net/sunrpc/pmap_clnt.c

   1 /*
   2  * linux/net/sunrpc/pmap.c
   3  *
   4  * Portmapper client.
   5  *
   6  * FIXME: In a secure environment, we may want to use an authentication
   7  * flavor other than AUTH_NULL.
   8  *
   9  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
  10  */
  11
  12 #include <linux/config.h>
  13 #include <linux/types.h>
  14 #include <linux/socket.h>
  15 #include <linux/kernel.h>
  16 #include <linux/errno.h>
  17 #include <linux/uio.h>
  18 #include <linux/in.h>
  19 #include <linux/sunrpc/clnt.h>
  20 #include <linux/sunrpc/xprt.h>
  21 #include <linux/sunrpc/sched.h>
  22
  23 #ifdef RPC_DEBUG
  24 # define RPCDBG_FACILITY        RPCDBG_PMAP
  25 #endif
  26
  27 #define PMAP_SET                1
  28 #define PMAP_UNSET              2
  29 #define PMAP_GETPORT            3
  30
  31 static struct rpc_procinfo      pmap_procedures[];
  32 static struct rpc_clnt *        pmap_create(char *, struct sockaddr_in *, int);
  33 static void                     pmap_getport_done(struct rpc_task *);
  34 extern struct rpc_program       pmap_program;
  35 static spinlock_t               pmap_lock = SPIN_LOCK_UNLOCKED;
  36
  37 /*
  38  * Obtain the port for a given RPC service on a given host. This one can
  39  * be called for an ongoing RPC request.
  40  */
  41 void
  42 rpc_getport(struct rpc_task *task, struct rpc_clnt *clnt)
  43 {
  44         struct rpc_portmap *map = clnt->cl_pmap;
  45         struct sockaddr_in *sap = &clnt->cl_xprt->addr;
  46         struct rpc_message msg = {
  47                 .rpc_proc       = &pmap_procedures[PMAP_GETPORT],
  48                 .rpc_argp       = map,
  49                 .rpc_resp       = &clnt->cl_port,
  50                 .rpc_cred       = NULL
  51         };
  52         struct rpc_clnt *pmap_clnt;
  53         struct rpc_task *child;
  54
  55         dprintk("RPC: %4d rpc_getport(%s, %d, %d, %d)\n",
  56                         task->tk_pid, clnt->cl_server,
  57                         map->pm_prog, map->pm_vers, map->pm_prot);
  58
  59         spin_lock(&pmap_lock);
  60         if (map->pm_binding) {
  61                 rpc_sleep_on(&map->pm_bindwait, task, NULL, NULL);
  62                 spin_unlock(&pmap_lock);
  63                 return;
  64         }
  65         map->pm_binding = 1;
  66         spin_unlock(&pmap_lock);
  67
  68         pmap_clnt = pmap_create(clnt->cl_server, sap, map->pm_prot);
  69         if (IS_ERR(pmap_clnt)) {
  70                 task->tk_status = PTR_ERR(pmap_clnt);
  71                 goto bailout;
  72         }
  73         task->tk_status = 0;
  74
  75         /*
  76          * Note: rpc_new_child will release client after a failure.
  77          */
  78         if (!(child = rpc_new_child(pmap_clnt, task)))
  79                 goto bailout;
  80
  81         /* Setup the call info struct */
  82         rpc_call_setup(child, &msg, 0);
  83
  84         /* ... and run the child task */
  85         rpc_run_child(task, child, pmap_getport_done);
  86         return;
  87
  88 bailout:
  89         spin_lock(&pmap_lock);
  90         map->pm_binding = 0;
  91         rpc_wake_up(&map->pm_bindwait);
  92         spin_unlock(&pmap_lock);
  93         task->tk_status = -EIO;
  94         task->tk_action = NULL;
  95 }
  96
  97 #ifdef CONFIG_ROOT_NFS
  98 int
  99 rpc_getport_external(struct sockaddr_in *sin, __u32 prog, __u32 vers, int prot)
 100 {
 101         struct rpc_portmap map = {
 102                 .pm_prog        = prog,
 103                 .pm_vers        = vers,
 104                 .pm_prot        = prot,
 105                 .pm_port        = 0
 106         };
 107         struct rpc_clnt *pmap_clnt;
 108         char            hostname[32];
 109         int             status;
 110
 111         dprintk("RPC:      rpc_getport_external(%u.%u.%u.%u, %d, %d, %d)\n",
 112                         NIPQUAD(sin->sin_addr.s_addr), prog, vers, prot);
 113
 114         sprintf(hostname, "%u.%u.%u.%u", NIPQUAD(sin->sin_addr.s_addr));
 115         pmap_clnt = pmap_create(hostname, sin, prot);
 116         if (IS_ERR(pmap_clnt))
 117                 return PTR_ERR(pmap_clnt);
 118
 119         /* Setup the call info struct */
 120         status = rpc_call(pmap_clnt, PMAP_GETPORT, &map, &map.pm_port, 0);
 121
 122         if (status >= 0) {
 123                 if (map.pm_port != 0)
 124                         return map.pm_port;
 125                 status = -EACCES;
 126         }
 127         return status;
 128 }
 129 #endif
 130
 131 static void
 132 pmap_getport_done(struct rpc_task *task)
 133 {
 134         struct rpc_clnt *clnt = task->tk_client;
 135         struct rpc_portmap *map = clnt->cl_pmap;
 136
 137         dprintk("RPC: %4d pmap_getport_done(status %d, port %d)\n",
 138                         task->tk_pid, task->tk_status, clnt->cl_port);
 139         if (task->tk_status < 0) {
 140                 /* Make the calling task exit with an error */
 141                 task->tk_action = NULL;
 142         } else if (clnt->cl_port == 0) {
 143                 /* Program not registered */
 144                 task->tk_status = -EACCES;
 145                 task->tk_action = NULL;
 146         } else {
 147                 /* byte-swap port number first */
 148                 clnt->cl_port = htons(clnt->cl_port);
 149                 clnt->cl_xprt->addr.sin_port = clnt->cl_port;
 150         }
 151         spin_lock(&pmap_lock);
 152         map->pm_binding = 0;
 153         rpc_wake_up(&map->pm_bindwait);
 154         spin_unlock(&pmap_lock);
 155 }
 156
 157 /*
 158  * Set or unset a port registration with the local portmapper.
 159  * port == 0 means unregister, port != 0 means register.
 160  */
 161 int
 162 rpc_register(u32 prog, u32 vers, int prot, unsigned short port, int *okay)
 163 {
 164         struct sockaddr_in      sin;
 165         struct rpc_portmap      map;
 166         struct rpc_clnt         *pmap_clnt;
 167         int error = 0;
 168
 169         dprintk("RPC: registering (%d, %d, %d, %d) with portmapper.\n",
 170                         prog, vers, prot, port);
 171
 172         sin.sin_family = AF_INET;
 173         sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 174         pmap_clnt = pmap_create("localhost", &sin, IPPROTO_UDP);
 175         if (IS_ERR(pmap_clnt)) {
 176                 error = PTR_ERR(pmap_clnt);
 177                 dprintk("RPC: couldn't create pmap client. Error = %d\n", error);
 178                 return error;
 179         }
 180
 181         map.pm_prog = prog;
 182         map.pm_vers = vers;
 183         map.pm_prot = prot;
 184         map.pm_port = port;
 185
 186         error = rpc_call(pmap_clnt, port? PMAP_SET : PMAP_UNSET,
