--- /dev/null
+/* Shared library add-on to iptables to add policy support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <syslog.h>
+#include <getopt.h>
+#include <netdb.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <iptables.h>
+
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include "../include/linux/netfilter_ipv4/ipt_policy.h"
+
+/*
+ * HACK: global pointer to current matchinfo for making
+ * final checks and adjustments in final_check.
+ */
+static struct ipt_policy_info *policy_info;
+
+static void policy_help(void)
+{
+ printf(
+"policy match options:\n"
+" --dir in|out match policy applied during decapsulation/\n"
+" policy to be applied during encapsulation\n"
+" --pol none|ipsec match policy\n"
+" --strict match entire policy instead of single element\n"
+" at any position\n"
+"[!] --reqid reqid match reqid\n"
+"[!] --spi spi match SPI\n"
+"[!] --proto proto match protocol (ah/esp/ipcomp)\n"
+"[!] --mode mode match mode (transport/tunnel)\n"
+"[!] --tunnel-src addr/mask match tunnel source\n"
+"[!] --tunnel-dst addr/mask match tunnel destination\n"
+" --next begin next element in policy\n");
+}
+
+static const struct option policy_opts[] =
+{
+ {
+ .name = "dir",
+ .has_arg = 1,
+ .val = '1',
+ },
+ {
+ .name = "pol",
+ .has_arg = 1,
+ .val = '2',
+ },
+ {
+ .name = "strict",
+ .val = '3'
+ },
+ {
+ .name = "reqid",
+ .has_arg = 1,
+ .val = '4',
+ },
+ {
+ .name = "spi",
+ .has_arg = 1,
+ .val = '5'
+ },
+ {
+ .name = "tunnel-src",
+ .has_arg = 1,
+ .val = '6'
+ },
+ {
+ .name = "tunnel-dst",
+ .has_arg = 1,
+ .val = '7'
+ },
+ {
+ .name = "proto",
+ .has_arg = 1,
+ .val = '8'
+ },
+ {
+ .name = "mode",
+ .has_arg = 1,
+ .val = '9'
+ },
+ {
+ .name = "next",
+ .val = 'a'
+ },
+ { .name = NULL }
+};
+
+static int parse_direction(char *s)
+{
+ if (strcmp(s, "in") == 0)
+ return IPT_POLICY_MATCH_IN;
+ if (strcmp(s, "out") == 0)
+ return IPT_POLICY_MATCH_OUT;
+ exit_error(PARAMETER_PROBLEM, "policy_match: invalid dir `%s'", s);
+}
+
+static int parse_policy(char *s)
+{
+ if (strcmp(s, "none") == 0)
+ return IPT_POLICY_MATCH_NONE;
+ if (strcmp(s, "ipsec") == 0)
+ return 0;
+ exit_error(PARAMETER_PROBLEM, "policy match: invalid policy `%s'", s);
+}
+
+static int parse_mode(char *s)
+{
+ if (strcmp(s, "transport") == 0)
+ return IPT_POLICY_MODE_TRANSPORT;
+ if (strcmp(s, "tunnel") == 0)
+ return IPT_POLICY_MODE_TUNNEL;
+ exit_error(PARAMETER_PROBLEM, "policy match: invalid mode `%s'", s);
+}
+
+static int policy_parse(int c, char **argv, int invert, unsigned int *flags,
+ const void *entry, struct xt_entry_match **match)
+{
+ struct ipt_policy_info *info = (void *)(*match)->data;
+ struct ipt_policy_elem *e = &info->pol[info->len];
+ struct in_addr *addr = NULL, mask;
+ unsigned int naddr = 0;
+ int mode;
+
+ check_inverse(optarg, &invert, &optind, 0);
+
+ switch (c) {
+ case '1':
+ if (info->flags & (IPT_POLICY_MATCH_IN|IPT_POLICY_MATCH_OUT))
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: double --dir option");
+ if (invert)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: can't invert --dir option");
+
+ info->flags |= parse_direction(argv[optind-1]);
+ break;
+ case '2':
+ if (invert)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: can't invert --policy option");
+
+ info->flags |= parse_policy(argv[optind-1]);
+ break;
+ case '3':
+ if (info->flags & IPT_POLICY_MATCH_STRICT)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: double --strict option");
