xref: /openbmc/linux/net/sunrpc/svcsock.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
1 /*
2  * linux/net/sunrpc/svcsock.c
3  *
4  * These are the RPC server socket internals.
5  *
6  * The server scheduling algorithm does not always distribute the load
7  * evenly when servicing a single client. May need to modify the
8  * svc_xprt_enqueue procedure...
9  *
10  * TCP support is largely untested and may be a little slow. The problem
11  * is that we currently do two separate recvfrom's, one for the 4-byte
12  * record length, and the second for the actual record. This could possibly
13  * be improved by always reading a minimum size of around 100 bytes and
14  * tucking any superfluous bytes away in a temporary store. Still, that
15  * leaves write requests out in the rain. An alternative may be to peek at
16  * the first skb in the queue, and if it matches the next TCP sequence
17  * number, to extract the record marker. Yuck.
18  *
19  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
20  */
21 
22 #include <linux/kernel.h>
23 #include <linux/sched.h>
24 #include <linux/errno.h>
25 #include <linux/fcntl.h>
26 #include <linux/net.h>
27 #include <linux/in.h>
28 #include <linux/inet.h>
29 #include <linux/udp.h>
30 #include <linux/tcp.h>
31 #include <linux/unistd.h>
32 #include <linux/slab.h>
33 #include <linux/netdevice.h>
34 #include <linux/skbuff.h>
35 #include <linux/file.h>
36 #include <linux/freezer.h>
37 #include <net/sock.h>
38 #include <net/checksum.h>
39 #include <net/ip.h>
40 #include <net/ipv6.h>
41 #include <net/tcp.h>
42 #include <net/tcp_states.h>
43 #include <asm/uaccess.h>
44 #include <asm/ioctls.h>
45 
46 #include <linux/sunrpc/types.h>
47 #include <linux/sunrpc/clnt.h>
48 #include <linux/sunrpc/xdr.h>
49 #include <linux/sunrpc/msg_prot.h>
50 #include <linux/sunrpc/svcsock.h>
51 #include <linux/sunrpc/stats.h>
52 #include <linux/sunrpc/xprt.h>
53 
54 #define RPCDBG_FACILITY	RPCDBG_SVCXPRT
55 
56 
57 static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
58 					 int *errp, int flags);
59 static void		svc_udp_data_ready(struct sock *, int);
60 static int		svc_udp_recvfrom(struct svc_rqst *);
61 static int		svc_udp_sendto(struct svc_rqst *);
62 static void		svc_sock_detach(struct svc_xprt *);
63 static void		svc_tcp_sock_detach(struct svc_xprt *);
64 static void		svc_sock_free(struct svc_xprt *);
65 
66 static struct svc_xprt *svc_create_socket(struct svc_serv *, int,
67 					  struct net *, struct sockaddr *,
68 					  int, int);
69 #ifdef CONFIG_DEBUG_LOCK_ALLOC
70 static struct lock_class_key svc_key[2];
71 static struct lock_class_key svc_slock_key[2];
72 
73 static void svc_reclassify_socket(struct socket *sock)
74 {
75 	struct sock *sk = sock->sk;
76 	BUG_ON(sock_owned_by_user(sk));
77 	switch (sk->sk_family) {
78 	case AF_INET:
79 		sock_lock_init_class_and_name(sk, "slock-AF_INET-NFSD",
80 					      &svc_slock_key[0],
81 					      "sk_xprt.xpt_lock-AF_INET-NFSD",
82 					      &svc_key[0]);
83 		break;
84 
85 	case AF_INET6:
86 		sock_lock_init_class_and_name(sk, "slock-AF_INET6-NFSD",
87 					      &svc_slock_key[1],
88 					      "sk_xprt.xpt_lock-AF_INET6-NFSD",
89 					      &svc_key[1]);
90 		break;
91 
92 	default:
93 		BUG();
94 	}
95 }
96 #else
97 static void svc_reclassify_socket(struct socket *sock)
98 {
99 }
100 #endif
101 
102 /*
103  * Release an skbuff after use
104  */
105 static void svc_release_skb(struct svc_rqst *rqstp)
106 {
107 	struct sk_buff *skb = rqstp->rq_xprt_ctxt;
108 
109 	if (skb) {
110 		struct svc_sock *svsk =
111 			container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
112 		rqstp->rq_xprt_ctxt = NULL;
113 
114 		dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
115 		skb_free_datagram_locked(svsk->sk_sk, skb);
116 	}
117 }
118 
119 union svc_pktinfo_u {
120 	struct in_pktinfo pkti;
121 	struct in6_pktinfo pkti6;
122 };
123 #define SVC_PKTINFO_SPACE \
124 	CMSG_SPACE(sizeof(union svc_pktinfo_u))
125 
126 static void svc_set_cmsg_data(struct svc_rqst *rqstp, struct cmsghdr *cmh)
127 {
128 	struct svc_sock *svsk =
129 		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
130 	switch (svsk->sk_sk->sk_family) {
131 	case AF_INET: {
132 			struct in_pktinfo *pki = CMSG_DATA(cmh);
133 
134 			cmh->cmsg_level = SOL_IP;
135 			cmh->cmsg_type = IP_PKTINFO;
136 			pki->ipi_ifindex = 0;
137 			pki->ipi_spec_dst.s_addr = rqstp->rq_daddr.addr.s_addr;
138 			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
139 		}
140 		break;
141 
142 	case AF_INET6: {
143 			struct in6_pktinfo *pki = CMSG_DATA(cmh);
144 
145 			cmh->cmsg_level = SOL_IPV6;
146 			cmh->cmsg_type = IPV6_PKTINFO;
147 			pki->ipi6_ifindex = 0;
148 			ipv6_addr_copy(&pki->ipi6_addr,
149 					&rqstp->rq_daddr.addr6);
150 			cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
151 		}
152 		break;
153 	}
154 }
155 
156 /*
157  * send routine intended to be shared by the fore- and back-channel
158  */
159 int svc_send_common(struct socket *sock, struct xdr_buf *xdr,
160 		    struct page *headpage, unsigned long headoffset,
161 		    struct page *tailpage, unsigned long tailoffset)
162 {
163 	int		result;
164 	int		size;
165 	struct page	**ppage = xdr->pages;
166 	size_t		base = xdr->page_base;
167 	unsigned int	pglen = xdr->page_len;
168 	unsigned int	flags = MSG_MORE;
169 	int		slen;
170 	int		len = 0;
171 
172 	slen = xdr->len;
173 
174 	/* send head */
175 	if (slen == xdr->head[0].iov_len)
176 		flags = 0;
177 	len = kernel_sendpage(sock, headpage, headoffset,
178 				  xdr->head[0].iov_len, flags);
179 	if (len != xdr->head[0].iov_len)
180 		goto out;
181 	slen -= xdr->head[0].iov_len;
182 	if (slen == 0)
183 		goto out;
184 
185 	/* send page data */
186 	size = PAGE_SIZE - base < pglen ? PAGE_SIZE - base : pglen;
187 	while (pglen > 0) {
188 		if (slen == size)
189 			flags = 0;
190 		result = kernel_sendpage(sock, *ppage, base, size, flags);
191 		if (result > 0)
192 			len += result;
193 		if (result != size)
194 			goto out;
195 		slen -= size;
196 		pglen -= size;
