| /* |
| * Copyright (c) 2007-2012 Nicira, Inc. |
| * |
| * 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 = ovs_vport_rcu(dp, 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); |
| } |