working base

2025-03-16 10:20:48 +01:00
parent 0ddf5f1c36
commit 5fbd72b370
19 changed files with 3261 additions and 0 deletions
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -0,0 +1,2 @@
+[target.aarch64-unknown-linux-gnu]
+linker = "aarch64-linux-gnu-gcc"
--- a/.dockerignore
+++ b/.dockerignore
@@ -0,0 +1,9 @@
+target/
+Dockerfile
+.dockerignore
+scripts/
+.git/
+.gitignore
+README.md
+ARCHITECTURE.md
+TESTING.md
--- a/.gitignore
+++ b/.gitignore
@@ -0,0 +1 @@
+/target
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -0,0 +1,12 @@
+Use code comments only when absolutely needed. Less comments the better.
+
+Documentation is contain in doc/ folder.
+
+For building the code, use docker/podman. Never build directly on the machine.
+
+Since the setup requires network manipulation, we need to execute docker-compose with sudo
+
+When testing code to compile and if it works in basic way, use
+`sudo podman-compose exec route-switcher-dev -- cargo build` and
+`sudo podman-compose exec route-switcher-dev -- cargo run`
+Do not add extra vars to those commands, RUST_LOG=debug is already configured.
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -0,0 +1,910 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "aho-corasick"
+version = "1.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ddd31a130427c27518df266943a5308ed92d4b226cc639f5a8f1002816174301"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "anstream"
+version = "0.6.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43d5b281e737544384e969a5ccad3f1cdd24b48086a0fc1b2a5262a26b8f4f4a"
+dependencies = [
+ "anstyle",
+ "anstyle-parse",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "is_terminal_polyfill",
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle"
+version = "1.0.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5192cca8006f1fd4f7237516f40fa183bb07f8fbdfedaa0036de5ea9b0b45e78"
+
+[[package]]
+name = "anstyle-parse"
+version = "0.2.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4e7644824f0aa2c7b9384579234ef10eb7efb6a0deb83f9630a49594dd9c15c2"
+dependencies = [
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle-query"
+version = "1.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "40c48f72fd53cd289104fc64099abca73db4166ad86ea0b4341abe65af83dadc"
+dependencies = [
+ "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "anstyle-wincon"
+version = "3.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "291e6a250ff86cd4a820112fb8898808a366d8f9f58ce16d1f538353ad55747d"
+dependencies = [
+ "anstyle",
+ "once_cell_polyfill",
+ "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "anyhow"
+version = "1.0.101"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f0e0fee31ef5ed1ba1316088939cea399010ed7731dba877ed44aeb407a75ea"
+
+[[package]]
+name = "bitflags"
+version = "2.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "843867be96c8daad0d758b57df9392b6d8d271134fce549de6ce169ff98a92af"
+
+[[package]]
+name = "byteorder"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"
+
+[[package]]
+name = "bytes"
+version = "1.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e748733b7cbc798e1434b6ac524f0c1ff2ab456fe201501e6497c8417a4fc33"
+
+[[package]]
+name = "cfg-if"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
+
+[[package]]
+name = "clap"
+version = "4.5.58"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63be97961acde393029492ce0be7a1af7e323e6bae9511ebfac33751be5e6806"
+dependencies = [
+ "clap_builder",
+ "clap_derive",
+]
+
+[[package]]
+name = "clap_builder"
+version = "4.5.58"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f13174bda5dfd69d7e947827e5af4b0f2f94a4a3ee92912fba07a66150f21e2"
+dependencies = [
+ "anstream",
+ "anstyle",
+ "clap_lex",
+ "strsim",
+]
+
+[[package]]
+name = "clap_derive"
+version = "4.5.55"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a92793da1a46a5f2a02a6f4c46c6496b28c43638adea8306fcb0caa1634f24e5"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "clap_lex"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3a822ea5bc7590f9d40f1ba12c0dc3c2760f3482c6984db1573ad11031420831"
+
+[[package]]
+name = "colorchoice"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b05b61dc5112cbb17e4b6cd61790d9845d13888356391624cbe7e41efeac1e75"
+
+[[package]]
+name = "crossbeam-channel"
+version = "0.5.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "82b8f8f868b36967f9606790d1903570de9ceaf870a7bf9fbbd3016d636a2cb2"
+dependencies = [
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.8.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d0a5c400df2834b80a4c3327b3aad3a4c4cd4de0629063962b03235697506a28"
+
+[[package]]
+name = "env_filter"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a1c3cc8e57274ec99de65301228b537f1e4eedc1b8e0f9411c6caac8ae7308f"
+dependencies = [
+ "log",
+ "regex",
+]
+
+[[package]]
+name = "env_logger"
+version = "0.11.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b2daee4ea451f429a58296525ddf28b45a3b64f1acf6587e2067437bb11e218d"
+dependencies = [
+ "anstream",
+ "anstyle",
+ "env_filter",
+ "jiff",
+ "log",
+]
+
+[[package]]
+name = "errno"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
+dependencies = [
+ "libc",
+ "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "getrandom"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "899def5c37c4fd7b2664648c28120ecec138e4d395b459e5ca34f9cce2dd77fd"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "r-efi",
+ "wasip2",
+]
+
+[[package]]
+name = "glob"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0cc23270f6e1808e30a928bdc84dea0b9b4136a8bc82338574f23baf47bbd280"
+
+[[package]]
+name = "heck"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
+
+[[package]]
+name = "ipnetwork"
+version = "0.20.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bf466541e9d546596ee94f9f69590f89473455f88372423e0008fc1a7daf100e"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "is_terminal_polyfill"
+version = "1.70.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
+
+[[package]]
+name = "jiff"
+version = "0.2.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c867c356cc096b33f4981825ab281ecba3db0acefe60329f044c1789d94c6543"
+dependencies = [
+ "jiff-static",
+ "log",
+ "portable-atomic",
+ "portable-atomic-util",
+ "serde_core",
+]
+
+[[package]]
+name = "jiff-static"
+version = "0.2.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7946b4325269738f270bb55b3c19ab5c5040525f83fd625259422a9d25d9be5"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.182"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6800badb6cb2082ffd7b6a67e6125bb39f18782f793520caee8cb8846be06112"
+
+[[package]]
+name = "lock_api"
+version = "0.4.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "224399e74b87b5f3557511d98dff8b14089b3dadafcab6bb93eab67d3aace965"
+dependencies = [
+ "scopeguard",
+]
+
+[[package]]
+name = "log"
+version = "0.4.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5e5032e24019045c762d3c0f28f5b6b8bbf38563a65908389bf7978758920897"
+
+[[package]]
+name = "memchr"
+version = "2.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
+
+[[package]]
+name = "mio"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a69bcab0ad47271a0234d9422b131806bf3968021e5dc9328caf2d4cd58557fc"
+dependencies = [
+ "libc",
+ "wasi",
+ "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "netlink-packet-core"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72724faf704479d67b388da142b186f916188505e7e0b26719019c525882eda4"
+dependencies = [
+ "anyhow",
+ "byteorder",
+ "netlink-packet-utils",
+]
+
+[[package]]
+name = "netlink-packet-route"
+version = "0.23.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0800eae8638a299eaa67476e1c6b6692922273e0f7939fd188fc861c837b9cd2"
+dependencies = [
+ "anyhow",
+ "bitflags",
+ "byteorder",
+ "libc",
+ "log",
+ "netlink-packet-core",
+ "netlink-packet-utils",
+]
+
+[[package]]
+name = "netlink-packet-utils"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ede8a08c71ad5a95cdd0e4e52facd37190977039a4704eb82a283f713747d34"
+dependencies = [
+ "anyhow",
+ "byteorder",
+ "paste",
+ "thiserror",
+]
+
+[[package]]
+name = "netlink-sys"
+version = "0.8.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cd6c30ed10fa69cc491d491b85cc971f6bdeb8e7367b7cde2ee6cc878d583fae"
+dependencies = [
+ "bytes",
+ "libc",
+ "log",
+]
+
+[[package]]
+name = "no-std-net"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43794a0ace135be66a25d3ae77d41b91615fb68ae937f904090203e81f755b65"
+
+[[package]]
+name = "once_cell_polyfill"
+version = "1.70.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
+
+[[package]]
+name = "parking_lot"
+version = "0.12.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93857453250e3077bd71ff98b6a65ea6621a19bb0f559a85248955ac12c45a1a"
+dependencies = [
+ "lock_api",
+ "parking_lot_core",
+]
+
+[[package]]
+name = "parking_lot_core"
+version = "0.9.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2621685985a2ebf1c516881c026032ac7deafcda1a2c9b7850dc81e3dfcb64c1"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "redox_syscall",
+ "smallvec",
+ "windows-link",
+]
+
+[[package]]
+name = "paste"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
+
+[[package]]
+name = "pin-project-lite"
+version = "0.2.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b3cff922bd51709b605d9ead9aa71031d81447142d828eb4a6eba76fe619f9b"
+
+[[package]]
+name = "pnet"
+version = "0.35.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "682396b533413cc2e009fbb48aadf93619a149d3e57defba19ff50ce0201bd0d"
+dependencies = [
+ "ipnetwork",
+ "pnet_base",
+ "pnet_datalink",
+ "pnet_packet",
+ "pnet_sys",
+ "pnet_transport",
+]
+
+[[package]]
+name = "pnet_base"
+version = "0.35.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ffc190d4067df16af3aba49b3b74c469e611cad6314676eaf1157f31aa0fb2f7"
+dependencies = [
+ "no-std-net",
+]
+
+[[package]]
+name = "pnet_datalink"
+version = "0.35.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e79e70ec0be163102a332e1d2d5586d362ad76b01cec86f830241f2b6452a7b7"
+dependencies = [
+ "ipnetwork",
+ "libc",
+ "pnet_base",
+ "pnet_sys",
+ "winapi",
+]
+
+[[package]]
+name = "pnet_macros"
+version = "0.35.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13325ac86ee1a80a480b0bc8e3d30c25d133616112bb16e86f712dcf8a71c863"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "regex",
