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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> | |
1d8206b9 | 9 | #include <linux/freezer.h> |
7086721f | 10 | #include <linux/kthread.h> |
1d8206b9 | 11 | #include <net/sock.h> |
1d8206b9 TT |
12 | #include <linux/sunrpc/stats.h> |
13 | #include <linux/sunrpc/svc_xprt.h> | |
14 | ||
15 | #define RPCDBG_FACILITY RPCDBG_SVCXPRT | |
16 | ||
0f0257ea TT |
17 | static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt); |
18 | static int svc_deferred_recv(struct svc_rqst *rqstp); | |
19 | static struct cache_deferred_req *svc_defer(struct cache_req *req); | |
20 | static void svc_age_temp_xprts(unsigned long closure); | |
21 | ||
22 | /* apparently the "standard" is that clients close | |
23 | * idle connections after 5 minutes, servers after | |
24 | * 6 minutes | |
25 | * http://www.connectathon.org/talks96/nfstcp.pdf | |
26 | */ | |
27 | static int svc_conn_age_period = 6*60; | |
28 | ||
1d8206b9 TT |
29 | /* List of registered transport classes */ |
30 | static DEFINE_SPINLOCK(svc_xprt_class_lock); | |
31 | static LIST_HEAD(svc_xprt_class_list); | |
32 | ||
0f0257ea TT |
33 | /* SMP locking strategy: |
34 | * | |
35 | * svc_pool->sp_lock protects most of the fields of that pool. | |
36 | * svc_serv->sv_lock protects sv_tempsocks, sv_permsocks, sv_tmpcnt. | |
37 | * when both need to be taken (rare), svc_serv->sv_lock is first. | |
38 | * BKL protects svc_serv->sv_nrthread. | |
39 | * svc_sock->sk_lock protects the svc_sock->sk_deferred list | |
40 | * and the ->sk_info_authunix cache. | |
41 | * | |
42 | * The XPT_BUSY bit in xprt->xpt_flags prevents a transport being | |
43 | * enqueued multiply. During normal transport processing this bit | |
44 | * is set by svc_xprt_enqueue and cleared by svc_xprt_received. | |
45 | * Providers should not manipulate this bit directly. | |
46 | * | |
47 | * Some flags can be set to certain values at any time | |
48 | * providing that certain rules are followed: | |
49 | * | |
50 | * XPT_CONN, XPT_DATA: | |
51 | * - Can be set or cleared at any time. | |
52 | * - After a set, svc_xprt_enqueue must be called to enqueue | |
53 | * the transport for processing. | |
54 | * - After a clear, the transport must be read/accepted. | |
55 | * If this succeeds, it must be set again. | |
56 | * XPT_CLOSE: | |
57 | * - Can set at any time. It is never cleared. | |
58 | * XPT_DEAD: | |
59 | * - Can only be set while XPT_BUSY is held which ensures | |
60 | * that no other thread will be using the transport or will | |
61 | * try to set XPT_DEAD. | |
62 | */ | |
63 | ||
1d8206b9 TT |
64 | int svc_reg_xprt_class(struct svc_xprt_class *xcl) |
65 | { | |
66 | struct svc_xprt_class *cl; | |
67 | int res = -EEXIST; | |
68 | ||
69 | dprintk("svc: Adding svc transport class '%s'\n", xcl->xcl_name); | |
70 | ||
71 | INIT_LIST_HEAD(&xcl->xcl_list); | |
72 | spin_lock(&svc_xprt_class_lock); | |
73 | /* Make sure there isn't already a class with the same name */ | |
74 | list_for_each_entry(cl, &svc_xprt_class_list, xcl_list) { | |
75 | if (strcmp(xcl->xcl_name, cl->xcl_name) == 0) | |
76 | goto out; | |
77 | } | |
78 | list_add_tail(&xcl->xcl_list, &svc_xprt_class_list); | |
79 | res = 0; | |
80 | out: | |
81 | spin_unlock(&svc_xprt_class_lock); | |
82 | return res; | |
83 | } | |
84 | EXPORT_SYMBOL_GPL(svc_reg_xprt_class); | |
85 | ||
86 | void svc_unreg_xprt_class(struct svc_xprt_class *xcl) | |
87 | { | |
88 | dprintk("svc: Removing svc transport class '%s'\n", xcl->xcl_name); | |
89 | spin_lock(&svc_xprt_class_lock); | |
90 | list_del_init(&xcl->xcl_list); | |
91 | spin_unlock(&svc_xprt_class_lock); | |
92 | } | |
93 | EXPORT_SYMBOL_GPL(svc_unreg_xprt_class); | |
94 | ||
dc9a16e4 TT |
95 | /* |
96 | * Format the transport list for printing | |
97 | */ | |
98 | int svc_print_xprts(char *buf, int maxlen) | |
99 | { | |
100 | struct list_head *le; | |
101 | char tmpstr[80]; | |
102 | int len = 0; | |
103 | buf[0] = '\0'; | |
104 | ||
105 | spin_lock(&svc_xprt_class_lock); | |
106 | list_for_each(le, &svc_xprt_class_list) { | |
107 | int slen; | |
108 | struct svc_xprt_class *xcl = | |
109 | list_entry(le, struct svc_xprt_class, xcl_list); | |
110 | ||
111 | sprintf(tmpstr, "%s %d\n", xcl->xcl_name, xcl->xcl_max_payload); | |
112 | slen = strlen(tmpstr); | |
113 | if (len + slen > maxlen) | |
114 | break; | |
115 | len += slen; | |
116 | strcat(buf, tmpstr); | |
117 | } | |
118 | spin_unlock(&svc_xprt_class_lock); | |
119 | ||
120 | return len; | |
121 | } | |
122 | ||
e1b3157f TT |
123 | static void svc_xprt_free(struct kref *kref) |
124 | { | |
125 | struct svc_xprt *xprt = | |
126 | container_of(kref, struct svc_xprt, xpt_ref); | |
127 | struct module *owner = xprt->xpt_class->xcl_owner; | |
def13d74 TT |
128 | if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags) |
129 | && xprt->xpt_auth_cache != NULL) | |
130 | svcauth_unix_info_release(xprt->xpt_auth_cache); | |
