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
  30 int inet6_csk_bind_conflict(const struct sock *sk,
  31                             const struct inet_bind_bucket *tb, bool relax)
  32 {
  33         const struct sock *sk2;
  34         int reuse = sk->sk_reuse;
  35         int reuseport = sk->sk_reuseport;
  36         kuid_t uid = sock_i_uid((struct sock *)sk);
  37
  38         /* We must walk the whole port owner list in this case. -DaveM */
  39         /*
  40          * See comment in inet_csk_bind_conflict about sock lookup
  41          * vs net namespaces issues.
  42          */
  43         sk_for_each_bound(sk2, &tb->owners) {
  44                 if (sk != sk2 &&
  45                     (!sk->sk_bound_dev_if ||
  46                      !sk2->sk_bound_dev_if ||
  47                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
  48                         if ((!reuse || !sk2->sk_reuse ||
  49                              sk2->sk_state == TCP_LISTEN) &&
  50                             (!reuseport || !sk2->sk_reuseport ||
  51                              (sk2->sk_state != TCP_TIME_WAIT &&
  52                               !uid_eq(uid,
  53                                       sock_i_uid((struct sock *)sk2))))) {
  54                                 if (ipv6_rcv_saddr_equal(sk, sk2))
  55                                         break;
  56                         }
  57                         if (!relax && reuse && sk2->sk_reuse &&
  58                             sk2->sk_state != TCP_LISTEN &&
  59                             ipv6_rcv_saddr_equal(sk, sk2))
  60                                 break;
  61                 }
  62         }
  63
  64         return sk2 != NULL;
  65 }
  66 EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict);
  67
  68 struct dst_entry *inet6_csk_route_req(const struct sock *sk,
  69                                       struct flowi6 *fl6,
  70                                       const struct request_sock *req,
  71                                       u8 proto)
  72 {
  73         struct inet_request_sock *ireq = inet_rsk(req);
  74         const struct ipv6_pinfo *np = inet6_sk(sk);
  75         struct in6_addr *final_p, final;
  76         struct dst_entry *dst;
  77
  78         memset(fl6, 0, sizeof(*fl6));
  79         fl6->flowi6_proto = proto;
  80         fl6->daddr = ireq->ir_v6_rmt_addr;
  81         final_p = fl6_update_dst(fl6, np->opt, &final);
  82         fl6->saddr = ireq->ir_v6_loc_addr;
  83         fl6->flowi6_oif = ireq->ir_iif;
  84         fl6->flowi6_mark = ireq->ir_mark;
  85         fl6->fl6_dport = ireq->ir_rmt_port;
  86         fl6->fl6_sport = htons(ireq->ir_num);
  87         security_req_classify_flow(req, flowi6_to_flowi(fl6));
  88
  89         dst = ip6_dst_lookup_flow(sk, fl6, final_p);
  90         if (IS_ERR(dst))
  91                 return NULL;
  92
  93         return dst;
  94 }
  95 EXPORT_SYMBOL(inet6_csk_route_req);
  96
  97 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr)
  98 {
  99         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
 100
 101         sin6->sin6_family = AF_INET6;
 102         sin6->sin6_addr = sk->sk_v6_daddr;
 103         sin6->sin6_port = inet_sk(sk)->inet_dport;
 104         /* We do not store received flowlabel for TCP */
 105         sin6->sin6_flowinfo = 0;
 106         sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,
 107                                                   sk->sk_bound_dev_if);
 108 }
 109 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
 110
 111 static inline
 112 void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
 113                            const struct in6_addr *daddr,
 114                            const struct in6_addr *saddr)
 115 {
 116         __ip6_dst_store(sk, dst, daddr, saddr);
 117 }
 118
 119 static inline
 120 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
 121 {
 122         return __sk_dst_check(sk, cookie);
 123 }
 124
 125 static struct dst_entry *inet6_csk_route_socket(struct sock *sk,
 126                                                 struct flowi6 *fl6)
 127 {
 128         struct inet_sock *inet = inet_sk(sk);
 129         struct ipv6_pinfo *np = inet6_sk(sk);
 130         struct in6_addr *final_p, final;
 131         struct dst_entry *dst;
 132
 133         memset(fl6, 0, sizeof(*fl6));
 134         fl6->flowi6_proto = sk->sk_protocol;
 135         fl6->daddr = sk->sk_v6_daddr;
 136         fl6->saddr = np->saddr;
 137         fl6->flowlabel = np->flow_label;
 138         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 139         fl6->flowi6_oif = sk->sk_bound_dev_if;
 140         fl6->flowi6_mark = sk->sk_mark;
 141         fl6->fl6_sport = inet->inet_sport;
 142         fl6->fl6_dport = inet->inet_dport;
 143         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
 144
 145         final_p = fl6_update_dst(fl6, np->opt, &final);
 146
 147         dst = __inet6_csk_dst_check(sk, np->dst_cookie);
 148         if (!dst) {
 149                 dst = ip6_dst_lookup_flow(sk, fl6, final_p);
 150
 151                 if (!IS_ERR(dst))
 152                         __inet6_csk_dst_store(sk, dst, NULL, NULL);
 153         }
 154         return dst;
 155 }
 156
 157 int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl_unused)
 158 {
 159         struct ipv6_pinfo *np = inet6_sk(sk);
 160         struct flowi6 fl6;
 161         struct dst_entry *dst;
 162         int res;
 163
 164         dst = inet6_csk_route_socket(sk, &fl6);
 165         if (IS_ERR(dst)) {
 166                 sk->sk_err_soft = -PTR_ERR(dst);
 167                 sk->sk_route_caps = 0;
 168                 kfree_skb(skb);
 169                 return PTR_ERR(dst);
 170         }
 171
 172         rcu_read_lock();
 173         skb_dst_set_noref(skb, dst);
 174
 175         /* Restore final destination back after routing done */
 176         fl6.daddr = sk->sk_v6_daddr;
 177
 178         res = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
 179         rcu_read_unlock();
 180         return res;
 181 }
 182 EXPORT_SYMBOL_GPL(inet6_csk_xmit);
 183
 184 struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu)
 185 {
 186         struct flowi6 fl6;
 187         struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6);
 188
 189         if (IS_ERR(dst))
 190                 return NULL;
 191         dst->ops->update_pmtu(dst, sk, NULL, mtu);
 192
 193         dst = inet6_csk_route_socket(sk, &fl6);
 194         return IS_ERR(dst) ? NULL : dst;
 195 }
 196 EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu);