CVPN-791: Add documentation about wireshark and PMTU

[kp-mariappan-ramasamy]

Add documentation about wireshark and PMTU

[github-actions]

Code coverage summary for 9570eee:

Filename                                                     Regions    Missed Regions     Cover   Functions  Missed Functions  Executed       Lines      Missed Lines     Cover    Branches   Missed Branches     Cover
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
lightway-app-utils/src/args/cipher.rs                              7                 7     0.00%           2                 2     0.00%           6                 6     0.00%           0                 0         -
lightway-app-utils/src/args/connection_type.rs                     7                 7     0.00%           2                 2     0.00%           6                 6     0.00%           0                 0         -
lightway-app-utils/src/args/duration.rs                            9                 9     0.00%           5                 5     0.00%          11                11     0.00%           0                 0         -
lightway-app-utils/src/args/logging.rs                            20                20     0.00%           4                 4     0.00%          18                18     0.00%           0                 0         -
lightway-app-utils/src/connection_ticker.rs                       35                 4    88.57%          17                 2    88.24%         182                 5    97.25%           0                 0         -
lightway-app-utils/src/dplpmtud_timer.rs                          53                 7    86.79%          22                 4    81.82%         323                11    96.59%           0                 0         -
lightway-app-utils/src/event_stream.rs                             6                 0   100.00%           3                 0   100.00%          13                 0   100.00%           0                 0         -
lightway-app-utils/src/iouring.rs                                 95                95     0.00%          20                20     0.00%         186               186     0.00%           0                 0         -
lightway-app-utils/src/tun.rs                                     89                89     0.00%          23                23     0.00%          96                96     0.00%           0                 0         -
lightway-app-utils/src/utils.rs                                    8                 8     0.00%           1                 1     0.00%           9                 9     0.00%           0                 0         -
lightway-client/src/args.rs                                       32                32     0.00%          30                30     0.00%          30                30     0.00%           0                 0         -
lightway-client/src/io/inside/tun.rs                              42                42     0.00%           7                 7     0.00%          50                50     0.00%           0                 0         -
lightway-client/src/io/outside/tcp.rs                             47                47     0.00%           9                 9     0.00%          43                43     0.00%           0                 0         -
lightway-client/src/io/outside/udp.rs                             58                58     0.00%          11                11     0.00%          58                58     0.00%           0                 0         -
lightway-client/src/io/outside/udp/sockopt.rs                     23                23     0.00%           4                 4     0.00%          66                66     0.00%           0                 0         -
lightway-client/src/keepalive.rs                                 185                35    81.08%          46                 7    84.78%         397                21    94.71%           0                 0         -
lightway-client/src/lib.rs                                       131               131     0.00%          16                16     0.00%         185               185     0.00%           0                 0         -
lightway-client/src/main.rs                                       20                20     0.00%           2                 2     0.00%         118               118     0.00%           0                 0         -
lightway-core/src/borrowed_bytesmut.rs                            87                 1    98.85%          24                 0   100.00%         196                 1    99.49%           0                 0         -
lightway-core/src/builder_predicates.rs                           20                10    50.00%           4                 2    50.00%          32                16    50.00%           0                 0         -
lightway-core/src/cipher.rs                                       10                 0   100.00%           4                 0   100.00%          14                 0   100.00%           0                 0         -
lightway-core/src/connection.rs                                  469               231    50.75%          50                19    62.00%         652               272    58.28%           0                 0         -
lightway-core/src/connection/builders.rs                          64                24    62.50%          18                 7    61.11%         219                49    77.63%           0                 0         -
lightway-core/src/connection/dplpmtud.rs                         767                90    88.27%          69                 1    98.55%         950                11    98.84%           0                 0         -
lightway-core/src/connection/fragment_map.rs                     141                13    90.78%          30                 1    96.67%         293                 8    97.27%           0                 0         -
lightway-core/src/connection/io_adapter.rs                       146                17    88.36%          42                 5    88.10%         338                23    93.20%           0                 0         -
lightway-core/src/context.rs                                      97                29    70.10%          28                 9    67.86%         201                42    79.10%           0                 0         -
lightway-core/src/context/ip_pool.rs                               7                 3    57.14%           1                 0   100.00%           6                 0   100.00%           0                 0         -
lightway-core/src/context/server_auth.rs                          14                11    21.43%           4                 3    25.00%          19                15    21.05%           0                 0         -
