sd-dhcp6-client: properly calculate buffer size when parsing options

[elogind.git] / src / timesync / timesyncd-manager.c

diff --git a/src/timesync/timesyncd-manager.c b/src/timesync/timesyncd-manager.c
index 333960669ce82d0aa20e5da328d01338df75da43..9b8b7d3eb6886790aba0cb2151806c4aa3c63b7c 100644 (file)
--- a/src/timesync/timesyncd-manager.c
+++ b/src/timesync/timesyncd-manager.c
@@ -89,6 +89,9 @@
 #define NTP_FIELD_MODE(f)               ((f) & 7)
 #define NTP_FIELD(l, v, m)              (((l) << 6) | ((v) << 3) | (m))
 
+/* Maximum acceptable root distance in seconds. */
+#define NTP_MAX_ROOT_DISTANCE           5.0
+
 /*
  * "NTP timestamps are represented as a 64-bit unsigned fixed-point number,
  * in seconds relative to 0h on 1 January 1900."
@@ -128,6 +131,10 @@ struct ntp_msg {
 static int manager_arm_timer(Manager *m, usec_t next);
 static int manager_clock_watch_setup(Manager *m);
 
+static double ntp_ts_short_to_d(const struct ntp_ts_short *ts) {
+        return be16toh(ts->sec) + (be16toh(ts->frac) / 65536.0);
+}
+
 static double ntp_ts_to_d(const struct ntp_ts *ts) {
         return be32toh(ts->sec) + ((double)be32toh(ts->frac) / UINT_MAX);
 }
@@ -136,10 +143,6 @@ static double ts_to_d(const struct timespec *ts) {
         return ts->tv_sec + (1.0e-9 * ts->tv_nsec);
 }
 
-static double tv_to_d(const struct timeval *tv) {
-        return tv->tv_sec + (1.0e-6 * tv->tv_usec);
-}
-
 static double square(double d) {
         return d * d;
 }
@@ -500,10 +503,11 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re
                 .msg_namelen = sizeof(server_addr),
         };
         struct cmsghdr *cmsg;
-        struct timeval *recv_time;
+        struct timespec *recv_time;
         ssize_t len;
         double origin, receive, trans, dest;
         double delay, offset;
+        double root_distance;
         bool spike;
         int leap_sec;
         int r;
@@ -543,8 +547,8 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re
                         continue;
 
                 switch (cmsg->cmsg_type) {
-                case SCM_TIMESTAMP:
-                        recv_time = (struct timeval *) CMSG_DATA(cmsg);
+                case SCM_TIMESTAMPNS:
+                        recv_time = (struct timespec *) CMSG_DATA(cmsg);
                         break;
                 }
         }
@@ -589,6 +593,12 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re
                 return manager_connect(m);
         }
 
+        root_distance = ntp_ts_short_to_d(&ntpmsg.root_delay) / 2 + ntp_ts_short_to_d(&ntpmsg.root_dispersion);
+        if (root_distance > NTP_MAX_ROOT_DISTANCE) {
+                log_debug("Server has too large root distance. Disconnecting.");
+                return manager_connect(m);
+        }
+
         /* valid packet */
         m->pending = false;
         m->retry_interval = 0;
@@ -615,7 +625,7 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re
         origin = ts_to_d(&m->trans_time) + OFFSET_1900_1970;
         receive = ntp_ts_to_d(&ntpmsg.recv_time);
         trans = ntp_ts_to_d(&ntpmsg.trans_time);
-        dest = tv_to_d(recv_time) + OFFSET_1900_1970;
+        dest = ts_to_d(recv_time) + OFFSET_1900_1970;
 
         offset = ((receive - origin) + (trans - dest)) / 2;
         delay = (dest - origin) - (trans - receive);
@@ -630,6 +640,7 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re
                   "  mode         : %u\n"
                   "  stratum      : %u\n"
                   "  precision    : %.6f sec (%d)\n"
+                  "  root distance: %.6f sec\n"
                   "  reference    : %.4s\n"
                   "  origin       : %.3f\n"
                   "  receive      : %.3f\n"
@@ -645,6 +656,7 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re
                   NTP_FIELD_MODE(ntpmsg.field),
                   ntpmsg.stratum,
                   exp2(ntpmsg.precision), ntpmsg.precision,
+                  root_distance,
                   ntpmsg.stratum == 1 ? ntpmsg.refid : "n/a",
                   origin - OFFSET_1900_1970,
                   receive - OFFSET_1900_1970,
@@ -697,7 +709,7 @@ static int manager_listen_setup(Manager *m) {
         if (r < 0)
                 return -errno;
 
-        r = setsockopt(m->server_socket, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on));
+        r = setsockopt(m->server_socket, SOL_SOCKET, SO_TIMESTAMPNS, &on, sizeof(on));
         if (r < 0)
                 return -errno;