diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /samples/bpf/tcbpf1_kern.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | samples/bpf/tcbpf1_kern.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/samples/bpf/tcbpf1_kern.c b/samples/bpf/tcbpf1_kern.c new file mode 100644 index 000000000..e9356130f --- /dev/null +++ b/samples/bpf/tcbpf1_kern.c @@ -0,0 +1,91 @@ +#define KBUILD_MODNAME "foo" +#include <uapi/linux/bpf.h> +#include <uapi/linux/if_ether.h> +#include <uapi/linux/if_packet.h> +#include <uapi/linux/ip.h> +#include <uapi/linux/in.h> +#include <uapi/linux/tcp.h> +#include <uapi/linux/filter.h> +#include <uapi/linux/pkt_cls.h> +#include <bpf/bpf_helpers.h> +#include "bpf_legacy.h" + +/* compiler workaround */ +#define _htonl __builtin_bswap32 + +static inline void set_dst_mac(struct __sk_buff *skb, char *mac) +{ + bpf_skb_store_bytes(skb, 0, mac, ETH_ALEN, 1); +} + +#define IP_CSUM_OFF (ETH_HLEN + offsetof(struct iphdr, check)) +#define TOS_OFF (ETH_HLEN + offsetof(struct iphdr, tos)) + +static inline void set_ip_tos(struct __sk_buff *skb, __u8 new_tos) +{ + __u8 old_tos = load_byte(skb, TOS_OFF); + + bpf_l3_csum_replace(skb, IP_CSUM_OFF, htons(old_tos), htons(new_tos), 2); + bpf_skb_store_bytes(skb, TOS_OFF, &new_tos, sizeof(new_tos), 0); +} + +#define TCP_CSUM_OFF (ETH_HLEN + sizeof(struct iphdr) + offsetof(struct tcphdr, check)) +#define IP_SRC_OFF (ETH_HLEN + offsetof(struct iphdr, saddr)) + +#define IS_PSEUDO 0x10 + +static inline void set_tcp_ip_src(struct __sk_buff *skb, __u32 new_ip) +{ + __u32 old_ip = _htonl(load_word(skb, IP_SRC_OFF)); + + bpf_l4_csum_replace(skb, TCP_CSUM_OFF, old_ip, new_ip, IS_PSEUDO | sizeof(new_ip)); + bpf_l3_csum_replace(skb, IP_CSUM_OFF, old_ip, new_ip, sizeof(new_ip)); + bpf_skb_store_bytes(skb, IP_SRC_OFF, &new_ip, sizeof(new_ip), 0); +} + +#define TCP_DPORT_OFF (ETH_HLEN + sizeof(struct iphdr) + offsetof(struct tcphdr, dest)) +static inline void set_tcp_dest_port(struct __sk_buff *skb, __u16 new_port) +{ + __u16 old_port = htons(load_half(skb, TCP_DPORT_OFF)); + + bpf_l4_csum_replace(skb, TCP_CSUM_OFF, old_port, new_port, sizeof(new_port)); + bpf_skb_store_bytes(skb, TCP_DPORT_OFF, &new_port, sizeof(new_port), 0); +} + +SEC("classifier") +int bpf_prog1(struct __sk_buff *skb) +{ + __u8 proto = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol)); + long *value; + + if (proto == IPPROTO_TCP) { + set_ip_tos(skb, 8); + set_tcp_ip_src(skb, 0xA010101); + set_tcp_dest_port(skb, 5001); + } + + return 0; +} +SEC("redirect_xmit") +int _redirect_xmit(struct __sk_buff *skb) +{ + return bpf_redirect(skb->ifindex + 1, 0); +} +SEC("redirect_recv") +int _redirect_recv(struct __sk_buff *skb) +{ + return bpf_redirect(skb->ifindex + 1, 1); +} +SEC("clone_redirect_xmit") +int _clone_redirect_xmit(struct __sk_buff *skb) +{ + bpf_clone_redirect(skb, skb->ifindex + 1, 0); + return TC_ACT_SHOT; +} +SEC("clone_redirect_recv") +int _clone_redirect_recv(struct __sk_buff *skb) +{ + bpf_clone_redirect(skb, skb->ifindex + 1, 1); + return TC_ACT_SHOT; +} +char _license[] SEC("license") = "GPL"; |