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author | Jesse Gross <jesse@nicira.com> | 2011-10-25 19:26:31 -0700 |
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committer | Jesse Gross <jesse@nicira.com> | 2011-12-03 09:35:17 -0800 |
commit | ccb1352e76cff0524e7ccb2074826a092dd13016 (patch) | |
tree | 9122ceff5d75ec64e327a9fad4ad2013744c2999 /net/openvswitch/actions.c | |
parent | 75f2811c6460ccc59d83c66059943ce9c9f81a18 (diff) | |
download | linux-stable-ccb1352e76cff0524e7ccb2074826a092dd13016.tar.gz linux-stable-ccb1352e76cff0524e7ccb2074826a092dd13016.tar.bz2 linux-stable-ccb1352e76cff0524e7ccb2074826a092dd13016.zip |
net: Add Open vSwitch kernel components.
Open vSwitch is a multilayer Ethernet switch targeted at virtualized
environments. In addition to supporting a variety of features
expected in a traditional hardware switch, it enables fine-grained
programmatic extension and flow-based control of the network.
This control is useful in a wide variety of applications but is
particularly important in multi-server virtualization deployments,
which are often characterized by highly dynamic endpoints and the need
to maintain logical abstractions for multiple tenants.
The Open vSwitch datapath provides an in-kernel fast path for packet
forwarding. It is complemented by a userspace daemon, ovs-vswitchd,
which is able to accept configuration from a variety of sources and
translate it into packet processing rules.
See http://openvswitch.org for more information and userspace
utilities.
Signed-off-by: Jesse Gross <jesse@nicira.com>
Diffstat (limited to 'net/openvswitch/actions.c')
-rw-r--r-- | net/openvswitch/actions.c | 415 |
1 files changed, 415 insertions, 0 deletions
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c new file mode 100644 index 000000000000..2725d1bdf291 --- /dev/null +++ b/net/openvswitch/actions.c @@ -0,0 +1,415 @@ +/* + * Copyright (c) 2007-2011 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))) + inet_proto_csum_replace4(&udp_hdr(skb)->check, skb, + *addr, new_addr, 1); + } + + 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 int set_udp_port(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_tp_port(skb, &uh->source, udp_port_key->udp_src, &uh->check); + + if (udp_port_key->udp_dst != uh->dest) + set_tp_port(skb, &uh->dest, udp_port_key->udp_dst, &uh->check); + + return 0; +} + +static int set_tcp_port(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_port(skb, nla_data(nested_attr)); + break; + + case OVS_KEY_ATTR_UDP: + err = set_udp_port(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); +} |