873 lines
21 KiB
C
873 lines
21 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2019 Facebook */
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#include <linux/rculist.h>
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#include <linux/list.h>
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#include <linux/hash.h>
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#include <linux/types.h>
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#include <linux/spinlock.h>
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#include <linux/bpf.h>
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#include <linux/btf_ids.h>
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#include <linux/bpf_local_storage.h>
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#include <net/bpf_sk_storage.h>
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#include <net/sock.h>
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#include <uapi/linux/sock_diag.h>
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#include <uapi/linux/btf.h>
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DEFINE_BPF_STORAGE_CACHE(sk_cache);
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static int omem_charge(struct sock *sk, unsigned int size)
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{
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/* same check as in sock_kmalloc() */
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if (size <= sysctl_optmem_max &&
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atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
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atomic_add(size, &sk->sk_omem_alloc);
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return 0;
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}
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return -ENOMEM;
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}
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static struct bpf_local_storage_data *
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sk_storage_lookup(struct sock *sk, struct bpf_map *map, bool cacheit_lockit)
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{
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struct bpf_local_storage *sk_storage;
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struct bpf_local_storage_map *smap;
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sk_storage = rcu_dereference(sk->sk_bpf_storage);
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if (!sk_storage)
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return NULL;
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smap = (struct bpf_local_storage_map *)map;
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return bpf_local_storage_lookup(sk_storage, smap, cacheit_lockit);
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}
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static int sk_storage_delete(struct sock *sk, struct bpf_map *map)
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{
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struct bpf_local_storage_data *sdata;
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sdata = sk_storage_lookup(sk, map, false);
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if (!sdata)
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return -ENOENT;
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bpf_selem_unlink(SELEM(sdata));
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return 0;
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}
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/* Called by __sk_destruct() & bpf_sk_storage_clone() */
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void bpf_sk_storage_free(struct sock *sk)
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{
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struct bpf_local_storage_elem *selem;
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struct bpf_local_storage *sk_storage;
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bool free_sk_storage = false;
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struct hlist_node *n;
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rcu_read_lock();
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sk_storage = rcu_dereference(sk->sk_bpf_storage);
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if (!sk_storage) {
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rcu_read_unlock();
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return;
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}
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/* Netiher the bpf_prog nor the bpf-map's syscall
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* could be modifying the sk_storage->list now.
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* Thus, no elem can be added-to or deleted-from the
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* sk_storage->list by the bpf_prog or by the bpf-map's syscall.
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*
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* It is racing with bpf_local_storage_map_free() alone
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* when unlinking elem from the sk_storage->list and
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* the map's bucket->list.
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*/
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raw_spin_lock_bh(&sk_storage->lock);
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hlist_for_each_entry_safe(selem, n, &sk_storage->list, snode) {
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/* Always unlink from map before unlinking from
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* sk_storage.
