[PATCH] knfsd: SUNRPC: Provide room in svc_rqst for larger addresses
[linux-3.10.git] / 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         int err;
62
63         __module_get(THIS_MODULE);
64         lock_kernel();
65
66         nfs_callback_info.pid = current->pid;
67         daemonize("nfsv4-svc");
68         /* Process request with signals blocked, but allow SIGKILL.  */
69         allow_signal(SIGKILL);
70
71         complete(&nfs_callback_info.started);
72
73         for(;;) {
74                 char buf[RPC_MAX_ADDRBUFLEN];
75
76                 if (signalled()) {
77                         if (nfs_callback_info.users == 0)
78                                 break;
79                         flush_signals(current);
80                 }
81                 /*
82                  * Listen for a request on the socket
83                  */
84                 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
85                 if (err == -EAGAIN || err == -EINTR)
86                         continue;
87                 if (err < 0) {
88                         printk(KERN_WARNING
89                                         "%s: terminating on error %d\n",
90                                         __FUNCTION__, -err);
91                         break;
92                 }
93                 dprintk("%s: request from %s\n", __FUNCTION__,
94                                 svc_print_addr(rqstp, buf, sizeof(buf)));
95                 svc_process(rqstp);
96         }
97
98         svc_exit_thread(rqstp);
99         nfs_callback_info.pid = 0;
100         complete(&nfs_callback_info.stopped);
101         unlock_kernel();
102         module_put_and_exit(0);
103 }
104
105 /*
106  * Bring up the server process if it is not already up.
107  */
108 int nfs_callback_up(void)
109 {
110         struct svc_serv *serv;
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, NULL);
120         ret = -ENOMEM;
121         if (!serv)
122                 goto out_err;
123
124         ret = svc_makesock(serv, IPPROTO_TCP, nfs_callback_set_tcpport,
125                                                         SVC_SOCK_ANONYMOUS);
126         if (ret <= 0)
127                 goto out_destroy;
128         nfs_callback_tcpport = ret;
129         dprintk("Callback port = 0x%x\n", nfs_callback_tcpport);
130
131         ret = svc_create_thread(nfs_callback_svc, serv);
132         if (ret < 0)
133                 goto out_destroy;
134         nfs_callback_info.serv = serv;
135         wait_for_completion(&nfs_callback_info.started);
136 out:
137         mutex_unlock(&nfs_callback_mutex);
138         unlock_kernel();
139         return ret;
140 out_destroy:
141         dprintk("Couldn't create callback socket or server thread; err = %d\n",
142                 ret);
143         svc_destroy(serv);
144 out_err:
145         nfs_callback_info.users--;
146         goto out;
147 }
148
149 /*
150  * Kill the server process if it is not already up.
151  */
152 void nfs_callback_down(void)
153 {
154         lock_kernel();
155         mutex_lock(&nfs_callback_mutex);
156         nfs_callback_info.users--;
157         do {
158                 if (nfs_callback_info.users != 0 || nfs_callback_info.pid == 0)
159                         break;
160                 if (kill_proc(nfs_callback_info.pid, SIGKILL, 1) < 0)
161                         break;
162         } while (wait_for_completion_timeout(&nfs_callback_info.stopped, 5*HZ) == 0);
163         mutex_unlock(&nfs_callback_mutex);
164         unlock_kernel();
165 }
166
167 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
168 {
169         struct sockaddr_in *addr = svc_addr_in(rqstp);
170         struct nfs_client *clp;
171         char buf[RPC_MAX_ADDRBUFLEN];
172
173         /* Don't talk to strangers */
174         clp = nfs_find_client(addr, 4);
175         if (clp == NULL)
176                 return SVC_DROP;
177
178         dprintk("%s: %s NFSv4 callback!\n", __FUNCTION__,
179                         svc_print_addr(rqstp, buf, sizeof(buf)));
180         nfs_put_client(clp);
181
182         switch (rqstp->rq_authop->flavour) {
183                 case RPC_AUTH_NULL:
184                         if (rqstp->rq_proc != CB_NULL)
185                                 return SVC_DENIED;
186                         break;
187                 case RPC_AUTH_UNIX:
188                         break;
189                 case RPC_AUTH_GSS:
190                         /* FIXME: RPCSEC_GSS handling? */
191                 default:
192                         return SVC_DENIED;
193         }
194         return SVC_OK;
195 }
196
197 /*
198  * Define NFS4 callback program
199  */
200 static struct svc_version *nfs4_callback_version[] = {
201         [1] = &nfs4_callback_version1,
202 };
203
204 static struct svc_stat nfs4_callback_stats;
205
206 static struct svc_program nfs4_callback_program = {
207         .pg_prog = NFS4_CALLBACK,                       /* RPC service number */
208         .pg_nvers = ARRAY_SIZE(nfs4_callback_version),  /* Number of entries */
209         .pg_vers = nfs4_callback_version,               /* version table */
210         .pg_name = "NFSv4 callback",                    /* service name */
211         .pg_class = "nfs",                              /* authentication class */
212         .pg_stats = &nfs4_callback_stats,
213         .pg_authenticate = nfs_callback_authenticate,
214 };