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/* $Id$ */
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <event.h>
#include "bbs.h"
struct timeval tv = {5, 0};
struct event ev;
int clients = 0;
#define READ_BLOCK 256
#define MAX_CLIENTS 10
#define AUTH_PASSWDS BBSHOME "/.AUTH_PASSWDS"
#define ENTRY_SIZE 64
struct client_state {
struct event ev;
int state;
int uid;
int len;
int response;
struct evbuffer *evb;
};
enum {
FSM_ENTER,
FSM_AUTH,
FSM_SETPASSWD,
FSM_RESPOND,
FSM_EXIT
};
/**
* 瑼Ｘ亙蝣
* @return 1 - 撖蝣潮航炊, 0 - 撖蝣潭迤蝣
*/
int check_passwd(int uid, char *passwd)
{
char buf[ENTRY_SIZE];
int i, result = 1;
if ((i = open(AUTH_PASSWDS, O_WRONLY)) < 0)
return result;
if (lseek(i, uid * ENTRY_SIZE, SEEK_SET) < 0)
goto end;
if (read(i, buf, ENTRY_SIZE) < ENTRY_SIZE)
goto end;
if (!strcmp(buf, crypt(passwd, buf)))
result = 0;
end:
memset(buf, 0, ENTRY_SIZE);
close(i);
return result;
}
/**
* 閮剖啣蝣
* DES crypt 撠勗末
*/
void set_passwd(int uid, char *passwd)
{
char buf[ENTRY_SIZE];
char saltc[3], c;
int i;
i = 9 * random();
saltc[0] = i & 077;
saltc[1] = (i >> 6) & 077;
for (i = 0; i < 2; i++) {
c = saltc[i] + '.';
if (c > '9')
c += 7;
if (c > 'Z')
c += 6;
saltc[i] = c;
}
saltc[2] = '\0';
memset(buf, 0, sizeof(buf));
strlcpy(buf, crypt(passwd, saltc), sizeof(buf));
if ((i = open(AUTH_PASSWDS, O_WRONLY)) < 0)
return;
if (lseek(i, uid * ENTRY_SIZE, SEEK_SET) < 0)
goto close;
write(i, buf, ENTRY_SIZE);
close:
close(i);
}
void connection_client(int cfd, short event, void *arg)
{
struct client_state *cs = arg;
int cmd;
static char buf[128];
// ignore clients that timeout
if (event & EV_TIMEOUT)
cs->state = FSM_EXIT;
if (event & EV_READ) {
if (evbuffer_read(cs->evb, cfd, READ_BLOCK) < 0)
cs->state = FSM_EXIT;
}
while (1) {
switch (cs->state) {
case FSM_ENTER:
if (EVBUFFER_LENGTH(cs->evb) < sizeof(int))
goto break_out;
evbuffer_remove(cs->evb, &cmd, sizeof(cmd));
cs->state = FSM_AUTH;
case FSM_AUTH:
if (EVBUFFER_LENGTH(cs->evb) < sizeof(int) * 2)
goto break_out;
evbuffer_remove(cs->evb, &cs->uid, sizeof(cs->uid));
evbuffer_remove(cs->evb, &cs->len, sizeof(cs->len));
if (EVBUFFER_LENGTH(cs->evb) < cs->len)
goto break_out;
memset(buf, 0, sizeof(buf));
evbuffer_remove(cs->evb, buf, cs->len);
cs->response = check_passwd(cs->uid, buf);
memset(buf, 0, sizeof(buf));
if (cmd == 2)
cs->state = FSM_SETPASSWD;
else {
cs->state = FSM_RESPOND;
goto break_out;
}
case FSM_SETPASSWD:
if (EVBUFFER_LENGTH(cs->evb) < sizeof(int))
goto break_out;
evbuffer_remove(cs->evb, &cs->len, sizeof(cs->len));
if (EVBUFFER_LENGTH(cs->evb) < cs->len)
goto break_out;
memset(buf, 0, sizeof(buf));
evbuffer_remove(cs->evb, buf, cs->len);
set_passwd(cs->uid, buf);
memset(buf, 0, sizeof(buf));
cs->state = FSM_RESPOND;
goto break_out;
case FSM_RESPOND:
write(cfd, &cs->response, sizeof(cs->response));
cs->state = FSM_EXIT;
case FSM_EXIT:
if (clients == MAX_CLIENTS)
event_add(&ev, NULL);
close(cfd);
evbuffer_free(cs->evb);
free(cs);
clients--;
return;
}
}
break_out:
if (cs->state == FSM_RESPOND)
event_set(&cs->ev, cfd, EV_WRITE, (void *) connection_client, cs);
event_add(&cs->ev, &tv);
}
void connection_accept(int fd, short event, void *arg)
{
struct sockaddr_in clientaddr;
socklen_t len = sizeof(clientaddr);
int cfd;
if ((cfd = accept(fd, (struct sockaddr *)&clientaddr, &len)) < 0 )
return;
fcntl(cfd, F_SETFL, fcntl(cfd, F_GETFL, 0) | O_NONBLOCK);
struct client_state *cs = calloc(1, sizeof(struct client_state));
cs->state = 0;
cs->evb = evbuffer_new();
event_set(&cs->ev, cfd, EV_READ, (void *) connection_client, cs);
event_add(&cs->ev, &tv);
clients++;
if (clients > MAX_CLIENTS)
event_del(&ev);
}
int main(int argc, char *argv[])
{
int ch, port = 5121, sfd;
char *iface_ip = NULL;
Signal(SIGPIPE, SIG_IGN);
while( (ch = getopt(argc, argv, "p:i:h")) != -1 )
switch( ch ){
case 'p':
port = atoi(optarg);
break;
case 'i':
iface_ip = optarg;
break;
case 'h':
default:
fprintf(stderr, "usage: authserver [-i interface_ip] [-p port]\n");
return 1;
}
if( (sfd = tobind(iface_ip, port)) < 0 )
return 1;
srandom(getpid() + time(NULL));
event_init();
event_set(&ev, sfd, EV_READ | EV_PERSIST, connection_accept, &ev);
event_add(&ev, NULL);
event_dispatch();
return 0;
}
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