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*/
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bpf_selem_unlink_map(selem);
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free_sk_storage = bpf_selem_unlink_storage_nolock(sk_storage,
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selem, true);
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}
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raw_spin_unlock_bh(&sk_storage->lock);
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rcu_read_unlock();
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if (free_sk_storage)
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kfree_rcu(sk_storage, rcu);
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}
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static void sk_storage_map_free(struct bpf_map *map)
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{
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struct bpf_local_storage_map *smap;
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smap = (struct bpf_local_storage_map *)map;
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bpf_local_storage_cache_idx_free(&sk_cache, smap->cache_idx);
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bpf_local_storage_map_free(smap);
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}
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static struct bpf_map *sk_storage_map_alloc(union bpf_attr *attr)
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{
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struct bpf_local_storage_map *smap;
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smap = bpf_local_storage_map_alloc(attr);
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if (IS_ERR(smap))
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return ERR_CAST(smap);
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smap->cache_idx = bpf_local_storage_cache_idx_get(&sk_cache);
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return &smap->map;
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}
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static int notsupp_get_next_key(struct bpf_map *map, void *key,
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void *next_key)
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{
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return -ENOTSUPP;
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}
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static void *bpf_fd_sk_storage_lookup_elem(struct bpf_map *map, void *key)
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{
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struct bpf_local_storage_data *sdata;
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struct socket *sock;
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int fd, err;
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fd = *(int *)key;
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sock = sockfd_lookup(fd, &err);
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if (sock) {
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sdata = sk_storage_lookup(sock->sk, map, true);
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sockfd_put(sock);
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return sdata ? sdata->data : NULL;
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}
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return ERR_PTR(err);
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}
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static int bpf_fd_sk_storage_update_elem(struct bpf_map *map, void *key,
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void *value, u64 map_flags)
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{
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struct bpf_local_storage_data *sdata;
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struct socket *sock;
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int fd, err;
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fd = *(int *)key;
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sock = sockfd_lookup(fd, &err);
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if (sock) {
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sdata = bpf_local_storage_update(
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sock->sk, (struct bpf_local_storage_map *)map, value,
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map_flags);
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sockfd_put(sock);
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return PTR_ERR_OR_ZERO(sdata);
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}
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return err;
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}
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static int bpf_fd_sk_storage_delete_elem(struct bpf_map *map, void *key)
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{
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struct socket *sock;
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int fd, err;
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fd = *(int *)key;
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sock = sockfd_lookup(fd, &err);
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if (sock) {
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err = sk_storage_delete(sock->sk, map);
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sockfd_put(sock);
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return err;
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}
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return err;
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}
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static struct bpf_local_storage_elem *
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bpf_sk_storage_clone_elem(struct sock *newsk,
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struct bpf_local_storage_map *smap,
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struct bpf_local_storage_elem *selem)
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{
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struct bpf_local_storage_elem *copy_selem;
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copy_selem = bpf_selem_alloc(smap, newsk, NULL, true);
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if (!copy_selem)
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return NULL;
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if (map_value_has_spin_lock(&smap->map))
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copy_map_value_locked(&smap->map, SDATA(copy_selem)->data,
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SDATA(selem)->data, true);
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else
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copy_map_value(&smap->map, SDATA(copy_selem)->data,
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SDATA(selem)->data);
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return copy_selem;
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}
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int bpf_sk_storage_clone(const struct sock *sk, struct sock *newsk)
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{
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struct bpf_local_storage *new_sk_storage = NULL;
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struct bpf_local_storage *sk_storage;
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struct bpf_local_storage_elem *selem;
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int ret = 0;
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RCU_INIT_POINTER(newsk->sk_bpf_storage, NULL);
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rcu_read_lock();
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sk_storage = rcu_dereference(sk->sk_bpf_storage);
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if (!sk_storage || hlist_empty(&sk_storage->list))
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goto out;
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hlist_for_each_entry_rcu(selem, &sk_storage->list, snode) {
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struct bpf_local_storage_elem *copy_selem;
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struct bpf_local_storage_map *smap;
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struct bpf_map *map;
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smap = rcu_dereference(SDATA(selem)->smap);
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if (!(smap->map.map_flags & BPF_F_CLONE))
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continue;
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/* Note that for lockless listeners adding new element
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* here can race with cleanup in bpf_local_storage_map_free.
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* Try to grab map refcnt to make sure that it's still
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* alive and prevent concurrent removal.
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*/
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map = bpf_map_inc_not_zero(&smap->map);
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if (IS_ERR(map))
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continue;
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copy_selem = bpf_sk_storage_clone_elem(newsk, smap, selem);
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if (!copy_selem) {
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ret = -ENOMEM;
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bpf_map_put(map);
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goto out;
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}
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if (new_sk_storage) {
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bpf_selem_link_map(smap, copy_selem);
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bpf_selem_link_storage_nolock(new_sk_storage, copy_selem);
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} else {
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ret = bpf_local_storage_alloc(newsk, smap, copy_selem);
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if (ret) {
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kfree(copy_selem);
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atomic_sub(smap->elem_size,
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&newsk->sk_omem_alloc);
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bpf_map_put(map);
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goto out;
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}
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new_sk_storage =
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rcu_dereference(copy_selem->local_storage);
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}
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bpf_map_put(map);
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}
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out:
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rcu_read_unlock();
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/* In case of an error, don't free anything explicitly here, the
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* caller is responsible to call bpf_sk_storage_free.
