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Linux/net/sunrpc/xprtsock.c

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  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
  7  * TCP send fixes (C) 1998 Red Hat
  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  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
 18  *   <gilles.quillard@bull.net>
 19  */
 20 
 21 #include <linux/types.h>
 22 #include <linux/string.h>
 23 #include <linux/slab.h>
 24 #include <linux/module.h>
 25 #include <linux/capability.h>
 26 #include <linux/pagemap.h>
 27 #include <linux/errno.h>
 28 #include <linux/socket.h>
 29 #include <linux/in.h>
 30 #include <linux/net.h>
 31 #include <linux/mm.h>
 32 #include <linux/un.h>
 33 #include <linux/udp.h>
 34 #include <linux/tcp.h>
 35 #include <linux/sunrpc/clnt.h>
 36 #include <linux/sunrpc/addr.h>
 37 #include <linux/sunrpc/sched.h>
 38 #include <linux/sunrpc/svcsock.h>
 39 #include <linux/sunrpc/xprtsock.h>
 40 #include <linux/file.h>
 41 #ifdef CONFIG_SUNRPC_BACKCHANNEL
 42 #include <linux/sunrpc/bc_xprt.h>
 43 #endif
 44 
 45 #include <net/sock.h>
 46 #include <net/checksum.h>
 47 #include <net/udp.h>
 48 #include <net/tcp.h>
 49 
 50 #include <trace/events/sunrpc.h>
 51 
 52 #include "sunrpc.h"
 53 
 54 static void xs_close(struct rpc_xprt *xprt);
 55 
 56 /*
 57  * xprtsock tunables
 58  */
 59 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
 60 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
 61 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
 62 
 63 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
 64 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
 65 
 66 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 67 
 68 #define XS_TCP_LINGER_TO        (15U * HZ)
 69 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
 70 
 71 /*
 72  * We can register our own files under /proc/sys/sunrpc by
 73  * calling register_sysctl_table() again.  The files in that
 74  * directory become the union of all files registered there.
 75  *
 76  * We simply need to make sure that we don't collide with
 77  * someone else's file names!
 78  */
 79 
 80 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
 81 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
 82 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
 83 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
 84 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
 85 
 86 static struct ctl_table_header *sunrpc_table_header;
 87 
 88 /*
 89  * FIXME: changing the UDP slot table size should also resize the UDP
 90  *        socket buffers for existing UDP transports
 91  */
 92 static struct ctl_table xs_tunables_table[] = {
 93         {
 94                 .procname       = "udp_slot_table_entries",
 95                 .data           = &xprt_udp_slot_table_entries,
 96                 .maxlen         = sizeof(unsigned int),
 97                 .mode           = 0644,
 98                 .proc_handler   = proc_dointvec_minmax,
 99                 .extra1         = &min_slot_table_size,
100                 .extra2         = &max_slot_table_size
101         },
102         {
103                 .procname       = "tcp_slot_table_entries",
104                 .data           = &xprt_tcp_slot_table_entries,
105                 .maxlen         = sizeof(unsigned int),
106                 .mode           = 0644,
107                 .proc_handler   = proc_dointvec_minmax,
108                 .extra1         = &min_slot_table_size,
109                 .extra2         = &max_slot_table_size
110         },
111         {
112                 .procname       = "tcp_max_slot_table_entries",
113                 .data           = &xprt_max_tcp_slot_table_entries,
114                 .maxlen         = sizeof(unsigned int),
115                 .mode           = 0644,
116                 .proc_handler   = proc_dointvec_minmax,
117                 .extra1         = &min_slot_table_size,
118                 .extra2         = &max_tcp_slot_table_limit
119         },
120         {
121                 .procname       = "min_resvport",
122                 .data           = &xprt_min_resvport,
123                 .maxlen         = sizeof(unsigned int),
124                 .mode           = 0644,
125                 .proc_handler   = proc_dointvec_minmax,
126                 .extra1         = &xprt_min_resvport_limit,
127                 .extra2         = &xprt_max_resvport_limit
128         },
129         {
130                 .procname       = "max_resvport",
131                 .data           = &xprt_max_resvport,
132                 .maxlen         = sizeof(unsigned int),
133                 .mode           = 0644,
134                 .proc_handler   = proc_dointvec_minmax,
135                 .extra1         = &xprt_min_resvport_limit,
136                 .extra2         = &xprt_max_resvport_limit
137         },
138         {
139                 .procname       = "tcp_fin_timeout",
140                 .data           = &xs_tcp_fin_timeout,
141                 .maxlen         = sizeof(xs_tcp_fin_timeout),
142                 .mode           = 0644,
143                 .proc_handler   = proc_dointvec_jiffies,
144         },
145         { },
146 };
147 
148 static struct ctl_table sunrpc_table[] = {
149         {
150                 .procname       = "sunrpc",
151                 .mode           = 0555,
152                 .child          = xs_tunables_table
153         },
154         { },
155 };
156 
157 #endif
158 
159 /*
160  * Wait duration for a reply from the RPC portmapper.
161  */
162 #define XS_BIND_TO              (60U * HZ)
163 
164 /*
165  * Delay if a UDP socket connect error occurs.  This is most likely some
166  * kind of resource problem on the local host.
167  */
168 #define XS_UDP_REEST_TO         (2U * HZ)
169 
170 /*
171  * The reestablish timeout allows clients to delay for a bit before attempting
172  * to reconnect to a server that just dropped our connection.
173  *
174  * We implement an exponential backoff when trying to reestablish a TCP
175  * transport connection with the server.  Some servers like to drop a TCP
176  * connection when they are overworked, so we start with a short timeout and
177  * increase over time if the server is down or not responding.
178  */
179 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
180 #define XS_TCP_MAX_REEST_TO     (5U * 60 * HZ)
181 
182 /*
183  * TCP idle timeout; client drops the transport socket if it is idle
184  * for this long.  Note that we also timeout UDP sockets to prevent
185  * holding port numbers when there is no RPC traffic.
186  */
187 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
188 
189 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
190 # undef  RPC_DEBUG_DATA
191 # define RPCDBG_FACILITY        RPCDBG_TRANS
192 #endif
193 
194 #ifdef RPC_DEBUG_DATA
195 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
196 {
197         u8 *buf = (u8 *) packet;
198         int j;
199 
200         dprintk("RPC:       %s\n", msg);
201         for (j = 0; j < count && j < 128; j += 4) {
202                 if (!(j & 31)) {
203                         if (j)
204                                 dprintk("\n");
205                         dprintk("0x%04x ", j);
206                 }
207                 dprintk("%02x%02x%02x%02x ",
208                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
209         }
210         dprintk("\n");
211 }
212 #else
213 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
214 {
215         /* NOP */
216 }
217 #endif
218 
219 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
220 {
221         return (struct rpc_xprt *) sk->sk_user_data;
222 }
223 
224 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
225 {
226         return (struct sockaddr *) &xprt->addr;
227 }
228 
229 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
230 {
231         return (struct sockaddr_un *) &xprt->addr;
232 }
233 
234 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
235 {
236         return (struct sockaddr_in *) &xprt->addr;
237 }
238 
239 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
240 {
241         return (struct sockaddr_in6 *) &xprt->addr;
242 }
243 
244 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
245 {
246         struct sockaddr *sap = xs_addr(xprt);
247         struct sockaddr_in6 *sin6;
248         struct sockaddr_in *sin;
249         struct sockaddr_un *sun;
250         char buf[128];
251 
252         switch (sap->sa_family) {
253         case AF_LOCAL:
254                 sun = xs_addr_un(xprt);
255                 strlcpy(buf, sun->sun_path, sizeof(buf));
256                 xprt->address_strings[RPC_DISPLAY_ADDR] =
257                                                 kstrdup(buf, GFP_KERNEL);
258                 break;
259         case AF_INET:
260                 (void)rpc_ntop(sap, buf, sizeof(buf));
261                 xprt->address_strings[RPC_DISPLAY_ADDR] =
262                                                 kstrdup(buf, GFP_KERNEL);
263                 sin = xs_addr_in(xprt);
264                 snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
265                 break;
266         case AF_INET6:
267                 (void)rpc_ntop(sap, buf, sizeof(buf));
268                 xprt->address_strings[RPC_DISPLAY_ADDR] =
269                                                 kstrdup(buf, GFP_KERNEL);
270                 sin6 = xs_addr_in6(xprt);
271                 snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
272                 break;
273         default:
274                 BUG();
275         }
276 
277         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
278 }
279 
280 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
281 {
282         struct sockaddr *sap = xs_addr(xprt);
283         char buf[128];
284 
285         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
286         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
287 
288         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
289         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
290 }
291 
292 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
293                                      const char *protocol,
294                                      const char *netid)
295 {
296         xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
297         xprt->address_strings[RPC_DISPLAY_NETID] = netid;
298         xs_format_common_peer_addresses(xprt);
299         xs_format_common_peer_ports(xprt);
300 }
301 
302 static void xs_update_peer_port(struct rpc_xprt *xprt)
303 {
304         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
305         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
306 
307         xs_format_common_peer_ports(xprt);
308 }
309 
310 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
311 {
312         unsigned int i;
313 
314         for (i = 0; i < RPC_DISPLAY_MAX; i++)
315                 switch (i) {
316                 case RPC_DISPLAY_PROTO:
317                 case RPC_DISPLAY_NETID:
318                         continue;
319                 default:
320                         kfree(xprt->address_strings[i]);
321                 }
322 }
323 
324 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
325 
326 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
327 {
328         struct msghdr msg = {
329                 .msg_name       = addr,
330                 .msg_namelen    = addrlen,
331                 .msg_flags      = XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
332         };
333         struct kvec iov = {
334                 .iov_base       = vec->iov_base + base,
335                 .iov_len        = vec->iov_len - base,
336         };
337 
338         if (iov.iov_len != 0)
339                 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
340         return kernel_sendmsg(sock, &msg, NULL, 0, 0);
341 }
342 
343 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy, int *sent_p)
344 {
345         ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
346                         int offset, size_t size, int flags);
347         struct page **ppage;
348         unsigned int remainder;
349         int err;
350 
351         remainder = xdr->page_len - base;
352         base += xdr->page_base;
353         ppage = xdr->pages + (base >> PAGE_SHIFT);
354         base &= ~PAGE_MASK;
355         do_sendpage = sock->ops->sendpage;
356         if (!zerocopy)
357                 do_sendpage = sock_no_sendpage;
358         for(;;) {
359                 unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
360                 int flags = XS_SENDMSG_FLAGS;
361 
362                 remainder -= len;
363                 if (more)
364                         flags |= MSG_MORE;
365                 if (remainder != 0)
366                         flags |= MSG_SENDPAGE_NOTLAST | MSG_MORE;
367                 err = do_sendpage(sock, *ppage, base, len, flags);
368                 if (remainder == 0 || err != len)
369                         break;
370                 *sent_p += err;
371                 ppage++;
372                 base = 0;
373         }
374         if (err > 0) {
375                 *sent_p += err;
376                 err = 0;
377         }
378         return err;
379 }
380 
381 /**
382  * xs_sendpages - write pages directly to a socket
383  * @sock: socket to send on
384  * @addr: UDP only -- address of destination
385  * @addrlen: UDP only -- length of destination address
386  * @xdr: buffer containing this request
387  * @base: starting position in the buffer
388  * @zerocopy: true if it is safe to use sendpage()
389  * @sent_p: return the total number of bytes successfully queued for sending
390  *
391  */
392 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy, int *sent_p)
393 {
394         unsigned int remainder = xdr->len - base;
395         int err = 0;
396         int sent = 0;
397 
398         if (unlikely(!sock))
399                 return -ENOTSOCK;
400 
401         if (base != 0) {
402                 addr = NULL;
403                 addrlen = 0;
404         }
405 
406         if (base < xdr->head[0].iov_len || addr != NULL) {
407                 unsigned int len = xdr->head[0].iov_len - base;
408                 remainder -= len;
409                 err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
410                 if (remainder == 0 || err != len)
411                         goto out;
412                 *sent_p += err;
413                 base = 0;
414         } else
415                 base -= xdr->head[0].iov_len;
416 
417         if (base < xdr->page_len) {
418                 unsigned int len = xdr->page_len - base;
419                 remainder -= len;
420                 err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy, &sent);
421                 *sent_p += sent;
422                 if (remainder == 0 || sent != len)
423                         goto out;
424                 base = 0;
425         } else
426                 base -= xdr->page_len;
427 
428         if (base >= xdr->tail[0].iov_len)
429                 return 0;
430         err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
431 out:
432         if (err > 0) {
433                 *sent_p += err;
434                 err = 0;
435         }
436         return err;
437 }
438 
439 static void xs_nospace_callback(struct rpc_task *task)
440 {
441         struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
442 
443         transport->inet->sk_write_pending--;
444 }
445 
446 /**
447  * xs_nospace - place task on wait queue if transmit was incomplete
448  * @task: task to put to sleep
449  *
450  */
451 static int xs_nospace(struct rpc_task *task)
452 {
453         struct rpc_rqst *req = task->tk_rqstp;
454         struct rpc_xprt *xprt = req->rq_xprt;
455         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
456         struct sock *sk = transport->inet;
457         int ret = -EAGAIN;
458 
459         dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
460                         task->tk_pid, req->rq_slen - req->rq_bytes_sent,
461                         req->rq_slen);
462 
463         /* Protect against races with write_space */
464         spin_lock_bh(&xprt->transport_lock);
465 
466         /* Don't race with disconnect */
467         if (xprt_connected(xprt)) {
468                 /* wait for more buffer space */
469                 sk->sk_write_pending++;
470                 xprt_wait_for_buffer_space(task, xs_nospace_callback);
471         } else
472                 ret = -ENOTCONN;
473 
474         spin_unlock_bh(&xprt->transport_lock);
475 
476         /* Race breaker in case memory is freed before above code is called */
477         sk->sk_write_space(sk);
478         return ret;
479 }
480 
481 /*
482  * Construct a stream transport record marker in @buf.
