// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2007-2017 Nicira, Inc. */ #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/sctp.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/dst.h> #include <net/ip.h> #include <net/ipv6.h> #include <net/ip6_fib.h> #include <net/checksum.h> #include <net/dsfield.h> #include <net/mpls.h> #include <net/sctp/checksum.h> #include "datapath.h" #include "flow.h" #include "conntrack.h" #include "vport.h" #include "flow_netlink.h" #include "openvswitch_trace.h" struct deferred_action { struct sk_buff *skb; const struct nlattr *actions; int actions_len; /* 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 network_offset; /* valid only for MPLS */ u16 vlan_tci; __be16 vlan_proto; unsigned int l2_len; u8 mac_proto; u8 l2_data[MAX_L2_LEN]; }; static DEFINE_PER_CPU(struct ovs_frag_data, ovs_frag_data_storage); #define DEFERRED_ACTION_FIFO_SIZE 10 #define OVS_RECURSION_LIMIT 5 #define OVS_DEFERRED_ACTION_THRESHOLD (OVS_RECURSION_LIMIT - 2) struct action_fifo { int head; int tail; /* Deferred action fifo queue storage. */ struct deferred_action fifo[DEFERRED_ACTION_FIFO_SIZE]; }; struct action_flow_keys { struct sw_flow_key key[OVS_DEFERRED_ACTION_THRESHOLD]; }; static struct action_fifo __percpu *action_fifos; static struct action_flow_keys __percpu *flow_keys; static DEFINE_PER_CPU(int, exec_actions_level); /* Make a clone of the 'key', using the pre-allocated percpu 'flow_keys' * space. Return NULL if out of key spaces. */ static struct sw_flow_key *clone_key(const struct sw_flow_key *key_) { struct action_flow_keys *keys = this_cpu_ptr(flow_keys); int level = this_cpu_read(exec_actions_level); struct sw_flow_key *key = NULL; if (level <= OVS_DEFERRED_ACTION_THRESHOLD) { key = &keys->key[level - 1]; *key = *key_; } return key; } 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 *actions, const int actions_len) { 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 = actions; da->actions_len = actions_len; da->pkt_key = *key; } return da; } static void invalidate_flow_key(struct sw_flow_key *key) { key->mac_proto |= SW_FLOW_KEY_INVALID; } static bool is_flow_key_valid(const struct sw_flow_key *key) { return !(key->mac_proto & SW_FLOW_KEY_INVALID); } static int clone_execute(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, u32 recirc_id, const struct nlattr *actions, int len, bool last, bool clone_flow_key); static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, const struct nlattr *attr, int len); static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key, __be32 mpls_lse, __be16 mpls_ethertype, __u16 mac_len) { int err; err = skb_mpls_push(skb, mpls_lse, mpls_ethertype, mac_len, !!mac_len); if (err) return err; if (!mac_len) key->mac_proto = MAC_PROTO_NONE; invalidate_flow_key(key); return 0; } static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key, const __be16 ethertype) { int err; err = skb_mpls_pop(skb, ethertype, skb->mac_len, ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET); if (err) return err; if (ethertype == htons(ETH_P_TEB)) key->mac_proto = MAC_PROTO_ETHERNET; 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) { struct mpls_shim_hdr *stack; __be32 lse; int err; if (!pskb_may_pull(skb, skb_network_offset(skb) + MPLS_HLEN)) return -ENOMEM; stack = mpls_hdr(skb); lse = OVS_MASKED(stack->label_stack_entry, *mpls_lse, *mask); err = skb_mpls_update_lse(skb, lse); if (err) return err; flow_key->mpls.lse[0] = 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.vlan.tci = 0; key->eth.vlan.tpid = 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.vlan.tci = vlan->vlan_tci; key->eth.vlan.tpid = vlan->vlan_tpid; } return skb_vlan_push(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_CFI_MASK); } /* '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); 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; } /* pop_eth does not support VLAN packets as this action is never