kernel-fxtec-pro1x/include/net/ip.h
Maciej Żenczykowski 9db62b7591 net/ipv4: always honour route mtu during forwarding
[ Upstream commit 02a1b175b0e92d9e0fa5df3957ade8d733ceb6a0 ]

Documentation/networking/ip-sysctl.txt:46 says:
  ip_forward_use_pmtu - BOOLEAN
    By default we don't trust protocol path MTUs while forwarding
    because they could be easily forged and can lead to unwanted
    fragmentation by the router.
    You only need to enable this if you have user-space software
    which tries to discover path mtus by itself and depends on the
    kernel honoring this information. This is normally not the case.
    Default: 0 (disabled)
    Possible values:
    0 - disabled
    1 - enabled

Which makes it pretty clear that setting it to 1 is a potential
security/safety/DoS issue, and yet it is entirely reasonable to want
forwarded traffic to honour explicitly administrator configured
route mtus (instead of defaulting to device mtu).

Indeed, I can't think of a single reason why you wouldn't want to.
Since you configured a route mtu you probably know better...

It is pretty common to have a higher device mtu to allow receiving
large (jumbo) frames, while having some routes via that interface
(potentially including the default route to the internet) specify
a lower mtu.

Note that ipv6 forwarding uses device mtu unless the route is locked
(in which case it will use the route mtu).

This approach is not usable for IPv4 where an 'mtu lock' on a route
also has the side effect of disabling TCP path mtu discovery via
disabling the IPv4 DF (don't frag) bit on all outgoing frames.

I'm not aware of a way to lock a route from an IPv6 RA, so that also
potentially seems wrong.

Signed-off-by: Maciej Żenczykowski <maze@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: Sunmeet Gill (Sunny) <sgill@quicinc.com>
Cc: Vinay Paradkar <vparadka@qti.qualcomm.com>
Cc: Tyler Wear <twear@quicinc.com>
Cc: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-29 09:54:56 +01:00

