2423 строки
56 KiB
C
2423 строки
56 KiB
C
/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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/* A BPF sock_map is used to store sock objects. This is primarly used
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* for doing socket redirect with BPF helper routines.
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*
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* A sock map may have BPF programs attached to it, currently a program
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* used to parse packets and a program to provide a verdict and redirect
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* decision on the packet are supported. Any programs attached to a sock
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* map are inherited by sock objects when they are added to the map. If
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* no BPF programs are attached the sock object may only be used for sock
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* redirect.
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*
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* A sock object may be in multiple maps, but can only inherit a single
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* parse or verdict program. If adding a sock object to a map would result
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* in having multiple parsing programs the update will return an EBUSY error.
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*
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* For reference this program is similar to devmap used in XDP context
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* reviewing these together may be useful. For an example please review
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* ./samples/bpf/sockmap/.
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*/
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#include <linux/bpf.h>
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#include <net/sock.h>
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#include <linux/filter.h>
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#include <linux/errno.h>
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#include <linux/file.h>
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#include <linux/kernel.h>
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#include <linux/net.h>
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#include <linux/skbuff.h>
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#include <linux/workqueue.h>
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#include <linux/list.h>
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#include <linux/mm.h>
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#include <net/strparser.h>
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#include <net/tcp.h>
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#include <linux/ptr_ring.h>
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#include <net/inet_common.h>
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#include <linux/sched/signal.h>
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#define SOCK_CREATE_FLAG_MASK \
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(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
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struct bpf_sock_progs {
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struct bpf_prog *bpf_tx_msg;
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struct bpf_prog *bpf_parse;
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struct bpf_prog *bpf_verdict;
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};
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struct bpf_stab {
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struct bpf_map map;
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struct sock **sock_map;
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struct bpf_sock_progs progs;
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};
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struct bucket {
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struct hlist_head head;
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raw_spinlock_t lock;
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};
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struct bpf_htab {
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struct bpf_map map;
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struct bucket *buckets;
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atomic_t count;
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u32 n_buckets;
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u32 elem_size;
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struct bpf_sock_progs progs;
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};
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struct htab_elem {
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struct rcu_head rcu;
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struct hlist_node hash_node;
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u32 hash;
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struct sock *sk;
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char key[0];
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};
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enum smap_psock_state {
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SMAP_TX_RUNNING,
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};
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struct smap_psock_map_entry {
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struct list_head list;
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struct sock **entry;
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struct htab_elem *hash_link;
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struct bpf_htab *htab;
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};
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struct smap_psock {
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struct rcu_head rcu;
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refcount_t refcnt;
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/* datapath variables */
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struct sk_buff_head rxqueue;
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bool strp_enabled;
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/* datapath error path cache across tx work invocations */
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int save_rem;
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int save_off;
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struct sk_buff *save_skb;
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/* datapath variables for tx_msg ULP */
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struct sock *sk_redir;
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int apply_bytes;
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int cork_bytes;
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int sg_size;
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int eval;
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struct sk_msg_buff *cork;
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struct list_head ingress;
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struct strparser strp;
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struct bpf_prog *bpf_tx_msg;
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struct bpf_prog *bpf_parse;
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struct bpf_prog *bpf_verdict;
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struct list_head maps;
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/* Back reference used when sock callback trigger sockmap operations */
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struct sock *sock;
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unsigned long state;
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struct work_struct tx_work;
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struct work_struct gc_work;
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struct proto *sk_proto;
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void (*save_close)(struct sock *sk, long timeout);
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void (*save_data_ready)(struct sock *sk);
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void (*save_write_space)(struct sock *sk);
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};
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static void smap_release_sock(struct smap_psock *psock, struct sock *sock);
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static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
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int nonblock, int flags, int *addr_len);
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static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size);
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static int bpf_tcp_sendpage(struct sock *sk, struct page *page,
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int offset, size_t size, int flags);
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static inline struct smap_psock *smap_psock_sk(const struct sock *sk)
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{
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return rcu_dereference_sk_user_data(sk);
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}
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static bool bpf_tcp_stream_read(const struct sock *sk)
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{
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struct smap_psock *psock;
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bool empty = true;
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rcu_read_lock();
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psock = smap_psock_sk(sk);
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if (unlikely(!psock))
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goto out;
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empty = list_empty(&psock->ingress);
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out:
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rcu_read_unlock();
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return !empty;
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}
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static struct proto tcp_bpf_proto;
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static int bpf_tcp_init(struct sock *sk)
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{
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struct smap_psock *psock;
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rcu_read_lock();
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psock = smap_psock_sk(sk);
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if (unlikely(!psock)) {
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rcu_read_unlock();
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return -EINVAL;
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}
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if (unlikely(psock->sk_proto)) {
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rcu_read_unlock();
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return -EBUSY;
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}
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psock->save_close = sk->sk_prot->close;
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psock->sk_proto = sk->sk_prot;
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if (psock->bpf_tx_msg) {
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tcp_bpf_proto.sendmsg = bpf_tcp_sendmsg;
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tcp_bpf_proto.sendpage = bpf_tcp_sendpage;
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tcp_bpf_proto.recvmsg = bpf_tcp_recvmsg;
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tcp_bpf_proto.stream_memory_read = bpf_tcp_stream_read;
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}
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sk->sk_prot = &tcp_bpf_proto;
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rcu_read_unlock();
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return 0;
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}
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static void smap_release_sock(struct smap_psock *psock, struct sock *sock);
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static int free_start_sg(struct sock *sk, struct sk_msg_buff *md);
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static void bpf_tcp_release(struct sock *sk)
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{
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struct smap_psock *psock;
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rcu_read_lock();
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psock = smap_psock_sk(sk);
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if (unlikely(!psock))
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goto out;
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if (psock->cork) {
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free_start_sg(psock->sock, psock->cork);
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kfree(psock->cork);
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psock->cork = NULL;
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}
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if (psock->sk_proto) {
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sk->sk_prot = psock->sk_proto;
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psock->sk_proto = NULL;
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}
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out:
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rcu_read_unlock();
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}
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static void free_htab_elem(struct bpf_htab *htab, struct htab_elem *l)
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{
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atomic_dec(&htab->count);
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kfree_rcu(l, rcu);
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}
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static void bpf_tcp_close(struct sock *sk, long timeout)
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{
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void (*close_fun)(struct sock *sk, long timeout);
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struct smap_psock_map_entry *e, *tmp;
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struct sk_msg_buff *md, *mtmp;
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struct smap_psock *psock;
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struct sock *osk;
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rcu_read_lock();
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psock = smap_psock_sk(sk);
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if (unlikely(!psock)) {
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rcu_read_unlock();
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return sk->sk_prot->close(sk, timeout);
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}
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/* The psock may be destroyed anytime after exiting the RCU critial
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* section so by the time we use close_fun the psock may no longer
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* be valid. However, bpf_tcp_close is called with the sock lock
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* held so the close hook and sk are still valid.
