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bpf_host.c
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bpf_host.c
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// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright Authors of Cilium */
#include <bpf/ctx/skb.h>
#include <bpf/api.h>
#include <node_config.h>
#include <ep_config.h>
#define IS_BPF_HOST 1
#define EVENT_SOURCE HOST_EP_ID
/* Host endpoint ID for the template bpf_host object file. Will be replaced
* at compile-time with the proper host endpoint ID.
*/
#define TEMPLATE_HOST_EP_ID 0xffff
/* These are configuration options which have a default value in their
* respective header files and must thus be defined beforehand:
*/
/* Pass unknown ICMPv6 NS to stack */
#define ACTION_UNKNOWN_ICMP6_NS CTX_ACT_OK
/* Controls the inclusion of the CILIUM_CALL_SEND_ICMP6_ECHO_REPLY section in
* the bpf_lxc object file.
*/
#define SKIP_ICMPV6_ECHO_HANDLING
#ifndef VLAN_FILTER
# define VLAN_FILTER(ifindex, vlan_id) return false;
#endif
#include "lib/common.h"
#include "lib/edt.h"
#include "lib/arp.h"
#include "lib/maps.h"
#include "lib/ipv6.h"
#include "lib/ipv4.h"
#include "lib/icmp6.h"
#include "lib/eth.h"
#include "lib/dbg.h"
#include "lib/proxy.h"
#include "lib/trace.h"
#include "lib/identity.h"
#include "lib/l3.h"
#include "lib/l4.h"
#include "lib/drop.h"
#include "lib/encap.h"
#include "lib/nat.h"
#include "lib/lb.h"
#include "lib/nodeport.h"
#include "lib/eps.h"
#include "lib/host_firewall.h"
#include "lib/egress_policies.h"
#include "lib/overloadable.h"
#include "lib/encrypt.h"
static __always_inline bool allow_vlan(__u32 __maybe_unused ifindex, __u32 __maybe_unused vlan_id) {
VLAN_FILTER(ifindex, vlan_id);
}
#if defined(ENABLE_IPV4) || defined(ENABLE_IPV6)
static __always_inline int rewrite_dmac_to_host(struct __ctx_buff *ctx,
__u32 src_identity)
{
/* When attached to cilium_host, we rewrite the DMAC to the mac of
* cilium_host (peer) to ensure the packet is being considered to be
* addressed to the host (PACKET_HOST).
*/
union macaddr cilium_net_mac = CILIUM_NET_MAC;
/* Rewrite to destination MAC of cilium_net (remote peer) */
if (eth_store_daddr(ctx, (__u8 *) &cilium_net_mac.addr, 0) < 0)
return send_drop_notify_error(ctx, src_identity, DROP_WRITE_ERROR,
CTX_ACT_OK, METRIC_INGRESS);
return CTX_ACT_OK;
}
#define SECCTX_FROM_IPCACHE_OK 2
#ifndef SECCTX_FROM_IPCACHE
# define SECCTX_FROM_IPCACHE 0
#endif
static __always_inline bool identity_from_ipcache_ok(void)
{
return SECCTX_FROM_IPCACHE == SECCTX_FROM_IPCACHE_OK;
}
#endif
#ifdef ENABLE_IPV6
static __always_inline __u32
derive_src_id(const union v6addr *node_ip, struct ipv6hdr *ip6, __u32 *identity)
{
if (ipv6_match_prefix_64((union v6addr *) &ip6->saddr, node_ip)) {
/* Read initial 4 bytes of header and then extract flowlabel */
__u32 *tmp = (__u32 *) ip6;
*identity = bpf_ntohl(*tmp & IPV6_FLOWLABEL_MASK);
/* A remote node will map any HOST_ID source to be presented as
* REMOTE_NODE_ID, therefore any attempt to signal HOST_ID as
* source from a remote node can be dropped.
