aboutsummaryrefslogtreecommitdiffstats
path: root/net/sunrpc/xprtsock.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/sunrpc/xprtsock.c')
-rw-r--r--net/sunrpc/xprtsock.c1252
1 files changed, 1252 insertions, 0 deletions
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
new file mode 100644
index 000000000000..2e1529217e65
--- /dev/null
+++ b/net/sunrpc/xprtsock.c
@@ -0,0 +1,1252 @@
1/*
2 * linux/net/sunrpc/xprtsock.c
3 *
4 * Client-side transport implementation for sockets.
5 *
6 * TCP callback races fixes (C) 1998 Red Hat Software <alan@redhat.com>
7 * TCP send fixes (C) 1998 Red Hat Software <alan@redhat.com>
8 * TCP NFS related read + write fixes
9 * (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
10 *
11 * Rewrite of larges part of the code in order to stabilize TCP stuff.
12 * Fix behaviour when socket buffer is full.
13 * (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
14 *
15 * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
16 */
17
18#include <linux/types.h>
19#include <linux/slab.h>
20#include <linux/capability.h>
21#include <linux/sched.h>
22#include <linux/pagemap.h>
23#include <linux/errno.h>
24#include <linux/socket.h>
25#include <linux/in.h>
26#include <linux/net.h>
27#include <linux/mm.h>
28#include <linux/udp.h>
29#include <linux/tcp.h>
30#include <linux/sunrpc/clnt.h>
31#include <linux/file.h>
32
33#include <net/sock.h>
34#include <net/checksum.h>
35#include <net/udp.h>
36#include <net/tcp.h>
37
38/*
39 * How many times to try sending a request on a socket before waiting
40 * for the socket buffer to clear.
41 */
42#define XS_SENDMSG_RETRY (10U)
43
44/*
45 * Time out for an RPC UDP socket connect. UDP socket connects are
46 * synchronous, but we set a timeout anyway in case of resource
47 * exhaustion on the local host.
48 */
49#define XS_UDP_CONN_TO (5U * HZ)
50
51/*
52 * Wait duration for an RPC TCP connection to be established. Solaris
53 * NFS over TCP uses 60 seconds, for example, which is in line with how
54 * long a server takes to reboot.
55 */
56#define XS_TCP_CONN_TO (60U * HZ)
57
58/*
59 * Wait duration for a reply from the RPC portmapper.
60 */
61#define XS_BIND_TO (60U * HZ)
62
63/*
64 * Delay if a UDP socket connect error occurs. This is most likely some
65 * kind of resource problem on the local host.
66 */
67#define XS_UDP_REEST_TO (2U * HZ)
68
69/*
70 * The reestablish timeout allows clients to delay for a bit before attempting
71 * to reconnect to a server that just dropped our connection.
72 *
73 * We implement an exponential backoff when trying to reestablish a TCP
74 * transport connection with the server. Some servers like to drop a TCP
75 * connection when they are overworked, so we start with a short timeout and
76 * increase over time if the server is down or not responding.
77 */
78#define XS_TCP_INIT_REEST_TO (3U * HZ)
79#define XS_TCP_MAX_REEST_TO (5U * 60 * HZ)
80
81/*
82 * TCP idle timeout; client drops the transport socket if it is idle
83 * for this long. Note that we also timeout UDP sockets to prevent
84 * holding port numbers when there is no RPC traffic.
85 */
86#define XS_IDLE_DISC_TO (5U * 60 * HZ)
87
88#ifdef RPC_DEBUG
89# undef RPC_DEBUG_DATA
90# define RPCDBG_FACILITY RPCDBG_TRANS
91#endif
92
93#ifdef RPC_DEBUG_DATA
94static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
95{
96 u8 *buf = (u8 *) packet;
97 int j;
98
99 dprintk("RPC: %s\n", msg);
100 for (j = 0; j < count && j < 128; j += 4) {
101 if (!(j & 31)) {
102 if (j)
103 dprintk("\n");
104 dprintk("0x%04x ", j);
105 }
106 dprintk("%02x%02x%02x%02x ",
107 buf[j], buf[j+1], buf[j+2], buf[j+3]);
108 }
109 dprintk("\n");
110}
111#else
112static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
113{
114 /* NOP */
115}
116#endif
117
118#define XS_SENDMSG_FLAGS (MSG_DONTWAIT | MSG_NOSIGNAL)
119
120static inline int xs_send_head(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, unsigned int len)
121{
122 struct kvec iov = {
123 .iov_base = xdr->head[0].iov_base + base,
124 .iov_len = len - base,
125 };
126 struct msghdr msg = {
127 .msg_name = addr,
128 .msg_namelen = addrlen,
129 .msg_flags = XS_SENDMSG_FLAGS,
130 };
131
132 if (xdr->len > len)
133 msg.msg_flags |= MSG_MORE;
134
135 if (likely(iov.iov_len))
136 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
137 return kernel_sendmsg(sock, &msg, NULL, 0, 0);
138}
139
140static int xs_send_tail(struct socket *sock, struct xdr_buf *xdr, unsigned int base, unsigned int len)
141{
142 struct kvec iov = {
143 .iov_base = xdr->tail[0].iov_base + base,
144 .iov_len = len - base,
145 };
146 struct msghdr msg = {
147 .msg_flags = XS_SENDMSG_FLAGS,
148 };
149
150 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
151}
152
153/**
154 * xs_sendpages - write pages directly to a socket
155 * @sock: socket to send on
156 * @addr: UDP only -- address of destination
157 * @addrlen: UDP only -- length of destination address
158 * @xdr: buffer containing this request
159 * @base: starting position in the buffer
160 *
161 */
