FreeBSD/Linux Kernel Cross Reference
sys/nfs/krpc_subr.c

     /*      $NetBSD: krpc_subr.c,v 1.12.4.1 1996/06/07 00:52:26 cgd Exp $   */
     /* $FreeBSD$    */
     
     /*
      * Copyright (c) 1995 Gordon Ross, Adam Glass
      * Copyright (c) 1992 Regents of the University of California.
      * All rights reserved.
      *
      * This software was developed by the Computer Systems Engineering group
     * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
     * contributed to Berkeley.
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by the University of
     *      California, Lawrence Berkeley Laboratory and its contributors.
     * 4. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     * partially based on:
     *      libnetboot/rpc.c
     *               @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp  (LBL)
     */
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/malloc.h>
    #include <sys/mbuf.h>
    #include <sys/socket.h>
    #include <sys/socketvar.h>
    #include <sys/uio.h>
    
    #include <net/if.h>
    #include <netinet/in.h>
    
    #include <nfs/rpcv2.h>
    #include <nfs/krpc.h>
    #include <nfs/xdr_subs.h>
    
    /*
     * Kernel support for Sun RPC
     *
     * Used currently for bootstrapping in nfs diskless configurations.
     */
    
    /*
     * Generic RPC headers
     */
    
    struct auth_info {
            u_int32_t       authtype;       /* auth type */
            u_int32_t       authlen;        /* auth length */
    };
    
    struct auth_unix {
            int32_t   ua_time;
            int32_t   ua_hostname;  /* null */
            int32_t   ua_uid;
            int32_t   ua_gid;
            int32_t   ua_gidlist;   /* null */
    };
    
    struct rpc_call {
            u_int32_t       rp_xid;         /* request transaction id */
            int32_t         rp_direction;   /* call direction (0) */
            u_int32_t       rp_rpcvers;     /* rpc version (2) */
            u_int32_t       rp_prog;        /* program */
            u_int32_t       rp_vers;        /* version */
            u_int32_t       rp_proc;        /* procedure */
            struct  auth_info rpc_auth;
            struct  auth_unix rpc_unix;
            struct  auth_info rpc_verf;
    };
    
    struct rpc_reply {
            u_int32_t rp_xid;               /* request transaction id */
            int32_t  rp_direction;          /* call direction (1) */
            int32_t  rp_astatus;            /* accept status (0: accepted) */
           union {
                   u_int32_t rpu_errno;
                   struct {
                           struct auth_info rok_auth;
                           u_int32_t       rok_status;
                   } rpu_rok;
           } rp_u;
   };
   #define rp_errno  rp_u.rpu_errno
   #define rp_auth   rp_u.rpu_rok.rok_auth
   #define rp_status rp_u.rpu_rok.rok_status
   
   #define MIN_REPLY_HDR 16        /* xid, dir, astat, errno */
   
   /*
    * What is the longest we will wait before re-sending a request?
    * Note this is also the frequency of "RPC timeout" messages.
    * The re-send loop count sup linearly to this maximum, so the
    * first complaint will happen after (1+2+3+4+5)=15 seconds.
    */
   #define MAX_RESEND_DELAY 5      /* seconds */
   
   /*
    * Call portmap to lookup a port number for a particular rpc program
    * Returns non-zero error on failure.
    */
   int
   krpc_portmap(sin,  prog, vers, portp, procp)
           struct sockaddr_in *sin;                /* server address */
           u_int prog, vers;       /* host order */
           u_int16_t *portp;       /* network order */
           struct proc *procp;
   {
           struct sdata {
                   u_int32_t prog;         /* call program */
                   u_int32_t vers;         /* call version */
                   u_int32_t proto;        /* call protocol */
                   u_int32_t port;         /* call port (unused) */
           } *sdata;
           struct rdata {
                   u_int16_t pad;
                   u_int16_t port;
           } *rdata;
           struct mbuf *m;
           int error;
   
           /* The portmapper port is fixed. */
           if (prog == PMAPPROG) {
                   *portp = htons(PMAPPORT);
                   return 0;
           }
   
           m = m_get(M_WAIT, MT_DATA);
           if (m == NULL)
                   return ENOBUFS;
           sdata = mtod(m, struct sdata *);
           m->m_len = sizeof(*sdata);
   
