tools: add option --cgroupmap to tcptop

man/man8/tcptop.8

@@ -1,8 +1,9 @@
-.TH tcptop 8  "2016-09-13" "USER COMMANDS"
+.TH tcptop 8  "2020-03-08" "USER COMMANDS"
 .SH NAME
 tcptop \- Summarize TCP send/recv throughput by host. Top for TCP.
 .SH SYNOPSIS
-.B tcptop [\-h] [\-C] [\-S] [\-p PID] [interval] [count]
+.B tcptop [\-h] [\-C] [\-S] [\-p PID] [\-\-cgroupmap MAPPATH]
+          [interval] [count]
 .SH DESCRIPTION
 This is top for TCP sessions.
 
@@ -35,6 +36,9 @@ Don't print the system summary line (load averages).
 \-p PID
 Trace this PID only.
 .TP
+\-\-cgroupmap MAPPATH
+Trace cgroups in this BPF map only (filtered in-kernel).
+.TP
 interval
 Interval between updates, seconds (default 1).
 .TP
@@ -53,6 +57,10 @@ Don't clear the screen (rolling output), and 5 second summaries:
 Trace PID 181 only, and don't clear the screen:
 #
 .B tcptop \-Cp 181
+.TP
+Trace a set of cgroups only (see filtering_by_cgroups.md from bcc sources for more details):
+#
+.B tcptop \-\-cgroupmap /sys/fs/bpf/test01
 .SH FIELDS
 .TP
 loadavg:

tools/tcptop.py

@@ -45,6 +45,7 @@ def range_check(string):
     ./tcptop           # trace TCP send/recv by host
     ./tcptop -C        # don't clear the screen
     ./tcptop -p 181    # only trace PID 181
+    ./tcptop --cgroupmap ./mappath  # only trace cgroups in this BPF map
 """
 parser = argparse.ArgumentParser(
     description="Summarize TCP send/recv throughput by host",
@@ -60,6 +61,8 @@ def range_check(string):
     help="output interval, in seconds (default 1)")
 parser.add_argument("count", nargs="?", default=-1, type=range_check,
     help="number of outputs")
+parser.add_argument("--cgroupmap",
+    help="trace cgroups in this BPF map only")
 parser.add_argument("--ebpf", action="store_true",
     help=argparse.SUPPRESS)
 args = parser.parse_args()
@@ -94,11 +97,21 @@ def range_check(string):
 BPF_HASH(ipv6_send_bytes, struct ipv6_key_t);
 BPF_HASH(ipv6_recv_bytes, struct ipv6_key_t);
 
+#if CGROUPSET
+BPF_TABLE_PINNED("hash", u64, u64, cgroupset, 1024, "CGROUPPATH");
+#endif
+
 int kprobe__tcp_sendmsg(struct pt_regs *ctx, struct sock *sk,
     struct msghdr *msg, size_t size)
 {
     u32 pid = bpf_get_current_pid_tgid() >> 32;
     FILTER
+#if CGROUPSET
+    u64 cgroupid = bpf_get_current_cgroup_id();
+    if (cgroupset.lookup(&cgroupid) == NULL) {
+        return 0;
+    }
+#endif
     u16 dport = 0, family = sk->__sk_common.skc_family;
 
     if (family == AF_INET) {
@@ -136,6 +149,12 @@ def range_check(string):
 {
     u32 pid = bpf_get_current_pid_tgid() >> 32;
     FILTER
+#if CGROUPSET
+    u64 cgroupid = bpf_get_current_cgroup_id();
+    if (cgroupset.lookup(&cgroupid) == NULL) {
+        return 0;
+    }
+#endif
     u16 dport = 0, family = sk->__sk_common.skc_family;
     u64 *val, zero = 0;
 
@@ -174,6 +193,11 @@ def range_check(string):
         'if (pid != %s) { return 0; }' % args.pid)
 else:
     bpf_text = bpf_text.replace('FILTER', '')
+if args.cgroupmap:
+    bpf_text = bpf_text.replace('CGROUPSET', '1')
+    bpf_text = bpf_text.replace('CGROUPPATH', args.cgroupmap)
+else:
+    bpf_text = bpf_text.replace('CGROUPSET', '0')
 if debug or args.ebpf:
     print(bpf_text)
     if args.ebpf:

tools/tcptop_example.txt

@@ -92,25 +92,36 @@ PID    COMM         LADDR                 RADDR                  RX_KB  TX_KB
 
 You can disable the loadavg summary line with -S if needed.
 
+The --cgroupmap option filters based on a cgroup set. It is meant to be used
+with an externally created map.
+
+# tcptop --cgroupmap /sys/fs/bpf/test01
+
+For more details, see docs/filtering_by_cgroups.md
+
 
 USAGE:
 
 # tcptop -h
-usage: tcptop.py [-h] [-C] [-S] [-p PID] [interval] [count]
+usage: tcptop.py [-h] [-C] [-S] [-p PID] [--cgroupmap CGROUPMAP]
+                 [interval] [count]
 
 Summarize TCP send/recv throughput by host
 
 positional arguments:
-  interval           output interval, in seconds (default 1)
-  count              number of outputs
+  interval              output interval, in seconds (default 1)
+  count                 number of outputs
 
 optional arguments:
-  -h, --help         show this help message and exit
-  -C, --noclear      don't clear the screen
-  -S, --nosummary    skip system summary line
-  -p PID, --pid PID  trace this PID only
+  -h, --help            show this help message and exit
+  -C, --noclear         don't clear the screen
+  -S, --nosummary       skip system summary line
+  -p PID, --pid PID     trace this PID only
+  --cgroupmap CGROUPMAP
+                        trace cgroups in this BPF map only
 
 examples:
     ./tcptop           # trace TCP send/recv by host
     ./tcptop -C        # don't clear the screen
     ./tcptop -p 181    # only trace PID 181
+    ./tcptop --cgroupmap ./mappath  # only trace cgroups in this BPF map