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Commit | Line | Data |
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1d8206b9 TT |
1 | /* |
2 | * linux/net/sunrpc/svc_xprt.c | |
3 | * | |
4 | * Author: Tom Tucker <tom@opengridcomputing.com> | |
5 | */ | |
6 | ||
7 | #include <linux/sched.h> | |
8 | #include <linux/errno.h> | |
9 | #include <linux/fcntl.h> | |
10 | #include <linux/net.h> | |
11 | #include <linux/in.h> | |
12 | #include <linux/inet.h> | |
13 | #include <linux/udp.h> | |
14 | #include <linux/tcp.h> | |
15 | #include <linux/unistd.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/netdevice.h> | |
18 | #include <linux/skbuff.h> | |
19 | #include <linux/file.h> | |
20 | #include <linux/freezer.h> | |
7086721f | 21 | #include <linux/kthread.h> |
1d8206b9 TT |
22 | #include <net/sock.h> |
23 | #include <net/checksum.h> | |
24 | #include <net/ip.h> | |
25 | #include <net/ipv6.h> | |
26 | #include <net/tcp_states.h> | |
27 | #include <linux/uaccess.h> | |
28 | #include <asm/ioctls.h> | |
29 | ||
30 | #include <linux/sunrpc/types.h> | |
31 | #include <linux/sunrpc/clnt.h> | |
32 | #include <linux/sunrpc/xdr.h> | |
1d8206b9 TT |
33 | #include <linux/sunrpc/stats.h> |
34 | #include <linux/sunrpc/svc_xprt.h> | |
35 | ||
36 | #define RPCDBG_FACILITY RPCDBG_SVCXPRT | |
37 | ||
0f0257ea TT |
38 | static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt); |
39 | static int svc_deferred_recv(struct svc_rqst *rqstp); | |
40 | static struct cache_deferred_req *svc_defer(struct cache_req *req); | |
41 | static void svc_age_temp_xprts(unsigned long closure); | |
42 | ||
43 | /* apparently the "standard" is that clients close | |
44 | * idle connections after 5 minutes, servers after | |
45 | * 6 minutes | |
46 | * http://www.connectathon.org/talks96/nfstcp.pdf | |
47 | */ | |
48 | static int svc_conn_age_period = 6*60; | |
49 | ||
1d8206b9 TT |
50 | /* List of registered transport classes */ |
51 | static DEFINE_SPINLOCK(svc_xprt_class_lock); | |
52 | static LIST_HEAD(svc_xprt_class_list); | |
53 | ||
0f0257ea TT |
54 | /* SMP locking strategy: |
55 | * | |
56 | * svc_pool->sp_lock protects most of the fields of that pool. | |
57 | * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt. | |
58 | * when both need to be taken (rare), svc_serv->sv_lock is first. | |
59 | * BKL protects svc_serv->sv_nrthread. | |
60 | * svc_sock->sk_lock protects the svc_sock->sk_deferred list | |
61 | * and the ->sk_info_authunix cache. | |
62 | * | |
63 | * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being | |
64 | * enqueued multiply. During normal transport processing this bit | |
65 | * is set by svc_xprt_enqueue and cleared by svc_xprt_received. | |
66 | * Providers should not manipulate this bit directly. | |
67 | * | |
68 | * Some flags can be set to certain values at any time | |
69 | * providing that certain rules are followed: | |
70 | * | |
71 | * XPT_CONN, XPT_DATA: | |
72 | * - Can be set or cleared at any time. | |
73 | * - After a set, svc_xprt_enqueue must be called to enqueue | |
74 | * the transport for processing. | |
75 | * - After a clear, the transport must be read/accepted. | |
76 | * If this succeeds, it must be set again. | |
77 | * XPT_CLOSE: | |
78 | * - Can set at any time. It is never cleared. | |
79 | * XPT_DEAD: | |
80 | * - Can only be set while XPT_BUSY is held which ensures | |
81 | * that no other thread will be using the transport or will | |
82 | * try to set XPT_DEAD. | |
83 | */ | |
84 | ||
1d8206b9 TT |
85 | int svc_reg_xprt_class(struct svc_xprt_class *xcl) |
86 | { | |
87 | struct svc_xprt_class *cl; | |
88 | int res = -EEXIST; | |
89 | ||
90 | dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name); | |
91 | ||
92 | INIT_LIST_HEAD(&xcl->xcl_list); | |
93 | spin_lock(&svc_xprt_class_lock); | |
94 | /* Make sure there isn't already a class with the same name */ | |
95 | list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) { | |
96 | if (strcmp(xcl->xcl_name, cl->xcl_name) == 0) | |
97 | goto out; | |
98 | } | |
99 | list_add_tail(&xcl->xcl_list, &svc_xprt_class_list); | |
100 | res = 0; | |
101 | out: | |
102 | spin_unlock(&svc_xprt_class_lock); | |
103 | return res; | |
104 | } | |
105 | EXPORT_SYMBOL_GPL(svc_reg_xprt_class); | |
106 | ||
107 | void svc_unreg_xprt_class(struct svc_xprt_class *xcl) | |
108 | { | |
109 | dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name); | |
110 | spin_lock(&svc_xprt_class_lock); | |
111 | list_del_init(&xcl->xcl_list); | |
112 | spin_unlock(&svc_xprt_class_lock); | |
113 | } | |
114 | EXPORT_SYMBOL_GPL(svc_unreg_xprt_class); | |
115 | ||
dc9a16e4 TT |
116 | /* |
117 | * Format the transport list for printing | |
118 | */ | |
119 | int svc_print_xprts(char *buf, int maxlen) | |
120 | { | |
121 | struct list_head *le; | |
122 | char tmpstr[80]; | |
123 | int len = 0; | |
124 | buf[0] = '\0'; | |
125 | ||
126 | spin_lock(&svc_xprt_class_lock); | |
