1d20a1676SBjörn Töpel // SPDX-License-Identifier: GPL-2.0 2d20a1676SBjörn Töpel /* XSKMAP used for AF_XDP sockets 3d20a1676SBjörn Töpel * Copyright(c) 2018 Intel Corporation. 4d20a1676SBjörn Töpel */ 5d20a1676SBjörn Töpel 6d20a1676SBjörn Töpel #include <linux/bpf.h> 7d20a1676SBjörn Töpel #include <linux/capability.h> 8d20a1676SBjörn Töpel #include <net/xdp_sock.h> 9d20a1676SBjörn Töpel #include <linux/slab.h> 10d20a1676SBjörn Töpel #include <linux/sched.h> 11d20a1676SBjörn Töpel 12d20a1676SBjörn Töpel #include "xsk.h" 13d20a1676SBjörn Töpel 14d20a1676SBjörn Töpel int xsk_map_inc(struct xsk_map *map) 15d20a1676SBjörn Töpel { 16d20a1676SBjörn Töpel bpf_map_inc(&map->map); 17d20a1676SBjörn Töpel return 0; 18d20a1676SBjörn Töpel } 19d20a1676SBjörn Töpel 20d20a1676SBjörn Töpel void xsk_map_put(struct xsk_map *map) 21d20a1676SBjörn Töpel { 22d20a1676SBjörn Töpel bpf_map_put(&map->map); 23d20a1676SBjörn Töpel } 24d20a1676SBjörn Töpel 25d20a1676SBjörn Töpel static struct xsk_map_node *xsk_map_node_alloc(struct xsk_map *map, 26d20a1676SBjörn Töpel struct xdp_sock **map_entry) 27d20a1676SBjörn Töpel { 28d20a1676SBjörn Töpel struct xsk_map_node *node; 29d20a1676SBjörn Töpel int err; 30d20a1676SBjörn Töpel 31d20a1676SBjörn Töpel node = kzalloc(sizeof(*node), GFP_ATOMIC | __GFP_NOWARN); 32d20a1676SBjörn Töpel if (!node) 33d20a1676SBjörn Töpel return ERR_PTR(-ENOMEM); 34d20a1676SBjörn Töpel 35d20a1676SBjörn Töpel err = xsk_map_inc(map); 36d20a1676SBjörn Töpel if (err) { 37d20a1676SBjörn Töpel kfree(node); 38d20a1676SBjörn Töpel return ERR_PTR(err); 39d20a1676SBjörn Töpel } 40d20a1676SBjörn Töpel 41d20a1676SBjörn Töpel node->map = map; 42d20a1676SBjörn Töpel node->map_entry = map_entry; 43d20a1676SBjörn Töpel return node; 44d20a1676SBjörn Töpel } 45d20a1676SBjörn Töpel 46d20a1676SBjörn Töpel static void xsk_map_node_free(struct xsk_map_node *node) 47d20a1676SBjörn Töpel { 48d20a1676SBjörn Töpel xsk_map_put(node->map); 49d20a1676SBjörn Töpel kfree(node); 50d20a1676SBjörn Töpel } 51d20a1676SBjörn Töpel 52d20a1676SBjörn Töpel static void xsk_map_sock_add(struct xdp_sock *xs, struct xsk_map_node *node) 53d20a1676SBjörn Töpel { 54d20a1676SBjörn Töpel spin_lock_bh(&xs->map_list_lock); 55d20a1676SBjörn Töpel list_add_tail(&node->node, &xs->map_list); 56d20a1676SBjörn Töpel spin_unlock_bh(&xs->map_list_lock); 57d20a1676SBjörn Töpel } 58d20a1676SBjörn Töpel 59d20a1676SBjörn Töpel static void xsk_map_sock_delete(struct xdp_sock *xs, 60d20a1676SBjörn Töpel struct xdp_sock **map_entry) 61d20a1676SBjörn Töpel { 62d20a1676SBjörn Töpel struct xsk_map_node *n, *tmp; 63d20a1676SBjörn Töpel 64d20a1676SBjörn Töpel spin_lock_bh(&xs->map_list_lock); 65d20a1676SBjörn Töpel list_for_each_entry_safe(n, tmp, &xs->map_list, node) { 66d20a1676SBjörn Töpel if (map_entry == n->map_entry) { 67d20a1676SBjörn Töpel list_del(&n->node); 68d20a1676SBjörn Töpel xsk_map_node_free(n); 69d20a1676SBjörn Töpel } 70d20a1676SBjörn Töpel } 71d20a1676SBjörn Töpel spin_unlock_bh(&xs->map_list_lock); 72d20a1676SBjörn Töpel } 73d20a1676SBjörn Töpel 74d20a1676SBjörn Töpel static struct bpf_map *xsk_map_alloc(union bpf_attr *attr) 75d20a1676SBjörn Töpel { 