*/
if (*identity == HOST_ID)
return DROP_INVALID_IDENTITY;
}
return 0;
}
static __always_inline __u32
resolve_srcid_ipv6(struct __ctx_buff *ctx, struct ipv6hdr *ip6,
__u32 srcid_from_proxy, const bool from_host)
{
__u32 src_id = WORLD_ID, srcid_from_ipcache = srcid_from_proxy;
struct remote_endpoint_info *info = NULL;
union v6addr *src;
int ret;
if (!from_host) {
union v6addr node_ip = {};
BPF_V6(node_ip, ROUTER_IP);
ret = derive_src_id(&node_ip, ip6, &src_id);
if (IS_ERR(ret))
return ret;
}
/* Packets from the proxy will already have a real identity. */
if (identity_is_reserved(srcid_from_ipcache)) {
src = (union v6addr *) &ip6->saddr;
info = lookup_ip6_remote_endpoint(src);
if (info) {
if (info->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 "srcid_from_proxy"
* (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 (info->sec_label != HOST_ID)
srcid_from_ipcache = info->sec_label;
}
}
cilium_dbg(ctx, info ? DBG_IP_ID_MAP_SUCCEED6 : DBG_IP_ID_MAP_FAILED6,
((__u32 *) src)[3], srcid_from_ipcache);
}
if (from_host)
src_id = srcid_from_ipcache;
else if (src_id == WORLD_ID &&
identity_from_ipcache_ok())
src_id = srcid_from_ipcache;
return src_id;
}
static __always_inline int
handle_ipv6(struct __ctx_buff *ctx, __u32 secctx, const bool from_host,
__s8 *ext_err __maybe_unused)
{
struct trace_ctx __maybe_unused trace = {
.reason = TRACE_REASON_UNKNOWN,
.monitor = TRACE_PAYLOAD_LEN,
};
struct remote_endpoint_info *info = NULL;
void *data, *data_end;
struct ipv6hdr *ip6;
union v6addr *dst;
__u32 __maybe_unused remote_id = WORLD_ID;
int ret, l3_off = ETH_HLEN, hdrlen;
struct endpoint_info *ep;
__u8 nexthdr;
__u8 encrypt_key __maybe_unused = 0;
bool from_ingress_proxy = tc_index_from_ingress_proxy(ctx);
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
nexthdr = ip6->nexthdr;
hdrlen = ipv6_hdrlen(ctx, &nexthdr);
if (hdrlen < 0)
return hdrlen;
if (likely(nexthdr == IPPROTO_ICMPV6)) {
ret = icmp6_host_handle(ctx);
if (ret == SKIP_HOST_FIREWALL)
goto skip_host_firewall;
if (IS_ERR(ret))
return ret;
}
#ifdef ENABLE_NODEPORT
if (!from_host) {
if (!(ctx_get_xfer(ctx, XFER_FLAGS) & XFER_PKT_NO_SVC) &&
!ctx_skip_nodeport(ctx)) {
ret = nodeport_lb6(ctx, secctx);
/* nodeport_lb6() returns with TC_ACT_REDIRECT for
* traffic to L7 LB. Policy enforcement needs to take
* place after L7 LB has processed the packet, so we
* return to stack immediately here with
* TC_ACT_REDIRECT.
*/
if (ret < 0 || ret == TC_ACT_REDIRECT)
return ret;
}
/* Verifier workaround: modified ctx access. */
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
}
#endif /* ENABLE_NODEPORT */
#ifdef ENABLE_HOST_FIREWALL
if (from_host) {
ret = ipv6_host_policy_egress(ctx, secctx, &trace, ext_err);
if (IS_ERR(ret))
return ret;
} else if (!ctx_skip_host_fw(ctx)) {
ret = ipv6_host_policy_ingress(ctx, &remote_id, &trace);
if (IS_ERR(ret))
return ret;
}
#endif /* ENABLE_HOST_FIREWALL */
skip_host_firewall:
/*
* Perform SRv6 Decap if incoming skb is a known SID.
* This must tailcall, as the decap could be for inner ipv6 or ipv4 making
* the remaining path potentially erroneous.
*
* Perform this before the ENABLE_HOST_ROUTING check as the decap is not dependent
* on this feature being enabled or not.
*/
#ifdef ENABLE_SRV6
if (!from_host) {
if (is_srv6_packet(ip6) && srv6_lookup_sid(&ip6->daddr)) {
/* This packet is destined to an SID so we need to decapsulate it
* and forward it.
*/
ep_tail_call(ctx, CILIUM_CALL_SRV6_DECAP);
return DROP_MISSED_TAIL_CALL;
}
}
#endif /* ENABLE_SRV6 */
#ifndef ENABLE_HOST_ROUTING
/* See the equivalent v4 path for comments */
if (!from_host)
return CTX_ACT_OK;
#endif /* !ENABLE_HOST_ROUTING */
if (from_host) {
/* If we are attached to cilium_host at egress, this will
* rewrite the destination MAC address to the MAC of cilium_net.
*/
ret = rewrite_dmac_to_host(ctx, secctx);
/* DIRECT PACKET READ INVALID */
if (IS_ERR(ret))
return ret;
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
}
/* Lookup IPv6 address in list of local endpoints */
ep = lookup_ip6_endpoint(ip6);
if (ep) {
/* Let through packets to the node-ip so they are
* processed by the local ip stack.
