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pcas/src/rsrv/cast_server.c
1999-11-18 15:51:32 +00:00

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/*
* Author: Jeffrey O. Hill
* hill@luke.lanl.gov
* (505) 665 1831
* Date: 5-88
*
* Experimental Physics and Industrial Control System (EPICS)
*
* Copyright 1991, the Regents of the University of California,
* and the University of Chicago Board of Governors.
*
* This software was produced under U.S. Government contracts:
* (W-7405-ENG-36) at the Los Alamos National Laboratory,
* and (W-31-109-ENG-38) at Argonne National Laboratory.
*
* Initial development by:
* The Controls and Automation Group (AT-8)
* Ground Test Accelerator
* Accelerator Technology Division
* Los Alamos National Laboratory
*
* Co-developed with
* The Controls and Computing Group
* Accelerator Systems Division
* Advanced Photon Source
* Argonne National Laboratory
*
* Modification Log:
* -----------------
* .00 joh 030191 Fixed cast server to not block on TCP
* .01 joh 030891 now reuses old client structure
* .02 joh 032091 allways flushes if the client changes and the old
* client has a TCP connection.(bug introduced by .00)
* .03 joh 071291 changes to avoid confusion when a rebooted
* client uses the same port number
* .04 joh 080591 changed printf() to a logMsg()
* .05 joh 082091 tick stamp init in create_udp_client()
* .06 joh 112291 dont change the address until after the flush
* .07 joh 112291 fixed the comments
* .08 joh 021192 better diagnostics
*
* Improvements
* ------------
* .01
* Dont send channel found message unless there is memory, a task slot,
* and a TCP socket available. Send a diagnostic instead.
* Or ... make the timeout shorter? This is only a problem if
* they persist in trying to make a connection after getting no
* response.
*
* Notes:
* ------
* .01
* Replies to broadcasts are not returned over
* an existing TCP connection to avoid a TCP
* pend which could lock up the cast server.
*/
static char *sccsId = "@(#) $Id$";
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <errno.h>
#include "osiSock.h"
#include "osiClock.h"
#include "os_depen.h"
#include "osiThread.h"
#include "errlog.h"
#include "ellLib.h"
#include "taskwd.h"
#include "db_access.h"
#include "envDefs.h"
#include "freeList.h"
#include "server.h"
#include "bsdSocketResource.h"
LOCAL void clean_addrq();
/*
* CAST_SERVER
*
* service UDP messages
*
*/
int cast_server(void)
{
struct sockaddr_in sin;
int status;
int count=0;
struct sockaddr_in new_recv_addr;
int recv_addr_size;
unsigned short port;
int nchars;
threadId tid;
taskwdInsert(threadGetIdSelf(),NULL,NULL);
port = caFetchPortConfig(&EPICS_CA_SERVER_PORT, CA_SERVER_PORT);
recv_addr_size = sizeof(new_recv_addr);
if( IOC_cast_sock!=0 && IOC_cast_sock!=ERROR ) {
if( (status = socket_close(IOC_cast_sock)) == ERROR ) {
epicsPrintf ("CAS: Unable to close master cast socket\n");
}
}
/*
* Open the socket.
* Use ARPA Internet address format and datagram socket.
