SUNRPC: select privileged port numbers at random
[linux-2.6] / net / sunrpc / xprtsock.c
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/sunrpc/sched.h>
32 #include <linux/file.h>
33
34 #include <net/sock.h>
35 #include <net/checksum.h>
36 #include <net/udp.h>
37 #include <net/tcp.h>
38
39 /*
40  * xprtsock tunables
41  */
42 unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
43 unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE;
44
45 unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
46 unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
47
48 /*
49  * How many times to try sending a request on a socket before waiting
50  * for the socket buffer to clear.
51  */
52 #define XS_SENDMSG_RETRY        (10U)
53
54 /*
55  * Time out for an RPC UDP socket connect.  UDP socket connects are
56  * synchronous, but we set a timeout anyway in case of resource
57  * exhaustion on the local host.
58  */
59 #define XS_UDP_CONN_TO          (5U * HZ)
60
61 /*
62  * Wait duration for an RPC TCP connection to be established.  Solaris
63  * NFS over TCP uses 60 seconds, for example, which is in line with how
64  * long a server takes to reboot.
65  */
66 #define XS_TCP_CONN_TO          (60U * HZ)
67
68 /*
69  * Wait duration for a reply from the RPC portmapper.
70  */
71 #define XS_BIND_TO              (60U * HZ)
72
73 /*
74  * Delay if a UDP socket connect error occurs.  This is most likely some
75  * kind of resource problem on the local host.
76  */
77 #define XS_UDP_REEST_TO         (2U * HZ)
78
79 /*
80  * The reestablish timeout allows clients to delay for a bit before attempting
81  * to reconnect to a server that just dropped our connection.
82  *
83  * We implement an exponential backoff when trying to reestablish a TCP
84  * transport connection with the server.  Some servers like to drop a TCP
85  * connection when they are overworked, so we start with a short timeout and
86  * increase over time if the server is down or not responding.
87  */
88 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
89 #define XS_TCP_MAX_REEST_TO     (5U * 60 * HZ)
90
91 /*
92  * TCP idle timeout; client drops the transport socket if it is idle
93  * for this long.  Note that we also timeout UDP sockets to prevent
94  * holding port numbers when there is no RPC traffic.
95  */
96 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
97
98 #ifdef RPC_DEBUG
99 # undef  RPC_DEBUG_DATA
100 # define RPCDBG_FACILITY        RPCDBG_TRANS
101 #endif
102
103 #ifdef RPC_DEBUG_DATA
104 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
105 {
106         u8 *buf = (u8 *) packet;
107         int j;
108
109         dprintk("RPC:      %s\n", msg);
110         for (j = 0; j < count && j < 128; j += 4) {
111                 if (!(j & 31)) {
112                         if (j)
113                                 dprintk("\n");
114                         dprintk("0x%04x ", j);
115                 }
116                 dprintk("%02x%02x%02x%02x ",
117                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
118         }
119         dprintk("\n");
120 }
121 #else
122 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
123 {
124         /* NOP */
125 }
126 #endif
127
128 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
129
130 static inline int xs_send_head(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, unsigned int len)
131 {
132         struct kvec iov = {
133                 .iov_base       = xdr->head[0].iov_base + base,
134                 .iov_len        = len - base,
135         };
136         struct msghdr msg = {
137                 .msg_name       = addr,
138                 .msg_namelen    = addrlen,
139                 .msg_flags      = XS_SENDMSG_FLAGS,
140         };
141
142         if (xdr->len > len)
143                 msg.msg_flags |= MSG_MORE;
144
145         if (likely(iov.iov_len))
146                 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
147         return kernel_sendmsg(sock, &msg, NULL, 0, 0);
148 }
149
150 static int xs_send_tail(struct socket *sock, struct xdr_buf *xdr, unsigned int base, unsigned int len)
151 {
152         struct kvec iov = {
153                 .iov_base       = xdr->tail[0].iov_base + base,
154                 .iov_len        = len - base,
155         };
156         struct msghdr msg = {
157                 .msg_flags      = XS_SENDMSG_FLAGS,
158         };
159
160         return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
161 }
162
163 /**
164  * xs_sendpages - write pages directly to a socket
165  * @sock: socket to send on
166  * @addr: UDP only -- address of destination
167  * @addrlen: UDP only -- length of destination address
168  * @xdr: buffer containing this request
169  * @base: starting position in the buffer
170  *
171  */
172 static inline int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
173 {
174         struct page **ppage = xdr->pages;
175         unsigned int len, pglen = xdr->page_len;
176         int err, ret = 0;
177         ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
178
179         if (unlikely(!sock))
180                 return -ENOTCONN;
181
182         clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
183
184         len = xdr->head[0].iov_len;
185         if (base < len || (addr != NULL && base == 0)) {
186                 err = xs_send_head(sock, addr, addrlen, xdr, base, len);
187                 if (ret == 0)
188                         ret = err;
189                 else if (err > 0)
190                         ret += err;
191                 if (err != (len - base))
192                         goto out;
193                 base = 0;
194         } else
195                 base -= len;
196
197         if (unlikely(pglen == 0))
198                 goto copy_tail;
199         if (unlikely(base >= pglen)) {
200                 base -= pglen;
201                 goto copy_tail;
202         }
203         if (base || xdr->page_base) {
204                 pglen -= base;
205                 base += xdr->page_base;
206                 ppage += base >> PAGE_CACHE_SHIFT;
207                 base &= ~PAGE_CACHE_MASK;
208         }
209
210         sendpage = sock->ops->sendpage ? : sock_no_sendpage;
211         do {
212                 int flags = XS_SENDMSG_FLAGS;
213
214                 len = PAGE_CACHE_SIZE;
215                 if (base)
216                         len -= base;
217                 if (pglen < len)
218                         len = pglen;
219
220                 if (pglen != len || xdr->tail[0].iov_len != 0)
221                         flags |= MSG_MORE;
222
223                 /* Hmm... We might be dealing with highmem pages */
224                 if (PageHighMem(*ppage))
225                         sendpage = sock_no_sendpage;
226                 err = sendpage(sock, *ppage, base, len, flags);
227                 if (ret == 0)
228                         ret = err;
229                 else if (err > 0)
230                         ret += err;
231                 if (err != len)
232                         goto out;
233                 base = 0;
234                 ppage++;
235         } while ((pglen -= len) != 0);
236 copy_tail:
237         len = xdr->tail[0].iov_len;
238         if (base < len) {
239                 err = xs_send_tail(sock, xdr, base, len);
240                 if (ret == 0)
241                         ret = err;
242                 else if (err > 0)
243                         ret += err;
244         }
245 out:
246         return ret;
247 }
248
249 /**
250  * xs_nospace - place task on wait queue if transmit was incomplete
251  * @task: task to put to sleep
252  *
253  */
254 static void xs_nospace(struct rpc_task *task)
255 {
256         struct rpc_rqst *req = task->tk_rqstp;
257         struct rpc_xprt *xprt = req->rq_xprt;
258
259         dprintk("RPC: %4d xmit incomplete (%u left of %u)\n",
260                         task->tk_pid, req->rq_slen - req->rq_bytes_sent,
261                         req->rq_slen);
262
263         if (test_bit(SOCK_ASYNC_NOSPACE, &xprt->sock->flags)) {
264                 /* Protect against races with write_space */
265                 spin_lock_bh(&xprt->transport_lock);
266
267                 /* Don't race with disconnect */
268                 if (!xprt_connected(xprt))
269                         task->tk_status = -ENOTCONN;
270                 else if (test_bit(SOCK_NOSPACE, &xprt->sock->flags))
271                         xprt_wait_for_buffer_space(task);
272
273                 spin_unlock_bh(&xprt->transport_lock);
274         } else
275                 /* Keep holding the socket if it is blocked */
276                 rpc_delay(task, HZ>>4);
277 }
278
279 /**
280  * xs_udp_send_request - write an RPC request to a UDP socket
281  * @task: address of RPC task that manages the state of an RPC request
282  *
283  * Return values:
284  *        0:    The request has been sent
285  *   EAGAIN:    The socket was blocked, please call again later to
286  *              complete the request
287  * ENOTCONN:    Caller needs to invoke connect logic then call again
288  *    other:    Some other error occured, the request was not sent
289  */
290 static int xs_udp_send_request(struct rpc_task *task)
291 {
292         struct rpc_rqst *req = task->tk_rqstp;
293         struct rpc_xprt *xprt = req->rq_xprt;
294         struct xdr_buf *xdr = &req->rq_snd_buf;
295         int status;
296
297         xs_pktdump("packet data:",
298                                 req->rq_svec->iov_base,
299                                 req->rq_svec->iov_len);
300
301         req->rq_xtime = jiffies;
302         status = xs_sendpages(xprt->sock, (struct sockaddr *) &xprt->addr,
303                                 sizeof(xprt->addr), xdr, req->rq_bytes_sent);
304
305         dprintk("RPC:      xs_udp_send_request(%u) = %d\n",
306                         xdr->len - req->rq_bytes_sent, status);
307
308         if (likely(status >= (int) req->rq_slen))
309                 return 0;
310
311         /* Still some bytes left; set up for a retry later. */
312         if (status > 0)
313                 status = -EAGAIN;
314
315         switch (status) {
316         case -ENETUNREACH:
317         case -EPIPE:
318         case -ECONNREFUSED:
319                 /* When the server has died, an ICMP port unreachable message
320                  * prompts ECONNREFUSED. */
321                 break;
322         case -EAGAIN:
323                 xs_nospace(task);
324                 break;
325         default:
326                 dprintk("RPC:      sendmsg returned unrecognized error %d\n",
327                         -status);
328                 break;
329         }
330
331         return status;
332 }
333
334 static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
335 {
336         u32 reclen = buf->len - sizeof(rpc_fraghdr);
337         rpc_fraghdr *base = buf->head[0].iov_base;
338         *base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
339 }
340
341 /**
342  * xs_tcp_send_request - write an RPC request to a TCP socket
343  * @task: address of RPC task that manages the state of an RPC request
344  *
345  * Return values:
346  *        0:    The request has been sent
347  *   EAGAIN:    The socket was blocked, please call again later to
348  *              complete the request
349  * ENOTCONN:    Caller needs to invoke connect logic then call again
350  *    other:    Some other error occured, the request was not sent
351  *
352  * XXX: In the case of soft timeouts, should we eventually give up
353  *      if sendmsg is not able to make progress?