127 | list_for_each(le, &svc_xprt_class_list) { | |
128 | int slen; | |
129 | struct svc_xprt_class *xcl = | |
130 | list_entry(le, struct svc_xprt_class, xcl_list); | |
131 | ||
132 | sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload); | |
133 | slen = strlen(tmpstr); | |
134 | if (len + slen > maxlen) | |
135 | break; | |
136 | len += slen; | |
137 | strcat(buf, tmpstr); | |
138 | } | |
139 | spin_unlock(&svc_xprt_class_lock); | |
140 | ||
141 | return len; | |
142 | } | |
143 | ||
e1b3157f TT |
144 | static void svc_xprt_free(struct kref *kref) |
145 | { | |
146 | struct svc_xprt *xprt = | |
147 | container_of(kref, struct svc_xprt, xpt_ref); | |
148 | struct module *owner = xprt->xpt_class->xcl_owner; | |
def13d74 TT |
149 | if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags) |
150 | && xprt->xpt_auth_cache != NULL) | |
151 | svcauth_unix_info_release(xprt->xpt_auth_cache); | |
e1b3157f TT |
152 | xprt->xpt_ops->xpo_free(xprt); |
153 | module_put(owner); | |
154 | } | |
155 | ||
156 | void svc_xprt_put(struct svc_xprt *xprt) | |
157 | { | |
158 | kref_put(&xprt->xpt_ref, svc_xprt_free); | |
159 | } | |
160 | EXPORT_SYMBOL_GPL(svc_xprt_put); | |
161 | ||
1d8206b9 TT |
162 | /* |
163 | * Called by transport drivers to initialize the transport independent | |
164 | * portion of the transport instance. | |
165 | */ | |
bb5cf160 TT |
166 | void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt, |
167 | struct svc_serv *serv) | |
1d8206b9 TT |
168 | { |
169 | memset(xprt, 0, sizeof(*xprt)); | |
170 | xprt->xpt_class = xcl; | |
171 | xprt->xpt_ops = xcl->xcl_ops; | |
e1b3157f | 172 | kref_init(&xprt->xpt_ref); |
bb5cf160 | 173 | xprt->xpt_server = serv; |
7a182083 TT |
174 | INIT_LIST_HEAD(&xprt->xpt_list); |
175 | INIT_LIST_HEAD(&xprt->xpt_ready); | |
8c7b0172 | 176 | INIT_LIST_HEAD(&xprt->xpt_deferred); |
a50fea26 | 177 | mutex_init(&xprt->xpt_mutex); |
def13d74 | 178 | spin_lock_init(&xprt->xpt_lock); |
4e5caaa5 | 179 | set_bit(XPT_BUSY, &xprt->xpt_flags); |
1d8206b9 TT |
180 | } |
181 | EXPORT_SYMBOL_GPL(svc_xprt_init); | |
b700cbb1 TT |
182 | |
183 | int svc_create_xprt(struct svc_serv *serv, char *xprt_name, unsigned short port, | |
184 | int flags) | |
185 | { | |
186 | struct svc_xprt_class *xcl; | |
b700cbb1 TT |
187 | struct sockaddr_in sin = { |
188 | .sin_family = AF_INET, | |
e6f1cebf | 189 | .sin_addr.s_addr = htonl(INADDR_ANY), |
b700cbb1 TT |
190 | .sin_port = htons(port), |
191 | }; | |
192 | dprintk("svc: creating transport %s[%d]\n", xprt_name, port); | |
193 | spin_lock(&svc_xprt_class_lock); | |
194 | list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { | |
4e5caaa5 TT |
195 | struct svc_xprt *newxprt; |
196 | ||
197 | if (strcmp(xprt_name, xcl->xcl_name)) | |
198 | continue; | |
199 | ||
200 | if (!try_module_get(xcl->xcl_owner)) | |
201 | goto err; | |
202 | ||
203 | spin_unlock(&svc_xprt_class_lock); | |
204 | newxprt = xcl->xcl_ops-> | |
205 | xpo_create(serv, (struct sockaddr *)&sin, sizeof(sin), | |
206 | flags); | |
207 | if (IS_ERR(newxprt)) { | |
208 | module_put(xcl->xcl_owner); | |
209 | return PTR_ERR(newxprt); | |
b700cbb1 | 210 | } |
4e5caaa5 TT |
211 | |
212 | clear_bit(XPT_TEMP, &newxprt->xpt_flags); | |
213 | spin_lock_bh(&serv->sv_lock); | |
214 | list_add(&newxprt->xpt_list, &serv->sv_permsocks); | |
215 | spin_unlock_bh(&serv->sv_lock); | |
216 | clear_bit(XPT_BUSY, &newxprt->xpt_flags); | |
217 | return svc_xprt_local_port(newxprt); | |
b700cbb1 | 218 | } |
4e5caaa5 | 219 | err: |
b700cbb1 TT |
220 | spin_unlock(&svc_xprt_class_lock); |
221 | dprintk("svc: transport %s not found\n", xprt_name); | |
4e5caaa5 | 222 | return -ENOENT; |
b700cbb1 TT |
223 | } |
224 | EXPORT_SYMBOL_GPL(svc_create_xprt); | |
9dbc240f TT |
225 | |
226 | /* | |
227 | * Copy the local and remote xprt addresses to the rqstp structure | |
228 | */ | |
229 | void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) | |
230 | { | |
231 | struct sockaddr *sin; | |
232 | ||
233 | memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); | |
234 | rqstp->rq_addrlen = xprt->xpt_remotelen; | |
235 | ||
236 | /* | |
237 | * Destination address in request is needed for binding the | |
238 | * source address in RPC replies/callbacks later. | |
239 | */ | |
240 | sin = (struct sockaddr *)&xprt->xpt_local; | |
241 | switch (sin->sa_family) { | |
242 | case AF_INET: | |
243 | rqstp->rq_daddr.addr = ((struct sockaddr_in *)sin)->sin_addr; | |
244 | break; | |
245 | case AF_INET6: | |
246 | rqstp->rq_daddr.addr6 = ((struct sockaddr_in6 *)sin)->sin6_addr; | |
247 | break; | |
248 | } | |
249 | } | |
250 | EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); | |
251 | ||
0f0257ea TT |
252 | /** |
253 | * svc_print_addr - Format rq_addr field for printing | |
254 | * @rqstp: svc_rqst struct containing address to print | |
255 | * @buf: target buffer for formatted address | |
