1 #!/usr/bin/env python3 1 #!/usr/bin/env python3
2 # SPDX-License-Identifier: GPL-2.0-only 2 # SPDX-License-Identifier: GPL-2.0-only
3 # 3 #
4 # Copyright (C) 2018-2019 Netronome Systems, I 4 # Copyright (C) 2018-2019 Netronome Systems, Inc.
5 # Copyright (C) 2021 Isovalent, Inc. 5 # Copyright (C) 2021 Isovalent, Inc.
6 6
7 # In case user attempts to run with Python 2. 7 # In case user attempts to run with Python 2.
8 from __future__ import print_function 8 from __future__ import print_function
9 9
10 import argparse 10 import argparse
11 import re 11 import re
12 import sys, os 12 import sys, os
13 import subprocess <<
14 <<
15 helpersDocStart = 'Start of BPF helper functio <<
16 13
17 class NoHelperFound(BaseException): 14 class NoHelperFound(BaseException):
18 pass 15 pass
19 16
20 class NoSyscallCommandFound(BaseException): 17 class NoSyscallCommandFound(BaseException):
21 pass 18 pass
22 19
23 class ParsingError(BaseException): 20 class ParsingError(BaseException):
24 def __init__(self, line='<line not provide 21 def __init__(self, line='<line not provided>', reader=None):
25 if reader: 22 if reader:
26 BaseException.__init__(self, 23 BaseException.__init__(self,
27 'Error at f 24 'Error at file offset %d, parsing line: %s' %
28 (reader.tel 25 (reader.tell(), line))
29 else: 26 else:
30 BaseException.__init__(self, 'Erro 27 BaseException.__init__(self, 'Error parsing line: %s' % line)
31 28
32 29
33 class APIElement(object): 30 class APIElement(object):
34 """ 31 """
35 An object representing the description of 32 An object representing the description of an aspect of the eBPF API.
36 @proto: prototype of the API symbol 33 @proto: prototype of the API symbol
37 @desc: textual description of the symbol 34 @desc: textual description of the symbol
38 @ret: (optional) description of any associ 35 @ret: (optional) description of any associated return value
39 """ 36 """
40 def __init__(self, proto='', desc='', ret= 37 def __init__(self, proto='', desc='', ret=''):
41 self.proto = proto 38 self.proto = proto
42 self.desc = desc 39 self.desc = desc
43 self.ret = ret 40 self.ret = ret
44 41
45 42
46 class Helper(APIElement): 43 class Helper(APIElement):
47 """ 44 """
48 An object representing the description of 45 An object representing the description of an eBPF helper function.
49 @proto: function prototype of the helper f 46 @proto: function prototype of the helper function
50 @desc: textual description of the helper f 47 @desc: textual description of the helper function
51 @ret: description of the return value of t 48 @ret: description of the return value of the helper function
52 """ 49 """
53 def __init__(self, *args, **kwargs): <<
54 super().__init__(*args, **kwargs) <<
55 self.enum_val = None <<
56 <<
57 def proto_break_down(self): 50 def proto_break_down(self):
58 """ 51 """
59 Break down helper function protocol in 52 Break down helper function protocol into smaller chunks: return type,
60 name, distincts arguments. 53 name, distincts arguments.
61 """ 54 """
62 arg_re = re.compile(r'((\w+ )*?(\w+|.. !! 55 arg_re = re.compile('((\w+ )*?(\w+|...))( (\**)(\w+))?$')
63 res = {} 56 res = {}
64 proto_re = re.compile(r'(.+) (\**)(\w+ !! 57 proto_re = re.compile('(.+) (\**)(\w+)\(((([^,]+)(, )?){1,5})\)$')
65 58
66 capture = proto_re.match(self.proto) 59 capture = proto_re.match(self.proto)
67 res['ret_type'] = capture.group(1) 60 res['ret_type'] = capture.group(1)
68 res['ret_star'] = capture.group(2) 61 res['ret_star'] = capture.group(2)
69 res['name'] = capture.group(3) 62 res['name'] = capture.group(3)
70 res['args'] = [] 63 res['args'] = []
71 64
72 args = capture.group(4).split(', ') 65 args = capture.group(4).split(', ')
73 for a in args: 66 for a in args:
74 capture = arg_re.match(a) 67 capture = arg_re.match(a)
75 res['args'].append({ 68 res['args'].append({
76 'type' : capture.group(1), 69 'type' : capture.group(1),
77 'star' : capture.group(5), 70 'star' : capture.group(5),
78 'name' : capture.group(6) 71 'name' : capture.group(6)
79 }) 72 })
80 73
81 return res 74 return res
82 75
83 76
84 class HeaderParser(object): 77 class HeaderParser(object):
85 """ 78 """
86 An object used to parse a file in order to 79 An object used to parse a file in order to extract the documentation of a
87 list of eBPF helper functions. All the hel 80 list of eBPF helper functions. All the helpers that can be retrieved are
88 stored as Helper object, in the self.helpe 81 stored as Helper object, in the self.helpers() array.
89 @filename: name of file to parse, usually 82 @filename: name of file to parse, usually include/uapi/linux/bpf.h in the
90 kernel tree 83 kernel tree
91 """ 84 """
92 def __init__(self, filename): 85 def __init__(self, filename):
93 self.reader = open(filename, 'r') 86 self.reader = open(filename, 'r')
94 self.line = '' 87 self.line = ''
95 self.helpers = [] 88 self.helpers = []
96 self.commands = [] 89 self.commands = []
97 self.desc_unique_helpers = set() 90 self.desc_unique_helpers = set()
98 self.define_unique_helpers = [] 91 self.define_unique_helpers = []
99 self.helper_enum_vals = {} <<
100 self.helper_enum_pos = {} <<
101 self.desc_syscalls = [] 92 self.desc_syscalls = []
102 self.enum_syscalls = [] 93 self.enum_syscalls = []
103 94
104 def parse_element(self): 95 def parse_element(self):
105 proto = self.parse_symbol() 96 proto = self.parse_symbol()
106 desc = self.parse_desc(proto) 97 desc = self.parse_desc(proto)
107 ret = self.parse_ret(proto) 98 ret = self.parse_ret(proto)
108 return APIElement(proto=proto, desc=de 99 return APIElement(proto=proto, desc=desc, ret=ret)
109 100
110 def parse_helper(self): 101 def parse_helper(self):
111 proto = self.parse_proto() 102 proto = self.parse_proto()
112 desc = self.parse_desc(proto) 103 desc = self.parse_desc(proto)
113 ret = self.parse_ret(proto) 104 ret = self.parse_ret(proto)
114 return Helper(proto=proto, desc=desc, 105 return Helper(proto=proto, desc=desc, ret=ret)
115 106
116 def parse_symbol(self): 107 def parse_symbol(self):
117 p = re.compile(r' \* ?(BPF\w+)$') !! 108 p = re.compile(' \* ?(BPF\w+)$')
118 capture = p.match(self.line) 109 capture = p.match(self.line)
119 if not capture: 110 if not capture:
120 raise NoSyscallCommandFound 111 raise NoSyscallCommandFound
121 end_re = re.compile(r' \* ?NOTES$') !! 112 end_re = re.compile(' \* ?NOTES$')
122 end = end_re.match(self.line) 113 end = end_re.match(self.line)
123 if end: 114 if end:
124 raise NoSyscallCommandFound 115 raise NoSyscallCommandFound
125 self.line = self.reader.readline() 116 self.line = self.reader.readline()
126 return capture.group(1) 117 return capture.group(1)
127 118
128 def parse_proto(self): 119 def parse_proto(self):
129 # Argument can be of shape: 120 # Argument can be of shape:
130 # - "void" 121 # - "void"
131 # - "type name" 122 # - "type name"
132 # - "type *name" 123 # - "type *name"
133 # - Same as above, with "const" and/ 124 # - Same as above, with "const" and/or "struct" in front of type
134 # - "..." (undefined number of argum 125 # - "..." (undefined number of arguments, for bpf_trace_printk())
135 # There is at least one term ("void"), 126 # There is at least one term ("void"), and at most five arguments.
136 p = re.compile(r' \* ?((.+) \**\w+\((( !! 127 p = re.compile(' \* ?((.+) \**\w+\((((const )?(struct )?(\w+|\.\.\.)( \**\w+)?)(, )?){1,5}\))$')
137 capture = p.match(self.line) 128 capture = p.match(self.line)
138 if not capture: 129 if not capture:
139 raise NoHelperFound 130 raise NoHelperFound
140 self.line = self.reader.readline() 131 self.line = self.reader.readline()
141 return capture.group(1) 132 return capture.group(1)
142 133
143 def parse_desc(self, proto): 134 def parse_desc(self, proto):
144 p = re.compile(r' \* ?(?:\t| {5,8})Des !! 135 p = re.compile(' \* ?(?:\t| {5,8})Description$')
145 capture = p.match(self.line) 136 capture = p.match(self.line)
146 if not capture: 137 if not capture:
147 raise Exception("No description se 138 raise Exception("No description section found for " + proto)
148 # Description can be several lines, so 139 # Description can be several lines, some of them possibly empty, and it
149 # stops when another subsection title 140 # stops when another subsection title is met.
150 desc = '' 141 desc = ''
151 desc_present = False 142 desc_present = False
152 while True: 143 while True:
153 self.line = self.reader.readline() 144 self.line = self.reader.readline()
154 if self.line == ' *\n': 145 if self.line == ' *\n':
155 desc += '\n' 146 desc += '\n'
156 else: 147 else:
157 p = re.compile(r' \* ?(?:\t| { !! 148 p = re.compile(' \* ?(?:\t| {5,8})(?:\t| {8})(.*)')
158 capture = p.match(self.line) 149 capture = p.match(self.line)
159 if capture: 150 if capture:
160 desc_present = True 151 desc_present = True
161 desc += capture.group(1) + 152 desc += capture.group(1) + '\n'
162 else: 153 else:
163 break 154 break
164 155
165 if not desc_present: 156 if not desc_present:
166 raise Exception("No description fo 157 raise Exception("No description found for " + proto)
167 return desc 158 return desc
168 159
169 def parse_ret(self, proto): 160 def parse_ret(self, proto):
170 p = re.compile(r' \* ?(?:\t| {5,8})Ret !! 161 p = re.compile(' \* ?(?:\t| {5,8})Return$')
171 capture = p.match(self.line) 162 capture = p.match(self.line)
172 if not capture: 163 if not capture:
173 raise Exception("No return section 164 raise Exception("No return section found for " + proto)
174 # Return value description can be seve 165 # Return value description can be several lines, some of them possibly
175 # empty, and it stops when another sub 166 # empty, and it stops when another subsection title is met.
176 ret = '' 167 ret = ''
177 ret_present = False 168 ret_present = False
178 while True: 169 while True:
179 self.line = self.reader.readline() 170 self.line = self.reader.readline()
180 if self.line == ' *\n': 171 if self.line == ' *\n':
181 ret += '\n' 172 ret += '\n'
182 else: 173 else:
183 p = re.compile(r' \* ?(?:\t| { !! 174 p = re.compile(' \* ?(?:\t| {5,8})(?:\t| {8})(.*)')
184 capture = p.match(self.line) 175 capture = p.match(self.line)
185 if capture: 176 if capture:
186 ret_present = True 177 ret_present = True
187 ret += capture.group(1) + 178 ret += capture.group(1) + '\n'
188 else: 179 else:
189 break 180 break
190 181
191 if not ret_present: 182 if not ret_present:
192 raise Exception("No return found f 183 raise Exception("No return found for " + proto)
193 return ret 184 return ret
194 185
195 def seek_to(self, target, help_message, di 186 def seek_to(self, target, help_message, discard_lines = 1):
196 self.reader.seek(0) 187 self.reader.seek(0)
197 offset = self.reader.read().find(targe 188 offset = self.reader.read().find(target)
198 if offset == -1: 189 if offset == -1:
199 raise Exception(help_message) 190 raise Exception(help_message)
200 self.reader.seek(offset) 191 self.reader.seek(offset)
201 self.reader.readline() 192 self.reader.readline()
202 for _ in range(discard_lines): 193 for _ in range(discard_lines):
203 self.reader.readline() 194 self.reader.readline()
204 self.line = self.reader.readline() 195 self.line = self.reader.readline()
205 196
206 def parse_desc_syscall(self): 197 def parse_desc_syscall(self):
207 self.seek_to('* DOC: eBPF Syscall Comm 198 self.seek_to('* DOC: eBPF Syscall Commands',
208 'Could not find start of 199 'Could not find start of eBPF syscall descriptions list')
209 while True: 200 while True:
210 try: 201 try:
211 command = self.parse_element() 202 command = self.parse_element()
212 self.commands.append(command) 203 self.commands.append(command)
213 self.desc_syscalls.append(comm 204 self.desc_syscalls.append(command.proto)
214 205
215 except NoSyscallCommandFound: 206 except NoSyscallCommandFound:
216 break 207 break
217 208
218 def parse_enum_syscall(self): 209 def parse_enum_syscall(self):
219 self.seek_to('enum bpf_cmd {', 210 self.seek_to('enum bpf_cmd {',
220 'Could not find start of 211 'Could not find start of bpf_cmd enum', 0)
221 # Searches for either one or more BPF\ 212 # Searches for either one or more BPF\w+ enums
222 bpf_p = re.compile(r'\s*(BPF\w+)+') !! 213 bpf_p = re.compile('\s*(BPF\w+)+')
223 # Searches for an enum entry assigned 214 # Searches for an enum entry assigned to another entry,
224 # for e.g. BPF_PROG_RUN = BPF_PROG_TES 215 # for e.g. BPF_PROG_RUN = BPF_PROG_TEST_RUN, which is
225 # not documented hence should be skipp 216 # not documented hence should be skipped in check to
226 # determine if the right number of sys 217 # determine if the right number of syscalls are documented
227 assign_p = re.compile(r'\s*(BPF\w+)\s* !! 218 assign_p = re.compile('\s*(BPF\w+)\s*=\s*(BPF\w+)')
228 bpf_cmd_str = '' 219 bpf_cmd_str = ''
229 while True: 220 while True:
230 capture = assign_p.match(self.line 221 capture = assign_p.match(self.line)
231 if capture: 222 if capture:
232 # Skip line if an enum entry i 223 # Skip line if an enum entry is assigned to another entry
233 self.line = self.reader.readli 224 self.line = self.reader.readline()
234 continue 225 continue
235 capture = bpf_p.match(self.line) 226 capture = bpf_p.match(self.line)
236 if capture: 227 if capture:
237 bpf_cmd_str += self.line 228 bpf_cmd_str += self.line
238 else: 229 else:
239 break 230 break
240 self.line = self.reader.readline() 231 self.line = self.reader.readline()
241 # Find the number of occurences of BPF 232 # Find the number of occurences of BPF\w+
242 self.enum_syscalls = re.findall(r'(BPF !! 233 self.enum_syscalls = re.findall('(BPF\w+)+', bpf_cmd_str)
243 234