354  */
355 static int xs_tcp_send_request(struct rpc_task *task)
356 {
357         struct rpc_rqst *req = task->tk_rqstp;
358         struct rpc_xprt *xprt = req->rq_xprt;
359         struct xdr_buf *xdr = &req->rq_snd_buf;
360         int status, retry = 0;
361
362         xs_encode_tcp_record_marker(&req->rq_snd_buf);
363
364         xs_pktdump("packet data:",
365                                 req->rq_svec->iov_base,
366                                 req->rq_svec->iov_len);
367
368         /* Continue transmitting the packet/record. We must be careful
369          * to cope with writespace callbacks arriving _after_ we have
370          * called sendmsg(). */
371         while (1) {
372                 req->rq_xtime = jiffies;
373                 status = xs_sendpages(xprt->sock, NULL, 0, xdr,
374                                                 req->rq_bytes_sent);
375
376                 dprintk("RPC:      xs_tcp_send_request(%u) = %d\n",
377                                 xdr->len - req->rq_bytes_sent, status);
378
379                 if (unlikely(status < 0))
380                         break;
381
382                 /* If we've sent the entire packet, immediately
383                  * reset the count of bytes sent. */
384                 req->rq_bytes_sent += status;
385                 task->tk_bytes_sent += status;
386                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
387                         req->rq_bytes_sent = 0;
388                         return 0;
389                 }
390
391                 status = -EAGAIN;
392                 if (retry++ > XS_SENDMSG_RETRY)
393                         break;
394         }
395
396         switch (status) {
397         case -EAGAIN:
398                 xs_nospace(task);
399                 break;
400         case -ECONNREFUSED:
401         case -ECONNRESET:
402         case -ENOTCONN:
403         case -EPIPE:
404                 status = -ENOTCONN;
405                 break;
406         default:
407                 dprintk("RPC:      sendmsg returned unrecognized error %d\n",
408                         -status);
409                 xprt_disconnect(xprt);
410                 break;
411         }
412
413         return status;
414 }
415
416 /**
417  * xs_close - close a socket
418  * @xprt: transport
419  *
420  * This is used when all requests are complete; ie, no DRC state remains
421  * on the server we want to save.
422  */
423 static void xs_close(struct rpc_xprt *xprt)
424 {
425         struct socket *sock = xprt->sock;
426         struct sock *sk = xprt->inet;
427
428         if (!sk)
429                 goto clear_close_wait;
430
431         dprintk("RPC:      xs_close xprt %p\n", xprt);
432
433         write_lock_bh(&sk->sk_callback_lock);
434         xprt->inet = NULL;
435         xprt->sock = NULL;
436
437         sk->sk_user_data = NULL;
438         sk->sk_data_ready = xprt->old_data_ready;
439         sk->sk_state_change = xprt->old_state_change;
440         sk->sk_write_space = xprt->old_write_space;
441         write_unlock_bh(&sk->sk_callback_lock);
442
443         sk->sk_no_check = 0;
444
445         sock_release(sock);
446 clear_close_wait:
447         smp_mb__before_clear_bit();
448         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
449         smp_mb__after_clear_bit();
450 }
451
452 /**
453  * xs_destroy - prepare to shutdown a transport
454  * @xprt: doomed transport
455  *
456  */
457 static void xs_destroy(struct rpc_xprt *xprt)
458 {
459         dprintk("RPC:      xs_destroy xprt %p\n", xprt);
460
461         cancel_delayed_work(&xprt->connect_worker);
462         flush_scheduled_work();
463
464         xprt_disconnect(xprt);
465         xs_close(xprt);
466         kfree(xprt->slot);
467 }
468
469 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
470 {
471         return (struct rpc_xprt *) sk->sk_user_data;
472 }
473
474 /**
475  * xs_udp_data_ready - "data ready" callback for UDP sockets
476  * @sk: socket with data to read
477  * @len: how much data to read
478  *
479  */
480 static void xs_udp_data_ready(struct sock *sk, int len)
481 {
482         struct rpc_task *task;
483         struct rpc_xprt *xprt;
484         struct rpc_rqst *rovr;
485         struct sk_buff *skb;
486         int err, repsize, copied;
487         u32 _xid, *xp;
488
489         read_lock(&sk->sk_callback_lock);
490         dprintk("RPC:      xs_udp_data_ready...\n");
491         if (!(xprt = xprt_from_sock(sk)))
492                 goto out;
493
494         if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
495                 goto out;
496
497         if (xprt->shutdown)
498                 goto dropit;
499
500         repsize = skb->len - sizeof(struct udphdr);
501         if (repsize < 4) {
502                 dprintk("RPC:      impossible RPC reply size %d!\n", repsize);
503                 goto dropit;
504         }
505
506         /* Copy the XID from the skb... */
507         xp = skb_header_pointer(skb, sizeof(struct udphdr),
508                                 sizeof(_xid), &_xid);
509         if (xp == NULL)
510                 goto dropit;
511
512         /* Look up and lock the request corresponding to the given XID */
513         spin_lock(&xprt->transport_lock);
514         rovr = xprt_lookup_rqst(xprt, *xp);
515         if (!rovr)
516                 goto out_unlock;
517         task = rovr->rq_task;
518
519         if ((copied = rovr->rq_private_buf.buflen) > repsize)
520                 copied = repsize;
521
522         /* Suck it into the iovec, verify checksum if not done by hw. */
523         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb))
524                 goto out_unlock;
525
526         /* Something worked... */
