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bpf_lxc.c
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bpf_lxc.c
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/*
* Copyright (C) 2016-2019 Authors of Cilium
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <node_config.h>
#include <lxc_config.h>
#define EVENT_SOURCE LXC_ID
#include <bpf/api.h>
#include <stdint.h>
#include <stdio.h>
#include <linux/icmpv6.h>
#include <linux/if_packet.h>
#include "lib/tailcall.h"
#include "lib/utils.h"
#include "lib/common.h"
#include "lib/config.h"
#include "lib/maps.h"
#include "lib/arp.h"
#include "lib/ipv6.h"
#include "lib/ipv4.h"
#include "lib/icmp6.h"
#include "lib/eth.h"
#include "lib/dbg.h"
#include "lib/l3.h"
#include "lib/lxc.h"
#include "lib/nat46.h"
#include "lib/identity.h"
#include "lib/policy.h"
#include "lib/lb.h"
#include "lib/drop.h"
#include "lib/dbg.h"
#include "lib/trace.h"
#include "lib/csum.h"
#include "lib/encap.h"
#include "lib/nat.h"
#include "lib/nodeport.h"
#if defined ENABLE_ARP_PASSTHROUGH && defined ENABLE_ARP_RESPONDER
#error "Either ENABLE_ARP_PASSTHROUGH or ENABLE_ARP_RESPONDER can be defined"
#endif
#if defined ENABLE_IPV4 || defined ENABLE_IPV6
static inline bool redirect_to_proxy(int verdict, __u8 dir)
{
return is_defined(ENABLE_HOST_REDIRECT) && verdict > 0 &&
(dir == CT_NEW || dir == CT_ESTABLISHED);
}
#endif
/* clang-7 workaround, the intended C code generates the following
* r1 = r6
* r1 += 8
* ... some other code r6 is ctx pointer buts it is lost after += op
* *(u32 *)(r1 +0) = r4
* resulting in verifier error,
* "dereference of modified ctx ptr R1 off=9 disallowed"
* to resolve this we use the below asm helper to force asm the
* verifier can follow.
*/
static inline void asm_set_seclabel_identity(struct __sk_buff *skb)
{
__u32 mark = MARK_MAGIC_IDENTITY;
__u32 key = MARK_MAGIC_KEY_MASK;
__u32 identity = SECLABEL;
bpf_barrier();
mark |= ((identity & 0xFFFF) << 16) | ((identity & 0xFF0000) >> 16);
asm volatile("r1 = *(u32 *)(%[ctx] +8)\n\t"
"r1 &= %[key]\n\t"
"r1 |= %[mark]\n\t"
"*(u32 *)(%[ctx] +8) = r1\n\t"
:
: [ctx]"r"(skb), [key]"i"(key), [mark]"r"(mark)
:"r1");
bpf_barrier();
}
#ifdef ENABLE_IPV6
static inline int ipv6_l3_from_lxc(struct __sk_buff *skb,
struct ipv6_ct_tuple *tuple, int l3_off,
struct ipv6hdr *ip6, __u32 *dstID)
{
#ifdef ENABLE_ROUTING
union macaddr router_mac = NODE_MAC;
#endif
int ret, verdict, l4_off, hdrlen;
struct csum_offset csum_off = {};
struct lb6_key key = {};
struct ct_state ct_state_new = {};
struct ct_state ct_state = {};
void *data, *data_end;
union v6addr *daddr, orig_dip;
__u32 tunnel_endpoint = 0;
__u8 encrypt_key = 0;
__u32 monitor = 0;
__u8 reason;
bool hairpin_flow = false; // endpoint wants to access itself via service IP
if (unlikely(!is_valid_lxc_src_ip(ip6)))
return DROP_INVALID_SIP;
ipv6_addr_copy(&tuple->daddr, (union v6addr *) &ip6->daddr);
ipv6_addr_copy(&tuple->saddr, (union v6addr *) &ip6->saddr);
hdrlen = ipv6_hdrlen(skb, l3_off, &tuple->nexthdr);
if (hdrlen < 0)
return hdrlen;
l4_off = l3_off + hdrlen;
ret = lb6_extract_key(skb, tuple, l4_off, &key, &csum_off, CT_EGRESS);
if (IS_ERR(ret)) {
if (ret == DROP_UNKNOWN_L4)
goto skip_service_lookup;
else
return ret;
}
ct_state_new.orig_dport = key.dport;
/*
* Check if the destination address is among the address that should be
* load balanced. This operation is performed before we go through the
* connection tracker to allow storing the reverse nat index in the CT
* entry for destination endpoints where we can't encode the state in the
* address.
