This patch implements "inner" flag option in set iptables match,
allowing matching based on the properties (source/destination IP address,
protocol, port and so on) of the original (inner) connection in the event
of the following ICMP[v4,v6] messages:
ICMPv4 destination-unreachable (code 3);
ICMPv4 source-quench (code 4);
ICMPv4 time-exceeded (code 11);
ICMPv6 destination-unreachable (code 1);
ICMPv6 packet-too-big (code 2);
ICMPv6 time-exceeded (code 3);
Revision history:
v1 * initial revision
v2 * redundant code removed;
* added a new header file (ip_set_icmp.h) with 2 inline functions,
allowing access to the internal icmp header properties;
* removed ip[46]inneraddr[ptr]functions as they are no longer needed
* added new ipv[46]addr[ptr] and ip_set_get*port functions, the old
functions are still preserved for backwards compatibility
Signed-off-by: Dash Four <mr.dash.four@xxxxxxxxxxxxxx>
---
kernel/include/linux/netfilter/ipset/ip_set.h | 66 ++++++++++++++
.../include/linux/netfilter/ipset/ip_set_getport.h | 16 ++++
kernel/include/linux/netfilter/ipset/ip_set_icmp.h | 91 ++++++++++++++++++++
kernel/include/uapi/linux/netfilter/ipset/ip_set.h | 2 +
kernel/net/netfilter/ipset/ip_set_getport.c | 78 +++++++++++++----
5 files changed, 238 insertions(+), 15 deletions(-)
create mode 100644 kernel/include/linux/netfilter/ipset/ip_set_icmp.h
diff --git a/kernel/include/linux/netfilter/ipset/ip_set.h b/kernel/include/linux/netfilter/ipset/ip_set.h
index 8499e25..5b6ef72 100644
--- a/kernel/include/linux/netfilter/ipset/ip_set.h
+++ b/kernel/include/linux/netfilter/ipset/ip_set.h
@@ -17,9 +17,13 @@
#include <linux/netfilter/x_tables.h>
#include <linux/stringify.h>
#include <linux/vmalloc.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+#include <net/icmp.h>
#include <net/netlink.h>
#include <uapi/linux/netfilter/ipset/ip_set.h>
#include <linux/netfilter/ipset/ip_set_compat.h>
+#include <linux/netfilter/ipset/ip_set_icmp.h>
#define _IP_SET_MODULE_DESC(a, b, c) \
MODULE_DESCRIPTION(a " type of IP sets, revisions " b "-" c)
@@ -361,6 +365,25 @@ static inline int nla_put_ipaddr6(struct sk_buff *skb, int type,
}
/* Get address from skbuff */
+static inline bool
+ipv4addrptr(const struct sk_buff *skb, bool inner, bool src, __be32 *addr)
+{
+ struct iphdr *ih = ip_hdr(skb);
+ unsigned int protooff = ip_hdrlen(skb);
+
+ if (ih == NULL ||
+ (inner &&
+ (ih->protocol != IPPROTO_ICMP ||
+ !ip_set_get_icmpv4_inner_hdr(skb, &protooff, &ih))))
+ goto err;
+
+ *addr = src ? ih->saddr : ih->daddr;
+ return true;
+
+err:
+ return false;
+}
+
static inline __be32
ip4addr(const struct sk_buff *skb, bool src)
{
@@ -373,12 +396,55 @@ ip4addrptr(const struct sk_buff *skb, bool src, __be32 *addr)
*addr = src ? ip_hdr(skb)->saddr : ip_hdr(skb)->daddr;
}
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+static inline bool
+ipv6addrptr(const struct sk_buff *skb, bool inner, bool src,
+ struct in6_addr *addr)
+{
+ struct ipv6hdr *ih = ipv6_hdr(skb);
+
+ if (ih == NULL)
+ goto err;
+
+ if (inner) {
+ unsigned int protooff;
+ u8 nexthdr = ih->nexthdr;
