// SPDX-License-Identifier: GPL-2.0-only
/*
* Fd transport layer. Includes deprecated socket layer.
*
* Copyright (C) 2006 by Russ Cox <[email protected]>
* Copyright (C) 2004-2005 by Latchesar Ionkov <[email protected]>
* Copyright (C) 2004-2008 by Eric Van Hensbergen <[email protected]>
* Copyright (C) 1997-2002 by Ron Minnich <[email protected]>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/in.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/ipv6.h>
#include <linux/kthread.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/un.h>
#include <linux/uaccess.h>
#include <linux/inet.h>
#include <linux/file.h>
#include <linux/parser.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <net/9p/9p.h>
#include <net/9p/client.h>
#include <net/9p/transport.h>
#include <linux/syscalls.h> /* killme */
#define P9_PORT 564
#define MAX_SOCK_BUF (1024*1024)
#define MAXPOLLWADDR 2
static struct p9_trans_module p9_tcp_trans;
static struct p9_trans_module p9_fd_trans;
/**
* struct p9_fd_opts - per-transport options
* @rfd: file descriptor for reading (trans=fd)
* @wfd: file descriptor for writing (trans=fd)
* @port: port to connect to (trans=tcp)
* @privport: port is privileged
*/
struct p9_fd_opts {
int rfd;
int wfd;
u16 port;
bool privport;
};
/*
* Option Parsing (code inspired by NFS code)
* - a little lazy - parse all fd-transport options
*/
enum {
/* Options that take integer arguments */
Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
/* Options that take no arguments */
Opt_privport,
};
static const match_table_t tokens = {
{Opt_port, "port=%u"},
{Opt_rfdno, "rfdno=%u"},
{Opt_wfdno, "wfdno=%u"},
{Opt_privport, "privport"},
{Opt_err, NULL},
};
enum {
Rworksched = 1, /* read work scheduled or running */
Rpending = 2, /* can read */
Wworksched = 4, /* write work scheduled or running */
Wpending = 8, /* can write */
};
struct p9_poll_wait {
struct p9_conn *conn;
wait_queue_entry_t wait;
wait_queue_head_t *wait_addr;
};
/**
* struct p9_conn - fd mux connection state information
* @mux_list: list link for mux to manage multiple connections (?)
* @client: reference to client instance for this connection
* @err: error state
* @req_lock: lock protecting req_list and requests statuses
* @req_list: accounting for requests which have been sent
* @unsent_req_list: accounting for requests that haven't been sent
* @rreq: read request
* @wreq: write request
* @tmp_buf: temporary buffer to read in header
* @rc: temporary fcall for reading current frame
* @wpos: write position for current frame
* @wsize: amount of data to write for current frame
* @wbuf: current write buffer
* @poll_pending_link: pending links to be polled per conn
* @poll_wait: array of wait_q's for various worker threads
* @pt: poll state
* @rq: current read work
* @wq: current write work
* @wsched: ????
*
*/
struct p9_conn {
struct list_head mux_list;
struct p9_client *client;
int err;
spinlock_t req_lock;
struct list_head req_list;
struct list_head unsent_req_list;
struct p9_req_t *rreq;
struct p9_req_t *wreq;
char tmp_buf[P9_HDRSZ];
struct p9_fcall rc;
int wpos;
int wsize;
char *wbuf;
struct list_head poll_pending_link;
struct p9_poll_wait poll_wait[MAXPOLLWADDR];
poll_table pt;
struct work_struct rq;
struct work_struct wq;
unsigned long wsched;
};
/**
* struct p9_trans_fd - transport state
* @rd: reference to file to read from
* @wr: reference of file to write to
* @conn: connection state reference
*
*/
struct p9_trans_fd {
struct file *rd;
struct file *wr;
struct p9_conn conn;
};
static void p9_poll_workfn(struct work_struct *work);
static DEFINE_SPINLOCK(p9_poll_lock);
static LIST_HEAD(p9_poll_pending_list);
static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
static unsigned int p9_ipport_resv_min = P9_DEF_MIN_RESVPORT;
static unsigned int p9_ipport_resv_max = P9_DEF_MAX_RESVPORT;
static void p9_mux_poll_stop(struct p9_conn *m)
{
unsigned long flags;
int i;
for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
struct p9_poll_wait *pwait = &m->poll_wait[i];