256 | * @len: length of target buffer | |
257 | * | |
258 | */ | |
259 | char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) | |
260 | { | |
261 | return __svc_print_addr(svc_addr(rqstp), buf, len); | |
262 | } | |
263 | EXPORT_SYMBOL_GPL(svc_print_addr); | |
264 | ||
265 | /* | |
266 | * Queue up an idle server thread. Must have pool->sp_lock held. | |
267 | * Note: this is really a stack rather than a queue, so that we only | |
268 | * use as many different threads as we need, and the rest don't pollute | |
269 | * the cache. | |
270 | */ | |
271 | static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp) | |
272 | { | |
273 | list_add(&rqstp->rq_list, &pool->sp_threads); | |
274 | } | |
275 | ||
276 | /* | |
277 | * Dequeue an nfsd thread. Must have pool->sp_lock held. | |
278 | */ | |
279 | static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp) | |
280 | { | |
281 | list_del(&rqstp->rq_list); | |
282 | } | |
283 | ||
284 | /* | |
285 | * Queue up a transport with data pending. If there are idle nfsd | |
286 | * processes, wake 'em up. | |
287 | * | |
288 | */ | |
289 | void svc_xprt_enqueue(struct svc_xprt *xprt) | |
290 | { | |
291 | struct svc_serv *serv = xprt->xpt_server; | |
292 | struct svc_pool *pool; | |
293 | struct svc_rqst *rqstp; | |
294 | int cpu; | |
295 | ||
296 | if (!(xprt->xpt_flags & | |
297 | ((1<<XPT_CONN)|(1<<XPT_DATA)|(1<<XPT_CLOSE)|(1<<XPT_DEFERRED)))) | |
298 | return; | |
299 | if (test_bit(XPT_DEAD, &xprt->xpt_flags)) | |
300 | return; | |
301 | ||
302 | cpu = get_cpu(); | |
303 | pool = svc_pool_for_cpu(xprt->xpt_server, cpu); | |
304 | put_cpu(); | |
305 | ||
306 | spin_lock_bh(&pool->sp_lock); | |
307 | ||
308 | if (!list_empty(&pool->sp_threads) && | |
309 | !list_empty(&pool->sp_sockets)) | |
310 | printk(KERN_ERR | |
311 | "svc_xprt_enqueue: " | |
312 | "threads and transports both waiting??\n"); | |
313 | ||
314 | if (test_bit(XPT_DEAD, &xprt->xpt_flags)) { | |
315 | /* Don't enqueue dead transports */ | |
316 | dprintk("svc: transport %p is dead, not enqueued\n", xprt); | |
317 | goto out_unlock; | |
318 | } | |
319 | ||
320 | /* Mark transport as busy. It will remain in this state until | |
321 | * the provider calls svc_xprt_received. We update XPT_BUSY | |
322 | * atomically because it also guards against trying to enqueue | |
323 | * the transport twice. | |
324 | */ | |
325 | if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) { | |
326 | /* Don't enqueue transport while already enqueued */ | |
327 | dprintk("svc: transport %p busy, not enqueued\n", xprt); | |
328 | goto out_unlock; | |
329 | } | |
330 | BUG_ON(xprt->xpt_pool != NULL); | |
331 | xprt->xpt_pool = pool; | |
332 | ||
333 | /* Handle pending connection */ | |
334 | if (test_bit(XPT_CONN, &xprt->xpt_flags)) | |
335 | goto process; | |
336 | ||
337 | /* Handle close in-progress */ | |
338 | if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) | |
339 | goto process; | |
340 | ||
341 | /* Check if we have space to reply to a request */ | |
342 | if (!xprt->xpt_ops->xpo_has_wspace(xprt)) { | |
343 | /* Don't enqueue while not enough space for reply */ | |
344 | dprintk("svc: no write space, transport %p not enqueued\n", | |
345 | xprt); | |
346 | xprt->xpt_pool = NULL; | |
347 | clear_bit(XPT_BUSY, &xprt->xpt_flags); | |
348 | goto out_unlock; | |
349 | } | |
350 | ||
351 | process: | |
352 | if (!list_empty(&pool->sp_threads)) { | |
353 | rqstp = list_entry(pool->sp_threads.next, | |
354 | struct svc_rqst, | |
355 | rq_list); | |
356 | dprintk("svc: transport %p served by daemon %p\n", | |
357 | xprt, rqstp); | |
358 | svc_thread_dequeue(pool, rqstp); | |
359 | if (rqstp->rq_xprt) | |
360 | printk(KERN_ERR | |
361 | "svc_xprt_enqueue: server %p, rq_xprt=%p!\n", | |
362 | rqstp, rqstp->rq_xprt); | |
363 | rqstp->rq_xprt = xprt; | |
364 | svc_xprt_get(xprt); | |
365 | rqstp->rq_reserved = serv->sv_max_mesg; | |
366 | atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); | |
367 | BUG_ON(xprt->xpt_pool != pool); | |
368 | wake_up(&rqstp->rq_wait); | |
369 | } else { | |
370 | dprintk("svc: transport %p put into queue\n", xprt); | |
371 | list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); | |
372 | BUG_ON(xprt->xpt_pool != pool); | |
373 | } | |
374 | ||
375 | out_unlock: | |
376 | spin_unlock_bh(&pool->sp_lock); | |
377 | } | |
378 | EXPORT_SYMBOL_GPL(svc_xprt_enqueue); | |
379 | ||
380 | /* | |
381 | * Dequeue the first transport. Must be called with the pool->sp_lock held. | |
382 | */ | |
383 | static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) | |
384 | { | |
385 | struct svc_xprt *xprt; | |
386 | ||
387 | if (list_empty(&pool->sp_sockets)) | |
388 | return NULL; | |
389 | ||
390 | xprt = list_entry(pool->sp_sockets.next, | |
391 | struct svc_xprt, xpt_ready); | |
392 | list_del_init(&xprt->xpt_ready); | |
393 | ||
394 | dprintk("svc: transport %p dequeued, inuse=%d\n", | |