76d20a1676SBjörn Töpel struct bpf_map_memory mem; 77d20a1676SBjörn Töpel int err, numa_node; 78d20a1676SBjörn Töpel struct xsk_map *m; 79d20a1676SBjörn Töpel u64 size; 80d20a1676SBjörn Töpel 81d20a1676SBjörn Töpel if (!capable(CAP_NET_ADMIN)) 82d20a1676SBjörn Töpel return ERR_PTR(-EPERM); 83d20a1676SBjörn Töpel 84d20a1676SBjörn Töpel if (attr->max_entries == 0 || attr->key_size != 4 || 85d20a1676SBjörn Töpel attr->value_size != 4 || 86d20a1676SBjörn Töpel attr->map_flags & ~(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)) 87d20a1676SBjörn Töpel return ERR_PTR(-EINVAL); 88d20a1676SBjörn Töpel 89d20a1676SBjörn Töpel numa_node = bpf_map_attr_numa_node(attr); 90d20a1676SBjörn Töpel size = struct_size(m, xsk_map, attr->max_entries); 91d20a1676SBjörn Töpel 92d20a1676SBjörn Töpel err = bpf_map_charge_init(&mem, size); 93d20a1676SBjörn Töpel if (err < 0) 94d20a1676SBjörn Töpel return ERR_PTR(err); 95d20a1676SBjörn Töpel 96d20a1676SBjörn Töpel m = bpf_map_area_alloc(size, numa_node); 97d20a1676SBjörn Töpel if (!m) { 98d20a1676SBjörn Töpel bpf_map_charge_finish(&mem); 99d20a1676SBjörn Töpel return ERR_PTR(-ENOMEM); 100d20a1676SBjörn Töpel } 101d20a1676SBjörn Töpel 102d20a1676SBjörn Töpel bpf_map_init_from_attr(&m->map, attr); 103d20a1676SBjörn Töpel bpf_map_charge_move(&m->map.memory, &mem); 104d20a1676SBjörn Töpel spin_lock_init(&m->lock); 105d20a1676SBjörn Töpel 106d20a1676SBjörn Töpel return &m->map; 107d20a1676SBjörn Töpel } 108d20a1676SBjörn Töpel 109d20a1676SBjörn Töpel static void xsk_map_free(struct bpf_map *map) 110d20a1676SBjörn Töpel { 111d20a1676SBjörn Töpel struct xsk_map *m = container_of(map, struct xsk_map, map); 112d20a1676SBjörn Töpel 113d20a1676SBjörn Töpel bpf_clear_redirect_map(map); 114d20a1676SBjörn Töpel synchronize_net(); 115d20a1676SBjörn Töpel bpf_map_area_free(m); 116d20a1676SBjörn Töpel } 117d20a1676SBjörn Töpel 118d20a1676SBjörn Töpel static int xsk_map_get_next_key(struct bpf_map *map, void *key, void *next_key) 119d20a1676SBjörn Töpel { 120d20a1676SBjörn Töpel struct xsk_map *m = container_of(map, struct xsk_map, map); 121d20a1676SBjörn Töpel u32 index = key ? *(u32 *)key : U32_MAX; 122d20a1676SBjörn Töpel u32 *next = next_key; 123d20a1676SBjörn Töpel 124d20a1676SBjörn Töpel if (index >= m->map.max_entries) { 125d20a1676SBjörn Töpel *next = 0; 126d20a1676SBjörn Töpel return 0; 127d20a1676SBjörn Töpel } 128d20a1676SBjörn Töpel 129d20a1676SBjörn Töpel if (index == m->map.max_entries - 1) 130d20a1676SBjörn Töpel return -ENOENT; 131d20a1676SBjörn Töpel *next = index + 1; 132d20a1676SBjörn Töpel return 0; 133d20a1676SBjörn Töpel } 134d20a1676SBjörn Töpel 1354a8f87e6SDaniel Borkmann static int xsk_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf) 136d20a1676SBjörn Töpel { 137d20a1676SBjörn Töpel const int ret = BPF_REG_0, mp = BPF_REG_1, index = BPF_REG_2; 138d20a1676SBjörn Töpel struct bpf_insn *insn = insn_buf; 139d20a1676SBjörn Töpel 140d20a1676SBjörn Töpel *insn++ = BPF_LDX_MEM(BPF_W, ret, index, 0); 141d20a1676SBjörn Töpel *insn++ = BPF_JMP_IMM(BPF_JGE, ret, map->max_entries, 5); 142d20a1676SBjörn Töpel *insn++ = BPF_ALU64_IMM(BPF_LSH, ret, ilog2(sizeof(struct