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authorKlement Sekera <ksekera@cisco.com>2021-11-22 21:26:20 +0100
committerOle Tr�an <otroan@employees.org>2021-12-14 09:15:48 +0000
commit9b7e8acf792cced80e6775bc5668d9db415cdb46 (patch)
treeb600764a60f9978017a567390a025d2777b864a1 /src/tools
parent755042dec0fcc733d456adc2a74042c529eff039 (diff)
api: verify message size on receipt
When a message is received, verify that it's sufficiently large to accomodate any VLAs within message. To do that, we need a way to calculate message size including any VLAs. This patch adds such funcionality to vppapigen and necessary C code to use those to validate message size on receipt. Drop messages which are malformed. Type: improvement Signed-off-by: Klement Sekera <ksekera@cisco.com> Change-Id: I2903aa21dee84be6822b064795ba314de46c18f4
Diffstat (limited to 'src/tools')
-rw-r--r--src/tools/vppapigen/vppapigen_c.py110
1 files changed, 100 insertions, 10 deletions
diff --git a/src/tools/vppapigen/vppapigen_c.py b/src/tools/vppapigen/vppapigen_c.py
index 1e18a83e65e..f93e89843a3 100644
--- a/src/tools/vppapigen/vppapigen_c.py
+++ b/src/tools/vppapigen/vppapigen_c.py
@@ -210,7 +210,8 @@ class ToJSON():
if b[1] == 0:
continue
write(' if (a & {})\n'.format(b[0]))
- write(' cJSON_AddItemToArray(array, cJSON_CreateString("{}"));\n'.format(b[0]))
+ write(
+ ' cJSON_AddItemToArray(array, cJSON_CreateString("{}"));\n'.format(b[0]))
write(' return array;\n')
write('}\n')
@@ -685,7 +686,7 @@ TOP_BOILERPLATE = '''\
|| defined(vl_printfun) ||defined(vl_endianfun) \\
|| defined(vl_api_version)||defined(vl_typedefs) \\
|| defined(vl_msg_name)||defined(vl_msg_name_crc_list) \\
- || defined(vl_api_version_tuple)
+ || defined(vl_api_version_tuple) || defined(vl_calcsizefun)
/* ok, something was selected */
#else
#warning no content included from {input_filename}
@@ -750,7 +751,7 @@ def msg_name_crc_list(s, suffix):
for t in s['Define']:
output += "\\\n_(VL_API_%s, %s, %08x) " % \
- (t.name.upper(), t.name, t.crc)
+ (t.name.upper(), t.name, t.crc)
output += "\n#endif"
return output
@@ -970,13 +971,13 @@ static inline void *vl_api_{name}_t_print{suffix} (vl_api_{name}_t *a, void *han
write(signature.format(name=t.name, suffix='_json'))
write(' cJSON * o = vl_api_{}_t_tojson(a);\n'.format(t.name))
- write(' (void)s;\n');
+ write(' (void)s;\n')
write(' char *out = cJSON_Print(o);\n')
- write(' vl_print(handle, out);\n');
+ write(' vl_print(handle, out);\n')
write(' cJSON_Delete(o);\n')
- write(' cJSON_free(out);\n');
+ write(' cJSON_free(out);\n')
write(' return handle;\n')
- write('}\n\n');
+ write('}\n\n')
write("\n#endif")
write("\n#endif /* vl_printfun */\n")
@@ -1145,7 +1146,7 @@ static inline void vl_api_{name}_t_endian (vl_api_{name}_t *a)
'''
for t in objs:
- if t.__class__.__name__ == 'Enum' or t.__class__.__name__ == 'EnumFlag' :
+ if t.__class__.__name__ == 'Enum' or t.__class__.__name__ == 'EnumFlag':
output += signature.format(name=t.name)
if t.enumtype in ENDIAN_STRINGS:
output += (' *a = {}(*a);\n'
@@ -1187,6 +1188,78 @@ static inline void vl_api_{name}_t_endian (vl_api_{name}_t *a)
return output
+def calc_size_fun(objs, modulename):
+ '''Main entry point for calculate size function generation'''
+ output = '''\
+
+/****** Calculate size functions *****/\n\
+#ifdef vl_calcsizefun
+#ifndef included_{module}_calcsizefun
+#define included_{module}_calcsizefun
+
+'''
+ output = output.format(module=modulename)
+
+ signature = '''\
+/* calculate message size of message in network byte order */
+static inline uword vl_api_{name}_t_calc_size (vl_api_{name}_t *a)
+{{
+'''
+
+ for o in objs:
+ tname = o.__class__.__name__
+
+ output += signature.format(name=o.name)
+ output += f" return sizeof(*a)"
+ if tname == 'Using':
+ if 'length' in o.alias:
+ try:
+ tmp = int(o.alias['length'])
+ if tmp == 0:
+ raise (f"Unexpected length '0' for alias {o}")
+ except:
+ # output += f" + vl_api_{o.alias.name}_t_calc_size({o.name})"
+ print("culprit:")
+ print(o)
+ print(dir(o.alias))
