Initial import

1 files changed, 1373 insertions, 0 deletions

diff --git a/net/phonet/pep.c b/net/phonet/pep.c
new file mode 100644
index 000000000..6de2aeb98
--- /dev/null
+++ b/net/phonet/pep.c
@@ -0,0 +1,1373 @@
+/*
+ * File: pep.c
+ *
+ * Phonet pipe protocol end point socket
+ *
+ * Copyright (C) 2008 Nokia Corporation.
+ *
+ * Author: Rémi Denis-Courmont
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/socket.h>
+#include <net/sock.h>
+#include <net/tcp_states.h>
+#include <asm/ioctls.h>
+
+#include <linux/phonet.h>
+#include <linux/module.h>
+#include <net/phonet/phonet.h>
+#include <net/phonet/pep.h>
+#include <net/phonet/gprs.h>
+
+/* sk_state values:
+ * TCP_CLOSE		sock not in use yet
+ * TCP_CLOSE_WAIT	disconnected pipe
+ * TCP_LISTEN		listening pipe endpoint
+ * TCP_SYN_RECV		connected pipe in disabled state
+ * TCP_ESTABLISHED	connected pipe in enabled state
+ *
+ * pep_sock locking:
+ *  - sk_state, hlist: sock lock needed
+ *  - listener: read only
+ *  - pipe_handle: read only
+ */
+
+#define CREDITS_MAX	10
+#define CREDITS_THR	7
+
+#define pep_sb_size(s) (((s) + 5) & ~3) /* 2-bytes head, 32-bits aligned */
+
+/* Get the next TLV sub-block. */
+static unsigned char *pep_get_sb(struct sk_buff *skb, u8 *ptype, u8 *plen,
+					void *buf)
+{
+	void *data = NULL;
+	struct {
+		u8 sb_type;
+		u8 sb_len;
+	} *ph, h;
+	int buflen = *plen;
+
+	ph = skb_header_pointer(skb, 0, 2, &h);
+	if (ph == NULL || ph->sb_len < 2 || !pskb_may_pull(skb, ph->sb_len))
+		return NULL;
+	ph->sb_len -= 2;
+	*ptype = ph->sb_type;
+	*plen = ph->sb_len;
+
+	if (buflen > ph->sb_len)
+		buflen = ph->sb_len;
+	data = skb_header_pointer(skb, 2, buflen, buf);
+	__skb_pull(skb, 2 + ph->sb_len);
+	return data;
+}
+
+static struct sk_buff *pep_alloc_skb(struct sock *sk, const void *payload,
+					int len, gfp_t priority)
+{
+	struct sk_buff *skb = alloc_skb(MAX_PNPIPE_HEADER + len, priority);
+	if (!skb)
+		return NULL;
+	skb_set_owner_w(skb, sk);
+
+	skb_reserve(skb, MAX_PNPIPE_HEADER);
+	__skb_put(skb, len);
+	skb_copy_to_linear_data(skb, payload, len);
+	__skb_push(skb, sizeof(struct pnpipehdr));
+	skb_reset_transport_header(skb);
+	return skb;
+}
+
+static int pep_reply(struct sock *sk, struct sk_buff *oskb, u8 code,
+			const void *data, int len, gfp_t priority)
+{
+	const struct pnpipehdr *oph = pnp_hdr(oskb);
+	struct pnpipehdr *ph;
+	struct sk_buff *skb;
+	struct sockaddr_pn peer;
+
+	skb = pep_alloc_skb(sk, data, len, priority);
+	if (!skb)
+		return -ENOMEM;
+
+	ph = pnp_hdr(skb);
+	ph->utid = oph->utid;
+	ph->message_id = oph->message_id + 1; /* REQ -> RESP */
+	ph->pipe_handle = oph->pipe_handle;
+	ph->error_code = code;
+
+	pn_skb_get_src_sockaddr(oskb, &peer);
+	return pn_skb_send(sk, skb, &peer);
+}
+
+static int pep_indicate(struct sock *sk, u8 id, u8 code,
+			const void *data, int len, gfp_t priority)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	struct pnpipehdr *ph;
+	struct sk_buff *skb;
+
+	skb = pep_alloc_skb(sk, data, len, priority);
+	if (!skb)
+		return -ENOMEM;
+
+	ph = pnp_hdr(skb);
+	ph->utid = 0;
+	ph->message_id = id;
+	ph->pipe_handle = pn->pipe_handle;
+	ph->data[0] = code;
+	return pn_skb_send(sk, skb, NULL);
+}
+
+#define PAD 0x00
+
+static int pipe_handler_request(struct sock *sk, u8 id, u8 code,
+				const void *data, int len)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	struct pnpipehdr *ph;
+	struct sk_buff *skb;
+
+	skb = pep_alloc_skb(sk, data, len, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	ph = pnp_hdr(skb);
+	ph->utid = id; /* whatever */
+	ph->message_id = id;
+	ph->pipe_handle = pn->pipe_handle;
+	ph->data[0] = code;
+	return pn_skb_send(sk, skb, NULL);
+}
+
+static int pipe_handler_send_created_ind(struct sock *sk)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	u8 data[4] = {
+		PN_PIPE_SB_NEGOTIATED_FC, pep_sb_size(2),
+		pn->tx_fc, pn->rx_fc,
+	};
+
+	return pep_indicate(sk, PNS_PIPE_CREATED_IND, 1 /* sub-blocks */,
+				data, 4, GFP_ATOMIC);
+}
+
+static int pep_accept_conn(struct sock *sk, struct sk_buff *skb)
+{
+	static const u8 data[20] = {
+		PAD, PAD, PAD, 2 /* sub-blocks */,
+		PN_PIPE_SB_REQUIRED_FC_TX, pep_sb_size(5), 3, PAD,
+			PN_MULTI_CREDIT_FLOW_CONTROL,
+			PN_ONE_CREDIT_FLOW_CONTROL,
