diff options
| -rw-r--r-- | include/net/udp.h | 4 | ||||
| -rw-r--r-- | net/ipv4/udp.c | 106 |
2 files changed, 110 insertions, 0 deletions
diff --git a/include/net/udp.h b/include/net/udp.h index ea53a87d880f..18f1e6b91927 100644 --- a/include/net/udp.h +++ b/include/net/udp.h @@ -246,6 +246,9 @@ static inline __be16 udp_flow_src_port(struct net *net, struct sk_buff *skb, } /* net/ipv4/udp.c */ +void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len); +int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb); + void udp_v4_early_demux(struct sk_buff *skb); int udp_get_port(struct sock *sk, unsigned short snum, int (*saddr_cmp)(const struct sock *, @@ -258,6 +261,7 @@ void udp_flush_pending_frames(struct sock *sk); void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst); int udp_rcv(struct sk_buff *skb); int udp_ioctl(struct sock *sk, int cmd, unsigned long arg); +int udp_init_sock(struct sock *sk); int udp_disconnect(struct sock *sk, int flags); unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait); struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 7d96dc2d3d08..be3c3312df8d 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1172,6 +1172,112 @@ out: return ret; } +static void udp_rmem_release(struct sock *sk, int size, int partial) +{ + int amt; + + atomic_sub(size, &sk->sk_rmem_alloc); + + spin_lock_bh(&sk->sk_receive_queue.lock); + sk->sk_forward_alloc += size; + amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1); + sk->sk_forward_alloc -= amt; + spin_unlock_bh(&sk->sk_receive_queue.lock); + + if (amt) + __sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT); +} + +static void udp_rmem_free(struct sk_buff *skb) +{ + udp_rmem_release(skb->sk, skb->truesize, 1); +} + +int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb) +{ + struct sk_buff_head *list = &sk->sk_receive_queue; + int rmem, delta, amt, err = -ENOMEM; + int size = skb->truesize; + + /* try to avoid the costly atomic add/sub pair when the receive + * queue is full; always allow at least a packet + */ + rmem = atomic_read(&sk->sk_rmem_alloc); + if (rmem && (rmem + size > sk->sk_rcvbuf)) + goto drop; + + /* we drop only if the receive buf is full and the receive + * queue contains some other skb + */ + rmem = atomic_add_return(size, &sk->sk_rmem_alloc); + if ((rmem > sk->sk_rcvbuf) && (rmem > size)) + goto uncharge_drop; + + spin_lock(&list->lock); + if (size >= sk->sk_forward_alloc) { + amt = sk_mem_pages(size); + delta = amt << SK_MEM_QUANTUM_SHIFT; + if (!__sk_mem_raise_allocated(sk, delta, amt, SK_MEM_RECV)) { + err = -ENOBUFS; + spin_unlock(&list->lock); + goto uncharge_drop; + } + + sk->sk_forward_alloc += delta; + } + + sk->sk_forward_alloc -= size; + + /* the skb owner in now the udp socket */ + skb->sk = sk; + skb->destructor = udp_rmem_free; + skb->dev = NULL; + sock_skb_set_dropcount(sk, skb); + + __skb_queue_tail(list, skb); + spin_unlock(&list->lock); + + if (!sock_flag(sk, SOCK_DEAD)) + sk->sk_data_ready(sk); + + return 0; + +uncharge_drop: + atomic_sub(skb->truesize, &sk->sk_rmem_alloc); + +drop: + atomic_inc(&sk->sk_drops); + return err; +} +EXPORT_SYMBOL_GPL(__udp_enqueue_schedule_skb); + +static void udp_destruct_sock(struct sock *sk) +{ + /* reclaim completely the forward allocated memory */ + __skb_queue_purge(&sk->sk_receive_queue); + udp_rmem_release(sk, 0, 0); + inet_sock_destruct(sk); +} + +int udp_init_sock(struct sock *sk) +{ + sk->sk_destruct = udp_destruct_sock; + return 0; +} +EXPORT_SYMBOL_GPL(udp_init_sock); + +void skb_consume_udp(struct sock *sk, struct sk_buff *skb, int len) +{ + if (unlikely(READ_ONCE(sk->sk_peek_off) >= 0)) { + bool slow = lock_sock_fast(sk); + + sk_peek_offset_bwd(sk, len); + unlock_sock_fast(sk, slow); + } + consume_skb(skb); +} +EXPORT_SYMBOL_GPL(skb_consume_udp); + /** * first_packet_length - return length of first packet in receive queue * @sk: socket |