linux/include/net/inet_sock.h
Eric Dumazet abc17a11ed inet: preserve const qualifier in inet_sk()
We can change inet_sk() to propagate const qualifier of its argument.

This should avoid some potential errors caused by accidental
(const -> not_const) promotion.

Other helpers like tcp_sk(), udp_sk(), raw_sk() will be handled
in separate patch series.

v2: use container_of_const() as advised by Jakub and Linus

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/netdev/20230315142841.3a2ac99a@kernel.org/
Link: https://lore.kernel.org/netdev/CAHk-=wiOf12nrYEF2vJMcucKjWPN-Ns_SW9fA7LwST_2Dzp7rw@mail.gmail.com/
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-03-17 08:56:37 +00:00

407 lines
10 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* 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 inet_sock
*
* Authors: Many, reorganised here by
* Arnaldo Carvalho de Melo <acme@mandriva.com>
*/
#ifndef _INET_SOCK_H
#define _INET_SOCK_H
#include <linux/bitops.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/jhash.h>
#include <linux/netdevice.h>
#include <net/flow.h>
#include <net/sock.h>
#include <net/request_sock.h>
#include <net/netns/hash.h>
#include <net/tcp_states.h>
#include <net/l3mdev.h>
/** struct ip_options - IP Options
*
* @faddr - Saved first hop address
* @nexthop - Saved nexthop address in LSRR and SSRR
* @is_strictroute - Strict source route
* @srr_is_hit - Packet destination addr was our one
* @is_changed - IP checksum more not valid
* @rr_needaddr - Need to record addr of outgoing dev
* @ts_needtime - Need to record timestamp
* @ts_needaddr - Need to record addr of outgoing dev
*/
struct ip_options {
__be32 faddr;
__be32 nexthop;
unsigned char optlen;
unsigned char srr;
unsigned char rr;
unsigned char ts;
unsigned char is_strictroute:1,
srr_is_hit:1,
is_changed:1,
rr_needaddr:1,
ts_needtime:1,
ts_needaddr:1;
unsigned char router_alert;
unsigned char cipso;
unsigned char __pad2;
unsigned char __data[];
};
struct ip_options_rcu {
struct rcu_head rcu;
struct ip_options opt;
};
struct ip_options_data {
struct ip_options_rcu opt;
char data[40];
};
struct inet_request_sock {
struct request_sock req;
#define ir_loc_addr req.__req_common.skc_rcv_saddr
#define ir_rmt_addr req.__req_common.skc_daddr
#define ir_num req.__req_common.skc_num
#define ir_rmt_port req.__req_common.skc_dport
#define ir_v6_rmt_addr req.__req_common.skc_v6_daddr
#define ir_v6_loc_addr req.__req_common.skc_v6_rcv_saddr
#define ir_iif req.__req_common.skc_bound_dev_if
#define ir_cookie req.__req_common.skc_cookie
#define ireq_net req.__req_common.skc_net
#define ireq_state req.__req_common.skc_state
#define ireq_family req.__req_common.skc_family
u16 snd_wscale : 4,
rcv_wscale : 4,
tstamp_ok : 1,
sack_ok : 1,
wscale_ok : 1,
ecn_ok : 1,
acked : 1,
no_srccheck: 1,
smc_ok : 1;
u32 ir_mark;
union {
struct ip_options_rcu __rcu *ireq_opt;
#if IS_ENABLED(CONFIG_IPV6)
struct {
struct ipv6_txoptions *ipv6_opt;
struct sk_buff *pktopts;
};
#endif
};
};
static inline struct inet_request_sock *inet_rsk(const struct request_sock *sk)
{
return (struct inet_request_sock *)sk;
}
static inline u32 inet_request_mark(const struct sock *sk, struct sk_buff *skb)
{
if (!sk->sk_mark &&
READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fwmark_accept))
return skb->mark;
return sk->sk_mark;
}
static inline int inet_request_bound_dev_if(const struct sock *sk,
struct sk_buff *skb)
{