197 		size = PAGE_SIZE < pglen ? PAGE_SIZE : pglen;
198 		base = 0;
199 		ppage++;
200 	}
201 
202 	/* send tail */
203 	if (xdr->tail[0].iov_len) {
204 		result = kernel_sendpage(sock, tailpage, tailoffset,
205 				   xdr->tail[0].iov_len, 0);
206 		if (result > 0)
207 			len += result;
208 	}
209 
210 out:
211 	return len;
212 }
213 
214 
215 /*
216  * Generic sendto routine
217  */
218 static int svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
219 {
220 	struct svc_sock	*svsk =
221 		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
222 	struct socket	*sock = svsk->sk_sock;
223 	union {
224 		struct cmsghdr	hdr;
225 		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
226 	} buffer;
227 	struct cmsghdr *cmh = &buffer.hdr;
228 	int		len = 0;
229 	unsigned long tailoff;
230 	unsigned long headoff;
231 	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
232 
233 	if (rqstp->rq_prot == IPPROTO_UDP) {
234 		struct msghdr msg = {
235 			.msg_name	= &rqstp->rq_addr,
236 			.msg_namelen	= rqstp->rq_addrlen,
237 			.msg_control	= cmh,
238 			.msg_controllen	= sizeof(buffer),
239 			.msg_flags	= MSG_MORE,
240 		};
241 
242 		svc_set_cmsg_data(rqstp, cmh);
243 
244 		if (sock_sendmsg(sock, &msg, 0) < 0)
245 			goto out;
246 	}
247 
248 	tailoff = ((unsigned long)xdr->tail[0].iov_base) & (PAGE_SIZE-1);
249 	headoff = 0;
250 	len = svc_send_common(sock, xdr, rqstp->rq_respages[0], headoff,
251 			       rqstp->rq_respages[0], tailoff);
252 
253 out:
254 	dprintk("svc: socket %p sendto([%p %Zu... ], %d) = %d (addr %s)\n",
255 		svsk, xdr->head[0].iov_base, xdr->head[0].iov_len,
256 		xdr->len, len, svc_print_addr(rqstp, buf, sizeof(buf)));
257 
258 	return len;
259 }
260 
261 /*
262  * Report socket names for nfsdfs
263  */
264 static int svc_one_sock_name(struct svc_sock *svsk, char *buf, int remaining)
265 {
266 	const struct sock *sk = svsk->sk_sk;
267 	const char *proto_name = sk->sk_protocol == IPPROTO_UDP ?
268 							"udp" : "tcp";
269 	int len;
270 
271 	switch (sk->sk_family) {
272 	case PF_INET:
273 		len = snprintf(buf, remaining, "ipv4 %s %pI4 %d\n",
274 				proto_name,
275 				&inet_sk(sk)->inet_rcv_saddr,
276 				inet_sk(sk)->inet_num);
277 		break;
278 	case PF_INET6:
279 		len = snprintf(buf, remaining, "ipv6 %s %pI6 %d\n",
280 				proto_name,
281 				&inet6_sk(sk)->rcv_saddr,
282 				inet_sk(sk)->inet_num);
283 		break;
284 	default:
285 		len = snprintf(buf, remaining, "*unknown-%d*\n",
286 				sk->sk_family);
287 	}
288 
289 	if (len >= remaining) {
290 		*buf = '\0';
291 		return -ENAMETOOLONG;
292 	}
293 	return len;
294 }
295 
296 /**
297  * svc_sock_names - construct a list of listener names in a string
298  * @serv: pointer to RPC service
299  * @buf: pointer to a buffer to fill in with socket names
300  * @buflen: size of the buffer to be filled
301  * @toclose: pointer to '\0'-terminated C string containing the name
302  *		of a listener to be closed
303  *
304  * Fills in @buf with a '\n'-separated list of names of listener
305  * sockets.  If @toclose is not NULL, the socket named by @toclose
306  * is closed, and is not included in the output list.
307  *
308  * Returns positive length of the socket name string, or a negative
309  * errno value on error.
310  */
311 int svc_sock_names(struct svc_serv *serv, char *buf, const size_t buflen,
312 		   const char *toclose)
313 {
314 	struct svc_sock *svsk, *closesk = NULL;
315 	int len = 0;
316 
317 	if (!serv)
318 		return 0;
319 
320 	spin_lock_bh(&serv->sv_lock);
321 	list_for_each_entry(svsk, &serv->sv_permsocks, sk_xprt.xpt_list) {
322 		int onelen = svc_one_sock_name(svsk, buf + len, buflen - len);
323 		if (onelen < 0) {
324 			len = onelen;
325 			break;
326 		}
327 		if (toclose && strcmp(toclose, buf + len) == 0)
328 			closesk = svsk;
329 		else
330 			len += onelen;
331 	}
332 	spin_unlock_bh(&serv->sv_lock);
333 
334 	if (closesk)
335 		/* Should unregister with portmap, but you cannot
336 		 * unregister just one protocol...
337 		 */
338 		svc_close_xprt(&closesk->sk_xprt);
339 	else if (toclose)
340 		return -ENOENT;
341 	return len;
342 }
343 EXPORT_SYMBOL_GPL(svc_sock_names);
344 
345 /*
346  * Check input queue length
347  */
348 static int svc_recv_available(struct svc_sock *svsk)
349 {
350 	struct socket	*sock = svsk->sk_sock;
351 	int		avail, err;
352 
353 	err = kernel_sock_ioctl(sock, TIOCINQ, (unsigned long) &avail);
354 
355 	return (err >= 0)? avail : err;
356 }
357 
358 /*
359  * Generic recvfrom routine.
360  */
361 static int svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr,
362 			int buflen)
363 {
364 	struct svc_sock *svsk =
365 		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
366 	struct msghdr msg = {
367 		.msg_flags	= MSG_DONTWAIT,
368 	};
369 	int len;
370 
371 	rqstp->rq_xprt_hlen = 0;
372 
373 	len = kernel_recvmsg(svsk->sk_sock, &msg, iov, nr, buflen,
374 				msg.msg_flags);
375 
376 	dprintk("svc: socket %p recvfrom(%p, %Zu) = %d\n",
377 		svsk, iov[0].iov_base, iov[0].iov_len, len);
378 	return len;
379 }
380 
381 /*
382  * Set socket snd and rcv buffer lengths
383  */
384 static void svc_sock_setbufsize(struct socket *sock, unsigned int snd,
385 				unsigned int rcv)
386 {
387 #if 0
388 	mm_segment_t	oldfs;
389 	oldfs = get_fs(); set_fs(KERNEL_DS);
390 	sock_setsockopt(sock, SOL_SOCKET, SO_SNDBUF,
391 			(char*)&snd, sizeof(snd));
392 	sock_setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
393 			(char*)&rcv, sizeof(rcv));
394 #else
395 	/* sock_setsockopt limits use to sysctl_?mem_max,
396 	 * which isn't acceptable.  Until that is made conditional
397 	 * on not having CAP_SYS_RESOURCE or similar, we go direct...
398 	 * DaveM said I could!
399 	 */
400 	lock_sock(sock->sk);
401 	sock->sk->sk_sndbuf = snd * 2;
402 	sock->sk->sk_rcvbuf = rcv * 2;
403 	sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK|SOCK_RCVBUF_LOCK;
404 	sock->sk->sk_write_space(sock->sk);
405 	release_sock(sock->sk);
406 #endif
407 }
408 /*
409  * INET callback when data has been received on the socket.
