High level conclusions

Fuzzers reach 7.467% of cyclomatic complexity.

Fuzzers reach 8.904% of all functions.

Reachability and coverage overview

Functions statically reachable by fuzzers

78 / 876

Cyclomatic complexity statically reachable by fuzzers

591 / 7914

Runtime code coverage of functions

78 / 876

The following table shows data about each function in the project. The functions included in this table correspond to all functions that exist in the executables of the fuzzers. As such, there may be functions that are from third-party libraries.

For further technical details on the meaning of columns in the below table, please see the Glossary .

Func name	Functions filename	Args	Function call depth	Reached by Fuzzers	Runtime reached by Fuzzers	Combined reached by Fuzzers	Fuzzers runtime hit	Func lines hit %	I Count	BB Count	Cyclomatic complexity	Functions reached	Reached by functions	Accumulated cyclomatic complexity	Undiscovered complexity

Fuzzer: split_uri_fuzzer

Call tree

The calltree shows the control flow of the fuzzer. This is overlaid with coverage information to display how much of the potential code a fuzzer can reach is in fact covered at runtime. In the following there is a link to a detailed calltree visualisation as well as a bitmap showing a high-level view of the calltree. For further information about these topics please see the glossary for full calltree and calltree overview

Call tree overview bitmap:

The distribution of callsites in terms of coloring is

Color	Runtime hitcount	Callsite count	Percentage
red	0	9	17.6%
gold	[1:9]	15	29.4%
yellow	[10:29]	2	3.92%
greenyellow	[30:49]	2	3.92%
lawngreen	50+	23	45.0%
All colors	51	100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked	Calltree index	Parent function	Callsite	Largest blocked function
2	30	coap_split_uri_sub	call site: 00030	coap_log_impl
2	37	coap_ws_is_supported	call site: 00037	coap_log_impl
2	43	coap_split_uri_sub	call site: 00043	coap_log_impl
1	0	EP	call site: 00000	coap_split_uri
1	7	coap_log_impl	call site: 00007	vsnprintf
1	19	coap_log_impl	call site: 00019	snprintf

Runtime coverage analysis

Covered functions

14

Functions that are reachable but not covered

14

Reachable functions

28

Percentage of reachable functions covered

50.0%

NB: The sum of covered functions and functions that are reachable but not covered need not be equal to Reachable functions . This is because the reachability analysis is an approximation and thus at runtime some functions may be covered that are not included in the reachability analysis. This is a limitation of our static analysis capabilities.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
tests/oss-fuzz/split_uri_target.c	1
src/coap_uri.c	2
src/coap_debug.c	4
src/coap_time.c	3
src/coap_notls.c	2
src/coap_strm_posix.c	1
src/coap_ws.c	2

Fuzzer: pdu_parse_ws_fuzzer

Call tree

The calltree shows the control flow of the fuzzer. This is overlaid with coverage information to display how much of the potential code a fuzzer can reach is in fact covered at runtime. In the following there is a link to a detailed calltree visualisation as well as a bitmap showing a high-level view of the calltree. For further information about these topics please see the glossary for full calltree and calltree overview

Call tree overview bitmap:

The distribution of callsites in terms of coloring is

Color	Runtime hitcount	Callsite count	Percentage
red	0	87	20.5%
gold	[1:9]	15	3.54%
yellow	[10:29]	10	2.36%
greenyellow	[30:49]	2	0.47%
lawngreen	50+	309	73.0%
All colors	423	100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked	Calltree index	Parent function	Callsite	Largest blocked function
14	379	coap_pdu_encode_header	call site: 00379	coap_log_impl
8	223	coap_show_pdu	call site: 00223	coap_log_impl
8	328	coap_show_pdu	call site: 00328	coap_log_impl
5	398	coap_lock_lock_func	call site: 00398	coap_log_impl
4	56	coap_pdu_parse2	call site: 00056	coap_log_impl
4	97	coap_pdu_parse_opt	call site: 00097	coap_log_impl
4	146	coap_get_query	call site: 00146	coap_log_impl
3	372	coap_pdu_encode_header	call site: 00372	coap_log_impl
2	25	coap_pdu_clear	call site: 00025	coap_pdu_parse
2	31	coap_pdu_parse2	call site: 00031	coap_log_impl
2	53	coap_realloc_type	call site: 00053	coap_log_impl
2	61	coap_pdu_parse_header	call site: 00061	coap_log_impl

