Systemd/src/network/networkd-ndisc.c
Tom Gundersen f5a8c43f39 networkd: IPv6 router discovery - follow IPv6AcceptRouterAdvertisemnt=
The previous behavior:
When DHCPv6 was enabled, router discover was performed first, and then DHCPv6 was
enabled only if the relevant flags were passed in the Router Advertisement message.
Moreover, router discovery was performed even if AcceptRouterAdvertisements=false,
moreover, even if router advertisements were accepted (by the kernel) the flags
indicating that DHCPv6 should be performed were ignored.

New behavior:
If RouterAdvertisements are accepted, and either no routers are found, or an
advertisement is received indicating DHCPv6 should be performed, the DHCPv6
client is started. Moreover, the DHCP option now truly enables the DHCPv6
client regardless of router discovery (though it will probably not be
very useful to get a lease withotu any routes, this seems the more consistent
approach).

The recommended default setting should be to set DHCP=ipv4 and to leave
IPv6AcceptRouterAdvertisements unset.
2015-11-11 15:42:38 +01:00

104 lines
3.2 KiB
C

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright (C) 2014 Intel Corporation. All rights reserved.
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <netinet/ether.h>
#include <netinet/icmp6.h>
#include <linux/if.h>
#include "sd-ndisc.h"
#include "networkd-link.h"
static void ndisc_router_handler(sd_ndisc *nd, uint8_t flags, const struct in6_addr *gateway, unsigned lifetime, int pref, void *userdata) {
Link *link = userdata;
int r;
assert(link);
assert(link->network);
if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
return;
if (flags & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER)) {
if (flags & ND_RA_FLAG_MANAGED)
dhcp6_request_address(link);
r = sd_dhcp6_client_start(link->dhcp6_client);
if (r < 0 && r != -EALREADY)
log_link_warning_errno(link, r, "Starting DHCPv6 client on NDisc request failed: %m");
}
}
static void ndisc_handler(sd_ndisc *nd, int event, void *userdata) {
Link *link = userdata;
int r;
assert(link);
if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER))
return;
switch (event) {
case SD_NDISC_EVENT_TIMEOUT:
dhcp6_request_address(link);
r = sd_dhcp6_client_start(link->dhcp6_client);
if (r < 0 && r != -EALREADY)
log_link_warning_errno(link, r, "Starting DHCPv6 client after NDisc timeout failed: %m");
break;
case SD_NDISC_EVENT_STOP:
break;
default:
log_link_warning(link, "IPv6 Neighbor Discovery unknown event: %d", event);
}
}
int ndisc_configure(Link *link) {
int r;
assert_return(link, -EINVAL);
r = sd_ndisc_new(&link->ndisc_router_discovery);
if (r < 0)
return r;
r = sd_ndisc_attach_event(link->ndisc_router_discovery, NULL, 0);
if (r < 0)
return r;
r = sd_ndisc_set_mac(link->ndisc_router_discovery, &link->mac);
if (r < 0)
return r;
r = sd_ndisc_set_index(link->ndisc_router_discovery, link->ifindex);
if (r < 0)
return r;
r = sd_ndisc_set_callback(link->ndisc_router_discovery,
ndisc_router_handler,
NULL,
NULL,
ndisc_handler,
link);
return r;
}