@@ -14,6 +14,9 @@ import sys, os
class NoHelperFound(BaseException):
pass
+class NoSyscallCommandFound(BaseException):
+ pass
+
class ParsingError(BaseException):
def __init__(self, line='<line not provided>', reader=None):
if reader:
@@ -23,18 +26,27 @@ class ParsingError(BaseException):
else:
BaseException.__init__(self, 'Error parsing line: %s' % line)
-class Helper(object):
+
+class APIElement(object):
"""
- An object representing the description of an eBPF helper function.
- @proto: function prototype of the helper function
- @desc: textual description of the helper function
- @ret: description of the return value of the helper function
+ An object representing the description of an aspect of the eBPF API.
+ @proto: prototype of the API symbol
+ @desc: textual description of the symbol
+ @ret: (optional) description of any associated return value
"""
def __init__(self, proto='', desc='', ret=''):
self.proto = proto
self.desc = desc
self.ret = ret
+
+class Helper(APIElement):
+ """
+ An object representing the description of an eBPF helper function.
+ @proto: function prototype of the helper function
+ @desc: textual description of the helper function
+ @ret: description of the return value of the helper function
+ """
def proto_break_down(self):
"""
Break down helper function protocol into smaller chunks: return type,
@@ -61,6 +73,7 @@ class Helper(object):
return res
+
class HeaderParser(object):
"""
An object used to parse a file in order to extract the documentation of a
@@ -73,6 +86,13 @@ class HeaderParser(object):
self.reader = open(filename, 'r')
self.line = ''
self.helpers = []
+ self.commands = []
+
+ def parse_element(self):
+ proto = self.parse_symbol()
+ desc = self.parse_desc()
+ ret = self.parse_ret()
+ return APIElement(proto=proto, desc=desc, ret=ret)
def parse_helper(self):
proto = self.parse_proto()
@@ -80,6 +100,18 @@ class HeaderParser(object):
ret = self.parse_ret()
return Helper(proto=proto, desc=desc, ret=ret)
+ def parse_symbol(self):
+ p = re.compile(' \* ?(.+)$')
+ capture = p.match(self.line)
+ if not capture:
+ raise NoSyscallCommandFound
+ end_re = re.compile(' \* ?NOTES$')
+ end = end_re.match(self.line)
+ if end:
+ raise NoSyscallCommandFound
+ self.line = self.reader.readline()
+ return capture.group(1)
+
def parse_proto(self):
# Argument can be of shape:
# - "void"
@@ -141,16 +173,29 @@ class HeaderParser(object):
break
return ret
- def run(self):
- # Advance to start of helper function descriptions.
- offset = self.reader.read().find('* Start of BPF helper function descriptions:')
+ def seek_to(self, target, help_message):
+ self.reader.seek(0)
+ offset = self.reader.read().find(target)
if offset == -1:
- raise Exception('Could not find start of eBPF helper descriptions list')
+ raise Exception(help_message)
self.reader.seek(offset)
self.reader.readline()
self.reader.readline()
self.line = self.reader.readline()
+ def parse_syscall(self):
+ self.seek_to('* Start of BPF syscall commands:',
+ 'Could not find start of eBPF syscall descriptions list')
+ while True:
+ try:
+ command = self.parse_element()
+ self.commands.append(command)
+ except NoSyscallCommandFound:
+ break
+
+ def parse_helpers(self):
+ self.seek_to('* Start of BPF helper function descriptions:',
+ 'Could not find start of eBPF helper descriptions list')
while True:
try:
helper = self.parse_helper()
@@ -158,6 +203,9 @@ class HeaderParser(object):
except NoHelperFound:
break
+ def run(self):
+ self.parse_syscall()
+ self.parse_helpers()
self.reader.close()
###############################################################################
@@ -420,6 +468,37 @@ SEE ALSO
self.print_elem(helper)
+class PrinterSyscallRST(PrinterRST):
+ """
+ A printer for dumping collected information about the syscall API as a
+ ReStructured Text page compatible with the rst2man program, which can be
+ used to generate a manual page for the syscall.
+ @parser: A HeaderParser with APIElement objects to print to standard
+ output
+ """
+ def __init__(self, parser):
+ self.elements = parser.commands
+
+ def print_header(self):
+ header = '''\
+===
+bpf
+===
+-------------------------------------------------------------------------------
+Perform a command on an extended BPF object
+-------------------------------------------------------------------------------
+
+:Manual section: 2
+
+COMMANDS
+========
+'''
+ PrinterRST.print_license(self)
+ print(header)
+
+ def print_one(self, command):
+ print('**%s**' % (command.proto))
+ self.print_elem(command)
class PrinterHelpers(Printer):
@@ -620,6 +699,7 @@ bpfh = os.path.join(linuxRoot, 'include/uapi/linux/bpf.h')
printers = {
'helpers': PrinterHelpersRST,
+ 'syscall': PrinterSyscallRST,
}
argParser = argparse.ArgumentParser(description="""