linux/net/phonet/socket.c
Rémi Denis-Courmont 297edb6003 Phonet: support active connection without pipe controller on modem
This provides support for newer ISI modems with no need for the
earlier experimental compile-time alternative choice. With this,
we can now use the same kernel and userspace with both types of
modems.

This also avoids confusing two different and incompatible state
machines, actively connected vs accepted sockets, and adds
connection response error handling (processing "SYN/RST" of sorts).

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-09 11:59:33 -08:00

829 lines
18 KiB
C

/*
* File: socket.c
*
* Phonet sockets
*
* Copyright (C) 2008 Nokia Corporation.
*
* Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
* Original author: Sakari Ailus <sakari.ailus@nokia.com>
*
* 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/gfp.h>
#include <linux/kernel.h>
#include <linux/net.h>
#include <linux/poll.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <linux/phonet.h>
#include <net/phonet/phonet.h>
#include <net/phonet/pep.h>
#include <net/phonet/pn_dev.h>
static int pn_socket_release(struct socket *sock)
{
struct sock *sk = sock->sk;
if (sk) {
sock->sk = NULL;
sk->sk_prot->close(sk, 0);
}
return 0;
}
#define PN_HASHSIZE 16
#define PN_HASHMASK (PN_HASHSIZE-1)
static struct {
struct hlist_head hlist[PN_HASHSIZE];
spinlock_t lock;
} pnsocks;
void __init pn_sock_init(void)
{
unsigned i;
for (i = 0; i < PN_HASHSIZE; i++)
INIT_HLIST_HEAD(pnsocks.hlist + i);
spin_lock_init(&pnsocks.lock);
}
static struct hlist_head *pn_hash_list(u16 obj)
{
return pnsocks.hlist + (obj & PN_HASHMASK);
}
/*
* Find address based on socket address, match only certain fields.
* Also grab sock if it was found. Remember to sock_put it later.
*/
struct sock *pn_find_sock_by_sa(struct net *net, const struct sockaddr_pn *spn)
{
struct hlist_node *node;
struct sock *sknode;
struct sock *rval = NULL;
u16 obj = pn_sockaddr_get_object(spn);
u8 res = spn->spn_resource;
struct hlist_head *hlist = pn_hash_list(obj);
spin_lock_bh(&pnsocks.lock);
sk_for_each(sknode, node, hlist) {
struct pn_sock *pn = pn_sk(sknode);
BUG_ON(!pn->sobject); /* unbound socket */
if (!net_eq(sock_net(sknode), net))
continue;
if (pn_port(obj)) {
/* Look up socket by port */
if (pn_port(pn->sobject) != pn_port(obj))
continue;
} else {
/* If port is zero, look up by resource */
if (pn->resource != res)
continue;
}
if (pn_addr(pn->sobject) &&
pn_addr(pn->sobject) != pn_addr(obj))
continue;
rval = sknode;
sock_hold(sknode);
break;
}
spin_unlock_bh(&pnsocks.lock);
return rval;
}
/* Deliver a broadcast packet (only in bottom-half) */
void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
{
struct hlist_head *hlist = pnsocks.hlist;
unsigned h;
spin_lock(&pnsocks.lock);
for (h = 0; h < PN_HASHSIZE; h++) {
struct hlist_node *node;
struct sock *sknode;
sk_for_each(sknode, node, hlist) {
struct sk_buff *clone;
if (!net_eq(sock_net(sknode), net))
continue;
if (!sock_flag(sknode, SOCK_BROADCAST))
continue;
clone = skb_clone(skb, GFP_ATOMIC);
if (clone) {
sock_hold(sknode);
sk_receive_skb(sknode, clone, 0);
}
}
hlist++;
}
spin_unlock(&pnsocks.lock);
}
void pn_sock_hash(struct sock *sk)
{
struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
spin_lock_bh(&pnsocks.lock);
sk_add_node(sk, hlist);
spin_unlock_bh(&pnsocks.lock);
}
EXPORT_SYMBOL(pn_sock_hash);
void pn_sock_unhash(struct sock *sk)
{
spin_lock_bh(&pnsocks.lock);
sk_del_node_init(sk);
spin_unlock_bh(&pnsocks.lock);
