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bpf_lxc.c
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bpf_lxc.c
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// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright Authors of Cilium */
#include "bpf/types_mapper.h"
#include <bpf/ctx/skb.h>
#include <bpf/api.h>
#include <ep_config.h>
#include <node_config.h>
#include <bpf/verifier.h>
#include <linux/icmpv6.h>
#define IS_BPF_LXC 1
/* Controls the inclusion of the CILIUM_CALL_SRV6 section in the object file.
*/
#define SKIP_SRV6_HANDLING
#define EVENT_SOURCE LXC_ID
#include "lib/tailcall.h"
#include "lib/common.h"
#include "lib/config.h"
#include "lib/maps.h"
#include "lib/arp.h"
#include "lib/edt.h"
#include "lib/qm.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/identity.h"
#include "lib/policy.h"
/* Override LB_SELECTION initially defined in node_config.h to force bpf_lxc to use the random backend selection
* algorithm for in-cluster traffic. Otherwise, it will fail with the Maglev hash algorithm because Cilium doesn't provision
* the Maglev table for ClusterIP unless bpf.lbExternalClusterIP is set to true.
*/
#undef LB_SELECTION
#define LB_SELECTION LB_SELECTION_RANDOM
#include "lib/lb.h"
#include "lib/drop.h"
#include "lib/dbg.h"
#include "lib/trace.h"
#include "lib/csum.h"
#include "lib/egress_policies.h"
#include "lib/encap.h"
#include "lib/eps.h"
#include "lib/nat.h"
#include "lib/fib.h"
#include "lib/nodeport.h"
#include "lib/policy_log.h"
/* Per-packet LB is needed if all LB cases can not be handled in bpf_sock.
* Most services with L7 LB flag can not be redirected to their proxy port
* in bpf_sock, so we must check for those via per packet LB as well.
* Furthermore, since SCTP cannot be handled as part of bpf_sock, also
* enable per-packet LB is SCTP is enabled.
*/
#if !defined(ENABLE_SOCKET_LB_FULL) || \
defined(ENABLE_SOCKET_LB_HOST_ONLY) || \
defined(ENABLE_L7_LB) || \
defined(ENABLE_SCTP) || \
defined(ENABLE_CLUSTER_AWARE_ADDRESSING)
# define ENABLE_PER_PACKET_LB 1
#endif
#ifdef ENABLE_PER_PACKET_LB
#ifdef ENABLE_IPV4
static __always_inline int __per_packet_lb_svc_xlate_4(void *ctx, struct iphdr *ip4)
{
struct ipv4_ct_tuple tuple = {};
struct ct_state ct_state_new = {};
bool has_l4_header;
struct lb4_service *svc;
struct lb4_key key = {};
__u16 proxy_port = 0;
__u32 cluster_id = 0;
int l4_off;
int ret = 0;
has_l4_header = ipv4_has_l4_header(ip4);
ret = lb4_extract_tuple(ctx, ip4, ETH_HLEN, &l4_off, &tuple);
if (IS_ERR(ret)) {
if (ret == DROP_NO_SERVICE || ret == DROP_UNKNOWN_L4)
goto skip_service_lookup;
else
return ret;
}
lb4_fill_key(&key, &tuple);
svc = lb4_lookup_service(&key, is_defined(ENABLE_NODEPORT), false);
if (svc) {
#if defined(ENABLE_L7_LB)
if (lb4_svc_is_l7loadbalancer(svc)) {
proxy_port = (__u16)svc->l7_lb_proxy_port;
goto skip_service_lookup;
}
#endif /* ENABLE_L7_LB */
ret = lb4_local(get_ct_map4(&tuple), ctx, ETH_HLEN, l4_off,
&key, &tuple, svc, &ct_state_new,
has_l4_header, false, &cluster_id);
if (IS_ERR(ret))
return ret;
}
skip_service_lookup:
/* Store state to be picked up on the continuation tail call. */
lb4_ctx_store_state(ctx, &ct_state_new, proxy_port, cluster_id);
ep_tail_call(ctx, CILIUM_CALL_IPV4_CT_EGRESS);
return DROP_MISSED_TAIL_CALL;
}
#endif /* ENABLE_IPV4 */
#ifdef ENABLE_IPV6
static __always_inline int __per_packet_lb_svc_xlate_6(void *ctx, struct ipv6hdr *ip6)
{
struct ipv6_ct_tuple tuple = {};
struct ct_state ct_state_new = {};
struct lb6_service *svc;
struct lb6_key key = {};
__u16 proxy_port = 0;
int l4_off;
int ret = 0;
ret = lb6_extract_tuple(ctx, ip6, ETH_HLEN, &l4_off, &tuple);
if (IS_ERR(ret)) {
if (ret == DROP_NO_SERVICE || ret == DROP_UNKNOWN_L4)
goto skip_service_lookup;
else
return ret;
}
lb6_fill_key(&key, &tuple);
/*
* 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.
*/
svc = lb6_lookup_service(&key, is_defined(ENABLE_NODEPORT), false);
if (svc) {
#if defined(ENABLE_L7_LB)
if (lb6_svc_is_l7loadbalancer(svc)) {
proxy_port = (__u16)svc->l7_lb_proxy_port;
goto skip_service_lookup;
}
#endif /* ENABLE_L7_LB */
ret = lb6_local(get_ct_map6(&tuple), ctx, ETH_HLEN, l4_off,
&key, &tuple, svc, &ct_state_new, false);
if (IS_ERR(ret))
return ret;
}
skip_service_lookup:
/* Store state to be picked up on the continuation tail call. */
lb6_ctx_store_state(ctx, &ct_state_new, proxy_port);
ep_tail_call(ctx, CILIUM_CALL_IPV6_CT_EGRESS);
return DROP_MISSED_TAIL_CALL;
}
#endif /* ENABLE_IPV6 */
#endif
#if defined(ENABLE_ARP_PASSTHROUGH) && defined(ENABLE_ARP_RESPONDER)
#error "Either ENABLE_ARP_PASSTHROUGH or ENABLE_ARP_RESPONDER can be defined"
#endif
#ifdef ENABLE_IPV4
static __always_inline void *
select_ct_map4(struct __ctx_buff *ctx __maybe_unused, int dir __maybe_unused,
struct ipv4_ct_tuple *tuple)
{
__u32 cluster_id = 0;
#ifdef ENABLE_CLUSTER_AWARE_ADDRESSING
if (dir == CT_EGRESS)
cluster_id = ctx_load_meta(ctx, CB_CLUSTER_ID_EGRESS);
else if (dir == CT_INGRESS)
cluster_id = ctx_load_meta(ctx, CB_CLUSTER_ID_INGRESS);
#endif
return get_cluster_ct_map4(tuple, cluster_id);
}
#endif
#define TAIL_CT_LOOKUP4(ID, NAME, DIR, CONDITION, TARGET_ID, TARGET_NAME) \
declare_tailcall_if(CONDITION, ID) \
int NAME(struct __ctx_buff *ctx) \
{ \
struct ct_buffer4 ct_buffer = {}; \
int l4_off, ret = CTX_ACT_OK; \
struct ipv4_ct_tuple *tuple; \
struct ct_state *ct_state; \
void *data, *data_end; \
struct iphdr *ip4; \
__u32 zero = 0; \
void *map; \
\
ct_state = (struct ct_state *)&ct_buffer.ct_state; \
tuple = (struct ipv4_ct_tuple *)&ct_buffer.tuple; \
\
if (!revalidate_data(ctx, &data, &data_end, &ip4)) \
return DROP_INVALID; \
\
tuple->nexthdr = ip4->protocol; \
tuple->daddr = ip4->daddr; \
tuple->saddr = ip4->saddr; \
\
l4_off = ETH_HLEN + ipv4_hdrlen(ip4); \
\
map = select_ct_map4(ctx, DIR, tuple); \
if (!map) \
return DROP_CT_NO_MAP_FOUND; \
\
ct_buffer.ret = ct_lookup4(map, tuple, ctx, l4_off, \
DIR, ct_state, &ct_buffer.monitor); \
if (ct_buffer.ret < 0) \
return ct_buffer.ret; \
\
if (map_update_elem(&CT_TAIL_CALL_BUFFER4, &zero, &ct_buffer, 0) < 0) \
return DROP_INVALID_TC_BUFFER; \
\
invoke_tailcall_if(CONDITION, TARGET_ID, TARGET_NAME); \
return ret; \
}
#define TAIL_CT_LOOKUP6(ID, NAME, DIR, CONDITION, TARGET_ID, TARGET_NAME) \
declare_tailcall_if(CONDITION, ID) \
int NAME(struct __ctx_buff *ctx) \
{ \
int l4_off, ret = CTX_ACT_OK, hdrlen; \
struct ct_buffer6 ct_buffer = {}; \
struct ipv6_ct_tuple *tuple; \
struct ct_state *ct_state; \
void *data, *data_end; \
struct ipv6hdr *ip6; \
__u32 zero = 0; \
\
ct_state = (struct ct_state *)&ct_buffer.ct_state; \
tuple = (struct ipv6_ct_tuple *)&ct_buffer.tuple; \
\
if (!revalidate_data(ctx, &data, &data_end, &ip6)) \
return DROP_INVALID; \
\
tuple->nexthdr = ip6->nexthdr; \
ipv6_addr_copy(&tuple->daddr, (union v6addr *)&ip6->daddr); \
ipv6_addr_copy(&tuple->saddr, (union v6addr *)&ip6->saddr); \
\
hdrlen = ipv6_hdrlen(ctx, &tuple->nexthdr); \
if (hdrlen < 0) \
return hdrlen; \
\
