diff options
Diffstat (limited to 'net/9p/trans_fd.c')
| -rw-r--r-- | net/9p/trans_fd.c | 1205 |
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"); |