mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 10:19:47 +00:00
![John Fastabend](/assets/img/avatar_default.png)
Before using the psock returned by sk_psock_get() when adding it to a
sockmap we need to ensure it is actually a sockmap based psock.
Previously we were only checking this after incrementing the reference
counter which was an error. This resulted in a slab-out-of-bounds
error when the psock was not actually a sockmap type.
This moves the check up so the reference counter is only used
if it is a sockmap psock.
Eric reported the following KASAN BUG,
BUG: KASAN: slab-out-of-bounds in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: slab-out-of-bounds in refcount_inc_not_zero_checked+0x97/0x2f0 lib/refcount.c:120
Read of size 4 at addr ffff88019548be58 by task syz-executor4/22387
CPU: 1 PID: 22387 Comm: syz-executor4 Not tainted 4.19.0-rc7+ #264
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113
print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
check_memory_region_inline mm/kasan/kasan.c:260 [inline]
check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272
atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
refcount_inc_not_zero_checked+0x97/0x2f0 lib/refcount.c:120
sk_psock_get include/linux/skmsg.h:379 [inline]
sock_map_link.isra.6+0x41f/0xe30 net/core/sock_map.c:178
sock_hash_update_common+0x19b/0x11e0 net/core/sock_map.c:669
sock_hash_update_elem+0x306/0x470 net/core/sock_map.c:738
map_update_elem+0x819/0xdf0 kernel/bpf/syscall.c:818
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: 604326b41a
("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
1003 lines
24 KiB
C
1003 lines
24 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
|
|
|
|
#include <linux/bpf.h>
|
|
#include <linux/filter.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/file.h>
|
|
#include <linux/net.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/skmsg.h>
|
|
#include <linux/list.h>
|
|
#include <linux/jhash.h>
|
|
|
|
struct bpf_stab {
|
|
struct bpf_map map;
|
|
struct sock **sks;
|
|
struct sk_psock_progs progs;
|
|
raw_spinlock_t lock;
|
|
};
|
|
|
|
#define SOCK_CREATE_FLAG_MASK \
|
|
(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
|
|
|
|
static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
|
|
{
|
|
struct bpf_stab *stab;
|
|
u64 cost;
|
|
int err;
|
|
|
|
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 & ~SOCK_CREATE_FLAG_MASK)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
stab = kzalloc(sizeof(*stab), GFP_USER);
|
|
if (!stab)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
bpf_map_init_from_attr(&stab->map, attr);
|
|
raw_spin_lock_init(&stab->lock);
|
|
|
|
/* Make sure page count doesn't overflow. */
|
|
cost = (u64) stab->map.max_entries * sizeof(struct sock *);
|
|
if (cost >= U32_MAX - PAGE_SIZE) {
|
|
err = -EINVAL;
|
|
goto free_stab;
|
|
}
|
|
|
|
stab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
|
|
err = bpf_map_precharge_memlock(stab->map.pages);
|
|
if (err)
|
|
goto free_stab;
|
|
|
|
stab->sks = bpf_map_area_alloc(stab->map.max_entries *
|
|
sizeof(struct sock *),
|
|
stab->map.numa_node);
|
|
if (stab->sks)
|
|
return &stab->map;
|
|
err = -ENOMEM;
|
|
free_stab:
|
|
kfree(stab);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog)
|
|
{
|
|
u32 ufd = attr->target_fd;
|
|
struct bpf_map *map;
|
|
struct fd f;
|
|
int ret;
|
|
|
|
f = fdget(ufd);
