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path: root/kernel/bpf/sockmap.c
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Diffstat (limited to 'kernel/bpf/sockmap.c')
-rw-r--r--kernel/bpf/sockmap.c824
1 files changed, 725 insertions, 99 deletions
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 95a84b2f10ce..c4d75c52b4fc 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -48,14 +48,41 @@
#define SOCK_CREATE_FLAG_MASK \
(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
-struct bpf_stab {
- struct bpf_map map;
- struct sock **sock_map;
+struct bpf_sock_progs {
struct bpf_prog *bpf_tx_msg;
struct bpf_prog *bpf_parse;
struct bpf_prog *bpf_verdict;
};
+struct bpf_stab {
+ struct bpf_map map;
+ struct sock **sock_map;
+ struct bpf_sock_progs progs;
+};
+
+struct bucket {
+ struct hlist_head head;
+ raw_spinlock_t lock;
+};
+
+struct bpf_htab {
+ struct bpf_map map;
+ struct bucket *buckets;
+ atomic_t count;
+ u32 n_buckets;
+ u32 elem_size;
+ struct bpf_sock_progs progs;
+ struct rcu_head rcu;
+};
+
+struct htab_elem {
+ struct rcu_head rcu;
+ struct hlist_node hash_node;
+ u32 hash;
+ struct sock *sk;
+ char key[0];
+};
+
enum smap_psock_state {
SMAP_TX_RUNNING,
};
@@ -63,6 +90,8 @@ enum smap_psock_state {
struct smap_psock_map_entry {
struct list_head list;
struct sock **entry;
+ struct htab_elem __rcu *hash_link;
+ struct bpf_htab __rcu *htab;
};
struct smap_psock {
@@ -92,6 +121,7 @@ struct smap_psock {
struct bpf_prog *bpf_parse;
struct bpf_prog *bpf_verdict;
struct list_head maps;
+ spinlock_t maps_lock;
/* Back reference used when sock callback trigger sockmap operations */
struct sock *sock;
@@ -112,6 +142,7 @@ static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
static int bpf_tcp_sendpage(struct sock *sk, struct page *page,
int offset, size_t size, int flags);
+static void bpf_tcp_close(struct sock *sk, long timeout);
static inline struct smap_psock *smap_psock_sk(const struct sock *sk)
{
@@ -133,7 +164,42 @@ out:
return !empty;
}
-static struct proto tcp_bpf_proto;
+enum {
+ SOCKMAP_IPV4,
+ SOCKMAP_IPV6,
+ SOCKMAP_NUM_PROTS,
+};
+
+enum {
+ SOCKMAP_BASE,
+ SOCKMAP_TX,
+ SOCKMAP_NUM_CONFIGS,
+};
+
+static struct proto *saved_tcpv6_prot __read_mostly;
+static DEFINE_SPINLOCK(tcpv6_prot_lock);
+static struct proto bpf_tcp_prots[SOCKMAP_NUM_PROTS][SOCKMAP_NUM_CONFIGS];
+static void build_protos(struct proto prot[SOCKMAP_NUM_CONFIGS],
+ struct proto *base)
+{
+ prot[SOCKMAP_BASE] = *base;
+ prot[SOCKMAP_BASE].close = bpf_tcp_close;
+ prot[SOCKMAP_BASE].recvmsg = bpf_tcp_recvmsg;
+ prot[SOCKMAP_BASE].stream_memory_read = bpf_tcp_stream_read;
+
+ prot[SOCKMAP_TX] = prot[SOCKMAP_BASE];
+ prot[SOCKMAP_TX].sendmsg = bpf_tcp_sendmsg;
+ prot[SOCKMAP_TX].sendpage = bpf_tcp_sendpage;
+}
+
+static void update_sk_prot(struct sock *sk, struct smap_psock *psock)
+{
+ int family = sk->sk_family == AF_INET6 ? SOCKMAP_IPV6 : SOCKMAP_IPV4;
+ int conf = psock->bpf_tx_msg ? SOCKMAP_TX : SOCKMAP_BASE;
+
+ sk->sk_prot = &bpf_tcp_prots[family][conf];
+}
+
static int bpf_tcp_init(struct sock *sk)
{
struct smap_psock *psock;
@@ -153,14 +219,17 @@ static int bpf_tcp_init(struct sock *sk)
psock->save_close = sk->sk_prot->close;
psock->sk_proto = sk->sk_prot;
- if (psock->bpf_tx_msg) {
- tcp_bpf_proto.sendmsg = bpf_tcp_sendmsg;
- tcp_bpf_proto.sendpage = bpf_tcp_sendpage;
- tcp_bpf_proto.recvmsg = bpf_tcp_recvmsg;
- tcp_bpf_proto.stream_memory_read = bpf_tcp_stream_read;
+ /* Build IPv6 sockmap whenever the address of tcpv6_prot changes */
+ if (sk->sk_family == AF_INET6 &&
+ unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv6_prot))) {
+ spin_lock_bh(&tcpv6_prot_lock);
+ if (likely(sk->sk_prot != saved_tcpv6_prot)) {
+ build_protos(bpf_tcp_prots[SOCKMAP_IPV6], sk->sk_prot);
