/* * Copyright (c) 2007-2014 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "datapath.h" #include "flow.h" #include "conntrack.h" #include "vport.h" static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, const struct nlattr *attr, int len); struct deferred_action { struct sk_buff *skb; const struct nlattr *actions; /* Store pkt_key clone when creating deferred action. */ struct sw_flow_key pkt_key; }; #define MAX_L2_LEN (VLAN_ETH_HLEN + 3 * MPLS_HLEN) struct ovs_frag_data { unsigned long dst; struct vport *vport; struct ovs_skb_cb cb; __be16 inner_protocol; __u16 vlan_tci; __be16 vlan_proto; unsigned int l2_len; u8 l2_data[MAX_L2_LEN]; }; static DEFINE_PER_CPU(struct ovs_frag_data, ovs_frag_data_storage); #define DEFERRED_ACTION_FIFO_SIZE 10 struct action_fifo { int head; int tail; /* Deferred action fifo queue storage. */ struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE]; }; static struct action_fifo __percpu *action_fifos; static DEFINE_PER_CPU(int, exec_actions_level); static void action_fifo_init(struct action_fifo *fifo) { fifo->head = 0; fifo->tail = 0; } static bool action_fifo_is_empty(const struct action_fifo *fifo) { return (fifo->head == fifo->tail); } static struct deferred_action *action_fifo_get(struct action_fifo *fifo) { if (action_fifo_is_empty(fifo)) return NULL; return &fifo->fifo[fifo->tail++]; } static struct deferred_action *action_fifo_put(struct action_fifo *fifo) { if (fifo->head >= DEFERRED_ACTION_FIFO_SIZE - 1) return NULL; return &fifo->fifo[fifo->head++]; } /* Return true if fifo is not full */ static struct deferred_action *add_deferred_actions(struct sk_buff *skb, const struct sw_flow_key *key, const struct nlattr *attr) { struct action_fifo *fifo; struct deferred_action *da; fifo = this_cpu_ptr(action_fifos); da = action_fifo_put(fifo); if (da) { da->skb = skb; da->actions = attr; da->pkt_key = *key; } return da; } static void invalidate_flow_key(struct sw_flow_key *key) { key->eth.type = htons(0); } static bool is_flow_key_valid(const struct sw_flow_key *key) { return !!key->eth.type; } static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key, const struct ovs_action_push_mpls *mpls) { __be32 *new_mpls_lse; struct ethhdr *hdr; /* Networking stack do not allow simultaneous Tunnel and MPLS GSO. */ if (skb->encapsulation) return -ENOTSUPP; if (skb_cow_head(skb, MPLS_HLEN) < 0) return -ENOMEM; skb_push(skb, MPLS_HLEN); memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb), skb->mac_len); skb_reset_mac_header(skb); new_mpls_lse = (__be32 *)skb_mpls_header(skb); *new_mpls_lse = mpls->mpls_lse; if (skb->ip_summed == CHECKSUM_COMPLETE) skb->csum = csum_add(skb->csum, csum_partial(new_mpls_lse, MPLS_HLEN, 0)); hdr = eth_hdr(skb); hdr->h_proto = mpls->mpls_ethertype; if (!skb->inner_protocol) skb_set_inner_protocol(skb, skb->protocol); skb->protocol = mpls->mpls_ethertype; invalidate_flow_key(key); return 0; } static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key, const __be16 ethertype) { struct ethhdr *hdr; int err; err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN); if (unlikely(err)) return err; skb_postpull_rcsum(skb, skb_mpls_header(skb), MPLS_HLEN); memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb), skb->mac_len); __skb_pull(skb, MPLS_HLEN); skb_reset_mac_header(skb); /* skb_mpls_header() is used to locate the ethertype * field correctly in the presence of VLAN tags. */ hdr = (struct ethhdr *)(skb_mpls_header(skb) - ETH_HLEN); hdr->h_proto = ethertype; if (eth_p_mpls(skb->protocol)) skb->protocol = ethertype; invalidate_flow_key(key); return 