static inline void
ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
{
	struct ip_vs_dest *dest = cp->dest;
	struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));

	if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
		struct ip_vs_cpu_stats *s;

		s = this_cpu_ptr(dest->stats.cpustats);
		s->ustats.outpkts++;
		u64_stats_update_begin(&s->syncp);
		s->ustats.outbytes += skb->len;
		u64_stats_update_end(&s->syncp);

		s = this_cpu_ptr(dest->svc->stats.cpustats);
		s->ustats.outpkts++;
		u64_stats_update_begin(&s->syncp);
		s->ustats.outbytes += skb->len;
		u64_stats_update_end(&s->syncp);

		s = this_cpu_ptr(ipvs->tot_stats.cpustats);
		s->ustats.outpkts++;
		u64_stats_update_begin(&s->syncp);
		s->ustats.outbytes += skb->len;
		u64_stats_update_end(&s->syncp);
	}
}
static struct ip_vs_conn *
ah_esp_conn_in_get(int af, const struct sk_buff *skb,
		   const struct ip_vs_iphdr *iph, unsigned int proto_off,
		   int inverse)
{
	struct ip_vs_conn *cp;
	struct ip_vs_conn_param p;
	struct net *net = skb_net(skb);

	ah_esp_conn_fill_param_proto(net, af, iph, inverse, &p);
	cp = ip_vs_conn_in_get(&p);
	if (!cp) {
		/*
		 * We are not sure if the packet is from our
		 * service, so our conn_schedule hook should return NF_ACCEPT
		 */
		IP_VS_DBG_BUF(12, "Unknown ISAKMP entry for outin packet "
			      "%s%s %s->%s\n",
			      inverse ? "ICMP+" : "",
			      ip_vs_proto_get(iph->protocol)->name,
			      IP_VS_DBG_ADDR(af, &iph->saddr),
			      IP_VS_DBG_ADDR(af, &iph->daddr));
	}

	return cp;
}
Exemple #3
0
static inline void
ip_vs_out_stats(struct ip_vs_conn *cp, struct sk_buff *skb)
{
	struct ip_vs_dest *dest = cp->dest;
	struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));

	if (dest && (dest->flags & IP_VS_DEST_F_AVAILABLE)) {
		struct ip_vs_cpu_stats *s;
		struct ip_vs_service *svc;

		s = this_cpu_ptr(dest->stats.cpustats);
		u64_stats_update_begin(&s->syncp);
		s->cnt.outpkts++;
		s->cnt.outbytes += skb->len;
		u64_stats_update_end(&s->syncp);

		rcu_read_lock();
		svc = rcu_dereference(dest->svc);
		s = this_cpu_ptr(svc->stats.cpustats);
		u64_stats_update_begin(&s->syncp);
		s->cnt.outpkts++;
		s->cnt.outbytes += skb->len;
		u64_stats_update_end(&s->syncp);
		rcu_read_unlock();

		s = this_cpu_ptr(ipvs->tot_stats.cpustats);
		u64_stats_update_begin(&s->syncp);
		s->cnt.outpkts++;
		s->cnt.outbytes += skb->len;
		u64_stats_update_end(&s->syncp);
	}
}
static int
sctp_conn_schedule(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd,
                   int *verdict, struct ip_vs_conn **cpp)
{
    struct net *net;
    struct ip_vs_service *svc;
    sctp_chunkhdr_t _schunkh, *sch;
    sctp_sctphdr_t *sh, _sctph;
    struct ip_vs_iphdr iph;

    ip_vs_fill_iphdr(af, skb_network_header(skb), &iph);

    sh = skb_header_pointer(skb, iph.len, sizeof(_sctph), &_sctph);
    if (sh == NULL)
        return 0;

    sch = skb_header_pointer(skb, iph.len + sizeof(sctp_sctphdr_t),
                             sizeof(_schunkh), &_schunkh);
    if (sch == NULL)
        return 0;
    net = skb_net(skb);
    if ((sch->type == SCTP_CID_INIT) &&
            (svc = ip_vs_service_get(net, af, skb->mark, iph.protocol,
                                     &iph.daddr, sh->dest))) {
        int ignored;

        if (ip_vs_todrop(net_ipvs(net))) {
            /*
             * It seems that we are very loaded.
             * We have to drop this packet :(
             */
            ip_vs_service_put(svc);
            *verdict = NF_DROP;
            return 0;
        }
        /*
         * Let the virtual server select a real server for the
         * incoming connection, and create a connection entry.
         */
        *cpp = ip_vs_schedule(svc, skb, pd, &ignored);
        if (!*cpp && ignored <= 0) {
            if (!ignored)
                *verdict = ip_vs_leave(svc, skb, pd);
            else {
                ip_vs_service_put(svc);
                *verdict = NF_DROP;
            }
            return 0;
        }
        ip_vs_service_put(svc);
    }
    /* NF_ACCEPT */
    return 1;
}
Exemple #5
0
static inline bool ensure_mtu_is_adequate(int skb_af, int rt_mode,
					  struct ip_vs_iphdr *ipvsh,
					  struct sk_buff *skb, int mtu)
{
#ifdef CONFIG_IP_VS_IPV6
	if (skb_af == AF_INET6) {
		struct net *net = dev_net(skb_dst(skb)->dev);

		if (unlikely(__mtu_check_toobig_v6(skb, mtu))) {
			if (!skb->dev)
				skb->dev = net->loopback_dev;
			/* only send ICMP too big on first fragment */
			if (!ipvsh->fragoffs)
				icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
			IP_VS_DBG(1, "frag needed for %pI6c\n",
				  &ipv6_hdr(skb)->saddr);
			return false;
		}
	} else
#endif
	{
		struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));

