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         int reuse = sk->sk_reuse;
  35         int reuseport = sk->sk_reuseport;
  36         kuid_t uid = sock_i_uid((struct sock *)sk);
  37
  38         /* We must walk the whole port owner list in this case. -DaveM */
  39         /*
  40          * See comment in inet_csk_bind_conflict about sock lookup
  41          * vs net namespaces issues.
  42          */
  43         sk_for_each_bound(sk2, &tb->owners) {
  44                 if (sk != sk2 &&
  45                     (!sk->sk_bound_dev_if ||
  46                      !sk2->sk_bound_dev_if ||
  47                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
  48                         if ((!reuse || !sk2->sk_reuse ||
  49                              sk2->sk_state == TCP_LISTEN) &&
  50                             (!reuseport || !sk2->sk_reuseport ||
  51                              (sk2->sk_state != TCP_TIME_WAIT &&
  52                               !uid_eq(uid,
  53                                       sock_i_uid((struct sock *)sk2))))) {
  54                                 if (ipv6_rcv_saddr_equal(sk, sk2))
  55                                         break;
  56                         }
  57                 }
  58         }
  59
  60         return sk2 != NULL;
  61 }
  62
  63 EXPORT_SYMBOL_GPL(inet6_csk_bind_conflict);
  64
  65 struct dst_entry *inet6_csk_route_req(struct sock *sk,
  66                                       struct flowi6 *fl6,
  67                                       const struct request_sock *req)
  68 {
  69         struct inet6_request_sock *treq = inet6_rsk(req);
  70         struct ipv6_pinfo *np = inet6_sk(sk);
  71         struct in6_addr *final_p, final;
  72         struct dst_entry *dst;
  73
  74         memset(fl6, 0, sizeof(*fl6));
  75         fl6->flowi6_proto = IPPROTO_TCP;
  76         fl6->daddr = treq->rmt_addr;
  77         final_p = fl6_update_dst(fl6, np->opt, &final);
  78         fl6->saddr = treq->loc_addr;
  79         fl6->flowi6_oif = treq->iif;
  80         fl6->flowi6_mark = sk->sk_mark;
  81         fl6->fl6_dport = inet_rsk(req)->rmt_port;
  82         fl6->fl6_sport = inet_rsk(req)->loc_port;
  83         security_req_classify_flow(req, flowi6_to_flowi(fl6));
  84
  85         dst = ip6_dst_lookup_flow(sk, fl6, final_p, false);
  86         if (IS_ERR(dst))
  87                 return NULL;
  88
  89         return dst;
  90 }
  91
  92 /*
  93  * request_sock (formerly open request) hash tables.
  94  */
  95 static u32 inet6_synq_hash(const struct in6_addr *raddr, const __be16 rport,
  96                            const u32 rnd, const u32 synq_hsize)
  97 {
  98         u32 c;
  99
 100         c = jhash_3words((__force u32)raddr->s6_addr32[0],
 101                          (__force u32)raddr->s6_addr32[1],
 102                          (__force u32)raddr->s6_addr32[2],
 103                          rnd);
 104
 105         c = jhash_2words((__force u32)raddr->s6_addr32[3],
 106                          (__force u32)rport,
 107                          c);
 108
 109         return c & (synq_hsize - 1);
 110 }
 111
 112 struct request_sock *inet6_csk_search_req(const struct sock *sk,
 113                                           struct request_sock ***prevp,
 114                                           const __be16 rport,
 115                                           const struct in6_addr *raddr,
 116                                           const struct in6_addr *laddr,
 117                                           const int iif)
 118 {
 119         const struct inet_connection_sock *icsk = inet_csk(sk);
 120         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 121         struct request_sock *req, **prev;
 122
 123         for (prev = &lopt->syn_table[inet6_synq_hash(raddr, rport,
 124                                                      lopt->hash_rnd,
 125                                                      lopt->nr_table_entries)];
 126              (req = *prev) != NULL;
 127              prev = &req->dl_next) {
 128                 const struct inet6_request_sock *treq = inet6_rsk(req);
 129
 130                 if (inet_rsk(req)->rmt_port == rport &&
 131                     req->rsk_ops->family == AF_INET6 &&
 132                     ipv6_addr_equal(&treq->rmt_addr, raddr) &&
 133                     ipv6_addr_equal(&treq->loc_addr, laddr) &&
 134                     (!treq->iif || treq->iif == iif)) {
 135                         WARN_ON(req->sk != NULL);
 136                         *prevp = prev;
 137                         return req;
 138                 }
 139         }
 140
 141         return NULL;
