minix/lib/nbsd_libc/rpc/svc_dg.c

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/* $NetBSD: svc_dg.c,v 1.12 2008/04/25 17:44:44 christos Exp $ */
/*
* 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
*/
/*
* Copyright (c) 1986-1991 by Sun Microsystems Inc.
*/
/* #ident "@(#)svc_dg.c 1.17 94/04/24 SMI" */
/*
* svc_dg.c, Server side for connectionless RPC.
*
* Does some caching in the hopes of achieving execute-at-most-once semantics.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: svc_dg.c,v 1.12 2008/04/25 17:44:44 christos Exp $");
#endif
#include "namespace.h"
#include "reentrant.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <rpc/rpc.h>
#include <assert.h>
#include <errno.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef RPC_CACHE_DEBUG
#include <netconfig.h>
#include <netdir.h>
#endif
#include <err.h>
#include "rpc_internal.h"
#include "svc_dg.h"
#define su_data(xprt) ((struct svc_dg_data *)(xprt->xp_p2))
#define rpc_buffer(xprt) ((xprt)->xp_p1)
#ifdef __weak_alias
__weak_alias(svc_dg_create,_svc_dg_create)
#endif
#ifndef MAX
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
#endif
static void svc_dg_ops __P((SVCXPRT *));
static enum xprt_stat svc_dg_stat __P((SVCXPRT *));
static bool_t svc_dg_recv __P((SVCXPRT *, struct rpc_msg *));
static bool_t svc_dg_reply __P((SVCXPRT *, struct rpc_msg *));
static bool_t svc_dg_getargs __P((SVCXPRT *, xdrproc_t, caddr_t));
static bool_t svc_dg_freeargs __P((SVCXPRT *, xdrproc_t, caddr_t));
static void svc_dg_destroy __P((SVCXPRT *));
static bool_t svc_dg_control __P((SVCXPRT *, const u_int, void *));
static int cache_get __P((SVCXPRT *, struct rpc_msg *, char **, size_t *));
static void cache_set __P((SVCXPRT *, size_t));
/*
* Usage:
* xprt = svc_dg_create(sock, sendsize, recvsize);
* Does other connectionless specific initializations.
* Once *xprt is initialized, it is registered.
* see (svc.h, xprt_register). If recvsize or sendsize are 0 suitable
* system defaults are chosen.
* The routines returns NULL if a problem occurred.
*/
static const char svc_dg_str[] = "svc_dg_create: %s";
static const char svc_dg_err1[] = "could not get transport information";
static const char svc_dg_err2[] = " transport does not support data transfer";
static const char __no_mem_str[] = "out of memory";
SVCXPRT *
svc_dg_create(fd, sendsize, recvsize)
int fd;
u_int sendsize;
u_int recvsize;
{
SVCXPRT *xprt;
struct svc_dg_data *su = NULL;
struct __rpc_sockinfo si;
struct sockaddr_storage ss;
socklen_t slen;
if (!__rpc_fd2sockinfo(fd, &si)) {
warnx(svc_dg_str, svc_dg_err1);
return (NULL);
}
/*
* Find the receive and the send size
*/
sendsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)sendsize);
recvsize = __rpc_get_t_size(si.si_af, si.si_proto, (int)recvsize);
if ((sendsize == 0) || (recvsize == 0)) {
warnx(svc_dg_str, svc_dg_err2);
return (NULL);
}
xprt = mem_alloc(sizeof (SVCXPRT));
if (xprt == NULL)
goto freedata;
memset(xprt, 0, sizeof (SVCXPRT));
su = mem_alloc(sizeof (*su));
if (su == NULL)
goto freedata;
su->su_iosz = ((MAX(sendsize, recvsize) + 3) / 4) * 4;
if ((rpc_buffer(xprt) = malloc(su->su_iosz)) == NULL)
goto freedata;
xdrmem_create(&(su->su_xdrs), rpc_buffer(xprt), su->su_iosz,
XDR_DECODE);
su->su_cache = NULL;
xprt->xp_fd = fd;
xprt->xp_p2 = (caddr_t)(void *)su;
xprt->xp_verf.oa_base = su->su_verfbody;
svc_dg_ops(xprt);
xprt->xp_rtaddr.maxlen = sizeof (struct sockaddr_storage);
slen = sizeof ss;
