| #!/usr/bin/python |
| # @lint-avoid-python-3-compatibility-imports |
| # |
| # tcpcong Measure tcp congestion control status duration. |
| # For Linux, uses BCC, eBPF. |
| # |
| # USAGE: tcpcong [-h] [-T] [-L] [-R] [-m] [-d] [interval] [outputs] |
| # |
| # Copyright (c) Ping Gan. |
| # |
| # 27-Jan-2022 Ping Gan Created this. |
| |
| from __future__ import print_function |
| from bcc import BPF |
| from time import sleep, strftime |
| from struct import pack |
| from socket import inet_ntop, AF_INET, AF_INET6 |
| from struct import pack |
| import argparse |
| |
| examples = """examples: |
| ./tcpcong # show tcp congestion status duration |
| ./tcpcong 1 10 # show 1 second summaries, 10 times |
| ./tcpcong -L 3000-3006 1 # 1s summaries, local port 3000-3006 |
| ./tcpcong -R 5000-5005 1 # 1s summaries, remote port 5000-5005 |
| ./tcpcong -uT 1 # 1s summaries, microseconds, and timestamps |
| ./tcpcong -d # show the duration as histograms |
| """ |
| |
| parser = argparse.ArgumentParser( |
| description="Summarize tcp socket congestion control status duration", |
| formatter_class=argparse.RawDescriptionHelpFormatter, |
| epilog=examples) |
| parser.add_argument("-L", "--localport", |
| help="trace local ports only") |
| parser.add_argument("-R", "--remoteport", |
| help="trace the dest ports only") |
| parser.add_argument("-T", "--timestamp", action="store_true", |
| help="include timestamp on output") |
| parser.add_argument("-d", "--dist", action="store_true", |
| help="show distributions as histograms") |
| parser.add_argument("-u", "--microseconds", action="store_true", |
| help="output in microseconds") |
| parser.add_argument("interval", nargs="?", default=99999999, |
| help="output interval, in seconds") |
| parser.add_argument("outputs", nargs="?", default=99999999, |
| help="number of outputs") |
| parser.add_argument("--ebpf", action="store_true", |
| help=argparse.SUPPRESS) |
| args = parser.parse_args() |
| countdown = int(args.outputs) |
| debug = 0 |
| |
| start_rport = end_rport = -1 |
| if args.remoteport: |
| rports = args.remoteport.split("-") |
| if (len(rports) != 2) and (len(rports) != 1): |
| print("unrecognized remote port range") |
| exit(1) |
| if len(rports) == 2: |
| start_rport = int(rports[0]) |
| end_rport = int(rports[1]) |
| else: |
| start_rport = int(rports[0]) |
| end_rport = int(rports[0]) |
| if start_rport > end_rport: |
| tmp = start_rport |
| start_rport = end_rport |
| end_rport = tmp |
| |
| start_lport = end_lport = -1 |
| if args.localport: |
| lports = args.localport.split("-") |
| if (len(lports) != 2) and (len(lports) != 1): |
| print("unrecognized local port range") |
| exit(1) |
| if len(lports) == 2: |
| start_lport = int(lports[0]) |
| end_lport = int(lports[1]) |
| else: |
| start_lport = int(lports[0]) |
| end_lport = int(lports[0]) |
| if start_lport > end_lport: |
| tmp = start_lport |
| start_lport = end_lport |
| end_lport = tmp |
| |
| # define BPF program |
| bpf_text = """ |
| #include <uapi/linux/ptrace.h> |
| #include <net/sock.h> |
| #include <bcc/proto.h> |
| #include <net/tcp.h> |
| #include <net/inet_connection_sock.h> |
| |
| typedef struct ipv4_flow_key { |
| u32 saddr; |
| u32 daddr; |
| u16 lport; |
| u16 dport; |
| } ipv4_flow_key_t; |
| |
| typedef struct ipv6_flow_key { |
| unsigned __int128 saddr; |
| unsigned __int128 daddr; |
| u16 lport; |
| u16 dport; |
| } ipv6_flow_key_t; |
| |
| typedef struct process_key { |
| char comm[TASK_COMM_LEN]; |
| u32 tid; |
| } process_key_t; |
| |
| typedef struct ipv4_flow_val { |
| ipv4_flow_key_t ipv4_key; |
| u16 cong_state; |
| } ipv4_flow_val_t; |
| |
| typedef struct ipv6_flow_val { |
| ipv6_flow_key_t ipv6_key; |
| u16 cong_state; |
| } ipv6_flow_val_t; |
| |
| BPF_HASH(start_ipv4, process_key_t, ipv4_flow_val_t); |
| BPF_HASH(start_ipv6, process_key_t, ipv6_flow_val_t); |
| SOCK_STORE_DEF |
| |
| typedef struct data_val { |
| DEF_TEXT |
| u64 last_ts; |
| u16 last_cong_stat; |
| } data_val_t; |
| |
| typedef struct cong { |
| u8 cong_stat:5, |
| ca_inited:1, |
| ca_setsockopt:1, |
| ca_dstlocked:1; |
| } cong_status_t; |
| |
| BPF_HASH(ipv4_stat, ipv4_flow_key_t, data_val_t); |
| BPF_HASH(ipv6_stat, ipv6_flow_key_t, data_val_t); |
| |
| HIST_TABLE |
| |
| static int entry_state_update_func(struct sock *sk) |
| { |
| u16 dport = 0, lport = 0; |
| u32 tid = bpf_get_current_pid_tgid(); |
| process_key_t key = {0}; |
| bpf_get_current_comm(&key.comm, sizeof(key.comm)); |
| key.tid = tid; |
| |
| u64 family = sk->__sk_common.skc_family; |
| struct inet_connection_sock *icsk = inet_csk(sk); |
| cong_status_t cong_status; |
| bpf_probe_read_kernel(&cong_status, sizeof(cong_status), |
| (void *)((long)&icsk->icsk_retransmits) - 1); |
| if (family == AF_INET) { |
| ipv4_flow_val_t ipv4_val = {0}; |
| ipv4_val.ipv4_key.saddr = sk->__sk_common.skc_rcv_saddr; |
| ipv4_val.ipv4_key.daddr = sk->__sk_common.skc_daddr; |
| ipv4_val.ipv4_key.lport = sk->__sk_common.skc_num; |
| dport = sk->__sk_common.skc_dport; |
| dport = ntohs(dport); |
| lport = ipv4_val.ipv4_key.lport; |
| FILTER_LPORT |
| FILTER_DPORT |
| ipv4_val.ipv4_key.dport = dport; |
| ipv4_val.cong_state = cong_status.cong_stat + 1; |
| start_ipv4.update(&key, &ipv4_val); |
| } else if (family == AF_INET6) { |
| ipv6_flow_val_t ipv6_val = {0}; |
| bpf_probe_read_kernel(&ipv6_val.ipv6_key.saddr, |
| sizeof(ipv6_val.ipv6_key.saddr), |
| &sk->__sk_common.skc_v6_rcv_saddr.in6_u.u6_addr32); |
| bpf_probe_read_kernel(&ipv6_val.ipv6_key.daddr, |
| sizeof(ipv6_val.ipv6_key.daddr), |
| &sk->__sk_common.skc_v6_daddr.in6_u.u6_addr32); |
| ipv6_val.ipv6_key.lport = sk->__sk_common.skc_num; |