l4_off = ETH_HLEN + hdrlen; \
\
ct_buffer.ret = ct_lookup6(get_ct_map6(tuple), tuple, ctx, l4_off, \
DIR, ct_state, &ct_buffer.monitor); \
if (ct_buffer.ret < 0) \
return ct_buffer.ret; \
\
if (map_update_elem(&CT_TAIL_CALL_BUFFER6, &zero, &ct_buffer, 0) < 0) \
return DROP_INVALID_TC_BUFFER; \
\
invoke_tailcall_if(CONDITION, TARGET_ID, TARGET_NAME); \
return ret; \
}
#ifdef ENABLE_CUSTOM_CALLS
/* Encode return value and identity into cb buffer. This is used before
* executing tail calls to custom programs. "ret" is the return value supposed
* to be returned to the kernel, needed by the callee to preserve the datapath
* logics. The "identity" is the security identity of the local endpoint: the
* source of the packet on ingress path, or its destination on the egress path.
* We encode it so that custom programs can retrieve it and use it at their
* convenience.
*/
static __always_inline int
encode_custom_prog_meta(struct __ctx_buff *ctx, int ret, __u32 identity)
{
__u32 custom_meta = 0;
/* If we cannot encode return value on 8 bits, return an error so we can
* skip the tail call entirely, as custom program has no way to return
* expected value and datapath logics will break.
*/
if ((ret & 0xff) != ret)
return -1;
custom_meta |= (__u32)(ret & 0xff) << 24;
custom_meta |= (identity & 0xffffff);
ctx_store_meta(ctx, CB_CUSTOM_CALLS, custom_meta);
return 0;
}
#endif
#ifdef ENABLE_IPV6
struct ct_buffer6 {
struct ipv6_ct_tuple tuple;
struct ct_state ct_state;
__u32 monitor;
int ret;
};
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__type(key, __u32);
__type(value, struct ct_buffer6);
__uint(max_entries, 1);
} CT_TAIL_CALL_BUFFER6 __section_maps_btf;
/* Handle egress IPv6 traffic from a container after service translation has been done
* either at the socket level or by the caller.
* In the case of the caller doing the service translation it passes in state via CB,
* which we take in with lb6_ctx_restore_state().
*
* Kernel 4.9 verifier is very finicky about the order of this code, modify with caution.
*/
static __always_inline int handle_ipv6_from_lxc(struct __ctx_buff *ctx, __u32 *dst_id,
__s8 *ext_err)
{
struct ct_state *ct_state, ct_state_new = {};
struct ipv6_ct_tuple *tuple;
#ifdef ENABLE_ROUTING
union macaddr router_mac = NODE_MAC;
#endif
struct ct_buffer6 *ct_buffer;
void *data, *data_end;
struct ipv6hdr *ip6;
int ret, verdict, l4_off, hdrlen, zero = 0;
struct trace_ctx trace = {
.reason = TRACE_REASON_UNKNOWN,
.monitor = 0,
};
__u32 __maybe_unused tunnel_endpoint = 0;
__u8 __maybe_unused encrypt_key = 0;
__u16 __maybe_unused node_id = 0;
enum ct_status ct_status;
bool hairpin_flow = false; /* endpoint wants to access itself via service IP */
__u8 policy_match_type = POLICY_MATCH_NONE;
__u8 audited = 0;
__u16 proxy_port = 0;
bool from_l7lb = false;
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
/* Determine the destination category for policy fallback. Service
* translation of the destination address is done before this function,
* so we can do this first. Also, verifier on kernel 4.9 insisted this
* be done before the CT lookup below.
