xsk: Move xskmap.c to net/xdp/

The XSKMAP is partly implemented by net/xdp/xsk.c. Move xskmap.c from
kernel/bpf/ to net/xdp/, which is the logical place for AF_XDP related
code. Also, move AF_XDP struct definitions, and function declarations
only used by AF_XDP internals into net/xdp/xsk.h.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200520192103.355233-3-bjorn.topel@gmail.com

2 files changed, 0 insertions, 268 deletions

diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index 37b2d8620153..375b933010dd 100644
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile
@@ -12,9 +12,6 @@ obj-$(CONFIG_BPF_JIT) += dispatcher.o
 ifeq ($(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-$(CONFIG_BPF_SYSCALL) += offload.o
 endif
 ifeq ($(CONFIG_PERF_EVENTS),y)
diff --git a/kernel/bpf/xskmap.c b/kernel/bpf/xskmap.c
deleted file mode 100644
index 2cc5c8f4c800..000000000000
--- a/kernel/bpf/xskmap.c
+++ /dev/null
@@ -1,265 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/* XSKMAP used for AF_XDP sockets
- * Copyright(c) 2018 Intel Corporation.
- */
-
-#include <linux/bpf.h>
-#include <linux/capability.h>
-#include <net/xdp_sock.h>
-#include <linux/slab.h>
-#include <linux/sched.h>
-
-int xsk_map_inc(struct xsk_map *map)
-{
-	bpf_map_inc(&map->map);
-	return 0;
-}
-
-void xsk_map_put(struct xsk_map *map)
-{
-	bpf_map_put(&map->map);
-}
-
-static struct xsk_map_node *xsk_map_node_alloc(struct xsk_map *map,
-					       struct xdp_sock **map_entry)
-{
-	struct xsk_map_node *node;
-	int err;
-
-	node = kzalloc(sizeof(*node), GFP_ATOMIC | __GFP_NOWARN);
-	if (!node)
-		return ERR_PTR(-ENOMEM);
-
-	err = xsk_map_inc(map);
-	if (err) {
-		kfree(node);
-		return ERR_PTR(err);
-	}
-
-	node->map = map;
-	node->map_entry = map_entry;
-	return node;
-}
-
-static void xsk_map_node_free(struct xsk_map_node *node)
-{
-	xsk_map_put(node->map);
-	kfree(node);
-}
-
-static void xsk_map_sock_add(struct xdp_sock *xs, struct xsk_map_node *node)
-{
-	spin_lock_bh(&xs->map_list_lock);
-	list_add_tail(&node->node, &xs->map_list);
-	spin_unlock_bh(&xs->map_list_lock);
-}
-
-static void xsk_map_sock_delete(struct xdp_sock *xs,
-				struct xdp_sock **map_entry)
-{
-	struct xsk_map_node *n, *tmp;
-
-	spin_lock_bh(&xs->map_list_lock);
-	list_for_each_entry_safe(n, tmp, &xs->map_list, node) {
-		if (map_entry == n->map_entry) {
-			list_del(&n->node);
-			xsk_map_node_free(n);
-		}
-	}
-	spin_unlock_bh(&xs->map_list_lock);
-}
-
-static struct bpf_map *xsk_map_alloc(union bpf_attr *attr)
-{
-	struct bpf_map_memory mem;
-	int err, numa_node;
-	struct xsk_map *m;
-	u64 size;
-
-	if (!capable(CAP_NET_ADMIN))
-		return ERR_PTR(-EPERM);
-
-	if (attr->max_entries == 0 || attr->key_size != 4 ||
-	    attr->value_size != 4 ||
-	    attr->map_flags & ~(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY))
-		return ERR_PTR(-EINVAL);
-
-	numa_node = bpf_map_attr_numa_node(attr);
-	size = struct_size(m, xsk_map, attr->max_entries);
-
-	err = bpf_map_charge_init(&mem, size);
-	if (err < 0)
-		return ERR_PTR(err);
-
-	m = bpf_map_area_alloc(size, numa_node);
-	if (!m) {
-		bpf_map_charge_finish(&mem);
-		return ERR_PTR(-ENOMEM);
-	}
-
-	bpf_map_init_from_attr(&m->map, attr);
-	bpf_map_charge_move(&m->map.memory, &mem);
-	spin_lock_init(&m->lock);
-
-	return &m->map;
-}
-
-static void xsk_map_free(struct bpf_map *map)
-{
-	struct xsk_map *m = container_of(map, struct xsk_map, map);
-
-	bpf_clear_redirect_map(map);
-	synchronize_net();
-	bpf_map_area_free(m);
-}
-
-static int xsk_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
-{
-	struct xsk_map *m = container_of(map, struct xsk_map, map);
-	u32 index = key ? *(u32 *)key : U32_MAX;
-	u32 *next = next_key;
-
-	if (index >= m->map.max_entries) {
-		*next = 0;
-		return 0;
-	}
-
-	if (index == m->map.max_entries - 1)
-		return -ENOENT;
-	*next = index + 1;
-	return 0;
-}
-
-static u32 xsk_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
-{
-	const int ret = BPF_REG_0, mp = BPF_REG_1, index = BPF_REG_2;
-	struct bpf_insn *insn = insn_buf;
-
-	*insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0);
-	*insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5);
-	*insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(sizeof(struct xsk_sock *)));
-	*insn++ = BPF_ALU64_IMM(BPF_ADD, mp, offsetof(struct xsk_map, xsk_map));
-	*insn++ = BPF_ALU64_REG(BPF_ADD, ret, mp);
-	*insn++ = BPF_LDX_MEM(BPF_SIZEOF(struct xsk_sock *), ret, ret, 0);
-	*insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1);
-	*insn++ = BPF_MOV64_IMM(ret, 0);
-	return insn - insn_buf;
-}
-
-static void *xsk_map_lookup_elem(struct bpf_map *map, void *key)
-{
-	WARN_ON_ONCE(!rcu_read_lock_held());
-	return __xsk_map_lookup_elem(map, *(u32 *)key);
-}
-
-static void *xsk_map_lookup_elem_sys_only(struct bpf_map *map, void *key)
-{
-	return ERR_PTR(-EOPNOTSUPP);
-}
-
-static int xsk_map_update_elem(struct bpf_map *map, void *key, void *value,
-			       u64 map_flags)
-{
-	struct xsk_map *m = container_of(map, struct xsk_map, map);
-	struct xdp_sock *xs, *old_xs, **map_entry;
-	u32 i = *(u32 *)key, fd = *(u32 *)value;
-	struct xsk_map_node *node;
-	struct socket *sock;
-	int err;
-
-	if (unlikely(map_flags > BPF_EXIST))
-		return -EINVAL;
-	if (unlikely(i >= m->map.max_entries))
-		return -E2BIG;
-
-	sock = sockfd_lookup(fd, &err);
-	if (!sock)
-		return err;
-
-	if (sock->sk->sk_family != PF_XDP) {
-		sockfd_put(sock);
-		return -EOPNOTSUPP;
-	}
-
-	xs = (struct xdp_sock *)sock->sk;
-
-	if (!xsk_is_setup_for_bpf_map(xs)) {
-		sockfd_put(sock);
-		return -EOPNOTSUPP;
-	}
-
-	map_entry = &m->xsk_map[i];
-	node = xsk_map_node_alloc(m, map_entry);
-	if (IS_ERR(node)) {
-		sockfd_put(sock);
-		return PTR_ERR(node);
-	}
-
-	spin_lock_bh(&m->lock);
-	old_xs = READ_ONCE(*map_entry);
-	if (old_xs == xs) {
-		err = 0;
-		goto out;
-	} else if (old_xs && map_flags == BPF_NOEXIST) {
-		err = -EEXIST;
-		goto out;
-	} else if (!old_xs && map_flags == BPF_EXIST) {
-		err = -ENOENT;
-		goto out;
-	}
-	xsk_map_sock_add(xs, node);
-	WRITE_ONCE(*map_entry, xs);
-	if (old_xs)
-		xsk_map_sock_delete(old_xs, map_entry);
-	spin_unlock_bh(&m->lock);
-	sockfd_put(sock);
-	return 0;
-
-out:
-	spin_unlock_bh(&m->lock);
-	sockfd_put(sock);
-	xsk_map_node_free(node);
-	return err;
-}
-
-static int xsk_map_delete_elem(struct bpf_map *map, void *key)
-{
-	struct xsk_map *m = container_of(map, struct xsk_map, map);
-	struct xdp_sock *old_xs, **map_entry;
-	int k = *(u32 *)key;
-
-	if (k >= map->max_entries)
-		return -EINVAL;
-
-	spin_lock_bh(&m->lock);
-	map_entry = &m->xsk_map[k];
-	old_xs = xchg(map_entry, NULL);
-	if (old_xs)
-		xsk_map_sock_delete(old_xs, map_entry);
-	spin_unlock_bh(&m->lock);
-
-	return 0;
-}
-
-void xsk_map_try_sock_delete(struct xsk_map *map, struct xdp_sock *xs,
-			     struct xdp_sock **map_entry)
-{
-	spin_lock_bh(&map->lock);
-	if (READ_ONCE(*map_entry) == xs) {
-		WRITE_ONCE(*map_entry, NULL);
-		xsk_map_sock_delete(xs, map_entry);
-	}
-	spin_unlock_bh(&map->lock);
-}
-
-const struct bpf_map_ops xsk_map_ops = {
-	.map_alloc = xsk_map_alloc,
-	.map_free = xsk_map_free,
-	.map_get_next_key = xsk_map_get_next_key,
-	.map_lookup_elem = xsk_map_lookup_elem,
-	.map_gen_lookup = xsk_map_gen_lookup,
-	.map_lookup_elem_sys_only = xsk_map_lookup_elem_sys_only,
-	.map_update_elem = xsk_map_update_elem,
-	.map_delete_elem = xsk_map_delete_elem,
-	.map_check_btf = map_check_no_btf,
-};