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bpf_host.c
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bpf_host.c
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// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2016-2020 Authors of Cilium */
#include <bpf/ctx/skb.h>
#include <bpf/api.h>
#include <node_config.h>
#ifdef POD_ENDPOINT
# include <netdev_config.h>
#else
# include <ep_config.h>
# define EVENT_SOURCE HOST_EP_ID
#endif
/* These are configuartion 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
/* Include policy_can_access_ingress() */
#define REQUIRES_CAN_ACCESS
/* CB_PROXY_MAGIC overlaps with CB_ENCRYPT_MAGIC */
#define ENCRYPT_OR_PROXY_MAGIC 0
#ifdef POD_ENDPOINT
# undef ENABLE_HOST_FIREWALL
#endif
#include "lib/utils.h"
#include "lib/common.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"
#ifdef ENABLE_HOST_FIREWALL
# include "lib/policy.h"
# include "lib/policy_log.h"
#endif
#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;
}
#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 droppped. */
if (*identity == HOST_ID)
return DROP_INVALID_IDENTITY;
}
return 0;
}
# ifdef ENABLE_HOST_FIREWALL
static __always_inline __u32
ipcache_lookup_srcid6(struct __ctx_buff *ctx)
{
struct remote_endpoint_info *info = NULL;
void *data, *data_end;
struct ipv6hdr *ip6;
__u32 srcid = 0;
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
info = lookup_ip6_remote_endpoint((union v6addr *) &ip6->saddr);
if (info != NULL)
srcid = info->sec_label;
cilium_dbg(ctx, info ? DBG_IP_ID_MAP_SUCCEED6 : DBG_IP_ID_MAP_FAILED6,
ip6->saddr.s6_addr32[3], srcid);
return srcid;
}
# endif /* ENABLE_HOST_FIREWALL */
static __always_inline __u32
resolve_srcid_ipv6(struct __ctx_buff *ctx, __u32 srcid_from_proxy,
bool from_host)
{
__u32 src_id = WORLD_ID, srcid_from_ipcache = srcid_from_proxy;
struct remote_endpoint_info *info = NULL;
void *data, *data_end;
struct ipv6hdr *ip6;
union v6addr *src;
int ret;
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
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 != NULL && info->sec_label)
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;
#ifdef ENABLE_SECCTX_FROM_IPCACHE
/* If we could not derive the secctx from the packet itself but
* from the ipcache instead, then use the ipcache identity. E.g.
* used in ipvlan master device's datapath on ingress.
*/
else if (src_id == WORLD_ID && !identity_is_reserved(srcid_from_ipcache))
src_id = srcid_from_ipcache;
#endif
return src_id;
}
#ifdef ENABLE_HOST_FIREWALL
static __always_inline int
ipv6_host_policy_egress(struct __ctx_buff *ctx, __u32 srcID)
{
int ret, verdict, l3_off = ETH_HLEN, l4_off, hdrlen;
struct ct_state ct_state_new = {}, ct_state = {};
__u8 policy_match_type = POLICY_MATCH_NONE;
struct remote_endpoint_info *info;
struct ipv6_ct_tuple tuple = {};
__u32 dstID = 0, monitor = 0;
union v6addr orig_dip;
void *data, *data_end;
struct ipv6hdr *ip6;
/* Only enforce host policies for packets from host IPs. */
if (srcID != HOST_ID)
return CTX_ACT_OK;
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
