feat(go): port socket detectors

go-agent/README.md

@@ -7,11 +7,13 @@ behavioral oracle until every subsystem reaches fixture and red-team parity.
 Current scope:
 
 - standard-library-only flat TOML loading for the settings used so far;
-- an injectable `/proc` process snapshot boundary;
+- an injectable `/proc` process/file-descriptor snapshot plus fail-open `ss`
+  socket collection;
 - a cancellable sweep loop that emits JSONL `enodia.event.v1` records;
 - exact `enodia.alert.v1` parity for `ld_preload` (SID `100011`),
   `deleted_exe` (`100012`), `input_snooper` (`100032`), and
-  `credential_access` (`100033`);
+  `credential_access` (`100033`), plus `reverse_shell` (`100010`), `egress`
+  (`100016`), and `stealth_network` (`100036`);
 - `enodia.status.v1` heartbeat records with no persistence or retained-alert
   claims;
 - a shared fixture checked against the Python detector by

go-agent/internal/agent/agent.go

@@ -57,6 +57,12 @@ func (a *Agent) Sweep() ([]map[string]any, error) {
 	timestamp := a.Now().Local().Format(time.RFC3339Nano)
 
 	alerts := make([]model.Alert, 0)
+	// Preserve the relative order of Python detectors.REGISTRY. Snapshot and
+	// parity consumers rely on stable alert ordering even while unported slots
+	// are temporarily absent from the Go implementation.
+	if a.Config.Enabled("reverse_shell") {
+		alerts = append(alerts, detectors.ReverseShell(state, a.Config)...)
+	}
 	if a.Config.Enabled("ld_preload") {
 		alerts = append(alerts, detectors.LDPreload(state)...)
 	}
@@ -69,6 +75,12 @@ func (a *Agent) Sweep() ([]map[string]any, error) {
 	if a.Config.Enabled("credential_access") {
 		alerts = append(alerts, detectors.CredentialAccess(state, a.Config)...)
 	}
+	if a.Config.Enabled("stealth_network") {
+		alerts = append(alerts, detectors.StealthNetwork(state, a.Config)...)
+	}
+	if a.Config.Enabled("egress") {
+		alerts = append(alerts, detectors.Egress(state, a.Config)...)
+	}
 	events := make([]map[string]any, 0, len(alerts)+1)
 	for _, alert := range alerts {
 		record, err := schema.Build("alert", alert, host, timestamp)

go-agent/internal/agent/agent_test.go

@@ -11,6 +11,8 @@ import (
 	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
 )
 
+func intPointer(value int) *int { return &value }
+
 func TestRunOnceEmitsAlertAndStatusEnvelopes(t *testing.T) {
 	agent := New(config.Default(), func() (model.State, error) {
 		return model.State{Processes: []model.Process{
@@ -57,19 +59,34 @@ func TestSweepPreservesPythonDetectorOrder(t *testing.T) {
 	agent := New(config.Default(), func() (model.State, error) {
 		return model.State{
 			LDPreload: "/tmp/global.so",
-			Processes: []model.Process{{
-				PID:       42,
-				Comm:      "dropper",
-				Exe:       "/tmp/dropper (deleted)",
-				FDTargets: map[string]string{"4": "/etc/shadow", "7": "/dev/input/event3"},
-			}},
+			Processes: []model.Process{
+				{
+					PID:       42,
+					Comm:      "dropper",
+					Exe:       "/tmp/dropper (deleted)",
+					FDTargets: map[string]string{"4": "/etc/shadow", "7": "/dev/input/event3"},
+				},
+				{
+					PID:       100,
+					Comm:      "bash",
+					Cmdline:   "bash -i",
+					FDTargets: map[string]string{"0": "socket:[999]"},
+				},
+			},
+			Sockets: []model.Socket{
+				{State: "ESTAB", Local: "127.0.0.1:55", Peer: "9.9.9.9:443", Inode: intPointer(999), Comm: "bash", PID: intPointer(100), Kind: "tcp"},
+				{State: "ESTAB", Local: "10.0.0.2:5000", Peer: "8.8.8.8:4443", Comm: "hoxha", PID: intPointer(340), Kind: "sctp"},
+			},
 		}, nil
 	})
 	events, err := agent.Sweep()
 	if err != nil {
 		t.Fatal(err)
 	}
-	want := []string{"ld_preload", "deleted_exe", "input_snooper", "credential_access"}
+	want := []string{
+		"reverse_shell", "ld_preload", "deleted_exe", "input_snooper",
+		"credential_access", "stealth_network", "egress",
+	}
 	if len(events) != len(want)+1 {
 		t.Fatalf("unexpected events: %#v", events)
 	}

