af_iucv: Provide new socket type SOCK_SEQPACKET

This patch provides the socket type SOCK_SEQPACKET in addition to
SOCK_STREAM.

AF_IUCV sockets of type SOCK_SEQPACKET supports an 1:1 mapping of
socket read or write operations to complete IUCV messages.
Socket data or IUCV message data is not fragmented as this is the
case for SOCK_STREAM sockets.

The intention is to help application developers who write
applications or device drivers using native IUCV interfaces
(Linux kernel or z/VM IUCV interfaces).

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ursula.braun@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Hendrik Brueckner 2009-04-21 23:26:25 +00:00 committed by David S. Miller
parent 44b1e6b5f9
commit aa8e71f58a

View file

@ -289,11 +289,22 @@ static int iucv_sock_create(struct net *net, struct socket *sock, int protocol)
{
struct sock *sk;
if (sock->type != SOCK_STREAM)
return -ESOCKTNOSUPPORT;
if (protocol && protocol != PF_IUCV)
return -EPROTONOSUPPORT;
sock->state = SS_UNCONNECTED;
sock->ops = &iucv_sock_ops;
switch (sock->type) {
case SOCK_STREAM:
sock->ops = &iucv_sock_ops;
break;
case SOCK_SEQPACKET:
/* currently, proto ops can handle both sk types */
sock->ops = &iucv_sock_ops;
break;
default:
return -ESOCKTNOSUPPORT;
}
sk = iucv_sock_alloc(sock, protocol, GFP_KERNEL);
if (!sk)
@ -504,11 +515,9 @@ static int iucv_sock_connect(struct socket *sock, struct sockaddr *addr,
if (sk->sk_state != IUCV_OPEN && sk->sk_state != IUCV_BOUND)
return -EBADFD;
if (sk->sk_type != SOCK_STREAM)
if (sk->sk_type != SOCK_STREAM && sk->sk_type != SOCK_SEQPACKET)
return -EINVAL;
iucv = iucv_sk(sk);
if (sk->sk_state == IUCV_OPEN) {
err = iucv_sock_autobind(sk);
if (unlikely(err))
@ -585,7 +594,10 @@ static int iucv_sock_listen(struct socket *sock, int backlog)
lock_sock(sk);
err = -EINVAL;
if (sk->sk_state != IUCV_BOUND || sock->type != SOCK_STREAM)
if (sk->sk_state != IUCV_BOUND)
goto done;
if (sock->type != SOCK_STREAM && sock->type != SOCK_SEQPACKET)
goto done;
sk->sk_max_ack_backlog = backlog;
@ -720,6 +732,10 @@ static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;
/* SOCK_SEQPACKET: we do not support segmented records */
if (sk->sk_type == SOCK_SEQPACKET && !(msg->msg_flags & MSG_EOR))
return -EOPNOTSUPP;
lock_sock(sk);
if (sk->sk_shutdown & SEND_SHUTDOWN) {
@ -770,6 +786,10 @@ static int iucv_sock_sendmsg(struct kiocb *iocb, struct socket *sock,
}
}
/* allocate one skb for each iucv message:
* this is fine for SOCK_SEQPACKET (unless we want to support
* segmented records using the MSG_EOR flag), but
* for SOCK_STREAM we might want to improve it in future */
if (!(skb = sock_alloc_send_skb(sk, len,
msg->msg_flags & MSG_DONTWAIT,
&err)))
@ -897,7 +917,11 @@ static void iucv_process_message(struct sock *sk, struct sk_buff *skb,
kfree_skb(skb);
return;
}
if (skb->truesize >= sk->sk_rcvbuf / 4) {
/* we need to fragment iucv messages for SOCK_STREAM only;
* for SOCK_SEQPACKET, it is only relevant if we support
* record segmentation using MSG_EOR (see also recvmsg()) */
if (sk->sk_type == SOCK_STREAM &&
skb->truesize >= sk->sk_rcvbuf / 4) {
rc = iucv_fragment_skb(sk, skb, len);
kfree_skb(skb);
skb = NULL;
@ -941,7 +965,8 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
int noblock = flags & MSG_DONTWAIT;
struct sock *sk = sock->sk;
struct iucv_sock *iucv = iucv_sk(sk);
int target, copied = 0;
int target;
unsigned int copied, rlen;
struct sk_buff *skb, *rskb, *cskb;
int err = 0;
@ -963,7 +988,8 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
return err;
}
copied = min_t(unsigned int, skb->len, len);
rlen = skb->len; /* real length of skb */
copied = min_t(unsigned int, rlen, len);
cskb = skb;
if (memcpy_toiovec(msg->msg_iov, cskb->data, copied)) {
@ -973,7 +999,13 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
goto done;
}
len -= copied;
/* SOCK_SEQPACKET: set MSG_TRUNC if recv buf size is too small */
if (sk->sk_type == SOCK_SEQPACKET) {
if (copied < rlen)
msg->msg_flags |= MSG_TRUNC;
/* each iucv message contains a complete record */
msg->msg_flags |= MSG_EOR;
}
/* create control message to store iucv msg target class:
* get the trgcls from the control buffer of the skb due to
@ -988,11 +1020,14 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
/* Mark read part of skb as used */
if (!(flags & MSG_PEEK)) {
skb_pull(skb, copied);
if (skb->len) {
skb_queue_head(&sk->sk_receive_queue, skb);
goto done;
/* SOCK_STREAM: re-queue skb if it contains unreceived data */
if (sk->sk_type == SOCK_STREAM) {
skb_pull(skb, copied);
if (skb->len) {
skb_queue_head(&sk->sk_receive_queue, skb);
goto done;
}
}
kfree_skb(skb);
@ -1019,7 +1054,11 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
skb_queue_head(&sk->sk_receive_queue, skb);
done:
return err ? : copied;
/* SOCK_SEQPACKET: return real length if MSG_TRUNC is set */
if (sk->sk_type == SOCK_SEQPACKET && (flags & MSG_TRUNC))
copied = rlen;
return copied;
}
static inline unsigned int iucv_accept_poll(struct sock *parent)
@ -1281,7 +1320,7 @@ static int iucv_callback_connreq(struct iucv_path *path,
}
/* Create the new socket */
nsk = iucv_sock_alloc(NULL, SOCK_STREAM, GFP_ATOMIC);
nsk = iucv_sock_alloc(NULL, sk->sk_type, GFP_ATOMIC);
if (!nsk) {
err = iucv_path_sever(path, user_data);
iucv_path_free(path);