483  */
484 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
485 {
486         u32 reclen = buf->len - sizeof(rpc_fraghdr);
487         rpc_fraghdr *base = buf->head[0].iov_base;
488         *base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
489 }
490 
491 /**
492  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
493  * @task: RPC task that manages the state of an RPC request
494  *
495  * Return values:
496  *        0:    The request has been sent
497  *   EAGAIN:    The socket was blocked, please call again later to
498  *              complete the request
499  * ENOTCONN:    Caller needs to invoke connect logic then call again
500  *    other:    Some other error occured, the request was not sent
501  */
502 static int xs_local_send_request(struct rpc_task *task)
503 {
504         struct rpc_rqst *req = task->tk_rqstp;
505         struct rpc_xprt *xprt = req->rq_xprt;
506         struct sock_xprt *transport =
507                                 container_of(xprt, struct sock_xprt, xprt);
508         struct xdr_buf *xdr = &req->rq_snd_buf;
509         int status;
510         int sent = 0;
511 
512         xs_encode_stream_record_marker(&req->rq_snd_buf);
513 
514         xs_pktdump("packet data:",
515                         req->rq_svec->iov_base, req->rq_svec->iov_len);
516 
517         status = xs_sendpages(transport->sock, NULL, 0, xdr, req->rq_bytes_sent,
518                               true, &sent);
519         dprintk("RPC:       %s(%u) = %d\n",
520                         __func__, xdr->len - req->rq_bytes_sent, status);
521 
522         if (status == -EAGAIN && sock_writeable(transport->inet))
523                 status = -ENOBUFS;
524 
525         if (likely(sent > 0) || status == 0) {
526                 req->rq_bytes_sent += sent;
527                 req->rq_xmit_bytes_sent += sent;
528                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
529                         req->rq_bytes_sent = 0;
530                         return 0;
531                 }
532                 status = -EAGAIN;
533         }
534 
535         switch (status) {
536         case -ENOBUFS:
537                 break;
538         case -EAGAIN:
539                 status = xs_nospace(task);
540                 break;
541         default:
542                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
543                         -status);
544         case -EPIPE:
545                 xs_close(xprt);
546                 status = -ENOTCONN;
547         }
548 
549         return status;
550 }
551 
552 /**
553  * xs_udp_send_request - write an RPC request to a UDP socket
554  * @task: address of RPC task that manages the state of an RPC request
555  *
556  * Return values:
557  *        0:    The request has been sent
558  *   EAGAIN:    The socket was blocked, please call again later to
559  *              complete the request
560  * ENOTCONN:    Caller needs to invoke connect logic then call again
561  *    other:    Some other error occurred, the request was not sent
562  */
563 static int xs_udp_send_request(struct rpc_task *task)
564 {
565         struct rpc_rqst *req = task->tk_rqstp;
566         struct rpc_xprt *xprt = req->rq_xprt;
567         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
568         struct xdr_buf *xdr = &req->rq_snd_buf;
569         int sent = 0;
570         int status;
571 
572         xs_pktdump("packet data:",
573                                 req->rq_svec->iov_base,
574                                 req->rq_svec->iov_len);
575 
576         if (!xprt_bound(xprt))
577                 return -ENOTCONN;
578         status = xs_sendpages(transport->sock, xs_addr(xprt), xprt->addrlen,
579                               xdr, req->rq_bytes_sent, true, &sent);
580 
581         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
582                         xdr->len - req->rq_bytes_sent, status);
583 
584         /* firewall is blocking us, don't return -EAGAIN or we end up looping */
585         if (status == -EPERM)
586                 goto process_status;
587 
588         if (status == -EAGAIN && sock_writeable(transport->inet))
589                 status = -ENOBUFS;
590 
591         if (sent > 0 || status == 0) {
592                 req->rq_xmit_bytes_sent += sent;
593                 if (sent >= req->rq_slen)
594                         return 0;
595                 /* Still some bytes left; set up for a retry later. */
596                 status = -EAGAIN;
597         }
598 
599 process_status:
600         switch (status) {
601         case -ENOTSOCK:
602                 status = -ENOTCONN;
603                 /* Should we call xs_close() here? */
604                 break;
605         case -EAGAIN:
606                 status = xs_nospace(task);
607                 break;
608         case -ENETUNREACH:
609         case -ENOBUFS:
610         case -EPIPE:
611         case -ECONNREFUSED:
612         case -EPERM:
613                 /* When the server has died, an ICMP port unreachable message
614                  * prompts ECONNREFUSED. */
615                 break;
616         default:
617                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
618                         -status);
619         }
620 
621         return status;
622 }
623 
624 /**
625  * xs_tcp_send_request - write an RPC request to a TCP socket
626  * @task: address of RPC task that manages the state of an RPC request
627  *
628  * Return values:
629  *        0:    The request has been sent
630  *   EAGAIN:    The socket was blocked, please call again later to
631  *              complete the request
632  * ENOTCONN:    Caller needs to invoke connect logic then call again
633  *    other:    Some other error occurred, the request was not sent
634  *
635  * XXX: In the case of soft timeouts, should we eventually give up
636  *      if sendmsg is not able to make progress?
637  */
638 static int xs_tcp_send_request(struct rpc_task *task)
639 {
640         struct rpc_rqst *req = task->tk_rqstp;
641         struct rpc_xprt *xprt = req->rq_xprt;
642         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
643         struct xdr_buf *xdr = &req->rq_snd_buf;
644         bool zerocopy = true;
645         int status;
646         int sent;
647 
648         xs_encode_stream_record_marker(&req->rq_snd_buf);
649 
650         xs_pktdump("packet data:",
651                                 req->rq_svec->iov_base,
652                                 req->rq_svec->iov_len);
653         /* Don't use zero copy if this is a resend. If the RPC call
654          * completes while the socket holds a reference to the pages,
655          * then we may end up resending corrupted data.
656          */
657         if (task->tk_flags & RPC_TASK_SENT)
658                 zerocopy = false;
659 
660         /* Continue transmitting the packet/record. We must be careful
661          * to cope with writespace callbacks arriving _after_ we have
662          * called sendmsg(). */
663         while (1) {
664                 sent = 0;
665                 status = xs_sendpages(transport->sock, NULL, 0, xdr,
666                                       req->rq_bytes_sent, zerocopy, &sent);
667 
668                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
669                                 xdr->len - req->rq_bytes_sent, status);
670 
671                 /* If we've sent the entire packet, immediately
672                  * reset the count of bytes sent. */
673                 req->rq_bytes_sent += sent;
674                 req->rq_xmit_bytes_sent += sent;
675                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
676                         req->rq_bytes_sent = 0;
677                         return 0;
678                 }
679 
680                 if (status < 0)
681                         break;
682                 if (sent == 0) {
683                         status = -EAGAIN;
684                         break;
685                 }
686         }
687         if (status == -EAGAIN && sk_stream_is_writeable(transport->inet))
688                 status = -ENOBUFS;
689 
690         switch (status) {
691         case -ENOTSOCK:
692                 status = -ENOTCONN;
693                 /* Should we call xs_close() here? */
694                 break;
695         case -EAGAIN:
696                 status = xs_nospace(task);
697                 break;
698         case -ECONNRESET:
699         case -ECONNREFUSED:
700         case -ENOTCONN:
701         case -EADDRINUSE:
702         case -ENOBUFS:
703         case -EPIPE:
704                 break;
705         default:
706                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
707                         -status);
708         }
709 
710         return status;
711 }
712 
713 /**
714  * xs_tcp_release_xprt - clean up after a tcp transmission
715  * @xprt: transport
716  * @task: rpc task
717  *
718  * This cleans up if an error causes us to abort the transmission of a request.
719  * In this case, the socket may need to be reset in order to avoid confusing
720  * the server.
721  */
722 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
723 {
724         struct rpc_rqst *req;
725 
726         if (task != xprt->snd_task)
727                 return;
728         if (task == NULL)
729                 goto out_release;
730         req = task->tk_rqstp;
731         if (req == NULL)
732                 goto out_release;
733         if (req->rq_bytes_sent == 0)
734                 goto out_release;
735         if (req->rq_bytes_sent == req->rq_snd_buf.len)
736                 goto out_release;
737         set_bit(XPRT_CLOSE_WAIT, &xprt->state);
738 out_release:
739         xprt_release_xprt(xprt, task);
740 }
741 
742 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
743 {
744         transport->old_data_ready = sk->sk_data_ready;
745         transport->old_state_change = sk->sk_state_change;
746         transport->old_write_space = sk->sk_write_space;
747         transport->old_error_report = sk->sk_error_report;
748 }
749 
750 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
751 {
752         sk->sk_data_ready = transport->old_data_ready;
753         sk->sk_state_change = transport->old_state_change;
754         sk->sk_write_space = transport->old_write_space;
755         sk->sk_error_report = transport->old_error_report;
756 }
757 
758 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
759 {
760         smp_mb__before_atomic();
761         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
762         clear_bit(XPRT_CLOSING, &xprt->state);
763         smp_mb__after_atomic();
764 }
765 
766 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
767 {
768         xs_sock_reset_connection_flags(xprt);
769         /* Mark transport as closed and wake up all pending tasks */
770         xprt_disconnect_done(xprt);
771 }
772 
773 /**
774  * xs_error_report - callback to handle TCP socket state errors
775  * @sk: socket
776  *
777  * Note: we don't call sock_error() since there may be a rpc_task
778  * using the socket, and so we don't want to clear sk->sk_err.
779  */
780 static void xs_error_report(struct sock *sk)
781 {
782         struct rpc_xprt *xprt;
783         int err;
784 
785         read_lock_bh(&sk->sk_callback_lock);
786         if (!(xprt = xprt_from_sock(sk)))
787                 goto out;
788 
789         err = -sk->sk_err;
790         if (err == 0)
791                 goto out;
792         /* Is this a reset event? */
793         if (sk->sk_state == TCP_CLOSE)
794                 xs_sock_mark_closed(xprt);
795         dprintk("RPC:       xs_error_report client %p, error=%d...\n",
796                         xprt, -err);
797         trace_rpc_socket_error(xprt, sk->sk_socket, err);
798         xprt_wake_pending_tasks(xprt, err);
799  out:
800         read_unlock_bh(&sk->sk_callback_lock);
801 }
802 
803 static void xs_reset_transport(struct sock_xprt *transport)
804 {
805         struct socket *sock = transport->sock;
806         struct sock *sk = transport->inet;
807         struct rpc_xprt *xprt = &transport->xprt;
808 
809         if (sk == NULL)
810                 return;
811 
812         if (atomic_read(&transport->xprt.swapper))
813                 sk_clear_memalloc(sk);
814 
815         kernel_sock_shutdown(sock, SHUT_RDWR);
816 
817         mutex_lock(&transport->recv_mutex);
818         write_lock_bh(&sk->sk_callback_lock);
819         transport->inet = NULL;
820         transport->sock = NULL;
821 
822         sk->sk_user_data = NULL;
823 
824         xs_restore_old_callbacks(transport, sk);
825         xprt_clear_connected(xprt);
826         write_unlock_bh(&sk->sk_callback_lock);
827         xs_sock_reset_connection_flags(xprt);
828         mutex_unlock(&transport->recv_mutex);
829 
830         trace_rpc_socket_close(xprt, sock);
831         sock_release(sock);
832 }
833 
834 /**
835  * xs_close - close a socket
836  * @xprt: transport
837  *
838  * This is used when all requests are complete; ie, no DRC state remains
839  * on the server we want to save.
840  *
841  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
842  * xs_reset_transport() zeroing the socket from underneath a writer.
843  */
844 static void xs_close(struct rpc_xprt *xprt)
845 {
846         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
847 
848         dprintk("RPC:       xs_close xprt %p\n", xprt);
849 
850         xs_reset_transport(transport);
851         xprt->reestablish_timeout = 0;
852 
853         xprt_disconnect_done(xprt);
854 }
855 
856 static void xs_inject_disconnect(struct rpc_xprt *xprt)
857 {
858         dprintk("RPC:       injecting transport disconnect on xprt=%p\n",
859                 xprt);
860         xprt_disconnect_done(xprt);
861 }
862 
863 static void xs_xprt_free(struct rpc_xprt *xprt)
864 {
865         xs_free_peer_addresses(xprt);
866         xprt_free(xprt);
867 }
868 
869 /**
870  * xs_destroy - prepare to shutdown a transport
871  * @xprt: doomed transport
872  *
873  */
874 static void xs_destroy(struct rpc_xprt *xprt)
875 {
876         struct sock_xprt *transport = container_of(xprt,
877                         struct sock_xprt, xprt);
878         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
879 
880         cancel_delayed_work_sync(&transport->connect_worker);
881         xs_close(xprt);
882         cancel_work_sync(&transport->recv_worker);
883         xs_xprt_free(xprt);
884         module_put(THIS_MODULE);
885 }
886 
887 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
888 {
889         struct xdr_skb_reader desc = {
890                 .skb            = skb,
891                 .offset         = sizeof(rpc_fraghdr),
892                 .count          = skb->len - sizeof(rpc_fraghdr),
893         };
894 
895         if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
896                 return -1;
897         if (desc.count)
898                 return -1;
899         return 0;
900 }
901 
902 /**
903  * xs_local_data_read_skb
904  * @xprt: transport
905  * @sk: socket
906  * @skb: skbuff
907  *
908  * Currently this assumes we can read the whole reply in a single gulp.
909  */
910 static void xs_local_data_read_skb(struct rpc_xprt *xprt,
911                 struct sock *sk,
912                 struct sk_buff *skb)
913 {
914         struct rpc_task *task;
915         struct rpc_rqst *rovr;
916         int repsize, copied;
917         u32 _xid;
918         __be32 *xp;
919 
920         repsize = skb->len - sizeof(rpc_fraghdr);
921         if (repsize < 4) {
922                 dprintk("RPC:       impossible RPC reply size %d\n", repsize);
923                 return;
924         }
925 
926         /* Copy the XID from the skb... */
927         xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
928         if (xp == NULL)
929                 return;
930 
931         /* Look up and lock the request corresponding to the given XID */
932         spin_lock_bh(&xprt->transport_lock);
933         rovr = xprt_lookup_rqst(xprt, *xp);
934         if (!rovr)
935                 goto out_unlock;
936         task = rovr->rq_task;
937 
938         copied = rovr->rq_private_buf.buflen;
939         if (copied > repsize)
940                 copied = repsize;
941 
942         if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
943                 dprintk("RPC:       sk_buff copy failed\n");
944                 goto out_unlock;
945         }
946 
947         xprt_complete_rqst(task, copied);
948 
949  out_unlock:
950         spin_unlock_bh(&xprt->transport_lock);
951 }
952 
953 static void xs_local_data_receive(struct sock_xprt *transport)
954 {
955         struct sk_buff *skb;
956         struct sock *sk;
957         int err;
958 
959         mutex_lock(&transport->recv_mutex);
960         sk = transport->inet;
961         if (sk == NULL)
962                 goto out;
963         for (;;) {
964                 skb = skb_recv_datagram(sk, 0, 1, &err);
965                 if (skb == NULL)
966                         break;
967                 xs_local_data_read_skb(&transport->xprt, sk, skb);
968                 skb_free_datagram(sk, skb);
969         }
970 out:
971         mutex_unlock(&transport->recv_mutex);
972 }
973 
974 static void xs_local_data_receive_workfn(struct work_struct *work)
975 {
976         struct sock_xprt *transport =
977                 container_of(work, struct sock_xprt, recv_worker);
978         xs_local_data_receive(transport);
979 }
980 
981 /**
982  * xs_udp_data_read_skb - receive callback for UDP sockets
983  * @xprt: transport
984  * @sk: socket
985  * @skb: skbuff
986  *
987  */
988 static void xs_udp_data_read_skb(struct rpc_xprt *xprt,
989                 struct sock *sk,
990                 struct sk_buff *skb)
991 {
992         struct rpc_task *task;
993         struct rpc_rqst *rovr;
994         int repsize, copied;
995         u32 _xid;
996         __be32 *xp;
997 
998         repsize = skb->len - sizeof(struct udphdr);
999         if (repsize < 4) {
1000                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1001                 return;
1002         }
1003 
1004         /* Copy the XID from the skb... */
1005         xp = skb_header_pointer(skb, sizeof(struct udphdr),
1006                                 sizeof(_xid), &_xid);
1007         if (xp == NULL)
1008                 return;
1009 
1010         /* Look up and lock the request corresponding to the given XID */
1011         spin_lock_bh(&xprt->transport_lock);
1012         rovr = xprt_lookup_rqst(xprt, *xp);
1013         if (!rovr)
1014                 goto out_unlock;
1015         task = rovr->rq_task;
1016 
1017         if ((copied = rovr->rq_private_buf.buflen) > repsize)
1018                 copied = repsize;
1019 
1020         /* Suck it into the iovec, verify checksum if not done by hw. */
1021         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1022                 UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
1023                 goto out_unlock;
1024         }
1025 
1026         UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
1027 
1028         xprt_adjust_cwnd(xprt, task, copied);
1029         xprt_complete_rqst(task, copied);
1030 
1031  out_unlock:
1032         spin_unlock_bh(&xprt->transport_lock);
1033 }
1034 
1035 static void xs_udp_data_receive(struct sock_xprt *transport)
1036 {
1037         struct sk_buff *skb;
1038         struct sock *sk;
1039         int err;
1040 
1041         mutex_lock(&transport->recv_mutex);
1042         sk = transport->inet;
1043         if (sk == NULL)
1044                 goto out;
1045         for (;;) {
1046                 skb = skb_recv_datagram(sk, 0, 1, &err);
1047                 if (skb == NULL)
1048                         break;
1049                 xs_udp_data_read_skb(&transport->xprt, sk, skb);
1050                 skb_free_datagram(sk, skb);
1051         }
1052 out:
1053         mutex_unlock(&transport->recv_mutex);
1054 }
1055 
1056 static void xs_udp_data_receive_workfn(struct work_struct *work)
1057 {
1058         struct sock_xprt *transport =
1059                 container_of(work, struct sock_xprt, recv_worker);
1060         xs_udp_data_receive(transport);
1061 }
1062 
1063 /**
1064  * xs_data_ready - "data ready" callback for UDP sockets
1065  * @sk: socket with data to read
1066  *
1067  */
1068 static void xs_data_ready(struct sock *sk)
1069 {
1070         struct rpc_xprt *xprt;
1071 
1072         read_lock_bh(&sk->sk_callback_lock);
1073         dprintk("RPC:       xs_data_ready...\n");
1074         xprt = xprt_from_sock(sk);
1075         if (xprt != NULL) {
1076                 struct sock_xprt *transport = container_of(xprt,
1077                                 struct sock_xprt, xprt);
1078                 queue_work(rpciod_workqueue, &transport->recv_worker);
1079         }
1080         read_unlock_bh(&sk->sk_callback_lock);
1081 }
1082 
1083 /*
1084  * Helper function to force a TCP close if the server is sending
1085  * junk and/or it has put us in CLOSE_WAIT
1086  */
1087 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1088 {
1089         xprt_force_disconnect(xprt);
1090 }
1091 
1092 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1093 {
1094         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1095         size_t len, used;
1096         char *p;
1097 
1098         p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1099         len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1100         used = xdr_skb_read_bits(desc, p, len);
1101         transport->tcp_offset += used;
1102         if (used != len)
1103                 return;
1104 
1105         transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1106         if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1107                 transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1108         else
1109                 transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1110         transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1111 
1112         transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1113         transport->tcp_offset = 0;
1114 
1115         /* Sanity check of the record length */
1116         if (unlikely(transport->tcp_reclen < 8)) {
1117                 dprintk("RPC:       invalid TCP record fragment length\n");
1118                 xs_tcp_force_close(xprt);
1119                 return;
1120         }
1121         dprintk("RPC:       reading TCP record fragment of length %d\n",
1122                         transport->tcp_reclen);
1123 }
1124 
1125 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1126 {
1127         if (transport->tcp_offset == transport->tcp_reclen) {
1128                 transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1129                 transport->tcp_offset = 0;
1130                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1131                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1132                         transport->tcp_flags |= TCP_RCV_COPY_XID;
1133                         transport->tcp_copied = 0;
1134                 }
1135         }
1136 }
1137 
1138 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1139 {
1140         size_t len, used;
1141         char *p;
1142 
1143         len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1144         dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1145         p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1146         used = xdr_skb_read_bits(desc, p, len);
1147         transport->tcp_offset += used;
1148         if (used != len)
1149                 return;
1150         transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1151         transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1152         transport->tcp_copied = 4;
1153         dprintk("RPC:       reading %s XID %08x\n",
1154                         (transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1155                                                               : "request with",
1156                         ntohl(transport->tcp_xid));
1157         xs_tcp_check_fraghdr(transport);
1158 }
1159 
1160 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1161                                        struct xdr_skb_reader *desc)
1162 {
1163         size_t len, used;
1164         u32 offset;
1165         char *p;
1166 
1167         /*
1168          * We want transport->tcp_offset to be 8 at the end of this routine
1169          * (4 bytes for the xid and 4 bytes for the call/reply flag).
1170          * When this function is called for the first time,
1171          * transport->tcp_offset is 4 (after having already read the xid).
1172          */
1173         offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1174         len = sizeof(transport->tcp_calldir) - offset;
1175         dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1176         p = ((char *) &transport->tcp_calldir) + offset;
1177         used = xdr_skb_read_bits(desc, p, len);
1178         transport->tcp_offset += used;
1179         if (used != len)
1180                 return;
1181         transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1182         /*
1183          * We don't yet have the XDR buffer, so we will write the calldir
1184          * out after we get the buffer from the 'struct rpc_rqst'
1185          */
1186         switch (ntohl(transport->tcp_calldir)) {
1187         case RPC_REPLY:
1188                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1189                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1190                 transport->tcp_flags |= TCP_RPC_REPLY;
1191                 break;
1192         case RPC_CALL:
1193                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1194                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1195                 transport->tcp_flags &= ~TCP_RPC_REPLY;
1196                 break;
1197         default:
1198                 dprintk("RPC:       invalid request message type\n");
1199                 xs_tcp_force_close(&transport->xprt);
1200         }
1201         xs_tcp_check_fraghdr(transport);
1202 }
1203 
1204 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1205                                      struct xdr_skb_reader *desc,
1206                                      struct rpc_rqst *req)
1207 {
1208         struct sock_xprt *transport =
1209                                 container_of(xprt, struct sock_xprt, xprt);
1210         struct xdr_buf *rcvbuf;
1211         size_t len;
1212         ssize_t r;
1213 
1214         rcvbuf = &req->rq_private_buf;
1215 
1216         if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1217                 /*
1218                  * Save the RPC direction in the XDR buffer
1219                  */
1220                 memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1221                         &transport->tcp_calldir,
1222                         sizeof(transport->tcp_calldir));
1223                 transport->tcp_copied += sizeof(transport->tcp_calldir);
1224                 transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1225         }
1226 
1227         len = desc->count;
1228         if (len > transport->tcp_reclen - transport->tcp_offset) {
1229                 struct xdr_skb_reader my_desc;
1230 
1231                 len = transport->tcp_reclen - transport->tcp_offset;
1232                 memcpy(&my_desc, desc, sizeof(my_desc));
1233                 my_desc.count = len;
1234                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1235                                           &my_desc, xdr_skb_read_bits);
1236                 desc->count -= r;
1237                 desc->offset += r;
1238         } else
1239                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1240                                           desc, xdr_skb_read_bits);
1241 
1242         if (r > 0) {
1243                 transport->tcp_copied += r;
1244                 transport->tcp_offset += r;
1245         }
1246         if (r != len) {
1247                 /* Error when copying to the receive buffer,
1248                  * usually because we weren't able to allocate
1249                  * additional buffer pages. All we can do now
1250                  * is turn off TCP_RCV_COPY_DATA, so the request
1251                  * will not receive any additional updates,
1252                  * and time out.
