trusty/storage/proxy/proxy.c - android-core - Git at Google

 /*
  * Copyright (C) 2016 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.
  */
 #include <errno.h>
 #include <getopt.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>
 #include <stdlib.h>
 #include <sys/capability.h>
 #include <sys/prctl.h>
 #include <sys/stat.h>
 #include <unistd.h>

 #include <cutils/android_filesystem_config.h>

 #include "ipc.h"
 #include "log.h"
 #include "rpmb.h"
 #include "storage.h"

 #define REQ_BUFFER_SIZE 4096
 static uint8_t req_buffer[REQ_BUFFER_SIZE + 1];

 static const char *ss_data_root;
 static const char *trusty_devname;
 static const char *rpmb_devname;
 static const char *ss_srv_name = STORAGE_DISK_PROXY_PORT;

 static const char *_sopts = "hp:d:r:";
 static const struct option _lopts[] =  {
     {"help",       no_argument,       NULL, 'h'},
     {"trusty_dev", required_argument, NULL, 'd'},
     {"data_path",  required_argument, NULL, 'p'},
     {"rpmb_dev",   required_argument, NULL, 'r'},
     {0, 0, 0, 0}
 };

 static void show_usage_and_exit(int code)
 {
     ALOGE("usage: storageproxyd -d <trusty_dev> -p <data_path> -r <rpmb_dev>\n");
     exit(code);
 }

 static int drop_privs(void)
 {
     struct __user_cap_header_struct capheader;
     struct __user_cap_data_struct capdata[2];

     if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) < 0) {
         return -1;
     }

     /*
      * ensure we're running as the system user
      */
     if (setgid(AID_SYSTEM) != 0) {
         return -1;
     }

     if (setuid(AID_SYSTEM) != 0) {
         return -1;
     }

     /*
      * drop all capabilities except SYS_RAWIO
      */
     memset(&capheader, 0, sizeof(capheader));
     memset(&capdata, 0, sizeof(capdata));
     capheader.version = _LINUX_CAPABILITY_VERSION_3;
     capheader.pid = 0;

     capdata[CAP_TO_INDEX(CAP_SYS_RAWIO)].permitted = CAP_TO_MASK(CAP_SYS_RAWIO);
     capdata[CAP_TO_INDEX(CAP_SYS_RAWIO)].effective = CAP_TO_MASK(CAP_SYS_RAWIO);

     if (capset(&capheader, &capdata[0]) < 0) {
         return -1;
     }

     /* no-execute for user, no access for group and other */
     umask(S_IXUSR | S_IRWXG | S_IRWXO);

     return 0;
 }

 static int handle_req(struct storage_msg *msg, const void *req, size_t req_len)
 {
     int rc;

     if ((msg->flags & STORAGE_MSG_FLAG_POST_COMMIT) &&
         (msg->cmd != STORAGE_RPMB_SEND)) {
         /*
          * handling post commit messages on non rpmb commands are not
          * implemented as there is no use case for this yet.
          */
         ALOGE("cmd 0x%x: post commit option is not implemented\n", msg->cmd);
         msg->result = STORAGE_ERR_UNIMPLEMENTED;
         return ipc_respond(msg, NULL, 0);
     }

     if (msg->flags & STORAGE_MSG_FLAG_PRE_COMMIT) {
         rc = storage_sync_checkpoint();
         if (rc < 0) {
             msg->result = STORAGE_ERR_GENERIC;
             return ipc_respond(msg, NULL, 0);
         }
     }

     switch (msg->cmd) {
     case STORAGE_FILE_DELETE:
         rc = storage_file_delete(msg, req, req_len);
         break;

     case STORAGE_FILE_OPEN:
         rc = storage_file_open(msg, req, req_len);
         break;

     case STORAGE_FILE_CLOSE:
         rc = storage_file_close(msg, req, req_len);
         break;

     case STORAGE_FILE_WRITE:
         rc = storage_file_write(msg, req, req_len);
         break;

     case STORAGE_FILE_READ:
         rc = storage_file_read(msg, req, req_len);
         break;

     case STORAGE_FILE_GET_SIZE:
         rc = storage_file_get_size(msg, req, req_len);
         break;

     case STORAGE_FILE_SET_SIZE:
         rc = storage_file_set_size(msg, req, req_len);
         break;

     case STORAGE_RPMB_SEND:
         rc = rpmb_send(msg, req, req_len);
         break;

     default:
         ALOGE("unhandled command 0x%x\n", msg->cmd);
         msg->result = STORAGE_ERR_UNIMPLEMENTED;
         rc = 1;
     }

     if (rc > 0) {
         /* still need to send response */
         rc = ipc_respond(msg, NULL, 0);
     }
     return rc;
 }

 static int proxy_loop(void)
 {
     ssize_t rc;
     struct storage_msg msg;

