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         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 struct dst_entry *inet6_csk_route_req(struct sock *sk,
  58                                       struct flowi6 *fl6,
  59                                       const struct request_sock *req)
  60 {
  61         struct inet6_request_sock *treq = inet6_rsk(req);
  62         struct ipv6_pinfo *np = inet6_sk(sk);
  63         struct in6_addr *final_p, final;
  64         struct dst_entry *dst;
  65
  66         memset(fl6, 0, sizeof(*fl6));
  67         fl6->flowi6_proto = IPPROTO_TCP;
  68         fl6->daddr = treq->rmt_addr;
  69         final_p = fl6_update_dst(fl6, np->opt, &final);
  70         fl6->saddr = treq->loc_addr;
  71         fl6->flowi6_oif = treq->iif;
  72         fl6->flowi6_mark = sk->sk_mark;
  73         fl6->fl6_dport = inet_rsk(req)->rmt_port;
  74         fl6->fl6_sport = inet_rsk(req)->loc_port;
  75         security_req_classify_flow(req, flowi6_to_flowi(fl6));
  76
  77         dst = ip6_dst_lookup_flow(sk, fl6, final_p, false);
  78         if (IS_ERR(dst))
  79                 return NULL;
  80
  81         return dst;
  82 }
  83
  84 /*
  85  * request_sock (formerly open request) hash tables.
  86  */
  87 static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
  88                            const u32 rnd, const u32 synq_hsize)
  89 {
  90         u32 c;
  91
  92         c = jhash_3words((__force u32)raddr->s6_addr32[0],
  93                          (__force u32)raddr->s6_addr32[1],
  94                          (__force u32)raddr->s6_addr32[2],
  95                          rnd);
  96
  97         c = jhash_2words((__force u32)raddr->s6_addr32[3],
  98                          (__force u32)rport,
  99                          c);
 100
 101         return c & (synq_hsize - 1);
 102 }
 103
 104 struct request_sock *inet6_csk_search_req(const struct sock *sk,
 105                                           struct request_sock ***prevp,
 106                                           const __be16 rport,
 107                                           const struct in6_addr *raddr,
 108                                           const struct in6_addr *laddr,
 109                                           const int iif)
 110 {
 111         const struct inet_connection_sock *icsk = inet_csk(sk);
 112         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 113         struct request_sock *req, **prev;
 114
 115         for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
 116                                                      lopt->hash_rnd,
 117                                                      lopt->nr_table_entries)];
 118              (req = *prev) != NULL;
 119              prev = &req->dl_next) {
 120                 const struct inet6_request_sock *treq = inet6_rsk(req);
 121
 122                 if (inet_rsk(req)->rmt_port == rport &&
 123                     req->rsk_ops->family == AF_INET6 &&
 124                     ipv6_addr_equal(&treq->rmt_addr, raddr) &&
 125                     ipv6_addr_equal(&treq->loc_addr, laddr) &&
 126                     (!treq->iif || treq->iif == iif)) {
 127                         WARN_ON(req->sk != NULL);
 128                         *prevp = prev;
 129                         return req;
 130                 }
 131         }
 132
 133         return NULL;
 134 }
 135
 136 EXPORT_SYMBOL_GPL(inet6_csk_search_req);
 137
 138 void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
 139                                     struct request_sock *req,
 140                                     const unsigned long timeout)
 141 {
 142         struct inet_connection_sock *icsk = inet_csk(sk);
 143         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 144         const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr,
 145                                       inet_rsk(req)->rmt_port,
 146                                       lopt->hash_rnd, lopt->nr_table_entries);
 147
 148         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 149         inet_csk_reqsk_queue_added(sk, timeout);
 150 }
 151
 152 EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
 153
 154 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
 155 {
 156         struct ipv6_pinfo *np = inet6_sk(sk);
 157         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
 158
 159         sin6->sin6_family = AF_INET6;
 160         sin6->sin6_addr = np->daddr;
 161         sin6->sin6_port = inet_sk(sk)->inet_dport;
 162         /* We do not store received flowlabel for TCP */
 163         sin6->sin6_flowinfo = 0;
 164         sin6->sin6_scope_id = 0;
 165         if (sk->sk_bound_dev_if &&
 166             ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 167                 sin6->sin6_scope_id = sk->sk_bound_dev_if;
 168 }
 169
 170 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
 171
 172 static inline
 173 void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
 174                            const struct in6_addr *daddr,
 175                            const struct in6_addr *saddr)
 176 {
 177         __ip6_dst_store(sk, dst, daddr, saddr);
 178 }
 179
 180 static inline
 181 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
 182 {
 183         return __sk_dst_check(sk, cookie);
 184 }
 185
 186 static struct dst_entry *inet6_csk_route_socket(struct sock *sk,
 187                                                 struct flowi6 *fl6)
 188 {
 189         struct inet_sock *inet = inet_sk(sk);
 190         struct ipv6_pinfo *np = inet6_sk(sk);
 191         struct in6_addr *final_p, final;
 192         struct dst_entry *dst;
 193
 194         memset(fl6, 0, sizeof(*fl6));
 195         fl6->flowi6_proto = sk->sk_protocol;
 196         fl6->daddr = np->daddr;
 197         fl6->saddr = np->saddr;
 198         fl6->flowlabel = np->flow_label;
 199         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 200         fl6->flowi6_oif = sk->sk_bound_dev_if;
 201         fl6->flowi6_mark = sk->sk_mark;
 202         fl6->fl6_sport = inet->inet_sport;
 203         fl6->fl6_dport = inet->inet_dport;
 204         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
 205
 206         final_p = fl6_update_dst(fl6, np->opt, &final);
 207
 208         dst = __inet6_csk_dst_check(sk, np->dst_cookie);
 209         if (!dst) {
 210                 dst = ip6_dst_lookup_flow(sk, fl6, final_p, false);
 211
 212                 if (!IS_ERR(dst))
 213                         __inet6_csk_dst_store(sk, dst, NULL, NULL);
 214         }
 215         return dst;
 216 }
 217
 218 int inet6_csk_xmit(struct sk_buff *skb, struct flowi *fl_unused)
 219 {
 220         struct sock *sk = skb->sk;
 221         struct ipv6_pinfo *np = inet6_sk(sk);
 222         struct flowi6 fl6;
 223         struct dst_entry *dst;
 224         int res;
 225
 226         dst = inet6_csk_route_socket(sk, &fl6);
 227         if (IS_ERR(dst)) {
 228                 sk->sk_err_soft = -PTR_ERR(dst);
 229                 sk->sk_route_caps = 0;
 230                 kfree_skb(skb);
 231                 return PTR_ERR(dst);
 232         }
 233
 234         rcu_read_lock();
 235         skb_dst_set_noref(skb, dst);
 236
 237         /* Restore final destination back after routing done */
 238         fl6.daddr = np->daddr;
 239
 240         res = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
 241         rcu_read_unlock();
 242         return res;
 243 }
 244 EXPORT_SYMBOL_GPL(inet6_csk_xmit);
 245
 246 struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu)
 247 {
 248         struct flowi6 fl6;
 249         struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6);
 250
 251         if (IS_ERR(dst))
 252                 return NULL;
 253         dst->ops->update_pmtu(dst, sk, NULL, mtu);
 254
 255         return inet6_csk_route_socket(sk, &fl6);
 256 }
 257 EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu);