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         /*
  37          * See comment in inet_csk_bind_conflict about sock lookup
  38          * vs net namespaces issues.
  39          */
  40         sk_for_each_bound(sk2, node, &tb->owners) {
  41                 if (sk != sk2 &&
  42                     (!sk->sk_bound_dev_if ||
  43                      !sk2->sk_bound_dev_if ||
  44                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if) &&
  45                     (!sk->sk_reuse || !sk2->sk_reuse ||
  46                      sk2->sk_state == TCP_LISTEN) &&
  47                      ipv6_rcv_saddr_equal(sk, sk2))
  48                         break;
  49         }
  50
  51         return node != NULL;
  52 }
  53
  54 EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict);
  55
  56 /*
  57  * request_sock (formerly open request) hash tables.
  58  */
  59 static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
  60                            const u32 rnd, const u16 synq_hsize)
  61 {
  62         u32 a = (__force u32)raddr->s6_addr32[0];
  63         u32 b = (__force u32)raddr->s6_addr32[1];
  64         u32 c = (__force u32)raddr->s6_addr32[2];
  65
  66         a += JHASH_GOLDEN_RATIO;
  67         b += JHASH_GOLDEN_RATIO;
  68         c += rnd;
  69         __jhash_mix(a, b, c);
  70
  71         a += (__force u32)raddr->s6_addr32[3];
  72         b += (__force u32)rport;
  73         __jhash_mix(a, b, c);
  74
  75         return c & (synq_hsize - 1);
  76 }
  77
  78 struct request_sock *inet6_csk_search_req(const struct sock *sk,
  79                                           struct request_sock ***prevp,
  80                                           const __be16 rport,
  81                                           const struct in6_addr *raddr,
  82                                           const struct in6_addr *laddr,
  83                                           const int iif)
  84 {
  85         const struct inet_connection_sock *icsk = inet_csk(sk);
  86         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
  87         struct request_sock *req, **prev;
  88
  89         for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
  90                                                      lopt->hash_rnd,
  91                                                      lopt->nr_table_entries)];
  92              (req = *prev) != NULL;
  93              prev = &req->dl_next) {
  94                 const struct inet6_request_sock *treq = inet6_rsk(req);
  95
  96                 if (inet_rsk(req)->rmt_port == rport &&
  97                     req->rsk_ops->family == AF_INET6 &&
  98                     ipv6_addr_equal(&treq->rmt_addr, raddr) &&
  99                     ipv6_addr_equal(&treq->loc_addr, laddr) &&
 100                     (!treq->iif || treq->iif == iif)) {
 101                         BUG_TRAP(req->sk == NULL);
 102                         *prevp = prev;
 103                         return req;
 104                 }
 105         }
 106
 107         return NULL;
 108 }
 109
 110 EXPORT_SYMBOL_GPL(inet6_csk_search_req);
 111
 112 void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
 113                                     struct request_sock *req,
 114                                     const unsigned long timeout)
 115 {
 116         struct inet_connection_sock *icsk = inet_csk(sk);
 117         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 118         const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr,
 119                                       inet_rsk(req)->rmt_port,
 120                                       lopt->hash_rnd, lopt->nr_table_entries);
 121
 122         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 123         inet_csk_reqsk_queue_added(sk, timeout);
 124 }
 125
 126 EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
 127
 128 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
 129 {
 130         struct ipv6_pinfo *np = inet6_sk(sk);
 131         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
 132
 133         sin6->sin6_family = AF_INET6;
 134         ipv6_addr_copy(&sin6->sin6_addr, &np->daddr);
 135         sin6->sin6_port = inet_sk(sk)->dport;
 136         /* We do not store received flowlabel for TCP */
 137         sin6->sin6_flowinfo = 0;
 138         sin6->sin6_scope_id = 0;
 139         if (sk->sk_bound_dev_if &&
 140             ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 141                 sin6->sin6_scope_id = sk->sk_bound_dev_if;
 142 }
 143
 144 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
 145
 146 static inline
 147 void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
 148                            struct in6_addr *daddr, struct in6_addr *saddr)
 149 {
 150         __ip6_dst_store(sk, dst, daddr, saddr);
 151
 152 #ifdef CONFIG_XFRM
 153         {
 154                 struct rt6_info *rt = (struct rt6_info  *)dst;
 155                 rt->rt6i_flow_cache_genid = atomic_read(&flow_cache_genid);
 156         }
 157 #endif
 158 }
 159
 160 static inline
 161 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
 162 {
 163         struct dst_entry *dst;
 164
 165         dst = __sk_dst_check(sk, cookie);
 166
 167 #ifdef CONFIG_XFRM
 168         if (dst) {
 169                 struct rt6_info *rt = (struct rt6_info *)dst;
 170                 if (rt->rt6i_flow_cache_genid != atomic_read(&flow_cache_genid)) {
 171                         sk->sk_dst_cache = NULL;
 172                         dst_release(dst);
 173                         dst = NULL;
 174                 }
 175         }
 176 #endif
 177
 178         return dst;
 179 }
 180
 181 int inet6_csk_xmit(struct sk_buff *skb, int ipfragok)
 182 {
 183         struct sock *sk = skb->sk;
 184         struct inet_sock *inet = inet_sk(sk);
 185         struct ipv6_pinfo *np = inet6_sk(sk);
 186         struct flowi fl;
 187         struct dst_entry *dst;
 188         struct in6_addr *final_p = NULL, final;
 189
 190         memset(&fl, 0, sizeof(fl));
 191         fl.proto = sk->sk_protocol;
 192         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 193         ipv6_addr_copy(&fl.fl6_src, &np->saddr);
 194         fl.fl6_flowlabel = np->flow_label;
 195         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 196         fl.oif = sk->sk_bound_dev_if;
 197         fl.fl_ip_sport = inet->sport;
 198         fl.fl_ip_dport = inet->dport;
 199         security_sk_classify_flow(sk, &fl);
 200
 201         if (np->opt && np->opt->srcrt) {
 202                 struct rt0_hdr *rt0 = (struct rt0_hdr *)np->opt->srcrt;
 203                 ipv6_addr_copy(&final, &fl.fl6_dst);
 204                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 205                 final_p = &final;
 206         }
 207
 208         dst = __inet6_csk_dst_check(sk, np->dst_cookie);
 209
 210         if (dst == NULL) {
 211                 int err = ip6_dst_lookup(sk, &dst, &fl);
 212
 213                 if (err) {
 214                         sk->sk_err_soft = -err;
 215                         kfree_skb(skb);
 216                         return err;
 217                 }
 218
 219                 if (final_p)
 220                         ipv6_addr_copy(&fl.fl6_dst, final_p);
 221
 222                 if ((err = xfrm_lookup(&dst, &fl, sk, 0)) < 0) {
 223                         sk->sk_route_caps = 0;
 224                         kfree_skb(skb);
 225                         return err;
 226                 }
 227
 228                 __inet6_csk_dst_store(sk, dst, NULL, NULL);
 229         }
 230
 231         skb->dst = dst_clone(dst);
 232
 233         /* Restore final destination back after routing done */
 234         ipv6_addr_copy(&fl.fl6_dst, &np->daddr);
 235
 236         return ip6_xmit(sk, skb, &fl, np->opt, 0);
 237 }
 238
 239 EXPORT_SYMBOL_GPL(inet6_csk_xmit);