pn_sock_unbind_all_res(sk);
}
EXPORT_SYMBOL(pn_sock_unhash);
static DEFINE_MUTEX(port_mutex);
static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
{
struct sock *sk = sock->sk;
struct pn_sock *pn = pn_sk(sk);
struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
int err;
u16 handle;
u8 saddr;
if (sk->sk_prot->bind)
return sk->sk_prot->bind(sk, addr, len);
if (len < sizeof(struct sockaddr_pn))
return -EINVAL;
if (spn->spn_family != AF_PHONET)
return -EAFNOSUPPORT;
handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
saddr = pn_addr(handle);
if (saddr && phonet_address_lookup(sock_net(sk), saddr))
return -EADDRNOTAVAIL;
lock_sock(sk);
if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
err = -EINVAL; /* attempt to rebind */
goto out;
}
WARN_ON(sk_hashed(sk));
mutex_lock(&port_mutex);
err = sk->sk_prot->get_port(sk, pn_port(handle));
if (err)
goto out_port;
/* get_port() sets the port, bind() sets the address if applicable */
pn->sobject = pn_object(saddr, pn_port(pn->sobject));
pn->resource = spn->spn_resource;
/* Enable RX on the socket */
sk->sk_prot->hash(sk);
out_port:
mutex_unlock(&port_mutex);
out:
release_sock(sk);
return err;
}
static int pn_socket_autobind(struct socket *sock)
{
struct sockaddr_pn sa;
int err;
memset(&sa, 0, sizeof(sa));
sa.spn_family = AF_PHONET;
err = pn_socket_bind(sock, (struct sockaddr *)&sa,
sizeof(struct sockaddr_pn));
if (err != -EINVAL)
return err;
BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
return 0; /* socket was already bound */
}
static int pn_socket_connect(struct socket *sock, struct sockaddr *addr,
int len, int flags)
{
struct sock *sk = sock->sk;
struct pn_sock *pn = pn_sk(sk);
struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
struct task_struct *tsk = current;
long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
int err;
if (pn_socket_autobind(sock))
return -ENOBUFS;
if (len < sizeof(struct sockaddr_pn))
return -EINVAL;
if (spn->spn_family != AF_PHONET)
return -EAFNOSUPPORT;
lock_sock(sk);
switch (sock->state) {
case SS_UNCONNECTED:
if (sk->sk_state != TCP_CLOSE) {
err = -EISCONN;
goto out;
}
break;
case SS_CONNECTING:
err = -EALREADY;
goto out;
default:
err = -EISCONN;
goto out;
}
pn->dobject = pn_sockaddr_get_object(spn);
pn->resource = pn_sockaddr_get_resource(spn);
sock->state = SS_CONNECTING;
err = sk->sk_prot->connect(sk, addr, len);
if (err) {
sock->state = SS_UNCONNECTED;
pn->dobject = 0;
goto out;
}
while (sk->sk_state == TCP_SYN_SENT) {
DEFINE_WAIT(wait);
if (!timeo) {
err = -EINPROGRESS;
goto out;
}
if (signal_pending(tsk)) {
err = sock_intr_errno(timeo);
goto out;
}
prepare_to_wait_exclusive(sk_sleep(sk), &wait,
TASK_INTERRUPTIBLE);
release_sock(sk);
timeo = schedule_timeout(timeo);
lock_sock(sk);
finish_wait(sk_sleep(sk), &wait);
}
if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED))
err = 0;
else if (sk->sk_state == TCP_CLOSE_WAIT)
err = -ECONNRESET;
else
err = -ECONNREFUSED;
sock->state = err ? SS_UNCONNECTED : SS_CONNECTED;
out:
release_sock(sk);
return err;
}
static int pn_socket_accept(struct socket *sock, struct socket *newsock,
int flags)
{
struct sock *sk = sock->sk;
struct sock *newsk;
int err;
if (unlikely(sk->sk_state != TCP_LISTEN))
return -EINVAL;
newsk = sk->sk_prot->accept(sk, flags, &err);
if (!newsk)
return err;
lock_sock(newsk);
sock_graft(newsk, newsock);
newsock->state = SS_CONNECTED;
release_sock(newsk);
return 0;
}
static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
int *sockaddr_len, int peer)
{
struct sock *sk = sock->sk;