if (pwait->wait_addr) {
remove_wait_queue(pwait->wait_addr, &pwait->wait);
pwait->wait_addr = NULL;
}
}
spin_lock_irqsave(&p9_poll_lock, flags);
list_del_init(&m->poll_pending_link);
spin_unlock_irqrestore(&p9_poll_lock, flags);
flush_work(&p9_poll_work);
}
/**
* p9_conn_cancel - cancel all pending requests with error
* @m: mux data
* @err: error code
*
*/
static void p9_conn_cancel(struct p9_conn *m, int err)
{
struct p9_req_t *req, *rtmp;
LIST_HEAD(cancel_list);
p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
spin_lock(&m->req_lock);
if (m->err) {
spin_unlock(&m->req_lock);
return;
}
m->err = err;
list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
list_move(&req->req_list, &cancel_list);
WRITE_ONCE(req->status, REQ_STATUS_ERROR);
}
list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
list_move(&req->req_list, &cancel_list);
WRITE_ONCE(req->status, REQ_STATUS_ERROR);
}
spin_unlock(&m->req_lock);
list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
list_del(&req->req_list);
if (!req->t_err)
req->t_err = err;
p9_client_cb(m->client, req, REQ_STATUS_ERROR);
}
}
static __poll_t
p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err)
{
__poll_t ret;
struct p9_trans_fd *ts = NULL;
if (client && client->status == Connected)
ts = client->trans;
if (!ts) {
if (err)
*err = -EREMOTEIO;
return EPOLLERR;
}
ret = vfs_poll(ts->rd, pt);
if (ts->rd != ts->wr)
ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN);
return ret;
}
/**
* p9_fd_read- read from a fd
* @client: client instance
* @v: buffer to receive data into
* @len: size of receive buffer
*
*/
static int p9_fd_read(struct p9_client *client, void *v, int len)
{
int ret;
struct p9_trans_fd *ts = NULL;
loff_t pos;
if (client && client->status != Disconnected)
ts = client->trans;
if (!ts)
return -EREMOTEIO;
if (!(ts->rd->f_flags & O_NONBLOCK))
p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
pos = ts->rd->f_pos;
ret = kernel_read(ts->rd, v, len, &pos);
if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
client->status = Disconnected;
return ret;
}
/**
* p9_read_work - called when there is some data to be read from a transport
* @work: container of work to be done
*
*/
static void p9_read_work(struct work_struct *work)
{
__poll_t n;
int err;
struct p9_conn *m;
m = container_of(work, struct p9_conn, rq);
if (m->err < 0)
return;
p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset);
if (!m->rc.sdata) {
m->rc.sdata = m->tmp_buf;
m->rc.offset = 0;
m->rc.capacity = P9_HDRSZ; /* start by reading header */
}
clear_bit(Rpending, &m->wsched);
p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n",
m, m->rc.offset, m->rc.capacity,
m->rc.capacity - m->rc.offset);
err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset,
m->rc.capacity - m->rc.offset);
p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
if (err == -EAGAIN)
goto end_clear;
if (err <= 0)
goto error;
m->rc.offset += err;
/* header read in */
if ((!m->rreq) && (m->rc.offset == m->rc.capacity)) {
p9_debug(P9_DEBUG_TRANS, "got new header\n");
/* Header size */
m->rc.size = P9_HDRSZ;
err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0);
if (err) {
p9_debug(P9_DEBUG_ERROR,
"error parsing header: %d\n", err);
goto error;
}
p9_debug(P9_DEBUG_TRANS,
"mux %p pkt: size: %d bytes tag: %d\n",
m, m->rc.size, m->rc.tag);
m->rreq = p9_tag_lookup(m->client, m->rc.tag);
if (!m->rreq || (m->rreq->status != REQ_STATUS_SENT)) {
p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
m->rc.tag);
err = -EIO;
goto error;
}
if (m->rc.size > m->rreq->rc.capacity) {
p9_debug(P9_DEBUG_ERROR,
"requested packet size too big: %d for tag %d with capacity %zd\n",
m->rc.size, m->rc.tag, m->rreq->rc.capacity);
err = -EIO;
goto error;
}
if (!m->rreq->rc.sdata) {
p9_debug(P9_DEBUG_ERROR,
"No recv fcall for tag %d (req %p), disconnecting!\n",
m->rc.tag, m->rreq);
p9_req_put(m->client, m->rreq);
m->rreq = NULL;
err = -EIO;
goto error;
}
m->rc.sdata = m->rreq->rc.sdata;
memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity);