+			PN_LEGACY_FLOW_CONTROL,
+			PAD,
+		PN_PIPE_SB_PREFERRED_FC_RX, pep_sb_size(5), 3, PAD,
+			PN_MULTI_CREDIT_FLOW_CONTROL,
+			PN_ONE_CREDIT_FLOW_CONTROL,
+			PN_LEGACY_FLOW_CONTROL,
+			PAD,
+	};
+
+	might_sleep();
+	return pep_reply(sk, skb, PN_PIPE_NO_ERROR, data, sizeof(data),
+				GFP_KERNEL);
+}
+
+static int pep_reject_conn(struct sock *sk, struct sk_buff *skb, u8 code,
+				gfp_t priority)
+{
+	static const u8 data[4] = { PAD, PAD, PAD, 0 /* sub-blocks */ };
+	WARN_ON(code == PN_PIPE_NO_ERROR);
+	return pep_reply(sk, skb, code, data, sizeof(data), priority);
+}
+
+/* Control requests are not sent by the pipe service and have a specific
+ * message format. */
+static int pep_ctrlreq_error(struct sock *sk, struct sk_buff *oskb, u8 code,
+				gfp_t priority)
+{
+	const struct pnpipehdr *oph = pnp_hdr(oskb);
+	struct sk_buff *skb;
+	struct pnpipehdr *ph;
+	struct sockaddr_pn dst;
+	u8 data[4] = {
+		oph->data[0], /* PEP type */
+		code, /* error code, at an unusual offset */
+		PAD, PAD,
+	};
+
+	skb = pep_alloc_skb(sk, data, 4, priority);
+	if (!skb)
+		return -ENOMEM;
+
+	ph = pnp_hdr(skb);
+	ph->utid = oph->utid;
+	ph->message_id = PNS_PEP_CTRL_RESP;
+	ph->pipe_handle = oph->pipe_handle;
+	ph->data[0] = oph->data[1]; /* CTRL id */
+
+	pn_skb_get_src_sockaddr(oskb, &dst);
+	return pn_skb_send(sk, skb, &dst);
+}
+
+static int pipe_snd_status(struct sock *sk, u8 type, u8 status, gfp_t priority)
+{
+	u8 data[4] = { type, PAD, PAD, status };
+
+	return pep_indicate(sk, PNS_PEP_STATUS_IND, PN_PEP_TYPE_COMMON,
+				data, 4, priority);
+}
+
+/* Send our RX flow control information to the sender.
+ * Socket must be locked. */
+static void pipe_grant_credits(struct sock *sk, gfp_t priority)
+{
+	struct pep_sock *pn = pep_sk(sk);
+
+	BUG_ON(sk->sk_state != TCP_ESTABLISHED);
+
+	switch (pn->rx_fc) {
+	case PN_LEGACY_FLOW_CONTROL: /* TODO */
+		break;
+	case PN_ONE_CREDIT_FLOW_CONTROL:
+		if (pipe_snd_status(sk, PN_PEP_IND_FLOW_CONTROL,
+					PEP_IND_READY, priority) == 0)
+			pn->rx_credits = 1;
+		break;
+	case PN_MULTI_CREDIT_FLOW_CONTROL:
+		if ((pn->rx_credits + CREDITS_THR) > CREDITS_MAX)
+			break;
+		if (pipe_snd_status(sk, PN_PEP_IND_ID_MCFC_GRANT_CREDITS,
+					CREDITS_MAX - pn->rx_credits,
+					priority) == 0)
+			pn->rx_credits = CREDITS_MAX;
+		break;
+	}
+}
+
+static int pipe_rcv_status(struct sock *sk, struct sk_buff *skb)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	struct pnpipehdr *hdr;
+	int wake = 0;
+
+	if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
+		return -EINVAL;
+
+	hdr = pnp_hdr(skb);
+	if (hdr->data[0] != PN_PEP_TYPE_COMMON) {
+		net_dbg_ratelimited("Phonet unknown PEP type: %u\n",
+				    (unsigned int)hdr->data[0]);
+		return -EOPNOTSUPP;
+	}
+
+	switch (hdr->data[1]) {
+	case PN_PEP_IND_FLOW_CONTROL:
+		switch (pn->tx_fc) {
+		case PN_LEGACY_FLOW_CONTROL:
+			switch (hdr->data[4]) {
+			case PEP_IND_BUSY:
+				atomic_set(&pn->tx_credits, 0);
+				break;
+			case PEP_IND_READY:
+				atomic_set(&pn->tx_credits, wake = 1);
+				break;
+			}
+			break;
+		case PN_ONE_CREDIT_FLOW_CONTROL:
+			if (hdr->data[4] == PEP_IND_READY)
+				atomic_set(&pn->tx_credits, wake = 1);
+			break;
+		}
+		break;
+
+	case PN_PEP_IND_ID_MCFC_GRANT_CREDITS:
+		if (pn->tx_fc != PN_MULTI_CREDIT_FLOW_CONTROL)
+			break;
+		atomic_add(wake = hdr->data[4], &pn->tx_credits);
+		break;
+
+	default:
+		net_dbg_ratelimited("Phonet unknown PEP indication: %u\n",
+				    (unsigned int)hdr->data[1]);
+		return -EOPNOTSUPP;
+	}
+	if (wake)
+		sk->sk_write_space(sk);
+	return 0;
+}
+
+static int pipe_rcv_created(struct sock *sk, struct sk_buff *skb)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	struct pnpipehdr *hdr = pnp_hdr(skb);
+	u8 n_sb = hdr->data[0];
+
+	pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
+	__skb_pull(skb, sizeof(*hdr));
+	while (n_sb > 0) {
+		u8 type, buf[2], len = sizeof(buf);
+		u8 *data = pep_get_sb(skb, &type, &len, buf);
+
+		if (data == NULL)
+			return -EINVAL;
+		switch (type) {
+		case PN_PIPE_SB_NEGOTIATED_FC:
+			if (len < 2 || (data[0] | data[1]) > 3)
+				break;
+			pn->tx_fc = data[0] & 3;
+			pn->rx_fc = data[1] & 3;
+			break;
+		}
+		n_sb--;
+	}
+	return 0;
+}
+
+/* Queue an skb to a connected sock.
