Add ramdisk compression option

native/jni/magiskboot/compress.cpp

@@ -44,7 +44,7 @@ void decompress(char *infile, const char *outfile) {
 			if (!COMPRESSED(type))
 				LOGE("Input file is not a compressed type!\n");
 
-			cmp = std::move(unique_ptr<Compression>(get_decoder(type)));
+			cmp.reset(get_decoder(type));
 			fprintf(stderr, "Detected format: [%s]\n", fmt2name[type]);
 
 			/* If user does not provide outfile, infile has to be either
@@ -66,7 +66,8 @@ void decompress(char *infile, const char *outfile) {
 				}
 			}
 
-			out_fd = strcmp(outfile, "-") == 0 ? STDOUT_FILENO : creat(outfile, 0644);
+			out_fd = strcmp(outfile, "-") == 0 ?
+					STDOUT_FILENO : xopen(outfile, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 			cmp->set_out(make_unique<FDOutStream>(out_fd));
 			if (ext) *ext = '.';
 		}
@@ -103,13 +104,14 @@ void compress(const char *method, const char *infile, const char *outfile) {
 			 * STDIN, output to <infile>.[ext] */
 			char *tmp = new char[strlen(infile) + 5];
 			sprintf(tmp, "%s%s", infile, fmt2ext[it->second]);
-			out_fd = creat(tmp, 0644);
+			out_fd = xopen(outfile, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 			fprintf(stderr, "Compressing to [%s]\n", tmp);
 			delete[] tmp;
 			rm_in = true;
 		}
 	} else {
-		out_fd = strcmp(outfile, "-") == 0 ? STDOUT_FILENO : creat(outfile, 0644);
+		out_fd = strcmp(outfile, "-") == 0 ?
+				 STDOUT_FILENO : xopen(outfile, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 	}
 
 	cmp->set_out(make_unique<FDOutStream>(out_fd));
@@ -127,9 +129,6 @@ void compress(const char *method, const char *infile, const char *outfile) {
 		unlink(infile);
 }
 
-
-/* Compression Streams */
-
 Compression *get_encoder(format_t type) {
 	switch (type) {
 		case XZ:
@@ -184,7 +183,7 @@ GZStream::GZStream(int mode) : mode(mode), strm({}) {
 }
 
 bool GZStream::write(const void *in, size_t size) {
-	return write(in, size, Z_NO_FLUSH);
+	return size ? write(in, size, Z_NO_FLUSH) : true;
 }
 
 uint64_t GZStream::finalize() {
@@ -237,7 +236,7 @@ BZStream::BZStream(int mode) : mode(mode), strm({}) {
 }
 
 bool BZStream::write(const void *in, size_t size) {
-	return write(in, size, BZ_RUN);
+	return size ? write(in, size, BZ_RUN) : true;
 }
 
 uint64_t BZStream::finalize() {
@@ -304,7 +303,7 @@ LZMAStream::LZMAStream(int mode) : mode(mode), strm(LZMA_STREAM_INIT) {
 }
 
 bool LZMAStream::write(const void *in, size_t size) {
-	return write(in, size, LZMA_RUN);
+	return size ? write(in, size, LZMA_RUN) : true;
 }
 
 uint64_t LZMAStream::finalize() {
@@ -394,6 +393,8 @@ LZ4FEncoder::~LZ4FEncoder() {
 bool LZ4FEncoder::write(const void *in, size_t size) {
 	if (!outbuf)
 		write_header();
+	if (size == 0)
+		return true;
 	auto inbuf = (const uint8_t *) in;
 	size_t read, write;
 	do {
@@ -507,6 +508,8 @@ bool LZ4Encoder::write(const void *in, size_t size) {
 		FilterOutStream::write("\x02\x21\x4c\x18", 4);
 		init = true;
 	}
+	if (size == 0)
+		return true;
 	in_total += size;
 	const char *inbuf = (const char *) in;
 	size_t consumed;

native/jni/magiskboot/ramdisk.cpp

@@ -6,17 +6,29 @@
 #include <cpio.h>
 
 #include "magiskboot.h"
+#include "compress.h"
 
 using namespace std;
 