+ __be16 frag_off;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 3, 0)
+ protooff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
+ &nexthdr, &frag_off);
+#else
+ protooff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr),
+ &nexthdr);
+#endif
+ if (protooff < 0 || nexthdr != IPPROTO_ICMPV6 ||
+ !ip_set_get_icmpv6_inner_hdr(skb, &protooff, &ih))
+ goto err;
+ }
+ memcpy(addr, src ? &ih->saddr : &ih->daddr, sizeof(*addr));
+ return true;
+
+err:
+ return false;
+}
+
static inline void
ip6addrptr(const struct sk_buff *skb, bool src, struct in6_addr *addr)
{
memcpy(addr, src ? &ipv6_hdr(skb)->saddr : &ipv6_hdr(skb)->daddr,
sizeof(*addr));
}
+#else
+static inline bool
+ipv6addrptr(const struct sk_buff *skb, bool inner, bool src,
+ struct in6_addr *addr)
+{
+ return false;
+}
+
+static inline void
+ip6addrptr(const struct sk_buff *skb, bool src, struct in6_addr *addr) { ; }
+#endif
/* Calculate the bytes required to store the inclusive range of a-b */
static inline int
diff --git a/kernel/include/linux/netfilter/ipset/ip_set_getport.h b/kernel/include/linux/netfilter/ipset/ip_set_getport.h
index 90d0930..8cdc177 100644
--- a/kernel/include/linux/netfilter/ipset/ip_set_getport.h
+++ b/kernel/include/linux/netfilter/ipset/ip_set_getport.h
@@ -1,13 +1,26 @@
#ifndef _IP_SET_GETPORT_H
#define _IP_SET_GETPORT_H
+extern bool ip_set_get_ipv4_port(const struct sk_buff *skb, bool inner,
+ bool src, __be16 *port, u8 *proto);
+
extern bool ip_set_get_ip4_port(const struct sk_buff *skb, bool src,
__be16 *port, u8 *proto);
#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+extern bool ip_set_get_ipv6_port(const struct sk_buff *skb, bool inner,
+ bool src, __be16 *port, u8 *proto);
+
extern bool ip_set_get_ip6_port(const struct sk_buff *skb, bool src,
__be16 *port, u8 *proto);
#else
+static inline bool ip_set_get_ipv6_port(const struct sk_buff *skb,
+ bool inner, bool src,
+ __be16 *port, u8 *proto)
+{
+ return false;
+}
+
static inline bool ip_set_get_ip6_port(const struct sk_buff *skb, bool src,
__be16 *port, u8 *proto)
{
@@ -15,6 +28,9 @@ static inline bool ip_set_get_ip6_port(const struct sk_buff *skb, bool src,
}
#endif
+extern bool ip_set_get_ipv_port(const struct sk_buff *skb, u8 pf, bool inner,
+ bool src, __be16 *port);
+
extern bool ip_set_get_ip_port(const struct sk_buff *skb, u8 pf, bool src,
__be16 *port);
diff --git a/kernel/include/linux/netfilter/ipset/ip_set_icmp.h b/kernel/include/linux/netfilter/ipset/ip_set_icmp.h
new file mode 100644
index 0000000..e116d28
--- /dev/null
+++ b/kernel/include/linux/netfilter/ipset/ip_set_icmp.h
@@ -0,0 +1,91 @@
+#ifndef _IP_SET_ICMP_H
+#define _IP_SET_ICMP_H
+
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/icmp.h>
+
+static inline
+bool ip_set_get_icmpv4_inner_hdr(const struct sk_buff *skb,
+ unsigned int *offset,
+ struct iphdr **ih)
+{
+ u8 type;
+ struct iphdr _iph;
+ struct icmphdr _icmph;
+ struct iphdr *iph;
+ const struct icmphdr *ich;
+ /* RFC 1122: 3.2.2: req'd len: IP header + 8 bytes of inner header */
+ static const size_t req_len = sizeof(struct iphdr) + 8;
+
+ if (offset == NULL || ih == NULL)
+ goto err;
