trans_fd.c 9.51 KB
Newer Older
1 2 3 4 5 6 7
/*
 * linux/fs/9p/trans_fd.c
 *
 * 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>
8
 *  Copyright (C) 2004-2007 by Eric Van Hensbergen <ericvh@gmail.com>
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38
 *  Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to:
 *  Free Software Foundation
 *  51 Franklin Street, Fifth Floor
 *  Boston, MA  02111-1301  USA
 *
 */

#include <linux/in.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/ipv6.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>
39
#include <linux/parser.h>
40 41 42 43
#include <net/9p/9p.h>
#include <net/9p/transport.h>

#define P9_PORT 564
44 45 46 47 48 49 50 51
#define MAX_SOCK_BUF (64*1024)


struct p9_fd_opts {
	int rfd;
	int wfd;
	u16 port;
};
52 53 54 55 56 57

struct p9_trans_fd {
	struct file *rd;
	struct file *wr;
};

58 59 60 61
/*
  * Option Parsing (code inspired by NFS code)
  *  - a little lazy - parse all fd-transport options
  */
62

63 64
enum {
	/* Options that take integer arguments */
65
	Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
66
};
67

68 69 70 71
static match_table_t tokens = {
	{Opt_port, "port=%u"},
	{Opt_rfdno, "rfdno=%u"},
	{Opt_wfdno, "wfdno=%u"},
72
	{Opt_err, NULL},
73
};
74

75 76 77 78 79 80
/**
 * v9fs_parse_options - parse mount options into session structure
 * @options: options string passed from mount
 * @v9ses: existing v9fs session information
 *
 */
81

82
static void parse_opts(char *options, struct p9_fd_opts *opts)
83
{
84 85 86 87
	char *p;
	substring_t args[MAX_OPT_ARGS];
	int option;
	int ret;
88

89 90 91
	opts->port = P9_PORT;
	opts->rfd = ~0;
	opts->wfd = ~0;
92

93 94
	if (!options)
		return;
95

96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119
	while ((p = strsep(&options, ",")) != NULL) {
		int token;
		if (!*p)
			continue;
		token = match_token(p, tokens, args);
		ret = match_int(&args[0], &option);
		if (ret < 0) {
			P9_DPRINTK(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;
		default:
			continue;
		}
120 121 122
	}
}

123
static int p9_fd_open(struct p9_trans *trans, int rfd, int wfd)
124
{
125 126 127 128
	struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
					   GFP_KERNEL);
	if (!ts)
		return -ENOMEM;
129

130 131 132 133 134 135 136 137 138
	ts->rd = fget(rfd);
	ts->wr = fget(wfd);
	if (!ts->rd || !ts->wr) {
		if (ts->rd)
			fput(ts->rd);
		if (ts->wr)
			fput(ts->wr);
		kfree(ts);
		return -EIO;
139 140
	}

141 142
	trans->priv = ts;
	trans->status = Connected;
143

144
	return 0;
145 146
}

147
static int p9_socket_open(struct p9_trans *trans, struct socket *csocket)
148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176
{
	int fd, ret;

	csocket->sk->sk_allocation = GFP_NOIO;
	fd = sock_map_fd(csocket);
	if (fd < 0) {
		P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
		return fd;
	}

	ret = p9_fd_open(trans, fd, fd);
	if (ret < 0) {
		P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to open fd\n");
		sockfd_put(csocket);
		return ret;
	}

	((struct p9_trans_fd *)trans->priv)->rd->f_flags |= O_NONBLOCK;

	return 0;
}

/**
 * p9_fd_read- read from a fd
 * @v9ses: session information
 * @v: buffer to receive data into
 * @len: size of receive buffer
 *
 */
177
static int p9_fd_read(struct p9_trans *trans, void *v, int len)
178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203
{
	int ret;
	struct p9_trans_fd *ts = NULL;

	if (trans && trans->status != Disconnected)
		ts = trans->priv;

	if (!ts)
		return -EREMOTEIO;

	if (!(ts->rd->f_flags & O_NONBLOCK))
		P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");

	ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
	if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
		trans->status = Disconnected;
	return ret;
}

/**
 * p9_fd_write - write to a socket
 * @v9ses: session information
 * @v: buffer to send data from
 * @len: size of send buffer
 *
 */
204
static int p9_fd_write(struct p9_trans *trans, void *v, int len)
205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230
{
	int ret;
	mm_segment_t oldfs;
	struct p9_trans_fd *ts = NULL;

	if (trans && trans->status != Disconnected)
		ts = trans->priv;

	if (!ts)
		return -EREMOTEIO;

	if (!(ts->wr->f_flags & O_NONBLOCK))
		P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");

	oldfs = get_fs();
	set_fs(get_ds());
	/* The cast to a user pointer is valid due to the set_fs() */
	ret = vfs_write(ts->wr, (void __user *)v, len, &ts->wr->f_pos);
	set_fs(oldfs);

	if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
		trans->status = Disconnected;
	return ret;
}

static unsigned int
231
p9_fd_poll(struct p9_trans *trans, struct poll_table_struct *pt)
232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274
{
	int ret, n;
	struct p9_trans_fd *ts = NULL;
	mm_segment_t oldfs;

	if (trans && trans->status == Connected)
		ts = trans->priv;

	if (!ts)
		return -EREMOTEIO;

	if (!ts->rd->f_op || !ts->rd->f_op->poll)
		return -EIO;