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*/
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return ret;
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}
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BPF_CALL_4(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk,
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void *, value, u64, flags)
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{
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struct bpf_local_storage_data *sdata;
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if (!sk || !sk_fullsock(sk) || flags > BPF_SK_STORAGE_GET_F_CREATE)
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return (unsigned long)NULL;
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sdata = sk_storage_lookup(sk, map, true);
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if (sdata)
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return (unsigned long)sdata->data;
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if (flags == BPF_SK_STORAGE_GET_F_CREATE &&
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/* Cannot add new elem to a going away sk.
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* Otherwise, the new elem may become a leak
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* (and also other memory issues during map
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* destruction).
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*/
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refcount_inc_not_zero(&sk->sk_refcnt)) {
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sdata = bpf_local_storage_update(
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sk, (struct bpf_local_storage_map *)map, value,
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BPF_NOEXIST);
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/* sk must be a fullsock (guaranteed by verifier),
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* so sock_gen_put() is unnecessary.
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*/
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sock_put(sk);
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return IS_ERR(sdata) ?
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(unsigned long)NULL : (unsigned long)sdata->data;
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}
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return (unsigned long)NULL;
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}
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BPF_CALL_2(bpf_sk_storage_delete, struct bpf_map *, map, struct sock *, sk)
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{
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if (!sk || !sk_fullsock(sk))
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return -EINVAL;
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if (refcount_inc_not_zero(&sk->sk_refcnt)) {
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int err;
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err = sk_storage_delete(sk, map);
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sock_put(sk);
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return err;
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}
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return -ENOENT;
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}
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static int sk_storage_charge(struct bpf_local_storage_map *smap,
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void *owner, u32 size)
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{
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return omem_charge(owner, size);
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}
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static void sk_storage_uncharge(struct bpf_local_storage_map *smap,
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void *owner, u32 size)
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{
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struct sock *sk = owner;
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atomic_sub(size, &sk->sk_omem_alloc);
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}
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static struct bpf_local_storage __rcu **
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sk_storage_ptr(void *owner)
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{
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struct sock *sk = owner;
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return &sk->sk_bpf_storage;
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}
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static int sk_storage_map_btf_id;
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const struct bpf_map_ops sk_storage_map_ops = {
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.map_meta_equal = bpf_map_meta_equal,
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.map_alloc_check = bpf_local_storage_map_alloc_check,
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.map_alloc = sk_storage_map_alloc,
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.map_free = sk_storage_map_free,
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.map_get_next_key = notsupp_get_next_key,
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.map_lookup_elem = bpf_fd_sk_storage_lookup_elem,
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.map_update_elem = bpf_fd_sk_storage_update_elem,
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.map_delete_elem = bpf_fd_sk_storage_delete_elem,
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.map_check_btf = bpf_local_storage_map_check_btf,
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.map_btf_name = "bpf_local_storage_map",
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.map_btf_id = &sk_storage_map_btf_id,
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.map_local_storage_charge = sk_storage_charge,
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.map_local_storage_uncharge = sk_storage_uncharge,
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.map_owner_storage_ptr = sk_storage_ptr,
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};