0; } static int set_mpls(struct sk_buff *skb, struct sw_flow_key *flow_key, const __be32 *mpls_lse, const __be32 *mask) { __be32 *stack; __be32 lse; int err; err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN); if (unlikely(err)) return err; stack = (__be32 *)skb_mpls_header(skb); lse = OVS_MASKED(*stack, *mpls_lse, *mask); if (skb->ip_summed == CHECKSUM_COMPLETE) { __be32 diff[] = { ~(*stack), lse }; skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum); } *stack = lse; flow_key->mpls.top_lse = lse; return 0; } static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key) { int err; err = skb_vlan_pop(skb); if (skb_vlan_tag_present(skb)) invalidate_flow_key(key); else key->eth.tci = 0; return err; } static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key, const struct ovs_action_push_vlan *vlan) { if (skb_vlan_tag_present(skb)) invalidate_flow_key(key); else key->eth.tci = vlan->vlan_tci; return skb_vlan_push(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT); } /* 'src' is already properly masked. */ static void ether_addr_copy_masked(u8 *dst_, const u8 *src_, const u8 *mask_) { u16 *dst = (u16 *)dst_; const u16 *src = (const u16 *)src_; const u16 *mask = (const u16 *)mask_; OVS_SET_MASKED(dst[0], src[0], mask[0]); OVS_SET_MASKED(dst[1], src[1], mask[1]); OVS_SET_MASKED(dst[2], src[2], mask[2]); } static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key, const struct ovs_key_ethernet *key, const struct ovs_key_ethernet *mask) { int err; err = skb_ensure_writable(skb, ETH_HLEN); if (unlikely(err)) return err; skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2); ether_addr_copy_masked(eth_hdr(skb)->h_source, key->eth_src, mask->eth_src); ether_addr_copy_masked(eth_hdr(skb)->h_dest, key->eth_dst, mask->eth_dst); ovs_skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2); ether_addr_copy(flow_key->eth.src, eth_hdr(skb)->h_source); ether_addr_copy(flow_key->eth.dst, eth_hdr(skb)->h_dest); return 0; } static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh, __be32 addr, __be32 new_addr) { int transport_len = skb->len - skb_transport_offset(skb); if (nh->frag_off & htons(IP_OFFSET)) return; if (nh->protocol == IPPROTO_TCP) { if (likely(transport_len >= sizeof(struct tcphdr))) inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb, addr, new_addr, true); } 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, true); if (!uh->check) uh->check = CSUM_MANGLED_0; } } } } static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh, __be32 *addr, __be32 new_addr) { update_ip_l4_checksum(skb, nh, *addr, new_addr); csum_replace4(&nh->check, *addr, new_addr); skb_clear_hash(skb); *addr = new_addr; } static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto, __be32 addr[4], const __be32 new_addr[4]) { int transport_len = skb->len - skb_transport_offset(skb); if (l4_proto == NEXTHDR_TCP) { if (likely(transport_len >= sizeof(struct tcphdr))) inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb, addr, new_addr, true); } else if (l4_proto == NEXTHDR_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_replace16(&uh->check, skb, addr, new_addr, true); if (!uh->check) uh->check = CSUM_MANGLED_0; } } } else if (l4_proto == NEXTHDR_ICMP) { if (likely(transport_len >= sizeof(struct icmp6hdr))) inet_proto_csum_replace16(&icmp6_hdr(skb)->icmp6_cksum, skb, addr, new_addr, true); } } static void mask_ipv6_addr(const __be32 old[4], const __be32 addr[4], const __be32 mask[4], __be32 masked[4]) { masked[0] = OVS_MASKED(old[0], addr[0], mask[0]); masked[1] = OVS_MASKED(old[1], addr[1], mask[1]); masked[2] = OVS_MASKED(old[2], addr[2], mask[2]); masked[3] = OVS_MASKED(old[3], addr[3], mask[3]); } static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto, __be32 addr[4], const __be32 new_addr[4], bool recalculate_csum) { if (recalculate_csum) update_ipv6_checksum(skb, l4_proto, addr, new_addr); skb_clear_hash(skb); memcpy(addr, new_addr, sizeof(__be32[4])); } static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl, u32 mask) { /* Bits 21-24 are always unmasked, so this retains their values. */ OVS_SET_MASKED(nh->flow_lbl[0], (u8)(fl >> 16), (u8)(mask >> 16)); OVS_SET_MASKED(nh->flow_lbl[1], (u8)(fl >> 8), (u8)(mask >> 8)); OVS_SET_MASKED(nh->flow_lbl[2], (u8)fl, (u8)mask); } static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl, u8 mask) { new_ttl = OVS_MASKED(nh->ttl, new_ttl, mask); csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8)); nh->ttl = new_ttl; } static int set_ipv4(struct sk_buff *skb, struct sw_flow_key *flow_key, const struct ovs_key_ipv4 *key, const struct ovs_key_ipv4 *mask) { struct iphdr *nh; __be32 new_addr; int err; err = skb_ensure_writable(skb, skb_network_offset(skb) + sizeof(struct iphdr)); if (unlikely(err)) return err; nh = ip_hdr(skb); /* Setting an IP addresses is typically only a side effect of * matching on them in the current userspace implementation, so it * makes sense to check if the value actually changed. */ if (mask->ipv4_src) { new_addr = OVS_MASKED(nh->saddr, key->ipv4_src, mask->ipv4_src); if (unlikely(new_addr != nh->saddr)) { set_ip_addr(skb, nh, &nh->saddr, new_addr); flow_key->ipv4.addr.src = new_addr; } } if (mask->ipv4_dst) { new_addr = OVS_MASKED(nh->daddr, key->ipv4_dst, mask->ipv4_dst); if (unlikely(new_addr != nh->daddr)) { set_ip_addr(skb, nh, &nh->daddr, new_addr); flow_key->ipv4.addr.dst = new_addr; } } if (mask->ipv4_tos) { ipv4_change_dsfield(nh, ~mask->ipv4_tos, key->ipv4_tos); flow_key->ip.tos = nh->tos; } if (mask->ipv4_ttl) { set_ip_ttl(skb, nh, key->ipv4_ttl, mask->ipv4_ttl); flow_key->ip.ttl = nh->ttl; } return 0; } static bool is_ipv6_mask_nonzero(const __be32 addr[4]) { return !!(addr[0] | addr[1] | addr[2] | addr[3]); } static int set_ipv6(struct sk_buff *skb, struct sw_flow_key *flow_key, const struct ovs_key_ipv6 *key, const struct ovs_key_ipv6 *mask) { struct ipv6hdr *nh; int err; err = skb_ensure_writable(skb, skb_network_offset(skb) + sizeof(struct ipv6hdr)); if (unlikely(err)) return err; nh = ipv6_hdr(skb); /* Setting an IP addresses is typically only a side effect of * matching on them in the current userspace implementation, so it * makes sense to check if the value actually changed. */ if (is_ipv6_mask_nonzero(mask->ipv6_src)) { __be32 *saddr = (__be32 *)&nh->saddr; __be32 masked[4]; mask_ipv6_addr(saddr, key->ipv6_src, mask->ipv6_src, masked); if (unlikely(memcmp(saddr, masked, sizeof(masked)))) { set_ipv6_addr(skb, key->ipv6_proto, saddr, masked, true); memcpy(&flow_key->ipv6.addr.src, masked, sizeof(flow_key->ipv6.addr.src)); } } if (is_ipv6_mask_nonzero(mask->ipv6_dst)) { unsigned int offset = 0; int flags = IP6_FH_F_SKIP_RH; bool recalc_csum = true; __be32 *daddr = (__be32 *)&nh->daddr; __be32 masked[4]; mask_ipv6_addr(daddr, key->ipv6_dst, mask->ipv6_dst, masked); if (unlikely(memcmp(daddr, masked, sizeof(masked)))) { if (ipv6_ext_hdr(nh->nexthdr)) recalc_csum = (ipv6_find_hdr(skb, &offset, NEXTHDR_ROUTING, NULL, &flags) != NEXTHDR_ROUTING); set_ipv6_addr(skb, key->ipv6_proto, daddr, masked, recalc_csum); memcpy(&flow_key->ipv6.addr.dst, masked, sizeof(flow_key->ipv6.addr.dst)); } } if (mask->ipv6_tclass) { ipv6_change_dsfield(nh, ~mask->ipv6_tclass, key->ipv6_tclass); flow_key->ip.tos = ipv6_get_dsfield(nh); } if (mask->ipv6_label) { set_ipv6_fl(nh, ntohl(key->ipv6_label), ntohl(mask->ipv6_label)); flow_key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL); } if (mask->ipv6_hlimit) { OVS_SET_MASKED(nh->hop_limit, key->ipv6_hlimit, mask->ipv6_hlimit); flow_key->ip.ttl = nh->hop_limit; } return 0; } /* Must follow skb_ensure_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, false); *port = new_port; } static int set_udp(struct sk_buff *skb, struct sw_flow_key *flow_key, const struct ovs_key_udp *key, const struct ovs_key_udp *mask) { struct udphdr *uh; __be16 src, dst; int err; err = skb_ensure_writable(skb, skb_transport_offset(skb) + sizeof(struct udphdr)); if (unlikely(err)) return err; uh = udp_hdr(skb); /* Either of the masks is non-zero, so do not bother checking them. */ src = OVS_MASKED(uh->source, key->udp_src, mask->udp_src); dst = OVS_MASKED(uh->dest, key->udp_dst, mask->udp_dst); if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) { if (likely(src != uh->source)) { set_tp_port(skb, &uh->source, src, &uh->check); flow_key->tp.src = src; } if (likely(dst != uh->dest)) { set_tp_port(skb, &uh->dest, dst, &uh->check); flow_key->tp.dst = dst; } if (unlikely(!uh->check)) uh->check = CSUM_MANGLED_0; } else { uh->source = src; uh->dest = dst; flow_key->tp.src = src; flow_key->tp.dst = dst; } skb_clear_hash(skb); return 0; } static int set_tcp(struct sk_buff *skb, struct sw_flow_key *flow_key, const struct ovs_key_tcp *key, const struct ovs_key_tcp *mask) { struct tcphdr *th; __be16 src, dst; int err; err = skb_ensure_writable(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)); if (unlikely(err)) return err; th = tcp_hdr(skb); src = OVS_MASKED(th->source, key->tcp_src, mask->tcp_src); if (likely(src != th->source)) { set_tp_port(skb, &th->source, src, &th->check); flow_key->tp.src = src; } dst = OVS_MASKED(th->dest, key->tcp_dst, mask->tcp_dst); if (likely(dst != th->dest)) { set_tp_port(skb, &th->dest, dst, &th->check); flow_key->tp.dst = dst; } skb_clear_hash(skb); return 0; } static int set_sctp(struct sk_buff *skb, struct sw_flow_key *flow_key, const struct ovs_key_sctp *key, const struct ovs_key_sctp *mask) { unsigned int sctphoff = skb_transport_offset(skb); struct sctphdr *sh; __le32 old_correct_csum, new_csum, old_csum; int err; err = skb_ensure_writable(skb, sctphoff + sizeof(struct sctphdr)); if (unlikely(err)) return err; sh = sctp_hdr(skb); old_csum = sh->checksum; old_correct_csum = sctp_compute_cksum(skb, sctphoff); sh->source = OVS_MASKED(sh->source, key->sctp_src, mask->sctp_src); sh->dest = OVS_MASKED(sh->dest, key->sctp_dst, mask->sctp_dst); new_csum = sctp_compute_cksum(skb, sctphoff); /* Carry any checksum errors through. */ sh->checksum = old_csum ^ old_correct_csum ^ new_csum; skb_clear_hash(skb); flow_key->tp.src = sh->source; flow_key->tp.dst = sh->dest; return 0; } static int ovs_vport_output(struct sock *sock, struct sk_buff *skb) { struct ovs_frag_data *data = this_cpu_ptr(&ovs_frag_data_storage); struct vport *vport = data->vport; if (skb_cow_head(skb, data->l2_len) < 0) { kfree_skb(skb); return -ENOMEM; } __skb_dst_copy(skb, data->dst); *OVS_CB(skb) = data->cb; skb->inner_protocol = data->inner_protocol; skb->vlan_tci = data->vlan_tci; skb->vlan_proto = data->vlan_proto; /* Reconstruct the MAC header. */ skb_push(skb, data->l2_len); memcpy(skb->data, &data->l2_data, data->l2_len); ovs_skb_postpush_rcsum(skb, skb->data, data->l2_len); skb_reset_mac_header(skb); ovs_vport_send(vport, skb); return 