|
|
map = __bpf_map_get(f);
|
|
if (IS_ERR(map))
|
|
return PTR_ERR(map);
|
|
ret = sock_map_prog_update(map, prog, attr->attach_type);
|
|
fdput(f);
|
|
return ret;
|
|
}
|
|
|
|
static void sock_map_sk_acquire(struct sock *sk)
|
|
__acquires(&sk->sk_lock.slock)
|
|
{
|
|
lock_sock(sk);
|
|
preempt_disable();
|
|
rcu_read_lock();
|
|
}
|
|
|
|
static void sock_map_sk_release(struct sock *sk)
|
|
__releases(&sk->sk_lock.slock)
|
|
{
|
|
rcu_read_unlock();
|
|
preempt_enable();
|
|
release_sock(sk);
|
|
}
|
|
|
|
static void sock_map_add_link(struct sk_psock *psock,
|
|
struct sk_psock_link *link,
|
|
struct bpf_map *map, void *link_raw)
|
|
{
|
|
link->link_raw = link_raw;
|
|
link->map = map;
|
|
spin_lock_bh(&psock->link_lock);
|
|
list_add_tail(&link->list, &psock->link);
|
|
spin_unlock_bh(&psock->link_lock);
|
|
}
|
|
|
|
static void sock_map_del_link(struct sock *sk,
|
|
struct sk_psock *psock, void *link_raw)
|
|
{
|
|
struct sk_psock_link *link, *tmp;
|
|
bool strp_stop = false;
|
|
|
|
spin_lock_bh(&psock->link_lock);
|
|
list_for_each_entry_safe(link, tmp, &psock->link, list) {
|
|
if (link->link_raw == link_raw) {
|
|
struct bpf_map *map = link->map;
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab,
|
|
map);
|
|
if (psock->parser.enabled && stab->progs.skb_parser)
|
|
strp_stop = true;
|
|
list_del(&link->list);
|
|
sk_psock_free_link(link);
|
|
}
|
|
}
|
|
spin_unlock_bh(&psock->link_lock);
|
|
if (strp_stop) {
|
|
write_lock_bh(&sk->sk_callback_lock);
|
|
sk_psock_stop_strp(sk, psock);
|
|
write_unlock_bh(&sk->sk_callback_lock);
|
|
}
|
|
}
|
|
|
|
static void sock_map_unref(struct sock *sk, void *link_raw)
|
|
{
|
|
struct sk_psock *psock = sk_psock(sk);
|
|
|
|
if (likely(psock)) {
|
|
sock_map_del_link(sk, psock, link_raw);
|
|
sk_psock_put(sk, psock);
|
|
}
|
|
}
|
|
|
|
static int sock_map_link(struct bpf_map *map, struct sk_psock_progs *progs,
|
|
struct sock *sk)
|
|
{
|
|
struct bpf_prog *msg_parser, *skb_parser, *skb_verdict;
|
|
bool skb_progs, sk_psock_is_new = false;
|
|
struct sk_psock *psock;
|
|
int ret;
|
|
|
|
skb_verdict = READ_ONCE(progs->skb_verdict);
|
|
skb_parser = READ_ONCE(progs->skb_parser);
|
|
skb_progs = skb_parser && skb_verdict;
|
|
if (skb_progs) {
|
|
skb_verdict = bpf_prog_inc_not_zero(skb_verdict);
|
|
if (IS_ERR(skb_verdict))
|
|
return PTR_ERR(skb_verdict);
|
|
skb_parser = bpf_prog_inc_not_zero(skb_parser);
|
|
if (IS_ERR(skb_parser)) {
|
|
bpf_prog_put(skb_verdict);
|
|
return PTR_ERR(skb_parser);
|
|
}
|
|
}
|
|
|
|
msg_parser = READ_ONCE(progs->msg_parser);
|
|
if (msg_parser) {
|
|
msg_parser = bpf_prog_inc_not_zero(msg_parser);
|
|
if (IS_ERR(msg_parser)) {
|
|
ret = PTR_ERR(msg_parser);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
psock = sk_psock_get_checked(sk);
|
|
if (IS_ERR(psock)) {
|
|
ret = PTR_ERR(psock);
|
|
goto out_progs;
|
|
}
|
|
|
|
if (psock) {
|
|
if ((msg_parser && READ_ONCE(psock->progs.msg_parser)) ||
|
|
(skb_progs && READ_ONCE(psock->progs.skb_parser))) {
|
|
sk_psock_put(sk, psock);
|
|
ret = -EBUSY;
|
|
goto out_progs;
|
|
}
|
|
} else {
|
|
psock = sk_psock_init(sk, map->numa_node);
|
|
if (!psock) {
|
|
ret = -ENOMEM;
|
|
goto out_progs;
|
|
}
|
|
sk_psock_is_new = true;
|
|
}
|
|
|
|
if (msg_parser)
|
|
psock_set_prog(&psock->progs.msg_parser, msg_parser);
|
|
if (sk_psock_is_new) {
|
|
ret = tcp_bpf_init(sk);
|
|
if (ret < 0)
|
|
goto out_drop;
|
