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

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

  #include <linux/netdevice.h>

  #include <linux/packet_diag.h>

  #include <linux/percpu.h>

  #include <net/net_namespace.h>
  #include <net/sock.h>
  
  #include "internal.h"

  static int pdiag_put_info(const struct packet_sock *po, struct sk_buff *nlskb)
  {
  	struct packet_diag_info pinfo;
  
  	pinfo.pdi_index = po->ifindex;
  	pinfo.pdi_version = po->tp_version;
  	pinfo.pdi_reserve = po->tp_reserve;
  	pinfo.pdi_copy_thresh = po->copy_thresh;
  	pinfo.pdi_tstamp = po->tp_tstamp;
  
  	pinfo.pdi_flags = 0;
  	if (po->running)
  		pinfo.pdi_flags |= PDI_RUNNING;
  	if (po->auxdata)
  		pinfo.pdi_flags |= PDI_AUXDATA;
  	if (po->origdev)
  		pinfo.pdi_flags |= PDI_ORIGDEV;
  	if (po->has_vnet_hdr)
  		pinfo.pdi_flags |= PDI_VNETHDR;
  	if (po->tp_loss)
  		pinfo.pdi_flags |= PDI_LOSS;
  
  	return nla_put(nlskb, PACKET_DIAG_INFO, sizeof(pinfo), &pinfo);
  }

  static int pdiag_put_mclist(const struct packet_sock *po, struct sk_buff *nlskb)
  {
  	struct nlattr *mca;
  	struct packet_mclist *ml;

  	mca = nla_nest_start_noflag(nlskb, PACKET_DIAG_MCLIST);

  	if (!mca)
  		return -EMSGSIZE;
  
  	rtnl_lock();
  	for (ml = po->mclist; ml; ml = ml->next) {
  		struct packet_diag_mclist *dml;
  
  		dml = nla_reserve_nohdr(nlskb, sizeof(*dml));
  		if (!dml) {
  			rtnl_unlock();
  			nla_nest_cancel(nlskb, mca);
  			return -EMSGSIZE;
  		}
  
  		dml->pdmc_index = ml->ifindex;
  		dml->pdmc_type = ml->type;
  		dml->pdmc_alen = ml->alen;
  		dml->pdmc_count = ml->count;
  		BUILD_BUG_ON(sizeof(dml->pdmc_addr) != sizeof(ml->addr));
  		memcpy(dml->pdmc_addr, ml->addr, sizeof(ml->addr));
  	}
  
  	rtnl_unlock();
  	nla_nest_end(nlskb, mca);
  
  	return 0;
  }

  static int pdiag_put_ring(struct packet_ring_buffer *ring, int ver, int nl_type,
  		struct sk_buff *nlskb)
  {
  	struct packet_diag_ring pdr;

  	if (!ring->pg_vec)

  		return 0;
  
  	pdr.pdr_block_size = ring->pg_vec_pages << PAGE_SHIFT;
  	pdr.pdr_block_nr = ring->pg_vec_len;
  	pdr.pdr_frame_size = ring->frame_size;
  	pdr.pdr_frame_nr = ring->frame_max + 1;
  
  	if (ver > TPACKET_V2) {
  		pdr.pdr_retire_tmo = ring->prb_bdqc.retire_blk_tov;
  		pdr.pdr_sizeof_priv = ring->prb_bdqc.blk_sizeof_priv;
  		pdr.pdr_features = ring->prb_bdqc.feature_req_word;
  	} else {
  		pdr.pdr_retire_tmo = 0;
  		pdr.pdr_sizeof_priv = 0;
  		pdr.pdr_features = 0;
  	}
  
  	return nla_put(nlskb, nl_type, sizeof(pdr), &pdr);
  }
  
  static int pdiag_put_rings_cfg(struct packet_sock *po, struct sk_buff *skb)
  {
  	int ret;
  
  	mutex_lock(&po->pg_vec_lock);
  	ret = pdiag_put_ring(&po->rx_ring, po->tp_version,
  			PACKET_DIAG_RX_RING, skb);
  	if (!ret)
  		ret = pdiag_put_ring(&po->tx_ring, po->tp_version,
  				PACKET_DIAG_TX_RING, skb);
  	mutex_unlock(&po->pg_vec_lock);
  
  	return ret;
  }

  static int pdiag_put_fanout(struct packet_sock *po, struct sk_buff *nlskb)
  {
  	int ret = 0;
  
  	mutex_lock(&fanout_mutex);
  	if (po->fanout) {
  		u32 val;
  
  		val = (u32)po->fanout->id | ((u32)po->fanout->type << 16);
  		ret = nla_put_u32(nlskb, PACKET_DIAG_FANOUT, val);
  	}
  	mutex_unlock(&fanout_mutex);
  
  	return ret;
  }

  static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
  			struct packet_diag_req *req,

  			bool may_report_filterinfo,

  			struct user_namespace *user_ns,
  			u32 portid, u32 seq, u32 flags, int sk_ino)

