Commit | Line | Data |
---|---|---|
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> |
945b34a7 | 19 | #include <linux/sunrpc/svcauth_gss.h> |
14c85021 ACM |
20 | |
21 | #include <net/inet_sock.h> | |
22 | ||
4ce79717 | 23 | #include "nfs4_fs.h" |
1da177e4 | 24 | #include "callback.h" |
24c8dbbb | 25 | #include "internal.h" |
1da177e4 LT |
26 | |
27 | #define NFSDBG_FACILITY NFSDBG_CALLBACK | |
28 | ||
29 | struct nfs_callback_data { | |
30 | unsigned int users; | |
5afc597c | 31 | struct svc_rqst *rqst; |
a277e33c | 32 | struct task_struct *task; |
1da177e4 LT |
33 | }; |
34 | ||
35 | static struct nfs_callback_data nfs_callback_info; | |
353ab6e9 | 36 | static DEFINE_MUTEX(nfs_callback_mutex); |
1da177e4 LT |
37 | static struct svc_program nfs4_callback_program; |
38 | ||
a72b4422 | 39 | unsigned int nfs_callback_set_tcpport; |
1da177e4 | 40 | unsigned short nfs_callback_tcpport; |
7d4e2747 DH |
41 | static const int nfs_set_port_min = 0; |
42 | static const int nfs_set_port_max = 65535; | |
43 | ||
18de9735 CL |
44 | /* |
45 | * If the kernel has IPv6 support available, always listen for | |
46 | * both AF_INET and AF_INET6 requests. | |
47 | */ | |
48 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) | |
49 | static const sa_family_t nfs_callback_family = AF_INET6; | |
50 | #else | |
51 | static const sa_family_t nfs_callback_family = AF_INET; | |
52 | #endif | |
53 | ||
7d4e2747 DH |
54 | static int param_set_port(const char *val, struct kernel_param *kp) |
55 | { | |
56 | char *endp; | |
57 | int num = simple_strtol(val, &endp, 0); | |
58 | if (endp == val || *endp || num < nfs_set_port_min || num > nfs_set_port_max) | |
59 | return -EINVAL; | |
60 | *((int *)kp->arg) = num; | |
61 | return 0; | |
62 | } | |
63 | ||
64 | module_param_call(callback_tcpport, param_set_port, param_get_int, | |
65 | &nfs_callback_set_tcpport, 0644); | |
1da177e4 LT |
66 | |
67 | /* | |
68 | * This is the callback kernel thread. | |
69 | */ | |
a277e33c JL |
70 | static int |
71 | nfs_callback_svc(void *vrqstp) | |
1da177e4 | 72 | { |
06e02d66 | 73 | int err, preverr = 0; |
a277e33c | 74 | struct svc_rqst *rqstp = vrqstp; |
1da177e4 | 75 | |
83144186 | 76 | set_freezable(); |
1da177e4 | 77 | |
a277e33c JL |
78 | /* |
79 | * FIXME: do we really need to run this under the BKL? If so, please | |
80 | * add a comment about what it's intended to protect. | |
81 | */ | |
82 | lock_kernel(); | |
83 | while (!kthread_should_stop()) { | |
1da177e4 LT |
84 | /* |
85 | * Listen for a request on the socket | |
86 | */ | |
6fb2b47f | 87 | err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT); |
06e02d66 JL |
88 | if (err == -EAGAIN || err == -EINTR) { |
89 | preverr = err; | |
1da177e4 | 90 | continue; |
06e02d66 | 91 | } |
1da177e4 | 92 | if (err < 0) { |
06e02d66 JL |
93 | if (err != preverr) { |
94 | printk(KERN_WARNING "%s: unexpected error " | |
95 | "from svc_recv (%d)\n", __func__, err); | |
96 | preverr = err; | |
97 | } | |
98 | schedule_timeout_uninterruptible(HZ); | |
