OpenBSD-4.6/lib/libc/rpc/svc_udp.c
/* $OpenBSD: svc_udp.c,v 1.18 2009/06/07 01:21:00 millert 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
*/
/*
* 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 <string.h>
#include <rpc/rpc.h>
#include <sys/socket.h>
#include <stdint.h>
#include <errno.h>
#include <unistd.h>
#define rpc_buffer(xprt) ((xprt)->xp_p1)
#define MAX(a, b) ((a > b) ? a : b)
static bool_t svcudp_recv(SVCXPRT *, struct rpc_msg *);
static enum xprt_stat svcudp_stat(SVCXPRT *);
static bool_t svcudp_getargs(SVCXPRT *, xdrproc_t, caddr_t);
static bool_t svcudp_reply(SVCXPRT *, struct rpc_msg *);
static bool_t svcudp_freeargs(SVCXPRT *, xdrproc_t, caddr_t);
static void svcudp_destroy(SVCXPRT *);
static void cache_set(SVCXPRT *, u_long);
static int cache_get(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(int sock, u_int sendsz, u_int recvsz)
{
bool_t madesock = FALSE;
SVCXPRT *xprt;
struct svcudp_data *su;
struct sockaddr_in addr;
socklen_t 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 (NULL);
}
madesock = TRUE;
}
memset(&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)close(sock);
return (NULL);
}
xprt = (SVCXPRT *)malloc(sizeof(SVCXPRT));
if (xprt == NULL) {
(void)fprintf(stderr, "svcudp_create: out of memory\n");
if (madesock)
(void)close(sock);
return (NULL);
}
su = (struct svcudp_data *)malloc(sizeof(*su));
if (su == NULL) {
(void)fprintf(stderr, "svcudp_create: out of memory\n");
if (madesock)
(void)close(sock);
free(xprt);
return (NULL);
}
su->su_iosz = ((MAX(sendsz, recvsz) + 3) / 4) * 4;
if ((rpc_buffer(xprt) = malloc(su->su_iosz)) == NULL) {
(void)fprintf(stderr, "svcudp_create: out of memory\n");
if (madesock)
(void)close(sock);
free(xprt);
free(su);
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;
if (__xprt_register(xprt) == 0) {
if (madesock)
(void)close(sock);
free(rpc_buffer(xprt));
free(xprt);
free(su);
return (NULL);
}
return (xprt);
}
SVCXPRT *
svcudp_create(int sock)
{
return(svcudp_bufcreate(sock, UDPMSGSIZE, UDPMSGSIZE));
}
/* ARGSUSED */
static enum xprt_stat
svcudp_stat(SVCXPRT *xprt)
{
return (XPRT_IDLE);
}
static bool_t
svcudp_recv(SVCXPRT *xprt, struct rpc_msg *msg)
{
struct svcudp_data *su = su_data(xprt);
XDR *xdrs = &(su->su_xdrs);
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(SVCXPRT *xprt, struct rpc_msg *msg)
{
struct svcudp_data *su = su_data(xprt);
XDR *xdrs = &(su->su_xdrs);
int slen;
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(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(SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t args_ptr)
{
XDR *xdrs = &(su_data(xprt)->su_xdrs);
xdrs->x_op = XDR_FREE;
return ((*xdr_args)(xdrs, args_ptr));
}
static void
svcudp_destroy(SVCXPRT *xprt)
{
struct svcudp_data *su = su_data(xprt);
xprt_unregister(xprt);
if (xprt->xp_sock != -1)
(void)close(xprt->xp_sock);
xprt->xp_sock = -1;
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));
}
/*
* 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)
/*
* 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(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 = malloc(sizeof(*uc));
if (uc == NULL) {
CACHE_PERROR("enablecache: could not allocate cache");
return(0);
}
uc->uc_size = size;
uc->uc_nextvictim = 0;
if (size > SIZE_MAX / (sizeof(cache_ptr) * SPARSENESS) ||
(uc->uc_entries = calloc(sizeof(cache_ptr) * SPARSENESS, size)) == NULL) {
CACHE_PERROR("enablecache: could not allocate cache data");
free(uc);
return(0);
}
uc->uc_fifo = calloc(sizeof(cache_ptr), size);
if (uc->uc_fifo == NULL) {
CACHE_PERROR("enablecache: could not allocate cache fifo");
free(uc->uc_entries);
free(uc);
return(0);
}
su->su_cache = (char *) uc;
return(1);
}
/*
* Set an entry in the cache
*/
static void
cache_set(SVCXPRT *xprt, u_long replylen)
{
cache_ptr victim;
cache_ptr *vicp;
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 = malloc(sizeof(struct cache_node));
if (victim == NULL) {
CACHE_PERROR("cache_set: victim alloc failed");
return;
}
newbuf = malloc(su->su_iosz);
if (newbuf == NULL) {
CACHE_PERROR("cache_set: could not allocate new rpc_buffer");
free(victim);
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(SVCXPRT *xprt, struct rpc_msg *msg, char **replyp, u_long *replylenp)
{
u_int loc;
cache_ptr ent;
struct svcudp_data *su = su_data(xprt);
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);
}