Commit | Line | Data |
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3cd046f1 | 1 | #!/usr/bin/env python3 |
56a092c8 QM |
2 | # SPDX-License-Identifier: GPL-2.0-only |
3 | # | |
748c7c82 | 4 | # Copyright (C) 2018-2019 Netronome Systems, Inc. |
56a092c8 QM |
5 | |
6 | # In case user attempts to run with Python 2. | |
7 | from __future__ import print_function | |
8 | ||
9 | import argparse | |
10 | import re | |
11 | import sys, os | |
12 | ||
13 | class NoHelperFound(BaseException): | |
14 | pass | |
15 | ||
16 | class ParsingError(BaseException): | |
17 | def __init__(self, line='<line not provided>', reader=None): | |
18 | if reader: | |
19 | BaseException.__init__(self, | |
20 | 'Error at file offset %d, parsing line: %s' % | |
21 | (reader.tell(), line)) | |
22 | else: | |
23 | BaseException.__init__(self, 'Error parsing line: %s' % line) | |
24 | ||
25 | class Helper(object): | |
26 | """ | |
27 | An object representing the description of an eBPF helper function. | |
28 | @proto: function prototype of the helper function | |
29 | @desc: textual description of the helper function | |
30 | @ret: description of the return value of the helper function | |
31 | """ | |
32 | def __init__(self, proto='', desc='', ret=''): | |
33 | self.proto = proto | |
34 | self.desc = desc | |
35 | self.ret = ret | |
36 | ||
37 | def proto_break_down(self): | |
38 | """ | |
39 | Break down helper function protocol into smaller chunks: return type, | |
40 | name, distincts arguments. | |
41 | """ | |
748c7c82 | 42 | arg_re = re.compile('((\w+ )*?(\w+|...))( (\**)(\w+))?$') |
56a092c8 | 43 | res = {} |
6f96674d | 44 | proto_re = re.compile('(.+) (\**)(\w+)\(((([^,]+)(, )?){1,5})\)$') |
56a092c8 QM |
45 | |
46 | capture = proto_re.match(self.proto) | |
47 | res['ret_type'] = capture.group(1) | |
48 | res['ret_star'] = capture.group(2) | |
49 | res['name'] = capture.group(3) | |
50 | res['args'] = [] | |
51 | ||
52 | args = capture.group(4).split(', ') | |
53 | for a in args: | |
54 | capture = arg_re.match(a) | |
55 | res['args'].append({ | |
56 | 'type' : capture.group(1), | |
748c7c82 QM |
57 | 'star' : capture.group(5), |
58 | 'name' : capture.group(6) | |
56a092c8 QM |
59 | }) |
60 | ||
61 | return res | |
62 | ||
63 | class HeaderParser(object): | |
64 | """ | |
65 | An object used to parse a file in order to extract the documentation of a | |
66 | list of eBPF helper functions. All the helpers that can be retrieved are | |
67 | stored as Helper object, in the self.helpers() array. | |
68 | @filename: name of file to parse, usually include/uapi/linux/bpf.h in the | |
69 | kernel tree | |
70 | """ | |
71 | def __init__(self, filename): | |
72 | self.reader = open(filename, 'r') | |
73 | self.line = '' | |
74 | self.helpers = [] | |
75 | ||
76 | def parse_helper(self): | |
77 | proto = self.parse_proto() | |
78 | desc = self.parse_desc() | |
79 | ret = self.parse_ret() | |
80 | return Helper(proto=proto, desc=desc, ret=ret) | |
81 | ||
82 | def parse_proto(self): | |
83 | # Argument can be of shape: | |
84 | # - "void" | |
85 | # - "type name" | |
86 | # - "type *name" | |
87 | # - Same as above, with "const" and/or "struct" in front of type | |
88 | # - "..." (undefined number of arguments, for bpf_trace_printk()) | |
89 | # There is at least one term ("void"), and at most five arguments. | |
6f96674d | 90 | p = re.compile(' \* ?((.+) \**\w+\((((const )?(struct )?(\w+|\.\.\.)( \**\w+)?)(, )?){1,5}\))$') |
56a092c8 QM |
91 | capture = p.match(self.line) |
92 | if not capture: | |
93 | raise NoHelperFound | |
94 | self.line = self.reader.readline() | |
95 | return capture.group(1) | |
96 | ||
97 | def parse_desc(self): | |
eeacb716 | 98 | p = re.compile(' \* ?(?:\t| {5,8})Description$') |
56a092c8 QM |
99 | capture = p.match(self.line) |
100 | if not capture: | |
101 | # Helper can have empty description and we might be parsing another | |
102 | # attribute: return but do not consume. | |
103 | return '' | |
104 | # Description can be several lines, some of them possibly empty, and it | |
105 | # stops when another subsection title is met. | |
106 | desc = '' | |
107 | while True: | |
108 | self.line = self.reader.readline() | |
109 | if self.line == ' *\n': | |
110 | desc += '\n' | |
111 | else: | |
eeacb716 | 112 | p = re.compile(' \* ?(?:\t| {5,8})(?:\t| {8})(.*)') |
56a092c8 QM |
113 | capture = p.match(self.line) |
114 | if capture: | |
115 | desc += capture.group(1) + '\n' | |
116 | else: | |
117 | break | |
118 | return desc | |
119 | ||
120 | def parse_ret(self): | |
eeacb716 | 121 | p = re.compile(' \* ?(?:\t| {5,8})Return$') |
56a092c8 QM |
122 | capture = p.match(self.line) |
123 | if not capture: | |
124 | # Helper can have empty retval and we might be parsing another | |
125 | # attribute: return but do not consume. | |
126 | return '' | |
127 | # Return value description can be several lines, some of them possibly | |
128 | # empty, and it stops when another subsection title is met. | |
129 | ret = '' | |
130 | while True: | |
131 | self.line = self.reader.readline() | |
132 | if self.line == ' *\n': | |
133 | ret += '\n' | |
134 | else: | |
eeacb716 | 135 | p = re.compile(' \* ?(?:\t| {5,8})(?:\t| {8})(.*)') |
56a092c8 QM |
136 | capture = p.match(self.line) |
137 | if capture: | |
138 | ret += capture.group(1) + '\n' | |
139 | else: | |
140 | break | |
141 | return ret | |
142 | ||
143 | def run(self): | |
144 | # Advance to start of helper function descriptions. | |
145 | offset = self.reader.read().find('* Start of BPF helper function descriptions:') | |
146 | if offset == -1: | |
147 | raise Exception('Could not find start of eBPF helper descriptions list') | |
148 | self.reader.seek(offset) | |
149 | self.reader.readline() | |
150 | self.reader.readline() | |
151 | self.line = self.reader.readline() | |
152 | ||
153 | while True: | |
154 | try: | |
155 | helper = self.parse_helper() | |
156 | self.helpers.append(helper) | |
157 | except NoHelperFound: | |
158 | break | |
159 | ||
160 | self.reader.close() | |
56a092c8 QM |
161 | |
162 | ############################################################################### | |
163 | ||
164 | class Printer(object): | |
165 | """ | |
166 | A generic class for printers. Printers should be created with an array of | |
167 | Helper objects, and implement a way to print them in the desired fashion. | |
168 | @helpers: array of Helper objects to print to standard output | |
169 | """ | |
170 | def __init__(self, helpers): | |
171 | self.helpers = helpers | |
172 | ||
173 | def print_header(self): | |
174 | pass | |
175 | ||
176 | def print_footer(self): | |
177 | pass | |
178 | ||
179 | def print_one(self, helper): | |
180 | pass | |
181 | ||
182 | def print_all(self): | |
183 | self.print_header() | |
184 | for helper in self.helpers: | |
185 | self.print_one(helper) | |
186 | self.print_footer() | |
187 | ||
188 | class PrinterRST(Printer): | |
189 | """ | |
190 | A printer for dumping collected information about helpers as a ReStructured | |
