Exemple #1
0
static int
nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
		      int event, u16 family, const char *name,
		      int rev, int target)
{
	struct nlmsghdr *nlh;
	struct nfgenmsg *nfmsg;
	unsigned int flags = portid ? NLM_F_MULTI : 0;

	event = nfnl_msg_type(NFNL_SUBSYS_NFT_COMPAT, event);
	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
	if (nlh == NULL)
		goto nlmsg_failure;

	nfmsg = nlmsg_data(nlh);
	nfmsg->nfgen_family = family;
	nfmsg->version = NFNETLINK_V0;
	nfmsg->res_id = 0;

	if (nla_put_string(skb, NFTA_COMPAT_NAME, name) ||
	    nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) ||
	    nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target)))
		goto nla_put_failure;

	nlmsg_end(skb, nlh);
	return skb->len;

nlmsg_failure:
nla_put_failure:
	nlmsg_cancel(skb, nlh);
	return -1;
}
/* This is an inline function, we don't really care about a long
 * list of arguments */
static inline int
__build_packet_message(struct nfnl_log_net *log,
			struct nfulnl_instance *inst,
			const struct sk_buff *skb,
			unsigned int data_len,
			u_int8_t pf,
			unsigned int hooknum,
			const struct net_device *indev,
			const struct net_device *outdev,
			const char *prefix, unsigned int plen,
			const struct nfnl_ct_hook *nfnl_ct,
			struct nf_conn *ct, enum ip_conntrack_info ctinfo)
{
	struct nfulnl_msg_packet_hdr pmsg;
	struct nlmsghdr *nlh;
	struct nfgenmsg *nfmsg;
	sk_buff_data_t old_tail = inst->skb->tail;
	struct sock *sk;
	const unsigned char *hwhdrp;

	nlh = nlmsg_put(inst->skb, 0, 0,
			nfnl_msg_type(NFNL_SUBSYS_ULOG, NFULNL_MSG_PACKET),
			sizeof(struct nfgenmsg), 0);
	if (!nlh)
		return -1;
	nfmsg = nlmsg_data(nlh);
	nfmsg->nfgen_family = pf;
	nfmsg->version = NFNETLINK_V0;
	nfmsg->res_id = htons(inst->group_num);

	memset(&pmsg, 0, sizeof(pmsg));
	pmsg.hw_protocol	= skb->protocol;
	pmsg.hook		= hooknum;

	if (nla_put(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg))
		goto nla_put_failure;

	if (prefix &&
	    nla_put(inst->skb, NFULA_PREFIX, plen, prefix))
		goto nla_put_failure;

	if (indev) {
#if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
		if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
				 htonl(indev->ifindex)))
			goto nla_put_failure;
#else
		if (pf == PF_BRIDGE) {
			/* Case 1: outdev is physical input device, we need to
			 * look for bridge group (when called from
			 * netfilter_bridge) */
			if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
					 htonl(indev->ifindex)) ||
			/* this is the bridge group "brX" */
			/* rcu_read_lock()ed by nf_hook_thresh or
			 * nf_log_packet.
			 */
			    nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
					 htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
				goto nla_put_failure;
		} else {
			struct net_device *physindev;

			/* Case 2: indev is bridge group, we need to look for
			 * physical device (when called from ipv4) */
			if (nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
					 htonl(indev->ifindex)))
				goto nla_put_failure;

			physindev = nf_bridge_get_physindev(skb);
			if (physindev &&
			    nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
					 htonl(physindev->ifindex)))
				goto nla_put_failure;
		}
#endif
	}

	if (outdev) {
#if !IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
		if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
				 htonl(outdev->ifindex)))
			goto nla_put_failure;
#else
		if (pf == PF_BRIDGE) {
			/* Case 1: outdev is physical output device, we need to
			 * look for bridge group (when called from
			 * netfilter_bridge) */
			if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
					 htonl(outdev->ifindex)) ||
			/* this is the bridge group "brX" */
			/* rcu_read_lock()ed by nf_hook_thresh or
			 * nf_log_packet.
			 */
			    nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
					 htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
				goto nla_put_failure;
		} else {
			struct net_device *physoutdev;

			/* Case 2: indev is a bridge group, we need to look
			 * for physical device (when called from ipv4) */
			if (nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
					 htonl(outdev->ifindex)))
				goto nla_put_failure;

			physoutdev = nf_bridge_get_physoutdev(skb);
			if (physoutdev &&
			    nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
					 htonl(physoutdev->ifindex)))
				goto nla_put_failure;
		}
#endif
	}

	if (skb->mark &&
	    nla_put_be32(inst->skb, NFULA_MARK, htonl(skb->mark)))
		goto nla_put_failure;

	if (indev && skb->dev &&
	    skb->mac_header != skb->network_header) {
		struct nfulnl_msg_packet_hw phw;
		int len;

		memset(&phw, 0, sizeof(phw));
		len = dev_parse_header(skb, phw.hw_addr);
		if (len > 0) {
			phw.hw_addrlen = htons(len);
			if (nla_put(inst->skb, NFULA_HWADDR, sizeof(phw), &phw))
				goto nla_put_failure;
		}
	}

	if (indev && skb_mac_header_was_set(skb)) {
		if (nla_put_be16(inst->skb, NFULA_HWTYPE, htons(skb->dev->type)) ||
		    nla_put_be16(inst->skb, NFULA_HWLEN,
				 htons(skb->dev->hard_header_len)))
			goto nla_put_failure;

		hwhdrp = skb_mac_header(skb);

		if (skb->dev->type == ARPHRD_SIT)
			hwhdrp -= ETH_HLEN;

		if (hwhdrp >= skb->head &&
		    nla_put(inst->skb, NFULA_HWHEADER,
			    skb->dev->hard_header_len, hwhdrp))
			goto nla_put_failure;
	}

	if (skb->tstamp) {
		struct nfulnl_msg_packet_timestamp ts;
		struct timespec64 kts = ktime_to_timespec64(skb->tstamp);
		ts.sec = cpu_to_be64(kts.tv_sec);
		ts.usec = cpu_to_be64(kts.tv_nsec / NSEC_PER_USEC);

		if (nla_put(inst->skb, NFULA_TIMESTAMP, sizeof(ts), &ts))
			goto nla_put_failure;
	}

	/* UID */
	sk = skb->sk;
	if (sk && sk_fullsock(sk)) {
		read_lock_bh(&sk->sk_callback_lock);
		if (sk->sk_socket && sk->sk_socket->file) {
			struct file *file = sk->sk_socket->file;
			const struct cred *cred = file->f_cred;
			struct user_namespace *user_ns = inst->peer_user_ns;
			__be32 uid = htonl(from_kuid_munged(user_ns, cred->fsuid));
			__be32 gid = htonl(from_kgid_munged(user_ns, cred->fsgid));
			read_unlock_bh(&sk->sk_callback_lock);
			if (nla_put_be32(inst->skb, NFULA_UID, uid) ||
			    nla_put_be32(inst->skb, NFULA_GID, gid))
				goto nla_put_failure;
		} else
			read_unlock_bh(&sk->sk_callback_lock);
	}

	/* local sequence number */
	if ((inst->flags & NFULNL_CFG_F_SEQ) &&
	    nla_put_be32(inst->skb, NFULA_SEQ, htonl(inst->seq++)))
		goto nla_put_failure;

	/* global sequence number */
	if ((inst->flags & NFULNL_CFG_F_SEQ_GLOBAL) &&
	    nla_put_be32(inst->skb, NFULA_SEQ_GLOBAL,
			 htonl(atomic_inc_return(&log->global_seq))))
		goto nla_put_failure;

	if (ct && nfnl_ct->build(inst->skb, ct, ctinfo,
				 NFULA_CT, NFULA_CT_INFO) < 0)
		goto nla_put_failure;

	if (data_len) {
		struct nlattr *nla;
		int size = nla_attr_size(data_len);

		if (skb_tailroom(inst->skb) < nla_total_size(data_len))
			goto nla_put_failure;

		nla = skb_put(inst->skb, nla_total_size(data_len));
		nla->nla_type = NFULA_PAYLOAD;
		nla->nla_len = size;

		if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
			BUG();
	}

	nlh->nlmsg_len = inst->skb->tail - old_tail;
	return 0;

nla_put_failure:
	PRINTR(KERN_ERR "nfnetlink_log: error creating log nlmsg\n");
	return -1;
}