+
+ if (invert)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: can't invert --strict option");
+
+ info->flags |= IPT_POLICY_MATCH_STRICT;
+ break;
+ case '4':
+ if (e->match.reqid)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: double --reqid option");
+
+ e->match.reqid = 1;
+ e->invert.reqid = invert;
+ e->reqid = strtol(argv[optind-1], NULL, 10);
+ break;
+ case '5':
+ if (e->match.spi)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: double --spi option");
+
+ e->match.spi = 1;
+ e->invert.spi = invert;
+ e->spi = strtol(argv[optind-1], NULL, 0x10);
+ break;
+ case '6':
+ if (e->match.saddr)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: double --tunnel-src option");
+
+ ipparse_hostnetworkmask(argv[optind-1], &addr, &mask, &naddr);
+ if (naddr > 1)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: name resolves to multiple IPs");
+
+ e->match.saddr = 1;
+ e->invert.saddr = invert;
+ e->saddr.a4 = addr[0];
+ e->smask.a4 = mask;
+ break;
+ case '7':
+ if (e->match.daddr)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: double --tunnel-dst option");
+
+ ipparse_hostnetworkmask(argv[optind-1], &addr, &mask, &naddr);
+ if (naddr > 1)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: name resolves to multiple IPs");
+
+ e->match.daddr = 1;
+ e->invert.daddr = invert;
+ e->daddr.a4 = addr[0];
+ e->dmask.a4 = mask;
+ break;
+ case '8':
+ if (e->match.proto)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: double --proto option");
+
+ e->proto = parse_protocol(argv[optind-1]);
+ if (e->proto != IPPROTO_AH && e->proto != IPPROTO_ESP &&
+ e->proto != IPPROTO_COMP)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: protocol must ah/esp/ipcomp");
+ e->match.proto = 1;
+ e->invert.proto = invert;
+ break;
+ case '9':
+ if (e->match.mode)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: double --mode option");
+
+ mode = parse_mode(argv[optind-1]);
+ e->match.mode = 1;
+ e->invert.mode = invert;
+ e->mode = mode;
+ break;
+ case 'a':
+ if (invert)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: can't invert --next option");
+
+ if (++info->len == IPT_POLICY_MAX_ELEM)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: maximum policy depth reached");
+ break;
+ default:
+ return 0;
+ }
+
+ policy_info = info;
+ return 1;
+}
+
+static void policy_check(unsigned int flags)
+{
+ struct ipt_policy_info *info = policy_info;
+ struct ipt_policy_elem *e;
+ int i;
+
+ if (info == NULL)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: no parameters given");
+
+ if (!(info->flags & (IPT_POLICY_MATCH_IN|IPT_POLICY_MATCH_OUT)))
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: neither --in nor --out specified");
+
+ if (info->flags & IPT_POLICY_MATCH_NONE) {
+ if (info->flags & IPT_POLICY_MATCH_STRICT)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: policy none but --strict given");
+
+ if (info->len != 0)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: policy none but policy given");
+ } else
+ info->len++; /* increase len by 1, no --next after last element */
+
+ if (!(info->flags & IPT_POLICY_MATCH_STRICT) && info->len > 1)
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: multiple elements but no --strict");
+
+ for (i = 0; i < info->len; i++) {
+ e = &info->pol[i];
+
+ if (info->flags & IPT_POLICY_MATCH_STRICT &&
+ !(e->match.reqid || e->match.spi || e->match.saddr ||
+ e->match.daddr || e->match.proto || e->match.mode))