		/* If we're going to tunnel the packet and pmtu discovery
		 * is disabled, we'll just fragment it anyway
		 */
		if ((rt_mode & IP_VS_RT_MODE_TUNNEL) && !sysctl_pmtu_disc(ipvs))
			return true;

		if (unlikely(ip_hdr(skb)->frag_off & htons(IP_DF) &&
			     skb->len > mtu && !skb_is_gso(skb))) {
			icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
				  htonl(mtu));
			IP_VS_DBG(1, "frag needed for %pI4\n",
				  &ip_hdr(skb)->saddr);
			return false;
		}
	}

	return true;
}
static struct ip_vs_conn *
ah_esp_conn_out_get(int af, const struct sk_buff *skb,
		    const struct ip_vs_iphdr *iph,
		    unsigned int proto_off,
		    int inverse)
{
	struct ip_vs_conn *cp;
	struct ip_vs_conn_param p;
	struct net *net = skb_net(skb);

	ah_esp_conn_fill_param_proto(net, af, iph, inverse, &p);
	cp = ip_vs_conn_out_get(&p);
	if (!cp) {
		IP_VS_DBG_BUF(12, "Unknown ISAKMP entry for inout packet "
			      "%s%s %s->%s\n",
			      inverse ? "ICMP+" : "",
			      ip_vs_proto_get(iph->protocol)->name,
			      IP_VS_DBG_ADDR(af, &iph->saddr),
			      IP_VS_DBG_ADDR(af, &iph->daddr));
	}

	return cp;
}
/*
 * Look at outgoing ftp packets to catch the response to a PASV command
 * from the server (inside-to-outside).
 * When we see one, we build a connection entry with the client address,
 * client port 0 (unknown at the moment), the server address and the
 * server port.  Mark the current connection entry as a control channel
 * of the new entry. All this work is just to make the data connection
 * can be scheduled to the right server later.
 *
 * The outgoing packet should be something like
 *   "227 Entering Passive Mode (xxx,xxx,xxx,xxx,ppp,ppp)".
 * xxx,xxx,xxx,xxx is the server address, ppp,ppp is the server port number.
 */
static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp,
			 struct sk_buff *skb, int *diff)
{
	struct iphdr *iph;
	struct tcphdr *th;
	char *data, *data_limit;
	char *start, *end;
	union nf_inet_addr from;
	__be16 port;
	struct ip_vs_conn *n_cp;
	char buf[24];		/* xxx.xxx.xxx.xxx,ppp,ppp\000 */
	unsigned buf_len;
	int ret = 0;
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;
	struct net *net;

#ifdef CONFIG_IP_VS_IPV6
	/* This application helper doesn't work with IPv6 yet,
	 * so turn this into a no-op for IPv6 packets
	 */
	if (cp->af == AF_INET6)
		return 1;
#endif

	*diff = 0;

	/* Only useful for established sessions */
	if (cp->state != IP_VS_TCP_S_ESTABLISHED)
		return 1;

	/* Linear packets are much easier to deal with. */
	if (!skb_make_writable(skb, skb->len))
		return 0;

	if (cp->app_data == &ip_vs_ftp_pasv) {
		iph = ip_hdr(skb);
		th = (struct tcphdr *)&(((char *)iph)[iph->ihl*4]);
		data = (char *)th + (th->doff << 2);
		data_limit = skb_tail_pointer(skb);

		if (ip_vs_ftp_get_addrport(data, data_limit,
					   SERVER_STRING,
					   sizeof(SERVER_STRING)-1,
					   '(', ')',
					   &from.ip, &port,
					   &start, &end) != 1)
			return 1;

		IP_VS_DBG(7, "PASV response (%pI4:%d) -> %pI4:%d detected\n",
			  &from.ip, ntohs(port), &cp->caddr.ip, 0);

		/*
		 * Now update or create an connection entry for it
		 */
		{
			struct ip_vs_conn_param p;
			ip_vs_conn_fill_param(ip_vs_conn_net(cp), AF_INET,
					      iph->protocol, &from, port,
					      &cp->caddr, 0, &p);
			n_cp = ip_vs_conn_out_get(&p);
		}
		if (!n_cp) {
			struct ip_vs_conn_param p;
			ip_vs_conn_fill_param(ip_vs_conn_net(cp),
					      AF_INET, IPPROTO_TCP, &cp->caddr,
					      0, &cp->vaddr, port, &p);
			n_cp = ip_vs_conn_new(&p, &from, port,
					      IP_VS_CONN_F_NO_CPORT |
					      IP_VS_CONN_F_NFCT,
					      cp->dest, skb->mark);
			if (!n_cp)
				return 0;

			/* add its controller */
			ip_vs_control_add(n_cp, cp);
		}

		/*
		 * Replace the old passive address with the new one
		 */
		from.ip = n_cp->vaddr.ip;
		port = n_cp->vport;
		snprintf(buf, sizeof(buf), "%u,%u,%u,%u,%u,%u",
			 ((unsigned char *)&from.ip)[0],
			 ((unsigned char *)&from.ip)[1],
			 ((unsigned char *)&from.ip)[2],
			 ((unsigned char *)&from.ip)[3],
			 ntohs(port) >> 8,
			 ntohs(port) & 0xFF);

		buf_len = strlen(buf);

		ct = nf_ct_get(skb, &ctinfo);
		if (ct && !nf_ct_is_untracked(ct) && nfct_nat(ct)) {
			/* If mangling fails this function will return 0
			 * which will cause the packet to be dropped.
			 * Mangling can only fail under memory pressure,
			 * hopefully it will succeed on the retransmitted
			 * packet.
			 */
			ret = nf_nat_mangle_tcp_packet(skb, ct, ctinfo,
						       start-data, end-start,
						       buf, buf_len);
			if (ret) {
				ip_vs_nfct_expect_related(skb, ct, n_cp,
							  IPPROTO_TCP, 0, 0);
				if (skb->ip_summed == CHECKSUM_COMPLETE)
					skb->ip_summed = CHECKSUM_UNNECESSARY;
				/* csum is updated */
				ret = 1;
			}
		}