go-agent/internal/config/config.go

@@ -30,6 +30,20 @@ var defaultCredentialAccessAllowComms = []string{
 	"chrome", "google-chrome", "brave", "brave-browser",
 }
 
+var defaultInterpreters = []string{
+	"bash", "sh", "dash", "zsh", "ksh", "ash", "nc", "ncat", "netcat",
+	"socat", "telnet", "python", "python2", "python3", "perl", "ruby",
+	"php", "lua", "awk",
+}
+
+// These defaults intentionally duplicate the Python Config values. The parity
+// harness catches detector output drift, while config tests catch tuning drift
+// before a detector ever runs.
+var defaultStealthNetworkAllowComms = []string{
+	"NetworkManager", "systemd-networkd", "wpa_supplicant", "dhcpcd",
+	"tcpdump", "dumpcap", "wireshark", "suricata", "zeek",
+}
+
 // Config mirrors the Phase 1 settings consumed by the Go sweep loop. More
 // fields are added as their detectors are ported.
 type Config struct {
@@ -39,6 +53,10 @@ type Config struct {
 	InputSnooperAllowComms     map[string]bool
 	CredentialAccessAllowComms map[string]bool
 	CredentialAccessExtraPaths []string
+	Interpreters               map[string]bool
+	EgressAllowCIDRs           []string
+	StealthNetworkAllowComms   map[string]bool
+	StealthNetworkAllowKinds   map[string]bool
 }
 
 // Default returns Python-compatible defaults for the fields currently used.
@@ -54,6 +72,10 @@ func Default() Config {
 		InputSnooperAllowComms:     stringSet(defaultInputSnooperAllowComms),
 		CredentialAccessAllowComms: stringSet(defaultCredentialAccessAllowComms),
 		CredentialAccessExtraPaths: []string{},
+		Interpreters:               stringSet(defaultInterpreters),
+		EgressAllowCIDRs:           []string{},
+		StealthNetworkAllowComms:   stringSet(defaultStealthNetworkAllowComms),
+		StealthNetworkAllowKinds:   map[string]bool{},
 	}
 }
 
@@ -125,6 +147,32 @@ func Load(path string) (Config, error) {
 				return Config{}, fmt.Errorf("credential_access_extra_paths: %w", err)
 			}
 			cfg.CredentialAccessExtraPaths = paths
+		case "interpreters":
+			// Keep arrays as sets where membership is the runtime operation. TOML
+			// order has no behavioral meaning for allowlists.
+			names, err := stringArray(value)
+			if err != nil {
+				return Config{}, fmt.Errorf("interpreters: %w", err)
+			}
+			cfg.Interpreters = stringSet(names)
+		case "egress_allow_cidrs":
+			cidrs, err := stringArray(value)
+			if err != nil {
+				return Config{}, fmt.Errorf("egress_allow_cidrs: %w", err)
+			}
+			cfg.EgressAllowCIDRs = cidrs
+		case "stealth_network_allow_comms":
+			names, err := stringArray(value)
+			if err != nil {
+				return Config{}, fmt.Errorf("stealth_network_allow_comms: %w", err)
+			}
+			cfg.StealthNetworkAllowComms = stringSet(names)
+		case "stealth_network_allow_kinds":
+			kinds, err := stringArray(value)
+			if err != nil {
+				return Config{}, fmt.Errorf("stealth_network_allow_kinds: %w", err)
+			}
+			cfg.StealthNetworkAllowKinds = stringSet(kinds)
 		}
 	}
 	return cfg, nil

