OpenSolaris_b135/ucblib/librpcsoc/svc_udp.c
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* University Copyright- Copyright (c) 1982, 1986, 1988
* The Regents of the University of California
* All Rights Reserved
*
* University Acknowledgment- Portions of this document are derived from
* software developed by the University of California, Berkeley, and its
* contributors.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* svc_udp.c,
* Server side for UDP/IP based RPC. (Does some caching in the hopes of
* achieving execute-at-most-once semantics.)
*/
#include <rpc/rpc.h>
#include <rpc/clnt_soc.h>
#include <sys/socket.h>
#include <errno.h>
#include <syslog.h>
#include <malloc.h>
#include <stdio.h>
#define rpc_buffer(xprt) ((xprt)->xp_p1)
static struct xp_ops *svcudp_ops();
extern int errno;
extern SVCXPRT *svc_xprt_alloc();
extern void svc_xprt_free();
extern int _socket(int, int, int);
extern int _bind(int, const struct sockaddr *, int);
extern int _getsockname(int, struct sockaddr *, int *);
extern int _listen(int, int);
extern int _accept(int, struct sockaddr *, int *);
extern int bindresvport(int, struct sockaddr_in *);
extern int _recvfrom(int, char *, int, int,
struct sockaddr *, int *);
extern int _sendto(int, const char *, int, int,
const struct sockaddr *, int);
static int cache_get(SVCXPRT *, struct rpc_msg *,
char **, uint_t *);
static void cache_set(SVCXPRT *, uint_t);
/*
* kept in xprt->xp_p2
*/
struct svcudp_data {
u_int su_iosz; /* byte size of send.recv buffer */
uint32_t 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) {
(void) syslog(LOG_ERR, "svcudp_create: socket",
" creation problem: %m");
return ((SVCXPRT *)NULL);
}
madesock = TRUE;
}
memset((char *)&addr, 0, sizeof (addr));
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) {
(void) syslog(LOG_ERR, "svcudp_create -",
" cannot getsockname: %m");
if (madesock)
(void) close(sock);
return ((SVCXPRT *)NULL);
}
xprt = svc_xprt_alloc();
if (xprt == NULL) {
(void) syslog(LOG_ERR, "svcudp_create: out of memory");
if (madesock)
(void) close(sock);
return ((SVCXPRT *)NULL);
}
su = (struct svcudp_data *)mem_alloc(sizeof (*su));
if (su == NULL) {
(void) syslog(LOG_ERR, "svcudp_create: out of memory");
svc_xprt_free(xprt);
if (madesock)
(void) close(sock);
return ((SVCXPRT *)NULL);
}
su->su_iosz = ((MAX(sendsz, recvsz) + 3) / 4) * 4;
if ((rpc_buffer(xprt) = (char *)mem_alloc(su->su_iosz)) == NULL) {
(void) syslog(LOG_ERR, "svcudp_create: out of memory");
mem_free((char *) su, sizeof (*su));
svc_xprt_free(xprt);
if (madesock)
(void) close(sock);
return ((SVCXPRT *)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_netid = NULL;
xprt->xp_verf.oa_base = su->su_verfbody;
xprt->xp_ops = svcudp_ops();
xprt->xp_port = ntohs(addr.sin_port);
xprt->xp_sock = sock;
xprt->xp_rtaddr.buf = &xprt->xp_raddr[0];
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;
uint_t 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 < 4*sizeof (uint32_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) {
(void) cache_set(xprt, (uint_t) 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) 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));
svc_xprt_free(xprt);
}
/* **********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 ALLOC(type, size) \
(type *) mem_alloc((unsigned) (sizeof (type) * (size)))
#define BZERO(addr, type, size) \
memset((char *) (addr), 0, sizeof (type) * (int) (size))
#define FREE(addr, type, size) \
(void) mem_free((char *) (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
*/
uint32_t cache_xid;
uint32_t cache_proc;
uint32_t cache_vers;
uint32_t cache_prog;
struct sockaddr_in cache_addr;
/*
* The cached reply and length
*/
char * cache_reply;
uint32_t cache_replylen;
/*
* Next node on the list, if there is a collision
*/
cache_ptr cache_next;
};
/*
* The entire cache
*/
struct udp_cache {
uint32_t 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 */
uint32_t uc_nextvictim; /* points to next victim in fifo list */
uint32_t uc_prog; /* saved program number */
uint32_t uc_vers; /* saved version number */
uint32_t 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;
uint_t size;
{
struct svcudp_data *su = su_data(transp);
struct udp_cache *uc;
if (su->su_cache != NULL) {
(void) syslog(LOG_ERR, "enablecache: cache already enabled");
return (0);
}
uc = ALLOC(struct udp_cache, 1);
if (uc == NULL) {
(void) syslog(LOG_ERR, "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) {
(void) syslog(LOG_ERR, "enablecache: could not",
" allocate cache data");
FREE(uc, struct udp_cache, 1);
return (0);
}
BZERO(uc->uc_entries, cache_ptr, size * SPARSENESS);
uc->uc_fifo = ALLOC(cache_ptr, size);
if (uc->uc_fifo == NULL) {
(void) syslog(LOG_ERR, "enablecache: could not",
" allocate cache fifo");
FREE((char *)uc->uc_entries, cache_ptr, size * SPARSENESS);
FREE((char *)uc, struct udp_cache, 1);
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;
uint_t 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) {
(void) syslog(LOG_ERR, "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) {
(void) syslog(LOG_ERR, "cache_set: victim alloc",
" failed");
return;
}
newbuf = (char *)mem_alloc(su->su_iosz);
if (newbuf == NULL) {
(void) syslog(LOG_ERR, "cache_set: could not",
" allocate new rpc_buffer");
FREE(victim, struct cache_node, 1);
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;
uint_t *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((char *)&a1, (char *)&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;
memcpy((char *)&uc->uc_addr, (char *)&xprt->xp_raddr,
sizeof (struct sockaddr_in));
return (0);
}
static struct xp_ops *
svcudp_ops()
{
static struct xp_ops ops;
if (ops.xp_recv == NULL) {
ops.xp_recv = svcudp_recv;
ops.xp_stat = svcudp_stat;
ops.xp_getargs = svcudp_getargs;
ops.xp_reply = svcudp_reply;
ops.xp_freeargs = svcudp_freeargs;
ops.xp_destroy = svcudp_destroy;
}
return (&ops);
}