summaryrefslogtreecommitdiffstats
path: root/net/9p/trans_fd.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--net/9p/trans_fd.c1205
1 files changed, 1205 insertions, 0 deletions
diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
new file mode 100644
index 000000000..a69422366
--- /dev/null
+++ b/net/9p/trans_fd.c
@@ -0,0 +1,1205 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Fd transport layer. Includes deprecated socket layer.
+ *
+ * Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
+ * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
+ * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
+ * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
+ */
+
+#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/idr.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
+ * @req: current request being processed (if any)
+ * @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);
+ if (m->err < 0)
+ return m->err;
+
+ spin_lock(&m->req_lock);
+ 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;
+ 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 = 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 = 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 <ericvh@gmail.com>");
+MODULE_DESCRIPTION("Filedescriptor Transport for 9P");
+MODULE_LICENSE("GPL");