source: rtems/c/src/exec/librpc/src/rpc/clnt_unix.c @ df3b242

/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 *
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

#if defined(LIBC_SCCS) && !defined(lint)
/*static char *sccsid = "from: @(#)clnt_unix.c 1.37 87/10/05 Copyr 1984 Sun Micro";*/
/*static char *sccsid = "from: @(#)clnt_unix.c  2.2 88/08/01 4.0 RPCSRC";*/
static char *rcsid = "$FreeBSD: src/lib/libc/rpc/clnt_unix.c,v 1.5 2000/01/27 23:06:37 jasone Exp $";
#endif

/*
 * clnt_unix.c, Implements a AF_UNIX based, client side RPC.
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 *
 * AF_UNIX based RPC supports 'batched calls'.
 * A sequence of calls may be batched-up in a send buffer.  The rpc call
 * return immediately to the client even though the call was not necessarily
 * sent.  The batching occurs if the results' xdr routine is NULL (0) AND
 * the rpc timeout value is zero (see clnt.h, rpc).
 *
 * Clients should NOT casually batch calls that in fact return results; that is,
 * the server side should be aware that a call is batched and not produce any
 * return message.  Batched calls that produce many result messages can
 * deadlock (netlock) the client and the server....
 *
 * Now go hang yourself.
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <rpc/rpc.h>
#include <sys/uio.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <netdb.h>
#include <errno.h>
#include <rpc/pmap_clnt.h>

#define MCALL_MSG_SIZE 24

static int      readunix();
static int      writeunix();

static enum clnt_stat   clntunix_call();
static void             clntunix_abort();
static void             clntunix_geterr();
static bool_t           clntunix_freeres();
static bool_t           clntunix_control();
static void             clntunix_destroy();

static struct clnt_ops unix_ops = {
        clntunix_call,
        clntunix_abort,
        clntunix_geterr,
        clntunix_freeres,
        clntunix_destroy,
        clntunix_control
};

struct ct_data {
        int             ct_sock;
        bool_t          ct_closeit;
        struct timeval  ct_wait;
        bool_t          ct_waitset;       /* wait set by clnt_control? */
        struct sockaddr_un ct_addr;
        struct rpc_err  ct_error;
        char            ct_mcall[MCALL_MSG_SIZE];       /* marshalled callmsg */
        u_int           ct_mpos;                        /* pos after marshal */
        XDR             ct_xdrs;
};

/*
 * Create a client handle for a unix/ip connection.
 * If *sockp<0, *sockp is set to a newly created TCP socket and it is
 * connected to raddr.  If *sockp non-negative then
 * raddr is ignored.  The rpc/unix package does buffering
 * similar to stdio, so the client must pick send and receive buffer sizes,];
 * 0 => use the default.
 * If raddr->sin_port is 0, then a binder on the remote machine is
 * consulted for the right port number.
 * NB: *sockp is copied into a private area.
 * NB: It is the clients responsibility to close *sockp.
 * NB: The rpch->cl_auth is set null authentication.  Caller may wish to set this
 * something more useful.
 */
CLIENT *
clntunix_create(raddr, prog, vers, sockp, sendsz, recvsz)
        struct sockaddr_un *raddr;
        u_long prog;
        u_long vers;
        register int *sockp;
        u_int sendsz;
        u_int recvsz;
{
        CLIENT *h;
        register struct ct_data *ct = NULL;
        struct timeval now;
        struct rpc_msg call_msg;
        static u_int32_t disrupt;
        int len;

        if (disrupt == 0)
                disrupt = (u_int32_t)(long)raddr;

        h  = (CLIENT *)mem_alloc(sizeof(*h));
        if (h == NULL) {
                (void)fprintf(stderr, "clntunix_create: out of memory\n");
                rpc_createerr.cf_stat = RPC_SYSTEMERROR;
                rpc_createerr.cf_error.re_errno = errno;
                goto fooy;
        }
        ct = (struct ct_data *)mem_alloc(sizeof(*ct));
        if (ct == NULL) {
                (void)fprintf(stderr, "clntunix_create: out of memory\n");
                rpc_createerr.cf_stat = RPC_SYSTEMERROR;
                rpc_createerr.cf_error.re_errno = errno;
                goto fooy;
        }

        /*
         * If no socket given, open one
         */
        if (*sockp < 0) {
                *sockp = socket(AF_UNIX, SOCK_STREAM, 0);
                len = strlen(raddr->sun_path) + sizeof(raddr->sun_family) +
                        sizeof(raddr->sun_len) + 1;
                raddr->sun_len = len;
                if ((*sockp < 0)
                    || (connect(*sockp, (struct sockaddr *)raddr, len) < 0)) {
                        rpc_createerr.cf_stat = RPC_SYSTEMERROR;
                        rpc_createerr.cf_error.re_errno = errno;
                        if (*sockp != -1)
                                (void)_RPC_close(*sockp);
                        goto fooy;
                }
                ct->ct_closeit = TRUE;
        } else {
                ct->ct_closeit = FALSE;
        }

        /*
         * Set up private data struct
         */
        ct->ct_sock = *sockp;
        ct->ct_wait.tv_usec = 0;
        ct->ct_waitset = FALSE;
        ct->ct_addr = *raddr;

        /*
         * Initialize call message
         */
        (void)gettimeofday(&now, (struct timezone *)0);
        call_msg.rm_xid = (++disrupt) ^ getpid() ^ now.tv_sec ^ now.tv_usec;
        call_msg.rm_direction = CALL;
        call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
        call_msg.rm_call.cb_prog = prog;
        call_msg.rm_call.cb_vers = vers;

        /*
         * pre-serialize the static part of the call msg and stash it away
         */
        xdrmem_create(&(ct->ct_xdrs), ct->ct_mcall, MCALL_MSG_SIZE,
            XDR_ENCODE);
        if (! xdr_callhdr(&(ct->ct_xdrs), &call_msg)) {
                if (ct->ct_closeit) {
                        (void)_RPC_close(*sockp);
                }
                goto fooy;
        }
        ct->ct_mpos = XDR_GETPOS(&(ct->ct_xdrs));
        XDR_DESTROY(&(ct->ct_xdrs));

        /*
         * Create a client handle which uses xdrrec for serialization
         * and authnone for authentication.
         */
        xdrrec_create(&(ct->ct_xdrs), sendsz, recvsz,
            (caddr_t)ct, readunix, writeunix);
        h->cl_ops = &unix_ops;
        h->cl_private = (caddr_t) ct;
        h->cl_auth = authnone_create();
        return (h);

fooy:
        /*
         * Something goofed, free stuff and barf
         */
        if (ct)
                mem_free((caddr_t)ct, sizeof(struct ct_data));
        if (h)
                mem_free((caddr_t)h, sizeof(CLIENT));
        return ((CLIENT *)NULL);
}

static enum clnt_stat
clntunix_call(h, proc, xdr_args, args_ptr, xdr_results, results_ptr, timeout)
        register CLIENT *h;
        u_long proc;
        xdrproc_t xdr_args;
        caddr_t args_ptr;
        xdrproc_t xdr_results;
        caddr_t results_ptr;
        struct timeval timeout;
{
        register struct ct_data *ct = (struct ct_data *) h->cl_private;
        register XDR *xdrs = &(ct->ct_xdrs);
        struct rpc_msg reply_msg;
        u_long x_id;
        u_int32_t *msg_x_id = (u_int32_t *)(ct->ct_mcall);      /* yuk */
        register bool_t shipnow;
        int refreshes = 2;

        if (!ct->ct_waitset) {
                ct->ct_wait = timeout;
        }

        shipnow =
            (xdr_results == (xdrproc_t)0 && timeout.tv_sec == 0
            && timeout.tv_usec == 0) ? FALSE : TRUE;