go-agent/internal/config/config_test.go

@@ -31,6 +31,10 @@ detectors = [
 input_snooper_allow_comms = ["Xorg"]
 credential_access_allow_comms = ["firefox"]
 credential_access_extra_paths = ["/srv/secrets/"]
+interpreters = ["bash", "python3"]
+egress_allow_cidrs = ["203.0.113.0/24"]
+stealth_network_allow_comms = ["tcpdump"]
+stealth_network_allow_kinds = ["mptcp"]
 unknown_future_key = true
 `)
 	if err := os.WriteFile(path, raw, 0o600); err != nil {
@@ -53,6 +57,13 @@ unknown_future_key = true
 		t.Fatalf("unexpected credential tuning: %#v %#v",
 			cfg.CredentialAccessAllowComms, cfg.CredentialAccessExtraPaths)
 	}
+	if !cfg.Interpreters["bash"] || len(cfg.EgressAllowCIDRs) != 1 {
+		t.Fatalf("unexpected network tuning: %#v %#v", cfg.Interpreters, cfg.EgressAllowCIDRs)
+	}
+	if !cfg.StealthNetworkAllowComms["tcpdump"] || !cfg.StealthNetworkAllowKinds["mptcp"] {
+		t.Fatalf("unexpected stealth tuning: %#v %#v",
+			cfg.StealthNetworkAllowComms, cfg.StealthNetworkAllowKinds)
+	}
 }
 
 func TestMissingFileKeepsDefaults(t *testing.T) {

go-agent/internal/detectors/egress.go

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package detectors
+
+import (
+	"fmt"
+
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/config"
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/netutil"
+)
+
+// Egress ports interpreter-to-public-IP detection (SID 100016).
+func Egress(state model.State, cfg config.Config) []model.Alert {
+	alerts := make([]model.Alert, 0)
+	for _, socket := range state.Sockets {
+		// Only established interpreter-owned sockets qualify. Listeners and
+		// connection setup states are handled by other detector families.
+		if socket.State != "ESTAB" || !cfg.Interpreters[socket.Comm] {
+			continue
+		}
+		host, port := netutil.SplitHostPort(socket.Peer)
+		// Private/special addresses and explicit trusted CIDRs are intentionally
+		// silent so routine local services and operator infrastructure stay quiet.
+		if !netutil.IsPublicIP(host) || netutil.IPInCIDRs(host, cfg.EgressAllowCIDRs) {
+			continue
+		}
+		alerts = append(alerts, model.Alert{
+			SID:       100016,
+			Severity:  "HIGH",
+			Signature: "egress",
+			Classtype: "c2-exfil",
+			Key:       fmt.Sprintf("egr:%s:%s", optionalPythonInt(socket.PID), host),
+			Detail: fmt.Sprintf(
+				"pid=%s comm=%s -> %s:%s (interpreter to public IP)",
+				optionalPythonInt(socket.PID), socket.Comm, host, port),
+			PIDs: alertPIDs(socket.PID),
+		})
+	}
+	return alerts
+}

go-agent/internal/detectors/egress_test.go

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package detectors
+
+import (
+	"testing"
+
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/config"
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
+)
+
+func TestEgressPublicPrivateAndAllowlist(t *testing.T) {
+	state := model.State{Sockets: []model.Socket{
+		{State: "ESTAB", Peer: "8.8.8.8:443", Comm: "python3", PID: intPointer(500)},
+		{State: "ESTAB", Peer: "10.0.0.5:443", Comm: "python3", PID: intPointer(501)},
+		{State: "ESTAB", Peer: "9.9.9.9:443", Comm: "nginx", PID: intPointer(502)},
+	}}
+	alerts := Egress(state, config.Default())
+	if len(alerts) != 1 || alerts[0].SID != 100016 || alerts[0].Key != "egr:500:8.8.8.8" {
+		t.Fatalf("unexpected alerts: %#v", alerts)
+	}
+	cfg := config.Default()
+	cfg.EgressAllowCIDRs = []string{"8.8.8.0/24"}
+	if alerts := Egress(state, cfg); len(alerts) != 0 {
+		t.Fatalf("allowlisted egress alerted: %#v", alerts)
+	}
+}