527         dst_confirm(skb->dst);
528
529         xprt_adjust_cwnd(task, copied);
530         xprt_update_rtt(task);
531         xprt_complete_rqst(task, copied);
532
533  out_unlock:
534         spin_unlock(&xprt->transport_lock);
535  dropit:
536         skb_free_datagram(sk, skb);
537  out:
538         read_unlock(&sk->sk_callback_lock);
539 }
540
541 static inline size_t xs_tcp_copy_data(skb_reader_t *desc, void *p, size_t len)
542 {
543         if (len > desc->count)
544                 len = desc->count;
545         if (skb_copy_bits(desc->skb, desc->offset, p, len)) {
546                 dprintk("RPC:      failed to copy %zu bytes from skb. %zu bytes remain\n",
547                                 len, desc->count);
548                 return 0;
549         }
550         desc->offset += len;
551         desc->count -= len;
552         dprintk("RPC:      copied %zu bytes from skb. %zu bytes remain\n",
553                         len, desc->count);
554         return len;
555 }
556
557 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc)
558 {
559         size_t len, used;
560         char *p;
561
562         p = ((char *) &xprt->tcp_recm) + xprt->tcp_offset;
563         len = sizeof(xprt->tcp_recm) - xprt->tcp_offset;
564         used = xs_tcp_copy_data(desc, p, len);
565         xprt->tcp_offset += used;
566         if (used != len)
567                 return;
568
569         xprt->tcp_reclen = ntohl(xprt->tcp_recm);
570         if (xprt->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
571                 xprt->tcp_flags |= XPRT_LAST_FRAG;
572         else
573                 xprt->tcp_flags &= ~XPRT_LAST_FRAG;
574         xprt->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
575
576         xprt->tcp_flags &= ~XPRT_COPY_RECM;
577         xprt->tcp_offset = 0;
578
579         /* Sanity check of the record length */
580         if (unlikely(xprt->tcp_reclen < 4)) {
581                 dprintk("RPC:      invalid TCP record fragment length\n");
582                 xprt_disconnect(xprt);
583                 return;
584         }
585         dprintk("RPC:      reading TCP record fragment of length %d\n",
586                         xprt->tcp_reclen);
587 }
588
589 static void xs_tcp_check_recm(struct rpc_xprt *xprt)
590 {
591         dprintk("RPC:      xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u, tcp_flags = %lx\n",
592                         xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen, xprt->tcp_flags);
593         if (xprt->tcp_offset == xprt->tcp_reclen) {
594                 xprt->tcp_flags |= XPRT_COPY_RECM;
595                 xprt->tcp_offset = 0;
596                 if (xprt->tcp_flags & XPRT_LAST_FRAG) {
597                         xprt->tcp_flags &= ~XPRT_COPY_DATA;
598                         xprt->tcp_flags |= XPRT_COPY_XID;
599                         xprt->tcp_copied = 0;
600                 }
601         }
602 }
603
604 static inline void xs_tcp_read_xid(struct rpc_xprt *xprt, skb_reader_t *desc)
605 {
606         size_t len, used;
607         char *p;
608
609         len = sizeof(xprt->tcp_xid) - xprt->tcp_offset;
610         dprintk("RPC:      reading XID (%Zu bytes)\n", len);
611         p = ((char *) &xprt->tcp_xid) + xprt->tcp_offset;
612         used = xs_tcp_copy_data(desc, p, len);
613         xprt->tcp_offset += used;
614         if (used != len)
615                 return;
616         xprt->tcp_flags &= ~XPRT_COPY_XID;
617         xprt->tcp_flags |= XPRT_COPY_DATA;
618         xprt->tcp_copied = 4;
619         dprintk("RPC:      reading reply for XID %08x\n",
620                                                 ntohl(xprt->tcp_xid));
621         xs_tcp_check_recm(xprt);
622 }
623
624 static inline void xs_tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc)
625 {
626         struct rpc_rqst *req;
627         struct xdr_buf *rcvbuf;
628         size_t len;
629         ssize_t r;
630
631         /* Find and lock the request corresponding to this xid */
632         spin_lock(&xprt->transport_lock);
633         req = xprt_lookup_rqst(xprt, xprt->tcp_xid);
634         if (!req) {
635                 xprt->tcp_flags &= ~XPRT_COPY_DATA;
636                 dprintk("RPC:      XID %08x request not found!\n",
637                                 ntohl(xprt->tcp_xid));
638                 spin_unlock(&xprt->transport_lock);
639                 return;
640         }
641
642         rcvbuf = &req->rq_private_buf;
643         len = desc->count;
644         if (len > xprt->tcp_reclen - xprt->tcp_offset) {
645                 skb_reader_t my_desc;
646
647                 len = xprt->tcp_reclen - xprt->tcp_offset;
648                 memcpy(&my_desc, desc, sizeof(my_desc));
649                 my_desc.count = len;
650                 r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
651                                           &my_desc, xs_tcp_copy_data);
652                 desc->count -= r;
653                 desc->offset += r;
654         } else
655                 r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
656                                           desc, xs_tcp_copy_data);
657
658         if (r > 0) {
659                 xprt->tcp_copied += r;
660                 xprt->tcp_offset += r;
661         }
662         if (r != len) {
663                 /* Error when copying to the receive buffer,
664                  * usually because we weren't able to allocate
665                  * additional buffer pages. All we can do now
666                  * is turn off XPRT_COPY_DATA, so the request
667                  * will not receive any additional updates,
668                  * and time out.
669                  * Any remaining data from this record will
670                  * be discarded.