	if (!ts->wr->f_op || !ts->wr->f_op->poll)
		return -EIO;

	oldfs = get_fs();
	set_fs(get_ds());

	ret = ts->rd->f_op->poll(ts->rd, pt);
	if (ret < 0)
		goto end;

	if (ts->rd != ts->wr) {
		n = ts->wr->f_op->poll(ts->wr, pt);
		if (n < 0) {
			ret = n;
			goto end;
		}
		ret = (ret & ~POLLOUT) | (n & ~POLLIN);
	}

end:
	set_fs(oldfs);
	return ret;
}

/**
 * p9_sock_close - shutdown socket
 * @trans: private socket structure
 *
 */
275
static void p9_fd_close(struct p9_trans *trans)
276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294
{
	struct p9_trans_fd *ts;

	if (!trans)
		return;

	ts = xchg(&trans->priv, NULL);

	if (!ts)
		return;

	trans->status = Disconnected;
	if (ts->rd)
		fput(ts->rd);
	if (ts->wr)
		fput(ts->wr);
	kfree(ts);
}

295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473
static struct p9_trans *p9_trans_create_tcp(const char *addr, char *args)
{
	int err;
	struct p9_trans *trans;
	struct socket *csocket;
	struct sockaddr_in sin_server;
	struct p9_fd_opts opts;

	parse_opts(args, &opts);

	csocket = NULL;
	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
	if (!trans)
		return ERR_PTR(-ENOMEM);

	trans->write = p9_fd_write;
	trans->read = p9_fd_read;
	trans->close = p9_fd_close;
	trans->poll = p9_fd_poll;

	sin_server.sin_family = AF_INET;
	sin_server.sin_addr.s_addr = in_aton(addr);
	sin_server.sin_port = htons(opts.port);
	sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &csocket);

	if (!csocket) {
		P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
		err = -EIO;
		goto error;
	}

	err = csocket->ops->connect(csocket,
				    (struct sockaddr *)&sin_server,
				    sizeof(struct sockaddr_in), 0);
	if (err < 0) {
		P9_EPRINTK(KERN_ERR,
			"p9_trans_tcp: problem connecting socket to %s\n",
			addr);
		goto error;
	}

	err = p9_socket_open(trans, csocket);
	if (err < 0)
		goto error;

	return trans;

error:
	if (csocket)
		sock_release(csocket);

	kfree(trans);
	return ERR_PTR(err);
}

static struct p9_trans *p9_trans_create_unix(const char *addr, char *args)
{
	int err;
	struct socket *csocket;
	struct sockaddr_un sun_server;
	struct p9_trans *trans;

	csocket = NULL;
	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
	if (!trans)
		return ERR_PTR(-ENOMEM);

	trans->write = p9_fd_write;
	trans->read = p9_fd_read;
	trans->close = p9_fd_close;
	trans->poll = p9_fd_poll;

	if (strlen(addr) > UNIX_PATH_MAX) {
		P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
			addr);
		err = -ENAMETOOLONG;
		goto error;
	}

	sun_server.sun_family = PF_UNIX;
	strcpy(sun_server.sun_path, addr);
	sock_create_kern(PF_UNIX, SOCK_STREAM, 0, &csocket);
	err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
			sizeof(struct sockaddr_un) - 1, 0);
	if (err < 0) {
		P9_EPRINTK(KERN_ERR,
			"p9_trans_unix: problem connecting socket: %s: %d\n",
			addr, err);
		goto error;
	}

	err = p9_socket_open(trans, csocket);
	if (err < 0)
		goto error;

	return trans;

error:
	if (csocket)
		sock_release(csocket);

	kfree(trans);
	return ERR_PTR(err);
}

static struct p9_trans *p9_trans_create_fd(const char *name, char *args)
{
	int err;
	struct p9_trans *trans;
	struct p9_fd_opts opts;

	parse_opts(args, &opts);

	if (opts.rfd == ~0 || opts.wfd == ~0) {
		printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
		return ERR_PTR(-ENOPROTOOPT);
	}

	trans = kmalloc(sizeof(struct p9_trans), GFP_KERNEL);
	if (!trans)
		return ERR_PTR(-ENOMEM);

	trans->write = p9_fd_write;
	trans->read = p9_fd_read;
	trans->close = p9_fd_close;
	trans->poll = p9_fd_poll;

	err = p9_fd_open(trans, opts.rfd, opts.wfd);
	if (err < 0)
		goto error;

	return trans;

error:
	kfree(trans);
	return ERR_PTR(err);
}

static struct p9_trans_module p9_tcp_trans = {
	.name = "tcp",
	.maxsize = MAX_SOCK_BUF,
	.def = 1,
	.create = p9_trans_create_tcp,
};

static struct p9_trans_module p9_unix_trans = {
	.name = "unix",
	.maxsize = MAX_SOCK_BUF,
	.def = 0,
	.create = p9_trans_create_unix,
};

static struct p9_trans_module p9_fd_trans = {
	.name = "fd",
	.maxsize = MAX_SOCK_BUF,
	.def = 0,
	.create = p9_trans_create_fd,
};

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 1;
}

static void __exit p9_trans_fd_exit(void) {
	printk(KERN_ERR "Removal of 9p transports not implemented\n");
	BUG();
}

module_init(p9_trans_fd_init);
module_exit(p9_trans_fd_exit);

MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
MODULE_LICENSE("GPL");