Subversion Repositories or1k

/*

 * 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: @(#)svc_udp.c 1.24 87/08/11 Copyr 1984 Sun Micro";*/

/*static char *sccsid = "from: @(#)svc_udp.c    2.2 88/07/29 4.0 RPCSRC";*/

static char *rcsid = "$FreeBSD: src/lib/libc/rpc/svc_udp.c,v 1.13 2000/01/27 23:06:41 jasone Exp $";

#endif

/*

 * svc_udp.c,

 * Server side for UDP/IP based RPC.  (Does some caching in the hopes of

 * achieving execute-at-most-once semantics.)

 *

 * Copyright (C) 1984, Sun Microsystems, Inc.

 */

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <string.h>

#include <rpc/rpc.h>

#include <sys/socket.h>

#include <errno.h>

#define rpc_buffer(xprt) ((xprt)->xp_p1)

#define MAX(a, b)     ((a > b) ? a : b)

static bool_t           svcudp_recv();

static bool_t           svcudp_reply();

static enum xprt_stat   svcudp_stat();

static bool_t           svcudp_getargs();

static bool_t           svcudp_freeargs();

static void             svcudp_destroy();

static void             cache_set __P((SVCXPRT *, u_long));

static int              cache_get __P((SVCXPRT *, struct rpc_msg *, char **, u_long *));

static struct xp_ops svcudp_op = {

        svcudp_recv,

        svcudp_stat,

        svcudp_getargs,

        svcudp_reply,

        svcudp_freeargs,

        svcudp_destroy

};

/*

 * kept in xprt->xp_p2

 */

struct svcudp_data {

        u_int   su_iosz;        /* byte size of send.recv buffer */

        u_long  su_xid;         /* transaction id */

        XDR     su_xdrs;        /* XDR handle */

        char    su_verfbody[MAX_AUTH_BYTES];    /* verifier body */

        char *  su_cache;       /* cached data, NULL if no cache */

};

#define su_data(xprt)   ((struct svcudp_data *)(xprt->xp_p2))

/*

 * Usage:

 *      xprt = svcudp_create(sock);

 *

 * If sock<0 then a socket is created, else sock is used.

 * If the socket, sock is not bound to a port then svcudp_create

 * binds it to an arbitrary port.  In any (successful) case,

 * xprt->xp_sock is the registered socket number and xprt->xp_port is the

 * associated port number.

 * Once *xprt is initialized, it is registered as a transporter;

 * see (svc.h, xprt_register).

 * The routines returns NULL if a problem occurred.

 */

SVCXPRT *

svcudp_bufcreate(sock, sendsz, recvsz)

        register int sock;

        u_int sendsz, recvsz;

{

        bool_t madesock = FALSE;

        register SVCXPRT *xprt;

        register struct svcudp_data *su;

        struct sockaddr_in addr;

        int len = sizeof(struct sockaddr_in);

        if (sock == RPC_ANYSOCK) {

                if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {

                        perror("svcudp_create: socket creation problem");

                        return ((SVCXPRT *)NULL);

                }

                madesock = TRUE;

        }

        memset((char *)&addr, 0, sizeof (addr));

        addr.sin_len = sizeof(struct sockaddr_in);

        addr.sin_family = AF_INET;

        if (bindresvport(sock, &addr)) {

                addr.sin_port = 0;

                (void)bind(sock, (struct sockaddr *)&addr, len);

        }

        if (getsockname(sock, (struct sockaddr *)&addr, &len) != 0) {

                perror("svcudp_create - cannot getsockname");

                if (madesock)

                        (void)_RPC_close(sock);

                return ((SVCXPRT *)NULL);

        }

        xprt = (SVCXPRT *)mem_alloc(sizeof(SVCXPRT));

        if (xprt == NULL) {

                (void)fprintf(stderr, "svcudp_create: out of memory\n");

                return (NULL);

        }

        su = (struct svcudp_data *)mem_alloc(sizeof(*su));

        if (su == NULL) {

                (void)fprintf(stderr, "svcudp_create: out of memory\n");

                return (NULL);

        }

        su->su_iosz = ((MAX(sendsz, recvsz) + 3) / 4) * 4;

        if ((rpc_buffer(xprt) = mem_alloc(su->su_iosz)) == NULL) {

                (void)fprintf(stderr, "svcudp_create: out of memory\n");

                return (NULL);

        }

        xdrmem_create(

            &(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_DECODE);

        su->su_cache = NULL;

        xprt->xp_p2 = (caddr_t)su;

        xprt->xp_verf.oa_base = su->su_verfbody;

        xprt->xp_ops = &svcudp_op;

        xprt->xp_port = ntohs(addr.sin_port);

        xprt->xp_sock = sock;

        xprt_register(xprt);

        return (xprt);

}

SVCXPRT *

svcudp_create(sock)

        int sock;

{

        return(svcudp_bufcreate(sock, UDPMSGSIZE, UDPMSGSIZE));

}

static enum xprt_stat

svcudp_stat(xprt)

        SVCXPRT *xprt;