*/
#ifdef ENABLE_SERVICES
# if !defined(ENABLE_HOST_SERVICES_FULL) || defined(ENABLE_EXTERNAL_IP)
{
struct lb6_service *svc;
if ((svc = lb6_lookup_service(&key)) != NULL) {
ret = lb6_local(get_ct_map6(tuple), skb, l3_off, l4_off,
&csum_off, &key, tuple, svc, &ct_state_new);
if (IS_ERR(ret))
return ret;
hairpin_flow |= ct_state_new.loopback;
}
}
# endif /* !ENABLE_HOST_SERVICES_FULL || ENABLE_EXTERNAL_IP*/
#endif /* ENABLE_SERVICES */
skip_service_lookup:
/* The verifier wants to see this assignment here in case the above goto
* skip_service_lookup is hit. However, in the case the packet
* is _not_ TCP or UDP we should not be using proxy logic anyways. For
* correctness it must be below the service handler in case the service
* logic re-writes the tuple daddr. In "theory" however the assignment
* should be OK to move above goto label.
*/
ipv6_addr_copy(&orig_dip, (union v6addr *) &tuple->daddr);
/* WARNING: ip6 offset check invalidated, revalidate before use */
/* Pass all outgoing packets through conntrack. This will create an
* entry to allow reverse packets and return set cb[CB_POLICY] to
* POLICY_SKIP if the packet is a reply packet to an existing
* incoming connection. */
ret = ct_lookup6(get_ct_map6(tuple), tuple, skb, l4_off, CT_EGRESS,
&ct_state, &monitor);
if (ret < 0) {
return ret;
}
reason = ret;
// Check it this is return traffic to an ingress proxy.
if ((ret == CT_REPLY || ret == CT_RELATED) && ct_state.proxy_redirect) {
// Stack will do a socket match and deliver locally
return skb_redirect_to_proxy(skb, 0);
}
if (!revalidate_data(skb, &data, &data_end, &ip6))
return DROP_INVALID;
/* Determine the destination category for policy fallback. */
if (1) {
struct remote_endpoint_info *info;
info = lookup_ip6_remote_endpoint(&orig_dip);
if (info != NULL && info->sec_label) {
*dstID = info->sec_label;
tunnel_endpoint = info->tunnel_endpoint;
encrypt_key = get_min_encrypt_key(info->key);
} else {
*dstID = WORLD_ID;
}
cilium_dbg(skb, info ? DBG_IP_ID_MAP_SUCCEED6 : DBG_IP_ID_MAP_FAILED6,
orig_dip.p4, *dstID);
}
/* If the packet is in the establishing direction and it's destined
* within the cluster, it must match policy or be dropped. If it's
* bound for the host/outside, perform the CIDR policy check. */
verdict = policy_can_egress6(skb, tuple, *dstID);
if (ret != CT_REPLY && ret != CT_RELATED && verdict < 0)
return verdict;
switch (ret) {
case CT_NEW:
ct_recreate6:
/* New connection implies that rev_nat_index remains untouched
* to the index provided by the loadbalancer (if it applied).
* Create a CT entry which allows to track replies and to
* reverse NAT.
*/
ct_state_new.src_sec_id = SECLABEL;
ret = ct_create6(get_ct_map6(tuple), &CT_MAP_ANY6, tuple, skb, CT_EGRESS, &ct_state_new, verdict > 0);
if (IS_ERR(ret))
return ret;
monitor = TRACE_PAYLOAD_LEN;
break;
case CT_ESTABLISHED:
/* Did we end up at a stale non-service entry? Recreate if so. */
if (unlikely(ct_state.rev_nat_index != ct_state_new.rev_nat_index)) {
goto ct_recreate6;
}
break;
case CT_RELATED:
case CT_REPLY:
policy_mark_skip(skb);
#ifdef ENABLE_NODEPORT
/* See comment in handle_ipv4_from_lxc(). */
if (ct_state.node_port) {
skb->tc_index |= TC_INDEX_F_SKIP_RECIRCULATION;
ep_tail_call(skb, CILIUM_CALL_IPV6_NODEPORT_REVNAT);
return DROP_MISSED_TAIL_CALL;
}
# ifdef ENABLE_DSR
if (ct_state.dsr) {
ret = xlate_dsr_v6(skb, tuple, l4_off);
if (ret != 0)
return ret;
}
# endif /* ENABLE_DSR */
#endif /* ENABLE_NODEPORT */
if (ct_state.rev_nat_index) {
ret = lb6_rev_nat(skb, l4_off, &csum_off,
ct_state.rev_nat_index, tuple, 0);
if (IS_ERR(ret))
return ret;
/* A reverse translate packet is always allowed except for delivery
* on the local node in which case this marking is cleared again. */
policy_mark_skip(skb);
}
break;
default:
return DROP_UNKNOWN_CT;
}
hairpin_flow |= ct_state.loopback;
if (redirect_to_proxy(verdict, reason)) {
// Trace the packet before its forwarded to proxy
send_trace_notify(skb, TRACE_TO_PROXY, SECLABEL, 0,
0, 0, reason, monitor);
return skb_redirect_to_proxy(skb, verdict);
}
if (!revalidate_data(skb, &data, &data_end, &ip6))
return DROP_INVALID;
daddr = (union v6addr *)&ip6->daddr;
/* See handle_ipv4_from_lxc() re hairpin_flow */
if (is_defined(ENABLE_ROUTING) || hairpin_flow) {
struct endpoint_info *ep;
/* Lookup IPv6 address, this will return a match if:
* - The destination IP address belongs to a local endpoint managed by
* cilium
* - The destination IP address is an IP address associated with the
* host itself.