162static inline int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
163{
164 struct page **ppage = xdr->pages;
165 unsigned int len, pglen = xdr->page_len;
166 int err, ret = 0;
167 ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
168
169 if (unlikely(!sock))
170 return -ENOTCONN;
171
172 clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
173
174 len = xdr->head[0].iov_len;
175 if (base < len || (addr != NULL && base == 0)) {
176 err = xs_send_head(sock, addr, addrlen, xdr, base, len);
177 if (ret == 0)
178 ret = err;
179 else if (err > 0)
180 ret += err;
181 if (err != (len - base))
182 goto out;
183 base = 0;
184 } else
185 base -= len;
186
187 if (unlikely(pglen == 0))
188 goto copy_tail;
189 if (unlikely(base >= pglen)) {
190 base -= pglen;
191 goto copy_tail;
192 }
193 if (base || xdr->page_base) {
194 pglen -= base;
195 base += xdr->page_base;
196 ppage += base >> PAGE_CACHE_SHIFT;
197 base &= ~PAGE_CACHE_MASK;
198 }
199
200 sendpage = sock->ops->sendpage ? : sock_no_sendpage;
201 do {
202 int flags = XS_SENDMSG_FLAGS;
203
204 len = PAGE_CACHE_SIZE;
205 if (base)
206 len -= base;
207 if (pglen < len)
208 len = pglen;
209
210 if (pglen != len || xdr->tail[0].iov_len != 0)
211 flags |= MSG_MORE;
212
213 /* Hmm... We might be dealing with highmem pages */
214 if (PageHighMem(*ppage))
215 sendpage = sock_no_sendpage;
216 err = sendpage(sock, *ppage, base, len, flags);
217 if (ret == 0)
218 ret = err;
219 else if (err > 0)
220 ret += err;
221 if (err != len)
222 goto out;
223 base = 0;
224 ppage++;
225 } while ((pglen -= len) != 0);
226copy_tail:
227 len = xdr->tail[0].iov_len;
228 if (base < len) {
229 err = xs_send_tail(sock, xdr, base, len);
230 if (ret == 0)
231 ret = err;
232 else if (err > 0)
233 ret += err;
234 }
235out:
236 return ret;
237}
238
239/**
240 * xs_nospace - place task on wait queue if transmit was incomplete
241 * @task: task to put to sleep
242 *
243 */
244static void xs_nospace(struct rpc_task *task)
245{
246 struct rpc_rqst *req = task->tk_rqstp;
247 struct rpc_xprt *xprt = req->rq_xprt;
248
249 dprintk("RPC: %4d xmit incomplete (%u left of %u)\n",
250 task->tk_pid, req->rq_slen - req->rq_bytes_sent,
251 req->rq_slen);
252
253 if (test_bit(SOCK_ASYNC_NOSPACE, &xprt->sock->flags)) {
254 /* Protect against races with write_space */
255 spin_lock_bh(&xprt->transport_lock);
256
257 /* Don't race with disconnect */
258 if (!xprt_connected(xprt))
259 task->tk_status = -ENOTCONN;
260 else if (test_bit(SOCK_NOSPACE, &xprt->sock->flags))
261 xprt_wait_for_buffer_space(task);
262
263 spin_unlock_bh(&xprt->transport_lock);
264 } else
265 /* Keep holding the socket if it is blocked */
266 rpc_delay(task, HZ>>4);
267}
268
269/**
270 * xs_udp_send_request - write an RPC request to a UDP socket
271 * @task: address of RPC task that manages the state of an RPC request
272 *
273 * Return values:
274 * 0: The request has been sent
275 * EAGAIN: The socket was blocked, please call again later to
276 * complete the request
277 * ENOTCONN: Caller needs to invoke connect logic then call again
278 * other: Some other error occured, the request was not sent
279 */
280static int xs_udp_send_request(struct rpc_task *task)
281{
282 struct rpc_rqst *req = task->tk_rqstp;
283 struct rpc_xprt *xprt = req->rq_xprt;
284 struct xdr_buf *xdr = &req->rq_snd_buf;
285 int status;
286
287 xs_pktdump("packet data:",
288 req->rq_svec->iov_base,
289 req->rq_svec->iov_len);
290
291 req->rq_xtime = jiffies;
292 status = xs_sendpages(xprt->sock, (struct sockaddr *) &xprt->addr,
293 sizeof(xprt->addr), xdr, req->rq_bytes_sent);
294
295 dprintk("RPC: xs_udp_send_request(%u) = %d\n",
296 xdr->len - req->rq_bytes_sent, status);
297
298 if (likely(status >= (int) req->rq_slen))
299 return 0;
300
301 /* Still some bytes left; set up for a retry later. */
302 if (status > 0)
303 status = -EAGAIN;
304
305 switch (status) {
306 case -ENETUNREACH:
307 case -EPIPE:
308 case -ECONNREFUSED:
309 /* When the server has died, an ICMP port unreachable message
310 * prompts ECONNREFUSED. */
311 break;
312 case -EAGAIN:
313 xs_nospace(task);
314 break;
315 default:
316 dprintk("RPC: sendmsg returned unrecognized error %d\n",
317 -status);
318 break;
319 }
320
321 return status;
322}
323
324static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
325{
326 u32 reclen = buf->len - sizeof(rpc_fraghdr);
327 rpc_fraghdr *base = buf->head[0].iov_base;
328 *base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
329}
330
331/**
332 * xs_tcp_send_request - write an RPC request to a TCP socket
333 * @task: address of RPC task that manages the state of an RPC request
334 *
335 * Return values:
336 * 0: The request has been sent
337 * EAGAIN: The socket was blocked, please call again later to
338 * complete the request
339 * ENOTCONN: Caller needs to invoke connect logic then call again
340 * other: Some other error occured, the request was not sent
341 *
342 * XXX: In the case of soft timeouts, should we eventually give up
343 * if sendmsg is not able to make progress?
