Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/nfs/callback.c | |
3 | * | |
4 | * Copyright (C) 2004 Trond Myklebust | |
5 | * | |
6 | * NFSv4 callback handling | |
7 | */ | |
8 | ||
1da177e4 LT |
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> | |
353ab6e9 | 16 | #include <linux/mutex.h> |
83144186 | 17 | #include <linux/freezer.h> |
a277e33c | 18 | #include <linux/kthread.h> |
14c85021 ACM |
19 | |
20 | #include <net/inet_sock.h> | |
21 | ||
4ce79717 | 22 | #include "nfs4_fs.h" |
1da177e4 | 23 | #include "callback.h" |
24c8dbbb | 24 | #include "internal.h" |
1da177e4 LT |
25 | |
26 | #define NFSDBG_FACILITY NFSDBG_CALLBACK | |
27 | ||
28 | struct nfs_callback_data { | |
29 | unsigned int users; | |
5afc597c | 30 | struct svc_rqst *rqst; |
a277e33c | 31 | struct task_struct *task; |
1da177e4 LT |
32 | }; |
33 | ||
34 | static struct nfs_callback_data nfs_callback_info; | |
353ab6e9 | 35 | static DEFINE_MUTEX(nfs_callback_mutex); |
1da177e4 LT |
36 | static struct svc_program nfs4_callback_program; |
37 | ||
a72b4422 | 38 | unsigned int nfs_callback_set_tcpport; |
1da177e4 | 39 | unsigned short nfs_callback_tcpport; |
7d4e2747 DH |
40 | static const int nfs_set_port_min = 0; |
41 | static const int nfs_set_port_max = 65535; | |
42 | ||
18de9735 CL |
43 | /* |
44 | * If the kernel has IPv6 support available, always listen for | |
45 | * both AF_INET and AF_INET6 requests. | |
46 | */ | |
47 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
48 | static const sa_family_t nfs_callback_family = AF_INET6; | |
49 | #else | |
50 | static const sa_family_t nfs_callback_family = AF_INET; | |
51 | #endif | |
52 | ||
7d4e2747 DH |
53 | static int param_set_port(const char *val, struct kernel_param *kp) |
54 | { | |
55 | char *endp; | |
56 | int num = simple_strtol(val, &endp, 0); | |
57 | if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max) | |
58 | return -EINVAL; | |
59 | *((int *)kp->arg) = num; | |
60 | return 0; | |
61 | } | |
62 | ||
63 | module_param_call(callback_tcpport, param_set_port, param_get_int, | |
64 | &nfs_callback_set_tcpport, 0644); | |
1da177e4 LT |
65 | |
66 | /* | |
67 | * This is the callback kernel thread. | |
68 | */ | |
a277e33c JL |
69 | static int |
70 | nfs_callback_svc(void *vrqstp) | |
1da177e4 | 71 | { |
06e02d66 | 72 | int err, preverr = 0; |
a277e33c | 73 | struct svc_rqst *rqstp = vrqstp; |
1da177e4 | 74 | |
83144186 | 75 | set_freezable(); |
1da177e4 | 76 | |
a277e33c JL |
77 | /* |
78 | * FIXME: do we really need to run this under the BKL? If so, please | |
79 | * add a comment about what it's intended to protect. | |
80 | */ | |
81 | lock_kernel(); | |
82 | while (!kthread_should_stop()) { | |
1da177e4 LT |
83 | /* |
84 | * Listen for a request on the socket | |
85 | */ | |
6fb2b47f | 86 | err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT); |
06e02d66 JL |
87 | if (err == -EAGAIN || err == -EINTR) { |
88 | preverr = err; | |
1da177e4 | 89 | continue; |
06e02d66 | 90 | } |
1da177e4 | 91 | if (err < 0) { |
06e02d66 JL |
92 | if (err != preverr) { |
93 | printk(KERN_WARNING "%s: unexpected error " | |
94 | "from svc_recv (%d)\n", __func__, err); | |
95 | preverr = err; | |
96 | } | |
97 | schedule_timeout_uninterruptible(HZ); | |
98 | continue; | |
1da177e4 | 99 | } |
06e02d66 | 100 | preverr = err; |
6fb2b47f | 101 | svc_process(rqstp); |
1da177e4 | 102 | } |
1da177e4 | 103 | unlock_kernel(); |
a277e33c | 104 | return 0; |
1da177e4 LT |
105 | } |
106 | ||
107 | /* | |
5afc597c | 108 | * Bring up the callback thread if it is not already up. |
1da177e4 LT |
109 | */ |
110 | int nfs_callback_up(void) | |
111 | { | |
8e60029f | 112 | struct svc_serv *serv = NULL; |
1da177e4 LT |
113 | int ret = 0; |
114 | ||
353ab6e9 | 115 | mutex_lock(&nfs_callback_mutex); |
a277e33c | 116 | if (nfs_callback_info.users++ || nfs_callback_info.task != NULL) |
1da177e4 | 117 | goto out; |
e851db5b | 118 | serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, |
18de9735 | 119 | nfs_callback_family, NULL); |
1da177e4 LT |
120 | ret = -ENOMEM; |
121 | if (!serv) | |
122 | goto out_err; | |
482fb94e | 123 | |
d7c9f1ed TT |
124 | ret = svc_create_xprt(serv, "tcp", nfs_callback_set_tcpport, |