+ "syn",
+]
+
+[[package]]
+name = "pnet_macros_support"
+version = "0.35.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eed67a952585d509dd0003049b1fc56b982ac665c8299b124b90ea2bdb3134ab"
+dependencies = [
+ "pnet_base",
+]
+
+[[package]]
+name = "pnet_packet"
+version = "0.35.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c96ebadfab635fcc23036ba30a7d33a80c39e8461b8bd7dc7bb186acb96560f"
+dependencies = [
+ "glob",
+ "pnet_base",
+ "pnet_macros",
+ "pnet_macros_support",
+]
+
+[[package]]
+name = "pnet_sys"
+version = "0.35.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d4643d3d4db6b08741050c2f3afa9a892c4244c085a72fcda93c9c2c9a00f4b"
+dependencies = [
+ "libc",
+ "winapi",
+]
+
+[[package]]
+name = "pnet_transport"
+version = "0.35.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f604d98bc2a6591cf719b58d3203fd882bdd6bf1db696c4ac97978e9f4776bf"
+dependencies = [
+ "libc",
+ "pnet_base",
+ "pnet_packet",
+ "pnet_sys",
+]
+
+[[package]]
+name = "portable-atomic"
+version = "1.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c33a9471896f1c69cecef8d20cbe2f7accd12527ce60845ff44c153bb2a21b49"
+
+[[package]]
+name = "portable-atomic-util"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a9db96d7fa8782dd8c15ce32ffe8680bbd1e978a43bf51a34d39483540495f5"
+dependencies = [
+ "portable-atomic",
+]
+
+[[package]]
+name = "ppv-lite86"
+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85eae3c4ed2f50dcfe72643da4befc30deadb458a9b590d720cde2f2b1e97da9"
+dependencies = [
+ "zerocopy",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.106"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.44"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "21b2ebcf727b7760c461f091f9f0f539b77b8e87f2fd88131e7f1b433b3cece4"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "r-efi"
+version = "5.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "69cdb34c158ceb288df11e18b4bd39de994f6657d83847bdffdbd7f346754b0f"
+
+[[package]]
+name = "rand"
+version = "0.9.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6db2770f06117d490610c7488547d543617b21bfa07796d7a12f6f1bd53850d1"
+dependencies = [
+ "rand_chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3022b5f1df60f26e1ffddd6c66e8aa15de382ae63b3a0c1bfc0e4d3e3f325cb"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "76afc826de14238e6e8c374ddcc1fa19e374fd8dd986b0d2af0d02377261d83c"
+dependencies = [
+ "getrandom",
+]
+
+[[package]]
+name = "redox_syscall"
+version = "0.5.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed2bf2547551a7053d6fdfafda3f938979645c44812fbfcda098faae3f1a362d"
+dependencies = [
+ "bitflags",
+]
+
+[[package]]
+name = "regex"
+version = "1.12.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e10754a14b9137dd7b1e3e5b0493cc9171fdd105e0ab477f51b72e7f3ac0e276"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e1dd4122fc1595e8162618945476892eefca7b88c52820e74af6262213cae8f"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a96887878f22d7bad8a3b6dc5b7440e0ada9a245242924394987b21cf2210a4c"
+
+[[package]]
+name = "route-switcher"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "bytes",
+ "clap",
+ "crossbeam-channel",
+ "env_logger",
+ "libc",
+ "log",
+ "netlink-packet-core",
+ "netlink-packet-route",
+ "netlink-sys",
+ "pnet",
+ "pnet_sys",
+ "rand",
+ "signal-hook",
+ "tokio",
+]
+
+[[package]]
+name = "scopeguard"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
+
+[[package]]
+name = "serde"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
+dependencies = [
+ "serde_core",
+]
+
+[[package]]
+name = "serde_core"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "signal-hook"
+version = "0.3.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d881a16cf4426aa584979d30bd82cb33429027e42122b169753d6ef1085ed6e2"
+dependencies = [
+ "libc",
+ "signal-hook-registry",
+]
+
+[[package]]
+name = "signal-hook-registry"
+version = "1.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c4db69cba1110affc0e9f7bcd48bbf87b3f4fc7c61fc9155afd4c469eb3d6c1b"
+dependencies = [
+ "errno",
+ "libc",
+]
+
+[[package]]
+name = "smallvec"
+version = "1.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "67b1b7a3b5fe4f1376887184045fcf45c69e92af734b7aaddc05fb777b6fbd03"
+
+[[package]]
+name = "socket2"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "86f4aa3ad99f2088c990dfa82d367e19cb29268ed67c574d10d0a4bfe71f07e0"
+dependencies = [
+ "libc",
+ "windows-sys 0.60.2",
+]
+
+[[package]]
+name = "strsim"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
+
+[[package]]
+name = "syn"
+version = "2.0.115"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e614ed320ac28113fa64972c4262d5dbc89deacdfd00c34a3e4cea073243c12"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "thiserror"
+version = "1.0.69"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6aaf5339b578ea85b50e080feb250a3e8ae8cfcdff9a461c9ec2904bc923f52"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.69"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4fee6c4efc90059e10f81e6d42c60a18f76588c3d74cb83a0b242a2b6c7504c1"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "tokio"
+version = "1.49.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72a2903cd7736441aac9df9d7688bd0ce48edccaadf181c3b90be801e81d3d86"
+dependencies = [
+ "bytes",
+ "libc",
+ "mio",
+ "parking_lot",
+ "pin-project-lite",
+ "signal-hook-registry",
+ "socket2",
+ "tokio-macros",
+ "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "tokio-macros"
+version = "2.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af407857209536a95c8e56f8231ef2c2e2aff839b22e07a1ffcbc617e9db9fa5"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "537dd038a89878be9b64dd4bd1b260315c1bb94f4d784956b81e27a088d9a09e"
+
+[[package]]
+name = "utf8parse"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
+
+[[package]]
+name = "wasi"
+version = "0.11.1+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
+
+[[package]]
+name = "wasip2"
+version = "1.0.2+wasi-0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9517f9239f02c069db75e65f174b3da828fe5f5b945c4dd26bd25d89c03ebcf5"
+dependencies = [
+ "wit-bindgen",
+]
+
+[[package]]
+name = "winapi"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
+dependencies = [
+ "winapi-i686-pc-windows-gnu",
+ "winapi-x86_64-pc-windows-gnu",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+
+[[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
+
+[[package]]
+name = "windows-link"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
+
+[[package]]
+name = "windows-sys"
+version = "0.60.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
+dependencies = [
+ "windows-targets",
+]
+
+[[package]]
+name = "windows-sys"
+version = "0.61.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
+dependencies = [
+ "windows-link",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.53.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4945f9f551b88e0d65f3db0bc25c33b8acea4d9e41163edf90dcd0b19f9069f3"
+dependencies = [
+ "windows-link",
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a9d8416fa8b42f5c947f8482c43e7d89e73a173cead56d044f6a56104a6d1b53"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9d782e804c2f632e395708e99a94275910eb9100b2114651e04744e9b125006"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "960e6da069d81e09becb0ca57a65220ddff016ff2d6af6a223cf372a506593a3"
+
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa7359d10048f68ab8b09fa71c3daccfb0e9b559aed648a8f95469c27057180c"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e7ac75179f18232fe9c285163565a57ef8d3c89254a30685b57d83a38d326c2"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c3842cdd74a865a8066ab39c8a7a473c0778a3f29370b5fd6b4b9aa7df4a499"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ffa179e2d07eee8ad8f57493436566c7cc30ac536a3379fdf008f47f6bb7ae1"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.53.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d6bbff5f0aada427a1e5a6da5f1f98158182f26556f345ac9e04d36d0ebed650"
+
+[[package]]
+name = "wit-bindgen"
+version = "0.51.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d7249219f66ced02969388cf2bb044a09756a083d0fab1e566056b04d9fbcaa5"
+
+[[package]]
+name = "zerocopy"
+version = "0.8.39"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "db6d35d663eadb6c932438e763b262fe1a70987f9ae936e60158176d710cae4a"
+dependencies = [
+ "zerocopy-derive",
+]
+
+[[package]]
+name = "zerocopy-derive"
+version = "0.8.39"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4122cd3169e94605190e77839c9a40d40ed048d305bfdc146e7df40ab0f3e517"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -0,0 +1,21 @@
+[package]
+name = "route-switcher"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+pnet = "0.35.0"
+pnet_sys = "0.35.0"
+rand = "0.9.1"
+log = "0.4.27"
+env_logger = "0.11.8"
+libc = "0.2.172"
+signal-hook = "0.3.18"
+crossbeam-channel = "0.5.15"
+netlink-packet-route = "0.23.0"
+netlink-packet-core = "0.7.0"
+netlink-sys = "0.8.7"
+anyhow = "1.0.98"
+bytes = "1.10.1"
+tokio = { version = "1.42", features = ["full"] }
+clap = { version = "4.5", features = ["derive"] }
--- a/31
+++ b/31
@@ -0,0 +1,31 @@
+FROM rust:1.93-alpine AS builder
+
+RUN apk add --no-cache musl-dev
+
+WORKDIR /app
+
+COPY Cargo.toml Cargo.lock ./
+
+# Create dummy main.rs to cache dependencies
+RUN mkdir src && echo "fn main() {}" > src/main.rs
+RUN cargo build --release && rm -rf src
+
+COPY src ./src
+RUN cargo build --release
+
+FROM alpine:latest
+
+RUN apk add --no-cache iputils iptables
+
+WORKDIR /app
+
+COPY --from=builder /app/target/release/route-switcher .
+
+ENV RUST_LOG=info
+ENV PRIMARY_INTERFACE=eth0
+ENV SECONDARY_INTERFACE=eth1
+ENV PRIMARY_GATEWAY=192.168.1.1
+ENV SECONDARY_GATEWAY=192.168.2.1
+ENV PING_TARGET=8.8.8.8
+
+CMD ["./route-switcher"]
--- a/README.md
+++ b/README.md
@@ -0,0 +1,181 @@
+# Route-Switcher
+
+A Linux-based network failover system written in Rust that automatically switches routing between dual network interfaces based on connectivity monitoring.
+
+## Overview
+
+Route-Switcher monitors connectivity to specified IP addresses via multiple network interfaces and automatically manages routing tables to ensure network redundancy. When the primary interface fails, it seamlessly switches to a secondary interface, and automatically fails back when the primary connection is restored.
+
+## Architecture
+
+### Core Components
+
+1. **Async Pingers** (`src/pinger.rs`)
+   - Dual-interface ICMP monitoring
+   - Explicit interface binding (equivalent to `ping -I <interface>`)
+   - Configurable ping targets and intervals
+   - Async/await implementation with tokio
+
+2. **Route Manager** (`src/routing.rs`)
+   - Netlink-based route manipulation
+   - No external dependencies on `ip` command
+   - Route addition and deletion
+   - Metric-based route prioritization
+
+3. **State Machine** (`src/main.rs`)
+   - Failover logic with anti-flapping protection
+   - Three consecutive failures trigger failover
+   - One minute of stable connectivity triggers failback
+   - Prevents switching when both interfaces fail
+
+4. **Configuration**
+   - Interface definitions (primary/secondary)
+   - Gateway configurations
+   - Ping targets and timing
+   - Route metrics
+
+## Key Features
+
+- **Dual Interface Monitoring**: Simultaneous ping testing via both network interfaces
+- **Automatic Failover**: Switches to secondary interface after 3 consecutive ping failures
+- **Smart Failback**: Returns to primary interface after 1 minute of stable connectivity
+- **Anti-Flapping**: Prevents frequent switching between interfaces
+- **Edge Case Handling**: Won't switch if secondary interface is also down
+- **Netlink Integration**: Direct kernel communication for route management
+- **Async Architecture**: Non-blocking monitoring and management
+
+## Requirements
+
+- Linux operating system
+- Rust 2024 edition
+- Two network interfaces with internet connectivity
+- Root privileges for route manipulation
+- Netlink kernel support
+
+## Configuration
+
+### Network Setup Example
+```bash
+# Primary interface
+eth0: 192.168.1.10/24, gateway 192.168.1.1
+
+# Secondary interface  
+eth1: 192.168.2.10/24, gateway 192.168.2.1
+```
+
+### Application Configuration
+The application is configured through command-line arguments:
+
+```bash
+sudo cargo run -- \
+    --primary-interface eth0 \
+    --secondary-interface eth1 \
+    --primary-gateway 192.168.1.1 \
+    --secondary-gateway 192.168.2.1 \
+    --ping-target 8.8.8.8
+```
+
+## Usage
+
+### Basic Usage
+```bash
+# Run with default settings
+sudo cargo run
+
+# Run with custom configuration
+sudo cargo run -- \
+    --primary-interface eth0 \
+    --secondary-interface eth1 \
+    --primary-gateway 192.168.1.1 \
+    --secondary-gateway 192.168.2.1
+```
+
+### Development
+```bash
+# Build
+cargo build
+
+# Run tests
+cargo test
+
+# Run with debug logging
+RUST_LOG=debug sudo cargo run
+
+# Run with custom log level
+RUST_LOG=info sudo cargo run
+```
+
+## Testing Environment
+
+### Podman-Compose Setup
+The project includes a complete testing environment using podman-compose:
+
+```bash
+# Start test environment
+podman-compose up -d
+
+# View logs
+podman-compose logs -f route-switcher
+
+# Stop test environment
+podman-compose down
+```
+
+### End-to-End Testing
+```bash
+# Simulate primary interface failure
+podman-compose exec primary ip link set eth0 down
+
+# Observe failover in logs
+podman-compose logs -f route-switcher
+
+# Restore primary interface
+podman-compose exec primary ip link set eth0 up
+
+# Observe failback after 1 minute
+```
+
+## Implementation Details
+
+### State Machine
+```
+[Boot] -> [Primary] (after initial connectivity check)
+[Primary] -> [Fallback] (after 3 consecutive failures)
+[Fallback] -> [Primary] (after 60 seconds of stability)
+```
+
+### Route Management
+- Primary route: `ip r add default via <primary-gw> dev <primary-iface> metric 10`
+- Secondary route: `ip r add default via <secondary-gw> dev <secondary-iface> metric 20`
+- Routes are managed via netlink, not external commands
+
+### Failover Logic
+1. **Detection**: 3 consecutive ping failures on primary interface
+2. **Verification**: Secondary interface must be responsive
+3. **Switch**: Update routing table to use secondary gateway
+4. **Monitor**: Continue monitoring both interfaces
+5. **Recovery**: After 60 seconds of stable primary connectivity, switch back
+
+### Error Handling
+- Graceful degradation on interface failures
+- Comprehensive logging for debugging
+- Signal handling for clean shutdown
+- Recovery from temporary network issues
+
+## Dependencies
+
+- `tokio` - Async runtime
+- `pnet` - Packet networking
+- `netlink-sys` - Netlink kernel communication
+- `anyhow` - Error handling
+- `log` + `env_logger` - Logging
+- `crossbeam-channel` - Inter-thread communication
+- `signal-hook` - Signal handling
+
+## Development Phases
+
+- [ ] End-to-end automated tests
+
+## License
+
+GPLv3
--- a/doc/ARCHITECTURE.md
+++ b/doc/ARCHITECTURE.md
@@ -0,0 +1,167 @@
+# Architecture Documentation
+
+## System Overview
+
+Route-Switcher is a network failover system that operates at the application layer to provide automatic network redundancy. The system monitors network connectivity through multiple interfaces and manages routing tables to ensure continuous connectivity.
+
+## Component Architecture
+
+```
+┌─────────────────┐    ┌──────────────────┐    ┌─────────────────┐
+│   Main Thread   │    │  Async Pingers   │    │  Route Manager  │
+│                 │    │                  │    │                 │
+│ • State Machine │◄──►│ • Interface A    │◄──►│ • Netlink API   │
+│ • Decision Logic│    │ • Interface B    │    │ • Route Add/Del │
+│ • Coordination  │    │ • ICMP Monitoring│    │ • Metric Mgmt   │
+└─────────────────┘    └──────────────────┘    └─────────────────┘
+         │                       │                       │
+         └───────────────────────┼───────────────────────┘
+                                 │
+                    ┌──────────────────┐
+                    │   Linux Kernel   │
+                    │                  │
+                    │ • Routing Table  │
+                    │ • Network Stack  │
+                    │ • Netlink Socket │
+                    └──────────────────┘
+```
+
+## Data Flow
+
+1. **Monitoring Phase**
+   - Async pingers send ICMP packets via both interfaces
+   - Results are collected and sent to main thread
+   - State machine evaluates connectivity patterns
+
+2. **Decision Phase**
+   - State machine determines if failover is needed
+   - Verifies secondary interface health
+   - Triggers route changes if conditions are met
+
+3. **Action Phase**
+   - Route manager updates kernel routing table
+   - Changes are applied via netlink interface
+   - System continues monitoring in new state
+
+## State Machine Design
+
+### States
+- **Boot**: Initial state, gathering connectivity data
+- **Primary**: Using primary interface for routing
+- **Fallback**: Using secondary interface for routing
+
+### Transitions
+```
+Boot → Primary: After 10 seconds of sampling (regardless of ping results)
+Primary → Fallback: After 3 consecutive failures AND secondary is healthy
+Fallback → Primary: After 60 seconds of stable primary connectivity
+```
+
+### Routing Behavior
+- **Boot State**: Both routes are set up initially - primary (metric 10) and secondary (metric 20)
+- **Primary State**: Primary route (metric 10) and secondary route (metric 20) present
+- **Fallback State**: All three routes present - primary (metric 10), secondary (metric 20), and failover secondary (metric 5)
+- **Exit**: Only the failover route (metric 5) is removed
+
+### Route Management Strategy
+The system follows a "both routes always present, extra failover on-demand" approach:
+1. **Initialization**: Set up primary route (metric 10) and secondary route (metric 20)
+2. **Boot Phase**: Collect 10 seconds of ping samples to establish baseline connectivity
+3. **Normal Operation**: Primary route serves traffic (metric 10), secondary available as backup (metric 20)
+4. **Failover**: Add extra secondary route with highest priority (metric 5) for immediate failover
+5. **Failback**: Remove extra failover route when primary recovers
+6. **Cleanup**: Only remove the extra failover route on exit, preserving base routes
+
+### State Persistence
+- Current state is maintained in memory
+- State changes are logged for debugging
+- No persistent storage required (state rebuilds on restart)
+
+## Interface Design
+
+### Pinger Interface
+```rust
+pub trait Pinger {
+    async fn ping(&self, target: Ipv4Addr, interface: &str) -> PingResult;
+    async fn start_monitoring(&self, targets: &[Ipv4Addr], interfaces: &[String]) -> Receiver<PingResult>;
+}
+```
+
+### Route Manager Interface
+```rust
+pub trait RouteManager {
+    fn add_default_route(&self, gateway: Ipv4Addr, interface: &str, metric: u32) -> Result<()>;
+    fn delete_default_route(&self, gateway: Ipv4Addr, interface: &str, metric: u32) -> Result<()>;
+    fn get_current_routes(&self) -> Result<Vec<RouteInfo>>;
+}
+```
+
+## Threading Model
+
+### Main Thread
+- Runs the state machine
+- Handles signals and graceful shutdown
+- Coordinates between components
+
+### Async Pinger Tasks
+- One task per interface
+- Non-blocking ICMP operations
+- Results sent via channels
+
+### Route Manager
+- Synchronous operations (netlink is sync)
+- Called from main thread
+- Thread-safe operations
+
+## Error Handling Strategy
+
+### Categories
+1. **Network Errors**: Temporary connectivity issues
+2. **System Errors**: Permission problems, interface not found
+3. **Configuration Errors**: Invalid IP addresses, missing interfaces
+
+### Recovery Mechanisms
+- **Network Errors**: Retry with exponential backoff
+- **System Errors**: Log and exit (requires admin intervention)
+- **Configuration Errors**: Validate on startup, exit if invalid
+
+## Security Considerations
+
+### Privileges
+- Requires root privileges for route manipulation
+- Drops unnecessary privileges where possible
+- Validates all user inputs
+
+### Network Security
+- Only sends ICMP packets to configured targets
+- No arbitrary packet crafting
+- Interface binding prevents traffic leakage
+
+## Performance Characteristics
+
+### Resource Usage
+- **Memory**: Minimal (~10MB)
+- **CPU**: Low (periodic ICMP packets)
+- **Network**: Very low (only ping traffic)
+
+### Scalability
+- Single target machine design
+- Supports multiple ping targets
+- Limited to 2 interfaces (current design)
+
+## Testing Architecture
+
+### Unit Tests
+- Individual component testing
+- Mock network interfaces
+- State machine logic verification
+
+### Integration Tests
+- Component interaction testing
+- Real network interface usage
+- Netlink operation verification
+
+### End-to-End Tests
+- Full system testing in containers
+- Network failure simulation
+- Failover timing verification
--- a/doc/TESTING.md
+++ b/doc/TESTING.md
@@ -0,0 +1,270 @@
+# Testing Guide
+
+## Overview
+
+This document describes the testing strategy and environment for the Route-Switcher project.
