mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-29 23:53:32 +00:00
6b2e04bc24
For IPv4, default route is learned via DHCPv4 and user is allowed to change
metric using config etc/network/interfaces. But for IPv6, default route can
be learned via RA, for which, currently a fixed metric value 1024 is used.
Ideally, user should be able to configure metric on default route for IPv6
similar to IPv4. This patch adds sysctl for the same.
Logs:
For IPv4:
Config in etc/network/interfaces:
auto eth0
iface eth0 inet dhcp
metric 4261413864
IPv4 Kernel Route Table:
$ ip route list
default via 172.21.47.1 dev eth0 metric 4261413864
FRR Table, if a static route is configured:
[In real scenario, it is useful to prefer BGP learned default route over DHCPv4 default route.]
Codes: K - kernel route, C - connected, S - static, R - RIP,
O - OSPF, I - IS-IS, B - BGP, P - PIM, E - EIGRP, N - NHRP,
T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
> - selected route, * - FIB route
S>* 0.0.0.0/0 [20/0] is directly connected, eth0, 00:00:03
K 0.0.0.0/0 [254/1000] via 172.21.47.1, eth0, 6d08h51m
i.e. User can prefer Default Router learned via Routing Protocol in IPv4.
Similar behavior is not possible for IPv6, without this fix.
After fix [for IPv6]:
sudo sysctl -w net.ipv6.conf.eth0.net.ipv6.conf.eth0.ra_defrtr_metric=1996489705
IP monitor: [When IPv6 RA is received]
default via fe80::xx16:xxxx:feb3:ce8e dev eth0 proto ra metric 1996489705 pref high
Kernel IPv6 routing table
$ ip -6 route list
default via fe80::be16:65ff:feb3:ce8e dev eth0 proto ra metric 1996489705 expires 21sec hoplimit 64 pref high
FRR Table, if a static route is configured:
[In real scenario, it is useful to prefer BGP learned default route over IPv6 RA default route.]
Codes: K - kernel route, C - connected, S - static, R - RIPng,
O - OSPFv3, I - IS-IS, B - BGP, N - NHRP, T - Table,
v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
> - selected route, * - FIB route
S>* ::/0 [20/0] is directly connected, eth0, 00:00:06
K ::/0 [119/1001] via fe80::xx16:xxxx:feb3:ce8e, eth0, 6d07h43m
If the metric is changed later, the effect will be seen only when next IPv6
RA is received, because the default route must be fully controlled by RA msg.
Below metric is changed from 1996489705 to 1996489704.
$ sudo sysctl -w net.ipv6.conf.eth0.ra_defrtr_metric=1996489704
net.ipv6.conf.eth0.ra_defrtr_metric = 1996489704
IP monitor:
[On next IPv6 RA msg, Kernel deletes prev route and installs new route with updated metric]
Deleted default via fe80::xx16:xxxx:feb3:ce8e dev eth0 proto ra metric 1996489705 expires 3sec hoplimit 64 pref high
default via fe80::xx16:xxxx:feb3:ce8e dev eth0 proto ra metric 1996489704 pref high
Signed-off-by: Praveen Chaudhary <pchaudhary@linkedin.com>
Signed-off-by: Zhenggen Xu <zxu@linkedin.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20210125214430.24079-1-pchaudhary@linkedin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
197 lines
4 KiB
C
197 lines
4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
|
|
#ifndef _UAPI_IPV6_H
|
|
#define _UAPI_IPV6_H
|
|
|
|
#include <linux/libc-compat.h>
|
|
#include <linux/types.h>
|
|
#include <linux/in6.h>
|
|
#include <asm/byteorder.h>
|
|
|
|
/* The latest drafts declared increase in minimal mtu up to 1280. */
|
|
|
|
#define IPV6_MIN_MTU 1280
|
|
|
|
/*
|
|
* Advanced API
|
|
* source interface/address selection, source routing, etc...
