High level conclusions

Fuzzers reach 34.46% of cyclomatic complexity.

Fuzzers reach 33.50% of all functions.

Fuzzer sdp_fuzzer is blocked:

The runtime code coverage of sdp_fuzzer covers 22.22% of its statically reachable code. This means there is some place that blocks the fuzzer to continue exploring more code at run time.

Reachability and coverage overview

Functions statically reachable by fuzzers

64 / 191

Cyclomatic complexity statically reachable by fuzzers

994 / 2884

Runtime code coverage of functions

60 / 191

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: rtp_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	16	10.5%
gold	[1:9]	8	5.26%
yellow	[10:29]	4	2.63%
greenyellow	[30:49]	14	9.21%
lawngreen	50+	110	72.3%
All colors	152	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
9	12	janus_rtp_header_extension_parse_rid	call site: 00012	janus_log_buffer_free
4	61	janus_rtp_header_extension_parse_dependency_desc	call site: 00061	janus_vprintf
1	45	janus_rtp_header_extension_parse_transport_wide_cc	call site: 00045	ntohs
1	48	janus_rtp_header_extension_parse_abs_send_time	call site: 00048	ntohl
1	51	janus_rtp_header_extension_parse_abs_capture_time	call site: 00051	ntohl

Runtime coverage analysis

Covered functions

23

Functions that are reachable but not covered

16

Reachable functions

39

Percentage of reachable functions covered

58.97%

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
fuzzers/rtp_fuzzer.c	2
src/rtp.c	13
src/log.c	2
src/utils.c	9

Fuzzer: sdp_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	16	7.54%
gold	[1:9]	21	9.90%
yellow	[10:29]	2	0.94%
greenyellow	[30:49]	10	4.71%
lawngreen	50+	163	76.8%
All colors	212	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
9	5	janus_sdp_parse	call site: 00005	janus_log_buffer_free
5	151	janus_sdp_write	call site: 00151	janus_vprintf
2	74	janus_sdp_parse	call site: 00074	janus_sdp_mline_destroy

Runtime coverage analysis

Covered functions

13

Functions that are reachable but not covered

35

Reachable functions

45

Percentage of reachable functions covered

22.22%

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
fuzzers/sdp_fuzzer.c	1
src/sdp-utils.c	8
src/log.c	2
src/utils.c	2

Fuzzer: rtcp_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	28	7.46%
gold	[1:9]	0	0.0%
yellow	[10:29]	5	1.33%
greenyellow	[30:49]	2	0.53%
lawngreen	50+	340	90.6%
All colors	375	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
9	7	janus_rtcp_check_len	call site: 00007	janus_log_buffer_free
9	169	janus_rtcp_rr_update_stats	call site: 00169	janus_vprintf
5	53	janus_rtcp_check_fci	call site: 00053	janus_vprintf
4	182	janus_rtcp_incoming_rr	call site: 00182	janus_vprintf
1	150	janus_rtcp_incoming_sr	call site: 00150	ntohl

Runtime coverage analysis

Covered functions

27

Functions that are reachable but not covered

30

Reachable functions

57

Percentage of reachable functions covered

47.37%

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
fuzzers/rtcp_fuzzer.c	1
src/rtcp.c	28
src/log.c	2
src/utils.c	3

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
janus_sdp_generate_offer	/src/janus-gateway/src/sdp-utils.c	2	['N/A', 'N/A']	5	0	1360	256	87	37	0	341	289
janus_sdp_generate_answer_mline	/src/janus-gateway/src/sdp-utils.c	3	['N/A', 'N/A', 'N/A']	3	0	3101	499	166	36	0	358	252
janus_rtp_simulcasting_context_process_rtp	/src/janus-gateway/src/rtp.c	10	['N/A', 'N/A', 'int', 'N/A', 'int', 'N/A', 'N/A', 'int', 'N/A', 'N/A']	5	0	2029	375	130	37	0	435	190
janus_rtp_svc_context_process_rtp	/src/janus-gateway/src/rtp.c	8	['N/A', 'N/A', 'int', 'N/A', 'int', 'int', 'N/A', 'N/A']	4	0	2307	409	131	26	0	287	131
janus_sdp_find_first_codec	/src/janus-gateway/src/sdp-utils.c	4	['N/A', 'int', 'int', 'N/A']	3	0	360	54	21	18	0	120	82
janus_log_init	/src/janus-gateway/src/log.c	4	['int', 'int', 'N/A', 'N/A']	4	0	218	42	17	29	0	105	79
janus_rtcp_transport_wide_cc_feedback	/src/janus-gateway/src/rtcp.c	6	['N/A', 'size_t', 'int', 'int', 'char', 'N/A']	3	0	912	125	43	27	0	103	61
janus_get_codec_from_pt	/src/janus-gateway/src/utils.c	2	['N/A', 'int']	3	0	439	107	42	17	0	82	42
janus_pidfile_create	/src/janus-gateway/src/utils.c	1	['N/A']	3	0	395	72	23	25	0	79	37
janus_get_codec_pt	/src/janus-gateway/src/utils.c	2	['N/A', 'N/A']	3	0	474	102	36	18	0	78	36

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

Functions statically reachable by fuzzers

99 / 191

Cyclomatic complexity statically reachable by fuzzers

2107 / 2884

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.

fuzzers/rtp_fuzzer.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=['janus_rtp_header_extension_parse_rid', 'janus_rtp_header_extension_parse_dependency_desc', 'janus_rtp_header_extension_parse_transport_wide_cc', 'janus_rtp_header_extension_parse_abs_send_time', 'janus_rtp_header_extension_parse_abs_capture_time']

fuzzers/sdp_fuzzer.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=['janus_sdp_parse', 'janus_sdp_write']

fuzzers/rtcp_fuzzer.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=['janus_rtcp_check_len', 'janus_rtcp_rr_update_stats', 'janus_rtcp_check_fci', 'janus_rtcp_incoming_rr', 'janus_rtcp_incoming_sr']

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
janus_rtcp_rr_update_stats	37	15	40.54%	['rtcp_fuzzer']

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/janus-gateway/fuzzers/sdp_fuzzer.c	['sdp_fuzzer']	['sdp_fuzzer']
/src/janus-gateway/src/sdp-utils.c	['sdp_fuzzer']	['sdp_fuzzer']
/src/janus-gateway/src/rtcp.c	['rtcp_fuzzer']	['rtcp_fuzzer']
/src/janus-gateway/fuzzers/rtp_fuzzer.c	['rtp_fuzzer']	['rtp_fuzzer']
/src/janus-gateway/src/log.c	['rtp_fuzzer', 'sdp_fuzzer', 'rtcp_fuzzer']	[]
/src/janus-gateway/src/rtp.c	['rtp_fuzzer']	['rtp_fuzzer']
/src/janus-gateway/src/utils.c	['rtp_fuzzer', 'sdp_fuzzer', 'rtcp_fuzzer']	['rtp_fuzzer', 'sdp_fuzzer', 'rtcp_fuzzer']
/src/janus-gateway/fuzzers/rtcp_fuzzer.c	['rtcp_fuzzer']	['rtcp_fuzzer']

Directories in report

Directory
/src/janus-gateway/src/
/src/janus-gateway/fuzzers/