191 | Text page compatible with the rst2man program, which can be used to | |
192 | generate a manual page for the helpers. | |
193 | @helpers: array of Helper objects to print to standard output | |
194 | """ | |
195 | def print_header(self): | |
196 | header = '''\ | |
197 | .. Copyright (C) All BPF authors and contributors from 2014 to present. | |
198 | .. See git log include/uapi/linux/bpf.h in kernel tree for details. | |
199 | .. | |
200 | .. %%%LICENSE_START(VERBATIM) | |
201 | .. Permission is granted to make and distribute verbatim copies of this | |
202 | .. manual provided the copyright notice and this permission notice are | |
203 | .. preserved on all copies. | |
204 | .. | |
205 | .. Permission is granted to copy and distribute modified versions of this | |
206 | .. manual under the conditions for verbatim copying, provided that the | |
207 | .. entire resulting derived work is distributed under the terms of a | |
208 | .. permission notice identical to this one. | |
209 | .. | |
210 | .. Since the Linux kernel and libraries are constantly changing, this | |
211 | .. manual page may be incorrect or out-of-date. The author(s) assume no | |
212 | .. responsibility for errors or omissions, or for damages resulting from | |
213 | .. the use of the information contained herein. The author(s) may not | |
214 | .. have taken the same level of care in the production of this manual, | |
215 | .. which is licensed free of charge, as they might when working | |
216 | .. professionally. | |
217 | .. | |
218 | .. Formatted or processed versions of this manual, if unaccompanied by | |
219 | .. the source, must acknowledge the copyright and authors of this work. | |
220 | .. %%%LICENSE_END | |
221 | .. | |
222 | .. Please do not edit this file. It was generated from the documentation | |
223 | .. located in file include/uapi/linux/bpf.h of the Linux kernel sources | |
224 | .. (helpers description), and from scripts/bpf_helpers_doc.py in the same | |
225 | .. repository (header and footer). | |
226 | ||
227 | =========== | |
228 | BPF-HELPERS | |
229 | =========== | |
230 | ------------------------------------------------------------------------------- | |
231 | list of eBPF helper functions | |
232 | ------------------------------------------------------------------------------- | |
233 | ||
234 | :Manual section: 7 | |
235 | ||
236 | DESCRIPTION | |
237 | =========== | |
238 | ||
239 | The extended Berkeley Packet Filter (eBPF) subsystem consists in programs | |
240 | written in a pseudo-assembly language, then attached to one of the several | |
241 | kernel hooks and run in reaction of specific events. This framework differs | |
242 | from the older, "classic" BPF (or "cBPF") in several aspects, one of them being | |
243 | the ability to call special functions (or "helpers") from within a program. | |
244 | These functions are restricted to a white-list of helpers defined in the | |
245 | kernel. | |
246 | ||
247 | These helpers are used by eBPF programs to interact with the system, or with | |
248 | the context in which they work. For instance, they can be used to print | |
249 | debugging messages, to get the time since the system was booted, to interact | |
250 | with eBPF maps, or to manipulate network packets. Since there are several eBPF | |
251 | program types, and that they do not run in the same context, each program type | |
252 | can only call a subset of those helpers. | |