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*/
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close_fun = psock->save_close;
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write_lock_bh(&sk->sk_callback_lock);
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if (psock->cork) {
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free_start_sg(psock->sock, psock->cork);
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kfree(psock->cork);
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psock->cork = NULL;
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}
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list_for_each_entry_safe(md, mtmp, &psock->ingress, list) {
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list_del(&md->list);
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free_start_sg(psock->sock, md);
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kfree(md);
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}
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list_for_each_entry_safe(e, tmp, &psock->maps, list) {
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if (e->entry) {
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osk = cmpxchg(e->entry, sk, NULL);
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if (osk == sk) {
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list_del(&e->list);
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smap_release_sock(psock, sk);
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}
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} else {
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hlist_del_rcu(&e->hash_link->hash_node);
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smap_release_sock(psock, e->hash_link->sk);
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free_htab_elem(e->htab, e->hash_link);
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}
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}
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write_unlock_bh(&sk->sk_callback_lock);
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rcu_read_unlock();
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close_fun(sk, timeout);
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}
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enum __sk_action {
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__SK_DROP = 0,
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__SK_PASS,
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__SK_REDIRECT,
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__SK_NONE,
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};
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static struct tcp_ulp_ops bpf_tcp_ulp_ops __read_mostly = {
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.name = "bpf_tcp",
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.uid = TCP_ULP_BPF,
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.user_visible = false,
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.owner = NULL,
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.init = bpf_tcp_init,
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.release = bpf_tcp_release,
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};
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static int memcopy_from_iter(struct sock *sk,
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struct sk_msg_buff *md,
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struct iov_iter *from, int bytes)
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{
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struct scatterlist *sg = md->sg_data;
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int i = md->sg_curr, rc = -ENOSPC;
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do {
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int copy;
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char *to;
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if (md->sg_copybreak >= sg[i].length) {
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md->sg_copybreak = 0;
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if (++i == MAX_SKB_FRAGS)
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i = 0;
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if (i == md->sg_end)
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break;
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}
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copy = sg[i].length - md->sg_copybreak;
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to = sg_virt(&sg[i]) + md->sg_copybreak;
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md->sg_copybreak += copy;
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if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY)
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rc = copy_from_iter_nocache(to, copy, from);
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else
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rc = copy_from_iter(to, copy, from);
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if (rc != copy) {
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rc = -EFAULT;
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goto out;
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}
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bytes -= copy;
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if (!bytes)
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break;
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md->sg_copybreak = 0;
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if (++i == MAX_SKB_FRAGS)
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i = 0;
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} while (i != md->sg_end);
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out:
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md->sg_curr = i;
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return rc;
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}
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static int bpf_tcp_push(struct sock *sk, int apply_bytes,
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struct sk_msg_buff *md,
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int flags, bool uncharge)
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{
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bool apply = apply_bytes;
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struct scatterlist *sg;
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int offset, ret = 0;
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struct page *p;
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size_t size;
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while (1) {
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sg = md->sg_data + md->sg_start;
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size = (apply && apply_bytes < sg->length) ?
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apply_bytes : sg->length;
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offset = sg->offset;
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tcp_rate_check_app_limited(sk);
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p = sg_page(sg);
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retry:
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ret = do_tcp_sendpages(sk, p, offset, size, flags);
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if (ret != size) {
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if (ret > 0) {
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if (apply)
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apply_bytes -= ret;
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sg->offset += ret;
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sg->length -= ret;
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size -= ret;
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offset += ret;
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if (uncharge)
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sk_mem_uncharge(sk, ret);
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goto retry;
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}
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return ret;
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}
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if (apply)
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apply_bytes -= ret;
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sg->offset += ret;
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sg->length -= ret;
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if (uncharge)
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sk_mem_uncharge(sk, ret);
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if (!sg->length) {
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put_page(p);
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md->sg_start++;
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if (md->sg_start == MAX_SKB_FRAGS)
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md->sg_start = 0;
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sg_init_table(sg, 1);
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if (md->sg_start == md->sg_end)
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break;
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}
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if (apply && !apply_bytes)
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break;
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}
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return 0;
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}
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static inline void bpf_compute_data_pointers_sg(struct sk_msg_buff *md)
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{
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struct scatterlist *sg = md->sg_data + md->sg_start;
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if (md->sg_copy[md->sg_start]) {
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md->data = md->data_end = 0;
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} else {
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md->data = sg_virt(sg);
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md->data_end = md->data + sg->length;
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}
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}
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static void return_mem_sg(struct sock *sk, int bytes, struct sk_msg_buff *md)
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{
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struct scatterlist *sg = md->sg_data;
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int i = md->sg_start;
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do {
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int uncharge = (bytes < sg[i].length) ? bytes : sg[i].length;
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sk_mem_uncharge(sk, uncharge);
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bytes -= uncharge;
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if (!bytes)
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break;
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i++;
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if (i == MAX_SKB_FRAGS)
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i = 0;
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} while (i != md->sg_end);
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}
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static void free_bytes_sg(struct sock *sk, int bytes,
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struct sk_msg_buff *md, bool charge)
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{
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struct scatterlist *sg = md->sg_data;
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int i = md->sg_start, free;
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while (bytes && sg[i].length) {
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free = sg[i].length;
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if (bytes < free) {
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sg[i].length -= bytes;
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sg[i].offset += bytes;
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if (charge)
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sk_mem_uncharge(sk, bytes);
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break;
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}
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if (charge)
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sk_mem_uncharge(sk, sg[i].length);
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put_page(sg_page(&sg[i]));
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bytes -= sg[i].length;
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sg[i].length = 0;
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sg[i].page_link = 0;
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sg[i].offset = 0;
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i++;
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if (i == MAX_SKB_FRAGS)
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i = 0;
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}
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md->sg_start = i;
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}
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static int free_sg(struct sock *sk, int start, struct sk_msg_buff *md)
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{
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struct scatterlist *sg = md->sg_data;
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int i = start, free = 0;
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while (sg[i].length) {
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free += sg[i].length;
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sk_mem_uncharge(sk, sg[i].length);
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put_page(sg_page(&sg[i]));
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sg[i].length = 0;
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sg[i].page_link = 0;
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sg[i].offset = 0;
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i++;
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if (i == MAX_SKB_FRAGS)
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i = 0;
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}
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return free;
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}
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static int free_start_sg(struct sock *sk, struct sk_msg_buff *md)
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{
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int free = free_sg(sk, md->sg_start, md);
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md->sg_start = md->sg_end;
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return free;
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}
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static int free_curr_sg(struct sock *sk, struct sk_msg_buff *md)
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{
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return free_sg(sk, md->sg_curr, md);
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}
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static int bpf_map_msg_verdict(int _rc, struct sk_msg_buff *md)
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{
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return ((_rc == SK_PASS) ?
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(md->sk_redir ? __SK_REDIRECT : __SK_PASS) :
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__SK_DROP);
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}
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static unsigned int smap_do_tx_msg(struct sock *sk,
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struct smap_psock *psock,
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struct sk_msg_buff *md)
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{
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struct bpf_prog *prog;
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unsigned int rc, _rc;
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preempt_disable();
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rcu_read_lock();
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/* If the policy was removed mid-send then default to 'accept' */
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prog = READ_ONCE(psock->bpf_tx_msg);
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if (unlikely(!prog)) {
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_rc = SK_PASS;
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goto verdict;
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}
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bpf_compute_data_pointers_sg(md);
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md->sk = sk;
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rc = (*prog->bpf_func)(md, prog->insnsi);
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psock->apply_bytes = md->apply_bytes;
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/* Moving return codes from UAPI namespace into internal namespace */
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_rc = bpf_map_msg_verdict(rc, md);
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|
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/* The psock has a refcount on the sock but not on the map and because
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* we need to drop rcu read lock here its possible the map could be
|
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* removed between here and when we need it to execute the sock
|
|
* redirect. So do the map lookup now for future use.
|
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*/
|
|
if (_rc == __SK_REDIRECT) {
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if (psock->sk_redir)
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sock_put(psock->sk_redir);
|
|
psock->sk_redir = do_msg_redirect_map(md);
|
|
if (!psock->sk_redir) {
|
|
_rc = __SK_DROP;
|
|
goto verdict;
|
|
}
|
|
sock_hold(psock->sk_redir);
|
|
}
|
|
verdict:
|
|
rcu_read_unlock();
|
|
preempt_enable();
|
|
|
|
return _rc;
|
|
}
|
|
|
|
static int bpf_tcp_ingress(struct sock *sk, int apply_bytes,
|
|
struct smap_psock *psock,
|
|
struct sk_msg_buff *md, int flags)
|
|
{
|
|
bool apply = apply_bytes;
|
|
size_t size, copied = 0;
|
|
struct sk_msg_buff *r;
|
|
int err = 0, i;
|
|
|
|
r = kzalloc(sizeof(struct sk_msg_buff), __GFP_NOWARN | GFP_KERNEL);
|
|
if (unlikely(!r))
|
|
return -ENOMEM;
|
|
|
|
lock_sock(sk);
|
|
r->sg_start = md->sg_start;
|
|
i = md->sg_start;
|
|
|
|
do {
|
|
size = (apply && apply_bytes < md->sg_data[i].length) ?
|
|
apply_bytes : md->sg_data[i].length;
|
|
|
|
if (!sk_wmem_schedule(sk, size)) {
|
|
if (!copied)
|
|
err = -ENOMEM;
|
|
break;
|
|
}
|
|
|
|
sk_mem_charge(sk, size);
|
|
r->sg_data[i] = md->sg_data[i];
|
|
r->sg_data[i].length = size;
|
|
md->sg_data[i].length -= size;
|
|
md->sg_data[i].offset += size;
|
|
copied += size;
|
|
|
|
if (md->sg_data[i].length) {
|
|
get_page(sg_page(&r->sg_data[i]));
|
|
r->sg_end = (i + 1) == MAX_SKB_FRAGS ? 0 : i + 1;
|
|
} else {
|
|
i++;
|
|
if (i == MAX_SKB_FRAGS)
|
|
i = 0;
|
|
r->sg_end = i;
|
|
}
|
|
|
|
if (apply) {
|
|
apply_bytes -= size;
|
|
if (!apply_bytes)
|
|
break;
|
|
}
|
|
} while (i != md->sg_end);
|
|
|
|
md->sg_start = i;
|
|
|
|
if (!err) {
|
|
list_add_tail(&r->list, &psock->ingress);
|
|
sk->sk_data_ready(sk);
|
|
} else {
|
|
free_start_sg(sk, r);
|
|
kfree(r);
|
|
}
|
|
|
|
release_sock(sk);
|
|
return err;
|
|
}
|
|
|
|
static int bpf_tcp_sendmsg_do_redirect(struct sock *sk, int send,
|
|
struct sk_msg_buff *md,
|
|
int flags)
|
|
{
|
|
bool ingress = !!(md->flags & BPF_F_INGRESS);
|
|
struct smap_psock *psock;
|
|
struct scatterlist *sg;
|
|
int err = 0;
|
|
|
|
sg = md->sg_data;
|
|
|
|
rcu_read_lock();
|
|
psock = smap_psock_sk(sk);
|
|
if (unlikely(!psock))
|
|
goto out_rcu;
|
|
|
|
if (!refcount_inc_not_zero(&psock->refcnt))
|
|
goto out_rcu;
|
|
|
|
rcu_read_unlock();
|
|
|
|
if (ingress) {
|
|
err = bpf_tcp_ingress(sk, send, psock, md, flags);
|
|
} else {
|
|
lock_sock(sk);
|
|
err = bpf_tcp_push(sk, send, md, flags, false);
|
|
release_sock(sk);
|
|
}
|
|
smap_release_sock(psock, sk);
|
|
if (unlikely(err))
|
|
goto out;
|
|
return 0;
|
|
out_rcu:
|
|
rcu_read_unlock();
|
|
out:
|
|
free_bytes_sg(NULL, send, md, false);
|
|
return err;
|
|
}
|
|
|
|
static inline void bpf_md_init(struct smap_psock *psock)
|
|
{
|
|
if (!psock->apply_bytes) {
|
|
psock->eval = __SK_NONE;
|
|
if (psock->sk_redir) {
|
|
sock_put(psock->sk_redir);
|
|
psock->sk_redir = NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void apply_bytes_dec(struct smap_psock *psock, int i)
|
|
{
|
|
if (psock->apply_bytes) {
|
|
if (psock->apply_bytes < i)
|
|
psock->apply_bytes = 0;
|
|
else
|
|
psock->apply_bytes -= i;
|
|
}
|
|
}
|
|
|
|
static int bpf_exec_tx_verdict(struct smap_psock *psock,
|
|
struct sk_msg_buff *m,
|
|
struct sock *sk,
|
|
int *copied, int flags)
|
|
{
|
|
bool cork = false, enospc = (m->sg_start == m->sg_end);
|
|
struct sock *redir;
|
|
int err = 0;
|
|
int send;
|
|
|
|
more_data:
|
|
if (psock->eval == __SK_NONE)
|
|
psock->eval = smap_do_tx_msg(sk, psock, m);
|
|
|
|
if (m->cork_bytes &&
|
|
m->cork_bytes > psock->sg_size && !enospc) {
|
|
psock->cork_bytes = m->cork_bytes - psock->sg_size;
|
|
if (!psock->cork) {
|
|
psock->cork = kcalloc(1,
|
|
sizeof(struct sk_msg_buff),
|
|
GFP_ATOMIC | __GFP_NOWARN);
|
|
|
|
if (!psock->cork) {
|
|
err = -ENOMEM;
|
|
goto out_err;
|
|
}
|
|
}
|
|
memcpy(psock->cork, m, sizeof(*m));
|
|
goto out_err;
|
|
}
|
|
|
|
send = psock->sg_size;
|
|
if (psock->apply_bytes && psock->apply_bytes < send)
|
|
send = psock->apply_bytes;
|
|
|
|
switch (psock->eval) {
|
|
case __SK_PASS:
|
|
err = bpf_tcp_push(sk, send, m, flags, true);
|
|
if (unlikely(err)) {
|
|
*copied -= free_start_sg(sk, m);
|
|
break;
|
|
}
|
|
|
|
apply_bytes_dec(psock, send);
|
|
psock->sg_size -= send;
|
|
break;
|
|
case __SK_REDIRECT:
|
|
redir = psock->sk_redir;
|
|
apply_bytes_dec(psock, send);
|
|
|
|
if (psock->cork) {
|
|
cork = true;
|
|
psock->cork = NULL;
|
|
}
|
|
|
|
return_mem_sg(sk, send, m);
|
|
release_sock(sk);
|
|
|
|
err = bpf_tcp_sendmsg_do_redirect(redir, send, m, flags);
|
|
lock_sock(sk);
|
|
|
|
if (unlikely(err < 0)) {
|
|
free_start_sg(sk, m);
|
|
psock->sg_size = 0;
|
|
if (!cork)
|
|
*copied -= send;
|
|
} else {
|
|
psock->sg_size -= send;
|
|
}
|
|
|
|
if (cork) {
|
|
free_start_sg(sk, m);
|
|
psock->sg_size = 0;
|
|
kfree(m);
|
|
m = NULL;
|
|
err = 0;
|
|
}
|
|
break;
|
|
case __SK_DROP:
|
|
default:
|
|
free_bytes_sg(sk, send, m, true);
|
|
apply_bytes_dec(psock, send);
|
|
*copied -= send;
|
|
psock->sg_size -= send;
|
|
err = -EACCES;
|
|
break;
|
|
}
|
|
|
|
if (likely(!err)) {
|
|
bpf_md_init(psock);
|
|
if (m &&
|
|
m->sg_data[m->sg_start].page_link &&
|
|
m->sg_data[m->sg_start].length)
|
|
goto more_data;
|
|
}
|
|
|
|
out_err:
|
|
return err;
|
|
}
|
|
|
|
static int bpf_wait_data(struct sock *sk,
|
|
struct smap_psock *psk, int flags,
|
|
long timeo, int *err)
|
|
{
|
|
int rc;
|
|
|
|
DEFINE_WAIT_FUNC(wait, woken_wake_function);
|
|
|
|
add_wait_queue(sk_sleep(sk), &wait);
|
|
sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
|
|
rc = sk_wait_event(sk, &timeo,
|
|
!list_empty(&psk->ingress) ||
|
|
!skb_queue_empty(&sk->sk_receive_queue),
|
|
&wait);
|
|
sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
|
|
remove_wait_queue(sk_sleep(sk), &wait);
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
|
|
int nonblock, int flags, int *addr_len)
|
|
{
|
|