|
|
* *under construction*
|
|
*/
|
|
|
|
#if __UAPI_DEF_IN6_PKTINFO
|
|
struct in6_pktinfo {
|
|
struct in6_addr ipi6_addr;
|
|
int ipi6_ifindex;
|
|
};
|
|
#endif
|
|
|
|
#if __UAPI_DEF_IP6_MTUINFO
|
|
struct ip6_mtuinfo {
|
|
struct sockaddr_in6 ip6m_addr;
|
|
__u32 ip6m_mtu;
|
|
};
|
|
#endif
|
|
|
|
struct in6_ifreq {
|
|
struct in6_addr ifr6_addr;
|
|
__u32 ifr6_prefixlen;
|
|
int ifr6_ifindex;
|
|
};
|
|
|
|
#define IPV6_SRCRT_STRICT 0x01 /* Deprecated; will be removed */
|
|
#define IPV6_SRCRT_TYPE_0 0 /* Deprecated; will be removed */
|
|
#define IPV6_SRCRT_TYPE_2 2 /* IPv6 type 2 Routing Header */
|
|
#define IPV6_SRCRT_TYPE_3 3 /* RPL Segment Routing with IPv6 */
|
|
#define IPV6_SRCRT_TYPE_4 4 /* Segment Routing with IPv6 */
|
|
|
|
/*
|
|
* routing header
|
|
*/
|
|
struct ipv6_rt_hdr {
|
|
__u8 nexthdr;
|
|
__u8 hdrlen;
|
|
__u8 type;
|
|
__u8 segments_left;
|
|
|
|
/*
|
|
* type specific data
|
|
* variable length field
|
|
*/
|
|
};
|
|
|
|
|
|
struct ipv6_opt_hdr {
|
|
__u8 nexthdr;
|
|
__u8 hdrlen;
|
|
/*
|
|
* TLV encoded option data follows.
|
|
*/
|
|
} __attribute__((packed)); /* required for some archs */
|
|
|
|
#define ipv6_destopt_hdr ipv6_opt_hdr
|
|
#define ipv6_hopopt_hdr ipv6_opt_hdr
|
|
|
|
/* Router Alert option values (RFC2711) */
|
|
#define IPV6_OPT_ROUTERALERT_MLD 0x0000 /* MLD(RFC2710) */
|
|
|
|
/*
|
|
* routing header type 0 (used in cmsghdr struct)
|
|
*/
|
|
|
|
struct rt0_hdr {
|
|
struct ipv6_rt_hdr rt_hdr;
|
|
__u32 reserved;
|
|
struct in6_addr addr[0];
|
|
|
|
#define rt0_type rt_hdr.type
|
|
};
|
|
|
|
/*
|
|
* routing header type 2
|
|
*/
|
|
|
|
struct rt2_hdr {
|
|
struct ipv6_rt_hdr rt_hdr;
|
|
__u32 reserved;
|
|
struct in6_addr addr;
|
|
|
|
#define rt2_type rt_hdr.type
|
|
};
|
|
|
|
/*
|
|
* home address option in destination options header
|
|
*/
|
|
|
|
struct ipv6_destopt_hao {
|
|
__u8 type;
|
|
__u8 length;
|
|
struct in6_addr addr;
|
|
} __attribute__((packed));
|
|
|
|
/*
|
|
* IPv6 fixed header
|
|
*
|
|
* BEWARE, it is incorrect. The first 4 bits of flow_lbl
|
|
* are glued to priority now, forming "class".