253 | ||
254 | Due to eBPF conventions, a helper can not have more than five arguments. | |
255 | ||
256 | Internally, eBPF programs call directly into the compiled helper functions | |
257 | without requiring any foreign-function interface. As a result, calling helpers | |
258 | introduces no overhead, thus offering excellent performance. | |
259 | ||
260 | This document is an attempt to list and document the helpers available to eBPF | |
261 | developers. They are sorted by chronological order (the oldest helpers in the | |
262 | kernel at the top). | |
263 | ||
264 | HELPERS | |
265 | ======= | |
266 | ''' | |
267 | print(header) | |
268 | ||
269 | def print_footer(self): | |
270 | footer = ''' | |
271 | EXAMPLES | |
272 | ======== | |
273 | ||
274 | Example usage for most of the eBPF helpers listed in this manual page are | |
275 | available within the Linux kernel sources, at the following locations: | |
276 | ||
277 | * *samples/bpf/* | |
278 | * *tools/testing/selftests/bpf/* | |
279 | ||
280 | LICENSE | |
281 | ======= | |
282 | ||
283 | eBPF programs can have an associated license, passed along with the bytecode | |
284 | instructions to the kernel when the programs are loaded. The format for that | |
285 | string is identical to the one in use for kernel modules (Dual licenses, such | |
286 | as "Dual BSD/GPL", may be used). Some helper functions are only accessible to | |
287 | programs that are compatible with the GNU Privacy License (GPL). | |
288 | ||
289 | In order to use such helpers, the eBPF program must be loaded with the correct | |
290 | license string passed (via **attr**) to the **bpf**\ () system call, and this | |
291 | generally translates into the C source code of the program containing a line | |
292 | similar to the following: | |
293 | ||
294 | :: | |
295 | ||
296 | char ____license[] __attribute__((section("license"), used)) = "GPL"; | |
297 | ||
298 | IMPLEMENTATION | |
299 | ============== | |
300 | ||
301 | This manual page is an effort to document the existing eBPF helper functions. | |
302 | But as of this writing, the BPF sub-system is under heavy development. New eBPF | |
303 | program or map types are added, along with new helper functions. Some helpers | |
304 | are occasionally made available for additional program types. So in spite of | |
305 | the efforts of the community, this page might not be up-to-date. If you want to | |
306 | check by yourself what helper functions exist in your kernel, or what types of | |
307 | programs they can support, here are some files among the kernel tree that you | |
308 | may be interested in: | |
309 | ||
310 | * *include/uapi/linux/bpf.h* is the main BPF header. It contains the full list | |
311 | of all helper functions, as well as many other BPF definitions including most | |
312 | of the flags, structs or constants used by the helpers. | |
313 | * *net/core/filter.c* contains the definition of most network-related helper | |
314 | functions, and the list of program types from which they can be used. | |
315 | * *kernel/trace/bpf_trace.c* is the equivalent for most tracing program-related | |
316 | helpers. | |
317 | * *kernel/bpf/verifier.c* contains the functions used to check that valid types | |
318 | of eBPF maps are used with a given helper function. | |
319 | * *kernel/bpf/* directory contains other files in which additional helpers are | |
320 | defined (for cgroups, sockmaps, etc.). | |
ab8d7809 QM |
321 | * The bpftool utility can be used to probe the availability of helper functions |
322 | on the system (as well as supported program and map types, and a number of | |
323 | other parameters). To do so, run **bpftool feature probe** (see | |
324 | **bpftool-feature**\ (8) for details). Add the **unprivileged** keyword to | |
325 | list features available to unprivileged users. | |
56a092c8 QM |
326 | |
327 | Compatibility between helper functions and program types can generally be found | |
328 | in the files where helper functions are defined. Look for the **struct | |
329 | bpf_func_proto** objects and for functions returning them: these functions | |
330 | contain a list of helpers that a given program type can call. Note that the | |
331 | **default:** label of the **switch ... case** used to filter helpers can call | |
332 | other functions, themselves allowing access to additional helpers. The | |
333 | requirement for GPL license is also in those **struct bpf_func_proto**. | |
334 | ||
335 | Compatibility between helper functions and map types can be found in the | |
336 | **check_map_func_compatibility**\ () function in file *kernel/bpf/verifier.c*. | |
337 | ||
338 | Helper functions that invalidate the checks on **data** and **data_end** | |
339 | pointers for network processing are listed in function | |
340 | **bpf_helper_changes_pkt_data**\ () in file *net/core/filter.c*. | |
341 | ||
342 | SEE ALSO | |
343 | ======== | |
344 | ||
345 | **bpf**\ (2), | |
ab8d7809 | 346 | **bpftool**\ (8), |
56a092c8 QM |
347 | **cgroups**\ (7), |
348 | **ip**\ (8), | |
349 | **perf_event_open**\ (2), | |
350 | **sendmsg**\ (2), | |
351 | **socket**\ (7), | |
352 | **tc-bpf**\ (8)''' | |
353 | print(footer) | |
354 | ||
355 | def print_proto(self, helper): | |
356 | """ | |
357 | Format function protocol with bold and italics markers. This makes RST | |
358 | file less readable, but gives nice results in the manual page. | |
359 | """ | |
360 | proto = helper.proto_break_down() | |
361 | ||
362 | print('**%s %s%s(' % (proto['ret_type'], | |
363 | proto['ret_star'].replace('*', '\\*'), | |
364 | proto['name']), | |
365 | end='') | |
366 | ||
367 | comma = '' | |
368 | for a in proto['args']: | |
369 | one_arg = '{}{}'.format(comma, a['type']) | |
370 | if a['name']: | |
371 | if a['star']: | |
372 | one_arg += ' {}**\ '.format(a['star'].replace('*', '\\*')) | |
373 | else: | |
374 | one_arg += '** ' | |
375 | one_arg += '*{}*\\ **'.format(a['name']) | |
376 | comma = ', ' | |
377 | print(one_arg, end='') | |
378 | ||
379 | print(')**') | |
380 | ||
381 | def print_one(self, helper): | |
382 | self.print_proto(helper) | |
383 | ||
384 | if (helper.desc): | |
385 | print('\tDescription') | |
386 | # Do not strip all newline characters: formatted code at the end of | |
387 | # a section must be followed by a blank line. | |
388 | for line in re.sub('\n$', '', helper.desc, count=1).split('\n'): | |
389 | print('{}{}'.format('\t\t' if line else '', line)) | |
390 | ||
391 | if (helper.ret): | |
392 | print('\tReturn') | |
393 | for line in helper.ret.rstrip().split('\n'): | |
394 | print('{}{}'.format('\t\t' if line else '', line)) | |
395 | ||
396 | print('') | |
397 | ||
7a387bed AN |
398 | class PrinterHelpers(Printer): |
399 | """ | |
400 | A printer for dumping collected information about helpers as C header to | |
401 | be included from BPF program. | |
402 | @helpers: array of Helper objects to print to standard output | |
403 | """ | |
404 | ||
405 | type_fwds = [ | |