e1b3157f TT |
131 | xprt->xpt_ops->xpo_free(xprt); |
132 | module_put(owner); | |
133 | } | |
134 | ||
135 | void svc_xprt_put(struct svc_xprt *xprt) | |
136 | { | |
137 | kref_put(&xprt->xpt_ref, svc_xprt_free); | |
138 | } | |
139 | EXPORT_SYMBOL_GPL(svc_xprt_put); | |
140 | ||
1d8206b9 TT |
141 | /* |
142 | * Called by transport drivers to initialize the transport independent | |
143 | * portion of the transport instance. | |
144 | */ | |
bb5cf160 TT |
145 | void svc_xprt_init(struct svc_xprt_class *xcl, struct svc_xprt *xprt, |
146 | struct svc_serv *serv) | |
1d8206b9 TT |
147 | { |
148 | memset(xprt, 0, sizeof(*xprt)); | |
149 | xprt->xpt_class = xcl; | |
150 | xprt->xpt_ops = xcl->xcl_ops; | |
e1b3157f | 151 | kref_init(&xprt->xpt_ref); |
bb5cf160 | 152 | xprt->xpt_server = serv; |
7a182083 TT |
153 | INIT_LIST_HEAD(&xprt->xpt_list); |
154 | INIT_LIST_HEAD(&xprt->xpt_ready); | |
8c7b0172 | 155 | INIT_LIST_HEAD(&xprt->xpt_deferred); |
a50fea26 | 156 | mutex_init(&xprt->xpt_mutex); |
def13d74 | 157 | spin_lock_init(&xprt->xpt_lock); |
4e5caaa5 | 158 | set_bit(XPT_BUSY, &xprt->xpt_flags); |
1d8206b9 TT |
159 | } |
160 | EXPORT_SYMBOL_GPL(svc_xprt_init); | |
b700cbb1 | 161 | |
5dd248f6 CL |
162 | static struct svc_xprt *__svc_xpo_create(struct svc_xprt_class *xcl, |
163 | struct svc_serv *serv, | |
164 | unsigned short port, int flags) | |
b700cbb1 | 165 | { |
b700cbb1 TT |
166 | struct sockaddr_in sin = { |
167 | .sin_family = AF_INET, | |
e6f1cebf | 168 | .sin_addr.s_addr = htonl(INADDR_ANY), |
b700cbb1 TT |
169 | .sin_port = htons(port), |
170 | }; | |
5dd248f6 CL |
171 | struct sockaddr_in6 sin6 = { |
172 | .sin6_family = AF_INET6, | |
173 | .sin6_addr = IN6ADDR_ANY_INIT, | |
174 | .sin6_port = htons(port), | |
175 | }; | |
176 | struct sockaddr *sap; | |
177 | size_t len; | |
178 | ||
179 | switch (serv->sv_family) { | |
180 | case AF_INET: | |
181 | sap = (struct sockaddr *)&sin; | |
182 | len = sizeof(sin); | |
183 | break; | |
184 | case AF_INET6: | |
185 | sap = (struct sockaddr *)&sin6; | |
186 | len = sizeof(sin6); | |
187 | break; | |
188 | default: | |
189 | return ERR_PTR(-EAFNOSUPPORT); | |
190 | } | |
191 | ||
192 | return xcl->xcl_ops->xpo_create(serv, sap, len, flags); | |
193 | } | |
194 | ||
195 | int svc_create_xprt(struct svc_serv *serv, char *xprt_name, unsigned short port, | |
196 | int flags) | |
197 | { | |
198 | struct svc_xprt_class *xcl; | |
199 | ||
b700cbb1 TT |
200 | dprintk("svc: creating transport %s[%d]\n", xprt_name, port); |
201 | spin_lock(&svc_xprt_class_lock); | |
202 | list_for_each_entry(xcl, &svc_xprt_class_list, xcl_list) { | |
4e5caaa5 TT |
203 | struct svc_xprt *newxprt; |
204 | ||
205 | if (strcmp(xprt_name, xcl->xcl_name)) | |
206 | continue; | |
207 | ||
208 | if (!try_module_get(xcl->xcl_owner)) | |
209 | goto err; | |
210 | ||
211 | spin_unlock(&svc_xprt_class_lock); | |
5dd248f6 | 212 | newxprt = __svc_xpo_create(xcl, serv, port, flags); |
4e5caaa5 TT |
213 | if (IS_ERR(newxprt)) { |
214 | module_put(xcl->xcl_owner); | |
215 | return PTR_ERR(newxprt); | |
b700cbb1 | 216 | } |
4e5caaa5 TT |
217 | |
218 | clear_bit(XPT_TEMP, &newxprt->xpt_flags); | |
219 | spin_lock_bh(&serv->sv_lock); | |
220 | list_add(&newxprt->xpt_list, &serv->sv_permsocks); | |
221 | spin_unlock_bh(&serv->sv_lock); | |
222 | clear_bit(XPT_BUSY, &newxprt->xpt_flags); | |
223 | return svc_xprt_local_port(newxprt); | |
b700cbb1 | 224 | } |
4e5caaa5 | 225 | err: |
b700cbb1 TT |
226 | spin_unlock(&svc_xprt_class_lock); |
227 | dprintk("svc: transport %s not found\n", xprt_name); | |
4e5caaa5 | 228 | return -ENOENT; |
b700cbb1 TT |
229 | } |
230 | EXPORT_SYMBOL_GPL(svc_create_xprt); | |
9dbc240f TT |
231 | |
232 | /* | |
233 | * Copy the local and remote xprt addresses to the rqstp structure | |
234 | */ | |
235 | void svc_xprt_copy_addrs(struct svc_rqst *rqstp, struct svc_xprt *xprt) | |
236 | { | |
237 | struct sockaddr *sin; | |
238 | ||
239 | memcpy(&rqstp->rq_addr, &xprt->xpt_remote, xprt->xpt_remotelen); | |
240 | rqstp->rq_addrlen = xprt->xpt_remotelen; | |
241 | ||
242 | /* | |
243 | * Destination address in request is needed for binding the | |
244 | * source address in RPC replies/callbacks later. | |
245 | */ | |
246 | sin = (struct sockaddr *)&xprt->xpt_local; | |
247 | switch (sin->sa_family) { | |
248 | case AF_INET: | |
249 | rqstp->rq_daddr.addr = ((struct sockaddr_in *)sin)->sin_addr; | |
250 | break; | |
251 | case AF_INET6: | |
252 | rqstp->rq_daddr.addr6 = ((struct sockaddr_in6 *)sin)->sin6_addr; | |
253 | break; | |
254 | } | |
255 | } | |
256 | EXPORT_SYMBOL_GPL(svc_xprt_copy_addrs); | |
257 | ||
0f0257ea TT |
258 | /** |
259 | * svc_print_addr - Format rq_addr field for printing | |
260 | * @rqstp: svc_rqst struct containing address to print | |
261 | * @buf: target buffer for formatted address | |
262 | * @len: length of target buffer | |
263 | * | |
264 | */ | |
265 | char *svc_print_addr(struct svc_rqst *rqstp, char *buf, size_t len) | |
266 | { | |
267 | return __svc_print_addr(svc_addr(rqstp), buf, len); | |
268 | } | |
269 | EXPORT_SYMBOL_GPL(svc_print_addr); | |
270 | ||
271 | /* | |
272 | * Queue up an idle server thread. Must have pool->sp_lock held. | |
273 | * Note: this is really a stack rather than a queue, so that we only | |
274 | * use as many different threads as we need, and the rest don't pollute | |
275 | * the cache. | |
276 | */ | |
277 | static void svc_thread_enqueue(struct svc_pool *pool, struct svc_rqst *rqstp) | |
278 | { | |
279 | list_add(&rqstp->rq_list, &pool->sp_threads); | |
280 | } | |
281 | ||
282 | /* | |
283 | * Dequeue an nfsd thread. Must have pool->sp_lock held. | |
284 | */ | |
285 | static void svc_thread_dequeue(struct svc_pool *pool, struct svc_rqst *rqstp) | |
286 | { | |
287 | list_del(&rqstp->rq_list); | |
288 | } | |
289 | ||
290 | /* | |
291 | * Queue up a transport with data pending. If there are idle nfsd | |
292 | * processes, wake 'em up. | |
293 | * | |
294 | */ | |
295 | void svc_xprt_enqueue(struct svc_xprt *xprt) | |
296 | { | |
297 | struct svc_serv *serv = xprt->xpt_server; | |
298 | struct svc_pool *pool; | |
299 | struct svc_rqst *rqstp; | |
300 | int cpu; | |
301 | ||
302 | if (!(xprt->xpt_flags & | |
303 | ((1<<XPT_CONN)|(1<<XPT_DATA)|(1<<XPT_CLOSE)|(1<<XPT_DEFERRED)))) | |
304 | return; | |
0f0257ea TT |
305 | |
306 | cpu = get_cpu(); | |
307 | pool = svc_pool_for_cpu(xprt->xpt_server, cpu); | |
308 | put_cpu(); | |
309 | ||
310 | spin_lock_bh(&pool->sp_lock); | |
311 | ||
312 | if (!list_empty(&pool->sp_threads) && | |
313 | !list_empty(&pool->sp_sockets)) | |
314 | printk(KERN_ERR | |
315 | "svc_xprt_enqueue: " | |
316 | "threads and transports both waiting??\n"); | |
317 | ||
318 | if (test_bit(XPT_DEAD, &xprt->xpt_flags)) { | |
319 | /* Don't enqueue dead transports */ | |
320 | dprintk("svc: transport %p is dead, not enqueued\n", xprt); | |
321 | goto out_unlock; | |
322 | } | |
323 | ||
324 | /* Mark transport as busy. It will remain in this state until | |
325 | * the provider calls svc_xprt_received. We update XPT_BUSY | |
326 | * atomically because it also guards against trying to enqueue | |
327 | * the transport twice. | |
328 | */ | |
329 | if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) { | |
330 | /* Don't enqueue transport while already enqueued */ | |
331 | dprintk("svc: transport %p busy, not enqueued\n", xprt); | |
332 | goto out_unlock; | |
333 | } | |
334 | BUG_ON(xprt->xpt_pool != NULL); | |
335 | xprt->xpt_pool = pool; | |
336 | ||
337 | /* Handle pending connection */ | |
338 | if (test_bit(XPT_CONN, &xprt->xpt_flags)) | |
339 | goto process; | |
340 | ||
341 | /* Handle close in-progress */ | |
342 | if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) | |
343 | goto process; | |
344 | ||
345 | /* Check if we have space to reply to a request */ | |
346 | if (!xprt->xpt_ops->xpo_has_wspace(xprt)) { | |
347 | /* Don't enqueue while not enough space for reply */ | |
348 | dprintk("svc: no write space, transport %p not enqueued\n", | |
349 | xprt); | |
350 | xprt->xpt_pool = NULL; | |
351 | clear_bit(XPT_BUSY, &xprt->xpt_flags); | |
352 | goto out_unlock; | |
353 | } | |
354 | ||
355 | process: | |
356 | if (!list_empty(&pool->sp_threads)) { | |
357 | rqstp = list_entry(pool->sp_threads.next, | |
358 | struct svc_rqst, | |
359 | rq_list); | |
360 | dprintk("svc: transport %p served by daemon %p\n", | |
361 | xprt, rqstp); | |
362 | svc_thread_dequeue(pool, rqstp); | |
363 | if (rqstp->rq_xprt) | |
364 | printk(KERN_ERR | |
365 | "svc_xprt_enqueue: server %p, rq_xprt=%p!\n", | |
366 | rqstp, rqstp->rq_xprt); | |
367 | rqstp->rq_xprt = xprt; | |
368 | svc_xprt_get(xprt); | |
369 | rqstp->rq_reserved = serv->sv_max_mesg; | |
370 | atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); | |
371 | BUG_ON(xprt->xpt_pool != pool); | |
372 | wake_up(&rqstp->rq_wait); | |
373 | } else { | |
374 | dprintk("svc: transport %p put into queue\n", xprt); | |
375 | list_add_tail(&xprt->xpt_ready, &pool->sp_sockets); | |
376 | BUG_ON(xprt->xpt_pool != pool); | |
377 | } | |
378 | ||
379 | out_unlock: | |
380 | spin_unlock_bh(&pool->sp_lock); | |
381 | } | |
382 | EXPORT_SYMBOL_GPL(svc_xprt_enqueue); | |
383 | ||
384 | /* | |
385 | * Dequeue the first transport. Must be called with the pool->sp_lock held. | |
386 | */ | |
387 | static struct svc_xprt *svc_xprt_dequeue(struct svc_pool *pool) | |
388 | { | |
389 | struct svc_xprt *xprt; | |
390 | ||
391 | if (list_empty(&pool->sp_sockets)) | |
392 | return NULL; | |
393 | ||
394 | xprt = list_entry(pool->sp_sockets.next, | |
395 | struct svc_xprt, xpt_ready); | |
396 | list_del_init(&xprt->xpt_ready); | |
397 | ||
398 | dprintk("svc: transport %p dequeued, inuse=%d\n", | |
399 | xprt, atomic_read(&xprt->xpt_ref.refcount)); | |
400 | ||
401 | return xprt; | |