*/
if ((ep = lookup_ip6_endpoint(ip6)) != NULL) {
#ifdef ENABLE_ROUTING
if (ep->flags & ENDPOINT_F_HOST) {
#ifdef HOST_IFINDEX
goto to_host;
#else
return DROP_HOST_UNREACHABLE;
#endif
}
#endif /* ENABLE_ROUTING */
policy_clear_mark(skb);
return ipv6_local_delivery(skb, l3_off, l4_off, SECLABEL,
ip6, tuple->nexthdr, ep,
METRIC_EGRESS);
}
}
/* The packet goes to a peer not managed by this agent instance */
#ifdef ENCAP_IFINDEX
{
struct endpoint_key key = {};
/* Lookup the destination prefix in the list of known
* destination prefixes. If there is a match, the packet will
* be encapsulated to that node and then routed by the agent on
* the remote node.
*
* IPv6 lookup key: daddr/96
*/
key.ip6.p1 = daddr->p1;
key.ip6.p2 = daddr->p2;
key.ip6.p3 = daddr->p3;
key.family = ENDPOINT_KEY_IPV6;
/* Three cases exist here either (a) the encap and redirect could
* not find the tunnel so fallthrough to nat46 and stack, (b)
* the packet needs IPSec encap so push skb to stack for encap, or
* (c) packet was redirected to tunnel device so return.
*/
ret = encap_and_redirect_lxc(skb, tunnel_endpoint, encrypt_key, &key, SECLABEL, monitor);
if (ret == IPSEC_ENDPOINT)
goto pass_to_stack;
else if (ret != DROP_NO_TUNNEL_ENDPOINT)
return ret;
}
#endif
#ifdef ENABLE_NAT46
if (unlikely(ipv6_addr_is_mapped(daddr))) {
ep_tail_call(skb, CILIUM_CALL_NAT64);
return DROP_MISSED_TAIL_CALL;
}
#endif
goto pass_to_stack;
#ifdef ENABLE_ROUTING
to_host:
if (is_defined(HOST_REDIRECT_TO_INGRESS)) {
union macaddr host_mac = HOST_IFINDEX_MAC;
ret = ipv6_l3(skb, l3_off, (__u8 *) &router_mac.addr, (__u8 *) &host_mac.addr, METRIC_EGRESS);
if (ret != TC_ACT_OK)
return ret;
send_trace_notify(skb, TRACE_TO_HOST, SECLABEL, HOST_ID, 0,
HOST_IFINDEX, reason, monitor);
cilium_dbg_capture(skb, DBG_CAPTURE_DELIVERY, HOST_IFINDEX);
return redirect(HOST_IFINDEX, BPF_F_INGRESS);
}
#endif
pass_to_stack:
#ifdef ENABLE_ROUTING
ret = ipv6_l3(skb, l3_off, NULL, (__u8 *) &router_mac.addr, METRIC_EGRESS);
if (unlikely(ret != TC_ACT_OK))
return ret;
#endif
if (ipv6_store_flowlabel(skb, l3_off, SECLABEL_NB) < 0)
return DROP_WRITE_ERROR;
send_trace_notify(skb, TRACE_TO_STACK, SECLABEL, *dstID, 0, 0,
reason, monitor);
cilium_dbg_capture(skb, DBG_CAPTURE_DELIVERY, 0);
#ifndef ENCAP_IFINDEX
#ifdef ENABLE_IPSEC
if (encrypt_key && tunnel_endpoint) {
set_encrypt_key(skb, encrypt_key);
#ifdef IP_POOLS
set_encrypt_dip(skb, tunnel_endpoint);
#endif
}
#endif
#endif
/* Always encode the source identity when passing to the stack. If the
* stack hairpins the packet back to a local endpoint the source
* identity can still be derived even if SNAT is performed by a
* component such as portmap */
asm_set_seclabel_identity(skb);
return TC_ACT_OK;
}
static inline int __inline__ handle_ipv6(struct __sk_buff *skb, __u32 *dstID)
{
struct ipv6_ct_tuple tuple = {};
void *data, *data_end;
struct ipv6hdr *ip6;
int ret;
if (!revalidate_data(skb, &data, &data_end, &ip6))
return DROP_INVALID;
/* Handle special ICMPv6 messages. This includes echo requests to the
* logical router address, neighbour advertisements to the router.
