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// SPDX-License-Identifier: GPL-2.0
#include <stddef.h>
#include <string.h>
#include <netinet/in.h>
#include <linux/bpf.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/tcp.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
#include "bpf_tcp_helpers.h"
#include "test_tcpbpf.h"
struct tcpbpf_globals global = {};
/**
* SOL_TCP is defined in <netinet/tcp.h> while
* TCP_SAVED_SYN is defined in already included <linux/tcp.h>
*/
#ifndef SOL_TCP
#define SOL_TCP 6
#endif
static __always_inline int get_tp_window_clamp(struct bpf_sock_ops *skops)
{
struct bpf_sock *sk;
struct tcp_sock *tp;
sk = skops->sk;
if (!sk)
return -1;
tp = bpf_skc_to_tcp_sock(sk);
if (!tp)
return -1;
return tp->window_clamp;
}
SEC("sockops")
int bpf_testcb(struct bpf_sock_ops *skops)
{
char header[sizeof(struct ipv6hdr) + sizeof(struct tcphdr)];
struct bpf_sock_ops *reuse = skops;
struct tcphdr *thdr;
int window_clamp = 9216;
int good_call_rv = 0;
int bad_call_rv = 0;
int save_syn = 1;
int rv = -1;
int v = 0;
int op;
/* Test reading fields in bpf_sock_ops using single register */
asm volatile (
"%[reuse] = *(u32 *)(%[reuse] +96)"
: [reuse] "+r"(reuse)
:);
asm volatile (
"%[op] = *(u32 *)(%[skops] +96)"
: [op] "+r"(op)
: [skops] "r"(skops)
:);
asm volatile (
"r9 = %[skops];\n"
"r8 = *(u32 *)(r9 +164);\n"
"*(u32 *)(r9 +164) = r8;\n"
:: [skops] "r"(skops)
: "r9", "r8");
asm volatile (
"r1 = %[skops];\n"
"r1 = *(u64 *)(r1 +184);\n"
"if r1 == 0 goto +1;\n"
"r1 = *(u32 *)(r1 +4);\n"
:: [skops] "r"(skops):"r1");
asm volatile (
"r9 = %[skops];\n"
"r9 = *(u64 *)(r9 +184);\n"
"if r9 == 0 goto +1;\n"
"r9 = *(u32 *)(r9 +4);\n"
:: [skops] "r"(skops):"r9");
asm volatile (
"r1 = %[skops];\n"
"r2 = *(u64 *)(r1 +184);\n"
"if r2 == 0 goto +1;\n"
"r2 = *(u32 *)(r2 +4);\n"
:: [skops] "r"(skops):"r1", "r2");
op = (int) skops->op;
global.event_map |= (1 << op);
switch (op) {
case BPF_SOCK_OPS_TCP_CONNECT_CB:
rv = bpf_setsockopt(skops, SOL_TCP, TCP_WINDOW_CLAMP,
&window_clamp, sizeof(window_clamp));
global.window_clamp_client = get_tp_window_clamp(skops);
break;
case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
/* Test failure to set largest cb flag (assumes not defined) */
global.bad_cb_test_rv = bpf_sock_ops_cb_flags_set(skops, 0x80);
/* Set callback */
global.good_cb_test_rv = bpf_sock_ops_cb_flags_set(skops,
BPF_SOCK_OPS_STATE_CB_FLAG);
break;
case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
skops->sk_txhash = 0x12345f;
v = 0xff;
rv = bpf_setsockopt(skops, SOL_IPV6, IPV6_TCLASS, &v,
sizeof(v));
if (skops->family == AF_INET6) {
v = bpf_getsockopt(skops, IPPROTO_TCP, TCP_SAVED_SYN,
header, (sizeof(struct ipv6hdr) +
sizeof(struct tcphdr)));
if (!v) {
int offset = sizeof(struct ipv6hdr);
thdr = (struct tcphdr *)(header + offset);
v = thdr->syn;
global.tcp_saved_syn = v;
}
}
rv = bpf_setsockopt(skops, SOL_TCP, TCP_WINDOW_CLAMP,
&window_clamp, sizeof(window_clamp));
global.window_clamp_server = get_tp_window_clamp(skops);
break;
case BPF_SOCK_OPS_RTO_CB:
break;
case BPF_SOCK_OPS_RETRANS_CB:
break;
case BPF_SOCK_OPS_STATE_CB:
if (skops->args[1] == BPF_TCP_CLOSE) {
if (skops->args[0] == BPF_TCP_LISTEN) {
global.num_listen++;
} else {
global.total_retrans = skops->total_retrans;
global.data_segs_in = skops->data_segs_in;
global.data_segs_out = skops->data_segs_out;
global.bytes_received = skops->bytes_received;
global.bytes_acked = skops->bytes_acked;
}
global.num_close_events++;
}
break;
case BPF_SOCK_OPS_TCP_LISTEN_CB:
bpf_sock_ops_cb_flags_set(skops, BPF_SOCK_OPS_STATE_CB_FLAG);
v = bpf_setsockopt(skops, IPPROTO_TCP, TCP_SAVE_SYN,
&save_syn, sizeof(save_syn));
/* Update global map w/ result of setsock opt */
global.tcp_save_syn = v;
break;
default:
rv = -1;
}
skops->reply = rv;
return 1;
}
char _license[] SEC("license") = "GPL";
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