called * for them. */ static int pop_eth(struct sk_buff *skb, struct sw_flow_key *key) { int err; err = skb_eth_pop(skb); if (err) return err; /* safe right before invalidate_flow_key */ key->mac_proto = MAC_PROTO_NONE; invalidate_flow_key(key); return 0; } static int push_eth(struct sk_buff *skb, struct sw_flow_key *key, const struct ovs_action_push_eth *ethh) { int err; err = skb_eth_push(skb, ethh->addresses.eth_dst, ethh->addresses.eth_src); if (err) return err; /* safe right before invalidate_flow_key */ key->mac_proto = MAC_PROTO_ETHERNET; invalidate_flow_key(key); return 0; } static int push_nsh(struct sk_buff *skb, struct sw_flow_key *key, const struct nshhdr *nh) { int err; err = nsh_push(skb, nh); if (err) return err; /* safe right before invalidate_flow_key */ key->mac_proto = MAC_PROTO_NONE; invalidate_flow_key(key); return 0; } static int pop_nsh(struct sk_buff *skb, struct sw_flow_key *key) { int err; err = nsh_pop(skb); if (err) return err; /* safe right before invalidate_flow_key */ if (skb->protocol == htons(ETH_P_TEB)) key->mac_proto = MAC_PROTO_ETHERNET; else key->mac_proto = MAC_PROTO_NONE; invalidate_flow_key(key); 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, flow_key->ip.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, flow_key->ip.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; } static int set_nsh(struct sk_buff *skb, struct sw_flow_key *flow_key, const struct nlattr *a) { struct nshhdr *nh; size_t length; int err; u8 flags; u8 ttl; int i; struct ovs_key_nsh key; struct ovs_key_nsh mask; err = nsh_key_from_nlattr(a, &key, &mask); if (err) return err; /* Make sure the NSH base header is there */ if (!pskb_may_pull(skb, skb_network_offset(skb) + NSH_BASE_HDR_LEN)) return -ENOMEM; nh = nsh_hdr(skb); length = nsh_hdr_len(nh); /* Make sure the whole NSH header is there */ err = skb_ensure_writable(skb, skb_network_offset(skb) + length); if (unlikely(err)) return err; nh = nsh_hdr(skb); skb_postpull_rcsum(skb, nh, length); flags = nsh_get_flags(nh); flags = OVS_MASKED(flags, key.base.flags, mask.base.flags); flow_key->nsh.base.flags = flags; ttl = nsh_get_ttl(nh); ttl = OVS_MASKED(ttl, key.base.ttl, mask.base.ttl); flow_key->nsh.base.ttl = ttl; nsh_set_flags_and_ttl(nh, flags, ttl); nh->path_hdr = OVS_MASKED(nh->path_hdr, key.base.path_hdr, mask.base.path_hdr); flow_key->nsh.base.path_hdr = nh->path_hdr; switch (nh->mdtype) { case NSH_M_TYPE1: for (i = 0; i < NSH_MD1_CONTEXT_SIZE; i++) { nh->md1.context[i] = OVS_MASKED(nh->md1.context[i], key.context[i], mask.context[i]); } memcpy(flow_key->nsh.context, nh->md1.context, sizeof(nh->md1.context)); break; case NSH_M_TYPE2: memset(flow_key->nsh.context, 0, sizeof(flow_key->nsh.context)); break; default: return -EINVAL; } skb_postpush_rcsum(skb, nh, length); 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 net *net, struct sock *sk, 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; if (data->vlan_tci & VLAN_CFI_MASK) __vlan_hwaccel_put_tag(skb, data->vlan_proto, data->vlan_tci & ~VLAN_CFI_MASK); else __vlan_hwaccel_clear_tag(skb); /* Reconstruct the MAC header. */ skb_push(skb, data->l2_len); memcpy(skb->data, &data->l2_data, data->l2_len); skb_postpush_rcsum(skb, skb->data, data->l2_len); skb_reset_mac_header(skb); if (eth_p_mpls(skb->protocol)) { skb->inner_network_header = skb->network_header; skb_set_network_header(skb, data->network_offset); skb_reset_mac_len(skb); } ovs_vport_send(vport, skb, data->mac_proto); 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, u16 orig_network_offset, u8 mac_proto) { 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->network_offset = orig_network_offset; if (skb_vlan_tag_present(skb)) data->vlan_tci = skb_vlan_tag_get(skb) | VLAN_CFI_MASK; else data->vlan_tci = 0; data->vlan_proto = skb->vlan_proto; data->mac_proto = mac_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 net *net, struct vport *vport, struct sk_buff *skb, u16 