1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2020 Facebook */ 3 #include "bpf_iter.h" 4 #include "bpf_tracing_net.h" 5 #include <bpf/bpf_helpers.h> 6 #include <bpf/bpf_tracing.h> 7 #include <bpf/bpf_endian.h> 8 9 char _license[] SEC("license") = "GPL"; 10 11 static int hlist_unhashed_lockless(const struct hlist_node *h) 12 { 13 return !(h->pprev); 14 } 15 16 static int timer_pending(const struct timer_list * timer) 17 { 18 return !hlist_unhashed_lockless(&timer->entry); 19 } 20 21 extern unsigned CONFIG_HZ __kconfig; 22 23 #define USER_HZ 100 24 #define NSEC_PER_SEC 1000000000ULL 25 static clock_t jiffies_to_clock_t(unsigned long x) 26 { 27 /* The implementation here tailored to a particular 28 * setting of USER_HZ. 29 */ 30 u64 tick_nsec = (NSEC_PER_SEC + CONFIG_HZ/2) / CONFIG_HZ; 31 u64 user_hz_nsec = NSEC_PER_SEC / USER_HZ; 32 33 if ((tick_nsec % user_hz_nsec) == 0) { 34 if (CONFIG_HZ < USER_HZ) 35 return x * (USER_HZ / CONFIG_HZ); 36 else 37 return x / (CONFIG_HZ / USER_HZ); 38 } 39 return x * tick_nsec/user_hz_nsec; 40 } 41 42 static clock_t jiffies_delta_to_clock_t(long delta) 43 { 44 if (delta <= 0) 45 return 0; 46 47 return jiffies_to_clock_t(delta); 48 } 49 50 static long sock_i_ino(const struct sock *sk) 51 { 52 const struct socket *sk_socket = sk->sk_socket; 53 const struct inode *inode; 54 unsigned long ino; 55 56 if (!sk_socket) 57 return 0; 58 59 inode = &container_of(sk_socket, struct socket_alloc, socket)->vfs_inode; 60 bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino); 61 return ino; 62 } 63 64 static bool 65 inet_csk_in_pingpong_mode(const struct inet_connection_sock *icsk) 66 { 67 return icsk->icsk_ack.pingpong >= TCP_PINGPONG_THRESH; 68 } 69 70 static bool tcp_in_initial_slowstart(const struct tcp_sock *tcp) 71 { 72 return tcp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; 73 } 74 75 static int dump_tcp_sock(struct seq_file *seq, struct tcp_sock *tp, 76 uid_t uid, __u32 seq_num) 77 { 78 const struct inet_connection_sock *icsk; 79 const struct fastopen_queue *fastopenq; 80 const struct inet_sock *inet; 81 unsigned long timer_expires; 82 const struct sock *sp; 83 __u16 destp, srcp; 84 __be32 dest, src; 85 int timer_active; 86 int rx_queue; 87 int state; 88 89 icsk = &tp->inet_conn; 90 inet = &icsk->icsk_inet; 91 sp = &inet->sk; 92 fastopenq = &icsk->icsk_accept_queue.fastopenq; 93 94 dest = inet->inet_daddr; 95 src = inet->inet_rcv_saddr; 96 destp = bpf_ntohs(inet->inet_dport); 97 srcp = bpf_ntohs(inet->inet_sport); 98 99 if (icsk->icsk_pending == ICSK_TIME_RETRANS || 100 icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT || 101 icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { 102 timer_active = 1; 103 timer_expires = icsk->icsk_timeout; 104 } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { 105 timer_active = 4; 106 timer_expires = icsk->icsk_timeout; 107 } else if (timer_pending(&sp->sk_timer)) { 108 timer_active = 2; 109 timer_expires = sp->sk_timer.expires; 110 } else { 111 timer_active = 0; 112 timer_expires = bpf_jiffies64(); 113 } 114 115 state = sp->sk_state; 116 if (state == TCP_LISTEN) { 117 rx_queue = sp->sk_ack_backlog; 118 } else { 119 rx_queue = tp->rcv_nxt - tp->copied_seq; 120 if (rx_queue < 0) 121 rx_queue = 0; 122 } 123 124 BPF_SEQ_PRINTF(seq, "%4d: %08X:%04X %08X:%04X ", 125 seq_num, src, srcp, destp, destp); 126 BPF_SEQ_PRINTF(seq, "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d ", 127 state, 128 tp->write_seq - tp->snd_una, rx_queue, 129 timer_active, 130 jiffies_delta_to_clock_t(timer_expires - bpf_jiffies64()), 131 icsk->icsk_retransmits, uid, 132 icsk->icsk_probes_out, 133 sock_i_ino(sp), 134 sp->sk_refcnt.refs.counter); 135 BPF_SEQ_PRINTF(seq, "%pK %lu %lu %u %u %d\n", 136 tp, 137 jiffies_to_clock_t(icsk->icsk_rto), 138 jiffies_to_clock_t(icsk->icsk_ack.ato), 139 (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(icsk), 140 tp->snd_cwnd, 141 state == TCP_LISTEN ? fastopenq->max_qlen 142 : (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh) 143 ); 144 145 return 0; 146 } 147 148 static int dump_tw_sock(struct seq_file *seq, struct tcp_timewait_sock *ttw, 149 uid_t uid, __u32 seq_num) 150 { 151 struct inet_timewait_sock *tw = &ttw->tw_sk; 152 __u16 destp, srcp; 153 __be32 dest, src; 154 long delta; 155 156 delta = tw->tw_timer.expires - bpf_jiffies64(); 157 dest = tw->tw_daddr; 158 src = tw->tw_rcv_saddr; 159 destp = bpf_ntohs(tw->tw_dport); 160 srcp = bpf_ntohs(tw->tw_sport); 161 162 BPF_SEQ_PRINTF(seq, "%4d: %08X:%04X %08X:%04X ", 163 seq_num, src, srcp, dest, destp); 164 165 BPF_SEQ_PRINTF(seq, "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n", 166 tw->tw_substate, 0, 0, 167 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0, 168 tw->tw_refcnt.refs.counter, tw); 169 170 return 0; 171 } 172 173 static int dump_req_sock(struct seq_file *seq, struct tcp_request_sock *treq, 174 uid_t uid, __u32 seq_num) 175 { 176 struct inet_request_sock *irsk = &treq->req; 177 struct request_sock *req = &irsk->req; 178 long ttd; 179 180 ttd = req->rsk_timer.expires - bpf_jiffies64(); 181 182 if (ttd < 0) 183 ttd = 0; 184 185 BPF_SEQ_PRINTF(seq, "%4d: %08X:%04X %08X:%04X ", 186 seq_num, irsk->ir_loc_addr, 187 irsk->ir_num, irsk->ir_rmt_addr, 188 bpf_ntohs(irsk->ir_rmt_port)); 189 BPF_SEQ_PRINTF(seq, "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n", 190 TCP_SYN_RECV, 0, 0, 1, jiffies_to_clock_t(ttd), 191 req->num_timeout, uid, 0, 0, 0, req); 192 193 return 0; 194 } 195 196 SEC("iter/tcp") 197 int dump_tcp4(struct bpf_iter__tcp *ctx) 198 { 199 struct sock_common *sk_common = ctx->sk_common; 200 struct seq_file *seq = ctx->meta->seq; 201 struct tcp_timewait_sock *tw; 202 struct tcp_request_sock *req; 203 struct tcp_sock *tp; 204 uid_t uid = ctx->uid; 205 __u32 seq_num; 206 207 if (sk_common == (void *)0) 208 return 0; 209 210 seq_num = ctx->meta->seq_num; 211 if (seq_num == 0) 212 BPF_SEQ_PRINTF(seq, " sl " 213 "local_address " 214 "rem_address " 215 "st tx_queue rx_queue tr tm->when retrnsmt" 216 " uid timeout inode\n"); 217 218 if (sk_common->skc_family != AF_INET) 219 return 0; 220 221 tp = bpf_skc_to_tcp_sock(sk_common); 222 if (tp) 223 return dump_tcp_sock(seq, tp, uid, seq_num); 224 225 tw = bpf_skc_to_tcp_timewait_sock(sk_common); 226 if (tw) 227 return dump_tw_sock(seq, tw, uid, seq_num); 228 229 req = bpf_skc_to_tcp_request_sock(sk_common); 230 if (req) 231 return dump_req_sock(seq, req, uid, seq_num); 232 233 return 0; 234 } 235