* All remaining packets are subjected to forwarding into the container.
*/
if (unlikely(ip6->nexthdr == IPPROTO_ICMPV6)) {
if (data + sizeof(*ip6) + ETH_HLEN + sizeof(struct icmp6hdr) > data_end) {
return DROP_INVALID;
}
ret = icmp6_handle(skb, ETH_HLEN, ip6, METRIC_EGRESS);
if (IS_ERR(ret))
return ret;
}
/* Perform L3 action on the frame */
tuple.nexthdr = ip6->nexthdr;
return ipv6_l3_from_lxc(skb, &tuple, ETH_HLEN, ip6, dstID);
}
declare_tailcall_if(__and(is_defined(ENABLE_IPV4), is_defined(ENABLE_IPV6)), CILIUM_CALL_IPV6_FROM_LXC)
int tail_handle_ipv6(struct __sk_buff *skb)
{
__u32 dstID = 0;
int ret = handle_ipv6(skb, &dstID);
if (IS_ERR(ret)) {
relax_verifier();
return send_drop_notify(skb, SECLABEL, dstID, 0, ret, TC_ACT_SHOT,
METRIC_EGRESS);
}
return ret;
}
#endif /* ENABLE_IPV6 */
#ifdef ENABLE_IPV4
static inline int handle_ipv4_from_lxc(struct __sk_buff *skb, __u32 *dstID)
{
struct ipv4_ct_tuple tuple = {};
#ifdef ENABLE_ROUTING
union macaddr router_mac = NODE_MAC;
#endif
void *data, *data_end;
struct iphdr *ip4;
int ret, verdict, l3_off = ETH_HLEN, l4_off;
struct csum_offset csum_off = {};
struct lb4_key key = {};
struct ct_state ct_state_new = {};
struct ct_state ct_state = {};
__be32 orig_dip;
__u32 tunnel_endpoint = 0;
__u8 encrypt_key = 0;
__u32 monitor = 0;
__u8 reason;
bool hairpin_flow = false; // endpoint wants to access itself via service IP
if (!revalidate_data(skb, &data, &data_end, &ip4))
return DROP_INVALID;
tuple.nexthdr = ip4->protocol;
if (unlikely(!is_valid_lxc_src_ipv4(ip4)))
return DROP_INVALID_SIP;
tuple.daddr = ip4->daddr;
tuple.saddr = ip4->saddr;
l4_off = l3_off + ipv4_hdrlen(ip4);
ret = lb4_extract_key(skb, &tuple, l4_off, &key, &csum_off, CT_EGRESS);
if (IS_ERR(ret)) {
if (ret == DROP_UNKNOWN_L4)
goto skip_service_lookup;
else
return ret;
}
ct_state_new.orig_dport = key.dport;
#ifdef ENABLE_SERVICES
# if !defined(ENABLE_HOST_SERVICES_FULL) || defined(ENABLE_EXTERNAL_IP)
{
struct lb4_service *svc;
if ((svc = lb4_lookup_service(&key)) != NULL) {
ret = lb4_local(get_ct_map4(&tuple), skb, l3_off, l4_off, &csum_off,
&key, &tuple, svc, &ct_state_new, ip4->saddr);
if (IS_ERR(ret))
return ret;
hairpin_flow |= ct_state_new.loopback;
}
}
# endif /* !ENABLE_HOST_SERVICES_FULL || ENABLE_EXTERNAL_IP */
#endif /* ENABLE_SERVICES */
skip_service_lookup:
/* The verifier wants to see this assignment here in case the above goto
* skip_service_lookup is hit. However, in the case the packet
* is _not_ TCP or UDP we should not be using proxy logic anyways. For
* correctness it must be below the service handler in case the service
* logic re-writes the tuple daddr. In "theory" however the assignment
* should be OK to move above goto label.
