1 /*
2 * Copyright (C) 2020 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_TAG "spiproxyd"
18
19 #include <assert.h>
20 #include <fcntl.h>
21 #include <getopt.h>
22 #include <log/log.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <trusty/tipc.h>
26 #include <unistd.h>
27
handle_msg(int trusty_dev_fd,int spi_dev_fd)28 int handle_msg(int trusty_dev_fd, int spi_dev_fd) {
29 int rc;
30 uint8_t msg_buf[4096];
31 size_t msg_len;
32
33 /* read request from SPI Trusty app */
34 rc = read(trusty_dev_fd, &msg_buf, sizeof(msg_buf));
35 if (rc < 0) {
36 ALOGE("failed (%d) to read request from TA\n", rc);
37 return rc;
38 }
39 msg_len = rc;
40
41 /* forward request to SPI host device */
42 rc = write(spi_dev_fd, &msg_buf, msg_len);
43 if (rc < 0 || (size_t)rc != msg_len) {
44 ALOGE("failed (%d) to forward request to host\n", rc);
45 return rc < 0 ? rc : -1;
46 }
47
48 /* read response from SPI host device */
49 rc = read(spi_dev_fd, &msg_buf, sizeof(msg_buf));
50 if (rc < 0) {
51 ALOGE("failed (%d) to read response from host\n", rc);
52 return rc;
53 }
54 msg_len = rc;
55
56 /* forward response to SPI Trusty app */
57 rc = write(trusty_dev_fd, &msg_buf, msg_len);
58 if (rc < 0 || (size_t)rc != msg_len) {
59 ALOGE("failed (%d) to forward response to TA\n", rc);
60 return rc < 0 ? rc : -1;
61 }
62
63 return 0;
64 }
65
event_loop(int trusty_dev_fd,int spi_dev_fd)66 int event_loop(int trusty_dev_fd, int spi_dev_fd) {
67 while (true) {
68 int rc = handle_msg(trusty_dev_fd, spi_dev_fd);
69 if (rc < 0) {
70 ALOGE("exiting event loop\n");
71 return EXIT_FAILURE;
72 }
73 }
74 }
75
show_usage()76 static void show_usage() {
77 ALOGE("usage: spiproxyd -t TRUSTY_DEVICE -s SPI_DEVICE -p SPI_PROXY_PORT\n");
78 }
79
parse_args(int argc,char * argv[],const char ** trusty_dev_name,const char ** spi_dev_name,const char ** spi_proxy_port)80 static void parse_args(int argc, char* argv[], const char** trusty_dev_name,
81 const char** spi_dev_name, const char** spi_proxy_port) {
82 int opt;
83 while ((opt = getopt(argc, argv, "ht:s:p:")) != -1) {
84 switch (opt) {
85 case 'h':
86 show_usage();
87 exit(EXIT_SUCCESS);
88 break;
89 case 't':
90 *trusty_dev_name = strdup(optarg);
91 break;
92 case 's':
93 *spi_dev_name = strdup(optarg);
94 break;
95 case 'p':
96 *spi_proxy_port = strdup(optarg);
97 break;
98 default:
99 show_usage();
100 exit(EXIT_FAILURE);
101 break;
102 }
103 }
104
105 if (!*trusty_dev_name || !*spi_dev_name || !*spi_proxy_port) {
106 show_usage();
107 exit(EXIT_FAILURE);
108 }
109 }
110
main(int argc,char * argv[])111 int main(int argc, char* argv[]) {
112 int rc;
113 const char* trusty_dev_name = NULL;
114 const char* spi_dev_name = NULL;
115 const char* spi_proxy_port = NULL;
116 int trusty_dev_fd;
117 int spi_dev_fd;
118
119 parse_args(argc, argv, &trusty_dev_name, &spi_dev_name, &spi_proxy_port);
120
121 rc = tipc_connect(trusty_dev_name, spi_proxy_port);
122 if (rc < 0) {
123 ALOGE("failed (%d) to connect to SPI proxy port\n", rc);
124 return rc;
125 }
126 trusty_dev_fd = rc;
127
128 rc = open(spi_dev_name, O_RDWR, 0);
129 if (rc < 0) {
130 ALOGE("failed (%d) to open SPI device\n", rc);
131 return rc;
132 }
133 spi_dev_fd = rc;
134
135 return event_loop(trusty_dev_fd, spi_dev_fd);
136 }
137