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linux/net/phonet/pep.c

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/*
* 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) {
LIMIT_NETDEBUG(KERN_DEBUG"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:
LIMIT_NETDEBUG(KERN_DEBUG"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:
LIMIT_NETDEBUG(KERN_DEBUG"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);
err = skb->len;
skb_queue_tail(queue, skb);
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_data_ready(sk, err);
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);
err = skb->len;
skb_queue_tail(&sk->sk_receive_queue, skb);
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_data_ready(sk, err);
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 hlist_node *node;
struct sock *sknode;
u16 dobj = pn_sockaddr_get_object(dst);
sk_for_each(sknode, node, 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, 0);
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 kiocb *iocb, 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_fromiovec(skb_put(skb, len), msg->msg_iov, 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 kiocb *iocb, 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_iovec(skb, 0, msg->msg_iov, 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);
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