Beispiel #1
0
void
nf_log_dump_packet_common(struct nf_log_buf *m, u_int8_t pf,
			  unsigned int hooknum, const struct sk_buff *skb,
			  const struct net_device *in,
			  const struct net_device *out,
			  const struct nf_loginfo *loginfo, const char *prefix)
{
	nf_log_buf_add(m, KERN_SOH "%c%sIN=%s OUT=%s ",
	       '0' + loginfo->u.log.level, prefix,
	       in ? in->name : "",
	       out ? out->name : "");
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
	if (skb->nf_bridge) {
		const struct net_device *physindev;
		const struct net_device *physoutdev;

		physindev = nf_bridge_get_physindev(skb);
		if (physindev && in != physindev)
			nf_log_buf_add(m, "PHYSIN=%s ", physindev->name);
		physoutdev = nf_bridge_get_physoutdev(skb);
		if (physoutdev && out != physoutdev)
			nf_log_buf_add(m, "PHYSOUT=%s ", physoutdev->name);
	}
#endif
}
Beispiel #2
0
static bool
physdev_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
	const struct xt_physdev_info *info = par->matchinfo;
	const struct net_device *physdev;
	unsigned long ret;
	const char *indev, *outdev;

	/* Not a bridged IP packet or no info available yet:
	 * LOCAL_OUT/mangle and LOCAL_OUT/nat don't know if
	 * the destination device will be a bridge. */
	if (!skb->nf_bridge) {
		/* Return MATCH if the invert flags of the used options are on */
		if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) &&
		    !(info->invert & XT_PHYSDEV_OP_BRIDGED))
			return false;
		if ((info->bitmask & XT_PHYSDEV_OP_ISIN) &&
		    !(info->invert & XT_PHYSDEV_OP_ISIN))
			return false;
		if ((info->bitmask & XT_PHYSDEV_OP_ISOUT) &&
		    !(info->invert & XT_PHYSDEV_OP_ISOUT))
			return false;
		if ((info->bitmask & XT_PHYSDEV_OP_IN) &&
		    !(info->invert & XT_PHYSDEV_OP_IN))
			return false;
		if ((info->bitmask & XT_PHYSDEV_OP_OUT) &&
		    !(info->invert & XT_PHYSDEV_OP_OUT))
			return false;
		return true;
	}

	physdev = nf_bridge_get_physoutdev(skb);
	outdev = physdev ? physdev->name : NULL;

	/* This only makes sense in the FORWARD and POSTROUTING chains */
	if ((info->bitmask & XT_PHYSDEV_OP_BRIDGED) &&
	    (!!outdev ^ !(info->invert & XT_PHYSDEV_OP_BRIDGED)))
		return false;

	physdev = nf_bridge_get_physindev(skb);
	indev = physdev ? physdev->name : NULL;

	if ((info->bitmask & XT_PHYSDEV_OP_ISIN &&
	    (!indev ^ !!(info->invert & XT_PHYSDEV_OP_ISIN))) ||
	    (info->bitmask & XT_PHYSDEV_OP_ISOUT &&
	    (!outdev ^ !!(info->invert & XT_PHYSDEV_OP_ISOUT))))
		return false;

	if (!(info->bitmask & XT_PHYSDEV_OP_IN))
		goto match_outdev;

	if (indev) {
		ret = ifname_compare_aligned(indev, info->physindev,
					     info->in_mask);

		if (!ret ^ !(info->invert & XT_PHYSDEV_OP_IN))
			return false;
	}

match_outdev:
	if (!(info->bitmask & XT_PHYSDEV_OP_OUT))
		return true;

	if (!outdev)
		return false;

	ret = ifname_compare_aligned(outdev, info->physoutdev, info->out_mask);

	return (!!ret ^ !(info->invert & XT_PHYSDEV_OP_OUT));
}
Beispiel #3
0
/* 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;
}
Beispiel #4
0
/* Send RST reply */
void nf_send_reset(struct net *net, struct sk_buff *oldskb, int hook)
{
	struct sk_buff *nskb;
	struct iphdr *niph;
	const struct tcphdr *oth;
	struct tcphdr _oth;

	oth = nf_reject_ip_tcphdr_get(oldskb, &_oth, hook);
	if (!oth)
		return;

	if (skb_rtable(oldskb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
		return;

	nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct tcphdr) +
			 LL_MAX_HEADER, GFP_ATOMIC);
	if (!nskb)
		return;

	/* ip_route_me_harder expects skb->dst to be set */
	skb_dst_set_noref(nskb, skb_dst(oldskb));

	nskb->mark = IP4_REPLY_MARK(net, oldskb->mark);

	skb_reserve(nskb, LL_MAX_HEADER);
	niph = nf_reject_iphdr_put(nskb, oldskb, IPPROTO_TCP,
				   ip4_dst_hoplimit(skb_dst(nskb)));
	nf_reject_ip_tcphdr_put(nskb, oldskb, oth);

	if (ip_route_me_harder(net, nskb, RTN_UNSPEC))
		goto free_nskb;

	niph = ip_hdr(nskb);

	/* "Never happens" */
	if (nskb->len > dst_mtu(skb_dst(nskb)))
		goto free_nskb;

	nf_ct_attach(nskb, oldskb);

#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
	/* If we use ip_local_out for bridged traffic, the MAC source on
	 * the RST will be ours, instead of the destination's.  This confuses
	 * some routers/firewalls, and they drop the packet.  So we need to
	 * build the eth header using the original destination's MAC as the
	 * source, and send the RST packet directly.
	 */
	if (oldskb->nf_bridge) {
		struct ethhdr *oeth = eth_hdr(oldskb);

		nskb->dev = nf_bridge_get_physindev(oldskb);
		niph->tot_len = htons(nskb->len);
		ip_send_check(niph);
		if (dev_hard_header(nskb, nskb->dev, ntohs(nskb->protocol),
				    oeth->h_source, oeth->h_dest, nskb->len) < 0)
			goto free_nskb;
		dev_queue_xmit(nskb);
	} else
#endif
		ip_local_out(net, nskb->sk, nskb);

	return;

 free_nskb:
	kfree_skb(nskb);
}
Beispiel #5
0
void nf_send_reset6(struct net *net, struct sk_buff *oldskb, int hook)
{
	struct sk_buff *nskb;
	struct tcphdr _otcph;
	const struct tcphdr *otcph;
	unsigned int otcplen, hh_len;
	const struct ipv6hdr *oip6h = ipv6_hdr(oldskb);
	struct ipv6hdr *ip6h;
	struct dst_entry *dst = NULL;
	struct flowi6 fl6;

	if ((!(ipv6_addr_type(&oip6h->saddr) & IPV6_ADDR_UNICAST)) ||
	    (!(ipv6_addr_type(&oip6h->daddr) & IPV6_ADDR_UNICAST))) {
		pr_debug("addr is not unicast.\n");
		return;
	}

	otcph = nf_reject_ip6_tcphdr_get(oldskb, &_otcph, &otcplen, hook);
	if (!otcph)
		return;

	memset(&fl6, 0, sizeof(fl6));
	fl6.flowi6_proto = IPPROTO_TCP;
	fl6.saddr = oip6h->daddr;
	fl6.daddr = oip6h->saddr;
	fl6.fl6_sport = otcph->dest;
	fl6.fl6_dport = otcph->source;
	security_skb_classify_flow(oldskb, flowi6_to_flowi(&fl6));
	dst = ip6_route_output(net, NULL, &fl6);
	if (dst == NULL || dst->error) {
		dst_release(dst);
		return;
	}
	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), NULL, 0);
	if (IS_ERR(dst))
		return;

	hh_len = (dst->dev->hard_header_len + 15)&~15;
	nskb = alloc_skb(hh_len + 15 + dst->header_len + sizeof(struct ipv6hdr)
			 + sizeof(struct tcphdr) + dst->trailer_len,
			 GFP_ATOMIC);

	if (!nskb) {
		net_dbg_ratelimited("cannot alloc skb\n");
		dst_release(dst);
		return;
	}

	skb_dst_set(nskb, dst);

	skb_reserve(nskb, hh_len + dst->header_len);
	ip6h = nf_reject_ip6hdr_put(nskb, oldskb, IPPROTO_TCP,
				    ip6_dst_hoplimit(dst));
	nf_reject_ip6_tcphdr_put(nskb, oldskb, otcph, otcplen);

	nf_ct_attach(nskb, oldskb);

#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
	/* If we use ip6_local_out for bridged traffic, the MAC source on
	 * the RST will be ours, instead of the destination's.  This confuses
	 * some routers/firewalls, and they drop the packet.  So we need to
	 * build the eth header using the original destination's MAC as the
	 * source, and send the RST packet directly.
	 */
	if (oldskb->nf_bridge) {
		struct ethhdr *oeth = eth_hdr(oldskb);

		nskb->dev = nf_bridge_get_physindev(oldskb);
		nskb->protocol = htons(ETH_P_IPV6);
		ip6h->payload_len = htons(sizeof(struct tcphdr));
		if (dev_hard_header(nskb, nskb->dev, ntohs(nskb->protocol),
				    oeth->h_source, oeth->h_dest, nskb->len) < 0)
			return;
		dev_queue_xmit(nskb);
	} else
#endif
		ip6_local_out(net, nskb->sk, nskb);
}