Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland...
[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/config.h>
10 #include <linux/completion.h>
11 #include <linux/ip.h>
12 #include <linux/module.h>
13 #include <linux/smp_lock.h>
14 #include <linux/sunrpc/svc.h>
15 #include <linux/sunrpc/svcsock.h>
16 #include <linux/nfs_fs.h>
17
18 #include <net/inet_sock.h>
19
20 #include "nfs4_fs.h"
21 #include "callback.h"
22
23 #define NFSDBG_FACILITY NFSDBG_CALLBACK
24
25 struct nfs_callback_data {
26         unsigned int users;
27         struct svc_serv *serv;
28         pid_t pid;
29         struct completion started;
30         struct completion stopped;
31 };
32
33 static struct nfs_callback_data nfs_callback_info;
34 static DECLARE_MUTEX(nfs_callback_sema);
35 static struct svc_program nfs4_callback_program;
36
37 unsigned int nfs_callback_set_tcpport;
38 unsigned short nfs_callback_tcpport;
39
40 /*
41  * This is the callback kernel thread.
42  */
43 static void nfs_callback_svc(struct svc_rqst *rqstp)
44 {
45         struct svc_serv *serv = rqstp->rq_server;
46         int err;
47
48         __module_get(THIS_MODULE);
49         lock_kernel();
50
51         nfs_callback_info.pid = current->pid;
52         daemonize("nfsv4-svc");
53         /* Process request with signals blocked, but allow SIGKILL.  */
54         allow_signal(SIGKILL);
55
56         complete(&nfs_callback_info.started);
57
58         while (nfs_callback_info.users != 0 || !signalled()) {
59                 /*
60                  * Listen for a request on the socket
61                  */
62                 err = svc_recv(serv, rqstp, MAX_SCHEDULE_TIMEOUT);
63                 if (err == -EAGAIN || err == -EINTR)
64                         continue;
65                 if (err < 0) {
66                         printk(KERN_WARNING
67                                         "%s: terminating on error %d\n",
68                                         __FUNCTION__, -err);
69                         break;
70                 }
71                 dprintk("%s: request from %u.%u.%u.%u\n", __FUNCTION__,
72                                 NIPQUAD(rqstp->rq_addr.sin_addr.s_addr));
73                 svc_process(serv, rqstp);
74         }
75
76         nfs_callback_info.pid = 0;
77         complete(&nfs_callback_info.stopped);
78         unlock_kernel();
79         module_put_and_exit(0);
80 }
81
82 /*
83  * Bring up the server process if it is not already up.
84  */
85 int nfs_callback_up(void)
86 {
87         struct svc_serv *serv;
88         struct svc_sock *svsk;
89         int ret = 0;
90
91         lock_kernel();
92         down(&nfs_callback_sema);
93         if (nfs_callback_info.users++ || nfs_callback_info.pid != 0)
94                 goto out;
95         init_completion(&nfs_callback_info.started);
96         init_completion(&nfs_callback_info.stopped);
97         serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE);
98         ret = -ENOMEM;
99         if (!serv)
100                 goto out_err;
101         /* FIXME: We don't want to register this socket with the portmapper */
102         ret = svc_makesock(serv, IPPROTO_TCP, nfs_callback_set_tcpport);
103         if (ret < 0)
104                 goto out_destroy;
105         if (!list_empty(&serv->sv_permsocks)) {
106                 svsk = list_entry(serv->sv_permsocks.next,
107                                 struct svc_sock, sk_list);
108                 nfs_callback_tcpport = ntohs(inet_sk(svsk->sk_sk)->sport);
109                 dprintk ("Callback port = 0x%x\n", nfs_callback_tcpport);
110         } else
111                 BUG();
112         ret = svc_create_thread(nfs_callback_svc, serv);
113         if (ret < 0)
114                 goto out_destroy;
115         nfs_callback_info.serv = serv;
116         wait_for_completion(&nfs_callback_info.started);
117 out:
118         up(&nfs_callback_sema);
119         unlock_kernel();
120         return ret;
121 out_destroy:
122         svc_destroy(serv);
123 out_err:
124         nfs_callback_info.users--;
125         goto out;
126 }
127
128 /*
129  * Kill the server process if it is not already up.
130  */
131 int nfs_callback_down(void)
132 {
133         int ret = 0;
134
135         lock_kernel();
136         down(&nfs_callback_sema);
137         if (--nfs_callback_info.users || nfs_callback_info.pid == 0)
138                 goto out;
139         kill_proc(nfs_callback_info.pid, SIGKILL, 1);
140         wait_for_completion(&nfs_callback_info.stopped);
141 out:
142         up(&nfs_callback_sema);
143         unlock_kernel();
144         return ret;
145 }
146
147 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
148 {
149         struct in_addr *addr = &rqstp->rq_addr.sin_addr;
150         struct nfs4_client *clp;
151
152         /* Don't talk to strangers */
153         clp = nfs4_find_client(addr);
154         if (clp == NULL)
155                 return SVC_DROP;
156         dprintk("%s: %u.%u.%u.%u NFSv4 callback!\n", __FUNCTION__, NIPQUAD(addr));
157         nfs4_put_client(clp);
158         switch (rqstp->rq_authop->flavour) {
159                 case RPC_AUTH_NULL:
160                         if (rqstp->rq_proc != CB_NULL)
161                                 return SVC_DENIED;
162                         break;
163                 case RPC_AUTH_UNIX:
164                         break;
165                 case RPC_AUTH_GSS:
166                         /* FIXME: RPCSEC_GSS handling? */
167                 default:
168                         return SVC_DENIED;
169         }
170         return SVC_OK;
171 }
172
173 /*
174  * Define NFS4 callback program
175  */
176 extern struct svc_version nfs4_callback_version1;
177
178 static struct svc_version *nfs4_callback_version[] = {
179         [1] = &nfs4_callback_version1,
180 };
181
182 static struct svc_stat nfs4_callback_stats;
183
184 static struct svc_program nfs4_callback_program = {
185         .pg_prog = NFS4_CALLBACK,                       /* RPC service number */
186         .pg_nvers = ARRAY_SIZE(nfs4_callback_version),  /* Number of entries */
187         .pg_vers = nfs4_callback_version,               /* version table */
188         .pg_name = "NFSv4 callback",                    /* service name */
189         .pg_class = "nfs",                              /* authentication class */
190         .pg_stats = &nfs4_callback_stats,
191         .pg_authenticate = nfs_callback_authenticate,
192 };