*/
orig_dip = tuple.daddr;
/* WARNING: ip4 offset check invalidated, revalidate before use */
/* Pass all outgoing packets through conntrack. This will create an
* entry to allow reverse packets and return set cb[CB_POLICY] to
* POLICY_SKIP if the packet is a reply packet to an existing
* incoming connection. */
ret = ct_lookup4(get_ct_map4(&tuple), &tuple, skb, l4_off, CT_EGRESS,
&ct_state, &monitor);
if (ret < 0)
return ret;
reason = ret;
// Check it this is return traffic to an ingress proxy.
if ((ret == CT_REPLY || ret == CT_RELATED) && ct_state.proxy_redirect) {
// Stack will do a socket match and deliver locally
return skb_redirect_to_proxy(skb, 0);
}
/* Determine the destination category for policy fallback. */
if (1) {
struct remote_endpoint_info *info;
info = lookup_ip4_remote_endpoint(orig_dip);
if (info != NULL && info->sec_label) {
*dstID = info->sec_label;
tunnel_endpoint = info->tunnel_endpoint;
encrypt_key = get_min_encrypt_key(info->key);
} else {
*dstID = WORLD_ID;
}
cilium_dbg(skb, info ? DBG_IP_ID_MAP_SUCCEED4 : DBG_IP_ID_MAP_FAILED4,
orig_dip, *dstID);
}
/* If the packet is in the establishing direction and it's destined
* within the cluster, it must match policy or be dropped. If it's
* bound for the host/outside, perform the CIDR policy check. */
verdict = policy_can_egress4(skb, &tuple, *dstID);
if (ret != CT_REPLY && ret != CT_RELATED && verdict < 0)
return verdict;
switch (ret) {
case CT_NEW:
ct_recreate4:
/* New connection implies that rev_nat_index remains untouched
* to the index provided by the loadbalancer (if it applied).
* Create a CT entry which allows to track replies and to
* reverse NAT.
*/
ct_state_new.src_sec_id = SECLABEL;
/* We could avoid creating related entries for legacy ClusterIP
* handling here, but turns out that verifier cannot handle it.
*/
ret = ct_create4(get_ct_map4(&tuple), &CT_MAP_ANY4, &tuple, skb,
CT_EGRESS, &ct_state_new, verdict > 0);
if (IS_ERR(ret))
return ret;
break;
case CT_ESTABLISHED:
/* Did we end up at a stale non-service entry? Recreate if so. */
if (unlikely(ct_state.rev_nat_index != ct_state_new.rev_nat_index)) {
goto ct_recreate4;
}
break;
case CT_RELATED:
case CT_REPLY:
policy_mark_skip(skb);
#ifdef ENABLE_NODEPORT
/* This handles reply traffic for the case where the nodeport EP
* is local to the node. We'll redirect to bpf_netdev egress to
* perform the reverse DNAT.
*/
if (ct_state.node_port) {
skb->tc_index |= TC_INDEX_F_SKIP_RECIRCULATION;
ep_tail_call(skb, CILIUM_CALL_IPV4_NODEPORT_REVNAT);
return DROP_MISSED_TAIL_CALL;
}
# ifdef ENABLE_DSR
if (ct_state.dsr) {
ret = xlate_dsr_v4(skb, &tuple, l4_off);
if (ret != 0)
return ret;
}
# endif /* ENABLE_DSR */
#endif /* ENABLE_NODEPORT */
if (ct_state.rev_nat_index) {
ret = lb4_rev_nat(skb, l3_off, l4_off, &csum_off,
&ct_state, &tuple, 0);
if (IS_ERR(ret)) {
relax_verifier();
return ret;
}
}
break;
default:
return DROP_UNKNOWN_CT;
}
hairpin_flow |= ct_state.loopback;
if (redirect_to_proxy(verdict, reason)) {
// Trace the packet before its forwarded to proxy
send_trace_notify(skb, TRACE_TO_PROXY, SECLABEL, 0,
0, 0, reason, monitor);
return skb_redirect_to_proxy(skb, verdict);
}
/* After L4 write in port mapping: revalidate for direct packet access */
if (!revalidate_data(skb, &data, &data_end, &ip4))
return DROP_INVALID;
orig_dip = ip4->daddr;
// Allow a hairpin packet to be redirected even if ENABLE_ROUTING is
// disabled. Otherwise, the packet will be dropped by the kernel if
// it's going to be routed via an interface it came from after it has
// been passed to the stack.
if (is_defined(ENABLE_ROUTING) || hairpin_flow) {
struct endpoint_info *ep;
/* Lookup IPv4 address, this will return a match if:
* - The destination IP address belongs to a local endpoint
* managed by cilium
* - The destination IP address is an IP address associated with the
* host itself
* - The destination IP address belongs to endpoint itself.
