feat: Build ioctl via musl toolchain

Author: feelfreelinux

scripts/build-ioctl-hook.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+mkdir build-ioctl
+cd build-ioctl
+
+echo "Building ioctl hook with musl cross platform toolchain"
+
+MUSL_AARCH64="aarch64-linux-musl"
+MUSL_ARMV7="arm-linux-musleabihf"
+MUSL_I686="i686-linux-musl"
+MUSL_X86_64="x86_64-linux-musl"
+
+cross_compile() {
+	curl -O "https://musl.cc/$1-cross.tgz"
+	tar xzf "$1-cross.tgz"
+	GCC_PATH=./$1-cross/bin/$1-gcc
+	$GCC_PATH -fPIC -c -o ioctlHook.o ioctlHook.c
+	$GCC_PATH -shared -o ioctlHook-$1.so ioctlHook.o -ldl
+}
+
+cp ../ioctlHook.c ioctlHook.c
+
+cross_compile $MUSL_AARCH64
+cross_compile $MUSL_I686
+cross_compile $MUSL_ARMV7
+cross_compile $MUSL_X86_64

scripts/generate-bootstraps.sh

@@ -11,9 +11,12 @@ cd ../minitar
 ./build.sh
 
 cd $SCRIPTS_PATH
-mkdir -p  build
+mkdir -p build
 cd build
 rm -rf *
+cp ../ioctlHook.c .
+../build-ioctl-hook.sh
+
 cp -r ../../external/proot/build/* .
 
 build_bootstrap () {
@@ -23,18 +26,22 @@ build_bootstrap () {
 	arm64)
 		PROOT_ARCH="aarch64"
 		ANDROID_ARCH="arm64-v8a"
+		MUSL_ARCH="aarch64-linux-musl"
 		;;
 	armhf)
 		PROOT_ARCH="armv7a"
 		ANDROID_ARCH="armeabi-v7a"
+		MUSL_ARCH="arm-linux-musleabihf"
 		;;
 	amd64)
 		PROOT_ARCH="x86_64"
-		ANDROID_ARCH="x86"
+		ANDROID_ARCH="x86_64"
+		MUSL_ARCH="x86_64-linux-musl"
 		;;
 	i386)
 		PROOT_ARCH="i686"
-		ANDROID_ARCH="x86_64"
+		ANDROID_ARCH="x86"
+		MUSL_ARCH="i686-linux-musl"
 		;;
 	*)
 		echo "Invalid arch"
@@ -49,11 +56,12 @@ build_bootstrap () {
 		cp root/bin/minitar root-pre5/bin/minitar
 	fi
 
-	curl -o rootfs.tar.xz -L "https://us.images.linuxcontainers.org/images/alpine/3.13/$1/default/20210330_13:00/rootfs.tar.xz"
+	curl -o rootfs.tar.xz -L "https://dl-cdn.alpinelinux.org/alpine/v3.13/releases/$1/alpine-minirootfs-3.13.5-$1.tar.gz"
 	cp ../../run-bootstrap.sh .
 	cp ../../install-bootstrap.sh .
 	cp ../../add-user.sh .
-	zip -r bootstrap-$PROOT_ARCH.zip root root-pre5 rootfs.tar.xz run-bootstrap.sh install-bootstrap.sh add-user.sh
+	cp ../build-ioctl/ioctlHook-${MUSL_ARCH}.so ioctlHook.so
+	zip -r bootstrap-$PROOT_ARCH.zip root ioctlHook.so root-pre5 rootfs.tar.xz run-bootstrap.sh install-bootstrap.sh add-user.sh
 	mv bootstrap-$PROOT_ARCH.zip ../
 	echo "Packed bootstrap $1"
 	cd ..

scripts/ioctlHook.c

@@ -0,0 +1,62 @@
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <dlfcn.h>
+#include <termios.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdlib.h>
+#include <signal.h>
+
+int g_obvio=0;
+#define DPRINTF(format, args...)	if (!g_obvio) { g_obvio=1; fprintf(stderr, format, ## args); g_obvio=0; }
+
+#ifndef RTLD_NEXT
+#define RTLD_NEXT ((void *)-1l)
+#endif
+
+#define REAL_LIBC RTLD_NEXT
+#define request_t int
+#define TIOCMBIS 0x5416
+
+static char fifoPath[] = "/dev/eventPipe";
+static char eventJsonStart[] = "{\"eventType\": \"";
+static char eventJsonEnd[] = "\"}\n";
+
+
+int writeEventToPipe(char* event, int len) {
+    int eventFifoFd = open(fifoPath, O_WRONLY);
+    write(eventFifoFd, eventJsonStart, sizeof(eventJsonStart)-1);
+    write(eventFifoFd, event, len);
+    write(eventFifoFd, eventJsonEnd, sizeof(eventJsonEnd)-1);
+    close(eventFifoFd);
+}
+
+int ioctl(int fd, int request, ...)
+{
+    static int (*funcIoctl)(int, request_t, void *) = NULL;
+    va_list args;
+    void *argp;
+
+    if (!funcIoctl)
+        funcIoctl = (int (*)(int, request_t, void *))dlsym(REAL_LIBC, "ioctl");
+    va_start(args, request);
+    argp = va_arg(args, void *);
+    va_end(args);
+
+    if (request == TIOCMBIS)
+    {
+        writeEventToPipe("rtsDts", 6);
+        return 0;
+    }
+
+    if (request == 0x802c542a || request == 0x402C542B)
+    {
+        writeEventToPipe("customBaud", 10);
+        return 0;
+    }
+    //DPRINTF ("HOOK: ioctl (fd=%d, request=%p, argp=%p [%02X])\n", fd, request, argp);
+    return funcIoctl(fd, request, argp);
+}