344 */
345static int xs_tcp_send_request(struct rpc_task *task)
346{
347 struct rpc_rqst *req = task->tk_rqstp;
348 struct rpc_xprt *xprt = req->rq_xprt;
349 struct xdr_buf *xdr = &req->rq_snd_buf;
350 int status, retry = 0;
351
352 xs_encode_tcp_record_marker(&req->rq_snd_buf);
353
354 xs_pktdump("packet data:",
355 req->rq_svec->iov_base,
356 req->rq_svec->iov_len);
357
358 /* Continue transmitting the packet/record. We must be careful
359 * to cope with writespace callbacks arriving _after_ we have
360 * called sendmsg(). */
361 while (1) {
362 req->rq_xtime = jiffies;
363 status = xs_sendpages(xprt->sock, NULL, 0, xdr,
364 req->rq_bytes_sent);
365
366 dprintk("RPC: xs_tcp_send_request(%u) = %d\n",
367 xdr->len - req->rq_bytes_sent, status);
368
369 if (unlikely(status < 0))
370 break;
371
372 /* If we've sent the entire packet, immediately
373 * reset the count of bytes sent. */
374 req->rq_bytes_sent += status;
375 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
376 req->rq_bytes_sent = 0;
377 return 0;
378 }
379
380 status = -EAGAIN;
381 if (retry++ > XS_SENDMSG_RETRY)
382 break;
383 }
384
385 switch (status) {
386 case -EAGAIN:
387 xs_nospace(task);
388 break;
389 case -ECONNREFUSED:
390 case -ECONNRESET:
391 case -ENOTCONN:
392 case -EPIPE:
393 status = -ENOTCONN;
394 break;
395 default:
396 dprintk("RPC: sendmsg returned unrecognized error %d\n",
397 -status);
398 xprt_disconnect(xprt);
399 break;
400 }
401
402 return status;
403}
404
405/**
406 * xs_close - close a socket
407 * @xprt: transport
408 *
409 * This is used when all requests are complete; ie, no DRC state remains
410 * on the server we want to save.
411 */
412static void xs_close(struct rpc_xprt *xprt)
413{
414 struct socket *sock = xprt->sock;
415 struct sock *sk = xprt->inet;
416
417 if (!sk)
418 return;
419
420 dprintk("RPC: xs_close xprt %p\n", xprt);
421
422 write_lock_bh(&sk->sk_callback_lock);
423 xprt->inet = NULL;
424 xprt->sock = NULL;
425
426 sk->sk_user_data = NULL;
427 sk->sk_data_ready = xprt->old_data_ready;
428 sk->sk_state_change = xprt->old_state_change;
429 sk->sk_write_space = xprt->old_write_space;
430 write_unlock_bh(&sk->sk_callback_lock);
431
432 sk->sk_no_check = 0;
433
434 sock_release(sock);
435}
436
437/**
438 * xs_destroy - prepare to shutdown a transport
439 * @xprt: doomed transport
440 *
441 */
442static void xs_destroy(struct rpc_xprt *xprt)
443{
444 dprintk("RPC: xs_destroy xprt %p\n", xprt);
445
446 cancel_delayed_work(&xprt->connect_worker);
447 flush_scheduled_work();
448
449 xprt_disconnect(xprt);
450 xs_close(xprt);
451 kfree(xprt->slot);
452}
453
454static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
455{
456 return (struct rpc_xprt *) sk->sk_user_data;
457}
458
459/**
460 * xs_udp_data_ready - "data ready" callback for UDP sockets
461 * @sk: socket with data to read
462 * @len: how much data to read
463 *
464 */
465static void xs_udp_data_ready(struct sock *sk, int len)
466{
467 struct rpc_task *task;
468 struct rpc_xprt *xprt;
469 struct rpc_rqst *rovr;
470 struct sk_buff *skb;
471 int err, repsize, copied;
472 u32 _xid, *xp;
473
474 read_lock(&sk->sk_callback_lock);
475 dprintk("RPC: xs_udp_data_ready...\n");
476 if (!(xprt = xprt_from_sock(sk)))
477 goto out;
478
479 if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
480 goto out;
481
482 if (xprt->shutdown)
483 goto dropit;
484
485 repsize = skb->len - sizeof(struct udphdr);
486 if (repsize < 4) {
487 dprintk("RPC: impossible RPC reply size %d!\n", repsize);
488 goto dropit;
489 }
490
491 /* Copy the XID from the skb... */
492 xp = skb_header_pointer(skb, sizeof(struct udphdr),
493 sizeof(_xid), &_xid);
494 if (xp == NULL)
495 goto dropit;
496
497 /* Look up and lock the request corresponding to the given XID */
498 spin_lock(&xprt->transport_lock);
499 rovr = xprt_lookup_rqst(xprt, *xp);
500 if (!rovr)
501 goto out_unlock;
502 task = rovr->rq_task;
503
504 if ((copied = rovr->rq_private_buf.buflen) > repsize)
505 copied = repsize;
506
507 /* Suck it into the iovec, verify checksum if not done by hw. */
508 if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb))
509 goto out_unlock;
510
511 /* Something worked... */
512 dst_confirm(skb->dst);