*/
if ((ep = lookup_ip4_endpoint(ip4)) != NULL) {
#ifdef ENABLE_ROUTING
if (ep->flags & ENDPOINT_F_HOST) {
#ifdef HOST_IFINDEX
goto to_host;
#else
return DROP_HOST_UNREACHABLE;
#endif
}
#endif /* ENABLE_ROUTING */
policy_clear_mark(skb);
return ipv4_local_delivery(skb, l3_off, l4_off, SECLABEL,
ip4, ep, METRIC_EGRESS);
}
}
#ifdef ENCAP_IFINDEX
{
struct endpoint_key key = {};
key.ip4 = orig_dip & IPV4_MASK;
key.family = ENDPOINT_KEY_IPV4;
ret = encap_and_redirect_lxc(skb, tunnel_endpoint, encrypt_key, &key, SECLABEL, monitor);
if (ret == DROP_NO_TUNNEL_ENDPOINT)
goto pass_to_stack;
/* If not redirected noteably due to IPSEC then pass up to stack
* for further processing.
*/
else if (ret == IPSEC_ENDPOINT)
goto pass_to_stack;
/* This is either redirect by encap code or an error has occured
* either way return and stack will consume skb.
*/
else
return ret;
}
#else
goto pass_to_stack;
#endif
#ifdef ENABLE_ROUTING
to_host:
if (is_defined(HOST_REDIRECT_TO_INGRESS)) {
union macaddr host_mac = HOST_IFINDEX_MAC;
ret = ipv4_l3(skb, l3_off, (__u8 *) &router_mac.addr, (__u8 *) &host_mac.addr, ip4);
if (ret != TC_ACT_OK)
return ret;
send_trace_notify(skb, TRACE_TO_HOST, SECLABEL, HOST_ID, 0, HOST_IFINDEX,
reason, monitor);
cilium_dbg_capture(skb, DBG_CAPTURE_DELIVERY, HOST_IFINDEX);
return redirect(HOST_IFINDEX, BPF_F_INGRESS);
}
#endif
pass_to_stack:
#ifdef ENABLE_ROUTING
ret = ipv4_l3(skb, l3_off, NULL, (__u8 *) &router_mac.addr, ip4);
if (unlikely(ret != TC_ACT_OK))
return ret;
#endif
/* FIXME: We can't store the security context anywhere here so all
* packets to other nodes will look like they come from an outside
* network.
*/
send_trace_notify(skb, TRACE_TO_STACK, SECLABEL, *dstID, 0, 0,
reason, monitor);
#ifndef ENCAP_IFINDEX
#ifdef ENABLE_IPSEC
if (encrypt_key && tunnel_endpoint) {
set_encrypt_key(skb, encrypt_key);
#ifdef IP_POOLS
set_encrypt_dip(skb, tunnel_endpoint);
#endif
}
#endif
#endif
/* Always encode the source identity when passing to the stack. If the
* stack hairpins the packet back to a local endpoint the source
* identity can still be derived even if SNAT is performed by a
* component such as portmap */
/* clang-7 workaround */
asm_set_seclabel_identity(skb);
cilium_dbg_capture(skb, DBG_CAPTURE_DELIVERY, 0);
return TC_ACT_OK;
}
declare_tailcall_if(__and(is_defined(ENABLE_IPV4), is_defined(ENABLE_IPV6)), CILIUM_CALL_IPV4_FROM_LXC)
int tail_handle_ipv4(struct __sk_buff *skb)
{
__u32 dstID = 0;
int ret = handle_ipv4_from_lxc(skb, &dstID);
if (IS_ERR(ret))
return send_drop_notify(skb, SECLABEL, dstID, 0, ret, TC_ACT_SHOT,
METRIC_EGRESS);
return ret;
}
#ifdef ENABLE_ARP_RESPONDER
/*
* ARP responder for ARP requests from container
* Respond to IPV4_GATEWAY with NODE_MAC