+ * Socket lock must be held. */
+static int pipe_do_rcv(struct sock *sk, struct sk_buff *skb)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	struct pnpipehdr *hdr = pnp_hdr(skb);
+	struct sk_buff_head *queue;
+	int err = 0;
+
+	BUG_ON(sk->sk_state == TCP_CLOSE_WAIT);
+
+	switch (hdr->message_id) {
+	case PNS_PEP_CONNECT_REQ:
+		pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_ATOMIC);
+		break;
+
+	case PNS_PEP_DISCONNECT_REQ:
+		pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
+		sk->sk_state = TCP_CLOSE_WAIT;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk->sk_state_change(sk);
+		break;
+
+	case PNS_PEP_ENABLE_REQ:
+		/* Wait for PNS_PIPE_(ENABLED|REDIRECTED)_IND */
+		pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
+		break;
+
+	case PNS_PEP_RESET_REQ:
+		switch (hdr->state_after_reset) {
+		case PN_PIPE_DISABLE:
+			pn->init_enable = 0;
+			break;
+		case PN_PIPE_ENABLE:
+			pn->init_enable = 1;
+			break;
+		default: /* not allowed to send an error here!? */
+			err = -EINVAL;
+			goto out;
+		}
+		/* fall through */
+	case PNS_PEP_DISABLE_REQ:
+		atomic_set(&pn->tx_credits, 0);
+		pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
+		break;
+
+	case PNS_PEP_CTRL_REQ:
+		if (skb_queue_len(&pn->ctrlreq_queue) >= PNPIPE_CTRLREQ_MAX) {
+			atomic_inc(&sk->sk_drops);
+			break;
+		}
+		__skb_pull(skb, 4);
+		queue = &pn->ctrlreq_queue;
+		goto queue;
+
+	case PNS_PIPE_ALIGNED_DATA:
+		__skb_pull(skb, 1);
+		/* fall through */
+	case PNS_PIPE_DATA:
+		__skb_pull(skb, 3); /* Pipe data header */
+		if (!pn_flow_safe(pn->rx_fc)) {
+			err = sock_queue_rcv_skb(sk, skb);
+			if (!err)
+				return NET_RX_SUCCESS;
+			err = -ENOBUFS;
+			break;
+		}
+
+		if (pn->rx_credits == 0) {
+			atomic_inc(&sk->sk_drops);
+			err = -ENOBUFS;
+			break;
+		}
+		pn->rx_credits--;
+		queue = &sk->sk_receive_queue;
+		goto queue;
+
+	case PNS_PEP_STATUS_IND:
+		pipe_rcv_status(sk, skb);
+		break;
+
+	case PNS_PIPE_REDIRECTED_IND:
+		err = pipe_rcv_created(sk, skb);
+		break;
+
+	case PNS_PIPE_CREATED_IND:
+		err = pipe_rcv_created(sk, skb);
+		if (err)
+			break;
+		/* fall through */
+	case PNS_PIPE_RESET_IND:
+		if (!pn->init_enable)
+			break;
+		/* fall through */
+	case PNS_PIPE_ENABLED_IND:
+		if (!pn_flow_safe(pn->tx_fc)) {
+			atomic_set(&pn->tx_credits, 1);
+			sk->sk_write_space(sk);
+		}
+		if (sk->sk_state == TCP_ESTABLISHED)
+			break; /* Nothing to do */
+		sk->sk_state = TCP_ESTABLISHED;
+		pipe_grant_credits(sk, GFP_ATOMIC);
+		break;
+
+	case PNS_PIPE_DISABLED_IND:
+		sk->sk_state = TCP_SYN_RECV;
+		pn->rx_credits = 0;
+		break;
+
+	default:
+		net_dbg_ratelimited("Phonet unknown PEP message: %u\n",
+				    hdr->message_id);
+		err = -EINVAL;
+	}
+out:
+	kfree_skb(skb);
+	return (err == -ENOBUFS) ? NET_RX_DROP : NET_RX_SUCCESS;
+
+queue:
+	skb->dev = NULL;
+	skb_set_owner_r(skb, sk);
+	skb_queue_tail(queue, skb);
+	if (!sock_flag(sk, SOCK_DEAD))
+		sk->sk_data_ready(sk);
+	return NET_RX_SUCCESS;
+}
+
+/* Destroy connected sock. */
+static void pipe_destruct(struct sock *sk)
+{
+	struct pep_sock *pn = pep_sk(sk);
+
+	skb_queue_purge(&sk->sk_receive_queue);
+	skb_queue_purge(&pn->ctrlreq_queue);
+}
+
+static u8 pipe_negotiate_fc(const u8 *fcs, unsigned int n)
+{
+	unsigned int i;
+	u8 final_fc = PN_NO_FLOW_CONTROL;
+
+	for (i = 0; i < n; i++) {
+		u8 fc = fcs[i];
+
+		if (fc > final_fc && fc < PN_MAX_FLOW_CONTROL)
+			final_fc = fc;
+	}
+	return final_fc;
+}
+
+static int pep_connresp_rcv(struct sock *sk, struct sk_buff *skb)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	struct pnpipehdr *hdr;
+	u8 n_sb;
+
+	if (!pskb_pull(skb, sizeof(*hdr) + 4))
+		return -EINVAL;
+
+	hdr = pnp_hdr(skb);