125 | SVC_SOCK_ANONYMOUS); | |
482fb94e | 126 | if (ret <= 0) |
8e60029f | 127 | goto out_err; |
482fb94e | 128 | nfs_callback_tcpport = ret; |
18de9735 CL |
129 | dprintk("NFS: Callback listener port = %u (af %u)\n", |
130 | nfs_callback_tcpport, nfs_callback_family); | |
482fb94e | 131 | |
5afc597c JL |
132 | nfs_callback_info.rqst = svc_prepare_thread(serv, &serv->sv_pools[0]); |
133 | if (IS_ERR(nfs_callback_info.rqst)) { | |
134 | ret = PTR_ERR(nfs_callback_info.rqst); | |
135 | nfs_callback_info.rqst = NULL; | |
8e60029f | 136 | goto out_err; |
a277e33c JL |
137 | } |
138 | ||
139 | svc_sock_update_bufs(serv); | |
a277e33c | 140 | |
5afc597c JL |
141 | nfs_callback_info.task = kthread_run(nfs_callback_svc, |
142 | nfs_callback_info.rqst, | |
a277e33c JL |
143 | "nfsv4-svc"); |
144 | if (IS_ERR(nfs_callback_info.task)) { | |
145 | ret = PTR_ERR(nfs_callback_info.task); | |
5afc597c JL |
146 | svc_exit_thread(nfs_callback_info.rqst); |
147 | nfs_callback_info.rqst = NULL; | |
a277e33c | 148 | nfs_callback_info.task = NULL; |
a277e33c JL |
149 | goto out_err; |
150 | } | |
1da177e4 | 151 | out: |
8e60029f JL |
152 | /* |
153 | * svc_create creates the svc_serv with sv_nrthreads == 1, and then | |
a277e33c | 154 | * svc_prepare_thread increments that. So we need to call svc_destroy |
8e60029f JL |
155 | * on both success and failure so that the refcount is 1 when the |
156 | * thread exits. | |
157 | */ | |
158 | if (serv) | |
159 | svc_destroy(serv); | |
353ab6e9 | 160 | mutex_unlock(&nfs_callback_mutex); |
1da177e4 | 161 | return ret; |
8e60029f | 162 | out_err: |
18de9735 CL |
163 | dprintk("NFS: Couldn't create callback socket or server thread; " |
164 | "err = %d\n", ret); | |
1da177e4 LT |
165 | nfs_callback_info.users--; |
166 | goto out; | |
167 | } | |
168 | ||
169 | /* | |
5afc597c | 170 | * Kill the callback thread if it's no longer being used. |
1da177e4 | 171 | */ |
5ae1fbce | 172 | void nfs_callback_down(void) |
1da177e4 | 173 | { |
353ab6e9 | 174 | mutex_lock(&nfs_callback_mutex); |
1dd761e9 | 175 | nfs_callback_info.users--; |
5afc597c | 176 | if (nfs_callback_info.users == 0 && nfs_callback_info.task != NULL) { |
a277e33c | 177 | kthread_stop(nfs_callback_info.task); |
5afc597c JL |
178 | svc_exit_thread(nfs_callback_info.rqst); |
179 | nfs_callback_info.rqst = NULL; | |
180 | nfs_callback_info.task = NULL; | |
181 | } | |
353ab6e9 | 182 | mutex_unlock(&nfs_callback_mutex); |
1da177e4 LT |
183 | } |
184 | ||
185 | static int nfs_callback_authenticate(struct svc_rqst *rqstp) | |
186 | { | |
adfa6f98 | 187 | struct nfs_client *clp; |
5216a8e7 | 188 | RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); |
1da177e4 LT |
189 | |
190 | /* Don't talk to strangers */ | |
ff052645 | 191 | clp = nfs_find_client(svc_addr(rqstp), 4); |
1da177e4 LT |
192 | if (clp == NULL) |
193 | return SVC_DROP; | |
ad06e4bd | 194 | |
3110ff80 | 195 | dprintk("%s: %s NFSv4 callback!\n", __func__, |
ad06e4bd | 196 | svc_print_addr(rqstp, buf, sizeof(buf))); |
24c8dbbb | 197 | nfs_put_client(clp); |
ad06e4bd | 198 | |
1da177e4 LT |
199 | switch (rqstp->rq_authop->flavour) { |
200 | case RPC_AUTH_NULL: | |
201 | if (rqstp->rq_proc != CB_NULL) | |
202 | return SVC_DENIED; | |
203 | break; | |
204 | case RPC_AUTH_UNIX: | |
205 | break; | |
206 | case RPC_AUTH_GSS: | |
207 | /* FIXME: RPCSEC_GSS handling? */ | |
208 | default: | |
209 | return SVC_DENIED; | |
210 | } | |
211 | return SVC_OK; | |
212 | } | |
213 | ||
214 | /* | |
215 | * Define NFS4 callback program | |
216 | */ | |
1da177e4 LT |
217 | static struct svc_version *nfs4_callback_version[] = { |
218 | [1] = &nfs4_callback_version1, | |
219 | }; | |
220 | ||
221 | static struct svc_stat nfs4_callback_stats; | |
222 | ||
223 | static struct svc_program nfs4_callback_program = { | |
224 | .pg_prog = NFS4_CALLBACK, /* RPC service number */ | |
225 | .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */ | |
226 | .pg_vers = nfs4_callback_version, /* version table */ | |
227 | .pg_name = "NFSv4 callback", /* service name */ | |
228 | .pg_class = "nfs", /* authentication class */ | |
229 | .pg_stats = &nfs4_callback_stats, | |
230 | .pg_authenticate = nfs_callback_authenticate, | |
231 | }; |