{

        return (XPRT_IDLE);

}

static bool_t

svcudp_recv(xprt, msg)

        register SVCXPRT *xprt;

        struct rpc_msg *msg;

{

        register struct svcudp_data *su = su_data(xprt);

        register XDR *xdrs = &(su->su_xdrs);

        register int rlen;

        char *reply;

        u_long replylen;

    again:

        xprt->xp_addrlen = sizeof(struct sockaddr_in);

        rlen = recvfrom(xprt->xp_sock, rpc_buffer(xprt), (int) su->su_iosz,

            0, (struct sockaddr *)&(xprt->xp_raddr), &(xprt->xp_addrlen));

        if (rlen == -1 && errno == EINTR)

                goto again;

        if (rlen == -1 || rlen < 4*sizeof(u_int32_t))

                return (FALSE);

        xdrs->x_op = XDR_DECODE;

        XDR_SETPOS(xdrs, 0);

        if (! xdr_callmsg(xdrs, msg))

                return (FALSE);

        su->su_xid = msg->rm_xid;

        if (su->su_cache != NULL) {

                if (cache_get(xprt, msg, &reply, &replylen)) {

                        (void) sendto(xprt->xp_sock, reply, (int) replylen, 0,

                          (struct sockaddr *) &xprt->xp_raddr, xprt->xp_addrlen);

                        return (TRUE);

                }

        }

        return (TRUE);

}

static bool_t

svcudp_reply(xprt, msg)

        register SVCXPRT *xprt;

        struct rpc_msg *msg;

{

        register struct svcudp_data *su = su_data(xprt);

        register XDR *xdrs = &(su->su_xdrs);

        register int slen;

        register bool_t stat = FALSE;

        xdrs->x_op = XDR_ENCODE;

        XDR_SETPOS(xdrs, 0);

        msg->rm_xid = su->su_xid;

        if (xdr_replymsg(xdrs, msg)) {

                slen = (int)XDR_GETPOS(xdrs);

                if (sendto(xprt->xp_sock, rpc_buffer(xprt), slen, 0,

                    (struct sockaddr *)&(xprt->xp_raddr), xprt->xp_addrlen)

                    == slen) {

                        stat = TRUE;

                        if (su->su_cache && slen >= 0) {

                                cache_set(xprt, (u_long) slen);

                        }

                }

        }

        return (stat);

}

static bool_t

svcudp_getargs(xprt, xdr_args, args_ptr)

        SVCXPRT *xprt;

        xdrproc_t xdr_args;

        caddr_t args_ptr;

{

        return ((*xdr_args)(&(su_data(xprt)->su_xdrs), args_ptr));

}

static bool_t

svcudp_freeargs(xprt, xdr_args, args_ptr)

        SVCXPRT *xprt;

        xdrproc_t xdr_args;

        caddr_t args_ptr;

{

        register XDR *xdrs = &(su_data(xprt)->su_xdrs);

        xdrs->x_op = XDR_FREE;

        return ((*xdr_args)(xdrs, args_ptr));

}

static void

svcudp_destroy(xprt)

        register SVCXPRT *xprt;

{

        register struct svcudp_data *su = su_data(xprt);

        xprt_unregister(xprt);

        (void)_RPC_close(xprt->xp_sock);

        XDR_DESTROY(&(su->su_xdrs));

        mem_free(rpc_buffer(xprt), su->su_iosz);

        mem_free((caddr_t)su, sizeof(struct svcudp_data));

        mem_free((caddr_t)xprt, sizeof(SVCXPRT));

}

/***********this could be a separate file*********************/

/*

 * Fifo cache for udp server

 * Copies pointers to reply buffers into fifo cache

 * Buffers are sent again if retransmissions are detected.

 */

#define SPARSENESS 4    /* 75% sparse */

#define CACHE_PERROR(msg)       \

        (void) fprintf(stderr,"%s\n", msg)

#define ALLOC(type, size)       \

        (type *) mem_alloc((unsigned) (sizeof(type) * (size)))

#define BZERO(addr, type, size)  \

        memset((char *) addr, 0, sizeof(type) * (int) (size))

/*

 * An entry in the cache

 */

typedef struct cache_node *cache_ptr;

struct cache_node {

        /*

         * Index into cache is xid, proc, vers, prog and address

         */

        u_long cache_xid;

        u_long cache_proc;

        u_long cache_vers;

        u_long cache_prog;

        struct sockaddr_in cache_addr;

        /*

         * The cached reply and length

         */

        char * cache_reply;

        u_long cache_replylen;

        /*

         * Next node on the list, if there is a collision

         */

        cache_ptr cache_next;

};

/*

 * The entire cache

 */

struct udp_cache {

        u_long uc_size;         /* size of cache */

        cache_ptr *uc_entries;  /* hash table of entries in cache */

        cache_ptr *uc_fifo;     /* fifo list of entries in cache */

        u_long uc_nextvictim;   /* points to next victim in fifo list */

        u_long uc_prog;         /* saved program number */

        u_long uc_vers;         /* saved version number */

        u_long uc_proc;         /* saved procedure number */

        struct sockaddr_in uc_addr; /* saved caller's address */

};

/*

 * the hashing function

 */

#define CACHE_LOC(transp, xid)  \

 (xid % (SPARSENESS*((struct udp_cache *) su_data(transp)->su_cache)->uc_size))

/*

 * Enable use of the cache.