244 def parse_desc_helpers(self): 235 def parse_desc_helpers(self):
245 self.seek_to(helpersDocStart, !! 236 self.seek_to('* Start of BPF helper function descriptions:',
246 'Could not find start of 237 'Could not find start of eBPF helper descriptions list')
247 while True: 238 while True:
248 try: 239 try:
249 helper = self.parse_helper() 240 helper = self.parse_helper()
250 self.helpers.append(helper) 241 self.helpers.append(helper)
251 proto = helper.proto_break_dow 242 proto = helper.proto_break_down()
252 self.desc_unique_helpers.add(p 243 self.desc_unique_helpers.add(proto['name'])
253 except NoHelperFound: 244 except NoHelperFound:
254 break 245 break
255 246
256 def parse_define_helpers(self): 247 def parse_define_helpers(self):
257 # Parse FN(...) in #define ___BPF_FUNC !! 248 # Parse the number of FN(...) in #define __BPF_FUNC_MAPPER to compare
258 # number of unique function names pres !! 249 # later with the number of unique function names present in description.
259 # correct enumeration value. <<
260 # Note: seek_to(..) discards the first 250 # Note: seek_to(..) discards the first line below the target search text,
261 # resulting in FN(unspec, 0, ##ctx) be !! 251 # resulting in FN(unspec) being skipped and not added to self.define_unique_helpers.
262 # self.define_unique_helpers. !! 252 self.seek_to('#define __BPF_FUNC_MAPPER(FN)',
263 self.seek_to('#define ___BPF_FUNC_MAPP <<
264 'Could not find start of 253 'Could not find start of eBPF helper definition list')
265 # Searches for one FN(\w+) define or a !! 254 # Searches for either one or more FN(\w+) defines or a backslash for newline
266 p = re.compile(r'\s*FN\((\w+), (\d+), !! 255 p = re.compile('\s*(FN\(\w+\))+|\\\\')
267 fn_defines_str = '' 256 fn_defines_str = ''
268 i = 0 <<
269 while True: 257 while True:
270 capture = p.match(self.line) 258 capture = p.match(self.line)
271 if capture: 259 if capture:
272 fn_defines_str += self.line 260 fn_defines_str += self.line
273 helper_name = capture.expand(r <<
274 self.helper_enum_vals[helper_n <<
275 self.helper_enum_pos[helper_na <<
276 i += 1 <<
277 else: 261 else:
278 break 262 break
279 self.line = self.reader.readline() 263 self.line = self.reader.readline()
280 # Find the number of occurences of FN( 264 # Find the number of occurences of FN(\w+)
281 self.define_unique_helpers = re.findal !! 265 self.define_unique_helpers = re.findall('FN\(\w+\)', fn_defines_str)
282 <<
283 def validate_helpers(self): <<
284 last_helper = '' <<
285 seen_helpers = set() <<
286 seen_enum_vals = set() <<
287 i = 0 <<
288 for helper in self.helpers: <<
289 proto = helper.proto_break_down() <<
290 name = proto['name'] <<
291 try: <<
292 enum_val = self.helper_enum_va <<
293 enum_pos = self.helper_enum_po <<
294 except KeyError: <<
295 raise Exception("Helper %s is <<
296 <<
297 if name in seen_helpers: <<
298 if last_helper != name: <<
299 raise Exception("Helper %s <<
300 continue <<
301 <<
302 # Enforce current practice of havi <<
303 # by enum value. <<
304 if enum_pos != i: <<
305 raise Exception("Helper %s (ID <<
306 if enum_val in seen_enum_vals: <<
307 raise Exception("Helper %s has <<
308 <<
309 seen_helpers.add(name) <<
310 last_helper = name <<
311 seen_enum_vals.add(enum_val) <<
312 <<
313 helper.enum_val = enum_val <<
314 i += 1 <<
315 266
316 def run(self): 267 def run(self):
317 self.parse_desc_syscall() 268 self.parse_desc_syscall()
318 self.parse_enum_syscall() 269 self.parse_enum_syscall()
319 self.parse_desc_helpers() 270 self.parse_desc_helpers()
320 self.parse_define_helpers() 271 self.parse_define_helpers()
321 self.validate_helpers() <<
322 self.reader.close() 272 self.reader.close()
323 273
324 ############################################## 274 ###############################################################################
325 275
326 class Printer(object): 276 class Printer(object):
327 """ 277 """
328 A generic class for printers. Printers sho 278 A generic class for printers. Printers should be created with an array of
329 Helper objects, and implement a way to pri 279 Helper objects, and implement a way to print them in the desired fashion.
330 @parser: A HeaderParser with objects to pr 280 @parser: A HeaderParser with objects to print to standard output
331 """ 281 """
332 def __init__(self, parser): 282 def __init__(self, parser):
333 self.parser = parser 283 self.parser = parser
334 self.elements = [] 284 self.elements = []
335 285
336 def print_header(self): 286 def print_header(self):
337 pass 287 pass
338 288
339 def print_footer(self): 289 def print_footer(self):
340 pass 290 pass
341 291
342 def print_one(self, helper): 292 def print_one(self, helper):
343 pass 293 pass
344 294
345 def print_all(self): 295 def print_all(self):
346 self.print_header() 296 self.print_header()
347 for elem in self.elements: 297 for elem in self.elements:
348 self.print_one(elem) 298 self.print_one(elem)
349 self.print_footer() 299 self.print_footer()
350 300
351 def elem_number_check(self, desc_unique_el 301 def elem_number_check(self, desc_unique_elem, define_unique_elem, type, instance):
352 """ 302 """
353 Checks the number of helpers/syscalls 303 Checks the number of helpers/syscalls documented within the header file
354 description with those defined as part 304 description with those defined as part of enum/macro and raise an
355 Exception if they don't match. 305 Exception if they don't match.
356 """ 306 """
357 nr_desc_unique_elem = len(desc_unique_ 307 nr_desc_unique_elem = len(desc_unique_elem)
358 nr_define_unique_elem = len(define_uni 308 nr_define_unique_elem = len(define_unique_elem)
359 if nr_desc_unique_elem != nr_define_un 309 if nr_desc_unique_elem != nr_define_unique_elem:
360 exception_msg = ''' 310 exception_msg = '''
361 The number of unique %s in description (%d) do 311 The number of unique %s in description (%d) doesn\'t match the number of unique %s defined in %s (%d)
362 ''' % (type, nr_desc_unique_elem, type, instan 312 ''' % (type, nr_desc_unique_elem, type, instance, nr_define_unique_elem)
363 if nr_desc_unique_elem < nr_define 313 if nr_desc_unique_elem < nr_define_unique_elem:
364 # Function description is pars 314 # Function description is parsed until no helper is found (which can be due to
365 # misformatting). Hence, only 315 # misformatting). Hence, only print the first missing/misformatted helper/enum.