*/
if (ep->flags & ENDPOINT_F_HOST)
return CTX_ACT_OK;
return ipv6_local_delivery(ctx, l3_off, secctx, ep,
METRIC_INGRESS, from_host, false);
}
/* Below remainder is only relevant when traffic is pushed via cilium_host.
* For traffic coming from external, we're done here.
*/
if (!from_host)
return CTX_ACT_OK;
dst = (union v6addr *) &ip6->daddr;
info = ipcache_lookup6(&IPCACHE_MAP, dst, V6_CACHE_KEY_LEN);
#ifdef ENABLE_IPSEC
/* See IPv4 comment. */
if (from_ingress_proxy && info)
encrypt_key = get_min_encrypt_key(info->key);
#endif
#ifdef TUNNEL_MODE
if (info != NULL && info->tunnel_endpoint != 0) {
return encap_and_redirect_with_nodeid(ctx, info->tunnel_endpoint,
encrypt_key, secctx, info->sec_label,
&trace);
} else {
struct tunnel_key key = {};
/* IPv6 lookup key: daddr/96 */
key.ip6.p1 = dst->p1;
key.ip6.p2 = dst->p2;
key.ip6.p3 = dst->p3;
key.ip6.p4 = 0;
key.family = ENDPOINT_KEY_IPV6;
ret = encap_and_redirect_netdev(ctx, &key, encrypt_key, secctx, &trace);
if (ret != DROP_NO_TUNNEL_ENDPOINT)
return ret;
}
#endif
if (!info || (!from_ingress_proxy &&
info->sec_label == WORLD_ID)) {
/* See IPv4 comment. */
return DROP_UNROUTABLE;
}
#if defined(ENABLE_IPSEC) && !defined(TUNNEL_MODE)
/* See IPv4 comment. */
if (from_ingress_proxy && info->tunnel_endpoint && encrypt_key)
return set_ipsec_encrypt(ctx, encrypt_key, info->tunnel_endpoint,
info->sec_label);
#endif
return CTX_ACT_OK;
}
static __always_inline int
tail_handle_ipv6(struct __ctx_buff *ctx, const bool from_host)
{
__u32 proxy_identity = ctx_load_meta(ctx, CB_SRC_LABEL);
int ret;
__s8 ext_err = 0;
ctx_store_meta(ctx, CB_SRC_LABEL, 0);
ret = handle_ipv6(ctx, proxy_identity, from_host, &ext_err);
if (IS_ERR(ret))
return send_drop_notify_error_ext(ctx, proxy_identity, ret, ext_err,
CTX_ACT_DROP, METRIC_INGRESS);
return ret;
}
__section_tail(CILIUM_MAP_CALLS, CILIUM_CALL_IPV6_FROM_HOST)
int tail_handle_ipv6_from_host(struct __ctx_buff *ctx __maybe_unused)
{
return tail_handle_ipv6(ctx, true);
}
__section_tail(CILIUM_MAP_CALLS, CILIUM_CALL_IPV6_FROM_NETDEV)
int tail_handle_ipv6_from_netdev(struct __ctx_buff *ctx)
{
return tail_handle_ipv6(ctx, false);
}
# ifdef ENABLE_HOST_FIREWALL
static __always_inline int
handle_to_netdev_ipv6(struct __ctx_buff *ctx, struct trace_ctx *trace, __s8 *ext_err)
{
void *data, *data_end;
struct ipv6hdr *ip6;
__u32 src_id = 0;
int hdrlen, ret;
__u8 nexthdr;
if (!revalidate_data_pull(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
nexthdr = ip6->nexthdr;
hdrlen = ipv6_hdrlen(ctx, &nexthdr);
if (hdrlen < 0)
return hdrlen;
if (likely(nexthdr == IPPROTO_ICMPV6)) {
ret = icmp6_host_handle(ctx);
if (ret == SKIP_HOST_FIREWALL)
return CTX_ACT_OK;
if (IS_ERR(ret))
return ret;
}
if ((ctx->mark & MARK_MAGIC_HOST_MASK) == MARK_MAGIC_HOST)
src_id = HOST_ID;
src_id = resolve_srcid_ipv6(ctx, ip6, src_id, true);
/* to-netdev is attached to the egress path of the native device. */
return ipv6_host_policy_egress(ctx, src_id, trace, ext_err);
}
#endif /* ENABLE_HOST_FIREWALL */
#endif /* ENABLE_IPV6 */
#ifdef ENABLE_IPV4
static __always_inline __u32
resolve_srcid_ipv4(struct __ctx_buff *ctx, struct iphdr *ip4,
__u32 srcid_from_proxy, __u32 *sec_label,
const bool from_host)
{
__u32 src_id = WORLD_ID, srcid_from_ipcache = srcid_from_proxy;
struct remote_endpoint_info *info = NULL;
/* Packets from the proxy will already have a real identity. */
if (identity_is_reserved(srcid_from_ipcache)) {
info = lookup_ip4_remote_endpoint(ip4->saddr);
if (info != NULL) {
*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 "srcid_from_proxy"
* (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)
srcid_from_ipcache = *sec_label;
}
}
cilium_dbg(ctx, info ? DBG_IP_ID_MAP_SUCCEED4 : DBG_IP_ID_MAP_FAILED4,
ip4->saddr, srcid_from_ipcache);
}
if (from_host)
src_id = srcid_from_ipcache;
/* If we could not derive the secctx from the packet itself but
* from the ipcache instead, then use the ipcache identity.
*/
else if (identity_from_ipcache_ok())
src_id = srcid_from_ipcache;
return src_id;
}
static __always_inline int
handle_ipv4(struct __ctx_buff *ctx, __u32 secctx,
__u32 ipcache_srcid __maybe_unused, const bool from_host, __s8 *ext_err __maybe_unused)
{
struct trace_ctx __maybe_unused trace = {
.reason = TRACE_REASON_UNKNOWN,
.monitor = TRACE_PAYLOAD_LEN,
};
struct remote_endpoint_info *info = NULL;
__u32 __maybe_unused remote_id = 0;
struct endpoint_info *ep;
void *data, *data_end;
struct iphdr *ip4;
int ret;
__u8 encrypt_key __maybe_unused = 0;
bool from_ingress_proxy = tc_index_from_ingress_proxy(ctx);
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
/* If IPv4 fragmentation is disabled
* AND a IPv4 fragmented packet is received,
* then drop the packet.
*/
#ifndef ENABLE_IPV4_FRAGMENTS
if (ipv4_is_fragment(ip4))
return DROP_FRAG_NOSUPPORT;
#endif
#ifdef ENABLE_NODEPORT
if (!from_host) {
if (!(ctx_get_xfer(ctx, XFER_FLAGS) & XFER_PKT_NO_SVC) &&
!ctx_skip_nodeport(ctx)) {
ret = nodeport_lb4(ctx, secctx);
if (ret == NAT_46X64_RECIRC) {
ctx_store_meta(ctx, CB_SRC_LABEL, secctx);
ep_tail_call(ctx, CILIUM_CALL_IPV6_FROM_NETDEV);
return send_drop_notify_error(ctx, secctx,
DROP_MISSED_TAIL_CALL,
CTX_ACT_DROP,
METRIC_INGRESS);
}
/* nodeport_lb4() returns with TC_ACT_REDIRECT for
* traffic to L7 LB. Policy enforcement needs to take
* place after L7 LB has processed the packet, so we
* return to stack immediately here with
* TC_ACT_REDIRECT.
*/
if (ret < 0 || ret == TC_ACT_REDIRECT)
return ret;
}
/* Verifier workaround: modified ctx access. */
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
}
#endif /* ENABLE_NODEPORT */
#ifdef ENABLE_HOST_FIREWALL
if (from_host) {
/* We're on the egress path of cilium_host. */
ret = ipv4_host_policy_egress(ctx, secctx, ipcache_srcid,
&trace, ext_err);
if (IS_ERR(ret))
return ret;
} else if (!ctx_skip_host_fw(ctx)) {
/* We're on the ingress path of the native device. */
ret = ipv4_host_policy_ingress(ctx, &remote_id, &trace);
if (IS_ERR(ret))
return ret;
}
#endif /* ENABLE_HOST_FIREWALL */
#ifndef ENABLE_HOST_ROUTING
/* Without bpf_redirect_neigh() helper, we cannot redirect a
* packet to a local endpoint in the direct routing mode, as
* the redirect bypasses nf_conntrack table. This makes a
* second reply from the endpoint to be MASQUERADEd or to be
* DROP-ed by k8s's "--ctstate INVALID -j DROP" depending via
* which interface it was inputed. With bpf_redirect_neigh()
* we bypass request and reply path in the host namespace and
* do not run into this issue.
*/
if (!from_host)
return CTX_ACT_OK;
#endif /* !ENABLE_HOST_ROUTING */
if (from_host) {
/* If we are attached to cilium_host at egress, this will
* rewrite the destination MAC address to the MAC of cilium_net.
*/
ret = rewrite_dmac_to_host(ctx, secctx);
/* DIRECT PACKET READ INVALID */
if (IS_ERR(ret))
return ret;
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
}
/* Lookup IPv4 address in list of local endpoints and host IPs */
ep = lookup_ip4_endpoint(ip4);
if (ep) {
/* Let through packets to the node-ip so they are processed by
* the local ip stack.
*/
if (ep->flags & ENDPOINT_F_HOST)
return CTX_ACT_OK;
return ipv4_local_delivery(ctx, ETH_HLEN, secctx, ip4, ep,
METRIC_INGRESS, from_host, false);
}
/* Below remainder is only relevant when traffic is pushed via cilium_host.
* For traffic coming from external, we're done here.
*/
if (!from_host)
return CTX_ACT_OK;
/* Handle VTEP integration in bpf_host to support pod L7 PROXY.
* It requires route setup to VTEP CIDR via dev cilium_host scope link.
*/
#ifdef ENABLE_VTEP
{
struct vtep_key vkey = {};
struct vtep_value *vtep;
vkey.vtep_ip = ip4->daddr & VTEP_MASK;
vtep = map_lookup_elem(&VTEP_MAP, &vkey);
if (!vtep)
goto skip_vtep;
if (vtep->vtep_mac && vtep->tunnel_endpoint) {
if (eth_store_daddr(ctx, (__u8 *)&vtep->vtep_mac, 0) < 0)
return DROP_WRITE_ERROR;
return __encap_and_redirect_with_nodeid(ctx, vtep->tunnel_endpoint,
secctx, WORLD_ID, WORLD_ID, &trace);
}
}
skip_vtep:
#endif
info = ipcache_lookup4(&IPCACHE_MAP, ip4->daddr, V4_CACHE_KEY_LEN);
#ifdef ENABLE_IPSEC
/* We encrypt host to remote pod packets only if they are from ingress proxy. */
if (from_ingress_proxy && info)
encrypt_key = get_min_encrypt_key(info->key);
#endif
#ifdef TUNNEL_MODE
if (info != NULL && info->tunnel_endpoint != 0) {
return encap_and_redirect_with_nodeid(ctx, info->tunnel_endpoint,
encrypt_key, secctx, info->sec_label,
&trace);
} else {
/* IPv4 lookup key: daddr & IPV4_MASK */
struct tunnel_key key = {};
key.ip4 = ip4->daddr & IPV4_MASK;
key.family = ENDPOINT_KEY_IPV4;
cilium_dbg(ctx, DBG_NETDEV_ENCAP4, key.ip4, secctx);
ret = encap_and_redirect_netdev(ctx, &key, encrypt_key, secctx, &trace);
if (ret != DROP_NO_TUNNEL_ENDPOINT)
return ret;
}
#endif
if (!info || (!from_ingress_proxy &&
info->sec_label == WORLD_ID)) {
/* We have received a packet for which no ipcache entry exists,
* we do not know what to do with this packet, drop it.
*
* The info == NULL test is soley to satisfy verifier requirements
* as in Cilium case we'll always hit the 0.0.0.0/32 catch-all
* entry. Therefore we need to test for WORLD_ID. It is clearly
* wrong to route a ctx to cilium_host for which we don't know
* anything about it as otherwise we'll run into a routing loop.
*
* Note that we do not drop packets from ingress proxy even if
* they are going to WORLD_ID. This is to avoid
* https://github.com/cilium/cilium/issues/21954.
