1 // SPDX-License-Identifier: GPL-2.0
2 /* XSKMAP used for AF_XDP sockets
3 * Copyright(c) 2018 Intel Corporation.
7 #include <linux/capability.h>
8 #include <net/xdp_sock.h>
9 #include <linux/slab.h>
10 #include <linux/sched.h>
14 struct xdp_sock **xsk_map;
15 struct list_head __percpu *flush_list;
18 static struct bpf_map *xsk_map_alloc(union bpf_attr *attr)
24 if (!capable(CAP_NET_ADMIN))
25 return ERR_PTR(-EPERM);
27 if (attr->max_entries == 0 || attr->key_size != 4 ||
28 attr->value_size != 4 ||
29 attr->map_flags & ~(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY))
30 return ERR_PTR(-EINVAL);
32 m = kzalloc(sizeof(*m), GFP_USER);
34 return ERR_PTR(-ENOMEM);
36 bpf_map_init_from_attr(&m->map, attr);
38 cost = (u64)m->map.max_entries * sizeof(struct xdp_sock *);
39 cost += sizeof(struct list_head) * num_possible_cpus();
41 /* Notice returns -EPERM on if map size is larger than memlock limit */
42 err = bpf_map_charge_init(&m->map.memory, cost);
48 m->flush_list = alloc_percpu(struct list_head);
52 for_each_possible_cpu(cpu)
53 INIT_LIST_HEAD(per_cpu_ptr(m->flush_list, cpu));
55 m->xsk_map = bpf_map_area_alloc(m->map.max_entries *
56 sizeof(struct xdp_sock *),
63 free_percpu(m->flush_list);
65 bpf_map_charge_finish(&m->map.memory);
71 static void xsk_map_free(struct bpf_map *map)
73 struct xsk_map *m = container_of(map, struct xsk_map, map);
76 bpf_clear_redirect_map(map);
79 for (i = 0; i < map->max_entries; i++) {
86 sock_put((struct sock *)xs);
89 free_percpu(m->flush_list);
90 bpf_map_area_free(m->xsk_map);
94 static int xsk_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
96 struct xsk_map *m = container_of(map, struct xsk_map, map);
97 u32 index = key ? *(u32 *)key : U32_MAX;
100 if (index >= m->map.max_entries) {
105 if (index == m->map.max_entries - 1)
111 struct xdp_sock *__xsk_map_lookup_elem(struct bpf_map *map, u32 key)
113 struct xsk_map *m = container_of(map, struct xsk_map, map);
116 if (key >= map->max_entries)
119 xs = READ_ONCE(m->xsk_map[key]);
123 int __xsk_map_redirect(struct bpf_map *map, struct xdp_buff *xdp,
126 struct xsk_map *m = container_of(map, struct xsk_map, map);
127 struct list_head *flush_list = this_cpu_ptr(m->flush_list);
130 err = xsk_rcv(xs, xdp);
134 if (!xs->flush_node.prev)
135 list_add(&xs->flush_node, flush_list);
140 void __xsk_map_flush(struct bpf_map *map)
142 struct xsk_map *m = container_of(map, struct xsk_map, map);
143 struct list_head *flush_list = this_cpu_ptr(m->flush_list);
144 struct xdp_sock *xs, *tmp;
146 list_for_each_entry_safe(xs, tmp, flush_list, flush_node) {
148 __list_del_clearprev(&xs->flush_node);
152 static void *xsk_map_lookup_elem(struct bpf_map *map, void *key)
154 WARN_ON_ONCE(!rcu_read_lock_held());
155 return __xsk_map_lookup_elem(map, *(u32 *)key);
158 static void *xsk_map_lookup_elem_sys_only(struct bpf_map *map, void *key)
160 return ERR_PTR(-EOPNOTSUPP);
163 static int xsk_map_update_elem(struct bpf_map *map, void *key, void *value,
166 struct xsk_map *m = container_of(map, struct xsk_map, map);
167 u32 i = *(u32 *)key, fd = *(u32 *)value;
168 struct xdp_sock *xs, *old_xs;
172 if (unlikely(map_flags > BPF_EXIST))
174 if (unlikely(i >= m->map.max_entries))
176 if (unlikely(map_flags == BPF_NOEXIST))
179 sock = sockfd_lookup(fd, &err);
183 if (sock->sk->sk_family != PF_XDP) {
188 xs = (struct xdp_sock *)sock->sk;
190 if (!xsk_is_setup_for_bpf_map(xs)) {
197 old_xs = xchg(&m->xsk_map[i], xs);
199 sock_put((struct sock *)old_xs);
205 static int xsk_map_delete_elem(struct bpf_map *map, void *key)
207 struct xsk_map *m = container_of(map, struct xsk_map, map);
208 struct xdp_sock *old_xs;
211 if (k >= map->max_entries)
214 old_xs = xchg(&m->xsk_map[k], NULL);
216 sock_put((struct sock *)old_xs);
221 const struct bpf_map_ops xsk_map_ops = {
222 .map_alloc = xsk_map_alloc,
223 .map_free = xsk_map_free,
224 .map_get_next_key = xsk_map_get_next_key,
225 .map_lookup_elem = xsk_map_lookup_elem,
226 .map_lookup_elem_sys_only = xsk_map_lookup_elem_sys_only,
227 .map_update_elem = xsk_map_update_elem,
228 .map_delete_elem = xsk_map_delete_elem,
229 .map_check_btf = map_check_no_btf,