671                  */
672                 xprt->tcp_flags &= ~XPRT_COPY_DATA;
673                 dprintk("RPC:      XID %08x truncated request\n",
674                                 ntohl(xprt->tcp_xid));
675                 dprintk("RPC:      xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
676                                 xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
677                 goto out;
678         }
679
680         dprintk("RPC:      XID %08x read %Zd bytes\n",
681                         ntohl(xprt->tcp_xid), r);
682         dprintk("RPC:      xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
683                         xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
684
685         if (xprt->tcp_copied == req->rq_private_buf.buflen)
686                 xprt->tcp_flags &= ~XPRT_COPY_DATA;
687         else if (xprt->tcp_offset == xprt->tcp_reclen) {
688                 if (xprt->tcp_flags & XPRT_LAST_FRAG)
689                         xprt->tcp_flags &= ~XPRT_COPY_DATA;
690         }
691
692 out:
693         if (!(xprt->tcp_flags & XPRT_COPY_DATA))
694                 xprt_complete_rqst(req->rq_task, xprt->tcp_copied);
695         spin_unlock(&xprt->transport_lock);
696         xs_tcp_check_recm(xprt);
697 }
698
699 static inline void xs_tcp_read_discard(struct rpc_xprt *xprt, skb_reader_t *desc)
700 {
701         size_t len;
702
703         len = xprt->tcp_reclen - xprt->tcp_offset;
704         if (len > desc->count)
705                 len = desc->count;
706         desc->count -= len;
707         desc->offset += len;
708         xprt->tcp_offset += len;
709         dprintk("RPC:      discarded %Zu bytes\n", len);
710         xs_tcp_check_recm(xprt);
711 }
712
713 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
714 {
715         struct rpc_xprt *xprt = rd_desc->arg.data;
716         skb_reader_t desc = {
717                 .skb    = skb,
718                 .offset = offset,
719                 .count  = len,
720                 .csum   = 0
721         };
722
723         dprintk("RPC:      xs_tcp_data_recv started\n");
724         do {
725                 /* Read in a new fragment marker if necessary */
726                 /* Can we ever really expect to get completely empty fragments? */
727                 if (xprt->tcp_flags & XPRT_COPY_RECM) {
728                         xs_tcp_read_fraghdr(xprt, &desc);
729                         continue;
730                 }
731                 /* Read in the xid if necessary */
732                 if (xprt->tcp_flags & XPRT_COPY_XID) {
733                         xs_tcp_read_xid(xprt, &desc);
734                         continue;
735                 }
736                 /* Read in the request data */
737                 if (xprt->tcp_flags & XPRT_COPY_DATA) {
738                         xs_tcp_read_request(xprt, &desc);
739                         continue;
740                 }
741                 /* Skip over any trailing bytes on short reads */
742                 xs_tcp_read_discard(xprt, &desc);
743         } while (desc.count);
744         dprintk("RPC:      xs_tcp_data_recv done\n");
745         return len - desc.count;
746 }
747
748 /**
749  * xs_tcp_data_ready - "data ready" callback for TCP sockets
750  * @sk: socket with data to read
751  * @bytes: how much data to read
752  *
753  */
754 static void xs_tcp_data_ready(struct sock *sk, int bytes)
755 {
756         struct rpc_xprt *xprt;
757         read_descriptor_t rd_desc;
758
759         read_lock(&sk->sk_callback_lock);
760         dprintk("RPC:      xs_tcp_data_ready...\n");
761         if (!(xprt = xprt_from_sock(sk)))
762                 goto out;
763         if (xprt->shutdown)
764                 goto out;
765
766         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
767         rd_desc.arg.data = xprt;
768         rd_desc.count = 65536;
769         tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
770 out:
771         read_unlock(&sk->sk_callback_lock);
772 }
773
774 /**
775  * xs_tcp_state_change - callback to handle TCP socket state changes
776  * @sk: socket whose state has changed
777  *
778  */
779 static void xs_tcp_state_change(struct sock *sk)
780 {
781         struct rpc_xprt *xprt;
782
783         read_lock(&sk->sk_callback_lock);
784         if (!(xprt = xprt_from_sock(sk)))
785                 goto out;
786         dprintk("RPC:      xs_tcp_state_change client %p...\n", xprt);
787         dprintk("RPC:      state %x conn %d dead %d zapped %d\n",
788                                 sk->sk_state, xprt_connected(xprt),
789                                 sock_flag(sk, SOCK_DEAD),
790                                 sock_flag(sk, SOCK_ZAPPED));
791
792         switch (sk->sk_state) {
793         case TCP_ESTABLISHED:
794                 spin_lock_bh(&xprt->transport_lock);
795                 if (!xprt_test_and_set_connected(xprt)) {
796                         /* Reset TCP record info */
797                         xprt->tcp_offset = 0;
798                         xprt->tcp_reclen = 0;
799                         xprt->tcp_copied = 0;
800                         xprt->tcp_flags = XPRT_COPY_RECM | XPRT_COPY_XID;
801                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
802                         xprt_wake_pending_tasks(xprt, 0);
803                 }
804                 spin_unlock_bh(&xprt->transport_lock);
805                 break;
806         case TCP_SYN_SENT:
807         case TCP_SYN_RECV:
808                 break;
809         case TCP_CLOSE_WAIT:
810                 /* Try to schedule an autoclose RPC calls */
811                 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
812                 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
813                         schedule_work(&xprt->task_cleanup);
814         default:
815                 xprt_disconnect(xprt);
816         }
817  out:
818         read_unlock(&sk->sk_callback_lock);
819 }
820
821 /**
822  * xs_udp_write_space - callback invoked when socket buffer space
823  *                             becomes available
824  * @sk: socket whose state has changed
825  *
826  * Called when more output buffer space is available for this socket.
827  * We try not to wake our writers until they can make "significant"
828  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
829  * with a bunch of small requests.
830  */
831 static void xs_udp_write_space(struct sock *sk)
832 {
833         read_lock(&sk->sk_callback_lock);
834
835         /* from net/core/sock.c:sock_def_write_space */
836         if (sock_writeable(sk)) {
837                 struct socket *sock;
838                 struct rpc_xprt *xprt;
839
840                 if (unlikely(!(sock = sk->sk_socket)))
841                         goto out;
842                 if (unlikely(!(xprt = xprt_from_sock(sk))))
843                         goto out;
844                 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
845                         goto out;
846
847                 xprt_write_space(xprt);
848         }
849
850  out:
851         read_unlock(&sk->sk_callback_lock);
852 }
853
854 /**
855  * xs_tcp_write_space - callback invoked when socket buffer space
856  *                             becomes available
857  * @sk: socket whose state has changed
858  *
859  * Called when more output buffer space is available for this socket.