402 | } | |
403 | ||
404 | /* | |
405 | * svc_xprt_received conditionally queues the transport for processing | |
406 | * by another thread. The caller must hold the XPT_BUSY bit and must | |
407 | * not thereafter touch transport data. | |
408 | * | |
409 | * Note: XPT_DATA only gets cleared when a read-attempt finds no (or | |
410 | * insufficient) data. | |
411 | */ | |
412 | void svc_xprt_received(struct svc_xprt *xprt) | |
413 | { | |
414 | BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags)); | |
415 | xprt->xpt_pool = NULL; | |
416 | clear_bit(XPT_BUSY, &xprt->xpt_flags); | |
417 | svc_xprt_enqueue(xprt); | |
418 | } | |
419 | EXPORT_SYMBOL_GPL(svc_xprt_received); | |
420 | ||
421 | /** | |
422 | * svc_reserve - change the space reserved for the reply to a request. | |
423 | * @rqstp: The request in question | |
424 | * @space: new max space to reserve | |
425 | * | |
426 | * Each request reserves some space on the output queue of the transport | |
427 | * to make sure the reply fits. This function reduces that reserved | |
428 | * space to be the amount of space used already, plus @space. | |
429 | * | |
430 | */ | |
431 | void svc_reserve(struct svc_rqst *rqstp, int space) | |
432 | { | |
433 | space += rqstp->rq_res.head[0].iov_len; | |
434 | ||
435 | if (space < rqstp->rq_reserved) { | |
436 | struct svc_xprt *xprt = rqstp->rq_xprt; | |
437 | atomic_sub((rqstp->rq_reserved - space), &xprt->xpt_reserved); | |
438 | rqstp->rq_reserved = space; | |
439 | ||
440 | svc_xprt_enqueue(xprt); | |
441 | } | |
442 | } | |
d2f7e79e | 443 | EXPORT_SYMBOL(svc_reserve); |
0f0257ea TT |
444 | |
445 | static void svc_xprt_release(struct svc_rqst *rqstp) | |
446 | { | |
447 | struct svc_xprt *xprt = rqstp->rq_xprt; | |
448 | ||
449 | rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); | |
450 | ||
451 | svc_free_res_pages(rqstp); | |
452 | rqstp->rq_res.page_len = 0; | |
453 | rqstp->rq_res.page_base = 0; | |
454 | ||
455 | /* Reset response buffer and release | |
456 | * the reservation. | |
457 | * But first, check that enough space was reserved | |
458 | * for the reply, otherwise we have a bug! | |
459 | */ | |
460 | if ((rqstp->rq_res.len) > rqstp->rq_reserved) | |
461 | printk(KERN_ERR "RPC request reserved %d but used %d\n", | |
462 | rqstp->rq_reserved, | |
463 | rqstp->rq_res.len); | |
464 | ||
465 | rqstp->rq_res.head[0].iov_len = 0; | |
466 | svc_reserve(rqstp, 0); | |
467 | rqstp->rq_xprt = NULL; | |
468 | ||
469 | svc_xprt_put(xprt); | |
470 | } | |
471 | ||
472 | /* | |
473 | * External function to wake up a server waiting for data | |
474 | * This really only makes sense for services like lockd | |
475 | * which have exactly one thread anyway. | |
476 | */ | |
477 | void svc_wake_up(struct svc_serv *serv) | |
478 | { | |
479 | struct svc_rqst *rqstp; | |
480 | unsigned int i; | |
481 | struct svc_pool *pool; | |
482 | ||
483 | for (i = 0; i < serv->sv_nrpools; i++) { | |
484 | pool = &serv->sv_pools[i]; | |
485 | ||
486 | spin_lock_bh(&pool->sp_lock); | |
487 | if (!list_empty(&pool->sp_threads)) { | |
488 | rqstp = list_entry(pool->sp_threads.next, | |
489 | struct svc_rqst, | |
490 | rq_list); | |
491 | dprintk("svc: daemon %p woken up.\n", rqstp); | |
492 | /* | |
493 | svc_thread_dequeue(pool, rqstp); | |
494 | rqstp->rq_xprt = NULL; | |
495 | */ | |
496 | wake_up(&rqstp->rq_wait); | |
497 | } | |
498 | spin_unlock_bh(&pool->sp_lock); | |
499 | } | |
500 | } | |
d2f7e79e | 501 | EXPORT_SYMBOL(svc_wake_up); |
0f0257ea TT |
502 | |
503 | int svc_port_is_privileged(struct sockaddr *sin) | |
504 | { | |
505 | switch (sin->sa_family) { | |
506 | case AF_INET: | |
507 | return ntohs(((struct sockaddr_in *)sin)->sin_port) | |
508 | < PROT_SOCK; | |
509 | case AF_INET6: | |
510 | return ntohs(((struct sockaddr_in6 *)sin)->sin6_port) | |
511 | < PROT_SOCK; | |
512 | default: | |
513 | return 0; | |
514 | } | |
515 | } | |
516 | ||
517 | /* | |
518 | * Make sure that we don't have too many active connections. If we | |
519 | * have, something must be dropped. | |
520 | * | |
521 | * There's no point in trying to do random drop here for DoS | |
522 | * prevention. The NFS clients does 1 reconnect in 15 seconds. An | |
523 | * attacker can easily beat that. | |
524 | * | |
525 | * The only somewhat efficient mechanism would be if drop old | |
526 | * connections from the same IP first. But right now we don't even | |
527 | * record the client IP in svc_sock. | |
528 | */ | |
529 | static void svc_check_conn_limits(struct svc_serv *serv) | |
530 | { | |
531 | if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*20) { | |
532 | struct svc_xprt *xprt = NULL; | |
533 | spin_lock_bh(&serv->sv_lock); | |
534 | if (!list_empty(&serv->sv_tempsocks)) { | |
535 | if (net_ratelimit()) { | |
536 | /* Try to help the admin */ | |
537 | printk(KERN_NOTICE "%s: too many open " | |
538 | "connections, consider increasing the " | |