*/
if (1) {
const union v6addr *daddr = (union v6addr *)&ip6->daddr;
struct remote_endpoint_info *info;
info = lookup_ip6_remote_endpoint(daddr, 0);
if (info && info->sec_label) {
*dst_id = info->sec_label;
tunnel_endpoint = info->tunnel_endpoint;
encrypt_key = get_min_encrypt_key(info->key);
node_id = info->node_id;
} else {
*dst_id = WORLD_ID;
}
cilium_dbg(ctx, info ? DBG_IP_ID_MAP_SUCCEED6 : DBG_IP_ID_MAP_FAILED6,
daddr->p4, *dst_id);
}
#ifdef ENABLE_PER_PACKET_LB
#if !defined(DEBUG) && defined(TUNNEL_MODE)
/* verifier workaround on kernel 4.9, not needed otherwise */
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
#endif
/* Restore ct_state from per packet lb handling in the previous tail call. */
lb6_ctx_restore_state(ctx, &ct_state_new, &proxy_port);
/* No hairpin/loopback support for IPv6, see lb6_local(). */
#endif /* ENABLE_PER_PACKET_LB */
ct_buffer = map_lookup_elem(&CT_TAIL_CALL_BUFFER6, &zero);
if (!ct_buffer)
return DROP_INVALID_TC_BUFFER;
if (ct_buffer->tuple.saddr.d1 == 0 && ct_buffer->tuple.saddr.d2 == 0)
/* The map value is zeroed so the map update didn't happen somehow. */
return DROP_INVALID_TC_BUFFER;
tuple = (struct ipv6_ct_tuple *)&ct_buffer->tuple;
ct_state = (struct ct_state *)&ct_buffer->ct_state;
trace.monitor = ct_buffer->monitor;
ret = ct_buffer->ret;
ct_status = (enum ct_status)ret;
trace.reason = (enum trace_reason)ret;
#if defined(ENABLE_L7_LB)
from_l7lb = ctx_load_meta(ctx, CB_FROM_HOST) == FROM_HOST_L7_LB;
if (proxy_port > 0) {
/* tuple addresses have been swapped by CT lookup */
cilium_dbg3(ctx, DBG_L7_LB, tuple->daddr.p4, tuple->saddr.p4,
bpf_ntohs(proxy_port));
goto skip_policy_enforcement;
}
#endif /* ENABLE_L7_LB */
/* Skip policy enforcement for return traffic. */
if (ct_status == CT_REPLY || ct_status == CT_RELATED) {
/* Check if this is return traffic to an ingress proxy. */
if (ct_state->proxy_redirect) {
/* Stack will do a socket match and deliver locally. */
return ctx_redirect_to_proxy6(ctx, tuple, 0, false);
}
/* proxy_port remains 0 in this case */
goto skip_policy_enforcement;
}
/* When an endpoint connects to itself via service clusterIP, we need
* to skip the policy enforcement. If we didn't, the user would have to
* define policy rules to allow pods to talk to themselves. We still
* want to execute the conntrack logic so that replies can be correctly
* matched.