706 lines
20 KiB
C

/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Definitions for the IP module.
*
* Version: @(#)ip.h 1.0.2 05/07/93
*
* Authors: Ross Biro
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
* Alan Cox, <gw4pts@gw4pts.ampr.org>
*
* Changes:
* Mike McLagan : Routing by source
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _IP_H
#define _IP_H
#include <linux/types.h>
#include <linux/ip.h>
#include <linux/in.h>
#include <linux/skbuff.h>
#include <linux/jhash.h>
#include <net/inet_sock.h>
#include <net/route.h>
#include <net/snmp.h>
#include <net/flow.h>
#include <net/flow_dissector.h>
#include <net/netns/hash.h>
#define IPV4_MAX_PMTU 65535U /* RFC 2675, Section 5.1 */
#define IPV4_MIN_MTU 68 /* RFC 791 */
struct sock;
struct inet_skb_parm {
int iif;
struct ip_options opt; /* Compiled IP options */
u16 flags;
#define IPSKB_FORWARDED BIT(0)
#define IPSKB_XFRM_TUNNEL_SIZE BIT(1)
#define IPSKB_XFRM_TRANSFORMED BIT(2)
#define IPSKB_FRAG_COMPLETE BIT(3)
#define IPSKB_REROUTED BIT(4)
#define IPSKB_DOREDIRECT BIT(5)
#define IPSKB_FRAG_PMTU BIT(6)
#define IPSKB_L3SLAVE BIT(7)
u16 frag_max_size;
};
static inline bool ipv4_l3mdev_skb(u16 flags)
{
return !!(flags & IPSKB_L3SLAVE);
}
static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
{
return ip_hdr(skb)->ihl * 4;
}
struct ipcm_cookie {
struct sockcm_cookie sockc;
__be32 addr;
int oif;
struct ip_options_rcu *opt;
__u8 ttl;
__s16 tos;
char priority;
__u16 gso_size;
};
static inline void ipcm_init(struct ipcm_cookie *ipcm)
{
*ipcm = (struct ipcm_cookie) { .tos = -1 };
}
static inline void ipcm_init_sk(struct ipcm_cookie *ipcm,
const struct inet_sock *inet)
{
ipcm_init(ipcm);
ipcm->sockc.tsflags = inet->sk.sk_tsflags;
ipcm->oif = inet->sk.sk_bound_dev_if;
ipcm->addr = inet->inet_saddr;
}
#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
#define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
/* return enslaved device index if relevant */
static inline int inet_sdif(struct sk_buff *skb)
{
#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
return IPCB(skb)->iif;
#endif
return 0;
}
/* Special input handler for packets caught by router alert option.
They are selected only by protocol field, and then processed likely
local ones; but only if someone wants them! Otherwise, router
not running rsvpd will kill RSVP.
It is user level problem, what it will make with them.
I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
but receiver should be enough clever f.e. to forward mtrace requests,
sent to multicast group to reach destination designated router.
*/
struct ip_ra_chain {
struct ip_ra_chain __rcu *next;
struct sock *sk;
union {
void (*destructor)(struct sock *);
struct sock *saved_sk;
};
struct rcu_head rcu;
};
/* IP flags. */
#define IP_CE 0x8000 /* Flag: "Congestion" */
#define IP_DF 0x4000 /* Flag: "Don't Fragment" */
#define IP_MF 0x2000 /* Flag: "More Fragments" */
#define IP_OFFSET 0x1FFF /* "Fragment Offset" part */
#define IP_FRAG_TIME (30 * HZ) /* fragment lifetime */
struct msghdr;
struct net_device;
struct packet_type;
struct rtable;
struct sockaddr;
int igmp_mc_init(void);
/*
* Functions provided by ip.c
*/
int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
__be32 saddr, __be32 daddr,
struct ip_options_rcu *opt);
int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
struct net_device *orig_dev);
void ip_list_rcv(struct list_head *head, struct packet_type *pt,
struct net_device *orig_dev);
int ip_local_deliver(struct sk_buff *skb);
int ip_mr_input(struct sk_buff *skb);
int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
int (*output)(struct net *, struct sock *, struct sk_buff *));
void ip_send_check(struct iphdr *ip);
int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
__u8 tos);
void ip_init(void);
int ip_append_data(struct sock *sk, struct flowi4 *fl4,
int getfrag(void *from, char *to, int offset, int len,
int odd, struct sk_buff *skb),
void *from, int len, int protolen,
struct ipcm_cookie *ipc,
struct rtable **rt,
unsigned int flags);
int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
struct sk_buff *skb);
ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
int offset, size_t size, int flags);
struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
struct sk_buff_head *queue,
struct inet_cork *cork);
int ip_send_skb(struct net *net, struct sk_buff *skb);
int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