406 | 'struct bpf_fib_lookup', | |
e9ddbb77 | 407 | 'struct bpf_sk_lookup', |
7a387bed AN |
408 | 'struct bpf_perf_event_data', |
409 | 'struct bpf_perf_event_value', | |
5996a587 | 410 | 'struct bpf_pidns_info', |
7a387bed AN |
411 | 'struct bpf_sock', |
412 | 'struct bpf_sock_addr', | |
413 | 'struct bpf_sock_ops', | |
414 | 'struct bpf_sock_tuple', | |
415 | 'struct bpf_spin_lock', | |
416 | 'struct bpf_sysctl', | |
417 | 'struct bpf_tcp_sock', | |
418 | 'struct bpf_tunnel_key', | |
419 | 'struct bpf_xfrm_state', | |
420 | 'struct pt_regs', | |
421 | 'struct sk_reuseport_md', | |
422 | 'struct sockaddr', | |
423 | 'struct tcphdr', | |
492e639f | 424 | 'struct seq_file', |
af7ec138 | 425 | 'struct tcp6_sock', |
478cfbdf YS |
426 | 'struct tcp_sock', |
427 | 'struct tcp_timewait_sock', | |
428 | 'struct tcp_request_sock', | |
0d4fad3e | 429 | 'struct udp6_sock', |
fa28dcb8 | 430 | 'struct task_struct', |
7a387bed AN |
431 | |
432 | 'struct __sk_buff', | |
433 | 'struct sk_msg_md', | |
e0b68fb1 | 434 | 'struct xdp_md', |
7a387bed AN |
435 | ] |
436 | known_types = { | |
437 | '...', | |
438 | 'void', | |
439 | 'const void', | |
440 | 'char', | |
441 | 'const char', | |
442 | 'int', | |
443 | 'long', | |
444 | 'unsigned long', | |
445 | ||
446 | '__be16', | |
447 | '__be32', | |
448 | '__wsum', | |
449 | ||
450 | 'struct bpf_fib_lookup', | |
451 | 'struct bpf_perf_event_data', | |
452 | 'struct bpf_perf_event_value', | |
b4490c5c | 453 | 'struct bpf_pidns_info', |
e9ddbb77 | 454 | 'struct bpf_sk_lookup', |
7a387bed AN |
455 | 'struct bpf_sock', |
456 | 'struct bpf_sock_addr', | |
457 | 'struct bpf_sock_ops', | |
458 | 'struct bpf_sock_tuple', | |
459 | 'struct bpf_spin_lock', | |
460 | 'struct bpf_sysctl', | |
461 | 'struct bpf_tcp_sock', | |
462 | 'struct bpf_tunnel_key', | |
463 | 'struct bpf_xfrm_state', | |
464 | 'struct pt_regs', | |
465 | 'struct sk_reuseport_md', | |
466 | 'struct sockaddr', | |
467 | 'struct tcphdr', | |
492e639f | 468 | 'struct seq_file', |
af7ec138 | 469 | 'struct tcp6_sock', |
478cfbdf YS |
470 | 'struct tcp_sock', |
471 | 'struct tcp_timewait_sock', | |
472 | 'struct tcp_request_sock', | |
0d4fad3e | 473 | 'struct udp6_sock', |
fa28dcb8 | 474 | 'struct task_struct', |
7a387bed AN |
475 | } |
476 | mapped_types = { | |
477 | 'u8': '__u8', | |
478 | 'u16': '__u16', | |
479 | 'u32': '__u32', | |
480 | 'u64': '__u64', | |
481 | 's8': '__s8', | |
482 | 's16': '__s16', | |
483 | 's32': '__s32', | |
484 | 's64': '__s64', | |
485 | 'size_t': 'unsigned long', | |
486 | 'struct bpf_map': 'void', | |
487 | 'struct sk_buff': 'struct __sk_buff', | |
488 | 'const struct sk_buff': 'const struct __sk_buff', | |
489 | 'struct sk_msg_buff': 'struct sk_msg_md', | |
490 | 'struct xdp_buff': 'struct xdp_md', | |
491 | } | |
e9ddbb77 JS |
492 | # Helpers overloaded for different context types. |
493 | overloaded_helpers = [ | |
494 | 'bpf_get_socket_cookie', | |
495 | 'bpf_sk_assign', | |
496 | ] | |
7a387bed AN |
497 | |
498 | def print_header(self): | |
499 | header = '''\ | |
500 | /* This is auto-generated file. See bpf_helpers_doc.py for details. */ | |
501 | ||
502 | /* Forward declarations of BPF structs */''' | |
503 | ||
504 | print(header) | |
505 | for fwd in self.type_fwds: | |
506 | print('%s;' % fwd) | |
507 | print('') | |
508 | ||
509 | def print_footer(self): | |
510 | footer = '' | |
511 | print(footer) | |
512 | ||
513 | def map_type(self, t): | |
514 | if t in self.known_types: | |
515 | return t | |