*/
if (hairpin_flow)
goto skip_policy_enforcement;
/* 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(ctx, tuple, SECLABEL, *dst_id,
&policy_match_type, &audited, ext_err, &proxy_port);
/* Create CT entry if drop for auth required. */
if (verdict == DROP_POLICY_AUTH_REQUIRED) {
if (ct_status == CT_NEW) {
ct_state_new.src_sec_id = SECLABEL;
ct_create6(get_ct_map6(tuple), &CT_MAP_ANY6, tuple, ctx,
CT_EGRESS, &ct_state_new, proxy_port > 0, from_l7lb,
true);
} else if (!ct_state->auth_required) {
verdict = CTX_ACT_OK; /* allow if auth done */
}
}
/* Emit verdict if drop or if allow for CT_NEW or CT_REOPENED. */
if (verdict != CTX_ACT_OK || ct_status != CT_ESTABLISHED) {
send_policy_verdict_notify(ctx, *dst_id, tuple->dport,
tuple->nexthdr, POLICY_EGRESS, 1,
verdict, proxy_port,
policy_match_type, audited);
}
if (verdict != CTX_ACT_OK)
return verdict;
skip_policy_enforcement:
switch (ct_status) {
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, ctx,
CT_EGRESS, &ct_state_new, proxy_port > 0, from_l7lb, false);
if (IS_ERR(ret))
return ret;
trace.monitor = TRACE_PAYLOAD_LEN;
break;
case CT_REOPENED:
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(ctx);
hdrlen = ipv6_hdrlen(ctx, &tuple->nexthdr);
if (hdrlen < 0)
return hdrlen;
l4_off = ETH_HLEN + hdrlen;
#ifdef ENABLE_NODEPORT
# ifdef ENABLE_DSR
/* See comment in handle_ipv4_from_lxc(). */
if (ct_state->dsr) {
ret = xlate_dsr_v6(ctx, tuple, l4_off);
if (ret != 0)
return ret;
} else
# endif /* ENABLE_DSR */
/* See comment in handle_ipv4_from_lxc(). */
if (ct_state->node_port) {
send_trace_notify(ctx, TRACE_TO_NETWORK, SECLABEL,
*dst_id, 0, 0,
trace.reason, trace.monitor);
ctx->tc_index |= TC_INDEX_F_SKIP_RECIRCULATION;
ep_tail_call(ctx, CILIUM_CALL_IPV6_NODEPORT_REVNAT);
return DROP_MISSED_TAIL_CALL;
}
#endif /* ENABLE_NODEPORT */
if (ct_state->rev_nat_index) {
struct csum_offset csum_off = {};
csum_l4_offset_and_flags(tuple->nexthdr, &csum_off);
ret = lb6_rev_nat(ctx, l4_off, &csum_off,
ct_state->rev_nat_index, tuple, 0);
if (IS_ERR(ret))
return ret;
}
break;
default:
return DROP_UNKNOWN_CT;
}
hairpin_flow |= ct_state->loopback;
/* L7 LB does L7 policy enforcement, so we only redirect packets
* NOT from L7 LB.
*/
if (!from_l7lb && proxy_port > 0) {
/* Trace the packet before it is forwarded to proxy */
send_trace_notify(ctx, TRACE_TO_PROXY, SECLABEL, 0,
bpf_ntohs(proxy_port), 0,
trace.reason, trace.monitor);
return ctx_redirect_to_proxy6(ctx, tuple, proxy_port, false);
}
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
/* 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.
*/
ep = lookup_ip6_endpoint(ip6);
if (ep) {
#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(ctx);
/* If the packet is from L7 LB it is coming from the host */
return ipv6_local_delivery(ctx, ETH_HLEN, SECLABEL, ep,
METRIC_EGRESS, from_l7lb, hairpin_flow);
}
}
#if defined(ENABLE_HOST_FIREWALL) && !defined(ENABLE_ROUTING)
/* If the destination is the local host and per-endpoint routes are
* enabled, jump to the bpf_host program to enforce ingress host policies.
*/
if (*dst_id == HOST_ID) {
ctx_store_meta(ctx, CB_FROM_HOST, 0);
tail_call_static(ctx, &POLICY_CALL_MAP, HOST_EP_ID);
return DROP_MISSED_TAIL_CALL;
}
#endif /* ENABLE_HOST_FIREWALL && !ENABLE_ROUTING */
/* The packet goes to a peer not managed by this agent instance */
#ifdef TUNNEL_MODE
{
struct tunnel_key key = {};
union v6addr *daddr = (union v6addr *)&ip6->daddr;
/* 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 ctx to stack for encap, or
* (c) packet was redirected to tunnel device so return.
*/
ret = encap_and_redirect_lxc(ctx, tunnel_endpoint, encrypt_key,
&key, node_id, SECLABEL, *dst_id,
&trace);
if (ret == CTX_ACT_OK)
goto encrypt_to_stack;
else if (ret != DROP_NO_TUNNEL_ENDPOINT)
return ret;
}
#endif
if (is_defined(ENABLE_HOST_ROUTING)) {
int oif = 0;
ret = fib_redirect_v6(ctx, ETH_HLEN, ip6, false, ext_err,
ctx_get_ifindex(ctx), &oif);
if (fib_ok(ret))
send_trace_notify(ctx, TRACE_TO_NETWORK, SECLABEL,
*dst_id, 0, oif,
trace.reason, trace.monitor);
return ret;
}
goto pass_to_stack;
#ifdef ENABLE_ROUTING
to_host:
if (is_defined(ENABLE_HOST_FIREWALL) && *dst_id == HOST_ID) {
send_trace_notify(ctx, TRACE_TO_HOST, SECLABEL, HOST_ID, 0,
HOST_IFINDEX, trace.reason, trace.monitor);
return ctx_redirect(ctx, HOST_IFINDEX, BPF_F_INGRESS);
}
#endif
pass_to_stack:
#ifdef ENABLE_ROUTING
ret = ipv6_l3(ctx, ETH_HLEN, NULL, (__u8 *)&router_mac.addr, METRIC_EGRESS);
if (unlikely(ret != CTX_ACT_OK))
return ret;
#endif
#ifndef TUNNEL_MODE
# ifdef ENABLE_IPSEC
if (encrypt_key && tunnel_endpoint) {
set_encrypt_key_mark(ctx, encrypt_key, node_id);
# ifdef ENABLE_IDENTITY_MARK
set_identity_meta(ctx, SECLABEL);
# endif /* ENABLE_IDENTITY_MARK */
} else
# endif /* ENABLE_IPSEC */
#endif /* TUNNEL_MODE */
{
#ifdef ENABLE_IDENTITY_MARK
/* 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.
*/
ctx->mark |= MARK_MAGIC_IDENTITY;
set_identity_mark(ctx, SECLABEL);
#endif
}
#ifdef TUNNEL_MODE
encrypt_to_stack:
#endif
send_trace_notify(ctx, TRACE_TO_STACK, SECLABEL, *dst_id, 0, 0,
trace.reason, trace.monitor);
cilium_dbg_capture(ctx, DBG_CAPTURE_DELIVERY, 0);
return CTX_ACT_OK;
}
declare_tailcall_if(is_defined(ENABLE_PER_PACKET_LB), CILIUM_CALL_IPV6_FROM_LXC_CONT)
int tail_handle_ipv6_cont(struct __ctx_buff *ctx)
{
__u32 dst_id = 0;
__s8 ext_err = 0;
int ret = handle_ipv6_from_lxc(ctx, &dst_id, &ext_err);
if (IS_ERR(ret))
return send_drop_notify_ext(ctx, SECLABEL, dst_id, 0, ret, ext_err,
CTX_ACT_DROP, METRIC_EGRESS);
#ifdef ENABLE_CUSTOM_CALLS
if (!encode_custom_prog_meta(ctx, ret, dst_id)) {
tail_call_static(ctx, &CUSTOM_CALLS_MAP,
CUSTOM_CALLS_IDX_IPV6_EGRESS);
update_metrics(ctx_full_len(ctx), METRIC_EGRESS,
REASON_MISSED_CUSTOM_CALL);
}
#endif
return ret;
}
TAIL_CT_LOOKUP6(CILIUM_CALL_IPV6_CT_EGRESS, tail_ipv6_ct_egress, CT_EGRESS,
is_defined(ENABLE_PER_PACKET_LB),
CILIUM_CALL_IPV6_FROM_LXC_CONT, tail_handle_ipv6_cont)
static __always_inline int __tail_handle_ipv6(struct __ctx_buff *ctx)
{
void *data, *data_end;
struct ipv6hdr *ip6;
int ret;
if (!revalidate_data_pull(ctx, &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(ctx, ETH_HLEN, ip6, METRIC_EGRESS);
if (IS_ERR(ret))
return ret;
}
if (unlikely(!is_valid_lxc_src_ip(ip6)))
return DROP_INVALID_SIP;
#ifdef ENABLE_PER_PACKET_LB
/* will tailcall internally or return error */
return __per_packet_lb_svc_xlate_6(ctx, ip6);
#else
/* won't be a tailcall, see TAIL_CT_LOOKUP6 */
return tail_ipv6_ct_egress(ctx);
#endif /* ENABLE_PER_PACKET_LB */
}
__section_tail(CILIUM_MAP_CALLS, CILIUM_CALL_IPV6_FROM_LXC)
int tail_handle_ipv6(struct __ctx_buff *ctx)
{
int ret = __tail_handle_ipv6(ctx);
if (IS_ERR(ret))
return send_drop_notify_error(ctx, SECLABEL, ret,
CTX_ACT_DROP, METRIC_EGRESS);
return ret;
}
#endif /* ENABLE_IPV6 */
#ifdef ENABLE_IPV4
struct ct_buffer4 {
struct ipv4_ct_tuple tuple;
struct ct_state ct_state;
__u32 monitor;
int ret;
};
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
__type(key, __u32);
__type(value, struct ct_buffer4);
__uint(max_entries, 1);
} CT_TAIL_CALL_BUFFER4 __section_maps_btf;
/* Handle egress IPv4 traffic from a container after service translation has been done
* either at the socket level or by the caller.