+
+## Testing Environment
+
+### Podman-Compose Setup
+
+The testing environment uses podman-compose to create a realistic network topology with routers and a single ICMP target:
+
+```
+┌─────────────────┐    ┌─────────────────┐    ┌─────────────────┐
+│  Route-Switcher │    │   Primary Router│    │                 │
+│                 │    │                 │    │                 │
+│ eth0 ────────────┼────►│ eth0 ──────────┼────►│  ICMP Target    │
+│ eth1 ────────────┼────►│ eth1 ──────────┼────►│                 │
+│                 │    │                 │    │                 │
+└─────────────────┘    └─────────────────┘    └─────────────────┘
+    │                       │                       │
+    │                       │                       │
+    ▼                       ▼                       ▼
+primary-net           secondary-net           target-net
+192.168.1.0/24        192.168.2.0/24        10.0.0.0/24
+```
+
+### Container Architecture
+
+- **route-switcher**: Dual interfaces (eth0→primary-net, eth1→secondary-net)
+- **primary-router**: Connects primary-net ↔ target-net (192.168.1.1 ↔ 10.0.0.1)
+- **secondary-router**: Connects secondary-net ↔ target-net (192.168.2.1 ↔ 10.0.0.2)
+- **icmp-target**: Single IP on target-net (10.0.0.100), reachable via either router
+
+### Quick Start
+
+```bash
+# Start the testing environment
+podman-compose up -d
+
+# Run automated failover test
+./scripts/test-failover.sh
+
+# View logs
+podman-compose logs -f route-switcher
+
+# Stop environment
+podman-compose down
+```
+
+### Network Configuration
+
+**Route-Switcher:**
+- eth0: 192.168.1.10 (primary network)
+- eth1: 192.168.2.10 (secondary network)
+- Default gateway: 192.168.1.1 (primary router)
+
+**Primary Router:**
+- eth0: 192.168.1.1 (primary network)
+- eth1: 10.0.0.1 (target network)
+- Routes traffic between networks with NAT
+
+**Secondary Router:**
+- eth0: 192.168.2.1 (secondary network)  
+- eth1: 10.0.0.2 (target network)
+- Routes traffic between networks with NAT
+
+**ICMP Target:**
+- Single IP: 10.0.0.100
+- Default route: 10.0.0.1 (primary router)
+- Responds to ping from both routers
+
+## Test Scenarios
+
+### 1. Basic Connectivity Test
+**Objective**: Verify basic ping functionality on both interfaces
+
+```bash
+# Start environment
+podman-compose up -d
+
+# Test primary connectivity
+podman-compose exec route-switcher ping -c 3 -I eth0 10.0.0.100
+
+# Test secondary connectivity  
+podman-compose exec route-switcher ping -c 3 -I eth1 10.0.0.100
+
+# Check routing table
+podman-compose exec route-switcher ip route show
+```
+
+### 2. Failover Test
+**Objective**: Verify automatic failover when primary router fails
+
+```bash
+# Start monitoring logs
+podman-compose logs -f route-switcher &
+
+# Simulate primary router failure
+podman-compose exec primary-router ip link set eth0 down
+
+# Verify failover occurs (should see in logs)
+# Wait for state change to Fallback
+
+# Check routing table after failover
+podman-compose exec route-switcher ip route show
+
+# Test connectivity via secondary router
+podman-compose exec route-switcher ping -c 3 10.0.0.100
+
+# Restore primary router
+podman-compose exec primary-router ip link set eth0 up
+
+# Verify failback after 60 seconds
+```
+
+### 3. Dual Failure Test
+**Objective**: Verify system doesn't failover when both routers fail
+
+```bash
+# Start monitoring logs
+podman-compose logs -f route-switcher &
+
+# Fail both routers
+podman-compose exec primary-router ip link set eth0 down
+podman-compose exec secondary-router ip link set eth0 down
+
+# Verify no routing changes occur
+# System should remain in current state
+
+# Restore routers
+podman-compose exec primary-router ip link set eth0 up
+podman-compose exec secondary-router ip link set eth0 up
+```
+
+### 4. Router Target Interface Failure
+**Objective**: Test upstream network failure simulation
+
+```bash
+# Fail primary router's connection to target network
+podman-compose exec primary-router ip link set eth1 down
+
+# Should trigger failover to secondary router
+# Verify connectivity still works via secondary path
+
+# Restore primary router's target connection
+podman-compose exec primary-router ip link set eth1 up
+```
+
+### 5. Automated Failover Test
+**Objective**: Run complete automated test sequence
+
+```bash
+# Run the comprehensive test script
+./scripts/test-failover.sh
+
+# This script will:
+# 1. Start the environment
+# 2. Verify initial connectivity
+# 3. Simulate primary router failure
+# 4. Monitor failover
+# 5. Restore primary router
+# 6. Verify failback after 60 seconds
+```
+
+## Unit Tests
+
+### Running Tests
+```bash
+# Run all tests
+cargo test
+
+# Run specific test module
+cargo test pinger
+
+# Run with coverage
+cargo tarpaulin --out Html
+```
+
+### Test Structure
+```
+tests/
+├── unit/
+│   ├── pinger_tests.rs
+│   ├── routing_tests.rs
+│   └── state_machine_tests.rs
+├── integration/
+│   ├── netlink_tests.rs
+│   └── dual_interface_tests.rs
+└── e2e/
+    └── failover_tests.rs
+```
+
+## Performance Testing
+
+### Load Testing
+```bash
+# Test with multiple ping targets
+cargo run -- --ping-target 8.8.8.8
+
+# Monitor resource usage
+podman stats route-switcher
+
+# Test long-running stability
+# Run for 24 hours and monitor for memory leaks
+```
+
+### Network Latency Testing
+```bash
+# Measure failover time
+# Start script to time the state transition
+start_time=$(date +%s%N)
+# Trigger failure
+# Wait for state change
+end_time=$(date +%s%N)
+failover_time=$((($end_time - $start_time) / 1000000))
+echo "Failover time: ${failover_time}ms"
+```
+
+## Debugging Tests
+
+### Common Issues
+1. **Permission Denied**: Ensure containers run with privileged mode
+2. **Interface Not Found**: Check network configuration in compose file
+3. **Netlink Errors**: Verify kernel supports required operations
+4. **Timing Issues**: Adjust test timeouts for your environment
+
+### Debug Commands
+```bash
+# Check container network interfaces
+podman-compose exec route-switcher ip addr show
+
+# Check routing table
+podman-compose exec route-switcher ip route show
+
+# Monitor network traffic
+podman-compose exec route-switcher tcpdump -i any icmp
+
+# Check system logs
+podman-compose exec route-switcher dmesg | tail -20
+```
+
+## Test Data
+
+### Sample Ping Results
+```rust
+// Mock data for testing
+let mock_ping_results = vec![
+    PingResult::Ok,      // Normal operation
+    PingResult::Failed,   // Single failure
+    PingResult::Failed,   // Consecutive failure
+    PingResult::Failed,   // Trigger failover
+];
+```
+
+### Network Configuration
+```bash
+# Test network setup
+ip addr add 192.168.1.10/24 dev eth0
+ip addr add 192.168.2.10/24 dev eth1
+ip route add default via 192.168.1.1 dev eth0 metric 10
+ip route add default via 192.168.2.1 dev eth1 metric 20
+```
+
+## Test Coverage Goals
+
+- **Unit Tests**: 90%+ code coverage
+- **Integration Tests**: All major component interactions
+- **E2E Tests**: All user scenarios and edge cases
+- **Performance Tests**: Resource usage and timing validation
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -0,0 +1,149 @@
+version: '3.8'
+
+services:
+  route-switcher:
+    build: .
+    privileged: true
+    depends_on:
+      - primary-router
+      - secondary-router
+      - icmp-target
+    networks:
+      primary-net:
+        ipv4_address: 192.168.200.10
+      secondary-net:
+        ipv4_address: 192.168.201.10
+    environment:
+      - RUST_LOG=debug
+      - PRIMARY_INTERFACE=eth0
+      - SECONDARY_INTERFACE=eth1
+      - PRIMARY_GATEWAY=192.168.200.11
+      - SECONDARY_GATEWAY=192.168.201.11
+      - PING_TARGET=192.168.202.100
+    cap_add:
+      - NET_ADMIN
+      - SYS_ADMIN
+    volumes:
+      - ./scripts:/scripts:ro
+
+  route-switcher-dev:
+    image: rust:1.93-bullseye
+    privileged: true
+    working_dir: /app
+    command: |
+      sh -c "
+         echo nameserver 192.168.10.1 > /etc/resolv.conf &&
+        /bin/sleep infinity
+      "
+    networks:
+      primary-net:
+        ipv4_address: 192.168.200.20
+      secondary-net:
+        ipv4_address: 192.168.201.20
+      default:
+    dns:
+      - 192.168.10.1
+    environment:
+      - RUST_LOG=debug
+      - PRIMARY_INTERFACE=eth0
+      - SECONDARY_INTERFACE=eth1
+      - PRIMARY_GATEWAY=192.168.200.11
+      - SECONDARY_GATEWAY=192.168.201.11
+      - PING_TARGET=192.168.202.100
+    cap_add:
+      - NET_ADMIN
+      - SYS_ADMIN
+    volumes:
+      - .:/app:rw
+      - cargo-cache:/usr/local/cargo/registry
+
+  primary-router:
+    image: alpine:latest
+    privileged: true
+    networks:
+      primary-net:
+        ipv4_address: 192.168.200.11
+      target-net:
+        ipv4_address: 192.168.202.11
+      default:
+    dns:
+      - 192.168.10.1
+    cap_add:
+      - NET_ADMIN
+      - SYS_ADMIN
+    command: sh /scripts/setup-router.sh primary
+    volumes:
+      - ./scripts:/scripts:ro
+
+  secondary-router:
+    image: alpine:latest
+    privileged: true
+    networks:
+      secondary-net:
+        ipv4_address: 192.168.201.11
+      target-net:
+        ipv4_address: 192.168.202.12
+      default:
+    dns:
+      - 192.168.10.1
+    cap_add:
+      - NET_ADMIN
+      - SYS_ADMIN
+    command: sh /scripts/setup-router.sh secondary
+    volumes:
+      - ./scripts:/scripts:ro
+
+  icmp-target:
+    image: alpine:latest
+    networks:
+      target-net:
+        ipv4_address: 192.168.202.100
+      default:
+    dns:
+      - 192.168.10.1
+    cap_add:
+      - NET_ADMIN
+    command: |
+      sh -c "
+        echo 'ICMP Target configured at 192.168.202.100' &&
+        echo 'Routes:' &&
+        ip route show &&
+        while true; do
+          echo $(date): ICMP Target alive
+          sleep 30
+        done
+      "
+    healthcheck:
+      test: ["CMD", "ping", "-c", "1", "192.168.202.11"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+
+networks:
+  primary-net:
+    driver: bridge
+    internal: true
+    ipam:
+      config:
+        - subnet: 192.168.200.0/24
+
+  secondary-net:
+    driver: bridge
+    internal: true
+    ipam:
+      config:
+        - subnet: 192.168.201.0/24
+
+  target-net:
+    driver: bridge
+    internal: true
+    ipam:
+      config:
+        - subnet: 192.168.202.0/24
+
+  default:
+    external: true
+    name: podman
+
+volumes:
+  cargo-cache:
--- a/route-switcher.service
+++ b/route-switcher.service
@@ -0,0 +1,44 @@
+[Unit]
+Description=Route-Switcher - Automatic network failover service
+Documentation=https://git.hudrydum.cz/michal.humpula/route-switcher
+After=network.target network-online.target
+Wants=network-online.target
+ConditionPathExists=/usr/local/sbin/route-switcher
+
+[Service]
+Type=simple
+ExecStart=/usr/local/sbin/route-switcher
+Restart=always
+RestartSec=5
+StandardOutput=journal
+StandardError=journal
+
+# Environment variables (customize these for your network)
+Environment=RUST_LOG=info
+Environment=PRIMARY_INTERFACE=eth0
+Environment=SECONDARY_INTERFACE=eth1
+Environment=PRIMARY_GATEWAY=192.168.1.1
+Environment=SECONDARY_GATEWAY=192.168.2.1
+Environment=PING_TARGET=8.8.8.8
+
+User=root
+Group=root
+CapabilityBoundingSet=CAP_NET_ADMIN CAP_NET_RAW
+AmbientCapabilities=CAP_NET_ADMIN CAP_NET_RAW
+NoNewPrivileges=true
+
+# Resource limits
+LimitNOFILE=65536
+LimitNPROC=4096
+
+# Process isolation
+ProtectSystem=strict
+ProtectHome=true
+ReadWritePaths=/var/log
+PrivateTmp=true
+ProtectKernelTunables=true
+ProtectControlGroups=true
+RestrictRealtime=true
+
+[Install]
+WantedBy=multi-user.target
--- a/scripts/setup-router.sh
+++ b/scripts/setup-router.sh
@@ -0,0 +1,53 @@
+#!/bin/sh
+
+set -e
+
+ROUTER_TYPE="$1"
+
+echo "Setting up $ROUTER_TYPE router..."
+
+# fix dns 
+echo "nameserver 192.168.10.1" > /etc/resolv.conf
+
+apk add --no-cache iputils iptables
+
+# Enable IP forwarding
+echo 1 > /proc/sys/net/ipv4/ip_forward
+sysctl -w net.ipv4.ip_forward=1
+
+if [ "$ROUTER_TYPE" = "primary" ]; then
+    echo "Configuring PRIMARY router (192.168.200.11 192.168.202.11 172.17.0.2)"
+    
+    ip addr show
+    echo "Routes:"
+    ip route show
+    
+    # NAT for traffic from primary network to target network
+    iptables -t nat -A POSTROUTING -s 192.168.200.0/24 -d 192.168.202.0/24 -j MASQUERADE
+    iptables -P FORWARD ACCEPT
+
+elif [ "$ROUTER_TYPE" = "secondary" ]; then
+    echo "Configuring SECONDARY router (192.168.201.11 ↔ 192.168.202.12 ↔ 172.17.0.3)"
+    
+    ip addr show
+    echo "Routes:"
+    ip route show
+    
+    # NAT for traffic from secondary network to target network
+    iptables -t nat -A POSTROUTING -s 192.168.201.0/24 -d 192.168.202.0/24 -j MASQUERADE
+    iptables -P FORWARD ACCEPT
+else
+    echo "Error: Invalid router type. Use 'primary' or 'secondary'"
+    exit 1
+fi
+
+echo "Secondary router setup complete"
+echo "NAT rules:"
+iptables -t nat -L POSTROUTING -n -v
+
+# Keep container running
+echo "Router is running. Monitoring interfaces..."
