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ntp: simplifications; libbb: simpler resolution of numeric hostnames

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function                                             old     new   delta
str2sockaddr                                         405     567    +162
ntp_init                                             310     317      +7
scale_interval                                        58      59      +1
error_interval                                        22      23      +1
ntpd_main                                           3257    3214     -43
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/1 up/down: 171/-43)           Total: 128 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
2009-11-24 07:07:42 +01:00
parent 887d963037
commit ca6c7e42f9
2 changed files with 147 additions and 108 deletions
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212
networking/ntpd.c
View File

@ -5,7 +5,6 @@
*
* Licensed under GPLv2, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
#include <netinet/ip.h> /* For IPTOS_LOWDELAY definition */
@ -59,30 +58,32 @@ typedef struct {
uint16_t fractions;
} s_fixedpt_t;
#define NTP_DIGESTSIZE 16
#define NTP_MSGSIZE_NOAUTH 48
#define NTP_MSGSIZE (NTP_MSGSIZE_NOAUTH + 4 + NTP_DIGESTSIZE)
enum {
NTP_DIGESTSIZE = 16,
NTP_MSGSIZE_NOAUTH = 48,
NTP_MSGSIZE = (NTP_MSGSIZE_NOAUTH + 4 + NTP_DIGESTSIZE),
};
typedef struct {
uint8_t status; /* status of local clock and leap info */
uint8_t stratum; /* Stratum level */
uint8_t ppoll; /* poll value */
int8_t precision;
uint8_t status; /* status of local clock and leap info */
uint8_t stratum; /* stratum level */
uint8_t ppoll; /* poll value */
int8_t precision;
s_fixedpt_t rootdelay;
s_fixedpt_t dispersion;
uint32_t refid;
uint32_t refid;
l_fixedpt_t reftime;
l_fixedpt_t orgtime;
l_fixedpt_t rectime;
l_fixedpt_t xmttime;
uint32_t keyid;
uint8_t digest[NTP_DIGESTSIZE];
uint32_t keyid;
uint8_t digest[NTP_DIGESTSIZE];
} ntp_msg_t;
typedef struct {
int fd;
ntp_msg_t msg;
double xmttime;
int fd;
ntp_msg_t msg;
double xmttime;
} ntp_query_t;
enum {
@ -97,6 +98,7 @@ enum {
/* Status Masks */
MODE_MASK = (7 << 0),
VERSION_MASK = (7 << 3),
VERSION_SHIFT = 3,
LI_MASK = (3 << 6),
/* Mode values */
@ -107,7 +109,7 @@ enum {
MODE_SERVER = 4, /* server */
MODE_BROADCAST = 5, /* broadcast */
MODE_RES1 = 6, /* reserved for NTP control message */
MODE_RES2 = 7 /* reserved for private use */
MODE_RES2 = 7, /* reserved for private use */
};
#define JAN_1970 2208988800UL /* 1970 - 1900 in seconds */
@ -115,7 +117,7 @@ enum {
enum client_state {
STATE_NONE,
STATE_QUERY_SENT,
STATE_REPLY_RECEIVED
STATE_REPLY_RECEIVED,
};
typedef struct {
@ -132,24 +134,27 @@ typedef struct {
} ntp_status_t;
typedef struct {
ntp_status_t status;
double offset;
double delay;
double error;
time_t rcvd;
uint8_t good;
ntp_status_t status;
double offset;
double delay;
double error;
time_t rcvd;
uint8_t good;
} ntp_offset_t;
typedef struct {
//TODO:
// (1) store dotted addr str, to avoid constant translations
// (2) periodically re-resolve DNS names
len_and_sockaddr *lsa;
ntp_query_t query;
ntp_offset_t reply[OFFSET_ARRAY_SIZE];
ntp_offset_t update;
enum client_state state;
time_t next;
time_t deadline;
uint8_t shift;
uint8_t trustlevel;
ntp_query_t query;
ntp_offset_t reply[OFFSET_ARRAY_SIZE];
ntp_offset_t update;
enum client_state state;
time_t next;
time_t deadline;
uint8_t shift;
uint8_t trustlevel;
} ntp_peer_t;
enum {
@ -211,8 +216,7 @@ add_peers(const char *s)
static double
gettime(void)
{
struct timeval tv;
struct timeval tv;
gettimeofday(&tv, NULL); /* never fails */
return (tv.tv_sec + JAN_1970 + 1.0e-6 * tv.tv_usec);
}
@ -228,11 +232,20 @@ d_to_tv(double d, struct timeval *tv)
static double
lfp_to_d(l_fixedpt_t lfp)
{
double ret;
double ret;
lfp.int_partl = ntohl(lfp.int_partl);
lfp.fractionl = ntohl(lfp.fractionl);
ret = (double)(lfp.int_partl) + ((double)lfp.fractionl / UINT_MAX);
ret = (double)lfp.int_partl + ((double)lfp.fractionl / UINT_MAX);
return ret;
}
static double
sfp_to_d(s_fixedpt_t sfp)
{
double ret;
sfp.int_parts = ntohs(sfp.int_parts);
sfp.fractions = ntohs(sfp.fractions);
ret = (double)sfp.int_parts + ((double)sfp.fractions / USHRT_MAX);
return ret;
}
@ -240,33 +253,22 @@ lfp_to_d(l_fixedpt_t lfp)
static l_fixedpt_t
d_to_lfp(double d)
{
l_fixedpt_t lfp;
lfp.int_partl = htonl((uint32_t)d);
lfp.fractionl = htonl((uint32_t)((d - (u_int32_t)d) * UINT_MAX));
l_fixedpt_t lfp;
lfp.int_partl = (uint32_t)d;
lfp.fractionl = (uint32_t)((d - lfp.int_partl) * UINT_MAX);
lfp.int_partl = htonl(lfp.int_partl);
lfp.fractionl = htonl(lfp.fractionl);
return lfp;
}
#endif
static double
sfp_to_d(s_fixedpt_t sfp)
{
double ret;
sfp.int_parts = ntohs(sfp.int_parts);
sfp.fractions = ntohs(sfp.fractions);
ret = (double)(sfp.int_parts) + ((double)sfp.fractions / USHRT_MAX);
return ret;
}
#if ENABLE_FEATURE_NTPD_SERVER
static s_fixedpt_t
d_to_sfp(double d)
{
s_fixedpt_t sfp;
sfp.int_parts = htons((uint16_t)d);
sfp.fractions = htons((uint16_t)((d - (u_int16_t)d) * USHRT_MAX));
s_fixedpt_t sfp;
sfp.int_parts = (uint16_t)d;
sfp.fractions = (uint16_t)((d - sfp.int_parts) * USHRT_MAX);
sfp.int_parts = htons(sfp.int_parts);
sfp.fractions = htons(sfp.fractions);
return sfp;
}
#endif
@ -282,9 +284,8 @@ static time_t
error_interval(void)
{
time_t interval, r;
interval = INTERVAL_QUERY_PATHETIC * QSCALE_OFF_MAX / QSCALE_OFF_MIN;
r = random() % (interval / 10);
r = (unsigned)random() % (unsigned long)(interval / 10);
return (interval + r);
}
@ -352,12 +353,8 @@ client_query(ntp_peer_t *p)
static int
offset_compare(const void *aa, const void *bb)
{
const ntp_peer_t * const *a;
const ntp_peer_t * const *b;
a = aa;
b = bb;
const ntp_peer_t *const *a = aa;
const ntp_peer_t *const *b = bb;
if ((*a)->update.offset < (*b)->update.offset)
return -1;
return ((*a)->update.offset > (*b)->update.offset);
@ -368,7 +365,6 @@ updated_scale(double offset)
{
if (offset < 0)
offset = -offset;
if (offset > QSCALE_OFF_MAX)
return 1;
if (offset < QSCALE_OFF_MIN)
@ -559,9 +555,8 @@ static time_t
scale_interval(time_t requested)
{
time_t interval, r;
interval = requested * G.scale;
r = random() % MAX(5, interval / 10);
r = (unsigned)random() % (unsigned long)(MAX(5, interval / 10));
return (interval + r);
}
@ -577,9 +572,10 @@ client_dispatch(ntp_peer_t *p)
addr = xmalloc_sockaddr2dotted_noport(&p->lsa->u.sa);
size = recvfrom(p->query.fd, &msg, sizeof(msg), 0, NULL, NULL);
//TODO: use MSG_DONTWAIT flag?
size = recv(p->query.fd, &msg, sizeof(msg), 0);
if (size == -1) {
bb_perror_msg("recvfrom(%s) error", addr);
bb_perror_msg("recv(%s) error", addr);
if (errno == EHOSTUNREACH || errno == EHOSTDOWN
|| errno == ENETUNREACH || errno == ENETDOWN
|| errno == ECONNREFUSED || errno == EADDRNOTAVAIL
@ -693,48 +689,58 @@ client_dispatch(ntp_peer_t *p)
static void
server_dispatch(int fd)
{
ssize_t size;
uint8_t version;
double rectime;
len_and_sockaddr *to;
struct sockaddr *from;
ntp_msg_t query, reply;
ssize_t size;
uint8_t version;
double rectime;
len_and_sockaddr *to;
struct sockaddr *from;
ntp_msg_t msg;
uint8_t query_status;
uint8_t query_ppoll;
l_fixedpt_t query_xmttime;
to = get_sock_lsa(G.listen_fd);
from = xzalloc(to->len);
size = recv_from_to(fd, &query, sizeof(query), 0, from, &to->u.sa, to->len);
if (size == -1)
bb_error_msg_and_die("recv_from_to");
//TODO: use MGS_DONTWAIT flag?
