#include <config.h>
#include "main.h"
#include "kod_management.h"
#include "networking.h"
#include "utilities.h"
#include "log.h"
int ai_fam_pref = AF_UNSPEC;
struct key *keys = NULL;
void set_li_vn_mode (struct pkt *spkt, char leap, char version, char mode);
int sntp_main (int argc, char **argv);
int on_wire (struct addrinfo *host, struct addrinfo *bcastaddr);
int set_time (double offset);
#define NORMALIZE_TIMEVAL(tv) \
do { \
while ((tv).tv_usec < 0) { \
(tv).tv_usec += 1000000; \
(tv).tv_sec--; \
} \
while ((tv).tv_usec > 999999) { \
(tv).tv_usec -= 1000000; \
(tv).tv_sec++; \
} \
} while (0)
/*
* The actual main function.
*/
int
sntp_main (
int argc,
char **argv
)
{
register int c;
struct kod_entry *reason = NULL;
int optct;
/* boolean, u_int quiets gcc4 signed overflow warning */
u_int sync_data_suc;
struct addrinfo **bcastaddr = NULL;
struct addrinfo **resh = NULL;
struct addrinfo *ai;
int resc;
int kodc;
int ow_ret;
int bcast = 0;
char *hostname;
optct = optionProcess(&sntpOptions, argc, argv);
argc -= optct;
argv += optct;
/* Initialize logging system */
init_logging();
if (HAVE_OPT(LOGFILE))
open_logfile(OPT_ARG(LOGFILE));
msyslog(LOG_NOTICE, "Started sntp");
/* IPv6 available? */
if (isc_net_probeipv6() != ISC_R_SUCCESS) {
ai_fam_pref = AF_INET;
#ifdef DEBUG
printf("No ipv6 support available, forcing ipv4\n");
#endif
} else {
/* Check for options -4 and -6 */
if (HAVE_OPT(IPV4))
ai_fam_pref = AF_INET;
else if (HAVE_OPT(IPV6))
ai_fam_pref = AF_INET6;
}
/* Parse config file if declared TODO */
/*
* If there's a specified KOD file init KOD system. If not use
* default file. For embedded systems with no writable
* filesystem, -K /dev/null can be used to disable KoD storage.
*/
if (HAVE_OPT(KOD))
kod_init_kod_db(OPT_ARG(KOD));
else
kod_init_kod_db("/var/db/ntp-kod");
if (HAVE_OPT(KEYFILE))
auth_init(OPT_ARG(KEYFILE), &keys);
#ifdef EXERCISE_KOD_DB
add_entry("192.168.169.170", "DENY");
add_entry("192.168.169.171", "DENY");
add_entry("192.168.169.172", "DENY");
add_entry("192.168.169.173", "DENY");
add_entry("192.168.169.174", "DENY");
delete_entry("192.168.169.174", "DENY");
delete_entry("192.168.169.172", "DENY");
delete_entry("192.168.169.170", "DENY");
if ((kodc = search_entry("192.168.169.173", &reason)) == 0)
printf("entry for 192.168.169.173 not found but should have been!\n");
else
free(reason);
#endif
/* Considering employing a variable that prevents functions of doing anything until
* everything is initialized properly
*/
resc = resolve_hosts((const char **)argv, argc, &resh, ai_fam_pref);
if (resc < 1) {
printf("Unable to resolve hostname(s)\n");
return -1;
}
bcast = ENABLED_OPT(BROADCAST);
if (bcast) {
const char * myargv[2];
myargv[0] = OPT_ARG(BROADCAST);
myargv[1] = NULL;
bcast = resolve_hosts(myargv, 1, &bcastaddr, ai_fam_pref);
}
/* Select a certain ntp server according to simple criteria? For now
* let's just pay attention to previous KoDs.