+ smp_store_release(&saved_tcpv6_prot, sk->sk_prot);
+ }
+ spin_unlock_bh(&tcpv6_prot_lock);
}
-
- sk->sk_prot = &tcp_bpf_proto;
+ update_sk_prot(sk, psock);
rcu_read_unlock();
return 0;
}
@@ -191,18 +260,64 @@ out:
rcu_read_unlock();
}
+static struct htab_elem *lookup_elem_raw(struct hlist_head *head,
+ u32 hash, void *key, u32 key_size)
+{
+ struct htab_elem *l;
+
+ hlist_for_each_entry_rcu(l, head, hash_node) {
+ if (l->hash == hash && !memcmp(&l->key, key, key_size))
+ return l;
+ }
+
+ return NULL;
+}
+
+static inline struct bucket *__select_bucket(struct bpf_htab *htab, u32 hash)
+{
+ return &htab->buckets[hash & (htab->n_buckets - 1)];
+}
+
+static inline struct hlist_head *select_bucket(struct bpf_htab *htab, u32 hash)
+{
+ return &__select_bucket(htab, hash)->head;
+}
+
+static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
+{
+ atomic_dec(&htab->count);
+ kfree_rcu(l, rcu);
+}
+
+static struct smap_psock_map_entry *psock_map_pop(struct sock *sk,
+ struct smap_psock *psock)
+{
+ struct smap_psock_map_entry *e;
+
+ spin_lock_bh(&psock->maps_lock);
+ e = list_first_entry_or_null(&psock->maps,
+ struct smap_psock_map_entry,
+ list);
+ if (e)
+ list_del(&e->list);
+ spin_unlock_bh(&psock->maps_lock);
+ return e;
+}
+
static void bpf_tcp_close(struct sock *sk, long timeout)
{
void (*close_fun)(struct sock *sk, long timeout);
- struct smap_psock_map_entry *e, *tmp;
+ struct smap_psock_map_entry *e;
struct sk_msg_buff *md, *mtmp;
struct smap_psock *psock;
struct sock *osk;
+ lock_sock(sk);
rcu_read_lock();
psock = smap_psock_sk(sk);
if (unlikely(!psock)) {
rcu_read_unlock();
+ release_sock(sk);
return sk->sk_prot->close(sk, timeout);
}
@@ -213,7 +328,6 @@ static void bpf_tcp_close(struct sock *sk, long timeout)
*/
close_fun = psock->save_close;
- write_lock_bh(&sk->sk_callback_lock);
if (psock->cork) {
free_start_sg(psock->sock, psock->cork);
kfree(psock->cork);
@@ -226,15 +340,40 @@ static void bpf_tcp_close(struct sock *sk, long timeout)
kfree(md);
}
- list_for_each_entry_safe(e, tmp, &psock->maps, list) {
- osk = cmpxchg(e->entry, sk, NULL);
- if (osk == sk) {
- list_del(&e->list);
- smap_release_sock(psock, sk);
+ e = psock_map_pop(sk, psock);
+ while (e) {
+ if (e->entry) {
+ osk = cmpxchg(e->entry, sk, NULL);
+ if (osk == sk) {
+ smap_release_sock(psock, sk);
+ }
+ } else {
+ struct htab_elem *link = rcu_dereference(e->hash_link);
+ struct bpf_htab *htab = rcu_dereference(e->htab);
+ struct hlist_head *head;
+ struct htab_elem *l;
+ struct bucket *b;
+
+ b = __select_bucket(htab, link->hash);
+ head = &b->head;
+ raw_spin_lock_bh(&b->lock);
+ l = lookup_elem_raw(head,
+ link->hash, link->key,
+ htab->map.key_size);
+ /* If another thread deleted this object skip deletion.
+ * The refcnt on psock may or may not be zero.
+ */
+ if (l) {
+ hlist_del_rcu(&link->hash_node);
+ smap_release_sock(psock, link->sk);
+ free_htab_elem(htab, link);
+ }
+ raw_spin_unlock_bh(&b->lock);
}
+ e = psock_map_pop(sk, psock);
}
- write_unlock_bh(&sk->sk_callback_lock);
rcu_read_unlock();
+ release_sock(sk);
close_fun(sk, timeout);
}
@@ -432,7 +571,8 @@ static int free_sg(struct sock *sk, int start, struct sk_msg_buff *md)
while (sg[i].length) {
free += sg[i].length;
sk_mem_uncharge(sk, sg[i].length);
- put_page(sg_page(&sg[i]));
+ if (!md->skb)
+ put_page(sg_page(&sg[i]));
sg[i].length = 0;
sg[i].page_link = 0;
sg[i].offset = 0;
@@ -441,6 +581,8 @@ static int free_sg(struct sock *sk, int start, struct sk_msg_buff *md)
if (i == MAX_SKB_FRAGS)
i = 0;
}
+ if (md->skb)
+ consume_skb(md->skb);
return free;
}
@@ -461,7 +603,7 @@ static int free_curr_sg(struct sock *sk, struct sk_msg_buff *md)
static int bpf_map_msg_verdict(int _rc, struct sk_msg_buff *md)
{
return ((_rc == SK_PASS) ?
- (md->map ? __SK_REDIRECT : __SK_PASS) :
+ (md->sk_redir ? __SK_REDIRECT : __SK_PASS) :
__SK_DROP);
}
@@ -483,6 +625,7 @@ static unsigned int smap_do_tx_msg(struct sock *sk,
}
bpf_compute_data_pointers_sg(md);
+ md->sk = sk;
rc = (*prog->bpf_func)(md, prog->insnsi);
psock->apply_bytes = md->apply_bytes;
@@ -905,12 +1048,12 @@ static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
while (msg_data_left(msg)) {
- struct sk_msg_buff *m;
+ struct sk_msg_buff *m = NULL;
bool enospc = false;
int copy;
if (sk->sk_err) {
- err = sk->sk_err;
+ err = -sk->sk_err;
goto out_err;
}
@@ -973,8 +1116,11 @@ wait_for_sndbuf:
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
wait_for_memory:
err = sk_stream_wait_memory(sk, &timeo);
- if (err)
+ if (err) {
+ if (m && m != psock->cork)
+ free_start_sg(sk, m);
goto out_err;
+ }
}
out_err:
if (err < 0)
@@ -1070,8 +1216,7 @@ static void bpf_tcp_msg_add(struct smap_psock *psock,
static int bpf_tcp_ulp_register(void)
{
- tcp_bpf_proto = tcp_prot;
- tcp_bpf_proto.close = bpf_tcp_close;
+ build_protos(bpf_tcp_prots[SOCKMAP_IPV4], &tcp_prot);
/* Once BPF TX ULP is registered it is never unregistered. It
* will be in the ULP list for the lifetime of the system. Doing
* duplicate registers is not a problem.
@@ -1092,9 +1237,9 @@ static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb)
* when we orphan the skb so that we don't have the possibility
* to reference a stale map.
*/
- TCP_SKB_CB(skb)->bpf.map = NULL;
+ TCP_SKB_CB(skb)->bpf.sk_redir = NULL;
skb->sk = psock->sock;
- bpf_compute_data_pointers(skb);
+ bpf_compute_data_end_sk_skb(skb);
preempt_disable();
rc = (*prog->bpf_func)(skb, prog->insnsi);
preempt_enable();
@@ -1102,7 +1247,7 @@ static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb)
/* Moving return codes from UAPI namespace into internal namespace */
return rc == SK_PASS ?
- (TCP_SKB_CB(skb)->bpf.map ? __SK_REDIRECT : __SK_PASS) :
+ (TCP_SKB_CB(skb)->bpf.sk_redir ? __SK_REDIRECT : __SK_PASS) :
__SK_DROP;
}
@@ -1316,7 +1461,9 @@ static void smap_release_sock(struct smap_psock *psock, struct sock *sock)
{
if (refcount_dec_and_test(&psock->refcnt)) {
tcp_cleanup_ulp(sock);
+ write_lock_bh(&sock->sk_callback_lock);
smap_stop_sock(psock, sock);
+ write_unlock_bh(&sock->sk_callback_lock);
clear_bit(SMAP_TX_RUNNING, &psock->state);
rcu_assign_sk_user_data(sock, NULL);
call_rcu_sched(&psock->rcu, smap_destroy_psock);
@@ -1347,7 +1494,7 @@ static int smap_parse_func_strparser(struct strparser *strp,
* any socket yet.