1253                  * Any remaining data from this record will
1254                  * be discarded.
1255                  */
1256                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1257                 dprintk("RPC:       XID %08x truncated request\n",
1258                                 ntohl(transport->tcp_xid));
1259                 dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1260                                 "tcp_offset = %u, tcp_reclen = %u\n",
1261                                 xprt, transport->tcp_copied,
1262                                 transport->tcp_offset, transport->tcp_reclen);
1263                 return;
1264         }
1265 
1266         dprintk("RPC:       XID %08x read %Zd bytes\n",
1267                         ntohl(transport->tcp_xid), r);
1268         dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1269                         "tcp_reclen = %u\n", xprt, transport->tcp_copied,
1270                         transport->tcp_offset, transport->tcp_reclen);
1271 
1272         if (transport->tcp_copied == req->rq_private_buf.buflen)
1273                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1274         else if (transport->tcp_offset == transport->tcp_reclen) {
1275                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1276                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1277         }
1278 }
1279 
1280 /*
1281  * Finds the request corresponding to the RPC xid and invokes the common
1282  * tcp read code to read the data.
1283  */
1284 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1285                                     struct xdr_skb_reader *desc)
1286 {
1287         struct sock_xprt *transport =
1288                                 container_of(xprt, struct sock_xprt, xprt);
1289         struct rpc_rqst *req;
1290 
1291         dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1292 
1293         /* Find and lock the request corresponding to this xid */
1294         spin_lock_bh(&xprt->transport_lock);
1295         req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1296         if (!req) {
1297                 dprintk("RPC:       XID %08x request not found!\n",
1298                                 ntohl(transport->tcp_xid));
1299                 spin_unlock_bh(&xprt->transport_lock);
1300                 return -1;
1301         }
1302 
1303         xs_tcp_read_common(xprt, desc, req);
1304 
1305         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1306                 xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1307 
1308         spin_unlock_bh(&xprt->transport_lock);
1309         return 0;
1310 }
1311 
1312 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1313 /*
1314  * Obtains an rpc_rqst previously allocated and invokes the common
1315  * tcp read code to read the data.  The result is placed in the callback
1316  * queue.
1317  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1318  * connection and return -1.
1319  */
1320 static int xs_tcp_read_callback(struct rpc_xprt *xprt,
1321                                        struct xdr_skb_reader *desc)
1322 {
1323         struct sock_xprt *transport =
1324                                 container_of(xprt, struct sock_xprt, xprt);
1325         struct rpc_rqst *req;
1326 
1327         /* Look up and lock the request corresponding to the given XID */
1328         spin_lock_bh(&xprt->transport_lock);
1329         req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
1330         if (req == NULL) {
1331                 spin_unlock_bh(&xprt->transport_lock);
1332                 printk(KERN_WARNING "Callback slot table overflowed\n");
1333                 xprt_force_disconnect(xprt);
1334                 return -1;
1335         }
1336 
1337         dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1338         xs_tcp_read_common(xprt, desc, req);
1339 
1340         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1341                 xprt_complete_bc_request(req, transport->tcp_copied);
1342         spin_unlock_bh(&xprt->transport_lock);
1343 
1344         return 0;
1345 }
1346 
1347 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1348                                         struct xdr_skb_reader *desc)
1349 {
1350         struct sock_xprt *transport =
1351                                 container_of(xprt, struct sock_xprt, xprt);
1352 
1353         return (transport->tcp_flags & TCP_RPC_REPLY) ?
1354                 xs_tcp_read_reply(xprt, desc) :
1355                 xs_tcp_read_callback(xprt, desc);
1356 }
1357 
1358 static int xs_tcp_bc_up(struct svc_serv *serv, struct net *net)
1359 {
1360         int ret;
1361 
1362         ret = svc_create_xprt(serv, "tcp-bc", net, PF_INET, 0,
1363                               SVC_SOCK_ANONYMOUS);
1364         if (ret < 0)
1365                 return ret;
1366         return 0;
1367 }
1368 #else
1369 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1370                                         struct xdr_skb_reader *desc)
1371 {
1372         return xs_tcp_read_reply(xprt, desc);
1373 }
1374 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1375 
1376 /*
1377  * Read data off the transport.  This can be either an RPC_CALL or an
1378  * RPC_REPLY.  Relay the processing to helper functions.
1379  */
1380 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1381                                     struct xdr_skb_reader *desc)
1382 {
1383         struct sock_xprt *transport =
1384                                 container_of(xprt, struct sock_xprt, xprt);
1385 
1386         if (_xs_tcp_read_data(xprt, desc) == 0)
1387                 xs_tcp_check_fraghdr(transport);
1388         else {
1389                 /*
1390                  * The transport_lock protects the request handling.
1391                  * There's no need to hold it to update the tcp_flags.
1392                  */
1393                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1394         }
1395 }
1396 
1397 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1398 {
1399         size_t len;
1400 
1401         len = transport->tcp_reclen - transport->tcp_offset;
1402         if (len > desc->count)
1403                 len = desc->count;
1404         desc->count -= len;
1405         desc->offset += len;
1406         transport->tcp_offset += len;
1407         dprintk("RPC:       discarded %Zu bytes\n", len);
1408         xs_tcp_check_fraghdr(transport);
1409 }
1410 
1411 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1412 {
1413         struct rpc_xprt *xprt = rd_desc->arg.data;
1414         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1415         struct xdr_skb_reader desc = {
1416                 .skb    = skb,
1417                 .offset = offset,
1418                 .count  = len,
1419         };
1420 
1421         dprintk("RPC:       xs_tcp_data_recv started\n");
1422         do {
1423                 trace_xs_tcp_data_recv(transport);
1424                 /* Read in a new fragment marker if necessary */
1425                 /* Can we ever really expect to get completely empty fragments? */
1426                 if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1427                         xs_tcp_read_fraghdr(xprt, &desc);
1428                         continue;
1429                 }
1430                 /* Read in the xid if necessary */
1431                 if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1432                         xs_tcp_read_xid(transport, &desc);
1433                         continue;
1434                 }
1435                 /* Read in the call/reply flag */
1436                 if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1437                         xs_tcp_read_calldir(transport, &desc);
1438                         continue;
1439                 }
1440                 /* Read in the request data */
1441                 if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1442                         xs_tcp_read_data(xprt, &desc);
1443                         continue;
1444                 }
1445                 /* Skip over any trailing bytes on short reads */
1446                 xs_tcp_read_discard(transport, &desc);
1447         } while (desc.count);
1448         trace_xs_tcp_data_recv(transport);
1449         dprintk("RPC:       xs_tcp_data_recv done\n");
1450         return len - desc.count;
1451 }
1452 
1453 static void xs_tcp_data_receive(struct sock_xprt *transport)
1454 {
1455         struct rpc_xprt *xprt = &transport->xprt;
1456         struct sock *sk;
1457         read_descriptor_t rd_desc = {
1458                 .count = 2*1024*1024,
1459                 .arg.data = xprt,
1460         };
1461         unsigned long total = 0;
1462         int read = 0;
1463 
1464         mutex_lock(&transport->recv_mutex);
1465         sk = transport->inet;
1466         if (sk == NULL)
1467                 goto out;
1468 
1469         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1470         for (;;) {
1471                 lock_sock(sk);
1472                 read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1473                 release_sock(sk);
1474                 if (read <= 0)
1475                         break;
1476                 total += read;
1477                 rd_desc.count = 65536;
1478         }
1479 out:
1480         mutex_unlock(&transport->recv_mutex);
1481         trace_xs_tcp_data_ready(xprt, read, total);
1482 }
1483 
1484 static void xs_tcp_data_receive_workfn(struct work_struct *work)
1485 {
1486         struct sock_xprt *transport =
1487                 container_of(work, struct sock_xprt, recv_worker);
1488         xs_tcp_data_receive(transport);
1489 }
1490 
1491 /**
1492  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1493  * @sk: socket with data to read
1494  *
1495  */
1496 static void xs_tcp_data_ready(struct sock *sk)
1497 {
1498         struct sock_xprt *transport;
1499         struct rpc_xprt *xprt;
1500 
1501         dprintk("RPC:       xs_tcp_data_ready...\n");
1502 
1503         read_lock_bh(&sk->sk_callback_lock);
1504         if (!(xprt = xprt_from_sock(sk)))
1505                 goto out;
1506         transport = container_of(xprt, struct sock_xprt, xprt);
1507 
1508         /* Any data means we had a useful conversation, so
1509          * the we don't need to delay the next reconnect
1510          */
1511         if (xprt->reestablish_timeout)
1512                 xprt->reestablish_timeout = 0;
1513         queue_work(rpciod_workqueue, &transport->recv_worker);
1514 
1515 out:
1516         read_unlock_bh(&sk->sk_callback_lock);
1517 }
1518 
1519 /**
1520  * xs_tcp_state_change - callback to handle TCP socket state changes
1521  * @sk: socket whose state has changed
1522  *
1523  */
1524 static void xs_tcp_state_change(struct sock *sk)
1525 {
1526         struct rpc_xprt *xprt;
1527         struct sock_xprt *transport;
1528 
1529         read_lock_bh(&sk->sk_callback_lock);
1530         if (!(xprt = xprt_from_sock(sk)))
1531                 goto out;
1532         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1533         dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1534                         sk->sk_state, xprt_connected(xprt),
1535                         sock_flag(sk, SOCK_DEAD),
1536                         sock_flag(sk, SOCK_ZAPPED),
1537                         sk->sk_shutdown);
1538 
1539         transport = container_of(xprt, struct sock_xprt, xprt);
1540         trace_rpc_socket_state_change(xprt, sk->sk_socket);
1541         switch (sk->sk_state) {
1542         case TCP_ESTABLISHED:
1543                 spin_lock(&xprt->transport_lock);
1544                 if (!xprt_test_and_set_connected(xprt)) {
1545 
1546                         /* Reset TCP record info */
1547                         transport->tcp_offset = 0;
1548                         transport->tcp_reclen = 0;
1549                         transport->tcp_copied = 0;
1550                         transport->tcp_flags =
1551                                 TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1552                         xprt->connect_cookie++;
1553                         clear_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
1554                         xprt_clear_connecting(xprt);
1555 
1556                         xprt_wake_pending_tasks(xprt, -EAGAIN);
1557                 }
1558                 spin_unlock(&xprt->transport_lock);
1559                 break;
1560         case TCP_FIN_WAIT1:
1561                 /* The client initiated a shutdown of the socket */
1562                 xprt->connect_cookie++;
1563                 xprt->reestablish_timeout = 0;
1564                 set_bit(XPRT_CLOSING, &xprt->state);
1565                 smp_mb__before_atomic();
1566                 clear_bit(XPRT_CONNECTED, &xprt->state);
1567                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1568                 smp_mb__after_atomic();
1569                 break;
1570         case TCP_CLOSE_WAIT:
1571                 /* The server initiated a shutdown of the socket */
1572                 xprt->connect_cookie++;
1573                 clear_bit(XPRT_CONNECTED, &xprt->state);
1574                 xs_tcp_force_close(xprt);
1575         case TCP_CLOSING:
1576                 /*
1577                  * If the server closed down the connection, make sure that
1578                  * we back off before reconnecting
1579                  */
1580                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1581                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1582                 break;
1583         case TCP_LAST_ACK:
1584                 set_bit(XPRT_CLOSING, &xprt->state);
1585                 smp_mb__before_atomic();
1586                 clear_bit(XPRT_CONNECTED, &xprt->state);
1587                 smp_mb__after_atomic();
1588                 break;
1589         case TCP_CLOSE:
1590                 if (test_and_clear_bit(XPRT_SOCK_CONNECTING,
1591                                         &transport->sock_state))
1592                         xprt_clear_connecting(xprt);
1593                 xs_sock_mark_closed(xprt);
1594         }
1595  out:
1596         read_unlock_bh(&sk->sk_callback_lock);
1597 }
1598 
1599 static void xs_write_space(struct sock *sk)
1600 {
1601         struct socket_wq *wq;
1602         struct rpc_xprt *xprt;
1603 
1604         if (!sk->sk_socket)
1605                 return;
1606         clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1607 
1608         if (unlikely(!(xprt = xprt_from_sock(sk))))
1609                 return;
1610         rcu_read_lock();
1611         wq = rcu_dereference(sk->sk_wq);
1612         if (!wq || test_and_clear_bit(SOCKWQ_ASYNC_NOSPACE, &wq->flags) == 0)
1613                 goto out;
1614 
1615         xprt_write_space(xprt);
1616 out:
1617         rcu_read_unlock();
1618 }
1619 
1620 /**
1621  * xs_udp_write_space - callback invoked when socket buffer space
1622  *                             becomes available
1623  * @sk: socket whose state has changed
1624  *
1625  * Called when more output buffer space is available for this socket.