int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
#ifdef CONFIG_NET_L3_MASTER_DEV
struct net *net = sock_net(sk);
if (!bound_dev_if && READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
return l3mdev_master_ifindex_by_index(net, skb->skb_iif);
#endif
return bound_dev_if;
}
static inline int inet_sk_bound_l3mdev(const struct sock *sk)
{
#ifdef CONFIG_NET_L3_MASTER_DEV
struct net *net = sock_net(sk);
if (!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept))
return l3mdev_master_ifindex_by_index(net,
sk->sk_bound_dev_if);
#endif
return 0;
}
static inline bool inet_bound_dev_eq(bool l3mdev_accept, int bound_dev_if,
int dif, int sdif)
{
if (!bound_dev_if)
return !sdif || l3mdev_accept;
return bound_dev_if == dif || bound_dev_if == sdif;
}
static inline bool inet_sk_bound_dev_eq(struct net *net, int bound_dev_if,
int dif, int sdif)
{
#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
return inet_bound_dev_eq(!!READ_ONCE(net->ipv4.sysctl_tcp_l3mdev_accept),
bound_dev_if, dif, sdif);
#else
return inet_bound_dev_eq(true, bound_dev_if, dif, sdif);
#endif
}
struct inet_cork {
unsigned int flags;
__be32 addr;
struct ip_options *opt;
unsigned int fragsize;
int length; /* Total length of all frames */
struct dst_entry *dst;
u8 tx_flags;
__u8 ttl;
__s16 tos;
char priority;
__u16 gso_size;
u64 transmit_time;
u32 mark;
};
struct inet_cork_full {
struct inet_cork base;
struct flowi fl;
};
struct ip_mc_socklist;
struct ipv6_pinfo;
struct rtable;
/** struct inet_sock - representation of INET sockets
*
* @sk - ancestor class
* @pinet6 - pointer to IPv6 control block
* @inet_daddr - Foreign IPv4 addr
* @inet_rcv_saddr - Bound local IPv4 addr
* @inet_dport - Destination port
* @inet_num - Local port
* @inet_saddr - Sending source
* @uc_ttl - Unicast TTL
* @inet_sport - Source port
* @inet_id - ID counter for DF pkts
* @tos - TOS
* @mc_ttl - Multicasting TTL
* @is_icsk - is this an inet_connection_sock?
* @uc_index - Unicast outgoing device index
* @mc_index - Multicast device index
* @mc_list - Group array
* @cork - info to build ip hdr on each ip frag while socket is corked
*/
struct inet_sock {
/* sk and pinet6 has to be the first two members of inet_sock */
struct sock sk;
#if IS_ENABLED(CONFIG_IPV6)
struct ipv6_pinfo *pinet6;
#endif
/* Socket demultiplex comparisons on incoming packets. */
#define inet_daddr sk.__sk_common.skc_daddr
#define inet_rcv_saddr sk.__sk_common.skc_rcv_saddr
#define inet_dport sk.__sk_common.skc_dport
#define inet_num sk.__sk_common.skc_num
__be32 inet_saddr;
__s16 uc_ttl;
__u16 cmsg_flags;
struct ip_options_rcu __rcu *inet_opt;
__be16 inet_sport;
__u16 inet_id;
__u8 tos;
__u8 min_ttl;
__u8 mc_ttl;
__u8 pmtudisc;
__u8 recverr:1,
is_icsk:1,
freebind:1,
hdrincl:1,
mc_loop:1,
transparent:1,
mc_all:1,
nodefrag:1;
__u8 bind_address_no_port:1,
recverr_rfc4884:1,
defer_connect:1; /* Indicates that fastopen_connect is set
* and cookie exists so we defer connect
* until first data frame is written
*/
__u8 rcv_tos;
__u8 convert_csum;
int uc_index;
int mc_index;
__be32 mc_addr;
struct ip_mc_socklist __rcu *mc_list;
struct inet_cork_full cork;
struct {
__u16 lo;
__u16 hi;
} local_port_range;
};
#define IPCORK_OPT 1 /* ip-options has been held in ipcork.opt */
#define IPCORK_ALLFRAG 2 /* always fragment (for ipv6 for now) */
/* cmsg flags for inet */
#define IP_CMSG_PKTINFO BIT(0)
#define IP_CMSG_TTL BIT(1)
#define IP_CMSG_TOS BIT(2)
#define IP_CMSG_RECVOPTS BIT(3)