*/
skb->sk = psock->sock;
- bpf_compute_data_pointers(skb);
+ bpf_compute_data_end_sk_skb(skb);
rc = (*prog->bpf_func)(skb, prog->insnsi);
skb->sk = NULL;
rcu_read_unlock();
@@ -1372,7 +1519,6 @@ static int smap_init_sock(struct smap_psock *psock,
}
static void smap_init_progs(struct smap_psock *psock,
- struct bpf_stab *stab,
struct bpf_prog *verdict,
struct bpf_prog *parse)
{
@@ -1450,14 +1596,13 @@ static void smap_gc_work(struct work_struct *w)
kfree(psock);
}
-static struct smap_psock *smap_init_psock(struct sock *sock,
- struct bpf_stab *stab)
+static struct smap_psock *smap_init_psock(struct sock *sock, int node)
{
struct smap_psock *psock;
psock = kzalloc_node(sizeof(struct smap_psock),
GFP_ATOMIC | __GFP_NOWARN,
- stab->map.numa_node);
+ node);
if (!psock)
return ERR_PTR(-ENOMEM);
@@ -1469,6 +1614,7 @@ static struct smap_psock *smap_init_psock(struct sock *sock,
INIT_LIST_HEAD(&psock->maps);
INIT_LIST_HEAD(&psock->ingress);
refcount_set(&psock->refcnt, 1);
+ spin_lock_init(&psock->maps_lock);
rcu_assign_sk_user_data(sock, psock);
sock_hold(sock);
@@ -1525,16 +1671,32 @@ free_stab:
return ERR_PTR(err);
}
-static void smap_list_remove(struct smap_psock *psock, struct sock **entry)
+static void smap_list_map_remove(struct smap_psock *psock,
+ struct sock **entry)
{
struct smap_psock_map_entry *e, *tmp;
+ spin_lock_bh(&psock->maps_lock);
list_for_each_entry_safe(e, tmp, &psock->maps, list) {
- if (e->entry == entry) {
+ if (e->entry == entry)
+ list_del(&e->list);
+ }
+ spin_unlock_bh(&psock->maps_lock);
+}
+
+static void smap_list_hash_remove(struct smap_psock *psock,
+ struct htab_elem *hash_link)
+{
+ struct smap_psock_map_entry *e, *tmp;
+
+ spin_lock_bh(&psock->maps_lock);
+ list_for_each_entry_safe(e, tmp, &psock->maps, list) {
+ struct htab_elem *c = rcu_dereference(e->hash_link);
+
+ if (c == hash_link)
list_del(&e->list);
- break;
- }
}
+ spin_unlock_bh(&psock->maps_lock);
}
static void sock_map_free(struct bpf_map *map)
@@ -1560,7 +1722,6 @@ static void sock_map_free(struct bpf_map *map)
if (!sock)
continue;
- write_lock_bh(&sock->sk_callback_lock);
psock = smap_psock_sk(sock);
/* This check handles a racing sock event that can get the
* sk_callback_lock before this case but after xchg happens
@@ -1568,10 +1729,9 @@ static void sock_map_free(struct bpf_map *map)
* to be null and queued for garbage collection.
*/
if (likely(psock)) {
- smap_list_remove(psock, &stab->sock_map[i]);
+ smap_list_map_remove(psock, &stab->sock_map[i]);
smap_release_sock(psock, sock);
}
- write_unlock_bh(&sock->sk_callback_lock);
}
rcu_read_unlock();
@@ -1620,17 +1780,15 @@ static int sock_map_delete_elem(struct bpf_map *map, void *key)
if (!sock)
return -EINVAL;
- write_lock_bh(&sock->sk_callback_lock);
psock = smap_psock_sk(sock);
if (!psock)
goto out;
if (psock->bpf_parse)
smap_stop_sock(psock, sock);
- smap_list_remove(psock, &stab->sock_map[k]);
+ smap_list_map_remove(psock, &stab->sock_map[k]);
smap_release_sock(psock, sock);
out:
- write_unlock_bh(&sock->sk_callback_lock);
return 0;
}
@@ -1662,40 +1820,26 @@ out:
* - sock_map must use READ_ONCE and (cmp)xchg operations
* - BPF verdict/parse programs must use READ_ONCE and xchg operations
*/
-static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
- struct bpf_map *map,
- void *key, u64 flags)
+
+static int __sock_map_ctx_update_elem(struct bpf_map *map,
+ struct bpf_sock_progs *progs,
+ struct sock *sock,
+ struct sock **map_link,
+ void *key)
{
- struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
- struct smap_psock_map_entry *e = NULL;
struct bpf_prog *verdict, *parse, *tx_msg;
- struct sock *osock, *sock;
+ struct smap_psock_map_entry *e = NULL;
struct smap_psock *psock;
- u32 i = *(u32 *)key;
bool new = false;
- int err;
-
- if (unlikely(flags > BPF_EXIST))
- return -EINVAL;
-
- if (unlikely(i >= stab->map.max_entries))
- return -E2BIG;
-
- sock = READ_ONCE(stab->sock_map[i]);
- if (flags == BPF_EXIST && !sock)
- return -ENOENT;
- else if (flags == BPF_NOEXIST && sock)
- return -EEXIST;
-
- sock = skops->sk;
+ int err = 0;
/* 1. If sock map has BPF programs those will be inherited by the
* sock being added. If the sock is already attached to BPF programs
* this results in an error.
*/
- verdict = READ_ONCE(stab->bpf_verdict);
- parse = READ_ONCE(stab->bpf_parse);
- tx_msg = READ_ONCE(stab->bpf_tx_msg);
+ verdict = READ_ONCE(progs->bpf_verdict);
+ parse = READ_ONCE(progs->bpf_parse);
+ tx_msg = READ_ONCE(progs->bpf_tx_msg);
if (parse && verdict) {
/* bpf prog refcnt may be zero if a concurrent attach operation
@@ -1725,7 +1869,6 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
}
}
- write_lock_bh(&sock->sk_callback_lock);
psock = smap_psock_sk(sock);
/* 2. Do not allow inheriting programs if psock exists and has
@@ -1748,7 +1891,7 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
goto out_progs;
}
} else {
- psock = smap_init_psock(sock, stab);
+ psock = smap_init_psock(sock, map->numa_node);
if (IS_ERR(psock)) {
err = PTR_ERR(psock);
goto out_progs;
@@ -1758,12 +1901,13 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
new = true;
}
- e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN);
- if (!e) {
- err = -ENOMEM;
- goto out_progs;
+ if (map_link) {
+ e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN);
+ if (!e) {
+ err = -ENOMEM;
+ goto out_free;
+ }
}
- e->entry = &stab->sock_map[i];
/* 3. At this point we have a reference to a valid psock that is
* running. Attach any BPF programs needed.
@@ -1780,8 +1924,10 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
err = smap_init_sock(psock, sock);
if (err)
goto out_free;
- smap_init_progs(psock, stab, verdict, parse);
+ smap_init_progs(psock, verdict, parse);
+ write_lock_bh(&sock->sk_callback_lock);
smap_start_sock(psock, sock);
+ write_unlock_bh(&sock->sk_callback_lock);
}
/* 4. Place psock in sockmap for use and stop any programs on
@@ -1789,19 +1935,13 @@ static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
* it with. Because we can only have a single set of programs if
* old_sock has a strp we can stop it.
*/
- list_add_tail(&e->list, &psock->maps);
- write_unlock_bh(&sock->sk_callback_lock);
-
- osock = xchg(&stab->sock_map[i], sock);
- if (osock) {
- struct smap_psock *opsock = smap_psock_sk(osock);
-
- write_lock_bh(&osock->sk_callback_lock);
- smap_list_remove(opsock, &stab->sock_map[i]);
- smap_release_sock(opsock, osock);
- write_unlock_bh(&osock->sk_callback_lock);
+ if (map_link) {
+ e->entry = map_link;
+ spin_lock_bh(&psock->maps_lock);
+ list_add_tail(&e->list, &psock->maps);
+ spin_unlock_bh(&psock->maps_lock);
}
- return 0;
+ return err;
out_free:
smap_release_sock(psock, sock);
out_progs:
@@ -1811,28 +1951,75 @@ out_progs:
}
if (tx_msg)
bpf_prog_put(tx_msg);
- write_unlock_bh(&sock->sk_callback_lock);
kfree(e);
return err;
}
-int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type)
+static int sock_map_ctx_update_elem(struct bpf_sock_ops_kern *skops,
+ struct bpf_map *map,
+ void *key, u64 flags)
{
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+ struct bpf_sock_progs *progs = &stab->progs;
+ struct sock *osock, *sock;
+ u32 i = *(u32 *)key;
+ int err;
+
+ if (unlikely(flags > BPF_EXIST))
+ return -EINVAL;
+
+ if (unlikely(i >= stab->map.max_entries))
+ return -E2BIG;
+
+ sock = READ_ONCE(stab->sock_map[i]);
+ if (flags == BPF_EXIST && !sock)
+ return -ENOENT;
+ else if (flags == BPF_NOEXIST && sock)
+ return -EEXIST;
+
+ sock = skops->sk;
+ err = __sock_map_ctx_update_elem(map, progs, sock, &stab->sock_map[i],
+ key);
+ if (err)
+ goto out;
+
+ osock = xchg(&stab->sock_map[i], sock);
+ if (osock) {
+ struct smap_psock *opsock = smap_psock_sk(osock);
+
+ smap_list_map_remove(opsock, &stab->sock_map[i]);
+ smap_release_sock(opsock, osock);
+ }
+out:
+ return err;
+}
+
+int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type)
+{
+ struct bpf_sock_progs *progs;
struct bpf_prog *orig;
- if (unlikely(map->map_type != BPF_MAP_TYPE_SOCKMAP))
+ if (map->map_type == BPF_MAP_TYPE_SOCKMAP) {
+ struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+
+ progs = &stab->progs;
+ } else if (map->map_type == BPF_MAP_TYPE_SOCKHASH) {
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+
+ progs = &htab->progs;
+ } else {
return -EINVAL;
+ }
switch (type) {
case BPF_SK_MSG_VERDICT:
- orig = xchg(&stab->bpf_tx_msg, prog);
+ orig = xchg(&progs->bpf_tx_msg, prog);
break;
case BPF_SK_SKB_STREAM_PARSER:
- orig = xchg(&stab->bpf_parse, prog);
+ orig = xchg(&progs->bpf_parse, prog);
break;
case BPF_SK_SKB_STREAM_VERDICT:
- orig = xchg(&stab->bpf_verdict, prog);
+ orig = xchg(&progs->bpf_verdict, prog);
break;
default:
return -EOPNOTSUPP;
@@ -1844,6 +2031,24 @@ int sock_map_prog(struct bpf_map *map, struct bpf_prog *prog, u32 type)
return 0;
}
+int sockmap_get_from_fd(const union bpf_attr *attr, int type,
+ struct bpf_prog *prog)
+{
+ int ufd = attr->target_fd;
+ struct bpf_map *map;
+ struct fd f;
+ int err;
+
+ f = fdget(ufd);
+ map = __bpf_map_get(f);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ err = sock_map_prog(map, prog, attr->attach_type);
+ fdput(f);
+ return err;
+}
+
static void *sock_map_lookup(struct bpf_map *map, void *key)
{
return NULL;
@@ -1873,28 +2078,421 @@ static int sock_map_update_elem(struct bpf_map *map,
return -EOPNOTSUPP;
}
+ lock_sock(skops.sk);
+ preempt_disable();
+ rcu_read_lock();
err = sock_map_ctx_update_elem(&skops, map, key, flags);
+ rcu_read_unlock();
+ preempt_enable();
+ release_sock(skops.sk);
fput(socket->file);
return err;
}
static void sock_map_release(struct bpf_map *map)
{
- struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+ struct bpf_sock_progs *progs;
struct bpf_prog *orig;
- orig = xchg(&stab->bpf_parse, NULL);
+ if (map->map_type == BPF_MAP_TYPE_SOCKMAP) {
+ struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
+
+ progs = &stab->progs;
+ } else {
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+
+ progs = &htab->progs;
+ }
+
+ orig = xchg(&progs->bpf_parse, NULL);
if (orig)
bpf_prog_put(orig);
- orig = xchg(&stab->bpf_verdict, NULL);
+ orig = xchg(&progs->bpf_verdict, NULL);
if (orig)
bpf_prog_put(orig);
- orig = xchg(&stab->bpf_tx_msg, NULL);
+ orig = xchg(&progs->bpf_tx_msg, NULL);
if (orig)
bpf_prog_put(orig);
}
+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);
+
+ /* check sanity of attributes */
+ if (attr->max_entries == 0 || attr->value_size != 4 ||
+ attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
+ return ERR_PTR(-EINVAL);
+
+ if (attr->key_size > MAX_BPF_STACK)
+ /* eBPF programs initialize keys on stack, so they cannot be
+ * larger than max stack size
+ */
+ return ERR_PTR(-E2BIG);
+
+ err = bpf_tcp_ulp_register();
+ if (err && err != -EEXIST)
+ return ERR_PTR(err);
+
+ htab = kzalloc(sizeof(*htab), GFP_USER);
+ if (!htab)
+ return ERR_PTR(-ENOMEM);
+
+ bpf_map_init_from_attr(&htab->map, attr);
+
+ htab->n_buckets = roundup_pow_of_two(htab->map.max_entries);
+ htab->elem_size = sizeof(struct htab_elem) +
+ round_up(htab->map.key_size, 8);
+ err = -EINVAL;
+ if (htab->n_buckets == 0 ||
+ htab->n_buckets > U32_MAX / sizeof(struct bucket))
+ goto free_htab;
+
+ cost = (u64) htab->n_buckets * sizeof(struct bucket) +
+ (u64) htab->elem_size * htab->map.max_entries;
+
+ if (cost >= U32_MAX - PAGE_SIZE)
+ goto free_htab;
+
+ htab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
+ err = bpf_map_precharge_memlock(htab->map.pages);
+ if (err)
+ goto free_htab;
+
+ err = -ENOMEM;
+ htab->buckets = bpf_map_area_alloc(
+ htab->n_buckets * sizeof(struct bucket),
+ htab->map.numa_node);
+ if (!htab->buckets)
+ goto free_htab;
+
+ for (i = 0; i < htab->n_buckets; 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 __bpf_htab_free(struct rcu_head *rcu)
+{
+ struct bpf_htab *htab;
+
+ htab = container_of(rcu, struct bpf_htab, rcu);
+ bpf_map_area_free(htab->buckets);
+ kfree(htab);
+}
+
+static void sock_hash_free(struct bpf_map *map)
+{
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+ int i;
+
+ synchronize_rcu();
+
+ /* At this point no update, lookup or delete operations can happen.
+ * However, be aware we can still get a socket state event updates,
+ * and data ready callabacks that reference the psock from sk_user_data
+ * Also psock worker threads are still in-flight. So smap_release_sock
+ * will only free the psock after cancel_sync on the worker threads
+ * and a grace period expire to ensure psock is really safe to remove.
+ */
+ rcu_read_lock();
+ for (i = 0; i < htab->n_buckets; i++) {
+ struct bucket *b = __select_bucket(htab, i);
+ struct hlist_head *head;
+ struct hlist_node *n;
+ struct htab_elem *l;
+
+ raw_spin_lock_bh(&b->lock);
+ head = &b->head;
+ hlist_for_each_entry_safe(l, n, head, hash_node) {
+ struct sock *sock = l->sk;
+ struct smap_psock *psock;
+
+ hlist_del_rcu(&l->hash_node);
+ psock = smap_psock_sk(sock);
+ /* This check handles a racing sock event that can get
+ * the sk_callback_lock before this case but after xchg
+ * causing the refcnt to hit zero and sock user data
+ * (psock) to be null and queued for garbage collection.
+ */
+ if (likely(psock)) {
+ smap_list_hash_remove(psock, l);
+ smap_release_sock(psock, sock);
+ }
+ free_htab_elem(htab, l);
+ }
+ raw_spin_unlock_bh(&b->lock);
+ }
+ rcu_read_unlock();
+ call_rcu(&htab->rcu, __bpf_htab_free);
+}
+
+static struct htab_elem *alloc_sock_hash_elem(struct bpf_htab *htab,
+ void *key, u32 key_size, u32 hash,
+ struct sock *sk,
+ struct htab_elem *old_elem)
+{
+ struct htab_elem *l_new;
+
+ if (atomic_inc_return(&htab->count) > htab->map.max_entries) {
+ if (!old_elem) {
+ atomic_dec(&htab->count);
+ return ERR_PTR(-E2BIG);
+ }
+ }
+ l_new = kmalloc_node(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN,
+ htab->map.numa_node);
+ if (!l_new)
+ return ERR_PTR(-ENOMEM);
+
+ memcpy(l_new->key, key, key_size);
+ l_new->sk = sk;
+ l_new->hash = hash;
+ return l_new;
+}
+
+static inline u32 htab_map_hash(const void *key, u32 key_len)
+{
+ return jhash(key, key_len, 0);
+}
+
+static int sock_hash_get_next_key(struct bpf_map *map,
+ void *key, void *next_key)
+{
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+ struct htab_elem *l, *next_l;
+ struct hlist_head *h;
+ u32 hash, key_size;
+ int i = 0;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ key_size = map->key_size;
+ if (!key)
+ goto find_first_elem;
+ hash = htab_map_hash(key, key_size);
+ h = select_bucket(htab, hash);
+
+ l = lookup_elem_raw(h, hash, key, key_size);
+ if (!l)
+ goto find_first_elem;
+ next_l = hlist_entry_safe(
+ rcu_dereference_raw(hlist_next_rcu(&l->hash_node)),
+ struct htab_elem, hash_node);
+ if (next_l) {
+ memcpy(next_key, next_l->key, key_size);
+ return 0;
+ }
+
+ /* no more elements in this hash list, go to the next bucket */
+ i = hash & (htab->n_buckets - 1);
+ i++;
+
+find_first_elem:
+ /* iterate over buckets */
+ for (; i < htab->n_buckets; i++) {
+ h = select_bucket(htab, i);
+
+ /* pick first element in the bucket */
+ next_l = hlist_entry_safe(
+ rcu_dereference_raw(hlist_first_rcu(h)),
+ struct htab_elem, hash_node);
+ if (next_l) {
+ /* if it's not empty, just return it */
+ memcpy(next_key, next_l->key, key_size);
+ return 0;
+ }
+ }
+
+ /* iterated over all buckets and all elements */
+ return -ENOENT;
+}
+
+static int sock_hash_ctx_update_elem(struct bpf_sock_ops_kern *skops,
+ struct bpf_map *map,
+ void *key, u64 map_flags)
+{
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+ struct bpf_sock_progs *progs = &htab->progs;
+ struct htab_elem *l_new = NULL, *l_old;
+ struct smap_psock_map_entry *e = NULL;
+ struct hlist_head *head;
+ struct smap_psock *psock;
+ u32 key_size, hash;
+ struct sock *sock;
+ struct bucket *b;
+ int err;
+
+ sock = skops->sk;
+
+ if (sock->sk_type != SOCK_STREAM ||
+ sock->sk_protocol != IPPROTO_TCP)
+ return -EOPNOTSUPP;
+
+ if (unlikely(map_flags > BPF_EXIST))
+ return -EINVAL;
+
+ e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN);
+ if (!e)
+ return -ENOMEM;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+ key_size = map->key_size;
+ hash = htab_map_hash(key, key_size);
+ b = __select_bucket(htab, hash);
+ head = &b->head;
+
+ err = __sock_map_ctx_update_elem(map, progs, sock, NULL, key);
+ if (err)
+ goto err;
+
+ /* psock is valid here because otherwise above *ctx_update_elem would
+ * have thrown an error. It is safe to skip error check.
