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 18 #include <net/inet_sock.h> 19 20 #include "nfs4_fs.h" 21 #include "callback.h" 22 23 #define NFSDBG_FACILITY NFSDBG_CALLBACK 24 25 struct nfs_callback_data { 26 unsigned int users; 27 struct svc_serv *serv; 28 pid_t pid; 29 struct completion started; 30 struct completion stopped; 31 }; 32 33 static struct nfs_callback_data nfs_callback_info; 34 static DECLARE_MUTEX(nfs_callback_sema); 35 static struct svc_program nfs4_callback_program; 36 37 unsigned int nfs_callback_set_tcpport; 38 unsigned short nfs_callback_tcpport; 39 40 /* 41 * This is the callback kernel thread. 42 */ 43 static void nfs_callback_svc(struct svc_rqst *rqstp) 44 { 45 struct svc_serv *serv = rqstp->rq_server; 46 int err; 47 48 __module_get(THIS_MODULE); 49 lock_kernel(); 50 51 nfs_callback_info.pid = current->pid; 52 daemonize("nfsv4-svc"); 53 /* Process request with signals blocked, but allow SIGKILL. */ 54 allow_signal(SIGKILL); 55 56 complete(&nfs_callback_info.started); 57 58 while (nfs_callback_info.users != 0 || !signalled()) { 59 /* 60 * Listen for a request on the socket 61 */ 62 err = svc_recv(serv, rqstp, MAX_SCHEDULE_TIMEOUT); 63 if (err == -EAGAIN || err == -EINTR) 64 continue; 65 if (err < 0) { 66 printk(KERN_WARNING 67 "%s: terminating on error %d\n", 68 __FUNCTION__, -err); 69 break; 70 } 71 dprintk("%s: request from %u.%u.%u.%u\n", __FUNCTION__, 72 NIPQUAD(rqstp->rq_addr.sin_addr.s_addr)); 73 svc_process(serv, rqstp); 74 } 75 76 nfs_callback_info.pid = 0; 77 complete(&nfs_callback_info.stopped); 78 unlock_kernel(); 79 module_put_and_exit(0); 80 } 81 82 /* 83 * Bring up the server process if it is not already up. 84 */ 85 int nfs_callback_up(void) 86 { 87 struct svc_serv *serv; 88 struct svc_sock *svsk; 89 int ret = 0; 90 91 lock_kernel(); 92 down(&nfs_callback_sema); 93 if (nfs_callback_info.users++ || nfs_callback_info.pid != 0) 94 goto out; 95 init_completion(&nfs_callback_info.started); 96 init_completion(&nfs_callback_info.stopped); 97 serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE); 98 ret = -ENOMEM; 99 if (!serv) 100 goto out_err; 101 /* FIXME: We don't want to register this socket with the portmapper */ 102 ret = svc_makesock(serv, IPPROTO_TCP, nfs_callback_set_tcpport); 103 if (ret < 0) 104 goto out_destroy; 105 if (!list_empty(&serv->sv_permsocks)) { 106 svsk = list_entry(serv->sv_permsocks.next, 107 struct svc_sock, sk_list); 108 nfs_callback_tcpport = ntohs(inet_sk(svsk->sk_sk)->sport); 109 dprintk ("Callback port = 0x%x\n", nfs_callback_tcpport); 110 } else 111 BUG(); 112 ret = svc_create_thread(nfs_callback_svc, serv); 113 if (ret < 0) 114 goto out_destroy; 115 nfs_callback_info.serv = serv; 116 wait_for_completion(&nfs_callback_info.started); 117 out: 118 up(&nfs_callback_sema); 119 unlock_kernel(); 120 return ret; 121 out_destroy: 122 svc_destroy(serv); 123 out_err: 124 nfs_callback_info.users--; 125 goto out; 126 } 127 128 /* 129 * Kill the server process if it is not already up. 130 */ 131 int nfs_callback_down(void) 132 { 133 int ret = 0; 134 135 lock_kernel(); 136 down(&nfs_callback_sema); 137 if (--nfs_callback_info.users || nfs_callback_info.pid == 0) 138 goto out; 139 kill_proc(nfs_callback_info.pid, SIGKILL, 1); 140 wait_for_completion(&nfs_callback_info.stopped); 141 out: 142 up(&nfs_callback_sema); 143 unlock_kernel(); 144 return ret; 145 } 146 147 static int nfs_callback_authenticate(struct svc_rqst *rqstp) 148 { 149 struct in_addr *addr = &rqstp->rq_addr.sin_addr; 150 struct nfs4_client *clp; 151 152 /* Don't talk to strangers */ 153 clp = nfs4_find_client(addr); 154 if (clp == NULL) 155 return SVC_DROP; 156 dprintk("%s: %u.%u.%u.%u NFSv4 callback!\n", __FUNCTION__, NIPQUAD(addr)); 157 nfs4_put_client(clp); 158 switch (rqstp->rq_authop->flavour) { 159 case RPC_AUTH_NULL: 160 if (rqstp->rq_proc != CB_NULL) 161 return SVC_DENIED; 162 break; 163 case RPC_AUTH_UNIX: 164 break; 165 case RPC_AUTH_GSS: 166 /* FIXME: RPCSEC_GSS handling? */ 167 default: 168 return SVC_DENIED; 169 } 170 return SVC_OK; 171 } 172 173 /* 174 * Define NFS4 callback program 175 */ 176 extern struct svc_version nfs4_callback_version1; 177 178 static struct svc_version *nfs4_callback_version[] = { 179 [1] = &nfs4_callback_version1, 180 }; 181 182 static struct svc_stat nfs4_callback_stats; 183 184 static struct svc_program nfs4_callback_program = { 185 .pg_prog = NFS4_CALLBACK, /* RPC service number */ 186 .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */ 187 .pg_vers = nfs4_callback_version, /* version table */ 188 .pg_name = "NFSv4 callback", /* service name */ 189 .pg_class = "nfs", /* authentication class */ 190 .pg_stats = &nfs4_callback_stats, 191 .pg_authenticate = nfs_callback_authenticate, 192 }; 193