From aabb0a93e947a2a3cd180b490ae6664396446f63 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 3 Jul 2016 17:58:54 +0200 Subject: [PATCH] ntpd: daemonize before DNS resolution This resolves the following use case problem: "I start ntpd by default from /etc/init.d There might be no working network connection (not configured properly for whatever reason, hardware problems, whatelse). With busybox 1.25 ntpd seems to loop forever if now NTP servers are found, blocking the boot process and I never get a login to solve a possible pb or to do a first time configuration." Signed-off-by: Denys Vlasenko --- networking/ntpd.c | 45 +++++++++++++++++++++++++-------------------- 1 file changed, 25 insertions(+), 20 deletions(-) diff --git a/networking/ntpd.c b/networking/ntpd.c index 98158a304..8e7175063 100644 --- a/networking/ntpd.c +++ b/networking/ntpd.c @@ -2213,6 +2213,31 @@ static NOINLINE void ntp_init(char **argv) // if (opts & OPT_x) /* disable stepping, only slew is allowed */ // G.time_was_stepped = 1; + +#if ENABLE_FEATURE_NTPD_SERVER + G_listen_fd = -1; + if (opts & OPT_l) { + G_listen_fd = create_and_bind_dgram_or_die(NULL, 123); + if (G.if_name) { + if (setsockopt_bindtodevice(G_listen_fd, G.if_name)) + xfunc_die(); + } + socket_want_pktinfo(G_listen_fd); + setsockopt_int(G_listen_fd, IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY); + } +#endif + /* I hesitate to set -20 prio. -15 should be high enough for timekeeping */ + if (opts & OPT_N) + setpriority(PRIO_PROCESS, 0, -15); + + /* add_peers() calls can retry DNS resolution (possibly forever). + * Daemonize before them, or else boot can stall forever. + */ + if (!(opts & OPT_n)) { + bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO, argv); + logmode = LOGMODE_NONE; + } + if (peers) { while (peers) add_peers(llist_pop(&peers)); @@ -2241,26 +2266,6 @@ static NOINLINE void ntp_init(char **argv) /* -l but no peers: "stratum 1 server" mode */ G.stratum = 1; } -#if ENABLE_FEATURE_NTPD_SERVER - G_listen_fd = -1; - if (opts & OPT_l) { - G_listen_fd = create_and_bind_dgram_or_die(NULL, 123); - if (opts & OPT_I) { - if (setsockopt_bindtodevice(G_listen_fd, G.if_name)) - xfunc_die(); - } - socket_want_pktinfo(G_listen_fd); - setsockopt_int(G_listen_fd, IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY); - } -#endif - if (!(opts & OPT_n)) { - bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO, argv); - logmode = LOGMODE_NONE; - } - /* I hesitate to set -20 prio. -15 should be high enough for timekeeping */ - if (opts & OPT_N) - setpriority(PRIO_PROCESS, 0, -15); - /* If network is up, syncronization occurs in ~10 seconds. * We give "ntpd -q" 10 seconds to get first reply, * then another 50 seconds to finish syncing. -- 2.25.1