linux/netfilter/nfnetlink.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _NFNETLINK_H
0003 #define _NFNETLINK_H
0004
0005 #include <linux/netlink.h>
0006 #include <linux/capability.h>
0007 #include <net/netlink.h>
0008 #include <uapi/linux/netfilter/nfnetlink.h>
0009
0010 struct nfnl_info {
0011     struct net      *net;
0012     struct sock     *sk;
0013     const struct nlmsghdr   *nlh;
0014     const struct nfgenmsg   *nfmsg;
0015     struct netlink_ext_ack  *extack;
0016 };
0017
0018 enum nfnl_callback_type {
0019     NFNL_CB_UNSPEC  = 0,
0020     NFNL_CB_MUTEX,
0021     NFNL_CB_RCU,
0022     NFNL_CB_BATCH,
0023 };
0024
0025 struct nfnl_callback {
0026     int (*call)(struct sk_buff *skb, const struct nfnl_info *info,
0027             const struct nlattr * const cda[]);
0028     const struct nla_policy *policy;
0029     enum nfnl_callback_type type;
0030     __u16           attr_count;
0031 };
0032
0033 enum nfnl_abort_action {
0034     NFNL_ABORT_NONE     = 0,
0035     NFNL_ABORT_AUTOLOAD,
0036     NFNL_ABORT_VALIDATE,
0037 };
0038
0039 struct nfnetlink_subsystem {
0040     const char *name;
0041     __u8 subsys_id;         /* nfnetlink subsystem ID */
0042     __u8 cb_count;          /* number of callbacks */
0043     const struct nfnl_callback *cb; /* callback for individual types */
0044     struct module *owner;
0045     int (*commit)(struct net *net, struct sk_buff *skb);
0046     int (*abort)(struct net *net, struct sk_buff *skb,
0047              enum nfnl_abort_action action);
0048     void (*cleanup)(struct net *net);
0049     bool (*valid_genid)(struct net *net, u32 genid);
0050 };
0051
0052 int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n);
0053 int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n);
0054
0055 int nfnetlink_has_listeners(struct net *net, unsigned int group);
0056 int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid,
0057            unsigned int group, int echo, gfp_t flags);
0058 int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error);
0059 int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid);
0060 void nfnetlink_broadcast(struct net *net, struct sk_buff *skb, __u32 portid,
0061              __u32 group, gfp_t allocation);
0062
0063 static inline u16 nfnl_msg_type(u8 subsys, u8 msg_type)
0064 {
0065     return subsys << 8 | msg_type;
0066 }
0067
0068 static inline void nfnl_fill_hdr(struct nlmsghdr *nlh, u8 family, u8 version,
0069                  __be16 res_id)
0070 {
0071     struct nfgenmsg *nfmsg;
0072
0073     nfmsg = nlmsg_data(nlh);
0074     nfmsg->nfgen_family = family;
0075     nfmsg->version = version;
0076     nfmsg->res_id = res_id;
0077 }
0078
0079 static inline struct nlmsghdr *nfnl_msg_put(struct sk_buff *skb, u32 portid,
0080                         u32 seq, int type, int flags,
0081                         u8 family, u8 version,
0082                         __be16 res_id)
0083 {
0084     struct nlmsghdr *nlh;
0085
0086     nlh = nlmsg_put(skb, portid, seq, type, sizeof(struct nfgenmsg), flags);
0087     if (!nlh)
0088         return NULL;
0089
0090     nfnl_fill_hdr(nlh, family, version, res_id);
0091
0092     return nlh;
0093 }
0094
0095 void nfnl_lock(__u8 subsys_id);
0096 void nfnl_unlock(__u8 subsys_id);
0097 #ifdef CONFIG_PROVE_LOCKING
0098 bool lockdep_nfnl_is_held(__u8 subsys_id);
0099 #else
0100 static inline bool lockdep_nfnl_is_held(__u8 subsys_id)
0101 {
0102     return true;
0103 }
0104 #endif /* CONFIG_PROVE_LOCKING */
0105
0106 #define MODULE_ALIAS_NFNL_SUBSYS(subsys) \
0107     MODULE_ALIAS("nfnetlink-subsys-" __stringify(subsys))
0108
0109 #endif  /* _NFNETLINK_H */