*/
if((IOC_cast_sock = socket (AF_INET, SOCK_DGRAM, 0)) == ERROR){
epicsPrintf ("CAS: casts socket creation error\n");
threadSuspend(threadGetIdSelf());
}
/*
* some concern that vxWorks will run out of mBuf's
* if this change is made
*
* joh 11-10-98
*/
#if 0
{
/*
*
* this allows for faster connects by queuing
* additional incomming UDP search frames
*
* this allocates a 32k buffer
* (uses a power of two)
*/
int size = 1u<<15u;
status = setsockopt (IOC_cast_sock, SOL_SOCKET,
SO_RCVBUF, (char *)&size, sizeof(size));
if (status<0) {
epicsPrintf ("CAS: unable to set cast socket size\n");
}
}
#endif
/* Zero the sock_addr structure */
memset((char *)&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = htonl(INADDR_ANY);
sin.sin_port = htons(port);
/* get server's Internet address */
if( bind(IOC_cast_sock, (struct sockaddr *)&sin, sizeof (sin)) == ERROR){
epicsPrintf ("CAS: cast bind error\n");
socket_close (IOC_cast_sock);
threadSuspend(threadGetIdSelf());
}
/* tell clients we are on line again */
tid = threadCreate("CAonline",threadPriorityChannelAccessClient-3,
threadGetStackSize(threadStackSmall),
(THREADFUNC)rsrv_online_notify_task,0);
if(tid == 0) {
epicsPrintf ("CAS: couldnt start up online notify task because \"%s\"\n",
strerror(errno));
}
/*
* setup new client structure but reuse old structure if
* possible
*
*/
while(TRUE){
prsrv_cast_client = create_udp_client(IOC_cast_sock);
if(prsrv_cast_client){
break;
}
threadSleep(300.0);
}
while (TRUE) {
status = recvfrom (
IOC_cast_sock,
prsrv_cast_client->recv.buf,
sizeof(prsrv_cast_client->recv.buf),
NULL,
(struct sockaddr *)&new_recv_addr,
&recv_addr_size);
if (status<0) {
epicsPrintf ("CAS: UDP recv error (errno=%s)\n",
SOCKERRSTR(SOCKERRNO));
threadSleep(1.0);
}
else {
prsrv_cast_client->recv.cnt = (unsigned long) status;
prsrv_cast_client->recv.stk = 0ul;
prsrv_cast_client->ticks_at_last_recv = clockGetRate();
/*
* If we are talking to a new client flush to the old one
* in case we are holding UDP messages waiting to
* see if the next message is for this same client.
*/
if (prsrv_cast_client->send.stk) {
status = memcmp( (void *)&prsrv_cast_client->addr, (void *)&new_recv_addr, recv_addr_size);
if(status){
/*
* if the address is different
*/
cas_send_msg(prsrv_cast_client, TRUE);
prsrv_cast_client->addr = new_recv_addr;
}
}
else {
prsrv_cast_client->addr = new_recv_addr;
}
if(CASDEBUG>1){
char buf[40];
ipAddrToA (&prsrv_cast_client->addr, buf, sizeof(buf));
epicsPrintf ("CAS: cast server msg of %d bytes from addr %s\n",
prsrv_cast_client->recv.cnt, buf);
}
if(CASDEBUG>2)
count = ellCount(&prsrv_cast_client->addrq);
status = camessage(
prsrv_cast_client,&prsrv_cast_client->recv);
if(status == OK){
if(prsrv_cast_client->recv.cnt !=
prsrv_cast_client->recv.stk){
char buf[40];
ipAddrToA (&prsrv_cast_client->addr, buf, sizeof(buf));
epicsPrintf ("CAS: partial (damaged?) UDP msg of %d bytes from %s ?\n",
prsrv_cast_client->recv.cnt-prsrv_cast_client->recv.stk, buf);
}
}
else {
char buf[40];
ipAddrToA (&prsrv_cast_client->addr, buf, sizeof(buf));
epicsPrintf ("CAS: invalid (damaged?) UDP request from %s ?\n", buf);
}
if(CASDEBUG>2){
if(ellCount(&prsrv_cast_client->addrq)){
epicsPrintf ("CAS: Fnd %d name matches (%d tot)\n",
ellCount(&prsrv_cast_client->addrq)-count,
ellCount(&prsrv_cast_client->addrq));
}
}
}
/*
* allow messages to batch up if more are comming
*/
status = socket_ioctl(IOC_cast_sock, FIONREAD, /* sic */(int) &nchars);
if(status == ERROR){
threadSuspend(threadGetIdSelf());
}
if(nchars == 0){
