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                         if ((!sk->sk_reuse || !sk2->sk_reuse ||
  47                              sk2->sk_state == TCP_LISTEN) &&
  48                              ipv6_rcv_saddr_equal(sk, sk2))
  49                                 break;
  50                         else if (sk->sk_reuse && sk2->sk_reuse &&
  51                                 !ipv6_addr_any(inet6_rcv_saddr(sk)) &&
  52                                 ipv6_rcv_saddr_equal(sk, sk2))
  53                                 break;
  54                 }
  55         }
  56
  57         return node != NULL;
  58 }
  59
  60 EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict);
  61
  62 /*
  63  * request_sock (formerly open request) hash tables.
  64  */
  65 static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
  66                            const u32 rnd, const u16 synq_hsize)
  67 {
  68         u32 a = (__force u32)raddr->s6_addr32[0];
  69         u32 b = (__force u32)raddr->s6_addr32[1];
  70         u32 c = (__force u32)raddr->s6_addr32[2];
  71
  72         a += JHASH_GOLDEN_RATIO;
  73         b += JHASH_GOLDEN_RATIO;
  74         c += rnd;
  75         __jhash_mix(a, b, c);
  76
  77         a += (__force u32)raddr->s6_addr32[3];
  78         b += (__force u32)rport;
  79         __jhash_mix(a, b, c);
  80
  81         return c & (synq_hsize - 1);
  82 }
  83
  84 struct request_sock *inet6_csk_search_req(const struct sock *sk,
  85                                           struct request_sock ***prevp,
  86                                           const __be16 rport,
  87                                           const struct in6_addr *raddr,
  88                                           const struct in6_addr *laddr,
  89                                           const int iif)
  90 {
  91         const struct inet_connection_sock *icsk = inet_csk(sk);
  92         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
  93         struct request_sock *req, **prev;
  94
  95         for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
  96                                                      lopt->hash_rnd,
  97                                                      lopt->nr_table_entries)];
  98              (req = *prev) != NULL;
  99              prev = &req->dl_next) {
 100                 const struct inet6_request_sock *treq = inet6_rsk(req);
 101
 102                 if (inet_rsk(req)->rmt_port == rport &&
 103                     req->rsk_ops->family == AF_INET6 &&
 104                     ipv6_addr_equal(&treq->rmt_addr, raddr) &&
 105                     ipv6_addr_equal(&treq->loc_addr, laddr) &&
 106                     (!treq->iif || treq->iif == iif)) {
 107                         WARN_ON(req->sk != NULL);
 108                         *prevp = prev;
 109                         return req;
 110                 }
 111         }
 112
 113         return NULL;
 114 }
 115
 116 EXPORT_SYMBOL_GPL(inet6_csk_search_req);
 117
 118 void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
 119                                     struct request_sock *req,
 120                                     const unsigned long timeout)
 121 {
 122         struct inet_connection_sock *icsk = inet_csk(sk);
 123         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 124         const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr,
 125                                       inet_rsk(req)->rmt_port,
 126                                       lopt->hash_rnd, lopt->nr_table_entries);
 127
 128         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 129         inet_csk_reqsk_queue_added(sk, timeout);
 130 }
 131
 132 EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
 133
 134 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
 135 {
 136         struct ipv6_pinfo *np = inet6_sk(sk);
 137         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
 138
 139         sin6->sin6_family = AF_INET6;
 140         ipv6_addr_copy(&sin6->sin6_addr, &np->daddr);
 141         sin6->sin6_port = inet_sk(sk)->inet_dport;
 142         /* We do not store received flowlabel for TCP */
 143         sin6->sin6_flowinfo = 0;
 144         sin6->sin6_scope_id = 0;
 145         if (sk->sk_bound_dev_if &&
 146             ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 147                 sin6->sin6_scope_id = sk->sk_bound_dev_if;
 148 }
 149
 150 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
 151
 152 static inline
 153 void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
 154                            struct in6_addr *daddr, struct in6_addr *saddr)
 155 {
 156         __ip6_dst_store(sk, dst, daddr, saddr);
 157
 158 #ifdef CONFIG_XFRM
 159         {
 160                 struct rt6_info *rt = (struct rt6_info  *)dst;
 161                 rt->rt6i_flow_cache_genid = atomic_read(&flow_cache_genid);
 162         }
 163 #endif
 164 }
 165
 166 static inline
 167 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
 168 {
 169         struct dst_entry *dst;
 170
 171         dst = __sk_dst_check(sk, cookie);
 172
 173 #ifdef CONFIG_XFRM
 174         if (dst) {
 175                 struct rt6_info *rt = (struct rt6_info *)dst;
 176                 if (rt->rt6i_flow_cache_genid != atomic_read(&flow_cache_genid)) {
 177                         __sk_dst_reset(sk);
 178                         dst = NULL;
 179                 }
 180         }
 181 #endif
 182
 183         return dst;
 184 }
 185
 186 int inet6_csk_xmit(struct sk_buff *skb, int ipfragok)
 187 {
 188         struct sock *sk = skb->sk;
 189         struct inet_sock *inet = inet_sk(sk);
 190         struct ipv6_pinfo *np = inet6_sk(sk);
 191         struct flowi fl;
 192         struct dst_entry *dst;
 193         struct in6_addr *final_p = NULL, final;
 194
 195         memset(&fl, 0, sizeof(fl));
 196         fl.proto = sk->sk_protocol;
 197         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 198         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 199         fl.fl6_flowlabel = np->flow_label;
 200         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 201         fl.oif = sk->sk_bound_dev_if;
 202         fl.mark = sk->sk_mark;
 203         fl.fl_ip_sport = inet->inet_sport;
 204         fl.fl_ip_dport = inet->inet_dport;
 205         security_sk_classify_flow(sk, &fl);
 206
 207         if (np->opt && np->opt->srcrt) {
 208                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
 209                 ipv6_addr_copy(&final, &fl.fl6_dst);
 210                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 211                 final_p = &final;
 212         }
 213
 214         dst = __inet6_csk_dst_check(sk, np->dst_cookie);
 215
 216         if (dst == NULL) {
 217                 int err = ip6_dst_lookup(sk, &dst, &fl);
 218
 219                 if (err) {
 220                         sk->sk_err_soft = -err;
 221                         kfree_skb(skb);
 222                         return err;
 223                 }
 224
 225                 if (final_p)
 226                         ipv6_addr_copy(&fl.fl6_dst, final_p);
 227
 228                 if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0) {
 229                         sk->sk_route_caps = 0;
 230                         kfree_skb(skb);
 231                         return err;
 232                 }
 233
 234                 __inet6_csk_dst_store(sk, dst, NULL, NULL);
 235         }
 236
 237         skb_dst_set(skb, dst_clone(dst));
 238
 239         /* Restore final destination back after routing done */
 240         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 241
 242         return ip6_xmit(sk, skb, &fl, np->opt, 0);
 243 }
 244
 245 EXPORT_SYMBOL_GPL(inet6_csk_xmit);