netfilter: ebtables: add IPv6 support

It implements matching functions for IPv6 address & traffic class
(merged from the patch sent by Jan Engelhardt [jengelh@computergmbh.de]
http://marc.info/?l=netfilter-devel&m=120182168424052&w=2), protocol,
and layer-4 port id. Corresponding watcher logging function is also
added for IPv6.

Signed-off-by: Kuo-lang Tseng <kuo-lang.tseng@intel.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 202 insertions, 16 deletions

diff --git a/net/bridge/netfilter/Kconfig b/net/bridge/netfilter/Kconfig
index 7beeefa0f9c0..fb684c2ff8b6 100644
--- a/net/bridge/netfilter/Kconfig
+++ b/net/bridge/netfilter/Kconfig
@@ -83,6 +83,15 @@ config BRIDGE_EBT_IP
 
           To compile it as a module, choose M here.  If unsure, say N.
 
+config BRIDGE_EBT_IP6
+        tristate "ebt: IP6 filter support"
+        depends on BRIDGE_NF_EBTABLES
+        help
+          This option adds the IP6 match, which allows basic IPV6 header field
+          filtering.
+
+          To compile it as a module, choose M here.  If unsure, say N.
+
 config BRIDGE_EBT_LIMIT
         tristate "ebt: limit match support"
         depends on BRIDGE_NF_EBTABLES
diff --git a/net/bridge/netfilter/Makefile b/net/bridge/netfilter/Makefile
index 83715d73a503..dd960645b413 100644
--- a/net/bridge/netfilter/Makefile
+++ b/net/bridge/netfilter/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_BRIDGE_EBT_802_3) += ebt_802_3.o
 obj-$(CONFIG_BRIDGE_EBT_AMONG) += ebt_among.o
 obj-$(CONFIG_BRIDGE_EBT_ARP) += ebt_arp.o
 obj-$(CONFIG_BRIDGE_EBT_IP) += ebt_ip.o
+obj-$(CONFIG_BRIDGE_EBT_IP) += ebt_ip6.o
 obj-$(CONFIG_BRIDGE_EBT_LIMIT) += ebt_limit.o
 obj-$(CONFIG_BRIDGE_EBT_MARK) += ebt_mark_m.o
 obj-$(CONFIG_BRIDGE_EBT_PKTTYPE) += ebt_pkttype.o
diff --git a/net/bridge/netfilter/ebt_ip6.c b/net/bridge/netfilter/ebt_ip6.c
new file mode 100644
index 000000000000..36efb3a75249
--- /dev/null
+++ b/net/bridge/netfilter/ebt_ip6.c
@@ -0,0 +1,144 @@
+/*
+ *  ebt_ip6
+ *
+ *      Authors:
+ *      Manohar Castelino <manohar.r.castelino@intel.com>
+ *      Kuo-Lang Tseng <kuo-lang.tseng@intel.com>
+ *      Jan Engelhardt <jengelh@computergmbh.de>
+ *
+ * Summary:
+ * This is just a modification of the IPv4 code written by
+ * Bart De Schuymer <bdschuym@pandora.be>
+ * with the changes required to support IPv6
+ *
+ *  Jan, 2008
+ */
+
+#include <linux/netfilter_bridge/ebtables.h>
+#include <linux/netfilter_bridge/ebt_ip6.h>
+#include <linux/ipv6.h>
+#include <net/ipv6.h>
+#include <linux/in.h>
+#include <linux/module.h>
+#include <net/dsfield.h>
+
+struct tcpudphdr {
+        __be16 src;
+        __be16 dst;
+};
+
+static int ebt_filter_ip6(const struct sk_buff *skb,
+   const struct net_device *in,
+   const struct net_device *out, const void *data,
+   unsigned int datalen)
+{
+        const struct ebt_ip6_info *info = (struct ebt_ip6_info *)data;
+        const struct ipv6hdr *ih6;
+        struct ipv6hdr _ip6h;
+        const struct tcpudphdr *pptr;
+        struct tcpudphdr _ports;
+        struct in6_addr tmp_addr;
+        int i;
+
+        ih6 = skb_header_pointer(skb, 0, sizeof(_ip6h), &_ip6h);
+        if (ih6 == NULL)
+                return EBT_NOMATCH;
+        if (info->bitmask & EBT_IP6_TCLASS &&
+           FWINV(info->tclass != ipv6_get_dsfield(ih6), EBT_IP6_TCLASS))
+                return EBT_NOMATCH;
+        for (i = 0; i < 4; i++)
+                tmp_addr.in6_u.u6_addr32[i] = ih6->saddr.in6_u.u6_addr32[i] &
+                        info->smsk.in6_u.u6_addr32[i];
+        if (info->bitmask & EBT_IP6_SOURCE &&
+                FWINV((ipv6_addr_cmp(&tmp_addr, &info->saddr) != 0),
+                        EBT_IP6_SOURCE))
+                return EBT_NOMATCH;
+        for (i = 0; i < 4; i++)
+                tmp_addr.in6_u.u6_addr32[i] = ih6->daddr.in6_u.u6_addr32[i] &