99 | continue; | |
1da177e4 | 100 | } |
06e02d66 | 101 | preverr = err; |
6fb2b47f | 102 | svc_process(rqstp); |
1da177e4 | 103 | } |
1da177e4 | 104 | unlock_kernel(); |
a277e33c | 105 | return 0; |
1da177e4 LT |
106 | } |
107 | ||
108 | /* | |
5afc597c | 109 | * Bring up the callback thread if it is not already up. |
1da177e4 LT |
110 | */ |
111 | int nfs_callback_up(void) | |
112 | { | |
8e60029f | 113 | struct svc_serv *serv = NULL; |
1da177e4 LT |
114 | int ret = 0; |
115 | ||
353ab6e9 | 116 | mutex_lock(&nfs_callback_mutex); |
a277e33c | 117 | if (nfs_callback_info.users++ || nfs_callback_info.task != NULL) |
1da177e4 | 118 | goto out; |
e851db5b | 119 | serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, |
18de9735 | 120 | nfs_callback_family, NULL); |
1da177e4 LT |
121 | ret = -ENOMEM; |
122 | if (!serv) | |
123 | goto out_err; | |
482fb94e | 124 | |
d7c9f1ed TT |
125 | ret = svc_create_xprt(serv, "tcp", nfs_callback_set_tcpport, |
126 | SVC_SOCK_ANONYMOUS); | |
482fb94e | 127 | if (ret <= 0) |
8e60029f | 128 | goto out_err; |
482fb94e | 129 | nfs_callback_tcpport = ret; |
18de9735 CL |
130 | dprintk("NFS: Callback listener port = %u (af %u)\n", |
131 | nfs_callback_tcpport, nfs_callback_family); | |
482fb94e | 132 | |
5afc597c JL |
133 | nfs_callback_info.rqst = svc_prepare_thread(serv, &serv->sv_pools[0]); |
134 | if (IS_ERR(nfs_callback_info.rqst)) { | |
135 | ret = PTR_ERR(nfs_callback_info.rqst); | |
136 | nfs_callback_info.rqst = NULL; | |
8e60029f | 137 | goto out_err; |
a277e33c JL |
138 | } |
139 | ||
140 | svc_sock_update_bufs(serv); | |
a277e33c | 141 | |
5afc597c JL |
142 | nfs_callback_info.task = kthread_run(nfs_callback_svc, |
143 | nfs_callback_info.rqst, | |
a277e33c JL |
144 | "nfsv4-svc"); |
145 | if (IS_ERR(nfs_callback_info.task)) { | |
146 | ret = PTR_ERR(nfs_callback_info.task); | |
5afc597c JL |
147 | svc_exit_thread(nfs_callback_info.rqst); |
148 | nfs_callback_info.rqst = NULL; | |
a277e33c | 149 | nfs_callback_info.task = NULL; |
a277e33c JL |
150 | goto out_err; |
151 | } | |
1da177e4 | 152 | out: |
8e60029f JL |
153 | /* |
154 | * svc_create creates the svc_serv with sv_nrthreads == 1, and then | |
a277e33c | 155 | * svc_prepare_thread increments that. So we need to call svc_destroy |
8e60029f JL |
156 | * on both success and failure so that the refcount is 1 when the |
157 | * thread exits. | |
158 | */ | |
159 | if (serv) | |
160 | svc_destroy(serv); | |
353ab6e9 | 161 | mutex_unlock(&nfs_callback_mutex); |
1da177e4 | 162 | return ret; |
8e60029f | 163 | out_err: |
18de9735 CL |
164 | dprintk("NFS: Couldn't create callback socket or server thread; " |
165 | "err = %d\n", ret); | |
1da177e4 LT |
166 | nfs_callback_info.users--; |
167 | goto out; | |
168 | } | |
169 | ||
170 | /* | |
5afc597c | 171 | * Kill the callback thread if it's no longer being used. |
1da177e4 | 172 | */ |
5ae1fbce | 173 | void nfs_callback_down(void) |
1da177e4 | 174 | { |
353ab6e9 | 175 | mutex_lock(&nfs_callback_mutex); |
1dd761e9 | 176 | nfs_callback_info.users--; |
