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authorYasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>2006-04-01 02:22:30 -0800
committerDavid S. Miller <davem@davemloft.net>2006-04-01 02:22:30 -0800
commitdc5ab2faece3b7473931357db7f63f596678481d (patch)
treed1e5fd3e805e7d2c4136459cca17d5f8ed44bfb6 /net/netfilter/xt_esp.c
parent9606a21635cec077e1928273751b44ecc824a49d (diff)
downloadlinux-stericsson-dc5ab2faece3b7473931357db7f63f596678481d.tar.gz
[NETFILTER]: x_tables: unify IPv4/IPv6 esp match
This unifies ipt_esp and ip6t_esp to xt_esp. Please note that now a user program needs to specify IPPROTO_ESP as protocol to use esp match with IPv6. This means that ip6tables requires '-p esp' like iptables. Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netfilter/xt_esp.c')
-rw-r--r--net/netfilter/xt_esp.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/net/netfilter/xt_esp.c b/net/netfilter/xt_esp.c
new file mode 100644
index 000000000000..9dad6281e0c1
--- /dev/null
+++ b/net/netfilter/xt_esp.c
@@ -0,0 +1,136 @@
+/* Kernel module to match ESP parameters. */
+
+/* (C) 1999-2000 Yon Uriarte <yon@astaro.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+
+#include <linux/netfilter/xt_esp.h>
+#include <linux/netfilter/x_tables.h>
+
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv6/ip6_tables.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Yon Uriarte <yon@astaro.de>");
+MODULE_DESCRIPTION("x_tables ESP SPI match module");
+MODULE_ALIAS("ipt_esp");
+MODULE_ALIAS("ip6t_esp");
+
+#if 0
+#define duprintf(format, args...) printk(format , ## args)
+#else
+#define duprintf(format, args...)
+#endif
+
+/* Returns 1 if the spi is matched by the range, 0 otherwise */
+static inline int
+spi_match(u_int32_t min, u_int32_t max, u_int32_t spi, int invert)
+{
+ int r = 0;
+ duprintf("esp spi_match:%c 0x%x <= 0x%x <= 0x%x", invert ? '!' : ' ',
+ min, spi, max);
+ r = (spi >= min && spi <= max) ^ invert;
+ duprintf(" result %s\n", r ? "PASS" : "FAILED");
+ return r;
+}
+
+static int
+match(const struct sk_buff *skb,
+ const struct net_device *in,
+ const struct net_device *out,
+ const struct xt_match *match,
+ const void *matchinfo,
+ int offset,
+ unsigned int protoff,
+ int *hotdrop)
+{
+ struct ip_esp_hdr _esp, *eh;
+ const struct xt_esp *espinfo = matchinfo;
+
+ /* Must not be a fragment. */
+ if (offset)
+ return 0;
+
+ eh = skb_header_pointer(skb, protoff, sizeof(_esp), &_esp);
+ if (eh == NULL) {
+ /* We've been asked to examine this packet, and we
+ * can't. Hence, no choice but to drop.
+ */
+ duprintf("Dropping evil ESP tinygram.\n");
+ *hotdrop = 1;
+ return 0;
+ }
+
+ return spi_match(espinfo->spis[0], espinfo->spis[1], ntohl(eh->spi),
+ !!(espinfo->invflags & XT_ESP_INV_SPI));
+}
+
+/* Called when user tries to insert an entry of this type. */
+static int
+checkentry(const char *tablename,
+ const void *ip_void,
+ const struct xt_match *match,
+ void *matchinfo,
+ unsigned int matchinfosize,
+ unsigned int hook_mask)
+{
+ const struct xt_esp *espinfo = matchinfo;
+
+ if (espinfo->invflags & ~XT_ESP_INV_MASK) {
+ duprintf("xt_esp: unknown flags %X\n", espinfo->invflags);
+ return 0;
+ }
+
+ return 1;
+}
+
+static struct xt_match esp_match = {
+ .name = "esp",
+ .family = AF_INET,
+ .proto = IPPROTO_ESP,
+ .match = &match,
+ .matchsize = sizeof(struct xt_esp),
+ .checkentry = &checkentry,
+ .me = THIS_MODULE,
+};
+
+static struct xt_match esp6_match = {
+ .name = "esp",
+ .family = AF_INET6,
+ .proto = IPPROTO_ESP,
+ .match = &match,
+ .matchsize = sizeof(struct xt_esp),
+ .checkentry = &checkentry,
+ .me = THIS_MODULE,
+};
+
+static int __init xt_esp_init(void)
+{
+ int ret;
+ ret = xt_register_match(&esp_match);
+ if (ret)
+ return ret;
+
+ ret = xt_register_match(&esp6_match);
+ if (ret)
+ xt_unregister_match(&esp_match);
+
+ return ret;
+}
+
+static void __exit xt_esp_cleanup(void)
+{
+ xt_unregister_match(&esp_match);
+ xt_unregister_match(&esp6_match);
+}
+
+module_init(xt_esp_init);
+module_exit(xt_esp_cleanup);