acpi_pad: build only on X86
[linux-2.6/linux-acpi-2.6.git] / fs / nfs / callback.c
blob7f604c7941fb9816f2bfebc57918a850b7ce1aa6
1 /*
2 * linux/fs/nfs/callback.c
4 * Copyright (C) 2004 Trond Myklebust
6 * NFSv4 callback handling
7 */
9 #include <linux/completion.h>
10 #include <linux/ip.h>
11 #include <linux/module.h>
12 #include <linux/smp_lock.h>
13 #include <linux/sunrpc/svc.h>
14 #include <linux/sunrpc/svcsock.h>
15 #include <linux/nfs_fs.h>
16 #include <linux/mutex.h>
17 #include <linux/freezer.h>
18 #include <linux/kthread.h>
19 #include <linux/sunrpc/svcauth_gss.h>
20 #if defined(CONFIG_NFS_V4_1)
21 #include <linux/sunrpc/bc_xprt.h>
22 #endif
24 #include <net/inet_sock.h>
26 #include "nfs4_fs.h"
27 #include "callback.h"
28 #include "internal.h"
30 #define NFSDBG_FACILITY NFSDBG_CALLBACK
32 struct nfs_callback_data {
33 unsigned int users;
34 struct svc_serv *serv;
35 struct svc_rqst *rqst;
36 struct task_struct *task;
39 static struct nfs_callback_data nfs_callback_info[NFS4_MAX_MINOR_VERSION + 1];
40 static DEFINE_MUTEX(nfs_callback_mutex);
41 static struct svc_program nfs4_callback_program;
43 unsigned int nfs_callback_set_tcpport;
44 unsigned short nfs_callback_tcpport;
45 unsigned short nfs_callback_tcpport6;
46 static const int nfs_set_port_min = 0;
47 static const int nfs_set_port_max = 65535;
49 static int param_set_port(const char *val, struct kernel_param *kp)
51 char *endp;
52 int num = simple_strtol(val, &endp, 0);
53 if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max)
54 return -EINVAL;
55 *((int *)kp->arg) = num;
56 return 0;
59 module_param_call(callback_tcpport, param_set_port, param_get_int,
60 &nfs_callback_set_tcpport, 0644);
63 * This is the NFSv4 callback kernel thread.
65 static int
66 nfs4_callback_svc(void *vrqstp)
68 int err, preverr = 0;
69 struct svc_rqst *rqstp = vrqstp;
71 set_freezable();
74 * FIXME: do we really need to run this under the BKL? If so, please
75 * add a comment about what it's intended to protect.
77 lock_kernel();
78 while (!kthread_should_stop()) {
80 * Listen for a request on the socket
82 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
83 if (err == -EAGAIN || err == -EINTR) {
84 preverr = err;
85 continue;
87 if (err < 0) {
88 if (err != preverr) {
89 printk(KERN_WARNING "%s: unexpected error "
90 "from svc_recv (%d)\n", __func__, err);
91 preverr = err;
93 schedule_timeout_uninterruptible(HZ);
94 continue;
96 preverr = err;
97 svc_process(rqstp);
99 unlock_kernel();
100 return 0;
104 * Prepare to bring up the NFSv4 callback service
106 struct svc_rqst *
107 nfs4_callback_up(struct svc_serv *serv)
109 int ret;
111 ret = svc_create_xprt(serv, "tcp", PF_INET,
112 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
113 if (ret <= 0)
114 goto out_err;
115 nfs_callback_tcpport = ret;
116 dprintk("NFS: Callback listener port = %u (af %u)\n",
117 nfs_callback_tcpport, PF_INET);
119 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
120 ret = svc_create_xprt(serv, "tcp", PF_INET6,
121 nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS);
122 if (ret > 0) {
123 nfs_callback_tcpport6 = ret;
124 dprintk("NFS: Callback listener port = %u (af %u)\n",
125 nfs_callback_tcpport6, PF_INET6);
126 } else if (ret == -EAFNOSUPPORT)
127 ret = 0;
128 else
129 goto out_err;
130 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
132 return svc_prepare_thread(serv, &serv->sv_pools[0]);
134 out_err:
135 if (ret == 0)
136 ret = -ENOMEM;
137 return ERR_PTR(ret);
140 #if defined(CONFIG_NFS_V4_1)
142 * The callback service for NFSv4.1 callbacks
144 static int
145 nfs41_callback_svc(void *vrqstp)
147 struct svc_rqst *rqstp = vrqstp;
148 struct svc_serv *serv = rqstp->rq_server;
149 struct rpc_rqst *req;
150 int error;
151 DEFINE_WAIT(wq);
153 set_freezable();
156 * FIXME: do we really need to run this under the BKL? If so, please
157 * add a comment about what it's intended to protect.
