From: Anders Kaseorg <andersk@mit.edu>
Date: Wed, 1 Jan 2020 19:42:47 +0000 (-0800)
Subject: Linux: fix RA time unit confusion
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F12%2Fhead;p=thirdparty%2Fdhcpcd.git

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 befdf183..fe05901e 100644
--- 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;