+	if (hdr->error_code != PN_PIPE_NO_ERROR)
+		return -ECONNREFUSED;
+
+	/* Parse sub-blocks */
+	n_sb = hdr->data[4];
+	while (n_sb > 0) {
+		u8 type, buf[6], len = sizeof(buf);
+		const u8 *data = pep_get_sb(skb, &type, &len, buf);
+
+		if (data == NULL)
+			return -EINVAL;
+
+		switch (type) {
+		case PN_PIPE_SB_REQUIRED_FC_TX:
+			if (len < 2 || len < data[0])
+				break;
+			pn->tx_fc = pipe_negotiate_fc(data + 2, len - 2);
+			break;
+
+		case PN_PIPE_SB_PREFERRED_FC_RX:
+			if (len < 2 || len < data[0])
+				break;
+			pn->rx_fc = pipe_negotiate_fc(data + 2, len - 2);
+			break;
+
+		}
+		n_sb--;
+	}
+
+	return pipe_handler_send_created_ind(sk);
+}
+
+static int pep_enableresp_rcv(struct sock *sk, struct sk_buff *skb)
+{
+	struct pnpipehdr *hdr = pnp_hdr(skb);
+
+	if (hdr->error_code != PN_PIPE_NO_ERROR)
+		return -ECONNREFUSED;
+
+	return pep_indicate(sk, PNS_PIPE_ENABLED_IND, 0 /* sub-blocks */,
+		NULL, 0, GFP_ATOMIC);
+
+}
+
+static void pipe_start_flow_control(struct sock *sk)
+{
+	struct pep_sock *pn = pep_sk(sk);
+
+	if (!pn_flow_safe(pn->tx_fc)) {
+		atomic_set(&pn->tx_credits, 1);
+		sk->sk_write_space(sk);
+	}
+	pipe_grant_credits(sk, GFP_ATOMIC);
+}
+
+/* Queue an skb to an actively connected sock.
+ * Socket lock must be held. */
+static int pipe_handler_do_rcv(struct sock *sk, struct sk_buff *skb)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	struct pnpipehdr *hdr = pnp_hdr(skb);
+	int err = NET_RX_SUCCESS;
+
+	switch (hdr->message_id) {
+	case PNS_PIPE_ALIGNED_DATA:
+		__skb_pull(skb, 1);
+		/* fall through */
+	case PNS_PIPE_DATA:
+		__skb_pull(skb, 3); /* Pipe data header */
+		if (!pn_flow_safe(pn->rx_fc)) {
+			err = sock_queue_rcv_skb(sk, skb);
+			if (!err)
+				return NET_RX_SUCCESS;
+			err = NET_RX_DROP;
+			break;
+		}
+
+		if (pn->rx_credits == 0) {
+			atomic_inc(&sk->sk_drops);
+			err = NET_RX_DROP;
+			break;
+		}
+		pn->rx_credits--;
+		skb->dev = NULL;
+		skb_set_owner_r(skb, sk);
+		skb_queue_tail(&sk->sk_receive_queue, skb);
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk->sk_data_ready(sk);
+		return NET_RX_SUCCESS;
+
+	case PNS_PEP_CONNECT_RESP:
+		if (sk->sk_state != TCP_SYN_SENT)
+			break;
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk->sk_state_change(sk);
+		if (pep_connresp_rcv(sk, skb)) {
+			sk->sk_state = TCP_CLOSE_WAIT;
+			break;
+		}
+		if (pn->init_enable == PN_PIPE_DISABLE)
+			sk->sk_state = TCP_SYN_RECV;
+		else {
+			sk->sk_state = TCP_ESTABLISHED;
+			pipe_start_flow_control(sk);
+		}
+		break;
+
+	case PNS_PEP_ENABLE_RESP:
+		if (sk->sk_state != TCP_SYN_SENT)
+			break;
+
+		if (pep_enableresp_rcv(sk, skb)) {
+			sk->sk_state = TCP_CLOSE_WAIT;
+			break;
+		}
+
+		sk->sk_state = TCP_ESTABLISHED;
+		pipe_start_flow_control(sk);
+		break;
+
+	case PNS_PEP_DISCONNECT_RESP:
+		/* sock should already be dead, nothing to do */
+		break;
+
+	case PNS_PEP_STATUS_IND:
+		pipe_rcv_status(sk, skb);
+		break;
+	}
+	kfree_skb(skb);
+	return err;
+}
+
+/* Listening sock must be locked */
+static struct sock *pep_find_pipe(const struct hlist_head *hlist,
+					const struct sockaddr_pn *dst,
+					u8 pipe_handle)
+{
+	struct sock *sknode;
+	u16 dobj = pn_sockaddr_get_object(dst);
+
+	sk_for_each(sknode, hlist) {
+		struct pep_sock *pnnode = pep_sk(sknode);
+
+		/* Ports match, but addresses might not: */
+		if (pnnode->pn_sk.sobject != dobj)
+			continue;
+		if (pnnode->pipe_handle != pipe_handle)
+			continue;
+		if (sknode->sk_state == TCP_CLOSE_WAIT)
+			continue;
+
+		sock_hold(sknode);
+		return sknode;
+	}
+	return NULL;
+}
+
+/*
+ * Deliver an skb to a listening sock.
+ * Socket lock must be held.
+ * We then queue the skb to the right connected sock (if any).
