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)
  32 {
  33         const struct sock *sk2;
  34         const struct hlist_node *node;
  35
  36         /* We must walk the whole port owner list in this case. -DaveM */
  37         /*
  38          * See comment in inet_csk_bind_conflict about sock lookup
  39          * vs net namespaces issues.
  40          */
  41         sk_for_each_bound(sk2, node, &tb->owners) {
  42                 if (sk != sk2 &&
  43                     (!sk->sk_bound_dev_if ||
  44                      !sk2->sk_bound_dev_if ||
  45                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if) &&
  46                     (!sk->sk_reuse || !sk2->sk_reuse ||
  47                      sk2->sk_state == TCP_LISTEN) &&
  48                      ipv6_rcv_saddr_equal(sk, sk2))
  49                         break;
  50         }
  51
  52         return node != NULL;
  53 }
  54
  55 EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict);
  56
  57 /*
  58  * request_sock (formerly open request) hash tables.
  59  */
  60 static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
  61                            const u32 rnd, const u16 synq_hsize)
  62 {
  63         u32 c;
  64
  65         c = jhash_3words((__force u32)raddr->s6_addr32[0],
  66                          (__force u32)raddr->s6_addr32[1],
  67                          (__force u32)raddr->s6_addr32[2],
  68                          rnd);
  69
  70         c = jhash_2words((__force u32)raddr->s6_addr32[3],
  71                          (__force u32)rport,
  72                          c);
  73
  74         return c & (synq_hsize - 1);
  75 }
  76
  77 struct request_sock *inet6_csk_search_req(const struct sock *sk,
  78                                           struct request_sock ***prevp,
  79                                           const __be16 rport,
  80                                           const struct in6_addr *raddr,
  81                                           const struct in6_addr *laddr,
  82                                           const int iif)
  83 {
  84         const struct inet_connection_sock *icsk = inet_csk(sk);
  85         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
  86         struct request_sock *req, **prev;
  87
  88         for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
  89                                                      lopt->hash_rnd,
  90                                                      lopt->nr_table_entries)];
  91              (req = *prev) != NULL;
  92              prev = &req->dl_next) {
  93                 const struct inet6_request_sock *treq = inet6_rsk(req);
  94
  95                 if (inet_rsk(req)->rmt_port == rport &&
  96                     req->rsk_ops->family == AF_INET6 &&
  97                     ipv6_addr_equal(&treq->rmt_addr, raddr) &&
  98                     ipv6_addr_equal(&treq->loc_addr, laddr) &&
  99                     (!treq->iif || treq->iif == iif)) {
 100                         WARN_ON(req->sk != NULL);
 101                         *prevp = prev;
 102                         return req;
 103                 }
 104         }
 105
 106         return NULL;
 107 }
 108
 109 EXPORT_SYMBOL_GPL(inet6_csk_search_req);
 110
 111 void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
 112                                     struct request_sock *req,
 113                                     const unsigned long timeout)
 114 {
 115         struct inet_connection_sock *icsk = inet_csk(sk);
 116         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 117         const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr,
 118                                       inet_rsk(req)->rmt_port,
 119                                       lopt->hash_rnd, lopt->nr_table_entries);
 120
 121         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 122         inet_csk_reqsk_queue_added(sk, timeout);
 123 }
 124
 125 EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
 126
 127 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
 128 {
 129         struct ipv6_pinfo *np = inet6_sk(sk);
 130         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
 131
 132         sin6->sin6_family = AF_INET6;
 133         ipv6_addr_copy(&sin6->sin6_addr, &np->daddr);
 134         sin6->sin6_port = inet_sk(sk)->inet_dport;
 135         /* We do not store received flowlabel for TCP */
 136         sin6->sin6_flowinfo = 0;
 137         sin6->sin6_scope_id = 0;
 138         if (sk->sk_bound_dev_if &&
 139             ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 140                 sin6->sin6_scope_id = sk->sk_bound_dev_if;
 141 }
 142
 143 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
 144
 145 static inline
 146 void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
 147                            struct in6_addr *daddr, struct in6_addr *saddr)
 148 {
 149         __ip6_dst_store(sk, dst, daddr, saddr);
 150
 151 #ifdef CONFIG_XFRM
 152         {
 153                 struct rt6_info *rt = (struct rt6_info  *)dst;
 154                 rt->rt6i_flow_cache_genid = atomic_read(&flow_cache_genid);
 155         }
 156 #endif
 157 }
 158
 159 static inline
 160 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
 161 {
 162         struct dst_entry *dst;
 163
 164         dst = __sk_dst_check(sk, cookie);
 165
 166 #ifdef CONFIG_XFRM
 167         if (dst) {
 168                 struct rt6_info *rt = (struct rt6_info *)dst;
 169                 if (rt->rt6i_flow_cache_genid != atomic_read(&flow_cache_genid)) {
 170                         __sk_dst_reset(sk);
 171                         dst = NULL;
 172                 }
 173         }
 174 #endif
 175
 176         return dst;
 177 }
 178
 179 int inet6_csk_xmit(struct sk_buff *skb)
 180 {
 181         struct sock *sk = skb->sk;
 182         struct inet_sock *inet = inet_sk(sk);
 183         struct ipv6_pinfo *np = inet6_sk(sk);
 184         struct flowi fl;
 185         struct dst_entry *dst;
 186         struct in6_addr *final_p, final;
 187
 188         memset(&fl, 0, sizeof(fl));
 189         fl.proto = sk->sk_protocol;
 190         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 191         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 192         fl.fl6_flowlabel = np->flow_label;
 193         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 194         fl.oif = sk->sk_bound_dev_if;
 195         fl.mark = sk->sk_mark;
 196         fl.fl_ip_sport = inet->inet_sport;
 197         fl.fl_ip_dport = inet->inet_dport;
 198         security_sk_classify_flow(sk, &fl);
 199
 200         final_p = fl6_update_dst(&fl, np->opt, &final);
 201
 202         dst = __inet6_csk_dst_check(sk, np->dst_cookie);
 203
 204         if (dst == NULL) {
 205                 int err = ip6_dst_lookup(sk, &dst, &fl);
 206
 207                 if (err) {
 208                         sk->sk_err_soft = -err;
 209                         kfree_skb(skb);
 210                         return err;
 211                 }
 212
 213                 if (final_p)
 214                         ipv6_addr_copy(&fl.fl6_dst, final_p);
 215
 216                 if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0) {
 217                         sk->sk_route_caps = 0;
 218                         kfree_skb(skb);
 219                         return err;
 220                 }
 221
 222                 __inet6_csk_dst_store(sk, dst, NULL, NULL);
 223         }
 224
 225         skb_dst_set(skb, dst_clone(dst));
 226
 227         /* Restore final destination back after routing done */
 228         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 229
 230         return ip6_xmit(sk, skb, &fl, np->opt);
 231 }
 232
 233 EXPORT_SYMBOL_GPL(inet6_csk_xmit);