513
514 xprt_adjust_cwnd(task, copied);
515 xprt_update_rtt(task);
516 xprt_complete_rqst(task, copied);
517
518 out_unlock:
519 spin_unlock(&xprt->transport_lock);
520 dropit:
521 skb_free_datagram(sk, skb);
522 out:
523 read_unlock(&sk->sk_callback_lock);
524}
525
526static inline size_t xs_tcp_copy_data(skb_reader_t *desc, void *p, size_t len)
527{
528 if (len > desc->count)
529 len = desc->count;
530 if (skb_copy_bits(desc->skb, desc->offset, p, len)) {
531 dprintk("RPC: failed to copy %zu bytes from skb. %zu bytes remain\n",
532 len, desc->count);
533 return 0;
534 }
535 desc->offset += len;
536 desc->count -= len;
537 dprintk("RPC: copied %zu bytes from skb. %zu bytes remain\n",
538 len, desc->count);
539 return len;
540}
541
542static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc)
543{
544 size_t len, used;
545 char *p;
546
547 p = ((char *) &xprt->tcp_recm) + xprt->tcp_offset;
548 len = sizeof(xprt->tcp_recm) - xprt->tcp_offset;
549 used = xs_tcp_copy_data(desc, p, len);
550 xprt->tcp_offset += used;
551 if (used != len)
552 return;
553
554 xprt->tcp_reclen = ntohl(xprt->tcp_recm);
555 if (xprt->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
556 xprt->tcp_flags |= XPRT_LAST_FRAG;
557 else
558 xprt->tcp_flags &= ~XPRT_LAST_FRAG;
559 xprt->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
560
561 xprt->tcp_flags &= ~XPRT_COPY_RECM;
562 xprt->tcp_offset = 0;
563
564 /* Sanity check of the record length */
565 if (unlikely(xprt->tcp_reclen < 4)) {
566 dprintk("RPC: invalid TCP record fragment length\n");
567 xprt_disconnect(xprt);
568 return;
569 }
570 dprintk("RPC: reading TCP record fragment of length %d\n",
571 xprt->tcp_reclen);
572}
573
574static void xs_tcp_check_recm(struct rpc_xprt *xprt)
575{
576 dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u, tcp_flags = %lx\n",
577 xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen, xprt->tcp_flags);
578 if (xprt->tcp_offset == xprt->tcp_reclen) {
579 xprt->tcp_flags |= XPRT_COPY_RECM;
580 xprt->tcp_offset = 0;
581 if (xprt->tcp_flags & XPRT_LAST_FRAG) {
582 xprt->tcp_flags &= ~XPRT_COPY_DATA;
583 xprt->tcp_flags |= XPRT_COPY_XID;
584 xprt->tcp_copied = 0;
585 }
586 }
587}
588
589static inline void xs_tcp_read_xid(struct rpc_xprt *xprt, skb_reader_t *desc)
590{
591 size_t len, used;
592 char *p;
593
594 len = sizeof(xprt->tcp_xid) - xprt->tcp_offset;
595 dprintk("RPC: reading XID (%Zu bytes)\n", len);
596 p = ((char *) &xprt->tcp_xid) + xprt->tcp_offset;
597 used = xs_tcp_copy_data(desc, p, len);
598 xprt->tcp_offset += used;
599 if (used != len)
600 return;
601 xprt->tcp_flags &= ~XPRT_COPY_XID;
602 xprt->tcp_flags |= XPRT_COPY_DATA;
603 xprt->tcp_copied = 4;
604 dprintk("RPC: reading reply for XID %08x\n",
605 ntohl(xprt->tcp_xid));
606 xs_tcp_check_recm(xprt);
607}
608
609static inline void xs_tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc)
610{
611 struct rpc_rqst *req;
612 struct xdr_buf *rcvbuf;
613 size_t len;
614 ssize_t r;
615
616 /* Find and lock the request corresponding to this xid */
617 spin_lock(&xprt->transport_lock);
618 req = xprt_lookup_rqst(xprt, xprt->tcp_xid);
619 if (!req) {
620 xprt->tcp_flags &= ~XPRT_COPY_DATA;
621 dprintk("RPC: XID %08x request not found!\n",
622 ntohl(xprt->tcp_xid));
623 spin_unlock(&xprt->transport_lock);
624 return;
625 }
626
627 rcvbuf = &req->rq_private_buf;
628 len = desc->count;
629 if (len > xprt->tcp_reclen - xprt->tcp_offset) {
630 skb_reader_t my_desc;
631
632 len = xprt->tcp_reclen - xprt->tcp_offset;
633 memcpy(&my_desc, desc, sizeof(my_desc));
634 my_desc.count = len;
635 r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
636 &my_desc, xs_tcp_copy_data);
637 desc->count -= r;
638 desc->offset += r;
639 } else
640 r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
641 desc, xs_tcp_copy_data);
642
643 if (r > 0) {
644 xprt->tcp_copied += r;
645 xprt->tcp_offset += r;
646 }
647 if (r != len) {
648 /* Error when copying to the receive buffer,
649 * usually because we weren't able to allocate
650 * additional buffer pages. All we can do now
651 * is turn off XPRT_COPY_DATA, so the request
652 * will not receive any additional updates,
653 * and time out.
