/* * Copyright (c) 2007-2012 Nicira Networks. * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/skbuff.h>#include <linux/in.h>#include <linux/ip.h>#include <linux/openvswitch.h>#include <linux/tcp.h>#include <linux/udp.h>#include <linux/in6.h>#include <linux/if_arp.h>#include <linux/if_vlan.h>#include <net/ip.h>#include <net/checksum.h>#include <net/dsfield.h> #include "datapath.h"#include "vport.h" static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,			const struct nlattr *attr, int len, bool keep_skb); static int make_writable(struct sk_buff *skb, int write_len){	if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))		return 0; 	return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);} /* remove VLAN header from packet and update csum accrodingly. */static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci){	struct vlan_hdr *vhdr;	int err; 	err = make_writable(skb, VLAN_ETH_HLEN);	if (unlikely(err))		return err; 	if (skb->ip_summed == CHECKSUM_COMPLETE)		skb->csum = csum_sub(skb->csum, csum_partial(skb->data					+ ETH_HLEN, VLAN_HLEN, 0)); 	vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);	*current_tci = vhdr->h_vlan_TCI; 	memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);	__skb_pull(skb, VLAN_HLEN); 	vlan_set_encap_proto(skb, vhdr);	skb->mac_header += VLAN_HLEN;	skb_reset_mac_len(skb); 	return 0;} static int pop_vlan(struct sk_buff *skb){	__be16 tci;	int err; 	if (likely(vlan_tx_tag_present(skb))) {		skb->vlan_tci = 0;	} else {		if (unlikely(skb->protocol != htons(ETH_P_8021Q) ||			     skb->len < VLAN_ETH_HLEN))			return 0; 		err = __pop_vlan_tci(skb, &tci);		if (err)			return err;	}	/* move next vlan tag to hw accel tag */	if (likely(skb->protocol != htons(ETH_P_8021Q) ||		   skb->len < VLAN_ETH_HLEN))		return 0; 	err = __pop_vlan_tci(skb, &tci);	if (unlikely(err))		return err; 	__vlan_hwaccel_put_tag(skb, ntohs(tci));	return 0;} static int push_vlan(struct sk_buff *skb, const struct ovs_action_push_vlan *vlan){	if (unlikely(vlan_tx_tag_present(skb))) {		u16 current_tag; 		/* push down current VLAN tag */		current_tag = vlan_tx_tag_get(skb); 		if (!__vlan_put_tag(skb, current_tag))			return -ENOMEM; 		if (skb->ip_summed == CHECKSUM_COMPLETE)			skb->csum = csum_add(skb->csum, csum_partial(skb->data					+ ETH_HLEN, VLAN_HLEN, 0)); 	}	__vlan_hwaccel_put_tag(skb, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);	return 0;} static int set_eth_addr(struct sk_buff *skb,			const struct ovs_key_ethernet *eth_key){	int err;	err = make_writable(skb, ETH_HLEN);	if (unlikely(err))		return err; 	memcpy(eth_hdr(skb)->h_source, eth_key->eth_src, ETH_ALEN);	memcpy(eth_hdr(skb)->h_dest, eth_key->eth_dst, ETH_ALEN); 	return 0;} static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,				__be32 *addr, __be32 new_addr){	int transport_len = skb->len - skb_transport_offset(skb); 	if (nh->protocol == IPPROTO_TCP) {		if (likely(transport_len >= sizeof(struct tcphdr)))			inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,						 *addr, new_addr, 1);	} else if (nh->protocol == IPPROTO_UDP) {		if (likely(transport_len >= sizeof(struct udphdr))) {			struct udphdr *uh = udp_hdr(skb); 			if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {				inet_proto_csum_replace4(&uh->check, skb,							 *addr, new_addr, 1);				if (!uh->check)					uh->check = CSUM_MANGLED_0;			}		}	} 	csum_replace4(&nh->check, *addr, new_addr);	skb->rxhash = 0;	*addr = new_addr;} static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl){	csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));	nh->ttl = new_ttl;} static int set_ipv4(struct sk_buff *skb, const struct ovs_key_ipv4 *ipv4_key){	struct iphdr *nh;	int err; 	err = make_writable(skb, skb_network_offset(skb) +				 sizeof(struct iphdr));	if (unlikely(err))		return err; 	nh = ip_hdr(skb); 	if (ipv4_key->ipv4_src != nh->saddr)		set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src); 	if (ipv4_key->ipv4_dst != nh->daddr)		set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst); 	if (ipv4_key->ipv4_tos != nh->tos)		ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos); 	if (ipv4_key->ipv4_ttl != nh->ttl)		set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl); 	return 0;} /* Must follow make_writable() since that can move the skb data. */static void set_tp_port(struct sk_buff *skb, __be16 *port,			 __be16 new_port, __sum16 *check){	inet_proto_csum_replace2(check, skb, *port, new_port, 0);	*port = new_port;	skb->rxhash = 0;} static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port){	struct udphdr *uh = udp_hdr(skb); 	if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {		set_tp_port(skb, port, new_port, &uh->check); 		if (!uh->check)			uh->check = CSUM_MANGLED_0;	} else {		*port = new_port;		skb->rxhash = 0;	}} static int set_udp(struct sk_buff *skb, const struct ovs_key_udp *udp_port_key){	struct udphdr *uh;	int err; 	err = make_writable(skb, skb_transport_offset(skb) +				 sizeof(struct udphdr));	if (unlikely(err))		return err; 	uh = udp_hdr(skb);	if (udp_port_key->udp_src != uh->source)		set_udp_port(skb, &uh->source, udp_port_key->udp_src); 	if (udp_port_key->udp_dst != uh->dest)		set_udp_port(skb, &uh->dest, udp_port_key->udp_dst); 	return 0;} static int set_tcp(struct sk_buff *skb, const struct ovs_key_tcp *tcp_port_key){	struct tcphdr *th;	int err; 	err = make_writable(skb, skb_transport_offset(skb) +				 sizeof(struct tcphdr));	if (unlikely(err))		return err; 	th = tcp_hdr(skb);	if (tcp_port_key->tcp_src != th->source)		set_tp_port(skb, &th->source, tcp_port_key->tcp_src, &th->check); 	if (tcp_port_key->tcp_dst != th->dest)		set_tp_port(skb, &th->dest, tcp_port_key->tcp_dst, &th->check); 	return 0;} static int do_output(struct datapath *dp, struct sk_buff *skb, int out_port){	struct vport *vport; 	if (unlikely(!skb))		return -ENOMEM; 	vport = rcu_dereference(dp->ports[out_port]);	if (unlikely(!vport)) {		kfree_skb(skb);		return -ENODEV;	} 	ovs_vport_send(vport, skb);	return 0;} static int output_userspace(struct datapath *dp, struct sk_buff *skb,			    const struct nlattr *attr){	struct dp_upcall_info upcall;	const struct nlattr *a;	int rem; 	upcall.cmd = OVS_PACKET_CMD_ACTION;	upcall.key = &OVS_CB(skb)->flow->key;	upcall.userdata = NULL;	upcall.pid = 0; 	for (a = nla_data(attr), rem = nla_len(attr); rem > 0;		 a = nla_next(a, &rem)) {		switch (nla_type(a)) {		case OVS_USERSPACE_ATTR_USERDATA:			upcall.userdata = a;			break; 		case OVS_USERSPACE_ATTR_PID:			upcall.pid = nla_get_u32(a);			break;		}	} 	return ovs_dp_upcall(dp, skb, &upcall);} static int sample(struct datapath *dp, struct sk_buff *skb,		  const struct nlattr *attr){	const struct nlattr *acts_list = NULL;	const struct nlattr *a;	int rem; 	for (a = nla_data(attr), rem = nla_len(attr); rem > 0;		 a = nla_next(a, &rem)) {		switch (nla_type(a)) {		case OVS_SAMPLE_ATTR_PROBABILITY:			if (net_random() >= nla_get_u32(a))				return 0;			break; 		case OVS_SAMPLE_ATTR_ACTIONS:			acts_list = a;			break;		}	} 	return do_execute_actions(dp, skb, nla_data(acts_list),						 nla_len(acts_list), true);} static int execute_set_action(struct sk_buff *skb,				 const struct nlattr *nested_attr){	int err = 0; 	switch (nla_type(nested_attr)) {	case OVS_KEY_ATTR_PRIORITY:		skb->priority = nla_get_u32(nested_attr);		break; 	case OVS_KEY_ATTR_ETHERNET:		err = set_eth_addr(skb, nla_data(nested_attr));		break; 	case OVS_KEY_ATTR_IPV4:		err = set_ipv4(skb, nla_data(nested_attr));		break; 	case OVS_KEY_ATTR_TCP:		err = set_tcp(skb, nla_data(nested_attr));		break; 	case OVS_KEY_ATTR_UDP:		err = set_udp(skb, nla_data(nested_attr));		break;	} 	return err;} /* Execute a list of actions against 'skb'. */static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,			const struct nlattr *attr, int len, bool keep_skb){	/* Every output action needs a separate clone of 'skb', but the common	 * case is just a single output action, so that doing a clone and	 * then freeing the original skbuff is wasteful.  So the following code	 * is slightly obscure just to avoid that. */	int prev_port = -1;	const struct nlattr *a;	int rem; 	for (a = attr, rem = len; rem > 0;	     a = nla_next(a, &rem)) {		int err = 0; 		if (prev_port != -1) {			do_output(dp, skb_clone(skb, GFP_ATOMIC), prev_port);			prev_port = -1;		} 		switch (nla_type(a)) {		case OVS_ACTION_ATTR_OUTPUT:			prev_port = nla_get_u32(a);			break; 		case OVS_ACTION_ATTR_USERSPACE:			output_userspace(dp, skb, a);			break; 		case OVS_ACTION_ATTR_PUSH_VLAN:			err = push_vlan(skb, nla_data(a));			if (unlikely(err)) /* skb already freed. */				return err;			break; 		case OVS_ACTION_ATTR_POP_VLAN:			err = pop_vlan(skb);			break; 		case OVS_ACTION_ATTR_SET:			err = execute_set_action(skb, nla_data(a));			break; 		case OVS_ACTION_ATTR_SAMPLE:			err = sample(dp, skb, a);			break;		} 		if (unlikely(err)) {			kfree_skb(skb);			return err;		}	} 	if (prev_port != -1) {		if (keep_skb)			skb = skb_clone(skb, GFP_ATOMIC); 		do_output(dp, skb, prev_port);	} else if (!keep_skb)		consume_skb(skb); 	return 0;} /* Execute a list of actions against 'skb'. */int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb){	struct sw_flow_actions *acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts); 	return do_execute_actions(dp, skb, acts->actions,					 acts->actions_len, false);}