[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>

3 files changed, 5 insertions, 116 deletions

diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig
index 882b842c25d4..ebbd644fa8c4 100644
--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
@@ -272,12 +272,12 @@ config IP_NF_MATCH_DSCP
 
           To compile it as a module, choose M here.  If unsure, say N.
 
-config IP_NF_MATCH_AH_ESP
-        tristate "AH/ESP match support"
+config IP_NF_MATCH_AH
+        tristate "AH match support"
         depends on IP_NF_IPTABLES
         help
-          These two match extensions (`ah' and `esp') allow you to match a
-          range of SPIs inside AH or ESP headers of IPSec packets.
+          This match extension allows you to match a range of SPIs
+          inside AH header of IPSec packets.
 
           To compile it as a module, choose M here.  If unsure, say N.
 
diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile
index f2cd9a6c5b91..09ae167632e7 100644
--- a/net/ipv4/netfilter/Makefile
+++ b/net/ipv4/netfilter/Makefile
@@ -59,7 +59,7 @@ obj-$(CONFIG_IP_NF_MATCH_TOS) += ipt_tos.o
 obj-$(CONFIG_IP_NF_MATCH_RECENT) += ipt_recent.o
 obj-$(CONFIG_IP_NF_MATCH_ECN) += ipt_ecn.o
 obj-$(CONFIG_IP_NF_MATCH_DSCP) += ipt_dscp.o
-obj-$(CONFIG_IP_NF_MATCH_AH_ESP) += ipt_ah.o ipt_esp.o
+obj-$(CONFIG_IP_NF_MATCH_AH) += ipt_ah.o
 obj-$(CONFIG_IP_NF_MATCH_TTL) += ipt_ttl.o
 obj-$(CONFIG_IP_NF_MATCH_ADDRTYPE) += ipt_addrtype.o
 
diff --git a/net/ipv4/netfilter/ipt_esp.c b/net/ipv4/netfilter/ipt_esp.c
deleted file mode 100644
index 3840b417a3c5..000000000000
--- a/net/ipv4/netfilter/ipt_esp.c
+++ /dev/null
@@ -1,111 +0,0 @@
-/* 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/ip.h>
-
-#include <linux/netfilter_ipv4/ipt_esp.h>
-#include <linux/netfilter_ipv4/ip_tables.h>
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Yon Uriarte <yon@astaro.de>");
-MODULE_DESCRIPTION("iptables ESP SPI match module");
-
-#ifdef DEBUG_CONNTRACK
-#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 ipt_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 & IPT_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 ipt_esp *espinfo = matchinfo;
-
-        /* Must specify no unknown invflags */
-        if (espinfo->invflags & ~IPT_ESP_INV_MASK) {
-                duprintf("ipt_esp: unknown flags %X\n", espinfo->invflags);
-                return 0;
-        }
-        return 1;
-}
-
-static struct ipt_match esp_match = {
-        .name           = "esp",
-        .match          = match,
-        .matchsize      = sizeof(struct ipt_esp),
-        .proto          = IPPROTO_ESP,
-        .checkentry     = checkentry,
-        .me             = THIS_MODULE,
-};
-
-static int __init ipt_esp_init(void)
-{
-        return ipt_register_match(&esp_match);
-}
-
-static void __exit ipt_esp_fini(void)
-{
-        ipt_unregister_match(&esp_match);
-}
-
-module_init(ipt_esp_init);
-module_exit(ipt_esp_fini);