 187                                         &map, okay, 0);
 188
 189         if (error < 0) {
 190                 printk(KERN_WARNING
 191                         "RPC: failed to contact portmap (errno %d).\n",
 192                         error);
 193         }
 194         dprintk("RPC: registration status %d/%d\n", error, *okay);
 195
 196         /* Client deleted automatically because cl_oneshot == 1 */
 197         return error;
 198 }
 199
 200 static struct rpc_clnt *
 201 pmap_create(char *hostname, struct sockaddr_in *srvaddr, int proto)
 202 {
 203         struct rpc_xprt *xprt;
 204         struct rpc_clnt *clnt;
 205
 206         /* printk("pmap: create xprt\n"); */
 207         xprt = xprt_create_proto(proto, srvaddr, NULL);
 208         if (IS_ERR(xprt))
 209                 return (struct rpc_clnt *)xprt;
 210         xprt->addr.sin_port = htons(RPC_PMAP_PORT);
 211
 212         /* printk("pmap: create clnt\n"); */
 213         clnt = rpc_create_client(xprt, hostname,
 214                                 &pmap_program, RPC_PMAP_VERSION,
 215                                 RPC_AUTH_NULL);
 216         if (IS_ERR(clnt)) {
 217                 xprt_destroy(xprt);
 218         } else {
 219                 clnt->cl_softrtry = 1;
 220                 clnt->cl_chatty   = 1;
 221                 clnt->cl_oneshot  = 1;
 222         }
 223         return clnt;
 224 }
 225
 226 /*
 227  * XDR encode/decode functions for PMAP
 228  */
 229 static int
 230 xdr_encode_mapping(struct rpc_rqst *req, u32 *p, struct rpc_portmap *map)
 231 {
 232         dprintk("RPC: xdr_encode_mapping(%d, %d, %d, %d)\n",
 233                 map->pm_prog, map->pm_vers, map->pm_prot, map->pm_port);
 234         *p++ = htonl(map->pm_prog);
 235         *p++ = htonl(map->pm_vers);
 236         *p++ = htonl(map->pm_prot);
 237         *p++ = htonl(map->pm_port);
 238
 239         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 240         return 0;
 241 }
 242
 243 static int
 244 xdr_decode_port(struct rpc_rqst *req, u32 *p, unsigned short *portp)
 245 {
 246         *portp = (unsigned short) ntohl(*p++);
 247         return 0;
 248 }
 249
 250 static int
 251 xdr_decode_bool(struct rpc_rqst *req, u32 *p, unsigned int *boolp)
 252 {
 253         *boolp = (unsigned int) ntohl(*p++);
 254         return 0;
 255 }
 256
 257 static struct rpc_procinfo      pmap_procedures[] = {
 258 [PMAP_SET] = {
 259           .p_proc               = PMAP_SET,
 260           .p_encode             = (kxdrproc_t) xdr_encode_mapping,
 261           .p_decode             = (kxdrproc_t) xdr_decode_bool,
 262           .p_bufsiz             = 4,
 263           .p_count              = 1,
 264         },
 265 [PMAP_UNSET] = {
 266           .p_proc               = PMAP_UNSET,
 267           .p_encode             = (kxdrproc_t) xdr_encode_mapping,
 268           .p_decode             = (kxdrproc_t) xdr_decode_bool,
 269           .p_bufsiz             = 4,
 270           .p_count              = 1,
 271         },
 272 [PMAP_GETPORT] = {
 273           .p_proc               = PMAP_GETPORT,
 274           .p_encode             = (kxdrproc_t) xdr_encode_mapping,
 275           .p_decode             = (kxdrproc_t) xdr_decode_port,
 276           .p_bufsiz             = 4,
 277           .p_count              = 1,
 278         },
 279 };
 280
 281 static struct rpc_version       pmap_version2 = {
 282         .number         = 2,
 283         .nrprocs        = 4,
 284         .procs          = pmap_procedures
 285 };
 286
 287 static struct rpc_version *     pmap_version[] = {
 288         NULL,
 289         NULL,
 290         &pmap_version2
 291 };
 292
 293 static struct rpc_stat          pmap_stats;
 294
 295 struct rpc_program      pmap_program = {
 296         .name           = "portmap",
 297         .number         = RPC_PMAP_PROGRAM,
 298         .nrvers         = ARRAY_SIZE(pmap_version),
 299         .version        = pmap_version,
 300         .stats          = &pmap_stats,
 301 };