Track pending events in time by using absolute times rather than relative
timeouts.
This commit is contained in:
Nicholas J. Kain
parent
9b3e1872cb
commit
83594bce4a
70
ndhc/arp.c
70
ndhc/arp.c
@ -67,7 +67,7 @@ typedef enum {
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AS_MAX,
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} arp_state_t;
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static int arp_timeout[AS_MAX] = { -1, -1, -1, -1, -1 };
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static long long arp_wake_ts[AS_MAX] = { -1, -1, -1, -1, -1 };
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typedef enum {
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ASEND_COLLISION_CHECK,
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@ -273,7 +273,7 @@ int arp_close_fd(struct client_state_t *cs)
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{
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arp_min_close_fd(cs);
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for (int i = 0; i < AS_MAX; ++i)
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arp_timeout[i] = -1;
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arp_wake_ts[i] = -1;
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return 1;
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}
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@ -372,7 +372,8 @@ int arp_check(struct client_state_t *cs, struct dhcpmsg *packet)
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cs->arpPrevState = cs->dhcpState;
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cs->dhcpState = DS_COLLISION_CHECK;
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arp_check_start_ts = arp_send_stats[ASEND_COLLISION_CHECK].ts;
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arp_timeout[AS_COLLISION_CHECK] = probe_wait_time = PROBE_WAIT;
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probe_wait_time = PROBE_WAIT;
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arp_wake_ts[AS_COLLISION_CHECK] = arp_check_start_ts + probe_wait_time;
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return 0;
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}
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@ -387,7 +388,8 @@ int arp_gw_check(struct client_state_t *cs)
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arp_switch_state(cs, AS_GW_CHECK);
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cs->arpPrevState = cs->dhcpState;
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cs->dhcpState = DS_BOUND_GW_CHECK;
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arp_timeout[AS_GW_CHECK] = ARP_RETRANS_DELAY + 250;
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arp_wake_ts[AS_GW_CHECK] =
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arp_send_stats[ASEND_GW_PING].ts + ARP_RETRANS_DELAY + 250;
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return 0;
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}
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@ -399,7 +401,8 @@ static int arp_get_gw_hwaddr(struct client_state_t *cs)
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log_line("arp: Searching for gw address...");
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if (arp_ping(cs, cs->routerAddr) == -1)
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return -1;
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arp_timeout[AS_GW_QUERY] = ARP_RETRANS_DELAY + 250;
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arp_wake_ts[AS_GW_QUERY] =
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arp_send_stats[ASEND_GW_PING].ts + ARP_RETRANS_DELAY + 250;
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return 0;
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}
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@ -407,7 +410,7 @@ static void arp_failed(struct client_state_t *cs)
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{
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log_line("arp: Offered address is in use -- declining");
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send_decline(cs, arp_dhcp_packet.yiaddr);
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arp_timeout[AS_COLLISION_CHECK] = -1;
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arp_wake_ts[AS_COLLISION_CHECK] = -1;
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reinit_selecting(cs, total_conflicts < MAX_CONFLICTS ?
