minix/commands/talkd/process.c
2005-04-21 14:53:53 +00:00

269 lines
5.7 KiB
C
Executable file

/* process.c Copyright Michael Temari 07/22/1996 All Rights Reserved */
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <ctype.h>
#include <time.h>
#include <net/hton.h>
#include <net/gen/socket.h>
#include <net/gen/in.h>
#include <net/gen/netdb.h>
#include "talk.h"
#include "talkd.h"
#include "process.h"
#include "finduser.h"
struct entry {
struct entry *prev;
struct talk_request rq;
time_t expire;
struct entry *next;
};
_PROTOTYPE(static int announce, (struct talk_request *request, char *rhost));
_PROTOTYPE(static struct talk_request *lookup, (struct talk_request *request, int type));
_PROTOTYPE(static int addreq, (struct talk_request *request));
_PROTOTYPE(static delete_invite, (long id));
_PROTOTYPE(static long nextid, (void));
_PROTOTYPE(static void delete, (struct entry *e));
static struct entry *entry = (struct entry *)NULL;
int processrequest(request, reply)
struct talk_request *request;
struct talk_reply *reply;
{
char *p;
struct talk_request *rq;
struct hostent *hp;
reply->version = TALK_VERSION;
reply->type = request->type;
reply->answer = 0;
reply->junk = 0;
reply->id = htonl(0);
/* check version */
if(request->version != TALK_VERSION) {
reply->answer = BADVERSION;
return(0);
}
/* check address family */
if(ntohs(request->addr.sa_family) != AF_INET) {
reply->answer = BADADDR;
return(0);
}
/* check control address family */
if(ntohs(request->ctl_addr.sa_family) != AF_INET) {
reply->answer = BADCTLADDR;
return(0);
}
/* check local name */
p = request->luser;
while(*p)
if(!isprint(*p)) {
reply->answer = FAILED;
return(0);
} else
p++;
switch(request->type) {
case ANNOUNCE:
reply->answer = find_user(request->ruser, request->rtty);
if(reply->answer != SUCCESS) break;
hp = gethostbyaddr((char *)&request->ctl_addr.sin_addr, sizeof(ipaddr_t), AF_INET);
if(hp == (struct hostent *)NULL) {
reply->answer = MACHINE_UNKNOWN;
break;
}
if((rq = lookup(request, 1)) == (struct talk_request *)NULL) {
reply->id = addreq(request);
reply->answer = announce(request, hp->h_name);
break;
}
if(ntohl(request->id) > ntohl(rq->id)) {
rq->id = nextid();
reply->id = rq->id;
reply->answer = announce(request, hp->h_name);
} else {
reply->id = rq->id;
reply->answer = SUCCESS;
}
break;
case LEAVE_INVITE:
rq = lookup(request, 1);
if(rq == (struct talk_request *)NULL)
reply->id = addreq(request);
else {
reply->id = rq->id;
reply->answer = SUCCESS;
}
break;
case LOOK_UP:
if((rq = lookup(request, 0)) == (struct talk_request *)NULL)
reply->answer = NOT_HERE;
else {
reply->id = rq->id;
memcpy((char *)&reply->addr, (char *)&rq->addr, sizeof(reply->addr));
reply->answer = SUCCESS;
}
break;
case DELETE:
reply->answer = delete_invite(request->id);
break;
default:
reply->answer = UNKNOWN_REQUEST;
}
return(0);
}
static int announce(request, rhost)
struct talk_request *request;
char *rhost;
{
char tty[5+TTY_SIZE+1];
struct stat st;
FILE *fp;
time_t now;
struct tm *tm;
sprintf(tty, "/dev/%s", request->rtty);
if(stat(tty, &st) < 0)
return(PERMISSION_DENIED);
if(!(st.st_mode & S_IWGRP))
return(PERMISSION_DENIED);
if((fp = fopen(tty, "w")) == (FILE *)NULL)
return(PERMISSION_DENIED);
(void) time(&now);
tm = localtime(&now);
fprintf(fp, "\007\007\007\rtalkd: Message from talkd@%s at %d:%02d:%02d\r\n",
myhostname, tm->tm_hour, tm->tm_min, tm->tm_sec);
fprintf(fp, "talkd: %s@%s would like to talk to you\r\n",
request->luser, rhost);
fprintf(fp, "talkd: to answer type: talk %s@%s\r\n",
request->luser, rhost);
fclose(fp);
return(SUCCESS);
}
static struct talk_request *lookup(request, type)
struct talk_request *request;
int type;
{
time_t now;
struct entry *e;
(void) time(&now);
for(e = entry; e != (struct entry *)NULL; e = e->next) {
if(now > e->expire) {
delete(e);
continue;
}
if(type == 0) {
if(!strncmp(request->luser, e->rq.ruser, USER_SIZE) &&
!strncmp(request->ruser, e->rq.luser, USER_SIZE) &&
e->rq.type == LEAVE_INVITE)
return(&e->rq);
} else {
if(request->type == e->rq.type &&
request->pid == e->rq.pid &&
!strncmp(request->luser, e->rq.luser, USER_SIZE) &&
!strncmp(request->ruser, e->rq.ruser, USER_SIZE)) {
e->expire = now + MAX_LIFE;
return(&e->rq);
}
}
}
return((struct talk_request *)NULL);
}
static int addreq(request)
struct talk_request *request;
{
time_t now;
struct entry *e;
(void) time(&now);
request->id = nextid();
e = (struct entry *) malloc(sizeof(struct entry));
if(e == (struct entry *)NULL) {
fprintf(stderr, "talkd: out of memory in insert table\n");
exit(1);
}
e->expire = now + MAX_LIFE;
memcpy((char *)&e->rq, (char *)request, sizeof(struct talk_request));
e->next = entry;
if(e->next != (struct entry *)NULL)
e->next->prev = e;
e->prev = (struct entry *)NULL;
entry = e;
return(request->id);
}
static int delete_invite(id)
long id;
{
time_t now;
struct entry *e;
(void) time(&now);
for(e = entry; e != (struct entry *)NULL; e = e->next) {
if(now > e->expire) {
delete(e);
continue;
}
if(e->rq.id == id) {
delete(e);
return(SUCCESS);
}
}
return(NOT_HERE);
}
static void delete(e)
struct entry *e;
{
if(e == (struct entry *)NULL) return;
if(entry == e)
entry = e->next;
else
if(e->prev != (struct entry *)NULL)
e->prev->next = e->next;
if(e->next != (struct entry *)NULL)
e->next->prev = e->prev;
free((char *)e);
return;
}
static long nextid()
{
static long id = 0;
id++;
if(id <= 0) id = 1;
return(htonl(id));
}