| dport = sk->__sk_common.skc_dport; |
| dport = ntohs(dport); |
| lport = ipv6_val.ipv6_key.lport; |
| FILTER_LPORT |
| FILTER_DPORT |
| ipv6_val.ipv6_key.dport = dport; |
| ipv6_val.cong_state = cong_status.cong_stat + 1; |
| start_ipv6.update(&key, &ipv6_val); |
| } |
| SOCK_STORE_ADD |
| return 0; |
| } |
| |
| static int ret_state_update_func(struct sock *sk) |
| { |
| u64 ts, ts1; |
| u16 family, last_cong_state; |
| u16 dport = 0, lport = 0; |
| u32 tid = bpf_get_current_pid_tgid(); |
| process_key_t key = {0}; |
| bpf_get_current_comm(&key.comm, sizeof(key.comm)); |
| key.tid = tid; |
| |
| struct inet_connection_sock *icsk = inet_csk(sk); |
| cong_status_t cong_status; |
| bpf_probe_read_kernel(&cong_status, sizeof(cong_status), |
| (void *)((long)&icsk->icsk_retransmits) - 1); |
| data_val_t *datap, data = {0}; |
| STATE_KEY |
| bpf_probe_read_kernel(&family, sizeof(family), |
| &sk->__sk_common.skc_family); |
| if (family == AF_INET) { |
| ipv4_flow_val_t *val4 = start_ipv4.lookup(&key); |
| if (val4 == 0) { |
| SOCK_STORE_DEL |
| return 0; //missed |
| } |
| ipv4_flow_key_t keyv4 = {0}; |
| bpf_probe_read_kernel(&keyv4, sizeof(ipv4_flow_key_t), |
| &(val4->ipv4_key)); |
| dport = keyv4.dport; |
| lport = keyv4.lport; |
| FILTER_LPORT |
| FILTER_DPORT |
| datap = ipv4_stat.lookup(&keyv4); |
| if (datap == 0) { |
| data.last_ts = bpf_ktime_get_ns(); |
| data.last_cong_stat = val4->cong_state; |
| ipv4_stat.update(&keyv4, &data); |
| } else { |
| last_cong_state = val4->cong_state; |
| if ((cong_status.cong_stat + 1) != last_cong_state) { |
| ts1 = bpf_ktime_get_ns(); |
| ts = ts1 - datap->last_ts; |
| datap->last_ts = ts1; |
| datap->last_cong_stat = cong_status.cong_stat + 1; |
| ts /= 1000; |
| STORE |
| } |
| } |
| start_ipv4.delete(&key); |
| } else if (family == AF_INET6) { |
| ipv6_flow_val_t *val6 = start_ipv6.lookup(&key); |
| if (val6 == 0) { |
| SOCK_STORE_DEL |
| return 0; //missed |
| } |
| ipv6_flow_key_t keyv6 = {0}; |
| bpf_probe_read_kernel(&keyv6, sizeof(ipv6_flow_key_t), |
| &(val6->ipv6_key)); |
| dport = keyv6.dport; |
| lport = keyv6.lport; |
| FILTER_LPORT |
| FILTER_DPORT |
| datap = ipv6_stat.lookup(&keyv6); |
| if (datap == 0) { |
| data.last_ts = bpf_ktime_get_ns(); |
| data.last_cong_stat = val6->cong_state; |
| ipv6_stat.update(&keyv6, &data); |
| } else { |
| last_cong_state = val6->cong_state; |
| if ((cong_status.cong_stat + 1) != last_cong_state) { |
| ts1 = bpf_ktime_get_ns(); |
| ts = ts1 - datap->last_ts; |
| datap->last_ts = ts1; |
| datap->last_cong_stat = (cong_status.cong_stat + 1); |
| ts /= 1000; |
| STORE |
| } |
| } |
| start_ipv6.delete(&key); |
| } |
| SOCK_STORE_DEL |
| return 0; |
| } |
| """ |
| |
| kprobe_program = """ |
| int entry_func(struct pt_regs *ctx, struct sock *sk) |
| { |
| return entry_state_update_func(sk); |
| } |
| |
