diff options
Diffstat (limited to 'extensions/libxt_TPROXY.c')
| -rw-r--r-- | extensions/libxt_TPROXY.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/extensions/libxt_TPROXY.c b/extensions/libxt_TPROXY.c new file mode 100644 index 00000000..0f910f40 --- /dev/null +++ b/extensions/libxt_TPROXY.c @@ -0,0 +1,151 @@ +/* + * Shared library add-on to iptables to add TPROXY target support. + * + * Copyright (C) 2002-2008 BalaBit IT Ltd. + */ +#include <getopt.h> +#include <stdbool.h> +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <limits.h> + +#include <iptables.h> +#include <xtables.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter/xt_TPROXY.h> + +static const struct option tproxy_tg_opts[] = { + { .name = "on-port", .has_arg = 1, .val = '1'}, + { .name = "on-ip", .has_arg = 1, .val = '2'}, + { .name = "tproxy-mark", .has_arg = 1, .val = '3'}, + {NULL}, +}; + +enum { + PARAM_ONPORT = 1 << 0, + PARAM_ONIP = 1 << 1, + PARAM_MARK = 1 << 2, +}; + +static void tproxy_tg_help(void) +{ + printf( +"TPROXY target options:\n" +" --on-port port Redirect connection to port, or the original port if 0\n" +" --on-ip ip Optionally redirect to the given IP\n" +" --tproxy-mark value[/mask] Mark packets with the given value/mask\n\n"); +} + +static void parse_tproxy_lport(const char *s, struct xt_tproxy_target_info *info) +{ + unsigned int lport; + + if (string_to_number(s, 0, 65535, &lport) != -1) + info->lport = htons(lport); + else + param_act(P_BAD_VALUE, "TPROXY", "--on-port", s); +} + +static void parse_tproxy_laddr(const char *s, struct xt_tproxy_target_info *info) +{ + struct in_addr *laddr; + + if ((laddr = numeric_to_ipaddr(s)) == NULL) + param_act(P_BAD_VALUE, "TPROXY", "--on-ip", s); + + info->laddr = laddr->s_addr; +} + +static void parse_tproxy_mark(char *s, struct xt_tproxy_target_info *info) +{ + unsigned int value, mask = ~0U; + char *end; + + if (!strtonum(s, &end, &value, 0, UINT_MAX)) + param_act(P_BAD_VALUE, "TPROXY", "--tproxy-mark", s); + if (*end == '/') + if (!strtonum(end + 1, &end, &mask, 0, UINT_MAX)) + param_act(P_BAD_VALUE, "TPROXY", "--tproxy-mark", s); + if (*end != '\0') + param_act(P_BAD_VALUE, "TPROXY", "--tproxy-mark", s); + + info->mark_mask = mask; + info->mark_value = value; +} + +static int tproxy_tg_parse(int c, char **argv, int invert, unsigned int *flags, + const void *entry, struct xt_entry_target **target) +{ + struct xt_tproxy_target_info *tproxyinfo = (void *)(*target)->data; + + switch (c) { + case '1': + param_act(P_ONLY_ONCE, "TPROXY", "--on-port", *flags & PARAM_ONPORT); + param_act(P_NO_INVERT, "TPROXY", "--on-port", invert); + parse_tproxy_lport(optarg, tproxyinfo); + *flags |= PARAM_ONPORT; + return 1; + case '2': + param_act(P_ONLY_ONCE, "TPROXY", "--on-ip", *flags & PARAM_ONIP); + param_act(P_NO_INVERT, "TPROXY", "--on-ip", invert); + parse_tproxy_laddr(optarg, tproxyinfo); + *flags |= PARAM_ONIP; + return 1; + case '3': + param_act(P_ONLY_ONCE, "TPROXY", "--tproxy-mark", *flags & PARAM_MARK); + param_act(P_NO_INVERT, "TPROXY", "--tproxy-mark", invert); + parse_tproxy_mark(optarg, tproxyinfo); + *flags |= PARAM_MARK; + return 1; + } + + return 0; +} + +static void tproxy_tg_check(unsigned int flags) +{ + if (!(flags & PARAM_ONPORT)) + exit_error(PARAMETER_PROBLEM, + "TPROXY target: Parameter --on-port is required"); +} + +static void tproxy_tg_print(const void *ip, const struct xt_entry_target *target, + int numeric) +{ + const struct xt_tproxy_target_info *info = (const void *)target->data; + printf("TPROXY redirect %s:%u mark 0x%x/0x%x", + ipaddr_to_numeric((const struct in_addr *)&info->laddr), + ntohs(info->lport), (unsigned int)info->mark_value, + (unsigned int)info->mark_mask); +} + +static void tproxy_tg_save(const void *ip, const struct xt_entry_target *target) +{ + const struct xt_tproxy_target_info *info = (const void *)target->data; + + printf("--on-port %u ", ntohs(info->lport)); + printf("--on-ip %s ", + ipaddr_to_numeric((const struct in_addr *)&info->laddr)); + printf("--tproxy-mark 0x%x/0x%x ", + (unsigned int)info->mark_value, (unsigned int)info->mark_mask); +} + +static struct xtables_target tproxy_tg_reg = { + .name = "TPROXY", + .family = AF_INET, + .version = XTABLES_VERSION, + .size = XT_ALIGN(sizeof(struct xt_tproxy_target_info)), + .userspacesize = XT_ALIGN(sizeof(struct xt_tproxy_target_info)), + .help = tproxy_tg_help, + .parse = tproxy_tg_parse, + .final_check = tproxy_tg_check, + .print = tproxy_tg_print, + .save = tproxy_tg_save, + .extra_opts = tproxy_tg_opts, +}; + +void _init(void) +{ + xtables_register_target(&tproxy_tg_reg); +} |