* In the case of the caller doing the service translation it passes in state via CB,
* which we take in with lb4_ctx_restore_state().
*/
static __always_inline int handle_ipv4_from_lxc(struct __ctx_buff *ctx, __u32 *dst_id,
__s8 *ext_err)
{
struct ct_state *ct_state, ct_state_new = {};
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, l4_off;
struct trace_ctx trace = {
.reason = TRACE_REASON_UNKNOWN,
.monitor = 0,
};
__u32 __maybe_unused tunnel_endpoint = 0, zero = 0;
__u8 __maybe_unused encrypt_key = 0;
__u16 __maybe_unused node_id = 0;
bool hairpin_flow = false; /* endpoint wants to access itself via service IP */
__u8 policy_match_type = POLICY_MATCH_NONE;
struct ct_buffer4 *ct_buffer;
__u8 audited = 0;
bool has_l4_header = false;
enum ct_status ct_status;
__u16 proxy_port = 0;
bool from_l7lb = false;
__u32 cluster_id = 0;
void *ct_map, *ct_related_map = NULL;
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
has_l4_header = ipv4_has_l4_header(ip4);
#ifdef ENABLE_PER_PACKET_LB
/* Restore ct_state from per packet lb handling in the previous tail call. */
lb4_ctx_restore_state(ctx, &ct_state_new, ip4->daddr, &proxy_port, &cluster_id);
hairpin_flow = ct_state_new.loopback;
#endif /* ENABLE_PER_PACKET_LB */
/* Determine the destination category for policy fallback. */
if (1) {
struct remote_endpoint_info *info;
info = lookup_ip4_remote_endpoint(ip4->daddr, cluster_id);
if (info && info->sec_label) {
*dst_id = info->sec_label;
tunnel_endpoint = info->tunnel_endpoint;
encrypt_key = get_min_encrypt_key(info->key);
node_id = info->node_id;
} else {
*dst_id = WORLD_ID;
}
cilium_dbg(ctx, info ? DBG_IP_ID_MAP_SUCCEED4 : DBG_IP_ID_MAP_FAILED4,
ip4->daddr, *dst_id);
}
l4_off = ETH_HLEN + ipv4_hdrlen(ip4);
ct_buffer = map_lookup_elem(&CT_TAIL_CALL_BUFFER4, &zero);
if (!ct_buffer)
return DROP_INVALID_TC_BUFFER;
if (ct_buffer->tuple.saddr == 0)
/* The map value is zeroed so the map update didn't happen somehow. */
return DROP_INVALID_TC_BUFFER;
tuple = (struct ipv4_ct_tuple *)&ct_buffer->tuple;
ct_state = (struct ct_state *)&ct_buffer->ct_state;
trace.monitor = ct_buffer->monitor;
ret = ct_buffer->ret;
ct_status = (enum ct_status)ret;
trace.reason = (enum trace_reason)ret;
#if defined(ENABLE_L7_LB)
from_l7lb = ctx_load_meta(ctx, CB_FROM_HOST) == FROM_HOST_L7_LB;
if (proxy_port > 0) {
/* tuple addresses have been swapped by CT lookup */
cilium_dbg3(ctx, DBG_L7_LB, tuple->daddr, tuple->saddr, bpf_ntohs(proxy_port));
goto skip_policy_enforcement;
}
#endif /* ENABLE_L7_LB */
/* Skip policy enforcement for return traffic. */
if (ct_status == CT_REPLY || ct_status == CT_RELATED) {
/* Check if this is return traffic to an ingress proxy. */
if (ct_state->proxy_redirect) {
/* Stack will do a socket match and deliver locally. */
return ctx_redirect_to_proxy4(ctx, tuple, 0, false);
}
/* proxy_port remains 0 in this case */
goto skip_policy_enforcement;
}
/* When an endpoint connects to itself via service clusterIP, we need
* to skip the policy enforcement. If we didn't, the user would have to
* define policy rules to allow pods to talk to themselves. We still
* want to execute the conntrack logic so that replies can be correctly
* matched.