           /* Do the RPC to get it. */
           sdata->prog = txdr_unsigned(prog);
           sdata->vers = txdr_unsigned(vers);
           sdata->proto = txdr_unsigned(IPPROTO_UDP);
           sdata->port = 0;
   
           sin->sin_port = htons(PMAPPORT);
           error = krpc_call(sin, PMAPPROG, PMAPVERS,
                                             PMAPPROC_GETPORT, &m, NULL, procp);
           if (error) 
                   return error;
   
           if (m->m_len < sizeof(*rdata)) {
                   m = m_pullup(m, sizeof(*rdata));
                   if (m == NULL)
                           return ENOBUFS;
           }
           rdata = mtod(m, struct rdata *);
           *portp = rdata->port;
   
           m_freem(m);
           return 0;
   }
   
   /*
    * Do a remote procedure call (RPC) and wait for its reply.
    * If from_p is non-null, then we are doing broadcast, and
    * the address from whence the response came is saved there.
    */
   int
   krpc_call(sa, prog, vers, func, data, from_p, procp)
           struct sockaddr_in *sa;
           u_int prog, vers, func;
           struct mbuf **data;     /* input/output */
           struct sockaddr **from_p;       /* output */
           struct proc *procp;
   {
           struct socket *so;
           struct sockaddr_in *sin, ssin;
           struct sockaddr *from;
           struct mbuf *m, *nam, *mhead;
           struct rpc_call *call;
           struct rpc_reply *reply;
           struct sockopt sopt;
           struct timeval tv;
           struct uio auio;
           int error, rcvflg, timo, secs, len;
           static u_int32_t xid = ~0xFF;
           u_int16_t tport;
   
           /*
            * Validate address family.
            * Sorry, this is INET specific...
            */
           if (sa->sin_family != AF_INET)
                   return (EAFNOSUPPORT);
   
           /* Free at end if not null. */
           nam = mhead = NULL;
           from = NULL;
   
           /*
            * Create socket and set its recieve timeout.
            */
           if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, procp)))
                   goto out;
   
           tv.tv_sec = 1;
           tv.tv_usec = 0;
           bzero(&sopt, sizeof sopt);
           sopt.sopt_level = SOL_SOCKET;
           sopt.sopt_name = SO_RCVTIMEO;
           sopt.sopt_val = &tv;
           sopt.sopt_valsize = sizeof tv;
   
           if (error = sosetopt(so, &sopt))
                   goto out;
   
           /*
            * Enable broadcast if necessary.
            */
           if (from_p) {
                   int on = 1;
                   sopt.sopt_name = SO_BROADCAST;
                   sopt.sopt_val = &on;
                   sopt.sopt_valsize = sizeof on;
                   if (error = sosetopt(so, &sopt))
                           goto out;
           }
   
           /*
            * Bind the local endpoint to a reserved port,
            * because some NFS servers refuse requests from
            * non-reserved (non-privileged) ports.
            */
           sin = &ssin;
           bzero(sin, sizeof *sin);
           sin->sin_len = sizeof(*sin);
           sin->sin_family = AF_INET;
           sin->sin_addr.s_addr = INADDR_ANY;
           tport = IPPORT_RESERVED;
           do {
                   tport--;
                   sin->sin_port = htons(tport);
                   error = sobind(so, (struct sockaddr *)sin, procp);
           } while (error == EADDRINUSE &&
                            tport > IPPORT_RESERVED / 2);
           if (error) {
                   printf("bind failed\n");
                   goto out;
           }
   
           /*
            * Setup socket address for the server.
            */
   
           /*
            * Prepend RPC message header.
            */
           mhead = m_gethdr(M_WAIT, MT_DATA);
           mhead->m_next = *data;
           call = mtod(mhead, struct rpc_call *);
           mhead->m_len = sizeof(*call);
           bzero((caddr_t)call, sizeof(*call));
           /* rpc_call part */
           xid++;
           call->rp_xid = txdr_unsigned(xid);
           /* call->rp_direction = 0; */
           call->rp_rpcvers = txdr_unsigned(2);
           call->rp_prog = txdr_unsigned(prog);
           call->rp_vers = txdr_unsigned(vers);
           call->rp_proc = txdr_unsigned(func);
           /* rpc_auth part (auth_unix as root) */
           call->rpc_auth.authtype = txdr_unsigned(RPCAUTH_UNIX);
           call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
           /* rpc_verf part (auth_null) */
           call->rpc_verf.authtype = 0;
           call->rpc_verf.authlen  = 0;
   
           /*
            * Setup packet header
            */
           len = 0;
           m = mhead;
           while (m) {
                   len += m->m_len;
                   m = m->m_next;
           }
           mhead->m_pkthdr.len = len;
           mhead->m_pkthdr.rcvif = NULL;
   