/* Lookup connection in conntrack map. */
tuple.nexthdr = ip6->nexthdr;
ipv6_addr_copy(&tuple.daddr, (union v6addr *) &ip6->daddr);
ipv6_addr_copy(&orig_dip, (union v6addr *) &ip6->daddr);
hdrlen = ipv6_hdrlen(ctx, ETH_HLEN, &tuple.nexthdr);
if (hdrlen < 0)
return hdrlen;
l4_off = l3_off + hdrlen;
ret = ct_lookup6(get_ct_map6(&tuple), &tuple, ctx, l4_off, CT_EGRESS,
&ct_state, &monitor);
if (ret < 0)
return ret;
/* Retrieve destination identity. */
info = lookup_ip6_remote_endpoint(&orig_dip);
if (info != NULL && info->sec_label)
dstID = info->sec_label;
cilium_dbg(ctx, info ? DBG_IP_ID_MAP_SUCCEED6 : DBG_IP_ID_MAP_FAILED6,
orig_dip.p4, dstID);
/* Perform policy lookup. */
verdict = policy_can_egress6(ctx, &tuple, srcID, dstID,
&policy_match_type);
/* Reply traffic and related are allowed regardless of policy verdict. */
if (ret != CT_REPLY && ret != CT_RELATED && verdict < 0) {
send_policy_verdict_notify(ctx, dstID, tuple.dport,
tuple.nexthdr, POLICY_EGRESS, 1,
verdict, policy_match_type);
return verdict;
}
switch (ret) {
case CT_NEW:
send_policy_verdict_notify(ctx, dstID, tuple.dport,
tuple.nexthdr, POLICY_EGRESS, 1,
verdict, policy_match_type);
ct_state_new.src_sec_id = HOST_ID;
ret = ct_create6(get_ct_map6(&tuple), &CT_MAP_ANY6, &tuple,
ctx, CT_EGRESS, &ct_state_new, verdict > 0);
if (IS_ERR(ret))
return ret;
break;
case CT_ESTABLISHED:
case CT_RELATED:
case CT_REPLY:
break;
default:
return DROP_UNKNOWN_CT;
}
return CTX_ACT_OK;
}
static __always_inline int
ipv6_host_policy_ingress(struct __ctx_buff *ctx, __u32 *srcID)
{
struct ct_state ct_state_new = {}, ct_state = {};
__u8 policy_match_type = POLICY_MATCH_NONE;
__u32 monitor = 0, dstID = WORLD_ID;
struct remote_endpoint_info *info;
int ret, verdict, l4_off, hdrlen;
struct ipv6_ct_tuple tuple = {};
union v6addr orig_sip;
void *data, *data_end;
struct ipv6hdr *ip6;
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
/* Retrieve destination identity. */
ipv6_addr_copy(&tuple.daddr, (union v6addr *) &ip6->daddr);
info = lookup_ip6_remote_endpoint(&tuple.daddr);
if (info != NULL && info->sec_label)
dstID = info->sec_label;
cilium_dbg(ctx, info ? DBG_IP_ID_MAP_SUCCEED6 : DBG_IP_ID_MAP_FAILED6,
tuple.daddr.p4, dstID);
/* Only enforce host policies for packets to host IPs. */
if (dstID != HOST_ID)
return CTX_ACT_OK;
/* Lookup connection in conntrack map. */
tuple.nexthdr = ip6->nexthdr;
ipv6_addr_copy(&tuple.saddr, (union v6addr *) &ip6->saddr);
ipv6_addr_copy(&orig_sip, (union v6addr *) &ip6->saddr);
hdrlen = ipv6_hdrlen(ctx, ETH_HLEN, &tuple.nexthdr);
if (hdrlen < 0)
return hdrlen;
l4_off = ETH_HLEN + hdrlen;
ret = ct_lookup6(get_ct_map6(&tuple), &tuple, ctx, l4_off, CT_INGRESS,
&ct_state, &monitor);
if (ret < 0)
return ret;
/* Retrieve source identity. */
info = lookup_ip6_remote_endpoint(&orig_sip);
if (info != NULL && info->sec_label)
*srcID = info->sec_label;
cilium_dbg(ctx, info ? DBG_IP_ID_MAP_SUCCEED6 : DBG_IP_ID_MAP_FAILED6,
orig_sip.p4, *srcID);
/* Perform policy lookup */
verdict = policy_can_access_ingress(ctx, *srcID, dstID, tuple.dport,