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0 : RATE_LIMIT_INTERVAL);
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}
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@ -415,7 +418,7 @@ static void arp_failed(struct client_state_t *cs)
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static void arp_gw_failed(struct client_state_t *cs)
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{
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log_line("arp: Gateway appears to have changed, getting new lease.");
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arp_timeout[AS_GW_CHECK] = -1;
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arp_wake_ts[AS_GW_CHECK] = -1;
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reinit_selecting(cs, 0);
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}
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@ -435,8 +438,6 @@ void arp_set_defense_mode(struct client_state_t *cs)
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void arp_success(struct client_state_t *cs)
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{
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cs->dhcp_timeout = (cs->renewTime * 1000) - (curms() - cs->leaseStartTime);
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struct in_addr temp_addr = {.s_addr = arp_dhcp_packet.yiaddr};
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log_line("arp: Lease of %s obtained, lease time %ld",
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inet_ntoa(temp_addr), cs->lease);
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@ -444,7 +445,7 @@ void arp_success(struct client_state_t *cs)
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cs->dhcpState = DS_BOUND;
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cs->init = 0;
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last_conflict_ts = 0;
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arp_timeout[AS_COLLISION_CHECK] = -1;
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arp_wake_ts[AS_COLLISION_CHECK] = -1;
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ifchange_bind(&arp_dhcp_packet);
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if (cs->arpPrevState == DS_RENEWING || cs->arpPrevState == DS_REBINDING) {
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arp_switch_state(cs, AS_DEFENSE);
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@ -472,7 +473,7 @@ static void arp_gw_success(struct client_state_t *cs)
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arp_switch_state(cs, AS_DEFENSE);
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arp_announcement(cs);
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arp_timeout[AS_GW_CHECK] = -1;
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arp_wake_ts[AS_GW_CHECK] = -1;
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cs->dhcpState = cs->arpPrevState;
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}
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@ -534,10 +535,10 @@ static int arp_gen_probe_wait(void)
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static void arp_defense_timeout(struct client_state_t *cs, long long nowts)
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{
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if (arp_timeout[AS_DEFENSE] != -1) {
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if (arp_wake_ts[AS_DEFENSE] != -1) {
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log_line("arp: Defending our lease IP.");
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arp_announcement(cs);
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arp_timeout[AS_DEFENSE] = -1;
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arp_wake_ts[AS_DEFENSE] = -1;
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}
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}
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@ -549,7 +550,7 @@ static void arp_check_timeout(struct client_state_t *cs, long long nowts)
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return;
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long long rtts = arp_send_stats[ASEND_GW_PING].ts + ARP_RETRANS_DELAY;
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if (nowts < rtts) {
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arp_timeout[arpState] = rtts - nowts;
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arp_wake_ts[arpState] = rtts;
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return;
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}
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log_line(arpState == AS_GW_CHECK ?
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@ -557,7 +558,8 @@ static void arp_check_timeout(struct client_state_t *cs, long long nowts)
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"arp: Still looking for gateway hardware address...");
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if (arp_ping(cs, cs->routerAddr) == -1)
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log_warning("arp: Failed to send ARP ping in retransmission.");
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arp_timeout[arpState] = ARP_RETRANS_DELAY;
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arp_wake_ts[arpState] =
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arp_send_stats[ASEND_GW_PING].ts + ARP_RETRANS_DELAY;
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}
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static void arp_collision_timeout(struct client_state_t *cs, long long nowts)
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@ -572,19 +574,21 @@ static void arp_collision_timeout(struct client_state_t *cs, long long nowts)
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long long rtts = arp_send_stats[ASEND_COLLISION_CHECK].ts +
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probe_wait_time;
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if (nowts < rtts) {
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arp_timeout[AS_COLLISION_CHECK] = rtts - nowts;
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arp_wake_ts[AS_COLLISION_CHECK] = rtts;
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return;
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}
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if (arp_ip_anon_ping(cs, arp_dhcp_packet.yiaddr) == -1)
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log_warning("arp: Failed to send ARP ping in retransmission.");
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arp_timeout[AS_COLLISION_CHECK] = probe_wait_time = arp_gen_probe_wait();
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probe_wait_time = arp_gen_probe_wait();
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arp_wake_ts[AS_COLLISION_CHECK] =
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arp_send_stats[ASEND_COLLISION_CHECK].ts + probe_wait_time;
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}
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static void arp_do_defense(struct client_state_t *cs)
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{
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log_line("arp: detected a peer attempting to use our IP!");
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long long nowts = curms();
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arp_timeout[AS_DEFENSE] = -1;
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arp_wake_ts[AS_DEFENSE] = -1;
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if (!last_conflict_ts ||
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nowts - last_conflict_ts < DEFEND_INTERVAL) {
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log_line("arp: Defending our lease IP.");
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@ -594,8 +598,8 @@ static void arp_do_defense(struct client_state_t *cs)
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send_release(cs);
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reinit_selecting(cs, 0);
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} else {
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arp_timeout[AS_DEFENSE] =
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arp_send_stats[ASEND_ANNOUNCE].ts + DEFEND_INTERVAL - nowts;
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arp_wake_ts[AS_DEFENSE] =