| int ret_func(struct pt_regs *ctx) |
| { |
| u32 tid = bpf_get_current_pid_tgid(); |
| process_key_t key = {0}; |
| bpf_get_current_comm(&key.comm, sizeof(key.comm)); |
| key.tid = tid; |
| struct sock **sockpp; |
| sockpp = sock_store.lookup(&key); |
| if (sockpp == 0) { |
| return 0; //miss the entry |
| } |
| struct sock *sk = *sockpp; |
| return ret_state_update_func(sk); |
| } |
| """ |
| |
| kfunc_program = """ |
| KFUNC_PROBE(tcp_fastretrans_alert, struct sock *sk) |
| { |
| return entry_state_update_func(sk); |
| } |
| |
| KRETFUNC_PROBE(tcp_fastretrans_alert, struct sock *sk) |
| { |
| return ret_state_update_func(sk); |
| } |
| |
| KFUNC_PROBE(tcp_enter_cwr, struct sock *sk) |
| { |
| return entry_state_update_func(sk); |
| } |
| |
| KRETFUNC_PROBE(tcp_enter_cwr, struct sock *sk) |
| { |
| return ret_state_update_func(sk); |
| } |
| |
| KFUNC_PROBE(tcp_enter_loss, struct sock *sk) |
| { |
| return entry_state_update_func(sk); |
| } |
| |
| KRETFUNC_PROBE(tcp_enter_loss, struct sock *sk) |
| { |
| return ret_state_update_func(sk); |
| } |
| |
| KFUNC_PROBE(tcp_enter_recovery, struct sock *sk) |
| { |
| return entry_state_update_func(sk); |
| } |
| |
| KRETFUNC_PROBE(tcp_enter_recovery, struct sock *sk) |
| { |
| return ret_state_update_func(sk); |
| } |
| |
| KFUNC_PROBE(tcp_process_tlp_ack, struct sock *sk) |
| { |
| return entry_state_update_func(sk); |
| } |
| |
| KRETFUNC_PROBE(tcp_process_tlp_ack, struct sock *sk) |
| { |
| return ret_state_update_func(sk); |
| } |
| """ |
| |
| # code replace |
| is_support_kfunc = BPF.support_kfunc() |
| if is_support_kfunc: |
| bpf_text += kfunc_program |
| bpf_text = bpf_text.replace('SOCK_STORE_DEF', '') |
| bpf_text = bpf_text.replace('SOCK_STORE_ADD', '') |
| bpf_text = bpf_text.replace('SOCK_STORE_DEL', '') |
| else: |
| bpf_text += kprobe_program |
| bpf_text = bpf_text.replace('SOCK_STORE_DEF', |
| 'BPF_HASH(sock_store, process_key_t, struct sock *);') |
| bpf_text = bpf_text.replace('SOCK_STORE_ADD', |
| 'sock_store.update(&key, &sk);') |
| bpf_text = bpf_text.replace('SOCK_STORE_DEL', |
| 'sock_store.delete(&key);') |
| |
| if args.localport: |
| bpf_text = bpf_text.replace('FILTER_LPORT', |
| 'if (lport < %d || lport > %d) { return 0; }' |
| % (start_lport, end_lport)) |
| else: |
| bpf_text = bpf_text.replace('FILTER_LPORT', '') |
| |
| if args.remoteport: |
| bpf_text = bpf_text.replace('FILTER_DPORT', |
| 'if (dport < %d || dport > %d) { return 0; }' |
| % (start_rport, end_rport)) |
| else: |
| bpf_text = bpf_text.replace('FILTER_DPORT', '') |
| |
| table_def_text = """ |
| u64 open_dura; |
| u64 loss_dura; |
| u64 disorder_dura; |
| u64 recover_dura; |
| u64 cwr_dura; |
| u64 total_changes; |
| """ |
| |
| store_text = """ |
| datap->total_changes += 1; |
| if (last_cong_state == (TCP_CA_Open + 1)) { |
| datap->open_dura += ts; |
