From: Jason A. Donenfeld <Jason@zx2c4.com>
Date: Fri, 12 Oct 2018 14:40:29 +0000 (+0200)
Subject: wg: don't fail if a netlink interface dump is inconsistent
X-Git-Tag: v1.0.20191226~68
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=599b84fbd18a0662661017f9f7e346567587ce31;p=thirdparty%2Fwireguard-tools.git

wg: don't fail if a netlink interface dump is inconsistent

Netlink returns NLM_F_DUMP_INTR if the set of all tunnels changed
during the dump. That's unfortunate, but is pretty common on busy
systems that are adding and removing tunnels all the time. Rather
than retrying, potentially indefinitely, we just work with the
partial results.

Reported-by: Robert Gerus <ar@is-a.cat>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---

diff --git a/contrib/embeddable-wg-library/wireguard.c b/contrib/embeddable-wg-library/wireguard.c
index a32fd50..b8368e9 100644
--- a/contrib/embeddable-wg-library/wireguard.c
+++ b/contrib/embeddable-wg-library/wireguard.c
@@ -998,8 +998,15 @@ another:
 		goto cleanup;
 	}
 	if ((len = mnl_cb_run(rtnl_buffer, len, seq, portid, read_devices_cb, buffer)) < 0) {
-		ret = -errno;
-		goto cleanup;
+		/* Netlink returns NLM_F_DUMP_INTR if the set of all tunnels changed
+		 * during the dump. That's unfortunate, but is pretty common on busy
+		 * systems that are adding and removing tunnels all the time. Rather
+		 * than retrying, potentially indefinitely, we just work with the
+		 * partial results. */
+		if (errno != EINTR) {
+			ret = -errno;
+			goto cleanup;
+		}
 	}
 	if (len == MNL_CB_OK + 1)
 		goto another;
diff --git a/src/ipc.c b/src/ipc.c
index c64e332..5879109 100644
--- a/src/ipc.c
+++ b/src/ipc.c
@@ -530,8 +530,15 @@ another:
 		goto cleanup;
 	}
 	if ((len = mnl_cb_run(rtnl_buffer, len, seq, portid, read_devices_cb, buffer)) < 0) {
-		ret = -errno;
-		goto cleanup;
+		/* Netlink returns NLM_F_DUMP_INTR if the set of all tunnels changed
+		 * during the dump. That's unfortunate, but is pretty common on busy
+		 * systems that are adding and removing tunnels all the time. Rather
+		 * than retrying, potentially indefinitely, we just work with the
+		 * partial results. */
+		if (errno != EINTR) {
+			ret = -errno;
+			goto cleanup;
+		}
 	}
 	if (len == MNL_CB_OK + 1)
 		goto another;