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arp_send_stats[ASEND_ANNOUNCE].ts + DEFEND_INTERVAL;
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}
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total_conflicts++;
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last_conflict_ts = nowts;
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@ -605,7 +609,7 @@ static void arp_do_gw_query(struct client_state_t *cs)
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{
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if (arp_is_query_reply(&arpreply) &&
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!memcmp(arpreply.sip4, &cs->routerAddr, 4)) {
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arp_timeout[AS_GW_QUERY] = -1;
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arp_wake_ts[AS_GW_QUERY] = -1;
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memcpy(cs->routerArp, arpreply.smac, 6);
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log_line("arp: Gateway hardware address %02x:%02x:%02x:%02x:%02x:%02x",
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cs->routerArp[0], cs->routerArp[1],
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@ -714,27 +718,15 @@ void handle_arp_timeout(struct client_state_t *cs, long long nowts)
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arp_states[arpState].timeout_fn(cs, nowts);
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}
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int get_arp_timeout(void)
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long long arp_get_wake_ts(void)
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{
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int mt = INT_MAX;
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long long mt = -1;
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for (int i = 0; i < AS_MAX; ++i) {
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log_line("DEBUG: arp_timeout[%u] == %d", i, arp_timeout[i]);
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if (arp_timeout[i] < mt && arp_timeout[i] >= 0)
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mt = arp_timeout[i];
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if (arp_wake_ts[i] == -1)
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continue;
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if (mt == -1 || mt > arp_wake_ts[i])
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mt = arp_wake_ts[i];
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}
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if (mt == INT_MAX)
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return -1;
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return mt;
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}
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void arp_timeout_adj(int off)
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{
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for (int i = 0; i < AS_MAX; ++i) {
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if (arp_timeout[i] == -1)
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continue;
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arp_timeout[i] -= off;
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if (arp_timeout[i] < 0)
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arp_timeout[i] = 0;
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}
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}
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@ -55,7 +55,6 @@ void arp_set_defense_mode(struct client_state_t *cs);
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void arp_success(struct client_state_t *cs);
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void handle_arp_response(struct client_state_t *cs);
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void handle_arp_timeout(struct client_state_t *cs, long long nowts);
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int get_arp_timeout(void);
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void arp_timeout_adj(int off);
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long long arp_get_wake_ts(void);
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#endif /* ARP_H_ */
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@ -30,7 +30,6 @@ struct client_state_t {
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int ifsPrevState;
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int listenMode;
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int epollFd, signalFd, listenFd, arpFd, nlFd;
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int dhcp_timeout;
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uint32_t clientAddr, serverAddr, routerAddr;
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uint32_t lease, renewTime, rebindTime, xid;
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int using_dhcp_bpf;
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58
ndhc/ndhc.c
58
ndhc/ndhc.c
@ -161,8 +161,8 @@ static int get_clientid_mac_string(char *str, size_t slen)
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static void do_work(void)
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{
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struct epoll_event events[3];
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long long last_awake, nowts;
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int timeout, timeout_delta;
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long long nowts;
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int timeout;
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cs.epollFd = epoll_create1(0);
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if (cs.epollFd == -1)
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@ -174,7 +174,6 @@ static void do_work(void)
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goto jumpstart;
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for (;;) {
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log_line("DEBUG: before epoll_wait()");
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int r = epoll_wait(cs.epollFd, events, 3, timeout);
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if (r == -1) {
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if (errno == EINTR)
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@ -182,7 +181,6 @@ static void do_work(void)
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else
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suicide("epoll_wait failed");
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}
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log_line("DEBUG: after epoll_wait()");
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for (int i = 0; i < r; ++i) {
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int fd = events[i].data.fd;
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if (fd == cs.signalFd)
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@ -197,39 +195,31 @@ static void do_work(void)
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suicide("epoll_wait: unknown fd");
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}
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nowts = curms();
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timeout_delta = nowts - last_awake;
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for (;;) {
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nowts = curms();
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long long arp_wake_ts = arp_get_wake_ts();
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long long dhcp_wake_ts = dhcp_get_wake_ts();
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if (arp_wake_ts == -1) {
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if (dhcp_wake_ts != -1) {
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timeout = dhcp_wake_ts - nowts;
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if (timeout < 0)
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timeout = 0;
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} else
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timeout = -1;
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} else {
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// If dhcp_wake_ts is -1 then we want to sleep anyway.
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timeout = (arp_wake_ts < dhcp_wake_ts ?
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arp_wake_ts : dhcp_wake_ts) - nowts;
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if (timeout < 0)
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timeout = 0;
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}
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cs.dhcp_timeout -= timeout_delta;
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if (cs.dhcp_timeout < 0)
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cs.dhcp_timeout = 0;
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arp_timeout_adj(timeout_delta);
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int arp_timeout = get_arp_timeout();
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log_line("DEBUG: arp_timeout = %d, dhcp_timeout = %d",
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arp_timeout, cs.dhcp_timeout);
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if (arp_timeout == -1)
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timeout = cs.dhcp_timeout;
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else if (arp_timeout < cs.dhcp_timeout)
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timeout = arp_timeout;
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else
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timeout = cs.dhcp_timeout;
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if (timeout <= 0) {
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if (!timeout) {
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jumpstart:
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timeout_action(&cs, nowts);
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int arp_timeout = get_arp_timeout();
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log_line("DEBUG: arp_timeout = %d, dhcp_timeout = %d",
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arp_timeout, cs.dhcp_timeout);
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if (arp_timeout == -1)
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timeout = cs.dhcp_timeout;
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else if (arp_timeout < cs.dhcp_timeout)
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timeout = arp_timeout;
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else
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timeout = cs.dhcp_timeout;
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timeout_action(&cs, nowts);
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} else
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break;
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}
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last_awake = nowts;
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}
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}
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57
ndhc/state.c
57
ndhc/state.c
@ -12,6 +12,8 @@
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#include "sys.h"
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#include "random.h"
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static long long dhcp_wake_ts = -1;
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static void selecting_packet(struct client_state_t *cs, struct dhcpmsg *packet,
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uint8_t *message);
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static void an_packet(struct client_state_t *cs, struct dhcpmsg *packet,
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@ -62,7 +64,7 @@ void reinit_selecting(struct client_state_t *cs, int timeout)
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ifchange_deconfig();
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arp_close_fd(cs);
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cs->dhcpState = DS_SELECTING;
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cs->dhcp_timeout = timeout;
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dhcp_wake_ts = curms() + timeout;
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cs->clientAddr = 0;
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num_dhcp_requests = 0;
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arp_reset_send_stats();
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@ -74,7 +76,7 @@ static void set_released(struct client_state_t *cs)
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ifchange_deconfig();
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arp_close_fd(cs);
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cs->dhcpState = DS_RELEASED;
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cs->dhcp_timeout = -1;
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dhcp_wake_ts = -1;
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cs->clientAddr = 0;
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num_dhcp_requests = 0;
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arp_reset_send_stats();
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@ -89,7 +91,7 @@ static void requesting_timeout(struct client_state_t *cs, long long nowts)
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{
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if (num_dhcp_requests < 5) {
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send_selecting(cs);
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cs->dhcp_timeout = delay_timeout(num_dhcp_requests);
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dhcp_wake_ts = nowts + delay_timeout(num_dhcp_requests);
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num_dhcp_requests++;
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} else
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reinit_selecting(cs, 0);
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@ -101,7 +103,7 @@ static void bound_timeout(struct client_state_t *cs, long long nowts)
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{
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long long rnt = cs->leaseStartTime + cs->renewTime * 1000;
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if (nowts < rnt) {
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cs->dhcp_timeout = rnt - nowts;