*/
__section_tail(CILIUM_MAP_CALLS, CILIUM_CALL_ARP) int tail_handle_arp(struct __sk_buff *skb)
{
union macaddr mac = NODE_MAC;
return arp_respond(skb, &mac, 0);
}
#endif /* ENABLE_ARP_RESPONDER */
#endif /* ENABLE_IPV4 */
/* Attachment/entry point is ingress for veth, egress for ipvlan. */
__section("from-container")
int handle_xgress(struct __sk_buff *skb)
{
__u16 proto;
int ret;
bpf_clear_cb(skb);
send_trace_notify(skb, TRACE_FROM_LXC, SECLABEL, 0, 0, 0, 0,
TRACE_PAYLOAD_LEN);
if (!validate_ethertype(skb, &proto)) {
ret = DROP_UNSUPPORTED_L2;
goto out;
}
switch (proto) {
#ifdef ENABLE_IPV6
case bpf_htons(ETH_P_IPV6):
invoke_tailcall_if(__and(is_defined(ENABLE_IPV4), is_defined(ENABLE_IPV6)),
CILIUM_CALL_IPV6_FROM_LXC, tail_handle_ipv6);
break;
#endif /* ENABLE_IPV6 */
#ifdef ENABLE_IPV4
case bpf_htons(ETH_P_IP):
invoke_tailcall_if(__and(is_defined(ENABLE_IPV4), is_defined(ENABLE_IPV6)),
CILIUM_CALL_IPV4_FROM_LXC, tail_handle_ipv4);
break;
#ifdef ENABLE_ARP_PASSTHROUGH
case bpf_htons(ETH_P_ARP):
ret = TC_ACT_OK;
break;
#elif defined ENABLE_ARP_RESPONDER
case bpf_htons(ETH_P_ARP):
ep_tail_call(skb, CILIUM_CALL_ARP);
ret = DROP_MISSED_TAIL_CALL;
break;
#endif /* ENABLE_ARP_RESPONDER */
#endif /* ENABLE_IPV4 */
default:
ret = DROP_UNKNOWN_L3;
}
out:
if (IS_ERR(ret))
return send_drop_notify(skb, SECLABEL, 0, 0, ret, TC_ACT_SHOT,
METRIC_EGRESS);
return ret;
}
#ifdef ENABLE_IPV6
static inline int __inline__
ipv6_policy(struct __sk_buff *skb, int ifindex, __u32 src_label, __u8 *reason, __u16 *proxy_port)
{
struct ipv6_ct_tuple tuple = {};
void *data, *data_end;
struct ipv6hdr *ip6;
struct csum_offset csum_off = {};
int ret, l4_off, verdict, hdrlen;
struct ct_state ct_state = {};
struct ct_state ct_state_new = {};
bool skip_ingress_proxy = false;
union v6addr orig_dip, orig_sip;
__u32 monitor = 0;
if (!revalidate_data(skb, &data, &data_end, &ip6))
return DROP_INVALID;
policy_clear_mark(skb);
tuple.nexthdr = ip6->nexthdr;
ipv6_addr_copy(&tuple.daddr, (union v6addr *) &ip6->daddr);
ipv6_addr_copy(&tuple.saddr, (union v6addr *) &ip6->saddr);
ipv6_addr_copy(&orig_dip, (union v6addr *) &ip6->daddr);
ipv6_addr_copy(&orig_sip, (union v6addr *) &ip6->saddr);
/* If packet is coming from the ingress proxy we have to skip
* redirection to the ingress proxy as we would loop forever. */
skip_ingress_proxy = tc_index_skip_ingress_proxy(skb);
hdrlen = ipv6_hdrlen(skb, ETH_HLEN, &tuple.nexthdr);
if (hdrlen < 0)
return hdrlen;
l4_off = ETH_HLEN + hdrlen;
csum_l4_offset_and_flags(tuple.nexthdr, &csum_off);
ret = ct_lookup6(get_ct_map6(&tuple), &tuple, skb, l4_off, CT_INGRESS,
&ct_state, &monitor);
if (ret < 0)
return ret;
*reason = ret;
// Check it this is return traffic to an egress proxy.