860  * We try not to wake our writers until they can make "significant"
861  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
862  * with a bunch of small requests.
863  */
864 static void xs_tcp_write_space(struct sock *sk)
865 {
866         read_lock(&sk->sk_callback_lock);
867
868         /* from net/core/stream.c:sk_stream_write_space */
869         if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
870                 struct socket *sock;
871                 struct rpc_xprt *xprt;
872
873                 if (unlikely(!(sock = sk->sk_socket)))
874                         goto out;
875                 if (unlikely(!(xprt = xprt_from_sock(sk))))
876                         goto out;
877                 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
878                         goto out;
879
880                 xprt_write_space(xprt);
881         }
882
883  out:
884         read_unlock(&sk->sk_callback_lock);
885 }
886
887 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
888 {
889         struct sock *sk = xprt->inet;
890
891         if (xprt->rcvsize) {
892                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
893                 sk->sk_rcvbuf = xprt->rcvsize * xprt->max_reqs *  2;
894         }
895         if (xprt->sndsize) {
896                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
897                 sk->sk_sndbuf = xprt->sndsize * xprt->max_reqs * 2;
898                 sk->sk_write_space(sk);
899         }
900 }
901
902 /**
903  * xs_udp_set_buffer_size - set send and receive limits
904  * @xprt: generic transport
905  * @sndsize: requested size of send buffer, in bytes
906  * @rcvsize: requested size of receive buffer, in bytes
907  *
908  * Set socket send and receive buffer size limits.
909  */
910 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
911 {
912         xprt->sndsize = 0;
913         if (sndsize)
914                 xprt->sndsize = sndsize + 1024;
915         xprt->rcvsize = 0;
916         if (rcvsize)
917                 xprt->rcvsize = rcvsize + 1024;
918
919         xs_udp_do_set_buffer_size(xprt);
920 }
921
922 /**
923  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
924  * @task: task that timed out
925  *
926  * Adjust the congestion window after a retransmit timeout has occurred.
927  */
928 static void xs_udp_timer(struct rpc_task *task)
929 {
930         xprt_adjust_cwnd(task, -ETIMEDOUT);
931 }
932
933 static unsigned short xs_get_random_port(void)
934 {
935         unsigned short range = xprt_max_resvport - xprt_min_resvport;
936         unsigned short rand = (unsigned short) net_random() % range;
937         return rand + xprt_min_resvport;
938 }
939
940 /**
941  * xs_set_port - reset the port number in the remote endpoint address
942  * @xprt: generic transport
943  * @port: new port number
944  *
945  */
946 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
947 {
948         dprintk("RPC:      setting port for xprt %p to %u\n", xprt, port);
949         xprt->addr.sin_port = htons(port);
950 }
951
952 static int xs_bindresvport(struct rpc_xprt *xprt, struct socket *sock)
953 {
954         struct sockaddr_in myaddr = {
955                 .sin_family = AF_INET,
956         };
957         int err;
958         unsigned short port = xprt->port;
959
960         do {
961                 myaddr.sin_port = htons(port);
962                 err = sock->ops->bind(sock, (struct sockaddr *) &myaddr,
963                                                 sizeof(myaddr));
964                 if (err == 0) {
965                         xprt->port = port;
966                         dprintk("RPC:      xs_bindresvport bound to port %u\n",
967                                         port);
968                         return 0;
969                 }
970                 if (port <= xprt_min_resvport)
971                         port = xprt_max_resvport;
972                 else
973                         port--;
974         } while (err == -EADDRINUSE && port != xprt->port);
975
976         dprintk("RPC:      can't bind to reserved port (%d).\n", -err);
977         return err;
978 }
979
980 /**
981  * xs_udp_connect_worker - set up a UDP socket
982  * @args: RPC transport to connect
983  *
984  * Invoked by a work queue tasklet.
985  */
986 static void xs_udp_connect_worker(void *args)
987 {
988         struct rpc_xprt *xprt = (struct rpc_xprt *) args;
989         struct socket *sock = xprt->sock;
990         int err, status = -EIO;
991
992         if (xprt->shutdown || xprt->addr.sin_port == 0)
993                 goto out;
994
995         dprintk("RPC:      xs_udp_connect_worker for xprt %p\n", xprt);
996
997         /* Start by resetting any existing state */
998         xs_close(xprt);
999
1000         if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
1001                 dprintk("RPC:      can't create UDP transport socket (%d).\n", -err);
1002                 goto out;
1003         }
1004
1005         if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
1006                 sock_release(sock);
1007                 goto out;
1008         }
1009
1010         if (!xprt->inet) {
1011                 struct sock *sk = sock->sk;
1012
1013                 write_lock_bh(&sk->sk_callback_lock);
1014
1015                 sk->sk_user_data = xprt;
1016                 xprt->old_data_ready = sk->sk_data_ready;
1017                 xprt->old_state_change = sk->sk_state_change;
1018                 xprt->old_write_space = sk->sk_write_space;
1019                 sk->sk_data_ready = xs_udp_data_ready;
1020                 sk->sk_write_space = xs_udp_write_space;
1021                 sk->sk_no_check = UDP_CSUM_NORCV;
1022                 sk->sk_allocation = GFP_ATOMIC;
1023
1024                 xprt_set_connected(xprt);
1025
1026                 /* Reset to new socket */
1027                 xprt->sock = sock;
1028                 xprt->inet = sk;
1029
1030                 write_unlock_bh(&sk->sk_callback_lock);
1031         }
1032         xs_udp_do_set_buffer_size(xprt);
1033         status = 0;
1034 out:
1035         xprt_wake_pending_tasks(xprt, status);
1036         xprt_clear_connecting(xprt);
1037 }
1038
1039 /*
1040  * We need to preserve the port number so the reply cache on the server can
1041  * find our cached RPC replies when we get around to reconnecting.