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const struct bpf_func_proto bpf_sk_storage_get_proto = {
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.func = bpf_sk_storage_get,
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.gpl_only = false,
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.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
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.arg1_type = ARG_CONST_MAP_PTR,
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.arg2_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON,
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.arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
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.arg4_type = ARG_ANYTHING,
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};
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const struct bpf_func_proto bpf_sk_storage_get_cg_sock_proto = {
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.func = bpf_sk_storage_get,
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.gpl_only = false,
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.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
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.arg1_type = ARG_CONST_MAP_PTR,
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.arg2_type = ARG_PTR_TO_CTX, /* context is 'struct sock' */
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.arg3_type = ARG_PTR_TO_MAP_VALUE_OR_NULL,
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.arg4_type = ARG_ANYTHING,
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};
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const struct bpf_func_proto bpf_sk_storage_delete_proto = {
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.func = bpf_sk_storage_delete,
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.gpl_only = false,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_CONST_MAP_PTR,
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.arg2_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON,
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};
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struct bpf_sk_storage_diag {
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u32 nr_maps;
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struct bpf_map *maps[];
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};
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/* The reply will be like:
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* INET_DIAG_BPF_SK_STORAGES (nla_nest)
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* SK_DIAG_BPF_STORAGE (nla_nest)
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* SK_DIAG_BPF_STORAGE_MAP_ID (nla_put_u32)
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* SK_DIAG_BPF_STORAGE_MAP_VALUE (nla_reserve_64bit)
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* SK_DIAG_BPF_STORAGE (nla_nest)
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* SK_DIAG_BPF_STORAGE_MAP_ID (nla_put_u32)
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* SK_DIAG_BPF_STORAGE_MAP_VALUE (nla_reserve_64bit)
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* ....
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*/
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static int nla_value_size(u32 value_size)
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{
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/* SK_DIAG_BPF_STORAGE (nla_nest)
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* SK_DIAG_BPF_STORAGE_MAP_ID (nla_put_u32)
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* SK_DIAG_BPF_STORAGE_MAP_VALUE (nla_reserve_64bit)
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*/
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return nla_total_size(0) + nla_total_size(sizeof(u32)) +
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nla_total_size_64bit(value_size);
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}
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void bpf_sk_storage_diag_free(struct bpf_sk_storage_diag *diag)
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{
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u32 i;
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if (!diag)
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return;
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for (i = 0; i < diag->nr_maps; i++)
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bpf_map_put(diag->maps[i]);
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kfree(diag);
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}
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EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_free);
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static bool diag_check_dup(const struct bpf_sk_storage_diag *diag,
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const struct bpf_map *map)
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{
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u32 i;
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for (i = 0; i < diag->nr_maps; i++) {
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if (diag->maps[i] == map)
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return true;
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}
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return false;
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}
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struct bpf_sk_storage_diag *
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bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs)
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{
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struct bpf_sk_storage_diag *diag;
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struct nlattr *nla;
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u32 nr_maps = 0;
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int rem, err;
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/* bpf_local_storage_map is currently limited to CAP_SYS_ADMIN as
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* the map_alloc_check() side also does.
