arg, int portok, struct nf_nat_range2 *range, int rev) |
| { |
| char *arg, *start, *end = NULL, *colon = NULL, *dash, *error; |
| const struct in6_addr *ip; |
| |
| arg = strdup(orig_arg); |
| if (arg == NULL) |
| xtables_error(RESOURCE_PROBLEM, "strdup"); |
| |
| start = strchr(arg, '['); |
| if (start == NULL) { |
| start = arg; |
| /* Lets assume one colon is port information. Otherwise its an IPv6 address */ |
| colon = strchr(arg, ':'); |
| if (colon && strchr(colon+1, ':')) |
| colon = NULL; |
| } |
| else { |
| start++; |
| end = strchr(start, ']'); |
| if (end == NULL) |
| xtables_error(PARAMETER_PROBLEM, |
| "Invalid address format"); |
| |
| *end = '\0'; |
| colon = strchr(end + 1, ':'); |
| } |
| |
| 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; |
| |
| 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); |
| |
| if (rev >= 2) { |
| char *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 colon or [] colon? No IP info...*/ |
| if (colon == arg || colon == arg+2) { |
| free(arg); |
| return; |
| } |
| *colon = '\0'; |
| } |
| |
| range->flags |= NF_NAT_RANGE_MAP_IPS; |
| dash = strchr(start, '-'); |
| if (colon && dash && dash > colon) |
| dash = NULL; |
| |
| if (dash) |
| *dash = '\0'; |
| |
| ip = xtables_numeric_to_ip6addr(start); |
| if (!ip) |
| xtables_error(PARAMETER_PROBLEM, "Bad IP address \"%s\"\n", |
| start); |
| range->min_addr.in6 = *ip; |
| if (dash) { |
| ip = xtables_numeric_to_ip6addr(dash + 1); |
| if (!ip) |
| xtables_error(PARAMETER_PROBLEM, "Bad IP address \"%s\"\n", |
| dash+1); |
| range->max_addr.in6 = *ip; |
| } else |
| range->max_addr = range->min_addr; |
| |
| free(arg); |
| return; |
| } |
| |
| static void _DNAT_parse(struct xt_option_call *cb, |
| struct nf_nat_range2 *range, int rev) |
| { |
| const struct ip6t_entry *entry = cb->xt_entry; |
| int portok; |
| |
| if (entry->ipv6.proto == IPPROTO_TCP || |
| entry->ipv6.proto == IPPROTO_UDP || |
| entry->ipv6.proto == IPPROTO_SCTP || |
| entry->ipv6.proto == IPPROTO_DCCP || |
| entry->ipv6.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(cb->arg, portok, range, rev); |
| cb->xflags |= F_X_TO_DEST; |
| break; |
| case O_PERSISTENT: |
| range->flags |= NF_NAT_RANGE_PERSISTENT; |
| break; |
| } |
| } |
| |
| static void DNAT_parse(struct xt_option_call *cb) |
| { |
| struct nf_nat_range *range_v1 = (void *)cb->data; |
| struct nf_nat_range2 range = {}; |
| |
| memcpy(&range, range_v1, sizeof(*range_v1)); |
| _DNAT_parse(cb, &range, 1); |
| memcpy(range_v1, &range, sizeof(*range_v1)); |
| } |
| |
| static void DNAT_parse_v2(struct xt_option_call *cb) |
| { |
| _DNAT_parse(cb, (struct nf_nat_range2 *)cb->data, 2); |
| } |
| |
| static void _DNAT_fcheck(struct xt_fcheck_call *cb, unsigned int *flags) |
| { |
| static const unsigned int f = F_TO_DEST | F_RANDOM; |
| |
| if ((cb->xflags & f) == f) |
| *flags |= NF_NAT_RANGE_PROTO_RANDOM; |
| } |
| |
| static void DNAT_fcheck(struct xt_fcheck_call *cb) |
| { |
| _DNAT_fcheck(cb, &((struct nf_nat_range *)cb->data)->flags); |
| } |
| |
| static void DNAT_fcheck_v2(struct xt_fcheck_call *cb) |
| { |
| _DNAT_fcheck(cb, &((struct nf_nat_range2 *)cb->data)->flags); |
| } |
| |
| static void print_range(const struct nf_nat_range2 *range, int rev) |
| { |
| if (range->flags & NF_NAT_RANGE_MAP_IPS) { |
| if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) |
| printf("["); |
| printf("%s", xtables_ip6addr_to_numeric(&range->min_addr.in6)); |
| if (memcmp(&range->min_addr, &range->max_addr, |
| sizeof(range->min_addr))) |
| printf("-%s", xtables_ip6addr_to_numeric(&range->max_addr.in6)); |
| if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) |
| printf("]"); |
| } |