410  */
411 static void svc_udp_data_ready(struct sock *sk, int count)
412 {
413 	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
414 
415 	if (svsk) {
416 		dprintk("svc: socket %p(inet %p), count=%d, busy=%d\n",
417 			svsk, sk, count,
418 			test_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags));
419 		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
420 		svc_xprt_enqueue(&svsk->sk_xprt);
421 	}
422 	if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
423 		wake_up_interruptible(sk_sleep(sk));
424 }
425 
426 /*
427  * INET callback when space is newly available on the socket.
428  */
429 static void svc_write_space(struct sock *sk)
430 {
431 	struct svc_sock	*svsk = (struct svc_sock *)(sk->sk_user_data);
432 
433 	if (svsk) {
434 		dprintk("svc: socket %p(inet %p), write_space busy=%d\n",
435 			svsk, sk, test_bit(XPT_BUSY, &svsk->sk_xprt.xpt_flags));
436 		svc_xprt_enqueue(&svsk->sk_xprt);
437 	}
438 
439 	if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk))) {
440 		dprintk("RPC svc_write_space: someone sleeping on %p\n",
441 		       svsk);
442 		wake_up_interruptible(sk_sleep(sk));
443 	}
444 }
445 
446 static void svc_tcp_write_space(struct sock *sk)
447 {
448 	struct socket *sock = sk->sk_socket;
449 
450 	if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) && sock)
451 		clear_bit(SOCK_NOSPACE, &sock->flags);
452 	svc_write_space(sk);
453 }
454 
455 /*
456  * See net/ipv6/ip_sockglue.c : ip_cmsg_recv_pktinfo
457  */
458 static int svc_udp_get_dest_address4(struct svc_rqst *rqstp,
459 				     struct cmsghdr *cmh)
460 {
461 	struct in_pktinfo *pki = CMSG_DATA(cmh);
462 	if (cmh->cmsg_type != IP_PKTINFO)
463 		return 0;
464 	rqstp->rq_daddr.addr.s_addr = pki->ipi_spec_dst.s_addr;
465 	return 1;
466 }
467 
468 /*
469  * See net/ipv6/datagram.c : datagram_recv_ctl
470  */
471 static int svc_udp_get_dest_address6(struct svc_rqst *rqstp,
472 				     struct cmsghdr *cmh)
473 {
474 	struct in6_pktinfo *pki = CMSG_DATA(cmh);
475 	if (cmh->cmsg_type != IPV6_PKTINFO)
476 		return 0;
477 	ipv6_addr_copy(&rqstp->rq_daddr.addr6, &pki->ipi6_addr);
478 	return 1;
479 }
480 
481 /*
482  * Copy the UDP datagram's destination address to the rqstp structure.
483  * The 'destination' address in this case is the address to which the
484  * peer sent the datagram, i.e. our local address. For multihomed
485  * hosts, this can change from msg to msg. Note that only the IP
486  * address changes, the port number should remain the same.
487  */
488 static int svc_udp_get_dest_address(struct svc_rqst *rqstp,
489 				    struct cmsghdr *cmh)
490 {
491 	switch (cmh->cmsg_level) {
492 	case SOL_IP:
493 		return svc_udp_get_dest_address4(rqstp, cmh);
494 	case SOL_IPV6:
495 		return svc_udp_get_dest_address6(rqstp, cmh);
496 	}
497 
498 	return 0;
499 }
500 
501 /*
502  * Receive a datagram from a UDP socket.
503  */
504 static int svc_udp_recvfrom(struct svc_rqst *rqstp)
505 {
506 	struct svc_sock	*svsk =
507 		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
508 	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
509 	struct sk_buff	*skb;
510 	union {
511 		struct cmsghdr	hdr;
512 		long		all[SVC_PKTINFO_SPACE / sizeof(long)];
513 	} buffer;
514 	struct cmsghdr *cmh = &buffer.hdr;
515 	struct msghdr msg = {
516 		.msg_name = svc_addr(rqstp),
517 		.msg_control = cmh,
518 		.msg_controllen = sizeof(buffer),
519 		.msg_flags = MSG_DONTWAIT,
520 	};
521 	size_t len;
522 	int err;
523 
524 	if (test_and_clear_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags))
525 	    /* udp sockets need large rcvbuf as all pending
526 	     * requests are still in that buffer.  sndbuf must
527 	     * also be large enough that there is enough space
528 	     * for one reply per thread.  We count all threads
529 	     * rather than threads in a particular pool, which
530 	     * provides an upper bound on the number of threads
531 	     * which will access the socket.
532 	     */
533 	    svc_sock_setbufsize(svsk->sk_sock,
534 				(serv->sv_nrthreads+3) * serv->sv_max_mesg,
535 				(serv->sv_nrthreads+3) * serv->sv_max_mesg);
536 
537 	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
538 	skb = NULL;
539 	err = kernel_recvmsg(svsk->sk_sock, &msg, NULL,
540 			     0, 0, MSG_PEEK | MSG_DONTWAIT);
541 	if (err >= 0)
542 		skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err);
543 
544 	if (skb == NULL) {
545 		if (err != -EAGAIN) {
546 			/* possibly an icmp error */
547 			dprintk("svc: recvfrom returned error %d\n", -err);
548 			set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
549 		}
550 		return -EAGAIN;
551 	}
552 	len = svc_addr_len(svc_addr(rqstp));
553 	if (len == 0)
554 		return -EAFNOSUPPORT;
555 	rqstp->rq_addrlen = len;
556 	if (skb->tstamp.tv64 == 0) {
557 		skb->tstamp = ktime_get_real();
558 		/* Don't enable netstamp, sunrpc doesn't
559 		   need that much accuracy */
560 	}
561 	svsk->sk_sk->sk_stamp = skb->tstamp;
562 	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags); /* there may be more data... */
563 
564 	len  = skb->len - sizeof(struct udphdr);
565 	rqstp->rq_arg.len = len;
566 
567 	rqstp->rq_prot = IPPROTO_UDP;
568 
569 	if (!svc_udp_get_dest_address(rqstp, cmh)) {
570 		if (net_ratelimit())
571 			printk(KERN_WARNING
572 				"svc: received unknown control message %d/%d; "
573 				"dropping RPC reply datagram\n",
574 					cmh->cmsg_level, cmh->cmsg_type);
575 		skb_free_datagram_locked(svsk->sk_sk, skb);
576 		return 0;
577 	}
578 
579 	if (skb_is_nonlinear(skb)) {
580 		/* we have to copy */
581 		local_bh_disable();
582 		if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb)) {
583 			local_bh_enable();
584 			/* checksum error */
585 			skb_free_datagram_locked(svsk->sk_sk, skb);
586 			return 0;
587 		}
588 		local_bh_enable();
589 		skb_free_datagram_locked(svsk->sk_sk, skb);
590 	} else {
591 		/* we can use it in-place */
592 		rqstp->rq_arg.head[0].iov_base = skb->data +
593 			sizeof(struct udphdr);
594 		rqstp->rq_arg.head[0].iov_len = len;
595 		if (skb_checksum_complete(skb)) {
596 			skb_free_datagram_locked(svsk->sk_sk, skb);
597 			return 0;
598 		}
599 		rqstp->rq_xprt_ctxt = skb;
600 	}
601 
602 	rqstp->rq_arg.page_base = 0;
603 	if (len <= rqstp->rq_arg.head[0].iov_len) {
604 		rqstp->rq_arg.head[0].iov_len = len;
605 		rqstp->rq_arg.page_len = 0;
606 		rqstp->rq_respages = rqstp->rq_pages+1;
607 	} else {
608 		rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
609 		rqstp->rq_respages = rqstp->rq_pages + 1 +
610 			DIV_ROUND_UP(rqstp->rq_arg.page_len, PAGE_SIZE);
611 	}
612 
613 	if (serv->sv_stats)
614 		serv->sv_stats->netudpcnt++;
615 
616 	return len;
617 }
618 
619 static int
620 svc_udp_sendto(struct svc_rqst *rqstp)
621 {
622 	int		error;
623 
624 	error = svc_sendto(rqstp, &rqstp->rq_res);
625 	if (error == -ECONNREFUSED)
626 		/* ICMP error on earlier request. */
627 		error = svc_sendto(rqstp, &rqstp->rq_res);
628 
629 	return error;
630 }
631 
632 static void svc_udp_prep_reply_hdr(struct svc_rqst *rqstp)
633 {
634 }
635 
636 static int svc_udp_has_wspace(struct svc_xprt *xprt)
637 {
638 	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
639 	struct svc_serv	*serv = xprt->xpt_server;
640 	unsigned long required;
641 
642 	/*
643 	 * Set the SOCK_NOSPACE flag before checking the available
644 	 * sock space.