mru, struct sw_flow_key *key) { u16 orig_network_offset = 0; if (eth_p_mpls(skb->protocol)) { orig_network_offset = skb_network_offset(skb); skb->network_header = skb->inner_network_header; } if (skb_network_offset(skb) > MAX_L2_LEN) { OVS_NLERR(1, "L2 header too long to fragment"); goto err; } if (key->eth.type == htons(ETH_P_IP)) { struct rtable ovs_rt = { 0 }; unsigned long orig_dst; prepare_frag(vport, skb, orig_network_offset, ovs_key_mac_proto(key)); 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); IPCB(skb)->frag_max_size = mru; ip_do_fragment(net, skb->sk, skb, ovs_vport_output); refdst_drop(orig_dst); } else if (key->eth.type == htons(ETH_P_IPV6)) { unsigned long orig_dst; struct rt6_info ovs_rt; prepare_frag(vport, skb, orig_network_offset, ovs_key_mac_proto(key)); 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; ipv6_stub->ipv6_fragment(net, 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(key->eth.type), mru, vport->dev->mtu); goto err; } return; err: 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; u32 cutlen = OVS_CB(skb)->cutlen; if (unlikely(cutlen > 0)) { if (skb->len - cutlen > ovs_mac_header_len(key)) pskb_trim(skb, skb->len - cutlen); else pskb_trim(skb, ovs_mac_header_len(key)); } if (likely(!mru || (skb->len <= mru + vport->dev->hard_header_len))) { ovs_vport_send(vport, skb, ovs_key_mac_proto(key)); } else if (mru <= vport->dev->mtu) { struct net *net = read_pnet(&dp->net); ovs_fragment(net, vport, skb, mru, key); } 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, uint32_t cutlen) { 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 = dev_fill_metadata_dst(vport->dev, skb); if (!err) upcall.egress_tun_info = skb_tunnel_info(skb); } 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, cutlen); } static int dec_ttl_exception_handler(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, const struct nlattr *attr) { /* The first attribute is always 'OVS_DEC_TTL_ATTR_ACTION'. */ struct nlattr *actions = nla_data(attr); if (nla_len(actions)) return clone_execute(dp, skb, key, 0, nla_data(actions), nla_len(actions), true, false); consume_skb(skb); return 0; } /* When 'last' is true, sample() should always consume the 'skb'. * Otherwise, sample() should keep 'skb' intact regardless what * actions are executed within sample(). */ static int sample(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, const struct nlattr *attr, bool last) { struct nlattr *actions; struct nlattr *sample_arg; int rem = nla_len(attr); const struct sample_arg *arg; bool clone_flow_key; /* The first action is always 'OVS_SAMPLE_ATTR_ARG'. */ sample_arg = nla_data(attr); arg = nla_data(sample_arg); actions = nla_next(sample_arg, &rem); if ((arg->probability != U32_MAX) && (!arg->probability || prandom_u32() > arg->probability)) { if (last) consume_skb(skb); return 0; } clone_flow_key = !arg->exec; return clone_execute(dp, skb, key, 0, actions, rem, last, clone_flow_key); } /* When 'last' is true, clone() should always consume the 'skb'. * Otherwise, clone() should keep 'skb' intact regardless what * actions are executed within clone(). */ static int clone(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, const struct nlattr *attr, bool last) { struct nlattr *actions; struct nlattr *clone_arg; int rem = nla_len(attr); bool dont_clone_flow_key; /* The first action is always 'OVS_CLONE_ATTR_ARG'. */ clone_arg = nla_data(attr); dont_clone_flow_key = nla_get_u32(clone_arg); actions = nla_next(clone_arg, &rem); return clone_execute(dp, skb, key, 0, actions, rem, last, !dont_clone_flow_key); } 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_NSH: err = set_nsh(skb, flow_key, a); 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_LABELS: case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4: case OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6: 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, bool last) { u32 recirc_id; 