struct pn_sock *pn = pn_sk(sk);
memset(addr, 0, sizeof(struct sockaddr_pn));
addr->sa_family = AF_PHONET;
if (!peer) /* Race with bind() here is userland's problem. */
pn_sockaddr_set_object((struct sockaddr_pn *)addr,
pn->sobject);
*sockaddr_len = sizeof(struct sockaddr_pn);
return 0;
}
static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
poll_table *wait)
{
struct sock *sk = sock->sk;
struct pep_sock *pn = pep_sk(sk);
unsigned int mask = 0;
poll_wait(file, sk_sleep(sk), wait);
if (sk->sk_state == TCP_CLOSE)
return POLLERR;
if (!skb_queue_empty(&sk->sk_receive_queue))
mask |= POLLIN | POLLRDNORM;
if (!skb_queue_empty(&pn->ctrlreq_queue))
mask |= POLLPRI;
if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
return POLLHUP;
if (sk->sk_state == TCP_ESTABLISHED &&
atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
atomic_read(&pn->tx_credits))
mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
return mask;
}
static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
unsigned long arg)
{
struct sock *sk = sock->sk;
struct pn_sock *pn = pn_sk(sk);
if (cmd == SIOCPNGETOBJECT) {
struct net_device *dev;
u16 handle;
u8 saddr;
if (get_user(handle, (__u16 __user *)arg))
return -EFAULT;
lock_sock(sk);
if (sk->sk_bound_dev_if)
dev = dev_get_by_index(sock_net(sk),
sk->sk_bound_dev_if);
else
dev = phonet_device_get(sock_net(sk));
if (dev && (dev->flags & IFF_UP))
saddr = phonet_address_get(dev, pn_addr(handle));
else
saddr = PN_NO_ADDR;
release_sock(sk);
if (dev)
dev_put(dev);
if (saddr == PN_NO_ADDR)
return -EHOSTUNREACH;
handle = pn_object(saddr, pn_port(pn->sobject));
return put_user(handle, (__u16 __user *)arg);
}
return sk->sk_prot->ioctl(sk, cmd, arg);
}
static int pn_socket_listen(struct socket *sock, int backlog)
{
struct sock *sk = sock->sk;
int err = 0;
if (pn_socket_autobind(sock))
return -ENOBUFS;
lock_sock(sk);
if (sock->state != SS_UNCONNECTED) {
err = -EINVAL;
goto out;
}
if (sk->sk_state != TCP_LISTEN) {
sk->sk_state = TCP_LISTEN;
sk->sk_ack_backlog = 0;
}
sk->sk_max_ack_backlog = backlog;
out:
release_sock(sk);
return err;
}
static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *m, size_t total_len)
{
struct sock *sk = sock->sk;
if (pn_socket_autobind(sock))
return -EAGAIN;
return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
}
const struct proto_ops phonet_dgram_ops = {
.family = AF_PHONET,
.owner = THIS_MODULE,
.release = pn_socket_release,
.bind = pn_socket_bind,
.connect = sock_no_connect,
.socketpair = sock_no_socketpair,
.accept = sock_no_accept,
.getname = pn_socket_getname,
.poll = datagram_poll,
.ioctl = pn_socket_ioctl,
.listen = sock_no_listen,
.shutdown = sock_no_shutdown,
.setsockopt = sock_no_setsockopt,
.getsockopt = sock_no_getsockopt,
#ifdef CONFIG_COMPAT
.compat_setsockopt = sock_no_setsockopt,
.compat_getsockopt = sock_no_getsockopt,
#endif
.sendmsg = pn_socket_sendmsg,
.recvmsg = sock_common_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
};
const struct proto_ops phonet_stream_ops = {
.family = AF_PHONET,
.owner = THIS_MODULE,
.release = pn_socket_release,
.bind = pn_socket_bind,
.connect = pn_socket_connect,
.socketpair = sock_no_socketpair,
.accept = pn_socket_accept,
.getname = pn_socket_getname,
.poll = pn_socket_poll,
.ioctl = pn_socket_ioctl,
.listen = pn_socket_listen,
.shutdown = sock_no_shutdown,
.setsockopt = sock_common_setsockopt,
.getsockopt = sock_common_getsockopt,
#ifdef CONFIG_COMPAT
.compat_setsockopt = compat_sock_common_setsockopt,