+
+ ich = skb_header_pointer(skb, *offset, sizeof(_icmph), &_icmph);
+ if (ich == NULL ||
+ (ich->type <= NR_ICMP_TYPES && skb->len - *offset < req_len))
+ goto err;
+
+ type = ich->type;
+ if (type == ICMP_DEST_UNREACH ||
+ type == ICMP_SOURCE_QUENCH ||
+ type == ICMP_TIME_EXCEEDED) {
+ *offset += sizeof(_icmph);
+ iph = skb_header_pointer(skb, *offset, sizeof(_iph), &_iph);
+ if (iph == NULL || ntohs(iph->frag_off) & IP_OFFSET)
+ goto err;
+
+ *ih = iph;
+ return true;
+ }
+
+err:
+ return false;
+}
+
+#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
+static inline
+bool ip_set_get_icmpv6_inner_hdr(const struct sk_buff *skb,
+ unsigned int *offset,
+ struct ipv6hdr **ih)
+{
+ u8 type;
+ const struct icmp6hdr *ic;
+ struct icmp6hdr _icmp6h;
+ struct ipv6hdr _ip6h;
+ struct ipv6hdr *iph;
+
+ if (offset == NULL || ih == NULL)
+ goto err;
+
+ ic = skb_header_pointer(skb, *offset, sizeof(_icmp6h), &_icmp6h);
+ if (ic == NULL)
+ goto err;
+
+ type = ic->icmp6_type;
+ if (type == ICMPV6_DEST_UNREACH ||
+ type == ICMPV6_PKT_TOOBIG ||
+ type == ICMPV6_TIME_EXCEED) {
+ *offset += sizeof(_icmp6h);
+ iph = skb_header_pointer(skb, *offset, sizeof(_ip6h), &_ip6h);
+ if (iph == NULL)
+ goto err;
+
+ *ih = iph;
+ return true;
+ }
+
+err:
+ return false;
+}
+#else
+static inline
+bool ip_set_get_icmpv6_inner_hdr(const struct sk_buff *skb,
+ unsigned int offset,
+ struct ipv6hdr **ih)
+{
+ return false;
+}
+#endif
+
+#endif /*_IP_SET_ICMP_H*/
diff --git a/kernel/include/uapi/linux/netfilter/ipset/ip_set.h b/kernel/include/uapi/linux/netfilter/ipset/ip_set.h
index 8024cdf..e9e6586 100644
--- a/kernel/include/uapi/linux/netfilter/ipset/ip_set.h
+++ b/kernel/include/uapi/linux/netfilter/ipset/ip_set.h
@@ -161,6 +161,8 @@ enum ipset_cmd_flags {
(1 << IPSET_FLAG_BIT_SKIP_SUBCOUNTER_UPDATE),
IPSET_FLAG_BIT_MATCH_COUNTERS = 5,
IPSET_FLAG_MATCH_COUNTERS = (1 << IPSET_FLAG_BIT_MATCH_COUNTERS),
+ IPSET_FLAG_BIT_INNER = 6,
+ IPSET_FLAG_INNER = (1 << IPSET_FLAG_BIT_INNER),
IPSET_FLAG_BIT_RETURN_NOMATCH = 7,
IPSET_FLAG_RETURN_NOMATCH = (1 << IPSET_FLAG_BIT_RETURN_NOMATCH),
IPSET_FLAG_CMD_MAX = 15,
diff --git a/kernel/net/netfilter/ipset/ip_set_getport.c b/kernel/net/netfilter/ipset/ip_set_getport.c
index a0d96eb..73ccfb3 100644
--- a/kernel/net/netfilter/ipset/ip_set_getport.c
+++ b/kernel/net/netfilter/ipset/ip_set_getport.c
@@ -19,7 +19,9 @@
#include <linux/netfilter_ipv6/ip6_tables.h>
#include <net/ip.h>
#include <net/ipv6.h>
+#include <net/icmp.h>
+#include <linux/netfilter/ipset/ip_set_icmp.h>
#include <linux/netfilter/ipset/ip_set_getport.h>
/* We must handle non-linear skbs */
@@ -97,10 +99,10 @@ get_port(const struct sk_buff *skb, int protocol, unsigned int protooff,
}
bool
-ip_set_get_ip4_port(const struct sk_buff *skb, bool src,
- __be16 *port, u8 *proto)
+ip_set_get_ipv4_port(const struct sk_buff *skb, bool inner, bool src,
+ __be16 *port, u8 *proto)
{
- const struct iphdr *iph = ip_hdr(skb);
+ struct iphdr *iph = ip_hdr(skb);
unsigned int protooff = ip_hdrlen(skb);
int protocol = iph->protocol;
@@ -116,54 +118,93 @@ ip_set_get_ip4_port(const struct sk_buff *skb, bool src,