if (getsockname(fd, (struct sockaddr *)(void *)&ss, &slen) < 0)
goto freedata;
xprt->xp_ltaddr.buf = mem_alloc(sizeof (struct sockaddr_storage));
xprt->xp_ltaddr.maxlen = sizeof (struct sockaddr_storage);
xprt->xp_ltaddr.len = slen;
memcpy(xprt->xp_ltaddr.buf, &ss, slen);
xprt_register(xprt);
return (xprt);
freedata:
(void) warnx(svc_dg_str, __no_mem_str);
if (xprt) {
if (su)
(void) mem_free(su, sizeof (*su));
(void) mem_free(xprt, sizeof (SVCXPRT));
}
return (NULL);
}
/*ARGSUSED*/
static enum xprt_stat
svc_dg_stat(xprt)
SVCXPRT *xprt;
{
return (XPRT_IDLE);
}
static bool_t
svc_dg_recv(xprt, msg)
SVCXPRT *xprt;
struct rpc_msg *msg;
{
struct svc_dg_data *su;
XDR *xdrs;
char *reply;
struct sockaddr_storage ss;
socklen_t alen;
size_t replylen;
ssize_t rlen;
_DIAGASSERT(xprt != NULL);
_DIAGASSERT(msg != NULL);
su = su_data(xprt);
xdrs = &(su->su_xdrs);
again:
alen = sizeof (struct sockaddr_storage);
rlen = recvfrom(xprt->xp_fd, rpc_buffer(xprt), su->su_iosz, 0,
(struct sockaddr *)(void *)&ss, &alen);
if (rlen == -1 && errno == EINTR)
goto again;
if (rlen == -1 || (rlen < (ssize_t)(4 * sizeof (u_int32_t))))
return (FALSE);
if (xprt->xp_rtaddr.len < alen) {
if (xprt->xp_rtaddr.len != 0)
mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.len);
xprt->xp_rtaddr.buf = mem_alloc(alen);
xprt->xp_rtaddr.len = alen;
}
memcpy(xprt->xp_rtaddr.buf, &ss, alen);
#ifdef PORTMAP
if (ss.ss_family == AF_INET) {
xprt->xp_raddr = *(struct sockaddr_in *)xprt->xp_rtaddr.buf;
xprt->xp_addrlen = sizeof (struct sockaddr_in);
}
#endif
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_fd, reply, replylen, 0,
(struct sockaddr *)(void *)&ss, alen);
return (FALSE);
}
}
return (TRUE);
}
static bool_t
svc_dg_reply(xprt, msg)
SVCXPRT *xprt;
struct rpc_msg *msg;
{
struct svc_dg_data *su;
XDR *xdrs;
bool_t stat = FALSE;
size_t slen;
_DIAGASSERT(xprt != NULL);
_DIAGASSERT(msg != NULL);
su = su_data(xprt);
xdrs = &(su->su_xdrs);
xdrs->x_op = XDR_ENCODE;
XDR_SETPOS(xdrs, 0);
msg->rm_xid = su->su_xid;
if (xdr_replymsg(xdrs, msg)) {
slen = XDR_GETPOS(xdrs);
if (sendto(xprt->xp_fd, rpc_buffer(xprt), slen, 0,
(struct sockaddr *)xprt->xp_rtaddr.buf,
(socklen_t)xprt->xp_rtaddr.len) == (ssize_t) slen) {
stat = TRUE;
if (su->su_cache)
cache_set(xprt, slen);
}
}
return (stat);
}
static bool_t
svc_dg_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
svc_dg_freeargs(xprt, xdr_args, args_ptr)
SVCXPRT *xprt;
xdrproc_t xdr_args;
caddr_t args_ptr;
{
XDR *xdrs;
_DIAGASSERT(xprt != NULL);
xdrs = &(su_data(xprt)->su_xdrs);
xdrs->x_op = XDR_FREE;
return (*xdr_args)(xdrs, args_ptr);
}
static void
svc_dg_destroy(xprt)
SVCXPRT *xprt;
{
struct svc_dg_data *su;
_DIAGASSERT(xprt != NULL);
su = su_data(xprt);
xprt_unregister(xprt);
if (xprt->xp_fd != -1)
(void)close(xprt->xp_fd);
XDR_DESTROY(&(su->su_xdrs));
(void) mem_free(rpc_buffer(xprt), su->su_iosz);
(void) mem_free(su, sizeof (*su));
if (xprt->xp_rtaddr.buf)
(void) mem_free(xprt->xp_rtaddr.buf, xprt->xp_rtaddr.maxlen);
if (xprt->xp_ltaddr.buf)
(void) mem_free(xprt->xp_ltaddr.buf, xprt->xp_ltaddr.maxlen);
if (xprt->xp_tp)
(void) free(xprt->xp_tp);
(void) mem_free(xprt, sizeof (SVCXPRT));
}
static bool_t
/*ARGSUSED*/
svc_dg_control(xprt, rq, in)
SVCXPRT *xprt;
const u_int rq;
void *in;
{
return (FALSE);
}
static void
svc_dg_ops(xprt)
SVCXPRT *xprt;
{
static struct xp_ops ops;
static struct xp_ops2 ops2;
#ifdef _REENTRANT
extern mutex_t ops_lock;
#endif
_DIAGASSERT(xprt != NULL);
/* VARIABLES PROTECTED BY ops_lock: ops */
mutex_lock(&ops_lock);
if (ops.xp_recv == NULL) {
ops.xp_recv = svc_dg_recv;
ops.xp_stat = svc_dg_stat;
ops.xp_getargs = svc_dg_getargs;
ops.xp_reply = svc_dg_reply;
ops.xp_freeargs = svc_dg_freeargs;
ops.xp_destroy = svc_dg_destroy;
ops2.xp_control = svc_dg_control;
}
xprt->xp_ops = &ops;
xprt->xp_ops2 = &ops2;
mutex_unlock(&ops_lock);
}
/* The CACHING COMPONENT */
/*
* Could have been a separate file, but some part of it depends upon the
* private structure of the client handle.
*
* Fifo cache for cl server
* Copies pointers to reply buffers into fifo cache
* Buffers are sent again if retransmissions are detected.
*/
#define SPARSENESS 4 /* 75% sparse */
#define ALLOC(type, size) \
mem_alloc((sizeof (type) * (size)))
#define MEMZERO(addr, type, size) \
(void) memset((void *) (addr), 0, sizeof (type) * (int) (size))
#define FREE(addr, type, size) \
mem_free((addr), (sizeof (type) * (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_int32_t cache_xid;
rpcproc_t cache_proc;
rpcvers_t cache_vers;
rpcprog_t cache_prog;
struct netbuf cache_addr;
/*
* The cached reply and length
*/
char *cache_reply;
size_t cache_replylen;
/*
* Next node on the list, if there is a collision
*/
cache_ptr cache_next;
};
/*
* The entire cache
*/
struct cl_cache {
u_int 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_int uc_nextvictim; /* points to next victim in fifo list */
rpcprog_t uc_prog; /* saved program number */
rpcvers_t uc_vers; /* saved version number */
rpcproc_t uc_proc; /* saved procedure number */
};
/*
* the hashing function
*/
#define CACHE_LOC(transp, xid) \
(xid % (SPARSENESS * ((struct cl_cache *) \
su_data(transp)->su_cache)->uc_size))
#ifdef _REENTRANT
extern mutex_t dupreq_lock;
#endif
/*
* Enable use of the cache. Returns 1 on success, 0 on failure.
* Note: there is no disable.
*/
static const char cache_enable_str[] = "svc_enablecache: %s %s";
static const char alloc_err[] = "could not allocate cache ";
static const char enable_err[] = "cache already enabled";
int
svc_dg_enablecache(transp, size)
SVCXPRT *transp;
u_int size;
{
struct svc_dg_data *su;
struct cl_cache *uc;
_DIAGASSERT(transp != NULL);
su = su_data(transp);
mutex_lock(&dupreq_lock);
if (su->su_cache != NULL) {
(void) warnx(cache_enable_str, enable_err, " ");
mutex_unlock(&dupreq_lock);
return (0);
}
uc = ALLOC(struct cl_cache, 1);
if (uc == NULL) {
warnx(cache_enable_str, alloc_err, " ");
mutex_unlock(&dupreq_lock);
return (0);
}
uc->uc_size = size;
uc->uc_nextvictim = 0;
uc->uc_entries = ALLOC(cache_ptr, size * SPARSENESS);
if (uc->uc_entries == NULL) {
warnx(cache_enable_str, alloc_err, "data");
FREE(uc, struct cl_cache, 1);
mutex_unlock(&dupreq_lock);
return (0);
}
MEMZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
uc->uc_fifo = ALLOC(cache_ptr, size);
if (uc->uc_fifo == NULL) {
warnx(cache_enable_str, alloc_err, "fifo");
FREE(uc->uc_entries, cache_ptr, size * SPARSENESS);
FREE(uc, struct cl_cache, 1);
mutex_unlock(&dupreq_lock);
return (0);
}
MEMZERO(uc->uc_fifo, cache_ptr, size);
su->su_cache = (char *)(void *)uc;
mutex_unlock(&dupreq_lock);
return (1);
}
/*
* Set an entry in the cache. It assumes that the uc entry is set from
* the earlier call to cache_get() for the same procedure. This will always
* happen because cache_get() is calle by svc_dg_recv and cache_set() is called
* by svc_dg_reply(). All this hoopla because the right RPC parameters are
* not available at svc_dg_reply time.