+                        info->dmsk.in6_u.u6_addr32[i];
+        if (info->bitmask & EBT_IP6_DEST &&
+           FWINV((ipv6_addr_cmp(&tmp_addr, &info->daddr) != 0), EBT_IP6_DEST))
+                return EBT_NOMATCH;
+        if (info->bitmask & EBT_IP6_PROTO) {
+                uint8_t nexthdr = ih6->nexthdr;
+                int offset_ph;
+
+                offset_ph = ipv6_skip_exthdr(skb, sizeof(_ip6h), &nexthdr);
+                if (offset_ph == -1)
+                        return EBT_NOMATCH;
+                if (FWINV(info->protocol != nexthdr, EBT_IP6_PROTO))
+                        return EBT_NOMATCH;
+                if (!(info->bitmask & EBT_IP6_DPORT) &&
+                    !(info->bitmask & EBT_IP6_SPORT))
+                        return EBT_MATCH;
+                pptr = skb_header_pointer(skb, offset_ph, sizeof(_ports),
+                                          &_ports);
+                if (pptr == NULL)
+                        return EBT_NOMATCH;
+                if (info->bitmask & EBT_IP6_DPORT) {
+                        u32 dst = ntohs(pptr->dst);
+                        if (FWINV(dst < info->dport[0] ||
+                                  dst > info->dport[1], EBT_IP6_DPORT))
+                                return EBT_NOMATCH;
+                }
+                if (info->bitmask & EBT_IP6_SPORT) {
+                        u32 src = ntohs(pptr->src);
+                        if (FWINV(src < info->sport[0] ||
+                                  src > info->sport[1], EBT_IP6_SPORT))
+                        return EBT_NOMATCH;
+                }
+                return EBT_MATCH;
+        }
+        return EBT_MATCH;
+}
+
+static int ebt_ip6_check(const char *tablename, unsigned int hookmask,
+   const struct ebt_entry *e, void *data, unsigned int datalen)
+{
+        struct ebt_ip6_info *info = (struct ebt_ip6_info *)data;
+
+        if (datalen != EBT_ALIGN(sizeof(struct ebt_ip6_info)))
+                return -EINVAL;
+        if (e->ethproto != htons(ETH_P_IPV6) || e->invflags & EBT_IPROTO)
+                return -EINVAL;
+        if (info->bitmask & ~EBT_IP6_MASK || info->invflags & ~EBT_IP6_MASK)
+                return -EINVAL;
+        if (info->bitmask & (EBT_IP6_DPORT | EBT_IP6_SPORT)) {
+                if (info->invflags & EBT_IP6_PROTO)
+                        return -EINVAL;
+                if (info->protocol != IPPROTO_TCP &&
+                    info->protocol != IPPROTO_UDP &&
+                    info->protocol != IPPROTO_UDPLITE &&
+                    info->protocol != IPPROTO_SCTP &&
+                    info->protocol != IPPROTO_DCCP)
+                         return -EINVAL;
+        }
+        if (info->bitmask & EBT_IP6_DPORT && info->dport[0] > info->dport[1])
+                return -EINVAL;
+        if (info->bitmask & EBT_IP6_SPORT && info->sport[0] > info->sport[1])
+                return -EINVAL;
+        return 0;
+}
+
+static struct ebt_match filter_ip6 =
+{
+        .name           = EBT_IP6_MATCH,
+        .match          = ebt_filter_ip6,
+        .check          = ebt_ip6_check,
+        .me             = THIS_MODULE,
+};
+
+static int __init ebt_ip6_init(void)
+{
+        return ebt_register_match(&filter_ip6);
+}
+
+static void __exit ebt_ip6_fini(void)
+{
+        ebt_unregister_match(&filter_ip6);
+}
+
+module_init(ebt_ip6_init);
+module_exit(ebt_ip6_fini);
+MODULE_DESCRIPTION("Ebtables: IPv6 protocol packet match");
+MODULE_LICENSE("GPL");
diff --git a/net/bridge/netfilter/ebt_log.c b/net/bridge/netfilter/ebt_log.c
index 0b209e4aad0a..c883ec8a28b4 100644
--- a/net/bridge/netfilter/ebt_log.c
+++ b/net/bridge/netfilter/ebt_log.c
@@ -18,6 +18,9 @@
 #include <linux/if_arp.h>
 #include <linux/spinlock.h>
 #include <net/netfilter/nf_log.h>
+#include <linux/ipv6.h>
+#include <net/ipv6.h>
+#include <linux/in6.h>
 