case IPPROTO_UDPLITE:
case IPPROTO_ICMP:
/* Port info not available for fragment offset > 0 */
- return false;
+ goto err;
default:
/* Other protocols doesn't have ports,
so we can match fragments */
*proto = protocol;
return true;
}
+ if (inner) {
+ if (protocol != IPPROTO_ICMP ||
+ !ip_set_get_icmpv4_inner_hdr(skb, &protooff, &iph))
+ goto err;
+ protocol = iph->protocol;
+ protooff += iph->ihl*4;
+ }
return get_port(skb, protocol, protooff, src, port, proto);
+
+err:
+ return false;
+}
+EXPORT_SYMBOL_GPL(ip_set_get_ipv4_port);
+
+bool
+ip_set_get_ip4_port(const struct sk_buff *skb, bool src,
+ __be16 *port, u8 *proto)
+{
+ return ip_set_get_ipv4_port(skb, false, src, port, proto);
}
EXPORT_SYMBOL_GPL(ip_set_get_ip4_port);
#if defined(CONFIG_IP6_NF_IPTABLES) || defined(CONFIG_IP6_NF_IPTABLES_MODULE)
bool
-ip_set_get_ip6_port(const struct sk_buff *skb, bool src,
- __be16 *port, u8 *proto)
+ip_set_get_ipv6_port(const struct sk_buff *skb, bool inner, bool src,
+ __be16 *port, u8 *proto)
{
- int protoff;
+ unsigned int protooff;
u8 nexthdr;
__be16 frag_off = 0;
nexthdr = ipv6_hdr(skb)->nexthdr;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 3, 0)
- protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
+ protooff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
&frag_off);
#else
- protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
+ protooff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr);
#endif
- if (protoff < 0 || (frag_off & htons(~0x7)) != 0)
- return false;
+ if (protooff < 0 || (frag_off & htons(~0x7)) != 0)
+ goto err;
+
+ if (inner) {
+ struct ipv6hdr *ih;
+ if (nexthdr != IPPROTO_ICMPV6 ||
+ !ip_set_get_icmpv6_inner_hdr(skb, &protooff, &ih))
+ goto err;
- return get_port(skb, nexthdr, protoff, src, port, proto);
+ nexthdr = ih->nexthdr;
+ protooff += sizeof(struct ipv6hdr);
+ }
+ return get_port(skb, nexthdr, protooff, src, port, proto);
+
+err:
+ return false;
+}
+EXPORT_SYMBOL_GPL(ip_set_get_ipv6_port);
+
+bool
+ip_set_get_ip6_port(const struct sk_buff *skb, bool src,
+ __be16 *port, u8 *proto)
+{
+ return ip_set_get_ipv6_port(skb, false, src, port, proto);
}
EXPORT_SYMBOL_GPL(ip_set_get_ip6_port);
#endif
bool
-ip_set_get_ip_port(const struct sk_buff *skb, u8 pf, bool src, __be16 *port)
+ip_set_get_ipv_port(const struct sk_buff *skb, u8 pf, bool inner, bool src,
+ __be16 *port)
{
bool ret;
u8 proto;
switch (pf) {
case NFPROTO_IPV4:
- ret = ip_set_get_ip4_port(skb, src, port, &proto);
+ ret = ip_set_get_ipv4_port(skb, inner, src, port, &proto);
break;
case NFPROTO_IPV6:
- ret = ip_set_get_ip6_port(skb, src, port, &proto);
+ ret = ip_set_get_ipv6_port(skb, inner, src, port, &proto);
break;
default:
return false;
@@ -178,4 +219,11 @@ ip_set_get_ip_port(const struct sk_buff *skb, u8 pf, bool src, __be16 *port)
return false;
}
}
+EXPORT_SYMBOL_GPL(ip_set_get_ipv_port);
+
+bool
+ip_set_get_ip_port(const struct sk_buff *skb, u8 pf, bool src, __be16 *port)
+{
+ return ip_set_get_ipv_port(skb, pf, false, src, port);
+}
EXPORT_SYMBOL_GPL(ip_set_get_ip_port);
--
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