call_again:
        xdrs->x_op = XDR_ENCODE;
        ct->ct_error.re_status = RPC_SUCCESS;
        x_id = ntohl(--(*msg_x_id));
        if ((! XDR_PUTBYTES(xdrs, ct->ct_mcall, ct->ct_mpos)) ||
            (! XDR_PUTLONG(xdrs, (long *)&proc)) ||
            (! AUTH_MARSHALL(h->cl_auth, xdrs)) ||
            (! (*xdr_args)(xdrs, args_ptr))) {
                if (ct->ct_error.re_status == RPC_SUCCESS)
                        ct->ct_error.re_status = RPC_CANTENCODEARGS;
                (void)xdrrec_endofrecord(xdrs, TRUE);
                return (ct->ct_error.re_status);
        }
        if (! xdrrec_endofrecord(xdrs, shipnow))
                return (ct->ct_error.re_status = RPC_CANTSEND);
        if (! shipnow)
                return (RPC_SUCCESS);
        /*
         * Hack to provide rpc-based message passing
         */
        if (timeout.tv_sec == 0 && timeout.tv_usec == 0) {
                return(ct->ct_error.re_status = RPC_TIMEDOUT);
        }


        /*
         * Keep receiving until we get a valid transaction id
         */
        xdrs->x_op = XDR_DECODE;
        while (TRUE) {
                reply_msg.acpted_rply.ar_verf = _null_auth;
                reply_msg.acpted_rply.ar_results.where = NULL;
                reply_msg.acpted_rply.ar_results.proc = xdr_void;
                if (! xdrrec_skiprecord(xdrs))
                        return (ct->ct_error.re_status);
                /* now decode and validate the response header */
                if (! xdr_replymsg(xdrs, &reply_msg)) {
                        if (ct->ct_error.re_status == RPC_SUCCESS)
                                continue;
                        return (ct->ct_error.re_status);
                }
                if (reply_msg.rm_xid == x_id)
                        break;
        }

        /*
         * process header
         */
        _seterr_reply(&reply_msg, &(ct->ct_error));
        if (ct->ct_error.re_status == RPC_SUCCESS) {
                if (! AUTH_VALIDATE(h->cl_auth, &reply_msg.acpted_rply.ar_verf)) {
                        ct->ct_error.re_status = RPC_AUTHERROR;
                        ct->ct_error.re_why = AUTH_INVALIDRESP;
                } else if (! (*xdr_results)(xdrs, results_ptr)) {
                        if (ct->ct_error.re_status == RPC_SUCCESS)
                                ct->ct_error.re_status = RPC_CANTDECODERES;
                }
                /* free verifier ... */
                if (reply_msg.acpted_rply.ar_verf.oa_base != NULL) {
                        xdrs->x_op = XDR_FREE;
                        (void)xdr_opaque_auth(xdrs, &(reply_msg.acpted_rply.ar_verf));
                }
        }  /* end successful completion */
        else {
                /* maybe our credentials need to be refreshed ... */
                if (refreshes-- && AUTH_REFRESH(h->cl_auth))
                        goto call_again;
        }  /* end of unsuccessful completion */
        return (ct->ct_error.re_status);
}

static void
clntunix_geterr(h, errp)
        CLIENT *h;
        struct rpc_err *errp;
{
        register struct ct_data *ct =
            (struct ct_data *) h->cl_private;

        *errp = ct->ct_error;
}

static bool_t
clntunix_freeres(cl, xdr_res, res_ptr)
        CLIENT *cl;
        xdrproc_t xdr_res;
        caddr_t res_ptr;
{
        register struct ct_data *ct = (struct ct_data *)cl->cl_private;
        register XDR *xdrs = &(ct->ct_xdrs);

        xdrs->x_op = XDR_FREE;
        return ((*xdr_res)(xdrs, res_ptr));
}

static void
clntunix_abort()
{
}


static bool_t
clntunix_control(cl, request, info)
        CLIENT *cl;
        int request;
        char *info;
{
        register struct ct_data *ct = (struct ct_data *)cl->cl_private;
        register struct timeval *tv;
        int len;

