fs/nfs/callback.c

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