*/
if (hairpin_flow)
goto skip_policy_enforcement;
/* 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(ctx, tuple, SECLABEL, *dst_id,
&policy_match_type, &audited, ext_err, &proxy_port);
/* Create CT entry if drop for auth required. */
if (verdict == DROP_POLICY_AUTH_REQUIRED) {
if (ct_status == CT_NEW) {
ct_state_new.src_sec_id = SECLABEL;
ct_create4(get_ct_map4(tuple), &CT_MAP_ANY4, tuple, ctx,
CT_EGRESS, &ct_state_new, proxy_port > 0, from_l7lb,
true);
} else if (!ct_state->auth_required) {
verdict = CTX_ACT_OK; /* allow if auth done */
}
}
/* Emit verdict if drop or if allow for CT_NEW or CT_REOPENED. */
if (verdict != CTX_ACT_OK || ct_status != CT_ESTABLISHED) {
send_policy_verdict_notify(ctx, *dst_id, tuple->dport,
tuple->nexthdr, POLICY_EGRESS, 0,
verdict, proxy_port,
policy_match_type, audited);
}
if (verdict != CTX_ACT_OK)
return verdict;
skip_policy_enforcement:
switch (ct_status) {
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;
ct_map = get_cluster_ct_map4(tuple, cluster_id);
if (!ct_map)
return DROP_CT_NO_MAP_FOUND;
ct_related_map = get_cluster_ct_any_map4(cluster_id);
if (!ct_related_map)
return DROP_CT_NO_MAP_FOUND;
/* We could avoid creating related entries for legacy ClusterIP
* handling here, but turns out that verifier cannot handle it.
*/
ret = ct_create4(ct_map, ct_related_map, tuple, ctx,
CT_EGRESS, &ct_state_new, proxy_port > 0, from_l7lb, false);
if (IS_ERR(ret))
return ret;
break;
case CT_REOPENED:
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(ctx);
#ifdef ENABLE_NODEPORT
# ifdef ENABLE_DSR
/* DSR RevDNAT typically happens in to-netdev. This part is only
* needed for old connections that were established prior to
* the bpf_host support:
*/
if (ct_state->dsr) {
ret = xlate_dsr_v4(ctx, tuple, l4_off, has_l4_header);
if (ret != 0)
return ret;
} else
# endif /* ENABLE_DSR */
/* This handles reply traffic for the case where the nodeport EP
* is local to the node. We'll do the tail call to perform
* the reverse DNAT.
*/
if (ct_state->node_port) {
send_trace_notify(ctx, TRACE_TO_NETWORK, SECLABEL,
*dst_id, 0, 0,
trace.reason, trace.monitor);
ctx->tc_index |= TC_INDEX_F_SKIP_RECIRCULATION;
ep_tail_call(ctx, CILIUM_CALL_IPV4_NODEPORT_REVNAT);
return DROP_MISSED_TAIL_CALL;
}
#endif /* ENABLE_NODEPORT */
if (ct_state->rev_nat_index) {
struct csum_offset csum_off = {};
csum_l4_offset_and_flags(tuple->nexthdr, &csum_off);
ret = lb4_rev_nat(ctx, ETH_HLEN, l4_off, &csum_off,
ct_state, tuple, 0, has_l4_header);
if (IS_ERR(ret))
return ret;
}
break;
default:
return DROP_UNKNOWN_CT;
}
hairpin_flow |= ct_state->loopback;
/* L7 LB does L7 policy enforcement, so we only redirect packets
* NOT from L7 LB.
*/
if (!from_l7lb && proxy_port > 0) {
/* Trace the packet before it is forwarded to proxy */
send_trace_notify(ctx, TRACE_TO_PROXY, SECLABEL, 0,
bpf_ntohs(proxy_port), 0,
trace.reason, trace.monitor);
return ctx_redirect_to_proxy4(ctx, tuple, proxy_port, false);
}