struct iov_iter *iter = &msg->msg_iter;
|
|
struct smap_psock *psock;
|
|
int copied = 0;
|
|
|
|
if (unlikely(flags & MSG_ERRQUEUE))
|
|
return inet_recv_error(sk, msg, len, addr_len);
|
|
|
|
rcu_read_lock();
|
|
psock = smap_psock_sk(sk);
|
|
if (unlikely(!psock))
|
|
goto out;
|
|
|
|
if (unlikely(!refcount_inc_not_zero(&psock->refcnt)))
|
|
goto out;
|
|
rcu_read_unlock();
|
|
|
|
if (!skb_queue_empty(&sk->sk_receive_queue))
|
|
return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
|
|
|
|
lock_sock(sk);
|
|
bytes_ready:
|
|
while (copied != len) {
|
|
struct scatterlist *sg;
|
|
struct sk_msg_buff *md;
|
|
int i;
|
|
|
|
md = list_first_entry_or_null(&psock->ingress,
|
|
struct sk_msg_buff, list);
|
|
if (unlikely(!md))
|
|
break;
|
|
i = md->sg_start;
|
|
do {
|
|
struct page *page;
|
|
int n, copy;
|
|
|
|
sg = &md->sg_data[i];
|
|
copy = sg->length;
|
|
page = sg_page(sg);
|
|
|
|
if (copied + copy > len)
|
|
copy = len - copied;
|
|
|
|
n = copy_page_to_iter(page, sg->offset, copy, iter);
|
|
if (n != copy) {
|
|
md->sg_start = i;
|
|
release_sock(sk);
|
|
smap_release_sock(psock, sk);
|
|
return -EFAULT;
|
|
}
|
|
|
|
copied += copy;
|
|
sg->offset += copy;
|
|
sg->length -= copy;
|
|
sk_mem_uncharge(sk, copy);
|
|
|
|
if (!sg->length) {
|
|
i++;
|
|
if (i == MAX_SKB_FRAGS)
|
|
i = 0;
|
|
if (!md->skb)
|
|
put_page(page);
|
|
}
|
|
if (copied == len)
|
|
break;
|
|
} while (i != md->sg_end);
|
|
md->sg_start = i;
|
|
|
|
if (!sg->length && md->sg_start == md->sg_end) {
|
|
list_del(&md->list);
|
|
if (md->skb)
|
|
consume_skb(md->skb);
|
|
kfree(md);
|
|
}
|
|
}
|
|
|
|
if (!copied) {
|
|
long timeo;
|
|
int data;
|
|
int err = 0;
|
|
|
|
timeo = sock_rcvtimeo(sk, nonblock);
|
|
data = bpf_wait_data(sk, psock, flags, timeo, &err);
|
|
|
|
if (data) {
|
|
if (!skb_queue_empty(&sk->sk_receive_queue)) {
|
|
release_sock(sk);
|
|
smap_release_sock(psock, sk);
|
|
copied = tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
|
|
return copied;
|
|
}
|
|
goto bytes_ready;
|
|
}
|
|
|
|
if (err)
|
|
copied = err;
|
|
}
|
|
|
|
release_sock(sk);
|
|
smap_release_sock(psock, sk);
|
|
return copied;
|
|
out:
|
|
rcu_read_unlock();
|
|
return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
|
|
}
|
|
|
|
|
|
static int bpf_tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
|
|
{
|
|
int flags = msg->msg_flags | MSG_NO_SHARED_FRAGS;
|
|
struct sk_msg_buff md = {0};
|
|
unsigned int sg_copy = 0;
|
|
struct smap_psock *psock;
|
|
int copied = 0, err = 0;
|
|
struct scatterlist *sg;
|
|
long timeo;
|
|
|
|
/* Its possible a sock event or user removed the psock _but_ the ops
|
|
* have not been reprogrammed yet so we get here. In this case fallback
|
|
* to tcp_sendmsg. Note this only works because we _only_ ever allow
|
|
* a single ULP there is no hierarchy here.
|
|
*/
|
|
rcu_read_lock();
|
|
psock = smap_psock_sk(sk);
|
|
if (unlikely(!psock)) {
|
|
rcu_read_unlock();
|
|
return tcp_sendmsg(sk, msg, size);
|
|
}
|
|
|
|
/* Increment the psock refcnt to ensure its not released while sending a
|
|
* message. Required because sk lookup and bpf programs are used in
|
|
* separate rcu critical sections. Its OK if we lose the map entry
|
|
* but we can't lose the sock reference.
|
|
*/
|
|
if (!refcount_inc_not_zero(&psock->refcnt)) {
|
|
rcu_read_unlock();
|
|
return tcp_sendmsg(sk, msg, size);
|
|
}
|
|
|
|
sg = md.sg_data;
|
|
sg_init_marker(sg, MAX_SKB_FRAGS);
|
|
rcu_read_unlock();
|
|
|
|
lock_sock(sk);
|
|
timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
|
|
|
|
while (msg_data_left(msg)) {
|
|
struct sk_msg_buff *m;
|
|
bool enospc = false;
|
|
int copy;
|
|
|
|
if (sk->sk_err) {
|
|
err = sk->sk_err;
|
|
goto out_err;
|
|
}
|
|
|
|
copy = msg_data_left(msg);
|
|
if (!sk_stream_memory_free(sk))
|
|
goto wait_for_sndbuf;
|
|
|
|
m = psock->cork_bytes ? psock->cork : &md;
|
|
m->sg_curr = m->sg_copybreak ? m->sg_curr : m->sg_end;
|
|
err = sk_alloc_sg(sk, copy, m->sg_data,
|
|
m->sg_start, &m->sg_end, &sg_copy,
|
|
m->sg_end - 1);
|
|
if (err) {
|
|
if (err != -ENOSPC)
|
|
goto wait_for_memory;
|
|
enospc = true;
|
|
copy = sg_copy;
|
|
}
|
|
|
|
err = memcopy_from_iter(sk, m, &msg->msg_iter, copy);
|
|
if (err < 0) {
|
|
free_curr_sg(sk, m);
|
|
goto out_err;
|
|
}
|
|
|
|
psock->sg_size += copy;
|
|
copied += copy;
|
|
sg_copy = 0;
|
|
|
|
/* When bytes are being corked skip running BPF program and
|
|
* applying verdict unless there is no more buffer space. In
|
|
* the ENOSPC case simply run BPF prorgram with currently
|
|
* accumulated data. We don't have much choice at this point
|
|
* we could try extending the page frags or chaining complex
|
|
* frags but even in these cases _eventually_ we will hit an
|
|
* OOM scenario. More complex recovery schemes may be
|
|
* implemented in the future, but BPF programs must handle
|
|
* the case where apply_cork requests are not honored. The
|
|
* canonical method to verify this is to check data length.
|
|
*/
|
|
if (psock->cork_bytes) {
|
|
if (copy > psock->cork_bytes)
|
|
psock->cork_bytes = 0;
|
|
else
|
|
psock->cork_bytes -= copy;
|
|
|
|
if (psock->cork_bytes && !enospc)
|
|
goto out_cork;
|
|
|
|
/* All cork bytes accounted for re-run filter */
|
|
psock->eval = __SK_NONE;
|
|
psock->cork_bytes = 0;
|
|
}
|
|
|
|
err = bpf_exec_tx_verdict(psock, m, sk, &copied, flags);
|
|
if (unlikely(err < 0))
|
|
goto out_err;
|
|
continue;
|
|
wait_for_sndbuf:
|
|
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
|
|
wait_for_memory:
|
|
err = sk_stream_wait_memory(sk, &timeo);
|
|
if (err)
|
|
goto out_err;
|
|
}
|
|
out_err:
|
|
if (err < 0)
|
|
err = sk_stream_error(sk, msg->msg_flags, err);
|
|
out_cork:
|
|
release_sock(sk);
|
|
smap_release_sock(psock, sk);
|
|
return copied ? copied : err;
|
|
}
|
|
|
|
static int bpf_tcp_sendpage(struct sock *sk, struct page *page,
|
|
int offset, size_t size, int flags)
|
|
{
|
|
struct sk_msg_buff md = {0}, *m = NULL;
|
|
int err = 0, copied = 0;
|
|
struct smap_psock *psock;
|
|
struct scatterlist *sg;
|
|
bool enospc = false;
|
|
|
|
rcu_read_lock();
|
|
psock = smap_psock_sk(sk);
|
|
if (unlikely(!psock))
|
|
goto accept;
|
|
|
|
if (!refcount_inc_not_zero(&psock->refcnt))
|
|
goto accept;
|
|
rcu_read_unlock();
|
|
|
|
lock_sock(sk);
|
|
|
|
if (psock->cork_bytes) {
|
|
m = psock->cork;
|
|
sg = &m->sg_data[m->sg_end];
|
|
} else {
|
|
m = &md;
|
|
sg = m->sg_data;
|
|
sg_init_marker(sg, MAX_SKB_FRAGS);
|
|
}
|
|
|
|
/* Catch case where ring is full and sendpage is stalled. */
|
|
if (unlikely(m->sg_end == m->sg_start &&
|
|
m->sg_data[m->sg_end].length))
|
|
goto out_err;
|
|
|
|
psock->sg_size += size;
|
|
sg_set_page(sg, page, size, offset);
|
|
get_page(page);
|
|
m->sg_copy[m->sg_end] = true;
|
|
sk_mem_charge(sk, size);
|
|
m->sg_end++;
|
|
copied = size;
|
|
|
|
if (m->sg_end == MAX_SKB_FRAGS)
|
|
m->sg_end = 0;
|
|
|
|
if (m->sg_end == m->sg_start)
|
|
enospc = true;
|
|
|
|
if (psock->cork_bytes) {
|
|
if (size > psock->cork_bytes)
|
|
psock->cork_bytes = 0;
|
|
else
|
|
psock->cork_bytes -= size;
|
|
|
|
if (psock->cork_bytes && !enospc)
|
|
goto out_err;
|
|
|
|
/* All cork bytes accounted for re-run filter */
|
|
psock->eval = __SK_NONE;
|
|
psock->cork_bytes = 0;
|
|
}
|
|
|
|
err = bpf_exec_tx_verdict(psock, m, sk, &copied, flags);
|
|
out_err:
|
|
release_sock(sk);
|
|
smap_release_sock(psock, sk);
|
|
return copied ? copied : err;
|
|
accept:
|
|
rcu_read_unlock();
|
|
return tcp_sendpage(sk, page, offset, size, flags);
|
|
}
|
|
|
|
static void bpf_tcp_msg_add(struct smap_psock *psock,
|
|
struct sock *sk,
|
|
struct bpf_prog *tx_msg)
|
|
{
|
|
struct bpf_prog *orig_tx_msg;
|
|
|
|
orig_tx_msg = xchg(&psock->bpf_tx_msg, tx_msg);
|
|
if (orig_tx_msg)
|
|
bpf_prog_put(orig_tx_msg);
|
|
}
|
|
|
|
static int bpf_tcp_ulp_register(void)
|
|
{
|
|
tcp_bpf_proto = tcp_prot;
|
|
tcp_bpf_proto.close = bpf_tcp_close;
|
|
/* 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.
|
|
*/
|
|
return tcp_register_ulp(&bpf_tcp_ulp_ops);
|
|
}
|
|
|
|
static int smap_verdict_func(struct smap_psock *psock, struct sk_buff *skb)
|
|
{
|
|
struct bpf_prog *prog = READ_ONCE(psock->bpf_verdict);
|
|
int rc;
|
|
|
|
if (unlikely(!prog))
|
|
return __SK_DROP;
|
|
|
|
skb_orphan(skb);
|
|
/* We need to ensure that BPF metadata for maps is also cleared
|
|
* when we orphan the skb so that we don't have the possibility
|
|
* to reference a stale map.
|
|
*/
|
|
TCP_SKB_CB(skb)->bpf.sk_redir = NULL;
|
|
skb->sk = psock->sock;
|
|
bpf_compute_data_pointers(skb);
|
|
preempt_disable();
|
|
rc = (*prog->bpf_func)(skb, prog->insnsi);
|
|
preempt_enable();
|
|
skb->sk = NULL;
|
|
|
|
/* Moving return codes from UAPI namespace into internal namespace */
|
|
return rc == SK_PASS ?
|
|
(TCP_SKB_CB(skb)->bpf.sk_redir ? __SK_REDIRECT : __SK_PASS) :
|
|
__SK_DROP;
|
|
}
|
|
|
|
static int smap_do_ingress(struct smap_psock *psock, struct sk_buff *skb)
|
|
{
|
|
struct sock *sk = psock->sock;
|
|
int copied = 0, num_sg;
|
|
struct sk_msg_buff *r;
|
|
|
|
r = kzalloc(sizeof(struct sk_msg_buff), __GFP_NOWARN | GFP_ATOMIC);
|
|
if (unlikely(!r))
|
|
return -EAGAIN;
|
|
|
|
if (!sk_rmem_schedule(sk, skb, skb->len)) {
|
|
kfree(r);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
sg_init_table(r->sg_data, MAX_SKB_FRAGS);
|
|
num_sg = skb_to_sgvec(skb, r->sg_data, 0, skb->len);
|
|
if (unlikely(num_sg < 0)) {
|
|
kfree(r);
|
|
return num_sg;
|
|
}
|
|
sk_mem_charge(sk, skb->len);
|
|
copied = skb->len;
|
|
r->sg_start = 0;
|
|
r->sg_end = num_sg == MAX_SKB_FRAGS ? 0 : num_sg;
|
|
r->skb = skb;
|
|
list_add_tail(&r->list, &psock->ingress);
|
|
sk->sk_data_ready(sk);
|
|
return copied;
|
|
}
|
|
|
|
static void smap_do_verdict(struct smap_psock *psock, struct sk_buff *skb)
|
|
{
|
|
struct smap_psock *peer;
|
|
struct sock *sk;
|
|
__u32 in;
|
|
int rc;
|
|
|
|
rc = smap_verdict_func(psock, skb);
|
|
switch (rc) {
|
|
case __SK_REDIRECT:
|
|
sk = do_sk_redirect_map(skb);
|
|
if (!sk) {
|
|
kfree_skb(skb);
|
|
break;
|
|
}
|
|
|
|
peer = smap_psock_sk(sk);
|
|
in = (TCP_SKB_CB(skb)->bpf.flags) & BPF_F_INGRESS;
|
|
|
|
if (unlikely(!peer || sock_flag(sk, SOCK_DEAD) ||
|
|
!test_bit(SMAP_TX_RUNNING, &peer->state))) {
|
|
kfree_skb(skb);
|
|
break;
|
|
}
|
|
|
|
if (!in && sock_writeable(sk)) {
|
|
skb_set_owner_w(skb, sk);
|
|
skb_queue_tail(&peer->rxqueue, skb);
|
|
schedule_work(&peer->tx_work);
|
|
break;
|
|
} else if (in &&
|
|
atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf) {
|
|
skb_queue_tail(&peer->rxqueue, skb);
|
|
schedule_work(&peer->tx_work);
|
|
break;
|
|
}
|
|
/* Fall through and free skb otherwise */
|
|
case __SK_DROP:
|
|
default:
|
|
kfree_skb(skb);
|
|
}
|
|
}
|
|
|
|
static void smap_report_sk_error(struct smap_psock *psock, int err)
|
|
{
|
|
struct sock *sk = psock->sock;
|
|
|
|
sk->sk_err = err;
|
|
sk->sk_error_report(sk);
|
|
}
|
|
|
|
static void smap_read_sock_strparser(struct strparser *strp,
|
|
struct sk_buff *skb)
|
|
{
|
|
struct smap_psock *psock;
|
|
|
|
rcu_read_lock();
|
|
psock = container_of(strp, struct smap_psock, strp);
|
|
smap_do_verdict(psock, skb);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
/* Called with lock held on socket */
|
|
static void smap_data_ready(struct sock *sk)
|
|
{
|
|
struct smap_psock *psock;
