forked from mirrors/linux
scripts/bpf: teach bpf_helpers_doc.py to dump BPF helper definitions
Enhance scripts/bpf_helpers_doc.py to emit C header with BPF helper definitions (to be included from libbpf's bpf_helpers.h). Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Andrii Nakryiko
Alexei Starovoitov
parent
5f0e541278
commit
7a387bed47
1 changed files with 154 additions and 1 deletions
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@ -391,6 +391,154 @@ SEE ALSO
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print('')
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class PrinterHelpers(Printer):
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"""
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A printer for dumping collected information about helpers as C header to
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be included from BPF program.
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@helpers: array of Helper objects to print to standard output
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"""
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type_fwds = [
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'struct bpf_fib_lookup',
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'struct bpf_perf_event_data',
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'struct bpf_perf_event_value',
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'struct bpf_sock',
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'struct bpf_sock_addr',
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'struct bpf_sock_ops',
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'struct bpf_sock_tuple',
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'struct bpf_spin_lock',
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'struct bpf_sysctl',
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'struct bpf_tcp_sock',
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'struct bpf_tunnel_key',
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'struct bpf_xfrm_state',
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'struct pt_regs',
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'struct sk_reuseport_md',
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'struct sockaddr',
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'struct tcphdr',
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'struct __sk_buff',
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'struct sk_msg_md',
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'struct xpd_md',
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]
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known_types = {
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'...',
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'void',
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'const void',
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'char',
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'const char',
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'int',
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'long',
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'unsigned long',
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'__be16',
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'__be32',
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'__wsum',
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'struct bpf_fib_lookup',
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'struct bpf_perf_event_data',
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'struct bpf_perf_event_value',
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'struct bpf_sock',
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'struct bpf_sock_addr',
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'struct bpf_sock_ops',
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'struct bpf_sock_tuple',
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'struct bpf_spin_lock',
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'struct bpf_sysctl',
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'struct bpf_tcp_sock',
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'struct bpf_tunnel_key',
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'struct bpf_xfrm_state',
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'struct pt_regs',
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'struct sk_reuseport_md',
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'struct sockaddr',
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'struct tcphdr',
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}
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mapped_types = {
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'u8': '__u8',
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'u16': '__u16',
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'u32': '__u32',
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'u64': '__u64',
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's8': '__s8',
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's16': '__s16',
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's32': '__s32',
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's64': '__s64',
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'size_t': 'unsigned long',
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'struct bpf_map': 'void',
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'struct sk_buff': 'struct __sk_buff',
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'const struct sk_buff': 'const struct __sk_buff',
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'struct sk_msg_buff': 'struct sk_msg_md',
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'struct xdp_buff': 'struct xdp_md',
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}
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def print_header(self):
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header = '''\
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/* This is auto-generated file. See bpf_helpers_doc.py for details. */
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/* Forward declarations of BPF structs */'''
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print(header)
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for fwd in self.type_fwds:
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print('%s;' % fwd)
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print('')
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def print_footer(self):
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footer = ''
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print(footer)
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def map_type(self, t):
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if t in self.known_types:
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return t
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if t in self.mapped_types:
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return self.mapped_types[t]
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print("")
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print("Unrecognized type '%s', please add it to known types!" % t)
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sys.exit(1)
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seen_helpers = set()
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def print_one(self, helper):
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proto = helper.proto_break_down()
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if proto['name'] in self.seen_helpers:
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return
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self.seen_helpers.add(proto['name'])
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print('/*')
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print(" * %s" % proto['name'])
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print(" *")
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if (helper.desc):
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# Do not strip all newline characters: formatted code at the end of
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# a section must be followed by a blank line.
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for line in re.sub('\n$', '', helper.desc, count=1).split('\n'):
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print(' *{}{}'.format(' \t' if line else '', line))
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if (helper.ret):
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print(' *')
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print(' * Returns')
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for line in helper.ret.rstrip().split('\n'):
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print(' *{}{}'.format(' \t' if line else '', line))
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print(' */')
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print('static %s %s(*%s)(' % (self.map_type(proto['ret_type']),
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proto['ret_star'], proto['name']), end='')
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comma = ''
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for i, a in enumerate(proto['args']):
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t = a['type']
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n = a['name']
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if proto['name'] == 'bpf_get_socket_cookie' and i == 0:
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t = 'void'
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n = 'ctx'
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one_arg = '{}{}'.format(comma, self.map_type(t))
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if n:
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if a['star']:
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one_arg += ' {}'.format(a['star'])
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else:
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one_arg += ' '
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one_arg += '{}'.format(n)
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comma = ', '
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print(one_arg, end='')
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print(') = (void *) %d;' % len(self.seen_helpers))
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print('')
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###############################################################################
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# If script is launched from scripts/ from kernel tree and can access
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@ -405,6 +553,8 @@ Parse eBPF header file and generate documentation for eBPF helper functions.
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The RST-formatted output produced can be turned into a manual page with the
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rst2man utility.
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""")
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argParser.add_argument('--header', action='store_true',
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help='generate C header file')
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if (os.path.isfile(bpfh)):
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argParser.add_argument('--filename', help='path to include/uapi/linux/bpf.h',
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default=bpfh)
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@ -417,5 +567,8 @@ headerParser = HeaderParser(args.filename)
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headerParser.run()
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# Print formatted output to standard output.
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printer = PrinterRST(headerParser.helpers)
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if args.header:
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printer = PrinterHelpers(headerParser.helpers)
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else:
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printer = PrinterRST(headerParser.helpers)
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printer.print_all()
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