[git commit master] ntp: simplifications; libbb: simpler resolution of numeric hostnames
Denys Vlasenko
vda.linux at googlemail.com
Tue Nov 24 06:07:42 UTC 2009
commit: http://git.busybox.net/busybox/commit/?id=ca6c7e42f93eb2b0ce246eafd8b0e4ac27414f6b
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
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 at googlemail.com>
---
libbb/xconnect.c | 41 +++++++++--
networking/ntpd.c | 208 +++++++++++++++++++++++++++-------------------------
2 files changed, 144 insertions(+), 105 deletions(-)
diff --git a/libbb/xconnect.c b/libbb/xconnect.c
index f018ca9..81a2b04 100644
--- a/libbb/xconnect.c
+++ b/libbb/xconnect.c
@@ -161,6 +161,7 @@ static len_and_sockaddr* str2sockaddr(
IF_FEATURE_IPV6(sa_family_t af,)
int ai_flags)
{
+IF_NOT_FEATURE_IPV6(sa_family_t af = AF_INET;)
int rc;
len_and_sockaddr *r;
struct addrinfo *result = NULL;
@@ -221,12 +222,40 @@ IF_FEATURE_IPV6(sa_family_t af,)
skip: ;
}
+ /* Next two if blocks allow to skip getaddrinfo()
+ * in case host is a numeric IP(v6) address,
+ * getaddrinfo() initializes DNS resolution machinery,
+ * scans network config and such - tens of syscalls.
+ */
+ /* If we were not asked specifically for IPv6,
+ * check whether this is a numeric IPv4 */
+ IF_FEATURE_IPV6(if(af != AF_INET6)) {
+ struct in_addr in4;
+ if (inet_aton(host, &in4) != 0) {
+ r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_in));
+ r->len = sizeof(struct sockaddr_in);
+ r->u.sa.sa_family = AF_INET;
+ r->u.sin.sin_addr = in4;
+ goto set_port;
+ }
+ }
+#if ENABLE_FEATURE_IPV6
+ /* If we were not asked specifically for IPv4,
+ * check whether this is a numeric IPv6 */
+ if (af != AF_INET) {
+ struct in6_addr in6;
+ if (inet_pton(AF_INET6, host, &in6) > 0) {
+ r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_in6));
+ r->len = sizeof(struct sockaddr_in6);
+ r->u.sa.sa_family = AF_INET6;
+ r->u.sin6.sin6_addr = in6;
+ goto set_port;
+ }
+ }
+#endif
+
memset(&hint, 0 , sizeof(hint));
-#if !ENABLE_FEATURE_IPV6
- hint.ai_family = AF_INET; /* do not try to find IPv6 */
-#else
hint.ai_family = af;
-#endif
/* Needed. Or else we will get each address thrice (or more)
* for each possible socket type (tcp,udp,raw...): */
hint.ai_socktype = SOCK_STREAM;
@@ -250,9 +279,11 @@ IF_FEATURE_IPV6(sa_family_t af,)
}
}
#endif
- r = xmalloc(offsetof(len_and_sockaddr, u.sa) + used_res->ai_addrlen);
+ r = xmalloc(LSA_LEN_SIZE + used_res->ai_addrlen);
r->len = used_res->ai_addrlen;
memcpy(&r->u.sa, used_res->ai_addr, used_res->ai_addrlen);
+
+ IF_FEATURE_IPV6(set_port:)
set_nport(r, htons(port));
ret:
freeaddrinfo(result);
diff --git a/networking/ntpd.c b/networking/ntpd.c
index 8ee42e6..4e661ce 100644
--- a/networking/ntpd.c
+++ b/networking/ntpd.c
@@ -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);
}
@@ -228,45 +232,43 @@ 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;
}
-#if ENABLE_FEATURE_NTPD_SERVER
-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));
- return lfp;
-}
-#endif
-
static double
sfp_to_d(s_fixedpt_t sfp)
{
- double ret;
-
+ double ret;
sfp.int_parts = ntohs(sfp.int_parts);
sfp.fractions = ntohs(sfp.fractions);
- ret = (double)(sfp.int_parts) + ((double)sfp.fractions / USHRT_MAX);
+ ret = (double)sfp.int_parts + ((double)sfp.fractions / USHRT_MAX);
return ret;
}
#if ENABLE_FEATURE_NTPD_SERVER
+static l_fixedpt_t
+d_to_lfp(double d)
+{
+ 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;
+}
+
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) */
--
1.6.3.3
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