tuple.nexthdr, false,
&policy_match_type);
/* Reply traffic and related are allowed regardless of policy verdict. */
if (ret != CT_REPLY && ret != CT_RELATED && verdict < 0) {
send_policy_verdict_notify(ctx, *srcID, tuple.dport,
tuple.nexthdr, POLICY_INGRESS, 1,
verdict, policy_match_type);
return verdict;
}
switch (ret) {
case CT_NEW:
send_policy_verdict_notify(ctx, *srcID, tuple.dport,
tuple.nexthdr, POLICY_INGRESS, 1,
verdict, policy_match_type);
/* Create new entry for connection in conntrack map. */
ct_state_new.src_sec_id = *srcID;
ct_state_new.node_port = ct_state.node_port;
ret = ct_create6(get_ct_map6(&tuple), &CT_MAP_ANY6, &tuple,
ctx, CT_INGRESS, &ct_state_new, verdict > 0);
if (IS_ERR(ret))
return ret;
case CT_ESTABLISHED:
case CT_RELATED:
case CT_REPLY:
break;
default:
return DROP_UNKNOWN_CT;
}
return CTX_ACT_OK;
}
#endif /* ENABLE_HOST_FIREWALL */
static __always_inline int
handle_ipv6(struct __ctx_buff *ctx, __u32 secctx, bool from_host)
{
struct remote_endpoint_info *info = NULL;
void *data, *data_end;
struct ipv6hdr *ip6;
union v6addr *dst;
int ret, l3_off = ETH_HLEN, hdrlen;
__u32 __maybe_unused remoteID = WORLD_ID;
bool skip_redirect = false;
struct endpoint_info *ep;
__u8 nexthdr;
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
#ifdef ENABLE_NODEPORT
if (!from_host) {
if (ctx_get_xfer(ctx) != XFER_PKT_NO_SVC &&
!bpf_skip_nodeport(ctx)) {
ret = nodeport_lb6(ctx, secctx);
if (ret < 0)
return ret;
}
#if defined(ENCAP_IFINDEX) || defined(NO_REDIRECT)
/* See IPv4 case for NO_REDIRECT comments */
# ifdef ENABLE_HOST_FIREWALL
skip_redirect = true;
# else
return CTX_ACT_OK;
# endif
#endif /* ENCAP_IFINDEX || NO_REDIRECT */
/* Verifier workaround: modified ctx access. */
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
}
#endif /* ENABLE_NODEPORT */
nexthdr = ip6->nexthdr;
hdrlen = ipv6_hdrlen(ctx, l3_off, &nexthdr);
if (hdrlen < 0)
return hdrlen;
#ifdef HANDLE_NS
if (!skip_redirect && unlikely(nexthdr == IPPROTO_ICMPV6)) {
ret = icmp6_handle(ctx, ETH_HLEN, ip6, METRIC_INGRESS);
if (IS_ERR(ret))
return ret;
}
#endif
if (from_host && !skip_redirect) {
/* 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;
}
#ifdef ENABLE_HOST_FIREWALL
if (from_host)
ret = ipv6_host_policy_egress(ctx, secctx);
else
ret = ipv6_host_policy_ingress(ctx, &remoteID);
if (IS_ERR(ret))
return ret;
if (skip_redirect)
return CTX_ACT_OK;
if (!revalidate_data(ctx, &data, &data_end, &ip6))
return DROP_INVALID;
#endif /* ENABLE_HOST_FIREWALL */
/* Lookup IPv4 address in list of local endpoints */
if ((ep = lookup_ip6_endpoint(ip6)) != NULL) {
/* 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);
}
#ifdef ENCAP_IFINDEX
dst = (union v6addr *) &ip6->daddr;
info = ipcache_lookup6(&IPCACHE_MAP, dst, V6_CACHE_KEY_LEN);
if (info != NULL && info->tunnel_endpoint != 0) {
ret = encap_and_redirect_with_nodeid(ctx, info->tunnel_endpoint,
info->key,
secctx, TRACE_PAYLOAD_LEN);
/* If IPSEC is needed recirc through ingress to use xfrm stack
* and then result will routed back through bpf_netdev on egress
* but with encrypt marks.
