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linux/net/phonet/pep.c
Breno Leitao e1d001fa5b net: ioctl: Use kernel memory on protocol ioctl callbacks 
Most of the ioctls to net protocols operates directly on userspace
argument (arg). Usually doing get_user()/put_user() directly in the
ioctl callback.  This is not flexible, because it is hard to reuse these
functions without passing userspace buffers.

Change the "struct proto" ioctls to avoid touching userspace memory and
operate on kernel buffers, i.e., all protocol's ioctl callbacks is
adapted to operate on a kernel memory other than on userspace (so, no
more {put,get}_user() and friends being called in the ioctl callback).

This changes the "struct proto" ioctl format in the following way:

    int                     (*ioctl)(struct sock *sk, int cmd,
-                                        unsigned long arg);
+                                        int *karg);

(Important to say that this patch does not touch the "struct proto_ops"
protocols)

So, the "karg" argument, which is passed to the ioctl callback, is a
pointer allocated to kernel space memory (inside a function wrapper).
This buffer (karg) may contain input argument (copied from userspace in
a prep function) and it might return a value/buffer, which is copied
back to userspace if necessary. There is not one-size-fits-all format
(that is I am using 'may' above), but basically, there are three type of
ioctls:

1) Do not read from userspace, returns a result to userspace
2) Read an input parameter from userspace, and does not return anything
  to userspace
3) Read an input from userspace, and return a buffer to userspace.

The default case (1) (where no input parameter is given, and an "int" is
returned to userspace) encompasses more than 90% of the cases, but there
are two other exceptions. Here is a list of exceptions:

* Protocol RAW:
   * cmd = SIOCGETVIFCNT:
     * input and output = struct sioc_vif_req
   * cmd = SIOCGETSGCNT
     * input and output = struct sioc_sg_req
   * Explanation: for the SIOCGETVIFCNT case, userspace passes the input
     argument, which is struct sioc_vif_req. Then the callback populates
     the struct, which is copied back to userspace.

* Protocol RAW6:
   * cmd = SIOCGETMIFCNT_IN6
     * input and output = struct sioc_mif_req6
   * cmd = SIOCGETSGCNT_IN6
     * input and output = struct sioc_sg_req6

* Protocol PHONET:
  * cmd == SIOCPNADDRESOURCE | SIOCPNDELRESOURCE
     * input int (4 bytes)
  * Nothing is copied back to userspace.

For the exception cases, functions sock_sk_ioctl_inout() will
copy the userspace input, and copy it back to kernel space.

The wrapper that prepare the buffer and put the buffer back to user is
sk_ioctl(), so, instead of calling sk->sk_prot->ioctl(), the callee now
calls sk_ioctl(), which will handle all cases.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230609152800.830401-1-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-15 22:33:26 -07:00

1366 lines
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// SPDX-License-Identifier: GPL-2.0-only
/*
* File: pep.c
*
* Phonet pipe protocol end point socket
*
* Copyright (C) 2008 Nokia Corporation.
*
* Author: Rémi Denis-Courmont
*/
#include <linux/kernel.h>
#include <linux/sched/signal.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->error_code = 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->error_code = 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->pep_type, /* 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->data0 = oph->data[0]; /* 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->pep_type != PN_PEP_TYPE_COMMON) {
net_dbg_ratelimited("Phonet unknown PEP type: %u\n",
(unsigned int)hdr->pep_type);
return -EOPNOTSUPP;
}
switch (hdr->data[0]) {
case PN_PEP_IND_FLOW_CONTROL:
switch (pn->tx_fc) {
case PN_LEGACY_FLOW_CONTROL:
switch (hdr->data[3]) {
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[3] == 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[3], &pn->tx_credits);
break;
default:
net_dbg_ratelimited("Phonet unknown PEP indication: %u\n",
(unsigned int)hdr->data[0]);
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->data0;
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;
}
fallthrough;
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);
fallthrough;
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;
fallthrough;
case PNS_PIPE_RESET_IND:
if (!pn->init_enable)
break;
fallthrough;
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[3];
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);
fallthrough;
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->data0 = 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,
bool kern)
{
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, (flags & O_NONBLOCK) ? MSG_DONTWAIT : 0,
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[3];
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,
kern);
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(sk);
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, int *karg)
{
struct pep_sock *pn = pep_sk(sk);
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))
*karg = skb_peek(&pn->ctrlreq_queue)->len;
else if (!skb_queue_empty(&sk->sk_receive_queue))
*karg = skb_peek(&sk->sk_receive_queue)->len;
else
*karg = 0;
release_sock(sk);
ret = 0;
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 if (!pn->pn_sk.sobject)
ret = -EADDRNOTAVAIL;
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,
sockptr_t 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 (copy_from_sockptr(&val, optval, sizeof(int)))
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->data0 = 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_FUNC(wait, woken_wake_function);
if (!timeo) {
err = -EAGAIN;
goto out;
}
if (signal_pending(current)) {
err = sock_intr_errno(timeo);
goto out;
}
add_wait_queue(sk_sleep(sk), &wait);
done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits), &wait);
remove_wait_queue(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 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, &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 const 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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