.compat_getsockopt = compat_sock_common_getsockopt,
#endif
.sendmsg = pn_socket_sendmsg,
.recvmsg = sock_common_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
};
EXPORT_SYMBOL(phonet_stream_ops);
/* allocate port for a socket */
int pn_sock_get_port(struct sock *sk, unsigned short sport)
{
static int port_cur;
struct net *net = sock_net(sk);
struct pn_sock *pn = pn_sk(sk);
struct sockaddr_pn try_sa;
struct sock *tmpsk;
memset(&try_sa, 0, sizeof(struct sockaddr_pn));
try_sa.spn_family = AF_PHONET;
WARN_ON(!mutex_is_locked(&port_mutex));
if (!sport) {
/* search free port */
int port, pmin, pmax;
phonet_get_local_port_range(&pmin, &pmax);
for (port = pmin; port <= pmax; port++) {
port_cur++;
if (port_cur < pmin || port_cur > pmax)
port_cur = pmin;
pn_sockaddr_set_port(&try_sa, port_cur);
tmpsk = pn_find_sock_by_sa(net, &try_sa);
if (tmpsk == NULL) {
sport = port_cur;
goto found;
} else
sock_put(tmpsk);
}
} else {
/* try to find specific port */
pn_sockaddr_set_port(&try_sa, sport);
tmpsk = pn_find_sock_by_sa(net, &try_sa);
if (tmpsk == NULL)
/* No sock there! We can use that port... */
goto found;
else
sock_put(tmpsk);
}
/* the port must be in use already */
return -EADDRINUSE;
found:
pn->sobject = pn_object(pn_addr(pn->sobject), sport);
return 0;
}
EXPORT_SYMBOL(pn_sock_get_port);
#ifdef CONFIG_PROC_FS
static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
{
struct net *net = seq_file_net(seq);
struct hlist_head *hlist = pnsocks.hlist;
struct hlist_node *node;
struct sock *sknode;
unsigned h;
for (h = 0; h < PN_HASHSIZE; h++) {
sk_for_each(sknode, node, hlist) {
if (!net_eq(net, sock_net(sknode)))
continue;
if (!pos)
return sknode;
pos--;
}
hlist++;
}
return NULL;
}
static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
{
struct net *net = seq_file_net(seq);
do
sk = sk_next(sk);
while (sk && !net_eq(net, sock_net(sk)));
return sk;
}
static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(pnsocks.lock)
{
spin_lock_bh(&pnsocks.lock);
return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
}
static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct sock *sk;
if (v == SEQ_START_TOKEN)
sk = pn_sock_get_idx(seq, 0);
else
sk = pn_sock_get_next(seq, v);
(*pos)++;
return sk;
}
static void pn_sock_seq_stop(struct seq_file *seq, void *v)
__releases(pnsocks.lock)
{
spin_unlock_bh(&pnsocks.lock);
}
static int pn_sock_seq_show(struct seq_file *seq, void *v)
{
int len;
if (v == SEQ_START_TOKEN)
seq_printf(seq, "%s%n", "pt loc rem rs st tx_queue rx_queue "
" uid inode ref pointer drops", &len);
else {
struct sock *sk = v;
struct pn_sock *pn = pn_sk(sk);
seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
"%d %p %d%n",
sk->sk_protocol, pn->sobject, pn->dobject,
pn->resource, sk->sk_state,
sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
sock_i_uid(sk), sock_i_ino(sk),
atomic_read(&sk->sk_refcnt), sk,
atomic_read(&sk->sk_drops), &len);
}
seq_printf(seq, "%*s\n", 127 - len, "");
return 0;
}
static const struct seq_operations pn_sock_seq_ops = {
.start = pn_sock_seq_start,
.next = pn_sock_seq_next,
.stop = pn_sock_seq_stop,
.show = pn_sock_seq_show,
};
static int pn_sock_open(struct inode *inode, struct file *file)
{
return seq_open_net(inode, file, &pn_sock_seq_ops,
sizeof(struct seq_net_private));
}
const struct file_operations pn_sock_seq_fops = {
.owner = THIS_MODULE,
.open = pn_sock_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
#endif
static struct {
struct sock *sk[256];
} pnres;
/*
* Find and hold socket based on resource.