xsk_sock *))); 143d20a1676SBjörn Töpel *insn++ = BPF_ALU64_IMM(BPF_ADD, mp, offsetof(struct xsk_map, xsk_map)); 144d20a1676SBjörn Töpel *insn++ = BPF_ALU64_REG(BPF_ADD, ret, mp); 145d20a1676SBjörn Töpel *insn++ = BPF_LDX_MEM(BPF_SIZEOF(struct xsk_sock *), ret, ret, 0); 146d20a1676SBjörn Töpel *insn++ = BPF_JMP_IMM(BPF_JA, 0, 0, 1); 147d20a1676SBjörn Töpel *insn++ = BPF_MOV64_IMM(ret, 0); 148d20a1676SBjörn Töpel return insn - insn_buf; 149d20a1676SBjörn Töpel } 150d20a1676SBjörn Töpel 151d20a1676SBjörn Töpel static void *xsk_map_lookup_elem(struct bpf_map *map, void *key) 152d20a1676SBjörn Töpel { 153d20a1676SBjörn Töpel WARN_ON_ONCE(!rcu_read_lock_held()); 154d20a1676SBjörn Töpel return __xsk_map_lookup_elem(map, *(u32 *)key); 155d20a1676SBjörn Töpel } 156d20a1676SBjörn Töpel 157d20a1676SBjörn Töpel static void *xsk_map_lookup_elem_sys_only(struct bpf_map *map, void *key) 158d20a1676SBjörn Töpel { 159d20a1676SBjörn Töpel return ERR_PTR(-EOPNOTSUPP); 160d20a1676SBjörn Töpel } 161d20a1676SBjörn Töpel 162d20a1676SBjörn Töpel static int xsk_map_update_elem(struct bpf_map *map, void *key, void *value, 163d20a1676SBjörn Töpel u64 map_flags) 164d20a1676SBjörn Töpel { 165d20a1676SBjörn Töpel struct xsk_map *m = container_of(map, struct xsk_map, map); 166d20a1676SBjörn Töpel struct xdp_sock *xs, *old_xs, **map_entry; 167d20a1676SBjörn Töpel u32 i = *(u32 *)key, fd = *(u32 *)value; 168d20a1676SBjörn Töpel struct xsk_map_node *node; 169d20a1676SBjörn Töpel struct socket *sock; 170d20a1676SBjörn Töpel int err; 171d20a1676SBjörn Töpel 172d20a1676SBjörn Töpel if (unlikely(map_flags > BPF_EXIST)) 173d20a1676SBjörn Töpel return -EINVAL; 174d20a1676SBjörn Töpel if (unlikely(i >= m->map.max_entries)) 175d20a1676SBjörn Töpel return -E2BIG; 176d20a1676SBjörn Töpel 177d20a1676SBjörn Töpel sock = sockfd_lookup(fd, &err); 178d20a1676SBjörn Töpel if (!sock) 179d20a1676SBjörn Töpel return err; 180d20a1676SBjörn Töpel 181d20a1676SBjörn Töpel if (sock->sk->sk_family != PF_XDP) { 182d20a1676SBjörn Töpel sockfd_put(sock); 183d20a1676SBjörn Töpel return -EOPNOTSUPP; 184d20a1676SBjörn Töpel } 185d20a1676SBjörn Töpel 186d20a1676SBjörn Töpel xs = (struct xdp_sock *)sock->sk; 187d20a1676SBjörn Töpel 188d20a1676SBjörn Töpel map_entry = &m->xsk_map[i]; 189d20a1676SBjörn Töpel node = xsk_map_node_alloc(m, map_entry); 190d20a1676SBjörn Töpel if (IS_ERR(node)) { 191d20a1676SBjörn Töpel sockfd_put(sock); 192d20a1676SBjörn Töpel return PTR_ERR(node); 193d20a1676SBjörn Töpel } 194d20a1676SBjörn Töpel 195d20a1676SBjörn Töpel spin_lock_bh(&m->lock); 196d20a1676SBjörn Töpel old_xs = READ_ONCE(*map_entry); 197d20a1676SBjörn Töpel if (old_xs == xs) { 198d20a1676SBjörn Töpel err = 0; 199d20a1676SBjörn Töpel goto out; 200d20a1676SBjörn Töpel } else if (old_xs && map_flags == BPF_NOEXIST) { 201d20a1676SBjörn Töpel err = -EEXIST; 202d20a1676SBjörn Töpel goto out; 203d20a1676SBjörn Töpel } else if (!old_xs && map_flags == BPF_EXIST) { 204d20a1676SBjörn Töpel err = -ENOENT; 205d20a1676SBjörn Töpel goto out; 206d20a1676SBjörn Töpel } 207d20a1676SBjörn Töpel xsk_map_sock_add(xs, node); 208d20a1676SBjörn Töpel WRITE_ONCE(*map_entry, xs); 209d20a1676SBjörn