| 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 (rev >= 2 && (range->flags & NF_NAT_RANGE_PROTO_OFFSET)) |
| printf("/%hu", ntohs(range->base_proto.tcp.port)); |
| } |
| } |
| |
| static void _DNAT_print(const struct nf_nat_range2 *range, int rev) |
| { |
| printf(" to:"); |
| print_range(range, rev); |
| if (range->flags & NF_NAT_RANGE_PROTO_RANDOM) |
| printf(" random"); |
| if (range->flags & NF_NAT_RANGE_PERSISTENT) |
| printf(" persistent"); |
| } |
| |
| static void DNAT_print(const void *ip, const struct xt_entry_target *target, |
| int numeric) |
| { |
| const struct nf_nat_range *range_v1 = (const void *)target->data; |
| struct nf_nat_range2 range = {}; |
| |
| memcpy(&range, range_v1, sizeof(*range_v1)); |
| _DNAT_print(&range, 1); |
| } |
| |
| static void DNAT_print_v2(const void *ip, const struct xt_entry_target *target, |
| int numeric) |
| { |
| _DNAT_print((const struct nf_nat_range2 *)target->data, 2); |
| } |
| |
| static void _DNAT_save(const struct nf_nat_range2 *range, int rev) |
| { |
| printf(" --to-destination "); |
| print_range(range, rev); |
| if (range->flags & NF_NAT_RANGE_PROTO_RANDOM) |
| printf(" --random"); |
| if (range->flags & NF_NAT_RANGE_PERSISTENT) |
| printf(" --persistent"); |
| } |
| |
| static void DNAT_save(const void *ip, const struct xt_entry_target *target) |
| { |
| const struct nf_nat_range *range_v1 = (const void *)target->data; |
| struct nf_nat_range2 range = {}; |
| |
| memcpy(&range, range_v1, sizeof(*range_v1)); |
| _DNAT_save(&range, 1); |
| } |
| |
| static void DNAT_save_v2(const void *ip, const struct xt_entry_target *target) |
| { |
| _DNAT_save((const struct nf_nat_range2 *)target->data, 2); |
| } |
| |
| static void print_range_xlate(const struct nf_nat_range2 *range, |
| struct xt_xlate *xl, int rev) |
| { |
| bool proto_specified = range->flags & NF_NAT_RANGE_PROTO_SPECIFIED; |
| |
| if (range->flags & NF_NAT_RANGE_MAP_IPS) { |
| xt_xlate_add(xl, "%s%s%s", |
| proto_specified ? "[" : "", |
| xtables_ip6addr_to_numeric(&range->min_addr.in6), |
| proto_specified ? "]" : ""); |
| |
| if (memcmp(&range->min_addr, &range->max_addr, |
| sizeof(range->min_addr))) { |
| xt_xlate_add(xl, "-%s%s%s", |
| proto_specified ? "[" : "", |
| xtables_ip6addr_to_numeric(&range->max_addr.in6), |
| proto_specified ? "]" : ""); |
| } |
| } |
| if (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)); |
| } |
| } |
| |
| static int _DNAT_xlate(struct xt_xlate *xl, |
| const struct nf_nat_range2 *range, int rev) |
| { |
| bool sep_need = false; |
| const char *sep = " "; |
| |
| xt_xlate_add(xl, "dnat to "); |
| print_range_xlate(range, xl, rev); |
| 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 int DNAT_xlate(struct xt_xlate *xl, |
| const struct xt_xlate_tg_params *params) |
| { |
| const struct nf_nat_range *range_v1 = (const void *)params->target->data; |
| struct nf_nat_range2 range = {}; |
| |
| memcpy(&range, range_v1, sizeof(*range_v1)); |
| _DNAT_xlate(xl, &range, 1); |
| |
| return 1; |
| } |
| |
| static int DNAT_xlate_v2(struct xt_xlate *xl, |
| const struct xt_xlate_tg_params *params) |
| { |
| _DNAT_xlate(xl, (const struct nf_nat_range2 *)params->target->data, 2); |
| |
| return 1; |
| } |
| |
| static struct xtables_target dnat_tg_reg[] = { |
| { |
| .name = "DNAT", |
| .version = XTABLES_VERSION, |
| .family = NFPROTO_IPV6, |
| .revision = 1, |
| .size = XT_ALIGN(sizeof(struct nf_nat_range)), |
| .userspacesize = XT_ALIGN(sizeof(struct nf_nat_range)), |
| .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_IPV6, |
| .revision = 2, |
| .size = XT_ALIGN(sizeof(struct nf_nat_range2)), |
| .userspacesize = XT_ALIGN(sizeof(struct nf_nat_range2)), |
| .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_targets(dnat_tg_reg, ARRAY_SIZE(dnat_tg_reg)); |
| } |