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author | Péter Szilágyi <peterke@gmail.com> | 2017-08-09 17:51:16 +0800 |
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committer | Péter Szilágyi <peterke@gmail.com> | 2017-08-09 18:26:07 +0800 |
commit | 5d9ac49c7e6027c60998a56287dbb3e407011c9b (patch) | |
tree | 325712b0955076ba81a91031e84f25dee88727b2 /accounts/usbwallet/ledger_hub.go | |
parent | db568a61e2a98880ab308bf2224aa34073dc7f39 (diff) | |
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accounts: refactor API for generalized USB wallets
Diffstat (limited to 'accounts/usbwallet/ledger_hub.go')
-rw-r--r-- | accounts/usbwallet/ledger_hub.go | 212 |
1 files changed, 0 insertions, 212 deletions
diff --git a/accounts/usbwallet/ledger_hub.go b/accounts/usbwallet/ledger_hub.go deleted file mode 100644 index ffe7cffe4..000000000 --- a/accounts/usbwallet/ledger_hub.go +++ /dev/null @@ -1,212 +0,0 @@ -// Copyright 2017 The go-ethereum Authors -// This file is part of the go-ethereum library. -// -// The go-ethereum library is free software: you can redistribute it and/or modify -// it under the terms of the GNU Lesser General Public License as published by -// the Free Software Foundation, either version 3 of the License, or -// (at your option) any later version. -// -// The go-ethereum library is distributed in the hope that it will be useful, -// but WITHOUT ANY WARRANTY; without even the implied warranty of -// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -// GNU Lesser General Public License for more details. -// -// You should have received a copy of the GNU Lesser General Public License -// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>. - -package usbwallet - -import ( - "errors" - "runtime" - "sync" - "time" - - "github.com/ethereum/go-ethereum/accounts" - "github.com/ethereum/go-ethereum/event" - "github.com/ethereum/go-ethereum/log" - "github.com/karalabe/hid" -) - -// LedgerScheme is the protocol scheme prefixing account and wallet URLs. -var LedgerScheme = "ledger" - -// ledgerDeviceIDs are the known device IDs that Ledger wallets use. -var ledgerDeviceIDs = []deviceID{ - {Vendor: 0x2c97, Product: 0x0000}, // Ledger Blue - {Vendor: 0x2c97, Product: 0x0001}, // Ledger Nano S -} - -// Maximum time between wallet refreshes (if USB hotplug notifications don't work). -const ledgerRefreshCycle = time.Second - -// Minimum time between wallet refreshes to avoid USB trashing. -const ledgerRefreshThrottling = 500 * time.Millisecond - -// LedgerHub is a accounts.Backend that can find and handle Ledger hardware wallets. -type LedgerHub struct { - refreshed time.Time // Time instance when the list of wallets was last refreshed - wallets []accounts.Wallet // List of Ledger devices currently tracking - updateFeed event.Feed // Event feed to notify wallet additions/removals - updateScope event.SubscriptionScope // Subscription scope tracking current live listeners - updating bool // Whether the event notification loop is running - - quit chan chan error - - stateLock sync.RWMutex // Protects the internals of the hub from racey access - - // TODO(karalabe): remove if hotplug lands on Windows - commsPend int // Number of operations blocking enumeration - commsLock sync.Mutex // Lock protecting the pending counter and enumeration -} - -// NewLedgerHub creates a new hardware wallet manager for Ledger devices. -func NewLedgerHub() (*LedgerHub, error) { - if !hid.Supported() { - return nil, errors.New("unsupported platform") - } - hub := &LedgerHub{ - quit: make(chan chan error), - } - hub.refreshWallets() - return hub, nil -} - -// Wallets implements accounts.Backend, returning all the currently tracked USB -// devices that appear to be Ledger hardware wallets. -func (hub *LedgerHub) Wallets() []accounts.Wallet { - // Make sure the list of wallets is up to date - hub.refreshWallets() - - hub.stateLock.RLock() - defer hub.stateLock.RUnlock() - - cpy := make([]accounts.Wallet, len(hub.wallets)) - copy(cpy, hub.wallets) - return cpy -} - -// refreshWallets scans the USB devices attached to the machine and updates the -// list of wallets based on the found devices. -func (hub *LedgerHub) refreshWallets() { - // Don't scan the USB like crazy it the user fetches wallets in a loop - hub.stateLock.RLock() - elapsed := time.Since(hub.refreshed) - hub.stateLock.RUnlock() - - if elapsed < ledgerRefreshThrottling { - return - } - // Retrieve the current list of Ledger devices - var ledgers []hid.DeviceInfo - - if runtime.GOOS == "linux" { - // hidapi on Linux opens the device during enumeration to retrieve some infos, - // breaking the Ledger protocol if that is waiting for user confirmation. This - // is a bug acknowledged at Ledger, but it won't be fixed on old devices so we - // need to prevent concurrent comms ourselves. The more elegant solution would - // be to ditch enumeration in favor of hutplug events, but that don't work yet - // on Windows so if we need to hack it anyway, this is more elegant for now. - hub.commsLock.Lock() - if hub.commsPend > 0 { // A confirmation is pending, don't refresh - hub.commsLock.Unlock() - return - } - } - for _, info := range hid.Enumerate(0, 0) { // Can't enumerate directly, one valid ID is the 0 wildcard - for _, id := range ledgerDeviceIDs { - if info.VendorID == id.Vendor && info.ProductID == id.Product { - ledgers = append(ledgers, info) - break - } - } - } - if runtime.GOOS == "linux" { - // See rationale before the enumeration why this is needed and only on Linux. - hub.commsLock.Unlock() - } - // Transform the current list of wallets into the new one - hub.stateLock.Lock() - - wallets := make([]accounts.Wallet, 0, len(ledgers)) - events := []accounts.WalletEvent{} - - for _, ledger := range ledgers { - url := accounts.URL{Scheme: LedgerScheme, Path: ledger.Path} - - // Drop wallets in front of the next device or those that failed for some reason - for len(hub.wallets) > 0 && (hub.wallets[0].URL().Cmp(url) < 0 || hub.wallets[0].(*ledgerWallet).failed()) { - events = append(events, accounts.WalletEvent{Wallet: hub.wallets[0], Kind: accounts.WalletDropped}) - hub.wallets = hub.wallets[1:] - } - // If there are no more wallets or the device is before the next, wrap new wallet - if len(hub.wallets) == 0 || hub.wallets[0].URL().Cmp(url) > 0 { - wallet := &ledgerWallet{hub: hub, url: &url, info: ledger, log: log.New("url", url)} - - events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletArrived}) - wallets = append(wallets, wallet) - continue - } - // If the device is the same as the first wallet, keep it - if hub.wallets[0].URL().Cmp(url) == 0 { - wallets = append(wallets, hub.wallets[0]) - hub.wallets = hub.wallets[1:] - continue - } - } - // Drop any leftover wallets and set the new batch - for _, wallet := range hub.wallets { - events = append(events, accounts.WalletEvent{Wallet: wallet, Kind: accounts.WalletDropped}) - } - hub.refreshed = time.Now() - hub.wallets = wallets - hub.stateLock.Unlock() - - // Fire all wallet events and return - for _, event := range events { - hub.updateFeed.Send(event) - } -} - -// Subscribe implements accounts.Backend, creating an async subscription to -// receive notifications on the addition or removal of Ledger wallets. -func (hub *LedgerHub) Subscribe(sink chan<- accounts.WalletEvent) event.Subscription { - // We need the mutex to reliably start/stop the update loop - hub.stateLock.Lock() - defer hub.stateLock.Unlock() - - // Subscribe the caller and track the subscriber count - sub := hub.updateScope.Track(hub.updateFeed.Subscribe(sink)) - - // Subscribers require an active notification loop, start it - if !hub.updating { - hub.updating = true - go hub.updater() - } - return sub -} - -// updater is responsible for maintaining an up-to-date list of wallets stored in -// the keystore, and for firing wallet addition/removal events. It listens for -// account change events from the underlying account cache, and also periodically -// forces a manual refresh (only triggers for systems where the filesystem notifier -// is not running). -func (hub *LedgerHub) updater() { - for { - // TODO: Wait for a USB hotplug event (not supported yet) or a refresh timeout - // <-hub.changes - time.Sleep(ledgerRefreshCycle) - - // Run the wallet refresher - hub.refreshWallets() - - // If all our subscribers left, stop the updater - hub.stateLock.Lock() - if hub.updateScope.Count() == 0 { - hub.updating = false - hub.stateLock.Unlock() - return - } - hub.stateLock.Unlock() - } -} |