Runtime coverage analysis

Covered functions

77

Functions that are reachable but not covered

20

Reachable functions

97

Percentage of reachable functions covered

79.38%

NB: The sum of covered functions and functions that are reachable but not covered need not be equal to Reachable functions . This is because the reachability analysis is an approximation and thus at runtime some functions may be covered that are not included in the reachability analysis. This is a limitation of our static analysis capabilities.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
tests/oss-fuzz/pdu_parse_ws_target.c	1
src/coap_net.c	2
src/coap_time.c	4
src/coap_prng.c	1
src/coap_mem.c	4
src/coap_notls.c	5
src/coap_pdu.c	18
src/coap_debug.c	13
src/coap_option.c	12
src/coap_encode.c	3
src/coap_uri.c	6
src/coap_str.c	3
src/coap_strm_posix.c	1
src/coap_ws.c	2
src/coap_block.c	1
src/coap_threadsafe.c	2

Fuzzer: pdu_parse_tcp_fuzzer

Call tree

The calltree shows the control flow of the fuzzer. This is overlaid with coverage information to display how much of the potential code a fuzzer can reach is in fact covered at runtime. In the following there is a link to a detailed calltree visualisation as well as a bitmap showing a high-level view of the calltree. For further information about these topics please see the glossary for full calltree and calltree overview

Call tree overview bitmap:

The distribution of callsites in terms of coloring is

Color	Runtime hitcount	Callsite count	Percentage
red	0	84	19.8%
gold	[1:9]	15	3.54%
yellow	[10:29]	12	2.83%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	312	73.7%
All colors	423	100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked	Calltree index	Parent function	Callsite	Largest blocked function
8	223	coap_show_pdu	call site: 00223	coap_log_impl
8	328	coap_show_pdu	call site: 00328	coap_log_impl
5	388	coap_pdu_encode_header	call site: 00388	coap_log_impl
5	398	coap_lock_lock_func	call site: 00398	coap_log_impl
4	97	coap_pdu_parse_opt	call site: 00097	coap_log_impl
4	146	coap_get_query	call site: 00146	coap_log_impl
3	56	coap_pdu_parse2	call site: 00056	coap_log_impl
3	60	coap_pdu_parse_header	call site: 00060	coap_log_impl
3	372	coap_pdu_encode_header	call site: 00372	coap_log_impl
2	25	coap_pdu_clear	call site: 00025	coap_pdu_parse
2	31	coap_pdu_parse2	call site: 00031	coap_log_impl
2	53	coap_realloc_type	call site: 00053	coap_log_impl

Runtime coverage analysis

Covered functions

77

Functions that are reachable but not covered

20

Reachable functions

97

Percentage of reachable functions covered

79.38%

NB: The sum of covered functions and functions that are reachable but not covered need not be equal to Reachable functions . This is because the reachability analysis is an approximation and thus at runtime some functions may be covered that are not included in the reachability analysis. This is a limitation of our static analysis capabilities.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
tests/oss-fuzz/pdu_parse_tcp_target.c	1
src/coap_net.c	2
src/coap_time.c	4
src/coap_prng.c	1
src/coap_mem.c	4
src/coap_notls.c	5
src/coap_pdu.c	18
src/coap_debug.c	13
src/coap_option.c	12
src/coap_encode.c	3
src/coap_uri.c	6
src/coap_str.c	3
src/coap_strm_posix.c	1
src/coap_ws.c	2
src/coap_block.c	1
src/coap_threadsafe.c	2

Fuzzer: pdu_parse_udp_fuzzer

Call tree

The calltree shows the control flow of the fuzzer. This is overlaid with coverage information to display how much of the potential code a fuzzer can reach is in fact covered at runtime. In the following there is a link to a detailed calltree visualisation as well as a bitmap showing a high-level view of the calltree. For further information about these topics please see the glossary for full calltree and calltree overview

Call tree overview bitmap:

The distribution of callsites in terms of coloring is

Color	Runtime hitcount	Callsite count	Percentage
red	0	86	20.3%
gold	[1:9]	17	4.01%
yellow	[10:29]	12	2.83%
greenyellow	[30:49]	0	0.0%
lawngreen	50+	308	72.8%
All colors	423	100