*/
if (ret == IPSEC_ENDPOINT)
return CTX_ACT_OK;
else
return ret;
} else {
struct endpoint_key key = {};
/* IPv6 lookup key: daddr/96 */
dst = (union v6addr *) &ip6->daddr;
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, secctx, TRACE_PAYLOAD_LEN);
if (ret == IPSEC_ENDPOINT)
return CTX_ACT_OK;
else if (ret != DROP_NO_TUNNEL_ENDPOINT)
return ret;
}
#endif
dst = (union v6addr *) &ip6->daddr;
info = ipcache_lookup6(&IPCACHE_MAP, dst, V6_CACHE_KEY_LEN);
if (from_host && (info == NULL || info->sec_label == WORLD_ID)) {
/* See IPv4 comment. */
return DROP_UNROUTABLE;
}
#ifdef ENABLE_IPSEC
if (info && info->key && info->tunnel_endpoint) {
__u8 key = get_min_encrypt_key(info->key);
set_encrypt_key_meta(ctx, key);
#ifdef IP_POOLS
set_encrypt_dip(ctx, info->tunnel_endpoint);
#else
set_identity_meta(ctx, secctx);
#endif
}
#endif
return CTX_ACT_OK;
}
static __always_inline int
tail_handle_ipv6(struct __ctx_buff *ctx, bool from_host)
{
__u32 proxy_identity = ctx_load_meta(ctx, CB_SRC_IDENTITY);
int ret;
ctx_store_meta(ctx, CB_SRC_IDENTITY, 0);
ret = handle_ipv6(ctx, proxy_identity, from_host);
if (IS_ERR(ret))
return send_drop_notify_error(ctx, proxy_identity, ret,
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_LXC)
int tail_handle_ipv6_from_netdev(struct __ctx_buff *ctx)
{
return tail_handle_ipv6(ctx, false);
}
#endif /* ENABLE_IPV6 */
#ifdef ENABLE_IPV4
# ifdef ENABLE_HOST_FIREWALL
static __always_inline __u32
ipcache_lookup_srcid4(struct __ctx_buff *ctx)
{
struct remote_endpoint_info *info = NULL;
void *data, *data_end;
struct iphdr *ip4;
__u32 srcid = 0;
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
info = lookup_ip4_remote_endpoint(ip4->saddr);
if (info != NULL)
srcid = info->sec_label;
cilium_dbg(ctx, info ? DBG_IP_ID_MAP_SUCCEED4 : DBG_IP_ID_MAP_FAILED4,
ip4->saddr, srcid);
return srcid;
}
# endif /* ENABLE_HOST_FIREWALL */
static __always_inline __u32
resolve_srcid_ipv4(struct __ctx_buff *ctx, __u32 srcid_from_proxy,
bool from_host)
{
__u32 src_id = WORLD_ID, srcid_from_ipcache = srcid_from_proxy;
struct remote_endpoint_info *info = NULL;
void *data, *data_end;
struct iphdr *ip4;
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
/* 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) {
__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
* "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.
*/
#ifndef ENABLE_EXTRA_HOST_DEV
if (from_host && sec_label != HOST_ID)
#endif
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;
#ifdef ENABLE_SECCTX_FROM_IPCACHE
/* If we could not derive the secctx from the packet itself but
* from the ipcache instead, then use the ipcache identity. E.g.
* used in ipvlan master device's datapath on ingress.
*/
else if (!identity_is_reserved(srcid_from_ipcache))
src_id = srcid_from_ipcache;
#endif
return src_id;
}
#ifdef ENABLE_HOST_FIREWALL
static __always_inline int
ipv4_host_policy_egress(struct __ctx_buff *ctx, __u32 srcID)
{
struct ct_state ct_state_new = {}, ct_state = {};
int ret, verdict, l4_off, l3_off = ETH_HLEN;
__u8 policy_match_type = POLICY_MATCH_NONE;
struct remote_endpoint_info *info;
struct ipv4_ct_tuple tuple = {};
__u32 dstID = 0, monitor = 0;
void *data, *data_end;
struct iphdr *ip4;
/* Only enforce host policies for packets from host IPs. */
if (srcID != HOST_ID)
return CTX_ACT_OK;
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