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: empty policy element");
+
+ if ((e->match.saddr || e->match.daddr)
+ && ((e->mode == IPT_POLICY_MODE_TUNNEL && e->invert.mode) ||
+ (e->mode == IPT_POLICY_MODE_TRANSPORT && !e->invert.mode)))
+ exit_error(PARAMETER_PROBLEM,
+ "policy match: --tunnel-src/--tunnel-dst "
+ "is only valid in tunnel mode");
+ }
+}
+
+static void print_mode(char *prefix, u_int8_t mode, int numeric)
+{
+ printf("%smode ", prefix);
+
+ switch (mode) {
+ case IPT_POLICY_MODE_TRANSPORT:
+ printf("transport ");
+ break;
+ case IPT_POLICY_MODE_TUNNEL:
+ printf("tunnel ");
+ break;
+ default:
+ printf("??? ");
+ break;
+ }
+}
+
+static void print_proto(char *prefix, u_int8_t proto, int numeric)
+{
+ struct protoent *p = NULL;
+
+ printf("%sproto ", prefix);
+ if (!numeric)
+ p = getprotobynumber(proto);
+ if (p != NULL)
+ printf("%s ", p->p_name);
+ else
+ printf("%u ", proto);
+}
+
+#define PRINT_INVERT(x) \
+do { \
+ if (x) \
+ printf("! "); \
+} while(0)
+
+static void print_entry(char *prefix, const struct ipt_policy_elem *e,
+ int numeric)
+{
+ if (e->match.reqid) {
+ PRINT_INVERT(e->invert.reqid);
+ printf("%sreqid %u ", prefix, e->reqid);
+ }
+ if (e->match.spi) {
+ PRINT_INVERT(e->invert.spi);
+ printf("%sspi 0x%x ", prefix, e->spi);
+ }
+ if (e->match.proto) {
+ PRINT_INVERT(e->invert.proto);
+ print_proto(prefix, e->proto, numeric);
+ }
+ if (e->match.mode) {
+ PRINT_INVERT(e->invert.mode);
+ print_mode(prefix, e->mode, numeric);
+ }
+ if (e->match.daddr) {
+ PRINT_INVERT(e->invert.daddr);
+ printf("%stunnel-dst %s%s ", prefix,
+ ipaddr_to_numeric((const void *)&e->daddr),
+ ipmask_to_numeric((const void *)&e->dmask));
+ }
+ if (e->match.saddr) {
+ PRINT_INVERT(e->invert.saddr);
+ printf("%stunnel-src %s%s ", prefix,
+ ipaddr_to_numeric((const void *)&e->saddr),
+ ipmask_to_numeric((const void *)&e->smask));
+ }
+}
+
+static void print_flags(char *prefix, const struct ipt_policy_info *info)
+{
+ if (info->flags & IPT_POLICY_MATCH_IN)
+ printf("%sdir in ", prefix);
+ else
+ printf("%sdir out ", prefix);
+
+ if (info->flags & IPT_POLICY_MATCH_NONE)
+ printf("%spol none ", prefix);
+ else
+ printf("%spol ipsec ", prefix);
+
+ if (info->flags & IPT_POLICY_MATCH_STRICT)
+ printf("%sstrict ", prefix);
+}
+
+static void policy_print(const void *ip, const struct xt_entry_match *match,
+ int numeric)
+{
+ const struct ipt_policy_info *info = (void *)match->data;
+ unsigned int i;
+
+ printf("policy match ");
+ print_flags("", info);
+ for (i = 0; i < info->len; i++) {
+ if (info->len > 1)
+ printf("[%u] ", i);
+ print_entry("", &info->pol[i], numeric);
+ }
+}
+
+static void policy_save(const void *ip, const struct xt_entry_match *match)
+{
+ const struct ipt_policy_info *info = (void *)match->data;
+ unsigned int i;
+
+ print_flags("--", info);
+ for (i = 0; i < info->len; i++) {
+ print_entry("--", &info->pol[i], 0);
+ if (i + 1 < info->len)
+ printf("--next ");
+ }
+}
+
+static struct xtables_match policy_mt_reg = {
+ .name = "policy",
+ .version = XTABLES_VERSION,
+ .family = PF_INET,
+ .size = XT_ALIGN(sizeof(struct ipt_policy_info)),
+ .userspacesize = XT_ALIGN(sizeof(struct ipt_policy_info)),
+ .help = policy_help,
+ .parse = policy_parse,
+ .final_check = policy_check,
+ .print = policy_print,
+ .save = policy_save,
+ .extra_opts = policy_opts,
+};
+
+void _init(void)
+{
+ xtables_register_match(&policy_mt_reg);
+}
git://git.onelab.eu / iptables.git / blobdiff