+while true; do
+    echo "$(date): Router $ROUTER_TYPE status - interfaces up"
+    sleep 60
+done
--- a/scripts/test-failover.sh
+++ b/scripts/test-failover.sh
@@ -0,0 +1,118 @@
+#!/bin/bash
+
+set -e
+
+echo "=== Route-Switcher Failover Test Script ==="
+echo
+
+# Colors for output
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m' # No Color
+
+# Function to print colored output
+print_status() {
+    echo -e "${GREEN}[INFO]${NC} $1"
+}
+
+print_warning() {
+    echo -e "${YELLOW}[WARN]${NC} $1"
+}
+
+print_error() {
+    echo -e "${RED}[ERROR]${NC} $1"
+}
+
+# Check if podman-compose is available
+if ! command -v podman-compose &> /dev/null; then
+    print_error "podman-compose is not installed or not in PATH"
+    exit 1
+fi
+
+# Start the environment
+print_status "Starting test environment..."
+podman-compose up -d
+
+# Wait for containers to be ready
+print_status "Waiting for containers to initialize..."
+sleep 10
+
+# Check if all containers are running
+print_status "Checking container status..."
+podman-compose ps
+
+# Set up initial default route for route-switcher (testing scenario only)
+# In production, this would be configured by the network admin
+print_status "Setting up initial default route via primary router..."
+podman-compose exec route-switcher ip route add default via 192.168.200.11 dev eth0
+
+# Verify network connectivity
+print_status "Testing initial connectivity..."
+
+# Test from route-switcher to target (should use default route via primary)
+print_status "Testing connectivity via primary router..."
+podman-compose exec route-switcher ping -c 3 192.168.202.100 || {
+    print_error "Primary connectivity test failed"
+    podman-compose down
+    exit 1
+}
+
+# Test specific interface connectivity
+print_status "Testing connectivity via secondary interface..."
+podman-compose exec route-switcher ping -c 3 -I eth1 192.168.202.100 || {
+    print_warning "Secondary interface connectivity test failed (might be expected initially)"
+}
+
+print_status "Initial connectivity tests passed!"
+
+# Show current routing table
+print_status "Current routing table in route-switcher:"
+podman-compose exec route-switcher ip route show
+
+echo
+print_warning "=== Starting Failover Test ==="
+print_status "Monitoring route-switcher logs (press Ctrl+C to stop monitoring)..."
+echo
+
+# Start monitoring logs in background
+podman-compose logs -f route-switcher &
+LOGS_PID=$!
+
+# Wait a bit for initial logs
+sleep 5
+
+print_status "Simulating primary router failure by shutting down eth0..."
+podman-compose exec primary-router ip link set eth0 down
+
+print_status "Waiting for failover to occur..."
+sleep 15
+
+# Check if failover happened
+print_status "Checking routing table after primary failure..."
+podman-compose exec route-switcher ip route show
+
+print_status "Testing connectivity after failover..."
+podman-compose exec route-switcher ping -c 3 192.168.202.100 || {
+    print_warning "Connectivity test after failover failed (this might be expected during transition)"
+}
+
+print_status "Restoring primary router..."
+podman-compose exec primary-router ip link set eth0 up
+
+print_status "Waiting for failback (should take ~60 seconds of stable connection)..."
+sleep 70
+
+print_status "Final routing table check:"
+podman-compose exec route-switcher ip route show
+
+print_status "Final connectivity test:"
+podman-compose exec route-switcher ping -c 3 192.168.202.100
+
+# Stop monitoring logs
+kill $LOGS_PID 2>/dev/null || true
+
+echo
+print_status "=== Test Complete ==="
+print_status "To stop the environment: podman-compose down"
+print_status "To view logs: podman-compose logs route-switcher"
--- a/scripts/verify-setup.sh
+++ b/scripts/verify-setup.sh
@@ -0,0 +1,35 @@
+#!/bin/bash
+
+set -e
+
+echo "=== Quick Setup Verification ==="
+
+# Start containers
+echo "Starting containers..."
+podman-compose up -d
+
+# Wait for initialization
+echo "Waiting for containers..."
+sleep 10
+
+# Check status
+echo "Container status:"
+podman-compose ps
+
+# Set up initial route
+echo "Setting up initial default route..."
+podman-compose exec route-switcher ip route add default via 192.168.200.11 dev eth0
+
+# Show routing table
+echo "Route-switcher routing table:"
+podman-compose exec route-switcher ip route show
+
+# Test basic connectivity
+echo "Testing connectivity to target..."
+if podman-compose exec route-switcher ping -c 2 192.168.202.100; then
+    echo "✓ Connectivity test passed"
+else
+    echo "✗ Connectivity test failed"
+fi
+
+echo "Setup complete. Use './scripts/test-failover.sh' for full failover testing."
--- a/src/main.rs
+++ b/src/main.rs
@@ -0,0 +1,226 @@
+use anyhow::Result;
+use clap::Parser;
+use env_logger::{Builder, Env};
+use log::{debug, error, info};
+use signal_hook::consts::signal::*;
+use signal_hook::flag as signal_flag;
+use std::net::Ipv4Addr;
+use std::panic;
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::time::Duration;
+use tokio::signal;
+use tokio::sync::broadcast;
+
+mod pinger;
+mod routing;
+mod state_machine;
+
+#[derive(Parser, Debug)]
+#[command(author, version, about, long_about = None)]
+struct Config {
+    /// Primary network interface
+    #[arg(long, default_value = "eth0")]
+    primary_interface: String,
+
+    /// Secondary network interface
+    #[arg(long, default_value = "eth1")]
+    secondary_interface: String,
+
+    /// Primary gateway IP
+    #[arg(long, default_value = "192.168.1.1")]
+    primary_gateway: String,
+
+    /// Secondary gateway IP
+    #[arg(long, default_value = "192.168.2.1")]
+    secondary_gateway: String,
+
+    /// Ping target IP
+    #[arg(long, default_value = "8.8.8.8")]
+    ping_target: String,
+
+    /// Ping interval in seconds
+    #[arg(long, default_value = "1")]
+    ping_interval: u64,
+
+    /// Failover threshold (consecutive failures)
+    #[arg(long, default_value = "3")]
+    failover_threshold: usize,
+
+    /// Failback delay in seconds
+    #[arg(long, default_value = "60")]
+    failback_delay: u64,
+}
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    let env = Env::default().filter_or("RUST_LOG", "info");
+    let mut builder = Builder::from_env(env);
+    builder.init();
+    info!("Starting Route-Switcher...");
+
+    let config = Config::parse();
+
+    // Override with environment variables if present
+    let primary_interface =
+        std::env::var("PRIMARY_INTERFACE").unwrap_or(config.primary_interface.clone());
+    let secondary_interface =
+        std::env::var("SECONDARY_INTERFACE").unwrap_or(config.secondary_interface.clone());
+    let primary_gateway =
+        std::env::var("PRIMARY_GATEWAY").unwrap_or(config.primary_gateway.clone());
+    let secondary_gateway =
+        std::env::var("SECONDARY_GATEWAY").unwrap_or(config.secondary_gateway.clone());
+    let ping_target = std::env::var("PING_TARGET").unwrap_or(config.ping_target.clone());
+
+    let mut config_with_env = config;
+    config_with_env.primary_interface = primary_interface;
+    config_with_env.secondary_interface = secondary_interface;
+    config_with_env.primary_gateway = primary_gateway;
+    config_with_env.secondary_gateway = secondary_gateway;
+    config_with_env.ping_target = ping_target;
+
+    debug!("Configuration: {:?}", config_with_env);
+
+    // Validate configuration
+    let primary_gateway: Ipv4Addr = config_with_env
+        .primary_gateway
+        .parse()
+        .map_err(|e| anyhow::anyhow!("Invalid primary gateway: {}", e))?;
+    let secondary_gateway: Ipv4Addr = config_with_env
+        .secondary_gateway
+        .parse()
+        .map_err(|e| anyhow::anyhow!("Invalid secondary gateway: {}", e))?;
+    let ping_target: Ipv4Addr = config_with_env
+        .ping_target
+        .parse()
+        .map_err(|e| anyhow::anyhow!("Invalid ping target: {}", e))?;
+
+    // Set up signal handling
+    let term = Arc::new(AtomicBool::new(false));
+    signal_flag::register(SIGINT, Arc::clone(&term))?;
+    signal_flag::register(SIGTERM, Arc::clone(&term))?;
+    signal_flag::register(SIGQUIT, Arc::clone(&term))?;
+
+    let (shutdown_tx, _) = broadcast::channel::<()>(1);
+
+    // Run the main service
+    let result = main_service(
+        config_with_env,
+        primary_gateway,
+        secondary_gateway,
+        ping_target,
+        term,
+        shutdown_tx,
+    )
+    .await;
+
+    if let Err(e) = result {
+        error!("Service error: {}", e);
+        return Err(e);
+    }
+
+    info!("Route-Switcher shut down gracefully");
+    Ok(())
+}
+
+use state_machine::StateMachine;
+
+async fn main_service(
+    config: Config,
+    primary_gateway: Ipv4Addr,
+    secondary_gateway: Ipv4Addr,
+    ping_target: Ipv4Addr,
+    term: Arc<AtomicBool>,
+    shutdown_tx: broadcast::Sender<()>,
+) -> Result<()> {
+    info!(
+        "Starting main service with interfaces: {} (primary), {} (secondary)",
+        config.primary_interface, config.secondary_interface
+    );
+
+    // Initialize route manager and set up initial routes
+    let mut route_manager = routing::RouteManager::new();
+    route_manager.setup_initial_routes(
+        primary_gateway,
+        config.primary_interface.clone(),
+        secondary_gateway,
+        config.secondary_interface.clone(),
+    )?;
+    info!("Initial routes configured: primary (metric 10), secondary (metric 20)");
+
+    // Create pingers
+    let primary_pinger = pinger::AsyncPinger::new(config.primary_interface.clone());
+    let secondary_pinger = pinger::AsyncPinger::new(config.secondary_interface.clone());
+
+    // Start monitoring
+    let ping_interval = Duration::from_secs(config.ping_interval);
+    let primary_shutdown = shutdown_tx.subscribe();
+    let secondary_shutdown = shutdown_tx.subscribe();
+
+    let mut primary_rx = primary_pinger
+        .start_monitoring(ping_target, ping_interval, primary_shutdown)
+        .await;
+
+    let mut secondary_rx = secondary_pinger
+        .start_monitoring(ping_target, ping_interval, secondary_shutdown)
+        .await;
+
+    // Initialize state machine
+    let mut state_machine = StateMachine::new(
+        config.failover_threshold,
+        Duration::from_secs(config.failback_delay),
+    );
+
+    // Main event loop
+    loop {
+        tokio::select! {
+            // Handle primary ping results
+            Some(result) = primary_rx.recv() => {
+                debug!("Primary ping result: {}", result);
+                state_machine.add_primary_result(result);
+
+                if let Some((old_state, new_state)) = state_machine.update_state() {
+                    state_machine::handle_state_change(new_state, old_state, &mut route_manager, &primary_gateway, &secondary_gateway, &config)?;
+                }
+            }
+
+            // Handle secondary ping results
+            Some(result) = secondary_rx.recv() => {
+                debug!("Secondary ping result: {}", result);
+                state_machine.add_secondary_result(result);
+
+                if let Some((old_state, new_state)) = state_machine.update_state() {
+                    state_machine::handle_state_change(new_state, old_state, &mut route_manager, &primary_gateway, &secondary_gateway, &config)?;
+                }
+            }
+
+            // Handle shutdown signal
+            _ = signal::ctrl_c() => {
+                info!("Received Ctrl+C, shutting down...");
+                break;
+            }
+
+            // Check termination flag
+            _ = tokio::task::spawn_blocking({
