/* This file is part of the Project Athena Zephyr Notification System.
 * It contains functions for the Client Manager subsystem of the Zephyr server.
 *
 *	Created by:	John T. Kohl
 *
 *	$Source: /mit/zephyr/repository/zephyr/server/client.c,v $
 *	$Author: ghudson $
 *
 *	Copyright (c) 1987,1988,1991 by the Massachusetts Institute of Technology.
 *	For copying and distribution information, see the file
 *	"mit-copyright.h". 
 */

#include <zephyr/mit-copyright.h>
#include "zserver.h"
#include <sys/socket.h>

#if !defined (lint) && !defined (SABER)
static const char rcsid_client_c[] =
"$Id: client.c,v 1.31 1995/07/07 22:11:53 ghudson Exp $";
#endif

/*
 * External functions:
 *
 * Code_t client_register(notice, who, client, server, wantdefaults)
 *	ZNotice_t *notice;
 *	struct sockaddr_in *who;
 *	Client **client; (RETURN)
 *	Server *server;
 *	int wantdefaults;
 *
 * Code_t client_deregister(client, host, flush)
 *	Client *client;
 *	Host *host;
 *	int flush;
 *
 * Client *client_which_client(who, notice)
 *	struct sockaddr_in *who;
 *	ZNotice_t *notice;
 *
 * void client_dump_clients(fp, clist)
 *	FILE *fp;
 *	Client *clist;
 */

/*
 * a client: allocate space, find or insert the address in the
 * 	server's list of hosts, initialize and insert the client into
 *	the host's list of clients.
 *
 * This routine assumes that the client has not been registered yet.
 * The caller should check by calling client_which_client
 */

#define HASHSIZE 1024
static Client *client_bucket[HASHSIZE];

#define INET_HASH(host, port) ((htonl((host)->s_addr) + \
				htons((unsigned short) (port))) % HASHSIZE)

static Client *client_find __P((struct in_addr *host, unsigned int port));

Code_t
client_register(notice, host, client_p, wantdefaults)
    ZNotice_t *notice;
    struct in_addr *host;
    Client **client_p;
    int wantdefaults;
{
    Client *client;
    Code_t retval;

    /* chain the client's host onto this server's host list */

#if 1
    zdbug((LOG_DEBUG, "client_register: adding %s at %s/%d",
	   notice->z_sender, inet_ntoa(*host), ntohs(notice->z_port)));
#endif

    if (!notice->z_port)
	return ZSRV_BADSUBPORT;

    *client_p = client = client_find(host, notice->z_port);
    if (!client) {
	*client_p = client = (Client *) malloc(sizeof(Client));
	if (!client)
	    return ENOMEM;
	memset(&client->addr, 0, sizeof(struct sockaddr_in));
#ifdef KERBEROS
	memset(&client->session_key, 0, sizeof(client->session_key));
#endif
	client->last_msg = 0;
	client->last_check = 0;
	client->last_send = 0;
	client->addr.sin_family = AF_INET;
	client->addr.sin_addr.s_addr = host->s_addr;
	client->addr.sin_port = notice->z_port;
	client->subs = NULL;
	client->principal = make_string(notice->z_sender, 0);
	LIST_INSERT(client_bucket[INET_HASH(&client->addr.sin_addr,
					    notice->z_port)], client);
    }

    /* Add default subscriptions only if this is not resulting from a brain
     * dump, AND this request wants defaults. */
    if (!bdumping && wantdefaults)
	return subscr_def_subs(client);
    else
	return ZERR_NONE;
}

/*
 * Deregister the client, freeing resources.  
 * Remove any packets in the nack queue, release subscriptions, release
 * locations, and dequeue him from the host.
 */

void
client_deregister(client, flush)
    Client *client;
    int flush;
{
    LIST_DELETE(client);
    nack_release(client);
    subscr_cancel_client(client);
    free_string(client->principal);
    if (flush)
	uloc_flush_client(&client->addr);
    free(client);
}

void
client_flush_host(host)
    struct in_addr *host;
{
    int i;
    Client *client, *next;

    for (i = 0; i < HASHSIZE; i++) {
	for (client = client_bucket[i]; client; client = next) {
	    next = client->next;
	    if (client->addr.sin_addr.s_addr == host->s_addr)
		client_deregister(client, 1);
	}
    }
}

/*
 * find the client which sent the notice
 */

Client *
client_which_client(host, notice)
    struct in_addr *host;
    ZNotice_t *notice;
{
    return client_find(host, notice->z_port);
}

Code_t
client_send_clients()
{
    int i;
    Client *client;
    Code_t retval;

    for (i = 0; i < HASHSIZE; i++) {
	/* Allow packets to be processed between rows of the hash table. */
	if (packets_waiting())
	    handle_packet();
	for (client = client_bucket[i]; client; client = client->next) {
	    if (client->subs) {
		retval = subscr_send_subs(client);
		if (retval != ZERR_NONE)
		    return retval;
	    }
	}
    }
    return ZERR_NONE;
}

/*
 * dump info about clients in this clist onto the fp.
 * assumed to be called with SIGFPE blocked
 * (true if called from signal handler)
 */

void
client_dump_clients(fp)
    FILE *fp;
{
    Client *client;
    int i;

    for (i = 0; i < HASHSIZE; i++) {
	for (client = client_bucket[i]; client; client = client->next) {
	    fprintf(fp, "\t%d (%s):\n", ntohs(client->addr.sin_port),
		    client->principal->string);
	    subscr_dump_subs(fp, client->subs);
	}
    }
}

static Client *
client_find(host, port)
    struct in_addr *host;
    unsigned int port;
{
    Client *client;
    long hashval;

    hashval = INET_HASH(host, port);
    for (client = client_bucket[hashval]; client; client = client->next) {
	if (client->addr.sin_addr.s_addr == host->s_addr
	    && client->addr.sin_port == port)
	    return client;
    }
    return NULL;
}