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Amount of callsites blocked	Calltree index	Parent function	Callsite	Largest blocked function
20	373	coap_pdu_encode_header	call site: 00373	coap_log_impl
8	223	coap_show_pdu	call site: 00223	coap_log_impl
8	328	coap_show_pdu	call site: 00328	coap_log_impl
5	398	coap_lock_lock_func	call site: 00398	coap_log_impl
4	59	coap_pdu_parse_header	call site: 00059	coap_log_impl
4	97	coap_pdu_parse_opt	call site: 00097	coap_log_impl
4	146	coap_get_query	call site: 00146	coap_log_impl
2	25	coap_pdu_clear	call site: 00025	coap_pdu_parse
2	31	coap_pdu_parse2	call site: 00031	coap_log_impl
2	53	coap_realloc_type	call site: 00053	coap_log_impl
2	69	coap_pdu_parse_opt	call site: 00069	coap_log_impl
2	155	coap_new_string	call site: 00155	coap_log_impl

Runtime coverage analysis

Covered functions

77

Functions that are reachable but not covered

20

Reachable functions

97

Percentage of reachable functions covered

79.38%

NB: The sum of covered functions and functions that are reachable but not covered need not be equal to Reachable functions . This is because the reachability analysis is an approximation and thus at runtime some functions may be covered that are not included in the reachability analysis. This is a limitation of our static analysis capabilities.

Function name	source code lines	source lines hit	percentage hit

Files reached

filename	functions hit
tests/oss-fuzz/pdu_parse_udp_target.c	1
src/coap_net.c	2
src/coap_time.c	4
src/coap_prng.c	1
src/coap_mem.c	4
src/coap_notls.c	5
src/coap_pdu.c	18
src/coap_debug.c	13
src/coap_option.c	12
src/coap_encode.c	3
src/coap_uri.c	6
src/coap_str.c	3
src/coap_strm_posix.c	1
src/coap_ws.c	2
src/coap_block.c	1
src/coap_threadsafe.c	2

Optimal target analysis

Remaining optimal interesting functions

The following table shows a list of functions that are optimal targets. Optimal targets are identified by finding the functions that in combination, yield a high code coverage.

Func name	Functions filename	Arg count	Args	Function depth	hitcount	instr count	bb count	cyclomatic complexity	Reachable functions	Incoming references	total cyclomatic complexity	Unreached complexity
coap_ws_close	/src/libcoap/src/coap_ws.c	1	['N/A']	32	0	378	50	17	514	2	5847	5249
coap_new_context	/src/libcoap/src/coap_net.c	1	['N/A']	53	0	311	69	20	526	0	5823	209
coap_persist_startup	/src/libcoap/src/coap_subscribe.c	5	['N/A', 'N/A', 'N/A', 'N/A', 'int']	59	0	51	10	3	510	0	5777	172
hnd_get_wellknown_lkd	/src/libcoap/src/coap_net.c	5	['N/A', 'N/A', 'N/A', 'N/A', 'N/A']	31	0	304	50	16	497	0	5709	108
coap_new_oscore_conf	/src/libcoap/src/coap_oscore.c	5	['size_t', 'N/A', 'N/A', 'N/A', 'size_t']	8	0	74	11	4	38	0	165	85
coap_netif_dgrm_write	/src/libcoap/src/coap_netif.c	3	['N/A', 'N/A', 'size_t']	8	0	155	30	9	63	0	306	60
coap_io_process_loop	/src/libcoap/src/coap_io_posix.c	5	['N/A', 'N/A', 'N/A', 'int', 'int']	60	0	59	12	4	498	0	5652	51
coap_add_resource	/src/libcoap/src/coap_resource.c	2	['N/A', 'N/A']	58	0	34	9	3	496	0	5667	46
coap_session_set_type_server	/src/libcoap/src/coap_session.c	1	['N/A']	56	0	39	10	3	494	0	5645	42
coap_op_resource_deleted	/src/libcoap/src/coap_subscribe.c	3	['N/A', 'N/A', 'N/A']	6	0	252	40	16	40	0	135	40

Implementing fuzzers that target the above functions will improve reachability such that it becomes:

Functions statically reachable by fuzzers

538 / 876

Cyclomatic complexity statically reachable by fuzzers

6541 / 7914

All functions overview

If you implement fuzzers for these functions, the status of all functions in the project will be:

Func name	Functions filename	Args	Function call depth	Reached by Fuzzers	Runtime reached by Fuzzers	Combined reached by Fuzzers	Fuzzers runtime hit	Func lines hit %	I Count	BB Count	Cyclomatic complexity	Functions reached	Reached by functions	Accumulated cyclomatic complexity	Undiscovered complexity

This sections provides heuristics that can be used as input to a fuzz engine when running a given fuzz target. The current focus is on providing input that is usable by libFuzzer.

tests/oss-fuzz/split_uri_target.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['coap_split_uri_sub', 'coap_ws_is_supported', 'coap_log_impl']

tests/oss-fuzz/pdu_parse_ws_target.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['coap_pdu_encode_header', 'coap_show_pdu', 'coap_lock_lock_func', 'coap_pdu_parse2', 'coap_pdu_parse_opt', 'coap_get_query', 'coap_pdu_clear']

tests/oss-fuzz/pdu_parse_tcp_target.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['coap_show_pdu', 'coap_pdu_encode_header', 'coap_lock_lock_func', 'coap_pdu_parse_opt', 'coap_get_query', 'coap_pdu_parse2', 'coap_pdu_parse_header', 'coap_pdu_clear']

tests/oss-fuzz/pdu_parse_udp_target.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['coap_pdu_encode_header', 'coap_show_pdu', 'coap_lock_lock_func', 'coap_pdu_parse_header', 'coap_pdu_parse_opt', 'coap_get_query', 'coap_pdu_clear', 'coap_pdu_parse2', 'coap_realloc_type']

This section shows analysis of runtime coverage data.

For futher technical details on how this section is generated, please see the Glossary .

Complex functions with low coverage

Func name	Function total lines	Lines covered at runtime	percentage covered	Reached by fuzzers

This section shows which files and directories are considered in this report. The main reason for showing this is fuzz introspector may include more code in the reasoning than is desired. This section helps identify if too many files/directories are included, e.g. third party code, which may be irrelevant for the threat model. In the event too much is included, fuzz introspector supports a configuration file that can exclude data from the report. See the following link for more information on how to create a config file: link

Files in report

Source file	Reached by	Covered by
	[]	[]
/src/libcoap/src/coap_threadsafe.c	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/src/coap_block.c	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/tests/oss-fuzz/pdu_parse_udp_target.c	['pdu_parse_udp_fuzzer']	[]
/src/libcoap/src/oscore/oscore.c	[]	[]
/src/libcoap/src/coap_async.c	[]	[]
/src/libcoap/src/oscore/oscore_cbor.c	[]	[]
/src/libcoap/src/coap_prng.c	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/src/coap_session.c	[]	[]
/src/libcoap/src/coap_netif.c	[]	[]
/src/libcoap/src/coap_uri.c	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/tests/oss-fuzz/pdu_parse_tcp_target.c	['pdu_parse_tcp_fuzzer']	[]
/src/libcoap/src/coap_cache.c	[]	[]
/src/libcoap/src/coap_debug.c	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/./include/coap3/coap_pdu_internal.h	[]	[]
/src/libcoap/src/coap_time.c	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/src/coap_subscribe.c	[]	[]
/src/libcoap/src/coap_str.c	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/src/coap_address.c	[]	[]
/src/libcoap/tests/oss-fuzz/split_uri_target.c	['split_uri_fuzzer']	[]
/src/libcoap/./include/coap3/coap_uri.h	[]	[]
/src/libcoap/src/oscore/oscore_cose.c	[]	[]
/src/libcoap/src/coap_dgrm_posix.c	[]	[]
/src/libcoap/src/coap_strm_posix.c	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/src/coap_io.c	[]	[]
/src/libcoap/src/oscore/oscore_context.c	[]	[]
/src/libcoap/src/coap_hashkey.c	[]	[]
/src/libcoap/src/coap_pdu.c	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/src/coap_mem.c	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/src/coap_ws.c	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/src/coap_option.c	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/src/coap_dtls.c	[]	[]
/src/libcoap/src/coap_resource.c	[]	[]
/src/libcoap/src/coap_io_posix.c	[]	[]
/src/libcoap/src/coap_net.c	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/src/oscore/oscore_crypto.c	[]	[]
/src/libcoap/./include/coap3/coap_address.h	[]	[]
/src/libcoap/src/coap_notls.c	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['split_uri_fuzzer', 'pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/tests/oss-fuzz/pdu_parse_ws_target.c	['pdu_parse_ws_fuzzer']	[]
/src/libcoap/src/coap_encode.c	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']	['pdu_parse_ws_fuzzer', 'pdu_parse_tcp_fuzzer', 'pdu_parse_udp_fuzzer']
/src/libcoap/src/coap_sha1.c	[]	[]
/src/libcoap/src/coap_proxy.c	[]	[]
/src/libcoap/src/coap_oscore.c	[]	[]

Directories in report

Directory
/src/libcoap/./include/coap3/
/src/libcoap/src/oscore/
/src/libcoap/tests/oss-fuzz/
/src/libcoap/src/