+                let term = Arc::clone(&term);
+                move || {
+                    while !term.load(Ordering::Relaxed) {
+                        std::thread::sleep(Duration::from_millis(100));
+                    }
+                }
+            }) => {
+                info!("Received termination signal");
+                break;
+            }
+        }
+    }
+
+    // Clean up only the failover route on exit if we're in Fallback state
+    if state_machine.get_state() == &state_machine::State::Fallback {
+        route_manager
+            .remove_failover_route(secondary_gateway, config.secondary_interface.clone())?;
+        info!("Failover route cleared on exit");
+    }
+
+    Ok(())
+}
--- a/src/pinger.rs
+++ b/src/pinger.rs
@@ -0,0 +1,205 @@
+use anyhow::Result;
+use log;
+use pnet::packet::Packet;
+use pnet::packet::icmp::echo_reply::EchoReplyPacket;
+use pnet::packet::icmp::{IcmpTypes, IcmpTypes::EchoReply, echo_request};
+use pnet::transport::{
+    TransportChannelType::Layer4, TransportProtocol::Ipv4, icmp_packet_iter, transport_channel,
+};
+use pnet_sys;
+use std::net::Ipv4Addr;
+use std::time::{Duration, Instant};
+
+const ICMP_HEADER_SIZE: usize = 8;
+const PAYLOAD: &str = "hello world!";
+
+#[derive(Debug, PartialEq, Clone)]
+pub enum PingResult {
+    Ok,
+    Failed,
+}
+impl std::fmt::Display for PingResult {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            PingResult::Ok => write!(f, "Ok"),
+            PingResult::Failed => write!(f, "Failed"),
+        }
+    }
+}
+
+pub struct AsyncPinger {
+    interface: String,
+}
+
+impl AsyncPinger {
+    pub fn new(interface: String) -> Self {
+        Self { interface }
+    }
+
+    pub async fn ping(&self, destination: Ipv4Addr) -> PingResult {
+        let (mut tx, mut rx) = match create_transport_channel() {
+            Ok((tx, rx)) => (tx, rx),
+            Err(_) => return PingResult::Failed,
+        };
+
+        let fd = tx.socket.fd;
+        let it = self.interface.as_bytes();
+
+        let res = unsafe {
+            pnet_sys::setsockopt(
+                fd,
+                pnet_sys::SOL_SOCKET,
+                libc::SO_BINDTODEVICE,
+                (it.as_ptr() as *const libc::c_char) as pnet_sys::Buf,
+                it.len() as pnet_sys::SockLen,
+            )
+        };
+
+        if res == -1 {
+            log::error!("Failed to bind to {}", self.interface);
+            return PingResult::Failed;
+        }
+
+        let identifier = rand::random::<u16>();
+        let sequence_number = rand::random::<u16>();
+
+        if let Err(_) = send_echo_request(&mut tx, destination, identifier, sequence_number) {
+            log::error!("Failed to send echo request");
+            return PingResult::Failed;
+        }
+        let r = receive_echo_reply(
+            &mut rx,
+            destination,
+            identifier,
+            sequence_number,
+            &self.interface,
+        )
+        .await;
+        r
+    }
+
+    pub async fn start_monitoring(
+        &self,
+        destination: Ipv4Addr,
+        interval: Duration,
+        mut shutdown: tokio::sync::broadcast::Receiver<()>,
+    ) -> tokio::sync::mpsc::UnboundedReceiver<PingResult> {
+        let (tx, rx) = tokio::sync::mpsc::unbounded_channel();
+        let interface = self.interface.clone();
+
+        tokio::spawn(async move {
+            let mut interval_timer = tokio::time::interval(interval);
+
+            loop {
+                tokio::select! {
+                    _ = interval_timer.tick() => {
+                        let pinger = AsyncPinger::new(interface.clone());
+                        let result = pinger.ping(destination).await;
+                        if tx.send(result).is_err() {
+                            break;
+                        }
+                    }
+                    _ = shutdown.recv() => {
+                        log::info!("Shutting down pinger for interface {}", interface);
+                        break;
+                    }
+                }
+            }
+        });
+
+        rx
+    }
+}
+
+fn create_transport_channel() -> Result<(
+    pnet::transport::TransportSender,
+    pnet::transport::TransportReceiver,
+)> {
+    transport_channel(
+        1024,
+        Layer4(Ipv4(pnet::packet::ip::IpNextHeaderProtocols::Icmp)),
+    )
+    .map_err(|e| anyhow::anyhow!("Failed to create transport channel: {}", e))
+}
+
+fn send_echo_request(
+    tx: &mut pnet::transport::TransportSender,
+    destination: Ipv4Addr,
+    identifier: u16,
+    sequence_number: u16,
+) -> Result<()> {
+    let mut buffer = [0u8; ICMP_HEADER_SIZE + 4 + PAYLOAD.len()];
+    let mut echo_request_packet = echo_request::MutableEchoRequestPacket::new(&mut buffer).unwrap();
+    echo_request_packet.set_icmp_type(IcmpTypes::EchoRequest);
+    echo_request_packet.set_identifier(identifier);
+    echo_request_packet.set_sequence_number(sequence_number);
+    echo_request_packet.set_payload(PAYLOAD.as_bytes());
+    echo_request_packet.set_checksum(pnet::util::checksum(echo_request_packet.packet(), 1));
+
+    tx.send_to(echo_request_packet, std::net::IpAddr::V4(destination))
+        .map_err(|e| anyhow::anyhow!("Failed to send packet: {}", e))?;
+
+    Ok(())
+}
+
+async fn receive_echo_reply(
+    rx: &mut pnet::transport::TransportReceiver,
+    destination: Ipv4Addr,
+    identifier: u16,
+    sequence_number: u16,
+    interface: &str,
+) -> PingResult {
+    let timeout = Duration::from_secs(3);
+    let start = Instant::now();
+    let mut iter = icmp_packet_iter(rx);
+
+    loop {
+        match iter.next_with_timeout(Duration::from_secs(1)) {
+            Ok(None) => {
+                log::debug!(
+                    "ICMP receive timeout for {} on interface {} (elapsed: {} ms)",
+                    destination,
+                    interface,
+                    start.elapsed().as_millis()
+                );
+            }
+            Ok(Some((packet, addr)))
+                if addr == destination && packet.get_icmp_type() == EchoReply =>
+            {
+                if let Some(reply) = EchoReplyPacket::new(packet.packet()) {
+                    if reply.get_identifier() == identifier
+                        && reply.get_sequence_number() == sequence_number
+                    {
+                        log::debug!(
+                            "Received ICMP Echo Reply from {} on interface {} in {} ms",
+                            addr,
+                            interface,
+                            start.elapsed().as_millis()
+                        );
+                        return PingResult::Ok;
+                    }
+                } else {
+                    log::error!("Got something, but it looks like it is not mine!");
+                }
+            }
+            Ok(Some((_packet, _addr))) => {
+                continue;
+            }
+            Err(e) => {
+                log::error!("Error receiving packet: {}", e);
+                break;
+            }
+        }
+
+        if start.elapsed() >= timeout {
+            log::debug!(
+                "Request timed out for {} on interface {}",
+                destination,
+                interface
+            );
+            break;
+        }
+    }
+
+    PingResult::Failed
+}
--- a/src/routing.rs
+++ b/src/routing.rs
@@ -0,0 +1,340 @@
+use anyhow::Result;
+use libc::if_nametoindex;
+use log::{debug, info};
+use netlink_packet_route::route::RouteAddress;
+use std::ffi::CString;
+use std::net::Ipv4Addr;
+
+const MAIN_TABLE_ID: u8 = 254;
+
+#[derive(Debug, Clone)]
+pub struct RouteInfo {
+    pub gateway: Ipv4Addr,
+    pub interface: String,
+    pub metric: u32,
+}
+
+pub struct RouteManager {
+    routes: Vec<RouteInfo>,
+}
+
+impl RouteManager {
+    pub fn new() -> Self {
+        RouteManager { routes: Vec::new() }
+    }
+
+    pub fn add_route(&mut self, gateway: Ipv4Addr, interface: String, metric: u32) -> Result<()> {
+        let route_info = RouteInfo {
+            gateway,
+            interface: interface.clone(),
+            metric,
+        };
+
+        self.add_default_route_internal(&route_info)?;
+        self.routes.push(route_info);
+
+        info!(
+            "Added route: {} via {} dev {} metric {}",
+            Ipv4Addr::new(0, 0, 0, 0),
+            gateway,
+            interface,
+            metric
+        );
+        Ok(())
+    }
+
+    pub fn remove_route(&mut self, gateway: Ipv4Addr, interface: &str, metric: u32) -> Result<()> {
+        self.delete_default_route_internal(gateway, interface, metric)?;
+
+        self.routes
+            .retain(|r| !(r.gateway == gateway && r.interface == interface && r.metric == metric));
+
+        info!(
+            "Removed route: {} via {} dev {} metric {}",
+            Ipv4Addr::new(0, 0, 0, 0),
+            gateway,
+            interface,
+            metric
+        );
+        Ok(())
+    }
+
+    pub fn set_primary_route(&mut self, gateway: Ipv4Addr, interface: String) -> Result<()> {
+        let primary_metric = 10;
+
+        // Remove existing routes for this interface if any
+        if let Some(pos) = self.routes.iter().position(|r| r.interface == interface) {
+            let existing_route = self.routes[pos].clone();
+            self.remove_route(
+                existing_route.gateway,
+                &existing_route.interface,
+                existing_route.metric,
+            )?;
+        }
+
+        // Add as primary route
+        self.add_route(gateway, interface, primary_metric)?;
+        Ok(())
+    }
+
+    pub fn setup_initial_routes(
+        &mut self,
+        primary_gateway: Ipv4Addr,
+        primary_interface: String,
+        secondary_gateway: Ipv4Addr,
+        secondary_interface: String,
+    ) -> Result<()> {
+        // Set primary route with metric 10 (default)
+        self.set_primary_route(primary_gateway, primary_interface)?;
+
+        // Set secondary route with metric 20 (lower priority)
+        let secondary_metric = 20;
+        self.add_route(secondary_gateway, secondary_interface, secondary_metric)?;
+        Ok(())
+    }
+
+    pub fn add_failover_route(&mut self, gateway: Ipv4Addr, interface: String) -> Result<()> {
+        let failover_metric = 5; // Higher priority than both primary (10) and secondary (20)
+        self.add_route(gateway, interface, failover_metric)?;
+        Ok(())
+    }
+
+    pub fn remove_failover_route(&mut self, gateway: Ipv4Addr, interface: String) -> Result<()> {
+        let failover_metric = 5;
+        self.remove_route(gateway, &interface, failover_metric)?;
+        Ok(())
+    }
+
+    #[allow(dead_code)]
+    pub fn get_routes(&self) -> &[RouteInfo] {
+        &self.routes
+    }
+
+    fn add_default_route_internal(&self, route_info: &RouteInfo) -> Result<()> {
+        let index = get_interface_index(&route_info.interface)?;
+
+        if index == 0 {
+            return Err(anyhow::anyhow!(
+                "Interface '{}' not found",
+                route_info.interface
+            ));
+        }
+
+        use netlink_packet_core::{
+            NLM_F_ACK, NLM_F_CREATE, NLM_F_REQUEST, NetlinkHeader, NetlinkMessage, NetlinkPayload,
+        };
+        use netlink_packet_route::{
+            AddressFamily, RouteNetlinkMessage,
+            route::RouteProtocol,
+            route::RouteScope,
+            route::{RouteAttribute, RouteHeader, RouteMessage, RouteType},
+        };