645 	 */
646 	set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
647 	required = atomic_read(&svsk->sk_xprt.xpt_reserved) + serv->sv_max_mesg;
648 	if (required*2 > sock_wspace(svsk->sk_sk))
649 		return 0;
650 	clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
651 	return 1;
652 }
653 
654 static struct svc_xprt *svc_udp_accept(struct svc_xprt *xprt)
655 {
656 	BUG();
657 	return NULL;
658 }
659 
660 static struct svc_xprt *svc_udp_create(struct svc_serv *serv,
661 				       struct net *net,
662 				       struct sockaddr *sa, int salen,
663 				       int flags)
664 {
665 	return svc_create_socket(serv, IPPROTO_UDP, net, sa, salen, flags);
666 }
667 
668 static struct svc_xprt_ops svc_udp_ops = {
669 	.xpo_create = svc_udp_create,
670 	.xpo_recvfrom = svc_udp_recvfrom,
671 	.xpo_sendto = svc_udp_sendto,
672 	.xpo_release_rqst = svc_release_skb,
673 	.xpo_detach = svc_sock_detach,
674 	.xpo_free = svc_sock_free,
675 	.xpo_prep_reply_hdr = svc_udp_prep_reply_hdr,
676 	.xpo_has_wspace = svc_udp_has_wspace,
677 	.xpo_accept = svc_udp_accept,
678 };
679 
680 static struct svc_xprt_class svc_udp_class = {
681 	.xcl_name = "udp",
682 	.xcl_owner = THIS_MODULE,
683 	.xcl_ops = &svc_udp_ops,
684 	.xcl_max_payload = RPCSVC_MAXPAYLOAD_UDP,
685 };
686 
687 static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv)
688 {
689 	int err, level, optname, one = 1;
690 
691 	svc_xprt_init(&svc_udp_class, &svsk->sk_xprt, serv);
692 	clear_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
693 	svsk->sk_sk->sk_data_ready = svc_udp_data_ready;
694 	svsk->sk_sk->sk_write_space = svc_write_space;
695 
696 	/* initialise setting must have enough space to
697 	 * receive and respond to one request.
698 	 * svc_udp_recvfrom will re-adjust if necessary
699 	 */
700 	svc_sock_setbufsize(svsk->sk_sock,
701 			    3 * svsk->sk_xprt.xpt_server->sv_max_mesg,
702 			    3 * svsk->sk_xprt.xpt_server->sv_max_mesg);
703 
704 	/* data might have come in before data_ready set up */
705 	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
706 	set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
707 
708 	/* make sure we get destination address info */
709 	switch (svsk->sk_sk->sk_family) {
710 	case AF_INET:
711 		level = SOL_IP;
712 		optname = IP_PKTINFO;
713 		break;
714 	case AF_INET6:
715 		level = SOL_IPV6;
716 		optname = IPV6_RECVPKTINFO;
717 		break;
718 	default:
719 		BUG();
720 	}
721 	err = kernel_setsockopt(svsk->sk_sock, level, optname,
722 					(char *)&one, sizeof(one));
723 	dprintk("svc: kernel_setsockopt returned %d\n", err);
724 }
725 
726 /*
727  * A data_ready event on a listening socket means there's a connection
728  * pending. Do not use state_change as a substitute for it.
729  */
730 static void svc_tcp_listen_data_ready(struct sock *sk, int count_unused)
731 {
732 	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
733 
734 	dprintk("svc: socket %p TCP (listen) state change %d\n",
735 		sk, sk->sk_state);
736 
737 	/*
738 	 * This callback may called twice when a new connection
739 	 * is established as a child socket inherits everything
740 	 * from a parent LISTEN socket.
741 	 * 1) data_ready method of the parent socket will be called
742 	 *    when one of child sockets become ESTABLISHED.
743 	 * 2) data_ready method of the child socket may be called
744 	 *    when it receives data before the socket is accepted.
745 	 * In case of 2, we should ignore it silently.
746 	 */
747 	if (sk->sk_state == TCP_LISTEN) {
748 		if (svsk) {
749 			set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
750 			svc_xprt_enqueue(&svsk->sk_xprt);
751 		} else
752 			printk("svc: socket %p: no user data\n", sk);
753 	}
754 
755 	if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
756 		wake_up_interruptible_all(sk_sleep(sk));
757 }
758 
759 /*
760  * A state change on a connected socket means it's dying or dead.
761  */
762 static void svc_tcp_state_change(struct sock *sk)
763 {
764 	struct svc_sock	*svsk = (struct svc_sock *)sk->sk_user_data;
765 
766 	dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n",
767 		sk, sk->sk_state, sk->sk_user_data);
768 
769 	if (!svsk)
770 		printk("svc: socket %p: no user data\n", sk);
771 	else {
772 		set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
773 		svc_xprt_enqueue(&svsk->sk_xprt);
774 	}
775 	if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
776 		wake_up_interruptible_all(sk_sleep(sk));
777 }
778 
779 static void svc_tcp_data_ready(struct sock *sk, int count)
780 {
781 	struct svc_sock *svsk = (struct svc_sock *)sk->sk_user_data;
782 
783 	dprintk("svc: socket %p TCP data ready (svsk %p)\n",
784 		sk, sk->sk_user_data);
785 	if (svsk) {
786 		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
787 		svc_xprt_enqueue(&svsk->sk_xprt);
788 	}
789 	if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
790 		wake_up_interruptible(sk_sleep(sk));
791 }
792 
793 /*
794  * Accept a TCP connection
795  */
796 static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt)
797 {
798 	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
799 	struct sockaddr_storage addr;
800 	struct sockaddr	*sin = (struct sockaddr *) &addr;
801 	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
802 	struct socket	*sock = svsk->sk_sock;
803 	struct socket	*newsock;
804 	struct svc_sock	*newsvsk;
805 	int		err, slen;
806 	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
807 
808 	dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);
809 	if (!sock)
810 		return NULL;
811 
812 	clear_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
813 	err = kernel_accept(sock, &newsock, O_NONBLOCK);
814 	if (err < 0) {
815 		if (err == -ENOMEM)
816 			printk(KERN_WARNING "%s: no more sockets!\n",
817 			       serv->sv_name);
818 		else if (err != -EAGAIN && net_ratelimit())
819 			printk(KERN_WARNING "%s: accept failed (err %d)!\n",
820 				   serv->sv_name, -err);
821 		return NULL;
822 	}
823 	set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
824 
825 	err = kernel_getpeername(newsock, sin, &slen);
826 	if (err < 0) {
827 		if (net_ratelimit())
828 			printk(KERN_WARNING "%s: peername failed (err %d)!\n",
829 				   serv->sv_name, -err);
830 		goto failed;		/* aborted connection or whatever */
831 	}
832 
833 	/* Ideally, we would want to reject connections from unauthorized
834 	 * hosts here, but when we get encryption, the IP of the host won't
835 	 * tell us anything.  For now just warn about unpriv connections.