		/*
		 * Not setting 'diff' is intentional, otherwise the sequence
		 * would be adjusted twice.
		 */

		net = skb_net(skb);
		cp->app_data = NULL;
		ip_vs_tcp_conn_listen(net, n_cp);
		ip_vs_conn_put(n_cp);
		return ret;
	}
Exemple #8
0
/*
 *   IP Tunneling transmitter
 *
 *   This function encapsulates the packet in a new IP packet, its
 *   destination will be set to cp->daddr. Most code of this function
 *   is taken from ipip.c.
 *
 *   It is used in VS/TUN cluster. The load balancer selects a real
 *   server from a cluster based on a scheduling algorithm,
 *   encapsulates the request packet and forwards it to the selected
 *   server. For example, all real servers are configured with
 *   "ifconfig tunl0 <Virtual IP Address> up". When the server receives
 *   the encapsulated packet, it will decapsulate the packet, processe
 *   the request and return the response packets directly to the client
 *   without passing the load balancer. This can greatly increase the
 *   scalability of virtual server.
 *
 *   Used for ANY protocol
 */
int
ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
		  struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
{
	struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));
	struct rtable *rt;			/* Route to the other host */
	__be32 saddr;				/* Source for tunnel */
	struct net_device *tdev;		/* Device to other host */
	struct iphdr  *old_iph = ip_hdr(skb);
	u8     tos = old_iph->tos;
	__be16 df;
	struct iphdr  *iph;			/* Our new IP header */
	unsigned int max_headroom;		/* The extra header space needed */
	int ret, local;

	EnterFunction(10);

	rcu_read_lock();
	local = __ip_vs_get_out_rt(skb, cp->dest, cp->daddr.ip,
				   IP_VS_RT_MODE_LOCAL |
				   IP_VS_RT_MODE_NON_LOCAL |
				   IP_VS_RT_MODE_CONNECT |
				   IP_VS_RT_MODE_TUNNEL, &saddr);
	if (local < 0)
		goto tx_error;
	if (local) {
		rcu_read_unlock();
		return ip_vs_send_or_cont(NFPROTO_IPV4, skb, cp, 1);
	}

	rt = skb_rtable(skb);
	tdev = rt->dst.dev;

	/* Copy DF, reset fragment offset and MF */
	df = sysctl_pmtu_disc(ipvs) ? old_iph->frag_off & htons(IP_DF) : 0;

	/*
	 * Okay, now see if we can stuff it in the buffer as-is.
	 */
	max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct iphdr);

	if (skb_headroom(skb) < max_headroom || skb_cloned(skb)) {
		struct sk_buff *new_skb =
			skb_realloc_headroom(skb, max_headroom);

		if (!new_skb)
			goto tx_error;
		consume_skb(skb);
		skb = new_skb;
		old_iph = ip_hdr(skb);
	}

	skb->transport_header = skb->network_header;

	/* fix old IP header checksum */
	ip_send_check(old_iph);

	skb_push(skb, sizeof(struct iphdr));
	skb_reset_network_header(skb);
	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));

	/*
	 *	Push down and install the IPIP header.
	 */
	iph			=	ip_hdr(skb);
	iph->version		=	4;
	iph->ihl		=	sizeof(struct iphdr)>>2;
	iph->frag_off		=	df;
	iph->protocol		=	IPPROTO_IPIP;
	iph->tos		=	tos;
	iph->daddr		=	cp->daddr.ip;
	iph->saddr		=	saddr;
	iph->ttl		=	old_iph->ttl;
	ip_select_ident(skb, &rt->dst, NULL);

	/* Another hack: avoid icmp_send in ip_fragment */
	skb->local_df = 1;

	ret = ip_vs_tunnel_xmit_prepare(skb, cp);
	if (ret == NF_ACCEPT)
		ip_local_out(skb);
	else if (ret == NF_DROP)
		kfree_skb(skb);
	rcu_read_unlock();

	LeaveFunction(10);

	return NF_STOLEN;

  tx_error:
	kfree_skb(skb);
	rcu_read_unlock();
	LeaveFunction(10);
	return NF_STOLEN;
}
Exemple #9
0
/*
 *   IP Tunneling transmitter
 *
 *   This function encapsulates the packet in a new IP packet, its
 *   destination will be set to cp->daddr. Most code of this function
 *   is taken from ipip.c.
 *
 *   It is used in VS/TUN cluster. The load balancer selects a real
 *   server from a cluster based on a scheduling algorithm,
 *   encapsulates the request packet and forwards it to the selected
 *   server. For example, all real servers are configured with
 *   "ifconfig tunl0 <Virtual IP Address> up". When the server receives
 *   the encapsulated packet, it will decapsulate the packet, processe
 *   the request and return the response packets directly to the client
 *   without passing the load balancer. This can greatly increase the
 *   scalability of virtual server.
 *
 *   Used for ANY protocol
 */
int
ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
		  struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
{
	struct net *net = skb_net(skb);
	struct netns_ipvs *ipvs = net_ipvs(net);
	struct rtable *rt;			/* Route to the other host */
	__be32 saddr;				/* Source for tunnel */
	struct net_device *tdev;		/* Device to other host */
	__u8 next_protocol = 0;
	__u8 dsfield = 0;
	__u8 ttl = 0;
	__be16 df = 0;
	__be16 *dfp = NULL;
	struct iphdr  *iph;			/* Our new IP header */
	unsigned int max_headroom;		/* The extra header space needed */
	int ret, local;