+ print(o.alias)
+ raise
+ elif tname == 'Enum' or tname == 'EnumFlag':
+ pass
+ else:
+ for b in o.block:
+ if b.type == 'Option':
+ continue
+ elif b.type == 'Field':
+ if b.fieldtype.startswith('vl_api_'):
+ output += f" - sizeof(a->{b.fieldname})"
+ output += f" + {b.fieldtype}_calc_size(&a->{b.fieldname})"
+ elif b.type == 'Array':
+ if b.lengthfield:
+ m = list(filter(lambda x: x.fieldname == b.lengthfield, o.block))
+ if len(m) != 1:
+ raise Exception(f"Expected 1 match for field '{b.lengthfield}', got '{m}'")
+ lf = m[0]
+ if lf.fieldtype in ENDIAN_STRINGS:
+ output += f" + {ENDIAN_STRINGS[lf.fieldtype]}(a->{b.lengthfield}) * sizeof(a->{b.fieldname}[0])"
+ elif lf.fieldtype == "u8":
+ output += f" + a->{b.lengthfield} * sizeof(a->{b.fieldname}[0])"
+ else:
+ raise Exception(f"Don't know how to endian swap {lf.fieldtype}")
+ else:
+ # Fixed length strings decay to nul terminated u8
+ if b.fieldtype == 'string':
+ if b.modern_vla:
+ output += f" + vl_api_string_len(&a->{b.fieldname})"
+
+ output += ";\n"
+ output += '}\n\n'
+ output += "\n#endif"
+ output += "\n#endif /* vl_calcsizefun */\n\n"
+
+ return output
+
+
def version_tuple(s, module):
'''Generate semantic version string'''
output = '''\
@@ -1336,6 +1409,10 @@ def generate_c_boilerplate(services, defines, counters, file_crc,
#include "{module}.api.h"
#undef vl_endianfun
+#define vl_calcsizefun
+#include "{module}.api.h"
+#undef vl_calsizefun
+
/* instantiate all the print functions we know about */
#define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__)
#define vl_printfun
@@ -1371,6 +1448,7 @@ def generate_c_boilerplate(services, defines, counters, file_crc,
' .print_json = vl_api_{n}_t_print_json,\n'
' .tojson = vl_api_{n}_t_tojson,\n'
' .fromjson = vl_api_{n}_t_fromjson,\n'
+ ' .calc_size = vl_api_{n}_t_calc_size,\n'
' .is_autoendian = {auto}}};\n'
.format(n=s.caller, ID=s.caller.upper(),
auto=d.autoendian))
@@ -1389,6 +1467,7 @@ def generate_c_boilerplate(services, defines, counters, file_crc,
' .print_json = vl_api_{n}_t_print_json,\n'
' .tojson = vl_api_{n}_t_tojson,\n'
' .fromjson = vl_api_{n}_t_fromjson,\n'
+ ' .calc_size = vl_api_{n}_t_calc_size,\n'
' .is_autoendian = {auto}}};\n'
.format(n=s.reply, ID=s.reply.upper(),
auto=d.autoendian))
@@ -1427,6 +1506,10 @@ def generate_c_test_boilerplate(services, defines, file_crc, module, plugin,
#include "{module}.api.h"
#undef vl_endianfun
+#define vl_calcsizefun
+#include "{module}.api.h"
+#undef vl_calsizefun
+
/* instantiate all the print functions we know about */
#define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__)
#define vl_printfun
@@ -1488,7 +1571,8 @@ def generate_c_test_boilerplate(services, defines, file_crc, module, plugin,
' sizeof(vl_api_{n}_t), 1,\n'
' vl_api_{n}_t_print_json,\n'
' vl_api_{n}_t_tojson,\n'
- ' vl_api_{n}_t_fromjson);\n'
+ ' vl_api_{n}_t_fromjson,\n'
+ ' vl_api_{n}_t_calc_size);\n'
.format(n=s.reply, ID=s.reply.upper()))
write(' hash_set_mem (vam->function_by_name, "{n}", api_{n});\n'
.format(n=s.caller))
@@ -1510,7 +1594,8 @@ def generate_c_test_boilerplate(services, defines, file_crc, module, plugin,
' sizeof(vl_api_{n}_t), 1,\n'
' vl_api_{n}_t_print_json,\n'
' vl_api_{n}_t_tojson,\n'
- ' vl_api_{n}_t_fromjson);\n'
+ ' vl_api_{n}_t_fromjson,\n'
+ ' vl_api_{n}_t_calc_size);\n'
.format(n=e, ID=e.upper()))
write('}\n')
@@ -1729,6 +1814,10 @@ def generate_c_test2_boilerplate(services, defines, module, stream):
#include "{module}.api.h"
#undef vl_endianfun
+#define vl_calcsizefun
+#include "{module}.api.h"
+#undef vl_calsizefun
+
#define vl_print(handle, ...) vlib_cli_output (handle, __VA_ARGS__)
#define vl_printfun
#include "{module}.api.h"
@@ -1863,6 +1952,7 @@ def run(args, apifilename, s):
output += stream.getvalue()
stream.close()
output += endianfun(s['types'] + s['Define'], modulename)
+ output += calc_size_fun(s['types'] + s['Define'], modulename)
output += version_tuple(s, basename)
output += BOTTOM_BOILERPLATE.format(input_filename=basename,
file_crc=s['file_crc'])