Add bpf-run command line tool

Example usage:
sudo bpf-run -p sys_clone -c 'bpf_trace_printk("Hello, World!\n");' -t
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

src/python/CMakeLists.txt

@@ -6,6 +6,7 @@ macro(symlink_file SRC DST)
 endmacro()
 
 symlink_file(${CMAKE_CURRENT_SOURCE_DIR}/bpf ${CMAKE_CURRENT_BINARY_DIR}/bpf)
+symlink_file(${CMAKE_CURRENT_SOURCE_DIR}/bpf-run ${CMAKE_CURRENT_BINARY_DIR}/bpf-run)
 
 set(PIP_INSTALLABLE "${CMAKE_CURRENT_BINARY_DIR}/dist/bpf-${REVISION}.tar.gz")
 configure_file(setup.py.in ${CMAKE_CURRENT_BINARY_DIR}/setup.py @ONLY)

src/python/MANIFEST

 # file GENERATED by distutils, do NOT edit
 setup.py
 bpf/__init__.py
+bpf-run

src/python/bpf-run

+#!/usr/bin/env python
+
+import sys
+
+USAGE = """\
+usage: {argv0} <opts> -p probe_func -c cmd
+ -c cmd      contents of the program to run, omitting prototype
+ -d name     dump table <name> upon exit
+ -n sec      run for <sec> seconds and then exit (default=-1)
+ -p probe    kernel entry point to trace (required)
+ -t          attach to kernel trace output
+ -v          increase verbosity
+example:
+ {argv0} -p sys_clone -c 'bpf_trace_printk("hello\\n");' -t\
+"""
+
+wrapper = """
+int run(void *ctx) {
+    %s
+    return 0;
+}
+"""
+
+def print_usage_and_exit(rc, msg=None):
+    if rc != 0:
+        sys.stdout = sys.stderr
+    if msg:
+        print(msg)
+    print(USAGE.format(argv0=sys.argv[0]))
+    sys.exit(rc)
+
+def main():
+    import getopt
+    import os
+    import signal
+
+    try:
+        opts, args = getopt.getopt(sys.argv[1:], "c:d:hn:p:tv")
+    except getopt.error, msg:
+        print_usage_and_exit(2, msg)
+
+    runcmd = None
+    probe_fn = None
+    trace = 0
+    dump_tables = []
+    verbose = 0
+    nsec = 0
+
+    for o, a in opts:
+        if o == "-d": dump_tables.append(a)
+        if o == "-n": nsec = int(a)
+        if o == "-t": trace = 1
+        if o == "-v": verbose += 1
+        if o == "-c": runcmd = a
+        if o == "-p": probe_fn = a
+        if o == "-h": print_usage_and_exit(0)
+
+    if not runcmd or not probe_fn:
+        print_usage_and_exit(2, "Error: -p and -c arguments are required")
+
+    from bpf import BPF
+
+    b = BPF(text=wrapper % runcmd, debug=verbose)
+    fn = b.load_func("run", BPF.KPROBE)
+    BPF.attach_kprobe(fn, probe_fn)
+
+    if nsec:
+        def receive_alarm(signo, stack):
+            os.kill(os.getpid(), signal.SIGINT)
+        signal.signal(signal.SIGALRM, receive_alarm)
+        signal.alarm(nsec)
+
+    try:
+        if trace:
+            with open("/sys/kernel/debug/tracing/trace_pipe") as f:
+                while True:
+                    line = f.readline(128)
+                    print(line.rstrip())
+                    sys.stdout.flush()
+        elif nsec:
+            signal.pause()
+    except KeyboardInterrupt:
+        pass
+
+    if dump_tables:
+        print("Table dump not yet implemented")
+
+if __name__ == "__main__":
+    main()

src/python/setup.py.in

@@ -14,4 +14,5 @@ setup(name='bpf',
       author_email='bblanco@plumgrid.com',
       url='http://plumgrid.com',
       packages=['bpf'],
+      scripts=['bpf-run'],
       platforms=['Linux'])