  {
  	struct nlmsghdr *nlh;
  	struct packet_diag_msg *rp;

  	struct packet_sock *po = pkt_sk(sk);

  	nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rp), flags);

  	if (!nlh)
  		return -EMSGSIZE;
  
  	rp = nlmsg_data(nlh);
  	rp->pdiag_family = AF_PACKET;
  	rp->pdiag_type = sk->sk_type;
  	rp->pdiag_num = ntohs(po->num);
  	rp->pdiag_ino = sk_ino;
  	sock_diag_save_cookie(sk, rp->pdiag_cookie);

  	if ((req->pdiag_show & PACKET_SHOW_INFO) &&
  			pdiag_put_info(po, skb))
  		goto out_nlmsg_trim;

  	if ((req->pdiag_show & PACKET_SHOW_INFO) &&
  	    nla_put_u32(skb, PACKET_DIAG_UID,
  			from_kuid_munged(user_ns, sock_i_uid(sk))))
  		goto out_nlmsg_trim;

  	if ((req->pdiag_show & PACKET_SHOW_MCLIST) &&
  			pdiag_put_mclist(po, skb))
  		goto out_nlmsg_trim;

  	if ((req->pdiag_show & PACKET_SHOW_RING_CFG) &&
  			pdiag_put_rings_cfg(po, skb))
  		goto out_nlmsg_trim;

  	if ((req->pdiag_show & PACKET_SHOW_FANOUT) &&
  			pdiag_put_fanout(po, skb))
  		goto out_nlmsg_trim;

  	if ((req->pdiag_show & PACKET_SHOW_MEMINFO) &&
  	    sock_diag_put_meminfo(sk, skb, PACKET_DIAG_MEMINFO))
  		goto out_nlmsg_trim;

  	if ((req->pdiag_show & PACKET_SHOW_FILTER) &&

  	    sock_diag_put_filterinfo(may_report_filterinfo, sk, skb,
  				     PACKET_DIAG_FILTER))

  		goto out_nlmsg_trim;

  	nlmsg_end(skb, nlh);
  	return 0;

  
  out_nlmsg_trim:
  	nlmsg_cancel(skb, nlh);
  	return -EMSGSIZE;

  }
  
  static int packet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
  {
  	int num = 0, s_num = cb->args[0];
  	struct packet_diag_req *req;
  	struct net *net;
  	struct sock *sk;

  	bool may_report_filterinfo;

  
  	net = sock_net(skb->sk);
  	req = nlmsg_data(cb->nlh);

  	may_report_filterinfo = netlink_net_capable(cb->skb, CAP_NET_ADMIN);

  	mutex_lock(&net->packet.sklist_lock);

  	sk_for_each(sk, &net->packet.sklist) {

  		if (!net_eq(sock_net(sk), net))
  			continue;
  		if (num < s_num)
  			goto next;

  		if (sk_diag_fill(sk, skb, req,

  				 may_report_filterinfo,

  				 sk_user_ns(NETLINK_CB(cb->skb).sk),
  				 NETLINK_CB(cb->skb).portid,
  				 cb->nlh->nlmsg_seq, NLM_F_MULTI,
  				 sock_i_ino(sk)) < 0)

  			goto done;
  next:
  		num++;
  	}
  done:

  	mutex_unlock(&net->packet.sklist_lock);

  	cb->args[0] = num;
  
  	return skb->len;
  }
  
  static int packet_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
  {
  	int hdrlen = sizeof(struct packet_diag_req);
  	struct net *net = sock_net(skb->sk);
  	struct packet_diag_req *req;
  
  	if (nlmsg_len(h) < hdrlen)
  		return -EINVAL;
  
  	req = nlmsg_data(h);
  	/* Make it possible to support protocol filtering later */
  	if (req->sdiag_protocol)
  		return -EINVAL;
  
  	if (h->nlmsg_flags & NLM_F_DUMP) {
  		struct netlink_dump_control c = {
  			.dump = packet_diag_dump,
  		};
  		return netlink_dump_start(net->diag_nlsk, skb, h, &c);
  	} else
  		return -EOPNOTSUPP;
  }
  
  static const struct sock_diag_handler packet_diag_handler = {
  	.family = AF_PACKET,
  	.dump = packet_diag_handler_dump,
  };
  
  static int __init packet_diag_init(void)
  {
  	return sock_diag_register(&packet_diag_handler);
  }
  
  static void __exit packet_diag_exit(void)
  {
  	sock_diag_unregister(&packet_diag_handler);
  }
  
  module_init(packet_diag_init);
  module_exit(packet_diag_exit);
  MODULE_LICENSE("GPL");
  MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 17 /* AF_PACKET */);