|
|
|
|
rcu_read_lock();
|
|
psock = smap_psock_sk(sk);
|
|
if (likely(psock)) {
|
|
write_lock_bh(&sk->sk_callback_lock);
|
|
strp_data_ready(&psock->strp);
|
|
write_unlock_bh(&sk->sk_callback_lock);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void smap_tx_work(struct work_struct *w)
|
|
{
|
|
struct smap_psock *psock;
|
|
struct sk_buff *skb;
|
|
int rem, off, n;
|
|
|
|
psock = container_of(w, struct smap_psock, tx_work);
|
|
|
|
/* lock sock to avoid losing sk_socket at some point during loop */
|
|
lock_sock(psock->sock);
|
|
if (psock->save_skb) {
|
|
skb = psock->save_skb;
|
|
rem = psock->save_rem;
|
|
off = psock->save_off;
|
|
psock->save_skb = NULL;
|
|
goto start;
|
|
}
|
|
|
|
while ((skb = skb_dequeue(&psock->rxqueue))) {
|
|
__u32 flags;
|
|
|
|
rem = skb->len;
|
|
off = 0;
|
|
start:
|
|
flags = (TCP_SKB_CB(skb)->bpf.flags) & BPF_F_INGRESS;
|
|
do {
|
|
if (likely(psock->sock->sk_socket)) {
|
|
if (flags)
|
|
n = smap_do_ingress(psock, skb);
|
|
else
|
|
n = skb_send_sock_locked(psock->sock,
|
|
skb, off, rem);
|
|
} else {
|
|
n = -EINVAL;
|
|
}
|
|
|
|
if (n <= 0) {
|
|
if (n == -EAGAIN) {
|
|
/* Retry when space is available */
|
|
psock->save_skb = skb;
|
|
psock->save_rem = rem;
|
|
psock->save_off = off;
|
|
goto out;
|
|
}
|
|
/* Hard errors break pipe and stop xmit */
|
|
smap_report_sk_error(psock, n ? -n : EPIPE);
|
|
clear_bit(SMAP_TX_RUNNING, &psock->state);
|
|
kfree_skb(skb);
|
|
goto out;
|
|
}
|
|
rem -= n;
|
|
off += n;
|
|
} while (rem);
|
|
|
|
if (!flags)
|
|
kfree_skb(skb);
|
|
}
|
|
out:
|
|
release_sock(psock->sock);
|
|
}
|
|
|
|
static void smap_write_space(struct sock *sk)
|
|
{
|
|
struct smap_psock *psock;
|
|
|
|
rcu_read_lock();
|
|
psock = smap_psock_sk(sk);
|
|
if (likely(psock && test_bit(SMAP_TX_RUNNING, &psock->state)))
|
|
schedule_work(&psock->tx_work);
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
static void smap_stop_sock(struct smap_psock *psock, struct sock *sk)
|
|
{
|
|
if (!psock->strp_enabled)
|
|
return;
|
|
sk->sk_data_ready = psock->save_data_ready;
|
|
sk->sk_write_space = psock->save_write_space;
|
|
psock->save_data_ready = NULL;
|
|
psock->save_write_space = NULL;
|
|
strp_stop(&psock->strp);
|
|
psock->strp_enabled = false;
|
|
}
|
|
|
|
static void smap_destroy_psock(struct rcu_head *rcu)
|
|
{
|
|
struct smap_psock *psock = container_of(rcu,
|
|
struct smap_psock, rcu);
|
|
|
|
/* Now that a grace period has passed there is no longer
|
|
* any reference to this sock in the sockmap so we can
|
|
* destroy the psock, strparser, and bpf programs. But,
|
|
* because we use workqueue sync operations we can not
|
|
* do it in rcu context
|
|
*/
|
|
schedule_work(&psock->gc_work);
|
|
}
|
|
|
|
static void smap_release_sock(struct smap_psock *psock, struct sock *sock)
|
|
{
|
|
if (refcount_dec_and_test(&psock->refcnt)) {
|
|
tcp_cleanup_ulp(sock);
|
|
smap_stop_sock(psock, sock);
|
|
clear_bit(SMAP_TX_RUNNING, &psock->state);
|
|
rcu_assign_sk_user_data(sock, NULL);
|
|
call_rcu_sched(&psock->rcu, smap_destroy_psock);
|
|
}
|
|
}
|
|
|
|
static int smap_parse_func_strparser(struct strparser *strp,
|
|
struct sk_buff *skb)
|
|
{
|
|
struct smap_psock *psock;
|
|
struct bpf_prog *prog;
|
|
int rc;
|
|
|
|
rcu_read_lock();
|
|
psock = container_of(strp, struct smap_psock, strp);
|
|
prog = READ_ONCE(psock->bpf_parse);
|
|
|
|
if (unlikely(!prog)) {
|
|
rcu_read_unlock();
|
|
return skb->len;
|
|
}
|
|
|
|
/* Attach socket for bpf program to use if needed we can do this
|
|
* because strparser clones the skb before handing it to a upper
|
|
* layer, meaning skb_orphan has been called. We NULL sk on the
|
|
* way out to ensure we don't trigger a BUG_ON in skb/sk operations
|
|
* later and because we are not charging the memory of this skb to
|
|
* any socket yet.
|
|
*/
|
|
skb->sk = psock->sock;
|
|
bpf_compute_data_pointers(skb);
|
|
rc = (*prog->bpf_func)(skb, prog->insnsi);
|
|
skb->sk = NULL;
|
|
rcu_read_unlock();
|
|
return rc;
|
|
}
|
|
|
|
static int smap_read_sock_done(struct strparser *strp, int err)
|
|
{
|
|
return err;
|
|
}
|
|
|
|
static int smap_init_sock(struct smap_psock *psock,
|
|
struct sock *sk)
|
|
{
|
|
static const struct strp_callbacks cb = {
|
|
.rcv_msg = smap_read_sock_strparser,
|
|
.parse_msg = smap_parse_func_strparser,
|
|
.read_sock_done = smap_read_sock_done,
|
|
};
|
|
|
|
return strp_init(&psock->strp, sk, &cb);
|
|
}
|
|
|
|
static void smap_init_progs(struct smap_psock *psock,
|
|
struct bpf_prog *verdict,
|
|
struct bpf_prog *parse)
|
|
{
|
|
struct bpf_prog *orig_parse, *orig_verdict;
|
|
|
|
orig_parse = xchg(&psock->bpf_parse, parse);
|
|
orig_verdict = xchg(&psock->bpf_verdict, verdict);
|
|
|
|
if (orig_verdict)
|
|
bpf_prog_put(orig_verdict);
|
|
if (orig_parse)
|
|
bpf_prog_put(orig_parse);
|
|
}
|
|
|
|
static void smap_start_sock(struct smap_psock *psock, struct sock *sk)
|
|
{
|
|
if (sk->sk_data_ready == smap_data_ready)
|
|
return;
|
|
psock->save_data_ready = sk->sk_data_ready;
|
|
psock->save_write_space = sk->sk_write_space;
|
|
sk->sk_data_ready = smap_data_ready;
|
|
sk->sk_write_space = smap_write_space;
|
|
psock->strp_enabled = true;
|
|
}
|
|
|
|
static void sock_map_remove_complete(struct bpf_stab *stab)
|
|
{
|
|
bpf_map_area_free(stab->sock_map);
|
|
kfree(stab);
|
|
}
|
|
|
|
static void smap_gc_work(struct work_struct *w)
|
|
{
|
|
struct smap_psock_map_entry *e, *tmp;
|
|
struct sk_msg_buff *md, *mtmp;
|
|
struct smap_psock *psock;
|
|
|
|
psock = container_of(w, struct smap_psock, gc_work);
|
|
|
|
/* no callback lock needed because we already detached sockmap ops */
|
|
if (psock->strp_enabled)
|
|
strp_done(&psock->strp);
|
|
|
|
cancel_work_sync(&psock->tx_work);
|
|
__skb_queue_purge(&psock->rxqueue);
|
|
|
|
/* At this point all strparser and xmit work must be complete */
|
|
if (psock->bpf_parse)
|
|
bpf_prog_put(psock->bpf_parse);
|
|
if (psock->bpf_verdict)
|
|
bpf_prog_put(psock->bpf_verdict);
|
|
if (psock->bpf_tx_msg)
|
|
bpf_prog_put(psock->bpf_tx_msg);
|
|
|
|
if (psock->cork) {
|
|
free_start_sg(psock->sock, psock->cork);
|
|
kfree(psock->cork);
|
|
}
|
|
|
|
list_for_each_entry_safe(md, mtmp, &psock->ingress, list) {
|
|
list_del(&md->list);
|
|
free_start_sg(psock->sock, md);
|
|
kfree(md);
|
|
}
|
|
|
|
list_for_each_entry_safe(e, tmp, &psock->maps, list) {