+ */
+static int pep_do_rcv(struct sock *sk, struct sk_buff *skb)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	struct sock *sknode;
+	struct pnpipehdr *hdr;
+	struct sockaddr_pn dst;
+	u8 pipe_handle;
+
+	if (!pskb_may_pull(skb, sizeof(*hdr)))
+		goto drop;
+
+	hdr = pnp_hdr(skb);
+	pipe_handle = hdr->pipe_handle;
+	if (pipe_handle == PN_PIPE_INVALID_HANDLE)
+		goto drop;
+
+	pn_skb_get_dst_sockaddr(skb, &dst);
+
+	/* Look for an existing pipe handle */
+	sknode = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
+	if (sknode)
+		return sk_receive_skb(sknode, skb, 1);
+
+	switch (hdr->message_id) {
+	case PNS_PEP_CONNECT_REQ:
+		if (sk->sk_state != TCP_LISTEN || sk_acceptq_is_full(sk)) {
+			pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE,
+					GFP_ATOMIC);
+			break;
+		}
+		skb_queue_head(&sk->sk_receive_queue, skb);
+		sk_acceptq_added(sk);
+		if (!sock_flag(sk, SOCK_DEAD))
+			sk->sk_data_ready(sk);
+		return NET_RX_SUCCESS;
+
+	case PNS_PEP_DISCONNECT_REQ:
+		pep_reply(sk, skb, PN_PIPE_NO_ERROR, NULL, 0, GFP_ATOMIC);
+		break;
+
+	case PNS_PEP_CTRL_REQ:
+		pep_ctrlreq_error(sk, skb, PN_PIPE_INVALID_HANDLE, GFP_ATOMIC);
+		break;
+
+	case PNS_PEP_RESET_REQ:
+	case PNS_PEP_ENABLE_REQ:
+	case PNS_PEP_DISABLE_REQ:
+		/* invalid handle is not even allowed here! */
+		break;
+
+	default:
+		if ((1 << sk->sk_state)
+				& ~(TCPF_CLOSE|TCPF_LISTEN|TCPF_CLOSE_WAIT))
+			/* actively connected socket */
+			return pipe_handler_do_rcv(sk, skb);
+	}
+drop:
+	kfree_skb(skb);
+	return NET_RX_SUCCESS;
+}
+
+static int pipe_do_remove(struct sock *sk)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	struct pnpipehdr *ph;
+	struct sk_buff *skb;
+
+	skb = pep_alloc_skb(sk, NULL, 0, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	ph = pnp_hdr(skb);
+	ph->utid = 0;
+	ph->message_id = PNS_PIPE_REMOVE_REQ;
+	ph->pipe_handle = pn->pipe_handle;
+	ph->data[0] = PAD;
+	return pn_skb_send(sk, skb, NULL);
+}
+
+/* associated socket ceases to exist */
+static void pep_sock_close(struct sock *sk, long timeout)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	int ifindex = 0;
+
+	sock_hold(sk); /* keep a reference after sk_common_release() */
+	sk_common_release(sk);
+
+	lock_sock(sk);
+	if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED)) {
+		if (sk->sk_backlog_rcv == pipe_do_rcv)
+			/* Forcefully remove dangling Phonet pipe */
+			pipe_do_remove(sk);
+		else
+			pipe_handler_request(sk, PNS_PEP_DISCONNECT_REQ, PAD,
+						NULL, 0);
+	}
+	sk->sk_state = TCP_CLOSE;
+
+	ifindex = pn->ifindex;
+	pn->ifindex = 0;
+	release_sock(sk);
+
+	if (ifindex)
+		gprs_detach(sk);
+	sock_put(sk);
+}
+
+static struct sock *pep_sock_accept(struct sock *sk, int flags, int *errp)
+{
+	struct pep_sock *pn = pep_sk(sk), *newpn;
+	struct sock *newsk = NULL;
+	struct sk_buff *skb;
+	struct pnpipehdr *hdr;
+	struct sockaddr_pn dst, src;
+	int err;
+	u16 peer_type;
+	u8 pipe_handle, enabled, n_sb;
+	u8 aligned = 0;
+
+	skb = skb_recv_datagram(sk, 0, flags & O_NONBLOCK, errp);
+	if (!skb)
+		return NULL;
+
+	lock_sock(sk);
+	if (sk->sk_state != TCP_LISTEN) {
+		err = -EINVAL;
+		goto drop;
+	}
+	sk_acceptq_removed(sk);
+
+	err = -EPROTO;
+	if (!pskb_may_pull(skb, sizeof(*hdr) + 4))
+		goto drop;
+
+	hdr = pnp_hdr(skb);
+	pipe_handle = hdr->pipe_handle;
+	switch (hdr->state_after_connect) {
+	case PN_PIPE_DISABLE:
+		enabled = 0;
+		break;
+	case PN_PIPE_ENABLE:
+		enabled = 1;
+		break;
+	default:
+		pep_reject_conn(sk, skb, PN_PIPE_ERR_INVALID_PARAM,
+				GFP_KERNEL);
+		goto drop;
+	}
+	peer_type = hdr->other_pep_type << 8;
+
+	/* Parse sub-blocks (options) */
+	n_sb = hdr->data[4];
+	while (n_sb > 0) {
+		u8 type, buf[1], len = sizeof(buf);
+		const u8 *data = pep_get_sb(skb, &type, &len, buf);
+
+		if (data == NULL)
+			goto drop;
+		switch (type) {
+		case PN_PIPE_SB_CONNECT_REQ_PEP_SUB_TYPE:
+			if (len < 1)
+				goto drop;
+			peer_type = (peer_type & 0xff00) | data[0];
+			break;
+		case PN_PIPE_SB_ALIGNED_DATA:
+			aligned = data[0] != 0;
+			break;
+		}
+		n_sb--;
+	}
+