395 | xprt, atomic_read(&xprt->xpt_ref.refcount)); | |
396 | ||
397 | return xprt; | |
398 | } | |
399 | ||
400 | /* | |
401 | * svc_xprt_received conditionally queues the transport for processing | |
402 | * by another thread. The caller must hold the XPT_BUSY bit and must | |
403 | * not thereafter touch transport data. | |
404 | * | |
405 | * Note: XPT_DATA only gets cleared when a read-attempt finds no (or | |
406 | * insufficient) data. | |
407 | */ | |
408 | void svc_xprt_received(struct svc_xprt *xprt) | |
409 | { | |
410 | BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags)); | |
411 | xprt->xpt_pool = NULL; | |
412 | clear_bit(XPT_BUSY, &xprt->xpt_flags); | |
413 | svc_xprt_enqueue(xprt); | |
414 | } | |
415 | EXPORT_SYMBOL_GPL(svc_xprt_received); | |
416 | ||
417 | /** | |
418 | * svc_reserve - change the space reserved for the reply to a request. | |
419 | * @rqstp: The request in question | |
420 | * @space: new max space to reserve | |
421 | * | |
422 | * Each request reserves some space on the output queue of the transport | |
423 | * to make sure the reply fits. This function reduces that reserved | |
424 | * space to be the amount of space used already, plus @space. | |
425 | * | |
426 | */ | |
427 | void svc_reserve(struct svc_rqst *rqstp, int space) | |
428 | { | |
429 | space += rqstp->rq_res.head[0].iov_len; | |
430 | ||
431 | if (space < rqstp->rq_reserved) { | |
432 | struct svc_xprt *xprt = rqstp->rq_xprt; | |
433 | atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved); | |
434 | rqstp->rq_reserved = space; | |
435 | ||
436 | svc_xprt_enqueue(xprt); | |
437 | } | |
438 | } | |
d2f7e79e | 439 | EXPORT_SYMBOL(svc_reserve); |
0f0257ea TT |
440 | |
441 | static void svc_xprt_release(struct svc_rqst *rqstp) | |
442 | { | |
443 | struct svc_xprt *xprt = rqstp->rq_xprt; | |
444 | ||
445 | rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); | |
446 | ||
447 | svc_free_res_pages(rqstp); | |
448 | rqstp->rq_res.page_len = 0; | |
449 | rqstp->rq_res.page_base = 0; | |
450 | ||
451 | /* Reset response buffer and release | |
452 | * the reservation. | |
453 | * But first, check that enough space was reserved | |
454 | * for the reply, otherwise we have a bug! | |
455 | */ | |
456 | if ((rqstp->rq_res.len) > rqstp->rq_reserved) | |
457 | printk(KERN_ERR "RPC request reserved %d but used %d\n", | |
458 | rqstp->rq_reserved, | |
459 | rqstp->rq_res.len); | |
460 | ||
461 | rqstp->rq_res.head[0].iov_len = 0; | |
462 | svc_reserve(rqstp, 0); | |
463 | rqstp->rq_xprt = NULL; | |
464 | ||
465 | svc_xprt_put(xprt); | |
466 | } | |
467 | ||
468 | /* | |
469 | * External function to wake up a server waiting for data | |
470 | * This really only makes sense for services like lockd | |
471 | * which have exactly one thread anyway. | |
472 | */ | |
473 | void svc_wake_up(struct svc_serv *serv) | |
474 | { | |
475 | struct svc_rqst *rqstp; | |
476 | unsigned int i; | |
477 | struct svc_pool *pool; | |
478 | ||
479 | for (i = 0; i < serv->sv_nrpools; i++) { | |
480 | pool = &serv->sv_pools[i]; | |
481 | ||
482 | spin_lock_bh(&pool->sp_lock); | |
483 | if (!list_empty(&pool->sp_threads)) { | |
484 | rqstp = list_entry(pool->sp_threads.next, | |
485 | struct svc_rqst, | |
486 | rq_list); | |
487 | dprintk("svc: daemon %p woken up.\n", rqstp); | |
488 | /* | |
489 | svc_thread_dequeue(pool, rqstp); | |
490 | rqstp->rq_xprt = NULL; | |
491 | */ | |
492 | wake_up(&rqstp->rq_wait); | |
493 | } | |
494 | spin_unlock_bh(&pool->sp_lock); | |
495 | } | |
496 | } | |
d2f7e79e | 497 | EXPORT_SYMBOL(svc_wake_up); |
0f0257ea TT |
498 | |
499 | int svc_port_is_privileged(struct sockaddr *sin) | |
500 | { | |
501 | switch (sin->sa_family) { | |
502 | case AF_INET: | |
503 | return ntohs(((struct sockaddr_in *)sin)->sin_port) | |
504 | < PROT_SOCK; | |
505 | case AF_INET6: | |
506 | return ntohs(((struct sockaddr_in6 *)sin)->sin6_port) | |
507 | < PROT_SOCK; | |
508 | default: | |
509 | return 0; | |
510 | } | |
511 | } | |
512 | ||
513 | /* | |
514 | * Make sure that we don't have too many active connections. If we | |
515 | * have, something must be dropped. | |
516 | * | |
517 | * There's no point in trying to do random drop here for DoS | |
518 | * prevention. The NFS clients does 1 reconnect in 15 seconds. An | |
519 | * attacker can easily beat that. | |
520 | * | |
521 | * The only somewhat efficient mechanism would be if drop old | |
522 | * connections from the same IP first. But right now we don't even | |
523 | * record the client IP in svc_sock. | |
524 | */ | |
525 | static void svc_check_conn_limits(struct svc_serv *serv) | |
526 | { | |
527 | if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*20) { | |
528 | struct svc_xprt *xprt = NULL; | |
529 | spin_lock_bh(&serv->sv_lock); | |
530 | if (!list_empty(&serv->sv_tempsocks)) { | |
531 | if (net_ratelimit()) { | |
532 | /* Try to help the admin */ | |