836 	 */
837 	if (!svc_port_is_privileged(sin)) {
838 		dprintk(KERN_WARNING
839 			"%s: connect from unprivileged port: %s\n",
840 			serv->sv_name,
841 			__svc_print_addr(sin, buf, sizeof(buf)));
842 	}
843 	dprintk("%s: connect from %s\n", serv->sv_name,
844 		__svc_print_addr(sin, buf, sizeof(buf)));
845 
846 	/* make sure that a write doesn't block forever when
847 	 * low on memory
848 	 */
849 	newsock->sk->sk_sndtimeo = HZ*30;
850 
851 	if (!(newsvsk = svc_setup_socket(serv, newsock, &err,
852 				 (SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY))))
853 		goto failed;
854 	svc_xprt_set_remote(&newsvsk->sk_xprt, sin, slen);
855 	err = kernel_getsockname(newsock, sin, &slen);
856 	if (unlikely(err < 0)) {
857 		dprintk("svc_tcp_accept: kernel_getsockname error %d\n", -err);
858 		slen = offsetof(struct sockaddr, sa_data);
859 	}
860 	svc_xprt_set_local(&newsvsk->sk_xprt, sin, slen);
861 
862 	if (serv->sv_stats)
863 		serv->sv_stats->nettcpconn++;
864 
865 	return &newsvsk->sk_xprt;
866 
867 failed:
868 	sock_release(newsock);
869 	return NULL;
870 }
871 
872 /*
873  * Receive data.
874  * If we haven't gotten the record length yet, get the next four bytes.
875  * Otherwise try to gobble up as much as possible up to the complete
876  * record length.
877  */
878 static int svc_tcp_recv_record(struct svc_sock *svsk, struct svc_rqst *rqstp)
879 {
880 	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
881 	int len;
882 
883 	if (test_and_clear_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags))
884 		/* sndbuf needs to have room for one request
885 		 * per thread, otherwise we can stall even when the
886 		 * network isn't a bottleneck.
887 		 *
888 		 * We count all threads rather than threads in a
889 		 * particular pool, which provides an upper bound
890 		 * on the number of threads which will access the socket.
891 		 *
892 		 * rcvbuf just needs to be able to hold a few requests.
893 		 * Normally they will be removed from the queue
894 		 * as soon a a complete request arrives.
895 		 */
896 		svc_sock_setbufsize(svsk->sk_sock,
897 				    (serv->sv_nrthreads+3) * serv->sv_max_mesg,
898 				    3 * serv->sv_max_mesg);
899 
900 	clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
901 
902 	if (svsk->sk_tcplen < sizeof(rpc_fraghdr)) {
903 		int		want = sizeof(rpc_fraghdr) - svsk->sk_tcplen;
904 		struct kvec	iov;
905 
906 		iov.iov_base = ((char *) &svsk->sk_reclen) + svsk->sk_tcplen;
907 		iov.iov_len  = want;
908 		if ((len = svc_recvfrom(rqstp, &iov, 1, want)) < 0)
909 			goto error;
910 		svsk->sk_tcplen += len;
911 
912 		if (len < want) {
913 			dprintk("svc: short recvfrom while reading record "
914 				"length (%d of %d)\n", len, want);
915 			goto err_again; /* record header not complete */
916 		}
917 
918 		svsk->sk_reclen = ntohl(svsk->sk_reclen);
919 		if (!(svsk->sk_reclen & RPC_LAST_STREAM_FRAGMENT)) {
920 			/* FIXME: technically, a record can be fragmented,
921 			 *  and non-terminal fragments will not have the top
922 			 *  bit set in the fragment length header.
923 			 *  But apparently no known nfs clients send fragmented
924 			 *  records. */
925 			if (net_ratelimit())
926 				printk(KERN_NOTICE "RPC: multiple fragments "
927 					"per record not supported\n");
928 			goto err_delete;
929 		}
930 
931 		svsk->sk_reclen &= RPC_FRAGMENT_SIZE_MASK;
932 		dprintk("svc: TCP record, %d bytes\n", svsk->sk_reclen);
933 		if (svsk->sk_reclen > serv->sv_max_mesg) {
934 			if (net_ratelimit())
935 				printk(KERN_NOTICE "RPC: "
936 					"fragment too large: 0x%08lx\n",
937 					(unsigned long)svsk->sk_reclen);
938 			goto err_delete;
939 		}
940 	}
941 
942 	/* Check whether enough data is available */
943 	len = svc_recv_available(svsk);
944 	if (len < 0)
945 		goto error;
946 
947 	if (len < svsk->sk_reclen) {
948 		dprintk("svc: incomplete TCP record (%d of %d)\n",
949 			len, svsk->sk_reclen);
950 		goto err_again;	/* record not complete */
951 	}
952 	len = svsk->sk_reclen;
953 	set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
954 
955 	return len;
956  error:
957 	if (len == -EAGAIN)
958 		dprintk("RPC: TCP recv_record got EAGAIN\n");
959 	return len;
960  err_delete:
961 	set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
962  err_again:
963 	return -EAGAIN;
964 }
965 
966 static int svc_process_calldir(struct svc_sock *svsk, struct svc_rqst *rqstp,
967 			       struct rpc_rqst **reqpp, struct kvec *vec)
968 {
969 	struct rpc_rqst *req = NULL;
970 	u32 *p;
971 	u32 xid;
972 	u32 calldir;
973 	int len;
974 
975 	len = svc_recvfrom(rqstp, vec, 1, 8);
976 	if (len < 0)
977 		goto error;
978 
979 	p = (u32 *)rqstp->rq_arg.head[0].iov_base;
980 	xid = *p++;
981 	calldir = *p;
982 
983 	if (calldir == 0) {
984 		/* REQUEST is the most common case */
985 		vec[0] = rqstp->rq_arg.head[0];
986 	} else {
987 		/* REPLY */
988 		if (svsk->sk_bc_xprt)
989 			req = xprt_lookup_rqst(svsk->sk_bc_xprt, xid);
990 
991 		if (!req) {
992 			printk(KERN_NOTICE
993 				"%s: Got unrecognized reply: "
994 				"calldir 0x%x sk_bc_xprt %p xid %08x\n",
995 				__func__, ntohl(calldir),
996 				svsk->sk_bc_xprt, xid);
997 			vec[0] = rqstp->rq_arg.head[0];
998 			goto out;
999 		}
1000 
1001 		memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
1002 		       sizeof(struct xdr_buf));
1003 		/* copy the xid and call direction */
1004 		memcpy(req->rq_private_buf.head[0].iov_base,
1005 		       rqstp->rq_arg.head[0].iov_base, 8);
1006 		vec[0] = req->rq_private_buf.head[0];
1007 	}
1008  out:
1009 	vec[0].iov_base += 8;
1010 	vec[0].iov_len -= 8;
1011 	len = svsk->sk_reclen - 8;
1012  error:
1013 	*reqpp = req;
1014 	return len;
1015 }
1016 
1017 /*
1018  * Receive data from a TCP socket.