m->rc.capacity = m->rc.size;
}
/* packet is read in
* not an else because some packets (like clunk) have no payload
*/
if ((m->rreq) && (m->rc.offset == m->rc.capacity)) {
p9_debug(P9_DEBUG_TRANS, "got new packet\n");
m->rreq->rc.size = m->rc.offset;
spin_lock(&m->req_lock);
if (m->rreq->status == REQ_STATUS_SENT) {
list_del(&m->rreq->req_list);
p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD);
} else if (m->rreq->status == REQ_STATUS_FLSHD) {
/* Ignore replies associated with a cancelled request. */
p9_debug(P9_DEBUG_TRANS,
"Ignore replies associated with a cancelled request\n");
} else {
spin_unlock(&m->req_lock);
p9_debug(P9_DEBUG_ERROR,
"Request tag %d errored out while we were reading the reply\n",
m->rc.tag);
err = -EIO;
goto error;
}
spin_unlock(&m->req_lock);
m->rc.sdata = NULL;
m->rc.offset = 0;
m->rc.capacity = 0;
p9_req_put(m->client, m->rreq);
m->rreq = NULL;
}
end_clear:
clear_bit(Rworksched, &m->wsched);
if (!list_empty(&m->req_list)) {
if (test_and_clear_bit(Rpending, &m->wsched))
n = EPOLLIN;
else
n = p9_fd_poll(m->client, NULL, NULL);
if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) {
p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
schedule_work(&m->rq);
}
}
return;
error:
p9_conn_cancel(m, err);
clear_bit(Rworksched, &m->wsched);
}
/**
* p9_fd_write - write to a socket
* @client: client instance
* @v: buffer to send data from
* @len: size of send buffer
*
*/
static int p9_fd_write(struct p9_client *client, void *v, int len)
{
ssize_t ret;
struct p9_trans_fd *ts = NULL;
if (client && client->status != Disconnected)
ts = client->trans;
if (!ts)
return -EREMOTEIO;
if (!(ts->wr->f_flags & O_NONBLOCK))
p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos);
if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
client->status = Disconnected;
return ret;
}
/**
* p9_write_work - called when a transport can send some data
* @work: container for work to be done
*
*/
static void p9_write_work(struct work_struct *work)
{
__poll_t n;
int err;
struct p9_conn *m;
struct p9_req_t *req;
m = container_of(work, struct p9_conn, wq);
if (m->err < 0) {
clear_bit(Wworksched, &m->wsched);
return;
}
if (!m->wsize) {
spin_lock(&m->req_lock);
if (list_empty(&m->unsent_req_list)) {
clear_bit(Wworksched, &m->wsched);
spin_unlock(&m->req_lock);
return;
}
req = list_entry(m->unsent_req_list.next, struct p9_req_t,
req_list);
WRITE_ONCE(req->status, REQ_STATUS_SENT);
p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
list_move_tail(&req->req_list, &m->req_list);
m->wbuf = req->tc.sdata;
m->wsize = req->tc.size;
m->wpos = 0;
p9_req_get(req);
m->wreq = req;
spin_unlock(&m->req_lock);
}
p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n",
m, m->wpos, m->wsize);
clear_bit(Wpending, &m->wsched);
err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
if (err == -EAGAIN)
goto end_clear;
if (err < 0)
goto error;
else if (err == 0) {
err = -EREMOTEIO;
goto error;
}
m->wpos += err;
if (m->wpos == m->wsize) {
m->wpos = m->wsize = 0;
p9_req_put(m->client, m->wreq);
m->wreq = NULL;
}
end_clear:
clear_bit(Wworksched, &m->wsched);
if (m->wsize || !list_empty(&m->unsent_req_list)) {
if (test_and_clear_bit(Wpending, &m->wsched))
n = EPOLLOUT;
else
n = p9_fd_poll(m->client, NULL, NULL);
if ((n & EPOLLOUT) &&
!test_and_set_bit(Wworksched, &m->wsched)) {
p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
schedule_work(&m->wq);
}
}
return;
error:
p9_conn_cancel(m, err);
clear_bit(Wworksched, &m->wsched);
}
static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
{
struct p9_poll_wait *pwait =
container_of(wait, struct p9_poll_wait, wait);
struct p9_conn *m = pwait->conn;
unsigned long flags;
spin_lock_irqsave(&p9_poll_lock, flags);
if (list_empty(&m->poll_pending_link))
list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
spin_unlock_irqrestore(&p9_poll_lock, flags);
schedule_work(&p9_poll_work);
return 1;
}
/**
* p9_pollwait - add poll task to the wait queue
* @filp: file pointer being polled
* @wait_address: wait_q to block on
