diff options
| author | Florian Obser <florian@cvs.openbsd.org> | 2020-10-30 18:28:39 +0000 |
|---|---|---|
| committer | Florian Obser <florian@cvs.openbsd.org> | 2020-10-30 18:28:39 +0000 |
| commit | 01f511c73fd8e90c3e0d24a20fa7f2787e8cdfdc (patch) | |
| tree | 2b75447327d29b67cf9c250ad25915d4ac66dfda | |
| parent | b6bc9705ae78312bfa61dd2bca3362846d40e2f7 (diff) | |
Follow RFC 4941 and calculate the desync_factor at startup.
There is probably nothing wrong with calculating a new random value
everytime we create an address, but we are also not gaining anything.
Makes math in upcomming diffs easier.
| -rw-r--r-- | sbin/slaacd/engine.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/sbin/slaacd/engine.c b/sbin/slaacd/engine.c index f10feb28301..edddd8573c1 100644 --- a/sbin/slaacd/engine.c +++ b/sbin/slaacd/engine.c @@ -1,4 +1,4 @@ -/* $OpenBSD: engine.c,v 1.54 2020/10/30 18:27:39 florian Exp $ */ +/* $OpenBSD: engine.c,v 1.55 2020/10/30 18:28:38 florian Exp $ */ /* * Copyright (c) 2017 Florian Obser <florian@openbsd.org> @@ -329,6 +329,8 @@ struct imsgev *iev_frontend; struct imsgev *iev_main; int64_t proposal_id; +uint32_t desync_factor; + void engine_sig_handler(int sig, short event, void *arg) { @@ -400,6 +402,8 @@ engine(int debug, int verbose) LIST_INIT(&slaacd_interfaces); + desync_factor = arc4random_uniform(PRIV_MAX_DESYNC_FACTOR); + event_dispatch(); engine_shutdown(); @@ -1910,11 +1914,11 @@ update_iface_ra_prefix(struct slaacd_iface *iface, struct radv *ra, /* privacy addresses do not depend on eui64 */ if (!found_privacy && iface->autoconfprivacy) { - if (prefix->pltime < PRIV_MAX_DESYNC_FACTOR) { + if (prefix->pltime < desync_factor) { log_warnx("%s: pltime from %s is too small: %d < %d; " "not generating privacy address", __func__, sin6_to_str(&ra->from), prefix->pltime, - PRIV_MAX_DESYNC_FACTOR); + desync_factor); } else /* new privacy proposal */ gen_address_proposal(iface, ra, prefix, 1); @@ -2048,8 +2052,8 @@ gen_address_proposal(struct slaacd_iface *iface, struct radv *ra, struct addr_proposal->vltime = prefix->vltime; if (prefix->pltime > PRIV_PREFERRED_LIFETIME) - addr_proposal->pltime = PRIV_PREFERRED_LIFETIME - - arc4random_uniform(PRIV_MAX_DESYNC_FACTOR); + addr_proposal->pltime = PRIV_PREFERRED_LIFETIME - + desync_factor; else addr_proposal->pltime = prefix->pltime; } else { |