diff options
| author | Florian Obser <florian@cvs.openbsd.org> | 2021-02-28 15:26:27 +0000 |
|---|---|---|
| committer | Florian Obser <florian@cvs.openbsd.org> | 2021-02-28 15:26:27 +0000 |
| commit | 59df72dbf83cee33f8188e2cebcc9879b2d571f6 (patch) | |
| tree | 5b39c953117c52b42d53bad57864fb3e62f483cb /sbin/dhcpleased | |
| parent | 289ec9d03af31f4376b6453450c7eccb79d5b4c5 (diff) | |
Introduce #defines for exponential backoff, explain where they come
from and explain why we are a bit more agressive during startup.
While here make the math a bit easier on the eyes.
Diffstat (limited to 'sbin/dhcpleased')
| -rw-r--r-- | sbin/dhcpleased/engine.c | 35 |
1 files changed, 19 insertions, 16 deletions
diff --git a/sbin/dhcpleased/engine.c b/sbin/dhcpleased/engine.c index 092aa45cf4c..58c66de2074 100644 --- a/sbin/dhcpleased/engine.c +++ b/sbin/dhcpleased/engine.c @@ -1,4 +1,4 @@ -/* $OpenBSD: engine.c,v 1.2 2021/02/27 10:07:41 florian Exp $ */ +/* $OpenBSD: engine.c,v 1.3 2021/02/28 15:26:26 florian Exp $ */ /* * Copyright (c) 2017, 2021 Florian Obser <florian@openbsd.org> @@ -50,7 +50,13 @@ #include "dhcpleased.h" #include "engine.h" -#define MINIMUM(a, b) (((a) < (b)) ? (a) : (b)) +/* + * RFC 2131 4.1 p23 has "SHOULD be 4 seconds", we are a bit more aggressive, + * networks are faster these days. + */ +#define START_EXP_BACKOFF 1 +#define MAX_EXP_BACKOFF 64 /* RFC 2131 4.1 p23 */ +#define MINIMUM(a, b) (((a) < (b)) ? (a) : (b)) enum if_state { IF_DOWN, @@ -1087,32 +1093,29 @@ state_transition(struct dhcpleased_iface *iface, enum if_state new_state) sizeof(iface->nameservers)); } if (old_state == IF_INIT) { - iface->timo.tv_sec *= 2; - if (iface->timo.tv_sec > 64) - iface->timo.tv_sec = 64; + if (iface->timo.tv_sec < MAX_EXP_BACKOFF) + iface->timo.tv_sec *= 2; } else - iface->timo.tv_sec = 1; + iface->timo.tv_sec = START_EXP_BACKOFF; request_dhcp_discover(iface); break; case IF_REBOOTING: if (old_state == IF_REBOOTING) { - iface->timo.tv_sec *= 2; - if (iface->timo.tv_sec > 64) - iface->timo.tv_sec = 64; + if (iface->timo.tv_sec < MAX_EXP_BACKOFF) + iface->timo.tv_sec *= 2; } else { /* make sure we send broadcast */ iface->dhcp_server.s_addr = INADDR_ANY; - iface->timo.tv_sec = 1; + iface->timo.tv_sec = START_EXP_BACKOFF; } request_dhcp_request(iface); break; case IF_REQUESTING: if (old_state == IF_REQUESTING) { - iface->timo.tv_sec *= 2; - if (iface->timo.tv_sec > 64) - iface->timo.tv_sec = 64; + if (iface->timo.tv_sec < MAX_EXP_BACKOFF) + iface->timo.tv_sec *= 2; } else - iface->timo.tv_sec = 1; + iface->timo.tv_sec = START_EXP_BACKOFF; request_dhcp_request(iface); break; case IF_BOUND: @@ -1176,13 +1179,13 @@ iface_timeout(int fd, short events, void *arg) state_transition(iface, IF_INIT); break; case IF_REBOOTING: - if (iface->timo.tv_sec >= 64) + if (iface->timo.tv_sec >= MAX_EXP_BACKOFF) state_transition(iface, IF_INIT); else state_transition(iface, IF_REBOOTING); break; case IF_REQUESTING: - if (iface->timo.tv_sec >= 64) + if (iface->timo.tv_sec >= MAX_EXP_BACKOFF) state_transition(iface, IF_INIT); else state_transition(iface, IF_REQUESTING); |