	EnterFunction(10);

	rcu_read_lock();
	local = __ip_vs_get_out_rt(cp->af, skb, cp->dest, cp->daddr.ip,
				   IP_VS_RT_MODE_LOCAL |
				   IP_VS_RT_MODE_NON_LOCAL |
				   IP_VS_RT_MODE_CONNECT |
				   IP_VS_RT_MODE_TUNNEL, &saddr, ipvsh);
	if (local < 0)
		goto tx_error;
	if (local) {
		rcu_read_unlock();
		return ip_vs_send_or_cont(NFPROTO_IPV4, skb, cp, 1);
	}

	rt = skb_rtable(skb);
	tdev = rt->dst.dev;

	/*
	 * Okay, now see if we can stuff it in the buffer as-is.
	 */
	max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct iphdr);

	/* We only care about the df field if sysctl_pmtu_disc(ipvs) is set */
	dfp = sysctl_pmtu_disc(ipvs) ? &df : NULL;
	skb = ip_vs_prepare_tunneled_skb(skb, cp->af, max_headroom,
					 &next_protocol, NULL, &dsfield,
					 &ttl, dfp);
	if (IS_ERR(skb))
		goto tx_error;

	skb = iptunnel_handle_offloads(
		skb, false, __tun_gso_type_mask(AF_INET, cp->af));
	if (IS_ERR(skb))
		goto tx_error;

	skb->transport_header = skb->network_header;

	skb_push(skb, sizeof(struct iphdr));
	skb_reset_network_header(skb);
	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));

	/*
	 *	Push down and install the IPIP header.
	 */
	iph			=	ip_hdr(skb);
	iph->version		=	4;
	iph->ihl		=	sizeof(struct iphdr)>>2;
	iph->frag_off		=	df;
	iph->protocol		=	next_protocol;
	iph->tos		=	dsfield;
	iph->daddr		=	cp->daddr.ip;
	iph->saddr		=	saddr;
	iph->ttl		=	ttl;
	ip_select_ident(net, skb, NULL);

	/* Another hack: avoid icmp_send in ip_fragment */
	skb->ignore_df = 1;

	ret = ip_vs_tunnel_xmit_prepare(skb, cp);
	if (ret == NF_ACCEPT)
		ip_local_out(skb);
	else if (ret == NF_DROP)
		kfree_skb(skb);
	rcu_read_unlock();

	LeaveFunction(10);

	return NF_STOLEN;

  tx_error:
	if (!IS_ERR(skb))
		kfree_skb(skb);
	rcu_read_unlock();
	LeaveFunction(10);
	return NF_STOLEN;
}
Exemple #10
0
/*
 *   IP Tunneling transmitter
 *
 *   This function encapsulates the packet in a new IP packet, its
 *   destination will be set to cp->daddr. Most code of this function
 *   is taken from ipip.c.
 *
 *   It is used in VS/TUN cluster. The load balancer selects a real
 *   server from a cluster based on a scheduling algorithm,
 *   encapsulates the request packet and forwards it to the selected
 *   server. For example, all real servers are configured with
 *   "ifconfig tunl0 <Virtual IP Address> up". When the server receives
 *   the encapsulated packet, it will decapsulate the packet, processe
 *   the request and return the response packets directly to the client
 *   without passing the load balancer. This can greatly increase the
 *   scalability of virtual server.
 *
 *   Used for ANY protocol
 */
int
ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
		  struct ip_vs_protocol *pp)
{
	struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));
	struct rtable *rt;			/* Route to the other host */
	__be32 saddr;				/* Source for tunnel */
	struct net_device *tdev;		/* Device to other host */
	struct iphdr  *old_iph = ip_hdr(skb);
	u8     tos = old_iph->tos;
	__be16 df;
	struct iphdr  *iph;			/* Our new IP header */
	unsigned int max_headroom;		/* The extra header space needed */
	int    mtu;
	int ret;

	EnterFunction(10);

	if (!(rt = __ip_vs_get_out_rt(skb, cp->dest, cp->daddr.ip,
				      RT_TOS(tos), IP_VS_RT_MODE_LOCAL |
						   IP_VS_RT_MODE_NON_LOCAL |
						   IP_VS_RT_MODE_CONNECT,
						   &saddr)))
		goto tx_error_icmp;
	if (rt->rt_flags & RTCF_LOCAL) {
		ip_rt_put(rt);
		IP_VS_XMIT(NFPROTO_IPV4, skb, cp, 1);
	}

	tdev = rt->dst.dev;

	mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
	if (mtu < 68) {
		IP_VS_DBG_RL("%s(): mtu less than 68\n", __func__);
		goto tx_error_put;
	}
	if (rt_is_output_route(skb_rtable(skb)))
		skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);

	/* Copy DF, reset fragment offset and MF */
	df = sysctl_pmtu_disc(ipvs) ? old_iph->frag_off & htons(IP_DF) : 0;

	if (df && mtu < ntohs(old_iph->tot_len) && !skb_is_gso(skb)) {
		icmp_send(skb, ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED, htonl(mtu));
		IP_VS_DBG_RL("%s(): frag needed\n", __func__);
		goto tx_error_put;
	}

	/*
	 * Okay, now see if we can stuff it in the buffer as-is.
	 */
	max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct iphdr);

	if (skb_headroom(skb) < max_headroom
	    || skb_cloned(skb) || skb_shared(skb)) {
		struct sk_buff *new_skb =
			skb_realloc_headroom(skb, max_headroom);
		if (!new_skb) {
			ip_rt_put(rt);
			kfree_skb(skb);
			IP_VS_ERR_RL("%s(): no memory\n", __func__);
			return NF_STOLEN;
		}
		consume_skb(skb);
		skb = new_skb;
		old_iph = ip_hdr(skb);
	}

	skb->transport_header = skb->network_header;

