main()
{
char *x;
int udp53;
x = env_get("IP");
if (!x)
strerr_die2x(111,fatal,"$IP not set");
if (!ip4_scan(x,ip))
strerr_die3x(111,fatal,"unable to parse IP address ",x);
udp53 = socket_udp();
if (udp53 == -1)
strerr_die2sys(111,fatal,"unable to create UDP socket: ");
if (socket_bind4_reuse(udp53,ip,53) == -1)
strerr_die2sys(111,fatal,"unable to bind UDP socket: ");
droproot(fatal);
initialize();
ndelay_off(udp53);
socket_tryreservein(udp53,65536);
for (;;) {
len = socket_recv4(udp53,buf,sizeof buf,ip,&port);
if (len < 0) continue;
if (!doit()) continue;
if (response_len > 512) response_tc();
socket_send4(udp53,response,response_len,ip,port);
/* may block for buffer space; if it fails, too bad */
}
}
void u_respond(int j)
{
if (!u[j].active) return;
response_id(u[j].id);
if (response_len > 512) response_tc();
socket_send6(udp53,response,response_len,u[j].ip,u[j].port,u[j].scope_id);
log_querydone(&u[j].active,response_len);
u[j].active = 0; --uactive;
}
void
u_respond (int j)
{
if (!u[j].active)
return;
response_id (u[j].id);
if (response_len > 512)
response_tc ();
socket_send4 (udp53, response, response_len, u[j].ip, u[j].port, &odst);
if (debug_level)
log_querydone (u[j].active, response, response_len);
u[j].active = 0;
--uactive;
}
int
main (int argc, char *argv[])
{
time_t t = 0;
char *x = NULL;
struct sigaction sa;
iopause_fd *iop = NULL;
int i = 0, n = 0, *udp53 = NULL;
prog = strdup ((x = strrchr (argv[0], '/')) != NULL ? x + 1 : argv[0]);
sa.sa_handler = handle_term;
sigaction (SIGINT, &sa, NULL);
sigaction (SIGTERM, &sa, NULL);
sa.sa_handler = SIG_IGN;
sigaction (SIGPIPE, &sa, NULL);
i = check_option (argc, argv);
argc -= i;
argv += i;
if (mode & DAEMON)
{
i = fork ();
if (i == -1)
err (-1, "could not fork a daemon process");
if (i > 0)
return 0;
}
time (&t);
memset (buf, 0, sizeof (buf));
strftime (buf, sizeof (buf), "%b-%d %Y %T %Z", localtime (&t));
warnx ("version %s: starting: %s\n", VERSION, buf);
set_timezone ();
if (debug_level)
warnx ("TIMEZONE: %s", env_get ("TZ"));
initialize ();
if (!debug_level)
if ((x = env_get ("DEBUG_LEVEL")))
debug_level = atol (x);
warnx ("DEBUG_LEVEL set to `%d'", debug_level);
if ((x = env_get ("DATALIMIT")))
{
struct rlimit r;
unsigned long dlimit = atol (x);
if (getrlimit (RLIMIT_DATA, &r) != 0)
err (-1, "could not get resource RLIMIT_DATA");
r.rlim_cur = (dlimit <= r.rlim_max) ? dlimit : r.rlim_max;
if (setrlimit (RLIMIT_DATA, &r) != 0)
err (-1, "could not set resource RLIMIT_DATA");
if (debug_level)
warnx ("DATALIMIT set to `%ld' bytes", r.rlim_cur);
}
if (!(x = env_get ("IP")))
err (-1, "$IP not set");
for (i = 0; (unsigned)i < strlen (x); i++)
n = (x[i] == ',') ? n+1 : n;
if (!(udp53 = calloc (n+1, sizeof (int))))
err (-1, "could not allocate enough memory for udp53");
if (!(iop = calloc (n+1, sizeof (iopause_fd))))
err (-1, "could not allocate enough memory for iop");
i = n = 0;
while (x[i])
{
unsigned int l = 0;
if (!(l = ip4_scan(x+i, ip)))
errx (-1, "could not parse IP address `%s'", x + i);
udp53[n] = socket_udp();
if (udp53[n] == -1)
errx (-1, "could not open UDP socket");
if (socket_bind4_reuse (udp53[n], ip, server_port) == -1)
errx (-1, "could not bind UDP socket");
ndelay_off (udp53[n]);
socket_tryreservein (udp53[n], 65536);
iop[n].fd = udp53[n];
iop[n].events = IOPAUSE_READ;
n++;
i += (x[i + l] == ',') ? l + 1 : l;
}
droproot ();
while (1)
{
struct taia stamp;
struct in_addr odst; /* original destination IP */
struct taia deadline;
taia_now (&stamp);
taia_uint (&deadline, 300);
taia_add (&deadline, &deadline, &stamp);
iopause (iop, n, &deadline, &stamp);
for (i = 0; i < n; i++)
{
if (!iop[i].revents)
continue;
len = socket_recv4 (udp53[i], buf, sizeof (buf), ip, &port, &odst);
if (len < 0)
continue;
if (!doit ())
continue;
if (response_len > 512)
response_tc ();
/* may block for buffer space; if it fails, too bad */
len = socket_send4 (udp53[i], response,
response_len, ip, port, &odst);
if (len < 0)
continue;
if (debug_level > 1)
log_querydone(qnum, response, response_len);
}
}
return 0;
}
