Commit fbfc504a authored by Björn Töpel's avatar Björn Töpel Committed by Alexei Starovoitov
Browse files

bpf: introduce new bpf AF_XDP map type BPF_MAP_TYPE_XSKMAP 



The xskmap is yet another BPF map, very much inspired by
dev/cpu/sockmap, and is a holder of AF_XDP sockets. A user application
adds AF_XDP sockets into the map, and by using the bpf_redirect_map
helper, an XDP program can redirect XDP frames to an AF_XDP socket.

Note that a socket that is bound to certain ifindex/queue index will
*only* accept XDP frames from that netdev/queue index. If an XDP
program tries to redirect from a netdev/queue index other than what
the socket is bound to, the frame will not be received on the socket.

A socket can reside in multiple maps.

v3: Fixed race and simplified code.
v2: Removed one indirection in map lookup.

Signed-off-by: default avatarBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent c497176c

include/linux/bpf.h

+25 −0
Original line number Diff line number Diff line
@@ -676,6 +676,31 @@ static inline int sock_map_prog(struct bpf_map *map, 
}

#endif



#if defined(CONFIG_XDP_SOCKETS)

struct xdp_sock;

struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map, u32 key);

int __xsk_map_redirect(struct bpf_map *map, struct xdp_buff *xdp,

		       struct xdp_sock *xs);

void __xsk_map_flush(struct bpf_map *map);

#else

struct xdp_sock;

static inline struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map,

						     u32 key)

{

	return NULL;

}



static inline int __xsk_map_redirect(struct bpf_map *map, struct xdp_buff *xdp,

				     struct xdp_sock *xs)

{

	return -EOPNOTSUPP;

}



static inline void __xsk_map_flush(struct bpf_map *map)

{

}

#endif



/* verifier prototypes for helper functions called from eBPF programs */

extern const struct bpf_func_proto bpf_map_lookup_elem_proto;

extern const struct bpf_func_proto bpf_map_update_elem_proto;

include/linux/bpf_types.h

+3 −0
Original line number Diff line number Diff line
@@ -49,4 +49,7 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_DEVMAP, dev_map_ops) 
BPF_MAP_TYPE(BPF_MAP_TYPE_SOCKMAP, sock_map_ops)

#endif

BPF_MAP_TYPE(BPF_MAP_TYPE_CPUMAP, cpu_map_ops)

#if defined(CONFIG_XDP_SOCKETS)

BPF_MAP_TYPE(BPF_MAP_TYPE_XSKMAP, xsk_map_ops)

#endif

#endif

include/net/xdp_sock.h

+7 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ struct xdp_sock { 
	struct xsk_queue *rx;

	struct net_device *dev;

	struct xdp_umem *umem;

	struct list_head flush_node;

	u16 queue_id;

	/* Protects multiple processes in the control path */

	struct mutex mutex;
@@ -39,6 +40,7 @@ struct xdp_buff; 
int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);

int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);

void xsk_flush(struct xdp_sock *xs);

bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs);

#else

static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)

{
@@ -53,6 +55,11 @@ static inline int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp) 
static inline void xsk_flush(struct xdp_sock *xs)

{

}



static inline bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)

{

	return false;

}

#endif /* CONFIG_XDP_SOCKETS */



#endif /* _LINUX_XDP_SOCK_H */

include/uapi/linux/bpf.h

+1 −0
Original line number Diff line number Diff line
@@ -116,6 +116,7 @@ enum bpf_map_type { 
	BPF_MAP_TYPE_DEVMAP,

	BPF_MAP_TYPE_SOCKMAP,

	BPF_MAP_TYPE_CPUMAP,

	BPF_MAP_TYPE_XSKMAP,

};



enum bpf_prog_type {

kernel/bpf/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -8,6 +8,9 @@ obj-$(CONFIG_BPF_SYSCALL) += btf.o 
ifeq ($(CONFIG_NET),y)

obj-$(CONFIG_BPF_SYSCALL) += devmap.o

obj-$(CONFIG_BPF_SYSCALL) += cpumap.o

ifeq ($(CONFIG_XDP_SOCKETS),y)

obj-$(CONFIG_BPF_SYSCALL) += xskmap.o

endif

obj-$(CONFIG_BPF_SYSCALL) += offload.o

ifeq ($(CONFIG_STREAM_PARSER),y)

ifeq ($(CONFIG_INET),y)

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