| // 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"); |