654 * Any remaining data from this record will
655 * be discarded.
656 */
657 xprt->tcp_flags &= ~XPRT_COPY_DATA;
658 dprintk("RPC: XID %08x truncated request\n",
659 ntohl(xprt->tcp_xid));
660 dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
661 xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
662 goto out;
663 }
664
665 dprintk("RPC: XID %08x read %Zd bytes\n",
666 ntohl(xprt->tcp_xid), r);
667 dprintk("RPC: xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
668 xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
669
670 if (xprt->tcp_copied == req->rq_private_buf.buflen)
671 xprt->tcp_flags &= ~XPRT_COPY_DATA;
672 else if (xprt->tcp_offset == xprt->tcp_reclen) {
673 if (xprt->tcp_flags & XPRT_LAST_FRAG)
674 xprt->tcp_flags &= ~XPRT_COPY_DATA;
675 }
676
677out:
678 if (!(xprt->tcp_flags & XPRT_COPY_DATA))
679 xprt_complete_rqst(req->rq_task, xprt->tcp_copied);
680 spin_unlock(&xprt->transport_lock);
681 xs_tcp_check_recm(xprt);
682}
683
684static inline void xs_tcp_read_discard(struct rpc_xprt *xprt, skb_reader_t *desc)
685{
686 size_t len;
687
688 len = xprt->tcp_reclen - xprt->tcp_offset;
689 if (len > desc->count)
690 len = desc->count;
691 desc->count -= len;
692 desc->offset += len;
693 xprt->tcp_offset += len;
694 dprintk("RPC: discarded %Zu bytes\n", len);
695 xs_tcp_check_recm(xprt);
696}
697
698static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
699{
700 struct rpc_xprt *xprt = rd_desc->arg.data;
701 skb_reader_t desc = {
702 .skb = skb,
703 .offset = offset,
704 .count = len,
705 .csum = 0
706 };
707
708 dprintk("RPC: xs_tcp_data_recv started\n");
709 do {
710 /* Read in a new fragment marker if necessary */
711 /* Can we ever really expect to get completely empty fragments? */
712 if (xprt->tcp_flags & XPRT_COPY_RECM) {
713 xs_tcp_read_fraghdr(xprt, &desc);
714 continue;
715 }
716 /* Read in the xid if necessary */
717 if (xprt->tcp_flags & XPRT_COPY_XID) {
718 xs_tcp_read_xid(xprt, &desc);
719 continue;
720 }
721 /* Read in the request data */
722 if (xprt->tcp_flags & XPRT_COPY_DATA) {
723 xs_tcp_read_request(xprt, &desc);
724 continue;
725 }
726 /* Skip over any trailing bytes on short reads */
727 xs_tcp_read_discard(xprt, &desc);
728 } while (desc.count);
729 dprintk("RPC: xs_tcp_data_recv done\n");
730 return len - desc.count;
731}
732
733/**
734 * xs_tcp_data_ready - "data ready" callback for TCP sockets
735 * @sk: socket with data to read
736 * @bytes: how much data to read
737 *
738 */
739static void xs_tcp_data_ready(struct sock *sk, int bytes)
740{
741 struct rpc_xprt *xprt;
742 read_descriptor_t rd_desc;
743
744 read_lock(&sk->sk_callback_lock);
745 dprintk("RPC: xs_tcp_data_ready...\n");
746 if (!(xprt = xprt_from_sock(sk)))
747 goto out;
748 if (xprt->shutdown)
749 goto out;
750
751 /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
752 rd_desc.arg.data = xprt;
753 rd_desc.count = 65536;
754 tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
755out:
756 read_unlock(&sk->sk_callback_lock);
757}
758
759/**
760 * xs_tcp_state_change - callback to handle TCP socket state changes
761 * @sk: socket whose state has changed
762 *
763 */
764static void xs_tcp_state_change(struct sock *sk)
765{
766 struct rpc_xprt *xprt;
767
768 read_lock(&sk->sk_callback_lock);
769 if (!(xprt = xprt_from_sock(sk)))
770 goto out;
771 dprintk("RPC: xs_tcp_state_change client %p...\n", xprt);
772 dprintk("RPC: state %x conn %d dead %d zapped %d\n",
773 sk->sk_state, xprt_connected(xprt),
774 sock_flag(sk, SOCK_DEAD),
775 sock_flag(sk, SOCK_ZAPPED));
776
777 switch (sk->sk_state) {
778 case TCP_ESTABLISHED:
779 spin_lock_bh(&xprt->transport_lock);
780 if (!xprt_test_and_set_connected(xprt)) {
781 /* Reset TCP record info */
782 xprt->tcp_offset = 0;
783 xprt->tcp_reclen = 0;
784 xprt->tcp_copied = 0;
785 xprt->tcp_flags = XPRT_COPY_RECM | XPRT_COPY_XID;
786 xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
787 xprt_wake_pending_tasks(xprt, 0);
788 }
789 spin_unlock_bh(&xprt->transport_lock);
790 break;
791 case TCP_SYN_SENT:
792 case TCP_SYN_RECV:
793 break;
794 default:
795 xprt_disconnect(xprt);
796 break;
797 }
798 out:
799 read_unlock(&sk->sk_callback_lock);
800}
801
802/**
803 * xs_udp_write_space - callback invoked when socket buffer space
804 * becomes available
805 * @sk: socket whose state has changed
806 *
807 * Called when more output buffer space is available for this socket.