*/
sync_data_suc = FALSE;
for (c = 0; c < resc && !sync_data_suc; c++) {
ai = resh[c];
do {
hostname = addrinfo_to_str(ai);
if ((kodc = search_entry(hostname, &reason)) == 0) {
if (is_reachable(ai)) {
ow_ret = on_wire(ai, bcast ? bcastaddr[0] : NULL);
if (0 == ow_ret)
sync_data_suc = TRUE;
}
} else {
printf("%d prior KoD%s for %s, skipping.\n",
kodc, (kodc > 1) ? "s" : "", hostname);
free(reason);
}
free(hostname);
ai = ai->ai_next;
} while (NULL != ai);
freeaddrinfo(resh[c]);
}
free(resh);
if (!sync_data_suc)
return 1;
return 0;
}
static union {
struct pkt pkt;
char buf[1500];
} rbuf;
#define r_pkt rbuf.pkt
int
generate_pkt (
struct pkt *x_pkt,
const struct timeval *tv_xmt,
int key_id,
struct key *pkt_key
)
{
l_fp xmt;
int pkt_len = LEN_PKT_NOMAC;
memset(x_pkt, 0, sizeof(struct pkt));
TVTOTS(tv_xmt, &xmt);
HTONL_FP(&xmt, &(x_pkt->xmt));
x_pkt->stratum = STRATUM_TO_PKT(STRATUM_UNSPEC);
x_pkt->ppoll = 8;
/* FIXME! Modus broadcast + adr. check -> bdr. pkt */
set_li_vn_mode(x_pkt, LEAP_NOTINSYNC, 4, 3);
if (pkt_key != NULL) {
int mac_size = 20; /* max room for MAC */
x_pkt->exten[0] = htonl(key_id);
mac_size = make_mac((char *)x_pkt, pkt_len, mac_size, pkt_key, (char *)&x_pkt->exten[1]);
if (mac_size)
pkt_len += mac_size + 4;
}
return pkt_len;
}
int
handle_pkt (
int rpktl,
struct pkt *rpkt,
struct addrinfo *host
)
{
struct timeval tv_dst;
int sw_case, digits;
char *hostname = NULL, *ref, *ts_str = NULL;
double offset, precision, root_dispersion;
char addr_buf[INET6_ADDRSTRLEN];
char *p_SNTP_PRETEND_TIME;
time_t pretend_time;
if(rpktl > 0)
sw_case = 1;
else
sw_case = rpktl;
switch(sw_case) {
case SERVER_UNUSEABLE:
return -1;
break;
case PACKET_UNUSEABLE:
break;
case SERVER_AUTH_FAIL:
break;
case KOD_DEMOBILIZE:
/* Received a DENY or RESTR KOD packet */
hostname = addrinfo_to_str(host);
ref = (char *)&rpkt->refid;
add_entry(hostname, ref);
if (ENABLED_OPT(NORMALVERBOSE))
printf("sntp handle_pkt: Received KOD packet with code: %c%c%c%c from %s, demobilizing all connections\n",
ref[0], ref[1], ref[2], ref[3],
hostname);
msyslog(LOG_WARNING, "Received a KOD packet with code %c%c%c%c from %s, demobilizing all connections",
ref[0], ref[1], ref[2], ref[3], hostname);
break;
case KOD_RATE:
/* Hmm... probably we should sleep a bit here */
break;
case 1:
if (ENABLED_OPT(NORMALVERBOSE)) {
getnameinfo(host->ai_addr, host->ai_addrlen, addr_buf,
sizeof(addr_buf), NULL, 0, NI_NUMERICHOST);
printf("sntp handle_pkt: Received %i bytes from %s\n", rpktl, addr_buf);
}
GETTIMEOFDAY(&tv_dst, (struct timezone *)NULL);
p_SNTP_PRETEND_TIME = getenv("SNTP_PRETEND_TIME");
if (p_SNTP_PRETEND_TIME) {
#if SIZEOF_TIME_T == 4
sscanf(p_SNTP_PRETEND_TIME, "%ld", &pretend_time);
#elif SIZEOF_TIME_T == 8
sscanf(p_SNTP_PRETEND_TIME, "%lld", &pretend_time);
#else
# include "GRONK: unexpected value for SIZEOF_TIME_T"
#endif
tv_dst.tv_sec = pretend_time;
}
offset_calculation(rpkt, rpktl, &tv_dst, &offset,
&precision, &root_dispersion);
for (digits = 0; (precision *= 10.) < 1.; ++digits)
/* empty */ ;
if (digits > 6)
digits = 6;
ts_str = tv_to_str(&tv_dst);
printf("%s ", ts_str);
if (offset > 0)
printf("+");
printf("%.*f", digits, offset);
if (root_dispersion > 0.)
printf(" +/- %f secs", root_dispersion);
printf("\n");
free(ts_str);
if (p_SNTP_PRETEND_TIME)
return 0;
if (ENABLED_OPT(SETTOD) || ENABLED_OPT(ADJTIME))
return set_time(offset);
return 0;
}
return 1;
}
void
offset_calculation (
struct pkt *rpkt,
int rpktl,
struct timeval *tv_dst,
double *offset,
double *precision,
double *root_dispersion
)
{
l_fp p_rec, p_xmt, p_ref, p_org, tmp, dst;
u_fp p_rdly, p_rdsp;
double t21, t34, delta;
/* Convert timestamps from network to host byte order */
p_rdly = NTOHS_FP(rpkt->rootdelay);
p_rdsp = NTOHS_FP(rpkt->rootdisp);
NTOHL_FP(&rpkt->reftime, &p_ref);
NTOHL_FP(&rpkt->org, &p_org);
NTOHL_FP(&rpkt->rec, &p_rec);
NTOHL_FP(&rpkt->xmt, &p_xmt);
*precision = LOGTOD(rpkt->precision);
#ifdef DEBUG
printf("sntp precision: %f\n", *precision);
#endif /* DEBUG */
*root_dispersion = FPTOD(p_rdsp);
#ifdef DEBUG
printf("sntp rootdelay: %f\n", FPTOD(p_rdly));
printf("sntp rootdisp: %f\n", *root_dispersion);
pkt_output(rpkt, rpktl, stdout);
printf("sntp offset_calculation: rpkt->reftime:\n");
l_fp_output(&(rpkt->reftime), stdout);
printf("sntp offset_calculation: rpkt->org:\n");
l_fp_output(&(rpkt->org), stdout);
printf("sntp offset_calculation: rpkt->rec:\n");
l_fp_output(&(rpkt->rec), stdout);
printf("sntp offset_calculation: rpkt->rec:\n");
l_fp_output_bin(&(rpkt->rec), stdout);
printf("sntp offset_calculation: rpkt->rec:\n");
l_fp_output_dec(&(rpkt->rec), stdout);
printf("sntp offset_calculation: rpkt->xmt:\n");
l_fp_output(&(rpkt->xmt), stdout);
#endif
/* Compute offset etc. */
tmp = p_rec;
L_SUB(&tmp, &p_org);
LFPTOD(&tmp, t21);
TVTOTS(tv_dst, &dst);
dst.l_ui += JAN_1970;
tmp = p_xmt;
L_SUB(&tmp, &dst);
LFPTOD(&tmp, t34);
*offset = (t21 + t34) / 2.;
delta = t21 - t34;
if (ENABLED_OPT(NORMALVERBOSE))
printf("sntp offset_calculation:\tt21: %.6f\t\t t34: %.6f\n\t\tdelta: %.6f\t offset: %.6f\n",
t21, t34, delta, *offset);
}
/* The heart of (S)NTP, exchange NTP packets and compute values to correct the local clock */
int
on_wire (
struct addrinfo *host,
struct addrinfo *bcast
)
{
char addr_buf[INET6_ADDRSTRLEN];
register int try;
SOCKET sock;
struct key *pkt_key = NULL;
int key_id = 0;
struct timeval tv_xmt;
struct pkt x_pkt;
int error, rpktl, handle_pkt_res;
if (ENABLED_OPT(AUTHENTICATION)) {
key_id = (int) OPT_ARG(AUTHENTICATION);
get_key(key_id, &pkt_key);
}
for (try=0; try<5; try++) {
memset(&r_pkt, 0, sizeof rbuf);
error = GETTIMEOFDAY(&tv_xmt, (struct timezone *)NULL);
tv_xmt.tv_sec += JAN_1970;
#ifdef DEBUG
printf("sntp on_wire: Current time sec: %i msec: %i\n", (unsigned int) tv_xmt.tv_sec,
(unsigned int) tv_xmt.tv_usec);
#endif
if (bcast) {
create_socket(&sock, (sockaddr_u *)bcast->ai_addr);
rpktl = recv_bcst_pkt(sock, &r_pkt, sizeof rbuf, (sockaddr_u *)bcast->ai_addr);
closesocket(sock);
} else {
int pkt_len = generate_pkt(&x_pkt, &tv_xmt, key_id, pkt_key);
create_socket(&sock, (sockaddr_u *)host->ai_addr);
sendpkt(sock, (sockaddr_u *)host->ai_addr, &x_pkt, pkt_len);
rpktl = recvpkt(sock, &r_pkt, sizeof rbuf, &x_pkt);
closesocket(sock);
}
handle_pkt_res = handle_pkt(rpktl, &r_pkt, host);
if (handle_pkt_res < 1)
return handle_pkt_res;
}
getnameinfo(host->ai_addr, host->ai_addrlen, addr_buf, sizeof(addr_buf), NULL, 0, NI_NUMERICHOST);
msyslog(LOG_DEBUG, "Received no useable packet from %s!", addr_buf);
return -1;
}
/* Compute the 8 bits for li_vn_mode */
void
set_li_vn_mode (
struct pkt *spkt,
char leap,
char version,
char mode
)
{
if (leap > 3) {
msyslog(LOG_DEBUG, "set_li_vn_mode: leap > 3 using max. 3");
leap = 3;
}
if (mode > 7) {
msyslog(LOG_DEBUG, "set_li_vn_mode: mode > 7, using client mode 3");
mode = 3;
}
spkt->li_vn_mode = leap << 6;
spkt->li_vn_mode |= version << 3;
spkt->li_vn_mode |= mode;
}
/* set_time corrects the local clock by offset with either settimeofday() or by default
* with adjtime()/adjusttimeofday().
*/
int
set_time(
double offset
)
{
struct timeval tp;
if (ENABLED_OPT(SETTOD)) {
GETTIMEOFDAY(&tp, NULL);
tp.tv_sec += (long)offset;
tp.tv_usec += 1e6 * (offset - (long)offset);
NORMALIZE_TIMEVAL(tp);
if (SETTIMEOFDAY(&tp, NULL) < 0) {
msyslog(LOG_ERR, "Time not set: settimeofday(): %m");
return -1;
}
return 0;
}
tp.tv_sec = (long)offset;
tp.tv_usec = 1e6 * (offset - (long)offset);
NORMALIZE_TIMEVAL(tp);
if (ADJTIMEOFDAY(&tp, NULL) < 0) {
msyslog(LOG_ERR, "Time not set: adjtime(): %m");
return -1;
}
return 0;
}
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