Töpel if (old_xs) 210d20a1676SBjörn Töpel xsk_map_sock_delete(old_xs, map_entry); 211d20a1676SBjörn Töpel spin_unlock_bh(&m->lock); 212d20a1676SBjörn Töpel sockfd_put(sock); 213d20a1676SBjörn Töpel return 0; 214d20a1676SBjörn Töpel 215d20a1676SBjörn Töpel out: 216d20a1676SBjörn Töpel spin_unlock_bh(&m->lock); 217d20a1676SBjörn Töpel sockfd_put(sock); 218d20a1676SBjörn Töpel xsk_map_node_free(node); 219d20a1676SBjörn Töpel return err; 220d20a1676SBjörn Töpel } 221d20a1676SBjörn Töpel 222d20a1676SBjörn Töpel static int xsk_map_delete_elem(struct bpf_map *map, void *key) 223d20a1676SBjörn Töpel { 224d20a1676SBjörn Töpel struct xsk_map *m = container_of(map, struct xsk_map, map); 225d20a1676SBjörn Töpel struct xdp_sock *old_xs, **map_entry; 226d20a1676SBjörn Töpel int k = *(u32 *)key; 227d20a1676SBjörn Töpel 228d20a1676SBjörn Töpel if (k >= map->max_entries) 229d20a1676SBjörn Töpel return -EINVAL; 230d20a1676SBjörn Töpel 231d20a1676SBjörn Töpel spin_lock_bh(&m->lock); 232d20a1676SBjörn Töpel map_entry = &m->xsk_map[k]; 233d20a1676SBjörn Töpel old_xs = xchg(map_entry, NULL); 234d20a1676SBjörn Töpel if (old_xs) 235d20a1676SBjörn Töpel xsk_map_sock_delete(old_xs, map_entry); 236d20a1676SBjörn Töpel spin_unlock_bh(&m->lock); 237d20a1676SBjörn Töpel 238d20a1676SBjörn Töpel return 0; 239d20a1676SBjörn Töpel } 240d20a1676SBjörn Töpel 241d20a1676SBjörn Töpel void xsk_map_try_sock_delete(struct xsk_map *map, struct xdp_sock *xs, 242d20a1676SBjörn Töpel struct xdp_sock **map_entry) 243d20a1676SBjörn Töpel { 244d20a1676SBjörn Töpel spin_lock_bh(&map->lock); 245d20a1676SBjörn Töpel if (READ_ONCE(*map_entry) == xs) { 246d20a1676SBjörn Töpel WRITE_ONCE(*map_entry, NULL); 247d20a1676SBjörn Töpel xsk_map_sock_delete(xs, map_entry); 248d20a1676SBjörn Töpel } 249d20a1676SBjörn Töpel spin_unlock_bh(&map->lock); 250d20a1676SBjörn Töpel } 251d20a1676SBjörn Töpel 252134fede4SMartin KaFai Lau static bool xsk_map_meta_equal(const struct bpf_map *meta0, 253134fede4SMartin KaFai Lau const struct bpf_map *meta1) 254134fede4SMartin KaFai Lau { 255134fede4SMartin KaFai Lau return meta0->max_entries == meta1->max_entries && 256134fede4SMartin KaFai Lau bpf_map_meta_equal(meta0, meta1); 257134fede4SMartin KaFai Lau } 258134fede4SMartin KaFai Lau 2592872e9acSAndrey Ignatov static int xsk_map_btf_id; 260d20a1676SBjörn Töpel const struct bpf_map_ops xsk_map_ops = { 261134fede4SMartin KaFai Lau .map_meta_equal = xsk_map_meta_equal, 262d20a1676SBjörn Töpel .map_alloc = xsk_map_alloc, 263d20a1676SBjörn Töpel .map_free = xsk_map_free, 264d20a1676SBjörn Töpel .map_get_next_key = xsk_map_get_next_key, 265d20a1676SBjörn Töpel .map_lookup_elem = xsk_map_lookup_elem, 266d20a1676SBjörn Töpel .map_gen_lookup = xsk_map_gen_lookup, 267d20a1676SBjörn Töpel .map_lookup_elem_sys_only = xsk_map_lookup_elem_sys_only, 268d20a1676SBjörn Töpel .map_update_elem = xsk_map_update_elem, 269d20a1676SBjörn Töpel .map_delete_elem = xsk_map_delete_elem, 270d20a1676SBjörn Töpel .map_check_btf = map_check_no_btf, 2712872e9acSAndrey Ignatov .map_btf_name = "xsk_map", 2722872e9acSAndrey Ignatov .map_btf_id = &xsk_map_btf_id, 273d20a1676SBjörn Töpel }; 274