Merge pull request #9832 from yuwata/fix-9831

network: fixes related to setting MTU
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2018-09-08 17:17:07 +02:00 committed by GitHub
commit 9d0798a2ed
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3 changed files with 41 additions and 16 deletions

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@ -1167,6 +1167,7 @@
<listitem>
<para>When true, the interface maximum transmission unit
from the DHCP server will be used on the current link.
If <varname>MTUBytes=</varname> is set, then this setting is ignored.
Defaults to false.</para>
</listitem>
</varlistentry>

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@ -1263,6 +1263,8 @@ static int link_set_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userd
return 0;
}
static int link_configure_after_setting_mtu(Link *link);
static int set_mtu_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) {
_cleanup_(link_unrefp) Link *link = userdata;
int r;
@ -1271,12 +1273,21 @@ static int set_mtu_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userda
assert(link);
assert(link->ifname);
link->setting_mtu = false;
if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
return 1;
r = sd_netlink_message_get_errno(m);
if (r < 0)
if (r < 0) {
log_link_warning_errno(link, r, "Could not set MTU: %m");
return 1;
}
log_link_debug(link, "Setting MTU done.");
if (link->state == LINK_STATE_PENDING)
(void) link_configure_after_setting_mtu(link);
return 1;
}
@ -1289,6 +1300,9 @@ int link_set_mtu(Link *link, uint32_t mtu) {
assert(link->manager);
assert(link->manager->rtnl);
if (link->mtu == mtu || link->setting_mtu)
return 0;
log_link_debug(link, "Setting MTU: %" PRIu32, mtu);
r = sd_rtnl_message_new_link(link->manager->rtnl, &req, RTM_SETLINK, link->ifindex);
@ -1296,23 +1310,19 @@ int link_set_mtu(Link *link, uint32_t mtu) {
return log_link_error_errno(link, r, "Could not allocate RTM_SETLINK message: %m");
/* If IPv6 not configured (no static IPv6 address and IPv6LL autoconfiguration is disabled)
for this interface, or if it is a bridge slave, then disable IPv6 else enable it. */
* for this interface, or if it is a bridge slave, then disable IPv6 else enable it. */
(void) link_enable_ipv6(link);
/* IPv6 protocol requires a minimum MTU of IPV6_MTU_MIN(1280) bytes
on the interface. Bump up MTU bytes to IPV6_MTU_MIN. */
if (link_ipv6_enabled(link) && link->network->mtu < IPV6_MIN_MTU) {
* on the interface. Bump up MTU bytes to IPV6_MTU_MIN. */
if (link_ipv6_enabled(link) && mtu < IPV6_MIN_MTU) {
log_link_warning(link, "Bumping MTU to " STRINGIFY(IPV6_MIN_MTU) ", as "
"IPv6 is requested and requires a minimum MTU of " STRINGIFY(IPV6_MIN_MTU) " bytes: %m");
link->network->mtu = IPV6_MIN_MTU;
mtu = IPV6_MIN_MTU;
}
r = sd_netlink_message_append_u32(req, IFLA_MTU, link->network->mtu);
if (r < 0)
return log_link_error_errno(link, r, "Could not set MTU: %m");
r = sd_netlink_message_append_u32(req, IFLA_MTU, mtu);
if (r < 0)
return log_link_error_errno(link, r, "Could not append MTU: %m");
@ -1691,11 +1701,6 @@ static int link_acquire_conf(Link *link) {
assert(link);
if (link->setting_mtu) {
link->setting_mtu = false;
return 0;
}
r = link_acquire_ipv4_conf(link);
if (r < 0)
return r;
@ -2859,6 +2864,19 @@ static int link_configure(Link *link) {
return r;
}
return link_configure_after_setting_mtu(link);
}
static int link_configure_after_setting_mtu(Link *link) {
int r;
assert(link);
assert(link->network);
assert(link->state == LINK_STATE_PENDING);
if (link->setting_mtu)
return 0;
if (link_has_carrier(link) || link->network->configure_without_carrier) {
r = link_acquire_conf(link);
if (r < 0)
@ -3406,8 +3424,8 @@ static int link_carrier_lost(Link *link) {
assert(link);
/* Some devices reset itself while setting the MTU. This causes the DHCP client fall into a loop.
setting_mtu keep track whether the device got reset because of setting MTU and does not drop the
configuration and stop the clients as well. */
* setting_mtu keep track whether the device got reset because of setting MTU and does not drop the
* configuration and stop the clients as well. */
if (link->setting_mtu)
return 0;

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@ -281,6 +281,12 @@ static int network_load_one(Manager *manager, const char *filename) {
if (network->ip_masquerade)
network->ip_forward |= ADDRESS_FAMILY_IPV4;
if (network->mtu > 0 && network->dhcp_use_mtu) {
log_warning("MTUBytes= in [Link] section and UseMTU= in [DHCP] section are set in %s. "
"Disabling UseMTU=.", filename);
network->dhcp_use_mtu = false;
}
LIST_PREPEND(networks, manager->networks, network);
r = hashmap_ensure_allocated(&manager->networks_by_name, &string_hash_ops);