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dhcp_wake_ts = rnt;
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return;
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}
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cs->dhcpState = DS_RENEWING;
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@ -126,21 +128,17 @@ static void renewing_timeout(struct client_state_t *cs, long long nowts)
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{
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long long rbt = cs->leaseStartTime + cs->rebindTime * 1000;
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if (nowts < rbt) {
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long long wt = (rbt - nowts) / 2;
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if (wt >= 30000)
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send_renew(cs);
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else
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wt = rbt - nowts;
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cs->dhcp_timeout = wt;
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return;
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}
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long long elt = cs->leaseStartTime + cs->lease * 1000;
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if (nowts < elt) {
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if (rbt - nowts < 30000) {
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dhcp_wake_ts = rbt;
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return;
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}
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send_renew(cs);
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dhcp_wake_ts = nowts + ((rbt - nowts) / 2);
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} else {
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cs->dhcpState = DS_REBINDING;
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cs->dhcp_timeout = (elt - nowts) / 2;
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log_line("Entering rebinding state.");
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} else
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lease_timedout(cs);
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rebinding_timeout(cs, nowts);
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}
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}
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// Triggered when a DHCP rebind request has been sent and no reply has been
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@ -151,19 +149,19 @@ static void rebinding_timeout(struct client_state_t *cs, long long nowts)
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{
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long long elt = cs->leaseStartTime + cs->lease * 1000;
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if (nowts < elt) {
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long long wt = (elt - nowts) / 2;
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if (wt >= 30000)
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send_rebind(cs);
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else
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wt = elt - nowts;
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cs->dhcp_timeout = wt;
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if (elt - nowts < 30000) {
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dhcp_wake_ts = elt;
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return;
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}
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send_rebind(cs);
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dhcp_wake_ts = nowts + ((elt - nowts) / 2);
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} else
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lease_timedout(cs);
|
||||
}
|
||||
|
||||
static void released_timeout(struct client_state_t *cs, long long nowts)
|
||||
{
|
||||
cs->dhcp_timeout = -1;
|
||||
dhcp_wake_ts = -1;
|
||||
}
|
||||
|
||||
// Can transition to DS_BOUND or DS_SELECTING.
|
||||
@ -189,6 +187,7 @@ static void an_packet(struct client_state_t *cs, struct dhcpmsg *packet,
|
||||
// the remote server values, if they even exist, for sanity.
|
||||
cs->renewTime = cs->lease >> 1;
|
||||
cs->rebindTime = (cs->lease >> 3) * 0x7; // * 0.875
|
||||
dhcp_wake_ts = cs->leaseStartTime + cs->renewTime * 1000;
|
||||
|
||||
// Only check if we are either in the REQUESTING state, or if we
|
||||
// have received a lease with a different IP than what we had before.
|
||||
@ -200,7 +199,6 @@ static void an_packet(struct client_state_t *cs, struct dhcpmsg *packet,
|
||||
}
|
||||
} else {
|
||||
cs->dhcpState = DS_BOUND;
|
||||
cs->dhcp_timeout = cs->renewTime * 1000;
|
||||
arp_set_defense_mode(cs);
|
||||
set_listen_none(cs);
|
||||
}
|
||||
@ -222,7 +220,7 @@ static void selecting_packet(struct client_state_t *cs, struct dhcpmsg *packet,
|
||||
cs->xid = packet->xid;
|
||||
cs->clientAddr = packet->yiaddr;
|
||||
cs->dhcpState = DS_REQUESTING;
|
||||
cs->dhcp_timeout = 0;
|
||||
dhcp_wake_ts = curms();
|
||||
num_dhcp_requests = 0;
|
||||
} else {
|
||||
log_line("No server ID in message");
|
||||
@ -249,7 +247,7 @@ static void selecting_timeout(struct client_state_t *cs, long long nowts)
|
||||
if (num_dhcp_requests == 0)
|
||||
cs->xid = libc_random_u32();
|
||||
send_discover(cs);
|
||||
cs->dhcp_timeout = delay_timeout(num_dhcp_requests);
|
||||
dhcp_wake_ts = nowts + delay_timeout(num_dhcp_requests);
|
||||
num_dhcp_requests++;
|
||||
}
|
||||
|
||||
@ -335,3 +333,8 @@ void force_release_action(struct client_state_t *cs)
|
||||
dhcp_states[cs->dhcpState].force_release_fn(cs);
|
||||
}
|
||||
|
||||
long long dhcp_get_wake_ts(void)
|
||||
{
|
||||
return dhcp_wake_ts;
|
||||
}
|
||||
|
||||
|
||||
@ -27,6 +27,7 @@ void force_release_action(struct client_state_t *cs);
|
||||
void ifup_action(struct client_state_t *cs);
|
||||
void ifnocarrier_action(struct client_state_t *cs);
|
||||
void ifdown_action(struct client_state_t *cs);
|
||||
long long dhcp_get_wake_ts(void);
|
||||
|
||||
#endif
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user