 142 }
 143
 144 EXPORT_SYMBOL_GPL(inet6_csk_search_req);
 145
 146 void inet6_csk_reqsk_queue_hash_add(struct sock *sk,
 147                                     struct request_sock *req,
 148                                     const unsigned long timeout)
 149 {
 150         struct inet_connection_sock *icsk = inet_csk(sk);
 151         struct listen_sock *lopt = icsk->icsk_accept_queue.listen_opt;
 152         const u32 h = inet6_synq_hash(&inet6_rsk(req)->rmt_addr,
 153                                       inet_rsk(req)->rmt_port,
 154                                       lopt->hash_rnd, lopt->nr_table_entries);
 155
 156         reqsk_queue_hash_req(&icsk->icsk_accept_queue, h, req, timeout);
 157         inet_csk_reqsk_queue_added(sk, timeout);
 158 }
 159
 160 EXPORT_SYMBOL_GPL(inet6_csk_reqsk_queue_hash_add);
 161
 162 void inet6_csk_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
 163 {
 164         struct ipv6_pinfo *np = inet6_sk(sk);
 165         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) uaddr;
 166
 167         sin6->sin6_family = AF_INET6;
 168         sin6->sin6_addr = np->daddr;
 169         sin6->sin6_port = inet_sk(sk)->inet_dport;
 170         /* We do not store received flowlabel for TCP */
 171         sin6->sin6_flowinfo = 0;
 172         sin6->sin6_scope_id = 0;
 173         if (sk->sk_bound_dev_if &&
 174             ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 175                 sin6->sin6_scope_id = sk->sk_bound_dev_if;
 176 }
 177
 178 EXPORT_SYMBOL_GPL(inet6_csk_addr2sockaddr);
 179
 180 static inline
 181 void __inet6_csk_dst_store(struct sock *sk, struct dst_entry *dst,
 182                            const struct in6_addr *daddr,
 183                            const struct in6_addr *saddr)
 184 {
 185         __ip6_dst_store(sk, dst, daddr, saddr);
 186 }
 187
 188 static inline
 189 struct dst_entry *__inet6_csk_dst_check(struct sock *sk, u32 cookie)
 190 {
 191         return __sk_dst_check(sk, cookie);
 192 }
 193
 194 static struct dst_entry *inet6_csk_route_socket(struct sock *sk,
 195                                                 struct flowi6 *fl6)
 196 {
 197         struct inet_sock *inet = inet_sk(sk);
 198         struct ipv6_pinfo *np = inet6_sk(sk);
 199         struct in6_addr *final_p, final;
 200         struct dst_entry *dst;
 201
 202         memset(fl6, 0, sizeof(*fl6));
 203         fl6->flowi6_proto = sk->sk_protocol;
 204         fl6->daddr = np->daddr;
 205         fl6->saddr = np->saddr;
 206         fl6->flowlabel = np->flow_label;
 207         IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 208         fl6->flowi6_oif = sk->sk_bound_dev_if;
 209         fl6->flowi6_mark = sk->sk_mark;
 210         fl6->fl6_sport = inet->inet_sport;
 211         fl6->fl6_dport = inet->inet_dport;
 212         security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
 213
 214         final_p = fl6_update_dst(fl6, np->opt, &final);
 215
 216         dst = __inet6_csk_dst_check(sk, np->dst_cookie);
 217         if (!dst) {
 218                 dst = ip6_dst_lookup_flow(sk, fl6, final_p, false);
 219
 220                 if (!IS_ERR(dst))
 221                         __inet6_csk_dst_store(sk, dst, NULL, NULL);
 222         }
 223         return dst;
 224 }
 225
 226 int inet6_csk_xmit(struct sk_buff *skb, struct flowi *fl_unused)
 227 {
 228         struct sock *sk = skb->sk;
 229         struct ipv6_pinfo *np = inet6_sk(sk);
 230         struct flowi6 fl6;
 231         struct dst_entry *dst;
 232         int res;
 233
 234         dst = inet6_csk_route_socket(sk, &fl6);
 235         if (IS_ERR(dst)) {
 236                 sk->sk_err_soft = -PTR_ERR(dst);
 237                 sk->sk_route_caps = 0;
 238                 kfree_skb(skb);
 239                 return PTR_ERR(dst);
 240         }
 241
 242         rcu_read_lock();
 243         skb_dst_set_noref(skb, dst);
 244
 245         /* Restore final destination back after routing done */
 246         fl6.daddr = np->daddr;
 247
 248         res = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
 249         rcu_read_unlock();
 250         return res;
 251 }
 252 EXPORT_SYMBOL_GPL(inet6_csk_xmit);
 253
 254 struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu)
 255 {
 256         struct flowi6 fl6;
 257         struct dst_entry *dst = inet6_csk_route_socket(sk, &fl6);
 258
 259         if (IS_ERR(dst))
 260                 return NULL;
 261         dst->ops->update_pmtu(dst, sk, NULL, mtu);
 262
 263         dst = inet6_csk_route_socket(sk, &fl6);
 264         return IS_ERR(dst) ? NULL : dst;
 265 }
 266 EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu);