Add file exchange proto

nim-peer/nim_peer.nimble

@@ -10,4 +10,4 @@ bin           = @["nim_peer"]
 
 # Dependencies
 
-requires "nim >= 2.2.0", "nimwave", "chronos", "libp2p", "illwill", "cligen"
+requires "nim >= 2.2.0", "nimwave", "chronos", "libp2p", "illwill", "cligen", "stew"

nim-peer/src/file_exchange.nim

@@ -0,0 +1,34 @@
+import os, strutils, sequtils
+import libp2p, chronos, stew/byteutils
+
+import ./utils
+
+const
+  MaxFileSize: int = 1024 # 1KiB
+  MaxFileIdSize: int = 1024 # 1KiB
+  FileExchangeCodec*: string = "/universal-connectivity-file/1"
+
+type FileExchange* = ref object of LPProtocol
+
+proc new*(T: typedesc[FileExchange]): T =
+  proc handle(conn: Connection, proto: string) {.async: (raises: [CancelledError]).} =
+    try:
+      let fileId = string.fromBytes(await conn.readLp(MaxFileIdSize))
+      # TODO: this is unsafe, fix it
+      let filename = "/tmp/" & fileId
+      # if /tmp/{fileid} exists
+      if fileExists(filename):
+        let fileContent = cast[seq[byte]](readFile(filename))
+        await conn.writeLp(fileContent)
+    except CancelledError as e:
+      raise e
+    except CatchableError as e:
+      echo "exception in handler", e.msg
+    finally:
+      await conn.close()
+
+  return T.new(codecs = @[FileExchangeCodec], handler = handle)
+
+proc requestFile*(p: FileExchange, conn: Connection, fileId: string): Future[seq[byte]] {.async.} =
+  await conn.writeLp(cast[seq[byte]](fileId))
+  await conn.readLp(MaxFileSize)

nim-peer/src/nim_peer.nim

@@ -1,16 +1,16 @@
 from illwave as iw import nil, `[]`, `[]=`, `==`, width, height
 from terminal import nil
 
+import std/sha1
 import chronos, tables, deques, strutils, sequtils
 import libp2p, cligen
 from libp2p/protocols/pubsub/rpc/message import Message
 
 import ./ui/root
 import ./utils
+import ./file_exchange
 
-const MAX_FILE_SIZE: int = 1024 # 1KiB
-
-proc start(peerId: PeerId, addrs: seq[MultiAddress]) {.async.} =
+proc start(peerId: PeerId, addrs: seq[MultiAddress], room: string) {.async.} =
   # setup peer
   let switch = SwitchBuilder
     .new()
@@ -22,6 +22,10 @@ proc start(peerId: PeerId, addrs: seq[MultiAddress]) {.async.} =
   let gossip =
     GossipSub.init(switch = switch, triggerSelf = true, verifySignature = false)
   switch.mount(gossip)
+
+  let fileExchange = FileExchange.new()
+  switch.mount(fileExchange)
+
   await switch.start()
 
   let recvQ = newAsyncQueue[string]()
@@ -48,18 +52,17 @@ proc start(peerId: PeerId, addrs: seq[MultiAddress]) {.async.} =
   let onNewFile = proc(
       topic: string, msg: Message
   ): Future[ValidationResult] {.async, gcsafe.} =
-    let fileId = msg.data
+    let fileId = cast[string](msg.data)
     # use known addresses since we can't use kad to get peer addrs
     # this means that we're unable to get files from a peer to which we don't have the addresses
-    let conn = await switch.dial(msg.fromPeer, addrs, "/universal-connectivity-file/1")
-    defer: await conn.close()
-    # Request file
-    await conn.writeLp(fileId)
-    # Read file contents
-    let fileContents = await conn.readLp(MAX_FILE_SIZE)
-    # TODO: do sth with file
-    let strFile = cast[string](fileContents)
-    echo "downloaded file: " & strFile
+    let conn = await switch.dial(msg.fromPeer, addrs, FileExchangeCodec)
+    # TODO: path appending is unsafe  (sanitize)
+    let filePath = "/tmp/" & fileId
+    let fileContents = await fileExchange.requestFile(conn, fileId)
+    writeFile(filePath, fileContents)
+    await conn.close()
+    # Save file in /tmp/fileId
+    echo "Downloaded file to " & filePath
     return ValidationResult.Accept
 
   # when a new peer is announced
@@ -70,18 +73,18 @@ proc start(peerId: PeerId, addrs: seq[MultiAddress]) {.async.} =
   # register validators and handlers
 
   # chat messages
-  gossip.subscribe(GOSSIPSUB_CHAT_TOPIC, nil)
-  gossip.addValidator(GOSSIPSUB_CHAT_TOPIC, onChatMsg)
+  gossip.subscribe(room, nil)
+  gossip.addValidator(room, onChatMsg)
 
   # files
-  gossip.subscribe(GOSSIPSUB_CHAT_FILE_TOPIC, nil)
-  gossip.addValidator(GOSSIPSUB_CHAT_FILE_TOPIC, onNewFile)
+  gossip.subscribe(ChatFileTopic, nil)
+  gossip.addValidator(ChatFileTopic, onNewFile)
 
   # peer discovery
-  gossip.subscribe(GOSSIPSUB_PEER_DISCOVERY_TOPIC, onNewPeer)
+  gossip.subscribe(PeerDiscoveryTopic, onNewPeer)
 
   try:
-    await runUI(gossip, recvQ, peerQ, switch.peerInfo.peerId)
+    await runUI(gossip, room, recvQ, peerQ, switch.peerInfo.peerId)
     iw.deinit()
   except Exception as exc:
     echo "runUI error: " & exc.msg
@@ -91,13 +94,13 @@ proc start(peerId: PeerId, addrs: seq[MultiAddress]) {.async.} =
       await switch.stop()
     terminal.showCursor()
 
-proc cli(args: seq[string]) =
+proc cli(room=ChatTopic, args: seq[string]) =
   if args.len < 2:
     echo "usage: nimble run -- <peer_id> <multiaddress>, [<multiaddresss>, ...]"
     return
   let peerId = PeerId.init(args[0]).get()
   let addrs = args[1 ..^ 1].mapIt(MultiAddress.init(it).get())
-  waitFor start(peerId, addrs)
+  waitFor start(peerId, addrs, room)
 
 when isMainModule:
   dispatch cli

nim-peer/src/ui/root.nim

@@ -16,8 +16,8 @@ type State = object
 include nimwave/prelude
 
 const
-  PEERS_PANEL_WIDTH: int = 10
-  TOP_HEIGHT: int = 15
+  PeersPanelWidth: int = 10
+  TopHeight: int = 15
 
 type
   PeersPanel = ref object of nw.Node
@@ -26,11 +26,11 @@ type
 
 method render(node: ChatPanel, ctx: var nw.Context[State]) =
   let width =
-    if PEERS_PANEL_WIDTH < iw.width(ctx.tb):
-      iw.width(ctx.tb) - PEERS_PANEL_WIDTH
+    if PeersPanelWidth < iw.width(ctx.tb):
+      iw.width(ctx.tb) - PeersPanelWidth
     else:
       iw.width(ctx.tb)
-  ctx = nw.slice(ctx, 0, 0, width, TOP_HEIGHT)
+  ctx = nw.slice(ctx, 0, 0, width, TopHeight)
   render(
     nw.Box(
       border: nw.Border.Single,
@@ -41,8 +41,8 @@ method render(node: ChatPanel, ctx: var nw.Context[State]) =
   )
 
 method render(node: PeersPanel, ctx: var nw.Context[State]) =
-  let width = PEERS_PANEL_WIDTH
-  let height = TOP_HEIGHT
+  let width = PeersPanelWidth
+  let height = TopHeight
   ctx = nw.slice(ctx, 0, 0, width, height)
   render(
     nw.Box(
@@ -56,8 +56,8 @@ method render(node: PeersPanel, ctx: var nw.Context[State]) =
 method render(node: SystemPanel, ctx: var nw.Context[State]) =
   let width = iw.width(ctx.tb)
   let height =
-    if TOP_HEIGHT < iw.height(ctx.tb):
-      iw.height(ctx.tb) - TOP_HEIGHT
+    if TopHeight < iw.height(ctx.tb):
+      iw.height(ctx.tb) - TopHeight
     else:
       iw.height(ctx.tb)
   ctx = nw.slice(ctx, 0, 0, width, height)
@@ -72,6 +72,7 @@ method render(node: SystemPanel, ctx: var nw.Context[State]) =
 
 proc runUI*(
     gossip: GossipSub,
+    room: string,
     recvQ: AsyncQueue[string],
     peerQ: AsyncQueue[PeerId],
     myPeerId: PeerId,
@@ -128,7 +129,7 @@ proc runUI*(
       # TODO: handle /file command to send/publish files
       # /file filename (registers ID in local database, sends fileId, handles incoming file requests)
       discard await gossip.publish(
-        GOSSIPSUB_CHAT_TOPIC, cast[seq[byte]](@(ctx.data.inputBuffer))
+        room, cast[seq[byte]](@(ctx.data.inputBuffer))
       )
       ctx.data.messages.add("You: " & ctx.data.inputBuffer) # show message in ui
       ctx.data.inputBuffer = "" # clear input buffer

nim-peer/src/utils.nim

@@ -1,7 +1,7 @@
 const
-  GOSSIPSUB_CHAT_TOPIC*: string = "universal-connectivity"
-  GOSSIPSUB_CHAT_FILE_TOPIC*: string = "universal-connectivity-file"
-  GOSSIPSUB_PEER_DISCOVERY_TOPIC*: string =
+  ChatTopic*: string = "universal-connectivity"
+  ChatFileTopic*: string = "universal-connectivity-file"
+  PeerDiscoveryTopic*: string =
     "universal-connectivity-browser-peer-discovery"
 
 import libp2p