go-agent/internal/detectors/reverse_shell.go

@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package detectors
+
+import (
+	"fmt"
+
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/config"
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
+)
+
+// ReverseShell ports the network-socket-on-stdio detector (SID 100010).
+func ReverseShell(state model.State, cfg config.Config) []model.Alert {
+	// Build the inode correlation table once. A stdio socket alone could be a
+	// benign Unix socket; requiring the inode in the network socket view is the
+	// high-signal condition that distinguishes a likely reverse shell.
+	peerByInode := make(map[int]string)
+	for _, socket := range state.Sockets {
+		if socket.Inode != nil {
+			peerByInode[*socket.Inode] = fmt.Sprintf("%s -> %s", socket.Local, socket.Peer)
+		}
+	}
+	alerts := make([]model.Alert, 0)
+	for _, process := range state.Processes {
+		// Restrict to shells/interpreters exactly as Python does. Networked
+		// daemons commonly inherit sockets and must not become false positives.
+		if !cfg.Interpreters[process.Comm] {
+			continue
+		}
+		inode := stdioSocketInode(process)
+		if inode == nil || peerByInode[*inode] == "" {
+			continue
+		}
+		alerts = append(alerts, model.Alert{
+			SID:       100010,
+			Severity:  "CRITICAL",
+			Signature: "reverse_shell",
+			Classtype: "c2-reverse-shell",
+			Key:       fmt.Sprintf("rsh:%d", process.PID),
+			Detail: fmt.Sprintf(
+				"pid=%d comm=%s stdio=net-socket peer=[%s] cmd=[%s]",
+				process.PID, process.Comm, peerByInode[*inode], truncateRunes(process.Cmdline, 90)),
+			PIDs: []int{process.PID},
+		})
+	}
+	return alerts
+}

go-agent/internal/detectors/reverse_shell_test.go

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package detectors
+
+import (
+	"testing"
+
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/config"
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
+)
+
+func intPointer(value int) *int { return &value }
+
+func TestReverseShellRequiresInterpreterAndNetworkInode(t *testing.T) {
+	state := model.State{
+		Processes: []model.Process{
+			{PID: 100, Comm: "bash", Cmdline: "bash -i", FDTargets: map[string]string{"0": "socket:[999]"}},
+			{PID: 101, Comm: "nginx", FDTargets: map[string]string{"0": "socket:[999]"}},
+			{PID: 102, Comm: "bash", FDTargets: map[string]string{"0": "socket:[777]"}},
+		},
+		Sockets: []model.Socket{{
+			State: "ESTAB", Local: "127.0.0.1:55", Peer: "9.9.9.9:443",
+			Inode: intPointer(999), Comm: "bash", PID: intPointer(100), Kind: "tcp",
+		}},
+	}
+	alerts := ReverseShell(state, config.Default())
+	if len(alerts) != 1 || alerts[0].SID != 100010 || alerts[0].Key != "rsh:100" {
+		t.Fatalf("unexpected alerts: %#v", alerts)
+	}
+	want := "pid=100 comm=bash stdio=net-socket peer=[127.0.0.1:55 -> 9.9.9.9:443] cmd=[bash -i]"
+	if alerts[0].Detail != want {
+		t.Fatalf("unexpected detail: %q", alerts[0].Detail)
+	}
+}

go-agent/internal/detectors/socket.go

@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package detectors
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
+)
+
+func stdioSocketInode(process model.Process) *int {
+	// The Python oracle checks descriptors in 0,1,2 order and stops at the
+	// first socket. That ordering avoids a map-iteration-dependent alert.
+	for _, fd := range []string{"0", "1", "2"} {
+		target := process.FDTargets[fd]
+		if strings.HasPrefix(target, "socket:[") && strings.HasSuffix(target, "]") {
+			value, err := strconv.Atoi(target[8 : len(target)-1])
+			if err == nil {
+				return &value
+			}
+		}
+	}
+	return nil
+}
+
+func optionalPythonInt(value *int) string {
+	// Python f-strings render a missing optional integer as "None". Keys are
+	// stable machine contracts, so preserve that spelling rather than Go's
+	// default <nil> representation.
+	if value == nil {
+		return "None"
+	}
+	return strconv.Itoa(*value)
+}
+
+func optionalDisplayInt(value *int) string {
+	// Human-facing stealth-network details use "?" for unknown ownership even
+	// though the corresponding dedup key uses Python's "None" spelling.
+	if value == nil || *value == 0 {
+		return "?"
+	}
+	return strconv.Itoa(*value)
+}
+
+func alertPIDs(value *int) []int {
+	if value == nil || *value == 0 {
+		return []int{}
+	}
+	return []int{*value}
+}
+
+func truncateRunes(value string, limit int) string {
+	// Python slices Unicode code points, not UTF-8 bytes. Rune truncation keeps
+	// command details identical for non-ASCII argv values.
+	runes := []rune(value)
+	if len(runes) <= limit {
+		return value
+	}
+	return string(runes[:limit])
+}
+
+func socketKey(kind string, socket model.Socket) string {
+	return fmt.Sprintf("stealthnet:%s:%s:%s:%s",
+		kind, optionalPythonInt(socket.PID), socket.Local, socket.Peer)
+}

go-agent/internal/detectors/stealth_network.go

@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package detectors
+
+import (
+	"fmt"
+	"strings"
+
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/config"
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/netutil"
+)
+
+var watchedSocketKinds = map[string]bool{
+	"raw": true, "sctp": true, "dccp": true, "packet": true,
+	"mptcp": true, "tipc": true, "xdp": true, "vsock": true,
+}
+
+var alwaysHighSocketKinds = map[string]bool{"raw": true, "packet": true, "xdp": true}
+
+var activeSocketStates = map[string]bool{
+	"ESTAB": true, "LISTEN": true, "UNCONN": true, "CONNECTED": true,
+	"SYN-SENT": true, "SYN-RECV": true,
+}
+
+// StealthNetwork ports unusual socket-family detection (SID 100036).
+func StealthNetwork(state model.State, cfg config.Config) []model.Alert {
+	alerts := make([]model.Alert, 0)
+	for _, socket := range state.Sockets {
+		kind := strings.ToLower(socket.Kind)
+		// TCP/UDP belong to reverse-shell, egress, and listener detectors. This
+		// detector is deliberately limited to less-common covert-channel paths.
+		if !watchedSocketKinds[kind] || cfg.StealthNetworkAllowKinds[kind] {
+			continue
+		}
+		if socket.Comm != "" && cfg.StealthNetworkAllowComms[socket.Comm] {
+			continue
+		}
+		if socket.State != "" && !activeSocketStates[socket.State] {
+			continue
+		}
+		severity := "MEDIUM"
+		host, _ := netutil.SplitHostPort(socket.Peer)
+		publicPeer := netutil.IsPublicIP(host) && !netutil.IPInCIDRs(host, cfg.EgressAllowCIDRs)
+		// Raw/packet/XDP access, listeners, and public peers are immediately
+		// high severity; inactive or locally scoped unusual families stay medium.
+		if alwaysHighSocketKinds[kind] || socket.State == "LISTEN" || publicPeer {
+			severity = "HIGH"
+		}
+		comm := socket.Comm
+		if comm == "" {
+			comm = "?"
+		}
+		alerts = append(alerts, model.Alert{
+			SID:       100036,
+			Severity:  severity,
+			Signature: "stealth_network",
+			Classtype: "covert-channel",
+			Key:       socketKey(kind, socket),
+			Detail: fmt.Sprintf(
+				"%s socket state=%s local=%s peer=%s comm=%s pid=%s",
+				kind, socket.State, socket.Local, socket.Peer, comm, optionalDisplayInt(socket.PID)),
+			PIDs: alertPIDs(socket.PID),
+		})
+	}
+	return alerts
+}

go-agent/internal/detectors/stealth_network_test.go

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package detectors
+
+import (
+	"testing"
+
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/config"
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
+)
+
+func TestStealthNetworkSeverityAndAllowlist(t *testing.T) {
+	state := model.State{Sockets: []model.Socket{
+		{State: "ESTAB", Local: "10.0.0.2:5000", Peer: "8.8.8.8:4443", Comm: "hoxha", PID: intPointer(340), Kind: "sctp"},
+		{State: "UNCONN", Local: "*:eth0", Peer: "*", Comm: "tcpdump", PID: intPointer(341), Kind: "packet"},
+		{State: "ESTAB", Local: "10.0.0.2:5", Peer: "8.8.8.8:443", Comm: "curl", PID: intPointer(342), Kind: "tcp"},
+	}}
+	alerts := StealthNetwork(state, config.Default())
+	if len(alerts) != 1 || alerts[0].SID != 100036 || alerts[0].Severity != "HIGH" {
+		t.Fatalf("unexpected alerts: %#v", alerts)
+	}
+	if alerts[0].Key != "stealthnet:sctp:340:10.0.0.2:5000:8.8.8.8:4443" {
+		t.Fatalf("unexpected key: %s", alerts[0].Key)
+	}
+}

go-agent/internal/model/model.go

@@ -19,9 +19,22 @@ type Process struct {
 // SystemState boundary.
 type State struct {
 	Processes []Process `json:"processes"`
+	Sockets   []Socket  `json:"sockets"`
 	LDPreload string    `json:"ld_preload"`
 }
 
+// Socket matches the Python SystemState socket view. Nil inode/PID values
+// preserve ss records where ownership metadata is unavailable.
+type Socket struct {
+	State string `json:"state"`
+	Local string `json:"local"`
+	Peer  string `json:"peer"`
+	Inode *int   `json:"inode"`
+	Comm  string `json:"comm"`
+	PID   *int   `json:"pid"`
+	Kind  string `json:"kind"`
+}
+
 // Alert matches enodia.alert.v1.
 type Alert struct {
 	SID       int    `json:"sid"`

go-agent/internal/netutil/netutil.go

@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+// Package netutil contains stdlib address helpers matching the Python oracle.
+package netutil
+
+import (
+	"net/netip"
+	"strings"
+)
+
+var carrierGradeNAT = netip.MustParsePrefix("100.64.0.0/10")
+
+// ParseAddr accepts brackets and IPv6 zone suffixes used by ss.
+func ParseAddr(value string) (netip.Addr, bool) {
+	value = strings.Trim(strings.TrimSpace(value), "[]")
+	if index := strings.IndexByte(value, '%'); index >= 0 {
+		value = value[:index]
+	}
+	address, err := netip.ParseAddr(value)
+	return address, err == nil
+}
+
+// IsPublicIP reports globally routable addresses and excludes CGNAT.
+func IsPublicIP(value string) bool {
+	address, ok := ParseAddr(value)
+	// netip's GlobalUnicast includes CGNAT, so explicitly exclude 100.64/10
+	// to match Python ipaddress.is_global and avoid treating carrier-local
+	// traffic as public C2 egress.
+	if !ok || !address.IsGlobalUnicast() || address.IsPrivate() ||
+		address.IsLoopback() || address.IsLinkLocalUnicast() {
+		return false
+	}
+	return !carrierGradeNAT.Contains(address)
+}
+
+// IPInCIDRs checks an address against valid same-family trust prefixes.
+func IPInCIDRs(value string, cidrs []string) bool {
+	address, ok := ParseAddr(value)
+	if !ok {
+		return false
+	}
+	for _, raw := range cidrs {
+		// Invalid operator entries are ignored just like Python Config. A typo
+		// must not crash or disable the detector sweep.
+		prefix, err := netip.ParsePrefix(strings.TrimSpace(raw))
+		if err == nil && prefix.Addr().BitLen() == address.BitLen() && prefix.Contains(address) {
+			return true
+		}
+	}
+	return false
+}
+
+// SplitHostPort splits ss-style IPv4, IPv6, and zone-qualified endpoints.
+func SplitHostPort(endpoint string) (string, string) {
+	endpoint = strings.TrimSpace(endpoint)
+	if strings.HasPrefix(endpoint, "[") {
+		if end := strings.Index(endpoint, "]"); end >= 0 {
+			return endpoint[1:end], strings.TrimPrefix(endpoint[end+1:], ":")
+		}
+	}
+	index := strings.LastIndex(endpoint, ":")
+	if index < 0 {
+		return "", endpoint
+	}
+	return endpoint[:index], endpoint[index+1:]
+}

go-agent/internal/netutil/netutil_test.go

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package netutil
+
+import "testing"
+
+func TestPublicIPMatchesPythonCases(t *testing.T) {
+	for _, address := range []string{"8.8.8.8", "1.1.1.1"} {
+		if !IsPublicIP(address) {
+			t.Fatalf("expected public: %s", address)
+		}
+	}
+	for _, address := range []string{
+		"10.0.0.5", "192.168.1.1", "172.16.0.1", "127.0.0.1",
+		"169.254.1.1", "100.64.0.1", "::1", "not-an-ip", "",
+	} {
+		if IsPublicIP(address) {
+			t.Fatalf("expected non-public: %s", address)
+		}
+	}
+}
+
+func TestCIDRAndEndpointHelpers(t *testing.T) {
+	if !IPInCIDRs("203.0.113.55", []string{"203.0.113.0/24"}) ||
+		IPInCIDRs("8.8.8.8", []string{"203.0.113.0/24"}) {
+		t.Fatal("CIDR matching failed")
+	}
+	host, port := SplitHostPort("[2001:db8::1]:22")
+	if host != "2001:db8::1" || port != "22" {
+		t.Fatalf("unexpected IPv6 split: %q %q", host, port)
+	}
+	host, port = SplitHostPort("10.2.0.2%proton0:61877")
+	if host != "10.2.0.2%proton0" || port != "61877" {
+		t.Fatalf("unexpected zone split: %q %q", host, port)
+	}
+}

go-agent/internal/system/state.go

@@ -4,11 +4,15 @@
 package system
 
 import (
+	"context"
 	"os"
+	"os/exec"
 	"path/filepath"
+	"regexp"
 	"sort"
 	"strconv"
 	"strings"
+	"time"
 
 	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
 )
@@ -17,6 +21,34 @@ import (
 type Paths struct {
 	ProcRoot      string
 	LDPreloadPath string
+	SocketSource  func() []model.Socket
+}
+
+var (
+	inodePattern = regexp.MustCompile(`\bino:(\d+)`)
+	userPattern  = regexp.MustCompile(`users:\(\("([^"]+)",pid=(\d+),fd=\d+`)
+)
+
+var socketSpecs = []struct {
+	args []string
+	kind string
+}{
+	{[]string{"-tanep"}, "tcp"},
+	{[]string{"-uanep"}, "udp"},
+	{[]string{"-wanep"}, "raw"},
+	{[]string{"-Sanep"}, "sctp"},
+	{[]string{"-danep"}, "dccp"},
+	{[]string{"-0anep"}, "packet"},
+	{[]string{"-Manep"}, "mptcp"},
+	{[]string{"--tipc", "-anep"}, "tipc"},
+	{[]string{"--xdp", "-anep"}, "xdp"},
+	{[]string{"--vsock", "-anep"}, "vsock"},
+}
+
+var socketNetIDs = map[string]bool{
+	"tcp": true, "udp": true, "raw": true, "sctp": true, "dccp": true,
+	"mptcp": true, "p_raw": true, "p_dgr": true, "packet": true,
+	"tipc": true, "xdp": true, "vsock": true,
 }
 
 // Capture reads process state once from procRoot. Transient per-process read
@@ -55,12 +87,79 @@ func CaptureWithPaths(paths Paths) (model.State, error) {
 		})
 	}
 	sort.Slice(processes, func(i, j int) bool { return processes[i].PID < processes[j].PID })
+	var sockets []model.Socket
+	if paths.SocketSource != nil {
+		sockets = paths.SocketSource()
+	} else {
+		sockets = captureSockets()
+	}
 	return model.State{
 		Processes: processes,
+		Sockets:   sockets,
 		LDPreload: strings.TrimSpace(readText(paths.LDPreloadPath)),
 	}, nil
 }
 
