From e39f0fa5c3da64181981ee9dc373b400e6453b19 Mon Sep 17 00:00:00 2001 From: Yu Watanabe Date: Mon, 16 Nov 2020 16:25:43 +0900 Subject: network: honor M or O flag in RA even if IPv6AcceptRA.DHCPv6Cleint=always Follow-up for ac24e418d9bc988ecf114c464701b35934948178. The original motivation of the commit and RFE #15339 is to start dhcpv6 client in managed mode when neither M nor O flag is set in the RA. But, previously, if the setting is set to "always", then the DHCPv6 client is always started in managed mode even if O flag is set in the RA. Such the behavior breaks RFC 7084. (cherry picked from commit 0e686feaff71465e3220f234871f66a39f0f57ad) --- man/systemd.network.xml | 8 +++++--- src/network/networkd-ndisc.c | 12 ++++++++---- 2 files changed, 13 insertions(+), 7 deletions(-) diff --git a/man/systemd.network.xml b/man/systemd.network.xml index 9d28de7ac7..b1880699ab 100644 --- a/man/systemd.network.xml +++ b/man/systemd.network.xml @@ -2052,9 +2052,11 @@ DHCPv6Client= - Takes a boolean, or the special value always. When true (the default), the DHCPv6 client will be started when the - RA has the managed or other information flag. If set to always, the DHCPv6 client will be started even if there is no - managed or other information flag in the RA. + Takes a boolean, or the special value always. When true or + always, the DHCPv6 client will be started when the RA has the managed or + other information flag. If set to always, the DHCPv6 client will also be + started in managed mode when neither managed nor other information flag is set in the RA. + Defaults to true. diff --git a/src/network/networkd-ndisc.c b/src/network/networkd-ndisc.c index bcea91c696..fed6aaba22 100644 --- a/src/network/networkd-ndisc.c +++ b/src/network/networkd-ndisc.c @@ -1116,13 +1116,17 @@ static int ndisc_router_handler(Link *link, sd_ndisc_router *rt) { if (r < 0) return log_link_error_errno(link, r, "Failed to get RA flags: %m"); - if ((flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER) && link->network->ipv6_accept_ra_start_dhcp6_client)) { + if ((flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER) && + link->network->ipv6_accept_ra_start_dhcp6_client != IPV6_ACCEPT_RA_START_DHCP6_CLIENT_NO) || + link->network->ipv6_accept_ra_start_dhcp6_client == IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS) { - if (link->network->ipv6_accept_ra_start_dhcp6_client == IPV6_ACCEPT_RA_START_DHCP6_CLIENT_ALWAYS) - r = dhcp6_request_address(link, false); - else + if (flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER)) /* (re)start DHCPv6 client in stateful or stateless mode according to RA flags */ r = dhcp6_request_address(link, !(flags & ND_RA_FLAG_MANAGED)); + else + /* When IPv6AcceptRA.DHCPv6Client=always, start dhcp6 client in managed mode + * even if router does not have M or O flag. */ + r = dhcp6_request_address(link, false); if (r < 0 && r != -EBUSY) return log_link_error_errno(link, r, "Could not acquire DHCPv6 lease on NDisc request: %m"); else -- cgit v1.2.1