void ip_flush_pending_frames(struct sock *sk);
struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
int getfrag(void *from, char *to, int offset,
int len, int odd, struct sk_buff *skb),
void *from, int length, int transhdrlen,
struct ipcm_cookie *ipc, struct rtable **rtp,
struct inet_cork *cork, unsigned int flags);
static inline int ip_queue_xmit(struct sock *sk, struct sk_buff *skb,
struct flowi *fl)
{
return __ip_queue_xmit(sk, skb, fl, inet_sk(sk)->tos);
}
static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
{
return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
}
static inline __u8 get_rttos(struct ipcm_cookie* ipc, struct inet_sock *inet)
{
return (ipc->tos != -1) ? RT_TOS(ipc->tos) : RT_TOS(inet->tos);
}
static inline __u8 get_rtconn_flags(struct ipcm_cookie* ipc, struct sock* sk)
{
return (ipc->tos != -1) ? RT_CONN_FLAGS_TOS(sk, ipc->tos) : RT_CONN_FLAGS(sk);
}
/* datagram.c */
int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
void ip4_datagram_release_cb(struct sock *sk);
struct ip_reply_arg {
struct kvec iov[1];
int flags;
__wsum csum;
int csumoffset; /* u16 offset of csum in iov[0].iov_base */
/* -1 if not needed */
int bound_dev_if;
u8 tos;
kuid_t uid;
};
#define IP_REPLY_ARG_NOSRCCHECK 1
static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
{
return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
}
void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
const struct ip_options *sopt,
__be32 daddr, __be32 saddr,
const struct ip_reply_arg *arg,
unsigned int len);
#define IP_INC_STATS(net, field) SNMP_INC_STATS64((net)->mib.ip_statistics, field)
#define __IP_INC_STATS(net, field) __SNMP_INC_STATS64((net)->mib.ip_statistics, field)
#define IP_ADD_STATS(net, field, val) SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
#define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
#define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
#define NET_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.net_statistics, field)
#define __NET_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.net_statistics, field)
#define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
#define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offct);
unsigned long snmp_fold_field(void __percpu *mib, int offt);
#if BITS_PER_LONG==32
u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
size_t syncp_offset);
u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
#else
static inline u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
size_t syncp_offset)
{
return snmp_get_cpu_field(mib, cpu, offct);
}
static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
{
return snmp_fold_field(mib, offt);
}
#endif
#define snmp_get_cpu_field64_batch(buff64, stats_list, mib_statistic, offset) \
{ \
int i, c; \
for_each_possible_cpu(c) { \
for (i = 0; stats_list[i].name; i++) \
buff64[i] += snmp_get_cpu_field64( \
mib_statistic, \
c, stats_list[i].entry, \
offset); \
} \
}
#define snmp_get_cpu_field_batch(buff, stats_list, mib_statistic) \
{ \
int i, c; \
for_each_possible_cpu(c) { \
for (i = 0; stats_list[i].name; i++) \
buff[i] += snmp_get_cpu_field( \
mib_statistic, \
c, stats_list[i].entry); \
} \
}
void inet_get_local_port_range(struct net *net, int *low, int *high);
#ifdef CONFIG_SYSCTL
static inline int inet_is_local_reserved_port(struct net *net, int port)
{
if (!net->ipv4.sysctl_local_reserved_ports)
return 0;
return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
}
static inline bool sysctl_dev_name_is_allowed(const char *name)
{
return strcmp(name, "default") != 0 && strcmp(name, "all") != 0;
}
static inline int inet_prot_sock(struct net *net)
{
return net->ipv4.sysctl_ip_prot_sock;
}
#else
static inline int inet_is_local_reserved_port(struct net *net, int port)
{
return 0;
}
static inline int inet_prot_sock(struct net *net)
{
return PROT_SOCK;
}
#endif
__be32 inet_current_timestamp(void);
/* From inetpeer.c */
extern int inet_peer_threshold;
extern int inet_peer_minttl;
extern int inet_peer_maxttl;
void ipfrag_init(void);
void ip_static_sysctl_init(void);
#define IP4_REPLY_MARK(net, mark) \
((net)->ipv4.sysctl_fwmark_reflect ? (mark) : 0)
static inline bool ip_is_fragment(const struct iphdr *iph)
{
return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
}
#ifdef CONFIG_INET
#include <net/dst.h>
/* The function in 2.2 was invalid, producing wrong result for
