Linux: fix RA time unit confusion

The RA times are provided in milliseconds, but commit
569051c8aa8fc297eb8edb7bd228e0fd353d30c1 (dhcpcd-8.1.3~18) “Linux:
prefer ms RA times” incorrectly scaled them by an extra factor of 1000
before writing them to retrans_time_ms and base_reachable_time_ms.
Instead, write the values in milliseconds directly to the *_ms files,
and correctly convert to jiffies or seconds for the other files if
necessary.

Fixes NixOS/nixpkgs#76710.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>

diff --git a/src/if-linux.c b/src/if-linux.c
index befdf183dd8d63492246da25e93c52a21eb5131f..fe05901ebd1422e02f2077166b3f73aa86f3a652 100644 (file)
--- a/src/if-linux.c
+++ b/src/if-linux.c
@@ -1948,20 +1948,20 @@ if_applyra(const struct ra *rap)
                error = -1;
 
        snprintf(path, sizeof(path), "%s/%s/retrans_time_ms", p_neigh, ifname);
-       if (if_writepathuint(ctx, path, rap->retrans * 1000) == -1) {
+       if (if_writepathuint(ctx, path, rap->retrans) == -1) {
                snprintf(path, sizeof(path), "%s/%s/retrans_time",
                    p_neigh, ifname);
                /* Jiffies */
-               if (if_writepathuint(ctx, path, rap->retrans * 100) == -1)
+               if (if_writepathuint(ctx, path, rap->retrans * sysconf(_SC_CLK_TCK) / 1000) == -1)
                        error = -1;
        }
 
        snprintf(path, sizeof(path), "%s/%s/base_reachable_time_ms",
            p_neigh, ifname);
-       if (if_writepathuint(ctx, path, rap->reachable * 1000) == -1) {
+       if (if_writepathuint(ctx, path, rap->reachable) == -1) {
                snprintf(path, sizeof(path), "%s/%s/base_reachable_time",
                    p_neigh, ifname);
-               if (if_writepathuint(ctx, path, rap->reachable) == -1)
+               if (if_writepathuint(ctx, path, rap->reachable / 1000) == -1)
                        error = -1;
        }
        return error;