533 | printk(KERN_NOTICE "%s: too many open " | |
534 | "connections, consider increasing the " | |
535 | "number of nfsd threads\n", | |
536 | serv->sv_name); | |
537 | } | |
538 | /* | |
539 | * Always select the oldest connection. It's not fair, | |
540 | * but so is life | |
541 | */ | |
542 | xprt = list_entry(serv->sv_tempsocks.prev, | |
543 | struct svc_xprt, | |
544 | xpt_list); | |
545 | set_bit(XPT_CLOSE, &xprt->xpt_flags); | |
546 | svc_xprt_get(xprt); | |
547 | } | |
548 | spin_unlock_bh(&serv->sv_lock); | |
549 | ||
550 | if (xprt) { | |
551 | svc_xprt_enqueue(xprt); | |
552 | svc_xprt_put(xprt); | |
553 | } | |
554 | } | |
555 | } | |
556 | ||
557 | /* | |
558 | * Receive the next request on any transport. This code is carefully | |
559 | * organised not to touch any cachelines in the shared svc_serv | |
560 | * structure, only cachelines in the local svc_pool. | |
561 | */ | |
562 | int svc_recv(struct svc_rqst *rqstp, long timeout) | |
563 | { | |
564 | struct svc_xprt *xprt = NULL; | |
565 | struct svc_serv *serv = rqstp->rq_server; | |
566 | struct svc_pool *pool = rqstp->rq_pool; | |
567 | int len, i; | |
568 | int pages; | |
569 | struct xdr_buf *arg; | |
570 | DECLARE_WAITQUEUE(wait, current); | |
571 | ||
572 | dprintk("svc: server %p waiting for data (to = %ld)\n", | |
573 | rqstp, timeout); | |
574 | ||
575 | if (rqstp->rq_xprt) | |
576 | printk(KERN_ERR | |
577 | "svc_recv: service %p, transport not NULL!\n", | |
578 | rqstp); | |
579 | if (waitqueue_active(&rqstp->rq_wait)) | |
580 | printk(KERN_ERR | |
581 | "svc_recv: service %p, wait queue active!\n", | |
582 | rqstp); | |
583 | ||
584 | /* now allocate needed pages. If we get a failure, sleep briefly */ | |
585 | pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE; | |
586 | for (i = 0; i < pages ; i++) | |
587 | while (rqstp->rq_pages[i] == NULL) { | |
588 | struct page *p = alloc_page(GFP_KERNEL); | |
589 | if (!p) { | |
590 | int j = msecs_to_jiffies(500); | |
7086721f JL |
591 | if (kthread_should_stop()) |
592 | return -EINTR; | |
0f0257ea TT |
593 | schedule_timeout_uninterruptible(j); |
594 | } | |
595 | rqstp->rq_pages[i] = p; | |
596 | } | |
597 | rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */ | |
598 | BUG_ON(pages >= RPCSVC_MAXPAGES); | |
599 | ||
600 | /* Make arg->head point to first page and arg->pages point to rest */ | |
601 | arg = &rqstp->rq_arg; | |
602 | arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); | |
603 | arg->head[0].iov_len = PAGE_SIZE; | |
604 | arg->pages = rqstp->rq_pages + 1; | |
605 | arg->page_base = 0; | |
606 | /* save at least one page for response */ | |
607 | arg->page_len = (pages-2)*PAGE_SIZE; | |
608 | arg->len = (pages-1)*PAGE_SIZE; | |
609 | arg->tail[0].iov_len = 0; | |
610 | ||
611 | try_to_freeze(); | |
612 | cond_resched(); | |
7086721f | 613 | if (signalled() || kthread_should_stop()) |
0f0257ea TT |
614 | return -EINTR; |
615 | ||
616 | spin_lock_bh(&pool->sp_lock); | |
617 | xprt = svc_xprt_dequeue(pool); | |
618 | if (xprt) { | |
619 | rqstp->rq_xprt = xprt; | |
620 | svc_xprt_get(xprt); | |
621 | rqstp->rq_reserved = serv->sv_max_mesg; | |
622 | atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); | |
623 | } else { | |
624 | /* No data pending. Go to sleep */ | |
625 | svc_thread_enqueue(pool, rqstp); | |
626 | ||
627 | /* | |
628 | * We have to be able to interrupt this wait | |
629 | * to bring down the daemons ... | |
630 | */ | |
631 | set_current_state(TASK_INTERRUPTIBLE); | |
7086721f JL |
632 | |
633 | /* | |
634 | * checking kthread_should_stop() here allows us to avoid | |
635 | * locking and signalling when stopping kthreads that call | |
636 | * svc_recv. If the thread has already been woken up, then | |
637 | * we can exit here without sleeping. If not, then it | |
638 | * it'll be woken up quickly during the schedule_timeout | |
639 | */ | |
640 | if (kthread_should_stop()) { | |
641 | set_current_state(TASK_RUNNING); | |
642 | spin_unlock_bh(&pool->sp_lock); | |
643 | return -EINTR; | |
644 | } | |
645 | ||
0f0257ea TT |
646 | add_wait_queue(&rqstp->rq_wait, &wait); |
647 | spin_unlock_bh(&pool->sp_lock); | |
648 | ||
649 | schedule_timeout(timeout); | |
650 | ||
651 | try_to_freeze(); | |
652 | ||
653 | spin_lock_bh(&pool->sp_lock); | |
654 | remove_wait_queue(&rqstp->rq_wait, &wait); | |
655 | ||
656 | xprt = rqstp->rq_xprt; | |
657 | if (!xprt) { | |
658 | svc_thread_dequeue(pool, rqstp); | |
659 | spin_unlock_bh(&pool->sp_lock); | |
660 | dprintk("svc: server %p, no data yet\n", rqstp); | |
7086721f JL |
661 | if (signalled() || kthread_should_stop()) |
662 | return -EINTR; | |
663 | else | |
664 | return -EAGAIN; | |
0f0257ea TT |
665 | } |
666 | } | |
667 | spin_unlock_bh(&pool->sp_lock); | |
668 | ||
669 | len = 0; | |
670 | if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { | |
671 | dprintk("svc_recv: found XPT_CLOSE\n"); | |