* check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
static inline
int ip_decrease_ttl(struct iphdr *iph)
{
u32 check = (__force u32)iph->check;
check += (__force u32)htons(0x0100);
iph->check = (__force __sum16)(check + (check>=0xFFFF));
return --iph->ttl;
}
static inline int ip_mtu_locked(const struct dst_entry *dst)
{
const struct rtable *rt = (const struct rtable *)dst;
return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU);
}
static inline
int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
{
u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
return pmtudisc == IP_PMTUDISC_DO ||
(pmtudisc == IP_PMTUDISC_WANT &&
!ip_mtu_locked(dst));
}
static inline bool ip_sk_accept_pmtu(const struct sock *sk)
{
return inet_sk(sk)->pmtudisc != IP_PMTUDISC_INTERFACE &&
inet_sk(sk)->pmtudisc != IP_PMTUDISC_OMIT;
}
static inline bool ip_sk_use_pmtu(const struct sock *sk)
{
return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
}
static inline bool ip_sk_ignore_df(const struct sock *sk)
{
return inet_sk(sk)->pmtudisc < IP_PMTUDISC_DO ||
inet_sk(sk)->pmtudisc == IP_PMTUDISC_OMIT;
}
static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
bool forwarding)
{
struct net *net = dev_net(dst->dev);
unsigned int mtu;
if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
ip_mtu_locked(dst) ||
!forwarding)
return dst_mtu(dst);
/* 'forwarding = true' case should always honour route mtu */
mtu = dst_metric_raw(dst, RTAX_MTU);
if (mtu)
return mtu;
return min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
}
static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
const struct sk_buff *skb)
{
if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
}
return min(READ_ONCE(skb_dst(skb)->dev->mtu), IP_MAX_MTU);
}
int ip_metrics_convert(struct net *net, struct nlattr *fc_mx, int fc_mx_len,
u32 *metrics);
u32 ip_idents_reserve(u32 hash, int segs);
void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
struct sock *sk, int segs)
{
struct iphdr *iph = ip_hdr(skb);
if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
/* This is only to work around buggy Windows95/2000
* VJ compression implementations. If the ID field
* does not change, they drop every other packet in
* a TCP stream using header compression.
*/
if (sk && inet_sk(sk)->inet_daddr) {
iph->id = htons(inet_sk(sk)->inet_id);
inet_sk(sk)->inet_id += segs;
} else {
iph->id = 0;
}
} else {
__ip_select_ident(net, iph, segs);
}
}
static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
struct sock *sk)
{
ip_select_ident_segs(net, skb, sk, 1);
}
static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
{
return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
skb->len, proto, 0);
}
/* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
* Equivalent to : flow->v4addrs.src = iph->saddr;
* flow->v4addrs.dst = iph->daddr;
*/
static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
const struct iphdr *iph)
{
BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
offsetof(typeof(flow->addrs), v4addrs.src) +
sizeof(flow->addrs.v4addrs.src));
memcpy(&flow->addrs.v4addrs, &iph->saddr, sizeof(flow->addrs.v4addrs));
flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
}
static inline __wsum inet_gro_compute_pseudo(struct sk_buff *skb, int proto)
{
const struct iphdr *iph = skb_gro_network_header(skb);
return csum_tcpudp_nofold(iph->saddr, iph->daddr,
skb_gro_len(skb), proto, 0);
}
/*
* Map a multicast IP onto multicast MAC for type ethernet.
*/
static inline void ip_eth_mc_map(__be32 naddr, char *buf)
{
__u32 addr=ntohl(naddr);
buf[0]=0x01;
buf[1]=0x00;
buf[2]=0x5e;
buf[5]=addr&0xFF;
addr>>=8;
buf[4]=addr&0xFF;
addr>>=8;
buf[3]=addr&0x7F;
}
/*
* Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
* Leave P_Key as 0 to be filled in by driver.
*/
static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
{
__u32 addr;
unsigned char scope = broadcast[5] & 0xF;
buf[0] = 0; /* Reserved */
buf[1] = 0xff; /* Multicast QPN */
buf[2] = 0xff;
buf[3] = 0xff;
addr = ntohl(naddr);
buf[4] = 0xff;
buf[5] = 0x10 | scope; /* scope from broadcast address */
buf[6] = 0x40; /* IPv4 signature */
buf[7] = 0x1b;
buf[8] = broadcast[8]; /* P_Key */
buf[9] = broadcast[9];
buf[10] = 0;
buf[11] = 0;
buf[12] = 0;
buf[13] = 0;
buf[14] = 0;
buf[15] = 0;
buf[19] = addr & 0xff;
addr >>= 8;
buf[18] = addr & 0xff;
addr >>= 8;
buf[17] = addr & 0xff;
addr >>= 8;
buf[16] = addr & 0x0f;
}
static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
{
if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
memcpy(buf, broadcast, 4);
else
memcpy(buf, &naddr, sizeof(naddr));
}
#if IS_ENABLED(CONFIG_IPV6)
#include <linux/ipv6.h>
#endif
static __inline__ void inet_reset_saddr(struct sock *sk)
{
inet_sk(sk)->inet_rcv_saddr = inet_sk(sk)->inet_saddr = 0;
#if IS_ENABLED(CONFIG_IPV6)
if (sk->sk_family == PF_INET6) {
struct ipv6_pinfo *np = inet6_sk(sk);
memset(&np->saddr, 0, sizeof(np->saddr));
memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
}
#endif
}
#endif
static inline unsigned int ipv4_addr_hash(__be32 ip)
{
return (__force unsigned int) ip;
}
static inline u32 ipv4_portaddr_hash(const struct net *net,
__be32 saddr,
unsigned int port)
{
return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
}
bool ip_call_ra_chain(struct sk_buff *skb);
/*
* Functions provided by ip_fragment.c
*/
enum ip_defrag_users {
IP_DEFRAG_LOCAL_DELIVER,
IP_DEFRAG_CALL_RA_CHAIN,
IP_DEFRAG_CONNTRACK_IN,
__IP_DEFRAG_CONNTRACK_IN_END = IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
IP_DEFRAG_CONNTRACK_OUT,
__IP_DEFRAG_CONNTRACK_OUT_END = IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
IP_DEFRAG_CONNTRACK_BRIDGE_IN,
__IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
IP_DEFRAG_VS_IN,
IP_DEFRAG_VS_OUT,
IP_DEFRAG_VS_FWD,
IP_DEFRAG_AF_PACKET,
IP_DEFRAG_MACVLAN,
};
/* Return true if the value of 'user' is between 'lower_bond'
* and 'upper_bond' inclusively.
*/
static inline bool ip_defrag_user_in_between(u32 user,
enum ip_defrag_users lower_bond,
enum ip_defrag_users upper_bond)
{
return user >= lower_bond && user <= upper_bond;
}
int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
#ifdef CONFIG_INET
struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
#else
static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
{
return skb;
}
#endif
/*
* Functions provided by ip_forward.c
*/
int ip_forward(struct sk_buff *skb);
/*
* Functions provided by ip_options.c
*/
void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
__be32 daddr, struct rtable *rt, int is_frag);
int __ip_options_echo(struct net *net, struct ip_options *dopt,
struct sk_buff *skb, const struct ip_options *sopt);
static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
struct sk_buff *skb)
{
return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
}
void ip_options_fragment(struct sk_buff *skb);
int __ip_options_compile(struct net *net, struct ip_options *opt,
struct sk_buff *skb, __be32 *info);
int ip_options_compile(struct net *net, struct ip_options *opt,
struct sk_buff *skb);
int ip_options_get(struct net *net, struct ip_options_rcu **optp,
unsigned char *data, int optlen);
int ip_options_get_from_user(struct net *net, struct ip_options_rcu **optp,
unsigned char __user *data, int optlen);
void ip_options_undo(struct ip_options *opt);
void ip_forward_options(struct sk_buff *skb);
int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev);
/*
* Functions provided by ip_sockglue.c
*/
void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb);
void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
struct sk_buff *skb, int tlen, int offset);
int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
struct ipcm_cookie *ipc, bool allow_ipv6);
int ip_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
unsigned int optlen);
int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
int __user *optlen);
int compat_ip_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, unsigned int optlen);
int compat_ip_getsockopt(struct sock *sk, int level, int optname,
char __user *optval, int __user *optlen);
int ip_ra_control(struct sock *sk, unsigned char on,
void (*destructor)(struct sock *));
int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len);
void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
u32 info, u8 *payload);
void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
u32 info);
static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
{
ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
}
bool icmp_global_allow(void);
extern int sysctl_icmp_msgs_per_sec;
extern int sysctl_icmp_msgs_burst;
#ifdef CONFIG_PROC_FS
int ip_misc_proc_init(void);
#endif
int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family,
struct netlink_ext_ack *extack);
static inline bool inetdev_valid_mtu(unsigned int mtu)
{
return likely(mtu >= IPV4_MIN_MTU);
}
#endif /* _IP_H */