Пример #1
0
static bool
socket_mt4_v1(const struct sk_buff *skb, struct xt_action_param *par)
{
	return socket_match(skb, par, par->matchinfo);
}
Пример #2
0
static bool
socket_mt4_v0(const struct sk_buff *skb, struct xt_action_param *par)
{
	static struct xt_socket_mtinfo1 xt_info_v0 = {
		.flags = 0,
	};

	return socket_match(skb, par, &xt_info_v0);
}

static bool
socket_mt4_v1_v2_v3(const struct sk_buff *skb, struct xt_action_param *par)
{
	return socket_match(skb, par, par->matchinfo);
}

#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
static bool
socket_mt6_v1_v2_v3(const struct sk_buff *skb, struct xt_action_param *par)
{
	const struct xt_socket_mtinfo1 *info = (struct xt_socket_mtinfo1 *) par->matchinfo;
	struct sk_buff *pskb = (struct sk_buff *)skb;
	struct sock *sk = skb->sk;

	if (sk && !net_eq(xt_net(par), sock_net(sk)))
		sk = NULL;

	if (!sk)
		sk = nf_sk_lookup_slow_v6(xt_net(par), skb, xt_in(par));

	if (sk) {
		bool wildcard;
		bool transparent = true;

		/* Ignore sockets listening on INADDR_ANY
		 * unless XT_SOCKET_NOWILDCARD is set
		 */
		wildcard = (!(info->flags & XT_SOCKET_NOWILDCARD) &&
			    sk_fullsock(sk) &&
			    ipv6_addr_any(&sk->sk_v6_rcv_saddr));

		/* Ignore non-transparent sockets,
		 * if XT_SOCKET_TRANSPARENT is used
		 */
		if (info->flags & XT_SOCKET_TRANSPARENT)
			transparent = inet_sk_transparent(sk);

		if (info->flags & XT_SOCKET_RESTORESKMARK && !wildcard &&
		    transparent && sk_fullsock(sk))
			pskb->mark = sk->sk_mark;

		if (sk != skb->sk)
			sock_gen_put(sk);

		if (wildcard || !transparent)
			sk = NULL;
	}

	return sk != NULL;
}
#endif

static int socket_mt_enable_defrag(struct net *net, int family)
{
	switch (family) {
	case NFPROTO_IPV4:
		return nf_defrag_ipv4_enable(net);
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
	case NFPROTO_IPV6:
		return nf_defrag_ipv6_enable(net);
#endif
	}
	WARN_ONCE(1, "Unknown family %d\n", family);
	return 0;
}

static int socket_mt_v1_check(const struct xt_mtchk_param *par)
{
	const struct xt_socket_mtinfo1 *info = (struct xt_socket_mtinfo1 *) par->matchinfo;
	int err;

	err = socket_mt_enable_defrag(par->net, par->family);
	if (err)
		return err;

	if (info->flags & ~XT_SOCKET_FLAGS_V1) {
		pr_info_ratelimited("unknown flags 0x%x\n",
				    info->flags & ~XT_SOCKET_FLAGS_V1);
		return -EINVAL;
	}
	return 0;
}

static int socket_mt_v2_check(const struct xt_mtchk_param *par)
{
	const struct xt_socket_mtinfo2 *info = (struct xt_socket_mtinfo2 *) par->matchinfo;
	int err;

	err = socket_mt_enable_defrag(par->net, par->family);
	if (err)
		return err;

	if (info->flags & ~XT_SOCKET_FLAGS_V2) {
		pr_info_ratelimited("unknown flags 0x%x\n",
				    info->flags & ~XT_SOCKET_FLAGS_V2);
		return -EINVAL;
	}
	return 0;
}

static int socket_mt_v3_check(const struct xt_mtchk_param *par)
{
	const struct xt_socket_mtinfo3 *info =
				    (struct xt_socket_mtinfo3 *)par->matchinfo;
	int err;

	err = socket_mt_enable_defrag(par->net, par->family);
	if (err)
		return err;
	if (info->flags & ~XT_SOCKET_FLAGS_V3) {
		pr_info_ratelimited("unknown flags 0x%x\n",
				    info->flags & ~XT_SOCKET_FLAGS_V3);
		return -EINVAL;
	}
	return 0;
}

static struct xt_match socket_mt_reg[] __read_mostly = {
	{
		.name		= "socket",
		.revision	= 0,
		.family		= NFPROTO_IPV4,
		.match		= socket_mt4_v0,
		.hooks		= (1 << NF_INET_PRE_ROUTING) |
				  (1 << NF_INET_LOCAL_IN),
		.me		= THIS_MODULE,
	},
	{
		.name		= "socket",
		.revision	= 1,
		.family		= NFPROTO_IPV4,
		.match		= socket_mt4_v1_v2_v3,
		.checkentry	= socket_mt_v1_check,
		.matchsize	= sizeof(struct xt_socket_mtinfo1),
		.hooks		= (1 << NF_INET_PRE_ROUTING) |
				  (1 << NF_INET_LOCAL_IN),
		.me		= THIS_MODULE,
	},
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
	{
		.name		= "socket",
Пример #3
0
static bool
socket_mt4_v0(const struct sk_buff *skb, struct xt_action_param *par)
{
	return socket_match(skb, par, NULL);
}
Пример #4
0
static bool
socket_mt4_v0(const struct sk_buff *skb, struct xt_action_param *par)
{
	static struct xt_socket_mtinfo1 xt_info_v0 = {
		.flags = 0,
	};

	return socket_match(skb, par, &xt_info_v0);
}

static bool
socket_mt4_v1_v2_v3(const struct sk_buff *skb, struct xt_action_param *par)
{
	return socket_match(skb, par, par->matchinfo);
}

#ifdef XT_SOCKET_HAVE_IPV6

static int
extract_icmp6_fields(const struct sk_buff *skb,
		     unsigned int outside_hdrlen,
		     int *protocol,
		     const struct in6_addr **raddr,
		     const struct in6_addr **laddr,
		     __be16 *rport,
		     __be16 *lport,
		     struct ipv6hdr *ipv6_var)
{
	const struct ipv6hdr *inside_iph;
	struct icmp6hdr *icmph, _icmph;
	__be16 *ports, _ports[2];
	u8 inside_nexthdr;
	__be16 inside_fragoff;
	int inside_hdrlen;

	icmph = skb_header_pointer(skb, outside_hdrlen,
				   sizeof(_icmph), &_icmph);
	if (icmph == NULL)
		return 1;

	if (icmph->icmp6_type & ICMPV6_INFOMSG_MASK)
		return 1;

	inside_iph = skb_header_pointer(skb, outside_hdrlen + sizeof(_icmph),
					sizeof(*ipv6_var), ipv6_var);
	if (inside_iph == NULL)
		return 1;
	inside_nexthdr = inside_iph->nexthdr;

	inside_hdrlen = ipv6_skip_exthdr(skb, outside_hdrlen + sizeof(_icmph) +
					      sizeof(*ipv6_var),
					 &inside_nexthdr, &inside_fragoff);
	if (inside_hdrlen < 0)
		return 1; /* hjm: Packet has no/incomplete transport layer headers. */

	if (inside_nexthdr != IPPROTO_TCP &&
	    inside_nexthdr != IPPROTO_UDP)
		return 1;

	ports = skb_header_pointer(skb, inside_hdrlen,
				   sizeof(_ports), &_ports);
	if (ports == NULL)
		return 1;

	/* the inside IP packet is the one quoted from our side, thus
	 * its saddr is the local address */
	*protocol = inside_nexthdr;
	*laddr = &inside_iph->saddr;
	*lport = ports[0];
	*raddr = &inside_iph->daddr;
	*rport = ports[1];

	return 0;
}

static struct sock *
xt_socket_get_sock_v6(struct net *net, const u8 protocol,
		      const struct in6_addr *saddr, const struct in6_addr *daddr,
		      const __be16 sport, const __be16 dport,
		      const struct net_device *in)
{
	switch (protocol) {
	case IPPROTO_TCP:
		return inet6_lookup(net, &tcp_hashinfo,
				    saddr, sport, daddr, dport,
				    in->ifindex);
	case IPPROTO_UDP:
		return udp6_lib_lookup(net, saddr, sport, daddr, dport,
				       in->ifindex);
	}

	return NULL;
}

static struct sock *xt_socket_lookup_slow_v6(struct net *net,
					     const struct sk_buff *skb,
					     const struct net_device *indev)
{
	__be16 uninitialized_var(dport), uninitialized_var(sport);
	const struct in6_addr *daddr = NULL, *saddr = NULL;
	struct ipv6hdr *iph = ipv6_hdr(skb);
	int thoff = 0, tproto;

	tproto = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL);
	if (tproto < 0) {
		pr_debug("unable to find transport header in IPv6 packet, dropping\n");
		return NULL;
	}

	if (tproto == IPPROTO_UDP || tproto == IPPROTO_TCP) {
		struct udphdr _hdr, *hp;

		hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr);
		if (hp == NULL)
			return NULL;

		saddr = &iph->saddr;
		sport = hp->source;
		daddr = &iph->daddr;
		dport = hp->dest;

	} else if (tproto == IPPROTO_ICMPV6) {
		struct ipv6hdr ipv6_var;

		if (extract_icmp6_fields(skb, thoff, &tproto, &saddr, &daddr,
					 &sport, &dport, &ipv6_var))
			return NULL;
	} else {
		return NULL;
	}

	return xt_socket_get_sock_v6(net, tproto, saddr, daddr,
				     sport, dport, indev);
}