size = recv_from_to(fd, &msg, sizeof(msg), 0, from, &to->u.sa, to->len);
if (size != NTP_MSGSIZE_NOAUTH && size != NTP_MSGSIZE) {
char *addr = xmalloc_sockaddr2dotted_noport(from);
char *addr;
if (size < 0)
bb_error_msg_and_die("recv_from_to");
addr = xmalloc_sockaddr2dotted_noport(from);
bb_error_msg("malformed packet received from %s", addr);
free(addr);
goto bail;
}
rectime = gettime();
version = (query.status & VERSION_MASK) >> 3;
query_status = msg.status;
query_ppoll = msg.ppoll;
query_xmttime = msg.xmttime;
memset(&reply, 0, sizeof(reply));
reply.status = G.status.synced ? G.status.leap : LI_ALARM;
reply.status |= (query.status & VERSION_MASK);
reply.status |= ((query.status & MODE_MASK) == MODE_CLIENT) ?
/* Build a reply packet */
memset(&msg, 0, sizeof(msg));
msg.status = G.status.synced ? G.status.leap : LI_ALARM;
msg.status |= (query_status & VERSION_MASK);
msg.status |= ((query_status & MODE_MASK) == MODE_CLIENT) ?
MODE_SERVER : MODE_SYM_PAS;
reply.stratum = G.status.stratum;
reply.ppoll = query.ppoll;
reply.precision = G.status.precision;
reply.rectime = d_to_lfp(rectime);
reply.reftime = d_to_lfp(G.status.reftime);
reply.xmttime = d_to_lfp(gettime());
reply.orgtime = query.xmttime;
reply.rootdelay = d_to_sfp(G.status.rootdelay);
reply.refid = (version > 3) ? G.status.refid4 : G.status.refid;
msg.stratum = G.status.stratum;
msg.ppoll = query_ppoll;
msg.precision = G.status.precision;
rectime = gettime();
msg.xmttime = msg.rectime = d_to_lfp(rectime);
msg.reftime = d_to_lfp(G.status.reftime);
//msg.xmttime = d_to_lfp(gettime()); // = msg.rectime
msg.orgtime = query_xmttime;
msg.rootdelay = d_to_sfp(G.status.rootdelay);
version = (query_status & VERSION_MASK); /* ... >> VERSION_SHIFT - done below instead */
msg.refid = (version > (3 << VERSION_SHIFT)) ? G.status.refid4 : G.status.refid;
/* We reply from the address packet was sent to,
* this makes to/from look swapped here: */
sendmsg_wrap(fd, /*from:*/ &to->u.sa, /*to:*/ from, /*addrlen:*/ to->len,
&reply, size);
sendmsg_wrap(fd,
/*from:*/ &to->u.sa, /*to:*/ from, /*addrlen:*/ to->len,
&msg, size);
bail:
free(to);
@ -835,7 +841,8 @@ static NOINLINE void ntp_init(char **argv)
unsigned opts;
llist_t *peers;
tzset();
srandom(getpid());
/* tzset(); - why? it's called automatically when needed, no? */
if (getuid())
bb_error_msg_and_die("need root privileges");
@ -911,7 +918,7 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv)
while (!bb_got_signal) {
llist_t *item;
unsigned i, j, idx_peers;
unsigned i, j, first_peer_idx;
unsigned sent_cnt, trial_cnt;
int nfds, timeout;
time_t nextaction;
@ -926,7 +933,7 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv)
i++;
}
#endif
idx_peers = i;
first_peer_idx = i;
sent_cnt = trial_cnt = 0;
for (item = g.ntp_peers; item != NULL; item = item->link) {
ntp_peer_t *p = (ntp_peer_t *) item->data;
@ -960,7 +967,7 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv)
if (p->state == STATE_QUERY_SENT) {
pfd[i].fd = p->query.fd;
pfd[i].events = POLLIN;
idx2peer[i - idx_peers] = p;
idx2peer[i - first_peer_idx] = p;
i++;
}
}
@ -978,7 +985,8 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv)
j = 0;
#if ENABLE_FEATURE_NTPD_SERVER
for (; nfds > 0 && j < idx_peers; j++) {
//TODO: simplify. There is only one server fd!
for (; nfds > 0 && j < first_peer_idx; j++) {
if (pfd[j].revents & (POLLIN|POLLERR)) {
nfds--;
server_dispatch(pfd[j].fd);
@ -988,7 +996,7 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv)
for (; nfds > 0 && j < i; j++) {
if (pfd[j].revents & (POLLIN|POLLERR)) {
nfds--;
client_dispatch(idx2peer[j - idx_peers]);
client_dispatch(idx2peer[j - first_peer_idx]);
}
}
} /* while (!bb_got_signal) */