Merge branch 'master' into upstream
[linux-2.6] / fs / nfs / callback.c
1 /*
2  * linux/fs/nfs/callback.c
3  *
4  * Copyright (C) 2004 Trond Myklebust
5  *
6  * NFSv4 callback handling
7  */
8
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
18 #include <net/inet_sock.h>
19
20 #include "nfs4_fs.h"
21 #include "callback.h"
22 #include "internal.h"
23
24 #define NFSDBG_FACILITY NFSDBG_CALLBACK
25
26 struct nfs_callback_data {
27         unsigned int users;
28         struct svc_serv *serv;
29         pid_t pid;
30         struct completion started;
31         struct completion stopped;
32 };
33
34 static struct nfs_callback_data nfs_callback_info;
35 static DEFINE_MUTEX(nfs_callback_mutex);
36 static struct svc_program nfs4_callback_program;
37
38 unsigned int nfs_callback_set_tcpport;
39 unsigned short nfs_callback_tcpport;
40 static const int nfs_set_port_min = 0;
41 static const int nfs_set_port_max = 65535;
42
43 static int param_set_port(const char *val, struct kernel_param *kp)
44 {
45         char *endp;
46         int num = simple_strtol(val, &endp, 0);
47         if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max)
48                 return -EINVAL;
49         *((int *)kp->arg) = num;
50         return 0;
51 }
52
53 module_param_call(callback_tcpport, param_set_port, param_get_int,
54                  &nfs_callback_set_tcpport, 0644);
55
56 /*
57  * This is the callback kernel thread.
58  */
59 static void nfs_callback_svc(struct svc_rqst *rqstp)
60 {
61         struct svc_serv *serv = rqstp->rq_server;
62         int err;
63
64         __module_get(THIS_MODULE);
65         lock_kernel();
66
67         nfs_callback_info.pid = current->pid;
68         daemonize("nfsv4-svc");
69         /* Process request with signals blocked, but allow SIGKILL.  */
70         allow_signal(SIGKILL);
71
72         complete(&nfs_callback_info.started);
73
74         for(;;) {
75                 if (signalled()) {
76                         if (nfs_callback_info.users == 0)
77                                 break;
78                         flush_signals(current);
79                 }
80                 /*
81                  * Listen for a request on the socket
82                  */
83                 err = svc_recv(serv, rqstp, MAX_SCHEDULE_TIMEOUT);
84                 if (err == -EAGAIN || err == -EINTR)
85                         continue;
86                 if (err < 0) {
87                         printk(KERN_WARNING
88                                         "%s: terminating on error %d\n",
89                                         __FUNCTION__, -err);
90                         break;
91                 }
92                 dprintk("%s: request from %u.%u.%u.%u\n", __FUNCTION__,
93                                 NIPQUAD(rqstp->rq_addr.sin_addr.s_addr));
94                 svc_process(serv, rqstp);
95         }
96
97         svc_exit_thread(rqstp);
98         nfs_callback_info.pid = 0;
99         complete(&nfs_callback_info.stopped);
100         unlock_kernel();
101         module_put_and_exit(0);
102 }
103
104 /*
105  * Bring up the server process if it is not already up.
106  */
107 int nfs_callback_up(void)
108 {
109         struct svc_serv *serv;
110         struct svc_sock *svsk;
111         int ret = 0;
112
113         lock_kernel();
114         mutex_lock(&nfs_callback_mutex);
115         if (nfs_callback_info.users++ || nfs_callback_info.pid != 0)
116                 goto out;
117         init_completion(&nfs_callback_info.started);
118         init_completion(&nfs_callback_info.stopped);
119         serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE);
120         ret = -ENOMEM;
121         if (!serv)
122                 goto out_err;
123         /* FIXME: We don't want to register this socket with the portmapper */
124         ret = svc_makesock(serv, IPPROTO_TCP, nfs_callback_set_tcpport);
125         if (ret < 0)
126                 goto out_destroy;
127         if (!list_empty(&serv->sv_permsocks)) {
128                 svsk = list_entry(serv->sv_permsocks.next,
129                                 struct svc_sock, sk_list);
130                 nfs_callback_tcpport = ntohs(inet_sk(svsk->sk_sk)->sport);
131                 dprintk ("Callback port = 0x%x\n", nfs_callback_tcpport);
132         } else
133                 BUG();
134         ret = svc_create_thread(nfs_callback_svc, serv);
135         if (ret < 0)
136                 goto out_destroy;
137         nfs_callback_info.serv = serv;
138         wait_for_completion(&nfs_callback_info.started);
139 out:
140         mutex_unlock(&nfs_callback_mutex);
141         unlock_kernel();
142         return ret;
143 out_destroy:
144         svc_destroy(serv);
145 out_err:
146         nfs_callback_info.users--;
147         goto out;
148 }
149
150 /*
151  * Kill the server process if it is not already up.
152  */
153 void nfs_callback_down(void)
154 {
155         lock_kernel();
156         mutex_lock(&nfs_callback_mutex);
157         nfs_callback_info.users--;
158         do {
159                 if (nfs_callback_info.users != 0 || nfs_callback_info.pid == 0)
160                         break;
161                 if (kill_proc(nfs_callback_info.pid, SIGKILL, 1) < 0)
162                         break;
163         } while (wait_for_completion_timeout(&nfs_callback_info.stopped, 5*HZ) == 0);
164         mutex_unlock(&nfs_callback_mutex);
165         unlock_kernel();
166 }
167
168 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
169 {
170         struct sockaddr_in *addr = &rqstp->rq_addr;
171         struct nfs_client *clp;
172
173         /* Don't talk to strangers */
174         clp = nfs_find_client(addr, 4);
175         if (clp == NULL)
176                 return SVC_DROP;
177         dprintk("%s: %u.%u.%u.%u NFSv4 callback!\n", __FUNCTION__, NIPQUAD(addr->sin_addr));
178         nfs_put_client(clp);
179         switch (rqstp->rq_authop->flavour) {
180                 case RPC_AUTH_NULL:
181                         if (rqstp->rq_proc != CB_NULL)
182                                 return SVC_DENIED;
183                         break;
184                 case RPC_AUTH_UNIX:
185                         break;
186                 case RPC_AUTH_GSS:
187                         /* FIXME: RPCSEC_GSS handling? */
188                 default:
189                         return SVC_DENIED;
190         }
191         return SVC_OK;
192 }
193
194 /*
195  * Define NFS4 callback program
196  */
197 static struct svc_version *nfs4_callback_version[] = {
198         [1] = &nfs4_callback_version1,
199 };
200
201 static struct svc_stat nfs4_callback_stats;
202
203 static struct svc_program nfs4_callback_program = {
204         .pg_prog = NFS4_CALLBACK,                       /* RPC service number */
205         .pg_nvers = ARRAY_SIZE(nfs4_callback_version),  /* Number of entries */
206         .pg_vers = nfs4_callback_version,               /* version table */
207         .pg_name = "NFSv4 callback",                    /* service name */
208         .pg_class = "nfs",                              /* authentication class */
209         .pg_stats = &nfs4_callback_stats,
210         .pg_authenticate = nfs_callback_authenticate,
211 };