svn commit: trunk/busybox/networking/udhcp
vda at busybox.net
vda at busybox.net
Sun Feb 1 00:40:46 UTC 2009
Author: vda
Date: 2009-02-01 00:40:45 +0000 (Sun, 01 Feb 2009)
New Revision: 25204
Log:
dhcpd,dumpleases: write and use 64-bit current time in lease file.
without it, determination of remaining lease time is unreliable.
Yes, it's costly in code size, but without it, dumpleases output
is misleading!
function old new delta
read_leases 143 282 +139
dumpleases_main 447 572 +125
write_leases 193 233 +40
hton64 29 58 +29
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/0 up/down: 333/0) Total: 333 bytes
Modified:
trunk/busybox/networking/udhcp/dumpleases.c
trunk/busybox/networking/udhcp/files.c
Changeset:
Modified: trunk/busybox/networking/udhcp/dumpleases.c
===================================================================
--- trunk/busybox/networking/udhcp/dumpleases.c 2009-01-31 23:33:54 UTC (rev 25203)
+++ trunk/busybox/networking/udhcp/dumpleases.c 2009-02-01 00:40:45 UTC (rev 25204)
@@ -6,14 +6,24 @@
#include "common.h"
#include "dhcpd.h"
+#if BB_LITTLE_ENDIAN
+static inline uint64_t hton64(uint64_t v)
+{
+ return (((uint64_t)htonl(v)) << 32) | htonl(v >> 32);
+}
+#else
+#define hton64(v) (v)
+#endif
+#define ntoh64(v) hton64(v)
+
+
int dumpleases_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int dumpleases_main(int argc UNUSED_PARAM, char **argv)
{
int fd;
int i;
unsigned opt;
- leasetime_t expires;
- leasetime_t curr;
+ int64_t written_at, curr, expires_abs;
const char *file = LEASES_FILE;
struct dhcpOfferedAddr lease;
struct in_addr addr;
@@ -40,7 +50,13 @@
printf("Mac Address IP-Address Expires %s\n", (opt & OPT_a) ? "at" : "in");
/* "00:00:00:00:00:00 255.255.255.255 Wed Jun 30 21:49:08 1993" */
+ if (full_read(fd, &written_at, sizeof(written_at)) != sizeof(written_at))
+ return 0;
+ written_at = ntoh64(written_at);
curr = time(NULL);
+ if (curr < written_at)
+ written_at = curr; /* lease file from future! :) */
+
while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
const char *fmt = ":%02x" + 1;
for (i = 0; i < 6; i++) {
@@ -49,13 +65,14 @@
}
addr.s_addr = lease.yiaddr;
printf(" %-15s ", inet_ntoa(addr));
- if (lease.expires == 0) {
+ expires_abs = ntohl(lease.expires) + written_at;
+ if (expires_abs <= curr) {
puts("expired");
continue;
}
- expires = ntohl(lease.expires);
if (!(opt & OPT_a)) { /* no -a */
unsigned d, h, m;
+ unsigned expires = expires_abs - curr;
d = expires / (24*60*60); expires %= (24*60*60);
h = expires / (60*60); expires %= (60*60);
m = expires / 60; expires %= 60;
@@ -63,7 +80,7 @@
printf("%u days ", d);
printf("%02u:%02u:%02u\n", h, m, (unsigned)expires);
} else { /* -a */
- time_t t = expires + curr;
+ time_t t = expires_abs;
fputs(ctime(&t), stdout);
}
}
Modified: trunk/busybox/networking/udhcp/files.c
===================================================================
--- trunk/busybox/networking/udhcp/files.c 2009-01-31 23:33:54 UTC (rev 25203)
+++ trunk/busybox/networking/udhcp/files.c 2009-02-01 00:40:45 UTC (rev 25204)
@@ -12,7 +12,17 @@
#include "dhcpd.h"
#include "options.h"
+#if BB_LITTLE_ENDIAN
+static inline uint64_t hton64(uint64_t v)
+{
+ return (((uint64_t)htonl(v)) << 32) | htonl(v >> 32);
+}
+#else
+#define hton64(v) (v)
+#endif
+#define ntoh64(v) hton64(v)
+
/* on these functions, make sure your datatype matches */
static int read_ip(const char *line, void *arg)
{
@@ -335,15 +345,17 @@
int fd;
unsigned i;
leasetime_t curr;
+ int64_t written_at;
fd = open_or_warn(server_config.lease_file, O_WRONLY|O_CREAT|O_TRUNC);
if (fd < 0)
return;
- curr = time(NULL);
-//TODO: write out current time? Readers need to adjust .expires field
-// to account for time between file was written and when it was read back.
+ curr = written_at = time(NULL);
+ written_at = hton64(written_at);
+ full_write(fd, &written_at, sizeof(written_at));
+
for (i = 0; i < server_config.max_leases; i++) {
leasetime_t tmp_time;
@@ -353,11 +365,9 @@
/* screw with the time in the struct, for easier writing */
tmp_time = leases[i].expires;
- //if (server_config.remaining) {
- leases[i].expires -= curr;
- if ((signed_leasetime_t) leases[i].expires < 0)
- leases[i].expires = 0;
- //} /* else stick with the time we got */
+ leases[i].expires -= curr;
+ if ((signed_leasetime_t) leases[i].expires < 0)
+ leases[i].expires = 0;
leases[i].expires = htonl(leases[i].expires);
/* No error check. If the file gets truncated,
@@ -382,14 +392,20 @@
{
int fd;
unsigned i;
-// leasetime_t curr;
struct dhcpOfferedAddr lease;
+ int64_t written_at, curr;
fd = open_or_warn(file, O_RDONLY);
if (fd < 0)
return;
-// curr = time(NULL);
+ if (full_read(fd, &written_at, sizeof(written_at)) != sizeof(written_at))
+ goto ret;
+ written_at = ntoh64(written_at);
+ curr = time(NULL);
+ if (curr < written_at)
+ written_at = curr; /* lease file from future! :) */
+
i = 0;
while (i < server_config.max_leases
&& full_read(fd, &lease, sizeof(lease)) == sizeof(lease)
@@ -397,9 +413,9 @@
/* ADDME: what if it matches some static lease? */
uint32_t y = ntohl(lease.yiaddr);
if (y >= server_config.start_ip && y <= server_config.end_ip) {
- leasetime_t expires = ntohl(lease.expires);
-// if (!server_config.remaining)
-// expires -= curr;
+ int64_t expires = ntohl(lease.expires) + written_at - curr;
+ if (expires <= 0)
+ continue;
/* NB: add_lease takes "relative time", IOW,
* lease duration, not lease deadline. */
if (!(add_lease(lease.chaddr, lease.yiaddr, expires))) {
@@ -410,5 +426,6 @@
}
}
DEBUG("Read %d leases", i);
+ ret:
close(fd);
}
More information about the busybox-cvs
mailing list