+	/* Check for duplicate pipe handle */
+	newsk = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
+	if (unlikely(newsk)) {
+		__sock_put(newsk);
+		newsk = NULL;
+		pep_reject_conn(sk, skb, PN_PIPE_ERR_PEP_IN_USE, GFP_KERNEL);
+		goto drop;
+	}
+
+	/* Create a new to-be-accepted sock */
+	newsk = sk_alloc(sock_net(sk), PF_PHONET, GFP_KERNEL, sk->sk_prot);
+	if (!newsk) {
+		pep_reject_conn(sk, skb, PN_PIPE_ERR_OVERLOAD, GFP_KERNEL);
+		err = -ENOBUFS;
+		goto drop;
+	}
+
+	sock_init_data(NULL, newsk);
+	newsk->sk_state = TCP_SYN_RECV;
+	newsk->sk_backlog_rcv = pipe_do_rcv;
+	newsk->sk_protocol = sk->sk_protocol;
+	newsk->sk_destruct = pipe_destruct;
+
+	newpn = pep_sk(newsk);
+	pn_skb_get_dst_sockaddr(skb, &dst);
+	pn_skb_get_src_sockaddr(skb, &src);
+	newpn->pn_sk.sobject = pn_sockaddr_get_object(&dst);
+	newpn->pn_sk.dobject = pn_sockaddr_get_object(&src);
+	newpn->pn_sk.resource = pn_sockaddr_get_resource(&dst);
+	sock_hold(sk);
+	newpn->listener = sk;
+	skb_queue_head_init(&newpn->ctrlreq_queue);
+	newpn->pipe_handle = pipe_handle;
+	atomic_set(&newpn->tx_credits, 0);
+	newpn->ifindex = 0;
+	newpn->peer_type = peer_type;
+	newpn->rx_credits = 0;
+	newpn->rx_fc = newpn->tx_fc = PN_LEGACY_FLOW_CONTROL;
+	newpn->init_enable = enabled;
+	newpn->aligned = aligned;
+
+	err = pep_accept_conn(newsk, skb);
+	if (err) {
+		sock_put(newsk);
+		newsk = NULL;
+		goto drop;
+	}
+	sk_add_node(newsk, &pn->hlist);
+drop:
+	release_sock(sk);
+	kfree_skb(skb);
+	*errp = err;
+	return newsk;
+}
+
+static int pep_sock_connect(struct sock *sk, struct sockaddr *addr, int len)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	int err;
+	u8 data[4] = { 0 /* sub-blocks */, PAD, PAD, PAD };
+
+	if (pn->pipe_handle == PN_PIPE_INVALID_HANDLE)
+		pn->pipe_handle = 1; /* anything but INVALID_HANDLE */
+
+	err = pipe_handler_request(sk, PNS_PEP_CONNECT_REQ,
+				pn->init_enable, data, 4);
+	if (err) {
+		pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
+		return err;
+	}
+
+	sk->sk_state = TCP_SYN_SENT;
+
+	return 0;
+}
+
+static int pep_sock_enable(struct sock *sk, struct sockaddr *addr, int len)
+{
+	int err;
+
+	err = pipe_handler_request(sk, PNS_PEP_ENABLE_REQ, PAD,
+				NULL, 0);
+	if (err)
+		return err;
+
+	sk->sk_state = TCP_SYN_SENT;
+
+	return 0;
+}
+
+static int pep_ioctl(struct sock *sk, int cmd, unsigned long arg)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	int answ;
+	int ret = -ENOIOCTLCMD;
+
+	switch (cmd) {
+	case SIOCINQ:
+		if (sk->sk_state == TCP_LISTEN) {
+			ret = -EINVAL;
+			break;
+		}
+
+		lock_sock(sk);
+		if (sock_flag(sk, SOCK_URGINLINE) &&
+		    !skb_queue_empty(&pn->ctrlreq_queue))
+			answ = skb_peek(&pn->ctrlreq_queue)->len;
+		else if (!skb_queue_empty(&sk->sk_receive_queue))
+			answ = skb_peek(&sk->sk_receive_queue)->len;
+		else
+			answ = 0;
+		release_sock(sk);
+		ret = put_user(answ, (int __user *)arg);
+		break;
+
+	case SIOCPNENABLEPIPE:
+		lock_sock(sk);
+		if (sk->sk_state == TCP_SYN_SENT)
+			ret =  -EBUSY;
+		else if (sk->sk_state == TCP_ESTABLISHED)
+			ret = -EISCONN;
+		else
+			ret = pep_sock_enable(sk, NULL, 0);
+		release_sock(sk);
+		break;
+	}
+
+	return ret;
+}
+
+static int pep_init(struct sock *sk)
+{
+	struct pep_sock *pn = pep_sk(sk);
+
+	sk->sk_destruct = pipe_destruct;
+	INIT_HLIST_HEAD(&pn->hlist);
+	pn->listener = NULL;
+	skb_queue_head_init(&pn->ctrlreq_queue);
+	atomic_set(&pn->tx_credits, 0);
+	pn->ifindex = 0;
+	pn->peer_type = 0;
+	pn->pipe_handle = PN_PIPE_INVALID_HANDLE;
+	pn->rx_credits = 0;
+	pn->rx_fc = pn->tx_fc = PN_LEGACY_FLOW_CONTROL;
+	pn->init_enable = 1;
+	pn->aligned = 0;
+	return 0;
+}
+
+static int pep_setsockopt(struct sock *sk, int level, int optname,
+				char __user *optval, unsigned int optlen)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	int val = 0, err = 0;
+
+	if (level != SOL_PNPIPE)
+		return -ENOPROTOOPT;
+	if (optlen >= sizeof(int)) {
+		if (get_user(val, (int __user *) optval))
+			return -EFAULT;
+	}
+
+	lock_sock(sk);
+	switch (optname) {
+	case PNPIPE_ENCAP:
+		if (val && val != PNPIPE_ENCAP_IP) {
+			err = -EINVAL;
+			break;
+		}
+		if (!pn->ifindex == !val)
+			break; /* Nothing to do! */
+		if (!capable(CAP_NET_ADMIN)) {
+			err = -EPERM;
+			break;
+		}
+		if (val) {
+			release_sock(sk);
+			err = gprs_attach(sk);
+			if (err > 0) {
+				pn->ifindex = err;
+				err = 0;
+			}
+		} else {
+			pn->ifindex = 0;
+			release_sock(sk);
+			gprs_detach(sk);
+			err = 0;
+		}
+		goto out_norel;
+
+	case PNPIPE_HANDLE:
+		if ((sk->sk_state == TCP_CLOSE) &&
+			(val >= 0) && (val < PN_PIPE_INVALID_HANDLE))
+			pn->pipe_handle = val;
+		else
+			err = -EINVAL;
+		break;
+
+	case PNPIPE_INITSTATE:
+		pn->init_enable = !!val;
+		break;
+
+	default:
+		err = -ENOPROTOOPT;
+	}
+	release_sock(sk);
+
+out_norel:
+	return err;
+}
+
+static int pep_getsockopt(struct sock *sk, int level, int optname,
+				char __user *optval, int __user *optlen)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	int len, val;
+
+	if (level != SOL_PNPIPE)
+		return -ENOPROTOOPT;
+	if (get_user(len, optlen))
+		return -EFAULT;
+
+	switch (optname) {
+	case PNPIPE_ENCAP:
+		val = pn->ifindex ? PNPIPE_ENCAP_IP : PNPIPE_ENCAP_NONE;
+		break;
+
+	case PNPIPE_IFINDEX:
+		val = pn->ifindex;
+		break;
+
+	case PNPIPE_HANDLE:
+		val = pn->pipe_handle;
+		if (val == PN_PIPE_INVALID_HANDLE)
+			return -EINVAL;
+		break;
+
+	case PNPIPE_INITSTATE:
+		val = pn->init_enable;
+		break;
+
+	default:
+		return -ENOPROTOOPT;
+	}
+
+	len = min_t(unsigned int, sizeof(int), len);
+	if (put_user(len, optlen))
+		return -EFAULT;
+	if (put_user(val, (int __user *) optval))
+		return -EFAULT;
+	return 0;
+}
+
+static int pipe_skb_send(struct sock *sk, struct sk_buff *skb)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	struct pnpipehdr *ph;
+	int err;
+
+	if (pn_flow_safe(pn->tx_fc) &&
+	    !atomic_add_unless(&pn->tx_credits, -1, 0)) {
+		kfree_skb(skb);
+		return -ENOBUFS;
+	}
+
+	skb_push(skb, 3 + pn->aligned);
+	skb_reset_transport_header(skb);
+	ph = pnp_hdr(skb);
+	ph->utid = 0;
+	if (pn->aligned) {
+		ph->message_id = PNS_PIPE_ALIGNED_DATA;
+		ph->data[0] = 0; /* padding */
+	} else
+		ph->message_id = PNS_PIPE_DATA;
+	ph->pipe_handle = pn->pipe_handle;
+	err = pn_skb_send(sk, skb, NULL);
+
+	if (err && pn_flow_safe(pn->tx_fc))
+		atomic_inc(&pn->tx_credits);
+	return err;
+
+}
+
+static int pep_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	struct sk_buff *skb;
+	long timeo;
+	int flags = msg->msg_flags;
+	int err, done;
+
+	if (len > USHRT_MAX)
+		return -EMSGSIZE;
+
+	if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL|
+				MSG_CMSG_COMPAT)) ||
+			!(msg->msg_flags & MSG_EOR))
+		return -EOPNOTSUPP;
+
+	skb = sock_alloc_send_skb(sk, MAX_PNPIPE_HEADER + len,
+					flags & MSG_DONTWAIT, &err);
+	if (!skb)
+		return err;
+
+	skb_reserve(skb, MAX_PHONET_HEADER + 3 + pn->aligned);
+	err = memcpy_from_msg(skb_put(skb, len), msg, len);
+	if (err < 0)
+		goto outfree;
+
+	lock_sock(sk);
+	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
+	if ((1 << sk->sk_state) & (TCPF_LISTEN|TCPF_CLOSE)) {
+		err = -ENOTCONN;
+		goto out;
+	}
+	if (sk->sk_state != TCP_ESTABLISHED) {
+		/* Wait until the pipe gets to enabled state */
+disabled:
+		err = sk_stream_wait_connect(sk, &timeo);
+		if (err)
+			goto out;
+
+		if (sk->sk_state == TCP_CLOSE_WAIT) {
+			err = -ECONNRESET;
+			goto out;
+		}
+	}
+	BUG_ON(sk->sk_state != TCP_ESTABLISHED);
+
+	/* Wait until flow control allows TX */
+	done = atomic_read(&pn->tx_credits);
+	while (!done) {
+		DEFINE_WAIT(wait);
+
+		if (!timeo) {
+			err = -EAGAIN;
+			goto out;
+		}
+		if (signal_pending(current)) {
+			err = sock_intr_errno(timeo);
+			goto out;
+		}
+
+		prepare_to_wait(sk_sleep(sk), &wait,
+				TASK_INTERRUPTIBLE);
+		done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
+		finish_wait(sk_sleep(sk), &wait);
+
+		if (sk->sk_state != TCP_ESTABLISHED)
+			goto disabled;
+	}
+
+	err = pipe_skb_send(sk, skb);
+	if (err >= 0)
+		err = len; /* success! */
+	skb = NULL;
+out:
+	release_sock(sk);
+outfree:
+	kfree_skb(skb);
+	return err;
+}
+
+int pep_writeable(struct sock *sk)
+{
+	struct pep_sock *pn = pep_sk(sk);
+
+	return atomic_read(&pn->tx_credits);
+}
+
+int pep_write(struct sock *sk, struct sk_buff *skb)
+{
+	struct sk_buff *rskb, *fs;
+	int flen = 0;
+
+	if (pep_sk(sk)->aligned)
+		return pipe_skb_send(sk, skb);
+
+	rskb = alloc_skb(MAX_PNPIPE_HEADER, GFP_ATOMIC);
+	if (!rskb) {
+		kfree_skb(skb);
+		return -ENOMEM;
+	}
+	skb_shinfo(rskb)->frag_list = skb;
+	rskb->len += skb->len;
+	rskb->data_len += rskb->len;
+	rskb->truesize += rskb->len;
+
+	/* Avoid nested fragments */
+	skb_walk_frags(skb, fs)
+		flen += fs->len;
+	skb->next = skb_shinfo(skb)->frag_list;
+	skb_frag_list_init(skb);
+	skb->len -= flen;
+	skb->data_len -= flen;
+	skb->truesize -= flen;
+
+	skb_reserve(rskb, MAX_PHONET_HEADER + 3);
+	return pipe_skb_send(sk, rskb);
+}
+
+struct sk_buff *pep_read(struct sock *sk)
+{
+	struct sk_buff *skb = skb_dequeue(&sk->sk_receive_queue);
+
+	if (sk->sk_state == TCP_ESTABLISHED)
+		pipe_grant_credits(sk, GFP_ATOMIC);
+	return skb;
+}
+
+static int pep_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
+		       int noblock, int flags, int *addr_len)
+{
+	struct sk_buff *skb;
+	int err;
+
+	if (flags & ~(MSG_OOB|MSG_PEEK|MSG_TRUNC|MSG_DONTWAIT|MSG_WAITALL|
+			MSG_NOSIGNAL|MSG_CMSG_COMPAT))
+		return -EOPNOTSUPP;
+
+	if (unlikely(1 << sk->sk_state & (TCPF_LISTEN | TCPF_CLOSE)))
+		return -ENOTCONN;
+
+	if ((flags & MSG_OOB) || sock_flag(sk, SOCK_URGINLINE)) {
+		/* Dequeue and acknowledge control request */
+		struct pep_sock *pn = pep_sk(sk);
+
+		if (flags & MSG_PEEK)
+			return -EOPNOTSUPP;
+		skb = skb_dequeue(&pn->ctrlreq_queue);
+		if (skb) {
+			pep_ctrlreq_error(sk, skb, PN_PIPE_NO_ERROR,
+						GFP_KERNEL);
+			msg->msg_flags |= MSG_OOB;
+			goto copy;
+		}
+		if (flags & MSG_OOB)
+			return -EINVAL;
+	}
+
+	skb = skb_recv_datagram(sk, flags, noblock, &err);
+	lock_sock(sk);
+	if (skb == NULL) {
+		if (err == -ENOTCONN && sk->sk_state == TCP_CLOSE_WAIT)
+			err = -ECONNRESET;
+		release_sock(sk);
+		return err;
+	}
+
+	if (sk->sk_state == TCP_ESTABLISHED)
+		pipe_grant_credits(sk, GFP_KERNEL);
+	release_sock(sk);
+copy:
+	msg->msg_flags |= MSG_EOR;
+	if (skb->len > len)
+		msg->msg_flags |= MSG_TRUNC;
+	else
+		len = skb->len;
+
+	err = skb_copy_datagram_msg(skb, 0, msg, len);
+	if (!err)
+		err = (flags & MSG_TRUNC) ? skb->len : len;
+
+	skb_free_datagram(sk, skb);
+	return err;
+}
+
+static void pep_sock_unhash(struct sock *sk)
+{
+	struct pep_sock *pn = pep_sk(sk);
+	struct sock *skparent = NULL;
+
+	lock_sock(sk);
+
+	if (pn->listener != NULL) {
+		skparent = pn->listener;
+		pn->listener = NULL;
+		release_sock(sk);
+
+		pn = pep_sk(skparent);
+		lock_sock(skparent);
+		sk_del_node_init(sk);
+		sk = skparent;
+	}
+
+	/* Unhash a listening sock only when it is closed
+	 * and all of its active connected pipes are closed. */
+	if (hlist_empty(&pn->hlist))
+		pn_sock_unhash(&pn->pn_sk.sk);
+	release_sock(sk);
+
+	if (skparent)
+		sock_put(skparent);
+}
+
+static struct proto pep_proto = {
+	.close		= pep_sock_close,
+	.accept		= pep_sock_accept,
+	.connect	= pep_sock_connect,
+	.ioctl		= pep_ioctl,
+	.init		= pep_init,
+	.setsockopt	= pep_setsockopt,
+	.getsockopt	= pep_getsockopt,
+	.sendmsg	= pep_sendmsg,
+	.recvmsg	= pep_recvmsg,
+	.backlog_rcv	= pep_do_rcv,
+	.hash		= pn_sock_hash,
+	.unhash		= pep_sock_unhash,
+	.get_port	= pn_sock_get_port,
+	.obj_size	= sizeof(struct pep_sock),
+	.owner		= THIS_MODULE,
+	.name		= "PNPIPE",
+};
+
+static struct phonet_protocol pep_pn_proto = {
+	.ops		= &phonet_stream_ops,
+	.prot		= &pep_proto,
+	.sock_type	= SOCK_SEQPACKET,
+};
+
+static int __init pep_register(void)
+{
+	return phonet_proto_register(PN_PROTO_PIPE, &pep_pn_proto);
+}
+
+static void __exit pep_unregister(void)
+{
+	phonet_proto_unregister(PN_PROTO_PIPE, &pep_pn_proto);
+}
+
+module_init(pep_register);
+module_exit(pep_unregister);
+MODULE_AUTHOR("Remi Denis-Courmont, Nokia");
+MODULE_DESCRIPTION("Phonet pipe protocol");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO(PF_PHONET, PN_PROTO_PIPE);