ADB Backup: add ability for TWRP GUI to restore

Restore adb backup files that TWRP made to your PC.
Put files in your backup directory to see them.

e.g. /sdcard/TWRP/BACKUPS/<sn>

Change-Id: I2c57970d77b64c39a302159041456e761c185259
diff --git a/adbbu/libtwadbbu.cpp b/adbbu/libtwadbbu.cpp
index cdc2170..a13ecb2 100644
--- a/adbbu/libtwadbbu.cpp
+++ b/adbbu/libtwadbbu.cpp
@@ -1,5 +1,5 @@
 /*
-		Copyright 2013 to 2016 TeamWin
+		Copyright 2013 to 2017 TeamWin
 		TWRP is free software: you can redistribute it and/or modify
 		it under the terms of the GNU General Public License as published by
 		the Free Software Foundation, either version 3 of the License, or
@@ -27,12 +27,107 @@
 #include <sys/select.h>
 #include <sys/time.h>
 #include <string>
+#include <vector>
 #include <fstream>
 #include <sstream>
 
 #include "twadbstream.h"
 #include "libtwadbbu.hpp"
 
+bool twadbbu::Check_ADB_Backup_File(std::string fname) {
+	struct AdbBackupStreamHeader adbbuhdr;
+	uint32_t crc, adbbuhdrcrc;
+	unsigned char buf[MAX_ADB_READ];
+	int bytes;
+
+	int fd = open(fname.c_str(), O_RDONLY);
+	if (fd < 0) {
+		printf("Unable to open %s for reading: %s.\n", fname.c_str(), strerror(errno));
+		close(fd);
+		return false;
+	}
+	bytes = read(fd, &buf, sizeof(buf));
+	close(fd);
+
+	if (memcpy(&adbbuhdr, buf, sizeof(adbbuhdr)) < 0) {
+		printf("Unable to memcpy: %s.\n", fname.c_str(), strerror(errno));
+		return false;
+	}
+	adbbuhdrcrc = adbbuhdr.crc;
+	memset(&adbbuhdr.crc, 0, sizeof(adbbuhdr.crc));
+	crc = crc32(0L, Z_NULL, 0);
+	crc = crc32(crc, (const unsigned char*) &adbbuhdr, sizeof(adbbuhdr));
+
+	return (crc == adbbuhdrcrc);
+}
+
+std::vector<std::string> twadbbu::Get_ADB_Backup_Files(std::string fname) {
+	unsigned char buf[MAX_ADB_READ];
+	struct AdbBackupControlType structcmd;
+	std::vector<std::string> adb_partitions;
+
+	int fd = open(fname.c_str(), O_RDONLY);
+	if (fd < 0) {
+		printf("Unable to open %s for reading: %s\n", fname.c_str(), strerror(errno));
+		close(fd);
+		return std::vector<std::string>();
+	}
+
+	while (1) {
+		std::string cmdstr;
+		int readbytes;
+		if (readbytes = read(fd, &buf, sizeof(buf)) > 0) {
+			memcpy(&structcmd, buf, sizeof(structcmd));
+			assert(structcmd.type == TWENDADB || structcmd.type == TWIMG || structcmd.type == TWFN);
+			cmdstr = structcmd.type;
+			std::string cmdtype = cmdstr.substr(0, sizeof(structcmd.type) - 1);
+			if (cmdtype == TWENDADB) {
+				struct AdbBackupControlType endadb;
+				uint32_t crc, endadbcrc;
+
+				memcpy(&endadb, buf, sizeof(endadb));
+				endadbcrc = endadb.crc;
+				memset(&endadb.crc, 0, sizeof(endadb.crc));
+				crc = crc32(0L, Z_NULL, 0);
+				crc = crc32(crc, (const unsigned char*) &endadb, sizeof(endadb));
+
+				if (crc == endadbcrc) {
+					break;
+				}
+				else {
+					printf("ADB TWENDADB crc header doesn't match\n");
+					close(fd);
+					return std::vector<std::string>();
+				}
+			}
+			else if (cmdtype == TWIMG || cmdtype == TWFN) {
+				struct twfilehdr twfilehdr;
+				uint32_t crc, twfilehdrcrc;
+
+				memcpy(&twfilehdr, buf, sizeof(twfilehdr));
+				twfilehdrcrc = twfilehdr.crc;
+				memset(&twfilehdr.crc, 0, sizeof(twfilehdr.crc));
+
+				crc = crc32(0L, Z_NULL, 0);
+				crc = crc32(crc, (const unsigned char*) &twfilehdr, sizeof(twfilehdr));
+				if (crc == twfilehdrcrc) {
+					std::string adbfile = twfilehdr.name;
+					int pos = adbfile.find_last_of("/") + 1;
+					adbfile = adbfile.substr(pos, adbfile.size());
+					adb_partitions.push_back(adbfile);
+				}
+				else {
+					printf("ADB crc header doesn't match\n");
+					close(fd);
+					return std::vector<std::string>();
+				}
+			}
+		}
+	}
+	close(fd);
+	return adb_partitions;
+}
+
 bool twadbbu::Write_ADB_Stream_Header(uint64_t partition_count) {
 	struct AdbBackupStreamHeader twhdr;
 	int adb_control_bu_fd;
@@ -40,7 +135,7 @@
 	memset(&twhdr, 0, sizeof(twhdr));
 	adb_control_bu_fd = open(TW_ADB_BU_CONTROL, O_WRONLY | O_NONBLOCK);
 	if (adb_control_bu_fd < 0) {
-		printf("Cannot write to TW_ADB_BU_CONTROL.\n");
+		printf("Cannot write to TW_ADB_BU_CONTROL: %s\n", strerror(errno));
 		return false;
 	}
 
@@ -52,7 +147,7 @@
 	twhdr.crc = crc32(0L, Z_NULL, 0);
 	twhdr.crc = crc32(twhdr.crc, (const unsigned char*) &twhdr, sizeof(twhdr));
 	if (write(adb_control_bu_fd, &twhdr, sizeof(twhdr)) < 0) {
-		printf("Cannot write to adb control channel\n");
+		printf("Cannot write to adb control channel: %s\n", strerror(errno));
 		close(adb_control_bu_fd);
 		return false;
 	}
@@ -67,7 +162,7 @@
 
 	adb_control_bu_fd = open(TW_ADB_BU_CONTROL, O_WRONLY);
 	if (adb_control_bu_fd < 0) {
-		printf("Error opening adb_control_bu_fd\n");
+		printf("Error opening adb_control_bu_fd: %s\n", strerror(errno));
 		return false;
 	}
 	strncpy(endadb.start_of_header, TWRP, sizeof(endadb.start_of_header));
@@ -75,7 +170,7 @@
 	endadb.crc = crc32(0L, Z_NULL, 0);
 	endadb.crc = crc32(endadb.crc, (const unsigned char*) &endadb, sizeof(endadb));
 	if (write(adb_control_bu_fd, &endadb, sizeof(endadb)) < 0) {
-		printf("Cannot write to ADB control.\n");
+		printf("Cannot write to ADB control: %s\n", strerror(errno));
 		close(adb_control_bu_fd);
 		return false;
 	}
@@ -97,10 +192,11 @@
 
 	printf("Sending TWFN to adb\n");
 	if (write(adb_control_bu_fd, &twfilehdr, sizeof(twfilehdr)) < 1) {
-		printf("Cannot that write to adb_control_bu_fd\n");
+		printf("Cannot that write to adb_control_bu_fd: %s\n", strerror(errno));
 		close(adb_control_bu_fd);
 		return false;
 	}
+	fsync(adb_control_bu_fd);
 	close(adb_control_bu_fd);
 	return true;
 }
@@ -118,7 +214,7 @@
 	twimghdr.crc = crc32(twimghdr.crc, (const unsigned char*) &twimghdr, sizeof(twimghdr));
 	printf("Sending TWIMG to adb\n");
 	if (write(adb_control_bu_fd, &twimghdr, sizeof(twimghdr)) < 1) {
-		printf("Cannot write to adb control channel\n");
+		printf("Cannot write to adb control channel: %s\n", strerror(errno));
 		return false;
 	}
 
@@ -168,7 +264,7 @@
 	twerror.crc = crc32(0L, Z_NULL, 0);
 	twerror.crc = crc32(twerror.crc, (const unsigned char*) &twerror, sizeof(twerror));
 	if (write(adb_control_bu_fd, &twerror, sizeof(twerror)) < 0) {
-		printf("Cannot write to adb control channel");
+		printf("Cannot write to adb control channel: %s\n", strerror(errno));
 		return false;
 	}
 	close(adb_control_bu_fd);