trusty: Android part of dynamic app loader

Implement the Android tool that uploads Trusty application package files
to the Trusty app loader.

Bug: 115420908
Test: trusty_apploader boot-start-srv.app
Change-Id: Ie21b8cad749fd565579483944a8b71e861d3a51a
diff --git a/trusty/apploader/Android.bp b/trusty/apploader/Android.bp
new file mode 100644
index 0000000..7e97cb8
--- /dev/null
+++ b/trusty/apploader/Android.bp
@@ -0,0 +1,36 @@
+//
+// Copyright (C) 2020 The Android Open-Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+cc_binary {
+    name: "trusty_apploader",
+    vendor: true,
+
+    srcs: [
+        "apploader.cpp",
+    ],
+
+    shared_libs: [
+        "libbase",
+        "libc",
+        "liblog",
+        "libtrusty",
+        "libdmabufheap",
+    ],
+    cflags: [
+        "-Wall",
+        "-Werror",
+    ],
+}
diff --git a/trusty/apploader/apploader.cpp b/trusty/apploader/apploader.cpp
new file mode 100644
index 0000000..5d5d882
--- /dev/null
+++ b/trusty/apploader/apploader.cpp
@@ -0,0 +1,272 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "TrustyAppLoader"
+
+#include <BufferAllocator/BufferAllocator.h>
+#include <android-base/logging.h>
+#include <android-base/unique_fd.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/sendfile.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <trusty/tipc.h>
+#include <unistd.h>
+#include <algorithm>
+#include <string>
+
+#include "apploader_ipc.h"
+
+using android::base::unique_fd;
+using std::string;
+
+constexpr const char kTrustyDefaultDeviceName[] = "/dev/trusty-ipc-dev0";
+
+static const char* dev_name = kTrustyDefaultDeviceName;
+
+static const char* _sopts = "hs";
+static const struct option _lopts[] = {
+        {"help", no_argument, 0, 'h'},
+        {"dev", required_argument, 0, 'D'},
+        {0, 0, 0, 0},
+};
+
+static const char* usage =
+        "Usage: %s [options] package-file\n"
+        "\n"
+        "options:\n"
+        "  -h, --help            prints this message and exit\n"
+        "  -D, --dev name        Trusty device name\n"
+        "\n";
+
+static void print_usage_and_exit(const char* prog, int code) {
+    fprintf(stderr, usage, prog);
+    exit(code);
+}
+
+static void parse_options(int argc, char** argv) {
+    int c;
+    int oidx = 0;
+
+    while (1) {
+        c = getopt_long(argc, argv, _sopts, _lopts, &oidx);
+        if (c == -1) {
+            break; /* done */
+        }
+
+        switch (c) {
+            case 'h':
+                print_usage_and_exit(argv[0], EXIT_SUCCESS);
+                break;
+
+            case 'D':
+                dev_name = strdup(optarg);
+                break;
+
+            default:
+                print_usage_and_exit(argv[0], EXIT_FAILURE);
+        }
+    }
+}
+
+static unique_fd read_file(const char* file_name, off64_t* out_file_size) {
+    int rc;
+    long page_size = sysconf(_SC_PAGESIZE);
+    off64_t file_size, file_page_offset, file_page_size;
+    struct stat64 st;
+
+    unique_fd file_fd(TEMP_FAILURE_RETRY(open(file_name, O_RDONLY)));
+    if (!file_fd.ok()) {
+        fprintf(stderr, "Error opening file '%s': %s\n", file_name, strerror(errno));
+        return {};
+    }
+
+    rc = fstat64(file_fd, &st);
+    if (rc < 0) {
+        fprintf(stderr, "Error calling stat on file '%s': %s\n", file_name, strerror(errno));
+        return {};
+    }
+
+    assert(st.st_size >= 0);
+    file_size = st.st_size;
+
+    /* The dmabuf size needs to be a multiple of the page size */
+    file_page_offset = file_size & (page_size - 1);
+    if (file_page_offset) {
+        file_page_offset = page_size - file_page_offset;
+    }
+    if (__builtin_add_overflow(file_size, file_page_offset, &file_page_size)) {
+        fprintf(stderr, "Failed to page-align file size\n");
+        return {};
+    }
+
+    BufferAllocator alloc;
+    unique_fd dmabuf_fd(alloc.Alloc(kDmabufSystemHeapName, file_page_size));
+    if (!dmabuf_fd.ok()) {
+        fprintf(stderr, "Error creating dmabuf: %d\n", dmabuf_fd.get());
+        return dmabuf_fd;
+    }
+
+    void* shm = mmap(0, file_page_size, PROT_READ | PROT_WRITE, MAP_SHARED, dmabuf_fd, 0);
+    if (shm == MAP_FAILED) {
+        return {};
+    }
+
+    off64_t file_offset = 0;
+    while (file_offset < file_size) {
+        ssize_t num_read = TEMP_FAILURE_RETRY(
+                pread(file_fd, (char*)shm + file_offset, file_size - file_offset, file_offset));
+
+        if (num_read < 0) {
+            fprintf(stderr, "Error reading package file '%s': %s\n", file_name, strerror(errno));
+            break;
+        }
+
+        if (num_read == 0) {
+            fprintf(stderr, "Unexpected end of file '%s'\n", file_name);
+            break;
+        }
+
+        file_offset += (off64_t)num_read;
+    }
+
+    munmap(shm, file_page_size);
+
+    if (file_offset < file_size) {
+        return {};
+    }
+
+    assert(file_offset == file_size);
+    if (out_file_size) {
+        *out_file_size = file_size;
+    }
+
+    return dmabuf_fd;
+}
+
+static ssize_t send_load_message(int tipc_fd, int package_fd, off64_t package_size) {
+    struct apploader_header hdr = {
+            .cmd = APPLOADER_CMD_LOAD_APPLICATION,
+    };
+    struct apploader_load_app_req req = {
+            .package_size = static_cast<uint64_t>(package_size),
+    };
+    struct iovec tx[2] = {{&hdr, sizeof(hdr)}, {&req, sizeof(req)}};
+    struct trusty_shm shm = {
+            .fd = package_fd,
+            .transfer = TRUSTY_SHARE,
+    };
+    return tipc_send(tipc_fd, tx, 2, &shm, 1);
+}
+
+static ssize_t read_response(int tipc_fd) {
+    struct apploader_resp resp;
+    ssize_t rc = read(tipc_fd, &resp, sizeof(resp));
+    if (rc < 0) {
+        fprintf(stderr, "Failed to read response: %zd\n", rc);
+        return rc;
+    }
+
+    if (rc < sizeof(resp)) {
+        fprintf(stderr, "Not enough data in response: %zd\n", rc);
+        return -EIO;
+    }
+
+    if (resp.hdr.cmd != (APPLOADER_CMD_LOAD_APPLICATION | APPLOADER_RESP_BIT)) {
+        fprintf(stderr, "Invalid command in response: %u\n", resp.hdr.cmd);
+        return -EINVAL;
+    }
+
+    switch (resp.error) {
+        case APPLOADER_NO_ERROR:
+            break;
+        case APPLOADER_ERR_UNKNOWN_CMD:
+            fprintf(stderr, "Error: unknown command\n");
+            break;
+        case APPLOADER_ERR_INVALID_CMD:
+            fprintf(stderr, "Error: invalid command arguments\n");
+            break;
+        case APPLOADER_ERR_NO_MEMORY:
+            fprintf(stderr, "Error: out of Trusty memory\n");
+            break;
+        case APPLOADER_ERR_VERIFICATION_FAILED:
+            fprintf(stderr, "Error: failed to verify the package\n");
+            break;
+        case APPLOADER_ERR_LOADING_FAILED:
+            fprintf(stderr, "Error: failed to load the package\n");
+            break;
+        case APPLOADER_ERR_ALREADY_EXISTS:
+            fprintf(stderr, "Error: application already exists\n");
+            break;
+        case APPLOADER_ERR_INTERNAL:
+            fprintf(stderr, "Error: internal apploader error\n");
+            break;
+        default:
+            fprintf(stderr, "Unrecognized error: %u\n", resp.error);
+            break;
+    }
+
+    return static_cast<ssize_t>(resp.error);
+}
+
+static ssize_t send_app_package(const char* package_file_name) {
+    ssize_t rc = 0;
+    int tipc_fd = -1;
+    off64_t package_size;
+
+    unique_fd package_fd = read_file(package_file_name, &package_size);
+    if (!package_fd.ok()) {
+        rc = -1;
+        goto err_read_file;
+    }
+
+    tipc_fd = tipc_connect(dev_name, APPLOADER_PORT);
+    if (tipc_fd < 0) {
+        fprintf(stderr, "Failed to connect to Trusty app loader: %s\n", strerror(-tipc_fd));
+        rc = tipc_fd;
+        goto err_tipc_connect;
+    }
+
+    rc = send_load_message(tipc_fd, package_fd, package_size);
+    if (rc < 0) {
+        fprintf(stderr, "Failed to send package: %zd\n", rc);
+        goto err_send;
+    }
+
+    rc = read_response(tipc_fd);
+
+err_send:
+    tipc_close(tipc_fd);
+err_tipc_connect:
+err_read_file:
+    return rc;
+}
+
+int main(int argc, char** argv) {
+    parse_options(argc, argv);
+    if (optind + 1 != argc) {
+        print_usage_and_exit(argv[0], EXIT_FAILURE);
+    }
+
+    int rc = send_app_package(argv[optind]);
+    return rc == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+}
diff --git a/trusty/apploader/apploader_ipc.h b/trusty/apploader/apploader_ipc.h
new file mode 100644
index 0000000..d8c915e
--- /dev/null
+++ b/trusty/apploader/apploader_ipc.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+#define APPLOADER_PORT "com.android.trusty.apploader"
+
+enum apploader_command : uint32_t {
+    APPLOADER_REQ_SHIFT = 1,
+    APPLOADER_RESP_BIT = 1,
+
+    APPLOADER_CMD_LOAD_APPLICATION = (0 << APPLOADER_REQ_SHIFT),
+    APPLOADER_CMD_GET_VERSION = (1 << APPLOADER_REQ_SHIFT),
+    APPLOADER_CMD_UNLOAD_APPLICATION = (2 << APPLOADER_REQ_SHIFT),
+};
+
+/**
+ * enum apploader_error - error codes for apploader
+ * @APPLOADER_NO_ERROR:                 no error
+ * @APPLOADER_ERR_UNKNOWN_CMD:          unknown or not implemented command
+ * @APPLOADER_ERR_INVALID_CMD:          invalid arguments or inputs passed to
+ *                                      command
+ * @APPLOADER_ERR_NO_MEMORY:            failed to allocate memory
+ * @APPLOADER_ERR_VERIFICATION_FAILED:  failed to verify input application
+ *                                      package for any reason, e.g., signature
+ *                                      verification failed
+ * @APPLOADER_ERR_LOADING_FAILED:       Trusty kernel or apploader service
+ *                                      failed to load application
+ * @APPLOADER_ERR_ALREADY_EXISTS:       application has already been loaded
+ * @APPLOADER_ERR_INTERNAL:             miscellaneous or internal apploader
+ *                                      error not covered by the above
+ */
+enum apploader_error : uint32_t {
+    APPLOADER_NO_ERROR = 0,
+    APPLOADER_ERR_UNKNOWN_CMD,
+    APPLOADER_ERR_INVALID_CMD,
+    APPLOADER_ERR_NO_MEMORY,
+    APPLOADER_ERR_VERIFICATION_FAILED,
+    APPLOADER_ERR_LOADING_FAILED,
+    APPLOADER_ERR_ALREADY_EXISTS,
+    APPLOADER_ERR_INTERNAL,
+};
+
+/**
+ * apploader_header - Serial header for communicating with apploader
+ * @cmd: the command; one of &enum apploader_command values.
+ */
+struct apploader_header {
+    uint32_t cmd;
+} __packed;
+
+/**
+ * apploader_load_app_req - Serial arguments for LOAD_APPLICATION command
+ * @package_size: size of the application package.
+ *
+ * Load an application from a given memory region. The request message also
+ * contains a handle for a memfd that contains the application package.
+ *
+ * The response is a &struct apploader_resp with the error code or
+ * %APPLOADER_NO_ERROR on success.
+ */
+struct apploader_load_app_req {
+    uint64_t package_size;
+} __packed;
+
+/**
+ * apploader_resp - Common header for all apploader responses
+ * @hdr - header with command value.
+ * @error - error code returned by peer; one of &enum apploader_error values.
+ *
+ * This structure is followed by the response-specific payload, if the command
+ * has one.
+ */
+struct apploader_resp {
+    struct apploader_header hdr;
+    uint32_t error;
+} __packed;
diff --git a/trusty/trusty-base.mk b/trusty/trusty-base.mk
index fd8daa8..12521b0 100644
--- a/trusty/trusty-base.mk
+++ b/trusty/trusty-base.mk
@@ -24,7 +24,8 @@
 
 PRODUCT_PACKAGES += \
 	android.hardware.keymaster@4.0-service.trusty \
-	android.hardware.gatekeeper@1.0-service.trusty
+	android.hardware.gatekeeper@1.0-service.trusty \
+	trusty_apploader
 
 PRODUCT_PROPERTY_OVERRIDES += \
 	ro.hardware.keystore=trusty \