366 exception_msg += ''' 316 exception_msg += '''
367 The description for %s is not present or forma 317 The description for %s is not present or formatted correctly.
368 ''' % (define_unique_elem[nr_desc_unique_elem] 318 ''' % (define_unique_elem[nr_desc_unique_elem])
369 raise Exception(exception_msg) 319 raise Exception(exception_msg)
370 320
371 class PrinterRST(Printer): 321 class PrinterRST(Printer):
372 """ 322 """
373 A generic class for printers that print Re 323 A generic class for printers that print ReStructured Text. Printers should
374 be created with a HeaderParser object, and 324 be created with a HeaderParser object, and implement a way to print API
375 elements in the desired fashion. 325 elements in the desired fashion.
376 @parser: A HeaderParser with objects to pr 326 @parser: A HeaderParser with objects to print to standard output
377 """ 327 """
378 def __init__(self, parser): 328 def __init__(self, parser):
379 self.parser = parser 329 self.parser = parser
380 330
381 def print_license(self): 331 def print_license(self):
382 license = '''\ 332 license = '''\
383 .. Copyright (C) All BPF authors and contribut 333 .. Copyright (C) All BPF authors and contributors from 2014 to present.
384 .. See git log include/uapi/linux/bpf.h in ker 334 .. See git log include/uapi/linux/bpf.h in kernel tree for details.
385 .. 335 ..
386 .. SPDX-License-Identifier: Linux-man-pages-co !! 336 .. %%%LICENSE_START(VERBATIM)
>> 337 .. Permission is granted to make and distribute verbatim copies of this
>> 338 .. manual provided the copyright notice and this permission notice are
>> 339 .. preserved on all copies.
>> 340 ..
>> 341 .. Permission is granted to copy and distribute modified versions of this
>> 342 .. manual under the conditions for verbatim copying, provided that the
>> 343 .. entire resulting derived work is distributed under the terms of a
>> 344 .. permission notice identical to this one.
>> 345 ..
>> 346 .. Since the Linux kernel and libraries are constantly changing, this
>> 347 .. manual page may be incorrect or out-of-date. The author(s) assume no
>> 348 .. responsibility for errors or omissions, or for damages resulting from
>> 349 .. the use of the information contained herein. The author(s) may not
>> 350 .. have taken the same level of care in the production of this manual,
>> 351 .. which is licensed free of charge, as they might when working
>> 352 .. professionally.
>> 353 ..
>> 354 .. Formatted or processed versions of this manual, if unaccompanied by
>> 355 .. the source, must acknowledge the copyright and authors of this work.
>> 356 .. %%%LICENSE_END
387 .. 357 ..
388 .. Please do not edit this file. It was genera 358 .. Please do not edit this file. It was generated from the documentation
389 .. located in file include/uapi/linux/bpf.h of 359 .. located in file include/uapi/linux/bpf.h of the Linux kernel sources
390 .. (helpers description), and from scripts/bpf 360 .. (helpers description), and from scripts/bpf_doc.py in the same
391 .. repository (header and footer). 361 .. repository (header and footer).
392 ''' 362 '''
393 print(license) 363 print(license)
394 364
395 def print_elem(self, elem): 365 def print_elem(self, elem):
396 if (elem.desc): 366 if (elem.desc):
397 print('\tDescription') 367 print('\tDescription')
398 # Do not strip all newline charact 368 # Do not strip all newline characters: formatted code at the end of
399 # a section must be followed by a 369 # a section must be followed by a blank line.
400 for line in re.sub('\n$', '', elem 370 for line in re.sub('\n$', '', elem.desc, count=1).split('\n'):
401 print('{}{}'.format('\t\t' if 371 print('{}{}'.format('\t\t' if line else '', line))
402 372
403 if (elem.ret): 373 if (elem.ret):
404 print('\tReturn') 374 print('\tReturn')
405 for line in elem.ret.rstrip().spli 375 for line in elem.ret.rstrip().split('\n'):
406 print('{}{}'.format('\t\t' if 376 print('{}{}'.format('\t\t' if line else '', line))
407 377
408 print('') 378 print('')
409 379
410 def get_kernel_version(self): <<
411 try: <<
412 version = subprocess.run(['git', ' <<
413 capture_o <<
414 version = version.stdout.decode(). <<
415 except: <<
416 try: <<
417 version = subprocess.run(['mak <<
418 cwd=l <<
419 version = version.stdout.decod <<
420 except: <<
421 return 'Linux' <<
422 return 'Linux {version}'.format(versio <<
423 <<
424 def get_last_doc_update(self, delimiter): <<
425 try: <<
426 cmd = ['git', 'log', '-1', '--pret <<
427 '-L', <<
428 '/{}/,/\\*\\//:include/uapi <<
429 date = subprocess.run(cmd, cwd=lin <<
430 capture_outp <<
431 return date.stdout.decode().rstrip <<
432 except: <<
433 return '' <<
434 <<
435 class PrinterHelpersRST(PrinterRST): 380 class PrinterHelpersRST(PrinterRST):
436 """ 381 """
437 A printer for dumping collected informatio 382 A printer for dumping collected information about helpers as a ReStructured
438 Text page compatible with the rst2man prog 383 Text page compatible with the rst2man program, which can be used to
439 generate a manual page for the helpers. 384 generate a manual page for the helpers.