* @p: poll state
*
* called by files poll operation to add v9fs-poll task to files wait queue
*/
static void
p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
{
struct p9_conn *m = container_of(p, struct p9_conn, pt);
struct p9_poll_wait *pwait = NULL;
int i;
for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
if (m->poll_wait[i].wait_addr == NULL) {
pwait = &m->poll_wait[i];
break;
}
}
if (!pwait) {
p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n");
return;
}
pwait->conn = m;
pwait->wait_addr = wait_address;
init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
add_wait_queue(wait_address, &pwait->wait);
}
/**
* p9_conn_create - initialize the per-session mux data
* @client: client instance
*
* Note: Creates the polling task if this is the first session.
*/
static void p9_conn_create(struct p9_client *client)
{
__poll_t n;
struct p9_trans_fd *ts = client->trans;
struct p9_conn *m = &ts->conn;
p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
INIT_LIST_HEAD(&m->mux_list);
m->client = client;
spin_lock_init(&m->req_lock);
INIT_LIST_HEAD(&m->req_list);
INIT_LIST_HEAD(&m->unsent_req_list);
INIT_WORK(&m->rq, p9_read_work);
INIT_WORK(&m->wq, p9_write_work);
INIT_LIST_HEAD(&m->poll_pending_link);
init_poll_funcptr(&m->pt, p9_pollwait);
n = p9_fd_poll(client, &m->pt, NULL);
if (n & EPOLLIN) {
p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
set_bit(Rpending, &m->wsched);
}
if (n & EPOLLOUT) {
p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
set_bit(Wpending, &m->wsched);
}
}
/**
* p9_poll_mux - polls a mux and schedules read or write works if necessary
* @m: connection to poll
*
*/
static void p9_poll_mux(struct p9_conn *m)
{
__poll_t n;
int err = -ECONNRESET;
if (m->err < 0)
return;
n = p9_fd_poll(m->client, NULL, &err);
if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) {
p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
p9_conn_cancel(m, err);
}
if (n & EPOLLIN) {
set_bit(Rpending, &m->wsched);
p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
if (!test_and_set_bit(Rworksched, &m->wsched)) {
p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
schedule_work(&m->rq);
}
}
if (n & EPOLLOUT) {
set_bit(Wpending, &m->wsched);
p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
!test_and_set_bit(Wworksched, &m->wsched)) {
p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
schedule_work(&m->wq);
}
}
}
/**
* p9_fd_request - send 9P request
* The function can sleep until the request is scheduled for sending.
* The function can be interrupted. Return from the function is not
* a guarantee that the request is sent successfully.
*
* @client: client instance
* @req: request to be sent
*
*/
static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
{
__poll_t n;
struct p9_trans_fd *ts = client->trans;
struct p9_conn *m = &ts->conn;
p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
m, current, &req->tc, req->tc.id);
spin_lock(&m->req_lock);
if (m->err < 0) {
spin_unlock(&m->req_lock);
return m->err;
}
WRITE_ONCE(req->status, REQ_STATUS_UNSENT);
list_add_tail(&req->req_list, &m->unsent_req_list);
spin_unlock(&m->req_lock);
if (test_and_clear_bit(Wpending, &m->wsched))
n = EPOLLOUT;
else
n = p9_fd_poll(m->client, NULL, NULL);
if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
schedule_work(&m->wq);
return 0;
}
static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
{
struct p9_trans_fd *ts = client->trans;
struct p9_conn *m = &ts->conn;
int ret = 1;
p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
spin_lock(&m->req_lock);
if (req->status == REQ_STATUS_UNSENT) {
list_del(&req->req_list);
WRITE_ONCE(req->status, REQ_STATUS_FLSHD);
p9_req_put(client, req);
ret = 0;
}
spin_unlock(&m->req_lock);
return ret;
}
static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req)
{
struct p9_trans_fd *ts = client->trans;
struct p9_conn *m = &ts->conn;
p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
spin_lock(&m->req_lock);
/* Ignore cancelled request if message has been received
* before lock.