        switch (request) {
        case CLSET_FD_CLOSE:
                ct->ct_closeit = TRUE;
                break;
        case CLSET_FD_NCLOSE:
                ct->ct_closeit = FALSE;
                break;
        case CLSET_TIMEOUT:
                if (info == NULL)
                        return(FALSE);
                tv = (struct timeval *)info;
                ct->ct_wait.tv_sec = tv->tv_sec;
                ct->ct_wait.tv_usec = tv->tv_usec;
                ct->ct_waitset = TRUE;
                break;
        case CLGET_TIMEOUT:
                if (info == NULL)
                        return(FALSE);
                *(struct timeval *)info = ct->ct_wait;
                break;
        case CLGET_SERVER_ADDR:
                if (info == NULL)
                        return(FALSE);
                *(struct sockaddr_un *)info = ct->ct_addr;
                break;
        case CLGET_FD:
                if (info == NULL)
                        return(FALSE);
                *(int *)info = ct->ct_sock;
                break;
        case CLGET_XID:
                /*
                 * use the knowledge that xid is the
                 * first element in the call structure *.
                 * This will get the xid of the PREVIOUS call
                 */
                if (info == NULL)
                        return(FALSE);
                *(u_long *)info = ntohl(*(u_long *)ct->ct_mcall);
                break;
        case CLSET_XID:
                /* This will set the xid of the NEXT call */
                if (info == NULL)
                        return(FALSE);
                *(u_long *)ct->ct_mcall =  htonl(*(u_long *)info - 1);
                /* decrement by 1 as clntunix_call() increments once */
        case CLGET_VERS:
                /*
                 * This RELIES on the information that, in the call body,
                 * the version number field is the fifth field from the
                 * begining of the RPC header. MUST be changed if the
                 * call_struct is changed
                 */
                if (info == NULL)
                        return(FALSE);
                *(u_long *)info = ntohl(*(u_long *)(ct->ct_mcall +
                                                4 * BYTES_PER_XDR_UNIT));
                break;
        case CLSET_VERS:
                if (info == NULL)
                        return(FALSE);
                *(u_long *)(ct->ct_mcall + 4 * BYTES_PER_XDR_UNIT)
                                = htonl(*(u_long *)info);
                break;
        case CLGET_PROG:
                /*
                 * This RELIES on the information that, in the call body,
                 * the program number field is the  field from the
                 * begining of the RPC header. MUST be changed if the
                 * call_struct is changed
                 */
                if (info == NULL)
                        return(FALSE);
                *(u_long *)info = ntohl(*(u_long *)(ct->ct_mcall +
                                                3 * BYTES_PER_XDR_UNIT));
                break;
        case CLSET_PROG:
                if (info == NULL)
                        return(FALSE);
                *(u_long *)(ct->ct_mcall + 3 * BYTES_PER_XDR_UNIT)
                                = htonl(*(u_long *)info);
                break;
        case CLGET_LOCAL_ADDR:
                len = sizeof(struct sockaddr);
                if (getsockname(ct->ct_sock, (struct sockaddr *)info, &len) <0)
                        return(FALSE);
                break;
        case CLGET_RETRY_TIMEOUT:
        case CLSET_RETRY_TIMEOUT:
        case CLGET_SVC_ADDR:
        case CLSET_SVC_ADDR:
        case CLSET_PUSH_TIMOD:
        case CLSET_POP_TIMOD:
        default:
                return (FALSE);
        }
        return (TRUE);
}


static void
clntunix_destroy(h)
        CLIENT *h;
{
        register struct ct_data *ct =
            (struct ct_data *) h->cl_private;

        if (ct->ct_closeit) {
                (void)_RPC_close(ct->ct_sock);
        }
        XDR_DESTROY(&(ct->ct_xdrs));
        mem_free((caddr_t)ct, sizeof(struct ct_data));
        mem_free((caddr_t)h, sizeof(CLIENT));
}