159 lock_kernel();
160 while (!kthread_should_stop()) {
161 prepare_to_wait(&serv->sv_cb_waitq, &wq, TASK_INTERRUPTIBLE);
162 spin_lock_bh(&serv->sv_cb_lock);
163 if (!list_empty(&serv->sv_cb_list)) {
164 req = list_first_entry(&serv->sv_cb_list,
165 struct rpc_rqst, rq_bc_list);
166 list_del(&req->rq_bc_list);
167 spin_unlock_bh(&serv->sv_cb_lock);
168 dprintk("Invoking bc_svc_process()\n");
169 error = bc_svc_process(serv, req, rqstp);
170 dprintk("bc_svc_process() returned w/ error code= %d\n",
171 error);
172 } else {
173 spin_unlock_bh(&serv->sv_cb_lock);
174 schedule();
176 finish_wait(&serv->sv_cb_waitq, &wq);
178 unlock_kernel();
179 return 0;
183 * Bring up the NFSv4.1 callback service
185 struct svc_rqst *
186 nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
188 struct svc_xprt *bc_xprt;
189 struct svc_rqst *rqstp = ERR_PTR(-ENOMEM);
191 dprintk("--> %s\n", __func__);
192 /* Create a svc_sock for the service */
193 bc_xprt = svc_sock_create(serv, xprt->prot);
194 if (!bc_xprt)
195 goto out;
198 * Save the svc_serv in the transport so that it can
199 * be referenced when the session backchannel is initialized
201 serv->bc_xprt = bc_xprt;
202 xprt->bc_serv = serv;
204 INIT_LIST_HEAD(&serv->sv_cb_list);
205 spin_lock_init(&serv->sv_cb_lock);
206 init_waitqueue_head(&serv->sv_cb_waitq);
207 rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
208 if (IS_ERR(rqstp))
209 svc_sock_destroy(bc_xprt);
210 out:
211 dprintk("--> %s return %p\n", __func__, rqstp);
212 return rqstp;
215 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
216 struct svc_serv *serv, struct rpc_xprt *xprt,
217 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
219 if (minorversion) {
220 *rqstpp = nfs41_callback_up(serv, xprt);
221 *callback_svc = nfs41_callback_svc;
223 return minorversion;
226 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
227 struct nfs_callback_data *cb_info)
229 if (minorversion)
230 xprt->bc_serv = cb_info->serv;
232 #else
233 static inline int nfs_minorversion_callback_svc_setup(u32 minorversion,
234 struct svc_serv *serv, struct rpc_xprt *xprt,
235 struct svc_rqst **rqstpp, int (**callback_svc)(void *vrqstp))
237 return 0;
240 static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
241 struct nfs_callback_data *cb_info)
244 #endif /* CONFIG_NFS_V4_1 */
247 * Bring up the callback thread if it is not already up.