+func captureSockets() []model.Socket {
+	result := make([]model.Socket, 0)
+	for _, spec := range socketSpecs {
+		// Python asks ss once per protocol family because several families use
+		// incompatible flags. Preserve that behavior instead of hiding gaps
+		// behind a single TCP/UDP-only invocation.
+		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+		command := exec.CommandContext(ctx, "ss", append([]string{"-H"}, spec.args...)...)
+		output, err := command.Output()
+		cancel()
+		if err != nil {
+			// Collection is fail-open by design: a missing/unsupported ss flag
+			// drops only that socket family and never stops process detection.
+			continue
+		}
+		result = append(result, parseSS(string(output), spec.kind)...)
+	}
+	return result
+}
+
+func parseSS(text, kind string) []model.Socket {
+	result := make([]model.Socket, 0)
+	for _, line := range strings.Split(text, "\n") {
+		fields := strings.Fields(line)
+		if len(fields) < 5 {
+			continue
+		}
+		var state, local, peer string
+		// Some ss versions prefix each row with the protocol netid and some
+		// begin directly with state. Python accepts both layouts; Go must too.
+		if socketNetIDs[strings.ToLower(fields[0])] && len(fields) >= 6 {
+			state, local, peer = fields[1], fields[4], fields[5]
+		} else {
+			state, local, peer = fields[0], fields[3], fields[4]
+		}
+		var inode, pid *int
+		// Ownership is best-effort. Nil values are meaningful because Python
+		// serializes an unknown PID differently in keys (None) and prose (?).
+		if match := inodePattern.FindStringSubmatch(line); len(match) == 2 {
+			value, err := strconv.Atoi(match[1])
+			if err == nil {
+				inode = &value
+			}
+		}
+		comm := ""
+		if match := userPattern.FindStringSubmatch(line); len(match) == 3 {
+			comm = match[1]
+			value, err := strconv.Atoi(match[2])
+			if err == nil {
+				pid = &value
+			}
+		}
+		result = append(result, model.Socket{
+			State: state, Local: local, Peer: peer, Inode: inode,
+			Comm: comm, PID: pid, Kind: kind,
+		})
+	}
+	return result
+}
+
 func parseEnviron(raw string) map[string]string {
 	result := make(map[string]string)
 	for _, item := range strings.Split(raw, "\x00") {

go-agent/internal/system/state_test.go

@@ -6,6 +6,8 @@ import (
 	"os"
 	"path/filepath"
 	"testing"
+
+	"codeberg.org/anassaeneroi/enodia-sentinal/go-agent/internal/model"
 )
 
 func TestCaptureUsesInjectableProcRoot(t *testing.T) {
@@ -37,7 +39,10 @@ func TestCaptureUsesInjectableProcRoot(t *testing.T) {
 	if err := os.WriteFile(preload, []byte("/tmp/global.so\n"), 0o600); err != nil {
 		t.Fatal(err)
 	}
-	state, err := CaptureWithPaths(Paths{ProcRoot: root, LDPreloadPath: preload})
+	state, err := CaptureWithPaths(Paths{
+		ProcRoot: root, LDPreloadPath: preload,
+		SocketSource: func() []model.Socket { return []model.Socket{} },
+	})
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -55,3 +60,18 @@ func TestCaptureUsesInjectableProcRoot(t *testing.T) {
 		t.Fatalf("unexpected global preload: %q", state.LDPreload)
 	}
 }
+
+func TestParseSSMatchesPythonShapes(t *testing.T) {
+	text := "tcp ESTAB 0 0 10.0.0.2:5555 8.8.8.8:443 users:((\"bash\",pid=42,fd=3)) ino:999\n"
+	sockets := parseSS(text, "tcp")
+	if len(sockets) != 1 {
+		t.Fatalf("unexpected sockets: %#v", sockets)
+	}
+	got := sockets[0]
+	if got.State != "ESTAB" || got.Local != "10.0.0.2:5555" || got.Peer != "8.8.8.8:443" {
+		t.Fatalf("unexpected endpoints: %#v", got)
+	}
+	if got.Inode == nil || *got.Inode != 999 || got.PID == nil || *got.PID != 42 || got.Comm != "bash" {
+		t.Fatalf("unexpected ownership: %#v", got)
+	}
+}