+ */
+ psock = smap_psock_sk(sock);
+ raw_spin_lock_bh(&b->lock);
+ l_old = lookup_elem_raw(head, hash, key, key_size);
+ if (l_old && map_flags == BPF_NOEXIST) {
+ err = -EEXIST;
+ goto bucket_err;
+ }
+ if (!l_old && map_flags == BPF_EXIST) {
+ err = -ENOENT;
+ goto bucket_err;
+ }
+
+ l_new = alloc_sock_hash_elem(htab, key, key_size, hash, sock, l_old);
+ if (IS_ERR(l_new)) {
+ err = PTR_ERR(l_new);
+ goto bucket_err;
+ }
+
+ rcu_assign_pointer(e->hash_link, l_new);
+ rcu_assign_pointer(e->htab,
+ container_of(map, struct bpf_htab, map));
+ spin_lock_bh(&psock->maps_lock);
+ list_add_tail(&e->list, &psock->maps);
+ spin_unlock_bh(&psock->maps_lock);
+
+ /* add new element to the head of the list, so that
+ * concurrent search will find it before old elem
+ */
+ hlist_add_head_rcu(&l_new->hash_node, head);
+ if (l_old) {
+ psock = smap_psock_sk(l_old->sk);
+
+ hlist_del_rcu(&l_old->hash_node);
+ smap_list_hash_remove(psock, l_old);
+ smap_release_sock(psock, l_old->sk);
+ free_htab_elem(htab, l_old);
+ }
+ raw_spin_unlock_bh(&b->lock);
+ return 0;
+bucket_err:
+ smap_release_sock(psock, sock);
+ raw_spin_unlock_bh(&b->lock);
+err:
+ kfree(e);
+ return err;
+}
+
+static int sock_hash_update_elem(struct bpf_map *map,
+ void *key, void *value, u64 flags)
+{
+ struct bpf_sock_ops_kern skops;
+ u32 fd = *(u32 *)value;
+ struct socket *socket;
+ int err;
+
+ socket = sockfd_lookup(fd, &err);
+ if (!socket)
+ return err;
+
+ skops.sk = socket->sk;
+ if (!skops.sk) {
+ fput(socket->file);
+ return -EINVAL;
+ }
+
+ lock_sock(skops.sk);
+ preempt_disable();
+ rcu_read_lock();
+ err = sock_hash_ctx_update_elem(&skops, map, key, flags);
+ rcu_read_unlock();
+ preempt_enable();
+ release_sock(skops.sk);
+ fput(socket->file);
+ return err;
+}
+
+static int sock_hash_delete_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+ struct hlist_head *head;
+ struct bucket *b;
+ struct htab_elem *l;
+ u32 hash, key_size;
+ int ret = -ENOENT;
+
+ key_size = map->key_size;
+ hash = htab_map_hash(key, key_size);
+ b = __select_bucket(htab, hash);
+ head = &b->head;
+
+ raw_spin_lock_bh(&b->lock);
+ l = lookup_elem_raw(head, hash, key, key_size);
+ if (l) {
+ struct sock *sock = l->sk;
+ struct smap_psock *psock;
+
+ hlist_del_rcu(&l->hash_node);
+ psock = smap_psock_sk(sock);
+ /* This check handles a racing sock event that can get the
+ * sk_callback_lock before this case but after xchg happens
+ * causing the refcnt to hit zero and sock user data (psock)
+ * to be null and queued for garbage collection.
+ */
+ if (likely(psock)) {
+ smap_list_hash_remove(psock, l);
+ smap_release_sock(psock, sock);
+ }
+ free_htab_elem(htab, l);
+ ret = 0;
+ }
+ raw_spin_unlock_bh(&b->lock);
+ return ret;
+}
+
+struct sock *__sock_hash_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_htab *htab = container_of(map, struct bpf_htab, map);
+ struct hlist_head *head;
+ struct htab_elem *l;
+ u32 key_size, hash;
+ struct bucket *b;
+ struct sock *sk;
+
+ key_size = map->key_size;
+ hash = htab_map_hash(key, key_size);
+ b = __select_bucket(htab, hash);
+ head = &b->head;
+
+ l = lookup_elem_raw(head, hash, key, key_size);
+ sk = l ? l->sk : NULL;
+ return sk;
+}
+
const struct bpf_map_ops sock_map_ops = {
.map_alloc = sock_map_alloc,
.map_free = sock_map_free,
@@ -1905,6 +2503,16 @@ const struct bpf_map_ops sock_map_ops = {
.map_release_uref = sock_map_release,
};
+const struct bpf_map_ops sock_hash_ops = {
+ .map_alloc = sock_hash_alloc,
+ .map_free = sock_hash_free,
+ .map_lookup_elem = sock_map_lookup,
+ .map_get_next_key = sock_hash_get_next_key,
+ .map_update_elem = sock_hash_update_elem,
+ .map_delete_elem = sock_hash_delete_elem,
+ .map_release_uref = sock_map_release,
+};
+
BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock,
struct bpf_map *, map, void *, key, u64, flags)
{
@@ -1922,3 +2530,21 @@ const struct bpf_func_proto bpf_sock_map_update_proto = {
.arg3_type = ARG_PTR_TO_MAP_KEY,
.arg4_type = ARG_ANYTHING,
};
+
+BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, bpf_sock,
+ struct bpf_map *, map, void *, key, u64, flags)
+{
+ WARN_ON_ONCE(!rcu_read_lock_held());
+ return sock_hash_ctx_update_elem(bpf_sock, map, key, flags);
+}
+
+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,
+};