249 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
251 struct svc_serv *serv = NULL;
252 struct svc_rqst *rqstp;
253 int (*callback_svc)(void *vrqstp);
254 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
255 char svc_name[12];
256 int ret = 0;
257 int minorversion_setup;
259 mutex_lock(&nfs_callback_mutex);
260 if (cb_info->users++ || cb_info->task != NULL) {
261 nfs_callback_bc_serv(minorversion, xprt, cb_info);
262 goto out;
264 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
265 if (!serv) {
266 ret = -ENOMEM;
267 goto out_err;
270 minorversion_setup = nfs_minorversion_callback_svc_setup(minorversion,
271 serv, xprt, &rqstp, &callback_svc);
272 if (!minorversion_setup) {
273 /* v4.0 callback setup */
274 rqstp = nfs4_callback_up(serv);
275 callback_svc = nfs4_callback_svc;
278 if (IS_ERR(rqstp)) {
279 ret = PTR_ERR(rqstp);
280 goto out_err;
283 svc_sock_update_bufs(serv);
285 sprintf(svc_name, "nfsv4.%u-svc", minorversion);
286 cb_info->serv = serv;
287 cb_info->rqst = rqstp;
288 cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
289 if (IS_ERR(cb_info->task)) {
290 ret = PTR_ERR(cb_info->task);
291 svc_exit_thread(cb_info->rqst);
292 cb_info->rqst = NULL;
293 cb_info->task = NULL;
294 goto out_err;
296 out:
298 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
299 * svc_prepare_thread increments that. So we need to call svc_destroy
300 * on both success and failure so that the refcount is 1 when the
301 * thread exits.
303 if (serv)
304 svc_destroy(serv);
305 mutex_unlock(&nfs_callback_mutex);
306 return ret;
307 out_err:
308 dprintk("NFS: Couldn't create callback socket or server thread; "
309 "err = %d\n", ret);
310 cb_info->users--;
311 goto out;
315 * Kill the callback thread if it's no longer being used.
317 void nfs_callback_down(int minorversion)
319 struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
321 mutex_lock(&nfs_callback_mutex);
322 cb_info->users--;
323 if (cb_info->users == 0 && cb_info->task != NULL) {
324 kthread_stop(cb_info->task);
325 svc_exit_thread(cb_info->rqst);
326 cb_info->serv = NULL;
327 cb_info->rqst = NULL;
328 cb_info->task = NULL;
330 mutex_unlock(&nfs_callback_mutex);
333 static int check_gss_callback_principal(struct nfs_client *clp,
334 struct svc_rqst *rqstp)
336 struct rpc_clnt *r = clp->cl_rpcclient;
337 char *p = svc_gss_principal(rqstp);
340 * It might just be a normal user principal, in which case
341 * userspace won't bother to tell us the name at all.
343 if (p == NULL)
344 return SVC_DENIED;
346 /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
348 if (memcmp(p, "nfs@", 4) != 0)
349 return SVC_DENIED;
350 p += 4;
351 if (strcmp(p, r->cl_server) != 0)
352 return SVC_DENIED;
353 return SVC_OK;
356 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
358 struct nfs_client *clp;
359 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
360 int ret = SVC_OK;
362 /* Don't talk to strangers */
363 clp = nfs_find_client(svc_addr(rqstp), 4);
364 if (clp == NULL)
365 return SVC_DROP;
367 dprintk("%s: %s NFSv4 callback!\n", __func__,
368 svc_print_addr(rqstp, buf, sizeof(buf)));
370 switch (rqstp->rq_authop->flavour) {
371 case RPC_AUTH_NULL:
372 if (rqstp->rq_proc != CB_NULL)
373 ret = SVC_DENIED;
374 break;
375 case RPC_AUTH_UNIX:
376 break;
377 case RPC_AUTH_GSS:
378 ret = check_gss_callback_principal(clp, rqstp);
379 break;
380 default:
381 ret = SVC_DENIED;
383 nfs_put_client(clp);
384 return ret;
388 * Define NFS4 callback program
390 static struct svc_version *nfs4_callback_version[] = {
391 [1] = &nfs4_callback_version1,
394 static struct svc_stat nfs4_callback_stats;
396 static struct svc_program nfs4_callback_program = {
397 .pg_prog = NFS4_CALLBACK, /* RPC service number */
398 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
399 .pg_vers = nfs4_callback_version, /* version table */
400 .pg_name = "NFSv4 callback", /* service name */
401 .pg_class = "nfs", /* authentication class */
402 .pg_stats = &nfs4_callback_stats,
403 .pg_authenticate = nfs_callback_authenticate,