|
} else {
|
|
tcp_bpf_reinit(sk);
|
|
}
|
|
|
|
write_lock_bh(&sk->sk_callback_lock);
|
|
if (skb_progs && !psock->parser.enabled) {
|
|
ret = sk_psock_init_strp(sk, psock);
|
|
if (ret) {
|
|
write_unlock_bh(&sk->sk_callback_lock);
|
|
goto out_drop;
|
|
}
|
|
psock_set_prog(&psock->progs.skb_verdict, skb_verdict);
|
|
psock_set_prog(&psock->progs.skb_parser, skb_parser);
|
|
sk_psock_start_strp(sk, psock);
|
|
}
|
|
write_unlock_bh(&sk->sk_callback_lock);
|
|
return 0;
|
|
out_drop:
|
|
sk_psock_put(sk, psock);
|
|
out_progs:
|
|
if (msg_parser)
|
|
bpf_prog_put(msg_parser);
|
|
out:
|
|
if (skb_progs) {
|
|
bpf_prog_put(skb_verdict);
|
|
bpf_prog_put(skb_parser);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void sock_map_free(struct bpf_map *map)
|
|
{
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
int i;
|
|
|
|
synchronize_rcu();
|
|
rcu_read_lock();
|
|
raw_spin_lock_bh(&stab->lock);
|
|
for (i = 0; i < stab->map.max_entries; i++) {
|
|
struct sock **psk = &stab->sks[i];
|
|
struct sock *sk;
|
|
|
|
sk = xchg(psk, NULL);
|
|
if (sk)
|
|
sock_map_unref(sk, psk);
|
|
}
|
|
raw_spin_unlock_bh(&stab->lock);
|
|
rcu_read_unlock();
|
|
|
|
bpf_map_area_free(stab->sks);
|
|
kfree(stab);
|
|
}
|
|
|
|
static void sock_map_release_progs(struct bpf_map *map)
|
|
{
|
|
psock_progs_drop(&container_of(map, struct bpf_stab, map)->progs);
|
|
}
|
|
|
|
static struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
|
|
{
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
if (unlikely(key >= map->max_entries))
|
|
return NULL;
|
|
return READ_ONCE(stab->sks[key]);
|
|
}
|
|
|
|
static void *sock_map_lookup(struct bpf_map *map, void *key)
|
|
{
|
|
return ERR_PTR(-EOPNOTSUPP);
|
|
}
|
|
|
|
static int __sock_map_delete(struct bpf_stab *stab, struct sock *sk_test,
|
|
struct sock **psk)
|
|
{
|
|
struct sock *sk;
|
|
|
|
raw_spin_lock_bh(&stab->lock);
|
|
sk = *psk;
|
|
if (!sk_test || sk_test == sk)
|
|
*psk = NULL;
|
|
raw_spin_unlock_bh(&stab->lock);
|
|
if (unlikely(!sk))
|
|
return -EINVAL;
|
|
sock_map_unref(sk, psk);
|
|
return 0;
|
|
}
|
|
|
|
static void sock_map_delete_from_link(struct bpf_map *map, struct sock *sk,
|
|
void *link_raw)
|
|
{
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
|
|
__sock_map_delete(stab, sk, link_raw);
|
|
}
|
|
|
|
static int sock_map_delete_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
u32 i = *(u32 *)key;
|
|
struct sock **psk;
|
|
|
|
if (unlikely(i >= map->max_entries))
|
|
return -EINVAL;
|
|
|
|
psk = &stab->sks[i];
|
|
return __sock_map_delete(stab, NULL, psk);
|
|
}
|
|
|
|
static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next)
|
|
{
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
u32 i = key ? *(u32 *)key : U32_MAX;
|
|
u32 *key_next = next;
|
|
|
|
if (i == stab->map.max_entries - 1)
|
|
return -ENOENT;
|
|
if (i >= stab->map.max_entries)
|
|
*key_next = 0;
|
|
else
|
|
*key_next = i + 1;
|
|
return 0;
|
|
}
|
|
|
|
static int sock_map_update_common(struct bpf_map *map, u32 idx,
|
|
struct sock *sk, u64 flags)
|
|
{
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
struct sk_psock_link *link;
|
|
struct sk_psock *psock;
|
|
struct sock *osk;
|
|
int ret;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
if (unlikely(flags > BPF_EXIST))
|
|
return -EINVAL;
|
|
if (unlikely(idx >= map->max_entries))
|
|
return -E2BIG;
|
|
|
|
link = sk_psock_init_link();
|
|
if (!link)
|
|
return -ENOMEM;
|
|
|
|
ret = sock_map_link(map, &stab->progs, sk);
|
|
if (ret < 0)
|
|
goto out_free;
|
|
|
|
psock = sk_psock(sk);
|
|
WARN_ON_ONCE(!psock);
|
|
|
|
raw_spin_lock_bh(&stab->lock);
|
|
osk = stab->sks[idx];
|
|
if (osk && flags == BPF_NOEXIST) {
|
|
ret = -EEXIST;
|
|
goto out_unlock;
|
|
} else if (!osk && flags == BPF_EXIST) {
|
|
ret = -ENOENT;
|
|
goto out_unlock;
|
|
}
|
|
|
|
sock_map_add_link(psock, link, map, &stab->sks[idx]);
|
|
stab->sks[idx] = sk;
|
|
if (osk)
|
|
sock_map_unref(osk, &stab->sks[idx]);
|
|
raw_spin_unlock_bh(&stab->lock);
|
|
return 0;
|
|
out_unlock:
|
|
raw_spin_unlock_bh(&stab->lock);
|
|
if (psock)
|
|
sk_psock_put(sk, psock);
|
|
out_free:
|
|
sk_psock_free_link(link);
|
|
return ret;
|
|
}
|
|
|
|
static bool sock_map_op_okay(const struct bpf_sock_ops_kern *ops)
|
|
{
|
|
return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
|
|
ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB;
|
|
}
|
|
|
|
static bool sock_map_sk_is_suitable(const struct sock *sk)
|
|
{
|
|
return sk->sk_type == SOCK_STREAM &&
|
|
sk->sk_protocol == IPPROTO_TCP;
|
|
}
|
|
|
|
static int sock_map_update_elem(struct bpf_map *map, void *key,
|
|
void *value, u64 flags)
|
|
{
|
|
u32 ufd = *(u32 *)value;
|
|
u32 idx = *(u32 *)key;
|
|
struct socket *sock;
|
|
struct sock *sk;
|
|
int ret;
|
|
|
|
sock = sockfd_lookup(ufd, &ret);
|
|
if (!sock)
|
|
return ret;
|
|
sk = sock->sk;
|
|
if (!sk) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (!sock_map_sk_is_suitable(sk) ||
|
|
sk->sk_state != TCP_ESTABLISHED) {
|
|
ret = -EOPNOTSUPP;
|
|
goto out;
|
|
}
|
|
|
|
sock_map_sk_acquire(sk);
|
|
ret = sock_map_update_common(map, idx, sk, flags);
|
|
sock_map_sk_release(sk);
|
|
out:
|
|
fput(sock->file);
|
|
return ret;
|
|
}
|
|
|
|
BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops,
|
|
struct bpf_map *, map, void *, key, u64, flags)
|
|
{
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
if (likely(sock_map_sk_is_suitable(sops->sk) &&
|
|
sock_map_op_okay(sops)))
|
|
return sock_map_update_common(map, *(u32 *)key, sops->sk,
|
|
flags);
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_sock_map_update_proto = {
|
|
.func = bpf_sock_map_update,
|
|
.gpl_only = false,
|
|
.pkt_access = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_PTR_TO_MAP_KEY,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_sk_redirect_map, struct sk_buff *, skb,
|
|
struct bpf_map *, map, u32, key, u64, flags)
|
|
{
|
|
struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
|
|
|
|
if (unlikely(flags & ~(BPF_F_INGRESS)))
|
|
return SK_DROP;
|
|
tcb->bpf.flags = flags;
|
|
tcb->bpf.sk_redir = __sock_map_lookup_elem(map, key);
|
|
if (!tcb->bpf.sk_redir)
|
|
return SK_DROP;
|
|
return SK_PASS;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_sk_redirect_map_proto = {
|
|
.func = bpf_sk_redirect_map,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_ANYTHING,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_msg_redirect_map, struct sk_msg *, msg,
|
|
struct bpf_map *, map, u32, key, u64, flags)
|
|
{
|
|
if (unlikely(flags & ~(BPF_F_INGRESS)))
|
|
return SK_DROP;
|
|
msg->flags = flags;
|
|
msg->sk_redir = __sock_map_lookup_elem(map, key);
|
|
if (!msg->sk_redir)
|
|
return SK_DROP;
|
|
return SK_PASS;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_msg_redirect_map_proto = {
|
|
.func = bpf_msg_redirect_map,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_ANYTHING,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
const struct bpf_map_ops sock_map_ops = {
|
|
.map_alloc = sock_map_alloc,
|
|
.map_free = sock_map_free,
|
|
.map_get_next_key = sock_map_get_next_key,
|
|
.map_update_elem = sock_map_update_elem,
|
|
.map_delete_elem = sock_map_delete_elem,
|
|
.map_lookup_elem = sock_map_lookup,
|
|
.map_release_uref = sock_map_release_progs,
|
|
.map_check_btf = map_check_no_btf,
|
|
};
|
|
|
|
struct bpf_htab_elem {
|
|
struct rcu_head rcu;
|
|
u32 hash;
|
|
struct sock *sk;
|
|
struct hlist_node node;
|
|
u8 key[0];
|
|
};
|
|
|
|
struct bpf_htab_bucket {
|
|
struct hlist_head head;
|
|
raw_spinlock_t lock;
|
|
};
|
|
|
|
struct bpf_htab {
|
|
struct bpf_map map;
|
|
struct bpf_htab_bucket *buckets;
|
|
u32 buckets_num;
|
|
u32 elem_size;
|
|
struct sk_psock_progs progs;
|
|
atomic_t count;
|
|
};
|
|
|
|
static inline u32 sock_hash_bucket_hash(const void *key, u32 len)
|
|
{
|
|
return jhash(key, len, 0);
|
|
}
|
|
|
|
static struct bpf_htab_bucket *sock_hash_select_bucket(struct bpf_htab *htab,
|
|
u32 hash)
|
|
{
|
|
return &htab->buckets[hash & (htab->buckets_num - 1)];
|
|
}
|
|
|
|
static struct bpf_htab_elem *
|
|
sock_hash_lookup_elem_raw(struct hlist_head *head, u32 hash, void *key,
|
|
u32 key_size)
|
|
{
|
|
struct bpf_htab_elem *elem;
|
|
|
|
hlist_for_each_entry_rcu(elem, head, node) {
|
|
if (elem->hash == hash &&
|
|
!memcmp(&elem->key, key, key_size))
|
|
return elem;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
u32 key_size = map->key_size, hash;
|
|
struct bpf_htab_bucket *bucket;
|
|
struct bpf_htab_elem *elem;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
hash = sock_hash_bucket_hash(key, key_size);
|
|
bucket = sock_hash_select_bucket(htab, hash);
|
|
elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
|
|
|
|
return elem ? elem->sk : NULL;
|
|
}
|
|
|
|
static void sock_hash_free_elem(struct bpf_htab *htab,
|
|
struct bpf_htab_elem *elem)
|
|
{
|
|
atomic_dec(&htab->count);
|
|
kfree_rcu(elem, rcu);
|
|
}
|
|
|
|
static void sock_hash_delete_from_link(struct bpf_map *map, struct sock *sk,
|
|
void *link_raw)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
struct bpf_htab_elem *elem_probe, *elem = link_raw;
|
|
struct bpf_htab_bucket *bucket;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
bucket = sock_hash_select_bucket(htab, elem->hash);
|
|
|
|
/* elem may be deleted in parallel from the map, but access here
|
|
* is okay since it's going away only after RCU grace period.
|
|
* However, we need to check whether it's still present.
|
|
*/
|
|
raw_spin_lock_bh(&bucket->lock);
|
|
elem_probe = sock_hash_lookup_elem_raw(&bucket->head, elem->hash,
|
|
elem->key, map->key_size);
|
|
if (elem_probe && elem_probe == elem) {
|
|
hlist_del_rcu(&elem->node);
|
|
sock_map_unref(elem->sk, elem);
|
|
sock_hash_free_elem(htab, elem);
|
|
}
|
|
raw_spin_unlock_bh(&bucket->lock);
|
|
}
|
|
|
|
static int sock_hash_delete_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
u32 hash, key_size = map->key_size;
|
|
struct bpf_htab_bucket *bucket;
|
|
struct bpf_htab_elem *elem;
|
|
int ret = -ENOENT;
|
|
|
|
hash = sock_hash_bucket_hash(key, key_size);
|
|
bucket = sock_hash_select_bucket(htab, hash);
|
|
|
|
raw_spin_lock_bh(&bucket->lock);
|
|
elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
|
|
if (elem) {
|
|
hlist_del_rcu(&elem->node);
|
|
sock_map_unref(elem->sk, elem);
|
|
sock_hash_free_elem(htab, elem);
|
|
ret = 0;
|
|
}
|
|
raw_spin_unlock_bh(&bucket->lock);
|
|
return ret;
|
|
}
|
|
|
|
static struct bpf_htab_elem *sock_hash_alloc_elem(struct bpf_htab *htab,
|
|
void *key, u32 key_size,
|
|
u32 hash, struct sock *sk,
|
|
struct bpf_htab_elem *old)
|
|
{
|
|
struct bpf_htab_elem *new;
|
|
|
|
if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
|
|
if (!old) {
|
|
atomic_dec(&htab->count);
|
|
return ERR_PTR(-E2BIG);
|
|
}
|
|
}
|
|
|
|
new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN,
|
|
htab->map.numa_node);
|
|
if (!new) {
|
|
atomic_dec(&htab->count);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
memcpy(new->key, key, key_size);
|
|
new->sk = sk;
|
|
new->hash = hash;
|
|
return new;
|
|
}
|
|
|
|
static int sock_hash_update_common(struct bpf_map *map, void *key,
|
|
struct sock *sk, u64 flags)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
u32 key_size = map->key_size, hash;
|
|
struct bpf_htab_elem *elem, *elem_new;
|
|
struct bpf_htab_bucket *bucket;
|
|
struct sk_psock_link *link;
|
|
struct sk_psock *psock;
|
|
int ret;
|
|
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
if (unlikely(flags > BPF_EXIST))
|
|
return -EINVAL;
|
|
|
|
link = sk_psock_init_link();
|
|
if (!link)
|
|
return -ENOMEM;
|
|
|
|
ret = sock_map_link(map, &htab->progs, sk);
|
|
if (ret < 0)
|
|
goto out_free;
|
|
|
|
psock = sk_psock(sk);
|
|
WARN_ON_ONCE(!psock);
|
|
|
|
hash = sock_hash_bucket_hash(key, key_size);
|
|
bucket = sock_hash_select_bucket(htab, hash);
|
|
|
|
raw_spin_lock_bh(&bucket->lock);
|
|
elem = sock_hash_lookup_elem_raw(&bucket->head, hash, key, key_size);
|
|
if (elem && flags == BPF_NOEXIST) {
|
|
ret = -EEXIST;
|
|
goto out_unlock;
|
|
} else if (!elem && flags == BPF_EXIST) {
|
|
ret = -ENOENT;
|
|
goto out_unlock;
|
|
}
|
|
|
|
elem_new = sock_hash_alloc_elem(htab, key, key_size, hash, sk, elem);
|
|
if (IS_ERR(elem_new)) {
|
|
ret = PTR_ERR(elem_new);
|
|
goto out_unlock;
|
|
}
|
|
|
|
sock_map_add_link(psock, link, map, elem_new);
|
|
/* Add new element to the head of the list, so that
|
|
* concurrent search will find it before old elem.
|
|
*/
|
|
hlist_add_head_rcu(&elem_new->node, &bucket->head);
|
|
if (elem) {
|
|
hlist_del_rcu(&elem->node);
|
|
sock_map_unref(elem->sk, elem);
|
|
sock_hash_free_elem(htab, elem);
|
|
}
|
|
raw_spin_unlock_bh(&bucket->lock);
|
|
return 0;
|
|
out_unlock:
|
|
raw_spin_unlock_bh(&bucket->lock);
|
|
sk_psock_put(sk, psock);
|
|
out_free:
|
|
sk_psock_free_link(link);
|
|
return ret;
|
|
}
|
|
|
|
static int sock_hash_update_elem(struct bpf_map *map, void *key,
|
|
void *value, u64 flags)
|
|
{
|
|
u32 ufd = *(u32 *)value;
|
|
struct socket *sock;
|
|
struct sock *sk;
|
|
int ret;
|
|
|
|
sock = sockfd_lookup(ufd, &ret);
|
|
if (!sock)
|
|
return ret;
|
|
sk = sock->sk;
|
|
if (!sk) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
if (!sock_map_sk_is_suitable(sk) ||
|
|
sk->sk_state != TCP_ESTABLISHED) {
|
|
ret = -EOPNOTSUPP;
|
|
goto out;
|
|
}
|
|
|
|
sock_map_sk_acquire(sk);
|
|
ret = sock_hash_update_common(map, key, sk, flags);
|
|
sock_map_sk_release(sk);
|
|
out:
|
|
fput(sock->file);
|
|
return ret;
|
|
}
|
|
|
|
static int sock_hash_get_next_key(struct bpf_map *map, void *key,
|
|
void *key_next)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
