*
* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*/
-
#include <syslog.h>
-
/* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
#define WANT_PIDFILE 1
#include "common.h"
#define LISTEN_RAW 2
static smallint listen_mode;
+/* initial state: (re)start DHCP negotiation */
#define INIT_SELECTING 0
+/* discover was sent, DHCPOFFER reply received */
#define REQUESTING 1
+/* select/renew was sent, DHCPACK reply received */
#define BOUND 2
+/* half of lease passed, want to renew it by sending unicast renew requests */
#define RENEWING 3
+/* renew requests were not answered, lease is almost over, send broadcast renew */
#define REBINDING 4
-#define INIT_REBOOT 5
-#define RENEW_REQUESTED 6
-#define RELEASED 7
+/* manually requested renew (SIGUSR1) */
+#define RENEW_REQUESTED 5
+/* release, possibly manually requested (SIGUSR2) */
+#define RELEASED 6
static smallint state;
/* struct client_config_t client_config is in bb_common_bufsiz1 */
static void change_listen_mode(int new_mode)
{
log1("Entering listen mode: %s",
- new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none");
+ new_mode != LISTEN_NONE
+ ? (new_mode == LISTEN_KERNEL ? "kernel" : "raw")
+ : "none"
+ );
listen_mode = new_mode;
if (sockfd >= 0) {
tv.tv_sec = timeout - already_waited_sec;
tv.tv_usec = 0;
retval = 0; /* If we already timed out, fall through, else... */
- if (tv.tv_sec > 0) {
+ if ((int)tv.tv_sec > 0) {
timestamp_before_wait = (unsigned)monotonic_sec();
log1("Waiting on select...");
retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
if (retval < 0) {
/* EINTR? A signal was caught, don't panic */
- if (errno == EINTR)
+ if (errno == EINTR) {
+ already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
continue;
+ }
/* Else: an error occured, panic! */
bb_perror_msg_and_die("select");
}
if (packet_num < discover_retries) {
if (packet_num == 0)
xid = random_xid();
-
- send_discover(xid, requested_ip); /* broadcast */
-
+ /* broadcast */
+ send_discover(xid, requested_ip);
timeout = discover_timeout;
packet_num++;
continue;
timeout = tryagain_timeout;
packet_num = 0;
continue;
- case RENEW_REQUESTED:
case REQUESTING:
if (packet_num < discover_retries) {
- /* send request packet */
- if (state == RENEW_REQUESTED) /* unicast */
- send_renew(xid, server_addr, requested_ip);
- else /* broadcast */
- send_select(xid, server_addr, requested_ip);
-
+ /* send broadcast select packet */
+ send_select(xid, server_addr, requested_ip);
timeout = discover_timeout;
packet_num++;
continue;
}
- /* timed out, go back to init state */
- if (state == RENEW_REQUESTED)
- udhcp_run_script(NULL, "deconfig");
- change_listen_mode(LISTEN_RAW);
- /* "discover...select...discover..." loops
+ /* Timed out, go back to init state.
+ * "discover...select...discover..." loops
* were seen in the wild. Treat them similarly
* to "no response to discover" case */
- if (state == REQUESTING) {
- state = INIT_SELECTING;
- goto leasefail;
- }
+ change_listen_mode(LISTEN_RAW);
state = INIT_SELECTING;
- timeout = 0;
- packet_num = 0;
- continue;
+ goto leasefail;
case BOUND:
- /* Half of the lease passed, time to enter renewing state */
+ /* 1/2 lease passed, enter renewing state */
+ state = RENEWING;
change_listen_mode(LISTEN_KERNEL);
log1("Entering renew state");
- state = RENEWING;
/* fall right through */
+ case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
+ case_RENEW_REQUESTED:
case RENEWING:
if (timeout > 60) {
- /* send a request packet */
- send_renew(xid, server_addr, requested_ip); /* unicast */
+ /* send an unicast renew request */
+ /* Sometimes observed to fail (EADDRNOTAVAIL) to bind
+ * a new UDP socket for sending inside send_renew.
+ * I hazard to guess existing listening socket
+ * is somehow conflicting with it, but why is it
+ * not deterministic then?! Strange.
+ * Anyway, it does recover by eventually failing through
+ * into INIT_SELECTING state.
+ */
+ send_renew(xid, server_addr, requested_ip);
timeout >>= 1;
continue;
}
state = REBINDING;
/* fall right through */
case REBINDING:
+ /* Switch to bcast receive */
+ change_listen_mode(LISTEN_RAW);
/* Lease is *really* about to run out,
* try to find DHCP server using broadcast */
if (timeout > 0) {
- /* send a request packet */
- send_renew(xid, 0 /*INADDR_ANY*/, requested_ip); /* broadcast */
+ /* send a broadcast renew request */
+ send_renew(xid, 0 /*INADDR_ANY*/, requested_ip);
timeout >>= 1;
continue;
}
/* Timed out, enter init state */
bb_info_msg("Lease lost, entering init state");
udhcp_run_script(NULL, "deconfig");
- change_listen_mode(LISTEN_RAW);
state = INIT_SELECTING;
/*timeout = 0; - already is */
packet_num = 0;
switch (udhcp_sp_read(&rfds)) {
case SIGUSR1:
perform_renew();
+ if (state == RENEW_REQUESTED)
+ goto case_RENEW_REQUESTED;
/* Start things over */
packet_num = 0;
- /* Kill any timeouts because the user wants this to hurry along */
+ /* Kill any timeouts, user wants this to hurry along */
timeout = 0;
continue;
case SIGUSR2:
already_waited_sec = 0;
}
continue;
- case RENEW_REQUESTED:
case REQUESTING:
case RENEWING:
+ case RENEW_REQUESTED:
case REBINDING:
if (*message == DHCPACK) {
temp = get_option(&packet, DHCP_LEASE_TIME);
inet_ntoa(temp_addr), (unsigned)lease_seconds);
}
requested_ip = packet.yiaddr;
- udhcp_run_script(&packet,
- ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));
+ udhcp_run_script(&packet, state == REQUESTING ? "bound" : "renew");
state = BOUND;
change_listen_mode(LISTEN_NONE);
perform_release(requested_ip, server_addr);
goto ret0;
}
+ /* future renew failures should not exit (JM) */
+ opt &= ~OPT_n;
#if BB_MMU /* NOMMU case backgrounded earlier */
if (!(opt & OPT_f)) {
client_background();
projects / oweals / busybox.git / blobdiff