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authorHarald Welte <laforge@netfilter.org>2005-08-09 19:30:24 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2005-08-29 15:31:29 -0700
commitf9e815b376dc19e6afc551cd755ac64e9e42d81f (patch)
tree1cbc3d1e64d3dd51404c8935e676beb468867979 /include
parentac3247baf8ecadf168642e3898b0212c29c79715 (diff)
[NETFITLER]: Add nfnetlink layer.
Introduce "nfnetlink" (netfilter netlink) layer. This layer is used as transport layer for all userspace communication of the new upcoming netfilter subsystems, such as ctnetlink, nfnetlink_queue and some day even the mythical pkttables ;) Signed-off-by: Harald Welte <laforge@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
-rw-r--r--include/linux/netfilter/nfnetlink.h145
1 files changed, 145 insertions, 0 deletions
diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h
new file mode 100644
index 00000000000..8f1bfb8d650
--- /dev/null
+++ b/include/linux/netfilter/nfnetlink.h
@@ -0,0 +1,145 @@
+#ifndef _NFNETLINK_H
+#define _NFNETLINK_H
+#include <linux/types.h>
+
+/* nfnetlink groups: Up to 32 maximum */
+#define NF_NETLINK_CONNTRACK_NEW 0x00000001
+#define NF_NETLINK_CONNTRACK_UPDATE 0x00000002
+#define NF_NETLINK_CONNTRACK_DESTROY 0x00000004
+#define NF_NETLINK_CONNTRACK_EXP_NEW 0x00000008
+#define NF_NETLINK_CONNTRACK_EXP_UPDATE 0x00000010
+#define NF_NETLINK_CONNTRACK_EXP_DESTROY 0x00000020
+
+/* Generic structure for encapsulation optional netfilter information.
+ * It is reminiscent of sockaddr, but with sa_family replaced
+ * with attribute type.
+ * ! This should someday be put somewhere generic as now rtnetlink and
+ * ! nfnetlink use the same attributes methods. - J. Schulist.
+ */
+
+struct nfattr
+{
+ u_int16_t nfa_len;
+ u_int16_t nfa_type;
+} __attribute__ ((packed));
+
+/* FIXME: Shamelessly copy and pasted from rtnetlink.h, it's time
+ * to put this in a generic file */
+
+#define NFA_ALIGNTO 4
+#define NFA_ALIGN(len) (((len) + NFA_ALIGNTO - 1) & ~(NFA_ALIGNTO - 1))
+#define NFA_OK(nfa,len) ((len) > 0 && (nfa)->nfa_len >= sizeof(struct nfattr) \
+ && (nfa)->nfa_len <= (len))
+#define NFA_NEXT(nfa,attrlen) ((attrlen) -= NFA_ALIGN((nfa)->nfa_len), \
+ (struct nfattr *)(((char *)(nfa)) + NFA_ALIGN((nfa)->nfa_len)))
+#define NFA_LENGTH(len) (NFA_ALIGN(sizeof(struct nfattr)) + (len))
+#define NFA_SPACE(len) NFA_ALIGN(NFA_LENGTH(len))
+#define NFA_DATA(nfa) ((void *)(((char *)(nfa)) + NFA_LENGTH(0)))
+#define NFA_PAYLOAD(nfa) ((int)((nfa)->nfa_len) - NFA_LENGTH(0))
+#define NFA_NEST(skb, type) \
+({ struct nfattr *__start = (struct nfattr *) (skb)->tail; \
+ NFA_PUT(skb, type, 0, NULL); \
+ __start; })
+#define NFA_NEST_END(skb, start) \
+({ (start)->nfa_len = ((skb)->tail - (unsigned char *) (start)); \
+ (skb)->len; })
+#define NFA_NEST_CANCEL(skb, start) \
+({ if (start) \
+ skb_trim(skb, (unsigned char *) (start) - (skb)->data); \
+ -1; })
+
+/* General form of address family dependent message.