|
|
*/
|
|
|
|
struct ipv6hdr {
|
|
#if defined(__LITTLE_ENDIAN_BITFIELD)
|
|
__u8 priority:4,
|
|
version:4;
|
|
#elif defined(__BIG_ENDIAN_BITFIELD)
|
|
__u8 version:4,
|
|
priority:4;
|
|
#else
|
|
#error "Please fix <asm/byteorder.h>"
|
|
#endif
|
|
__u8 flow_lbl[3];
|
|
|
|
__be16 payload_len;
|
|
__u8 nexthdr;
|
|
__u8 hop_limit;
|
|
|
|
struct in6_addr saddr;
|
|
struct in6_addr daddr;
|
|
};
|
|
|
|
|
|
/* index values for the variables in ipv6_devconf */
|
|
enum {
|
|
DEVCONF_FORWARDING = 0,
|
|
DEVCONF_HOPLIMIT,
|
|
DEVCONF_MTU6,
|
|
DEVCONF_ACCEPT_RA,
|
|
DEVCONF_ACCEPT_REDIRECTS,
|
|
DEVCONF_AUTOCONF,
|
|
DEVCONF_DAD_TRANSMITS,
|
|
DEVCONF_RTR_SOLICITS,
|
|
DEVCONF_RTR_SOLICIT_INTERVAL,
|
|
DEVCONF_RTR_SOLICIT_DELAY,
|
|
DEVCONF_USE_TEMPADDR,
|
|
DEVCONF_TEMP_VALID_LFT,
|
|
DEVCONF_TEMP_PREFERED_LFT,
|
|
DEVCONF_REGEN_MAX_RETRY,
|
|
DEVCONF_MAX_DESYNC_FACTOR,
|
|
DEVCONF_MAX_ADDRESSES,
|
|
DEVCONF_FORCE_MLD_VERSION,
|
|
DEVCONF_ACCEPT_RA_DEFRTR,
|
|
DEVCONF_ACCEPT_RA_PINFO,
|
|
DEVCONF_ACCEPT_RA_RTR_PREF,
|
|
DEVCONF_RTR_PROBE_INTERVAL,
|
|
DEVCONF_ACCEPT_RA_RT_INFO_MAX_PLEN,
|
|
DEVCONF_PROXY_NDP,
|
|
DEVCONF_OPTIMISTIC_DAD,
|
|
DEVCONF_ACCEPT_SOURCE_ROUTE,
|
|
DEVCONF_MC_FORWARDING,
|
|
DEVCONF_DISABLE_IPV6,
|
|
DEVCONF_ACCEPT_DAD,
|
|
DEVCONF_FORCE_TLLAO,
|
|
DEVCONF_NDISC_NOTIFY,
|
|
DEVCONF_MLDV1_UNSOLICITED_REPORT_INTERVAL,
|
|
DEVCONF_MLDV2_UNSOLICITED_REPORT_INTERVAL,
|
|
DEVCONF_SUPPRESS_FRAG_NDISC,
|
|
DEVCONF_ACCEPT_RA_FROM_LOCAL,
|
|
DEVCONF_USE_OPTIMISTIC,
|
|
DEVCONF_ACCEPT_RA_MTU,
|
|
DEVCONF_STABLE_SECRET,
|
|
DEVCONF_USE_OIF_ADDRS_ONLY,
|
|
DEVCONF_ACCEPT_RA_MIN_HOP_LIMIT,
|
|
DEVCONF_IGNORE_ROUTES_WITH_LINKDOWN,
|
|
DEVCONF_DROP_UNICAST_IN_L2_MULTICAST,
|
|
DEVCONF_DROP_UNSOLICITED_NA,
|
|
DEVCONF_KEEP_ADDR_ON_DOWN,
|
|
DEVCONF_RTR_SOLICIT_MAX_INTERVAL,
|
|
DEVCONF_SEG6_ENABLED,
|
|
DEVCONF_SEG6_REQUIRE_HMAC,
|
|
DEVCONF_ENHANCED_DAD,
|
|
DEVCONF_ADDR_GEN_MODE,
|
|
DEVCONF_DISABLE_POLICY,
|
|
DEVCONF_ACCEPT_RA_RT_INFO_MIN_PLEN,
|
|
DEVCONF_NDISC_TCLASS,
|
|
DEVCONF_RPL_SEG_ENABLED,
|
|
DEVCONF_RA_DEFRTR_METRIC,
|
|
DEVCONF_MAX
|
|
};
|
|
|
|
|
|
#endif /* _UAPI_IPV6_H */
|