672 | svc_delete_xprt(xprt); | |
673 | } else if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { | |
674 | struct svc_xprt *newxpt; | |
675 | newxpt = xprt->xpt_ops->xpo_accept(xprt); | |
676 | if (newxpt) { | |
677 | /* | |
678 | * We know this module_get will succeed because the | |
679 | * listener holds a reference too | |
680 | */ | |
681 | __module_get(newxpt->xpt_class->xcl_owner); | |
682 | svc_check_conn_limits(xprt->xpt_server); | |
683 | spin_lock_bh(&serv->sv_lock); | |
684 | set_bit(XPT_TEMP, &newxpt->xpt_flags); | |
685 | list_add(&newxpt->xpt_list, &serv->sv_tempsocks); | |
686 | serv->sv_tmpcnt++; | |
687 | if (serv->sv_temptimer.function == NULL) { | |
688 | /* setup timer to age temp transports */ | |
689 | setup_timer(&serv->sv_temptimer, | |
690 | svc_age_temp_xprts, | |
691 | (unsigned long)serv); | |
692 | mod_timer(&serv->sv_temptimer, | |
693 | jiffies + svc_conn_age_period * HZ); | |
694 | } | |
695 | spin_unlock_bh(&serv->sv_lock); | |
696 | svc_xprt_received(newxpt); | |
697 | } | |
698 | svc_xprt_received(xprt); | |
699 | } else { | |
700 | dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", | |
701 | rqstp, pool->sp_id, xprt, | |
702 | atomic_read(&xprt->xpt_ref.refcount)); | |
703 | rqstp->rq_deferred = svc_deferred_dequeue(xprt); | |
704 | if (rqstp->rq_deferred) { | |
705 | svc_xprt_received(xprt); | |
706 | len = svc_deferred_recv(rqstp); | |
707 | } else | |
708 | len = xprt->xpt_ops->xpo_recvfrom(rqstp); | |
709 | dprintk("svc: got len=%d\n", len); | |
710 | } | |
711 | ||
712 | /* No data, incomplete (TCP) read, or accept() */ | |
713 | if (len == 0 || len == -EAGAIN) { | |
714 | rqstp->rq_res.len = 0; | |
715 | svc_xprt_release(rqstp); | |
716 | return -EAGAIN; | |
717 | } | |
718 | clear_bit(XPT_OLD, &xprt->xpt_flags); | |
719 | ||
720 | rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp)); | |
721 | rqstp->rq_chandle.defer = svc_defer; | |
722 | ||
723 | if (serv->sv_stats) | |
724 | serv->sv_stats->netcnt++; | |
725 | return len; | |
726 | } | |
d2f7e79e | 727 | EXPORT_SYMBOL(svc_recv); |
0f0257ea TT |
728 | |
729 | /* | |
730 | * Drop request | |
731 | */ | |
732 | void svc_drop(struct svc_rqst *rqstp) | |
733 | { | |
734 | dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt); | |
735 | svc_xprt_release(rqstp); | |
736 | } | |
d2f7e79e | 737 | EXPORT_SYMBOL(svc_drop); |
0f0257ea TT |
738 | |
739 | /* | |
740 | * Return reply to client. | |
741 | */ | |
742 | int svc_send(struct svc_rqst *rqstp) | |
743 | { | |
744 | struct svc_xprt *xprt; | |
745 | int len; | |
746 | struct xdr_buf *xb; | |
747 | ||
748 | xprt = rqstp->rq_xprt; | |
749 | if (!xprt) | |
750 | return -EFAULT; | |
751 | ||
752 | /* release the receive skb before sending the reply */ | |
753 | rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); | |
754 | ||
755 | /* calculate over-all length */ | |
756 | xb = &rqstp->rq_res; | |
757 | xb->len = xb->head[0].iov_len + | |
758 | xb->page_len + | |
759 | xb->tail[0].iov_len; | |
760 | ||
761 | /* Grab mutex to serialize outgoing data. */ | |
762 | mutex_lock(&xprt->xpt_mutex); | |
763 | if (test_bit(XPT_DEAD, &xprt->xpt_flags)) | |
764 | len = -ENOTCONN; | |
765 | else | |
766 | len = xprt->xpt_ops->xpo_sendto(rqstp); | |
767 | mutex_unlock(&xprt->xpt_mutex); | |
768 | svc_xprt_release(rqstp); | |
769 | ||
770 | if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN) | |
771 | return 0; | |
772 | return len; | |
773 | } | |
774 | ||
775 | /* | |
776 | * Timer function to close old temporary transports, using | |
777 | * a mark-and-sweep algorithm. | |
778 | */ | |
779 | static void svc_age_temp_xprts(unsigned long closure) | |
780 | { | |
781 | struct svc_serv *serv = (struct svc_serv *)closure; | |
782 | struct svc_xprt *xprt; | |
783 | struct list_head *le, *next; | |
784 | LIST_HEAD(to_be_aged); | |
785 | ||
786 | dprintk("svc_age_temp_xprts\n"); | |
787 | ||
788 | if (!spin_trylock_bh(&serv->sv_lock)) { | |
789 | /* busy, try again 1 sec later */ | |
790 | dprintk("svc_age_temp_xprts: busy\n"); | |
791 | mod_timer(&serv->sv_temptimer, jiffies + HZ); | |
792 | return; | |
793 | } | |
794 | ||
795 | list_for_each_safe(le, next, &serv->sv_tempsocks) { | |
796 | xprt = list_entry(le, struct svc_xprt, xpt_list); | |
797 | ||
798 | /* First time through, just mark it OLD. Second time | |
799 | * through, close it. */ | |
800 | if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) | |
801 | continue; | |
802 | if (atomic_read(&xprt->xpt_ref.refcount) > 1 | |
803 | || test_bit(XPT_BUSY, &xprt->xpt_flags)) | |
804 | continue; | |
805 | svc_xprt_get(xprt); | |
806 | list_move(le, &to_be_aged); | |
807 | set_bit(XPT_CLOSE, &xprt->xpt_flags); | |
808 | set_bit(XPT_DETACHED, &xprt->xpt_flags); | |
809 | } | |
810 | spin_unlock_bh(&serv->sv_lock); | |
811 | ||
812 | while (!list_empty(&to_be_aged)) { | |
813 | le = to_be_aged.next; | |