1019  */
1020 static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
1021 {
1022 	struct svc_sock	*svsk =
1023 		container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
1024 	struct svc_serv	*serv = svsk->sk_xprt.xpt_server;
1025 	int		len;
1026 	struct kvec *vec;
1027 	int pnum, vlen;
1028 	struct rpc_rqst *req = NULL;
1029 
1030 	dprintk("svc: tcp_recv %p data %d conn %d close %d\n",
1031 		svsk, test_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags),
1032 		test_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags),
1033 		test_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags));
1034 
1035 	len = svc_tcp_recv_record(svsk, rqstp);
1036 	if (len < 0)
1037 		goto error;
1038 
1039 	vec = rqstp->rq_vec;
1040 	vec[0] = rqstp->rq_arg.head[0];
1041 	vlen = PAGE_SIZE;
1042 
1043 	/*
1044 	 * We have enough data for the whole tcp record. Let's try and read the
1045 	 * first 8 bytes to get the xid and the call direction. We can use this
1046 	 * to figure out if this is a call or a reply to a callback. If
1047 	 * sk_reclen is < 8 (xid and calldir), then this is a malformed packet.
1048 	 * In that case, don't bother with the calldir and just read the data.
1049 	 * It will be rejected in svc_process.
1050 	 */
1051 	if (len >= 8) {
1052 		len = svc_process_calldir(svsk, rqstp, &req, vec);
1053 		if (len < 0)
1054 			goto err_again;
1055 		vlen -= 8;
1056 	}
1057 
1058 	pnum = 1;
1059 	while (vlen < len) {
1060 		vec[pnum].iov_base = (req) ?
1061 			page_address(req->rq_private_buf.pages[pnum - 1]) :
1062 			page_address(rqstp->rq_pages[pnum]);
1063 		vec[pnum].iov_len = PAGE_SIZE;
1064 		pnum++;
1065 		vlen += PAGE_SIZE;
1066 	}
1067 	rqstp->rq_respages = &rqstp->rq_pages[pnum];
1068 
1069 	/* Now receive data */
1070 	len = svc_recvfrom(rqstp, vec, pnum, len);
1071 	if (len < 0)
1072 		goto err_again;
1073 
1074 	/*
1075 	 * Account for the 8 bytes we read earlier
1076 	 */
1077 	len += 8;
1078 
1079 	if (req) {
1080 		xprt_complete_rqst(req->rq_task, len);
1081 		len = 0;
1082 		goto out;
1083 	}
1084 	dprintk("svc: TCP complete record (%d bytes)\n", len);
1085 	rqstp->rq_arg.len = len;
1086 	rqstp->rq_arg.page_base = 0;
1087 	if (len <= rqstp->rq_arg.head[0].iov_len) {
1088 		rqstp->rq_arg.head[0].iov_len = len;
1089 		rqstp->rq_arg.page_len = 0;
1090 	} else {
1091 		rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
1092 	}
1093 
1094 	rqstp->rq_xprt_ctxt   = NULL;
1095 	rqstp->rq_prot	      = IPPROTO_TCP;
1096 
1097 out:
1098 	/* Reset TCP read info */
1099 	svsk->sk_reclen = 0;
1100 	svsk->sk_tcplen = 0;
1101 
1102 	svc_xprt_copy_addrs(rqstp, &svsk->sk_xprt);
1103 	if (serv->sv_stats)
1104 		serv->sv_stats->nettcpcnt++;
1105 
1106 	return len;
1107 
1108 err_again:
1109 	if (len == -EAGAIN) {
1110 		dprintk("RPC: TCP recvfrom got EAGAIN\n");
1111 		return len;
1112 	}
1113 error:
1114 	if (len != -EAGAIN) {
1115 		printk(KERN_NOTICE "%s: recvfrom returned errno %d\n",
1116 		       svsk->sk_xprt.xpt_server->sv_name, -len);
1117 		set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
1118 	}
1119 	return -EAGAIN;
1120 }
1121 
1122 /*
1123  * Send out data on TCP socket.
1124  */
1125 static int svc_tcp_sendto(struct svc_rqst *rqstp)
1126 {
1127 	struct xdr_buf	*xbufp = &rqstp->rq_res;
1128 	int sent;
1129 	__be32 reclen;
1130 
1131 	/* Set up the first element of the reply kvec.
1132 	 * Any other kvecs that may be in use have been taken
1133 	 * care of by the server implementation itself.
1134 	 */
1135 	reclen = htonl(0x80000000|((xbufp->len ) - 4));
1136 	memcpy(xbufp->head[0].iov_base, &reclen, 4);
1137 
1138 	sent = svc_sendto(rqstp, &rqstp->rq_res);
1139 	if (sent != xbufp->len) {
1140 		printk(KERN_NOTICE
1141 		       "rpc-srv/tcp: %s: %s %d when sending %d bytes "
1142 		       "- shutting down socket\n",
1143 		       rqstp->rq_xprt->xpt_server->sv_name,
1144 		       (sent<0)?"got error":"sent only",
1145 		       sent, xbufp->len);
1146 		set_bit(XPT_CLOSE, &rqstp->rq_xprt->xpt_flags);
1147 		svc_xprt_enqueue(rqstp->rq_xprt);
1148 		sent = -EAGAIN;
1149 	}
1150 	return sent;
1151 }
1152 
1153 /*
1154  * Setup response header. TCP has a 4B record length field.
1155  */
1156 static void svc_tcp_prep_reply_hdr(struct svc_rqst *rqstp)
1157 {
1158 	struct kvec *resv = &rqstp->rq_res.head[0];
1159 
1160 	/* tcp needs a space for the record length... */
1161 	svc_putnl(resv, 0);
1162 }
1163 
1164 static int svc_tcp_has_wspace(struct svc_xprt *xprt)
1165 {
1166 	struct svc_sock *svsk =	container_of(xprt, struct svc_sock, sk_xprt);
1167 	struct svc_serv *serv = svsk->sk_xprt.xpt_server;
1168 	int required;
1169 
1170 	if (test_bit(XPT_LISTENER, &xprt->xpt_flags))
1171 		return 1;
1172 	required = atomic_read(&xprt->xpt_reserved) + serv->sv_max_mesg;
1173 	if (sk_stream_wspace(svsk->sk_sk) >= required)
1174 		return 1;
1175 	set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
1176 	return 0;
1177 }
1178 
1179 static struct svc_xprt *svc_tcp_create(struct svc_serv *serv,
1180 				       struct net *net,
1181 				       struct sockaddr *sa, int salen,
1182 				       int flags)
1183 {
1184 	return svc_create_socket(serv, IPPROTO_TCP, net, sa, salen, flags);
1185 }
1186 
1187 static struct svc_xprt_ops svc_tcp_ops = {
1188 	.xpo_create = svc_tcp_create,
1189 	.xpo_recvfrom = svc_tcp_recvfrom,
1190 	.xpo_sendto = svc_tcp_sendto,
1191 	.xpo_release_rqst = svc_release_skb,
1192 	.xpo_detach = svc_tcp_sock_detach,
1193 	.xpo_free = svc_sock_free,
1194 	.xpo_prep_reply_hdr = svc_tcp_prep_reply_hdr,
1195 	.xpo_has_wspace = svc_tcp_has_wspace,
1196 	.xpo_accept = svc_tcp_accept,
1197 };
1198 
1199 static struct svc_xprt_class svc_tcp_class = {
1200 	.xcl_name = "tcp",
1201 	.xcl_owner = THIS_MODULE,
1202 	.xcl_ops = &svc_tcp_ops,
1203 	.xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP,
1204 };
1205 
1206 void svc_init_xprt_sock(void)
1207 {
1208 	svc_reg_xprt_class(&svc_tcp_class);
1209 	svc_reg_xprt_class(&svc_udp_class);
1210 }
1211 
1212 void svc_cleanup_xprt_sock(void)
1213 {
1214 	svc_unreg_xprt_class(&svc_tcp_class);
1215 	svc_unreg_xprt_class(&svc_udp_class);
1216 }
1217 
1218 static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
1219 {
1220 	struct sock	*sk = svsk->sk_sk;
1221 
1222 	svc_xprt_init(&svc_tcp_class, &svsk->sk_xprt, serv);
1223 	set_bit(XPT_CACHE_AUTH, &svsk->sk_xprt.xpt_flags);
1224 	if (sk->sk_state == TCP_LISTEN) {
1225 		dprintk("setting up TCP socket for listening\n");
1226 		set_bit(XPT_LISTENER, &svsk->sk_xprt.xpt_flags);
1227 		sk->sk_data_ready = svc_tcp_listen_data_ready;
1228 		set_bit(XPT_CONN, &svsk->sk_xprt.xpt_flags);
1229 	} else {
1230 		dprintk("setting up TCP socket for reading\n");
1231 		sk->sk_state_change = svc_tcp_state_change;
1232 		sk->sk_data_ready = svc_tcp_data_ready;
1233 		sk->sk_write_space = svc_tcp_write_space;
1234 
1235 		svsk->sk_reclen = 0;
1236 		svsk->sk_tcplen = 0;
1237 
1238 		tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1239 
1240 		/* initialise setting must have enough space to
1241 		 * receive and respond to one request.
1242 		 * svc_tcp_recvfrom will re-adjust if necessary
1243 		 */
1244 		svc_sock_setbufsize(svsk->sk_sock,
1245 				    3 * svsk->sk_xprt.xpt_server->sv_max_mesg,
1246 				    3 * svsk->sk_xprt.xpt_server->sv_max_mesg);
1247 
1248 		set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
1249 		set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
1250 		if (sk->sk_state != TCP_ESTABLISHED)
1251 			set_bit(XPT_CLOSE, &svsk->sk_xprt.xpt_flags);
1252 	}
1253 }
1254 
1255 void svc_sock_update_bufs(struct svc_serv *serv)
1256 {
1257 	/*
1258 	 * The number of server threads has changed. Update
1259 	 * rcvbuf and sndbuf accordingly on all sockets
1260 	 */
1261 	struct svc_sock *svsk;
1262 
1263 	spin_lock_bh(&serv->sv_lock);
1264 	list_for_each_entry(svsk, &serv->sv_permsocks, sk_xprt.xpt_list)
1265 		set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
1266 	list_for_each_entry(svsk, &serv->sv_tempsocks, sk_xprt.xpt_list)
1267 		set_bit(XPT_CHNGBUF, &svsk->sk_xprt.xpt_flags);
1268 	spin_unlock_bh(&serv->sv_lock);
1269 }
1270 EXPORT_SYMBOL_GPL(svc_sock_update_bufs);
1271 
1272 /*
1273  * Initialize socket for RPC use and create svc_sock struct
1274  * XXX: May want to setsockopt SO_SNDBUF and SO_RCVBUF.
1275  */
1276 static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
1277 						struct socket *sock,
1278 						int *errp, int flags)
1279 {
1280 	struct svc_sock	*svsk;
1281 	struct sock	*inet;
1282 	int		pmap_register = !(flags & SVC_SOCK_ANONYMOUS);
1283 
1284 	dprintk("svc: svc_setup_socket %p\n", sock);
1285 	if (!(svsk = kzalloc(sizeof(*svsk), GFP_KERNEL))) {
1286 		*errp = -ENOMEM;
1287 		return NULL;
1288 	}
1289 
1290 	inet = sock->sk;
1291 
1292 	/* Register socket with portmapper */
1293 	if (*errp >= 0 && pmap_register)
1294 		*errp = svc_register(serv, inet->sk_family, inet->sk_protocol,
1295 				     ntohs(inet_sk(inet)->inet_sport));
1296 
1297 	if (*errp < 0) {
1298 		kfree(svsk);
1299 		return NULL;
1300 	}
1301 
1302 	inet->sk_user_data = svsk;
1303 	svsk->sk_sock = sock;
1304 	svsk->sk_sk = inet;
1305 	svsk->sk_ostate = inet->sk_state_change;
1306 	svsk->sk_odata = inet->sk_data_ready;
1307 	svsk->sk_owspace = inet->sk_write_space;
1308 
1309 	/* Initialize the socket */
1310 	if (sock->type == SOCK_DGRAM)
1311 		svc_udp_init(svsk, serv);
1312 	else
1313 		svc_tcp_init(svsk, serv);
1314 
1315 	dprintk("svc: svc_setup_socket created %p (inet %p)\n",
1316 				svsk, svsk->sk_sk);
1317 
1318 	return svsk;
1319 }
1320 
1321 /**
1322  * svc_addsock - add a listener socket to an RPC service
1323  * @serv: pointer to RPC service to which to add a new listener
1324  * @fd: file descriptor of the new listener
1325  * @name_return: pointer to buffer to fill in with name of listener
1326  * @len: size of the buffer
1327  *
1328  * Fills in socket name and returns positive length of name if successful.
1329  * Name is terminated with '\n'.  On error, returns a negative errno
1330  * value.
1331  */
1332 int svc_addsock(struct svc_serv *serv, const int fd, char *name_return,
1333 		const size_t len)
1334 {
1335 	int err = 0;
1336 	struct socket *so = sockfd_lookup(fd, &err);
1337 	struct svc_sock *svsk = NULL;
1338 
1339 	if (!so)
1340 		return err;
1341 	if ((so->sk->sk_family != PF_INET) && (so->sk->sk_family != PF_INET6))
1342 		err =  -EAFNOSUPPORT;
1343 	else if (so->sk->sk_protocol != IPPROTO_TCP &&
1344 	    so->sk->sk_protocol != IPPROTO_UDP)
1345 		err =  -EPROTONOSUPPORT;
1346 	else if (so->state > SS_UNCONNECTED)
1347 		err = -EISCONN;
1348 	else {
1349 		if (!try_module_get(THIS_MODULE))
1350 			err = -ENOENT;
1351 		else
1352 			svsk = svc_setup_socket(serv, so, &err,
1353 						SVC_SOCK_DEFAULTS);
1354 		if (svsk) {
1355 			struct sockaddr_storage addr;
1356 			struct sockaddr *sin = (struct sockaddr *)&addr;
1357 			int salen;
1358 			if (kernel_getsockname(svsk->sk_sock, sin, &salen) == 0)
1359 				svc_xprt_set_local(&svsk->sk_xprt, sin, salen);
1360 			clear_bit(XPT_TEMP, &svsk->sk_xprt.xpt_flags);
1361 			spin_lock_bh(&serv->sv_lock);
1362 			list_add(&svsk->sk_xprt.xpt_list, &serv->sv_permsocks);
1363 			spin_unlock_bh(&serv->sv_lock);
1364 			svc_xprt_received(&svsk->sk_xprt);
1365 			err = 0;
1366 		} else
1367 			module_put(THIS_MODULE);
1368 	}
1369 	if (err) {
1370 		sockfd_put(so);
1371 		return err;
1372 	}
1373 	return svc_one_sock_name(svsk, name_return, len);
1374 }
1375 EXPORT_SYMBOL_GPL(svc_addsock);
1376 
1377 /*
1378  * Create socket for RPC service.
1379  */
1380 static struct svc_xprt *svc_create_socket(struct svc_serv *serv,
1381 					  int protocol,
1382 					  struct net *net,
1383 					  struct sockaddr *sin, int len,
1384 					  int flags)
1385 {
1386 	struct svc_sock	*svsk;
1387 	struct socket	*sock;
1388 	int		error;
1389 	int		type;
1390 	struct sockaddr_storage addr;
1391 	struct sockaddr *newsin = (struct sockaddr *)&addr;
1392 	int		newlen;
1393 	int		family;
1394 	int		val;
1395 	RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
1396 
1397 	dprintk("svc: svc_create_socket(%s, %d, %s)\n",
1398 			serv->sv_program->pg_name, protocol,
1399 			__svc_print_addr(sin, buf, sizeof(buf)));
1400 
1401 	if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
1402 		printk(KERN_WARNING "svc: only UDP and TCP "
1403 				"sockets supported\n");
1404 		return ERR_PTR(-EINVAL);
1405 	}
1406 
1407 	type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
1408 	switch (sin->sa_family) {
1409 	case AF_INET6:
1410 		family = PF_INET6;
1411 		break;
1412 	case AF_INET:
1413 		family = PF_INET;
1414 		break;
1415 	default:
1416 		return ERR_PTR(-EINVAL);
1417 	}
1418 
1419 	error = __sock_create(net, family, type, protocol, &sock, 1);
1420 	if (error < 0)
1421 		return ERR_PTR(error);
1422 
1423 	svc_reclassify_socket(sock);
1424 
1425 	/*
1426 	 * If this is an PF_INET6 listener, we want to avoid
1427 	 * getting requests from IPv4 remotes.  Those should
1428 	 * be shunted to a PF_INET listener via rpcbind.
1429 	 */
1430 	val = 1;
1431 	if (family == PF_INET6)
1432 		kernel_setsockopt(sock, SOL_IPV6, IPV6_V6ONLY,
1433 					(char *)&val, sizeof(val));
1434 
1435 	if (type == SOCK_STREAM)
1436 		sock->sk->sk_reuse = 1;		/* allow address reuse */
1437 	error = kernel_bind(sock, sin, len);
1438 	if (error < 0)
1439 		goto bummer;
1440 
1441 	newlen = len;
1442 	error = kernel_getsockname(sock, newsin, &newlen);
1443 	if (error < 0)
1444 		goto bummer;
1445 
1446 	if (protocol == IPPROTO_TCP) {
1447 		if ((error = kernel_listen(sock, 64)) < 0)
1448 			goto bummer;
1449 	}
1450 
1451 	if ((svsk = svc_setup_socket(serv, sock, &error, flags)) != NULL) {
1452 		svc_xprt_set_local(&svsk->sk_xprt, newsin, newlen);
1453 		return (struct svc_xprt *)svsk;
1454 	}
1455 
1456 bummer:
1457 	dprintk("svc: svc_create_socket error = %d\n", -error);
1458 	sock_release(sock);
1459 	return ERR_PTR(error);
1460 }
1461 
1462 /*
1463  * Detach the svc_sock from the socket so that no
1464  * more callbacks occur.
1465  */
1466 static void svc_sock_detach(struct svc_xprt *xprt)
1467 {
1468 	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1469 	struct sock *sk = svsk->sk_sk;
1470 
1471 	dprintk("svc: svc_sock_detach(%p)\n", svsk);
1472 
1473 	/* put back the old socket callbacks */
1474 	sk->sk_state_change = svsk->sk_ostate;
1475 	sk->sk_data_ready = svsk->sk_odata;
1476 	sk->sk_write_space = svsk->sk_owspace;
1477 
1478 	if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
1479 		wake_up_interruptible(sk_sleep(sk));
1480 }
1481 
1482 /*
1483  * Disconnect the socket, and reset the callbacks
1484  */
1485 static void svc_tcp_sock_detach(struct svc_xprt *xprt)
1486 {
1487 	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1488 
1489 	dprintk("svc: svc_tcp_sock_detach(%p)\n", svsk);
1490 
1491 	svc_sock_detach(xprt);
1492 
1493 	if (!test_bit(XPT_LISTENER, &xprt->xpt_flags))
1494 		kernel_sock_shutdown(svsk->sk_sock, SHUT_RDWR);
1495 }
1496 
1497 /*
1498  * Free the svc_sock's socket resources and the svc_sock itself.
1499  */
1500 static void svc_sock_free(struct svc_xprt *xprt)
1501 {
1502 	struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt);
1503 	dprintk("svc: svc_sock_free(%p)\n", svsk);
1504 
1505 	if (svsk->sk_sock->file)
1506 		sockfd_put(svsk->sk_sock);
1507 	else
1508 		sock_release(svsk->sk_sock);
1509 	kfree(svsk);
1510 }
1511 
1512 /*
1513  * Create a svc_xprt.
1514  *
1515  * For internal use only (e.g. nfsv4.1 backchannel).
1516  * Callers should typically use the xpo_create() method.
1517  */
1518 struct svc_xprt *svc_sock_create(struct svc_serv *serv, int prot)
1519 {
1520 	struct svc_sock *svsk;
1521 	struct svc_xprt *xprt = NULL;
1522 
1523 	dprintk("svc: %s\n", __func__);
1524 	svsk = kzalloc(sizeof(*svsk), GFP_KERNEL);
1525 	if (!svsk)
1526 		goto out;
1527 
1528 	xprt = &svsk->sk_xprt;
1529 	if (prot == IPPROTO_TCP)
1530 		svc_xprt_init(&svc_tcp_class, xprt, serv);
1531 	else if (prot == IPPROTO_UDP)
1532 		svc_xprt_init(&svc_udp_class, xprt, serv);
1533 	else
1534 		BUG();
1535 out:
1536 	dprintk("svc: %s return %p\n", __func__, xprt);
1537 	return xprt;
1538 }
1539 EXPORT_SYMBOL_GPL(svc_sock_create);
1540 
1541 /*
1542  * Destroy a svc_sock.
1543  */
1544 void svc_sock_destroy(struct svc_xprt *xprt)
1545 {
1546 	if (xprt)
1547 		kfree(container_of(xprt, struct svc_sock, sk_xprt));
1548 }
1549 EXPORT_SYMBOL_GPL(svc_sock_destroy);
1550