+ */
+struct nfgenmsg {
+ u_int8_t nfgen_family; /* AF_xxx */
+ u_int8_t version; /* nfnetlink version */
+ u_int16_t res_id; /* resource id */
+} __attribute__ ((packed));
+
+#define NFNETLINK_V1 1
+
+#define NFM_NFA(n) ((struct nfattr *)(((char *)(n)) \
+ + NLMSG_ALIGN(sizeof(struct nfgenmsg))))
+#define NFM_PAYLOAD(n) NLMSG_PAYLOAD(n, sizeof(struct nfgenmsg))
+
+/* netfilter netlink message types are split in two pieces:
+ * 8 bit subsystem, 8bit operation.
+ */
+
+#define NFNL_SUBSYS_ID(x) ((x & 0xff00) >> 8)
+#define NFNL_MSG_TYPE(x) (x & 0x00ff)
+
+enum nfnl_subsys_id {
+ NFNL_SUBSYS_NONE = 0,
+ NFNL_SUBSYS_CTNETLINK,
+ NFNL_SUBSYS_CTNETLINK_EXP,
+ NFNL_SUBSYS_IPTNETLINK,
+ NFNL_SUBSYS_QUEUE,
+ NFNL_SUBSYS_ULOG,
+ NFNL_SUBSYS_COUNT,
+};
+
+#ifdef __KERNEL__
+
+#include <linux/capability.h>
+
+struct nfnl_callback
+{
+ kernel_cap_t cap_required; /* capabilities required for this msg */
+ int (*call)(struct sock *nl, struct sk_buff *skb,
+ struct nlmsghdr *nlh, struct nfattr *cda[], int *errp);
+};
+
+struct nfnetlink_subsystem
+{
+ const char *name;
+ __u8 subsys_id; /* nfnetlink subsystem ID */
+ __u8 cb_count; /* number of callbacks */
+ u_int32_t attr_count; /* number of nfattr's */
+ struct nfnl_callback *cb; /* callback for individual types */
+};
+
+extern void __nfa_fill(struct sk_buff *skb, int attrtype,
+ int attrlen, const void *data);
+#define NFA_PUT(skb, attrtype, attrlen, data) \
+({ if (skb_tailroom(skb) < (int)NFA_SPACE(attrlen)) goto nfattr_failure; \
+ __nfa_fill(skb, attrtype, attrlen, data); })
+
+extern struct semaphore nfnl_sem;
+
+#define nfnl_shlock() down(&nfnl_sem)
+#define nfnl_shlock_nowait() down_trylock(&nfnl_sem)
+
+#define nfnl_shunlock() do { up(&nfnl_sem); \
+ if(nfnl && nfnl->sk_receive_queue.qlen) \
+ nfnl->sk_data_ready(nfnl, 0); \
+ } while(0)
+
+extern void nfnl_lock(void);
+extern void nfnl_unlock(void);
+
+extern int nfnetlink_subsys_register(struct nfnetlink_subsystem *n);
+extern int nfnetlink_subsys_unregister(struct nfnetlink_subsystem *n);
+
+extern int nfattr_parse(struct nfattr *tb[], int maxattr,
+ struct nfattr *nfa, int len);
+
+#define nfattr_parse_nested(tb, max, nfa) \
+ nfattr_parse((tb), (max), NFA_DATA((nfa)), NFA_PAYLOAD((nfa)))
+
+#define nfattr_bad_size(tb, max, cta_min) \
+({ int __i, __res = 0; \
+ for (__i=0; __i<max; __i++) \
+ if (tb[__i] && NFA_PAYLOAD(tb[__i]) < cta_min[__i]){ \
+ __res = 1; \
+ break; \
+ } \
+ __res; \
+})
+
+extern int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group,
+ int echo);
+extern int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags);
+
+#endif /* __KERNEL__ */
+#endif /* _NFNETLINK_H */