linux/net/ipv4/udp_diag.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * udp_diag.c   Module for monitoring UDP transport protocols sockets.
   4 *
   5 * Authors:     Pavel Emelyanov, <xemul@parallels.com>
   6 */
   7
   8
   9#include <linux/module.h>
  10#include <linux/inet_diag.h>
  11#include <linux/udp.h>
  12#include <net/udp.h>
  13#include <net/udplite.h>
  14#include <linux/sock_diag.h>
  15
  16static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
  17                        struct netlink_callback *cb,
  18                        const struct inet_diag_req_v2 *req,
  19                        struct nlattr *bc, bool net_admin)
  20{
  21        if (!inet_diag_bc_sk(bc, sk))
  22                return 0;
  23
  24        return inet_sk_diag_fill(sk, NULL, skb, cb, req, NLM_F_MULTI,
  25                                 net_admin);
  26}
  27
  28static int udp_dump_one(struct udp_table *tbl,
  29                        struct netlink_callback *cb,
  30                        const struct inet_diag_req_v2 *req)
  31{
  32        struct sk_buff *in_skb = cb->skb;
  33        int err;
  34        struct sock *sk = NULL;
  35        struct sk_buff *rep;
  36        struct net *net = sock_net(in_skb->sk);
  37
  38        rcu_read_lock();
  39        if (req->sdiag_family == AF_INET)
  40                /* src and dst are swapped for historical reasons */
  41                sk = __udp4_lib_lookup(net,
  42                                req->id.idiag_src[0], req->id.idiag_sport,
  43                                req->id.idiag_dst[0], req->id.idiag_dport,
  44                                req->id.idiag_if, 0, tbl, NULL);
  45#if IS_ENABLED(CONFIG_IPV6)
  46        else if (req->sdiag_family == AF_INET6)
  47                sk = __udp6_lib_lookup(net,
  48                                (struct in6_addr *)req->id.idiag_src,
  49                                req->id.idiag_sport,
  50                                (struct in6_addr *)req->id.idiag_dst,
  51                                req->id.idiag_dport,
  52                                req->id.idiag_if, 0, tbl, NULL);
  53#endif
  54        if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
  55                sk = NULL;
  56        rcu_read_unlock();
  57        err = -ENOENT;
  58        if (!sk)
  59                goto out_nosk;
  60
  61        err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
  62        if (err)
  63                goto out;
  64
  65        err = -ENOMEM;
  66        rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) +
  67                        inet_diag_msg_attrs_size() +
  68                        nla_total_size(sizeof(struct inet_diag_meminfo)) + 64,
  69                        GFP_KERNEL);
  70        if (!rep)
  71                goto out;
  72
  73        err = inet_sk_diag_fill(sk, NULL, rep, cb, req, 0,
  74                                netlink_net_capable(in_skb, CAP_NET_ADMIN));
  75        if (err < 0) {
  76                WARN_ON(err == -EMSGSIZE);
  77                kfree_skb(rep);
  78                goto out;
  79        }
  80        err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
  81                              MSG_DONTWAIT);
  82        if (err > 0)
  83                err = 0;
  84out:
  85        if (sk)
  86                sock_put(sk);
  87out_nosk:
  88        return err;
  89}
  90
  91static void udp_dump(struct udp_table *table, struct sk_buff *skb,
  92                     struct netlink_callback *cb,
  93                     const struct inet_diag_req_v2 *r)
  94{
  95        bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
  96        struct net *net = sock_net(skb->sk);
  97        struct inet_diag_dump_data *cb_data;
  98        int num, s_num, slot, s_slot;
  99        struct nlattr *bc;
 100
 101        cb_data = cb->data;
 102        bc = cb_data->inet_diag_nla_bc;
 103        s_slot = cb->args[0];
 104        num = s_num = cb->args[1];
 105
 106        for (slot = s_slot; slot <= table->mask; s_num = 0, slot++) {
 107                struct udp_hslot *hslot = &table->hash[slot];
 108                struct sock *sk;
 109
 110                num = 0;
 111
 112                if (hlist_empty(&hslot->head))
 113                        continue;
 114
 115                spin_lock_bh(&hslot->lock);
 116                sk_for_each(sk, &hslot->head) {
 117                        struct inet_sock *inet = inet_sk(sk);
 118
 119                        if (!net_eq(sock_net(sk), net))
 120                                continue;
 121                        if (num < s_num)
 122                                goto next;
 123                        if (!(r->idiag_states & (1 << sk->sk_state)))
 124                                goto next;
 125                        if (r->sdiag_family != AF_UNSPEC &&
 126                                        sk->sk_family != r->sdiag_family)
 127                                goto next;
 128                        if (r->id.idiag_sport != inet->inet_sport &&
 129                            r->id.idiag_sport)
 130                                goto next;
 131                        if (r->id.idiag_dport != inet->inet_dport &&
 132                            r->id.idiag_dport)
 133                                goto next;
 134
 135                        if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0) {
 136                                spin_unlock_bh(&hslot->lock);
 137                                goto done;
 138                        }
 139next:
 140                        num++;
 141                }
 142                spin_unlock_bh(&hslot->lock);
 143        }
 144done:
 145        cb->args[0] = slot;
 146        cb->args[1] = num;
 147}
 148
 149static void udp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 150                          const struct inet_diag_req_v2 *r)
 151{
 152        udp_dump(&udp_table, skb, cb, r);
 153}
 154
 155static int udp_diag_dump_one(struct netlink_callback *cb,
 156                             const struct inet_diag_req_v2 *req)
 157{
 158        return udp_dump_one(&udp_table, cb, req);
 159}
 160
 161static void udp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
 162                void *info)
 163{
 164        r->idiag_rqueue = udp_rqueue_get(sk);
 165        r->idiag_wqueue = sk_wmem_alloc_get(sk);
 166}
 167
 168#ifdef CONFIG_INET_DIAG_DESTROY
 169static int __udp_diag_destroy(struct sk_buff *in_skb,
 170                              const struct inet_diag_req_v2 *req,
 171                              struct udp_table *tbl)
 172{
 173        struct net *net = sock_net(in_skb->sk);
 174        struct sock *sk;
 175        int err;
 176
 177        rcu_read_lock();
 178
 179        if (req->sdiag_family == AF_INET)
 180                sk = __udp4_lib_lookup(net,
 181                                req->id.idiag_dst[0], req->id.idiag_dport,
 182                                req->id.idiag_src[0], req->id.idiag_sport,
 183                                req->id.idiag_if, 0, tbl, NULL);
 184#if IS_ENABLED(CONFIG_IPV6)
 185        else if (req->sdiag_family == AF_INET6) {
 186                if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) &&
 187                    ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src))
 188                        sk = __udp4_lib_lookup(net,
 189                                        req->id.idiag_dst[3], req->id.idiag_dport,
 190                                        req->id.idiag_src[3], req->id.idiag_sport,
 191                                        req->id.idiag_if, 0, tbl, NULL);
 192
 193                else
 194                        sk = __udp6_lib_lookup(net,
 195                                        (struct in6_addr *)req->id.idiag_dst,
 196                                        req->id.idiag_dport,
 197                                        (struct in6_addr *)req->id.idiag_src,
 198                                        req->id.idiag_sport,
 199                                        req->id.idiag_if, 0, tbl, NULL);
 200        }
 201#endif
 202        else {
 203                rcu_read_unlock();
 204                return -EINVAL;
 205        }
 206
 207        if (sk && !refcount_inc_not_zero(&sk->sk_refcnt))
 208                sk = NULL;
 209
 210        rcu_read_unlock();
 211
 212        if (!sk)
 213                return -ENOENT;
 214
 215        if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) {
 216                sock_put(sk);
 217                return -ENOENT;
 218        }
 219
 220        err = sock_diag_destroy(sk, ECONNABORTED);
 221
 222        sock_put(sk);
 223
 224        return err;
 225}
 226
 227static int udp_diag_destroy(struct sk_buff *in_skb,
 228                            const struct inet_diag_req_v2 *req)
 229{
 230        return __udp_diag_destroy(in_skb, req, &udp_table);
 231}
 232
 233static int udplite_diag_destroy(struct sk_buff *in_skb,
 234                                const struct inet_diag_req_v2 *req)
 235{
 236        return __udp_diag_destroy(in_skb, req, &udplite_table);
 237}
 238
 239#endif
 240
 241static const struct inet_diag_handler udp_diag_handler = {
 242        .dump            = udp_diag_dump,
 243        .dump_one        = udp_diag_dump_one,
 244        .idiag_get_info  = udp_diag_get_info,
 245        .idiag_type      = IPPROTO_UDP,
 246        .idiag_info_size = 0,
 247#ifdef CONFIG_INET_DIAG_DESTROY
 248        .destroy         = udp_diag_destroy,
 249#endif
 250};
 251
 252static void udplite_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 253                              const struct inet_diag_req_v2 *r)
 254{
 255        udp_dump(&udplite_table, skb, cb, r);
 256}
 257
 258static int udplite_diag_dump_one(struct netlink_callback *cb,
 259                                 const struct inet_diag_req_v2 *req)
 260{
 261        return udp_dump_one(&udplite_table, cb, req);
 262}
 263
 264static const struct inet_diag_handler udplite_diag_handler = {
 265        .dump            = udplite_diag_dump,
 266        .dump_one        = udplite_diag_dump_one,
 267        .idiag_get_info  = udp_diag_get_info,
 268        .idiag_type      = IPPROTO_UDPLITE,
 269        .idiag_info_size = 0,
 270#ifdef CONFIG_INET_DIAG_DESTROY
 271        .destroy         = udplite_diag_destroy,
 272#endif
 273};
 274
 275static int __init udp_diag_init(void)
 276{
 277        int err;
 278
 279        err = inet_diag_register(&udp_diag_handler);
 280        if (err)
 281                goto out;
 282        err = inet_diag_register(&udplite_diag_handler);
 283        if (err)
 284                goto out_lite;
 285out:
 286        return err;
 287out_lite:
 288        inet_diag_unregister(&udp_diag_handler);
 289        goto out;
 290}
 291
 292static void __exit udp_diag_exit(void)
 293{
 294        inet_diag_unregister(&udplite_diag_handler);
 295        inet_diag_unregister(&udp_diag_handler);
 296}
 297
 298module_init(udp_diag_init);
 299module_exit(udp_diag_exit);
 300MODULE_LICENSE("GPL");
 301MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-17 /* AF_INET - IPPROTO_UDP */);
 302MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-136 /* AF_INET - IPPROTO_UDPLITE */);
 303