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*/
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if (!bpf_capable())
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return ERR_PTR(-EPERM);
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nla_for_each_nested(nla, nla_stgs, rem) {
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if (nla_type(nla) == SK_DIAG_BPF_STORAGE_REQ_MAP_FD)
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nr_maps++;
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}
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diag = kzalloc(sizeof(*diag) + sizeof(diag->maps[0]) * nr_maps,
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GFP_KERNEL);
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if (!diag)
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return ERR_PTR(-ENOMEM);
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nla_for_each_nested(nla, nla_stgs, rem) {
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struct bpf_map *map;
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int map_fd;
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if (nla_type(nla) != SK_DIAG_BPF_STORAGE_REQ_MAP_FD)
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continue;
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map_fd = nla_get_u32(nla);
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map = bpf_map_get(map_fd);
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if (IS_ERR(map)) {
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err = PTR_ERR(map);
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goto err_free;
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}
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if (map->map_type != BPF_MAP_TYPE_SK_STORAGE) {
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bpf_map_put(map);
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err = -EINVAL;
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goto err_free;
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}
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if (diag_check_dup(diag, map)) {
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bpf_map_put(map);
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err = -EEXIST;
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goto err_free;
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}
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diag->maps[diag->nr_maps++] = map;
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}
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return diag;
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err_free:
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bpf_sk_storage_diag_free(diag);
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return ERR_PTR(err);
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}
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EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_alloc);
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static int diag_get(struct bpf_local_storage_data *sdata, struct sk_buff *skb)
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{
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struct nlattr *nla_stg, *nla_value;
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struct bpf_local_storage_map *smap;