440 @parser: A HeaderParser with Helper object 385 @parser: A HeaderParser with Helper objects to print to standard output
441 """ 386 """
442 def __init__(self, parser): 387 def __init__(self, parser):
443 self.elements = parser.helpers 388 self.elements = parser.helpers
444 self.elem_number_check(parser.desc_uni !! 389 self.elem_number_check(parser.desc_unique_helpers, parser.define_unique_helpers, 'helper', '__BPF_FUNC_MAPPER')
445 390
446 def print_header(self): 391 def print_header(self):
447 header = '''\ 392 header = '''\
448 =========== 393 ===========
449 BPF-HELPERS 394 BPF-HELPERS
450 =========== 395 ===========
451 ---------------------------------------------- 396 -------------------------------------------------------------------------------
452 list of eBPF helper functions 397 list of eBPF helper functions
453 ---------------------------------------------- 398 -------------------------------------------------------------------------------
454 399
455 :Manual section: 7 400 :Manual section: 7
456 :Version: {version} <<
457 {date_field}{date} <<
458 401
459 DESCRIPTION 402 DESCRIPTION
460 =========== 403 ===========
461 404
462 The extended Berkeley Packet Filter (eBPF) sub 405 The extended Berkeley Packet Filter (eBPF) subsystem consists in programs
463 written in a pseudo-assembly language, then at 406 written in a pseudo-assembly language, then attached to one of the several
464 kernel hooks and run in reaction of specific e 407 kernel hooks and run in reaction of specific events. This framework differs
465 from the older, "classic" BPF (or "cBPF") in s 408 from the older, "classic" BPF (or "cBPF") in several aspects, one of them being
466 the ability to call special functions (or "hel 409 the ability to call special functions (or "helpers") from within a program.
467 These functions are restricted to a white-list 410 These functions are restricted to a white-list of helpers defined in the
468 kernel. 411 kernel.
469 412
470 These helpers are used by eBPF programs to int 413 These helpers are used by eBPF programs to interact with the system, or with
471 the context in which they work. For instance, 414 the context in which they work. For instance, they can be used to print
472 debugging messages, to get the time since the 415 debugging messages, to get the time since the system was booted, to interact
473 with eBPF maps, or to manipulate network packe 416 with eBPF maps, or to manipulate network packets. Since there are several eBPF
474 program types, and that they do not run in the 417 program types, and that they do not run in the same context, each program type
475 can only call a subset of those helpers. 418 can only call a subset of those helpers.
476 419
477 Due to eBPF conventions, a helper can not have 420 Due to eBPF conventions, a helper can not have more than five arguments.
478 421
479 Internally, eBPF programs call directly into t 422 Internally, eBPF programs call directly into the compiled helper functions
480 without requiring any foreign-function interfa 423 without requiring any foreign-function interface. As a result, calling helpers
481 introduces no overhead, thus offering excellen 424 introduces no overhead, thus offering excellent performance.
482 425
483 This document is an attempt to list and docume 426 This document is an attempt to list and document the helpers available to eBPF
484 developers. They are sorted by chronological o 427 developers. They are sorted by chronological order (the oldest helpers in the
485 kernel at the top). 428 kernel at the top).
486 429
487 HELPERS 430 HELPERS
488 ======= 431 =======
489 ''' 432 '''
490 kernelVersion = self.get_kernel_versio <<
491 lastUpdate = self.get_last_doc_update( <<
492 <<
493 PrinterRST.print_license(self) 433 PrinterRST.print_license(self)
494 print(header.format(version=kernelVers !! 434 print(header)
495 date_field = ':Dat <<
496 date=lastUpdate)) <<
497 435
498 def print_footer(self): 436 def print_footer(self):
499 footer = ''' 437 footer = '''
500 EXAMPLES 438 EXAMPLES
501 ======== 439 ========
502 440
503 Example usage for most of the eBPF helpers lis 441 Example usage for most of the eBPF helpers listed in this manual page are
504 available within the Linux kernel sources, at 442 available within the Linux kernel sources, at the following locations:
505 443
506 * *samples/bpf/* 444 * *samples/bpf/*
507 * *tools/testing/selftests/bpf/* 445 * *tools/testing/selftests/bpf/*
508 446
509 LICENSE 447 LICENSE
510 ======= 448 =======
511 449
512 eBPF programs can have an associated license, 450 eBPF programs can have an associated license, passed along with the bytecode
513 instructions to the kernel when the programs a 451 instructions to the kernel when the programs are loaded. The format for that
514 string is identical to the one in use for kern 452 string is identical to the one in use for kernel modules (Dual licenses, such
515 as "Dual BSD/GPL", may be used). Some helper f 453 as "Dual BSD/GPL", may be used). Some helper functions are only accessible to
516 programs that are compatible with the GNU Gene !! 454 programs that are compatible with the GNU Privacy License (GPL).
517 455
518 In order to use such helpers, the eBPF program 456 In order to use such helpers, the eBPF program must be loaded with the correct
519 license string passed (via **attr**) to the ** !! 457 license string passed (via **attr**) to the **bpf**\ () system call, and this
520 generally translates into the C source code of 458 generally translates into the C source code of the program containing a line
521 similar to the following: 459 similar to the following:
522 460
523 :: 461 ::
524 462
525 char ____license[] __attribute__((sect 463 char ____license[] __attribute__((section("license"), used)) = "GPL";
526 464
527 IMPLEMENTATION 465 IMPLEMENTATION
528 ============== 466 ==============
529 467
530 This manual page is an effort to document the 468 This manual page is an effort to document the existing eBPF helper functions.
531 But as of this writing, the BPF sub-system is 469 But as of this writing, the BPF sub-system is under heavy development. New eBPF
532 program or map types are added, along with new 470 program or map types are added, along with new helper functions. Some helpers
533 are occasionally made available for additional 471 are occasionally made available for additional program types. So in spite of
534 the efforts of the community, this page might 472 the efforts of the community, this page might not be up-to-date. If you want to
535 check by yourself what helper functions exist 473 check by yourself what helper functions exist in your kernel, or what types of
536 programs they can support, here are some files 474 programs they can support, here are some files among the kernel tree that you
537 may be interested in: 475 may be interested in:
538 476
539 * *include/uapi/linux/bpf.h* is the main BPF h 477 * *include/uapi/linux/bpf.h* is the main BPF header. It contains the full list
540 of all helper functions, as well as many oth 478 of all helper functions, as well as many other BPF definitions including most
541 of the flags, structs or constants used by t 479 of the flags, structs or constants used by the helpers.
542 * *net/core/filter.c* contains the definition 480 * *net/core/filter.c* contains the definition of most network-related helper
543 functions, and the list of program types fro 481 functions, and the list of program types from which they can be used.
544 * *kernel/trace/bpf_trace.c* is the equivalent 482 * *kernel/trace/bpf_trace.c* is the equivalent for most tracing program-related
545 helpers. 483 helpers.
546 * *kernel/bpf/verifier.c* contains the functio 484 * *kernel/bpf/verifier.c* contains the functions used to check that valid types
547 of eBPF maps are used with a given helper fu 485 of eBPF maps are used with a given helper function.
548 * *kernel/bpf/* directory contains other files 486 * *kernel/bpf/* directory contains other files in which additional helpers are
549 defined (for cgroups, sockmaps, etc.). 487 defined (for cgroups, sockmaps, etc.).
550 * The bpftool utility can be used to probe the 488 * The bpftool utility can be used to probe the availability of helper functions
551 on the system (as well as supported program 489 on the system (as well as supported program and map types, and a number of
552 other parameters). To do so, run **bpftool f 490 other parameters). To do so, run **bpftool feature probe** (see
553 **bpftool-feature**\\ (8) for details). Add !! 491 **bpftool-feature**\ (8) for details). Add the **unprivileged** keyword to
554 list features available to unprivileged user 492 list features available to unprivileged users.