+        use netlink_sys::{Socket, SocketAddr, protocols::NETLINK_ROUTE};
+
+        let mut socket = Socket::new(NETLINK_ROUTE)?;
+        let _port_number = socket.bind_auto()?.port_number();
+        socket.connect(&SocketAddr::new(0, 0))?;
+        let route_msg_hdr = RouteHeader {
+            address_family: AddressFamily::Inet,
+            table: MAIN_TABLE_ID,
+            destination_prefix_length: 0, // Default route
+            protocol: RouteProtocol::Boot,
+            scope: RouteScope::Universe,
+            kind: RouteType::Unicast,
+            ..Default::default()
+        };
+
+        let mut route_msg = RouteMessage::default();
+        route_msg.header = route_msg_hdr;
+        route_msg.attributes = vec![
+            RouteAttribute::Gateway(RouteAddress::Inet(route_info.gateway)),
+            RouteAttribute::Oif(index),
+            RouteAttribute::Priority(route_info.metric),
+        ];
+        let mut nl_hdr = NetlinkHeader::default();
+        nl_hdr.flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_ACK; // Remove NLM_F_EXCL to allow updates
+
+        let mut msg = NetlinkMessage::new(
+            nl_hdr,
+            NetlinkPayload::from(RouteNetlinkMessage::NewRoute(route_msg)),
+        );
+
+        msg.finalize();
+        let mut buf = vec![0; 1024 * 8];
+
+        msg.serialize(&mut buf[..msg.buffer_len()]);
+
+        // Debug: Log the netlink message being sent
+        debug!("Netlink message being sent: {:?}", &buf[..msg.buffer_len()]);
+        debug!(
+            "Route addition attempt: gateway={}, interface={}, metric={}, interface_index={}",
+            route_info.gateway, route_info.interface, route_info.metric, index
+        );
+
+        socket.send(&buf, 0)?;
+
+        let mut receive_buffer = Vec::with_capacity(256);
+        let size = socket.recv(&mut receive_buffer, 0)?;
+
+        if size == 0 {
+            return Err(anyhow::anyhow!("No response from netlink"));
+        }
+
+        let bytes = &receive_buffer[..size];
+        let rx_packet = <NetlinkMessage<RouteNetlinkMessage>>::deserialize(bytes);
+
+        match rx_packet {
+            Ok(rx_packet) => {
+                if let NetlinkPayload::Error(error_msg) = rx_packet.payload {
+                    if let Some(code) = error_msg.code {
+                        let error_code = code.get();
+                        if error_code == -17 {
+                            // EEXIST - Route already exists, treat as success
+                            info!(
+                                "Route already exists: {} via {} dev {} metric {}",
+                                Ipv4Addr::new(0, 0, 0, 0),
+                                route_info.gateway,
+                                route_info.interface,
+                                route_info.metric
+                            );
+                        } else {
+                            let error_str = match error_code {
+                                -1 => "EPERM - Operation not permitted (need root privileges)",
+                                -2 => "ENOENT - No such file or directory",
+                                -13 => "EACCES - Permission denied",
+                                -22 => "EINVAL - Invalid argument",
+                                _ => "Unknown error",
+                            };
+                            return Err(anyhow::anyhow!(
+                                "Failed to add route: {} (code: {}): {:?}",
+                                error_str,
+                                error_code,
+                                error_msg
+                            ));
+                        }
+                    }
+                    debug!("Route added successfully");
+                }
+            }
+            Err(e) => {
+                return Err(anyhow::anyhow!(
+                    "Failed to deserialize netlink message: {}",
+                    e
+                ));
+            }
+        }
+
+        Ok(())
+    }
+
+    fn delete_default_route_internal(
+        &self,
+        gateway: Ipv4Addr,
+        interface: &str,
+        metric: u32,
+    ) -> Result<()> {
+        let index = get_interface_index(interface)?;
+
+        if index == 0 {
+            return Err(anyhow::anyhow!("Interface '{}' not found", interface));
+        }
+
+        use netlink_packet_core::{
+            NLM_F_ACK, NLM_F_REQUEST, NetlinkHeader, NetlinkMessage, NetlinkPayload,
+        };
+        use netlink_packet_route::{
+            AddressFamily, RouteNetlinkMessage,
+            route::RouteProtocol,
+            route::RouteScope,
+            route::{RouteAttribute, RouteHeader, RouteMessage, RouteType},
+        };
+        use netlink_sys::{Socket, SocketAddr, protocols::NETLINK_ROUTE};
+
+        let mut socket = Socket::new(NETLINK_ROUTE)?;
+        let _port_number = socket.bind_auto()?.port_number();
+        socket.connect(&SocketAddr::new(0, 0))?;
+
+        let route_msg_hdr = RouteHeader {
+            address_family: AddressFamily::Inet,
+            table: MAIN_TABLE_ID,
+            destination_prefix_length: 0, // Default route
+            protocol: RouteProtocol::Boot,
+            scope: RouteScope::Universe,
+            kind: RouteType::Unicast,
+            ..Default::default()
+        };
+
+        let mut route_msg = RouteMessage::default();
+        route_msg.header = route_msg_hdr;
+        route_msg.attributes = vec![
+            RouteAttribute::Gateway(RouteAddress::Inet(gateway)),
+            RouteAttribute::Oif(index),
+            RouteAttribute::Priority(metric),
+        ];
+
+        let mut nl_hdr = NetlinkHeader::default();
+        nl_hdr.flags = NLM_F_REQUEST | NLM_F_ACK;
+
+        let mut msg = NetlinkMessage::new(
+            nl_hdr,
+            NetlinkPayload::from(RouteNetlinkMessage::DelRoute(route_msg)),
+        );
+
+        msg.finalize();
+        let mut buf = vec![0; 1024 * 8];
+
+        msg.serialize(&mut buf[..msg.buffer_len()]);
+
+        // Debug: Log the netlink message being sent
+        debug!(
+            "Netlink delete message being sent: {:?}",
+            &buf[..msg.buffer_len()]
+        );
+        debug!(
+            "Route deletion attempt: gateway={}, interface={}, metric={}, interface_index={}",
+            gateway, interface, metric, index
+        );
+
+        socket.send(&buf, 0)?;
+
+        let mut receive_buffer = Vec::with_capacity(256);
+        let size = socket.recv(&mut receive_buffer, 0)?;
+
+        if size == 0 {
+            return Err(anyhow::anyhow!("No response from netlink"));
+        }
+
+        let bytes = &receive_buffer[..size];
+        let rx_packet = <NetlinkMessage<RouteNetlinkMessage>>::deserialize(bytes);
+
+        match rx_packet {
+            Ok(rx_packet) => {
+                if let NetlinkPayload::Error(error_msg) = rx_packet.payload {
+                    if error_msg.code.is_some() {
+                        return Err(anyhow::anyhow!("Failed to delete route: {:?}", error_msg));
+                    }
+                    debug!("Route deleted successfully");
+                }
+            }
+            Err(e) => {
+                return Err(anyhow::anyhow!(
+                    "Failed to deserialize netlink message: {}",
+                    e
+                ));
+            }
+        }
+
+        Ok(())
+    }
+}
+
+fn get_interface_index(iface_name: &str) -> Result<u32> {
+    let c_name = CString::new(iface_name)?;
+    let index = unsafe { if_nametoindex(c_name.as_ptr()) };
+
+    if index == 0 {
+        Err(anyhow::anyhow!("Interface '{}' not found", iface_name))
+    } else {
+        Ok(index)
+    }
+}
--- a/src/state_machine.rs
+++ b/src/state_machine.rs
@@ -0,0 +1,487 @@
+use log::{info, warn};
+use std::collections::VecDeque;
+use std::time::Duration;
+
+use crate::pinger;
+use crate::routing;
+
+#[derive(Debug, PartialEq, Clone)]
+pub enum State {
+    Boot,
+    Primary,
+    Fallback,
+}
+
+pub struct StateMachine {
+    state: State,
+    primary_history: VecDeque<pinger::PingResult>,
+    secondary_history: VecDeque<pinger::PingResult>,
+    failover_threshold: usize,
+    failback_delay: Duration,
+    last_failover: Option<std::time::Instant>,
+    boot_start_time: std::time::Instant,
+}
+
+impl StateMachine {
+    pub fn new(failover_threshold: usize, failback_delay: Duration) -> Self {
+        Self {
+            state: State::Boot,
+            primary_history: VecDeque::with_capacity(60),
+            secondary_history: VecDeque::with_capacity(60),
+            failover_threshold,
+            failback_delay,
+            last_failover: None,
+            boot_start_time: std::time::Instant::now(),
+        }
+    }
+
+    pub fn add_primary_result(&mut self, result: pinger::PingResult) {
+        self.primary_history.push_front(result);
+        if self.primary_history.len() > 60 {
+            self.primary_history.pop_back();
+        }
+    }
+
+    pub fn add_secondary_result(&mut self, result: pinger::PingResult) {
+        self.secondary_history.push_front(result);
+        if self.secondary_history.len() > 60 {
+            self.secondary_history.pop_back();
+        }
+    }
+
+    fn should_fallback(&self) -> bool {
+        if self.primary_history.len() < self.failover_threshold {
+            return false;
+        }
+
+        // Check if we have enough consecutive failures
+        self.primary_history
+            .iter()
+            .take(self.failover_threshold)
+            .all(|x| *x == pinger::PingResult::Failed)
+    }
+
+    fn should_failback(&self) -> bool {
+        if self.secondary_history.len() < 3 {
+            return false;
+        }
+
+        // Check if secondary is working
+        let secondary_working = self
+            .secondary_history
+            .iter()
+            .take(3)
+            .any(|x| *x == pinger::PingResult::Ok);
+
+        if !secondary_working {
+            return false;
+        }
+
+        // Check if primary is working consistently
+        if self.primary_history.len() < 10 {
+            return false;
+        }
+
+        let primary_working = self
+            .primary_history
+            .iter()
+            .take(10)
+            .all(|x| *x == pinger::PingResult::Ok);
+
+        if !primary_working {
+            return false;
+        }
+
+        // Check if enough time has passed since last failover
+        if let Some(last_failover) = self.last_failover {
+            last_failover.elapsed() >= self.failback_delay
+        } else {
+            true
+        }
+    }
+
+    pub fn get_state(&self) -> &State {
+        &self.state
+    }
+
+    pub fn update_state(&mut self) -> Option<(State, State)> {
+        let old_state = self.state.clone();
+
+        match self.state {
+            State::Boot => {
+                // Check if 10 seconds have passed since boot start
+                if self.boot_start_time.elapsed() >= Duration::from_secs(10) {
+                    self.state = State::Primary;
+                    info!("Boot phase complete (10s sampling), switching to Primary state");
+                }
+            }
+            State::Primary => {
+                if self.should_fallback() {
+                    // Verify secondary is working before failing over
+                    if self.secondary_history.len() >= 3 {
+                        let secondary_working = self
+                            .secondary_history
+                            .iter()
+                            .take(3)
