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discover loss of client by connecting UDP sockets

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This commit is contained in:
Jeff Hill
1995-08-12 00:37:28 +00:00
parent c7005b4783
commit 1bd52dfef9
1 changed files with 156 additions and 170 deletions
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326
src/ca/repeater.c
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@@ -57,29 +57,36 @@
* .06 120492 joh removed unnecessary includes
* .07 120992 joh now uses dll list routines
* .08 102993 joh toggle set sock opt to set
*
* .09 070195 joh discover client has vanished by connecting its
* datagram socket (and watching for ECONNREFUSED)
*/
static char *sccsId = "@(#)$Id$";
#include "iocinf.h"
/*
* one socket per client so we will get the ECONNREFUSED
* error code (and then delete the client)
*/
struct one_client{
ELLNODE node;
struct sockaddr_in from;
SOCKET sock;
};
/*
* these can be external since there is only one instance
* per machine so we dont care about reentrancy
*/
struct one_client{
ELLNODE node;
struct sockaddr_in from;
};
static ELLLIST client_list;
static char buf[MAX_UDP];
LOCAL int clean_client(struct one_client *pclient);
LOCAL void register_new_client(SOCKET sock, struct sockaddr_in *pLocal,
LOCAL void register_new_client(struct sockaddr_in *pLocal,
struct sockaddr_in *pFrom);
#define PORT_ANY 0
LOCAL int makeSocket(int port);
/*
@@ -93,14 +100,12 @@ void ca_repeater()
int status;
int size;
SOCKET sock;
int true = 1;
struct sockaddr_in from;
struct sockaddr_in bd;
struct sockaddr_in local;
int from_size = sizeof from;
struct one_client *pclient;
struct one_client *pnxtclient;
short port;
ELLLIST theClients;
port = caFetchPortConfig(
&EPICS_CA_REPEATER_PORT,
@@ -108,37 +113,13 @@ void ca_repeater()
ellInit(&client_list);
/* allocate a socket */
sock = socket( AF_INET, /* domain */
SOCK_DGRAM, /* type */
0); /* deflt proto */
assert(sock != INVALID_SOCKET);
memset((char *)&bd, 0, sizeof(bd));
bd.sin_family = AF_INET;
bd.sin_addr.s_addr = INADDR_ANY;
bd.sin_port = htons(port);
status = bind(sock, (struct sockaddr *)&bd, sizeof(bd));
if(status<0){
if(MYERRNO != EADDRINUSE){
ca_printf("CA Repeater: unexpected bind fail %s\n",
strerror(MYERRNO));
}
socket_close(sock);
sock = makeSocket(port);
if (sock==INVALID_SOCKET) {
ca_printf("%s: unable to make recv sock\n",
__FILE__);
exit(0);
}
status = setsockopt( sock,
SOL_SOCKET,
SO_REUSEADDR,
(char *)&true,
sizeof(true));
if(status<0){
ca_printf( "%s: set socket option failed\n",
__FILE__);
}
status = local_addr(sock, &local);
if(status != OK){
ca_printf(
@@ -164,86 +145,128 @@ void ca_repeater()
if(size < 0){
ca_printf("CA Repeater: recv err %s\n",
strerror(MYERRNO));
continue;
}
pMsg = (struct extmsg *) buf;
/*
* both zero leng message and a registartion message
* both zero length message and a registration message
* will register a new client
*/
if(size >= sizeof(*pMsg)){
if(ntohs(pMsg->m_cmmd) == REPEATER_REGISTER){
register_new_client(sock, &local, &from);
register_new_client(&local, &from);
/*
* strip register client message
*/
pMsg++;
size -= sizeof(*pMsg);
if (size==0) {
continue;
}
}
}
else if(size == 0){
register_new_client(sock, &local, &from);
register_new_client(&local, &from);
continue;
}
/*
* size may have been adjusted above
*/
if(size){
for( pclient = (struct one_client *)
client_list.node.next;
pclient;
pclient = (struct one_client *)
pclient->node.next){
ellInit(&theClients);
while (pclient=(struct one_client *)ellGet(&client_list)) {
ellAdd(&theClients, &pclient->node);
/*
* Dont reflect back to sender
*/
if(from.sin_port == pclient->from.sin_port &&
from.sin_addr.s_addr ==
pclient->from.sin_addr.s_addr){
continue;
}
/*
* Dont reflect back to sender
*/
if(from.sin_port == pclient->from.sin_port &&
from.sin_addr.s_addr ==
pclient->from.sin_addr.s_addr){
continue;
}
status = sendto(
sock,
(char *)pMsg,
size,
0,
(struct sockaddr *)&pclient->from,
sizeof pclient->from);
if(status < 0){
ca_printf("CA Repeater: fanout err %s\n",
strerror(MYERRNO));
}
status = send(
pclient->sock,
(char *)pMsg,
size,
0);
if (status>=0) {
#ifdef DEBUG
ca_printf("Sent\n");
ca_printf("Sent to %d\n",
pclient->from.sin_port);
#endif
}
if(status < 0){
if (MYERRNO == ECONNREFUSED) {
#ifdef DEBUG
ca_printf("Deleted client %d\n",
pclient->from.sin_port);
#endif
ellDelete(&theClients,
&pclient->node);
socket_close(pclient->sock);
free(pclient);
}
else {
ca_printf(
"CA Repeater: fan out err was \"%s\"\n",
strerror(MYERRNO));
}
}
}
/*
* remove any dead wood prior to pending
*/
for( pclient = (struct one_client *)
client_list.node.next;
pclient;
pclient = pnxtclient){
/* do it now in case item deleted */
pnxtclient = (struct one_client *)
pclient->node.next;
clean_client(pclient);
}
ellConcat(&client_list, &theClients);
}
}
/*
* makeSocket()
*/
LOCAL int makeSocket(int port)
{
int status;
struct sockaddr_in bd;
int sock;
int true = 1;
sock = socket( AF_INET, /* domain */
SOCK_DGRAM, /* type */
0); /* deflt proto */
if (sock == INVALID_SOCKET) {
return sock;
}
status = setsockopt( sock,
SOL_SOCKET,
SO_REUSEADDR,
(char *)&true,
sizeof(true));
if(status<0){
ca_printf( "%s: set socket option failed\n",
__FILE__);
}
memset((char *)&bd, 0, sizeof(bd));
bd.sin_family = AF_INET;
bd.sin_addr.s_addr = INADDR_ANY;
bd.sin_port = htons(port);
status = bind(sock, (struct sockaddr *)&bd, sizeof(bd));
if(status<0){
ca_printf("CA Repeater: unexpected bind fail %s\n",
strerror(MYERRNO));
socket_close(sock);
return INVALID_SOCKET;
}
return sock;
}
/*
* register_new_client()
*/
LOCAL void register_new_client(
SOCKET sock,
struct sockaddr_in *pLocal,
struct sockaddr_in *pFrom)
{
@@ -251,9 +274,9 @@ struct sockaddr_in *pFrom)
struct one_client *pclient;
struct extmsg confirm;
for( pclient = (struct one_client *) client_list.node.next;
for( pclient = (struct one_client *) ellFirst(&client_list);
pclient;
pclient = (struct one_client *) pclient->node.next){
pclient = (struct one_client *) ellNext(&pclient->node)){
if( pFrom->sin_port == pclient->from.sin_port &&
pFrom->sin_addr.s_addr == pclient->from.sin_addr.s_addr)
@@ -262,101 +285,64 @@ struct sockaddr_in *pFrom)
if(!pclient){
pclient = (struct one_client *)calloc (1, sizeof(*pclient));
if(pclient){
pclient->from = *pFrom;
ellAdd (&client_list, &pclient->node);
#ifdef DEBUG
ca_printf (
"Added %d\n",
pFrom->sin_port);
#endif
if(!pclient){
ca_printf("%s: no memory for new client\n",
__FILE__);
return;
}
pclient->sock = makeSocket(PORT_ANY);
if (!pclient->sock) {
free(pclient);
ca_printf("%s: unable to make client sock\n",
__FILE__);
return;
}
status = connect(pclient->sock,
(struct sockaddr *)pFrom,
sizeof(*pFrom));
if (status<0) {
socket_close(pclient->sock);
free(pclient);
ca_printf("%s: unable to connect client sock\n",
__FILE__);
return;
}
pclient->from = *pFrom;
ellAdd (&client_list, &pclient->node);
#ifdef DEBUG
ca_printf (
"Added %d\n",
pFrom->sin_port);
#endif
}
memset((char *)&confirm, 0, sizeof confirm);
confirm.m_cmmd = htons(REPEATER_CONFIRM);
confirm.m_available = pLocal->sin_addr.s_addr;
status = sendto(
sock,
status = send(
pclient->sock,
(char *)&confirm,
sizeof(confirm),
0,
(struct sockaddr *)pFrom, /* back to sender */
sizeof(*pFrom));
if(status != sizeof(confirm)){
ca_printf("CA Repeater: confirm err %s\n",
strerror(MYERRNO));
0);
if(status >= 0){
assert(status == sizeof(confirm));
}
}
/*
*
* check to see if this client is still around
*
* NOTE:
* This closes the socket only whenever we are
* able to bind so that we free the port.
*/
LOCAL int clean_client(struct one_client *pclient)
{
static int sockExists;
static SOCKET sock;
int port = pclient->from.sin_port;
struct sockaddr_in bd;
int status;
int present = FALSE;
/*
* allocate a socket
* (no lock required because this is implemented with
* a single thread)
*/
if(!sockExists){
sock = socket(
AF_INET, /* domain */
SOCK_DGRAM, /* type */
0); /* deflt proto */
if(sock != INVALID_SOCKET){
sockExists = TRUE;
}
else{
ca_printf("CA Repeater: no bind test sock err %s\n",
strerror(MYERRNO));
return OK;
}
}
memset((char *)&bd, 0, sizeof(bd));
bd.sin_family = AF_INET;
bd.sin_addr.s_addr = INADDR_ANY;
bd.sin_port = port;
status = bind(sock, (struct sockaddr *)&bd, sizeof(bd));
if(status>=0){
socket_close (sock);
sockExists = FALSE;
}
else{
if(MYERRNO == EADDRINUSE){
present = TRUE;
}
else{
ca_printf("CA Repeater: client cleanup err %s\n",
strerror(MYERRNO));
ca_printf("CA Repeater: sock=%d family=%d addr=%x port=%d\n",
sock, bd.sin_family, bd.sin_addr.s_addr,
bd.sin_port);
}
}
if(!present){
else if (MYERRNO == ECONNREFUSED){
#ifdef DEBUG
ca_printf("Deleted %d\n", pclient->from.sin_port);
ca_printf("Deleted repeater client=%d sending ack\n",
pFrom->sin_port);
#endif
ellDelete(&client_list, &pclient->node);
socket_close(pclient->sock);
free(pclient);
}
return OK;
else {
ca_printf("CA Repeater: confirm err was \"%s\"\n",
strerror(MYERRNO));
}
}