Cygwin support (#499)

CMakeLists.txt

@@ -1,3 +1,5 @@
+set(CMAKE_LEGACY_CYGWIN_WIN32 0)
+
 # 3.0.2 preferred, but we can often get by with 2.8.
 cmake_minimum_required(VERSION 2.8)
 if (${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}.${CMAKE_PATCH_VERSION} LESS 3.0.2)
@@ -73,16 +75,27 @@ if (APPLE)
    endif()
 endif()
 
-if (WIN32 OR APPLE)
+if (CYGWIN OR WIN32 OR APPLE)
   set(DEFAULT_CASE_INSENSITIVE TRUE)
 else()
   set(DEFAULT_CASE_INSENSITIVE FALSE)
 endif()
 
+if (CYGWIN)
+  find_program(PKILL NAMES "pkill")
+  if(NOT PKILL)
+    message(FATAL_ERROR "pkill not found, please install procps-ng package.")
+  endif()
+endif()
+
 # Check for FUSE.
 find_package (FUSE REQUIRED)
 include_directories (SYSTEM ${FUSE_INCLUDE_DIR})
 add_definitions (-D_FILE_OFFSET_BITS=64 -DFUSE_USE_VERSION=29)
+if (CYGWIN)
+  # Cygwin build is intended to use WinFsp
+  add_definitions(-DCYGFUSE)
+endif()
 
 # Check for OpenSSL.
 find_package (OpenSSL REQUIRED)
@@ -92,8 +105,10 @@ find_program (POD2MAN pod2man)
 
 # Check for include files and stdlib properties.
 include (CheckIncludeFileCXX)
-check_include_file_cxx (attr/xattr.h HAVE_ATTR_XATTR_H)
-check_include_file_cxx (sys/xattr.h HAVE_SYS_XATTR_H)
+if (NOT CYGWIN)
+  check_include_file_cxx (attr/xattr.h HAVE_ATTR_XATTR_H)
+  check_include_file_cxx (sys/xattr.h HAVE_SYS_XATTR_H)
+endif()
 
 include(CheckStructHasMember)
 check_struct_has_member("struct dirent" d_type dirent.h HAVE_DIRENT_D_TYPE LANGUAGE CXX)

README.md

@@ -81,7 +81,10 @@ How about a nice email instead?
 
 ## Windows
 
-A Windows port exists and is maintained by JetWhiz in the GitHub
+EncFS works on Cygwin, see [the wiki](https://github.com/vgough/encfs/wiki)
+for additional info.
+
+A Windows port also exists and is maintained by JetWhiz in the GitHub
 [jetwhiz/encfs4win](https://github.com/jetwhiz/encfs4win) repository.
 
 ## FAQ

encfs/Context.cpp

@@ -171,6 +171,15 @@ void EncFS_Context::eraseNode(const char *path,
   Lock lock(contextMutex);
 
   auto it = openFiles.find(std::string(path));
+#ifdef __CYGWIN__
+  // When renaming a file, Windows first opens it, renames it and then closes it
+  // Filenode may have then been renamed too
+  if (it == openFiles.end()) {
+    RLOG(WARNING) << "Filenode to erase not found, file has certainly be renamed: "
+                  << path;
+    return;
+  }
+#endif
   rAssert(it != openFiles.end());
   auto &list = it->second;
 