*/
return DROP_UNROUTABLE;
}
#if defined(ENABLE_IPSEC) && !defined(TUNNEL_MODE)
/* We encrypt host to remote pod packets only if they are from ingress proxy. */
if (from_ingress_proxy && info->tunnel_endpoint && encrypt_key)
return set_ipsec_encrypt(ctx, encrypt_key, info->tunnel_endpoint,
info->sec_label);
#endif
return CTX_ACT_OK;
}
static __always_inline int
tail_handle_ipv4(struct __ctx_buff *ctx, __u32 ipcache_srcid, const bool from_host)
{
__u32 proxy_identity = ctx_load_meta(ctx, CB_SRC_LABEL);
int ret;
__s8 ext_err = 0;
ctx_store_meta(ctx, CB_SRC_LABEL, 0);
ret = handle_ipv4(ctx, proxy_identity, ipcache_srcid, from_host, &ext_err);
if (IS_ERR(ret))
return send_drop_notify_error_ext(ctx, proxy_identity, ret, ext_err,
CTX_ACT_DROP, METRIC_INGRESS);
return ret;
}
__section_tail(CILIUM_MAP_CALLS, CILIUM_CALL_IPV4_FROM_HOST)
int tail_handle_ipv4_from_host(struct __ctx_buff *ctx)
{
__u32 ipcache_srcid = 0;
#if defined(ENABLE_HOST_FIREWALL) && !defined(ENABLE_MASQUERADE)
ipcache_srcid = ctx_load_meta(ctx, CB_IPCACHE_SRC_LABEL);
ctx_store_meta(ctx, CB_IPCACHE_SRC_LABEL, 0);
#endif
return tail_handle_ipv4(ctx, ipcache_srcid, true);
}
__section_tail(CILIUM_MAP_CALLS, CILIUM_CALL_IPV4_FROM_NETDEV)
int tail_handle_ipv4_from_netdev(struct __ctx_buff *ctx)
{
return tail_handle_ipv4(ctx, 0, false);
}
#ifdef ENABLE_HOST_FIREWALL
static __always_inline int
handle_to_netdev_ipv4(struct __ctx_buff *ctx, struct trace_ctx *trace, __s8 *ext_err)
{
void *data, *data_end;
struct iphdr *ip4;
__u32 src_id = 0, ipcache_srcid = 0;
if ((ctx->mark & MARK_MAGIC_HOST_MASK) == MARK_MAGIC_HOST)
src_id = HOST_ID;
if (!revalidate_data_pull(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
src_id = resolve_srcid_ipv4(ctx, ip4, src_id, &ipcache_srcid, true);
/* We need to pass the srcid from ipcache to host firewall. See
* comment in ipv4_host_policy_egress() for details.
*/
return ipv4_host_policy_egress(ctx, src_id, ipcache_srcid, trace, ext_err);
}
#endif /* ENABLE_HOST_FIREWALL */
#endif /* ENABLE_IPV4 */
#ifdef ENABLE_IPSEC
#ifndef TUNNEL_MODE
static __always_inline int
do_netdev_encrypt_pools(struct __ctx_buff *ctx __maybe_unused)
{
int ret = 0;
__u32 tunnel_endpoint = 0;
void *data, *data_end;
__u32 tunnel_source = IPV4_ENCRYPT_IFACE;
struct iphdr *ip4;
__be32 sum;
tunnel_endpoint = ctx_load_meta(ctx, CB_ENCRYPT_DST);
ctx->mark = 0;
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
/* We only need to replace the IPsec outer IP addresses if they are set to
* 0.0.0.0 -> 192.168.0.0. In that case, it means the packet was
* encapsulated by the old XFRM OUT state and we need this BPF logic.
* Otherwise, it means the packet was encapsulated by the new XFRM OUT
* states, which already set the proper outer IP addresses; nothing needed
* here.
* This whole function can be removed in 1.15.
*/
if (ip4->saddr != 0)
return 0;
/* When IP_POOLS is enabled ip addresses are not
* assigned on a per node basis so lacking node
* affinity we can not use IP address to assign the
* destination IP. Instead rewrite it here from cb[].
*/
sum = csum_diff(&ip4->daddr, sizeof(__u32), &tunnel_endpoint,
sizeof(tunnel_endpoint), 0);
if (ctx_store_bytes(ctx, ETH_HLEN + offsetof(struct iphdr, daddr),
&tunnel_endpoint, sizeof(tunnel_endpoint), 0) < 0)
return DROP_WRITE_ERROR;
if (l3_csum_replace(ctx, ETH_HLEN + offsetof(struct iphdr, check),
0, sum, 0) < 0)
return DROP_CSUM_L3;
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
sum = csum_diff(&ip4->saddr, sizeof(__u32), &tunnel_source,
sizeof(tunnel_source), 0);
if (ctx_store_bytes(ctx, ETH_HLEN + offsetof(struct iphdr, saddr),
&tunnel_source, sizeof(tunnel_source), 0) < 0)
return DROP_WRITE_ERROR;
if (l3_csum_replace(ctx, ETH_HLEN + offsetof(struct iphdr, check),
0, sum, 0) < 0)
return DROP_CSUM_L3;
return ret;
}
static __always_inline int
