vmlinux.h declarations are more ergnomic, especially when working with kfuncs. The uapi headers are often incomplete for kfunc definitions.
This commit also switches bitfield accesses to use CO-RE helpers. Switching to vmlinux.h definitions makes the verifier very unhappy with raw bitfield accesses. The error is:
; md.u.md2.dir = direction; 33: (69) r1 = *(u16 *)(r2 +11) misaligned stack access off (0x0; 0x0)+-64+11 size 2
Fix by using CO-RE-aware bitfield reads and writes.
Co-developed-by: Antony Antony antony.antony@secunet.com Signed-off-by: Antony Antony antony.antony@secunet.com Signed-off-by: Daniel Xu dxu@dxuuu.xyz --- .../selftests/bpf/progs/bpf_tracing_net.h | 1 + .../selftests/bpf/progs/test_tunnel_kern.c | 76 +++++-------------- 2 files changed, 22 insertions(+), 55 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h index 0b793a102791..1bdc680b0e0e 100644 --- a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h +++ b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h @@ -26,6 +26,7 @@ #define IPV6_AUTOFLOWLABEL 70
#define TC_ACT_UNSPEC (-1) +#define TC_ACT_OK 0 #define TC_ACT_SHOT 2
#define SOL_TCP 6 diff --git a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c index f66af753bbbb..b320fb7bb080 100644 --- a/tools/testing/selftests/bpf/progs/test_tunnel_kern.c +++ b/tools/testing/selftests/bpf/progs/test_tunnel_kern.c @@ -6,62 +6,26 @@ * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. */ -#include <stddef.h> -#include <string.h> -#include <arpa/inet.h> -#include <linux/bpf.h> -#include <linux/if_ether.h> -#include <linux/if_packet.h> -#include <linux/if_tunnel.h> -#include <linux/ip.h> -#include <linux/ipv6.h> -#include <linux/icmp.h> -#include <linux/types.h> -#include <linux/socket.h> -#include <linux/pkt_cls.h> -#include <linux/erspan.h> -#include <linux/udp.h> +#include "vmlinux.h" +#include <bpf/bpf_core_read.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_endian.h> +#include "bpf_kfuncs.h" +#include "bpf_tracing_net.h"
#define log_err(__ret) bpf_printk("ERROR line:%d ret:%d\n", __LINE__, __ret)
-#define VXLAN_UDP_PORT 4789 +#define VXLAN_UDP_PORT 4789 +#define ETH_P_IP 0x0800 +#define PACKET_HOST 0 +#define TUNNEL_CSUM bpf_htons(0x01) +#define TUNNEL_KEY bpf_htons(0x04)
/* Only IPv4 address assigned to veth1. * 172.16.1.200 */ #define ASSIGNED_ADDR_VETH1 0xac1001c8
-struct geneve_opt { - __be16 opt_class; - __u8 type; - __u8 length:5; - __u8 r3:1; - __u8 r2:1; - __u8 r1:1; - __u8 opt_data[8]; /* hard-coded to 8 byte */ -}; - -struct vxlanhdr { - __be32 vx_flags; - __be32 vx_vni; -} __attribute__((packed)); - -struct vxlan_metadata { - __u32 gbp; -}; - -struct bpf_fou_encap { - __be16 sport; - __be16 dport; -}; - -enum bpf_fou_encap_type { - FOU_BPF_ENCAP_FOU, - FOU_BPF_ENCAP_GUE, -}; - int bpf_skb_set_fou_encap(struct __sk_buff *skb_ctx, struct bpf_fou_encap *encap, int type) __ksym; int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx, @@ -205,9 +169,9 @@ int erspan_set_tunnel(struct __sk_buff *skb) __u8 hwid = 7;
md.version = 2; - md.u.md2.dir = direction; - md.u.md2.hwid = hwid & 0xf; - md.u.md2.hwid_upper = (hwid >> 4) & 0x3; + BPF_CORE_WRITE_BITFIELD(&md.u.md2, dir, direction); + BPF_CORE_WRITE_BITFIELD(&md.u.md2, hwid, (hwid & 0xf)); + BPF_CORE_WRITE_BITFIELD(&md.u.md2, hwid_upper, (hwid >> 4) & 0x3); #endif
ret = bpf_skb_set_tunnel_opt(skb, &md, sizeof(md)); @@ -246,8 +210,9 @@ int erspan_get_tunnel(struct __sk_buff *skb) bpf_printk("\tindex %x\n", index); #else bpf_printk("\tdirection %d hwid %x timestamp %u\n", - md.u.md2.dir, - (md.u.md2.hwid_upper << 4) + md.u.md2.hwid, + BPF_CORE_READ_BITFIELD(&md.u.md2, dir), + (BPF_CORE_READ_BITFIELD(&md.u.md2, hwid_upper) << 4) + + BPF_CORE_READ_BITFIELD(&md.u.md2, hwid), bpf_ntohl(md.u.md2.timestamp)); #endif
@@ -284,9 +249,9 @@ int ip4ip6erspan_set_tunnel(struct __sk_buff *skb) __u8 hwid = 17;
md.version = 2; - md.u.md2.dir = direction; - md.u.md2.hwid = hwid & 0xf; - md.u.md2.hwid_upper = (hwid >> 4) & 0x3; + BPF_CORE_WRITE_BITFIELD(&md.u.md2, dir, direction); + BPF_CORE_WRITE_BITFIELD(&md.u.md2, hwid, (hwid & 0xf)); + BPF_CORE_WRITE_BITFIELD(&md.u.md2, hwid_upper, (hwid >> 4) & 0x3); #endif
ret = bpf_skb_set_tunnel_opt(skb, &md, sizeof(md)); @@ -326,8 +291,9 @@ int ip4ip6erspan_get_tunnel(struct __sk_buff *skb) bpf_printk("\tindex %x\n", index); #else bpf_printk("\tdirection %d hwid %x timestamp %u\n", - md.u.md2.dir, - (md.u.md2.hwid_upper << 4) + md.u.md2.hwid, + BPF_CORE_READ_BITFIELD(&md.u.md2, dir), + (BPF_CORE_READ_BITFIELD(&md.u.md2, hwid_upper) << 4) + + BPF_CORE_READ_BITFIELD(&md.u.md2, hwid), bpf_ntohl(md.u.md2.timestamp)); #endif