LXR linux/net/ipv6/inet6_connection

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * INET        An implementation of the TCP/IP protocol suite for the LINUX
   4 *             operating system.  INET is implemented using the  BSD Socket
   5 *             interface as the means of communication with the user level.
   6 *
   7 *             Support for INET6 connection oriented protocols.
   8 *
   9 * Authors:    See the TCPv6 sources
  10 */
  11
  12#include <linux/module.h>
  13#include <linux/in6.h>
  14#include <linux/ipv6.h>
  15#include <linux/jhash.h>
  16#include <linux/slab.h>
  17
  18#include <net/addrconf.h>
  19#include <net/inet_connection_sock.h>
  20#include <net/inet_ecn.h>
  21#include <net/inet_hashtables.h>
  22#include <net/ip6_route.h>
  23#include <net/sock.h>
  24#include <net/inet6_connection_sock.h>
  25#include <net/sock_reuseport.h>
  26
  27struct dst_entry *inet6_csk_route_req(const struct sock *sk,
  28                                      struct flowi6 *fl6,
  29                                      const struct request_sock *req,
  30                                      u8 proto)
  31{
  32        struct inet_request_sock *ireq = inet_rsk(req);
  33        const struct ipv6_pinfo *np = inet6_sk(sk);
  34        struct in6_addr *final_p, final;
  35        struct dst_entry *dst;
  36
  37        memset(fl6, 0, sizeof(*fl6));
  38        fl6->flowi6_proto = proto;
  39        fl6->daddr = ireq->ir_v6_rmt_addr;
  40        rcu_read_lock();
  41        final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
  42        rcu_read_unlock();
  43        fl6->saddr = ireq->ir_v6_loc_addr;
  44        fl6->flowi6_oif = ireq->ir_iif;
  45        fl6->flowi6_mark = ireq->ir_mark;
  46        fl6->fl6_dport = ireq->ir_rmt_port;
  47        fl6->fl6_sport = htons(ireq->ir_num);
  48        fl6->flowi6_uid = sk->sk_uid;
  49        security_req_classify_flow(req, flowi6_to_flowi_common(fl6));
  50
  51        dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
  52        if (IS_ERR(dst))
  53                return NULL;
  54
  55        return dst;
  56}
  57EXPORT_SYMBOL(inet6_csk_route_req);
  58
  59void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
  60{
  61        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
  62
  63        sin6->sin6_family = AF_INET6;
  64        sin6->sin6_addr = sk->sk_v6_daddr;
  65        sin6->sin6_port = inet_sk(sk)->inet_dport;
  66        /* We do not store received flowlabel for TCP */
  67        sin6->sin6_flowinfo = 0;
  68        sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,
  69                                                  sk->sk_bound_dev_if);
  70}
  71EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
  72
  73static inline
  74struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
  75{
  76        return __sk_dst_check(sk, cookie);
  77}
  78
  79static struct dst_entry *inet6_csk_route_socket(struct sock *sk,
  80                                                struct flowi6 *fl6)
  81{
  82        struct inet_sock *inet = inet_sk(sk);
  83        struct ipv6_pinfo *np = inet6_sk(sk);
  84        struct in6_addr *final_p, final;
  85        struct dst_entry *dst;
  86
  87        memset(fl6, 0, sizeof(*fl6));
  88        fl6->flowi6_proto = sk->sk_protocol;
  89        fl6->daddr = sk->sk_v6_daddr;
  90        fl6->saddr = np->saddr;
  91        fl6->flowlabel = np->flow_label;
  92        IP6_ECN_flow_xmit(sk, fl6->flowlabel);
  93        fl6->flowi6_oif = sk->sk_bound_dev_if;
  94        fl6->flowi6_mark = sk->sk_mark;
  95        fl6->fl6_sport = inet->inet_sport;
  96        fl6->fl6_dport = inet->inet_dport;
  97        fl6->flowi6_uid = sk->sk_uid;
  98        security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
  99
 100        rcu_read_lock();
 101        final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 102        rcu_read_unlock();
 103
 104        dst = __inet6_csk_dst_check(sk, np->dst_cookie);
 105        if (!dst) {
 106                dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
 107
 108                if (!IS_ERR(dst))
 109                        ip6_dst_store(sk, dst, NULL, NULL);
 110        }
 111        return dst;
 112}
 113
 114int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl_unused)
 115{
 116        struct ipv6_pinfo *np = inet6_sk(sk);
 117        struct flowi6 fl6;
 118        struct dst_entry *dst;
 119        int res;
 120
 121        dst = inet6_csk_route_socket(sk, &fl6);
 122        if (IS_ERR(dst)) {
 123                sk->sk_err_soft = -PTR_ERR(dst);
 124                sk->sk_route_caps = 0;
 125                kfree_skb(skb);
 126                return PTR_ERR(dst);
 127        }
 128
 129        rcu_read_lock();
 130        skb_dst_set_noref(skb, dst);
 131
 132        /* Restore final destination back after routing done */
 133        fl6.daddr = sk->sk_v6_daddr;
 134
 135        res = ip6_xmit(sk, skb, &fl6, sk->sk_mark, rcu_dereference(np->opt),
 136                       np->tclass,  sk->sk_priority);
 137        rcu_read_unlock();
 138        return res;
 139}
 140EXPORT_SYMBOL_GPL(inet6_csk_xmit);
 141
 142struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu)
 143{
 144        struct flowi6 fl6;
 145        struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6);
 146
 147        if (IS_ERR(dst))
 148                return NULL;
 149        dst->ops->update_pmtu(dst, sk, NULL, mtu, true);
 150
 151        dst = inet6_csk_route_socket(sk, &fl6);
 152        return IS_ERR(dst) ? NULL : dst;
 153}
 154EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu);
 155