/* Lookup connection in conntrack map. */
tuple.nexthdr = ip4->protocol;
tuple.daddr = ip4->daddr;
tuple.saddr = ip4->saddr;
l4_off = l3_off + ipv4_hdrlen(ip4);
ret = ct_lookup4(get_ct_map4(&tuple), &tuple, ctx, l4_off, CT_EGRESS,
&ct_state, &monitor);
if (ret < 0)
return ret;
/* Retrieve destination identity. */
info = lookup_ip4_remote_endpoint(ip4->daddr);
if (info != NULL && info->sec_label)
dstID = info->sec_label;
cilium_dbg(ctx, info ? DBG_IP_ID_MAP_SUCCEED4 : DBG_IP_ID_MAP_FAILED4,
ip4->daddr, dstID);
/* Perform policy lookup. */
verdict = policy_can_egress4(ctx, &tuple, srcID, dstID,
&policy_match_type);
/* Reply traffic and related are allowed regardless of policy verdict. */
if (ret != CT_REPLY && ret != CT_RELATED && verdict < 0) {
send_policy_verdict_notify(ctx, dstID, tuple.dport,
tuple.nexthdr, POLICY_EGRESS, 0,
verdict, policy_match_type);
return verdict;
}
switch (ret) {
case CT_NEW:
send_policy_verdict_notify(ctx, dstID, tuple.dport,
tuple.nexthdr, POLICY_EGRESS, 0,
verdict, policy_match_type);
ct_state_new.src_sec_id = HOST_ID;
ret = ct_create4(get_ct_map4(&tuple), &CT_MAP_ANY4, &tuple,
ctx, CT_EGRESS, &ct_state_new, verdict > 0);
if (IS_ERR(ret))
return ret;
break;
case CT_ESTABLISHED:
case CT_RELATED:
case CT_REPLY:
break;
default:
return DROP_UNKNOWN_CT;
}
return CTX_ACT_OK;
}
static __always_inline int
ipv4_host_policy_ingress(struct __ctx_buff *ctx, __u32 *srcID)
{
struct ct_state ct_state_new = {}, ct_state = {};
int ret, verdict, l4_off, l3_off = ETH_HLEN;
__u8 policy_match_type = POLICY_MATCH_NONE;
__u32 monitor = 0, dstID = WORLD_ID;
struct remote_endpoint_info *info;
struct ipv4_ct_tuple tuple = {};
bool is_untracked_fragment = false;
void *data, *data_end;
struct iphdr *ip4;
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
/* Retrieve destination identity. */
info = lookup_ip4_remote_endpoint(ip4->daddr);
if (info != NULL && info->sec_label)
dstID = info->sec_label;
cilium_dbg(ctx, info ? DBG_IP_ID_MAP_SUCCEED4 : DBG_IP_ID_MAP_FAILED4,
ip4->daddr, dstID);
/* Only enforce host policies for packets to host IPs. */
if (dstID != HOST_ID)
return CTX_ACT_OK;
/* Lookup connection in conntrack map. */
tuple.nexthdr = ip4->protocol;
tuple.daddr = ip4->daddr;
tuple.saddr = ip4->saddr;
l4_off = l3_off + ipv4_hdrlen(ip4);
#ifndef IPV4_FRAGMENTS
/* Indicate that this is a datagram fragment for which we cannot
* retrieve L4 ports. Do not set flag if we support fragmentation.
*/
is_untracked_fragment = ipv4_is_fragment(ip4);
#endif
ret = ct_lookup4(get_ct_map4(&tuple), &tuple, ctx, l4_off, CT_INGRESS,
&ct_state, &monitor);
if (ret < 0)
return ret;
/* Retrieve source identity. */
info = lookup_ip4_remote_endpoint(ip4->saddr);
if (info != NULL && info->sec_label)
*srcID = info->sec_label;
cilium_dbg(ctx, info ? DBG_IP_ID_MAP_SUCCEED4 : DBG_IP_ID_MAP_FAILED4,
ip4->saddr, *srcID);
/* Perform policy lookup */
verdict = policy_can_access_ingress(ctx, *srcID, dstID, tuple.dport,
tuple.nexthdr,
is_untracked_fragment,
&policy_match_type);
/* Reply traffic and related are allowed regardless of policy verdict. */
if (ret != CT_REPLY && ret != CT_RELATED && verdict < 0) {
send_policy_verdict_notify(ctx, *srcID, tuple.dport,
tuple.nexthdr, POLICY_INGRESS, 0,
verdict, policy_match_type);
return verdict;
}
switch (ret) {
case CT_NEW:
send_policy_verdict_notify(ctx, *srcID, tuple.dport,
