net/ipv4/raw_diag.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 #include <linux/module.h>
   3
   4 #include <linux/inet_diag.h>
   5 #include <linux/sock_diag.h>
   6
   7 #include <net/inet_sock.h>
   8 #include <net/raw.h>
   9 #include <net/rawv6.h>
  10
  11 #ifdef pr_fmt
  12 # undef pr_fmt
  13 #endif
  14
  15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  16
  17 static struct raw_hashinfo *
  18 raw_get_hashinfo(const struct inet_diag_req_v2 *r)
  19 {
  20         if (r->sdiag_family == AF_INET) {
  21                 return &raw_v4_hashinfo;
  22 #if IS_ENABLED(CONFIG_IPV6)
  23         } else if (r->sdiag_family == AF_INET6) {
  24                 return &raw_v6_hashinfo;
  25 #endif
  26         } else {
  27                 return ERR_PTR(-EINVAL);
  28         }
  29 }
  30
  31 /*
  32  * Due to requirement of not breaking user API we can't simply
  33  * rename @pad field in inet_diag_req_v2 structure, instead
  34  * use helper to figure it out.
  35  */
  36
  37 static bool raw_lookup(struct net *net, const struct sock *sk,
  38                        const struct inet_diag_req_v2 *req)
  39 {
  40         struct inet_diag_req_raw *r = (void *)req;
  41
  42         if (r->sdiag_family == AF_INET)
  43                 return raw_v4_match(net, sk, r->sdiag_raw_protocol,
  44                                     r->id.idiag_dst[0],
  45                                     r->id.idiag_src[0],
  46                                     r->id.idiag_if, 0);
  47 #if IS_ENABLED(CONFIG_IPV6)
  48         else
  49                 return raw_v6_match(net, sk, r->sdiag_raw_protocol,
  50                                     (const struct in6_addr *)r->id.idiag_src,
  51                                     (const struct in6_addr *)r->id.idiag_dst,
  52                                     r->id.idiag_if, 0);
  53 #endif
  54         return false;
  55 }
  56
  57 static struct sock *raw_sock_get(struct net *net, const struct inet_diag_req_v2 *r)
  58 {
  59         struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
  60         struct hlist_head *hlist;
  61         struct sock *sk;
  62         int slot;
  63
  64         if (IS_ERR(hashinfo))
  65                 return ERR_CAST(hashinfo);
  66
  67         rcu_read_lock();
  68         for (slot = 0; slot < RAW_HTABLE_SIZE; slot++) {
  69                 hlist = &hashinfo->ht[slot];
  70                 sk_for_each_rcu(sk, hlist) {
  71                         if (raw_lookup(net, sk, r)) {
  72                                 /*
  73                                  * Grab it and keep until we fill
  74                                  * diag message to be reported, so
  75                                  * caller should call sock_put then.
  76                                  */
  77                                 if (refcount_inc_not_zero(&sk->sk_refcnt))
  78                                         goto out_unlock;
  79                         }
  80                 }
  81         }
  82         sk = ERR_PTR(-ENOENT);
  83 out_unlock:
  84         rcu_read_unlock();
  85
  86         return sk;
  87 }
  88
  89 static int raw_diag_dump_one(struct netlink_callback *cb,
  90                              const struct inet_diag_req_v2 *r)
  91 {
  92         struct sk_buff *in_skb = cb->skb;
  93         struct sk_buff *rep;
  94         struct sock *sk;
  95         struct net *net;
  96         int err;
  97
  98         net = sock_net(in_skb->sk);
  99         sk = raw_sock_get(net, r);
 100         if (IS_ERR(sk))
 101                 return PTR_ERR(sk);
 102
 103         rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) +
 104                         inet_diag_msg_attrs_size() +
 105                         nla_total_size(sizeof(struct inet_diag_meminfo)) + 64,
 106                         GFP_KERNEL);
 107         if (!rep) {
 108                 sock_put(sk);
 109                 return -ENOMEM;
 110         }
 111
 112         err = inet_sk_diag_fill(sk, NULL, rep, cb, r, 0,
 113                                 netlink_net_capable(in_skb, CAP_NET_ADMIN));
 114         sock_put(sk);
 115
 116         if (err < 0) {
 117                 kfree_skb(rep);
 118                 return err;
 119         }
 120
 121         err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid);
 122
 123         return err;
 124 }
 125
 126 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
 127                         struct netlink_callback *cb,
 128                         const struct inet_diag_req_v2 *r,
 129                         struct nlattr *bc, bool net_admin)
 130 {
 131         if (!inet_diag_bc_sk(bc, sk))
 132                 return 0;
 133
 134         return inet_sk_diag_fill(sk, NULL, skb, cb, r, NLM_F_MULTI, net_admin);
 135 }