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)); recirc_id = nla_get_u32(a); return clone_execute(dp, skb, key, recirc_id, NULL, 0, last, true); } static int execute_check_pkt_len(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, const struct nlattr *attr, bool last) { struct ovs_skb_cb *ovs_cb = OVS_CB(skb); const struct nlattr *actions, *cpl_arg; int len, max_len, rem = nla_len(attr); const struct check_pkt_len_arg *arg; bool clone_flow_key; /* The first netlink attribute in 'attr' is always * 'OVS_CHECK_PKT_LEN_ATTR_ARG'. */ cpl_arg = nla_data(attr); arg = nla_data(cpl_arg); len = ovs_cb->mru ? ovs_cb->mru + skb->mac_len : skb->len; max_len = arg->pkt_len; if ((skb_is_gso(skb) && skb_gso_validate_mac_len(skb, max_len)) || len <= max_len) { /* Second netlink attribute in 'attr' is always * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL'. */ actions = nla_next(cpl_arg, &rem); clone_flow_key = !arg->exec_for_lesser_equal; } else { /* Third netlink attribute in 'attr' is always * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER'. */ actions = nla_next(cpl_arg, &rem); actions = nla_next(actions, &rem); clone_flow_key = !arg->exec_for_greater; } return clone_execute(dp, skb, key, 0, nla_data(actions), nla_len(actions), last, clone_flow_key); } static int execute_dec_ttl(struct sk_buff *skb, struct sw_flow_key *key) { int err; if (skb->protocol == htons(ETH_P_IPV6)) { struct ipv6hdr *nh; err = skb_ensure_writable(skb, skb_network_offset(skb) + sizeof(*nh)); if (unlikely(err)) return err; nh = ipv6_hdr(skb); if (nh->hop_limit <= 1) return -EHOSTUNREACH; key->ip.ttl = --nh->hop_limit; } else if (skb->protocol == htons(ETH_P_IP)) { struct iphdr *nh; u8 old_ttl; err = skb_ensure_writable(skb, skb_network_offset(skb) + sizeof(*nh)); if (unlikely(err)) return err; nh = ip_hdr(skb); if (nh->ttl <= 1) return -EHOSTUNREACH; old_ttl = nh->ttl--; csum_replace2(&nh->check, htons(old_ttl << 8), htons(nh->ttl << 8)); key->ip.ttl = nh->ttl; } 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) { const struct nlattr *a; int rem; for (a = attr, rem = len; rem > 0; a = nla_next(a, &rem)) { int err = 0; if (trace_ovs_do_execute_action_enabled()) trace_ovs_do_execute_action(dp, skb, key, a, rem); switch (nla_type(a)) { case OVS_ACTION_ATTR_OUTPUT: { int port = nla_get_u32(a); struct sk_buff *clone; /* Every output action needs a separate clone * of 'skb', In case the output action is the * last action, cloning can be avoided. */ if (nla_is_last(a, rem)) { do_output(dp, skb, port, key); /* 'skb' has been used for output. */ return 0; } clone = skb_clone(skb, GFP_ATOMIC); if (clone) do_output(dp, clone, port, key); OVS_CB(skb)->cutlen = 0; break; } case OVS_ACTION_ATTR_TRUNC: { struct ovs_action_trunc *trunc = nla_data(a); if (skb->len > trunc->max_len) OVS_CB(skb)->cutlen = skb->len - trunc->max_len; break; } case OVS_ACTION_ATTR_USERSPACE: output_userspace(dp, skb, key, a, attr, len, OVS_CB(skb)->cutlen); OVS_CB(skb)->cutlen = 0; break; case OVS_ACTION_ATTR_HASH: execute_hash(skb, key, a); break; case OVS_ACTION_ATTR_PUSH_MPLS: { struct ovs_action_push_mpls *mpls = nla_data(a); err = push_mpls(skb, key, mpls->mpls_lse, mpls->mpls_ethertype, skb->mac_len); break; } case OVS_ACTION_ATTR_ADD_MPLS: { struct ovs_action_add_mpls *mpls = nla_data(a); __u16 mac_len = 0; if (mpls->tun_flags & OVS_MPLS_L3_TUNNEL_FLAG_MASK) mac_len = skb->mac_len; err = push_mpls(skb, key, mpls->mpls_lse, mpls->mpls_ethertype, mac_len); 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: { bool last = nla_is_last(a, rem); err = execute_recirc(dp, skb, key, a, last); if (last) { /* 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: { bool last = nla_is_last(a, rem); err = sample(dp, skb, key, a, last); if (last) return err; break; } case OVS_ACTION_ATTR_CT: if (!is_flow_key_valid(key)) { err = ovs_flow_key_update(skb, key); if (err) return err; } err = ovs_ct_execute(ovs_dp_get_net(dp), skb, key, nla_data(a)); /* Hide stolen IP fragments from user space. */ if (err) return err == -EINPROGRESS ? 