814 | /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */ | |
815 | list_del_init(le); | |
816 | xprt = list_entry(le, struct svc_xprt, xpt_list); | |
817 | ||
818 | dprintk("queuing xprt %p for closing\n", xprt); | |
819 | ||
820 | /* a thread will dequeue and close it soon */ | |
821 | svc_xprt_enqueue(xprt); | |
822 | svc_xprt_put(xprt); | |
823 | } | |
824 | ||
825 | mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); | |
826 | } | |
827 | ||
828 | /* | |
829 | * Remove a dead transport | |
830 | */ | |
831 | void svc_delete_xprt(struct svc_xprt *xprt) | |
832 | { | |
833 | struct svc_serv *serv = xprt->xpt_server; | |
834 | ||
835 | dprintk("svc: svc_delete_xprt(%p)\n", xprt); | |
836 | xprt->xpt_ops->xpo_detach(xprt); | |
837 | ||
838 | spin_lock_bh(&serv->sv_lock); | |
839 | if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags)) | |
840 | list_del_init(&xprt->xpt_list); | |
841 | /* | |
842 | * We used to delete the transport from whichever list | |
843 | * it's sk_xprt.xpt_ready node was on, but we don't actually | |
844 | * need to. This is because the only time we're called | |
845 | * while still attached to a queue, the queue itself | |
846 | * is about to be destroyed (in svc_destroy). | |
847 | */ | |
848 | if (!test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) { | |
849 | BUG_ON(atomic_read(&xprt->xpt_ref.refcount) < 2); | |
850 | if (test_bit(XPT_TEMP, &xprt->xpt_flags)) | |
851 | serv->sv_tmpcnt--; | |
852 | svc_xprt_put(xprt); | |
853 | } | |
854 | spin_unlock_bh(&serv->sv_lock); | |
855 | } | |
856 | ||
857 | void svc_close_xprt(struct svc_xprt *xprt) | |
858 | { | |
859 | set_bit(XPT_CLOSE, &xprt->xpt_flags); | |
860 | if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) | |
861 | /* someone else will have to effect the close */ | |
862 | return; | |
863 | ||
864 | svc_xprt_get(xprt); | |
865 | svc_delete_xprt(xprt); | |
866 | clear_bit(XPT_BUSY, &xprt->xpt_flags); | |
867 | svc_xprt_put(xprt); | |
868 | } | |
a217813f | 869 | EXPORT_SYMBOL_GPL(svc_close_xprt); |
0f0257ea TT |
870 | |
871 | void svc_close_all(struct list_head *xprt_list) | |
872 | { | |
873 | struct svc_xprt *xprt; | |
874 | struct svc_xprt *tmp; | |
875 | ||
876 | list_for_each_entry_safe(xprt, tmp, xprt_list, xpt_list) { | |
877 | set_bit(XPT_CLOSE, &xprt->xpt_flags); | |
878 | if (test_bit(XPT_BUSY, &xprt->xpt_flags)) { | |
879 | /* Waiting to be processed, but no threads left, | |
880 | * So just remove it from the waiting list | |
881 | */ | |
882 | list_del_init(&xprt->xpt_ready); | |
883 | clear_bit(XPT_BUSY, &xprt->xpt_flags); | |
884 | } | |
885 | svc_close_xprt(xprt); | |
886 | } | |
887 | } | |
888 | ||
889 | /* | |
890 | * Handle defer and revisit of requests | |
891 | */ | |
892 | ||
893 | static void svc_revisit(struct cache_deferred_req *dreq, int too_many) | |
894 | { | |
895 | struct svc_deferred_req *dr = | |
896 | container_of(dreq, struct svc_deferred_req, handle); | |
897 | struct svc_xprt *xprt = dr->xprt; | |
898 | ||
899 | if (too_many) { | |
900 | svc_xprt_put(xprt); | |
901 | kfree(dr); | |
902 | return; | |
903 | } | |
904 | dprintk("revisit queued\n"); | |
905 | dr->xprt = NULL; | |
906 | spin_lock(&xprt->xpt_lock); | |
907 | list_add(&dr->handle.recent, &xprt->xpt_deferred); | |
908 | spin_unlock(&xprt->xpt_lock); | |
909 | set_bit(XPT_DEFERRED, &xprt->xpt_flags); | |
910 | svc_xprt_enqueue(xprt); | |
911 | svc_xprt_put(xprt); | |
912 | } | |
913 | ||
260c1d12 TT |
914 | /* |
915 | * Save the request off for later processing. The request buffer looks | |
916 | * like this: | |
917 | * | |
918 | * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> | |
919 | * | |
920 | * This code can only handle requests that consist of an xprt-header | |
921 | * and rpc-header. | |
922 | */ | |
0f0257ea TT |
923 | static struct cache_deferred_req *svc_defer(struct cache_req *req) |
924 | { | |
925 | struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); | |
0f0257ea TT |
926 | struct svc_deferred_req *dr; |
927 | ||
928 | if (rqstp->rq_arg.page_len) | |
929 | return NULL; /* if more than a page, give up FIXME */ | |
930 | if (rqstp->rq_deferred) { | |
931 | dr = rqstp->rq_deferred; | |
932 | rqstp->rq_deferred = NULL; | |
933 | } else { | |
260c1d12 TT |
934 | size_t skip; |
935 | size_t size; | |
0f0257ea | 936 | /* FIXME maybe discard if size too large */ |
260c1d12 | 937 | size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; |
0f0257ea TT |
938 | dr = kmalloc(size, GFP_KERNEL); |
939 | if (dr == NULL) | |
940 | return NULL; | |
941 | ||
942 | dr->handle.owner = rqstp->rq_server; | |
943 | dr->prot = rqstp->rq_prot; | |
944 | memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); | |
945 | dr->addrlen = rqstp->rq_addrlen; | |
946 | dr->daddr = rqstp->rq_daddr; | |
947 | dr->argslen = rqstp->rq_arg.len >> 2; | |
260c1d12 TT |
948 | dr->xprt_hlen = rqstp->rq_xprt_hlen; |
949 | ||