555 493
556 Compatibility between helper functions and pro 494 Compatibility between helper functions and program types can generally be found
557 in the files where helper functions are define 495 in the files where helper functions are defined. Look for the **struct
558 bpf_func_proto** objects and for functions ret 496 bpf_func_proto** objects and for functions returning them: these functions
559 contain a list of helpers that a given program 497 contain a list of helpers that a given program type can call. Note that the
560 **default:** label of the **switch ... case** 498 **default:** label of the **switch ... case** used to filter helpers can call
561 other functions, themselves allowing access to 499 other functions, themselves allowing access to additional helpers. The
562 requirement for GPL license is also in those * 500 requirement for GPL license is also in those **struct bpf_func_proto**.
563 501
564 Compatibility between helper functions and map 502 Compatibility between helper functions and map types can be found in the
565 **check_map_func_compatibility**\\ () function !! 503 **check_map_func_compatibility**\ () function in file *kernel/bpf/verifier.c*.
566 504
567 Helper functions that invalidate the checks on 505 Helper functions that invalidate the checks on **data** and **data_end**
568 pointers for network processing are listed in 506 pointers for network processing are listed in function
569 **bpf_helper_changes_pkt_data**\\ () in file * !! 507 **bpf_helper_changes_pkt_data**\ () in file *net/core/filter.c*.
570 508
571 SEE ALSO 509 SEE ALSO
572 ======== 510 ========
573 511
574 **bpf**\\ (2), !! 512 **bpf**\ (2),
575 **bpftool**\\ (8), !! 513 **bpftool**\ (8),
576 **cgroups**\\ (7), !! 514 **cgroups**\ (7),
577 **ip**\\ (8), !! 515 **ip**\ (8),
578 **perf_event_open**\\ (2), !! 516 **perf_event_open**\ (2),
579 **sendmsg**\\ (2), !! 517 **sendmsg**\ (2),
580 **socket**\\ (7), !! 518 **socket**\ (7),
581 **tc-bpf**\\ (8)''' !! 519 **tc-bpf**\ (8)'''
582 print(footer) 520 print(footer)
583 521
584 def print_proto(self, helper): 522 def print_proto(self, helper):
585 """ 523 """
586 Format function protocol with bold and 524 Format function protocol with bold and italics markers. This makes RST
587 file less readable, but gives nice res 525 file less readable, but gives nice results in the manual page.
588 """ 526 """
589 proto = helper.proto_break_down() 527 proto = helper.proto_break_down()
590 528
591 print('**%s %s%s(' % (proto['ret_type' 529 print('**%s %s%s(' % (proto['ret_type'],
592 proto['ret_star' 530 proto['ret_star'].replace('*', '\\*'),
593 proto['name']), 531 proto['name']),
594 end='') 532 end='')
595 533
596 comma = '' 534 comma = ''
597 for a in proto['args']: 535 for a in proto['args']:
598 one_arg = '{}{}'.format(comma, a[' 536 one_arg = '{}{}'.format(comma, a['type'])
599 if a['name']: 537 if a['name']:
600 if a['star']: 538 if a['star']:
601 one_arg += ' {}**\\ '.form !! 539 one_arg += ' {}**\ '.format(a['star'].replace('*', '\\*'))
602 else: 540 else:
603 one_arg += '** ' 541 one_arg += '** '
604 one_arg += '*{}*\\ **'.format( 542 one_arg += '*{}*\\ **'.format(a['name'])
605 comma = ', ' 543 comma = ', '
606 print(one_arg, end='') 544 print(one_arg, end='')
607 545
608 print(')**') 546 print(')**')
609 547
610 def print_one(self, helper): 548 def print_one(self, helper):
611 self.print_proto(helper) 549 self.print_proto(helper)
612 self.print_elem(helper) 550 self.print_elem(helper)
613 551
614 552
615 class PrinterSyscallRST(PrinterRST): 553 class PrinterSyscallRST(PrinterRST):
616 """ 554 """
617 A printer for dumping collected informatio 555 A printer for dumping collected information about the syscall API as a
618 ReStructured Text page compatible with the 556 ReStructured Text page compatible with the rst2man program, which can be
619 used to generate a manual page for the sys 557 used to generate a manual page for the syscall.
620 @parser: A HeaderParser with APIElement ob 558 @parser: A HeaderParser with APIElement objects to print to standard
621 output 559 output
622 """ 560 """
623 def __init__(self, parser): 561 def __init__(self, parser):
624 self.elements = parser.commands 562 self.elements = parser.commands
625 self.elem_number_check(parser.desc_sys 563 self.elem_number_check(parser.desc_syscalls, parser.enum_syscalls, 'syscall', 'bpf_cmd')
626 564
627 def print_header(self): 565 def print_header(self):
628 header = '''\ 566 header = '''\
629 === 567 ===
630 bpf 568 bpf
631 === 569 ===
632 ---------------------------------------------- 570 -------------------------------------------------------------------------------
633 Perform a command on an extended BPF object 571 Perform a command on an extended BPF object
634 ---------------------------------------------- 572 -------------------------------------------------------------------------------
635 573
636 :Manual section: 2 574 :Manual section: 2
637 575
638 COMMANDS 576 COMMANDS
639 ======== 577 ========
640 ''' 578 '''
641 PrinterRST.print_license(self) 579 PrinterRST.print_license(self)
642 print(header) 580 print(header)
643 581
644 def print_one(self, command): 582 def print_one(self, command):
645 print('**%s**' % (command.proto)) 583 print('**%s**' % (command.proto))
646 self.print_elem(command) 584 self.print_elem(command)
647 585
648 586
649 class PrinterHelpers(Printer): 587 class PrinterHelpers(Printer):
650 """ 588 """
651 A printer for dumping collected informatio 589 A printer for dumping collected information about helpers as C header to
652 be included from BPF program. 590 be included from BPF program.
