linux/net/phonet/socket.c
Eric Dumazet 3ef7cf57c7 net: use skb_queue_empty_lockless() in poll() handlers
Many poll() handlers are lockless. Using skb_queue_empty_lockless()
instead of skb_queue_empty() is more appropriate.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-28 13:33:41 -07:00

786 lines
17 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* File: socket.c
*
* Phonet sockets
*
* Copyright (C) 2008 Nokia Corporation.
*
* Authors: Sakari Ailus <sakari.ailus@nokia.com>
* Rémi Denis-Courmont
*/
#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/net.h>
#include <linux/poll.h>
#include <linux/sched/signal.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <linux/phonet.h>
#include <linux/export.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];
struct mutex lock;
} pnsocks;
void __init pn_sock_init(void)
{
unsigned int i;
for (i = 0; i < PN_HASHSIZE; i++)
INIT_HLIST_HEAD(pnsocks.hlist + i);
mutex_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 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);
rcu_read_lock();
sk_for_each_rcu(sknode, 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;
}
rcu_read_unlock();
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 int h;
rcu_read_lock();
for (h = 0; h < PN_HASHSIZE; h++) {
struct sock *sknode;
sk_for_each(sknode, 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++;
}
rcu_read_unlock();
}
int pn_sock_hash(struct sock *sk)
{
struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
mutex_lock(&pnsocks.lock);
sk_add_node_rcu(sk, hlist);
mutex_unlock(&pnsocks.lock);
return 0;
}
EXPORT_SYMBOL(pn_sock_hash);
void pn_sock_unhash(struct sock *sk)
{
mutex_lock(&pnsocks.lock);
sk_del_node_init_rcu(sk);
mutex_unlock(&pnsocks.lock);
pn_sock_unbind_all_res(sk);
synchronize_rcu();
}
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 */
err = 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, bool kern)
{
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, kern);
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 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);
return sizeof(struct sockaddr_pn);
}
static __poll_t pn_socket_poll(struct file *file, struct socket *sock,
poll_table *wait)
{
struct sock *sk = sock->sk;
struct pep_sock *pn = pep_sk(sk);
__poll_t mask = 0;
poll_wait(file, sk_sleep(sk), wait);
if (sk->sk_state == TCP_CLOSE)
return EPOLLERR;
if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= EPOLLIN | EPOLLRDNORM;
if (!skb_queue_empty_lockless(&pn->ctrlreq_queue))
mask |= EPOLLPRI;
if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
return EPOLLHUP;
if (sk->sk_state == TCP_ESTABLISHED &&
refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
atomic_read(&pn->tx_credits))
mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
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 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(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 sock *sknode;
unsigned int h;
for (h = 0; h < PN_HASHSIZE; h++) {
sk_for_each_rcu(sknode, 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(rcu)
{
rcu_read_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(rcu)
{
rcu_read_unlock();
}
static int pn_sock_seq_show(struct seq_file *seq, void *v)
{
seq_setwidth(seq, 127);
if (v == SEQ_START_TOKEN)
seq_puts(seq, "pt loc rem rs st tx_queue rx_queue "
" uid inode ref pointer drops");
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 %pK %u",
sk->sk_protocol, pn->sobject, pn->dobject,
pn->resource, sk->sk_state,
sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
sock_i_ino(sk),
refcount_read(&sk->sk_refcnt), sk,
atomic_read(&sk->sk_drops));
}
seq_pad(seq, '\n');
return 0;
}
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,
};
#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_INIT_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 int res, match = 0;
mutex_lock(&resource_mutex);
for (res = 0; res < 256; res++) {
if (pnres.sk[res] == sk) {
RCU_INIT_POINTER(pnres.sk[res], NULL);
match++;
}
}
mutex_unlock(&resource_mutex);
while (match > 0) {
__sock_put(sk);
match--;
}
/* Caller is responsible for RCU sync before final sock_put() */
}
#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 int 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 int 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)
{
seq_setwidth(seq, 63);
if (v == SEQ_START_TOKEN)
seq_puts(seq, "rs uid inode");
else {
struct sock **psk = v;
struct sock *sk = *psk;
seq_printf(seq, "%02X %5u %lu",
(int) (psk - pnres.sk),
from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
sock_i_ino(sk));
}
seq_pad(seq, '\n');
return 0;
}
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,
};
#endif