+                            .all(|x| *x == pinger::PingResult::Ok);
+
+                        if secondary_working {
+                            self.state = State::Fallback;
+                            self.last_failover = Some(std::time::Instant::now());
+                            warn!("Primary interface failing over to secondary");
+                        } else {
+                            warn!(
+                                "Primary interface failing but secondary also down - not switching"
+                            );
+                        }
+                    }
+                }
+            }
+            State::Fallback => {
+                if self.should_failback() {
+                    self.state = State::Primary;
+                    info!("Primary interface restored, failing back");
+                }
+            }
+        }
+
+        if old_state != self.state {
+            Some((old_state, self.state.clone()))
+        } else {
+            None
+        }
+    }
+}
+
+pub fn handle_state_change(
+    new_state: State,
+    old_state: State,
+    route_manager: &mut routing::RouteManager,
+    _primary_gateway: &std::net::Ipv4Addr,
+    secondary_gateway: &std::net::Ipv4Addr,
+    config: &crate::Config,
+) -> anyhow::Result<()> {
+    match (old_state, new_state) {
+        (State::Fallback, State::Primary) => {
+            // Only remove failover route when transitioning from Fallback to Primary
+            info!("Switching to primary route (failback)");
+            route_manager
+                .remove_failover_route(*secondary_gateway, config.secondary_interface.clone())?;
+        }
+        (_, State::Fallback) => {
+            info!("Switching to secondary route (failover)");
+            // Add extra failover route with higher priority (metric 5)
+            route_manager
+                .add_failover_route(*secondary_gateway, config.secondary_interface.clone())?;
+        }
+        (State::Boot, State::Primary) => {
+            // Boot -> Primary transition should not remove any routes
+            info!("Boot phase complete, entering Primary state");
+        }
+        _ => {
+            // Other transitions don't require route changes
+        }
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::pinger::PingResult;
+
+    #[test]
+    fn test_state_machine_initialization() {
+        let sm = StateMachine::new(3, Duration::from_secs(60));
+        assert_eq!(sm.state, State::Boot);
+        assert_eq!(sm.failover_threshold, 3);
+        assert_eq!(sm.failback_delay, Duration::from_secs(60));
+        assert!(sm.primary_history.is_empty());
+        assert!(sm.secondary_history.is_empty());
+        assert!(sm.last_failover.is_none());
+    }
+
+    #[test]
+    fn test_add_primary_result() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+
+        sm.add_primary_result(PingResult::Ok);
+        assert_eq!(sm.primary_history.len(), 1);
+        assert_eq!(sm.primary_history[0], PingResult::Ok);
+
+        sm.add_primary_result(PingResult::Failed);
+        assert_eq!(sm.primary_history.len(), 2);
+        assert_eq!(sm.primary_history[0], PingResult::Failed);
+        assert_eq!(sm.primary_history[1], PingResult::Ok);
+    }
+
+    #[test]
+    fn test_add_secondary_result() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+
+        sm.add_secondary_result(PingResult::Ok);
+        assert_eq!(sm.secondary_history.len(), 1);
+        assert_eq!(sm.secondary_history[0], PingResult::Ok);
+
+        sm.add_secondary_result(PingResult::Failed);
+        assert_eq!(sm.secondary_history.len(), 2);
+        assert_eq!(sm.secondary_history[0], PingResult::Failed);
+        assert_eq!(sm.secondary_history[1], PingResult::Ok);
+    }
+
+    #[test]
+    fn test_history_capacity_limit() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+
+        // Add 65 results (more than capacity of 60)
+        for _ in 0..65 {
+            sm.add_primary_result(PingResult::Ok);
+        }
+
+        assert_eq!(sm.primary_history.len(), 60);
+    }
+
+    #[test]
+    fn test_should_fallback_insufficient_history() {
+        let sm = StateMachine::new(3, Duration::from_secs(60));
+        assert!(!sm.should_fallback()); // Empty history
+
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+        sm.add_primary_result(PingResult::Failed);
+        sm.add_primary_result(PingResult::Failed);
+        assert!(!sm.should_fallback()); // Only 2 results, need 3
+    }
+
+    #[test]
+    fn test_should_fallback_consecutive_failures() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+
+        // Add 3 consecutive failures
+        sm.add_primary_result(PingResult::Failed);
+        sm.add_primary_result(PingResult::Failed);
+        sm.add_primary_result(PingResult::Failed);
+
+        assert!(sm.should_fallback());
+    }
+
+    #[test]
+    fn test_should_fallback_mixed_results() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+
+        // Add mixed results (not all failures)
+        sm.add_primary_result(PingResult::Failed);
+        sm.add_primary_result(PingResult::Ok);
+        sm.add_primary_result(PingResult::Failed);
+
+        assert!(!sm.should_fallback());
+    }
+
+    #[test]
+    fn test_should_failback_insufficient_secondary_history() {
+        let sm = StateMachine::new(3, Duration::from_secs(60));
+        assert!(!sm.should_failback()); // Empty secondary history
+
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+        sm.add_secondary_result(PingResult::Ok);
+        sm.add_secondary_result(PingResult::Ok);
+        assert!(!sm.should_failback()); // Only 2 results, need 3
+    }
+
+    #[test]
+    fn test_should_failback_secondary_not_working() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+
+        // Add 3 secondary failures
+        for _ in 0..3 {
+            sm.add_secondary_result(PingResult::Failed);
+        }
+
+        assert!(!sm.should_failback());
+    }
+
+    #[test]
+    fn test_should_failback_insufficient_primary_history() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+
+        // Add 3 working secondary results
+        for _ in 0..3 {
+            sm.add_secondary_result(PingResult::Ok);
+        }
+
+        // Add only 5 primary results (need 10)
+        for _ in 0..5 {
+            sm.add_primary_result(PingResult::Ok);
+        }
+
+        assert!(!sm.should_failback());
+    }
+
+    #[test]
+    fn test_should_failback_primary_not_working() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+
+        // Add 3 working secondary results
+        for _ in 0..3 {
+            sm.add_secondary_result(PingResult::Ok);
+        }
+
+        // Add 10 mixed primary results
+        for _ in 0..5 {
+            sm.add_primary_result(PingResult::Ok);
+            sm.add_primary_result(PingResult::Failed);
+        }
+
+        assert!(!sm.should_failback());
+    }
+
+    #[test]
+    fn test_should_failback_success() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+
+        // Add 3 working secondary results
+        for _ in 0..3 {
+            sm.add_secondary_result(PingResult::Ok);
+        }
+
+        // Add 10 working primary results
+        for _ in 0..10 {
+            sm.add_primary_result(PingResult::Ok);
+        }
+
+        assert!(sm.should_failback());
+    }
+
+    #[test]
+    fn test_should_failback_respect_delay() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+
+        // Set up conditions for failback
+        for _ in 0..3 {
+            sm.add_secondary_result(PingResult::Ok);
+        }
+        for _ in 0..10 {
+            sm.add_primary_result(PingResult::Ok);
+        }
+
+        // Simulate recent failover
+        sm.last_failover = Some(std::time::Instant::now());
+
+        assert!(!sm.should_failback()); // Should not failback immediately
+    }
+
+    #[test]
+    fn test_update_state_boot_to_primary() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+
+        // Simulate boot phase completion by manipulating boot_start_time
+        sm.boot_start_time = std::time::Instant::now() - Duration::from_secs(11);
+
+        let transition = sm.update_state();
+        assert!(transition.is_some());
+        assert_eq!(transition.unwrap(), (State::Boot, State::Primary));
+        assert_eq!(sm.state, State::Primary);
+    }
+
+    #[test]
+    fn test_update_state_still_in_boot() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+
+        // Still in boot phase (less than 10 seconds)
+        let transition = sm.update_state();
+        assert!(transition.is_none());
+        assert_eq!(sm.state, State::Boot);
+    }
+
+    #[test]
+    fn test_update_state_primary_to_fallback() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+        sm.state = State::Primary;
+
+        // Add consecutive primary failures
+        for _ in 0..3 {
+            sm.add_primary_result(PingResult::Failed);
+        }
+
+        // Add working secondary results
+        for _ in 0..3 {
+            sm.add_secondary_result(PingResult::Ok);
+        }
+
+        let transition = sm.update_state();
+        assert!(transition.is_some());
+        assert_eq!(transition.unwrap(), (State::Primary, State::Fallback));
+        assert_eq!(sm.state, State::Fallback);
+        assert!(sm.last_failover.is_some());
+    }
+
+    #[test]
+    fn test_update_state_primary_no_fallback_secondary_down() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+        sm.state = State::Primary;
+
+        // Add consecutive primary failures
+        for _ in 0..3 {
+            sm.add_primary_result(PingResult::Failed);
+        }
+
+        // Add failing secondary results
+        for _ in 0..3 {
+            sm.add_secondary_result(PingResult::Failed);
+        }
+
+        let transition = sm.update_state();
+        assert!(transition.is_none());
+        assert_eq!(sm.state, State::Primary);
+    }
+
+    #[test]
+    fn test_update_state_fallback_to_primary() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+        sm.state = State::Fallback;
+
+        // Set up conditions for failback
+        for _ in 0..3 {
+            sm.add_secondary_result(PingResult::Ok);
+        }
+        for _ in 0..10 {
+            sm.add_primary_result(PingResult::Ok);
+        }
+
+        let transition = sm.update_state();
+        assert!(transition.is_some());
+        assert_eq!(transition.unwrap(), (State::Fallback, State::Primary));
+        assert_eq!(sm.state, State::Primary);
+    }
+
+    #[test]
+    fn test_update_state_no_transition() {
+        let mut sm = StateMachine::new(3, Duration::from_secs(60));
+        sm.state = State::Primary;
+
+        // Add some mixed results that don't trigger transitions
+        sm.add_primary_result(PingResult::Ok);
+        sm.add_primary_result(PingResult::Failed);
+
+        let transition = sm.update_state();
+        assert!(transition.is_none());
+        assert_eq!(sm.state, State::Primary);
+    }
+
+    #[test]
+    fn test_state_equality() {
+        assert_eq!(State::Boot, State::Boot);
+        assert_eq!(State::Primary, State::Primary);
+        assert_eq!(State::Fallback, State::Fallback);
+
+        assert_ne!(State::Boot, State::Primary);
+        assert_ne!(State::Primary, State::Fallback);
+        assert_ne!(State::Fallback, State::Boot);
+    }
+
+    #[test]
+    fn test_state_clone() {
+        let state = State::Primary;
+        let cloned = state.clone();
+        assert_eq!(state, cloned);
+    }
+}