539 | "number of nfsd threads\n", | |
540 | serv->sv_name); | |
541 | } | |
542 | /* | |
543 | * Always select the oldest connection. It's not fair, | |
544 | * but so is life | |
545 | */ | |
546 | xprt = list_entry(serv->sv_tempsocks.prev, | |
547 | struct svc_xprt, | |
548 | xpt_list); | |
549 | set_bit(XPT_CLOSE, &xprt->xpt_flags); | |
550 | svc_xprt_get(xprt); | |
551 | } | |
552 | spin_unlock_bh(&serv->sv_lock); | |
553 | ||
554 | if (xprt) { | |
555 | svc_xprt_enqueue(xprt); | |
556 | svc_xprt_put(xprt); | |
557 | } | |
558 | } | |
559 | } | |
560 | ||
561 | /* | |
562 | * Receive the next request on any transport. This code is carefully | |
563 | * organised not to touch any cachelines in the shared svc_serv | |
564 | * structure, only cachelines in the local svc_pool. | |
565 | */ | |
566 | int svc_recv(struct svc_rqst *rqstp, long timeout) | |
567 | { | |
568 | struct svc_xprt *xprt = NULL; | |
569 | struct svc_serv *serv = rqstp->rq_server; | |
570 | struct svc_pool *pool = rqstp->rq_pool; | |
571 | int len, i; | |
572 | int pages; | |
573 | struct xdr_buf *arg; | |
574 | DECLARE_WAITQUEUE(wait, current); | |
575 | ||
576 | dprintk("svc: server %p waiting for data (to = %ld)\n", | |
577 | rqstp, timeout); | |
578 | ||
579 | if (rqstp->rq_xprt) | |
580 | printk(KERN_ERR | |
581 | "svc_recv: service %p, transport not NULL!\n", | |
582 | rqstp); | |
583 | if (waitqueue_active(&rqstp->rq_wait)) | |
584 | printk(KERN_ERR | |
585 | "svc_recv: service %p, wait queue active!\n", | |
586 | rqstp); | |
587 | ||
588 | /* now allocate needed pages. If we get a failure, sleep briefly */ | |
589 | pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE; | |
590 | for (i = 0; i < pages ; i++) | |
591 | while (rqstp->rq_pages[i] == NULL) { | |
592 | struct page *p = alloc_page(GFP_KERNEL); | |
593 | if (!p) { | |
7b54fe61 JL |
594 | set_current_state(TASK_INTERRUPTIBLE); |
595 | if (signalled() || kthread_should_stop()) { | |
596 | set_current_state(TASK_RUNNING); | |
7086721f | 597 | return -EINTR; |
7b54fe61 JL |
598 | } |
599 | schedule_timeout(msecs_to_jiffies(500)); | |
0f0257ea TT |
600 | } |
601 | rqstp->rq_pages[i] = p; | |
602 | } | |
603 | rqstp->rq_pages[i++] = NULL; /* this might be seen in nfs_read_actor */ | |
604 | BUG_ON(pages >= RPCSVC_MAXPAGES); | |
605 | ||
606 | /* Make arg->head point to first page and arg->pages point to rest */ | |
607 | arg = &rqstp->rq_arg; | |
608 | arg->head[0].iov_base = page_address(rqstp->rq_pages[0]); | |
609 | arg->head[0].iov_len = PAGE_SIZE; | |
610 | arg->pages = rqstp->rq_pages + 1; | |
611 | arg->page_base = 0; | |
612 | /* save at least one page for response */ | |
613 | arg->page_len = (pages-2)*PAGE_SIZE; | |
614 | arg->len = (pages-1)*PAGE_SIZE; | |
615 | arg->tail[0].iov_len = 0; | |
616 | ||
617 | try_to_freeze(); | |
618 | cond_resched(); | |
7086721f | 619 | if (signalled() || kthread_should_stop()) |
0f0257ea TT |
620 | return -EINTR; |
621 | ||
622 | spin_lock_bh(&pool->sp_lock); | |
623 | xprt = svc_xprt_dequeue(pool); | |
624 | if (xprt) { | |
625 | rqstp->rq_xprt = xprt; | |
626 | svc_xprt_get(xprt); | |
627 | rqstp->rq_reserved = serv->sv_max_mesg; | |
628 | atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved); | |
629 | } else { | |
630 | /* No data pending. Go to sleep */ | |
631 | svc_thread_enqueue(pool, rqstp); | |
632 | ||
633 | /* | |
634 | * We have to be able to interrupt this wait | |
635 | * to bring down the daemons ... | |
636 | */ | |
637 | set_current_state(TASK_INTERRUPTIBLE); | |
7086721f JL |
638 | |
639 | /* | |
640 | * checking kthread_should_stop() here allows us to avoid | |
641 | * locking and signalling when stopping kthreads that call | |
642 | * svc_recv. If the thread has already been woken up, then | |
643 | * we can exit here without sleeping. If not, then it | |
644 | * it'll be woken up quickly during the schedule_timeout | |
645 | */ | |
646 | if (kthread_should_stop()) { | |
647 | set_current_state(TASK_RUNNING); | |
648 | spin_unlock_bh(&pool->sp_lock); | |
649 | return -EINTR; | |
650 | } | |
651 | ||
0f0257ea TT |
652 | add_wait_queue(&rqstp->rq_wait, &wait); |
653 | spin_unlock_bh(&pool->sp_lock); | |
654 | ||
655 | schedule_timeout(timeout); | |
656 | ||
657 | try_to_freeze(); | |
658 | ||
659 | spin_lock_bh(&pool->sp_lock); | |
660 | remove_wait_queue(&rqstp->rq_wait, &wait); | |
661 | ||
662 | xprt = rqstp->rq_xprt; | |
663 | if (!xprt) { | |
664 | svc_thread_dequeue(pool, rqstp); | |
665 | spin_unlock_bh(&pool->sp_lock); | |
666 | dprintk("svc: server %p, no data yet\n", rqstp); | |
7086721f JL |
667 | if (signalled() || kthread_should_stop()) |
668 | return -EINTR; | |
669 | else | |
670 | return -EAGAIN; | |
0f0257ea TT |
671 | } |
672 | } | |
673 | spin_unlock_bh(&pool->sp_lock); | |
674 | ||
675 | len = 0; | |
676 | if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) { | |
677 | dprintk("svc_recv: found XPT_CLOSE\n"); | |