cas_send_msg(prsrv_cast_client, TRUE);
clean_addrq();
}
}
}
/*
* clean_addrq
*
*
*/
#define TIMEOUT 60 /* sec */
LOCAL void clean_addrq()
{
struct channel_in_use *pciu;
struct channel_in_use *pnextciu;
unsigned long current;
unsigned long delay;
unsigned long maxdelay = 0;
unsigned ndelete=0;
unsigned long timeout = TIMEOUT*clockGetRate();
int s;
current = clockGetRate();
semMutexTakeAssert(prsrv_cast_client->addrqLock);
pnextciu = (struct channel_in_use *)
prsrv_cast_client->addrq.node.next;
while( (pciu = pnextciu) ) {
pnextciu = (struct channel_in_use *)pciu->node.next;
if (current >= pciu->ticks_at_creation) {
delay = current - pciu->ticks_at_creation;
}
else {
delay = current + (~0L - pciu->ticks_at_creation);
}
if (delay > timeout) {
ellDelete(&prsrv_cast_client->addrq, &pciu->node);
LOCK_CLIENTQ;
s = bucketRemoveItemUnsignedId (
pCaBucket,
&pciu->sid);
if(s){
errMessage (s, "Bad id at close");
}
UNLOCK_CLIENTQ;
freeListFree(rsrvChanFreeList, pciu);
ndelete++;
maxdelay = max(delay, maxdelay);
}
}
semMutexGive(prsrv_cast_client->addrqLock);
# ifdef DEBUG
if(ndelete){
epicsPrintf ("CAS: %d CA channels have expired after %d sec\n",
ndelete, maxdelay / clockGetRate());
}
# endif
}
/*
* CREATE_UDP_CLIENT
*
*
*/
struct client *create_udp_client(SOCKET sock)
{
struct client *client;
client = freeListMalloc(rsrvClientFreeList);
if(!client){
epicsPrintf ("CAS: no space in pool for a new client\n");
return NULL;
}
if(CASDEBUG>2)
epicsPrintf ("CAS: Creating new udp client\n");
/*
* The following inits to zero done instead of a bfill since the send
* and recv buffers are large and don't need initialization.
*
* memset(client, 0, sizeof(*client));
*/
client->blockSem = semBinaryCreate(semEmpty);
if(!client->blockSem){
freeListFree(rsrvClientFreeList, client);
return NULL;
}
/*
* user name initially unknown
*/
client->pUserName = malloc(1);
if(!client->pUserName){
semBinaryDestroy(client->blockSem);
freeListFree(rsrvClientFreeList, client);
return NULL;
}
client->pUserName[0] = '\0';
/*
* host name initially unknown
*/
client->pHostName = malloc(1);
if(!client->pHostName){
semBinaryDestroy(client->blockSem);
free(client->pUserName);
freeListFree(rsrvClientFreeList, client);
return NULL;
}
client->pHostName[0] = '\0';
ellInit(&client->addrq);
ellInit(&client->putNotifyQue);
memset((char *)&client->addr, 0, sizeof(client->addr));
client->tid = threadGetIdSelf();
client->send.stk = 0ul;
client->send.cnt = 0ul;
client->recv.stk = 0ul;
client->recv.cnt = 0ul;
client->evuser = NULL;
client->disconnect = FALSE; /* for TCP only */
client->ticks_at_last_send = clockGetRate();
client->ticks_at_last_recv = clockGetRate();
client->proto = IPPROTO_UDP;
client->sock = sock;
client->minor_version_number = CA_UKN_MINOR_VERSION;
client->send.maxstk = MAX_UDP;
client->lock = semMutexCreate();
client->putNotifyLock = semMutexCreate();
client->addrqLock = semMutexCreate();
client->eventqLock = semMutexCreate();
client->recv.maxstk = ETHERNET_MAX_UDP;
return client;
}
/*
* UDP_TO_TCP
*
* send lock must be applied
*
*/
int udp_to_tcp(
struct client *client,
SOCKET sock
)
{
int status;
int addrSize;
if(CASDEBUG>2){
epicsPrintf ("CAS: converting udp client to tcp\n");
}
client->proto = IPPROTO_TCP;
client->send.maxstk = MAX_TCP;
client->recv.maxstk = MAX_TCP;
client->sock = sock;
client->tid = threadGetIdSelf();
addrSize = sizeof(client->addr);
status = getpeername(
sock,
(struct sockaddr *)&client->addr,
&addrSize);
if(status == ERROR){
epicsPrintf ("CAS: peer address fetch failed\n");
return ERROR;
}
return OK;
}