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 | ||
9 | #include <linux/config.h> | |
10 | #include <linux/completion.h> | |
11 | #include <linux/ip.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/smp_lock.h> | |
14 | #include <linux/sunrpc/svc.h> | |
15 | #include <linux/sunrpc/svcsock.h> | |
16 | #include <linux/nfs_fs.h> | |
17 | #include "callback.h" | |
18 | ||
19 | #define NFSDBG_FACILITY NFSDBG_CALLBACK | |
20 | ||
21 | struct nfs_callback_data { | |
22 | unsigned int users; | |
23 | struct svc_serv *serv; | |
24 | pid_t pid; | |
25 | struct completion started; | |
26 | struct completion stopped; | |
27 | }; | |
28 | ||
29 | static struct nfs_callback_data nfs_callback_info; | |
30 | static DECLARE_MUTEX(nfs_callback_sema); | |
31 | static struct svc_program nfs4_callback_program; | |
32 | ||
33 | unsigned short nfs_callback_tcpport; | |
34 | ||
35 | /* | |
36 | * This is the callback kernel thread. | |
37 | */ | |
38 | static void nfs_callback_svc(struct svc_rqst *rqstp) | |
39 | { | |
40 | struct svc_serv *serv = rqstp->rq_server; | |
41 | int err; | |
42 | ||
43 | __module_get(THIS_MODULE); | |
44 | lock_kernel(); | |
45 | ||
46 | nfs_callback_info.pid = current->pid; | |
47 | daemonize("nfsv4-svc"); | |
48 | /* Process request with signals blocked, but allow SIGKILL. */ | |
49 | allow_signal(SIGKILL); | |
50 | ||
51 | complete(&nfs_callback_info.started); | |
52 | ||
53 | while (nfs_callback_info.users != 0 || !signalled()) { | |
54 | /* | |
55 | * Listen for a request on the socket | |
56 | */ | |
57 | err = svc_recv(serv, rqstp, MAX_SCHEDULE_TIMEOUT); | |
58 | if (err == -EAGAIN || err == -EINTR) | |
59 | continue; | |
60 | if (err < 0) { | |
61 | printk(KERN_WARNING | |
62 | "%s: terminating on error %d\n", | |
63 | __FUNCTION__, -err); | |
64 | break; | |
65 | } | |
66 | dprintk("%s: request from %u.%u.%u.%u\n", __FUNCTION__, | |
67 | NIPQUAD(rqstp->rq_addr.sin_addr.s_addr)); | |
68 | svc_process(serv, rqstp); | |
69 | } | |
70 | ||
71 | nfs_callback_info.pid = 0; | |
72 | complete(&nfs_callback_info.stopped); | |
73 | unlock_kernel(); | |
74 | module_put_and_exit(0); | |
75 | } | |
76 | ||
77 | /* | |
78 | * Bring up the server process if it is not already up. | |
79 | */ | |
80 | int nfs_callback_up(void) | |
81 | { | |
82 | struct svc_serv *serv; | |
83 | struct svc_sock *svsk; | |
84 | int ret = 0; | |
85 | ||
86 | lock_kernel(); | |
87 | down(&nfs_callback_sema); | |
88 | if (nfs_callback_info.users++ || nfs_callback_info.pid != 0) | |
89 | goto out; | |
90 | init_completion(&nfs_callback_info.started); | |
91 | init_completion(&nfs_callback_info.stopped); | |
92 | serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE); | |
93 | ret = -ENOMEM; | |
94 | if (!serv) | |
95 | goto out_err; | |
96 | /* FIXME: We don't want to register this socket with the portmapper */ | |
97 | ret = svc_makesock(serv, IPPROTO_TCP, 0); | |
98 | if (ret < 0) | |
99 | goto out_destroy; | |
100 | if (!list_empty(&serv->sv_permsocks)) { | |
101 | svsk = list_entry(serv->sv_permsocks.next, | |
102 | struct svc_sock, sk_list); | |
103 | nfs_callback_tcpport = ntohs(inet_sk(svsk->sk_sk)->sport); | |
104 | dprintk ("Callback port = 0x%x\n", nfs_callback_tcpport); | |
105 | } else | |
106 | BUG(); | |
107 | ret = svc_create_thread(nfs_callback_svc, serv); | |
108 | if (ret < 0) | |
109 | goto out_destroy; | |
110 | nfs_callback_info.serv = serv; | |
111 | wait_for_completion(&nfs_callback_info.started); | |
112 | out: | |
113 | up(&nfs_callback_sema); | |
114 | unlock_kernel(); | |
115 | return ret; | |
116 | out_destroy: | |
117 | svc_destroy(serv); | |
118 | out_err: | |
119 | nfs_callback_info.users--; | |
120 | goto out; | |
121 | } | |
122 | ||
123 | /* | |
124 | * Kill the server process if it is not already up. | |
125 | */ | |
126 | int nfs_callback_down(void) | |
127 | { | |
128 | int ret = 0; | |
129 | ||
130 | lock_kernel(); | |
131 | down(&nfs_callback_sema); | |
132 | if (--nfs_callback_info.users || nfs_callback_info.pid == 0) | |
133 | goto out; | |
134 | kill_proc(nfs_callback_info.pid, SIGKILL, 1); | |
135 | wait_for_completion(&nfs_callback_info.stopped); | |
136 | out: | |
137 | up(&nfs_callback_sema); | |
138 | unlock_kernel(); | |
139 | return ret; | |
140 | } | |
141 | ||
142 | static int nfs_callback_authenticate(struct svc_rqst *rqstp) | |
143 | { | |
144 | struct in_addr *addr = &rqstp->rq_addr.sin_addr; | |
145 | struct nfs4_client *clp; | |
146 | ||
147 | /* Don't talk to strangers */ | |
148 | clp = nfs4_find_client(addr); | |
149 | if (clp == NULL) | |
150 | return SVC_DROP; | |
151 | dprintk("%s: %u.%u.%u.%u NFSv4 callback!\n", __FUNCTION__, NIPQUAD(addr)); | |
152 | nfs4_put_client(clp); | |
153 | switch (rqstp->rq_authop->flavour) { | |
154 | case RPC_AUTH_NULL: | |
155 | if (rqstp->rq_proc != CB_NULL) | |
156 | return SVC_DENIED; | |
157 | break; | |
158 | case RPC_AUTH_UNIX: | |
159 | break; | |
160 | case RPC_AUTH_GSS: | |
161 | /* FIXME: RPCSEC_GSS handling? */ | |
162 | default: | |
163 | return SVC_DENIED; | |
164 | } | |
165 | return SVC_OK; | |
166 | } | |
167 | ||
168 | /* | |
169 | * Define NFS4 callback program | |
170 | */ | |
171 | extern struct svc_version nfs4_callback_version1; | |
172 | ||
173 | static struct svc_version *nfs4_callback_version[] = { | |
174 | [1] = &nfs4_callback_version1, | |
175 | }; | |
176 | ||
177 | static struct svc_stat nfs4_callback_stats; | |
178 | ||
179 | static struct svc_program nfs4_callback_program = { | |
180 | .pg_prog = NFS4_CALLBACK, /* RPC service number */ | |
181 | .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */ | |
182 | .pg_vers = nfs4_callback_version, /* version table */ | |
183 | .pg_name = "NFSv4 callback", /* service name */ | |
184 | .pg_class = "nfs", /* authentication class */ | |
185 | .pg_stats = &nfs4_callback_stats, | |
186 | .pg_authenticate = nfs_callback_authenticate, | |
187 | }; |