678 | svc_delete_xprt(xprt); | |
679 | } else if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) { | |
680 | struct svc_xprt *newxpt; | |
681 | newxpt = xprt->xpt_ops->xpo_accept(xprt); | |
682 | if (newxpt) { | |
683 | /* | |
684 | * We know this module_get will succeed because the | |
685 | * listener holds a reference too | |
686 | */ | |
687 | __module_get(newxpt->xpt_class->xcl_owner); | |
688 | svc_check_conn_limits(xprt->xpt_server); | |
689 | spin_lock_bh(&serv->sv_lock); | |
690 | set_bit(XPT_TEMP, &newxpt->xpt_flags); | |
691 | list_add(&newxpt->xpt_list, &serv->sv_tempsocks); | |
692 | serv->sv_tmpcnt++; | |
693 | if (serv->sv_temptimer.function == NULL) { | |
694 | /* setup timer to age temp transports */ | |
695 | setup_timer(&serv->sv_temptimer, | |
696 | svc_age_temp_xprts, | |
697 | (unsigned long)serv); | |
698 | mod_timer(&serv->sv_temptimer, | |
699 | jiffies + svc_conn_age_period * HZ); | |
700 | } | |
701 | spin_unlock_bh(&serv->sv_lock); | |
702 | svc_xprt_received(newxpt); | |
703 | } | |
704 | svc_xprt_received(xprt); | |
705 | } else { | |
706 | dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n", | |
707 | rqstp, pool->sp_id, xprt, | |
708 | atomic_read(&xprt->xpt_ref.refcount)); | |
709 | rqstp->rq_deferred = svc_deferred_dequeue(xprt); | |
710 | if (rqstp->rq_deferred) { | |
711 | svc_xprt_received(xprt); | |
712 | len = svc_deferred_recv(rqstp); | |
713 | } else | |
714 | len = xprt->xpt_ops->xpo_recvfrom(rqstp); | |
715 | dprintk("svc: got len=%d\n", len); | |
716 | } | |
717 | ||
718 | /* No data, incomplete (TCP) read, or accept() */ | |
719 | if (len == 0 || len == -EAGAIN) { | |
720 | rqstp->rq_res.len = 0; | |
721 | svc_xprt_release(rqstp); | |
722 | return -EAGAIN; | |
723 | } | |
724 | clear_bit(XPT_OLD, &xprt->xpt_flags); | |
725 | ||
726 | rqstp->rq_secure = svc_port_is_privileged(svc_addr(rqstp)); | |
727 | rqstp->rq_chandle.defer = svc_defer; | |
728 | ||
729 | if (serv->sv_stats) | |
730 | serv->sv_stats->netcnt++; | |
731 | return len; | |
732 | } | |
d2f7e79e | 733 | EXPORT_SYMBOL(svc_recv); |
0f0257ea TT |
734 | |
735 | /* | |
736 | * Drop request | |
737 | */ | |
738 | void svc_drop(struct svc_rqst *rqstp) | |
739 | { | |
740 | dprintk("svc: xprt %p dropped request\n", rqstp->rq_xprt); | |
741 | svc_xprt_release(rqstp); | |
742 | } | |
d2f7e79e | 743 | EXPORT_SYMBOL(svc_drop); |
0f0257ea TT |
744 | |
745 | /* | |
746 | * Return reply to client. | |
747 | */ | |
748 | int svc_send(struct svc_rqst *rqstp) | |
749 | { | |
750 | struct svc_xprt *xprt; | |
751 | int len; | |
752 | struct xdr_buf *xb; | |
753 | ||
754 | xprt = rqstp->rq_xprt; | |
755 | if (!xprt) | |
756 | return -EFAULT; | |
757 | ||
758 | /* release the receive skb before sending the reply */ | |
759 | rqstp->rq_xprt->xpt_ops->xpo_release_rqst(rqstp); | |
760 | ||
761 | /* calculate over-all length */ | |
762 | xb = &rqstp->rq_res; | |
763 | xb->len = xb->head[0].iov_len + | |
764 | xb->page_len + | |
765 | xb->tail[0].iov_len; | |
766 | ||
767 | /* Grab mutex to serialize outgoing data. */ | |
768 | mutex_lock(&xprt->xpt_mutex); | |
769 | if (test_bit(XPT_DEAD, &xprt->xpt_flags)) | |
770 | len = -ENOTCONN; | |
771 | else | |
772 | len = xprt->xpt_ops->xpo_sendto(rqstp); | |
773 | mutex_unlock(&xprt->xpt_mutex); | |
774 | svc_xprt_release(rqstp); | |
775 | ||
776 | if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN) | |
777 | return 0; | |
778 | return len; | |
779 | } | |
780 | ||
781 | /* | |
782 | * Timer function to close old temporary transports, using | |
783 | * a mark-and-sweep algorithm. | |
784 | */ | |
785 | static void svc_age_temp_xprts(unsigned long closure) | |
786 | { | |
787 | struct svc_serv *serv = (struct svc_serv *)closure; | |
788 | struct svc_xprt *xprt; | |
789 | struct list_head *le, *next; | |
790 | LIST_HEAD(to_be_aged); | |
791 | ||
792 | dprintk("svc_age_temp_xprts\n"); | |
793 | ||
794 | if (!spin_trylock_bh(&serv->sv_lock)) { | |
795 | /* busy, try again 1 sec later */ | |
796 | dprintk("svc_age_temp_xprts: busy\n"); | |
797 | mod_timer(&serv->sv_temptimer, jiffies + HZ); | |
798 | return; | |
799 | } | |
800 | ||
801 | list_for_each_safe(le, next, &serv->sv_tempsocks) { | |
802 | xprt = list_entry(le, struct svc_xprt, xpt_list); | |
803 | ||
804 | /* First time through, just mark it OLD. Second time | |
805 | * through, close it. */ | |
806 | if (!test_and_set_bit(XPT_OLD, &xprt->xpt_flags)) | |
807 | continue; | |
808 | if (atomic_read(&xprt->xpt_ref.refcount) > 1 | |
809 | || test_bit(XPT_BUSY, &xprt->xpt_flags)) | |
810 | continue; | |
811 | svc_xprt_get(xprt); | |
812 | list_move(le, &to_be_aged); | |
813 | set_bit(XPT_CLOSE, &xprt->xpt_flags); | |
814 | set_bit(XPT_DETACHED, &xprt->xpt_flags); | |
815 | } | |
816 | spin_unlock_bh(&serv->sv_lock); | |
817 | ||
818 | while (!list_empty(&to_be_aged)) { | |
819 | le = to_be_aged.next; | |
