CGI support

3 files changed, 181 insertions, 39 deletions

diff --git a/server/src/net/usebox/gemini/server/Response.scala b/server/src/net/usebox/gemini/server/Response.scala
index 6c243b2..a6993c4 100644
--- a/server/src/net/usebox/gemini/server/Response.scala
+++ b/server/src/net/usebox/gemini/server/Response.scala
@@ -2,6 +2,11 @@ package net.usebox.gemini.server
 
 import java.nio.file.Path
 
+import scala.sys.process._
+import scala.util.Try
+
+import org.log4s._
+
 import akka.stream.ActorAttributes
 import akka.stream.scaladsl.{Source, FileIO}
 import akka.util.ByteString
@@ -78,6 +83,86 @@ case class DirListing(
     )
 }
 
+case class Cgi(
+    req: String,
+    filename: String,
+    queryString: String,
+    pathInfo: String,
+    scriptName: String,
+    host: String,
+    port: String,
+    remoteAddr: String
+) extends Response {
+
+  private[this] val logger = getLogger
+
+  val bodyPath: Option[Path] = None
+
+  val responseRe = "([0-9]{2}) (.*)".r
+
+  val env = Map(
+    "GATEWAY_INTERFACE" -> "CGI/1.1",
+    "SERVER_SOFTWARE" -> s"${BuildInfo.name}/${BuildInfo.version}",
+    "SERVER_PROTOCOL" -> "GEMINI",
+    "GEMINI_URL" -> req,
+    "SCRIPT_NAME" -> scriptName,
+    "PATH_INFO" -> pathInfo,
+    "QUERY_STRING" -> queryString,
+    "SERVER_NAME" -> host,
+    "SERVER_PORT" -> port,
+    "REMOTE_ADDR" -> remoteAddr,
+    "REMOTE_HOST" -> remoteAddr
+  ).toSeq
+
+  val (status: Int, meta: String, body: String) = {
+    val output = new java.io.ByteArrayOutputStream
+    Try {
+      val jpb = new java.lang.ProcessBuilder(filename)
+      jpb.environment.clear()
+      env.foreach { case (k, v) => jpb.environment.put(k, v) }
+
+      val exit = (Process(jpb) #> output).!
+      output.close()
+
+      exit
+    }.toEither match {
+      case Right(0) =>
+        val body = output.toString("UTF-8")
+        body.split("\r\n").headOption match {
+          case Some(req @ responseRe(status, meta))
+              if req.length <= Server.maxReqLen =>
+            (status.toInt, meta, body)
+          case _ =>
+            logger.warn(s"$scriptName: invalid CGI response")
+            respError(40, "Invalid response from CGI")
+        }
+
+      case Right(exit) =>
+        logger.warn(s"$scriptName: failed to execute CGI (exit: $exit)")
+        respError(50, s"Error executing CGI")
+
+      case Left(error) =>
+        logger.warn(
+          s"$scriptName: failed to execute CGI (${error.getMessage()})"
+        )
+        respError(50, s"Error executing CGI")
+    }
+  }
+
+  def respError(
+      status: Int,
+      meta: String
+  ): (Int, String, String) = {
+    // response should fit in 1024 bytes: XX META\r\n
+    val limited = meta.substring(0, Math.min(meta.length, Server.maxReqLen - 5))
+    (status, meta, s"$status $limited\r\n")
+  }
+
+  def bodySize: Long = body.size
+
+  override def toSource = Source.single(ByteString(body))
+}
+
 case class TempRedirect(
     req: String,
     meta: String = "Redirect - temporary"
diff --git a/server/src/net/usebox/gemini/server/Server.scala b/server/src/net/usebox/gemini/server/Server.scala
index a250158..3c78721 100644
--- a/server/src/net/usebox/gemini/server/Server.scala
+++ b/server/src/net/usebox/gemini/server/Server.scala
@@ -23,9 +23,6 @@ case class Server(conf: ServiceConf) {
 
   private[this] val logger = getLogger
 
-  val defPort = 1965
-  val maxReqLen = 1024
-
   val mimeTypes = conf.mimeTypes
   val defaultMimeType = conf.defaultMimeType
   val vHosts = conf.virtualHosts
@@ -67,7 +64,7 @@ case class Server(conf: ServiceConf) {
       case mime => mime
     }
 
-  def handleReq(req: String): Response =
+  def handleReq(req: String, remoteAddr: String): Response =
     (for {
       uri <- Try(URI.create(req)).toEither
       resp <- Try(
@@ -83,7 +80,7 @@ case class Server(conf: ServiceConf) {
           case _ if uri.getPort() != -1 && uri.getPort() != conf.port =>
             logger.debug(s"invalid port, is a proxy request")
             ProxyRequestRefused(req)
-          case _ if uri.getPort() == -1 && conf.port != defPort =>
+          case _ if uri.getPort() == -1 && conf.port != Server.defPort =>
             logger.debug(
               s"default port but non default was configured, is a proxy request"
             )
@@ -107,10 +104,41 @@ case class Server(conf: ServiceConf) {
               .getDefault()
               .getPath(root, path)
               .normalize()
+            val cgi = vhost.getCgi(resource)
 
-            logger.debug(s"requesting: '$resource'")
+            logger.debug(s"requesting: '$resource', cgi is '$cgi'")
 
             resource.toFile() match {
+              case file
+                  if cgi
+                    .map(_.toFile())
+                    .map(f => f.isFile() && f.canExecute())
+                    .getOrElse(false) =>
+                logger.debug("is cgi, will execute")
+
+                val cgiFile = cgi.get
+                val queryString =
+                  if (uri.getQuery() == null) "" else uri.getQuery()
+                val pathInfo =
+                  if (cgiFile.compareTo(resource) == 0) ""
+                  else
+                    "/" + resource
+                      .subpath(
+                        cgiFile.getNameCount(),
+                        resource.getNameCount()
+                      )
+                      .toString()
+
+                Cgi(
+                  req,
+                  filename = cgiFile.toString(),
+                  queryString = queryString,
+                  pathInfo = pathInfo,
+                  scriptName = cgiFile.getFileName().toString(),
+                  host = vhost.host,
+                  port = conf.port.toString(),
+                  remoteAddr = remoteAddr
+                )
               case path if !path.exists() =>
                 logger.debug("no resource")
                 NotFound(req)
@@ -227,15 +255,15 @@ case class Server(conf: ServiceConf) {
         closing = TLSClosing.ignoreCancel
       )
       .runForeach { connection =>
-        val remoteHost = connection.remoteAddress.getHostString()
-        logger.debug(s"new connection $remoteHost")
+        val remoteAddr = connection.remoteAddress.getHostString()
+        logger.debug(s"new connection $remoteAddr")
 
         val handler = Flow[ByteString]
           .watchTermination() { (_, f) =>
             f.onComplete {
               _.toEither.swap.map(error =>
                 logger.warn(
-                  s"$remoteHost - stream terminated: ${error.getMessage()}"
+                  s"$remoteAddr - stream terminated: ${error.getMessage()}"
                 )
               )
             }
@@ -244,7 +272,7 @@ case class Server(conf: ServiceConf) {
             Framing
               .delimiter(
                 ByteString("\r\n"),
-                maximumFrameLength = maxReqLen + 1,
+                maximumFrameLength = Server.maxReqLen + 1,
                 allowTruncation = true
               )
           )
@@ -257,16 +285,16 @@ case class Server(conf: ServiceConf) {
                   logger.debug(s"invalid UTF-8 encoding: ${error.getMessage()}")
                   BadRequest(req.utf8String)
                 case Right(reqStr) =>
-                  if (req.size > maxReqLen)
+                  if (req.size > Server.maxReqLen)
                     BadRequest(reqStr.take(1024) + "{...}")
                   else
-                    handleReq(reqStr)
+                    handleReq(reqStr, remoteAddr)
               }
           }
           .take(1)
           .wireTap(resp =>
             logger.info(
-              s"""$remoteHost "${resp.req}" ${resp.status} ${resp.bodySize}"""
+              s"""$remoteAddr "${resp.req}" ${resp.status} ${resp.bodySize}"""
             )
           )
           .flatMapConcat(_.toSource)
@@ -275,3 +303,12 @@ case class Server(conf: ServiceConf) {
       }
   }
 }
+
+object Server {
+
+  /** Maximum request length in bytes. */
+  val maxReqLen = 1024
+
+  /** Default port. */
+  val defPort = 1965
+}
diff --git a/server/src/net/usebox/gemini/server/ServiceConf.scala b/server/src/net/usebox/gemini/server/ServiceConf.scala
index 74ed548..dc28650 100644
--- a/server/src/net/usebox/gemini/server/ServiceConf.scala
+++ b/server/src/net/usebox/gemini/server/ServiceConf.scala
@@ -11,7 +11,11 @@ import org.log4s._
 
 case class KeyStore(path: String, alias: String, password: String)
 
-case class Directory(path: String, directoryListing: Option[Boolean])
+case class Directory(
+    path: String,
+    directoryListing: Option[Boolean],
+    allowCgi: Option[Boolean]
+)
 
 case class VirtualHost(
     host: String,
@@ -34,9 +38,24 @@ object VirtualHost {
     def getDirectoryListing(path: Path): Boolean =
       vhost.directories
         .find(_.path == path.toString())
-        .fold(vhost.directoryListing)(loc =>
-          loc.directoryListing.getOrElse(vhost.directoryListing)
+        .flatMap(_.directoryListing)
+        .getOrElse(vhost.directoryListing)
+
+    def getCgi(path: Path): Option[Path] =
+      vhost.directories
+        .find(d =>
+          path.startsWith(
+            d.path
+          ) && path.toString != d.path && d.allowCgi == Some(true)
         )
+        .collect {
+          case d =>
+            val dp =
+              FileSystems.getDefault().getPath(d.path).normalize()
+            FileSystems
+              .getDefault()
+              .getPath(d.path, path.getName(dp.getNameCount()).toString())
+        }
 
     def getRoot(path: String): (String, String) =
       path match {
@@ -75,32 +94,33 @@ object ServiceConf {
 
   import VirtualHost.userTag
 
-  def load(confFile: String) =
-    ConfigSource.file(confFile).load[ServiceConf].map { conf =>
-      conf.copy(virtualHosts = conf.virtualHosts.map { vhost =>
-        if (
-          vhost.userDirectories && !vhost.userDirectoryPath
-            .fold(false)(dir => dir.contains(userTag))
+  def initConf(conf: ServiceConf): ServiceConf =
+    conf.copy(virtualHosts = conf.virtualHosts.map { vhost =>
+      if (
+        vhost.userDirectories && !vhost.userDirectoryPath
+          .fold(false)(dir => dir.contains(userTag))
+      )
+        logger.warn(
+          s"In virtual host '${vhost.host}': user-directories is enabled but $userTag not found in user-directory-path"
         )
-          logger.warn(
-            s"In virtual host '${vhost.host}': user-directories is enabled but $userTag not found in user-directory-path"
-          )
 
-        vhost.copy(directories = vhost.directories.map { dir =>
-          val path =
-            FileSystems
-              .getDefault()
-              .getPath(vhost.root, dir.path)
-              .normalize()
+      vhost.copy(directories = vhost.directories.map { dir =>
+        val path =
+          FileSystems
+            .getDefault()
+            .getPath(vhost.root, dir.path)
+            .normalize()
 
-          if (!path.toFile().isDirectory())
-            logger.warn(
-              s"In virtual host '${vhost.host}': directory entry '${dir.path}' is not a directory"
-            )
+        if (!path.toFile().isDirectory())
+          logger.warn(
+            s"In virtual host '${vhost.host}': directory entry '${dir.path}' is not a directory"
+          )
 
-          dir
-            .copy(path = path.toString())
-        })
+        dir
+          .copy(path = path.toString())
       })
-    }
+    })
+
+  def load(confFile: String) =
+    ConfigSource.file(confFile).load[ServiceConf].map(initConf)
 }