tuple.nexthdr, POLICY_INGRESS, 0,
verdict, policy_match_type);
/* Create new entry for connection in conntrack map. */
ct_state_new.src_sec_id = *srcID;
ct_state_new.node_port = ct_state.node_port;
ret = ct_create4(get_ct_map4(&tuple), &CT_MAP_ANY4, &tuple,
ctx, CT_INGRESS, &ct_state_new, verdict > 0);
if (IS_ERR(ret))
return ret;
case CT_ESTABLISHED:
case CT_RELATED:
case CT_REPLY:
break;
default:
return DROP_UNKNOWN_CT;
}
return CTX_ACT_OK;
}
#endif /* ENABLE_HOST_FIREWALL */
static __always_inline int
handle_ipv4(struct __ctx_buff *ctx, __u32 secctx, bool from_host)
{
struct remote_endpoint_info *info = NULL;
__u32 __maybe_unused remoteID = 0;
struct ipv4_ct_tuple tuple = {};
bool skip_redirect = false;
struct endpoint_info *ep;
void *data, *data_end;
struct iphdr *ip4;
int ret;
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
#ifdef ENABLE_NODEPORT
if (!from_host) {
if (ctx_get_xfer(ctx) != XFER_PKT_NO_SVC &&
!bpf_skip_nodeport(ctx)) {
ret = nodeport_lb4(ctx, secctx);
if (ret < 0)
return ret;
}
#if defined(ENCAP_IFINDEX) || defined(NO_REDIRECT)
/* 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 DROPed by k8s's "--ctstate INVALID -j DROP"
* depending via which interface it was inputed. */
# ifdef ENABLE_HOST_FIREWALL
skip_redirect = true;
# else
return CTX_ACT_OK;
#endif /* ENABLE_HOST_FIREWALL */
#endif /* ENCAP_IFINDEX || NO_REDIRECT */
/* Verifier workaround: modified ctx access. */
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
}
#endif /* ENABLE_NODEPORT */
tuple.nexthdr = ip4->protocol;
if (from_host && !skip_redirect) {
/* 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;
}
#ifdef ENABLE_HOST_FIREWALL
if (from_host)
/* We're on the egress path of cilium_host. */
ret = ipv4_host_policy_egress(ctx, secctx);
else
/* We're on the ingress path of the native device. */
ret = ipv4_host_policy_ingress(ctx, &remoteID);
if (IS_ERR(ret))
return ret;
if (skip_redirect)
return CTX_ACT_OK;
if (!revalidate_data(ctx, &data, &data_end, &ip4))
return DROP_INVALID;
#endif /* ENABLE_HOST_FIREWALL */
/* Lookup IPv4 address in list of local endpoints and host IPs */
if ((ep = lookup_ip4_endpoint(ip4)) != NULL) {
/* Let through packets to the node-ip so they are
* processed by the local ip stack */
if (ep->flags & ENDPOINT_F_HOST)
#ifdef HOST_REDIRECT_TO_INGRESS
/* This is required for L7 proxy to send packets to the host. */
return redirect(HOST_IFINDEX, BPF_F_INGRESS);
#else
return CTX_ACT_OK;
#endif
return ipv4_local_delivery(ctx, ETH_HLEN, secctx, ip4, ep,
METRIC_INGRESS, from_host);
}
#ifdef ENCAP_IFINDEX
info = ipcache_lookup4(&IPCACHE_MAP, ip4->daddr, V4_CACHE_KEY_LEN);
if (info != NULL && info->tunnel_endpoint != 0) {
ret = encap_and_redirect_with_nodeid(ctx, info->tunnel_endpoint,
info->key, secctx,
TRACE_PAYLOAD_LEN);
if (ret == IPSEC_ENDPOINT)
return CTX_ACT_OK;
else
return ret;
} else {
/* IPv4 lookup key: daddr & IPV4_MASK */
struct endpoint_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, secctx, TRACE_PAYLOAD_LEN);
if (ret == IPSEC_ENDPOINT)
return CTX_ACT_OK;
else if (ret != DROP_NO_TUNNEL_ENDPOINT)
return ret;
}
#endif
#ifdef HOST_REDIRECT_TO_INGRESS
return redirect(HOST_IFINDEX, BPF_F_INGRESS);
#else
info = ipcache_lookup4(&IPCACHE_MAP, ip4->daddr, V4_CACHE_KEY_LEN);
if (from_host && (info == NULL || 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.