 136
 137 static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 138                           const struct inet_diag_req_v2 *r)
 139 {
 140         bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
 141         struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
 142         struct net *net = sock_net(skb->sk);
 143         struct inet_diag_dump_data *cb_data;
 144         int num, s_num, slot, s_slot;
 145         struct hlist_head *hlist;
 146         struct sock *sk = NULL;
 147         struct nlattr *bc;
 148
 149         if (IS_ERR(hashinfo))
 150                 return;
 151
 152         cb_data = cb->data;
 153         bc = cb_data->inet_diag_nla_bc;
 154         s_slot = cb->args[0];
 155         num = s_num = cb->args[1];
 156
 157         rcu_read_lock();
 158         for (slot = s_slot; slot < RAW_HTABLE_SIZE; s_num = 0, slot++) {
 159                 num = 0;
 160
 161                 hlist = &hashinfo->ht[slot];
 162                 sk_for_each_rcu(sk, hlist) {
 163                         struct inet_sock *inet = inet_sk(sk);
 164
 165                         if (!net_eq(sock_net(sk), net))
 166                                 continue;
 167                         if (num < s_num)
 168                                 goto next;
 169                         if (sk->sk_family != r->sdiag_family)
 170                                 goto next;
 171                         if (r->id.idiag_sport != inet->inet_sport &&
 172                             r->id.idiag_sport)
 173                                 goto next;
 174                         if (r->id.idiag_dport != inet->inet_dport &&
 175                             r->id.idiag_dport)
 176                                 goto next;
 177                         if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0)
 178                                 goto out_unlock;
 179 next:
 180                         num++;
 181                 }
 182         }
 183
 184 out_unlock:
 185         rcu_read_unlock();
 186
 187         cb->args[0] = slot;
 188         cb->args[1] = num;
 189 }
 190
 191 static void raw_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 192                               void *info)
 193 {
 194         r->idiag_rqueue = sk_rmem_alloc_get(sk);
 195         r->idiag_wqueue = sk_wmem_alloc_get(sk);
 196 }
 197
 198 #ifdef CONFIG_INET_DIAG_DESTROY
 199 static int raw_diag_destroy(struct sk_buff *in_skb,
 200                             const struct inet_diag_req_v2 *r)
 201 {
 202         struct net *net = sock_net(in_skb->sk);
 203         struct sock *sk;
 204         int err;
 205
 206         sk = raw_sock_get(net, r);
 207         if (IS_ERR(sk))
 208                 return PTR_ERR(sk);
 209         err = sock_diag_destroy(sk, ECONNABORTED);
 210         sock_put(sk);
 211         return err;
 212 }
 213 #endif
 214
 215 static const struct inet_diag_handler raw_diag_handler = {
 216         .dump                   = raw_diag_dump,
 217         .dump_one               = raw_diag_dump_one,
 218         .idiag_get_info         = raw_diag_get_info,
 219         .idiag_type             = IPPROTO_RAW,
 220         .idiag_info_size        = 0,
 221 #ifdef CONFIG_INET_DIAG_DESTROY
 222         .destroy                = raw_diag_destroy,
 223 #endif
 224 };
 225
 226 static void __always_unused __check_inet_diag_req_raw(void)
 227 {
 228         /*
 229          * Make sure the two structures are identical,
 230          * except the @pad field.
 231          */
 232 #define __offset_mismatch(m1, m2)                       \
 233         (offsetof(struct inet_diag_req_v2, m1) !=       \
 234          offsetof(struct inet_diag_req_raw, m2))
 235
 236         BUILD_BUG_ON(sizeof(struct inet_diag_req_v2) !=
 237                      sizeof(struct inet_diag_req_raw));
 238         BUILD_BUG_ON(__offset_mismatch(sdiag_family, sdiag_family));
 239         BUILD_BUG_ON(__offset_mismatch(sdiag_protocol, sdiag_protocol));
 240         BUILD_BUG_ON(__offset_mismatch(idiag_ext, idiag_ext));
 241         BUILD_BUG_ON(__offset_mismatch(pad, sdiag_raw_protocol));
 242         BUILD_BUG_ON(__offset_mismatch(idiag_states, idiag_states));
 243         BUILD_BUG_ON(__offset_mismatch(id, id));
 244 #undef __offset_mismatch
 245 }
 246
 247 static int __init raw_diag_init(void)
 248 {
 249         return inet_diag_register(&raw_diag_handler);
 250 }
 251
 252 static void __exit raw_diag_exit(void)
 253 {
 254         inet_diag_unregister(&raw_diag_handler);
 255 }
 256
 257 module_init(raw_diag_init);
 258 module_exit(raw_diag_exit);
 259 MODULE_LICENSE("GPL");
 260 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-255 /* AF_INET - IPPROTO_RAW */);
 261 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10-255 /* AF_INET6 - IPPROTO_RAW */);