	/* fix old IP header checksum */
	ip_send_check(old_iph);

	skb_push(skb, sizeof(struct iphdr));
	skb_reset_network_header(skb);
	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));

	/* drop old route */
	skb_dst_drop(skb);
	skb_dst_set(skb, &rt->dst);

	/*
	 *	Push down and install the IPIP header.
	 */
	iph			=	ip_hdr(skb);
	iph->version		=	4;
	iph->ihl		=	sizeof(struct iphdr)>>2;
	iph->frag_off		=	df;
	iph->protocol		=	IPPROTO_IPIP;
	iph->tos		=	tos;
	iph->daddr		=	cp->daddr.ip;
	iph->saddr		=	saddr;
	iph->ttl		=	old_iph->ttl;
	ip_select_ident(iph, &rt->dst, NULL);

	/* Another hack: avoid icmp_send in ip_fragment */
	skb->local_df = 1;

	ret = IP_VS_XMIT_TUNNEL(skb, cp);
	if (ret == NF_ACCEPT)
		ip_local_out(skb);
	else if (ret == NF_DROP)
		kfree_skb(skb);

	LeaveFunction(10);

	return NF_STOLEN;

  tx_error_icmp:
	dst_link_failure(skb);
  tx_error:
	kfree_skb(skb);
	LeaveFunction(10);
	return NF_STOLEN;
tx_error_put:
	ip_rt_put(rt);
	goto tx_error;
}
static struct ip_vs_conn *
ip_vs_sched_persist(struct ip_vs_service *svc,
		    struct sk_buff *skb,
		    __be16 src_port, __be16 dst_port, int *ignored)
{
	struct ip_vs_conn *cp = NULL;
	struct ip_vs_iphdr iph;
	struct ip_vs_dest *dest;
	struct ip_vs_conn *ct;
	__be16 dport = 0;		
	unsigned int flags;
	struct ip_vs_conn_param param;
	const union nf_inet_addr fwmark = { .ip = htonl(svc->fwmark) };
	union nf_inet_addr snet;	

	ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);

	
#ifdef CONFIG_IP_VS_IPV6
	if (svc->af == AF_INET6)
		ipv6_addr_prefix(&snet.in6, &iph.saddr.in6, svc->netmask);
	else
#endif
		snet.ip = iph.saddr.ip & svc->netmask;

	IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u "
		      "mnet %s\n",
		      IP_VS_DBG_ADDR(svc->af, &iph.saddr), ntohs(src_port),
		      IP_VS_DBG_ADDR(svc->af, &iph.daddr), ntohs(dst_port),
		      IP_VS_DBG_ADDR(svc->af, &snet));

	{
		int protocol = iph.protocol;
		const union nf_inet_addr *vaddr = &iph.daddr;
		__be16 vport = 0;

		if (dst_port == svc->port) {
			if (svc->port != FTPPORT)
				vport = dst_port;
		} else {
			if (svc->fwmark) {
				protocol = IPPROTO_IP;
				vaddr = &fwmark;
			}
		}
		
		if (ip_vs_conn_fill_param_persist(svc, skb, protocol, &snet, 0,
						  vaddr, vport, &param) < 0) {
			*ignored = -1;
			return NULL;
		}
	}

	
	ct = ip_vs_ct_in_get(&param);
	if (!ct || !ip_vs_check_template(ct)) {
		dest = svc->scheduler->schedule(svc, skb);
		if (!dest) {
			IP_VS_DBG(1, "p-schedule: no dest found.\n");
			kfree(param.pe_data);
			*ignored = 0;
			return NULL;
		}

		if (dst_port == svc->port && svc->port != FTPPORT)
			dport = dest->port;

		ct = ip_vs_conn_new(&param, &dest->addr, dport,
				    IP_VS_CONN_F_TEMPLATE, dest, skb->mark);
		if (ct == NULL) {
			kfree(param.pe_data);
			*ignored = -1;
			return NULL;
		}

		ct->timeout = svc->timeout;
	} else {
		
		dest = ct->dest;
		kfree(param.pe_data);
	}

	dport = dst_port;
	if (dport == svc->port && dest->port)
		dport = dest->port;

	flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
		 && iph.protocol == IPPROTO_UDP)?
		IP_VS_CONN_F_ONE_PACKET : 0;

	ip_vs_conn_fill_param(svc->net, svc->af, iph.protocol, &iph.saddr,
			      src_port, &iph.daddr, dst_port, &param);

	cp = ip_vs_conn_new(&param, &dest->addr, dport, flags, dest, skb->mark);
	if (cp == NULL) {
		ip_vs_conn_put(ct);
		*ignored = -1;
		return NULL;
	}

	ip_vs_control_add(cp, ct);
	ip_vs_conn_put(ct);

	ip_vs_conn_stats(cp, svc);
	return cp;
}


struct ip_vs_conn *
ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
	       struct ip_vs_proto_data *pd, int *ignored)
{
	struct ip_vs_protocol *pp = pd->pp;
	struct ip_vs_conn *cp = NULL;
	struct ip_vs_iphdr iph;
	struct ip_vs_dest *dest;
	__be16 _ports[2], *pptr;
	unsigned int flags;

	*ignored = 1;
	ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);
	pptr = skb_header_pointer(skb, iph.len, sizeof(_ports), _ports);
	if (pptr == NULL)
		return NULL;

	if (pptr[0] == FTPDATA) {
		IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
			      "Not scheduling FTPDATA");
		return NULL;
	}

	if ((!skb->dev || skb->dev->flags & IFF_LOOPBACK) &&
	    (cp = pp->conn_in_get(svc->af, skb, &iph, iph.len, 1))) {
		IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
			      "Not scheduling reply for existing connection");
		__ip_vs_conn_put(cp);
		return NULL;
	}

	if (svc->flags & IP_VS_SVC_F_PERSISTENT)
		return ip_vs_sched_persist(svc, skb, pptr[0], pptr[1], ignored);

	*ignored = 0;

	if (!svc->fwmark && pptr[1] != svc->port) {
		if (!svc->port)
			pr_err("Schedule: port zero only supported "
			       "in persistent services, "
			       "check your ipvs configuration\n");
		return NULL;
	}

	dest = svc->scheduler->schedule(svc, skb);
	if (dest == NULL) {
		IP_VS_DBG(1, "Schedule: no dest found.\n");
		return NULL;
	}

	flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
		 && iph.protocol == IPPROTO_UDP)?
		IP_VS_CONN_F_ONE_PACKET : 0;

	{
		struct ip_vs_conn_param p;

		ip_vs_conn_fill_param(svc->net, svc->af, iph.protocol,
				      &iph.saddr, pptr[0], &iph.daddr, pptr[1],
				      &p);
		cp = ip_vs_conn_new(&p, &dest->addr,
				    dest->port ? dest->port : pptr[1],
				    flags, dest, skb->mark);
		if (!cp) {
			*ignored = -1;
			return NULL;
		}
	}

	IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u "
		      "d:%s:%u conn->flags:%X conn->refcnt:%d\n",
		      ip_vs_fwd_tag(cp),
		      IP_VS_DBG_ADDR(svc->af, &cp->caddr), ntohs(cp->cport),
		      IP_VS_DBG_ADDR(svc->af, &cp->vaddr), ntohs(cp->vport),
		      IP_VS_DBG_ADDR(svc->af, &cp->daddr), ntohs(cp->dport),
		      cp->flags, atomic_read(&cp->refcnt));

	ip_vs_conn_stats(cp, svc);
	return cp;
}


int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
		struct ip_vs_proto_data *pd)
{
	__be16 _ports[2], *pptr;
	struct ip_vs_iphdr iph;
#ifdef CONFIG_SYSCTL
	struct net *net;
	struct netns_ipvs *ipvs;
	int unicast;
#endif

	ip_vs_fill_iphdr(svc->af, skb_network_header(skb), &iph);

	pptr = skb_header_pointer(skb, iph.len, sizeof(_ports), _ports);
	if (pptr == NULL) {
		ip_vs_service_put(svc);
		return NF_DROP;
	}

#ifdef CONFIG_SYSCTL
	net = skb_net(skb);

#ifdef CONFIG_IP_VS_IPV6
	if (svc->af == AF_INET6)
		unicast = ipv6_addr_type(&iph.daddr.in6) & IPV6_ADDR_UNICAST;
	else
#endif
		unicast = (inet_addr_type(net, iph.daddr.ip) == RTN_UNICAST);

	ipvs = net_ipvs(net);
	if (ipvs->sysctl_cache_bypass && svc->fwmark && unicast) {
		int ret;
		struct ip_vs_conn *cp;
		unsigned int flags = (svc->flags & IP_VS_SVC_F_ONEPACKET &&
				      iph.protocol == IPPROTO_UDP)?
				      IP_VS_CONN_F_ONE_PACKET : 0;
		union nf_inet_addr daddr =  { .all = { 0, 0, 0, 0 } };

		ip_vs_service_put(svc);

		
		IP_VS_DBG(6, "%s(): create a cache_bypass entry\n", __func__);
		{
			struct ip_vs_conn_param p;
			ip_vs_conn_fill_param(svc->net, svc->af, iph.protocol,
					      &iph.saddr, pptr[0],
					      &iph.daddr, pptr[1], &p);
			cp = ip_vs_conn_new(&p, &daddr, 0,
					    IP_VS_CONN_F_BYPASS | flags,
					    NULL, skb->mark);
			if (!cp)
				return NF_DROP;
		}

		
		ip_vs_in_stats(cp, skb);

		
		ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);

		
		ret = cp->packet_xmit(skb, cp, pd->pp);
		

		atomic_inc(&cp->in_pkts);
		ip_vs_conn_put(cp);
		return ret;
	}
Exemple #12
0
/*
 *  IPVS persistent scheduling function
 *  It creates a connection entry according to its template if exists,
 *  or selects a server and creates a connection entry plus a template.
 *  Locking: we are svc user (svc->refcnt), so we hold all dests too
 *  Protocols supported: TCP, UDP
 */
static struct ip_vs_conn *
ip_vs_sched_persist(struct ip_vs_service *svc,
		    struct sk_buff *skb, __be16 src_port, __be16 dst_port,
		    int *ignored, struct ip_vs_iphdr *iph)
{
	struct ip_vs_conn *cp = NULL;
	struct ip_vs_dest *dest;
	struct ip_vs_conn *ct;
	__be16 dport = 0;		/* destination port to forward */
	unsigned int flags;
	struct ip_vs_conn_param param;
	const union nf_inet_addr fwmark = { .ip = htonl(svc->fwmark) };
	union nf_inet_addr snet;	/* source network of the client,
					   after masking */

	/* Mask saddr with the netmask to adjust template granularity */
#ifdef CONFIG_IP_VS_IPV6
	if (svc->af == AF_INET6)
		ipv6_addr_prefix(&snet.in6, &iph->saddr.in6,
				 (__force __u32) svc->netmask);
	else
#endif
		snet.ip = iph->saddr.ip & svc->netmask;

	IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u "
		      "mnet %s\n",
		      IP_VS_DBG_ADDR(svc->af, &iph->saddr), ntohs(src_port),
		      IP_VS_DBG_ADDR(svc->af, &iph->daddr), ntohs(dst_port),
		      IP_VS_DBG_ADDR(svc->af, &snet));

	/*
	 * As far as we know, FTP is a very complicated network protocol, and
	 * it uses control connection and data connections. For active FTP,
	 * FTP server initialize data connection to the client, its source port
	 * is often 20. For passive FTP, FTP server tells the clients the port
	 * that it passively listens to,  and the client issues the data
	 * connection. In the tunneling or direct routing mode, the load
	 * balancer is on the client-to-server half of connection, the port
	 * number is unknown to the load balancer. So, a conn template like
	 * <caddr, 0, vaddr, 0, daddr, 0> is created for persistent FTP
	 * service, and a template like <caddr, 0, vaddr, vport, daddr, dport>
	 * is created for other persistent services.
	 */
	{
		int protocol = iph->protocol;
		const union nf_inet_addr *vaddr = &iph->daddr;
		__be16 vport = 0;

		if (dst_port == svc->port) {
			/* non-FTP template:
			 * <protocol, caddr, 0, vaddr, vport, daddr, dport>
			 * FTP template:
			 * <protocol, caddr, 0, vaddr, 0, daddr, 0>
			 */
			if (svc->port != FTPPORT)
				vport = dst_port;
		} else {
			/* Note: persistent fwmark-based services and
			 * persistent port zero service are handled here.
			 * fwmark template:
			 * <IPPROTO_IP,caddr,0,fwmark,0,daddr,0>
			 * port zero template:
			 * <protocol,caddr,0,vaddr,0,daddr,0>
			 */
			if (svc->fwmark) {
				protocol = IPPROTO_IP;
				vaddr = &fwmark;
			}
		}
		/* return *ignored = -1 so NF_DROP can be used */
		if (ip_vs_conn_fill_param_persist(svc, skb, protocol, &snet, 0,
						  vaddr, vport, &param) < 0) {
			*ignored = -1;
			return NULL;
		}
	}

	/* Check if a template already exists */
	ct = ip_vs_ct_in_get(&param);
	if (!ct || !ip_vs_check_template(ct)) {
		struct ip_vs_scheduler *sched;

		/*
		 * No template found or the dest of the connection
		 * template is not available.
		 * return *ignored=0 i.e. ICMP and NF_DROP
		 */
		sched = rcu_dereference(svc->scheduler);
		if (sched) {
			/* read svc->sched_data after svc->scheduler */
			smp_rmb();
			dest = sched->schedule(svc, skb, iph);
		} else {
			dest = NULL;
		}
		if (!dest) {
			IP_VS_DBG(1, "p-schedule: no dest found.\n");
			kfree(param.pe_data);
			*ignored = 0;
			return NULL;
		}

		if (dst_port == svc->port && svc->port != FTPPORT)
			dport = dest->port;

		/* Create a template
		 * This adds param.pe_data to the template,
		 * and thus param.pe_data will be destroyed
		 * when the template expires */
		ct = ip_vs_conn_new(&param, dest->af, &dest->addr, dport,
				    IP_VS_CONN_F_TEMPLATE, dest, skb->mark);
		if (ct == NULL) {
			kfree(param.pe_data);
			*ignored = -1;
			return NULL;
		}

		ct->timeout = svc->timeout;
	} else {
		/* set destination with the found template */
		dest = ct->dest;
		kfree(param.pe_data);
	}

	dport = dst_port;
	if (dport == svc->port && dest->port)
		dport = dest->port;

	flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
		 && iph->protocol == IPPROTO_UDP) ?
		IP_VS_CONN_F_ONE_PACKET : 0;

	/*
	 *    Create a new connection according to the template
	 */
	ip_vs_conn_fill_param(svc->net, svc->af, iph->protocol, &iph->saddr,
			      src_port, &iph->daddr, dst_port, &param);

	cp = ip_vs_conn_new(&param, dest->af, &dest->addr, dport, flags, dest,
			    skb->mark);
	if (cp == NULL) {
		ip_vs_conn_put(ct);
		*ignored = -1;
		return NULL;
	}

	/*
	 *    Add its control
	 */
	ip_vs_control_add(cp, ct);
	ip_vs_conn_put(ct);

	ip_vs_conn_stats(cp, svc);
	return cp;
}


/*
 *  IPVS main scheduling function
 *  It selects a server according to the virtual service, and
 *  creates a connection entry.
 *  Protocols supported: TCP, UDP
 *
 *  Usage of *ignored
 *
 * 1 :   protocol tried to schedule (eg. on SYN), found svc but the
 *       svc/scheduler decides that this packet should be accepted with
 *       NF_ACCEPT because it must not be scheduled.
 *
 * 0 :   scheduler can not find destination, so try bypass or
 *       return ICMP and then NF_DROP (ip_vs_leave).
 *
 * -1 :  scheduler tried to schedule but fatal error occurred, eg.
 *       ip_vs_conn_new failure (ENOMEM) or ip_vs_sip_fill_param
 *       failure such as missing Call-ID, ENOMEM on skb_linearize
 *       or pe_data. In this case we should return NF_DROP without
 *       any attempts to send ICMP with ip_vs_leave.
 */
struct ip_vs_conn *
ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
	       struct ip_vs_proto_data *pd, int *ignored,
	       struct ip_vs_iphdr *iph)
{
	struct ip_vs_protocol *pp = pd->pp;
	struct ip_vs_conn *cp = NULL;
	struct ip_vs_scheduler *sched;
	struct ip_vs_dest *dest;
	__be16 _ports[2], *pptr;
	unsigned int flags;