|
|
list_del(&e->list);
|
|
kfree(e);
|
|
}
|
|
|
|
if (psock->sk_redir)
|
|
sock_put(psock->sk_redir);
|
|
|
|
sock_put(psock->sock);
|
|
kfree(psock);
|
|
}
|
|
|
|
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,
|
|
node);
|
|
if (!psock)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
psock->eval = __SK_NONE;
|
|
psock->sock = sock;
|
|
skb_queue_head_init(&psock->rxqueue);
|
|
INIT_WORK(&psock->tx_work, smap_tx_work);
|
|
INIT_WORK(&psock->gc_work, smap_gc_work);
|
|
INIT_LIST_HEAD(&psock->maps);
|
|
INIT_LIST_HEAD(&psock->ingress);
|
|
refcount_set(&psock->refcnt, 1);
|
|
|
|
rcu_assign_sk_user_data(sock, psock);
|
|
sock_hold(sock);
|
|
return psock;
|
|
}
|
|
|
|
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);
|
|
|
|
/* check sanity of attributes */
|
|
if (attr->max_entries == 0 || attr->key_size != 4 ||
|
|
attr->value_size != 4 || attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
err = bpf_tcp_ulp_register();
|
|
if (err && err != -EEXIST)
|
|
return ERR_PTR(err);
|
|
|
|
stab = kzalloc(sizeof(*stab), GFP_USER);
|
|
if (!stab)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
bpf_map_init_from_attr(&stab->map, attr);
|
|
|
|
/* make sure page count doesn't overflow */
|
|
cost = (u64) stab->map.max_entries * sizeof(struct sock *);
|
|
err = -EINVAL;
|
|
if (cost >= U32_MAX - PAGE_SIZE)
|
|
goto free_stab;
|
|
|
|
stab->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
|
|
|
|
/* if map size is larger than memlock limit, reject it early */
|
|
err = bpf_map_precharge_memlock(stab->map.pages);
|
|
if (err)
|
|
goto free_stab;
|
|
|
|
err = -ENOMEM;
|
|
stab->sock_map = bpf_map_area_alloc(stab->map.max_entries *
|
|
sizeof(struct sock *),
|
|
stab->map.numa_node);
|
|
if (!stab->sock_map)
|
|
goto free_stab;
|
|
|
|
return &stab->map;
|
|
free_stab:
|
|
kfree(stab);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
static void smap_list_remove(struct smap_psock *psock,
|
|
struct sock **entry,
|
|
struct htab_elem *hash_link)
|
|
{
|
|
struct smap_psock_map_entry *e, *tmp;
|
|
|
|
list_for_each_entry_safe(e, tmp, &psock->maps, list) {
|
|
if (e->entry == entry || e->hash_link == hash_link) {
|
|
list_del(&e->list);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void sock_map_free(struct bpf_map *map)
|
|
{
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, 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 < stab->map.max_entries; i++) {
|
|
struct smap_psock *psock;
|
|
struct sock *sock;
|
|
|
|
sock = xchg(&stab->sock_map[i], NULL);
|
|
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
|
|
* causing the refcnt to hit zero and sock user data (psock)
|
|
* to be null and queued for garbage collection.
|
|
*/
|
|
if (likely(psock)) {
|
|
smap_list_remove(psock, &stab->sock_map[i], NULL);
|
|
smap_release_sock(psock, sock);
|
|
}
|
|
write_unlock_bh(&sock->sk_callback_lock);
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
sock_map_remove_complete(stab);
|
|
}
|
|
|
|
static int sock_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
|
|
{
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
u32 i = key ? *(u32 *)key : U32_MAX;
|
|
u32 *next = (u32 *)next_key;
|
|
|
|
if (i >= stab->map.max_entries) {
|
|
*next = 0;
|
|
return 0;
|
|
}
|
|
|
|
if (i == stab->map.max_entries - 1)
|
|
return -ENOENT;
|
|
|
|
*next = i + 1;
|
|
return 0;
|
|
}
|
|
|
|
struct sock *__sock_map_lookup_elem(struct bpf_map *map, u32 key)
|
|
{
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
|
|
if (key >= map->max_entries)
|
|
return NULL;
|
|
|
|
return READ_ONCE(stab->sock_map[key]);
|
|
}
|
|
|
|
static int sock_map_delete_elem(struct bpf_map *map, void *key)
|
|
{
|
|
struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
|
|
struct smap_psock *psock;
|
|
int k = *(u32 *)key;
|
|
struct sock *sock;
|
|
|
|
if (k >= map->max_entries)
|
|
return -EINVAL;
|
|
|
|
sock = xchg(&stab->sock_map[k], NULL);
|
|
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], NULL);
|
|
smap_release_sock(psock, sock);
|
|
out:
|
|
write_unlock_bh(&sock->sk_callback_lock);
|
|
return 0;
|
|
}
|
|
|
|
/* Locking notes: Concurrent updates, deletes, and lookups are allowed and are
|
|
* done inside rcu critical sections. This ensures on updates that the psock
|
|
* will not be released via smap_release_sock() until concurrent updates/deletes
|
|
* complete. All operations operate on sock_map using cmpxchg and xchg
|
|
* operations to ensure we do not get stale references. Any reads into the
|
|
* map must be done with READ_ONCE() because of this.
|
|
*
|
|
* A psock is destroyed via call_rcu and after any worker threads are cancelled
|
|
* and syncd so we are certain all references from the update/lookup/delete
|
|
* operations as well as references in the data path are no longer in use.
|
|
*
|
|
* Psocks may exist in multiple maps, but only a single set of parse/verdict
|
|
* programs may be inherited from the maps it belongs to. A reference count
|
|
* is kept with the total number of references to the psock from all maps. The
|
|
* psock will not be released until this reaches zero. The psock and sock
|
|
* user data data use the sk_callback_lock to protect critical data structures
|
|
* from concurrent access. This allows us to avoid two updates from modifying
|
|
* the user data in sock and the lock is required anyways for modifying
|
|
* callbacks, we simply increase its scope slightly.
|
|
*
|
|
* Rules to follow,
|
|
* - psock must always be read inside RCU critical section
|
|
* - sk_user_data must only be modified inside sk_callback_lock and read
|
|
* inside RCU critical section.
|
|
* - psock->maps list must only be read & modified inside sk_callback_lock
|
|
* - 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_map *map,
|
|
struct bpf_sock_progs *progs,
|
|
struct sock *sock,
|
|
struct sock **map_link,
|
|
void *key)
|
|
{
|
|
struct bpf_prog *verdict, *parse, *tx_msg;
|
|
struct smap_psock_map_entry *e = NULL;
|
|
struct smap_psock *psock;
|
|
bool new = false;
|
|
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(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
|
|
* removes the program after the above READ_ONCE() but before
|
|
* we increment the refcnt. If this is the case abort with an
|
|
* error.