*/
struct sock *pn_find_sock_by_res(struct net *net, u8 res)
{
struct sock *sk;
if (!net_eq(net, &init_net))
return NULL;
rcu_read_lock();
sk = rcu_dereference(pnres.sk[res]);
if (sk)
sock_hold(sk);
rcu_read_unlock();
return sk;
}
static DEFINE_MUTEX(resource_mutex);
int pn_sock_bind_res(struct sock *sk, u8 res)
{
int ret = -EADDRINUSE;
if (!net_eq(sock_net(sk), &init_net))
return -ENOIOCTLCMD;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (pn_socket_autobind(sk->sk_socket))
return -EAGAIN;
mutex_lock(&resource_mutex);
if (pnres.sk[res] == NULL) {
sock_hold(sk);
rcu_assign_pointer(pnres.sk[res], sk);
ret = 0;
}
mutex_unlock(&resource_mutex);
return ret;
}
int pn_sock_unbind_res(struct sock *sk, u8 res)
{
int ret = -ENOENT;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
mutex_lock(&resource_mutex);
if (pnres.sk[res] == sk) {
rcu_assign_pointer(pnres.sk[res], NULL);
ret = 0;
}
mutex_unlock(&resource_mutex);
if (ret == 0) {
synchronize_rcu();
sock_put(sk);
}
return ret;
}
void pn_sock_unbind_all_res(struct sock *sk)
{
unsigned res, match = 0;
mutex_lock(&resource_mutex);
for (res = 0; res < 256; res++) {
if (pnres.sk[res] == sk) {
rcu_assign_pointer(pnres.sk[res], NULL);
match++;
}
}
mutex_unlock(&resource_mutex);
if (match == 0)
return;
synchronize_rcu();
while (match > 0) {
sock_put(sk);
match--;
}
}
#ifdef CONFIG_PROC_FS
static struct sock **pn_res_get_idx(struct seq_file *seq, loff_t pos)
{
struct net *net = seq_file_net(seq);
unsigned i;
if (!net_eq(net, &init_net))
return NULL;
for (i = 0; i < 256; i++) {
if (pnres.sk[i] == NULL)
continue;
if (!pos)
return pnres.sk + i;
pos--;
}
return NULL;
}
static struct sock **pn_res_get_next(struct seq_file *seq, struct sock **sk)
{
struct net *net = seq_file_net(seq);
unsigned i;
BUG_ON(!net_eq(net, &init_net));
for (i = (sk - pnres.sk) + 1; i < 256; i++)
if (pnres.sk[i])
return pnres.sk + i;
return NULL;
}
static void *pn_res_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(resource_mutex)
{
mutex_lock(&resource_mutex);
return *pos ? pn_res_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
}
static void *pn_res_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct sock **sk;
if (v == SEQ_START_TOKEN)
sk = pn_res_get_idx(seq, 0);
else
sk = pn_res_get_next(seq, v);
(*pos)++;
return sk;
}
static void pn_res_seq_stop(struct seq_file *seq, void *v)
__releases(resource_mutex)
{
mutex_unlock(&resource_mutex);
}
static int pn_res_seq_show(struct seq_file *seq, void *v)
{
int len;
if (v == SEQ_START_TOKEN)
seq_printf(seq, "%s%n", "rs uid inode", &len);
else {
struct sock **psk = v;
struct sock *sk = *psk;
seq_printf(seq, "%02X %5d %lu%n",
(int) (psk - pnres.sk), sock_i_uid(sk),
sock_i_ino(sk), &len);
}
seq_printf(seq, "%*s\n", 63 - len, "");
return 0;
}
static const struct seq_operations pn_res_seq_ops = {
.start = pn_res_seq_start,
.next = pn_res_seq_next,
.stop = pn_res_seq_stop,
.show = pn_res_seq_show,
};
static int pn_res_open(struct inode *inode, struct file *file)
{
return seq_open_net(inode, file, &pn_res_seq_ops,
sizeof(struct seq_net_private));
}
const struct file_operations pn_res_seq_fops = {
.owner = THIS_MODULE,
.open = pn_res_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_net,
};
#endif