| } else if (last_cong_state == (TCP_CA_Disorder + 1)) { |
| datap->disorder_dura += ts; |
| } else if (last_cong_state == (TCP_CA_CWR + 1)) { |
| datap->cwr_dura += ts; |
| } else if (last_cong_state == (TCP_CA_Recovery + 1)) { |
| datap->recover_dura += ts; |
| } else if (last_cong_state == (TCP_CA_Loss + 1)) { |
| datap->loss_dura += ts; |
| } |
| """ |
| |
| store_dist_text = """ |
| if (last_cong_state == (TCP_CA_Open + 1)) { |
| key_s.state = TCP_CA_Open; |
| } else if (last_cong_state == (TCP_CA_Disorder + 1)) { |
| key_s.state = TCP_CA_Disorder; |
| } else if (last_cong_state == (TCP_CA_CWR + 1)) { |
| key_s.state = TCP_CA_CWR; |
| } else if (last_cong_state == (TCP_CA_Recovery + 1)) { |
| key_s.state = TCP_CA_Recovery; |
| } else if (last_cong_state == (TCP_CA_Loss + 1)) { |
| key_s.state = TCP_CA_Loss; |
| } |
| TIME_UNIT |
| key_s.slot = bpf_log2l(ts); |
| dist.atomic_increment(key_s); |
| """ |
| |
| hist_table_text = """ |
| typedef struct congest_state_key { |
| u32 state; |
| u64 slot; |
| }congest_state_key_t; |
| |
| BPF_HISTOGRAM(dist, congest_state_key_t); |
| """ |
| |
| if args.dist: |
| bpf_text = bpf_text.replace('DEF_TEXT', '') |
| bpf_text = bpf_text.replace('STORE', store_dist_text) |
| bpf_text = bpf_text.replace('STATE_KEY', |
| 'congest_state_key_t key_s = {0};') |
| bpf_text = bpf_text.replace('HIST_TABLE', hist_table_text) |
| if args.microseconds: |
| bpf_text = bpf_text.replace('TIME_UNIT', '') |
| else: |
| bpf_text = bpf_text.replace('TIME_UNIT', 'ts /= 1000;') |
| else: |
| bpf_text = bpf_text.replace('DEF_TEXT', table_def_text) |
| bpf_text = bpf_text.replace('STORE', store_text) |
| bpf_text = bpf_text.replace('STATE_KEY', '') |
| bpf_text = bpf_text.replace('HIST_TABLE', '') |
| |
| |
| if debug or args.ebpf: |
| print(bpf_text) |
| if args.ebpf: |
| exit() |
| |
| # load BPF program |
| b = BPF(text=bpf_text) |
| |
| if not is_support_kfunc: |
| # all the tcp congestion control status update functions |
| # are called by below 5 functions. |
| b.attach_kprobe(event="tcp_fastretrans_alert", fn_name="entry_func") |
| b.attach_kretprobe(event="tcp_fastretrans_alert", fn_name="ret_func") |
| b.attach_kprobe(event="tcp_enter_cwr", fn_name="entry_func") |
| b.attach_kretprobe(event="tcp_enter_cwr", fn_name="ret_func") |
| b.attach_kprobe(event="tcp_process_tlp_ack", fn_name="entry_func") |
| b.attach_kretprobe(event="tcp_process_tlp_ack", fn_name="ret_func") |
| b.attach_kprobe(event="tcp_enter_loss", fn_name="entry_func") |
| b.attach_kretprobe(event="tcp_enter_loss", fn_name="ret_func") |
| b.attach_kprobe(event="tcp_enter_recovery", fn_name="entry_func") |
| b.attach_kretprobe(event="tcp_enter_recovery", fn_name="ret_func") |
| |
| print("Tracing tcp congestion control status duration... Hit Ctrl-C to end.") |
| |
| |
| def cong_state_to_name(state): |
| # this need to match with kernel state |
| state_name = ["open", "disorder", "cwr", "recovery", "loss"] |
| return state_name[state] |
| |
| # output |
| exiting = 0 if args.interval else 1 |
| ipv6_stat = b.get_table("ipv6_stat") |
| ipv4_stat = b.get_table("ipv4_stat") |
| if args.dist: |
| dist = b.get_table("dist") |
| label = "ms" |
| if args.microseconds: |
| label = "us" |
| while (1): |
| try: |
| sleep(int(args.interval)) |
| except KeyboardInterrupt: |
| exiting = 1 |
| |
| print() |
| if args.timestamp: |
| print("%-8s\n" % strftime("%H:%M:%S"), end="") |
| if args.dist: |
| if args.microseconds: |
| dist.print_log2_hist("usecs", "tcp_congest_state", |
| section_print_fn=cong_state_to_name) |
| else: |
| dist.print_log2_hist("msecs", "tcp_congest_state", |
| section_print_fn=cong_state_to_name) |
| dist.clear() |
| else: |
| if ipv4_stat: |
| print("%-21s% -21s %-7s %-6s %-7s %-7s %-6s %-5s" % ("LAddrPort", |
| "RAddrPort", "Open_" + label, "Dod_" + label, |
| "Rcov_" + label, "Cwr_" + label, "Los_" + label, "Chgs")) |
| laddr = "" |
| raddr = "" |
| for k, v in sorted(ipv4_stat.items(), key=lambda ipv4_stat: ipv4_stat[0].lport): |
| laddr = inet_ntop(AF_INET, pack("I", k.saddr)) |
| raddr = inet_ntop(AF_INET, pack("I", k.daddr)) |
| open_dura = v.open_dura |
| disorder_dura = v.disorder_dura |
| recover_dura = v.recover_dura |
| cwr_dura = v.cwr_dura |
| loss_dura = v.loss_dura |
| if not args.microseconds: |
| open_dura /= 1000 |
| disorder_dura /= 1000 |
| recover_dura /= 1000 |
| cwr_dura /= 1000 |
| loss_dura /= 1000 |
| if v.total_changes != 0: |
| print("%-21s %-21s %-7d %-6d %-7d %-7d %-6d %-5d" % (laddr + |
| "/" + str(k.lport), raddr + "/" + str(k.dport), open_dura, |
| disorder_dura, recover_dura, cwr_dura, loss_dura, |
| v.total_changes)) |
| if ipv6_stat: |
| print("%-32s %-32s %-7s %-6s %-7s %-7s %-6s %-5s" % ("LAddrPort6", |
| "RAddrPort6", "Open_" + label, "Dod_" + label, "Rcov_" + label, |
| "Cwr_" + label, "Los_" + label, "Chgs")) |
| for k, v in sorted(ipv6_stat.items(), key=lambda ipv6_stat: ipv6_stat[0].lport): |
| laddr = inet_ntop(AF_INET6, bytes(k.saddr)) |
| raddr = inet_ntop(AF_INET6, bytes(k.daddr)) |
| open_dura = v.open_dura |
| disorder_dura = v.disorder_dura |
| recover_dura = v.recover_dura |
| cwr_dura = v.cwr_dura |
| loss_dura = v.loss_dura |
| if not args.microseconds: |
| open_dura /= 1000 |
| disorder_dura /= 1000 |
| recover_dura /= 1000 |
| cwr_dura /= 1000 |
| loss_dura /= 1000 |
| if v.total_changes != 0: |
| print("%-32s %-32s %-7d %-7d %-7d %-6d %-6d %-5d" % (laddr + |
| "/" + str(k.lport), raddr + "/" + str(k.dport), open_dura, |
| disorder_dura, recover_dura, cwr_dura, loss_dura, |
| v.total_changes)) |
| ipv4_stat.clear() |
| ipv6_stat.clear() |
| countdown -= 1 |
| if exiting or countdown == 0: |
| exit() |