653 @parser: A HeaderParser with Helper object 591 @parser: A HeaderParser with Helper objects to print to standard output
654 """ 592 """
655 def __init__(self, parser): 593 def __init__(self, parser):
656 self.elements = parser.helpers 594 self.elements = parser.helpers
657 self.elem_number_check(parser.desc_uni !! 595 self.elem_number_check(parser.desc_unique_helpers, parser.define_unique_helpers, 'helper', '__BPF_FUNC_MAPPER')
658 596
659 type_fwds = [ 597 type_fwds = [
660 'struct bpf_fib_lookup', 598 'struct bpf_fib_lookup',
661 'struct bpf_sk_lookup', 599 'struct bpf_sk_lookup',
662 'struct bpf_perf_event_data', 600 'struct bpf_perf_event_data',
663 'struct bpf_perf_event_value', 601 'struct bpf_perf_event_value',
664 'struct bpf_pidns_info', 602 'struct bpf_pidns_info',
665 'struct bpf_redir_neigh', 603 'struct bpf_redir_neigh',
666 'struct bpf_sock', 604 'struct bpf_sock',
667 'struct bpf_sock_addr', 605 'struct bpf_sock_addr',
668 'struct bpf_sock_ops', 606 'struct bpf_sock_ops',
669 'struct bpf_sock_tuple', 607 'struct bpf_sock_tuple',
670 'struct bpf_spin_lock', 608 'struct bpf_spin_lock',
671 'struct bpf_sysctl', 609 'struct bpf_sysctl',
672 'struct bpf_tcp_sock', 610 'struct bpf_tcp_sock',
673 'struct bpf_tunnel_key', 611 'struct bpf_tunnel_key',
674 'struct bpf_xfrm_state', 612 'struct bpf_xfrm_state',
675 'struct linux_binprm', 613 'struct linux_binprm',
676 'struct pt_regs', 614 'struct pt_regs',
677 'struct sk_reuseport_md', 615 'struct sk_reuseport_md',
678 'struct sockaddr', 616 'struct sockaddr',
679 'struct tcphdr', 617 'struct tcphdr',
680 'struct seq_file', 618 'struct seq_file',
681 'struct tcp6_sock', 619 'struct tcp6_sock',
682 'struct tcp_sock', 620 'struct tcp_sock',
683 'struct tcp_timewait_sock', 621 'struct tcp_timewait_sock',
684 'struct tcp_request_sock', 622 'struct tcp_request_sock',
685 'struct udp6_sock', 623 'struct udp6_sock',
686 'struct unix_sock', 624 'struct unix_sock',
687 'struct task_struct', 625 'struct task_struct',
688 'struct cgroup', <<
689 626
690 'struct __sk_buff', 627 'struct __sk_buff',
691 'struct sk_msg_md', 628 'struct sk_msg_md',
692 'struct xdp_md', 629 'struct xdp_md',
693 'struct path', 630 'struct path',
694 'struct btf_ptr', 631 'struct btf_ptr',
695 'struct inode', 632 'struct inode',
696 'struct socket', 633 'struct socket',
697 'struct file', 634 'struct file',
698 'struct bpf_timer', 635 'struct bpf_timer',
699 'struct mptcp_sock', 636 'struct mptcp_sock',
700 'struct bpf_dynptr', 637 'struct bpf_dynptr',
701 'struct iphdr', <<
702 'struct ipv6hdr', <<
703 ] 638 ]
704 known_types = { 639 known_types = {
705 '...', 640 '...',
706 'void', 641 'void',
707 'const void', 642 'const void',
708 'char', 643 'char',
709 'const char', 644 'const char',
710 'int', 645 'int',
711 'long', 646 'long',
712 'unsigned long', 647 'unsigned long',
713 648
714 '__be16', 649 '__be16',
715 '__be32', 650 '__be32',
716 '__wsum', 651 '__wsum',
717 652
718 'struct bpf_fib_lookup', 653 'struct bpf_fib_lookup',
719 'struct bpf_perf_event_data', 654 'struct bpf_perf_event_data',
720 'struct bpf_perf_event_value', 655 'struct bpf_perf_event_value',
721 'struct bpf_pidns_info', 656 'struct bpf_pidns_info',
722 'struct bpf_redir_neigh', 657 'struct bpf_redir_neigh',
723 'struct bpf_sk_lookup', 658 'struct bpf_sk_lookup',
724 'struct bpf_sock', 659 'struct bpf_sock',
725 'struct bpf_sock_addr', 660 'struct bpf_sock_addr',
726 'struct bpf_sock_ops', 661 'struct bpf_sock_ops',
727 'struct bpf_sock_tuple', 662 'struct bpf_sock_tuple',
728 'struct bpf_spin_lock', 663 'struct bpf_spin_lock',
729 'struct bpf_sysctl', 664 'struct bpf_sysctl',
730 'struct bpf_tcp_sock', 665 'struct bpf_tcp_sock',
731 'struct bpf_tunnel_key', 666 'struct bpf_tunnel_key',
732 'struct bpf_xfrm_state', 667 'struct bpf_xfrm_state',
733 'struct linux_binprm', 668 'struct linux_binprm',
734 'struct pt_regs', 669 'struct pt_regs',
735 'struct sk_reuseport_md', 670 'struct sk_reuseport_md',
736 'struct sockaddr', 671 'struct sockaddr',
737 'struct tcphdr', 672 'struct tcphdr',
738 'struct seq_file', 673 'struct seq_file',
739 'struct tcp6_sock', 674 'struct tcp6_sock',
740 'struct tcp_sock', 675 'struct tcp_sock',
741 'struct tcp_timewait_sock', 676 'struct tcp_timewait_sock',
742 'struct tcp_request_sock', 677 'struct tcp_request_sock',
743 'struct udp6_sock', 678 'struct udp6_sock',
744 'struct unix_sock', 679 'struct unix_sock',
745 'struct task_struct', 680 'struct task_struct',
746 'struct cgroup', <<
747 'struct path', 681 'struct path',
748 'struct btf_ptr', 682 'struct btf_ptr',
749 'struct inode', 683 'struct inode',
750 'struct socket', 684 'struct socket',
751 'struct file', 685 'struct file',
752 'struct bpf_timer', 686 'struct bpf_timer',
753 'struct mptcp_sock', 687 'struct mptcp_sock',
754 'struct bpf_dynptr', 688 'struct bpf_dynptr',
755 'const struct bpf_dynptr', <<
756 'struct iphdr', <<
757 'struct ipv6hdr', <<
758 } 689 }
759 mapped_types = { 690 mapped_types = {
760 'u8': '__u8', 691 'u8': '__u8',
761 'u16': '__u16', 692 'u16': '__u16',
762 'u32': '__u32', 693 'u32': '__u32',
763 'u64': '__u64', 694 'u64': '__u64',
764 's8': '__s8', 695 's8': '__s8',
765 's16': '__s16', 696 's16': '__s16',
766 's32': '__s32', 697 's32': '__s32',
767 's64': '__s64', 698 's64': '__s64',
768 'size_t': 'unsigned long', 699 'size_t': 'unsigned long',
769 'struct bpf_map': 'void', 700 'struct bpf_map': 'void',
770 'struct sk_buff': 'struct __sk_buf 701 'struct sk_buff': 'struct __sk_buff',
771 'const struct sk_buff': 'const str 702 'const struct sk_buff': 'const struct __sk_buff',
772 'struct sk_msg_buff': 'struct sk_m 703 'struct sk_msg_buff': 'struct sk_msg_md',
773 'struct xdp_buff': 'struct xdp_md' 704 'struct xdp_buff': 'struct xdp_md',
774 } 705 }
775 # Helpers overloaded for different context 706 # Helpers overloaded for different context types.
