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/config.h>
  17 #include <linux/module.h>
  18 #include <linux/in6.h>
  19 #include <linux/ipv6.h>
  20 #include <linux/jhash.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         sk_for_each_bound(sk2, node, &tb->owners) {
  38                 if (sk != sk2 &&
  39                     (!sk->sk_bound_dev_if ||
  40                      !sk2->sk_bound_dev_if ||
  41                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if) &&
  42                     (!sk->sk_reuse || !sk2->sk_reuse ||
  43                      sk2->sk_state == TCP_LISTEN) &&
  44                      ipv6_rcv_saddr_equal(sk, sk2))
  45                         break;
  46         }
  47
  48         return node != NULL;
  49 }
  50
  51 EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict);
  52
  53 /*
  54  * request_sock (formerly open request) hash tables.
  55  */
  56 static u32 inet6_synq_hash(const struct in6_addr *raddr, const u16 rport,
  57                            const u32 rnd, const u16 synq_hsize)
  58 {
  59         u32 a = raddr->s6_addr32[0];
  60         u32 b = raddr->s6_addr32[1];
  61         u32 c = raddr->s6_addr32[2];
  62
  63         a += JHASH_GOLDEN_RATIO;
  64         b += JHASH_GOLDEN_RATIO;
  65         c += rnd;
  66         __jhash_mix(a, b, c);
  67
  68         a += raddr->s6_addr32[3];
  69         b += (u32)rport;
  70         __jhash_mix(a, b, c);
  71
  72         return c & (synq_hsize - 1);
  73 }
  74
  75 struct request_sock *inet6_csk_search_req(const struct sock *sk,
  76                                           struct request_sock ***prevp,
  77                                           const __u16 rport,
  78                                           const struct in6_addr *raddr,
  79                                           const struct in6_addr *laddr,
  80                                           const int iif)
  81 {
  82         const struct inet_connection_sock *icsk = inet_csk(sk);
  83         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
  84         struct request_sock *req, **prev;
  85
  86         for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
  87                                                      lopt->hash_rnd,
  88                                                      lopt->nr_table_entries)];
  89              (req = *prev) != NULL;
  90              prev = &req->dl_next) {
  91                 const struct inet6_request_sock *treq = inet6_rsk(req);
  92
  93                 if (inet_rsk(req)->rmt_port == rport &&
  94                     req->rsk_ops->family == AF_INET6 &&
  95                     ipv6_addr_equal(&treq->rmt_addr, raddr) &&
  96                     ipv6_addr_equal(&treq->loc_addr, laddr) &&
  97                     (!treq->iif || treq->iif == iif)) {
  98                         BUG_TRAP(req->sk == NULL);
  99                         *prevp = prev;
 100                         return req;
 101                 }
 102         }
 103
 104         return NULL;
 105 }
 106
 107 EXPORT_SYMBOL_GPL(inet6_csk_search_req);
 108
 109 void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
 110                                     struct request_sock *req,
 111                                     const unsigned long timeout)
 112 {
 113         struct inet_connection_sock *icsk = inet_csk(sk);
 114         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 115         const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr,
 116                                       inet_rsk(req)->rmt_port,
 117                                       lopt->hash_rnd, lopt->nr_table_entries);
 118
 119         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 120         inet_csk_reqsk_queue_added(sk, timeout);
 121 }
 122
 123 EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
 124
 125 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
 126 {
 127         struct ipv6_pinfo *np = inet6_sk(sk);
 128         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
 129
 130         sin6->sin6_family = AF_INET6;
 131         ipv6_addr_copy(&sin6->sin6_addr, &np->daddr);
 132         sin6->sin6_port = inet_sk(sk)->dport;
 133         /* We do not store received flowlabel for TCP */
 134         sin6->sin6_flowinfo = 0;
 135         sin6->sin6_scope_id = 0;
 136         if (sk->sk_bound_dev_if &&
 137             ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 138                 sin6->sin6_scope_id = sk->sk_bound_dev_if;
 139 }
 140
 141 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
 142
 143 int inet6_csk_xmit(struct sk_buff *skb, int ipfragok)
 144 {
 145         struct sock *sk = skb->sk;
 146         struct inet_sock *inet = inet_sk(sk);
 147         struct ipv6_pinfo *np = inet6_sk(sk);
 148         struct flowi fl;
 149         struct dst_entry *dst;
 150         struct in6_addr *final_p = NULL, final;
 151
 152         memset(&fl, 0, sizeof(fl));
 153         fl.proto = sk->sk_protocol;
 154         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 155         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 156         fl.fl6_flowlabel = np->flow_label;
 157         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 158         fl.oif = sk->sk_bound_dev_if;
 159         fl.fl_ip_sport = inet->sport;
 160         fl.fl_ip_dport = inet->dport;
 161
 162         if (np->opt && np->opt->srcrt) {
 163                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
 164                 ipv6_addr_copy(&final, &fl.fl6_dst);
 165                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 166                 final_p = &final;
 167         }
 168
 169         dst = __sk_dst_check(sk, np->dst_cookie);
 170
 171         if (dst == NULL) {
 172                 int err = ip6_dst_lookup(sk, &dst, &fl);
 173
 174                 if (err) {
 175                         sk->sk_err_soft = -err;
 176                         kfree_skb(skb);
 177                         return err;
 178                 }
 179
 180                 if (final_p)
 181                         ipv6_addr_copy(&fl.fl6_dst, final_p);
 182
 183                 if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) {
 184                         sk->sk_route_caps = 0;
 185                         kfree_skb(skb);
 186                         return err;
 187                 }
 188
 189                 ip6_dst_store(sk, dst, NULL);
 190                 sk->sk_route_caps = dst->dev->features &
 191                         ~(NETIF_F_IP_CSUM | NETIF_F_TSO);
 192         }
 193
 194         skb->dst = dst_clone(dst);
 195
 196         /* Restore final destination back after routing done */
 197         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 198
 199         return ip6_xmit(sk, skb, &fl, np->opt, 0);
 200 }
 201
 202 EXPORT_SYMBOL_GPL(inet6_csk_xmit);