struct bpf_htab_elem *elem, *elem_next;
|
|
u32 hash, key_size = map->key_size;
|
|
struct hlist_head *head;
|
|
int i = 0;
|
|
|
|
if (!key)
|
|
goto find_first_elem;
|
|
hash = sock_hash_bucket_hash(key, key_size);
|
|
head = &sock_hash_select_bucket(htab, hash)->head;
|
|
elem = sock_hash_lookup_elem_raw(head, hash, key, key_size);
|
|
if (!elem)
|
|
goto find_first_elem;
|
|
|
|
elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_next_rcu(&elem->node)),
|
|
struct bpf_htab_elem, node);
|
|
if (elem_next) {
|
|
memcpy(key_next, elem_next->key, key_size);
|
|
return 0;
|
|
}
|
|
|
|
i = hash & (htab->buckets_num - 1);
|
|
i++;
|
|
find_first_elem:
|
|
for (; i < htab->buckets_num; i++) {
|
|
head = &sock_hash_select_bucket(htab, i)->head;
|
|
elem_next = hlist_entry_safe(rcu_dereference_raw(hlist_first_rcu(head)),
|
|
struct bpf_htab_elem, node);
|
|
if (elem_next) {
|
|
memcpy(key_next, elem_next->key, key_size);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return -ENOENT;
|
|
}
|
|
|
|
static struct bpf_map *sock_hash_alloc(union bpf_attr *attr)
|
|
{
|
|
struct bpf_htab *htab;
|
|
int i, err;
|
|
u64 cost;
|
|
|
|
if (!capable(CAP_NET_ADMIN))
|
|
return ERR_PTR(-EPERM);
|
|
if (attr->max_entries == 0 ||
|
|
attr->key_size == 0 ||
|
|
attr->value_size != 4 ||
|
|
attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
|
|
return ERR_PTR(-EINVAL);
|
|
if (attr->key_size > MAX_BPF_STACK)
|
|
return ERR_PTR(-E2BIG);
|
|
|
|
htab = kzalloc(sizeof(*htab), GFP_USER);
|
|
if (!htab)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
bpf_map_init_from_attr(&htab->map, attr);
|
|
|
|
htab->buckets_num = roundup_pow_of_two(htab->map.max_entries);
|
|
htab->elem_size = sizeof(struct bpf_htab_elem) +
|
|
round_up(htab->map.key_size, 8);
|
|
if (htab->buckets_num == 0 ||
|
|
htab->buckets_num > U32_MAX / sizeof(struct bpf_htab_bucket)) {
|
|
err = -EINVAL;
|
|
goto free_htab;
|
|
}
|
|
|
|
cost = (u64) htab->buckets_num * sizeof(struct bpf_htab_bucket) +
|
|
(u64) htab->elem_size * htab->map.max_entries;
|
|
if (cost >= U32_MAX - PAGE_SIZE) {
|
|
err = -EINVAL;
|
|
goto free_htab;
|
|
}
|
|
|
|
htab->buckets = bpf_map_area_alloc(htab->buckets_num *
|
|
sizeof(struct bpf_htab_bucket),
|
|
htab->map.numa_node);
|
|
if (!htab->buckets) {
|
|
err = -ENOMEM;
|
|
goto free_htab;
|
|
}
|
|
|
|
for (i = 0; i < htab->buckets_num; i++) {
|
|
INIT_HLIST_HEAD(&htab->buckets[i].head);
|
|
raw_spin_lock_init(&htab->buckets[i].lock);
|
|
}
|
|
|
|
return &htab->map;
|
|
free_htab:
|
|
kfree(htab);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
static void sock_hash_free(struct bpf_map *map)
|
|
{
|
|
struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
|
|
struct bpf_htab_bucket *bucket;
|
|
struct bpf_htab_elem *elem;
|
|
struct hlist_node *node;
|
|
int i;
|
|
|
|
synchronize_rcu();
|
|
rcu_read_lock();
|
|
for (i = 0; i < htab->buckets_num; i++) {
|
|
bucket = sock_hash_select_bucket(htab, i);
|
|
raw_spin_lock_bh(&bucket->lock);
|
|
hlist_for_each_entry_safe(elem, node, &bucket->head, node) {
|
|
hlist_del_rcu(&elem->node);
|
|
sock_map_unref(elem->sk, elem);
|
|
}
|
|
raw_spin_unlock_bh(&bucket->lock);
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
bpf_map_area_free(htab->buckets);
|
|
kfree(htab);
|
|
}
|
|
|
|
static void sock_hash_release_progs(struct bpf_map *map)
|
|
{
|
|
psock_progs_drop(&container_of(map, struct bpf_htab, map)->progs);
|
|
}
|
|
|
|
BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, sops,
|
|
struct bpf_map *, map, void *, key, u64, flags)
|
|
{
|
|
WARN_ON_ONCE(!rcu_read_lock_held());
|
|
|
|
if (likely(sock_map_sk_is_suitable(sops->sk) &&
|
|
sock_map_op_okay(sops)))
|
|
return sock_hash_update_common(map, key, sops->sk, flags);
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_sock_hash_update_proto = {
|
|
.func = bpf_sock_hash_update,
|
|
.gpl_only = false,
|
|
.pkt_access = true,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_PTR_TO_MAP_KEY,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_sk_redirect_hash, struct sk_buff *, skb,
|
|
struct bpf_map *, map, void *, key, u64, flags)
|
|
{
|
|
struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
|
|
|
|
if (unlikely(flags & ~(BPF_F_INGRESS)))
|
|
return SK_DROP;
|
|
tcb->bpf.flags = flags;
|
|
tcb->bpf.sk_redir = __sock_hash_lookup_elem(map, key);
|
|
if (!tcb->bpf.sk_redir)
|
|
return SK_DROP;
|
|
return SK_PASS;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_sk_redirect_hash_proto = {
|
|
.func = bpf_sk_redirect_hash,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_PTR_TO_MAP_KEY,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_msg_redirect_hash, struct sk_msg *, msg,
|
|
struct bpf_map *, map, void *, key, u64, flags)
|
|
{
|
|
if (unlikely(flags & ~(BPF_F_INGRESS)))
|
|
return SK_DROP;
|
|
msg->flags = flags;
|
|
msg->sk_redir = __sock_hash_lookup_elem(map, key);
|
|
if (!msg->sk_redir)
|
|
return SK_DROP;
|
|
return SK_PASS;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_msg_redirect_hash_proto = {
|
|
.func = bpf_msg_redirect_hash,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_CONST_MAP_PTR,
|
|
.arg3_type = ARG_PTR_TO_MAP_KEY,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
const struct bpf_map_ops sock_hash_ops = {
|
|
.map_alloc = sock_hash_alloc,
|
|
.map_free = sock_hash_free,
|
|
.map_get_next_key = sock_hash_get_next_key,
|
|
.map_update_elem = sock_hash_update_elem,
|
|
.map_delete_elem = sock_hash_delete_elem,
|
|
.map_lookup_elem = sock_map_lookup,
|
|
.map_release_uref = sock_hash_release_progs,
|
|
.map_check_btf = map_check_no_btf,
|
|
};
|
|
|
|
static struct sk_psock_progs *sock_map_progs(struct bpf_map *map)
|
|
{
|
|
switch (map->map_type) {
|
|
case BPF_MAP_TYPE_SOCKMAP:
|
|
return &container_of(map, struct bpf_stab, map)->progs;
|
|
case BPF_MAP_TYPE_SOCKHASH:
|
|
return &container_of(map, struct bpf_htab, map)->progs;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog,
|
|
u32 which)
|
|
{
|
|
struct sk_psock_progs *progs = sock_map_progs(map);
|
|
|
|
if (!progs)
|
|
return -EOPNOTSUPP;
|
|
|
|
switch (which) {
|
|
case BPF_SK_MSG_VERDICT:
|
|
psock_set_prog(&progs->msg_parser, prog);
|
|
break;
|
|
case BPF_SK_SKB_STREAM_PARSER:
|
|
psock_set_prog(&progs->skb_parser, prog);
|
|
break;
|
|
case BPF_SK_SKB_STREAM_VERDICT:
|
|
psock_set_prog(&progs->skb_verdict, prog);
|
|
break;
|
|
default:
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void sk_psock_unlink(struct sock *sk, struct sk_psock_link *link)
|
|
{
|
|
switch (link->map->map_type) {
|
|
case BPF_MAP_TYPE_SOCKMAP:
|
|
return sock_map_delete_from_link(link->map, sk,
|
|
link->link_raw);
|
|
case BPF_MAP_TYPE_SOCKHASH:
|
|
return sock_hash_delete_from_link(link->map, sk,
|
|
link->link_raw);
|
|
default:
|
|
break;
|
|
}
|
|
}
|