diff options
Diffstat (limited to 'include/net/genetlink.h')
| -rw-r--r-- | include/net/genetlink.h | 354 |
1 files changed, 299 insertions, 55 deletions
diff --git a/include/net/genetlink.h b/include/net/genetlink.h index 805de50df00..93695f0e22a 100644 --- a/include/net/genetlink.h +++ b/include/net/genetlink.h @@ -3,6 +3,20 @@ #include <linux/genetlink.h> #include <net/netlink.h> +#include <net/net_namespace.h> + +#define GENLMSG_DEFAULT_SIZE (NLMSG_DEFAULT_SIZE - GENL_HDRLEN) + +/** + * struct genl_multicast_group - generic netlink multicast group + * @name: name of the multicast group, names are per-family + */ +struct genl_multicast_group { + char name[GENL_NAMSIZ]; +}; + +struct genl_ops; +struct genl_info; /** * struct genl_family - generic netlink family @@ -11,101 +25,214 @@ * @name: name of family * @version: protocol version * @maxattr: maximum number of attributes supported + * @netnsok: set to true if the family can handle network + * namespaces and should be presented in all of them + * @pre_doit: called before an operation's doit callback, it may + * do additional, common, filtering and return an error + * @post_doit: called after an operation's doit callback, it may + * undo operations done by pre_doit, for example release locks * @attrbuf: buffer to store parsed attributes - * @ops_list: list of all assigned operations * @family_list: family list + * @mcgrps: multicast groups used by this family (private) + * @n_mcgrps: number of multicast groups (private) + * @mcgrp_offset: starting number of multicast group IDs in this family + * @ops: the operations supported by this family (private) + * @n_ops: number of operations supported by this family (private) */ -struct genl_family -{ +struct genl_family { unsigned int id; unsigned int hdrsize; char name[GENL_NAMSIZ]; unsigned int version; unsigned int maxattr; + bool netnsok; + bool parallel_ops; + int (*pre_doit)(const struct genl_ops *ops, + struct sk_buff *skb, + struct genl_info *info); + void (*post_doit)(const struct genl_ops *ops, + struct sk_buff *skb, + struct genl_info *info); struct nlattr ** attrbuf; /* private */ - struct list_head ops_list; /* private */ + const struct genl_ops * ops; /* private */ + const struct genl_multicast_group *mcgrps; /* private */ + unsigned int n_ops; /* private */ + unsigned int n_mcgrps; /* private */ + unsigned int mcgrp_offset; /* private */ struct list_head family_list; /* private */ + struct module *module; }; -#define GENL_ADMIN_PERM 0x01 - /** * struct genl_info - receiving information * @snd_seq: sending sequence number - * @snd_pid: netlink pid of sender + * @snd_portid: netlink portid of sender * @nlhdr: netlink message header * @genlhdr: generic netlink message header * @userhdr: user specific header * @attrs: netlink attributes + * @_net: network namespace + * @user_ptr: user pointers + * @dst_sk: destination socket */ -struct genl_info -{ +struct genl_info { u32 snd_seq; - u32 snd_pid; + u32 snd_portid; struct nlmsghdr * nlhdr; struct genlmsghdr * genlhdr; void * userhdr; struct nlattr ** attrs; +#ifdef CONFIG_NET_NS + struct net * _net; +#endif + void * user_ptr[2]; + struct sock * dst_sk; }; +static inline struct net *genl_info_net(struct genl_info *info) +{ + return read_pnet(&info->_net); +} + +static inline void genl_info_net_set(struct genl_info *info, struct net *net) +{ + write_pnet(&info->_net, net); +} + /** * struct genl_ops - generic netlink operations * @cmd: command identifier + * @internal_flags: flags used by the family * @flags: flags * @policy: attribute validation policy * @doit: standard command callback * @dumpit: callback for dumpers + * @done: completion callback for dumps * @ops_list: operations list */ -struct genl_ops -{ - u8 cmd; - unsigned int flags; - struct nla_policy *policy; +struct genl_ops { + const struct nla_policy *policy; int (*doit)(struct sk_buff *skb, struct genl_info *info); int (*dumpit)(struct sk_buff *skb, struct netlink_callback *cb); - struct list_head ops_list; + int (*done)(struct netlink_callback *cb); + u8 cmd; + u8 internal_flags; + u8 flags; }; -extern int genl_register_family(struct genl_family *family); -extern int genl_unregister_family(struct genl_family *family); -extern int genl_register_ops(struct genl_family *, struct genl_ops *ops); -extern int genl_unregister_ops(struct genl_family *, struct genl_ops *ops); +int __genl_register_family(struct genl_family *family); -extern struct sock *genl_sock; +static inline int genl_register_family(struct genl_family *family) +{ + family->module = THIS_MODULE; + return __genl_register_family(family); +} /** - * genlmsg_put - Add generic netlink header to netlink message - * @skb: socket buffer holding the message - * @pid: netlink pid the message is addressed to - * @seq: sequence number (usually the one of the sender) - * @type: netlink message type - * @hdrlen: length of the user specific header - * @flags netlink message flags - * @cmd: generic netlink command - * @version: version + * genl_register_family_with_ops - register a generic netlink family with ops + * @family: generic netlink family + * @ops: operations to be registered + * @n_ops: number of elements to register * - * Returns pointer to user specific header + * Registers the specified family and operations from the specified table. + * Only one family may be registered with the same family name or identifier. + * + * The family id may equal GENL_ID_GENERATE causing an unique id to + * be automatically generated and assigned. + * + * Either a doit or dumpit callback must be specified for every registered + * operation or the function will fail. Only one operation structure per + * command identifier may be registered. + * + * See include/net/genetlink.h for more documenation on the operations + * structure. + * + * Return 0 on success or a negative error code. */ -static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, - int type, int hdrlen, int flags, - u8 cmd, u8 version) +static inline int +_genl_register_family_with_ops_grps(struct genl_family *family, + const struct genl_ops *ops, size_t n_ops, + const struct genl_multicast_group *mcgrps, + size_t n_mcgrps) { - struct nlmsghdr *nlh; - struct genlmsghdr *hdr; + family->module = THIS_MODULE; + family->ops = ops; + family->n_ops = n_ops; + family->mcgrps = mcgrps; + family->n_mcgrps = n_mcgrps; + return __genl_register_family(family); +} + +#define genl_register_family_with_ops(family, ops) \ + _genl_register_family_with_ops_grps((family), \ + (ops), ARRAY_SIZE(ops), \ + NULL, 0) +#define genl_register_family_with_ops_groups(family, ops, grps) \ + _genl_register_family_with_ops_grps((family), \ + (ops), ARRAY_SIZE(ops), \ + (grps), ARRAY_SIZE(grps)) - nlh = nlmsg_put(skb, pid, seq, type, GENL_HDRLEN + hdrlen, flags); - if (nlh == NULL) - return NULL; +int genl_unregister_family(struct genl_family *family); +void genl_notify(struct genl_family *family, + struct sk_buff *skb, struct net *net, u32 portid, + u32 group, struct nlmsghdr *nlh, gfp_t flags); + +struct sk_buff *genlmsg_new_unicast(size_t payload, struct genl_info *info, + gfp_t flags); +void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, + struct genl_family *family, int flags, u8 cmd); + +/** + * genlmsg_nlhdr - Obtain netlink header from user specified header + * @user_hdr: user header as returned from genlmsg_put() + * @family: generic netlink family + * + * Returns pointer to netlink header. + */ +static inline struct nlmsghdr *genlmsg_nlhdr(void *user_hdr, + struct genl_family *family) +{ + return (struct nlmsghdr *)((char *)user_hdr - + family->hdrsize - + GENL_HDRLEN - + NLMSG_HDRLEN); +} - hdr = nlmsg_data(nlh); - hdr->cmd = cmd; - hdr->version = version; - hdr->reserved = 0; +/** + * genl_dump_check_consistent - check if sequence is consistent and advertise if not + * @cb: netlink callback structure that stores the sequence number + * @user_hdr: user header as returned from genlmsg_put() + * @family: generic netlink family + * + * Cf. nl_dump_check_consistent(), this just provides a wrapper to make it + * simpler to use with generic netlink. + */ +static inline void genl_dump_check_consistent(struct netlink_callback *cb, + void *user_hdr, + struct genl_family *family) +{ + nl_dump_check_consistent(cb, genlmsg_nlhdr(user_hdr, family)); +} - return (char *) hdr + GENL_HDRLEN; +/** + * genlmsg_put_reply - Add generic netlink header to a reply message + * @skb: socket buffer holding the message + * @info: receiver info + * @family: generic netlink family + * @flags: netlink message flags + * @cmd: generic netlink command + * + * Returns pointer to user specific header + */ +static inline void *genlmsg_put_reply(struct sk_buff *skb, + struct genl_info *info, + struct genl_family *family, + int flags, u8 cmd) +{ + return genlmsg_put(skb, info->snd_portid, info->snd_seq, family, + flags, cmd); } /** @@ -123,31 +250,148 @@ static inline int genlmsg_end(struct sk_buff *skb, void *hdr) * @skb: socket buffer the message is stored in * @hdr: generic netlink message header */ -static inline int genlmsg_cancel(struct sk_buff *skb, void *hdr) +static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr) +{ + if (hdr) + nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); +} + +/** + * genlmsg_multicast_netns - multicast a netlink message to a specific netns + * @family: the generic netlink family + * @net: the net namespace + * @skb: netlink message as socket buffer + * @portid: own netlink portid to avoid sending to yourself + * @group: offset of multicast group in groups array + * @flags: allocation flags + */ +static inline int genlmsg_multicast_netns(struct genl_family *family, + struct net *net, struct sk_buff *skb, + u32 portid, unsigned int group, gfp_t flags) { - return nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN); + if (WARN_ON_ONCE(group >= family->n_mcgrps)) + return -EINVAL; + group = family->mcgrp_offset + group; + return nlmsg_multicast(net->genl_sock, skb, portid, group, flags); } /** - * genlmsg_multicast - multicast a netlink message + * genlmsg_multicast - multicast a netlink message to the default netns + * @family: the generic netlink family * @skb: netlink message as socket buffer - * @pid: own netlink pid to avoid sending to yourself - * @group: multicast group id + * @portid: own netlink portid to avoid sending to yourself + * @group: offset of multicast group in groups array + * @flags: allocation flags */ -static inline int genlmsg_multicast(struct sk_buff *skb, u32 pid, - unsigned int group) +static inline int genlmsg_multicast(struct genl_family *family, + struct sk_buff *skb, u32 portid, + unsigned int group, gfp_t flags) { - return nlmsg_multicast(genl_sock, skb, pid, group); + return genlmsg_multicast_netns(family, &init_net, skb, + portid, group, flags); } /** + * genlmsg_multicast_allns - multicast a netlink message to all net namespaces + * @family: the generic netlink family + * @skb: netlink message as socket buffer + * @portid: own netlink portid to avoid sending to yourself + * @group: offset of multicast group in groups array + * @flags: allocation flags + * + * This function must hold the RTNL or rcu_read_lock(). + */ +int genlmsg_multicast_allns(struct genl_family *family, + struct sk_buff *skb, u32 portid, + unsigned int group, gfp_t flags); + +/** * genlmsg_unicast - unicast a netlink message * @skb: netlink message as socket buffer - * @pid: netlink pid of the destination socket + * @portid: netlink portid of the destination socket + */ +static inline int genlmsg_unicast(struct net *net, struct sk_buff *skb, u32 portid) +{ + return nlmsg_unicast(net->genl_sock, skb, portid); +} + +/** + * genlmsg_reply - reply to a request + * @skb: netlink message to be sent back + * @info: receiver information + */ +static inline int genlmsg_reply(struct sk_buff *skb, struct genl_info *info) +{ + return genlmsg_unicast(genl_info_net(info), skb, info->snd_portid); +} + +/** + * gennlmsg_data - head of message payload + * @gnlh: genetlink message header + */ +static inline void *genlmsg_data(const struct genlmsghdr *gnlh) +{ + return ((unsigned char *) gnlh + GENL_HDRLEN); +} + +/** + * genlmsg_len - length of message payload + * @gnlh: genetlink message header + */ +static inline int genlmsg_len(const struct genlmsghdr *gnlh) +{ + struct nlmsghdr *nlh = (struct nlmsghdr *)((unsigned char *)gnlh - + NLMSG_HDRLEN); + return (nlh->nlmsg_len - GENL_HDRLEN - NLMSG_HDRLEN); +} + +/** + * genlmsg_msg_size - length of genetlink message not including padding + * @payload: length of message payload + */ +static inline int genlmsg_msg_size(int payload) +{ + return GENL_HDRLEN + payload; +} + +/** + * genlmsg_total_size - length of genetlink message including padding + * @payload: length of message payload + */ +static inline int genlmsg_total_size(int payload) +{ + return NLMSG_ALIGN(genlmsg_msg_size(payload)); +} + +/** + * genlmsg_new - Allocate a new generic netlink message + * @payload: size of the message payload + * @flags: the type of memory to allocate. + */ +static inline struct sk_buff *genlmsg_new(size_t payload, gfp_t flags) +{ + return nlmsg_new(genlmsg_total_size(payload), flags); +} + +/** + * genl_set_err - report error to genetlink broadcast listeners + * @family: the generic netlink family + * @net: the network namespace to report the error to + * @portid: the PORTID of a process that we want to skip (if any) + * @group: the broadcast group that will notice the error + * (this is the offset of the multicast group in the groups array) + * @code: error code, must be negative (as usual in kernelspace) + * + * This function returns the number of broadcast listeners that have set the + * NETLINK_RECV_NO_ENOBUFS socket option. */ -static inline int genlmsg_unicast(struct sk_buff *skb, u32 pid) +static inline int genl_set_err(struct genl_family *family, struct net *net, + u32 portid, u32 group, int code) { - return nlmsg_unicast(genl_sock, skb, pid); + if (WARN_ON_ONCE(group >= family->n_mcgrps)) + return -EINVAL; + group = family->mcgrp_offset + group; + return netlink_set_err(net->genl_sock, portid, group, code); } #endif /* __NET_GENERIC_NETLINK_H */ |