do_netdev_encrypt(struct __ctx_buff *ctx __maybe_unused,
__u32 src_id __maybe_unused)
{
int ret;
ret = do_netdev_encrypt_pools(ctx);
if (ret)
return send_drop_notify_error(ctx, src_id, ret, CTX_ACT_DROP, METRIC_INGRESS);
return CTX_ACT_OK;
}
#else /* TUNNEL_MODE */
static __always_inline int do_netdev_encrypt_encap(struct __ctx_buff *ctx, __u32 src_id)
{
struct trace_ctx trace = {
.reason = TRACE_REASON_ENCRYPTED,
.monitor = 0,
};
struct remote_endpoint_info *ep = NULL;
void *data, *data_end;
struct ipv6hdr *ip6 __maybe_unused;
struct iphdr *ip4 __maybe_unused;
__u16 proto;
if (!validate_ethertype(ctx, &proto))
return DROP_UNSUPPORTED_L2;
switch (proto) {
# ifdef ENABLE_IPV6
case bpf_htons(ETH_P_IPV6):
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
ep = lookup_ip6_remote_endpoint((union v6addr *)&ip6->daddr);
break;
# endif /* ENABLE_IPV6 */
# ifdef ENABLE_IPV4
case bpf_htons(ETH_P_IP):
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
ep = lookup_ip4_remote_endpoint(ip4->daddr);
break;
# endif /* ENABLE_IPV4 */
}
if (!ep || !ep->tunnel_endpoint)
return DROP_NO_TUNNEL_ENDPOINT;
ctx->mark = 0;
bpf_clear_meta(ctx);
return __encap_and_redirect_with_nodeid(ctx, ep->tunnel_endpoint, src_id,
0, NOT_VTEP_DST, &trace);
}
static __always_inline int do_netdev_encrypt(struct __ctx_buff *ctx,
__u32 src_id)
{
return do_netdev_encrypt_encap(ctx, src_id);
}
#endif /* TUNNEL_MODE */
#endif /* ENABLE_IPSEC */
static __always_inline int
do_netdev(struct __ctx_buff *ctx, __u16 proto, const bool from_host)
{
__u32 __maybe_unused identity = 0;
__u32 __maybe_unused ipcache_srcid = 0;
void __maybe_unused *data, *data_end;
struct ipv6hdr __maybe_unused *ip6;
struct iphdr __maybe_unused *ip4;
int ret;
#if defined(ENABLE_L7_LB)
if (from_host) {
__u32 magic = ctx->mark & MARK_MAGIC_HOST_MASK;
if (magic == MARK_MAGIC_PROXY_EGRESS_EPID) {
__u32 lxc_id = get_epid(ctx);
ctx->mark = 0;
tail_call_dynamic(ctx, &POLICY_EGRESSCALL_MAP, lxc_id);
return send_drop_notify_error(ctx, identity, DROP_MISSED_TAIL_CALL,
CTX_ACT_DROP, METRIC_EGRESS);
}
}
#endif
#ifdef ENABLE_IPSEC
if (!from_host && !do_decrypt(ctx, proto))
return CTX_ACT_OK;
#endif
if (from_host) {
__u32 magic;
enum trace_point trace = TRACE_FROM_HOST;
magic = inherit_identity_from_host(ctx, &identity);
if (magic == MARK_MAGIC_PROXY_INGRESS || magic == MARK_MAGIC_PROXY_EGRESS)
trace = TRACE_FROM_PROXY;
#ifdef ENABLE_IPSEC
if (magic == MARK_MAGIC_ENCRYPT) {
send_trace_notify(ctx, TRACE_FROM_STACK, identity, 0, 0,
ctx->ingress_ifindex, TRACE_REASON_ENCRYPTED, 0);
ret = do_netdev_encrypt(ctx, identity);
if (IS_ERR(ret))
return send_drop_notify_error(ctx, identity, ret,
CTX_ACT_DROP, METRIC_EGRESS);
return ret;
}
#endif
send_trace_notify(ctx, trace, identity, 0, 0,
ctx->ingress_ifindex,
TRACE_REASON_UNKNOWN, TRACE_PAYLOAD_LEN);
} else {
ctx_skip_nodeport_clear(ctx);
send_trace_notify(ctx, TRACE_FROM_NETWORK, 0, 0, 0,
ctx->ingress_ifindex,
TRACE_REASON_UNKNOWN, TRACE_PAYLOAD_LEN);
}
bpf_clear_meta(ctx);
switch (proto) {
# if defined ENABLE_ARP_PASSTHROUGH || defined ENABLE_ARP_RESPONDER
case bpf_htons(ETH_P_ARP):
ret = CTX_ACT_OK;
break;
# endif
#ifdef ENABLE_IPV6
case bpf_htons(ETH_P_IPV6):
if (!revalidate_data_pull(ctx, &data, &data_end, &ip6))
return send_drop_notify_error(ctx, identity, DROP_INVALID,
CTX_ACT_DROP, METRIC_INGRESS);
identity = resolve_srcid_ipv6(ctx, ip6, identity, from_host);
ctx_store_meta(ctx, CB_SRC_LABEL, identity);
if (from_host)
ep_tail_call(ctx, CILIUM_CALL_IPV6_FROM_HOST);
else
ep_tail_call(ctx, CILIUM_CALL_IPV6_FROM_NETDEV);
/* See comment below for IPv4. */
return send_drop_notify_error(ctx, identity, DROP_MISSED_TAIL_CALL,
CTX_ACT_OK, METRIC_INGRESS);
#endif
#ifdef ENABLE_IPV4
case bpf_htons(ETH_P_IP):
/* This is the first time revalidate_data() is going to be called.