	*ignored = 1;
	/*
	 * IPv6 frags, only the first hit here.
	 */
	pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph);
	if (pptr == NULL)
		return NULL;

	/*
	 * FTPDATA needs this check when using local real server.
	 * Never schedule Active FTPDATA connections from real server.
	 * For LVS-NAT they must be already created. For other methods
	 * with persistence the connection is created on SYN+ACK.
	 */
	if (pptr[0] == FTPDATA) {
		IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
			      "Not scheduling FTPDATA");
		return NULL;
	}

	/*
	 *    Do not schedule replies from local real server.
	 */
	if ((!skb->dev || skb->dev->flags & IFF_LOOPBACK) &&
	    (cp = pp->conn_in_get(svc->af, skb, iph, 1))) {
		IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
			      "Not scheduling reply for existing connection");
		__ip_vs_conn_put(cp);
		return NULL;
	}

	/*
	 *    Persistent service
	 */
	if (svc->flags & IP_VS_SVC_F_PERSISTENT)
		return ip_vs_sched_persist(svc, skb, pptr[0], pptr[1], ignored,
					   iph);

	*ignored = 0;

	/*
	 *    Non-persistent service
	 */
	if (!svc->fwmark && pptr[1] != svc->port) {
		if (!svc->port)
			pr_err("Schedule: port zero only supported "
			       "in persistent services, "
			       "check your ipvs configuration\n");
		return NULL;
	}

	sched = rcu_dereference(svc->scheduler);
	if (sched) {
		/* read svc->sched_data after svc->scheduler */
		smp_rmb();
		dest = sched->schedule(svc, skb, iph);
	} else {
		dest = NULL;
	}
	if (dest == NULL) {
		IP_VS_DBG(1, "Schedule: no dest found.\n");
		return NULL;
	}

	flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
		 && iph->protocol == IPPROTO_UDP) ?
		IP_VS_CONN_F_ONE_PACKET : 0;

	/*
	 *    Create a connection entry.
	 */
	{
		struct ip_vs_conn_param p;

		ip_vs_conn_fill_param(svc->net, svc->af, iph->protocol,
				      &iph->saddr, pptr[0], &iph->daddr,
				      pptr[1], &p);
		cp = ip_vs_conn_new(&p, dest->af, &dest->addr,
				    dest->port ? dest->port : pptr[1],
				    flags, dest, skb->mark);
		if (!cp) {
			*ignored = -1;
			return NULL;
		}
	}

	IP_VS_DBG_BUF(6, "Schedule fwd:%c c:%s:%u v:%s:%u "
		      "d:%s:%u conn->flags:%X conn->refcnt:%d\n",
		      ip_vs_fwd_tag(cp),
		      IP_VS_DBG_ADDR(cp->af, &cp->caddr), ntohs(cp->cport),
		      IP_VS_DBG_ADDR(cp->af, &cp->vaddr), ntohs(cp->vport),
		      IP_VS_DBG_ADDR(cp->daf, &cp->daddr), ntohs(cp->dport),
		      cp->flags, atomic_read(&cp->refcnt));

	ip_vs_conn_stats(cp, svc);
	return cp;
}


/*
 *  Pass or drop the packet.
 *  Called by ip_vs_in, when the virtual service is available but
 *  no destination is available for a new connection.
 */
int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
		struct ip_vs_proto_data *pd, struct ip_vs_iphdr *iph)
{
	__be16 _ports[2], *pptr;
#ifdef CONFIG_SYSCTL
	struct net *net;
	struct netns_ipvs *ipvs;
	int unicast;
#endif

	pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph);
	if (pptr == NULL) {
		return NF_DROP;
	}

#ifdef CONFIG_SYSCTL
	net = skb_net(skb);

#ifdef CONFIG_IP_VS_IPV6
	if (svc->af == AF_INET6)
		unicast = ipv6_addr_type(&iph->daddr.in6) & IPV6_ADDR_UNICAST;
	else
#endif
		unicast = (inet_addr_type(net, iph->daddr.ip) == RTN_UNICAST);

	/* if it is fwmark-based service, the cache_bypass sysctl is up
	   and the destination is a non-local unicast, then create
	   a cache_bypass connection entry */
	ipvs = net_ipvs(net);
	if (ipvs->sysctl_cache_bypass && svc->fwmark && unicast) {
		int ret;
		struct ip_vs_conn *cp;
		unsigned int flags = (svc->flags & IP_VS_SVC_F_ONEPACKET &&
				      iph->protocol == IPPROTO_UDP) ?
				      IP_VS_CONN_F_ONE_PACKET : 0;
		union nf_inet_addr daddr =  { .all = { 0, 0, 0, 0 } };

		/* create a new connection entry */
		IP_VS_DBG(6, "%s(): create a cache_bypass entry\n", __func__);
		{
			struct ip_vs_conn_param p;
			ip_vs_conn_fill_param(svc->net, svc->af, iph->protocol,
					      &iph->saddr, pptr[0],
					      &iph->daddr, pptr[1], &p);
			cp = ip_vs_conn_new(&p, svc->af, &daddr, 0,
					    IP_VS_CONN_F_BYPASS | flags,
					    NULL, skb->mark);
			if (!cp)
				return NF_DROP;
		}

		/* statistics */
		ip_vs_in_stats(cp, skb);

		/* set state */
		ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);

		/* transmit the first SYN packet */
		ret = cp->packet_xmit(skb, cp, pd->pp, iph);
		/* do not touch skb anymore */

		atomic_inc(&cp->in_pkts);
		ip_vs_conn_put(cp);
		return ret;
	}