950 | /* back up head to the start of the buffer and copy */ | |
951 | skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; | |
952 | memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, | |
953 | dr->argslen << 2); | |
0f0257ea TT |
954 | } |
955 | svc_xprt_get(rqstp->rq_xprt); | |
956 | dr->xprt = rqstp->rq_xprt; | |
957 | ||
958 | dr->handle.revisit = svc_revisit; | |
959 | return &dr->handle; | |
960 | } | |
961 | ||
962 | /* | |
963 | * recv data from a deferred request into an active one | |
964 | */ | |
965 | static int svc_deferred_recv(struct svc_rqst *rqstp) | |
966 | { | |
967 | struct svc_deferred_req *dr = rqstp->rq_deferred; | |
968 | ||
260c1d12 TT |
969 | /* setup iov_base past transport header */ |
970 | rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2); | |
971 | /* The iov_len does not include the transport header bytes */ | |
972 | rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen; | |
0f0257ea | 973 | rqstp->rq_arg.page_len = 0; |
260c1d12 TT |
974 | /* The rq_arg.len includes the transport header bytes */ |
975 | rqstp->rq_arg.len = dr->argslen<<2; | |
0f0257ea TT |
976 | rqstp->rq_prot = dr->prot; |
977 | memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); | |
978 | rqstp->rq_addrlen = dr->addrlen; | |
260c1d12 TT |
979 | /* Save off transport header len in case we get deferred again */ |
980 | rqstp->rq_xprt_hlen = dr->xprt_hlen; | |
0f0257ea TT |
981 | rqstp->rq_daddr = dr->daddr; |
982 | rqstp->rq_respages = rqstp->rq_pages; | |
260c1d12 | 983 | return (dr->argslen<<2) - dr->xprt_hlen; |
0f0257ea TT |
984 | } |
985 | ||
986 | ||
987 | static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) | |
988 | { | |
989 | struct svc_deferred_req *dr = NULL; | |
990 | ||
991 | if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) | |
992 | return NULL; | |
993 | spin_lock(&xprt->xpt_lock); | |
994 | clear_bit(XPT_DEFERRED, &xprt->xpt_flags); | |
995 | if (!list_empty(&xprt->xpt_deferred)) { | |
996 | dr = list_entry(xprt->xpt_deferred.next, | |
997 | struct svc_deferred_req, | |
998 | handle.recent); | |
999 | list_del_init(&dr->handle.recent); | |
1000 | set_bit(XPT_DEFERRED, &xprt->xpt_flags); | |
1001 | } | |
1002 | spin_unlock(&xprt->xpt_lock); | |
1003 | return dr; | |
1004 | } | |
7fcb98d5 TT |
1005 | |
1006 | /* | |
1007 | * Return the transport instance pointer for the endpoint accepting | |
1008 | * connections/peer traffic from the specified transport class, | |
1009 | * address family and port. | |
1010 | * | |
1011 | * Specifying 0 for the address family or port is effectively a | |
1012 | * wild-card, and will result in matching the first transport in the | |
1013 | * service's list that has a matching class name. | |
1014 | */ | |
1015 | struct svc_xprt *svc_find_xprt(struct svc_serv *serv, char *xcl_name, | |
1016 | int af, int port) | |
1017 | { | |
1018 | struct svc_xprt *xprt; | |
1019 | struct svc_xprt *found = NULL; | |
1020 | ||
1021 | /* Sanity check the args */ | |
1022 | if (!serv || !xcl_name) | |
1023 | return found; | |
1024 | ||
1025 | spin_lock_bh(&serv->sv_lock); | |
1026 | list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { | |
1027 | if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) | |
1028 | continue; | |
1029 | if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) | |
1030 | continue; | |
1031 | if (port && port != svc_xprt_local_port(xprt)) | |
1032 | continue; | |
1033 | found = xprt; | |
a217813f | 1034 | svc_xprt_get(xprt); |
7fcb98d5 TT |
1035 | break; |
1036 | } | |
1037 | spin_unlock_bh(&serv->sv_lock); | |
1038 | return found; | |
1039 | } | |
1040 | EXPORT_SYMBOL_GPL(svc_find_xprt); | |
9571af18 TT |
1041 | |
1042 | /* | |
1043 | * Format a buffer with a list of the active transports. A zero for | |
1044 | * the buflen parameter disables target buffer overflow checking. | |
1045 | */ | |
1046 | int svc_xprt_names(struct svc_serv *serv, char *buf, int buflen) | |
1047 | { | |
1048 | struct svc_xprt *xprt; | |
1049 | char xprt_str[64]; | |
1050 | int totlen = 0; | |
1051 | int len; | |
1052 | ||
1053 | /* Sanity check args */ | |
1054 | if (!serv) | |
1055 | return 0; | |
1056 | ||
1057 | spin_lock_bh(&serv->sv_lock); | |
1058 | list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { | |
1059 | len = snprintf(xprt_str, sizeof(xprt_str), | |
1060 | "%s %d\n", xprt->xpt_class->xcl_name, | |
1061 | svc_xprt_local_port(xprt)); | |
1062 | /* If the string was truncated, replace with error string */ | |
1063 | if (len >= sizeof(xprt_str)) | |
1064 | strcpy(xprt_str, "name-too-long\n"); | |
1065 | /* Don't overflow buffer */ | |
1066 | len = strlen(xprt_str); | |
1067 | if (buflen && (len + totlen >= buflen)) | |
1068 | break; | |
1069 | strcpy(buf+totlen, xprt_str); | |
1070 | totlen += len; | |
1071 | } | |
1072 | spin_unlock_bh(&serv->sv_lock); | |
1073 | return totlen; | |
1074 | } | |
1075 | EXPORT_SYMBOL_GPL(svc_xprt_names); |