From f9e815b376dc19e6afc551cd755ac64e9e42d81f Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Tue, 9 Aug 2005 19:30:24 -0700 Subject: [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 Signed-off-by: David S. Miller --- include/linux/netfilter/nfnetlink.h | 145 ++++++++++++++++++++++++++++++++++++ 1 file changed, 145 insertions(+) create mode 100644 include/linux/netfilter/nfnetlink.h (limited to 'include') 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 + +/* 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 + +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