808 * We try not to wake our writers until they can make "significant"
809 * progress, otherwise we'll waste resources thrashing kernel_sendmsg
810 * with a bunch of small requests.
811 */
812static void xs_udp_write_space(struct sock *sk)
813{
814 read_lock(&sk->sk_callback_lock);
815
816 /* from net/core/sock.c:sock_def_write_space */
817 if (sock_writeable(sk)) {
818 struct socket *sock;
819 struct rpc_xprt *xprt;
820
821 if (unlikely(!(sock = sk->sk_socket)))
822 goto out;
823 if (unlikely(!(xprt = xprt_from_sock(sk))))
824 goto out;
825 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
826 goto out;
827
828 xprt_write_space(xprt);
829 }
830
831 out:
832 read_unlock(&sk->sk_callback_lock);
833}
834
835/**
836 * xs_tcp_write_space - callback invoked when socket buffer space
837 * becomes available
838 * @sk: socket whose state has changed
839 *
840 * Called when more output buffer space is available for this socket.
841 * We try not to wake our writers until they can make "significant"
842 * progress, otherwise we'll waste resources thrashing kernel_sendmsg
843 * with a bunch of small requests.
844 */
845static void xs_tcp_write_space(struct sock *sk)
846{
847 read_lock(&sk->sk_callback_lock);
848
849 /* from net/core/stream.c:sk_stream_write_space */
850 if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
851 struct socket *sock;
852 struct rpc_xprt *xprt;
853
854 if (unlikely(!(sock = sk->sk_socket)))
855 goto out;
856 if (unlikely(!(xprt = xprt_from_sock(sk))))
857 goto out;
858 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
859 goto out;
860
861 xprt_write_space(xprt);
862 }
863
864 out:
865 read_unlock(&sk->sk_callback_lock);
866}
867
868static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
869{
870 struct sock *sk = xprt->inet;
871
872 if (xprt->rcvsize) {
873 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
874 sk->sk_rcvbuf = xprt->rcvsize * xprt->max_reqs * 2;
875 }
876 if (xprt->sndsize) {
877 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
878 sk->sk_sndbuf = xprt->sndsize * xprt->max_reqs * 2;
879 sk->sk_write_space(sk);
880 }
881}
882
883/**
884 * xs_udp_set_buffer_size - set send and receive limits
885 * @xprt: generic transport
886 * @sndsize: requested size of send buffer, in bytes
887 * @rcvsize: requested size of receive buffer, in bytes
888 *
889 * Set socket send and receive buffer size limits.
890 */
891static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
892{
893 xprt->sndsize = 0;
894 if (sndsize)
895 xprt->sndsize = sndsize + 1024;
896 xprt->rcvsize = 0;
897 if (rcvsize)
898 xprt->rcvsize = rcvsize + 1024;
899
900 xs_udp_do_set_buffer_size(xprt);
901}
902
903/**
904 * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
905 * @task: task that timed out
906 *
907 * Adjust the congestion window after a retransmit timeout has occurred.
908 */
909static void xs_udp_timer(struct rpc_task *task)
910{
911 xprt_adjust_cwnd(task, -ETIMEDOUT);
912}
913
914static int xs_bindresvport(struct rpc_xprt *xprt, struct socket *sock)
915{
916 struct sockaddr_in myaddr = {
917 .sin_family = AF_INET,
918 };
919 int err;
920 unsigned short port = xprt->port;
921
922 do {
923 myaddr.sin_port = htons(port);
924 err = sock->ops->bind(sock, (struct sockaddr *) &myaddr,
925 sizeof(myaddr));
926 if (err == 0) {
927 xprt->port = port;
928 dprintk("RPC: xs_bindresvport bound to port %u\n",
929 port);
930 return 0;
931 }
932 if (port <= xprt_min_resvport)
933 port = xprt_max_resvport;
934 else
935 port--;
936 } while (err == -EADDRINUSE && port != xprt->port);
937
938 dprintk("RPC: can't bind to reserved port (%d).\n", -err);
939 return err;
940}
941
942/**
943 * xs_udp_connect_worker - set up a UDP socket
944 * @args: RPC transport to connect
945 *
946 * Invoked by a work queue tasklet.