 static DEFINE_SPINLOCK(ebt_log_lock);
 
@@ -58,6 +61,27 @@ static void print_MAC(const unsigned char *p)
                 printk("%02x%c", *p, i == ETH_ALEN - 1 ? ' ':':');
 }
 
+static void
+print_ports(const struct sk_buff *skb, uint8_t protocol, int offset)
+{
+        if (protocol == IPPROTO_TCP ||
+            protocol == IPPROTO_UDP ||
+            protocol == IPPROTO_UDPLITE ||
+            protocol == IPPROTO_SCTP ||
+            protocol == IPPROTO_DCCP) {
+                const struct tcpudphdr *pptr;
+                struct tcpudphdr _ports;
+
+                pptr = skb_header_pointer(skb, offset,
+                                          sizeof(_ports), &_ports);
+                if (pptr == NULL) {
+                        printk(" INCOMPLETE TCP/UDP header");
+                        return;
+                }
+                printk(" SPT=%u DPT=%u", ntohs(pptr->src), ntohs(pptr->dst));
+        }
+}
+
 #define myNIPQUAD(a) a[0], a[1], a[2], a[3]
 static void
 ebt_log_packet(unsigned int pf, unsigned int hooknum,
@@ -95,23 +119,31 @@ ebt_log_packet(unsigned int pf, unsigned int hooknum,
                 printk(" IP SRC=%u.%u.%u.%u IP DST=%u.%u.%u.%u, IP "
                        "tos=0x%02X, IP proto=%d", NIPQUAD(ih->saddr),
                        NIPQUAD(ih->daddr), ih->tos, ih->protocol);
-                if (ih->protocol == IPPROTO_TCP ||
-                    ih->protocol == IPPROTO_UDP ||
-                    ih->protocol == IPPROTO_UDPLITE ||
-                    ih->protocol == IPPROTO_SCTP ||
-                    ih->protocol == IPPROTO_DCCP) {
-                        const struct tcpudphdr *pptr;
-                        struct tcpudphdr _ports;
-
-                        pptr = skb_header_pointer(skb, ih->ihl*4,
-                                                  sizeof(_ports), &_ports);
-                        if (pptr == NULL) {
-                                printk(" INCOMPLETE TCP/UDP header");
-                                goto out;
-                        }
-                        printk(" SPT=%u DPT=%u", ntohs(pptr->src),
-                           ntohs(pptr->dst));
+                print_ports(skb, ih->protocol, ih->ihl*4);
+                goto out;
+        }
+
+        if ((bitmask & EBT_LOG_IP6) && eth_hdr(skb)->h_proto ==
+           htons(ETH_P_IPV6)) {
+                const struct ipv6hdr *ih;
+                struct ipv6hdr _iph;
+                uint8_t nexthdr;
+                int offset_ph;
+
+                ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph);
+                if (ih == NULL) {
+                        printk(" INCOMPLETE IPv6 header");
+                        goto out;
                 }
+                printk(" IPv6 SRC=%x:%x:%x:%x:%x:%x:%x:%x "
+                       "IPv6 DST=%x:%x:%x:%x:%x:%x:%x:%x, IPv6 "
+                       "priority=0x%01X, Next Header=%d", NIP6(ih->saddr),
+                       NIP6(ih->daddr), ih->priority, ih->nexthdr);
+                nexthdr = ih->nexthdr;
+                offset_ph = ipv6_skip_exthdr(skb, sizeof(_iph), &nexthdr);
+                if (offset_ph == -1)
+                        goto out;
+                print_ports(skb, nexthdr, offset_ph);
                 goto out;
         }