*/
return DROP_UNROUTABLE;
}
#ifdef ENABLE_IPSEC
if (info && info->key && info->tunnel_endpoint) {
__u8 key = get_min_encrypt_key(info->key);
set_encrypt_key_meta(ctx, key);
#ifdef IP_POOLS
set_encrypt_dip(ctx, info->tunnel_endpoint);
#else
set_identity_meta(ctx, secctx);
#endif
}
#endif
return CTX_ACT_OK;
#endif
}
static __always_inline int
tail_handle_ipv4(struct __ctx_buff *ctx, bool from_host)
{
__u32 proxy_identity = ctx_load_meta(ctx, CB_SRC_IDENTITY);
int ret;
ctx_store_meta(ctx, CB_SRC_IDENTITY, 0);
ret = handle_ipv4(ctx, proxy_identity, from_host);
if (IS_ERR(ret))
return send_drop_notify_error(ctx, proxy_identity,
ret, 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)
{
return tail_handle_ipv4(ctx, true);
}
__section_tail(CILIUM_MAP_CALLS, CILIUM_CALL_IPV4_FROM_LXC)
int tail_handle_ipv4_from_netdev(struct __ctx_buff *ctx)
{
return tail_handle_ipv4(ctx, false);
}
#endif /* ENABLE_IPV4 */
#ifdef ENABLE_IPSEC
#ifndef ENCAP_IFINDEX
static __always_inline int
do_netdev_encrypt_pools(struct __ctx_buff *ctx __maybe_unused)
{
int ret = 0;
#ifdef IP_POOLS
__u32 tunnel_endpoint = 0;
void *data, *data_end;
__u32 tunnel_source = IPV4_ENCRYPT_IFACE;
struct iphdr *iphdr;
__be32 sum;
tunnel_endpoint = ctx_load_meta(ctx, 4);
ctx->mark = 0;
if (!revalidate_data(ctx, &data, &data_end, &iphdr)) {
ret = DROP_INVALID;
goto drop_err;
}
/* 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(&iphdr->daddr, 4, &tunnel_endpoint, 4, 0);
if (ctx_store_bytes(ctx, ETH_HLEN + offsetof(struct iphdr, daddr),
&tunnel_endpoint, 4, 0) < 0) {
ret = DROP_WRITE_ERROR;
goto drop_err;
}
if (l3_csum_replace(ctx, ETH_HLEN + offsetof(struct iphdr, check),
0, sum, 0) < 0) {
ret = DROP_CSUM_L3;
goto drop_err;
}
if (!revalidate_data(ctx, &data, &data_end, &iphdr)) {
ret = DROP_INVALID;
goto drop_err;
}
sum = csum_diff(&iphdr->saddr, 4, &tunnel_source, 4, 0);
if (ctx_store_bytes(ctx, ETH_HLEN + offsetof(struct iphdr, saddr),
&tunnel_source, 4, 0) < 0) {
ret = DROP_WRITE_ERROR;
goto drop_err;
}
if (l3_csum_replace(ctx, ETH_HLEN + offsetof(struct iphdr, check),
0, sum, 0) < 0) {
ret = DROP_CSUM_L3;
goto drop_err;
}
drop_err:
#endif /* IP_POOLS */
return ret;
}
static __always_inline int
do_netdev_encrypt_fib(struct __ctx_buff *ctx __maybe_unused,
__u16 proto __maybe_unused,
int *encrypt_iface __maybe_unused)
{
int ret = 0;
#ifdef BPF_HAVE_FIB_LOOKUP
struct bpf_fib_lookup fib_params = {};
void *data, *data_end;
int err;
if (proto == bpf_htons(ETH_P_IP)) {
struct iphdr *ip4;
if (!revalidate_data(ctx, &data, &data_end, &ip4)) {
ret = DROP_INVALID;
goto drop_err_fib;
}
fib_params.family = AF_INET;
fib_params.ipv4_src = ip4->saddr;
fib_params.ipv4_dst = ip4->daddr;
} else {
struct ipv6hdr *ip6;
if (!revalidate_data(ctx, &data, &data_end, &ip6)) {
ret = DROP_INVALID;
goto drop_err_fib;
}