947 */
948static void xs_udp_connect_worker(void *args)
949{
950 struct rpc_xprt *xprt = (struct rpc_xprt *) args;
951 struct socket *sock = xprt->sock;
952 int err, status = -EIO;
953
954 if (xprt->shutdown || xprt->addr.sin_port == 0)
955 goto out;
956
957 dprintk("RPC: xs_udp_connect_worker for xprt %p\n", xprt);
958
959 /* Start by resetting any existing state */
960 xs_close(xprt);
961
962 if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
963 dprintk("RPC: can't create UDP transport socket (%d).\n", -err);
964 goto out;
965 }
966
967 if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
968 sock_release(sock);
969 goto out;
970 }
971
972 if (!xprt->inet) {
973 struct sock *sk = sock->sk;
974
975 write_lock_bh(&sk->sk_callback_lock);
976
977 sk->sk_user_data = xprt;
978 xprt->old_data_ready = sk->sk_data_ready;
979 xprt->old_state_change = sk->sk_state_change;
980 xprt->old_write_space = sk->sk_write_space;
981 sk->sk_data_ready = xs_udp_data_ready;
982 sk->sk_write_space = xs_udp_write_space;
983 sk->sk_no_check = UDP_CSUM_NORCV;
984
985 xprt_set_connected(xprt);
986
987 /* Reset to new socket */
988 xprt->sock = sock;
989 xprt->inet = sk;
990
991 write_unlock_bh(&sk->sk_callback_lock);
992 }
993 xs_udp_do_set_buffer_size(xprt);
994 status = 0;
995out:
996 xprt_wake_pending_tasks(xprt, status);
997 xprt_clear_connecting(xprt);
998}
999
1000/*
1001 * We need to preserve the port number so the reply cache on the server can
1002 * find our cached RPC replies when we get around to reconnecting.
1003 */
1004static void xs_tcp_reuse_connection(struct rpc_xprt *xprt)
1005{
1006 int result;
1007 struct socket *sock = xprt->sock;
1008 struct sockaddr any;
1009
1010 dprintk("RPC: disconnecting xprt %p to reuse port\n", xprt);
1011
1012 /*
1013 * Disconnect the transport socket by doing a connect operation
1014 * with AF_UNSPEC. This should return immediately...
1015 */
1016 memset(&any, 0, sizeof(any));
1017 any.sa_family = AF_UNSPEC;
1018 result = sock->ops->connect(sock, &any, sizeof(any), 0);
1019 if (result)
1020 dprintk("RPC: AF_UNSPEC connect return code %d\n",
1021 result);
1022}
1023
1024/**
1025 * xs_tcp_connect_worker - connect a TCP socket to a remote endpoint
1026 * @args: RPC transport to connect
1027 *
1028 * Invoked by a work queue tasklet.
1029 */
1030static void xs_tcp_connect_worker(void *args)
1031{
1032 struct rpc_xprt *xprt = (struct rpc_xprt *)args;
1033 struct socket *sock = xprt->sock;
1034 int err, status = -EIO;
1035
1036 if (xprt->shutdown || xprt->addr.sin_port == 0)
1037 goto out;
1038
1039 dprintk("RPC: xs_tcp_connect_worker for xprt %p\n", xprt);
1040
1041 if (!xprt->sock) {
1042 /* start from scratch */
1043 if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
1044 dprintk("RPC: can't create TCP transport socket (%d).\n", -err);
1045 goto out;
1046 }
1047
1048 if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
1049 sock_release(sock);
1050 goto out;
1051 }
1052 } else
1053 /* "close" the socket, preserving the local port */
1054 xs_tcp_reuse_connection(xprt);
1055
1056 if (!xprt->inet) {
1057 struct sock *sk = sock->sk;
1058
1059 write_lock_bh(&sk->sk_callback_lock);
1060
1061 sk->sk_user_data = xprt;
1062 xprt->old_data_ready = sk->sk_data_ready;
1063 xprt->old_state_change = sk->sk_state_change;
1064 xprt->old_write_space = sk->sk_write_space;
1065 sk->sk_data_ready = xs_tcp_data_ready;
1066 sk->sk_state_change = xs_tcp_state_change;
1067 sk->sk_write_space = xs_tcp_write_space;
1068
1069 /* socket options */
1070 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
1071 sock_reset_flag(sk, SOCK_LINGER);
1072 tcp_sk(sk)->linger2 = 0;
1073 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1074
1075 xprt_clear_connected(xprt);
1076
1077 /* Reset to new socket */
1078 xprt->sock = sock;
1079 xprt->inet = sk;
1080
1081 write_unlock_bh(&sk->sk_callback_lock);
1082 }
1083
1084 /* Tell the socket layer to start connecting... */
1085 status = sock->ops->connect(sock, (struct sockaddr *) &xprt->addr,
1086 sizeof(xprt->addr), O_NONBLOCK);
1087 dprintk("RPC: %p connect status %d connected %d sock state %d\n",
1088 xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
1089 if (status < 0) {
1090 switch (status) {
1091 case -EINPROGRESS:
1092 case -EALREADY:
1093 goto out_clear;
1094 case -ECONNREFUSED:
1095 case -ECONNRESET:
1096 /* retry with existing socket, after a delay */
1097 break;
1098 default:
1099 /* get rid of existing socket, and retry */
1100 xs_close(xprt);
1101 break;
1102 }
1103 }
1104out:
1105 xprt_wake_pending_tasks(xprt, status);
1106out_clear:
1107 xprt_clear_connecting(xprt);
1108}
1109
1110/**
1111 * xs_connect - connect a socket to a remote endpoint
1112 * @task: address of RPC task that manages state of connect request
1113 *
1114 * TCP: If the remote end dropped the connection, delay reconnecting.
