1 /* Generates a random, valid protobuf message. Useful to seed
2 * external fuzzers such as afl-fuzz.
3 */
4
5 #include <pb_encode.h>
6 #include <pb_common.h>
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <string.h>
10 #include <assert.h>
11 #include "alltypes_static.pb.h"
12 #include "random_data.h"
13
14 #ifndef FUZZTEST_BUFSIZE
15 #define FUZZTEST_BUFSIZE 4096
16 #endif
17
18 /* Check that size/count fields do not exceed their max size.
19 * Otherwise we would have to loop pretty long in generate_message().
20 * Note that there may still be a few encoding errors from submessages.
21 */
limit_sizes(alltypes_static_AllTypes * msg)22 static void limit_sizes(alltypes_static_AllTypes *msg)
23 {
24 pb_field_iter_t iter;
25 pb_field_iter_begin(&iter, alltypes_static_AllTypes_fields, msg);
26 while (pb_field_iter_next(&iter))
27 {
28 if (PB_LTYPE(iter.type) == PB_LTYPE_BYTES)
29 {
30 ((pb_bytes_array_t*)iter.pData)->size %= iter.data_size - PB_BYTES_ARRAY_T_ALLOCSIZE(0);
31 }
32
33 if (PB_HTYPE(iter.type) == PB_HTYPE_REPEATED)
34 {
35 *((pb_size_t*)iter.pSize) %= iter.array_size;
36 }
37
38 if (PB_HTYPE(iter.type) == PB_HTYPE_ONEOF)
39 {
40 /* Set the oneof to this message type with 50% chance. */
41 if (rand_word() & 1)
42 {
43 *((pb_size_t*)iter.pSize) = iter.tag;
44 }
45 }
46 }
47 }
48
generate_message()49 static void generate_message()
50 {
51 alltypes_static_AllTypes msg;
52 alltypes_static_TestExtension extmsg = alltypes_static_TestExtension_init_zero;
53 pb_extension_t ext = pb_extension_init_zero;
54
55 static uint8_t buf[FUZZTEST_BUFSIZE];
56 pb_ostream_t stream = {0};
57
58 do {
59 rand_fill((void*)&msg, sizeof(msg));
60 limit_sizes(&msg);
61
62 rand_fill((void*)&extmsg, sizeof(extmsg));
63 ext.type = &alltypes_static_TestExtension_testextension;
64 ext.dest = &extmsg;
65 ext.next = NULL;
66 msg.extensions = &ext;
67
68 stream = pb_ostream_from_buffer(buf, sizeof(buf));
69 } while (!pb_encode(&stream, alltypes_static_AllTypes_fields, &msg));
70
71 fwrite(buf, 1, stream.bytes_written, stdout);
72 }
73
main(int argc,char ** argv)74 int main(int argc, char **argv)
75 {
76 if (argc < 2)
77 {
78 fprintf(stderr, "Usage: generate_message <seed>\n");
79 return 1;
80 }
81
82 random_set_seed(atol(argv[1]));
83
84 generate_message();
85
86 return 0;
87 }
88
89