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/* It cannot exceed max nlattr's payload */
|
|
BUILD_BUG_ON(U16_MAX - NLA_HDRLEN < BPF_LOCAL_STORAGE_MAX_VALUE_SIZE);
|
|
|
|
nla_stg = nla_nest_start(skb, SK_DIAG_BPF_STORAGE);
|
|
if (!nla_stg)
|
|
return -EMSGSIZE;
|
|
|
|
smap = rcu_dereference(sdata->smap);
|
|
if (nla_put_u32(skb, SK_DIAG_BPF_STORAGE_MAP_ID, smap->map.id))
|
|
goto errout;
|
|
|
|
nla_value = nla_reserve_64bit(skb, SK_DIAG_BPF_STORAGE_MAP_VALUE,
|
|
smap->map.value_size,
|
|
SK_DIAG_BPF_STORAGE_PAD);
|
|
if (!nla_value)
|
|
goto errout;
|
|
|
|
if (map_value_has_spin_lock(&smap->map))
|
|
copy_map_value_locked(&smap->map, nla_data(nla_value),
|
|
sdata->data, true);
|
|
else
|
|
copy_map_value(&smap->map, nla_data(nla_value), sdata->data);
|
|
|
|
nla_nest_end(skb, nla_stg);
|
|
return 0;
|
|
|
|
errout:
|
|
nla_nest_cancel(skb, nla_stg);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
static int bpf_sk_storage_diag_put_all(struct sock *sk, struct sk_buff *skb,
|
|
int stg_array_type,
|
|
unsigned int *res_diag_size)
|
|
{
|
|
/* stg_array_type (e.g. INET_DIAG_BPF_SK_STORAGES) */
|
|
unsigned int diag_size = nla_total_size(0);
|
|
struct bpf_local_storage *sk_storage;
|
|
struct bpf_local_storage_elem *selem;
|
|
struct bpf_local_storage_map *smap;
|
|
struct nlattr *nla_stgs;
|
|
unsigned int saved_len;
|
|
int err = 0;
|
|
|
|
rcu_read_lock();
|
|
|
|
sk_storage = rcu_dereference(sk->sk_bpf_storage);
|
|
if (!sk_storage || hlist_empty(&sk_storage->list)) {
|
|
rcu_read_unlock();
|
|
return 0;
|
|
}
|
|
|
|
nla_stgs = nla_nest_start(skb, stg_array_type);
|
|
if (!nla_stgs)
|
|
/* Continue to learn diag_size */
|
|
err = -EMSGSIZE;
|
|
|
|
saved_len = skb->len;
|
|
hlist_for_each_entry_rcu(selem, &sk_storage->list, snode) {
|
|
smap = rcu_dereference(SDATA(selem)->smap);
|
|
diag_size += nla_value_size(smap->map.value_size);
|
|
|
|
if (nla_stgs && diag_get(SDATA(selem), skb))
|
|
/* Continue to learn diag_size */
|
|
err = -EMSGSIZE;
|
|
}
|
|
|
|
rcu_read_unlock();
|
|
|
|
if (nla_stgs) {
|
|
if (saved_len == skb->len)
|
|
nla_nest_cancel(skb, nla_stgs);
|
|
else
|
|
nla_nest_end(skb, nla_stgs);
|
|
}
|
|
|
|
if (diag_size == nla_total_size(0)) {
|
|
*res_diag_size = 0;
|
|
return 0;
|
|
}
|
|
|
|
*res_diag_size = diag_size;
|
|
return err;
|
|
}
|
|
|
|
int bpf_sk_storage_diag_put(struct bpf_sk_storage_diag *diag,
|
|
struct sock *sk, struct sk_buff *skb,
|
|
int stg_array_type,
|
|
unsigned int *res_diag_size)
|
|
{
|
|
/* stg_array_type (e.g. INET_DIAG_BPF_SK_STORAGES) */
|
|
unsigned int diag_size = nla_total_size(0);
|
|
struct bpf_local_storage *sk_storage;
|
|
struct bpf_local_storage_data *sdata;
|
|
struct nlattr *nla_stgs;
|
|
unsigned int saved_len;
|
|
int err = 0;
|
|
u32 i;
|
|
|
|
*res_diag_size = 0;
|
|
|
|
/* No map has been specified. Dump all. */
|
|
if (!diag->nr_maps)
|
|
return bpf_sk_storage_diag_put_all(sk, skb, stg_array_type,
|
|
res_diag_size);
|
|
|
|
rcu_read_lock();
|
|
sk_storage = rcu_dereference(sk->sk_bpf_storage);
|
|
if (!sk_storage || hlist_empty(&sk_storage->list)) {
|
|
rcu_read_unlock();
|
|
return 0;
|
|
}
|
|
|
|
nla_stgs = nla_nest_start(skb, stg_array_type);
|
|
if (!nla_stgs)
|
|
/* Continue to learn diag_size */
|
|
err = -EMSGSIZE;
|
|
|
|
saved_len = skb->len;
|
|
for (i = 0; i < diag->nr_maps; i++) {
|
|
sdata = bpf_local_storage_lookup(sk_storage,
|
|
(struct bpf_local_storage_map *)diag->maps[i],
