From: Denys Vlasenko Date: Fri, 4 Mar 2016 06:06:53 +0000 (+0100) Subject: ntpd: do not use a peer more than once (say, if two peers resolve to the same IP) X-Git-Tag: 1_25_0~115 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=f37f28199f508f5fee44753d320f044a91e76e39;p=oweals%2Fbusybox.git ntpd: do not use a peer more than once (say, if two peers resolve to the same IP) function old new delta add_peers 98 166 +68 Signed-off-by: Denys Vlasenko --- diff --git a/networking/ntpd.c b/networking/ntpd.c index 4695c3366..517806e75 100644 --- a/networking/ntpd.c +++ b/networking/ntpd.c @@ -727,7 +727,7 @@ reset_peer_stats(peer_t *p, double offset) /* Used to set p->filter_datapoint[i].d_dispersion = MAXDISP * and clear reachable bits, but this proved to be too agressive: - * after step (tested with suspinding laptop for ~30 secs), + * after step (tested with suspending laptop for ~30 secs), * this caused all previous data to be considered invalid, * making us needing to collect full ~8 datapoins per peer * after step in order to start trusting them. @@ -766,11 +766,26 @@ reset_peer_stats(peer_t *p, double offset) static void add_peers(const char *s) { + llist_t *item; peer_t *p; p = xzalloc(sizeof(*p)); p->p_lsa = xhost2sockaddr(s, 123); p->p_dotted = xmalloc_sockaddr2dotted_noport(&p->p_lsa->u.sa); + + /* Names like N..pool.ntp.org are randomly resolved + * to a pool of machines. Sometimes different N's resolve to the same IP. + * It is not useful to have two peers with same IP. We skip duplicates. + */ + for (item = G.ntp_peers; item != NULL; item = item->link) { + peer_t *pp = (peer_t *) item->data; + if (strcmp(p->p_dotted, pp->p_dotted) == 0) { + bb_error_msg("duplicate peer %s (%s)", s, p->p_dotted); + free(p); + return; + } + } + p->p_fd = -1; p->p_xmt_msg.m_status = MODE_CLIENT | (NTP_VERSION << 3); p->next_action_time = G.cur_time; /* = set_next(p, 0); */