encfs/DirNode.cpp

@@ -599,11 +599,26 @@ int DirNode::rename(const char *fromPlaintext, const char *toPlaintext) {
       if (renameOp) {
         renameOp->undo();
       }
-    } else if (preserve_mtime) {
-      struct utimbuf ut;
-      ut.actime = st.st_atime;
-      ut.modtime = st.st_mtime;
-      ::utime(toCName.c_str(), &ut);
+    }
+    else {
+#ifdef __CYGWIN__
+      // When renaming a file, Windows first opens it, renames it and then closes it
+      // We then must decrease the target openFiles count
+      // We could recreate the source so that close will not (silently) fails,
+      // however it will update modification time of the file, so break what we do below.
+      // Let's simply warn in eraseNode().
+      if (!isDirectory(toCName.c_str())) {
+        std::shared_ptr<FileNode> toNode = findOrCreate(toPlaintext);
+        ctx->eraseNode(toPlaintext, toNode);
+        //ctx->putNode(fromPlaintext, toNode);
+      }
+#endif
+      if (preserve_mtime) {
+        struct utimbuf ut;
+        ut.actime = st.st_atime;
+        ut.modtime = st.st_mtime;
+        ::utime(toCName.c_str(), &ut);
+      }
     }
   } catch (encfs::Error &err) {
     // exception from renameNode, just show the error and continue..
@@ -739,7 +754,9 @@ int DirNode::unlink(const char *plaintextName) {
 
   Lock _lock(mutex);
 
-  int res = 0;
+// Windows does not allow deleting opened files, so no need to check
+// There is this "issue" however : https://github.com/billziss-gh/winfsp/issues/157
+#ifndef __CYGWIN__
   if ((ctx != nullptr) && ctx->lookupNode(plaintextName)) {
     // If FUSE is running with "hard_remove" option where it doesn't
     // hide open files for us, then we can't allow an unlink of an open
@@ -747,14 +764,16 @@ int DirNode::unlink(const char *plaintextName) {
     RLOG(WARNING) << "Refusing to unlink open file: " << cyName
                   << ", hard_remove option "
                      "is probably in effect";
-    res = -EBUSY;
-  } else {
-    string fullName = rootDir + cyName;
-    res = ::unlink(fullName.c_str());
-    if (res == -1) {
-      res = -errno;
-      VLOG(1) << "unlink error: " << strerror(-res);
-    }
+    return -EBUSY;
+  }
+#endif
+
+  int res = 0;
+  string fullName = rootDir + cyName;
+  res = ::unlink(fullName.c_str());
+  if (res == -1) {
+    res = -errno;
+    VLOG(1) << "unlink error: " << strerror(-res);
   }
 
   return res;

encfs/Error.h

@@ -6,6 +6,13 @@
 #include "easylogging++.h"
 #include <stdexcept>
 
+// Cygwin / WinFsp does not support EBADMSG yet
+// https://github.com/billziss-gh/winfsp/issues/156
+#ifdef __CYGWIN__
+#undef EBADMSG
+#define EBADMSG EINVAL
+#endif
+
 namespace encfs {
 
 class Error : public std::runtime_error {

encfs/FileUtils.cpp

@@ -1089,7 +1089,7 @@ RootPtr createV6Config(EncFS_Context *ctx,
     alg = findCipherAlgorithm("AES", keySize);
 
 // If case-insensitive system, opt for Block32 filename encoding
-#if defined(__APPLE__) || defined(WIN32)
+#if defined(DEFAULT_CASE_INSENSITIVE)
     nameIOIface = BlockNameIO::CurrentInterface(true);
 #else
     nameIOIface = BlockNameIO::CurrentInterface();
@@ -1739,6 +1739,14 @@ void unmountFS(const char *mountPoint) {
   // fuse_unmount does not work on Mac OS, see #428
   unmount(mountPoint, MNT_FORCE);
 #endif
+#ifdef __CYGWIN__
+  if(fork() == 0)
+  {
+    execl("/usr/bin/pkill", "/usr/bin/pkill", "-f", string("(^|/)encfs .*/.* ").append(mountPoint).append("?( |$)").c_str(), (char *)0);
+  }
+  int status;
+  wait(&status);
+#endif
 }
 
 int remountFS(EncFS_Context *ctx) {

encfs/FileUtils.h

@@ -72,6 +72,7 @@ enum ConfigMode { Config_Prompt, Config_Standard, Config_Paranoia };
 struct EncFS_Opts {
   std::string rootDir;
   std::string mountPoint;  // where to make filesystem visible
+  std::string cygDrive;    // Cygwin mount drive
   bool createIfNotFound;   // create filesystem if not found
   bool idleTracking;       // turn on idle monitoring of filesystem
   bool mountOnDemand;      // mounting on-demand

encfs/encfs.cpp

@@ -167,6 +167,13 @@ static int withFileNode(const char *opName, const char *path,
     if (fi != nullptr && fi->fh != 0) {
       auto node = ctx->lookupFuseFh(fi->fh);
       if (node == nullptr) {
+#ifdef __CYGWIN__
+        if (strcmp(opName, "flush") == 0) {
+          RLOG(WARNING) << "Filenode to flush not found, file has certainly be renamed: "
+                        << path;
+          return 0;
+        }
+#endif
         auto msg = "fh=" + std::to_string(fi->fh) + " not found in fuseFhMap";
         throw Error(msg.c_str());
       }

encfs/encfs.pod

@@ -649,6 +649,8 @@ Support, bug reports... : B<https://github.com/vgough/encfs>.
 
 Mailing list : none.
 
+Cygwin : B<https://github.com/vgough/encfs/wiki>.
+
 Windows port : B<https://github.com/jetwhiz/encfs4win>.
 
 =head1 SEE ALSO

encfs/main.cpp

@@ -380,6 +380,11 @@ static bool processArgs(int argc, char *argv[],
         /* Disable kernel dentry cache
          * Fallout unknown, disabling for safety */
         PUSHARG("-oentry_timeout=0");
+#ifdef __CYGWIN__
+        // Should be enforced due to attr_timeout=0, but does not seem to work correctly
+        // https://github.com/billziss-gh/winfsp/issues/155
+        PUSHARG("-oFileInfoTimeout=0");
+#endif
         break;
       case 'm':
         out->opts->mountOnDemand = true;
@@ -542,18 +547,38 @@ static bool processArgs(int argc, char *argv[],
   if (!isDirectory(out->opts->rootDir.c_str()) &&
       !userAllowMkdir(out->opts->annotate ? 1 : 0, out->opts->rootDir.c_str(),
                       0700)) {
-    cerr << _("Unable to locate root directory, aborting.");
+    cerr << _("Unable to locate root directory, aborting.") << endl;
     return false;
   }
+#ifdef __CYGWIN__
+  if (isDirectory(out->opts->mountPoint.c_str())) {
+    cerr << _("Mount point must not exist before mouting, aborting.") << endl;
+    return false;
+  }
+  if ((strncmp(out->opts->mountPoint.c_str(), "/cygdrive/", 10) != 0) ||
+      (out->opts->mountPoint.length() != 12)) {
+    cerr << _("A drive is prefered for mouting, ")
+         << _("so a path like /cygdrive/x should rather be used. ")
+         << _("Mounting anyway.")  << endl;
+  }
+#else
   if (!isDirectory(out->opts->mountPoint.c_str()) &&
       !userAllowMkdir(out->opts->annotate ? 2 : 0,
                       out->opts->mountPoint.c_str(), 0700)) {
-    cerr << _("Unable to locate mount point, aborting.");
+    cerr << _("Unable to locate mount point, aborting.") << endl;
     return false;
   }
+#endif
 
   // fill in mount path for fuse
   out->fuseArgv[1] = out->opts->mountPoint.c_str();
+#ifdef __CYGWIN__
+  if ((strncmp(out->opts->mountPoint.c_str(), "/cygdrive/", 10) == 0) &&
+      (out->opts->mountPoint.length() == 12)) {
+    out->opts->cygDrive = out->opts->mountPoint.substr(10,1).append(":");
+    out->fuseArgv[1] = out->opts->cygDrive.c_str();
+  }
+#endif
 
   return true;
 }

integration/normal.t.pl

@@ -107,6 +107,10 @@ sub newWorkingDir
 
     our $raw = "$workingDir/raw";
     our $crypt = "$workingDir/crypt";
+    if ($^O eq "cygwin")
+    {
+        $crypt = "/cygdrive/x";
+    }
 }
 
 # Test Corruption
@@ -124,7 +128,8 @@ sub corruption
     ok( open(IN, "< $crypt/corrupt"), "open corrupted file");
     my $content;
     $result = read(IN, $content, 20);
-    ok($!{EBADMSG} && (! defined $result), "corrupted file with MAC returns read error: $!");
+    # Cygwin returns EINVAL for now
+    ok(($!{EBADMSG} || $!{EINVAL}) && (! defined $result), "corrupted file with MAC returns read error: $!");
 }
 
 # Test internal modification
@@ -363,7 +368,10 @@ sub mount
 
     # When these fail, the rest of the tests makes no sense
     mkdir($raw) || BAIL_OUT("Could not create $raw: $!");
-    mkdir($crypt)  || BAIL_OUT("Could not create $crypt: $!");
+    if ($^O ne "cygwin")
+    {
+        mkdir($crypt)  || BAIL_OUT("Could not create $crypt: $!");
+    }
 
     delete $ENV{"ENCFS6_CONFIG"};
     remount($args);
@@ -425,8 +433,15 @@ sub create_unmount_remount
 {
     my $crypt = "$workingDir/create_remount.crypt";
     my $mnt = "$workingDir/create_remount.mnt";
+    if ($^O eq "cygwin")
+    {
+        $mnt = "/cygdrive/y";
+    }
     mkdir($crypt) || BAIL_OUT($!);
-    mkdir($mnt)  || BAIL_OUT($!);
+    if ($^O ne "cygwin")
+    {
+        mkdir($mnt)  || BAIL_OUT($!);
+    }
 
     system("./build/encfs --standard --extpass=\"echo test\" $crypt $mnt 2>&1");
     ok( $? == 0, "encfs command returns 0") || return;
@@ -472,8 +487,15 @@ sub checkWriteError
     else {
             my $crypt = "$workingDir/checkWriteError.crypt";
             my $mnt = "$workingDir/checkWriteError.mnt";
+            if ($^O eq "cygwin")
+            {
+                $mnt = "/cygdrive/z";
+            }
             mkdir($crypt) || BAIL_OUT($!);
-            mkdir($mnt)  || BAIL_OUT($!);
+            if ($^O ne "cygwin")
+            {
+                mkdir($mnt)  || BAIL_OUT($!);
+            }
             system("$sudo_cmd mount -t tmpfs -o size=1m tmpfs $crypt");
             ok( $? == 0, "mount command returns 0") || return;
             system("./build/encfs --standard --extpass=\"echo test\" $crypt $mnt 2>&1");

integration/reverse.t.pl

@@ -49,9 +49,23 @@ sub newWorkingDir
     our $plain = "$workingDir/plain";
     mkdir($plain);
     our $ciphertext = "$workingDir/ciphertext";
-    mkdir($ciphertext);
+    if ($^O ne "cygwin")
+    {
+        mkdir($ciphertext);
+    }
+    else
+    {
+        $ciphertext = "/cygdrive/x";
+    }
     our $decrypted = "$workingDir/decrypted";
-    mkdir($decrypted);
+    if ($^O ne "cygwin")
+    {
+        mkdir($decrypted);
+    }
+    else
+    {
+        $decrypted = "/cygdrive/y";
+    }
 }
 
 # Helper function
@@ -231,7 +245,14 @@ encfsctl_cat_test();
 symlink_test("/"); # absolute
 symlink_test("foo"); # relative
 symlink_test("/1/2/3/4/5/6/7/8/9/10/11/12/13/14/15/15/17/18"); # long
-symlink_test("!§\$%&/()\\<>#+="); # special characters
+if ($^O ne "cygwin")
+{
+    symlink_test("!§\$%&/()\\<>#+="); # special characters
+}
+else
+{
+    symlink_test("!§\$%&/()//<>#+="); # special characters but without \ which is not Windows compliant
+}                                     # Absolute symlinks may failed on Windows : https://github.com/billziss-gh/winfsp/issues/153
 symlink_test("$plain/foo");
 writesDenied();