blob: a796be5051bfa4886254f7bd40a9cb4f7ff4f7de [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/nfs/callback.c
3 *
4 * Copyright (C) 2004 Trond Myklebust
5 *
6 * NFSv4 callback handling
7 */
8
Linus Torvalds1da177e2005-04-16 15:20:36 -07009#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>
Ingo Molnar353ab6e2006-03-26 01:37:12 -080016#include <linux/mutex.h>
Rafael J. Wysocki83144182007-07-17 04:03:35 -070017#include <linux/freezer.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020018
19#include <net/inet_sock.h>
20
Trond Myklebust4ce79712005-06-22 17:16:21 +000021#include "nfs4_fs.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include "callback.h"
David Howells24c8dbb2006-08-22 20:06:10 -040023#include "internal.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25#define NFSDBG_FACILITY NFSDBG_CALLBACK
26
27struct nfs_callback_data {
28 unsigned int users;
29 struct svc_serv *serv;
30 pid_t pid;
31 struct completion started;
32 struct completion stopped;
33};
34
35static struct nfs_callback_data nfs_callback_info;
Ingo Molnar353ab6e2006-03-26 01:37:12 -080036static DEFINE_MUTEX(nfs_callback_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070037static struct svc_program nfs4_callback_program;
38
Trond Myklebusta72b4422006-01-03 09:55:41 +010039unsigned int nfs_callback_set_tcpport;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040unsigned short nfs_callback_tcpport;
David Howells7d4e2742006-08-22 20:06:07 -040041static const int nfs_set_port_min = 0;
42static const int nfs_set_port_max = 65535;
43
44static int param_set_port(const char *val, struct kernel_param *kp)
45{
46 char *endp;
47 int num = simple_strtol(val, &endp, 0);
48 if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max)
49 return -EINVAL;
50 *((int *)kp->arg) = num;
51 return 0;
52}
53
54module_param_call(callback_tcpport, param_set_port, param_get_int,
55 &nfs_callback_set_tcpport, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
57/*
58 * This is the callback kernel thread.
59 */
60static void nfs_callback_svc(struct svc_rqst *rqstp)
61{
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 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);
Rafael J. Wysocki83144182007-07-17 04:03:35 -070071 set_freezable();
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73 complete(&nfs_callback_info.started);
74
Trond Myklebust1dd761e2006-03-20 13:44:49 -050075 for(;;) {
Chuck Leverad06e4b2007-02-12 00:53:32 -080076 char buf[RPC_MAX_ADDRBUFLEN];
77
Trond Myklebust1dd761e2006-03-20 13:44:49 -050078 if (signalled()) {
79 if (nfs_callback_info.users == 0)
80 break;
81 flush_signals(current);
82 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 /*
84 * Listen for a request on the socket
85 */
NeilBrown6fb2b472006-10-02 02:17:50 -070086 err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 if (err == -EAGAIN || err == -EINTR)
88 continue;
89 if (err < 0) {
90 printk(KERN_WARNING
91 "%s: terminating on error %d\n",
92 __FUNCTION__, -err);
93 break;
94 }
Chuck Leverad06e4b2007-02-12 00:53:32 -080095 dprintk("%s: request from %s\n", __FUNCTION__,
96 svc_print_addr(rqstp, buf, sizeof(buf)));
NeilBrown6fb2b472006-10-02 02:17:50 -070097 svc_process(rqstp);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 }
99
Trond Myklebustf25bc342006-03-20 13:44:46 -0500100 svc_exit_thread(rqstp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 nfs_callback_info.pid = 0;
102 complete(&nfs_callback_info.stopped);
103 unlock_kernel();
104 module_put_and_exit(0);
105}
106
107/*
108 * Bring up the server process if it is not already up.