|
|
false);
|
|
|
|
if (!sdata)
|
|
continue;
|
|
|
|
diag_size += nla_value_size(diag->maps[i]->value_size);
|
|
|
|
if (nla_stgs && diag_get(sdata, skb))
|
|
/* Continue to learn diag_size */
|
|
err = -EMSGSIZE;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
if (nla_stgs) {
|
|
if (saved_len == skb->len)
|
|
nla_nest_cancel(skb, nla_stgs);
|
|
else
|
|
nla_nest_end(skb, nla_stgs);
|
|
}
|
|
|
|
if (diag_size == nla_total_size(0)) {
|
|
*res_diag_size = 0;
|
|
return 0;
|
|
}
|
|
|
|
*res_diag_size = diag_size;
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(bpf_sk_storage_diag_put);
|
|
|
|
struct bpf_iter_seq_sk_storage_map_info {
|
|
struct bpf_map *map;
|
|
unsigned int bucket_id;
|
|
unsigned skip_elems;
|
|
};
|
|
|
|
static struct bpf_local_storage_elem *
|
|
bpf_sk_storage_map_seq_find_next(struct bpf_iter_seq_sk_storage_map_info *info,
|
|
struct bpf_local_storage_elem *prev_selem)
|
|
__acquires(RCU) __releases(RCU)
|
|
{
|
|
struct bpf_local_storage *sk_storage;
|
|
struct bpf_local_storage_elem *selem;
|
|
u32 skip_elems = info->skip_elems;
|
|
struct bpf_local_storage_map *smap;
|
|
u32 bucket_id = info->bucket_id;
|
|
u32 i, count, n_buckets;
|
|
struct bpf_local_storage_map_bucket *b;
|
|
|
|
smap = (struct bpf_local_storage_map *)info->map;
|
|
n_buckets = 1U << smap->bucket_log;
|
|
if (bucket_id >= n_buckets)
|
|
return NULL;
|
|
|
|
/* try to find next selem in the same bucket */
|
|
selem = prev_selem;
|
|
count = 0;
|
|
while (selem) {
|
|
selem = hlist_entry_safe(rcu_dereference(hlist_next_rcu(&selem->map_node)),
|
|
struct bpf_local_storage_elem, map_node);
|
|
if (!selem) {
|
|
/* not found, unlock and go to the next bucket */
|
|
b = &smap->buckets[bucket_id++];
|
|
rcu_read_unlock();
|
|
skip_elems = 0;
|
|
break;
|
|
}
|
|
sk_storage = rcu_dereference(selem->local_storage);
|
|
if (sk_storage) {
|
|
info->skip_elems = skip_elems + count;
|
|
return selem;
|
|
}
|
|
count++;
|
|
}
|
|
|
|
for (i = bucket_id; i < (1U << smap->bucket_log); i++) {
|
|
b = &smap->buckets[i];
|
|
rcu_read_lock();
|
|
count = 0;
|
|
hlist_for_each_entry_rcu(selem, &b->list, map_node) {
|
|
sk_storage = rcu_dereference(selem->local_storage);
|
|
if (sk_storage && count >= skip_elems) {
|
|
info->bucket_id = i;
|
|
info->skip_elems = count;
|
|
return selem;
|
|
}
|
|
count++;
|
|
}
|
|
rcu_read_unlock();
|
|
skip_elems = 0;
|
|
}
|
|
|
|
info->bucket_id = i;
|
|
info->skip_elems = 0;
|
|
return NULL;
|
|
}
|
|
|
|
static void *bpf_sk_storage_map_seq_start(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
struct bpf_local_storage_elem *selem;
|
|
|
|
selem = bpf_sk_storage_map_seq_find_next(seq->private, NULL);
|
|
if (!selem)
|
|
return NULL;
|
|
|
|
if (*pos == 0)
|
|
++*pos;
|
|
return selem;
|
|
}
|
|
|
|
static void *bpf_sk_storage_map_seq_next(struct seq_file *seq, void *v,
|
|
loff_t *pos)
|
|
{
|
|
struct bpf_iter_seq_sk_storage_map_info *info = seq->private;
|
|
|
|
++*pos;
|
|
++info->skip_elems;
|
|
return bpf_sk_storage_map_seq_find_next(seq->private, v);
|
|
}
|
|
|
|
struct bpf_iter__bpf_sk_storage_map {
|
|
__bpf_md_ptr(struct bpf_iter_meta *, meta);
|
|
__bpf_md_ptr(struct bpf_map *, map);
|
|
__bpf_md_ptr(struct sock *, sk);
|
|
__bpf_md_ptr(void *, value);
|
|
};
|
|
|
|
DEFINE_BPF_ITER_FUNC(bpf_sk_storage_map, struct bpf_iter_meta *meta,
|
|
struct bpf_map *map, struct sock *sk,
|
|
void *value)
|
|