1042  */
1043 static void xs_tcp_reuse_connection(struct rpc_xprt *xprt)
1044 {
1045         int result;
1046         struct socket *sock = xprt->sock;
1047         struct sockaddr any;
1048
1049         dprintk("RPC:      disconnecting xprt %p to reuse port\n", xprt);
1050
1051         /*
1052          * Disconnect the transport socket by doing a connect operation
1053          * with AF_UNSPEC.  This should return immediately...
1054          */
1055         memset(&any, 0, sizeof(any));
1056         any.sa_family = AF_UNSPEC;
1057         result = sock->ops->connect(sock, &any, sizeof(any), 0);
1058         if (result)
1059                 dprintk("RPC:      AF_UNSPEC connect return code %d\n",
1060                                 result);
1061 }
1062
1063 /**
1064  * xs_tcp_connect_worker - connect a TCP socket to a remote endpoint
1065  * @args: RPC transport to connect
1066  *
1067  * Invoked by a work queue tasklet.
1068  */
1069 static void xs_tcp_connect_worker(void *args)
1070 {
1071         struct rpc_xprt *xprt = (struct rpc_xprt *)args;
1072         struct socket *sock = xprt->sock;
1073         int err, status = -EIO;
1074
1075         if (xprt->shutdown || xprt->addr.sin_port == 0)
1076                 goto out;
1077
1078         dprintk("RPC:      xs_tcp_connect_worker for xprt %p\n", xprt);
1079
1080         if (!xprt->sock) {
1081                 /* start from scratch */
1082                 if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
1083                         dprintk("RPC:      can't create TCP transport socket (%d).\n", -err);
1084                         goto out;
1085                 }
1086
1087                 if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
1088                         sock_release(sock);
1089                         goto out;
1090                 }
1091         } else
1092                 /* "close" the socket, preserving the local port */
1093                 xs_tcp_reuse_connection(xprt);
1094
1095         if (!xprt->inet) {
1096                 struct sock *sk = sock->sk;
1097
1098                 write_lock_bh(&sk->sk_callback_lock);
1099
1100                 sk->sk_user_data = xprt;
1101                 xprt->old_data_ready = sk->sk_data_ready;
1102                 xprt->old_state_change = sk->sk_state_change;
1103                 xprt->old_write_space = sk->sk_write_space;
1104                 sk->sk_data_ready = xs_tcp_data_ready;
1105                 sk->sk_state_change = xs_tcp_state_change;
1106                 sk->sk_write_space = xs_tcp_write_space;
1107                 sk->sk_allocation = GFP_ATOMIC;
1108
1109                 /* socket options */
1110                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
1111                 sock_reset_flag(sk, SOCK_LINGER);
1112                 tcp_sk(sk)->linger2 = 0;
1113                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1114
1115                 xprt_clear_connected(xprt);
1116
1117                 /* Reset to new socket */
1118                 xprt->sock = sock;
1119                 xprt->inet = sk;
1120
1121                 write_unlock_bh(&sk->sk_callback_lock);
1122         }
1123
1124         /* Tell the socket layer to start connecting... */
1125         xprt->stat.connect_count++;
1126         xprt->stat.connect_start = jiffies;
1127         status = sock->ops->connect(sock, (struct sockaddr *) &xprt->addr,
1128                         sizeof(xprt->addr), O_NONBLOCK);
1129         dprintk("RPC: %p  connect status %d connected %d sock state %d\n",
1130                         xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
1131         if (status < 0) {
1132                 switch (status) {
1133                         case -EINPROGRESS:
1134                         case -EALREADY:
1135                                 goto out_clear;
1136                         case -ECONNREFUSED:
1137                         case -ECONNRESET:
1138                                 /* retry with existing socket, after a delay */
1139                                 break;
1140                         default:
1141                                 /* get rid of existing socket, and retry */
1142                                 xs_close(xprt);
1143                                 break;
1144                 }
1145         }
1146 out:
1147         xprt_wake_pending_tasks(xprt, status);
1148 out_clear:
1149         xprt_clear_connecting(xprt);
1150 }
1151
1152 /**
1153  * xs_connect - connect a socket to a remote endpoint
1154  * @task: address of RPC task that manages state of connect request
1155  *
1156  * TCP: If the remote end dropped the connection, delay reconnecting.
1157  *
1158  * UDP socket connects are synchronous, but we use a work queue anyway
1159  * to guarantee that even unprivileged user processes can set up a
1160  * socket on a privileged port.
1161  *
1162  * If a UDP socket connect fails, the delay behavior here prevents
1163  * retry floods (hard mounts).