*/
if (req->status == REQ_STATUS_RCVD) {
spin_unlock(&m->req_lock);
return 0;
}
/* we haven't received a response for oldreq,
* remove it from the list.
*/
list_del(&req->req_list);
WRITE_ONCE(req->status, REQ_STATUS_FLSHD);
spin_unlock(&m->req_lock);
p9_req_put(client, req);
return 0;
}
static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt)
{
if (clnt->trans_mod == &p9_tcp_trans) {
if (clnt->trans_opts.tcp.port != P9_PORT)
seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port);
} else if (clnt->trans_mod == &p9_fd_trans) {
if (clnt->trans_opts.fd.rfd != ~0)
seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd);
if (clnt->trans_opts.fd.wfd != ~0)
seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd);
}
return 0;
}
/**
* parse_opts - parse mount options into p9_fd_opts structure
* @params: options string passed from mount
* @opts: fd transport-specific structure to parse options into
*
* Returns 0 upon success, -ERRNO upon failure
*/
static int parse_opts(char *params, struct p9_fd_opts *opts)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int option;
char *options, *tmp_options;
opts->port = P9_PORT;
opts->rfd = ~0;
opts->wfd = ~0;
opts->privport = false;
if (!params)
return 0;
tmp_options = kstrdup(params, GFP_KERNEL);
if (!tmp_options) {
p9_debug(P9_DEBUG_ERROR,
"failed to allocate copy of option string\n");
return -ENOMEM;
}
options = tmp_options;
while ((p = strsep(&options, ",")) != NULL) {
int token;
int r;
if (!*p)
continue;
token = match_token(p, tokens, args);
if ((token != Opt_err) && (token != Opt_privport)) {
r = match_int(&args[0], &option);
if (r < 0) {
p9_debug(P9_DEBUG_ERROR,
"integer field, but no integer?\n");
continue;
}
}
switch (token) {
case Opt_port:
opts->port = option;
break;
case Opt_rfdno:
opts->rfd = option;
break;
case Opt_wfdno:
opts->wfd = option;
break;
case Opt_privport:
opts->privport = true;
break;
default:
continue;
}
}
kfree(tmp_options);
return 0;
}
static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
{
struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd),
GFP_KERNEL);
if (!ts)
return -ENOMEM;
ts->rd = fget(rfd);
if (!ts->rd)
goto out_free_ts;
if (!(ts->rd->f_mode & FMODE_READ))
goto out_put_rd;
/* Prevent workers from hanging on IO when fd is a pipe.
* It's technically possible for userspace or concurrent mounts to
* modify this flag concurrently, which will likely result in a
* broken filesystem. However, just having bad flags here should
* not crash the kernel or cause any other sort of bug, so mark this
* particular data race as intentional so that tooling (like KCSAN)
* can allow it and detect further problems.
