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authorBenedikt Morbach <benedikt.morbach@googlemail.com>2015-05-10 20:52:40 +0200
committerLennart Poettering <lennart@poettering.net>2015-05-15 12:13:35 +0200
commit505c5f6de1a5c0afb238a46db94fe3571902cc9d (patch)
tree2cd76ca1686b1a036b98eb19cc7c10ab465c97c0 /src
parent57ab2eabb8f92fad5239c7d4492e9c6e23ee0678 (diff)
networkd: don't touch global forwarding setting
This reverts commit 43c6d5abacaebf813845934ec8d5e5ee3c431854 (and a small part of 4046d8361c55c80ab8577aea52523b9e6eab0d0c) It turns out we don't actually need to set the global ip_forward setting. The only relevant setting is the one on each interface. What the global toggle actually does is switch forwarding on/off for all currently present interfaces and change the default for new ones. That means that by setting the global ip_forward we - Introduce a race condition, because if the interface with IPForward=yes is brought up after one with IPForward=no, both will have forwarding enabled, because the global switch turns it on for all interfaces. If the other interface comes up first networkd correctly sets forward=0 and it doesn't get overridden. - Change the forwarding setting for interfaces that networkd is not configured to touch, even if the user disabled forwarding via sysctl, either globally or per-interface As forwarding works fine without this, as long as all relevant interfacest individually set IPForward=yes: just drop it This means that non-networkd interfaces use the global default while networkd interfaces default to off if IPForward isn't given.
Diffstat (limited to 'src')
-rw-r--r--src/network/networkd-link.c28
1 files changed, 1 insertions, 27 deletions
diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index 5628ed92bf..1c59e150d5 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -1475,39 +1475,13 @@ static int link_enter_join_netdev(Link *link) {
static int link_set_ipv4_forward(Link *link) {
const char *p = NULL;
- bool b;
int r;
- b = link_ipv4_forward_enabled(link);
-
p = strjoina("/proc/sys/net/ipv4/conf/", link->ifname, "/forwarding");
- r = write_string_file_no_create(p, one_zero(b));
+ r = write_string_file_no_create(p, one_zero(link_ipv4_forward_enabled(link)));
if (r < 0)
log_link_warning_errno(link, r, "Cannot configure IPv4 forwarding for interface %s: %m", link->ifname);
- if (b) {
- _cleanup_free_ char *buf = NULL;
-
- /* If IP forwarding is turned on for this interface,
- * then propagate this to the global setting. Given
- * that turning this on has side-effects on other
- * fields, we'll try to avoid doing this unless
- * necessary, hence check the previous value
- * first. Note that we never turn this option off
- * again, since all interfaces we manage do not do
- * forwarding anyway by default, and ownership rules
- * of this control are so unclear. */
-
- r = read_one_line_file("/proc/sys/net/ipv4/ip_forward", &buf);
- if (r < 0)
- log_link_warning_errno(link, r, "Cannot read /proc/sys/net/ipv4/ip_forward: %m");
- else if (!streq(buf, "1")) {
- r = write_string_file_no_create("/proc/sys/net/ipv4/ip_forward", "1");
- if (r < 0)
- log_link_warning_errno(link, r, "Cannot write /proc/sys/net/ipv4/ip_forward: %m");
- }
- }
-
return 0;
}