|
|
static int __bpf_sk_storage_map_seq_show(struct seq_file *seq,
|
|
struct bpf_local_storage_elem *selem)
|
|
{
|
|
struct bpf_iter_seq_sk_storage_map_info *info = seq->private;
|
|
struct bpf_iter__bpf_sk_storage_map ctx = {};
|
|
struct bpf_local_storage *sk_storage;
|
|
struct bpf_iter_meta meta;
|
|
struct bpf_prog *prog;
|
|
int ret = 0;
|
|
|
|
meta.seq = seq;
|
|
prog = bpf_iter_get_info(&meta, selem == NULL);
|
|
if (prog) {
|
|
ctx.meta = &meta;
|
|
ctx.map = info->map;
|
|
if (selem) {
|
|
sk_storage = rcu_dereference(selem->local_storage);
|
|
ctx.sk = sk_storage->owner;
|
|
ctx.value = SDATA(selem)->data;
|
|
}
|
|
ret = bpf_iter_run_prog(prog, &ctx);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int bpf_sk_storage_map_seq_show(struct seq_file *seq, void *v)
|
|
{
|
|
return __bpf_sk_storage_map_seq_show(seq, v);
|
|
}
|
|
|
|
static void bpf_sk_storage_map_seq_stop(struct seq_file *seq, void *v)
|
|
__releases(RCU)
|
|
{
|
|
if (!v)
|
|
(void)__bpf_sk_storage_map_seq_show(seq, v);
|
|
else
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static int bpf_iter_init_sk_storage_map(void *priv_data,
|
|
struct bpf_iter_aux_info *aux)
|
|
{
|
|
struct bpf_iter_seq_sk_storage_map_info *seq_info = priv_data;
|
|
|
|
seq_info->map = aux->map;
|
|
return 0;
|
|
}
|
|
|
|
static int bpf_iter_attach_map(struct bpf_prog *prog,
|
|
union bpf_iter_link_info *linfo,
|
|
struct bpf_iter_aux_info *aux)
|
|
{
|
|
struct bpf_map *map;
|
|
int err = -EINVAL;
|
|
|
|
if (!linfo->map.map_fd)
|
|
return -EBADF;
|
|
|
|
map = bpf_map_get_with_uref(linfo->map.map_fd);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
|
|
if (map->map_type != BPF_MAP_TYPE_SK_STORAGE)
|
|
goto put_map;
|
|
|
|
if (prog->aux->max_rdonly_access > map->value_size) {
|
|
err = -EACCES;
|
|
goto put_map;
|
|
}
|
|
|
|
aux->map = map;
|
|
return 0;
|
|
|
|
put_map:
|
|
bpf_map_put_with_uref(map);
|
|
return err;
|
|
}
|
|
|
|
static void bpf_iter_detach_map(struct bpf_iter_aux_info *aux)
|
|
{
|
|
bpf_map_put_with_uref(aux->map);
|
|
}
|
|
|
|
static const struct seq_operations bpf_sk_storage_map_seq_ops = {
|
|
.start = bpf_sk_storage_map_seq_start,
|
|
.next = bpf_sk_storage_map_seq_next,
|
|
.stop = bpf_sk_storage_map_seq_stop,
|
|
.show = bpf_sk_storage_map_seq_show,
|
|
};
|
|
|
|
static const struct bpf_iter_seq_info iter_seq_info = {
|
|
.seq_ops = &bpf_sk_storage_map_seq_ops,
|
|
.init_seq_private = bpf_iter_init_sk_storage_map,
|
|
.fini_seq_private = NULL,
|
|
.seq_priv_size = sizeof(struct bpf_iter_seq_sk_storage_map_info),
|
|
};
|
|
|
|
static struct bpf_iter_reg bpf_sk_storage_map_reg_info = {
|
|
.target = "bpf_sk_storage_map",
|
|
.attach_target = bpf_iter_attach_map,
|
|
.detach_target = bpf_iter_detach_map,
|
|
.show_fdinfo = bpf_iter_map_show_fdinfo,
|
|
.fill_link_info = bpf_iter_map_fill_link_info,
|
|
.ctx_arg_info_size = 2,
|
|
.ctx_arg_info = {
|
|
{ offsetof(struct bpf_iter__bpf_sk_storage_map, sk),
|
|
PTR_TO_BTF_ID_OR_NULL },
|
|
{ offsetof(struct bpf_iter__bpf_sk_storage_map, value),
|
|
PTR_TO_RDWR_BUF_OR_NULL },
|
|
},
|
|
.seq_info = &iter_seq_info,
|
|
};
|
|
|
|
static int __init bpf_sk_storage_map_iter_init(void)
|
|
{
|
|
bpf_sk_storage_map_reg_info.ctx_arg_info[0].btf_id =
|
|
btf_sock_ids[BTF_SOCK_TYPE_SOCK];
|
|
return bpf_iter_reg_target(&bpf_sk_storage_map_reg_info);
|
|
}
|
|
late_initcall(bpf_sk_storage_map_iter_init);
|