     /* enter main message handling loop */
     while (true) {

         /* get incoming message */
         rc = ipc_get_msg(&msg, req_buffer, REQ_BUFFER_SIZE);
         if (rc < 0)
             return rc;

         /* handle request */
         req_buffer[rc] = 0; /* force zero termination */
         rc = handle_req(&msg, req_buffer, rc);
         if (rc)
             return rc;
     }

     return 0;
 }

 static void parse_args(int argc, char *argv[])
 {
     int opt;
     int oidx = 0;

     while ((opt = getopt_long(argc, argv, _sopts, _lopts, &oidx)) != -1) {
         switch (opt) {

         case 'd':
             trusty_devname = strdup(optarg);
             break;

         case 'p':
             ss_data_root = strdup(optarg);
             break;

         case 'r':
             rpmb_devname = strdup(optarg);
             break;

         default:
             ALOGE("unrecognized option (%c):\n", opt);
             show_usage_and_exit(EXIT_FAILURE);
         }
     }

     if (ss_data_root == NULL ||
         trusty_devname == NULL ||
         rpmb_devname == NULL) {
         ALOGE("missing required argument(s)\n");
         show_usage_and_exit(EXIT_FAILURE);
     }

     ALOGI("starting storageproxyd\n");
     ALOGI("storage data root: %s\n", ss_data_root);
     ALOGI("trusty dev: %s\n", trusty_devname);
     ALOGI("rpmb dev: %s\n", rpmb_devname);
 }

 int main(int argc, char *argv[])
 {
     int rc;

     /* drop privileges */
     if (drop_privs() < 0)
         return EXIT_FAILURE;

     /* parse arguments */
     parse_args(argc, argv);

     /* initialize secure storage directory */
     rc = storage_init(ss_data_root);
     if (rc < 0)
         return EXIT_FAILURE;

     /* open rpmb device */
     rc = rpmb_open(rpmb_devname);
     if (rc < 0)
         return EXIT_FAILURE;

     /* connect to Trusty secure storage server */
     rc = ipc_connect(trusty_devname, ss_srv_name);
     if (rc < 0)
         return EXIT_FAILURE;

     /* enter main loop */
     rc = proxy_loop();
     ALOGE("exiting proxy loop with status (%d)\n", rc);

     ipc_disconnect();
     rpmb_close();

     return (rc < 0) ? EXIT_FAILURE : EXIT_SUCCESS;
 }
	/*
	* Copyright (C) 2016 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.
	*/
	#include <errno.h>
	#include <getopt.h>
	#include <stdbool.h>
	#include <stdint.h>
	#include <string.h>
	#include <stdlib.h>
	#include <sys/capability.h>
	#include <sys/prctl.h>
	#include <sys/stat.h>
	#include <unistd.h>

	#include <cutils/android_filesystem_config.h>

	#include "ipc.h"
	#include "log.h"
	#include "rpmb.h"
	#include "storage.h"

	#define REQ_BUFFER_SIZE 4096
	static uint8_t req_buffer[REQ_BUFFER_SIZE + 1];

	static const char *ss_data_root;
	static const char *trusty_devname;
	static const char *rpmb_devname;
	static const char *ss_srv_name = STORAGE_DISK_PROXY_PORT;

	static const char *_sopts = "hp:d:r:";
	static const struct option _lopts[] = {
	{"help", no_argument, NULL, 'h'},
	{"trusty_dev", required_argument, NULL, 'd'},
	{"data_path", required_argument, NULL, 'p'},
	{"rpmb_dev", required_argument, NULL, 'r'},
	{0, 0, 0, 0}
	};

	static void show_usage_and_exit(int code)
	{
	ALOGE("usage: storageproxyd -d <trusty_dev> -p <data_path> -r <rpmb_dev>\n");
	exit(code);
	}

	static int drop_privs(void)
	{
	struct __user_cap_header_struct capheader;
	struct __user_cap_data_struct capdata[2];

	if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) < 0) {
	return -1;
	}

	/*
	* ensure we're running as the system user
	*/
	if (setgid(AID_SYSTEM) != 0) {
	return -1;
	}

	if (setuid(AID_SYSTEM) != 0) {
	return -1;
	}

	/*
	* drop all capabilities except SYS_RAWIO
	*/
	memset(&capheader, 0, sizeof(capheader));
	memset(&capdata, 0, sizeof(capdata));
	capheader.version = _LINUX_CAPABILITY_VERSION_3;
	capheader.pid = 0;

	capdata[CAP_TO_INDEX(CAP_SYS_RAWIO)].permitted = CAP_TO_MASK(CAP_SYS_RAWIO);
	capdata[CAP_TO_INDEX(CAP_SYS_RAWIO)].effective = CAP_TO_MASK(CAP_SYS_RAWIO);

