diff options
Diffstat (limited to 'extensions/libipt_DNAT.c')
-rw-r--r-- | extensions/libipt_DNAT.c | 147 |
1 files changed, 70 insertions, 77 deletions
diff --git a/extensions/libipt_DNAT.c b/extensions/libipt_DNAT.c index 57c5888..ff18799 100644 --- a/extensions/libipt_DNAT.c +++ b/extensions/libipt_DNAT.c @@ -1,44 +1,50 @@ -/* Shared library add-on to iptables to add destination-NAT support. */ #include <stdio.h> #include <netdb.h> #include <string.h> #include <stdlib.h> -#include <getopt.h> #include <xtables.h> #include <iptables.h> /* get_kernel_version */ #include <limits.h> /* INT_MAX in ip_tables.h */ #include <linux/netfilter_ipv4/ip_tables.h> -#include <net/netfilter/nf_nat.h> - -#define IPT_DNAT_OPT_DEST 0x1 -#define IPT_DNAT_OPT_RANDOM 0x2 +#include <linux/netfilter/nf_nat.h> + +enum { + O_TO_DEST = 0, + O_RANDOM, + O_PERSISTENT, + O_X_TO_DEST, /* hidden flag */ + F_TO_DEST = 1 << O_TO_DEST, + F_RANDOM = 1 << O_RANDOM, + F_X_TO_DEST = 1 << O_X_TO_DEST, +}; /* Dest NAT data consists of a multi-range, indicating where to map to. */ struct ipt_natinfo { struct xt_entry_target t; - struct nf_nat_multi_range mr; + struct nf_nat_ipv4_multi_range_compat mr; }; static void DNAT_help(void) { printf( "DNAT target options:\n" -" --to-destination <ipaddr>[-<ipaddr>][:port-port]\n" +" --to-destination [<ipaddr>[-<ipaddr>]][:port[-port]]\n" " Address to map destination to.\n" "[--random] [--persistent]\n"); } -static const struct option DNAT_opts[] = { - { "to-destination", 1, NULL, '1' }, - { "random", 0, NULL, '2' }, - { "persistent", 0, NULL, '3' }, - { .name = NULL } +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, }; static struct ipt_natinfo * -append_range(struct ipt_natinfo *info, const struct nf_nat_range *range) +append_range(struct ipt_natinfo *info, const struct nf_nat_ipv4_range *range) { unsigned int size; @@ -58,12 +64,15 @@ append_range(struct ipt_natinfo *info, const struct nf_nat_range *range) /* Ranges expected in network order. */ static struct xt_entry_target * -parse_to(char *arg, int portok, struct ipt_natinfo *info) +parse_to(const char *orig_arg, int portok, struct ipt_natinfo *info) { - struct nf_nat_range range; - char *colon, *dash, *error; + struct nf_nat_ipv4_range range; + char *arg, *colon, *dash, *error; const struct in_addr *ip; + arg = strdup(orig_arg); + if (arg == NULL) + xtables_error(RESOURCE_PROBLEM, "strdup"); memset(&range, 0, sizeof(range)); colon = strchr(arg, ':'); @@ -74,7 +83,7 @@ parse_to(char *arg, int portok, struct ipt_natinfo *info) xtables_error(PARAMETER_PROBLEM, "Need TCP, UDP, SCTP or DCCP with port specification"); - range.flags |= IP_NAT_RANGE_PROTO_SPECIFIED; + range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED; port = atoi(colon+1); if (port <= 0 || port > 65535) @@ -106,12 +115,14 @@ parse_to(char *arg, int portok, struct ipt_natinfo *info) range.max.tcp.port = htons(maxport); } /* Starts with a colon? No IP info...*/ - if (colon == arg) + if (colon == arg) { + free(arg); return &(append_range(info, &range)->t); + } *colon = '\0'; } - range.flags |= IP_NAT_RANGE_MAP_IPS; + range.flags |= NF_NAT_RANGE_MAP_IPS; dash = strchr(arg, '-'); if (colon && dash && dash > colon) dash = NULL; @@ -133,14 +144,14 @@ parse_to(char *arg, int portok, struct ipt_natinfo *info) } else range.max_ip = range.min_ip; + free(arg); return &(append_range(info, &range)->t); } -static int DNAT_parse(int c, char **argv, int invert, unsigned int *flags, - const void *e, struct xt_entry_target **target) +static void DNAT_parse(struct xt_option_call *cb) { - const struct ipt_entry *entry = e; - struct ipt_natinfo *info = (void *)*target; + const struct ipt_entry *entry = cb->xt_entry; + struct ipt_natinfo *info = (void *)(*cb->target); int portok; if (entry->ip.proto == IPPROTO_TCP @@ -152,53 +163,37 @@ static int DNAT_parse(int c, char **argv, int invert, unsigned int *flags, else portok = 0; - switch (c) { - case '1': - if (xtables_check_inverse(optarg, &invert, NULL, 0, argv)) - xtables_error(PARAMETER_PROBLEM, - "Unexpected `!' after --to-destination"); - - if (*flags & IPT_DNAT_OPT_DEST) { + xtables_option_parse(cb); + switch (cb->entry->id) { + case O_TO_DEST: + if (cb->xflags & F_X_TO_DEST) { if (!kernel_version) get_kernel_version(); if (kernel_version > LINUX_VERSION(2, 6, 10)) xtables_error(PARAMETER_PROBLEM, - "Multiple --to-destination not supported"); + "DNAT: Multiple --to-destination not supported"); } - *target = parse_to(optarg, portok, info); - /* WTF do we need this for?? */ - if (*flags & IPT_DNAT_OPT_RANDOM) - info->mr.range[0].flags |= IP_NAT_RANGE_PROTO_RANDOM; - *flags |= IPT_DNAT_OPT_DEST; - return 1; - - case '2': - if (*flags & IPT_DNAT_OPT_DEST) { - info->mr.range[0].flags |= IP_NAT_RANGE_PROTO_RANDOM; - *flags |= IPT_DNAT_OPT_RANDOM; - } else - *flags |= IPT_DNAT_OPT_RANDOM; - return 1; - - case '3': - info->mr.range[0].flags |= IP_NAT_RANGE_PERSISTENT; - return 1; - - default: - return 0; + *cb->target = parse_to(cb->arg, portok, info); + cb->xflags |= F_X_TO_DEST; + break; + case O_PERSISTENT: + info->mr.range[0].flags |= NF_NAT_RANGE_PERSISTENT; + break; } } -static void DNAT_check(unsigned int flags) +static void DNAT_fcheck(struct xt_fcheck_call *cb) { - if (!flags) - xtables_error(PARAMETER_PROBLEM, - "You must specify --to-destination"); + static const unsigned int f = F_TO_DEST | F_RANDOM; + struct nf_nat_ipv4_multi_range_compat *mr = cb->data; + + if ((cb->xflags & f) == f) + mr->range[0].flags |= NF_NAT_RANGE_PROTO_RANDOM; } -static void print_range(const struct nf_nat_range *r) +static void print_range(const struct nf_nat_ipv4_range *r) { - if (r->flags & IP_NAT_RANGE_MAP_IPS) { + if (r->flags & NF_NAT_RANGE_MAP_IPS) { struct in_addr a; a.s_addr = r->min_ip; @@ -208,7 +203,7 @@ static void print_range(const struct nf_nat_range *r) printf("-%s", xtables_ipaddr_to_numeric(&a)); } } - if (r->flags & IP_NAT_RANGE_PROTO_SPECIFIED) { + if (r->flags & NF_NAT_RANGE_PROTO_SPECIFIED) { printf(":"); printf("%hu", ntohs(r->min.tcp.port)); if (r->max.tcp.port != r->min.tcp.port) @@ -222,14 +217,13 @@ static void DNAT_print(const void *ip, const struct xt_entry_target *target, const struct ipt_natinfo *info = (const void *)target; unsigned int i = 0; - printf("to:"); + printf(" to:"); for (i = 0; i < info->mr.rangesize; i++) { print_range(&info->mr.range[i]); - printf(" "); - if (info->mr.range[i].flags & IP_NAT_RANGE_PROTO_RANDOM) - printf("random "); - if (info->mr.range[i].flags & IP_NAT_RANGE_PERSISTENT) - printf("persistent "); + if (info->mr.range[i].flags & NF_NAT_RANGE_PROTO_RANDOM) + printf(" random"); + if (info->mr.range[i].flags & NF_NAT_RANGE_PERSISTENT) + printf(" persistent"); } } @@ -239,13 +233,12 @@ static void DNAT_save(const void *ip, const struct xt_entry_target *target) unsigned int i = 0; for (i = 0; i < info->mr.rangesize; i++) { - printf("--to-destination "); + printf(" --to-destination "); print_range(&info->mr.range[i]); - printf(" "); - if (info->mr.range[i].flags & IP_NAT_RANGE_PROTO_RANDOM) - printf("--random "); - if (info->mr.range[i].flags & IP_NAT_RANGE_PERSISTENT) - printf("--persistent "); + if (info->mr.range[i].flags & NF_NAT_RANGE_PROTO_RANDOM) + printf(" --random"); + if (info->mr.range[i].flags & NF_NAT_RANGE_PERSISTENT) + printf(" --persistent"); } } @@ -253,14 +246,14 @@ static struct xtables_target dnat_tg_reg = { .name = "DNAT", .version = XTABLES_VERSION, .family = NFPROTO_IPV4, - .size = XT_ALIGN(sizeof(struct nf_nat_multi_range)), - .userspacesize = XT_ALIGN(sizeof(struct nf_nat_multi_range)), + .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, - .parse = DNAT_parse, - .final_check = DNAT_check, + .x6_parse = DNAT_parse, + .x6_fcheck = DNAT_fcheck, .print = DNAT_print, .save = DNAT_save, - .extra_opts = DNAT_opts, + .x6_options = DNAT_opts, }; void _init(void) |