1115 *
1116 * UDP socket connects are synchronous, but we use a work queue anyway
1117 * to guarantee that even unprivileged user processes can set up a
1118 * socket on a privileged port.
1119 *
1120 * If a UDP socket connect fails, the delay behavior here prevents
1121 * retry floods (hard mounts).
1122 */
1123static void xs_connect(struct rpc_task *task)
1124{
1125 struct rpc_xprt *xprt = task->tk_xprt;
1126
1127 if (xprt_test_and_set_connecting(xprt))
1128 return;
1129
1130 if (xprt->sock != NULL) {
1131 dprintk("RPC: xs_connect delayed xprt %p for %lu seconds\n",
1132 xprt, xprt->reestablish_timeout / HZ);
1133 schedule_delayed_work(&xprt->connect_worker,
1134 xprt->reestablish_timeout);
1135 xprt->reestablish_timeout <<= 1;
1136 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
1137 xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
1138 } else {
1139 dprintk("RPC: xs_connect scheduled xprt %p\n", xprt);
1140 schedule_work(&xprt->connect_worker);
1141
1142 /* flush_scheduled_work can sleep... */
1143 if (!RPC_IS_ASYNC(task))
1144 flush_scheduled_work();
1145 }
1146}
1147
1148static struct rpc_xprt_ops xs_udp_ops = {
1149 .set_buffer_size = xs_udp_set_buffer_size,
1150 .reserve_xprt = xprt_reserve_xprt_cong,
1151 .release_xprt = xprt_release_xprt_cong,
1152 .connect = xs_connect,
1153 .send_request = xs_udp_send_request,
1154 .set_retrans_timeout = xprt_set_retrans_timeout_rtt,
1155 .timer = xs_udp_timer,
1156 .release_request = xprt_release_rqst_cong,
1157 .close = xs_close,
1158 .destroy = xs_destroy,
1159};
1160
1161static struct rpc_xprt_ops xs_tcp_ops = {
1162 .reserve_xprt = xprt_reserve_xprt,
1163 .release_xprt = xprt_release_xprt,
1164 .connect = xs_connect,
1165 .send_request = xs_tcp_send_request,
1166 .set_retrans_timeout = xprt_set_retrans_timeout_def,
1167 .close = xs_close,
1168 .destroy = xs_destroy,
1169};
1170
1171/**
1172 * xs_setup_udp - Set up transport to use a UDP socket
1173 * @xprt: transport to set up
1174 * @to: timeout parameters
1175 *
1176 */
1177int xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to)
1178{
1179 size_t slot_table_size;
1180
1181 dprintk("RPC: setting up udp-ipv4 transport...\n");
1182
1183 xprt->max_reqs = xprt_udp_slot_table_entries;
1184 slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]);
1185 xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
1186 if (xprt->slot == NULL)
1187 return -ENOMEM;
1188 memset(xprt->slot, 0, slot_table_size);
1189
1190 xprt->prot = IPPROTO_UDP;
1191 xprt->port = xprt_max_resvport;
1192 xprt->tsh_size = 0;
1193 xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
1194 /* XXX: header size can vary due to auth type, IPv6, etc. */
1195 xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
1196
1197 INIT_WORK(&xprt->connect_worker, xs_udp_connect_worker, xprt);
1198 xprt->bind_timeout = XS_BIND_TO;
1199 xprt->connect_timeout = XS_UDP_CONN_TO;
1200 xprt->reestablish_timeout = XS_UDP_REEST_TO;
1201 xprt->idle_timeout = XS_IDLE_DISC_TO;
1202
1203 xprt->ops = &xs_udp_ops;
1204
1205 if (to)
1206 xprt->timeout = *to;
1207 else
1208 xprt_set_timeout(&xprt->timeout, 5, 5 * HZ);
1209
1210 return 0;
1211}
1212
1213/**
1214 * xs_setup_tcp - Set up transport to use a TCP socket
1215 * @xprt: transport to set up
1216 * @to: timeout parameters
1217 *
1218 */
1219int xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to)
1220{
1221 size_t slot_table_size;
1222
1223 dprintk("RPC: setting up tcp-ipv4 transport...\n");
1224
1225 xprt->max_reqs = xprt_tcp_slot_table_entries;
1226 slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]);
1227 xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
1228 if (xprt->slot == NULL)
1229 return -ENOMEM;
1230 memset(xprt->slot, 0, slot_table_size);
1231
1232 xprt->prot = IPPROTO_TCP;
1233 xprt->port = xprt_max_resvport;
1234 xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
1235 xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
1236 xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
1237
1238 INIT_WORK(&xprt->connect_worker, xs_tcp_connect_worker, xprt);
1239 xprt->bind_timeout = XS_BIND_TO;
1240 xprt->connect_timeout = XS_TCP_CONN_TO;
1241 xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1242 xprt->idle_timeout = XS_IDLE_DISC_TO;
1243
1244 xprt->ops = &xs_tcp_ops;
1245
1246 if (to)
1247 xprt->timeout = *to;
1248 else
1249 xprt_set_timeout(&xprt->timeout, 2, 60 * HZ);
1250
1251 return 0;
1252}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-13 06:40:07 -0500