shaba/systemd
1
0
Fork 0
mirror of https://github.com/systemd/systemd.git synced 2024-10-29 21:55:36 +03:00
Code

network: set ipv6 mtu after link-up or device mtu change

Browse Source 
The kernel resets the ipv6 mtu after NETDEV_UP or NETDEV_CHANGEMTU event,
so we must reset the ipv6 mtu to our configured value after we detect
IFF_UP flag set or after we set the device mtu.

Fixes: #13914.
This commit is contained in:
Dan Streetman 2019-10-29 10:31:58 -04:00
parent a0b7f19876
commit d236718c16
2 changed files with 54 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

61
src/network/networkd-link.c
View File

@ -1341,7 +1341,7 @@ int link_set_mtu(Link *link, uint32_t mtu) {
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");
"IPv6 is requested and requires a minimum MTU of " STRINGIFY(IPV6_MIN_MTU) " bytes");
mtu = IPV6_MIN_MTU;
}
@ -2378,9 +2378,23 @@ static int link_set_ipv6_mtu(Link *link) {
if (link->network->ipv6_mtu == 0)
return 0;
/* IPv6 protocol requires a minimum MTU of IPV6_MTU_MIN(1280) bytes
* on the interface. Bump up IPv6 MTU bytes to IPV6_MTU_MIN. */
if (link->network->ipv6_mtu < IPV6_MIN_MTU) {
log_link_notice(link, "Bumping IPv6 MTU to "STRINGIFY(IPV6_MIN_MTU)" byte minimum required");
link->network->ipv6_mtu = IPV6_MIN_MTU;
}
r = sysctl_write_ip_property_uint32(AF_INET6, link->ifname, "mtu", link->network->ipv6_mtu);
if (r < 0)
log_link_warning_errno(link, r, "Cannot set IPv6 MTU for interface: %m");
if (r < 0) {
if (link->mtu < link->network->ipv6_mtu)
log_link_warning(link, "Cannot set IPv6 MTU %"PRIu32" higher than device MTU %"PRIu32,
link->network->ipv6_mtu, link->mtu);
else
log_link_warning_errno(link, r, "Cannot set IPv6 MTU for interface: %m");
}
link->ipv6_mtu_set = true;
return 0;
}
@ -2669,10 +2683,6 @@ static int link_configure(Link *link) {
if (r < 0)
return r;
r = link_set_ipv6_mtu(link);
if (r < 0)
return r;
if (link_ipv4ll_enabled(link, ADDRESS_FAMILY_IPV4 | ADDRESS_FAMILY_FALLBACK_IPV4)) {
r = ipv4ll_configure(link);
if (r < 0)
@ -2745,6 +2755,12 @@ static int link_configure_after_setting_mtu(Link *link) {
if (link->setting_mtu)
return 0;
/* The kernel resets ipv6 mtu after changing device mtu;
* we must set this here, after we've set device mtu */
r = link_set_ipv6_mtu(link);
if (r < 0)
return r;
if (link_has_carrier(link) || link->network->configure_without_carrier) {
r = link_acquire_conf(link);
if (r < 0)
@ -3453,11 +3469,30 @@ int link_carrier_reset(Link *link) {
return 0;
}
/* This is called every time an interface admin state changes to up;
* specifically, when IFF_UP flag changes from unset to set */
static int link_admin_state_up(Link *link) {
int r;
/* We set the ipv6 mtu after the device mtu, but the kernel resets
* ipv6 mtu on NETDEV_UP, so we need to reset it. The check for
* ipv6_mtu_set prevents this from trying to set it too early before
* the link->network has been setup; we only need to reset it
* here if we've already set it during normal initialization. */
if (link->ipv6_mtu_set) {
r = link_set_ipv6_mtu(link);
if (r < 0)
return r;
}
return 0;
}
int link_update(Link *link, sd_netlink_message *m) {
struct ether_addr mac;
const char *ifname;
uint32_t mtu;
bool had_carrier, carrier_gained, carrier_lost;
bool had_carrier, carrier_gained, carrier_lost, link_was_admin_up;
int old_master, r;
assert(link);
@ -3587,12 +3622,22 @@ int link_update(Link *link, sd_netlink_message *m) {
old_master = link->master_ifindex;
(void) sd_netlink_message_read_u32(m, IFLA_MASTER, (uint32_t *) &link->master_ifindex);
link_was_admin_up = link->flags & IFF_UP;
had_carrier = link_has_carrier(link);
r = link_update_flags(link, m, old_master != link->master_ifindex);
if (r < 0)
return r;
if (!link_was_admin_up && (link->flags & IFF_UP)) {
log_link_info(link, "Link UP");
r = link_admin_state_up(link);
if (r < 0)
return r;
} else if (link_was_admin_up && !(link->flags & IFF_UP))
log_link_info(link, "Link DOWN");
r = link_update_lldp(link);
if (r < 0)
return r;

1
src/network/networkd-link.h
View File

@ -116,6 +116,7 @@ typedef struct Link {
bool routing_policy_rules_configured:1;
bool qdiscs_configured:1;
bool setting_mtu:1;
bool ipv6_mtu_set:1;
LIST_HEAD(Address, pool_addresses);