Change license of libsquashfs.so

This this commit, the code that is compiled and linked to produce
libsquashfs.so (and *only* libsquashfs.so) is released under the
terms and conditions of the GNU Lesser General Public license,
allowing 3rd party programs to dynamically link against it and still
being able to release their programs under a license of their choosing.

The libutil library is also relicensed, because it is statically linked
into libsquashfs.so. This does not affect the command line programs that
remain under the GPLv3.

At the current time, the two libraries do not contain any 3rd party
contributions and thus do not require anybodys consent other than mine
to change the licensing terms (unlike e.g. libfstree.a).

The libfstree.a and libsqfshelper.a utility libraries will also remain
under the GPLv3 license.

Going forward, some parts of libsqfshelper.a will be moved to
libsquashfs.so. The parts absorbed by libsquashfs.so will then also have
their licensing conditions changed *at that time*.

For the public headers, this commit adds the full boiler-plate comment
about the license, for the source files and internal headers, only the
SPDX identifier is changed.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

14 files changed, 210 insertions, 28 deletions

diff --git a/include/sqfs/block_processor.h b/include/sqfs/block_processor.h
index 1ec2f7c..70cff09 100644
--- a/include/sqfs/block_processor.h
+++ b/include/sqfs/block_processor.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * block_processor.h
+ * block_processor.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SFQS_BLOCK_PROCESSOR_H
 #define SFQS_BLOCK_PROCESSOR_H
diff --git a/include/sqfs/compress.h b/include/sqfs/compress.h
index e781e02..eaec2b5 100644
--- a/include/sqfs/compress.h
+++ b/include/sqfs/compress.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * compress.h
+ * compress.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SQFS_COMPRESS_H
 #define SQFS_COMPRESS_H
diff --git a/include/sqfs/data.h b/include/sqfs/data.h
index e8efa73..818d427 100644
--- a/include/sqfs/data.h
+++ b/include/sqfs/data.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * data.h
+ * data.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SQFS_DATA_H
 #define SQFS_DATA_H
diff --git a/include/sqfs/dir.h b/include/sqfs/dir.h
index 196d135..6bcb278 100644
--- a/include/sqfs/dir.h
+++ b/include/sqfs/dir.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * dir.h
+ * dir.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SQFS_DIR_H
 #define SQFS_DIR_H
diff --git a/include/sqfs/error.h b/include/sqfs/error.h
index 5bbf26c..a755c0b 100644
--- a/include/sqfs/error.h
+++ b/include/sqfs/error.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * error.h
+ * error.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SQFS_ERROR_H
 #define SQFS_ERROR_H
diff --git a/include/sqfs/id_table.h b/include/sqfs/id_table.h
index 6b058ae..87e13f5 100644
--- a/include/sqfs/id_table.h
+++ b/include/sqfs/id_table.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * id_table.h
+ * id_table.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SQFS_ID_TABLE_H
 #define SQFS_ID_TABLE_H
diff --git a/include/sqfs/inode.h b/include/sqfs/inode.h
index 76d1a7c..d0c49a1 100644
--- a/include/sqfs/inode.h
+++ b/include/sqfs/inode.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * inode.h
+ * inode.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SQFS_INODE_H
 #define SQFS_INODE_H
diff --git a/include/sqfs/io.h b/include/sqfs/io.h
index f290c2d..59739ec 100644
--- a/include/sqfs/io.h
+++ b/include/sqfs/io.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * io.h
+ * io.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SQFS_IO_H
 #define SQFS_IO_H
diff --git a/include/sqfs/meta_reader.h b/include/sqfs/meta_reader.h
index 00a6d65..1a9e869 100644
--- a/include/sqfs/meta_reader.h
+++ b/include/sqfs/meta_reader.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * meta_reader.h
+ * meta_reader.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SQFS_META_READER_H
 #define SQFS_META_READER_H
diff --git a/include/sqfs/meta_writer.h b/include/sqfs/meta_writer.h
index 3b255f2..b3da355 100644
--- a/include/sqfs/meta_writer.h
+++ b/include/sqfs/meta_writer.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * meta_writer.h
+ * meta_writer.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SQFS_META_WRITER_H
 #define SQFS_META_WRITER_H
diff --git a/include/sqfs/predef.h b/include/sqfs/predef.h
index df08b1b..c8d0c19 100644
--- a/include/sqfs/predef.h
+++ b/include/sqfs/predef.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * predef.h
+ * predef.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SQFS_PREDEF_H
 #define SQFS_PREDEF_H
diff --git a/include/sqfs/super.h b/include/sqfs/super.h
index a8697a1..4556d3d 100644
--- a/include/sqfs/super.h
+++ b/include/sqfs/super.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * super.h
+ * super.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SQFS_SUPER_H
 #define SQFS_SUPER_H
diff --git a/include/sqfs/table.h b/include/sqfs/table.h
index 010d5f9..0788538 100644
--- a/include/sqfs/table.h
+++ b/include/sqfs/table.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * table.h
+ * table.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SQFS_TABLE_H
 #define SQFS_TABLE_H
diff --git a/include/sqfs/xattr.h b/include/sqfs/xattr.h
index 23587d1..d1f242b 100644
--- a/include/sqfs/xattr.h
+++ b/include/sqfs/xattr.h
@@ -1,8 +1,21 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * xattr.h
+ * xattr.h - This file is part of libsquashfs
  *
  * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #ifndef SQFS_XATTR_H
 #define SQFS_XATTR_H