0 : err; break; case OVS_ACTION_ATTR_CT_CLEAR: err = ovs_ct_clear(skb, key); break; case OVS_ACTION_ATTR_PUSH_ETH: err = push_eth(skb, key, nla_data(a)); break; case OVS_ACTION_ATTR_POP_ETH: err = pop_eth(skb, key); break; case OVS_ACTION_ATTR_PUSH_NSH: { u8 buffer[NSH_HDR_MAX_LEN]; struct nshhdr *nh = (struct nshhdr *)buffer; err = nsh_hdr_from_nlattr(nla_data(a), nh, NSH_HDR_MAX_LEN); if (unlikely(err)) break; err = push_nsh(skb, key, nh); break; } case OVS_ACTION_ATTR_POP_NSH: err = pop_nsh(skb, key); break; case OVS_ACTION_ATTR_METER: if (ovs_meter_execute(dp, skb, key, nla_get_u32(a))) { consume_skb(skb); return 0; } break; case OVS_ACTION_ATTR_CLONE: { bool last = nla_is_last(a, rem); err = clone(dp, skb, key, a, last); if (last) return err; break; } case OVS_ACTION_ATTR_CHECK_PKT_LEN: { bool last = nla_is_last(a, rem); err = execute_check_pkt_len(dp, skb, key, a, last); if (last) return err; break; } case OVS_ACTION_ATTR_DEC_TTL: err = execute_dec_ttl(skb, key); if (err == -EHOSTUNREACH) return dec_ttl_exception_handler(dp, skb, key, a); break; } if (unlikely(err)) { kfree_skb(skb); return err; } } consume_skb(skb); return 0; } /* Execute the actions on the clone of the packet. The effect of the * execution does not affect the original 'skb' nor the original 'key'. * * The execution may be deferred in case the actions can not be executed * immediately. */ static int clone_execute(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, u32 recirc_id, const struct nlattr *actions, int len, bool last, bool clone_flow_key) { struct deferred_action *da; struct sw_flow_key *clone; skb = last ? skb : skb_clone(skb, GFP_ATOMIC); if (!skb) { /* Out of memory, skip this action. */ return 0; } /* When clone_flow_key is false, the 'key' will not be change * by the actions, then the 'key' can be used directly. * Otherwise, try to clone key from the next recursion level of * 'flow_keys'. If clone is successful, execute the actions * without deferring. */ clone = clone_flow_key ? clone_key(key) : key; if (clone) { int err = 0; if (actions) { /* Sample action */ if (clone_flow_key) __this_cpu_inc(exec_actions_level); err = do_execute_actions(dp, skb, clone, actions, len); if (clone_flow_key) __this_cpu_dec(exec_actions_level); } else { /* Recirc action */ clone->recirc_id = recirc_id; ovs_dp_process_packet(skb, clone); } return err; } /* Out of 'flow_keys' space. Defer actions */ da = add_deferred_actions(skb, key, actions, len); if (da) { if (!actions) { /* Recirc action */ key = &da->pkt_key; key->recirc_id = recirc_id; } } else { /* Out of per CPU action FIFO space. Drop the 'skb' and * log an error. */ kfree_skb(skb); if (net_ratelimit()) { if (actions) { /* Sample action */ pr_warn("%s: deferred action limit reached, drop sample action\n", ovs_dp_name(dp)); } else { /* Recirc action */ pr_warn("%s: deferred action limit reached, drop recirc action\n", ovs_dp_name(dp)); } } } 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; int actions_len = da->actions_len; if (actions) do_execute_actions(dp, skb, key, actions, actions_len); 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 err, level; level = __this_cpu_inc_return(exec_actions_level); if (unlikely(level > OVS_RECURSION_LIMIT)) { net_crit_ratelimited("ovs: recursion limit reached on datapath %s, probable configuration error\n", ovs_dp_name(dp)); kfree_skb(skb); err = -ENETDOWN; goto out; } OVS_CB(skb)->acts_origlen = acts->orig_len; err = do_execute_actions(dp, skb, key, acts->actions, acts->actions_len); if (level == 1) process_deferred_actions(dp); out: __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; flow_keys = alloc_percpu(struct action_flow_keys); if (!flow_keys) { free_percpu(action_fifos); return -ENOMEM; } return 0; } void action_fifos_exit(void) { free_percpu(action_fifos); free_percpu(flow_keys); }