*/
data_race(ts->rd->f_flags |= O_NONBLOCK);
ts->wr = fget(wfd);
if (!ts->wr)
goto out_put_rd;
if (!(ts->wr->f_mode & FMODE_WRITE))
goto out_put_wr;
data_race(ts->wr->f_flags |= O_NONBLOCK);
client->trans = ts;
client->status = Connected;
return 0;
out_put_wr:
fput(ts->wr);
out_put_rd:
fput(ts->rd);
out_free_ts:
kfree(ts);
return -EIO;
}
static int p9_socket_open(struct p9_client *client, struct socket *csocket)
{
struct p9_trans_fd *p;
struct file *file;
p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
if (!p) {
sock_release(csocket);
return -ENOMEM;
}
csocket->sk->sk_allocation = GFP_NOIO;
csocket->sk->sk_use_task_frag = false;
file = sock_alloc_file(csocket, 0, NULL);
if (IS_ERR(file)) {
pr_err("%s (%d): failed to map fd\n",
__func__, task_pid_nr(current));
kfree(p);
return PTR_ERR(file);
}
get_file(file);
p->wr = p->rd = file;
client->trans = p;
client->status = Connected;
p->rd->f_flags |= O_NONBLOCK;
p9_conn_create(client);
return 0;
}
/**
* p9_conn_destroy - cancels all pending requests of mux
* @m: mux to destroy
*
*/
static void p9_conn_destroy(struct p9_conn *m)
{
p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n",
m, m->mux_list.prev, m->mux_list.next);
p9_mux_poll_stop(m);
cancel_work_sync(&m->rq);
if (m->rreq) {
p9_req_put(m->client, m->rreq);
m->rreq = NULL;
}
cancel_work_sync(&m->wq);
if (m->wreq) {
p9_req_put(m->client, m->wreq);
m->wreq = NULL;
}
p9_conn_cancel(m, -ECONNRESET);
m->client = NULL;
}
/**
* p9_fd_close - shutdown file descriptor transport
* @client: client instance
*
*/
static void p9_fd_close(struct p9_client *client)
{
struct p9_trans_fd *ts;
if (!client)
return;
ts = client->trans;
if (!ts)
return;
client->status = Disconnected;
p9_conn_destroy(&ts->conn);
if (ts->rd)
fput(ts->rd);
if (ts->wr)
fput(ts->wr);
kfree(ts);
}
/*
* stolen from NFS - maybe should be made a generic function?
*/
static inline int valid_ipaddr4(const char *buf)
{
int rc, count, in[4];
rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
if (rc != 4)
return -EINVAL;
for (count = 0; count < 4; count++) {
if (in[count] > 255)
return -EINVAL;
}
return 0;
}
static int p9_bind_privport(struct socket *sock)
{
struct sockaddr_in cl;
int port, err = -EINVAL;
memset(&cl, 0, sizeof(cl));
cl.sin_family = AF_INET;
cl.sin_addr.s_addr = htonl(INADDR_ANY);
for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) {
cl.sin_port = htons((ushort)port);
err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl));
if (err != -EADDRINUSE)
break;
}
return err;
}
static int
p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
{
int err;
struct socket *csocket;
struct sockaddr_in sin_server;
struct p9_fd_opts opts;
err = parse_opts(args, &opts);
if (err < 0)
return err;
if (addr == NULL || valid_ipaddr4(addr) < 0)
return -EINVAL;
csocket = NULL;
client->trans_opts.tcp.port = opts.port;
client->trans_opts.tcp.privport = opts.privport;
sin_server.sin_family = AF_INET;
sin_server.sin_addr.s_addr = in_aton(addr);
sin_server.sin_port = htons(opts.port);
err = __sock_create(current->nsproxy->net_ns, PF_INET,
SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
if (err) {
pr_err("%s (%d): problem creating socket\n",
__func__, task_pid_nr(current));
return err;
}
if (opts.privport) {
err = p9_bind_privport(csocket);
if (err < 0) {
pr_err("%s (%d): problem binding to privport\n",
__func__, task_pid_nr(current));
sock_release(csocket);
return err;
}
}
err = READ_ONCE(csocket->ops)->connect(csocket,
(struct sockaddr *)&sin_server,
sizeof(struct sockaddr_in), 0);
if (err < 0) {
pr_err("%s (%d): problem connecting socket to %s\n",
__func__, task_pid_nr(current), addr);
sock_release(csocket);
return err;
}