109 */
110int nfs_callback_up(void)
111{
112 struct svc_serv *serv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 int ret = 0;
114
115 lock_kernel();
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800116 mutex_lock(&nfs_callback_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 if (nfs_callback_info.users++ || nfs_callback_info.pid != 0)
118 goto out;
119 init_completion(&nfs_callback_info.started);
120 init_completion(&nfs_callback_info.stopped);
NeilBrownbc591cc2006-10-02 02:17:44 -0700121 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 ret = -ENOMEM;
123 if (!serv)
124 goto out_err;
Chuck Lever482fb942007-02-12 00:53:29 -0800125
126 ret = svc_makesock(serv, IPPROTO_TCP, nfs_callback_set_tcpport,
127 SVC_SOCK_ANONYMOUS);
128 if (ret <= 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 goto out_destroy;
Chuck Lever482fb942007-02-12 00:53:29 -0800130 nfs_callback_tcpport = ret;
131 dprintk("Callback port = 0x%x\n", nfs_callback_tcpport);
132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 ret = svc_create_thread(nfs_callback_svc, serv);
134 if (ret < 0)
135 goto out_destroy;
136 nfs_callback_info.serv = serv;
137 wait_for_completion(&nfs_callback_info.started);
138out:
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800139 mutex_unlock(&nfs_callback_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 unlock_kernel();
141 return ret;
142out_destroy:
Chuck Lever482fb942007-02-12 00:53:29 -0800143 dprintk("Couldn't create callback socket or server thread; err = %d\n",
144 ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 svc_destroy(serv);
146out_err:
147 nfs_callback_info.users--;
148 goto out;
149}
150
151/*
152 * Kill the server process if it is not already up.
153 */
David Howells5ae1fbc2006-08-22 20:06:08 -0400154void nfs_callback_down(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 lock_kernel();
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800157 mutex_lock(&nfs_callback_mutex);
Trond Myklebust1dd761e2006-03-20 13:44:49 -0500158 nfs_callback_info.users--;
159 do {
160 if (nfs_callback_info.users != 0 || nfs_callback_info.pid == 0)
161 break;
162 if (kill_proc(nfs_callback_info.pid, SIGKILL, 1) < 0)
163 break;
164 } while (wait_for_completion_timeout(&nfs_callback_info.stopped, 5*HZ) == 0);
Ingo Molnar353ab6e2006-03-26 01:37:12 -0800165 mutex_unlock(&nfs_callback_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167}
168
169static int nfs_callback_authenticate(struct svc_rqst *rqstp)
170{
Chuck Lever27459f02007-02-12 00:53:34 -0800171 struct sockaddr_in *addr = svc_addr_in(rqstp);
David Howellsadfa6f92006-08-22 20:06:08 -0400172 struct nfs_client *clp;
Chuck Leverad06e4b2007-02-12 00:53:32 -0800173 char buf[RPC_MAX_ADDRBUFLEN];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174
175 /* Don't talk to strangers */
David Howells24c8dbb2006-08-22 20:06:10 -0400176 clp = nfs_find_client(addr, 4);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 if (clp == NULL)
178 return SVC_DROP;
Chuck Leverad06e4b2007-02-12 00:53:32 -0800179
180 dprintk("%s: %s NFSv4 callback!\n", __FUNCTION__,
181 svc_print_addr(rqstp, buf, sizeof(buf)));
David Howells24c8dbb2006-08-22 20:06:10 -0400182 nfs_put_client(clp);
Chuck Leverad06e4b2007-02-12 00:53:32 -0800183
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 switch (rqstp->rq_authop->flavour) {
185 case RPC_AUTH_NULL:
186 if (rqstp->rq_proc != CB_NULL)
187 return SVC_DENIED;
188 break;
189 case RPC_AUTH_UNIX:
190 break;
191 case RPC_AUTH_GSS:
192 /* FIXME: RPCSEC_GSS handling? */
193 default:
194 return SVC_DENIED;
195 }
196 return SVC_OK;
197}
198
199/*
200 * Define NFS4 callback program
201 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202static struct svc_version *nfs4_callback_version[] = {
203 [1] = &nfs4_callback_version1,
204};
205
206static struct svc_stat nfs4_callback_stats;
207
208static struct svc_program nfs4_callback_program = {
209 .pg_prog = NFS4_CALLBACK, /* RPC service number */
210 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */
211 .pg_vers = nfs4_callback_version, /* version table */
212 .pg_name = "NFSv4 callback", /* service name */
213 .pg_class = "nfs", /* authentication class */
214 .pg_stats = &nfs4_callback_stats,
215 .pg_authenticate = nfs_callback_authenticate,
216};