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 | ||
44 | static 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 | ||
54 | module_param_call(callback_tcpport, param_set_port, param_get_int, | |
55 | &nfs_callback_set_tcpport, 0644); | |
1da177e4 LT |
56 | |
57 | /* | |
58 | * This is the callback kernel thread. | |
59 | */ | |
a277e33c JL |
60 | static int |
61 | nfs_callback_svc(void *vrqstp) | |
1da177e4 | 62 | { |
06e02d66 | 63 | int err, preverr = 0; |
a277e33c | 64 | struct svc_rqst *rqstp = vrqstp; |
1da177e4 | 65 | |
83144186 | 66 | set_freezable(); |
1da177e4 | 67 | |
a277e33c JL |
68 | /* |
69 | * FIXME: do we really need to run this under the BKL? If so, please | |
70 | * add a comment about what it's intended to protect. | |
71 | */ | |
72 | lock_kernel(); | |
73 | while (!kthread_should_stop()) { | |
1da177e4 LT |
74 | /* |
75 | * Listen for a request on the socket | |
76 | */ | |
6fb2b47f | 77 | err = svc_recv(rqstp, MAX_SCHEDULE_TIMEOUT); |
06e02d66 JL |
78 | if (err == -EAGAIN || err == -EINTR) { |
79 | preverr = err; | |
1da177e4 | 80 | continue; |
06e02d66 | 81 | } |
1da177e4 | 82 | if (err < 0) { |
06e02d66 JL |
83 | if (err != preverr) { |
84 | printk(KERN_WARNING "%s: unexpected error " | |
85 | "from svc_recv (%d)\n", __func__, err); | |
86 | preverr = err; | |
87 | } | |
88 | schedule_timeout_uninterruptible(HZ); | |
89 | continue; | |
1da177e4 | 90 | } |
06e02d66 | 91 | preverr = err; |
6fb2b47f | 92 | svc_process(rqstp); |
1da177e4 | 93 | } |
1da177e4 | 94 | unlock_kernel(); |
a277e33c | 95 | return 0; |
1da177e4 LT |
96 | } |
97 | ||
98 | /* | |
5afc597c | 99 | * Bring up the callback thread if it is not already up. |
1da177e4 LT |
100 | */ |
101 | int nfs_callback_up(void) | |
102 | { | |
8e60029f | 103 | struct svc_serv *serv = NULL; |
1da177e4 LT |
104 | int ret = 0; |
105 | ||
353ab6e9 | 106 | mutex_lock(&nfs_callback_mutex); |
a277e33c | 107 | if (nfs_callback_info.users++ || nfs_callback_info.task != NULL) |
1da177e4 | 108 | goto out; |
49a9072f | 109 | serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE, NULL); |
1da177e4 LT |
110 | ret = -ENOMEM; |
111 | if (!serv) | |
112 | goto out_err; | |
482fb94e | 113 | |
26298caa | 114 | ret = svc_create_xprt(serv, "tcp", PF_INET, |
9652ada3 | 115 | nfs_callback_set_tcpport, SVC_SOCK_ANONYMOUS); |
482fb94e | 116 | if (ret <= 0) |
8e60029f | 117 | goto out_err; |
482fb94e | 118 | nfs_callback_tcpport = ret; |
18de9735 | 119 | dprintk("NFS: Callback listener port = %u (af %u)\n", |
26298caa | 120 | nfs_callback_tcpport, PF_INET); |
482fb94e | 121 | |
5afc597c JL |
122 | nfs_callback_info.rqst = svc_prepare_thread(serv, &serv->sv_pools[0]); |
123 | if (IS_ERR(nfs_callback_info.rqst)) { | |
124 | ret = PTR_ERR(nfs_callback_info.rqst); | |
125 | nfs_callback_info.rqst = NULL; | |
8e60029f | 126 | goto out_err; |
a277e33c JL |
127 | } |
128 | ||
129 | svc_sock_update_bufs(serv); | |
a277e33c | 130 | |
5afc597c JL |
131 | nfs_callback_info.task = kthread_run(nfs_callback_svc, |
132 | nfs_callback_info.rqst, | |
a277e33c JL |
133 | "nfsv4-svc"); |
134 | if (IS_ERR(nfs_callback_info.task)) { | |
135 | ret = PTR_ERR(nfs_callback_info.task); | |
5afc597c JL |
136 | svc_exit_thread(nfs_callback_info.rqst); |
137 | nfs_callback_info.rqst = NULL; | |
a277e33c | 138 | nfs_callback_info.task = NULL; |
a277e33c JL |
139 | goto out_err; |
140 | } | |
1da177e4 | 141 | out: |
8e60029f JL |
142 | /* |
143 | * svc_create creates the svc_serv with sv_nrthreads == 1, and then | |
a277e33c | 144 | * svc_prepare_thread increments that. So we need to call svc_destroy |
8e60029f JL |
145 | * on both success and failure so that the refcount is 1 when the |
146 | * thread exits. | |