* Make sure that we don't legitimately drop the packet if the skb
* arrived with the header not being not in the linear data.
*/
if (!revalidate_data_pull(ctx, &data, &data_end, &ip4))
return send_drop_notify_error(ctx, identity, DROP_INVALID,
CTX_ACT_DROP, METRIC_INGRESS);
identity = resolve_srcid_ipv4(ctx, ip4, identity, &ipcache_srcid,
from_host);
ctx_store_meta(ctx, CB_SRC_LABEL, identity);
if (from_host) {
# if defined(ENABLE_HOST_FIREWALL) && !defined(ENABLE_MASQUERADE)
/* If we don't rely on BPF-based masquerading, we need
* to pass the srcid from ipcache to host firewall. See
* comment in ipv4_host_policy_egress() for details.
*/
ctx_store_meta(ctx, CB_IPCACHE_SRC_LABEL, ipcache_srcid);
# endif
ep_tail_call(ctx, CILIUM_CALL_IPV4_FROM_HOST);
} else {
ep_tail_call(ctx, CILIUM_CALL_IPV4_FROM_NETDEV);
}
/* We are not returning an error here to always allow traffic to
* the stack in case maps have become unavailable.
*
* Note: Since drop notification requires a tail call as well,
* this notification is unlikely to succeed.
*/
return send_drop_notify_error(ctx, identity, DROP_MISSED_TAIL_CALL,
CTX_ACT_OK, METRIC_INGRESS);
#endif
default:
#ifdef ENABLE_HOST_FIREWALL
ret = send_drop_notify_error(ctx, identity, DROP_UNKNOWN_L3,
CTX_ACT_DROP, METRIC_INGRESS);
#else
/* Pass unknown traffic to the stack */
ret = CTX_ACT_OK;
#endif /* ENABLE_HOST_FIREWALL */
}
return ret;
}
/**
* handle_netdev
* @ctx The packet context for this program
* @from_host True if the packet is from the local host
*
* Handle netdev traffic coming towards the Cilium-managed network.
*/
static __always_inline int
handle_netdev(struct __ctx_buff *ctx, const bool from_host)
{
__u16 proto;
if (!validate_ethertype(ctx, &proto)) {
#ifdef ENABLE_HOST_FIREWALL
int ret = DROP_UNSUPPORTED_L2;
return send_drop_notify(ctx, SECLABEL, WORLD_ID, 0, ret,
CTX_ACT_DROP, METRIC_EGRESS);
#else
send_trace_notify(ctx, TRACE_TO_STACK, HOST_ID, 0, 0, 0,
TRACE_REASON_UNKNOWN, 0);
/* Pass unknown traffic to the stack */
return CTX_ACT_OK;
#endif /* ENABLE_HOST_FIREWALL */
}
return do_netdev(ctx, proto, from_host);
}
#ifdef ENABLE_SRV6
static __always_inline int
handle_srv6(struct __ctx_buff *ctx)
{
__u32 *vrf_id, dst_id;
struct srv6_ipv6_2tuple *outer_ips;
struct iphdr *ip4 __maybe_unused;
struct remote_endpoint_info *ep;
void *data, *data_end;
struct ipv6hdr *ip6;
union v6addr *sid;
__u16 proto;
if (!validate_ethertype(ctx, &proto))
return DROP_UNSUPPORTED_L2;
switch (proto) {
case bpf_htons(ETH_P_IPV6):
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
outer_ips = srv6_lookup_state_entry6(ip6);
if (outer_ips) {
ep_tail_call(ctx, CILIUM_CALL_SRV6_REPLY);
return DROP_MISSED_TAIL_CALL;
}
ep = lookup_ip6_remote_endpoint((union v6addr *)&ip6->daddr);