From aa8e71f58ab8e01d63c33df40ff1bcb997c9df92 Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Tue, 21 Apr 2009 23:26:25 +0000 Subject: 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 Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/iucv/af_iucv.c | 73 +++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 56 insertions(+), 17 deletions(-) diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c index 47c5c8d..95e38d3 100644 --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -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); -- cgit v1.1