/*
 * read() and write() are replaced with recvmsg()/sendmsg() so that
 * we can pass ancillary control data. In this case, the data constists
 * of credential information which the kernel will fill in for us.
 * XXX: This code is specific to FreeBSD and will not work on other
 * platforms without the requisite kernel modifications.
 */
struct cmessage {
        struct cmsghdr cmsg;
        struct cmsgcred cmcred;
};

static int __msgread(sock, buf, cnt)
        int sock;
        void *buf;
        size_t cnt;
{
        struct iovec iov[1];
        struct msghdr msg;
        struct cmessage cm;

        bzero((char *)&cm, sizeof(cm));
        iov[0].iov_base = buf;
        iov[0].iov_len = cnt;

        msg.msg_iov = iov;
        msg.msg_iovlen = 1;
        msg.msg_name = NULL;
        msg.msg_namelen = 0;
        msg.msg_control = (caddr_t)&cm;
        msg.msg_controllen = sizeof(struct cmessage);
        msg.msg_flags = 0;

        return(recvmsg(sock, &msg, 0));
}

static int __msgwrite(sock, buf, cnt)
        int sock;
        void *buf;
        size_t cnt;
{
        struct iovec iov[1];
        struct msghdr msg;
        struct cmessage cm;

        bzero((char *)&cm, sizeof(cm));
        iov[0].iov_base = buf;
        iov[0].iov_len = cnt;

        cm.cmsg.cmsg_type = SCM_CREDS;
        cm.cmsg.cmsg_level = SOL_SOCKET;
        cm.cmsg.cmsg_len = sizeof(struct cmessage);

        msg.msg_iov = iov;
        msg.msg_iovlen = 1;
        msg.msg_name = NULL;
        msg.msg_namelen = 0;
        msg.msg_control = (caddr_t)&cm;
        msg.msg_controllen = sizeof(struct cmessage);
        msg.msg_flags = 0;

        return(sendmsg(sock, &msg, 0));
}

/*
 * Interface between xdr serializer and unix connection.
 * Behaves like the system calls, read & write, but keeps some error state
 * around for the rpc level.
 */
static int
readunix(ct, buf, len)
        register struct ct_data *ct;
        caddr_t buf;
        register int len;
{
        fd_set *fds, readfds;
        struct timeval start, after, duration, delta, tmp, tv;
        int r, save_errno;

        if (len == 0)
                return (0);

        if (ct->ct_sock + 1 > FD_SETSIZE) {
                int bytes = howmany(ct->ct_sock + 1, NFDBITS) * sizeof(fd_mask);
                fds = (fd_set *)malloc(bytes);
                if (fds == NULL)
                        return (-1);
                memset(fds, 0, bytes);
        } else {
                fds = &readfds;
                FD_ZERO(fds);
        }

        gettimeofday(&start, NULL);
        delta = ct->ct_wait;
        while (TRUE) {
                /* XXX we know the other bits are still clear */
                FD_SET(ct->ct_sock, fds);
                tv = delta;     /* in case select writes back */
                r = select(ct->ct_sock+1, fds, NULL, NULL, &tv);
                save_errno = errno;

                gettimeofday(&after, NULL);
                timersub(&start, &after, &duration);
                timersub(&delta, &duration, &tmp);
                delta = tmp;
                if (delta.tv_sec < 0 || !timerisset(&delta))
                        r = 0;

                switch (r) {
                case 0:
                        if (fds != &readfds)
                                free(fds);
                        ct->ct_error.re_status = RPC_TIMEDOUT;
                        return (-1);

                case -1:
                        if (errno == EINTR)
                                continue;
                        if (fds != &readfds)
                                free(fds);
                        ct->ct_error.re_status = RPC_CANTRECV;
                        ct->ct_error.re_errno = save_errno;
                        return (-1);
                }
                break;
        }
        switch (len = __msgread(ct->ct_sock, buf, len)) {

        case 0:
                /* premature eof */
                ct->ct_error.re_errno = ECONNRESET;
                ct->ct_error.re_status = RPC_CANTRECV;
                len = -1;  /* it's really an error */
                break;

        case -1:
                ct->ct_error.re_errno = errno;
                ct->ct_error.re_status = RPC_CANTRECV;
                break;
        }
        return (len);
}

static int
writeunix(ct, buf, len)
        struct ct_data *ct;
        caddr_t buf;
        int len;
{
        register int i, cnt;

        for (cnt = len; cnt > 0; cnt -= i, buf += i) {
                if ((i = __msgwrite(ct->ct_sock, buf, cnt)) == -1) {
                        ct->ct_error.re_errno = errno;
                        ct->ct_error.re_status = RPC_CANTSEND;
                        return (-1);
                }
        }
        return (len);
}