return p9_socket_open(client, csocket);
}
static int
p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
{
int err;
struct socket *csocket;
struct sockaddr_un sun_server;
csocket = NULL;
if (!addr || !strlen(addr))
return -EINVAL;
if (strlen(addr) >= UNIX_PATH_MAX) {
pr_err("%s (%d): address too long: %s\n",
__func__, task_pid_nr(current), addr);
return -ENAMETOOLONG;
}
sun_server.sun_family = PF_UNIX;
strcpy(sun_server.sun_path, addr);
err = __sock_create(current->nsproxy->net_ns, PF_UNIX,
SOCK_STREAM, 0, &csocket, 1);
if (err < 0) {
pr_err("%s (%d): problem creating socket\n",
__func__, task_pid_nr(current));
return err;
}
err = READ_ONCE(csocket->ops)->connect(csocket, (struct sockaddr *)&sun_server,
sizeof(struct sockaddr_un) - 1, 0);
if (err < 0) {
pr_err("%s (%d): problem connecting socket: %s: %d\n",
__func__, task_pid_nr(current), addr, err);
sock_release(csocket);
return err;
}
return p9_socket_open(client, csocket);
}
static int
p9_fd_create(struct p9_client *client, const char *addr, char *args)
{
int err;
struct p9_fd_opts opts;
err = parse_opts(args, &opts);
if (err < 0)
return err;
client->trans_opts.fd.rfd = opts.rfd;
client->trans_opts.fd.wfd = opts.wfd;
if (opts.rfd == ~0 || opts.wfd == ~0) {
pr_err("Insufficient options for proto=fd\n");
return -ENOPROTOOPT;
}
err = p9_fd_open(client, opts.rfd, opts.wfd);
if (err < 0)
return err;
p9_conn_create(client);
return 0;
}
static struct p9_trans_module p9_tcp_trans = {
.name = "tcp",
.maxsize = MAX_SOCK_BUF,
.pooled_rbuffers = false,
.def = 0,
.create = p9_fd_create_tcp,
.close = p9_fd_close,
.request = p9_fd_request,
.cancel = p9_fd_cancel,
.cancelled = p9_fd_cancelled,
.show_options = p9_fd_show_options,
.owner = THIS_MODULE,
};
MODULE_ALIAS_9P("tcp");
static struct p9_trans_module p9_unix_trans = {
.name = "unix",
.maxsize = MAX_SOCK_BUF,
.def = 0,
.create = p9_fd_create_unix,
.close = p9_fd_close,
.request = p9_fd_request,
.cancel = p9_fd_cancel,
.cancelled = p9_fd_cancelled,
.show_options = p9_fd_show_options,
.owner = THIS_MODULE,
};
MODULE_ALIAS_9P("unix");
static struct p9_trans_module p9_fd_trans = {
.name = "fd",
.maxsize = MAX_SOCK_BUF,
.def = 0,
.create = p9_fd_create,
.close = p9_fd_close,
.request = p9_fd_request,
.cancel = p9_fd_cancel,
.cancelled = p9_fd_cancelled,
.show_options = p9_fd_show_options,
.owner = THIS_MODULE,
};
MODULE_ALIAS_9P("fd");
/**
* p9_poll_workfn - poll worker thread
* @work: work queue
*
* polls all v9fs transports for new events and queues the appropriate
* work to the work queue
*
*/
static void p9_poll_workfn(struct work_struct *work)
{
unsigned long flags;
p9_debug(P9_DEBUG_TRANS, "start %p\n", current);
spin_lock_irqsave(&p9_poll_lock, flags);
while (!list_empty(&p9_poll_pending_list)) {
struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
struct p9_conn,
poll_pending_link);
list_del_init(&conn->poll_pending_link);
spin_unlock_irqrestore(&p9_poll_lock, flags);
p9_poll_mux(conn);
spin_lock_irqsave(&p9_poll_lock, flags);
}
spin_unlock_irqrestore(&p9_poll_lock, flags);
p9_debug(P9_DEBUG_TRANS, "finish\n");
}
static int __init p9_trans_fd_init(void)
{
v9fs_register_trans(&p9_tcp_trans);
v9fs_register_trans(&p9_unix_trans);
v9fs_register_trans(&p9_fd_trans);
return 0;
}
static void __exit p9_trans_fd_exit(void)
{
flush_work(&p9_poll_work);
v9fs_unregister_trans(&p9_tcp_trans);
v9fs_unregister_trans(&p9_unix_trans);
v9fs_unregister_trans(&p9_fd_trans);
}
module_init(p9_trans_fd_init);
module_exit(p9_trans_fd_exit);
MODULE_AUTHOR("Eric Van Hensbergen <[email protected]>");
MODULE_DESCRIPTION("Filedescriptor Transport for 9P");
MODULE_LICENSE("GPL");
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