lightway-core/src/io.rs                                            3                 3     0.00%           3                 3     0.00%          10                10     0.00%           0                 0         -
lightway-core/src/lib.rs                                           9                 6    33.33%           4                 1    75.00%          18                 9    50.00%           0                 0         -
lightway-core/src/metrics.rs                                       7                 7     0.00%           3                 3     0.00%          10                10     0.00%           0                 0         -
lightway-core/src/packet.rs                                       29                 9    68.97%           5                 2    60.00%          31                 7    77.42%           0                 0         -
lightway-core/src/plugin.rs                                       73                11    84.93%          27                 7    74.07%         164                11    93.29%           0                 0         -
lightway-core/src/utils.rs                                       111                19    82.88%          26                 0   100.00%         184                11    94.02%           0                 0         -
lightway-core/src/version.rs                                      49                 0   100.00%          24                 0   100.00%          94                 0   100.00%           0                 0         -
lightway-core/src/wire.rs                                        152                22    85.53%          39                 1    97.44%         262                 3    98.85%           0                 0         -
lightway-core/src/wire/auth_failure.rs                             9                 1    88.89%           3                 0   100.00%          19                 0   100.00%           0                 0         -
lightway-core/src/wire/auth_request.rs                           152                12    92.11%          36                 0   100.00%         289                 0   100.00%           0                 0         -
lightway-core/src/wire/auth_success_with_config_ipv4.rs           69                 4    94.20%          13                 0   100.00%         145                 0   100.00%           0                 0         -
lightway-core/src/wire/data.rs                                    21                 1    95.24%           7                 0   100.00%          41                 0   100.00%           0                 0         -
lightway-core/src/wire/data_frag.rs                               47                 1    97.87%          19                 0   100.00%          94                 0   100.00%           0                 0         -
lightway-core/src/wire/ping.rs                                    24                 3    87.50%           8                 0   100.00%          69                 0   100.00%           0                 0         -
lightway-core/src/wire/pong.rs                                    15                 2    86.67%           5                 0   100.00%          34                 0   100.00%           0                 0         -
lightway-core/src/wire/server_config.rs                           20                 2    90.00%           5                 0   100.00%          44                 0   100.00%           0                 0         -
lightway-server/src/args.rs                                       29                29     0.00%          27                27     0.00%          27                27     0.00%           0                 0         -
lightway-server/src/connection.rs                                 48                48     0.00%          23                23     0.00%         105               105     0.00%           0                 0         -
lightway-server/src/connection_manager.rs                         99                99     0.00%          31                31     0.00%         187               187     0.00%           0                 0         -
lightway-server/src/connection_manager/connection_map.rs          92                11    88.04%          28                 3    89.29%         275                10    96.36%           0                 0         -
lightway-server/src/io/inside/tun.rs                              27                27     0.00%           7                 7     0.00%          34                34     0.00%           0                 0         -
lightway-server/src/io/outside/tcp.rs                             33                33     0.00%           6                 6     0.00%          40                40     0.00%           0                 0         -
lightway-server/src/io/outside/udp.rs                             41                41     0.00%          10                10     0.00%          59                59     0.00%           0                 0         -
lightway-server/src/ip_manager.rs                                134                24    82.09%          29                 4    86.21%         325                26    92.00%           0                 0         -
lightway-server/src/lib.rs                                        80                80     0.00%          12                12     0.00%         122               122     0.00%           0                 0         -
lightway-server/src/main.rs                                       39                39     0.00%           5                 5     0.00%         128               128     0.00%           0                 0         -
lightway-server/src/metrics.rs                                    70                68     2.86%          29                28     3.45%         113               110     2.65%           0                 0         -
lightway-server/src/statistics.rs                                 56                24    57.14%           9                 4    55.56%         104                42    59.62%           0                 0         -
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
TOTAL                                                           4227              1689    60.04%         941               373    60.36%        7744              2307    70.21%           0                 0         -

✅ Region coverage 60% passes
✅ Line coverage 70% passes

[xv-ian-c]

Re the wireguard bit, I wonder if maybe we should pull lightway-core/wireshark up to the top level so it is a bit less hidden?

I'm also not sure it makes sense to have the plugin docs separate from the plugin code, perhaps it would be better to just leave them together and have a pointer from the docs dir?

[xv-ian-c]

Some really minor comments on the pmtu stuff.