776 overloaded_helpers = [ 707 overloaded_helpers = [
777 'bpf_get_socket_cookie', 708 'bpf_get_socket_cookie',
778 'bpf_sk_assign', 709 'bpf_sk_assign',
779 ] 710 ]
780 711
781 def print_header(self): 712 def print_header(self):
782 header = '''\ 713 header = '''\
783 /* This is auto-generated file. See bpf_doc.py 714 /* This is auto-generated file. See bpf_doc.py for details. */
784 715
785 /* Forward declarations of BPF structs */''' 716 /* Forward declarations of BPF structs */'''
786 717
787 print(header) 718 print(header)
788 for fwd in self.type_fwds: 719 for fwd in self.type_fwds:
789 print('%s;' % fwd) 720 print('%s;' % fwd)
790 print('') 721 print('')
791 722
792 def print_footer(self): 723 def print_footer(self):
793 footer = '' 724 footer = ''
794 print(footer) 725 print(footer)
795 726
796 def map_type(self, t): 727 def map_type(self, t):
797 if t in self.known_types: 728 if t in self.known_types:
798 return t 729 return t
799 if t in self.mapped_types: 730 if t in self.mapped_types:
800 return self.mapped_types[t] 731 return self.mapped_types[t]
801 print("Unrecognized type '%s', please 732 print("Unrecognized type '%s', please add it to known types!" % t,
802 file=sys.stderr) 733 file=sys.stderr)
803 sys.exit(1) 734 sys.exit(1)
804 735
805 seen_helpers = set() 736 seen_helpers = set()
806 737
807 def print_one(self, helper): 738 def print_one(self, helper):
808 proto = helper.proto_break_down() 739 proto = helper.proto_break_down()
809 740
810 if proto['name'] in self.seen_helpers: 741 if proto['name'] in self.seen_helpers:
811 return 742 return
812 self.seen_helpers.add(proto['name']) 743 self.seen_helpers.add(proto['name'])
813 744
814 print('/*') 745 print('/*')
815 print(" * %s" % proto['name']) 746 print(" * %s" % proto['name'])
816 print(" *") 747 print(" *")
817 if (helper.desc): 748 if (helper.desc):
818 # Do not strip all newline charact 749 # Do not strip all newline characters: formatted code at the end of
819 # a section must be followed by a 750 # a section must be followed by a blank line.
820 for line in re.sub('\n$', '', help 751 for line in re.sub('\n$', '', helper.desc, count=1).split('\n'):
821 print(' *{}{}'.format(' \t' if 752 print(' *{}{}'.format(' \t' if line else '', line))
822 753
823 if (helper.ret): 754 if (helper.ret):
824 print(' *') 755 print(' *')
825 print(' * Returns') 756 print(' * Returns')
826 for line in helper.ret.rstrip().sp 757 for line in helper.ret.rstrip().split('\n'):
827 print(' *{}{}'.format(' \t' if 758 print(' *{}{}'.format(' \t' if line else '', line))
828 759
829 print(' */') 760 print(' */')
830 print('static %s %s(* const %s)(' % (s !! 761 print('static %s %s(*%s)(' % (self.map_type(proto['ret_type']),
831 proto['r 762 proto['ret_star'], proto['name']), end='')
832 comma = '' 763 comma = ''
833 for i, a in enumerate(proto['args']): 764 for i, a in enumerate(proto['args']):
834 t = a['type'] 765 t = a['type']
835 n = a['name'] 766 n = a['name']
836 if proto['name'] in self.overloade 767 if proto['name'] in self.overloaded_helpers and i == 0:
837 t = 'void' 768 t = 'void'
838 n = 'ctx' 769 n = 'ctx'
839 one_arg = '{}{}'.format(comma, sel 770 one_arg = '{}{}'.format(comma, self.map_type(t))
840 if n: 771 if n:
841 if a['star']: 772 if a['star']:
842 one_arg += ' {}'.format(a[ 773 one_arg += ' {}'.format(a['star'])
843 else: 774 else:
844 one_arg += ' ' 775 one_arg += ' '
845 one_arg += '{}'.format(n) 776 one_arg += '{}'.format(n)
846 comma = ', ' 777 comma = ', '
847 print(one_arg, end='') 778 print(one_arg, end='')
848 779
849 print(') = (void *) %d;' % helper.enum !! 780 print(') = (void *) %d;' % len(self.seen_helpers))
850 print('') 781 print('')
851 782
852 ############################################## 783 ###############################################################################
853 784
854 # If script is launched from scripts/ from ker 785 # If script is launched from scripts/ from kernel tree and can access
855 # ../include/uapi/linux/bpf.h, use it as a def 786 # ../include/uapi/linux/bpf.h, use it as a default name for the file to parse,
856 # otherwise the --filename argument will be re 787 # otherwise the --filename argument will be required from the command line.
857 script = os.path.abspath(sys.argv[0]) 788 script = os.path.abspath(sys.argv[0])
858 linuxRoot = os.path.dirname(os.path.dirname(sc 789 linuxRoot = os.path.dirname(os.path.dirname(script))
859 bpfh = os.path.join(linuxRoot, 'include/uapi/l 790 bpfh = os.path.join(linuxRoot, 'include/uapi/linux/bpf.h')
860 791
861 printers = { 792 printers = {
862 'helpers': PrinterHelpersRST, 793 'helpers': PrinterHelpersRST,
863 'syscall': PrinterSyscallRST, 794 'syscall': PrinterSyscallRST,
864 } 795 }
865 796
866 argParser = argparse.ArgumentParser(descriptio 797 argParser = argparse.ArgumentParser(description="""
867 Parse eBPF header file and generate documentat 798 Parse eBPF header file and generate documentation for the eBPF API.
868 The RST-formatted output produced can be turne 799 The RST-formatted output produced can be turned into a manual page with the
869 rst2man utility. 800 rst2man utility.
870 """) 801 """)
871 argParser.add_argument('--header', action='sto 802 argParser.add_argument('--header', action='store_true',
872 help='generate C header 803 help='generate C header file')
873 if (os.path.isfile(bpfh)): 804 if (os.path.isfile(bpfh)):
874 argParser.add_argument('--filename', help= 805 argParser.add_argument('--filename', help='path to include/uapi/linux/bpf.h',
875 default=bpfh) 806 default=bpfh)
876 else: 807 else:
877 argParser.add_argument('--filename', help= 808 argParser.add_argument('--filename', help='path to include/uapi/linux/bpf.h')
878 argParser.add_argument('target', nargs='?', de 809 argParser.add_argument('target', nargs='?', default='helpers',
879 choices=printers.keys() 810 choices=printers.keys(), help='eBPF API target')
880 args = argParser.parse_args() 811 args = argParser.parse_args()
881 812
882 # Parse file. 813 # Parse file.
883 headerParser = HeaderParser(args.filename) 814 headerParser = HeaderParser(args.filename)
884 headerParser.run() 815 headerParser.run()
885 816
886 # Print formatted output to standard output. 817 # Print formatted output to standard output.
887 if args.header: 818 if args.header:
888 if args.target != 'helpers': 819 if args.target != 'helpers':
889 raise NotImplementedError('Only helper 820 raise NotImplementedError('Only helpers header generation is supported')
890 printer = PrinterHelpers(headerParser) 821 printer = PrinterHelpers(headerParser)
891 else: 822 else:
892 printer = printers[args.target](headerPars 823 printer = printers[args.target](headerParser)
893 printer.print_all() 824 printer.print_all()
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