0; } static unsigned int ovs_dst_get_mtu(const struct dst_entry *dst) { return dst->dev->mtu; } static struct dst_ops ovs_dst_ops = { .family = AF_UNSPEC, .mtu = ovs_dst_get_mtu, }; /* prepare_frag() is called once per (larger-than-MTU) frame; its inverse is * ovs_vport_output(), which is called once per fragmented packet. */ static void prepare_frag(struct vport *vport, struct sk_buff *skb) { unsigned int hlen = skb_network_offset(skb); struct ovs_frag_data *data; data = this_cpu_ptr(&ovs_frag_data_storage); data->dst = skb->_skb_refdst; data->vport = vport; data->cb = *OVS_CB(skb); data->inner_protocol = skb->inner_protocol; data->vlan_tci = skb->vlan_tci; data->vlan_proto = skb->vlan_proto; data->l2_len = hlen; memcpy(&data->l2_data, skb->data, hlen); memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); skb_pull(skb, hlen); } static void ovs_fragment(struct vport *vport, struct sk_buff *skb, u16 mru, __be16 ethertype) { if (skb_network_offset(skb) > MAX_L2_LEN) { OVS_NLERR(1, "L2 header too long to fragment"); return; } if (ethertype == htons(ETH_P_IP)) { struct dst_entry ovs_dst; unsigned long orig_dst; prepare_frag(vport, skb); dst_init(&ovs_dst, &ovs_dst_ops, NULL, 1, DST_OBSOLETE_NONE, DST_NOCOUNT); ovs_dst.dev = vport->dev; orig_dst = skb->_skb_refdst; skb_dst_set_noref(skb, &ovs_dst); IPCB(skb)->frag_max_size = mru; ip_do_fragment(skb->sk, skb, ovs_vport_output); refdst_drop(orig_dst); } else if (ethertype == htons(ETH_P_IPV6)) { const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops(); unsigned long orig_dst; struct rt6_info ovs_rt; if (!v6ops) { kfree_skb(skb); return; } prepare_frag(vport, skb); memset(&ovs_rt, 0, sizeof(ovs_rt)); dst_init(&ovs_rt.dst, &ovs_dst_ops, NULL, 1, DST_OBSOLETE_NONE, DST_NOCOUNT); ovs_rt.dst.dev = vport->dev; orig_dst = skb->_skb_refdst; skb_dst_set_noref(skb, &ovs_rt.dst); IP6CB(skb)->frag_max_size = mru; v6ops->fragment(skb->sk, skb, ovs_vport_output); refdst_drop(orig_dst); } else { WARN_ONCE(1, "Failed fragment ->%s: eth=%04x, MRU=%d, MTU=%d.", ovs_vport_name(vport), ntohs(ethertype), mru, vport->dev->mtu); kfree_skb(skb); } } static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port, struct sw_flow_key *key) { struct vport *vport = ovs_vport_rcu(dp, out_port); if (likely(vport)) { u16 mru = OVS_CB(skb)->mru; if (likely(!mru || (skb->len <= mru + ETH_HLEN))) { ovs_vport_send(vport, skb); } else if (mru <= vport->dev->mtu) { __be16 ethertype = key->eth.type; if (!is_flow_key_valid(key)) { if (eth_p_mpls(skb->protocol)) ethertype = skb->inner_protocol; else ethertype = vlan_get_protocol(skb); } ovs_fragment(vport, skb, mru, ethertype); } else { kfree_skb(skb); } } else { kfree_skb(skb); } } static int output_userspace(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, const struct nlattr *attr, const struct nlattr *actions, int actions_len) { struct ip_tunnel_info info; struct dp_upcall_info upcall; const struct nlattr *a; int rem; memset(&upcall, 0, sizeof(upcall)); upcall.cmd = OVS_PACKET_CMD_ACTION; upcall.mru = OVS_CB(skb)->mru; 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.portid = nla_get_u32(a); break; case OVS_USERSPACE_ATTR_EGRESS_TUN_PORT: { /* Get out tunnel info. */ struct vport *vport; vport = ovs_vport_rcu(dp, nla_get_u32(a)); if (vport) { int err; err = ovs_vport_get_egress_tun_info(vport, skb, &info); if (!err) upcall.egress_tun_info = &info; } break; } case OVS_USERSPACE_ATTR_ACTIONS: { /* Include actions. */ upcall.actions = actions; upcall.actions_len = actions_len; break; } } /* End of switch. */ } return ovs_dp_upcall(dp, skb, key, &upcall); } static int sample(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, const struct nlattr *attr, const struct nlattr *actions, int actions_len) { 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)) { u32 probability; switch (nla_type(a)) { case OVS_SAMPLE_ATTR_PROBABILITY: probability = nla_get_u32(a); if (!probability || prandom_u32() > probability) return 0; break; case OVS_SAMPLE_ATTR_ACTIONS: acts_list = a; break; } } rem = nla_len(acts_list); a = nla_data(acts_list); /* Actions list is empty, do nothing */ if (unlikely(!rem)) return 0; /* The only known usage of sample action is having a single user-space * action. Treat this usage as a special case. * The output_userspace() should clone the skb to be sent to the * user space. This skb will be consumed by its caller. */ if (likely(nla_type(a) == OVS_ACTION_ATTR_USERSPACE && nla_is_last(a, rem))) return output_userspace(dp, skb, key, a, actions, actions_len); skb = skb_clone(skb, GFP_ATOMIC); if (!skb) /* Skip the sample action when out of memory. */ return 0; if (!add_deferred_actions(skb, key, a)) { if (net_ratelimit()) pr_warn("%s: deferred actions limit reached, dropping sample action\n", ovs_dp_name(dp)); kfree_skb(skb); } return 0; } static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key, const struct nlattr *attr) { struct ovs_action_hash *hash_act = nla_data(attr); u32 hash = 0; /* OVS_HASH_ALG_L4 is the only possible hash algorithm. */ hash = skb_get_hash(skb); hash = jhash_1word(hash, hash_act->hash_basis); if (!hash) hash = 0x1; key->ovs_flow_hash = hash; } static int execute_set_action(struct sk_buff *skb, struct sw_flow_key *flow_key, const struct nlattr *a) { /* Only tunnel set execution is supported without a mask. */ if (nla_type(a) == OVS_KEY_ATTR_TUNNEL_INFO) { struct ovs_tunnel_info *tun = nla_data(a); skb_dst_drop(skb); dst_hold((struct dst_entry *)tun->tun_dst); skb_dst_set(skb, (struct dst_entry *)tun->tun_dst); return 0; } return -EINVAL; } /* Mask is at the midpoint of the data. */ #define get_mask(a, type) ((const type)nla_data(a) + 1) static int execute_masked_set_action(struct sk_buff *skb, struct sw_flow_key *flow_key, const struct nlattr *a) { int err = 0; switch (nla_type(a)) { case OVS_KEY_ATTR_PRIORITY: OVS_SET_MASKED(skb->priority, nla_get_u32(a), *get_mask(a, u32 *)); flow_key->phy.priority = skb->priority; break; case OVS_KEY_ATTR_SKB_MARK: OVS_SET_MASKED(skb->mark, nla_get_u32(a), *get_mask(a, u32 *)); flow_key->phy.skb_mark = skb->mark; break; case OVS_KEY_ATTR_TUNNEL_INFO: /* Masked data not supported for tunnel. */ err = -EINVAL; break; case OVS_KEY_ATTR_ETHERNET: err = set_eth_addr(skb, flow_key, nla_data(a), get_mask(a, struct ovs_key_ethernet *)); break; case OVS_KEY_ATTR_IPV4: err = set_ipv4(skb, flow_key, nla_data(a), get_mask(a, struct ovs_key_ipv4 *)); break; case OVS_KEY_ATTR_IPV6: err = set_ipv6(skb, flow_key, nla_data(a), get_mask(a, struct ovs_key_ipv6 *)); break; case OVS_KEY_ATTR_TCP: err = set_tcp(skb, flow_key, nla_data(a), get_mask(a, struct ovs_key_tcp *)); break; case OVS_KEY_ATTR_UDP: err = set_udp(skb, flow_key, nla_data(a), get_mask(a, struct ovs_key_udp *)); break; case OVS_KEY_ATTR_SCTP: err = set_sctp(skb, flow_key, nla_data(a), get_mask(a, struct ovs_key_sctp *)); break; case OVS_KEY_ATTR_MPLS: err = set_mpls(skb, flow_key, nla_data(a), get_mask(a, __be32 *)); break; case OVS_KEY_ATTR_CT_STATE: case OVS_KEY_ATTR_CT_ZONE: case OVS_KEY_ATTR_CT_MARK: case OVS_KEY_ATTR_CT_LABEL: err = -EINVAL; break; } return err; } static int execute_recirc(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, const struct nlattr *a, int rem) { struct deferred_action *da; if (!is_flow_key_valid(key)) { int err; err = ovs_flow_key_update(skb, key); if (err) return err; } BUG_ON(!is_flow_key_valid(key)); if (!nla_is_last(a, rem)) { /* Recirc action is the not the last action * of the action list, need to clone the skb. */ skb = skb_clone(skb, GFP_ATOMIC); /* Skip the recirc action when out of memory, but * continue on with the rest of the action list. */ if (!skb) return 0; } da = add_deferred_actions(skb, key, NULL); if (da) { da->pkt_key.recirc_id = nla_get_u32(a); } else { kfree_skb(skb); if (net_ratelimit()) pr_warn("%s: deferred action limit reached, drop recirc action\n", ovs_dp_name(dp)); } return 0; } /* Execute a list of actions against 'skb'. */ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, const struct nlattr *attr, int len) { /* 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 (unlikely(prev_port != -1)) { struct sk_buff *out_skb = skb_clone(skb, GFP_ATOMIC); if (out_skb) do_output(dp, out_skb, prev_port, key); 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, key, a, attr, len); break; case OVS_ACTION_ATTR_HASH: execute_hash(skb, key, a); break; case OVS_ACTION_ATTR_PUSH_MPLS: err = push_mpls(skb, key, nla_data(a)); break; case OVS_ACTION_ATTR_POP_MPLS: err = pop_mpls(skb, key, nla_get_be16(a)); break; case OVS_ACTION_ATTR_PUSH_VLAN: err = push_vlan(skb, key, nla_data(a)); break; case OVS_ACTION_ATTR_POP_VLAN: err = pop_vlan(skb, key); break; case OVS_ACTION_ATTR_RECIRC: err = execute_recirc(dp, skb, key, a, rem); if (nla_is_last(a, rem)) { /* If this is the last action, the skb has * been consumed or freed. * Return immediately. */ return err; } break; case OVS_ACTION_ATTR_SET: err = execute_set_action(skb, key, nla_data(a)); break; case OVS_ACTION_ATTR_SET_MASKED: case OVS_ACTION_ATTR_SET_TO_MASKED: err = execute_masked_set_action(skb, key, nla_data(a)); break; case OVS_ACTION_ATTR_SAMPLE: err = sample(dp, skb, key, a, attr, len); break; case OVS_ACTION_ATTR_CT: err = ovs_ct_execute(ovs_dp_get_net(dp), skb, key, nla_data(a)); /* Hide stolen IP fragments from user space. */ if (err == -EINPROGRESS) return 0; break; } if (unlikely(err)) { kfree_skb(skb); return err; } } if (prev_port != -1) do_output(dp, skb, prev_port, key); else consume_skb(skb); return 0; } static void process_deferred_actions(struct datapath *dp) { struct action_fifo *fifo = this_cpu_ptr(action_fifos); /* Do not touch the FIFO in case there is no deferred actions. */ if (action_fifo_is_empty(fifo)) return; /* Finishing executing all deferred actions. */ do { struct deferred_action *da = action_fifo_get(fifo); struct sk_buff *skb = da->skb; struct sw_flow_key *key = &da->pkt_key; const struct nlattr *actions = da->actions; if (actions) do_execute_actions(dp, skb, key, actions, nla_len(actions)); else ovs_dp_process_packet(skb, key); } while (!action_fifo_is_empty(fifo)); /* Reset FIFO for the next packet. */ action_fifo_init(fifo); } /* Execute a list of actions against 'skb'. */ int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb, const struct sw_flow_actions *acts, struct sw_flow_key *key) { int level = this_cpu_read(exec_actions_level); int err; this_cpu_inc(exec_actions_level); err = do_execute_actions(dp, skb, key, acts->actions, acts->actions_len); if (!level) process_deferred_actions(dp); this_cpu_dec(exec_actions_level); return err; } int action_fifos_init(void) { action_fifos = alloc_percpu(struct action_fifo); if (!action_fifos) return -ENOMEM; return 0; } void action_fifos_exit(void) { free_percpu(action_fifos); }