820 | /* fiddling the xpt_list node is safe 'cos we're XPT_DETACHED */ | |
821 | list_del_init(le); | |
822 | xprt = list_entry(le, struct svc_xprt, xpt_list); | |
823 | ||
824 | dprintk("queuing xprt %p for closing\n", xprt); | |
825 | ||
826 | /* a thread will dequeue and close it soon */ | |
827 | svc_xprt_enqueue(xprt); | |
828 | svc_xprt_put(xprt); | |
829 | } | |
830 | ||
831 | mod_timer(&serv->sv_temptimer, jiffies + svc_conn_age_period * HZ); | |
832 | } | |
833 | ||
834 | /* | |
835 | * Remove a dead transport | |
836 | */ | |
837 | void svc_delete_xprt(struct svc_xprt *xprt) | |
838 | { | |
839 | struct svc_serv *serv = xprt->xpt_server; | |
840 | ||
841 | dprintk("svc: svc_delete_xprt(%p)\n", xprt); | |
842 | xprt->xpt_ops->xpo_detach(xprt); | |
843 | ||
844 | spin_lock_bh(&serv->sv_lock); | |
845 | if (!test_and_set_bit(XPT_DETACHED, &xprt->xpt_flags)) | |
846 | list_del_init(&xprt->xpt_list); | |
847 | /* | |
848 | * We used to delete the transport from whichever list | |
849 | * it's sk_xprt.xpt_ready node was on, but we don't actually | |
850 | * need to. This is because the only time we're called | |
851 | * while still attached to a queue, the queue itself | |
852 | * is about to be destroyed (in svc_destroy). | |
853 | */ | |
854 | if (!test_and_set_bit(XPT_DEAD, &xprt->xpt_flags)) { | |
855 | BUG_ON(atomic_read(&xprt->xpt_ref.refcount) < 2); | |
856 | if (test_bit(XPT_TEMP, &xprt->xpt_flags)) | |
857 | serv->sv_tmpcnt--; | |
858 | svc_xprt_put(xprt); | |
859 | } | |
860 | spin_unlock_bh(&serv->sv_lock); | |
861 | } | |
862 | ||
863 | void svc_close_xprt(struct svc_xprt *xprt) | |
864 | { | |
865 | set_bit(XPT_CLOSE, &xprt->xpt_flags); | |
866 | if (test_and_set_bit(XPT_BUSY, &xprt->xpt_flags)) | |
867 | /* someone else will have to effect the close */ | |
868 | return; | |
869 | ||
870 | svc_xprt_get(xprt); | |
871 | svc_delete_xprt(xprt); | |
872 | clear_bit(XPT_BUSY, &xprt->xpt_flags); | |
873 | svc_xprt_put(xprt); | |
874 | } | |
a217813f | 875 | EXPORT_SYMBOL_GPL(svc_close_xprt); |
0f0257ea TT |
876 | |
877 | void svc_close_all(struct list_head *xprt_list) | |
878 | { | |
879 | struct svc_xprt *xprt; | |
880 | struct svc_xprt *tmp; | |
881 | ||
882 | list_for_each_entry_safe(xprt, tmp, xprt_list, xpt_list) { | |
883 | set_bit(XPT_CLOSE, &xprt->xpt_flags); | |
884 | if (test_bit(XPT_BUSY, &xprt->xpt_flags)) { | |
885 | /* Waiting to be processed, but no threads left, | |
886 | * So just remove it from the waiting list | |
887 | */ | |
888 | list_del_init(&xprt->xpt_ready); | |
889 | clear_bit(XPT_BUSY, &xprt->xpt_flags); | |
890 | } | |
891 | svc_close_xprt(xprt); | |
892 | } | |
893 | } | |
894 | ||
895 | /* | |
896 | * Handle defer and revisit of requests | |
897 | */ | |
898 | ||
899 | static void svc_revisit(struct cache_deferred_req *dreq, int too_many) | |
900 | { | |
901 | struct svc_deferred_req *dr = | |
902 | container_of(dreq, struct svc_deferred_req, handle); | |
903 | struct svc_xprt *xprt = dr->xprt; | |
904 | ||
905 | if (too_many) { | |
906 | svc_xprt_put(xprt); | |
907 | kfree(dr); | |
908 | return; | |
909 | } | |
910 | dprintk("revisit queued\n"); | |
911 | dr->xprt = NULL; | |
912 | spin_lock(&xprt->xpt_lock); | |
913 | list_add(&dr->handle.recent, &xprt->xpt_deferred); | |
914 | spin_unlock(&xprt->xpt_lock); | |
915 | set_bit(XPT_DEFERRED, &xprt->xpt_flags); | |
916 | svc_xprt_enqueue(xprt); | |
917 | svc_xprt_put(xprt); | |
918 | } | |
919 | ||
260c1d12 TT |
920 | /* |
921 | * Save the request off for later processing. The request buffer looks | |
922 | * like this: | |
923 | * | |
924 | * <xprt-header><rpc-header><rpc-pagelist><rpc-tail> | |
925 | * | |
926 | * This code can only handle requests that consist of an xprt-header | |
927 | * and rpc-header. | |
928 | */ | |
0f0257ea TT |
929 | static struct cache_deferred_req *svc_defer(struct cache_req *req) |
930 | { | |
931 | struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle); | |
0f0257ea TT |
932 | struct svc_deferred_req *dr; |
933 | ||
934 | if (rqstp->rq_arg.page_len) | |
935 | return NULL; /* if more than a page, give up FIXME */ | |
936 | if (rqstp->rq_deferred) { | |
937 | dr = rqstp->rq_deferred; | |
938 | rqstp->rq_deferred = NULL; | |
939 | } else { | |
260c1d12 TT |
940 | size_t skip; |
941 | size_t size; | |
0f0257ea | 942 | /* FIXME maybe discard if size too large */ |
260c1d12 | 943 | size = sizeof(struct svc_deferred_req) + rqstp->rq_arg.len; |
0f0257ea TT |
944 | dr = kmalloc(size, GFP_KERNEL); |
945 | if (dr == NULL) | |
946 | return NULL; | |
947 | ||
948 | dr->handle.owner = rqstp->rq_server; | |
949 | dr->prot = rqstp->rq_prot; | |
950 | memcpy(&dr->addr, &rqstp->rq_addr, rqstp->rq_addrlen); | |
951 | dr->addrlen = rqstp->rq_addrlen; | |
952 | dr->daddr = rqstp->rq_daddr; | |
953 | dr->argslen = rqstp->rq_arg.len >> 2; | |
260c1d12 TT |
954 | dr->xprt_hlen = rqstp->rq_xprt_hlen; |
955 | ||