// Do not redirect again if the packet is coming from the egress proxy.
if ((ret == CT_REPLY || ret == CT_RELATED) && ct_state.proxy_redirect &&
!tc_index_skip_egress_proxy(skb)) {
// This is a reply, the proxy port does not need to be embedded
// into skb->mark and *proxy_port can be left unset.
send_trace_notify6(skb, TRACE_TO_PROXY, src_label, SECLABEL, &orig_sip,
0, ifindex, 0, monitor);
return POLICY_ACT_PROXY_REDIRECT;
}
if (unlikely(ct_state.rev_nat_index)) {
int ret2;
ret2 = lb6_rev_nat(skb, l4_off, &csum_off,
ct_state.rev_nat_index, &tuple, 0);
if (IS_ERR(ret2))
return ret2;
}
verdict = policy_can_access_ingress(skb, src_label, tuple.dport,
tuple.nexthdr, false);
/* Reply packets and related packets are allowed, all others must be
* permitted by policy */
if (ret != CT_REPLY && ret != CT_RELATED && verdict < 0)
return verdict;
if (skip_ingress_proxy)
verdict = 0;
if (ret == CT_NEW) {
#ifdef ENABLE_DSR
bool dsr = false;
ret = handle_dsr_v6(skb, &dsr);
if (ret != 0)
return ret;
ct_state_new.dsr = dsr;
#endif /* ENABLE_DSR */
ct_state_new.orig_dport = tuple.dport;
ct_state_new.src_sec_id = src_label;
ct_state_new.node_port = ct_state.node_port;
ret = ct_create6(get_ct_map6(&tuple), &CT_MAP_ANY6, &tuple, skb, CT_INGRESS,
&ct_state_new, verdict > 0);
if (IS_ERR(ret))
return ret;
/* NOTE: tuple has been invalidated after this */
}
if (!revalidate_data(skb, &data, &data_end, &ip6))
return DROP_INVALID;
if (redirect_to_proxy(verdict, *reason)) {
*proxy_port = verdict;
send_trace_notify6(skb, TRACE_TO_PROXY, src_label, SECLABEL, &orig_sip,
0, ifindex, *reason, monitor);
return POLICY_ACT_PROXY_REDIRECT;
} else { // Not redirected to host / proxy.
send_trace_notify6(skb, TRACE_TO_LXC, src_label, SECLABEL, &orig_sip,
LXC_ID, ifindex, *reason, monitor);
}
ifindex = skb->cb[CB_IFINDEX];
if (ifindex)
return redirect_peer(ifindex, 0);
return TC_ACT_OK;
}
declare_tailcall_if(__and(is_defined(ENABLE_IPV4), is_defined(ENABLE_IPV6)), CILIUM_CALL_IPV6_TO_LXC_POLICY_ONLY)
int tail_ipv6_policy(struct __sk_buff *skb)
{
int ret, ifindex = skb->cb[CB_IFINDEX];
__u32 src_label = skb->cb[CB_SRC_LABEL];
__u16 proxy_port = 0;
__u8 reason = 0;
skb->cb[CB_SRC_LABEL] = 0;
ret = ipv6_policy(skb, ifindex, src_label, &reason, &proxy_port);
if (ret == POLICY_ACT_PROXY_REDIRECT)
ret = skb_redirect_to_proxy(skb, proxy_port);
if (IS_ERR(ret))
return send_drop_notify(skb, src_label, SECLABEL, LXC_ID,
ret, TC_ACT_SHOT, METRIC_INGRESS);
skb->cb[0] = skb->mark; // essential for proxy ingress, see bpf_ipsec.c
return ret;
}
declare_tailcall_if(__and(is_defined(ENABLE_IPV4), is_defined(ENABLE_IPV6)), CILIUM_CALL_IPV6_TO_ENDPOINT)
int tail_ipv6_to_endpoint(struct __sk_buff *skb)
{
__u32 src_identity = skb->cb[CB_SRC_LABEL];
void *data, *data_end;
struct ipv6hdr *ip6;
__u16 proxy_port = 0;
__u8 reason;
int ret;
if (!revalidate_data(skb, &data, &data_end, &ip6)) {
ret = DROP_INVALID;
goto out;
}
/* Packets from the proxy will already have a real identity. */
if (identity_is_reserved(src_identity)) {
union v6addr *src = (union v6addr *) &ip6->saddr;
struct remote_endpoint_info *info;
info = ipcache_lookup6(&IPCACHE_MAP, src, V6_CACHE_KEY_LEN);
if (info != NULL) {
__u32 sec_label = info->sec_label;
if (sec_label) {
/* When SNAT is enabled on traffic ingressing
* into Cilium, all traffic from the world will
* have a source IP of the host. It will only
* actually be from the host if "src_identity"
* (passed into this function) reports the src
* as the host. So we can ignore the ipcache
* if it reports the source as HOST_ID.
*/
if (sec_label != HOST_ID)
src_identity = sec_label;
}
}
cilium_dbg(skb, info ? DBG_IP_ID_MAP_SUCCEED6 : DBG_IP_ID_MAP_FAILED6,