net/ipv6/inet6_connection_sock.c

   1 /*
   2  * INET        An implementation of the TCP/IP protocol suite for the LINUX
   3  *             operating system.  INET is implemented using the  BSD Socket
   4  *             interface as the means of communication with the user level.
   5  *
   6  *             Support for INET6 connection oriented protocols.
   7  *
   8  * Authors:    See the TCPv6 sources
   9  *
  10  *             This program is free software; you can redistribute it and/or
  11  *             modify it under the terms of the GNU General Public License
  12  *             as published by the Free Software Foundation; either version
  13  *             2 of the License, or(at your option) any later version.
  14  */
  15
  16 #include <linux/module.h>
  17 #include <linux/in6.h>
  18 #include <linux/ipv6.h>
  19 #include <linux/jhash.h>
  20 #include <linux/slab.h>
  21
  22 #include <net/addrconf.h>
  23 #include <net/inet_connection_sock.h>
  24 #include <net/inet_ecn.h>
  25 #include <net/inet_hashtables.h>
  26 #include <net/ip6_route.h>
  27 #include <net/sock.h>
  28 #include <net/inet6_connection_sock.h>
  29 #include <net/sock_reuseport.h>
  30
  31 struct dst_entry *inet6_csk_route_req(const struct sock *sk,
  32                                       struct flowi6 *fl6,
  33                                       const struct request_sock *req,
  34                                       u8 proto)
  35 {
  36         struct inet_request_sock *ireq = inet_rsk(req);
  37         const struct ipv6_pinfo *np = inet6_sk(sk);
  38         struct in6_addr *final_p, final;
  39         struct dst_entry *dst;
  40
  41         memset(fl6, 0, sizeof(*fl6));
  42         fl6->flowi6_proto = proto;
  43         fl6->daddr = ireq->ir_v6_rmt_addr;
  44         rcu_read_lock();
  45         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
  46         rcu_read_unlock();
  47         fl6->saddr = ireq->ir_v6_loc_addr;
  48         fl6->flowi6_oif = ireq->ir_iif;
  49         fl6->flowi6_mark = ireq->ir_mark;
  50         fl6->fl6_dport = ireq->ir_rmt_port;
  51         fl6->fl6_sport = htons(ireq->ir_num);
  52         fl6->flowi6_uid = sk->sk_uid;
  53         security_req_classify_flow(req, flowi6_to_flowi(fl6));
  54
  55         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
  56         if (IS_ERR(dst))
  57                 return NULL;
  58
  59         return dst;
  60 }
  61 EXPORT_SYMBOL(inet6_csk_route_req);
  62
  63 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
  64 {
  65         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
  66
  67         sin6->sin6_family = AF_INET6;
  68         sin6->sin6_addr = sk->sk_v6_daddr;
  69         sin6->sin6_port = inet_sk(sk)->inet_dport;
  70         /* We do not store received flowlabel for TCP */
  71         sin6->sin6_flowinfo = 0;
  72         sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,
  73                                                   sk->sk_bound_dev_if);
  74 }
  75 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
  76
  77 static inline
  78 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
  79 {
  80         return __sk_dst_check(sk, cookie);
  81 }
  82
  83 static struct dst_entry *inet6_csk_route_socket(struct sock *sk,
  84                                                 struct flowi6 *fl6)
  85 {
  86         struct inet_sock *inet = inet_sk(sk);
  87         struct ipv6_pinfo *np = inet6_sk(sk);
  88         struct in6_addr *final_p, final;
  89         struct dst_entry *dst;
  90
  91         memset(fl6, 0, sizeof(*fl6));
  92         fl6->flowi6_proto = sk->sk_protocol;
  93         fl6->daddr = sk->sk_v6_daddr;
  94         fl6->saddr = np->saddr;
  95         fl6->flowlabel = np->flow_label;
  96         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
  97         fl6->flowi6_oif = sk->sk_bound_dev_if;
  98         fl6->flowi6_mark = sk->sk_mark;
  99         fl6->fl6_sport = inet->inet_sport;
 100         fl6->fl6_dport = inet->inet_dport;
 101         fl6->flowi6_uid = sk->sk_uid;
 102         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
 103
 104         rcu_read_lock();
 105         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 106         rcu_read_unlock();
 107
 108         dst = __inet6_csk_dst_check(sk, np->dst_cookie);
 109         if (!dst) {
 110                 dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 111
 112                 if (!IS_ERR(dst))
 113                         ip6_dst_store(sk, dst, NULL, NULL);
 114         }
 115         return dst;
 116 }
 117
 118 int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl_unused)
 119 {
 120         struct ipv6_pinfo *np = inet6_sk(sk);
 121         struct flowi6 fl6;
 122         struct dst_entry *dst;
 123         int res;
 124
 125         dst = inet6_csk_route_socket(sk, &fl6);
 126         if (IS_ERR(dst)) {
 127                 sk->sk_err_soft = -PTR_ERR(dst);
 128                 sk->sk_route_caps = 0;
 129                 kfree_skb(skb);
 130                 return PTR_ERR(dst);
 131         }
 132
 133         rcu_read_lock();
 134         skb_dst_set_noref(skb, dst);
 135
 136         /* Restore final destination back after routing done */
 137         fl6.daddr = sk->sk_v6_daddr;
 138
 139         res = ip6_xmit(sk, skb, &fl6, sk->sk_mark, rcu_dereference(np->opt),
 140                        np->tclass);
 141         rcu_read_unlock();
 142         return res;
 143 }
 144 EXPORT_SYMBOL_GPL(inet6_csk_xmit);
 145
 146 struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu)
 147 {
 148         struct flowi6 fl6;
 149         struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6);
 150
 151         if (IS_ERR(dst))
 152                 return NULL;
 153         dst->ops->update_pmtu(dst, sk, NULL, mtu);
 154
 155         dst = inet6_csk_route_socket(sk, &fl6);
 156         return IS_ERR(dst) ? NULL : dst;
 157 }
 158 EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu);