// SPDX-License-Identifier: GPL-2.0-only

  #include <linux/module.h>
  
  #include <linux/inet_diag.h>
  #include <linux/sock_diag.h>

  #include <net/inet_sock.h>

  #include <net/raw.h>
  #include <net/rawv6.h>
  
  #ifdef pr_fmt
  # undef pr_fmt
  #endif
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  static struct raw_hashinfo *
  raw_get_hashinfo(const struct inet_diag_req_v2 *r)
  {
  	if (r->sdiag_family == AF_INET) {
  		return &raw_v4_hashinfo;
  #if IS_ENABLED(CONFIG_IPV6)
  	} else if (r->sdiag_family == AF_INET6) {
  		return &raw_v6_hashinfo;
  #endif
  	} else {

  		return ERR_PTR(-EINVAL);
  	}
  }
  
  /*
   * Due to requirement of not breaking user API we can't simply
   * rename @pad field in inet_diag_req_v2 structure, instead
   * use helper to figure it out.
   */
  
  static struct sock *raw_lookup(struct net *net, struct sock *from,
  			       const struct inet_diag_req_v2 *req)
  {
  	struct inet_diag_req_raw *r = (void *)req;
  	struct sock *sk = NULL;
  
  	if (r->sdiag_family == AF_INET)
  		sk = __raw_v4_lookup(net, from, r->sdiag_raw_protocol,
  				     r->id.idiag_dst[0],
  				     r->id.idiag_src[0],

  				     r->id.idiag_if, 0);

  #if IS_ENABLED(CONFIG_IPV6)
  	else
  		sk = __raw_v6_lookup(net, from, r->sdiag_raw_protocol,
  				     (const struct in6_addr *)r->id.idiag_src,
  				     (const struct in6_addr *)r->id.idiag_dst,

  				     r->id.idiag_if, 0);

  #endif
  	return sk;
  }
  
  static struct sock *raw_sock_get(struct net *net, const struct inet_diag_req_v2 *r)
  {
  	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
  	struct sock *sk = NULL, *s;
  	int slot;
  
  	if (IS_ERR(hashinfo))
  		return ERR_CAST(hashinfo);
  
  	read_lock(&hashinfo->lock);
  	for (slot = 0; slot < RAW_HTABLE_SIZE; slot++) {
  		sk_for_each(s, &hashinfo->ht[slot]) {
  			sk = raw_lookup(net, s, r);
  			if (sk) {
  				/*
  				 * Grab it and keep until we fill
  				 * diag meaage to be reported, so
  				 * caller should call sock_put then.
  				 * We can do that because we're keeping
  				 * hashinfo->lock here.
  				 */
  				sock_hold(sk);

  				goto out_unlock;

  			}
  		}
  	}

  out_unlock:

  	read_unlock(&hashinfo->lock);
  
  	return sk ? sk : ERR_PTR(-ENOENT);
  }

  static int raw_diag_dump_one(struct netlink_callback *cb,

  			     const struct inet_diag_req_v2 *r)
  {

  	struct sk_buff *in_skb = cb->skb;

  	struct sk_buff *rep;
  	struct sock *sk;

  	struct net *net;

  	int err;

  	net = sock_net(in_skb->sk);

  	sk = raw_sock_get(net, r);
  	if (IS_ERR(sk))
  		return PTR_ERR(sk);

  	rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) +
  			inet_diag_msg_attrs_size() +
  			nla_total_size(sizeof(struct inet_diag_meminfo)) + 64,

  			GFP_KERNEL);
  	if (!rep) {
  		sock_put(sk);
  		return -ENOMEM;
  	}

  	err = inet_sk_diag_fill(sk, NULL, rep, cb, r, 0,

  				netlink_net_capable(in_skb, CAP_NET_ADMIN));
  	sock_put(sk);
  
  	if (err < 0) {
  		kfree_skb(rep);
  		return err;
  	}
  
  	err = netlink_unicast(net->diag_nlsk, rep,
  			      NETLINK_CB(in_skb).portid,
  			      MSG_DONTWAIT);
  	if (err > 0)
  		err = 0;
  	return err;
  }
  
  static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
  			struct netlink_callback *cb,
  			const struct inet_diag_req_v2 *r,
  			struct nlattr *bc, bool net_admin)
  {
  	if (!inet_diag_bc_sk(bc, sk))
  		return 0;

  	return inet_sk_diag_fill(sk, NULL, skb, cb, r, NLM_F_MULTI, net_admin);

  }
  
  static void raw_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,

  			  const struct inet_diag_req_v2 *r)

  {
  	bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
  	struct raw_hashinfo *hashinfo = raw_get_hashinfo(r);
  	struct net *net = sock_net(skb->sk);

  	struct inet_diag_dump_data *cb_data;

  	int num, s_num, slot, s_slot;
  	struct sock *sk = NULL;

  	struct nlattr *bc;

  
  	if (IS_ERR(hashinfo))
  		return;

  	cb_data = cb->data;
  	bc = cb_data->inet_diag_nla_bc;

  	s_slot = cb->args[0];
  	num = s_num = cb->args[1];
  
  	read_lock(&hashinfo->lock);
  	for (slot = s_slot; slot < RAW_HTABLE_SIZE; s_num = 0, slot++) {
  		num = 0;
  
  		sk_for_each(sk, &hashinfo->ht[slot]) {
  			struct inet_sock *inet = inet_sk(sk);
  
  			if (!net_eq(sock_net(sk), net))
  				continue;
  			if (num < s_num)
  				goto next;
  			if (sk->sk_family != r->sdiag_family)
  				goto next;
  			if (r->id.idiag_sport != inet->inet_sport &&
  			    r->id.idiag_sport)
  				goto next;
  			if (r->id.idiag_dport != inet->inet_dport &&
  			    r->id.idiag_dport)
  				goto next;
  			if (sk_diag_dump(sk, skb, cb, r, bc, net_admin) < 0)
  				goto out_unlock;
  next:
  			num++;
  		}
  	}
  
  out_unlock:
  	read_unlock(&hashinfo->lock);
  
  	cb->args[0] = slot;
  	cb->args[1] = num;
  }
  
  static void raw_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
  			      void *info)
  {
  	r->idiag_rqueue = sk_rmem_alloc_get(sk);
  	r->idiag_wqueue = sk_wmem_alloc_get(sk);
  }
  
  #ifdef CONFIG_INET_DIAG_DESTROY
  static int raw_diag_destroy(struct sk_buff *in_skb,
  			    const struct inet_diag_req_v2 *r)
  {
  	struct net *net = sock_net(in_skb->sk);
  	struct sock *sk;

  	int err;

  
  	sk = raw_sock_get(net, r);
  	if (IS_ERR(sk))
  		return PTR_ERR(sk);

  	err = sock_diag_destroy(sk, ECONNABORTED);
  	sock_put(sk);
  	return err;

  }
  #endif
  
  static const struct inet_diag_handler raw_diag_handler = {
  	.dump			= raw_diag_dump,
  	.dump_one		= raw_diag_dump_one,
  	.idiag_get_info		= raw_diag_get_info,
  	.idiag_type		= IPPROTO_RAW,
  	.idiag_info_size	= 0,
  #ifdef CONFIG_INET_DIAG_DESTROY
  	.destroy		= raw_diag_destroy,
  #endif
  };
  
  static void __always_unused __check_inet_diag_req_raw(void)
  {
  	/*
  	 * Make sure the two structures are identical,
  	 * except the @pad field.
  	 */
  #define __offset_mismatch(m1, m2)			\
  	(offsetof(struct inet_diag_req_v2, m1) !=	\
  	 offsetof(struct inet_diag_req_raw, m2))
  
  	BUILD_BUG_ON(sizeof(struct inet_diag_req_v2) !=
  		     sizeof(struct inet_diag_req_raw));
  	BUILD_BUG_ON(__offset_mismatch(sdiag_family, sdiag_family));
  	BUILD_BUG_ON(__offset_mismatch(sdiag_protocol, sdiag_protocol));
  	BUILD_BUG_ON(__offset_mismatch(idiag_ext, idiag_ext));
  	BUILD_BUG_ON(__offset_mismatch(pad, sdiag_raw_protocol));
  	BUILD_BUG_ON(__offset_mismatch(idiag_states, idiag_states));
  	BUILD_BUG_ON(__offset_mismatch(id, id));
  #undef __offset_mismatch
  }
  
  static int __init raw_diag_init(void)
  {
  	return inet_diag_register(&raw_diag_handler);
  }
  
  static void __exit raw_diag_exit(void)
  {
  	inet_diag_unregister(&raw_diag_handler);
  }
  
  module_init(raw_diag_init);
  module_exit(raw_diag_exit);
  MODULE_LICENSE("GPL");
  MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-255 /* AF_INET - IPPROTO_RAW */);
  MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10-255 /* AF_INET6 - IPPROTO_RAW */);