#define IP_CMSG_RETOPTS BIT(4)
#define IP_CMSG_PASSSEC BIT(5)
#define IP_CMSG_ORIGDSTADDR BIT(6)
#define IP_CMSG_CHECKSUM BIT(7)
#define IP_CMSG_RECVFRAGSIZE BIT(8)
static inline bool sk_is_inet(struct sock *sk)
{
return sk->sk_family == AF_INET || sk->sk_family == AF_INET6;
}
/**
* sk_to_full_sk - Access to a full socket
* @sk: pointer to a socket
*
* SYNACK messages might be attached to request sockets.
* Some places want to reach the listener in this case.
*/
static inline struct sock *sk_to_full_sk(struct sock *sk)
{
#ifdef CONFIG_INET
if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
sk = inet_reqsk(sk)->rsk_listener;
#endif
return sk;
}
/* sk_to_full_sk() variant with a const argument */
static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)
{
#ifdef CONFIG_INET
if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
sk = ((const struct request_sock *)sk)->rsk_listener;
#endif
return sk;
}
static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
{
return sk_to_full_sk(skb->sk);
}
#define inet_sk(ptr) container_of_const(ptr, struct inet_sock, sk)
static inline void __inet_sk_copy_descendant(struct sock *sk_to,
const struct sock *sk_from,
const int ancestor_size)
{
memcpy(inet_sk(sk_to) + 1, inet_sk(sk_from) + 1,
sk_from->sk_prot->obj_size - ancestor_size);
}
int inet_sk_rebuild_header(struct sock *sk);
/**
* inet_sk_state_load - read sk->sk_state for lockless contexts
* @sk: socket pointer
*
* Paired with inet_sk_state_store(). Used in places we don't hold socket lock:
* tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
*/
static inline int inet_sk_state_load(const struct sock *sk)
{
/* state change might impact lockless readers. */
return smp_load_acquire(&sk->sk_state);
}
/**
* inet_sk_state_store - update sk->sk_state
* @sk: socket pointer
* @newstate: new state
*
* Paired with inet_sk_state_load(). Should be used in contexts where
* state change might impact lockless readers.
*/
void inet_sk_state_store(struct sock *sk, int newstate);
void inet_sk_set_state(struct sock *sk, int state);
static inline unsigned int __inet_ehashfn(const __be32 laddr,
const __u16 lport,
const __be32 faddr,
const __be16 fport,
u32 initval)
{
return jhash_3words((__force __u32) laddr,
(__force __u32) faddr,
((__u32) lport) << 16 | (__force __u32)fport,
initval);
}
struct request_sock *inet_reqsk_alloc(const struct request_sock_ops *ops,
struct sock *sk_listener,
bool attach_listener);
static inline __u8 inet_sk_flowi_flags(const struct sock *sk)
{
__u8 flags = 0;
if (inet_sk(sk)->transparent || inet_sk(sk)->hdrincl)
flags |= FLOWI_FLAG_ANYSRC;
return flags;
}
static inline void inet_inc_convert_csum(struct sock *sk)
{
inet_sk(sk)->convert_csum++;
}
static inline void inet_dec_convert_csum(struct sock *sk)
{
if (inet_sk(sk)->convert_csum > 0)
inet_sk(sk)->convert_csum--;
}
static inline bool inet_get_convert_csum(struct sock *sk)
{
return !!inet_sk(sk)->convert_csum;
}
static inline bool inet_can_nonlocal_bind(struct net *net,
struct inet_sock *inet)
{
return READ_ONCE(net->ipv4.sysctl_ip_nonlocal_bind) ||
inet->freebind || inet->transparent;
}
static inline bool inet_addr_valid_or_nonlocal(struct net *net,
struct inet_sock *inet,
__be32 addr,
int addr_type)
{
return inet_can_nonlocal_bind(net, inet) ||
addr == htonl(INADDR_ANY) ||
addr_type == RTN_LOCAL ||
addr_type == RTN_MULTICAST ||
addr_type == RTN_BROADCAST;
}
#endif /* _INET_SOCK_H */