516 | if t in self.mapped_types: | |
517 | return self.mapped_types[t] | |
ab81e203 JS |
518 | print("Unrecognized type '%s', please add it to known types!" % t, |
519 | file=sys.stderr) | |
7a387bed AN |
520 | sys.exit(1) |
521 | ||
522 | seen_helpers = set() | |
523 | ||
524 | def print_one(self, helper): | |
525 | proto = helper.proto_break_down() | |
526 | ||
527 | if proto['name'] in self.seen_helpers: | |
528 | return | |
529 | self.seen_helpers.add(proto['name']) | |
530 | ||
531 | print('/*') | |
532 | print(" * %s" % proto['name']) | |
533 | print(" *") | |
534 | if (helper.desc): | |
535 | # Do not strip all newline characters: formatted code at the end of | |
536 | # a section must be followed by a blank line. | |
537 | for line in re.sub('\n$', '', helper.desc, count=1).split('\n'): | |
538 | print(' *{}{}'.format(' \t' if line else '', line)) | |
539 | ||
540 | if (helper.ret): | |
541 | print(' *') | |
542 | print(' * Returns') | |
543 | for line in helper.ret.rstrip().split('\n'): | |
544 | print(' *{}{}'.format(' \t' if line else '', line)) | |
545 | ||
546 | print(' */') | |
547 | print('static %s %s(*%s)(' % (self.map_type(proto['ret_type']), | |
548 | proto['ret_star'], proto['name']), end='') | |
549 | comma = '' | |
550 | for i, a in enumerate(proto['args']): | |
551 | t = a['type'] | |
552 | n = a['name'] | |
e9ddbb77 | 553 | if proto['name'] in self.overloaded_helpers and i == 0: |
7a387bed AN |
554 | t = 'void' |
555 | n = 'ctx' | |
556 | one_arg = '{}{}'.format(comma, self.map_type(t)) | |
557 | if n: | |
558 | if a['star']: | |
559 | one_arg += ' {}'.format(a['star']) | |
560 | else: | |
561 | one_arg += ' ' | |
562 | one_arg += '{}'.format(n) | |
563 | comma = ', ' | |
564 | print(one_arg, end='') | |
565 | ||
566 | print(') = (void *) %d;' % len(self.seen_helpers)) | |
567 | print('') | |
568 | ||
56a092c8 QM |
569 | ############################################################################### |
570 | ||
571 | # If script is launched from scripts/ from kernel tree and can access | |
572 | # ../include/uapi/linux/bpf.h, use it as a default name for the file to parse, | |
573 | # otherwise the --filename argument will be required from the command line. | |
574 | script = os.path.abspath(sys.argv[0]) | |
575 | linuxRoot = os.path.dirname(os.path.dirname(script)) | |
576 | bpfh = os.path.join(linuxRoot, 'include/uapi/linux/bpf.h') | |
577 | ||
578 | argParser = argparse.ArgumentParser(description=""" | |
579 | Parse eBPF header file and generate documentation for eBPF helper functions. | |
580 | The RST-formatted output produced can be turned into a manual page with the | |
581 | rst2man utility. | |
582 | """) | |
7a387bed AN |
583 | argParser.add_argument('--header', action='store_true', |
584 | help='generate C header file') | |
56a092c8 QM |
585 | if (os.path.isfile(bpfh)): |
586 | argParser.add_argument('--filename', help='path to include/uapi/linux/bpf.h', | |
587 | default=bpfh) | |
588 | else: | |
589 | argParser.add_argument('--filename', help='path to include/uapi/linux/bpf.h') | |
590 | args = argParser.parse_args() | |
591 | ||
592 | # Parse file. | |
593 | headerParser = HeaderParser(args.filename) | |
594 | headerParser.run() | |
595 | ||
596 | # Print formatted output to standard output. | |
7a387bed AN |
597 | if args.header: |
598 | printer = PrinterHelpers(headerParser.helpers) | |
599 | else: | |
600 | printer = PrinterRST(headerParser.helpers) | |
56a092c8 | 601 | printer.print_all() |