           /*
            * Send it, repeatedly, until a reply is received,
            * but delay each re-send by an increasing amount.
            * If the delay hits the maximum, start complaining.
            */
           timo = 0;
           for (;;) {
                   /* Send RPC request (or re-send). */
                   m = m_copym(mhead, 0, M_COPYALL, M_WAIT);
                   if (m == NULL) {
                           error = ENOBUFS;
                           goto out;
                   }
                   error = sosend(so, (struct sockaddr *)sa, NULL, m,
                                  NULL, 0, 0);
                   if (error) {
                           printf("krpc_call: sosend: %d\n", error);
                           goto out;
                   }
                   m = NULL;
   
                   /* Determine new timeout. */
                   if (timo < MAX_RESEND_DELAY)
                           timo++;
                   else
                           printf("RPC timeout for server 0x%lx\n",
                                  (u_long)ntohl(sa->sin_addr.s_addr));
   
                   /*
                    * Wait for up to timo seconds for a reply.
                    * The socket receive timeout was set to 1 second.
                    */
                   secs = timo;
                   while (secs > 0) {
                           if (from) {
                                   FREE(from, M_SONAME);
                                   from = NULL;
                           }
                           if (m) {
                                   m_freem(m);
                                   m = NULL;
                           }
                           bzero(&auio,sizeof(auio));
                           auio.uio_resid = len = 1<<16;
                           rcvflg = 0;
                           error = soreceive(so, &from, &auio, &m, NULL, &rcvflg);
                           if (error == EWOULDBLOCK) {
                                   secs--;
                                   continue;
                           }
                           if (error)
                                   goto out;
                           len -= auio.uio_resid;
   
                           /* Does the reply contain at least a header? */
                           if (len < MIN_REPLY_HDR)
                                   continue;
                           if (m->m_len < MIN_REPLY_HDR)
                                   continue;
                           reply = mtod(m, struct rpc_reply *);
   
                           /* Is it the right reply? */
                           if (reply->rp_direction != txdr_unsigned(RPC_REPLY))
                                   continue;
   
                           if (reply->rp_xid != txdr_unsigned(xid))
                                   continue;
   
                           /* Was RPC accepted? (authorization OK) */
                           if (reply->rp_astatus != 0) {
                                   error = fxdr_unsigned(u_int32_t, reply->rp_errno);
                                   printf("rpc denied, error=%d\n", error);
                                   continue;
                           }
   
                           /* Did the call succeed? */
                           if (reply->rp_status != 0) {
                                   error = fxdr_unsigned(u_int32_t, reply->rp_status);
                                   if (error == RPC_PROGMISMATCH) {
                                     error = EBADRPC;
                                     goto out;
                                   }
                                   printf("rpc denied, status=%d\n", error);
                                   continue;
                           }
   
                           goto gotreply;  /* break two levels */
   
                   } /* while secs */
           } /* forever send/receive */
   
           error = ETIMEDOUT;
           goto out;
   
    gotreply:
   
           /*
            * Get RPC reply header into first mbuf,
            * get its length, then strip it off.
            */
           len = sizeof(*reply);
           if (m->m_len < len) {
                   m = m_pullup(m, len);
                   if (m == NULL) {
                           error = ENOBUFS;
                           goto out;
                   }
           }
           reply = mtod(m, struct rpc_reply *);
           if (reply->rp_auth.authtype != 0) {
                   len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
                   len = (len + 3) & ~3; /* XXX? */
           }
           m_adj(m, len);
   
           /* result */
           *data = m;
           if (from_p) {
                   *from_p = from;
                   from = NULL;
           }
   
    out:
           if (mhead) m_freem(mhead);
           if (from) free(from, M_SONAME);
           soclose(so);
           return error;
   }
   
   /*
    * eXternal Data Representation routines.
    * (but with non-standard args...)
    */
   
   /*
    * String representation for RPC.
    */
   struct xdr_string {
           u_int32_t len;          /* length without null or padding */
           char data[4];   /* data (longer, of course) */
       /* data is padded to a long-word boundary */
   };
   
   struct mbuf *
   xdr_string_encode(str, len)
           char *str;
           int len;
   {
           struct mbuf *m;
           struct xdr_string *xs;
           int dlen;       /* padded string length */
           int mlen;       /* message length */
   
           dlen = (len + 3) & ~3;
           mlen = dlen + 4;
   
           if (mlen > MCLBYTES)            /* If too big, we just can't do it. */
                   return (NULL);
   
           m = m_get(M_WAIT, MT_DATA);
           if (mlen > MLEN) {
                   MCLGET(m, M_WAIT);
                   if ((m->m_flags & M_EXT) == 0) {
                           (void) m_free(m);       /* There can be only one. */
                           return (NULL);
                   }
           }
           xs = mtod(m, struct xdr_string *);
           m->m_len = mlen;
           xs->len = txdr_unsigned(len);
           bcopy(str, xs->data, len);
           return (m);
   }

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