linux/include/net/if_inet6.h
Rocco Yue 49b99da2c9 ipv6: add IFLA_INET6_RA_MTU to expose mtu value
The kernel provides a "/proc/sys/net/ipv6/conf/<iface>/mtu"
file, which can temporarily record the mtu value of the last
received RA message when the RA mtu value is lower than the
interface mtu, but this proc has following limitations:

(1) when the interface mtu (/sys/class/net/<iface>/mtu) is
updeated, mtu6 (/proc/sys/net/ipv6/conf/<iface>/mtu) will
be updated to the value of interface mtu;
(2) mtu6 (/proc/sys/net/ipv6/conf/<iface>/mtu) only affect
ipv6 connection, and not affect ipv4.

Therefore, when the mtu option is carried in the RA message,
there will be a problem that the user sometimes cannot obtain
RA mtu value correctly by reading mtu6.

After this patch set, if a RA message carries the mtu option,
you can send a netlink msg which nlmsg_type is RTM_GETLINK,
and then by parsing the attribute of IFLA_INET6_RA_MTU to
get the mtu value carried in the RA message received on the
inet6 device. In addition, you can also get a link notification
when ra_mtu is updated so it doesn't have to poll.

In this way, if the MTU values that the device receives from
the network in the PCO IPv4 and the RA IPv6 procedures are
different, the user can obtain the correct ipv6 ra_mtu value
and compare the value of ra_mtu and ipv4 mtu, then the device
can use the lower MTU value for both IPv4 and IPv6.

Signed-off-by: Rocco Yue <rocco.yue@mediatek.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20210827150412.9267-1-rocco.yue@mediatek.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-27 17:29:18 -07:00

270 lines
6.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* inet6 interface/address list definitions
* Linux INET6 implementation
*
* Authors:
* Pedro Roque <roque@di.fc.ul.pt>
*/
#ifndef _NET_IF_INET6_H
#define _NET_IF_INET6_H
#include <net/snmp.h>
#include <linux/ipv6.h>
#include <linux/refcount.h>
/* inet6_dev.if_flags */
#define IF_RA_OTHERCONF 0x80
#define IF_RA_MANAGED 0x40
#define IF_RA_RCVD 0x20
#define IF_RS_SENT 0x10
#define IF_READY 0x80000000
/* prefix flags */
#define IF_PREFIX_ONLINK 0x01
#define IF_PREFIX_AUTOCONF 0x02
enum {
INET6_IFADDR_STATE_PREDAD,
INET6_IFADDR_STATE_DAD,
INET6_IFADDR_STATE_POSTDAD,
INET6_IFADDR_STATE_ERRDAD,
INET6_IFADDR_STATE_DEAD,
};
struct inet6_ifaddr {
struct in6_addr addr;
__u32 prefix_len;
__u32 rt_priority;
/* In seconds, relative to tstamp. Expiry is at tstamp + HZ * lft. */
__u32 valid_lft;
__u32 prefered_lft;
refcount_t refcnt;
spinlock_t lock;
int state;
__u32 flags;
__u8 dad_probes;
__u8 stable_privacy_retry;
__u16 scope;
__u64 dad_nonce;
unsigned long cstamp; /* created timestamp */
unsigned long tstamp; /* updated timestamp */
struct delayed_work dad_work;
struct inet6_dev *idev;
struct fib6_info *rt;
struct hlist_node addr_lst;
struct list_head if_list;
struct list_head tmp_list;
struct inet6_ifaddr *ifpub;
int regen_count;
bool tokenized;
struct rcu_head rcu;
struct in6_addr peer_addr;
};
struct ip6_sf_socklist {
unsigned int sl_max;
unsigned int sl_count;
struct rcu_head rcu;
struct in6_addr sl_addr[];
};
#define IP6_SFBLOCK 10 /* allocate this many at once */
struct ipv6_mc_socklist {
struct in6_addr addr;
int ifindex;
unsigned int sfmode; /* MCAST_{INCLUDE,EXCLUDE} */
struct ipv6_mc_socklist __rcu *next;
struct ip6_sf_socklist __rcu *sflist;
struct rcu_head rcu;
};
struct ip6_sf_list {
struct ip6_sf_list __rcu *sf_next;
struct in6_addr sf_addr;
unsigned long sf_count[2]; /* include/exclude counts */
unsigned char sf_gsresp; /* include in g & s response? */
unsigned char sf_oldin; /* change state */
unsigned char sf_crcount; /* retrans. left to send */
struct rcu_head rcu;
};
#define MAF_TIMER_RUNNING 0x01
#define MAF_LAST_REPORTER 0x02
#define MAF_LOADED 0x04
#define MAF_NOREPORT 0x08
#define MAF_GSQUERY 0x10
struct ifmcaddr6 {
struct in6_addr mca_addr;
struct inet6_dev *idev;
struct ifmcaddr6 __rcu *next;
struct ip6_sf_list __rcu *mca_sources;
struct ip6_sf_list __rcu *mca_tomb;
unsigned int mca_sfmode;
unsigned char mca_crcount;
unsigned long mca_sfcount[2];
struct delayed_work mca_work;
unsigned int mca_flags;
int mca_users;
refcount_t mca_refcnt;
unsigned long mca_cstamp;
unsigned long mca_tstamp;
struct rcu_head rcu;
};
/* Anycast stuff */
struct ipv6_ac_socklist {
struct in6_addr acl_addr;
int acl_ifindex;
struct ipv6_ac_socklist *acl_next;
};
struct ifacaddr6 {
struct in6_addr aca_addr;
struct fib6_info *aca_rt;
struct ifacaddr6 *aca_next;
struct hlist_node aca_addr_lst;
int aca_users;
refcount_t aca_refcnt;
unsigned long aca_cstamp;
unsigned long aca_tstamp;
struct rcu_head rcu;
};
#define IFA_HOST IPV6_ADDR_LOOPBACK
#define IFA_LINK IPV6_ADDR_LINKLOCAL
#define IFA_SITE IPV6_ADDR_SITELOCAL
struct ipv6_devstat {
struct proc_dir_entry *proc_dir_entry;
DEFINE_SNMP_STAT(struct ipstats_mib, ipv6);
DEFINE_SNMP_STAT_ATOMIC(struct icmpv6_mib_device, icmpv6dev);
DEFINE_SNMP_STAT_ATOMIC(struct icmpv6msg_mib_device, icmpv6msgdev);
};
struct inet6_dev {
struct net_device *dev;
struct list_head addr_list;
struct ifmcaddr6 __rcu *mc_list;
struct ifmcaddr6 __rcu *mc_tomb;
unsigned char mc_qrv; /* Query Robustness Variable */
unsigned char mc_gq_running;
unsigned char mc_ifc_count;
unsigned char mc_dad_count;
unsigned long mc_v1_seen; /* Max time we stay in MLDv1 mode */
unsigned long mc_qi; /* Query Interval */
unsigned long mc_qri; /* Query Response Interval */
unsigned long mc_maxdelay;
struct delayed_work mc_gq_work; /* general query work */
struct delayed_work mc_ifc_work; /* interface change work */
struct delayed_work mc_dad_work; /* dad complete mc work */
struct delayed_work mc_query_work; /* mld query work */
struct delayed_work mc_report_work; /* mld report work */
struct sk_buff_head mc_query_queue; /* mld query queue */
struct sk_buff_head mc_report_queue; /* mld report queue */
spinlock_t mc_query_lock; /* mld query queue lock */
spinlock_t mc_report_lock; /* mld query report lock */
struct mutex mc_lock; /* mld global lock */
struct ifacaddr6 *ac_list;
rwlock_t lock;
refcount_t refcnt;
__u32 if_flags;
int dead;
u32 desync_factor;
struct list_head tempaddr_list;
struct in6_addr token;
struct neigh_parms *nd_parms;
struct ipv6_devconf cnf;
struct ipv6_devstat stats;
struct timer_list rs_timer;
__s32 rs_interval; /* in jiffies */
__u8 rs_probes;
unsigned long tstamp; /* ipv6InterfaceTable update timestamp */
struct rcu_head rcu;
unsigned int ra_mtu;
};
static inline void ipv6_eth_mc_map(const struct in6_addr *addr, char *buf)
{
/*
* +-------+-------+-------+-------+-------+-------+
* | 33 | 33 | DST13 | DST14 | DST15 | DST16 |
* +-------+-------+-------+-------+-------+-------+
*/
buf[0]= 0x33;
buf[1]= 0x33;
memcpy(buf + 2, &addr->s6_addr32[3], sizeof(__u32));
}
static inline void ipv6_arcnet_mc_map(const struct in6_addr *addr, char *buf)
{
buf[0] = 0x00;
}
static inline void ipv6_ib_mc_map(const struct in6_addr *addr,
const unsigned char *broadcast, char *buf)
{
unsigned char scope = broadcast[5] & 0xF;
buf[0] = 0; /* Reserved */
buf[1] = 0xff; /* Multicast QPN */
buf[2] = 0xff;
buf[3] = 0xff;
buf[4] = 0xff;
buf[5] = 0x10 | scope; /* scope from broadcast address */
buf[6] = 0x60; /* IPv6 signature */
buf[7] = 0x1b;
buf[8] = broadcast[8]; /* P_Key */
buf[9] = broadcast[9];
memcpy(buf + 10, addr->s6_addr + 6, 10);
}
static inline int ipv6_ipgre_mc_map(const struct in6_addr *addr,
const unsigned char *broadcast, char *buf)
{
if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0) {
memcpy(buf, broadcast, 4);
} else {
/* v4mapped? */
if ((addr->s6_addr32[0] | addr->s6_addr32[1] |
(addr->s6_addr32[2] ^ htonl(0x0000ffff))) != 0)
return -EINVAL;
memcpy(buf, &addr->s6_addr32[3], 4);
}
return 0;
}
#endif