1 // SPDX-License-Identifier: GPL-2.0 2 #include "bpf_tracing_net.h" 3 #include <bpf/bpf_helpers.h> 4 #include <bpf/bpf_endian.h> 5 #include "test_tcpbpf.h" 6 7 struct tcpbpf_globals global = {}; 8 9 /** 10 * SOL_TCP is defined in <netinet/tcp.h> while 11 * TCP_SAVED_SYN is defined in already included <linux/tcp.h> 12 */ 13 #ifndef SOL_TCP 14 #define SOL_TCP 6 15 #endif 16 17 static __always_inline int get_tp_window_clamp(struct bpf_sock_ops *skops) 18 { 19 struct bpf_sock *sk; 20 struct tcp_sock *tp; 21 22 sk = skops->sk; 23 if (!sk) 24 return -1; 25 tp = bpf_skc_to_tcp_sock(sk); 26 if (!tp) 27 return -1; 28 return tp->window_clamp; 29 } 30 31 SEC("sockops") 32 int bpf_testcb(struct bpf_sock_ops *skops) 33 { 34 char header[sizeof(struct ipv6hdr) + sizeof(struct tcphdr)]; 35 struct bpf_sock_ops *reuse = skops; 36 struct tcphdr *thdr; 37 int window_clamp = 9216; 38 int save_syn = 1; 39 int rv = -1; 40 int v = 0; 41 int op; 42 43 /* Test reading fields in bpf_sock_ops using single register */ 44 asm volatile ( 45 "%[reuse] = *(u32 *)(%[reuse] +96)" 46 : [reuse] "+r"(reuse) 47 :); 48 49 asm volatile ( 50 "%[op] = *(u32 *)(%[skops] +96)" 51 : [op] "=r"(op) 52 : [skops] "r"(skops) 53 :); 54 55 asm volatile ( 56 "r9 = %[skops];\n" 57 "r8 = *(u32 *)(r9 +164);\n" 58 "*(u32 *)(r9 +164) = r8;\n" 59 :: [skops] "r"(skops) 60 : "r9", "r8"); 61 62 asm volatile ( 63 "r1 = %[skops];\n" 64 "r1 = *(u64 *)(r1 +184);\n" 65 "if r1 == 0 goto +1;\n" 66 "r1 = *(u32 *)(r1 +4);\n" 67 :: [skops] "r"(skops):"r1"); 68 69 asm volatile ( 70 "r9 = %[skops];\n" 71 "r9 = *(u64 *)(r9 +184);\n" 72 "if r9 == 0 goto +1;\n" 73 "r9 = *(u32 *)(r9 +4);\n" 74 :: [skops] "r"(skops):"r9"); 75 76 asm volatile ( 77 "r1 = %[skops];\n" 78 "r2 = *(u64 *)(r1 +184);\n" 79 "if r2 == 0 goto +1;\n" 80 "r2 = *(u32 *)(r2 +4);\n" 81 :: [skops] "r"(skops):"r1", "r2"); 82 83 op = (int) skops->op; 84 85 global.event_map |= (1 << op); 86 87 switch (op) { 88 case BPF_SOCK_OPS_TCP_CONNECT_CB: 89 rv = bpf_setsockopt(skops, SOL_TCP, TCP_WINDOW_CLAMP, 90 &window_clamp, sizeof(window_clamp)); 91 global.window_clamp_client = get_tp_window_clamp(skops); 92 break; 93 case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: 94 /* Test failure to set largest cb flag (assumes not defined) */ 95 global.bad_cb_test_rv = bpf_sock_ops_cb_flags_set(skops, 0x80); 96 /* Set callback */ 97 global.good_cb_test_rv = bpf_sock_ops_cb_flags_set(skops, 98 BPF_SOCK_OPS_STATE_CB_FLAG); 99 break; 100 case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: 101 skops->sk_txhash = 0x12345f; 102 v = 0xff; 103 rv = bpf_setsockopt(skops, SOL_IPV6, IPV6_TCLASS, &v, 104 sizeof(v)); 105 if (skops->family == AF_INET6) { 106 v = bpf_getsockopt(skops, IPPROTO_TCP, TCP_SAVED_SYN, 107 header, (sizeof(struct ipv6hdr) + 108 sizeof(struct tcphdr))); 109 if (!v) { 110 int offset = sizeof(struct ipv6hdr); 111 112 thdr = (struct tcphdr *)(header + offset); 113 v = thdr->syn; 114 115 global.tcp_saved_syn = v; 116 } 117 } 118 rv = bpf_setsockopt(skops, SOL_TCP, TCP_WINDOW_CLAMP, 119 &window_clamp, sizeof(window_clamp)); 120 121 global.window_clamp_server = get_tp_window_clamp(skops); 122 break; 123 case BPF_SOCK_OPS_RTO_CB: 124 break; 125 case BPF_SOCK_OPS_RETRANS_CB: 126 break; 127 case BPF_SOCK_OPS_STATE_CB: 128 if (skops->args[1] == BPF_TCP_CLOSE) { 129 if (skops->args[0] == BPF_TCP_LISTEN) { 130 global.num_listen++; 131 } else { 132 global.total_retrans = skops->total_retrans; 133 global.data_segs_in = skops->data_segs_in; 134 global.data_segs_out = skops->data_segs_out; 135 global.bytes_received = skops->bytes_received; 136 global.bytes_acked = skops->bytes_acked; 137 } 138 global.num_close_events++; 139 } 140 break; 141 case BPF_SOCK_OPS_TCP_LISTEN_CB: 142 bpf_sock_ops_cb_flags_set(skops, BPF_SOCK_OPS_STATE_CB_FLAG); 143 v = bpf_setsockopt(skops, IPPROTO_TCP, TCP_SAVE_SYN, 144 &save_syn, sizeof(save_syn)); 145 /* Update global map w/ result of setsock opt */ 146 global.tcp_save_syn = v; 147 break; 148 default: 149 rv = -1; 150 } 151 skops->reply = rv; 152 return 1; 153 } 154 char _license[] SEC("license") = "GPL"; 155