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
  21 #include <net/addrconf.h>
  22 #include <net/inet_connection_sock.h>
  23 #include <net/inet_ecn.h>
  24 #include <net/inet_hashtables.h>
  25 #include <net/ip6_route.h>
  26 #include <net/sock.h>
  27 #include <net/inet6_connection_sock.h>
  28
  29 int inet6_csk_bind_conflict(const struct sock *sk,
  30                             const struct inet_bind_bucket *tb)
  31 {
  32         const struct sock *sk2;
  33         const struct hlist_node *node;
  34
  35         /* We must walk the whole port owner list in this case. -DaveM */
  36         sk_for_each_bound(sk2, node, &tb->owners) {
  37                 if (sk != sk2 &&
  38                     (!sk->sk_bound_dev_if ||
  39                      !sk2->sk_bound_dev_if ||
  40                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if) &&
  41                     (!sk->sk_reuse || !sk2->sk_reuse ||
  42                      sk2->sk_state == TCP_LISTEN) &&
  43                      ipv6_rcv_saddr_equal(sk, sk2))
  44                         break;
  45         }
  46
  47         return node != NULL;
  48 }
  49
  50 EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict);
  51
  52 /*
  53  * request_sock (formerly open request) hash tables.
  54  */
  55 static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
  56                            const u32 rnd, const u16 synq_hsize)
  57 {
  58         u32 a = (__force u32)raddr->s6_addr32[0];
  59         u32 b = (__force u32)raddr->s6_addr32[1];
  60         u32 c = (__force u32)raddr->s6_addr32[2];
  61
  62         a += JHASH_GOLDEN_RATIO;
  63         b += JHASH_GOLDEN_RATIO;
  64         c += rnd;
  65         __jhash_mix(a, b, c);
  66
  67         a += (__force u32)raddr->s6_addr32[3];
  68         b += (__force u32)rport;
  69         __jhash_mix(a, b, c);
  70
  71         return c & (synq_hsize - 1);
  72 }
  73
  74 struct request_sock *inet6_csk_search_req(const struct sock *sk,
  75                                           struct request_sock ***prevp,
  76                                           const __be16 rport,
  77                                           const struct in6_addr *raddr,
  78                                           const struct in6_addr *laddr,
  79                                           const int iif)
  80 {
  81         const struct inet_connection_sock *icsk = inet_csk(sk);
  82         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
  83         struct request_sock *req, **prev;
  84
  85         for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
  86                                                      lopt->hash_rnd,
  87                                                      lopt->nr_table_entries)];
  88              (req = *prev) != NULL;
  89              prev = &req->dl_next) {
  90                 const struct inet6_request_sock *treq = inet6_rsk(req);
  91
  92                 if (inet_rsk(req)->rmt_port == rport &&
  93                     req->rsk_ops->family == AF_INET6 &&
  94                     ipv6_addr_equal(&treq->rmt_addr, raddr) &&
  95                     ipv6_addr_equal(&treq->loc_addr, laddr) &&
  96                     (!treq->iif || treq->iif == iif)) {
  97                         BUG_TRAP(req->sk == NULL);
  98                         *prevp = prev;
  99                         return req;
 100                 }
 101         }
 102
 103         return NULL;
 104 }
 105
 106 EXPORT_SYMBOL_GPL(inet6_csk_search_req);
 107
 108 void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
 109                                     struct request_sock *req,
 110                                     const unsigned long timeout)
 111 {
 112         struct inet_connection_sock *icsk = inet_csk(sk);
 113         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 114         const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr,
 115                                       inet_rsk(req)->rmt_port,
 116                                       lopt->hash_rnd, lopt->nr_table_entries);
 117
 118         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 119         inet_csk_reqsk_queue_added(sk, timeout);
 120 }
 121
 122 EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
 123
 124 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
 125 {
 126         struct ipv6_pinfo *np = inet6_sk(sk);
 127         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
 128
 129         sin6->sin6_family = AF_INET6;
 130         ipv6_addr_copy(&sin6->sin6_addr, &np->daddr);
 131         sin6->sin6_port = inet_sk(sk)->dport;
 132         /* We do not store received flowlabel for TCP */
 133         sin6->sin6_flowinfo = 0;
 134         sin6->sin6_scope_id = 0;
 135         if (sk->sk_bound_dev_if &&
 136             ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 137                 sin6->sin6_scope_id = sk->sk_bound_dev_if;
 138 }
 139
 140 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
 141
 142 static inline
 143 void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
 144                            struct in6_addr *daddr, struct in6_addr *saddr)
 145 {
 146         __ip6_dst_store(sk, dst, daddr, saddr);
 147
 148 #ifdef CONFIG_XFRM
 149         {
 150                 struct rt6_info *rt = (struct rt6_info  *)dst;
 151                 rt->rt6i_flow_cache_genid = atomic_read(&flow_cache_genid);
 152         }
 153 #endif
 154 }
 155
 156 static inline
 157 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
 158 {
 159         struct dst_entry *dst;
 160
 161         dst = __sk_dst_check(sk, cookie);
 162
 163 #ifdef CONFIG_XFRM
 164         if (dst) {
 165                 struct rt6_info *rt = (struct rt6_info *)dst;
 166                 if (rt->rt6i_flow_cache_genid != atomic_read(&flow_cache_genid)) {
 167                         sk->sk_dst_cache = NULL;
 168                         dst_release(dst);
 169                         dst = NULL;
 170                 }
 171         }
 172 #endif
 173
 174         return dst;
 175 }
 176
 177 int inet6_csk_xmit(struct sk_buff *skb, int ipfragok)
 178 {
 179         struct sock *sk = skb->sk;
 180         struct inet_sock *inet = inet_sk(sk);
 181         struct ipv6_pinfo *np = inet6_sk(sk);
 182         struct flowi fl;
 183         struct dst_entry *dst;
 184         struct in6_addr *final_p = NULL, final;
 185
 186         memset(&fl, 0, sizeof(fl));
 187         fl.proto = sk->sk_protocol;
 188         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 189         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 190         fl.fl6_flowlabel = np->flow_label;
 191         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 192         fl.oif = sk->sk_bound_dev_if;
 193         fl.fl_ip_sport = inet->sport;
 194         fl.fl_ip_dport = inet->dport;
 195         security_sk_classify_flow(sk, &fl);
 196
 197         if (np->opt && np->opt->srcrt) {
 198                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
 199                 ipv6_addr_copy(&final, &fl.fl6_dst);
 200                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 201                 final_p = &final;
 202         }
 203
 204         dst = __inet6_csk_dst_check(sk, np->dst_cookie);
 205
 206         if (dst == NULL) {
 207                 int err = ip6_dst_lookup(sk, &dst, &fl);
 208
 209                 if (err) {
 210                         sk->sk_err_soft = -err;
 211                         kfree_skb(skb);
 212                         return err;
 213                 }
 214
 215                 if (final_p)
 216                         ipv6_addr_copy(&fl.fl6_dst, final_p);
 217
 218                 if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) {
 219                         sk->sk_route_caps = 0;
 220                         kfree_skb(skb);
 221                         return err;
 222                 }
 223
 224                 __inet6_csk_dst_store(sk, dst, NULL, NULL);
 225         }
 226
 227         skb->dst = dst_clone(dst);
 228
 229         /* Restore final destination back after routing done */
 230         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 231
 232         return ip6_xmit(sk, skb, &fl, np->opt, 0);
 233 }
 234
 235 EXPORT_SYMBOL_GPL(inet6_csk_xmit);