147 | */ | |
148 | if (serv) | |
149 | svc_destroy(serv); | |
353ab6e9 | 150 | mutex_unlock(&nfs_callback_mutex); |
1da177e4 | 151 | return ret; |
8e60029f | 152 | out_err: |
18de9735 CL |
153 | dprintk("NFS: Couldn't create callback socket or server thread; " |
154 | "err = %d\n", ret); | |
1da177e4 LT |
155 | nfs_callback_info.users--; |
156 | goto out; | |
157 | } | |
158 | ||
159 | /* | |
5afc597c | 160 | * Kill the callback thread if it's no longer being used. |
1da177e4 | 161 | */ |
5ae1fbce | 162 | void nfs_callback_down(void) |
1da177e4 | 163 | { |
353ab6e9 | 164 | mutex_lock(&nfs_callback_mutex); |
1dd761e9 | 165 | nfs_callback_info.users--; |
5afc597c | 166 | if (nfs_callback_info.users == 0 && nfs_callback_info.task != NULL) { |
a277e33c | 167 | kthread_stop(nfs_callback_info.task); |
5afc597c JL |
168 | svc_exit_thread(nfs_callback_info.rqst); |
169 | nfs_callback_info.rqst = NULL; | |
170 | nfs_callback_info.task = NULL; | |
171 | } | |
353ab6e9 | 172 | mutex_unlock(&nfs_callback_mutex); |
1da177e4 LT |
173 | } |
174 | ||
945b34a7 OK |
175 | static int check_gss_callback_principal(struct nfs_client *clp, |
176 | struct svc_rqst *rqstp) | |
177 | { | |
178 | struct rpc_clnt *r = clp->cl_rpcclient; | |
179 | char *p = svc_gss_principal(rqstp); | |
180 | ||
181 | /* | |
182 | * It might just be a normal user principal, in which case | |
183 | * userspace won't bother to tell us the name at all. | |
184 | */ | |
185 | if (p == NULL) | |
186 | return SVC_DENIED; | |
187 | ||
188 | /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */ | |
189 | ||
190 | if (memcmp(p, "nfs@", 4) != 0) | |
191 | return SVC_DENIED; | |
192 | p += 4; | |
193 | if (strcmp(p, r->cl_server) != 0) | |
194 | return SVC_DENIED; | |
195 | return SVC_OK; | |
196 | } | |
197 | ||
1da177e4 LT |
198 | static int nfs_callback_authenticate(struct svc_rqst *rqstp) |
199 | { | |
adfa6f98 | 200 | struct nfs_client *clp; |
5216a8e7 | 201 | RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]); |
945b34a7 | 202 | int ret = SVC_OK; |
1da177e4 LT |
203 | |
204 | /* Don't talk to strangers */ | |
ff052645 | 205 | clp = nfs_find_client(svc_addr(rqstp), 4); |
1da177e4 LT |
206 | if (clp == NULL) |
207 | return SVC_DROP; | |
ad06e4bd | 208 | |
3110ff80 | 209 | dprintk("%s: %s NFSv4 callback!\n", __func__, |
ad06e4bd | 210 | svc_print_addr(rqstp, buf, sizeof(buf))); |
ad06e4bd | 211 | |
1da177e4 LT |
212 | switch (rqstp->rq_authop->flavour) { |
213 | case RPC_AUTH_NULL: | |
214 | if (rqstp->rq_proc != CB_NULL) | |
945b34a7 | 215 | ret = SVC_DENIED; |
1da177e4 LT |
216 | break; |
217 | case RPC_AUTH_UNIX: | |
218 | break; | |
219 | case RPC_AUTH_GSS: | |
945b34a7 OK |
220 | ret = check_gss_callback_principal(clp, rqstp); |
221 | break; | |
1da177e4 | 222 | default: |
945b34a7 | 223 | ret = SVC_DENIED; |
1da177e4 | 224 | } |
945b34a7 OK |
225 | nfs_put_client(clp); |
226 | return ret; | |
1da177e4 LT |
227 | } |
228 | ||
229 | /* | |
230 | * Define NFS4 callback program | |
231 | */ | |
1da177e4 LT |
232 | static struct svc_version *nfs4_callback_version[] = { |
233 | [1] = &nfs4_callback_version1, | |
234 | }; | |
235 | ||
236 | static struct svc_stat nfs4_callback_stats; | |
237 | ||
238 | static struct svc_program nfs4_callback_program = { | |
239 | .pg_prog = NFS4_CALLBACK, /* RPC service number */ | |
240 | .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */ | |
241 | .pg_vers = nfs4_callback_version, /* version table */ | |
242 | .pg_name = "NFSv4 callback", /* service name */ | |
243 | .pg_class = "nfs", /* authentication class */ | |
244 | .pg_stats = &nfs4_callback_stats, | |
245 | .pg_authenticate = nfs_callback_authenticate, | |
246 | }; |