|
|
*/
|
|
verdict = bpf_prog_inc_not_zero(verdict);
|
|
if (IS_ERR(verdict))
|
|
return PTR_ERR(verdict);
|
|
|
|
parse = bpf_prog_inc_not_zero(parse);
|
|
if (IS_ERR(parse)) {
|
|
bpf_prog_put(verdict);
|
|
return PTR_ERR(parse);
|
|
}
|
|
}
|
|
|
|
if (tx_msg) {
|
|
tx_msg = bpf_prog_inc_not_zero(tx_msg);
|
|
if (IS_ERR(tx_msg)) {
|
|
if (parse && verdict) {
|
|
bpf_prog_put(parse);
|
|
bpf_prog_put(verdict);
|
|
}
|
|
return PTR_ERR(tx_msg);
|
|
}
|
|
}
|
|
|
|
write_lock_bh(&sock->sk_callback_lock);
|
|
psock = smap_psock_sk(sock);
|
|
|
|
/* 2. Do not allow inheriting programs if psock exists and has
|
|
* already inherited programs. This would create confusion on
|
|
* which parser/verdict program is running. If no psock exists
|
|
* create one. Inside sk_callback_lock to ensure concurrent create
|
|
* doesn't update user data.
|
|
*/
|
|
if (psock) {
|
|
if (READ_ONCE(psock->bpf_parse) && parse) {
|
|
err = -EBUSY;
|
|
goto out_progs;
|
|
}
|
|
if (READ_ONCE(psock->bpf_tx_msg) && tx_msg) {
|
|
err = -EBUSY;
|
|
goto out_progs;
|
|
}
|
|
if (!refcount_inc_not_zero(&psock->refcnt)) {
|
|
err = -EAGAIN;
|
|
goto out_progs;
|
|
}
|
|
} else {
|
|
psock = smap_init_psock(sock, map->numa_node);
|
|
if (IS_ERR(psock)) {
|
|
err = PTR_ERR(psock);
|
|
goto out_progs;
|
|
}
|
|
|
|
set_bit(SMAP_TX_RUNNING, &psock->state);
|
|
new = true;
|
|
}
|
|
|
|
if (map_link) {
|
|
e = kzalloc(sizeof(*e), GFP_ATOMIC | __GFP_NOWARN);
|
|
if (!e) {
|
|
err = -ENOMEM;
|
|
goto out_progs;
|
|
}
|
|
}
|
|
|
|
/* 3. At this point we have a reference to a valid psock that is
|
|
* running. Attach any BPF programs needed.
|
|
*/
|
|
if (tx_msg)
|
|
bpf_tcp_msg_add(psock, sock, tx_msg);
|
|
if (new) {
|
|
err = tcp_set_ulp_id(sock, TCP_ULP_BPF);
|
|
if (err)
|
|
goto out_free;
|
|
}
|
|
|
|
if (parse && verdict && !psock->strp_enabled) {
|
|
err = smap_init_sock(psock, sock);
|
|
if (err)
|
|
goto out_free;
|
|
smap_init_progs(psock, verdict, parse);
|
|
smap_start_sock(psock, sock);
|
|
}
|
|
|
|
/* 4. Place psock in sockmap for use and stop any programs on
|
|
* the old sock assuming its not the same sock we are replacing
|
|
* it with. Because we can only have a single set of programs if
|
|
* old_sock has a strp we can stop it.
|
|
*/
|
|
if (map_link) {
|
|
e->entry = map_link;
|
|
list_add_tail(&e->list, &psock->maps);
|
|
}
|
|
write_unlock_bh(&sock->sk_callback_lock);
|
|
return err;
|
|
out_free:
|
|
smap_release_sock(psock, sock);
|
|
out_progs:
|
|
if (parse && verdict) {
|
|
bpf_prog_put(parse);
|
|
bpf_prog_put(verdict);
|
|
}
|
|
if (tx_msg)
|
|
bpf_prog_put(tx_msg);
|
|
write_unlock_bh(&sock->sk_callback_lock);
|
|
kfree(e);
|
|
return err;
|
|
}
|
|
|
|
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);
|
|
|
|
write_lock_bh(&osock->sk_callback_lock);
|
|
smap_list_remove(opsock, &stab->sock_map[i], NULL);
|
|
smap_release_sock(opsock, osock);
|
|
write_unlock_bh(&osock->sk_callback_lock);
|
|
}
|
|
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 (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(&progs->bpf_tx_msg, prog);
|
|
break;
|
|
case BPF_SK_SKB_STREAM_PARSER:
|
|
orig = xchg(&progs->bpf_parse, prog);
|
|
break;
|
|
case BPF_SK_SKB_STREAM_VERDICT:
|
|
orig = xchg(&progs->bpf_verdict, prog);
|
|
break;
|
|
default:
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
if (orig)
|
|
bpf_prog_put(orig);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void *sock_map_lookup(struct bpf_map *map, void *key)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
static int sock_map_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;
|
|
}
|
|
|
|
if (skops.sk->sk_type != SOCK_STREAM ||
|
|
skops.sk->sk_protocol != IPPROTO_TCP) {
|
|
fput(socket->file);
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
err = sock_map_ctx_update_elem(&skops, map, key, flags);
|
|
fput(socket->file);
|
|
return err;
|
|
}
|
|
|
|
static void sock_map_release(struct bpf_map *map)
|
|
{
|
|
struct bpf_sock_progs *progs;
|
|
struct bpf_prog *orig;
|
|
|
|
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(&progs->bpf_verdict, NULL);
|
|
if (orig)
|
|
bpf_prog_put(orig);
|
|
|
|
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 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 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 hlist_head *head = select_bucket(htab, i);
|
|
struct hlist_node *n;
|
|
struct htab_elem *l;
|
|
|
|
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);
|
|
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
|
|
* causing the refcnt to hit zero and sock user data
|
|
* (psock) to be null and queued for garbage collection.
|
|
*/
|
|
if (likely(psock)) {
|
|
smap_list_remove(psock, NULL, l);
|
|
smap_release_sock(psock, sock);
|
|
}
|
|
write_unlock_bh(&sock->sk_callback_lock);
|
|
kfree(l);
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
bpf_map_area_free(htab->buckets);
|
|
kfree(htab);
|
|
}
|
|
|
|
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 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 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;
|
|
|
|
/* bpf_map_update_elem() can be called in_irq() */
|
|
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;
|
|
}
|
|
|
|
psock = smap_psock_sk(sock);
|
|
if (unlikely(!psock)) {
|
|
err = -EINVAL;
|
|
goto bucket_err;
|
|
}
|
|
|
|
e->hash_link = l_new;
|
|
e->htab = container_of(map, struct bpf_htab, map);
|
|
list_add_tail(&e->list, &psock->maps);
|
|
|
|
/* 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_remove(psock, NULL, 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:
|
|
raw_spin_unlock_bh(&b->lock);
|
|
err:
|
|
kfree(e);
|
|
psock = smap_psock_sk(sock);
|
|
if (psock)
|
|
smap_release_sock(psock, sock);
|
|
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;
|
|
}
|
|
|
|
err = sock_hash_ctx_update_elem(&skops, map, key, flags);
|
|
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);
|
|
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
|
|
* causing the refcnt to hit zero and sock user data (psock)
|
|
* to be null and queued for garbage collection.
|
|
*/
|
|
if (likely(psock)) {
|
|
smap_list_remove(psock, NULL, l);
|
|
smap_release_sock(psock, sock);
|
|
}
|
|
write_unlock_bh(&sock->sk_callback_lock);
|
|
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;
|
|
|
|
raw_spin_lock_bh(&b->lock);
|
|
l = lookup_elem_raw(head, hash, key, key_size);
|
|
sk = l ? l->sk : NULL;
|
|
raw_spin_unlock_bh(&b->lock);
|
|
return sk;
|
|
}
|
|
|
|
const struct bpf_map_ops sock_map_ops = {
|
|
.map_alloc = sock_map_alloc,
|
|
.map_free = sock_map_free,
|
|
.map_lookup_elem = sock_map_lookup,
|
|
.map_get_next_key = sock_map_get_next_key,
|
|
.map_update_elem = sock_map_update_elem,
|
|
.map_delete_elem = sock_map_delete_elem,
|
|
.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,
|
|
};
|
|
|
|
BPF_CALL_4(bpf_sock_map_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_map_ctx_update_elem(bpf_sock, map, key, flags);
|
|
}
|
|
|
|
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_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,
|
|
};
|