 * Note: there is no disable.

 */

int svcudp_enablecache(transp, size)

        SVCXPRT *transp;

        u_long size;

{

        struct svcudp_data *su = su_data(transp);

        struct udp_cache *uc;

        if (su->su_cache != NULL) {

                CACHE_PERROR("enablecache: cache already enabled");

                return(0);

        }

        uc = ALLOC(struct udp_cache, 1);

        if (uc == NULL) {

                CACHE_PERROR("enablecache: could not allocate cache");

                return(0);

        }

        uc->uc_size = size;

        uc->uc_nextvictim = 0;

        uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);

        if (uc->uc_entries == NULL) {

                CACHE_PERROR("enablecache: could not allocate cache data");

                return(0);

        }

        BZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);

        uc->uc_fifo = ALLOC(cache_ptr, size);

        if (uc->uc_fifo == NULL) {

                CACHE_PERROR("enablecache: could not allocate cache fifo");

                return(0);

        }

        BZERO(uc->uc_fifo, cache_ptr, size);

        su->su_cache = (char *) uc;

        return(1);

}

/*

 * Set an entry in the cache

 */

static void

cache_set(xprt, replylen)

        SVCXPRT *xprt;

        u_long replylen;

{

        register cache_ptr victim;

        register cache_ptr *vicp;

        register struct svcudp_data *su = su_data(xprt);

        struct udp_cache *uc = (struct udp_cache *) su->su_cache;

        u_int loc;

        char *newbuf;

        /*

         * Find space for the new entry, either by

         * reusing an old entry, or by mallocing a new one

         */

        victim = uc->uc_fifo[uc->uc_nextvictim];

        if (victim != NULL) {

                loc = CACHE_LOC(xprt, victim->cache_xid);

                for (vicp = &uc->uc_entries[loc];

                  *vicp != NULL && *vicp != victim;

                  vicp = &(*vicp)->cache_next)

                                ;

                if (*vicp == NULL) {

                        CACHE_PERROR("cache_set: victim not found");

                        return;

                }

                *vicp = victim->cache_next;     /* remote from cache */

                newbuf = victim->cache_reply;

        } else {

                victim = ALLOC(struct cache_node, 1);

                if (victim == NULL) {

                        CACHE_PERROR("cache_set: victim alloc failed");

                        return;

                }

                newbuf = mem_alloc(su->su_iosz);

                if (newbuf == NULL) {

                        CACHE_PERROR("cache_set: could not allocate new rpc_buffer");

                        return;

                }

        }

        /*

         * Store it away

         */

        victim->cache_replylen = replylen;

        victim->cache_reply = rpc_buffer(xprt);

        rpc_buffer(xprt) = newbuf;

        xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz, XDR_ENCODE);

        victim->cache_xid = su->su_xid;

        victim->cache_proc = uc->uc_proc;

        victim->cache_vers = uc->uc_vers;

        victim->cache_prog = uc->uc_prog;

        victim->cache_addr = uc->uc_addr;

        loc = CACHE_LOC(xprt, victim->cache_xid);

        victim->cache_next = uc->uc_entries[loc];

        uc->uc_entries[loc] = victim;

        uc->uc_fifo[uc->uc_nextvictim++] = victim;

        uc->uc_nextvictim %= uc->uc_size;

}

/*

 * Try to get an entry from the cache

 * return 1 if found, 0 if not found

 */

static int

cache_get(xprt, msg, replyp, replylenp)

        SVCXPRT *xprt;

        struct rpc_msg *msg;

        char **replyp;

        u_long *replylenp;

{

        u_int loc;

        register cache_ptr ent;

        register struct svcudp_data *su = su_data(xprt);

        register struct udp_cache *uc = (struct udp_cache *) su->su_cache;

#       define EQADDR(a1, a2)   (memcmp(&a1, &a2, sizeof(a1)) == 0)

        loc = CACHE_LOC(xprt, su->su_xid);

        for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next) {

                if (ent->cache_xid == su->su_xid &&

                  ent->cache_proc == uc->uc_proc &&

                  ent->cache_vers == uc->uc_vers &&

                  ent->cache_prog == uc->uc_prog &&

                  EQADDR(ent->cache_addr, uc->uc_addr)) {

                        *replyp = ent->cache_reply;

                        *replylenp = ent->cache_replylen;

                        return(1);

                }

        }

        /*

         * Failed to find entry

         * Remember a few things so we can do a set later

         */

        uc->uc_proc = msg->rm_call.cb_proc;

        uc->uc_vers = msg->rm_call.cb_vers;

        uc->uc_prog = msg->rm_call.cb_prog;

        uc->uc_addr = xprt->xp_raddr;

        return(0);

}