int rxrpc_recvmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t len, int flags)
{
struct rxrpc_skb_priv *sp;
struct rxrpc_call *call = NULL, *continue_call = NULL;
struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
struct sk_buff *skb;
long timeo;
int copy, ret, ullen, offset, copied = 0;
u32 abort_code;
DEFINE_WAIT(wait);
_enter(",,,%zu,%d", len, flags);
if (flags & (MSG_OOB | MSG_TRUNC))
return -EOPNOTSUPP;
ullen = msg->msg_flags & MSG_CMSG_COMPAT ? 4 : sizeof(unsigned long);
timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT);
msg->msg_flags |= MSG_MORE;
lock_sock(&rx->sk);
for (;;) {
/* return immediately if a client socket has no outstanding
* calls */
if (RB_EMPTY_ROOT(&rx->calls)) {
if (copied)
goto out;
if (rx->sk.sk_state != RXRPC_SERVER_LISTENING) {
release_sock(&rx->sk);
if (continue_call)
rxrpc_put_call(continue_call);
return -ENODATA;
}
}
/* get the next message on the Rx queue */
skb = skb_peek(&rx->sk.sk_receive_queue);
if (!skb) {
/* nothing remains on the queue */
if (copied &&
(msg->msg_flags & MSG_PEEK || timeo == 0))
goto out;
/* wait for a message to turn up */
release_sock(&rx->sk);
prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait,
TASK_INTERRUPTIBLE);
ret = sock_error(&rx->sk);
if (ret)
goto wait_error;
if (skb_queue_empty(&rx->sk.sk_receive_queue)) {
if (signal_pending(current))
goto wait_interrupted;
timeo = schedule_timeout(timeo);
}
finish_wait(sk_sleep(&rx->sk), &wait);
lock_sock(&rx->sk);
continue;
}
peek_next_packet:
sp = rxrpc_skb(skb);
call = sp->call;
ASSERT(call != NULL);
_debug("next pkt %s", rxrpc_pkts[sp->hdr.type]);
/* make sure we wait for the state to be updated in this call */
spin_lock_bh(&call->lock);
spin_unlock_bh(&call->lock);
if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) {
_debug("packet from released call");
if (skb_dequeue(&rx->sk.sk_receive_queue) != skb)
BUG();
rxrpc_free_skb(skb);
continue;
}
/* determine whether to continue last data receive */
if (continue_call) {
_debug("maybe cont");
if (call != continue_call ||
skb->mark != RXRPC_SKB_MARK_DATA) {
release_sock(&rx->sk);
rxrpc_put_call(continue_call);
_leave(" = %d [noncont]", copied);
return copied;
}
}
rxrpc_get_call(call);
/* copy the peer address and timestamp */
if (!continue_call) {
if (msg->msg_name && msg->msg_namelen > 0)
memcpy(msg->msg_name,
&call->conn->trans->peer->srx,
sizeof(call->conn->trans->peer->srx));
sock_recv_ts_and_drops(msg, &rx->sk, skb);
}
/* receive the message */
if (skb->mark != RXRPC_SKB_MARK_DATA)
goto receive_non_data_message;
_debug("recvmsg DATA #%u { %d, %d }",
ntohl(sp->hdr.seq), skb->len, sp->offset);
if (!continue_call) {
/* only set the control data once per recvmsg() */
ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID,
ullen, &call->user_call_ID);
if (ret < 0)
goto copy_error;
ASSERT(test_bit(RXRPC_CALL_HAS_USERID, &call->flags));
}
ASSERTCMP(ntohl(sp->hdr.seq), >=, call->rx_data_recv);
ASSERTCMP(ntohl(sp->hdr.seq), <=, call->rx_data_recv + 1);
call->rx_data_recv = ntohl(sp->hdr.seq);
ASSERTCMP(ntohl(sp->hdr.seq), >, call->rx_data_eaten);
offset = sp->offset;
copy = skb->len - offset;
if (copy > len - copied)
copy = len - copied;
if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
ret = skb_copy_datagram_iovec(skb, offset,
msg->msg_iov, copy);
} else {
ret = skb_copy_and_csum_datagram_iovec(skb, offset,
msg->msg_iov);
if (ret == -EINVAL)
goto csum_copy_error;
}
if (ret < 0)
goto copy_error;
/* handle piecemeal consumption of data packets */
_debug("copied %d+%d", copy, copied);
offset += copy;
copied += copy;
if (!(flags & MSG_PEEK))
sp->offset = offset;
if (sp->offset < skb->len) {
_debug("buffer full");
ASSERTCMP(copied, ==, len);
break;
}
/* we transferred the whole data packet */
if (sp->hdr.flags & RXRPC_LAST_PACKET) {
_debug("last");
if (call->conn->out_clientflag) {
/* last byte of reply received */
ret = copied;
goto terminal_message;
}
/* last bit of request received */
if (!(flags & MSG_PEEK)) {
_debug("eat packet");
if (skb_dequeue(&rx->sk.sk_receive_queue) !=
skb)
BUG();
rxrpc_free_skb(skb);
}
msg->msg_flags &= ~MSG_MORE;
break;
}
/* move on to the next data message */
_debug("next");
if (!continue_call)
continue_call = sp->call;
else
rxrpc_put_call(call);
call = NULL;
if (flags & MSG_PEEK) {
_debug("peek next");
skb = skb->next;
if (skb == (struct sk_buff *) &rx->sk.sk_receive_queue)
break;
goto peek_next_packet;
}
_debug("eat packet");
if (skb_dequeue(&rx->sk.sk_receive_queue) != skb)
BUG();
rxrpc_free_skb(skb);
}
int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, int len,
int noblock, int flags, int *addr_len)
{
struct sk_buff *skb;
int copied, err;
if (addr_len)
*addr_len=sizeof(struct sockaddr_in6);
if (flags & MSG_ERRQUEUE)
return ipv6_recv_error(sk, msg, len);
skb = skb_recv_datagram(sk, flags, noblock, &err);
if (!skb)
goto out;
copied = skb->len - sizeof(struct udphdr);
if (copied > len) {
copied = len;
msg->msg_flags |= MSG_TRUNC;
}
if (skb->ip_summed==CHECKSUM_UNNECESSARY) {
err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
copied);
} else if (msg->msg_flags&MSG_TRUNC) {
if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)))
goto csum_copy_err;
err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov,
copied);
} else {
err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);
if (err == -EINVAL)
goto csum_copy_err;
}
if (err)
goto out_free;
sock_recv_timestamp(msg, sk, skb);
/* Copy the address. */
if (msg->msg_name) {
struct sockaddr_in6 *sin6;
sin6 = (struct sockaddr_in6 *) msg->msg_name;
sin6->sin6_family = AF_INET6;
sin6->sin6_port = skb->h.uh->source;
sin6->sin6_flowinfo = 0;
sin6->sin6_scope_id = 0;
if (skb->protocol == __constant_htons(ETH_P_IP)) {
ipv6_addr_set(&sin6->sin6_addr, 0, 0,
__constant_htonl(0xffff), skb->nh.iph->saddr);
if (sk->protinfo.af_inet.cmsg_flags)
ip_cmsg_recv(msg, skb);
} else {
memcpy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr,
sizeof(struct in6_addr));
if (sk->net_pinfo.af_inet6.rxopt.all)
datagram_recv_ctl(sk, msg, skb);
if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
sin6->sin6_scope_id = opt->iif;
}
}
}
err = copied;
out_free:
skb_free_datagram(sk, skb);
out:
return err;
csum_copy_err:
/* Clear queue. */
if (flags&MSG_PEEK) {
int clear = 0;
spin_lock_irq(&sk->receive_queue.lock);
if (skb == skb_peek(&sk->receive_queue)) {
__skb_unlink(skb, &sk->receive_queue);
clear = 1;
}
spin_unlock_irq(&sk->receive_queue.lock);
if (clear)
kfree_skb(skb);
}
/* Error for blocking case is chosen to masquerade
as some normal condition.
*/
err = (flags&MSG_DONTWAIT) ? -EAGAIN : -EHOSTUNREACH;
UDP6_INC_STATS_USER(UdpInErrors);
goto out_free;
}