5afc597c | 177 | if (nfs_callback_info.users == 0 && nfs_callback_info.task != NULL) { |
a277e33c | 178 | kthread_stop(nfs_callback_info.task); |
5afc597c JL |
179 | svc_exit_thread(nfs_callback_info.rqst); |
180 | nfs_callback_info.rqst = NULL; | |
181 | nfs_callback_info.task = NULL; | |
182 | } | |
353ab6e9 | 183 | mutex_unlock(&nfs_callback_mutex); |
1da177e4 LT |
184 | } |
185 | ||
945b34a7 OK |
186 | static int check_gss_callback_principal(struct nfs_client *clp, |
187 | struct svc_rqst *rqstp) | |
188 | { | |
189 | struct rpc_clnt *r = clp->cl_rpcclient; | |
190 | char *p = svc_gss_principal(rqstp); | |
191 | ||
192 | /* | |
193 | * It might just be a normal user principal, in which case | |
194 | * userspace won't bother to tell us the name at all. | |
195 | */ | |
196 | if (p == NULL) | |
197 | return SVC_DENIED; | |
198 | ||
199 | /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */ | |
200 | ||
201 | if (memcmp(p, "nfs@", 4) != 0) | |
202 | return SVC_DENIED; | |
203 | p += 4; | |
204 | if (strcmp(p, r->cl_server) != 0) | |
205 | return SVC_DENIED; | |
206 | return SVC_OK; | |
207 | } | |
208 | ||
1da177e4 LT |
209 | static int nfs_callback_authenticate(struct svc_rqst *rqstp) |
210 | { | |
adfa6f98 | 211 | struct nfs_client *clp; |
5216a8e7 | 212 | RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); |
945b34a7 | 213 | int ret = SVC_OK; |
1da177e4 LT |
214 | |
215 | /* Don't talk to strangers */ | |
ff052645 | 216 | clp = nfs_find_client(svc_addr(rqstp), 4); |
1da177e4 LT |
217 | if (clp == NULL) |
218 | return SVC_DROP; | |
ad06e4bd | 219 | |
3110ff80 | 220 | dprintk("%s: %s NFSv4 callback!\n", __func__, |
ad06e4bd | 221 | svc_print_addr(rqstp, buf, sizeof(buf))); |
ad06e4bd | 222 | |
1da177e4 LT |
223 | switch (rqstp->rq_authop->flavour) { |
224 | case RPC_AUTH_NULL: | |
225 | if (rqstp->rq_proc != CB_NULL) | |
945b34a7 | 226 | ret = SVC_DENIED; |
1da177e4 LT |
227 | break; |
228 | case RPC_AUTH_UNIX: | |
229 | break; | |
230 | case RPC_AUTH_GSS: | |
945b34a7 OK |
231 | ret = check_gss_callback_principal(clp, rqstp); |
232 | break; | |
1da177e4 | 233 | default: |
945b34a7 | 234 | ret = SVC_DENIED; |
1da177e4 | 235 | } |
945b34a7 OK |
236 | nfs_put_client(clp); |
237 | return ret; | |
1da177e4 LT |
238 | } |
239 | ||
240 | /* | |
241 | * Define NFS4 callback program | |
242 | */ | |
1da177e4 LT |
243 | static struct svc_version *nfs4_callback_version[] = { |
244 | [1] = &nfs4_callback_version1, | |
245 | }; | |
246 | ||
247 | static struct svc_stat nfs4_callback_stats; | |
248 | ||
249 | static struct svc_program nfs4_callback_program = { | |
250 | .pg_prog = NFS4_CALLBACK, /* RPC service number */ | |
251 | .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */ | |
252 | .pg_vers = nfs4_callback_version, /* version table */ | |
253 | .pg_name = "NFSv4 callback", /* service name */ | |
254 | .pg_class = "nfs", /* authentication class */ | |
255 | .pg_stats = &nfs4_callback_stats, | |
256 | .pg_authenticate = nfs_callback_authenticate, | |
257 | }; |