1626  * We try not to wake our writers until they can make "significant"
1627  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1628  * with a bunch of small requests.
1629  */
1630 static void xs_udp_write_space(struct sock *sk)
1631 {
1632         read_lock_bh(&sk->sk_callback_lock);
1633 
1634         /* from net/core/sock.c:sock_def_write_space */
1635         if (sock_writeable(sk))
1636                 xs_write_space(sk);
1637 
1638         read_unlock_bh(&sk->sk_callback_lock);
1639 }
1640 
1641 /**
1642  * xs_tcp_write_space - callback invoked when socket buffer space
1643  *                             becomes available
1644  * @sk: socket whose state has changed
1645  *
1646  * Called when more output buffer space is available for this socket.
1647  * We try not to wake our writers until they can make "significant"
1648  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1649  * with a bunch of small requests.
1650  */
1651 static void xs_tcp_write_space(struct sock *sk)
1652 {
1653         read_lock_bh(&sk->sk_callback_lock);
1654 
1655         /* from net/core/stream.c:sk_stream_write_space */
1656         if (sk_stream_is_writeable(sk))
1657                 xs_write_space(sk);
1658 
1659         read_unlock_bh(&sk->sk_callback_lock);
1660 }
1661 
1662 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1663 {
1664         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1665         struct sock *sk = transport->inet;
1666 
1667         if (transport->rcvsize) {
1668                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1669                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1670         }
1671         if (transport->sndsize) {
1672                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1673                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1674                 sk->sk_write_space(sk);
1675         }
1676 }
1677 
1678 /**
1679  * xs_udp_set_buffer_size - set send and receive limits
1680  * @xprt: generic transport
1681  * @sndsize: requested size of send buffer, in bytes
1682  * @rcvsize: requested size of receive buffer, in bytes
1683  *
1684  * Set socket send and receive buffer size limits.
1685  */
1686 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1687 {
1688         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1689 
1690         transport->sndsize = 0;
1691         if (sndsize)
1692                 transport->sndsize = sndsize + 1024;
1693         transport->rcvsize = 0;
1694         if (rcvsize)
1695                 transport->rcvsize = rcvsize + 1024;
1696 
1697         xs_udp_do_set_buffer_size(xprt);
1698 }
1699 
1700 /**
1701  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1702  * @task: task that timed out
1703  *
1704  * Adjust the congestion window after a retransmit timeout has occurred.
1705  */
1706 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1707 {
1708         xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1709 }
1710 
1711 static unsigned short xs_get_random_port(void)
1712 {
1713         unsigned short range = xprt_max_resvport - xprt_min_resvport;
1714         unsigned short rand = (unsigned short) prandom_u32() % range;
1715         return rand + xprt_min_resvport;
1716 }
1717 
1718 /**
1719  * xs_set_reuseaddr_port - set the socket's port and address reuse options
1720  * @sock: socket
1721  *
1722  * Note that this function has to be called on all sockets that share the
1723  * same port, and it must be called before binding.
1724  */
1725 static void xs_sock_set_reuseport(struct socket *sock)
1726 {
1727         int opt = 1;
1728 
1729         kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEPORT,
1730                         (char *)&opt, sizeof(opt));
1731 }
1732 
1733 static unsigned short xs_sock_getport(struct socket *sock)
1734 {
1735         struct sockaddr_storage buf;
1736         int buflen;
1737         unsigned short port = 0;
1738 
1739         if (kernel_getsockname(sock, (struct sockaddr *)&buf, &buflen) < 0)
1740                 goto out;
1741         switch (buf.ss_family) {
1742         case AF_INET6:
1743                 port = ntohs(((struct sockaddr_in6 *)&buf)->sin6_port);
1744                 break;
1745         case AF_INET:
1746                 port = ntohs(((struct sockaddr_in *)&buf)->sin_port);
1747         }
1748 out:
1749         return port;
1750 }
1751 
1752 /**
1753  * xs_set_port - reset the port number in the remote endpoint address
1754  * @xprt: generic transport
1755  * @port: new port number
1756  *
1757  */
1758 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1759 {
1760         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1761 
1762         rpc_set_port(xs_addr(xprt), port);
1763         xs_update_peer_port(xprt);
1764 }
1765 
1766 static void xs_set_srcport(struct sock_xprt *transport, struct socket *sock)
1767 {
1768         if (transport->srcport == 0)
1769                 transport->srcport = xs_sock_getport(sock);
1770 }
1771 
1772 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1773 {
1774         unsigned short port = transport->srcport;
1775 
1776         if (port == 0 && transport->xprt.resvport)
1777                 port = xs_get_random_port();
1778         return port;
1779 }
1780 
1781 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1782 {
1783         if (transport->srcport != 0)
1784                 transport->srcport = 0;
1785         if (!transport->xprt.resvport)
1786                 return 0;
1787         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1788                 return xprt_max_resvport;
1789         return --port;
1790 }
1791 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1792 {
1793         struct sockaddr_storage myaddr;
1794         int err, nloop = 0;
1795         unsigned short port = xs_get_srcport(transport);
1796         unsigned short last;
1797 
1798         /*
1799          * If we are asking for any ephemeral port (i.e. port == 0 &&
1800          * transport->xprt.resvport == 0), don't bind.  Let the local
1801          * port selection happen implicitly when the socket is used
1802          * (for example at connect time).
1803          *
1804          * This ensures that we can continue to establish TCP
1805          * connections even when all local ephemeral ports are already
1806          * a part of some TCP connection.  This makes no difference
1807          * for UDP sockets, but also doens't harm them.
1808          *
1809          * If we're asking for any reserved port (i.e. port == 0 &&
1810          * transport->xprt.resvport == 1) xs_get_srcport above will
1811          * ensure that port is non-zero and we will bind as needed.
1812          */
1813         if (port == 0)
1814                 return 0;
1815 
1816         memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1817         do {
1818                 rpc_set_port((struct sockaddr *)&myaddr, port);
1819                 err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1820                                 transport->xprt.addrlen);
1821                 if (err == 0) {
1822                         transport->srcport = port;
1823                         break;
1824                 }
1825                 last = port;
1826                 port = xs_next_srcport(transport, port);
1827                 if (port > last)
1828                         nloop++;
1829         } while (err == -EADDRINUSE && nloop != 2);
1830 
1831         if (myaddr.ss_family == AF_INET)
1832                 dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1833                                 &((struct sockaddr_in *)&myaddr)->sin_addr,
1834                                 port, err ? "failed" : "ok", err);
1835         else
1836                 dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1837                                 &((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1838                                 port, err ? "failed" : "ok", err);
1839         return err;
1840 }
1841 
1842 /*
1843  * We don't support autobind on AF_LOCAL sockets
1844  */
1845 static void xs_local_rpcbind(struct rpc_task *task)
1846 {
1847         xprt_set_bound(task->tk_xprt);
1848 }
1849 
1850 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1851 {
1852 }
1853 
1854 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1855 static struct lock_class_key xs_key[2];
1856 static struct lock_class_key xs_slock_key[2];
1857 
1858 static inline void xs_reclassify_socketu(struct socket *sock)
1859 {
1860         struct sock *sk = sock->sk;
1861 
1862         sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1863                 &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1864 }
1865 
1866 static inline void xs_reclassify_socket4(struct socket *sock)
1867 {
1868         struct sock *sk = sock->sk;
1869 
1870         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1871                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1872 }
1873 
1874 static inline void xs_reclassify_socket6(struct socket *sock)
1875 {
1876         struct sock *sk = sock->sk;
1877 
1878         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1879                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1880 }
1881 
1882 static inline void xs_reclassify_socket(int family, struct socket *sock)
1883 {
1884         WARN_ON_ONCE(sock_owned_by_user(sock->sk));
1885         if (sock_owned_by_user(sock->sk))
1886                 return;
1887 
1888         switch (family) {
1889         case AF_LOCAL:
1890                 xs_reclassify_socketu(sock);
1891                 break;
1892         case AF_INET:
1893                 xs_reclassify_socket4(sock);
1894                 break;
1895         case AF_INET6:
1896                 xs_reclassify_socket6(sock);
1897                 break;
1898         }
1899 }
1900 #else
1901 static inline void xs_reclassify_socket(int family, struct socket *sock)
1902 {
1903 }
1904 #endif
1905 
1906 static void xs_dummy_setup_socket(struct work_struct *work)
1907 {
1908 }
1909 
1910 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1911                 struct sock_xprt *transport, int family, int type,
1912                 int protocol, bool reuseport)
1913 {
1914         struct socket *sock;
1915         int err;
1916 
1917         err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1918         if (err < 0) {
1919                 dprintk("RPC:       can't create %d transport socket (%d).\n",
1920                                 protocol, -err);
1921                 goto out;
1922         }
1923         xs_reclassify_socket(family, sock);
1924 
1925         if (reuseport)
1926                 xs_sock_set_reuseport(sock);
1927 
1928         err = xs_bind(transport, sock);
1929         if (err) {
1930                 sock_release(sock);
1931                 goto out;
1932         }
1933 
1934         return sock;
1935 out:
1936         return ERR_PTR(err);
1937 }
1938 
1939 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1940                                       struct socket *sock)
1941 {
1942         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1943                                                                         xprt);
1944 
1945         if (!transport->inet) {
1946                 struct sock *sk = sock->sk;
1947 
1948                 write_lock_bh(&sk->sk_callback_lock);
1949 
1950                 xs_save_old_callbacks(transport, sk);
1951 
1952                 sk->sk_user_data = xprt;
1953                 sk->sk_data_ready = xs_data_ready;
1954                 sk->sk_write_space = xs_udp_write_space;
1955                 sk->sk_error_report = xs_error_report;
1956                 sk->sk_allocation = GFP_NOIO;
1957 
1958                 xprt_clear_connected(xprt);
1959 
1960                 /* Reset to new socket */
1961                 transport->sock = sock;
1962                 transport->inet = sk;
1963 
1964                 write_unlock_bh(&sk->sk_callback_lock);
1965         }
1966 
1967         /* Tell the socket layer to start connecting... */
1968         xprt->stat.connect_count++;
1969         xprt->stat.connect_start = jiffies;
1970         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1971 }
1972 
1973 /**
1974  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1975  * @transport: socket transport to connect
1976  */
1977 static int xs_local_setup_socket(struct sock_xprt *transport)
1978 {
1979         struct rpc_xprt *xprt = &transport->xprt;
1980         struct socket *sock;
1981         int status = -EIO;
1982 
1983         status = __sock_create(xprt->xprt_net, AF_LOCAL,
1984                                         SOCK_STREAM, 0, &sock, 1);
1985         if (status < 0) {
1986                 dprintk("RPC:       can't create AF_LOCAL "
1987                         "transport socket (%d).\n", -status);
1988                 goto out;
1989         }
1990         xs_reclassify_socket(AF_LOCAL, sock);
1991 
1992         dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1993                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1994 
1995         status = xs_local_finish_connecting(xprt, sock);
1996         trace_rpc_socket_connect(xprt, sock, status);
1997         switch (status) {
1998         case 0:
1999                 dprintk("RPC:       xprt %p connected to %s\n",
2000                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2001                 xprt_set_connected(xprt);
2002         case -ENOBUFS:
2003                 break;
2004         case -ENOENT:
2005                 dprintk("RPC:       xprt %p: socket %s does not exist\n",
2006                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2007                 break;
2008         case -ECONNREFUSED:
2009                 dprintk("RPC:       xprt %p: connection refused for %s\n",
2010                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
2011                 break;
2012         default:
2013                 printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
2014                                 __func__, -status,
2015                                 xprt->address_strings[RPC_DISPLAY_ADDR]);
2016         }
2017 
2018 out:
2019         xprt_clear_connecting(xprt);
2020         xprt_wake_pending_tasks(xprt, status);
2021         return status;
2022 }
2023 
2024 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2025 {
2026         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2027         int ret;
2028 
2029          if (RPC_IS_ASYNC(task)) {
2030                 /*
2031                  * We want the AF_LOCAL connect to be resolved in the
2032                  * filesystem namespace of the process making the rpc
2033                  * call.  Thus we connect synchronously.
2034                  *
2035                  * If we want to support asynchronous AF_LOCAL calls,
2036                  * we'll need to figure out how to pass a namespace to
2037                  * connect.
2038                  */
2039                 rpc_exit(task, -ENOTCONN);
2040                 return;
2041         }
2042         ret = xs_local_setup_socket(transport);
2043         if (ret && !RPC_IS_SOFTCONN(task))
2044                 msleep_interruptible(15000);
2045 }
2046 
2047 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2048 /*
2049  * Note that this should be called with XPRT_LOCKED held (or when we otherwise
2050  * know that we have exclusive access to the socket), to guard against
2051  * races with xs_reset_transport.
2052  */
2053 static void xs_set_memalloc(struct rpc_xprt *xprt)
2054 {
2055         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2056                         xprt);
2057 
2058         /*
2059          * If there's no sock, then we have nothing to set. The
2060          * reconnecting process will get it for us.
2061          */
2062         if (!transport->inet)
2063                 return;
2064         if (atomic_read(&xprt->swapper))
2065                 sk_set_memalloc(transport->inet);
2066 }
2067 
2068 /**
2069  * xs_enable_swap - Tag this transport as being used for swap.
2070  * @xprt: transport to tag
2071  *
2072  * Take a reference to this transport on behalf of the rpc_clnt, and
2073  * optionally mark it for swapping if it wasn't already.
2074  */
2075 static int
2076 xs_enable_swap(struct rpc_xprt *xprt)
2077 {
2078         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2079 
2080         if (atomic_inc_return(&xprt->swapper) != 1)
2081                 return 0;
2082         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2083                 return -ERESTARTSYS;
2084         if (xs->inet)
2085                 sk_set_memalloc(xs->inet);
2086         xprt_release_xprt(xprt, NULL);
2087         return 0;
2088 }
2089 
2090 /**
2091  * xs_disable_swap - Untag this transport as being used for swap.
2092  * @xprt: transport to tag
2093  *
2094  * Drop a "swapper" reference to this xprt on behalf of the rpc_clnt. If the
2095  * swapper refcount goes to 0, untag the socket as a memalloc socket.
2096  */
2097 static void
2098 xs_disable_swap(struct rpc_xprt *xprt)
2099 {
2100         struct sock_xprt *xs = container_of(xprt, struct sock_xprt, xprt);
2101 
2102         if (!atomic_dec_and_test(&xprt->swapper))
2103                 return;
2104         if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE))
2105                 return;
2106         if (xs->inet)
2107                 sk_clear_memalloc(xs->inet);
2108         xprt_release_xprt(xprt, NULL);
2109 }
2110 #else
2111 static void xs_set_memalloc(struct rpc_xprt *xprt)
2112 {
2113 }
2114 
2115 static int
2116 xs_enable_swap(struct rpc_xprt *xprt)
2117 {
2118         return -EINVAL;
2119 }
2120 
2121 static void
2122 xs_disable_swap(struct rpc_xprt *xprt)
2123 {
2124 }
2125 #endif
2126 
2127 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2128 {
2129         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2130 
2131         if (!transport->inet) {
2132                 struct sock *sk = sock->sk;
2133 
2134                 write_lock_bh(&sk->sk_callback_lock);
2135 
2136                 xs_save_old_callbacks(transport, sk);
2137 
2138                 sk->sk_user_data = xprt;
2139                 sk->sk_data_ready = xs_data_ready;
2140                 sk->sk_write_space = xs_udp_write_space;
2141                 sk->sk_allocation = GFP_NOIO;
2142 
2143                 xprt_set_connected(xprt);
2144 
2145                 /* Reset to new socket */
2146                 transport->sock = sock;
2147                 transport->inet = sk;
2148 
2149                 xs_set_memalloc(xprt);
2150 
2151                 write_unlock_bh(&sk->sk_callback_lock);
2152         }
2153         xs_udp_do_set_buffer_size(xprt);
2154 }
2155 
2156 static void xs_udp_setup_socket(struct work_struct *work)
2157 {
2158         struct sock_xprt *transport =
2159                 container_of(work, struct sock_xprt, connect_worker.work);
2160         struct rpc_xprt *xprt = &transport->xprt;
2161         struct socket *sock = transport->sock;
2162         int status = -EIO;
2163 
2164         sock = xs_create_sock(xprt, transport,
2165                         xs_addr(xprt)->sa_family, SOCK_DGRAM,
2166                         IPPROTO_UDP, false);
2167         if (IS_ERR(sock))
2168                 goto out;
2169 
2170         dprintk("RPC:       worker connecting xprt %p via %s to "
2171                                 "%s (port %s)\n", xprt,
2172                         xprt->address_strings[RPC_DISPLAY_PROTO],
2173                         xprt->address_strings[RPC_DISPLAY_ADDR],
2174                         xprt->address_strings[RPC_DISPLAY_PORT]);
2175 
2176         xs_udp_finish_connecting(xprt, sock);
2177         trace_rpc_socket_connect(xprt, sock, 0);
2178         status = 0;
2179 out:
2180         xprt_unlock_connect(xprt, transport);
2181         xprt_clear_connecting(xprt);
2182         xprt_wake_pending_tasks(xprt, status);
2183 }
2184 
2185 /**
2186  * xs_tcp_shutdown - gracefully shut down a TCP socket
2187  * @xprt: transport
2188  *
2189  * Initiates a graceful shutdown of the TCP socket by calling the
2190  * equivalent of shutdown(SHUT_RDWR);
2191  */
2192 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
2193 {
2194         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2195         struct socket *sock = transport->sock;
2196 
2197         if (sock == NULL)
2198                 return;
2199         if (xprt_connected(xprt)) {
2200                 kernel_sock_shutdown(sock, SHUT_RDWR);
2201                 trace_rpc_socket_shutdown(xprt, sock);
2202         } else
2203                 xs_reset_transport(transport);
2204 }
2205 
2206 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2207 {
2208         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2209         int ret = -ENOTCONN;
2210 
2211         if (!transport->inet) {
2212                 struct sock *sk = sock->sk;
2213                 unsigned int keepidle = xprt->timeout->to_initval / HZ;
2214                 unsigned int keepcnt = xprt->timeout->to_retries + 1;
2215                 unsigned int opt_on = 1;
2216                 unsigned int timeo;
2217 
2218                 /* TCP Keepalive options */
2219                 kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2220                                 (char *)&opt_on, sizeof(opt_on));
2221                 kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2222                                 (char *)&keepidle, sizeof(keepidle));
2223                 kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2224                                 (char *)&keepidle, sizeof(keepidle));
2225                 kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2226                                 (char *)&keepcnt, sizeof(keepcnt));
2227 
2228                 /* TCP user timeout (see RFC5482) */
2229                 timeo = jiffies_to_msecs(xprt->timeout->to_initval) *
2230                         (xprt->timeout->to_retries + 1);
2231                 kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
2232                                 (char *)&timeo, sizeof(timeo));
2233 
2234                 write_lock_bh(&sk->sk_callback_lock);
2235 
2236                 xs_save_old_callbacks(transport, sk);
2237 
2238                 sk->sk_user_data = xprt;
2239                 sk->sk_data_ready = xs_tcp_data_ready;
2240                 sk->sk_state_change = xs_tcp_state_change;
2241                 sk->sk_write_space = xs_tcp_write_space;
2242                 sk->sk_error_report = xs_error_report;
2243                 sk->sk_allocation = GFP_NOIO;
2244 
2245                 /* socket options */
2246                 sock_reset_flag(sk, SOCK_LINGER);
2247                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2248 
2249                 xprt_clear_connected(xprt);
2250 
2251                 /* Reset to new socket */
2252                 transport->sock = sock;
2253                 transport->inet = sk;
2254 
2255                 write_unlock_bh(&sk->sk_callback_lock);
2256         }
2257 
2258         if (!xprt_bound(xprt))
2259                 goto out;
2260 
2261         xs_set_memalloc(xprt);
2262 
2263         /* Tell the socket layer to start connecting... */
2264         xprt->stat.connect_count++;
2265         xprt->stat.connect_start = jiffies;
2266         set_bit(XPRT_SOCK_CONNECTING, &transport->sock_state);
2267         ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2268         switch (ret) {
2269         case 0:
2270                 xs_set_srcport(transport, sock);
2271         case -EINPROGRESS:
2272                 /* SYN_SENT! */
2273                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2274                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2275         }
2276 out:
2277         return ret;
2278 }
2279 
2280 /**
2281  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2282  *
2283  * Invoked by a work queue tasklet.
2284  */
2285 static void xs_tcp_setup_socket(struct work_struct *work)
2286 {
2287         struct sock_xprt *transport =
2288                 container_of(work, struct sock_xprt, connect_worker.work);
2289         struct socket *sock = transport->sock;
2290         struct rpc_xprt *xprt = &transport->xprt;
2291         int status = -EIO;
2292 
2293         if (!sock) {
2294                 sock = xs_create_sock(xprt, transport,
2295                                 xs_addr(xprt)->sa_family, SOCK_STREAM,
2296                                 IPPROTO_TCP, true);
2297                 if (IS_ERR(sock)) {
2298                         status = PTR_ERR(sock);
2299                         goto out;
2300                 }
2301         }
2302 
2303         dprintk("RPC:       worker connecting xprt %p via %s to "
2304                                 "%s (port %s)\n", xprt,
2305                         xprt->address_strings[RPC_DISPLAY_PROTO],
2306                         xprt->address_strings[RPC_DISPLAY_ADDR],
2307                         xprt->address_strings[RPC_DISPLAY_PORT]);
2308 
2309         status = xs_tcp_finish_connecting(xprt, sock);
2310         trace_rpc_socket_connect(xprt, sock, status);
2311         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2312                         xprt, -status, xprt_connected(xprt),
2313                         sock->sk->sk_state);
2314         switch (status) {
2315         default:
2316                 printk("%s: connect returned unhandled error %d\n",
2317                         __func__, status);
2318         case -EADDRNOTAVAIL:
2319                 /* We're probably in TIME_WAIT. Get rid of existing socket,
2320                  * and retry
2321                  */
2322                 xs_tcp_force_close(xprt);
2323                 break;
2324         case 0:
2325         case -EINPROGRESS:
2326         case -EALREADY:
2327                 xprt_unlock_connect(xprt, transport);
2328                 return;
2329         case -EINVAL:
2330                 /* Happens, for instance, if the user specified a link
2331                  * local IPv6 address without a scope-id.
2332                  */
2333         case -ECONNREFUSED:
2334         case -ECONNRESET:
2335         case -ENETUNREACH:
2336         case -EADDRINUSE:
2337         case -ENOBUFS:
2338                 /* retry with existing socket, after a delay */
2339                 xs_tcp_force_close(xprt);
2340                 goto out;
2341         }
2342         status = -EAGAIN;
2343 out:
2344         xprt_unlock_connect(xprt, transport);
2345         xprt_clear_connecting(xprt);
2346         xprt_wake_pending_tasks(xprt, status);
2347 }
2348 
2349 /**
2350  * xs_connect - connect a socket to a remote endpoint
2351  * @xprt: pointer to transport structure
2352  * @task: address of RPC task that manages state of connect request
2353  *
2354  * TCP: If the remote end dropped the connection, delay reconnecting.
2355  *
2356  * UDP socket connects are synchronous, but we use a work queue anyway
2357  * to guarantee that even unprivileged user processes can set up a
2358  * socket on a privileged port.
2359  *
2360  * If a UDP socket connect fails, the delay behavior here prevents
2361  * retry floods (hard mounts).
2362  */
2363 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2364 {
2365         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2366 
2367         WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport));
2368 
2369         if (transport->sock != NULL) {
2370                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2371                                 "seconds\n",
2372                                 xprt, xprt->reestablish_timeout / HZ);
2373 
2374                 /* Start by resetting any existing state */
2375                 xs_reset_transport(transport);
2376 
2377                 queue_delayed_work(rpciod_workqueue,
2378                                    &transport->connect_worker,
2379                                    xprt->reestablish_timeout);
2380                 xprt->reestablish_timeout <<= 1;
2381                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2382                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2383                 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2384                         xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2385         } else {
2386                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2387                 queue_delayed_work(rpciod_workqueue,
2388                                    &transport->connect_worker, 0);
2389         }
2390 }
2391 
2392 /**
2393  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2394  * @xprt: rpc_xprt struct containing statistics
2395  * @seq: output file
2396  *
2397  */
2398 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2399 {
2400         long idle_time = 0;
2401 
2402         if (xprt_connected(xprt))
2403                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2404 
2405         seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2406                         "%llu %llu %lu %llu %llu\n",
2407                         xprt->stat.bind_count,
2408                         xprt->stat.connect_count,
2409                         xprt->stat.connect_time,
2410                         idle_time,
2411                         xprt->stat.sends,
2412                         xprt->stat.recvs,
2413                         xprt->stat.bad_xids,
2414                         xprt->stat.req_u,
2415                         xprt->stat.bklog_u,
2416                         xprt->stat.max_slots,
2417                         xprt->stat.sending_u,
2418                         xprt->stat.pending_u);
2419 }
2420 
2421 /**
2422  * xs_udp_print_stats - display UDP socket-specifc stats
2423  * @xprt: rpc_xprt struct containing statistics
2424  * @seq: output file
2425  *
2426  */
2427 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2428 {
2429         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2430 
2431         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2432                         "%lu %llu %llu\n",
2433                         transport->srcport,
2434                         xprt->stat.bind_count,
2435                         xprt->stat.sends,
2436                         xprt->stat.recvs,
2437                         xprt->stat.bad_xids,
2438                         xprt->stat.req_u,
2439                         xprt->stat.bklog_u,
2440                         xprt->stat.max_slots,
2441                         xprt->stat.sending_u,
2442                         xprt->stat.pending_u);
2443 }
2444 
2445 /**
2446  * xs_tcp_print_stats - display TCP socket-specifc stats
2447  * @xprt: rpc_xprt struct containing statistics
2448  * @seq: output file
2449  *
2450  */
2451 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2452 {
2453         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2454         long idle_time = 0;
2455 
2456         if (xprt_connected(xprt))
2457                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2458 
2459         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2460                         "%llu %llu %lu %llu %llu\n",
2461                         transport->srcport,
2462                         xprt->stat.bind_count,
2463                         xprt->stat.connect_count,
2464                         xprt->stat.connect_time,
2465                         idle_time,
2466                         xprt->stat.sends,
2467                         xprt->stat.recvs,
2468                         xprt->stat.bad_xids,
2469                         xprt->stat.req_u,
2470                         xprt->stat.bklog_u,
2471                         xprt->stat.max_slots,
2472                         xprt->stat.sending_u,
2473                         xprt->stat.pending_u);
2474 }
2475 
2476 /*
2477  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2478  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2479  * to use the server side send routines.
2480  */
2481 static void *bc_malloc(struct rpc_task *task, size_t size)
2482 {
2483         struct page *page;
2484         struct rpc_buffer *buf;
2485 
2486         WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2487         if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2488                 return NULL;
2489 
2490         page = alloc_page(GFP_KERNEL);
2491         if (!page)
2492                 return NULL;
2493 
2494         buf = page_address(page);
2495         buf->len = PAGE_SIZE;
2496 
2497         return buf->data;
2498 }
2499 
2500 /*
2501  * Free the space allocated in the bc_alloc routine
2502  */
2503 static void bc_free(void *buffer)
2504 {
2505         struct rpc_buffer *buf;
2506 
2507         if (!buffer)
2508                 return;
2509 
2510         buf = container_of(buffer, struct rpc_buffer, data);
2511         free_page((unsigned long)buf);
2512 }
2513 
2514 /*
2515  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2516  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2517  */
2518 static int bc_sendto(struct rpc_rqst *req)
2519 {
2520         int len;
2521         struct xdr_buf *xbufp = &req->rq_snd_buf;
2522         struct rpc_xprt *xprt = req->rq_xprt;
2523         struct sock_xprt *transport =
2524                                 container_of(xprt, struct sock_xprt, xprt);
2525         struct socket *sock = transport->sock;
2526         unsigned long headoff;
2527         unsigned long tailoff;
2528 
2529         xs_encode_stream_record_marker(xbufp);
2530 
2531         tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2532         headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2533         len = svc_send_common(sock, xbufp,
2534                               virt_to_page(xbufp->head[0].iov_base), headoff,
2535                               xbufp->tail[0].iov_base, tailoff);
2536 
2537         if (len != xbufp->len) {
2538                 printk(KERN_NOTICE "Error sending entire callback!\n");
2539                 len = -EAGAIN;
2540         }
2541 
2542         return len;
2543 }
2544 
2545 /*
2546  * The send routine. Borrows from svc_send
2547  */
2548 static int bc_send_request(struct rpc_task *task)
2549 {
2550         struct rpc_rqst *req = task->tk_rqstp;
2551         struct svc_xprt *xprt;
2552         int len;
2553 
2554         dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2555         /*
2556          * Get the server socket associated with this callback xprt
2557          */
2558         xprt = req->rq_xprt->bc_xprt;
2559 
2560         /*
2561          * Grab the mutex to serialize data as the connection is shared
2562          * with the fore channel
2563          */
2564         if (!mutex_trylock(&xprt->xpt_mutex)) {
2565                 rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2566                 if (!mutex_trylock(&xprt->xpt_mutex))
2567                         return -EAGAIN;
2568                 rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2569         }
2570         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2571                 len = -ENOTCONN;
2572         else
2573                 len = bc_sendto(req);
2574         mutex_unlock(&xprt->xpt_mutex);
2575 
2576         if (len > 0)
2577                 len = 0;
2578 
2579         return len;
2580 }
2581 
2582 /*
2583  * The close routine. Since this is client initiated, we do nothing
2584  */
2585 
2586 static void bc_close(struct rpc_xprt *xprt)
2587 {
2588 }
2589 
2590 /*
2591  * The xprt destroy routine. Again, because this connection is client
2592  * initiated, we do nothing
2593  */
2594 
2595 static void bc_destroy(struct rpc_xprt *xprt)
2596 {
2597         dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2598 
2599         xs_xprt_free(xprt);
2600         module_put(THIS_MODULE);
2601 }
2602 
2603 static struct rpc_xprt_ops xs_local_ops = {
2604         .reserve_xprt           = xprt_reserve_xprt,
2605         .release_xprt           = xs_tcp_release_xprt,
2606         .alloc_slot             = xprt_alloc_slot,
2607         .rpcbind                = xs_local_rpcbind,
2608         .set_port               = xs_local_set_port,
2609         .connect                = xs_local_connect,
2610         .buf_alloc              = rpc_malloc,
2611         .buf_free               = rpc_free,
2612         .send_request           = xs_local_send_request,
2613         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2614         .close                  = xs_close,
2615         .destroy                = xs_destroy,
2616         .print_stats            = xs_local_print_stats,
2617         .enable_swap            = xs_enable_swap,
2618         .disable_swap           = xs_disable_swap,
2619 };
2620 
2621 static struct rpc_xprt_ops xs_udp_ops = {
2622         .set_buffer_size        = xs_udp_set_buffer_size,
2623         .reserve_xprt           = xprt_reserve_xprt_cong,
2624         .release_xprt           = xprt_release_xprt_cong,
2625         .alloc_slot             = xprt_alloc_slot,
2626         .rpcbind                = rpcb_getport_async,
2627         .set_port               = xs_set_port,
2628         .connect                = xs_connect,
2629         .buf_alloc              = rpc_malloc,
2630         .buf_free               = rpc_free,
2631         .send_request           = xs_udp_send_request,
2632         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
2633         .timer                  = xs_udp_timer,
2634         .release_request        = xprt_release_rqst_cong,
2635         .close                  = xs_close,
2636         .destroy                = xs_destroy,
2637         .print_stats            = xs_udp_print_stats,
2638         .enable_swap            = xs_enable_swap,
2639         .disable_swap           = xs_disable_swap,
2640         .inject_disconnect      = xs_inject_disconnect,
2641 };
2642 
2643 static struct rpc_xprt_ops xs_tcp_ops = {
2644         .reserve_xprt           = xprt_reserve_xprt,
2645         .release_xprt           = xs_tcp_release_xprt,
2646         .alloc_slot             = xprt_lock_and_alloc_slot,
2647         .rpcbind                = rpcb_getport_async,
2648         .set_port               = xs_set_port,
2649         .connect                = xs_connect,
2650         .buf_alloc              = rpc_malloc,
2651         .buf_free               = rpc_free,
2652         .send_request           = xs_tcp_send_request,
2653         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2654         .close                  = xs_tcp_shutdown,
2655         .destroy                = xs_destroy,
2656         .print_stats            = xs_tcp_print_stats,
2657         .enable_swap            = xs_enable_swap,
2658         .disable_swap           = xs_disable_swap,
2659         .inject_disconnect      = xs_inject_disconnect,
2660 #ifdef CONFIG_SUNRPC_BACKCHANNEL
2661         .bc_setup               = xprt_setup_bc,
2662         .bc_up                  = xs_tcp_bc_up,
2663         .bc_free_rqst           = xprt_free_bc_rqst,
2664         .bc_destroy             = xprt_destroy_bc,
2665 #endif
2666 };
2667 
2668 /*
2669  * The rpc_xprt_ops for the server backchannel
2670  */
2671 
2672 static struct rpc_xprt_ops bc_tcp_ops = {
2673         .reserve_xprt           = xprt_reserve_xprt,
2674         .release_xprt           = xprt_release_xprt,
2675         .alloc_slot             = xprt_alloc_slot,
2676         .buf_alloc              = bc_malloc,
2677         .buf_free               = bc_free,
2678         .send_request           = bc_send_request,
2679         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2680         .close                  = bc_close,
2681         .destroy                = bc_destroy,
2682         .print_stats            = xs_tcp_print_stats,
2683         .enable_swap            = xs_enable_swap,
2684         .disable_swap           = xs_disable_swap,
2685         .inject_disconnect      = xs_inject_disconnect,
2686 };
2687 
2688 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2689 {
2690         static const struct sockaddr_in sin = {
2691                 .sin_family             = AF_INET,
2692                 .sin_addr.s_addr        = htonl(INADDR_ANY),
2693         };
2694         static const struct sockaddr_in6 sin6 = {
2695                 .sin6_family            = AF_INET6,
2696                 .sin6_addr              = IN6ADDR_ANY_INIT,
2697         };
2698 
2699         switch (family) {
2700         case AF_LOCAL:
2701                 break;
2702         case AF_INET:
2703                 memcpy(sap, &sin, sizeof(sin));
2704                 break;
2705         case AF_INET6:
2706                 memcpy(sap, &sin6, sizeof(sin6));
2707                 break;
2708         default:
2709                 dprintk("RPC:       %s: Bad address family\n", __func__);
2710                 return -EAFNOSUPPORT;
2711         }
2712         return 0;
2713 }
2714 
2715 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2716                                       unsigned int slot_table_size,
2717                                       unsigned int max_slot_table_size)
2718 {
2719         struct rpc_xprt *xprt;
2720         struct sock_xprt *new;
2721 
2722         if (args->addrlen > sizeof(xprt->addr)) {
2723                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2724                 return ERR_PTR(-EBADF);
2725         }
2726 
2727         xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2728                         max_slot_table_size);
2729         if (xprt == NULL) {
2730                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2731                                 "rpc_xprt\n");
2732                 return ERR_PTR(-ENOMEM);
2733         }
2734 
2735         new = container_of(xprt, struct sock_xprt, xprt);
2736         mutex_init(&new->recv_mutex);
2737         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2738         xprt->addrlen = args->addrlen;
2739         if (args->srcaddr)
2740                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2741         else {
2742                 int err;
2743                 err = xs_init_anyaddr(args->dstaddr->sa_family,
2744                                         (struct sockaddr *)&new->srcaddr);
2745                 if (err != 0) {
2746                         xprt_free(xprt);
2747                         return ERR_PTR(err);
2748                 }
2749         }
2750 
2751         return xprt;
2752 }
2753 
2754 static const struct rpc_timeout xs_local_default_timeout = {
2755         .to_initval = 10 * HZ,
2756         .to_maxval = 10 * HZ,
2757         .to_retries = 2,
2758 };
2759 
2760 /**
2761  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2762  * @args: rpc transport creation arguments
2763  *
2764  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2765  */
2766 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2767 {
2768         struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2769         struct sock_xprt *transport;
2770         struct rpc_xprt *xprt;
2771         struct rpc_xprt *ret;
2772 
2773         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2774                         xprt_max_tcp_slot_table_entries);
2775         if (IS_ERR(xprt))
2776                 return xprt;
2777         transport = container_of(xprt, struct sock_xprt, xprt);
2778 
2779         xprt->prot = 0;
2780         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2781         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2782 
2783         xprt->bind_timeout = XS_BIND_TO;
2784         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2785         xprt->idle_timeout = XS_IDLE_DISC_TO;
2786 
2787         xprt->ops = &xs_local_ops;
2788         xprt->timeout = &xs_local_default_timeout;
2789 
2790         INIT_WORK(&transport->recv_worker, xs_local_data_receive_workfn);
2791         INIT_DELAYED_WORK(&transport->connect_worker,
2792                         xs_dummy_setup_socket);
2793 
2794         switch (sun->sun_family) {
2795         case AF_LOCAL:
2796                 if (sun->sun_path[0] != '/') {
2797                         dprintk("RPC:       bad AF_LOCAL address: %s\n",
2798                                         sun->sun_path);
2799                         ret = ERR_PTR(-EINVAL);
2800                         goto out_err;
2801                 }
2802                 xprt_set_bound(xprt);
2803                 xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2804                 ret = ERR_PTR(xs_local_setup_socket(transport));
2805                 if (ret)
2806                         goto out_err;
2807                 break;
2808         default:
2809                 ret = ERR_PTR(-EAFNOSUPPORT);
2810                 goto out_err;
2811         }
2812 
2813         dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2814                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2815 
2816         if (try_module_get(THIS_MODULE))
2817                 return xprt;
2818         ret = ERR_PTR(-EINVAL);
2819 out_err:
2820         xs_xprt_free(xprt);
2821         return ret;
2822 }
2823 
2824 static const struct rpc_timeout xs_udp_default_timeout = {
2825         .to_initval = 5 * HZ,
2826         .to_maxval = 30 * HZ,
2827         .to_increment = 5 * HZ,
2828         .to_retries = 5,
2829 };
2830 
2831 /**
2832  * xs_setup_udp - Set up transport to use a UDP socket
2833  * @args: rpc transport creation arguments
2834  *
2835  */
2836 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2837 {
2838         struct sockaddr *addr = args->dstaddr;
2839         struct rpc_xprt *xprt;
2840         struct sock_xprt *transport;
2841         struct rpc_xprt *ret;
2842 
2843         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2844                         xprt_udp_slot_table_entries);
2845         if (IS_ERR(xprt))
2846                 return xprt;
2847         transport = container_of(xprt, struct sock_xprt, xprt);
2848 
2849         xprt->prot = IPPROTO_UDP;
2850         xprt->tsh_size = 0;
2851         /* XXX: header size can vary due to auth type, IPv6, etc. */
2852         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2853 
2854         xprt->bind_timeout = XS_BIND_TO;
2855         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2856         xprt->idle_timeout = XS_IDLE_DISC_TO;
2857 
2858         xprt->ops = &xs_udp_ops;
2859 
2860         xprt->timeout = &xs_udp_default_timeout;
2861 
2862         INIT_WORK(&transport->recv_worker, xs_udp_data_receive_workfn);
2863         INIT_DELAYED_WORK(&transport->connect_worker, xs_udp_setup_socket);
2864 
2865         switch (addr->sa_family) {
2866         case AF_INET:
2867                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2868                         xprt_set_bound(xprt);
2869 
2870                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2871                 break;
2872         case AF_INET6:
2873                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2874                         xprt_set_bound(xprt);
2875 
2876                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2877                 break;
2878         default:
2879                 ret = ERR_PTR(-EAFNOSUPPORT);
2880                 goto out_err;
2881         }
2882 
2883         if (xprt_bound(xprt))
2884                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2885                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2886                                 xprt->address_strings[RPC_DISPLAY_PORT],
2887                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2888         else
2889                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2890                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2891                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2892 
2893         if (try_module_get(THIS_MODULE))
2894                 return xprt;
2895         ret = ERR_PTR(-EINVAL);
2896 out_err:
2897         xs_xprt_free(xprt);
2898         return ret;
2899 }
2900 
2901 static const struct rpc_timeout xs_tcp_default_timeout = {
2902         .to_initval = 60 * HZ,
2903         .to_maxval = 60 * HZ,
2904         .to_retries = 2,
2905 };
2906 
2907 /**
2908  * xs_setup_tcp - Set up transport to use a TCP socket
2909  * @args: rpc transport creation arguments
2910  *
2911  */
2912 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2913 {
2914         struct sockaddr *addr = args->dstaddr;
2915         struct rpc_xprt *xprt;
2916         struct sock_xprt *transport;
2917         struct rpc_xprt *ret;
2918         unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2919 
2920         if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2921                 max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2922 
2923         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2924                         max_slot_table_size);
2925         if (IS_ERR(xprt))
2926                 return xprt;
2927         transport = container_of(xprt, struct sock_xprt, xprt);
2928 
2929         xprt->prot = IPPROTO_TCP;
2930         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2931         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2932 
2933         xprt->bind_timeout = XS_BIND_TO;
2934         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2935         xprt->idle_timeout = XS_IDLE_DISC_TO;
2936 
2937         xprt->ops = &xs_tcp_ops;
2938         xprt->timeout = &xs_tcp_default_timeout;
2939 
2940         INIT_WORK(&transport->recv_worker, xs_tcp_data_receive_workfn);
2941         INIT_DELAYED_WORK(&transport->connect_worker, xs_tcp_setup_socket);
2942 
2943         switch (addr->sa_family) {
2944         case AF_INET:
2945                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2946                         xprt_set_bound(xprt);
2947 
2948                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2949                 break;
2950         case AF_INET6:
2951                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2952                         xprt_set_bound(xprt);
2953 
2954                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2955                 break;
2956         default:
2957                 ret = ERR_PTR(-EAFNOSUPPORT);
2958                 goto out_err;
2959         }
2960 
2961         if (xprt_bound(xprt))
2962                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2963                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2964                                 xprt->address_strings[RPC_DISPLAY_PORT],
2965                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2966         else
2967                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2968                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2969                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2970 
2971         if (try_module_get(THIS_MODULE))
2972                 return xprt;
2973         ret = ERR_PTR(-EINVAL);
2974 out_err:
2975         xs_xprt_free(xprt);
2976         return ret;
2977 }
2978 
2979 /**
2980  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2981  * @args: rpc transport creation arguments
2982  *
2983  */
2984 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2985 {
2986         struct sockaddr *addr = args->dstaddr;
2987         struct rpc_xprt *xprt;
2988         struct sock_xprt *transport;
2989         struct svc_sock *bc_sock;
2990         struct rpc_xprt *ret;
2991 
2992         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2993                         xprt_tcp_slot_table_entries);
2994         if (IS_ERR(xprt))
2995                 return xprt;
2996         transport = container_of(xprt, struct sock_xprt, xprt);
2997 
2998         xprt->prot = IPPROTO_TCP;
2999         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
3000         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
3001         xprt->timeout = &xs_tcp_default_timeout;
3002 
3003         /* backchannel */
3004         xprt_set_bound(xprt);
3005         xprt->bind_timeout = 0;
3006         xprt->reestablish_timeout = 0;
3007         xprt->idle_timeout = 0;
3008 
3009         xprt->ops = &bc_tcp_ops;
3010 
3011         switch (addr->sa_family) {
3012         case AF_INET:
3013                 xs_format_peer_addresses(xprt, "tcp",
3014                                          RPCBIND_NETID_TCP);
3015                 break;
3016         case AF_INET6:
3017                 xs_format_peer_addresses(xprt, "tcp",
3018                                    RPCBIND_NETID_TCP6);
3019                 break;
3020         default:
3021                 ret = ERR_PTR(-EAFNOSUPPORT);
3022                 goto out_err;
3023         }
3024 
3025         dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
3026                         xprt->address_strings[RPC_DISPLAY_ADDR],
3027                         xprt->address_strings[RPC_DISPLAY_PORT],
3028                         xprt->address_strings[RPC_DISPLAY_PROTO]);
3029 
3030         /*
3031          * Once we've associated a backchannel xprt with a connection,
3032          * we want to keep it around as long as the connection lasts,
3033          * in case we need to start using it for a backchannel again;
3034          * this reference won't be dropped until bc_xprt is destroyed.
3035          */
3036         xprt_get(xprt);
3037         args->bc_xprt->xpt_bc_xprt = xprt;
3038         xprt->bc_xprt = args->bc_xprt;
3039         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
3040         transport->sock = bc_sock->sk_sock;
3041         transport->inet = bc_sock->sk_sk;
3042 
3043         /*
3044          * Since we don't want connections for the backchannel, we set
3045          * the xprt status to connected
3046          */
3047         xprt_set_connected(xprt);
3048 
3049         if (try_module_get(THIS_MODULE))
3050                 return xprt;
3051 
3052         args->bc_xprt->xpt_bc_xprt = NULL;
3053         args->bc_xprt->xpt_bc_xps = NULL;
3054         xprt_put(xprt);
3055         ret = ERR_PTR(-EINVAL);
3056 out_err:
3057         xs_xprt_free(xprt);
3058         return ret;
3059 }
3060 
3061 static struct xprt_class        xs_local_transport = {
3062         .list           = LIST_HEAD_INIT(xs_local_transport.list),
3063         .name           = "named UNIX socket",
3064         .owner          = THIS_MODULE,
3065         .ident          = XPRT_TRANSPORT_LOCAL,
3066         .setup          = xs_setup_local,
3067 };
3068 
3069 static struct xprt_class        xs_udp_transport = {
3070         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
3071         .name           = "udp",
3072         .owner          = THIS_MODULE,
3073         .ident          = XPRT_TRANSPORT_UDP,
3074         .setup          = xs_setup_udp,
3075 };
3076 
3077 static struct xprt_class        xs_tcp_transport = {
3078         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
3079         .name           = "tcp",
3080         .owner          = THIS_MODULE,
3081         .ident          = XPRT_TRANSPORT_TCP,
3082         .setup          = xs_setup_tcp,
3083 };
3084 
3085 static struct xprt_class        xs_bc_tcp_transport = {
3086         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3087         .name           = "tcp NFSv4.1 backchannel",
3088         .owner          = THIS_MODULE,
3089         .ident          = XPRT_TRANSPORT_BC_TCP,
3090         .setup          = xs_setup_bc_tcp,
3091 };
3092 
3093 /**
3094  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3095  *
3096  */
3097 int init_socket_xprt(void)
3098 {
3099 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3100         if (!sunrpc_table_header)
3101                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
3102 #endif
3103 
3104         xprt_register_transport(&xs_local_transport);
3105         xprt_register_transport(&xs_udp_transport);
3106         xprt_register_transport(&xs_tcp_transport);
3107         xprt_register_transport(&xs_bc_tcp_transport);
3108 
3109         return 0;
3110 }
3111 
3112 /**
3113  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3114  *
3115  */
3116 void cleanup_socket_xprt(void)
3117 {
3118 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
3119         if (sunrpc_table_header) {
3120                 unregister_sysctl_table(sunrpc_table_header);
3121                 sunrpc_table_header = NULL;
3122         }
3123 #endif
3124 
3125         xprt_unregister_transport(&xs_local_transport);
3126         xprt_unregister_transport(&xs_udp_transport);
3127         xprt_unregister_transport(&xs_tcp_transport);
3128         xprt_unregister_transport(&xs_bc_tcp_transport);
3129 }
3130 
3131 static int param_set_uint_minmax(const char *val,
3132                 const struct kernel_param *kp,
3133                 unsigned int min, unsigned int max)
3134 {
3135         unsigned int num;
3136         int ret;
3137 
3138         if (!val)
3139                 return -EINVAL;
3140         ret = kstrtouint(val, 0, &num);
3141         if (ret == -EINVAL || num < min || num > max)
3142                 return -EINVAL;
3143         *((unsigned int *)kp->arg) = num;
3144         return 0;
3145 }
3146 
3147 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3148 {
3149         return param_set_uint_minmax(val, kp,
3150                         RPC_MIN_RESVPORT,
3151                         RPC_MAX_RESVPORT);
3152 }
3153 
3154 static const struct kernel_param_ops param_ops_portnr = {
3155         .set = param_set_portnr,
3156         .get = param_get_uint,
3157 };
3158 
3159 #define param_check_portnr(name, p) \
3160         __param_check(name, p, unsigned int);
3161 
3162 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3163 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3164 
3165 static int param_set_slot_table_size(const char *val,
3166                                      const struct kernel_param *kp)
3167 {
3168         return param_set_uint_minmax(val, kp,
3169                         RPC_MIN_SLOT_TABLE,
3170                         RPC_MAX_SLOT_TABLE);
3171 }
3172 
3173 static const struct kernel_param_ops param_ops_slot_table_size = {
3174         .set = param_set_slot_table_size,
3175         .get = param_get_uint,
3176 };
3177 
3178 #define param_check_slot_table_size(name, p) \
3179         __param_check(name, p, unsigned int);
3180 
3181 static int param_set_max_slot_table_size(const char *val,
3182                                      const struct kernel_param *kp)
3183 {
3184         return param_set_uint_minmax(val, kp,
3185                         RPC_MIN_SLOT_TABLE,
3186                         RPC_MAX_SLOT_TABLE_LIMIT);
3187 }
3188 
3189 static const struct kernel_param_ops param_ops_max_slot_table_size = {
3190         .set = param_set_max_slot_table_size,
3191         .get = param_get_uint,
3192 };
3193 
3194 #define param_check_max_slot_table_size(name, p) \
3195         __param_check(name, p, unsigned int);
3196 
3197 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3198                    slot_table_size, 0644);
3199 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3200                    max_slot_table_size, 0644);
3201 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3202                    slot_table_size, 0644);
3203 
3204 

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