+static const char *ramdisk_xz = "ramdisk.cpio.xz";
+
+static const char *UNSUPPORT_LIST[] =
+		{ "sbin/launch_daemonsu.sh", "sbin/su", "init.xposed.rc",
+		  "boot/sbin/launch_daemonsu.sh" };
+
+static const char *MAGISK_LIST[] =
+		{ ".backup/.magisk", "init.magisk.rc",
+		  "overlay/init.magisk.rc", ramdisk_xz };
+
 class magisk_cpio : public cpio_rw {
 public:
 	explicit magisk_cpio(const char *filename) : cpio_rw(filename) {}
 	void patch(bool keepverity, bool keepforceencrypt);
 	int test();
-	char * sha1();
+	char *sha1();
 	void restore();
 	void backup(const char *orig);
+	void compress();
 };
 
 void magisk_cpio::patch(bool keepverity, bool keepforceencrypt) {
@@ -47,13 +59,6 @@ void magisk_cpio::patch(bool keepverity, bool keepforceencrypt) {
 #define MAGISK_PATCH     0x1
 #define UNSUPPORT_PATCH  0x2
 int magisk_cpio::test() {
-	static const char *UNSUPPORT_LIST[] =
-			{ "sbin/launch_daemonsu.sh", "sbin/su", "init.xposed.rc",
-	 		"boot/sbin/launch_daemonsu.sh" };
-	static const char *MAGISK_LIST[] =
-			{ ".backup/.magisk", "init.magisk.rc",
-	 		"overlay/init.magisk.rc" };
-
 	for (auto file : UNSUPPORT_LIST)
 		if (exists(file))
 			return UNSUPPORT_PATCH;
@@ -202,6 +207,21 @@ void magisk_cpio::backup(const char *orig) {
 		entries.merge(bkup_entries);
 }
 
+void magisk_cpio::compress() {
+	fprintf(stderr, "Compressing cpio -> [%s]\n", ramdisk_xz);
+	auto init = entries.extract("init");
+	XZEncoder encoder;
+	encoder.set_out(make_unique<BufOutStream>());
+	output(encoder);
+	encoder.finalize();
+	entries.clear();
+	entries.insert(std::move(init));
+	auto xz = new cpio_entry(ramdisk_xz);
+	xz->mode = S_IFREG;
+	static_cast<BufOutStream *>(encoder.get_out())->release(xz->data, xz->filesize);
+	insert(xz);
+}
+
 int cpio_commands(int argc, char *argv[]) {
 	char *incpio = argv[0];
 	++argv;
@@ -232,6 +252,8 @@ int cpio_commands(int argc, char *argv[]) {
 			char *sha1 = cpio.sha1();
 			if (sha1) printf("%s\n", sha1);
 			return 0;
+		} else if (strcmp(cmdv[0], "compress") == 0){
+			cpio.compress();
 		} else if (cmdc == 2 && strcmp(cmdv[0], "exists") == 0) {
 			exit(!cpio.exists(cmdv[1]));
 		} else if (cmdc == 2 && strcmp(cmdv[0], "backup") == 0) {

native/jni/utils/include/OutStream.h

@@ -19,6 +19,8 @@ public:
 
 	void set_out(strm_ptr &&ptr) { out = std::move(ptr); }
 
+	OutStream *get_out() { return out.get(); }
+
 	bool write(const void *buf, size_t len) override {
 		return out ? out->write(buf, len) : false;
 	}
@@ -44,3 +46,38 @@ protected:
 	int fd;
 	bool close;
 };
+
+class BufOutStream : public OutStream {
+public:
+	BufOutStream() : buf(nullptr), off(0), cap(0) {};
+
+	bool write(const void *b, size_t len) override {
+		bool resize = false;
+		while (off + len > cap) {
+			cap = cap ? cap << 1 : 1 << 19;
+			resize = true;
+		}
+		if (resize)
+			buf = (char *) xrealloc(buf, cap);
+		memcpy(buf + off, b, len);
+		off += len;
+		return true;
+	}
+
+	template <typename T>
+	void release(void *&b, T &len) {
+		b = buf;
+		len = off;
+		buf = nullptr;
+		off = cap = 0;
+	}
+
+	~BufOutStream() override {
+		free(buf);
+	}
+
+protected:
+	char *buf;
+	size_t off;
+	size_t cap;
+};