*/
static const char cache_set_str[] = "cache_set: %s";
static const char cache_set_err1[] = "victim not found";
static const char cache_set_err2[] = "victim alloc failed";
static const char cache_set_err3[] = "could not allocate new rpc buffer";
static void
cache_set(xprt, replylen)
SVCXPRT *xprt;
size_t replylen;
{
cache_ptr victim;
cache_ptr *vicp;
struct svc_dg_data *su;
struct cl_cache *uc;
u_int loc;
char *newbuf;
#ifdef RPC_CACHE_DEBUG
struct netconfig *nconf;
char *uaddr;
#endif
_DIAGASSERT(xprt != NULL);
su = su_data(xprt);
uc = (struct cl_cache *) su->su_cache;
mutex_lock(&dupreq_lock);
/*
* 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) {
warnx(cache_set_str, cache_set_err1);
mutex_unlock(&dupreq_lock);
return;
}
*vicp = victim->cache_next; /* remove from cache */
newbuf = victim->cache_reply;
} else {
victim = ALLOC(struct cache_node, 1);
if (victim == NULL) {
warnx(cache_set_str, cache_set_err2);
mutex_unlock(&dupreq_lock);
return;
}
newbuf = mem_alloc(su->su_iosz);
if (newbuf == NULL) {
warnx(cache_set_str, cache_set_err3);
FREE(victim, struct cache_node, 1);
mutex_unlock(&dupreq_lock);
return;
}
}
/*
* Store it away
*/
#ifdef RPC_CACHE_DEBUG
if (nconf = getnetconfigent(xprt->xp_netid)) {
uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
freenetconfigent(nconf);
printf(
"cache set for xid= %x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
su->su_xid, uc->uc_prog, uc->uc_vers,
uc->uc_proc, uaddr);
free(uaddr);
}
#endif
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 = xprt->xp_rtaddr;
victim->cache_addr.buf = ALLOC(char, xprt->xp_rtaddr.len);
(void) memcpy(victim->cache_addr.buf, xprt->xp_rtaddr.buf,
(size_t)xprt->xp_rtaddr.len);
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;
mutex_unlock(&dupreq_lock);
}
/*
* Try to get an entry from the cache
* return 1 if found, 0 if not found and set the stage for cache_set()
*/
static int
cache_get(xprt, msg, replyp, replylenp)
SVCXPRT *xprt;
struct rpc_msg *msg;
char **replyp;
size_t *replylenp;
{
u_int loc;
cache_ptr ent;
struct svc_dg_data *su;
struct cl_cache *uc;
#ifdef RPC_CACHE_DEBUG
struct netconfig *nconf;
char *uaddr;
#endif
_DIAGASSERT(xprt != NULL);
_DIAGASSERT(msg != NULL);
_DIAGASSERT(replyp != NULL);
_DIAGASSERT(replylenp != NULL);
su = su_data(xprt);
uc = (struct cl_cache *) su->su_cache;
mutex_lock(&dupreq_lock);
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 == msg->rm_call.cb_proc &&
ent->cache_vers == msg->rm_call.cb_vers &&
ent->cache_prog == msg->rm_call.cb_prog &&
ent->cache_addr.len == xprt->xp_rtaddr.len &&
(memcmp(ent->cache_addr.buf, xprt->xp_rtaddr.buf,
xprt->xp_rtaddr.len) == 0)) {
#ifdef RPC_CACHE_DEBUG
if (nconf = getnetconfigent(xprt->xp_netid)) {
uaddr = taddr2uaddr(nconf, &xprt->xp_rtaddr);
freenetconfigent(nconf);
printf(
"cache entry found for xid=%x prog=%d vers=%d proc=%d for rmtaddr=%s\n",
su->su_xid, msg->rm_call.cb_prog,
msg->rm_call.cb_vers,
msg->rm_call.cb_proc, uaddr);
free(uaddr);
}
#endif
*replyp = ent->cache_reply;
*replylenp = ent->cache_replylen;
mutex_unlock(&dupreq_lock);
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;
mutex_unlock(&dupreq_lock);
return (0);
}