Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[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 #include "nfs4_fs.h"
18 #include "callback.h"
19
20 #define NFSDBG_FACILITY NFSDBG_CALLBACK
21
22 struct nfs_callback_data {
23         unsigned int users;
24         struct svc_serv *serv;
25         pid_t pid;
26         struct completion started;
27         struct completion stopped;
28 };
29
30 static struct nfs_callback_data nfs_callback_info;
31 static DECLARE_MUTEX(nfs_callback_sema);
32 static struct svc_program nfs4_callback_program;
33
34 unsigned short nfs_callback_tcpport;
35
36 /*
37  * This is the callback kernel thread.
38  */
39 static void nfs_callback_svc(struct svc_rqst *rqstp)
40 {
41         struct svc_serv *serv = rqstp->rq_server;
42         int err;
43
44         __module_get(THIS_MODULE);
45         lock_kernel();
46
47         nfs_callback_info.pid = current->pid;
48         daemonize("nfsv4-svc");
49         /* Process request with signals blocked, but allow SIGKILL.  */
50         allow_signal(SIGKILL);
51
52         complete(&nfs_callback_info.started);
53
54         while (nfs_callback_info.users != 0 || !signalled()) {
55                 /*
56                  * Listen for a request on the socket
57                  */
58                 err = svc_recv(serv, rqstp, MAX_SCHEDULE_TIMEOUT);
59                 if (err == -EAGAIN || err == -EINTR)
60                         continue;
61                 if (err < 0) {
62                         printk(KERN_WARNING
63                                         "%s: terminating on error %d\n",
64                                         __FUNCTION__, -err);
65                         break;
66                 }
67                 dprintk("%s: request from %u.%u.%u.%u\n", __FUNCTION__,
68                                 NIPQUAD(rqstp->rq_addr.sin_addr.s_addr));
69                 svc_process(serv, rqstp);
70         }
71
72         nfs_callback_info.pid = 0;
73         complete(&nfs_callback_info.stopped);
74         unlock_kernel();
75         module_put_and_exit(0);
76 }
77
78 /*
79  * Bring up the server process if it is not already up.
80  */
81 int nfs_callback_up(void)
82 {
83         struct svc_serv *serv;
84         struct svc_sock *svsk;
85         int ret = 0;
86
87         lock_kernel();
88         down(&nfs_callback_sema);
89         if (nfs_callback_info.users++ || nfs_callback_info.pid != 0)
90                 goto out;
91         init_completion(&nfs_callback_info.started);
92         init_completion(&nfs_callback_info.stopped);
93         serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE);
94         ret = -ENOMEM;
95         if (!serv)
96                 goto out_err;
97         /* FIXME: We don't want to register this socket with the portmapper */
98         ret = svc_makesock(serv, IPPROTO_TCP, 0);
99         if (ret < 0)
100                 goto out_destroy;
101         if (!list_empty(&serv->sv_permsocks)) {
102                 svsk = list_entry(serv->sv_permsocks.next,
103                                 struct svc_sock, sk_list);
104                 nfs_callback_tcpport = ntohs(inet_sk(svsk->sk_sk)->sport);
105                 dprintk ("Callback port = 0x%x\n", nfs_callback_tcpport);
106         } else
107                 BUG();
108         ret = svc_create_thread(nfs_callback_svc, serv);
109         if (ret < 0)
110                 goto out_destroy;
111         nfs_callback_info.serv = serv;
112         wait_for_completion(&nfs_callback_info.started);
113 out:
114         up(&nfs_callback_sema);
115         unlock_kernel();
116         return ret;
117 out_destroy:
118         svc_destroy(serv);
119 out_err:
120         nfs_callback_info.users--;
121         goto out;
122 }
123
124 /*
125  * Kill the server process if it is not already up.
126  */
127 int nfs_callback_down(void)
128 {
129         int ret = 0;
130
131         lock_kernel();
132         down(&nfs_callback_sema);
133         if (--nfs_callback_info.users || nfs_callback_info.pid == 0)
134                 goto out;
135         kill_proc(nfs_callback_info.pid, SIGKILL, 1);
136         wait_for_completion(&nfs_callback_info.stopped);
137 out:
138         up(&nfs_callback_sema);
139         unlock_kernel();
140         return ret;
141 }
142
143 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
144 {
145         struct in_addr *addr = &rqstp->rq_addr.sin_addr;
146         struct nfs4_client *clp;
147
148         /* Don't talk to strangers */
149         clp = nfs4_find_client(addr);
150         if (clp == NULL)
151                 return SVC_DROP;
152         dprintk("%s: %u.%u.%u.%u NFSv4 callback!\n", __FUNCTION__, NIPQUAD(addr));
153         nfs4_put_client(clp);
154         switch (rqstp->rq_authop->flavour) {
155                 case RPC_AUTH_NULL:
156                         if (rqstp->rq_proc != CB_NULL)
157                                 return SVC_DENIED;
158                         break;
159                 case RPC_AUTH_UNIX:
160                         break;
161                 case RPC_AUTH_GSS:
162                         /* FIXME: RPCSEC_GSS handling? */
163                 default:
164                         return SVC_DENIED;
165         }
166         return SVC_OK;
167 }
168
169 /*
170  * Define NFS4 callback program
171  */
172 extern struct svc_version nfs4_callback_version1;
173
174 static struct svc_version *nfs4_callback_version[] = {
175         [1] = &nfs4_callback_version1,
176 };
177
178 static struct svc_stat nfs4_callback_stats;
179
180 static struct svc_program nfs4_callback_program = {
181         .pg_prog = NFS4_CALLBACK,                       /* RPC service number */
182         .pg_nvers = ARRAY_SIZE(nfs4_callback_version),  /* Number of entries */
183         .pg_vers = nfs4_callback_version,               /* version table */
184         .pg_name = "NFSv4 callback",                    /* service name */
185         .pg_class = "nfs",                              /* authentication class */
186         .pg_stats = &nfs4_callback_stats,
187         .pg_authenticate = nfs_callback_authenticate,
188 };