1164  */
1165 static void xs_connect(struct rpc_task *task)
1166 {
1167         struct rpc_xprt *xprt = task->tk_xprt;
1168
1169         if (xprt_test_and_set_connecting(xprt))
1170                 return;
1171
1172         if (xprt->sock != NULL) {
1173                 dprintk("RPC:      xs_connect delayed xprt %p for %lu seconds\n",
1174                                 xprt, xprt->reestablish_timeout / HZ);
1175                 schedule_delayed_work(&xprt->connect_worker,
1176                                         xprt->reestablish_timeout);
1177                 xprt->reestablish_timeout <<= 1;
1178                 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
1179                         xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
1180         } else {
1181                 dprintk("RPC:      xs_connect scheduled xprt %p\n", xprt);
1182                 schedule_work(&xprt->connect_worker);
1183
1184                 /* flush_scheduled_work can sleep... */
1185                 if (!RPC_IS_ASYNC(task))
1186                         flush_scheduled_work();
1187         }
1188 }
1189
1190 /**
1191  * xs_udp_print_stats - display UDP socket-specifc stats
1192  * @xprt: rpc_xprt struct containing statistics
1193  * @seq: output file
1194  *
1195  */
1196 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1197 {
1198         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %Lu %Lu\n",
1199                         xprt->port,
1200                         xprt->stat.bind_count,
1201                         xprt->stat.sends,
1202                         xprt->stat.recvs,
1203                         xprt->stat.bad_xids,
1204                         xprt->stat.req_u,
1205                         xprt->stat.bklog_u);
1206 }
1207
1208 /**
1209  * xs_tcp_print_stats - display TCP socket-specifc stats
1210  * @xprt: rpc_xprt struct containing statistics
1211  * @seq: output file
1212  *
1213  */
1214 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1215 {
1216         long idle_time = 0;
1217
1218         if (xprt_connected(xprt))
1219                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
1220
1221         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu\n",
1222                         xprt->port,
1223                         xprt->stat.bind_count,
1224                         xprt->stat.connect_count,
1225                         xprt->stat.connect_time,
1226                         idle_time,
1227                         xprt->stat.sends,
1228                         xprt->stat.recvs,
1229                         xprt->stat.bad_xids,
1230                         xprt->stat.req_u,
1231                         xprt->stat.bklog_u);
1232 }
1233
1234 static struct rpc_xprt_ops xs_udp_ops = {
1235         .set_buffer_size        = xs_udp_set_buffer_size,
1236         .reserve_xprt           = xprt_reserve_xprt_cong,
1237         .release_xprt           = xprt_release_xprt_cong,
1238         .set_port               = xs_set_port,
1239         .connect                = xs_connect,
1240         .buf_alloc              = rpc_malloc,
1241         .buf_free               = rpc_free,
1242         .send_request           = xs_udp_send_request,
1243         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
1244         .timer                  = xs_udp_timer,
1245         .release_request        = xprt_release_rqst_cong,
1246         .close                  = xs_close,
1247         .destroy                = xs_destroy,
1248         .print_stats            = xs_udp_print_stats,
1249 };
1250
1251 static struct rpc_xprt_ops xs_tcp_ops = {
1252         .reserve_xprt           = xprt_reserve_xprt,
1253         .release_xprt           = xprt_release_xprt,
1254         .set_port               = xs_set_port,
1255         .connect                = xs_connect,
1256         .buf_alloc              = rpc_malloc,
1257         .buf_free               = rpc_free,
1258         .send_request           = xs_tcp_send_request,
1259         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
1260         .close                  = xs_close,
1261         .destroy                = xs_destroy,
1262         .print_stats            = xs_tcp_print_stats,
1263 };
1264
1265 /**
1266  * xs_setup_udp - Set up transport to use a UDP socket
1267  * @xprt: transport to set up
1268  * @to:   timeout parameters
1269  *
1270  */
1271 int xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to)
1272 {
1273         size_t slot_table_size;
1274
1275         dprintk("RPC:      setting up udp-ipv4 transport...\n");
1276
1277         xprt->max_reqs = xprt_udp_slot_table_entries;
1278         slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]);
1279         xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
1280         if (xprt->slot == NULL)
1281                 return -ENOMEM;
1282         memset(xprt->slot, 0, slot_table_size);
1283
1284         xprt->prot = IPPROTO_UDP;
1285         xprt->port = xs_get_random_port();
1286         xprt->tsh_size = 0;
1287         xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
1288         /* XXX: header size can vary due to auth type, IPv6, etc. */
1289         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
1290
1291         INIT_WORK(&xprt->connect_worker, xs_udp_connect_worker, xprt);
1292         xprt->bind_timeout = XS_BIND_TO;
1293         xprt->connect_timeout = XS_UDP_CONN_TO;
1294         xprt->reestablish_timeout = XS_UDP_REEST_TO;
1295         xprt->idle_timeout = XS_IDLE_DISC_TO;
1296
1297         xprt->ops = &xs_udp_ops;
1298
1299         if (to)
1300                 xprt->timeout = *to;
1301         else
1302                 xprt_set_timeout(&xprt->timeout, 5, 5 * HZ);
1303
1304         return 0;
1305 }
1306
1307 /**
1308  * xs_setup_tcp - Set up transport to use a TCP socket
1309  * @xprt: transport to set up
1310  * @to: timeout parameters
1311  *
1312  */
1313 int xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to)
1314 {
1315         size_t slot_table_size;
1316
1317         dprintk("RPC:      setting up tcp-ipv4 transport...\n");
1318
1319         xprt->max_reqs = xprt_tcp_slot_table_entries;
1320         slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]);
1321         xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
1322         if (xprt->slot == NULL)
1323                 return -ENOMEM;
1324         memset(xprt->slot, 0, slot_table_size);
1325
1326         xprt->prot = IPPROTO_TCP;
1327         xprt->port = xs_get_random_port();
1328         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
1329         xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
1330         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
1331
1332         INIT_WORK(&xprt->connect_worker, xs_tcp_connect_worker, xprt);
1333         xprt->bind_timeout = XS_BIND_TO;
1334         xprt->connect_timeout = XS_TCP_CONN_TO;
1335         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1336         xprt->idle_timeout = XS_IDLE_DISC_TO;
1337
1338         xprt->ops = &xs_tcp_ops;
1339
1340         if (to)
1341                 xprt->timeout = *to;
1342         else
1343                 xprt_set_timeout(&xprt->timeout, 2, 60 * HZ);
1344
1345         return 0;
1346 }