	if (capset(&capheader, &capdata[0]) < 0) {
	return -1;
	}

	/* no-execute for user, no access for group and other */
	umask(S_IXUSR \| S_IRWXG \| S_IRWXO);

	return 0;
	}

	static int handle_req(struct storage_msg msg, const void req, size_t req_len)
	{
	int rc;

	if ((msg->flags & STORAGE_MSG_FLAG_POST_COMMIT) &&
	(msg->cmd != STORAGE_RPMB_SEND)) {
	/*
	* handling post commit messages on non rpmb commands are not
	* implemented as there is no use case for this yet.
	*/
	ALOGE("cmd 0x%x: post commit option is not implemented\n", msg->cmd);
	msg->result = STORAGE_ERR_UNIMPLEMENTED;
	return ipc_respond(msg, NULL, 0);
	}

	if (msg->flags & STORAGE_MSG_FLAG_PRE_COMMIT) {
	rc = storage_sync_checkpoint();
	if (rc < 0) {
	msg->result = STORAGE_ERR_GENERIC;
	return ipc_respond(msg, NULL, 0);
	}
	}

	switch (msg->cmd) {
	case STORAGE_FILE_DELETE:
	rc = storage_file_delete(msg, req, req_len);
	break;

	case STORAGE_FILE_OPEN:
	rc = storage_file_open(msg, req, req_len);
	break;

	case STORAGE_FILE_CLOSE:
	rc = storage_file_close(msg, req, req_len);
	break;

	case STORAGE_FILE_WRITE:
	rc = storage_file_write(msg, req, req_len);
	break;

	case STORAGE_FILE_READ:
	rc = storage_file_read(msg, req, req_len);
	break;

	case STORAGE_FILE_GET_SIZE:
	rc = storage_file_get_size(msg, req, req_len);
	break;

	case STORAGE_FILE_SET_SIZE:
	rc = storage_file_set_size(msg, req, req_len);
	break;

	case STORAGE_RPMB_SEND:
	rc = rpmb_send(msg, req, req_len);
	break;

	default:
	ALOGE("unhandled command 0x%x\n", msg->cmd);
	msg->result = STORAGE_ERR_UNIMPLEMENTED;
	rc = 1;
	}

	if (rc > 0) {
	/* still need to send response */
	rc = ipc_respond(msg, NULL, 0);
	}
	return rc;
	}

	static int proxy_loop(void)
	{
	ssize_t rc;
	struct storage_msg msg;

	/* enter main message handling loop */
	while (true) {

	/* get incoming message */
	rc = ipc_get_msg(&msg, req_buffer, REQ_BUFFER_SIZE);
	if (rc < 0)
	return rc;

	/* handle request */
	req_buffer[rc] = 0; /* force zero termination */
	rc = handle_req(&msg, req_buffer, rc);
	if (rc)
	return rc;
	}

	return 0;
	}

	static void parse_args(int argc, char *argv[])
	{
	int opt;
	int oidx = 0;

	while ((opt = getopt_long(argc, argv, _sopts, _lopts, &oidx)) != -1) {
	switch (opt) {

	case 'd':
	trusty_devname = strdup(optarg);
	break;

	case 'p':
	ss_data_root = strdup(optarg);
	break;

	case 'r':
	rpmb_devname = strdup(optarg);
	break;

	default:
	ALOGE("unrecognized option (%c):\n", opt);
	show_usage_and_exit(EXIT_FAILURE);
	}
	}

	if (ss_data_root == NULL \|\|
	trusty_devname == NULL \|\|
	rpmb_devname == NULL) {
	ALOGE("missing required argument(s)\n");
	show_usage_and_exit(EXIT_FAILURE);
	}

	ALOGI("starting storageproxyd\n");
	ALOGI("storage data root: %s\n", ss_data_root);
	ALOGI("trusty dev: %s\n", trusty_devname);
	ALOGI("rpmb dev: %s\n", rpmb_devname);
	}

	int main(int argc, char *argv[])
	{
	int rc;

	/* drop privileges */
	if (drop_privs() < 0)
	return EXIT_FAILURE;

	/* parse arguments */
	parse_args(argc, argv);

	/* initialize secure storage directory */
	rc = storage_init(ss_data_root);
	if (rc < 0)
	return EXIT_FAILURE;

	/* open rpmb device */
	rc = rpmb_open(rpmb_devname);
	if (rc < 0)
	return EXIT_FAILURE;

	/* connect to Trusty secure storage server */
	rc = ipc_connect(trusty_devname, ss_srv_name);
	if (rc < 0)
	return EXIT_FAILURE;

	/* enter main loop */
	rc = proxy_loop();
	ALOGE("exiting proxy loop with status (%d)\n", rc);

	ipc_disconnect();
	rpmb_close();

	return (rc < 0) ? EXIT_FAILURE : EXIT_SUCCESS;
	}