956 | /* back up head to the start of the buffer and copy */ | |
957 | skip = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len; | |
958 | memcpy(dr->args, rqstp->rq_arg.head[0].iov_base - skip, | |
959 | dr->argslen << 2); | |
0f0257ea TT |
960 | } |
961 | svc_xprt_get(rqstp->rq_xprt); | |
962 | dr->xprt = rqstp->rq_xprt; | |
963 | ||
964 | dr->handle.revisit = svc_revisit; | |
965 | return &dr->handle; | |
966 | } | |
967 | ||
968 | /* | |
969 | * recv data from a deferred request into an active one | |
970 | */ | |
971 | static int svc_deferred_recv(struct svc_rqst *rqstp) | |
972 | { | |
973 | struct svc_deferred_req *dr = rqstp->rq_deferred; | |
974 | ||
260c1d12 TT |
975 | /* setup iov_base past transport header */ |
976 | rqstp->rq_arg.head[0].iov_base = dr->args + (dr->xprt_hlen>>2); | |
977 | /* The iov_len does not include the transport header bytes */ | |
978 | rqstp->rq_arg.head[0].iov_len = (dr->argslen<<2) - dr->xprt_hlen; | |
0f0257ea | 979 | rqstp->rq_arg.page_len = 0; |
260c1d12 TT |
980 | /* The rq_arg.len includes the transport header bytes */ |
981 | rqstp->rq_arg.len = dr->argslen<<2; | |
0f0257ea TT |
982 | rqstp->rq_prot = dr->prot; |
983 | memcpy(&rqstp->rq_addr, &dr->addr, dr->addrlen); | |
984 | rqstp->rq_addrlen = dr->addrlen; | |
260c1d12 TT |
985 | /* Save off transport header len in case we get deferred again */ |
986 | rqstp->rq_xprt_hlen = dr->xprt_hlen; | |
0f0257ea TT |
987 | rqstp->rq_daddr = dr->daddr; |
988 | rqstp->rq_respages = rqstp->rq_pages; | |
260c1d12 | 989 | return (dr->argslen<<2) - dr->xprt_hlen; |
0f0257ea TT |
990 | } |
991 | ||
992 | ||
993 | static struct svc_deferred_req *svc_deferred_dequeue(struct svc_xprt *xprt) | |
994 | { | |
995 | struct svc_deferred_req *dr = NULL; | |
996 | ||
997 | if (!test_bit(XPT_DEFERRED, &xprt->xpt_flags)) | |
998 | return NULL; | |
999 | spin_lock(&xprt->xpt_lock); | |
1000 | clear_bit(XPT_DEFERRED, &xprt->xpt_flags); | |
1001 | if (!list_empty(&xprt->xpt_deferred)) { | |
1002 | dr = list_entry(xprt->xpt_deferred.next, | |
1003 | struct svc_deferred_req, | |
1004 | handle.recent); | |
1005 | list_del_init(&dr->handle.recent); | |
1006 | set_bit(XPT_DEFERRED, &xprt->xpt_flags); | |
1007 | } | |
1008 | spin_unlock(&xprt->xpt_lock); | |
1009 | return dr; | |
1010 | } | |
7fcb98d5 TT |
1011 | |
1012 | /* | |
1013 | * Return the transport instance pointer for the endpoint accepting | |
1014 | * connections/peer traffic from the specified transport class, | |
1015 | * address family and port. | |
1016 | * | |
1017 | * Specifying 0 for the address family or port is effectively a | |
1018 | * wild-card, and will result in matching the first transport in the | |
1019 | * service's list that has a matching class name. | |
1020 | */ | |
1021 | struct svc_xprt *svc_find_xprt(struct svc_serv *serv, char *xcl_name, | |
1022 | int af, int port) | |
1023 | { | |
1024 | struct svc_xprt *xprt; | |
1025 | struct svc_xprt *found = NULL; | |
1026 | ||
1027 | /* Sanity check the args */ | |
1028 | if (!serv || !xcl_name) | |
1029 | return found; | |
1030 | ||
1031 | spin_lock_bh(&serv->sv_lock); | |
1032 | list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { | |
1033 | if (strcmp(xprt->xpt_class->xcl_name, xcl_name)) | |
1034 | continue; | |
1035 | if (af != AF_UNSPEC && af != xprt->xpt_local.ss_family) | |
1036 | continue; | |
1037 | if (port && port != svc_xprt_local_port(xprt)) | |
1038 | continue; | |
1039 | found = xprt; | |
a217813f | 1040 | svc_xprt_get(xprt); |
7fcb98d5 TT |
1041 | break; |
1042 | } | |
1043 | spin_unlock_bh(&serv->sv_lock); | |
1044 | return found; | |
1045 | } | |
1046 | EXPORT_SYMBOL_GPL(svc_find_xprt); | |
9571af18 TT |
1047 | |
1048 | /* | |
1049 | * Format a buffer with a list of the active transports. A zero for | |
1050 | * the buflen parameter disables target buffer overflow checking. | |
1051 | */ | |
1052 | int svc_xprt_names(struct svc_serv *serv, char *buf, int buflen) | |
1053 | { | |
1054 | struct svc_xprt *xprt; | |
1055 | char xprt_str[64]; | |
1056 | int totlen = 0; | |
1057 | int len; | |
1058 | ||
1059 | /* Sanity check args */ | |
1060 | if (!serv) | |
1061 | return 0; | |
1062 | ||
1063 | spin_lock_bh(&serv->sv_lock); | |
1064 | list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list) { | |
1065 | len = snprintf(xprt_str, sizeof(xprt_str), | |
1066 | "%s %d\n", xprt->xpt_class->xcl_name, | |
1067 | svc_xprt_local_port(xprt)); | |
1068 | /* If the string was truncated, replace with error string */ | |
1069 | if (len >= sizeof(xprt_str)) | |
1070 | strcpy(xprt_str, "name-too-long\n"); | |
1071 | /* Don't overflow buffer */ | |
1072 | len = strlen(xprt_str); | |
1073 | if (buflen && (len + totlen >= buflen)) | |
1074 | break; | |
1075 | strcpy(buf+totlen, xprt_str); | |
1076 | totlen += len; | |
1077 | } | |
1078 | spin_unlock_bh(&serv->sv_lock); | |
1079 | return totlen; | |
1080 | } | |
1081 | EXPORT_SYMBOL_GPL(svc_xprt_names); |