1 /*
2 * Copyright (c) 2019 Intel Corporation
3 * Copyright (c) 2022 Martin Jäger <martin@libre.solar>
4 *
5 * SPDX-License-Identifier: Apache-2.0
6 */
7
8 /**
9 * @file
10 *
11 * Routines setting up the host system. Those are placed in separate file
12 * because there is naming conflicts between host and zephyr network stacks.
13 */
14
15 #include <stdio.h>
16 #include <stdlib.h>
17 #include <stdarg.h>
18 #include <errno.h>
19 #include <string.h>
20 #include <stdbool.h>
21
22 /* Linux host include files. */
23 #ifdef __linux
24 #include <unistd.h>
25 #include <fcntl.h>
26 #include <sys/ioctl.h>
27 #include <sys/socket.h>
28 #include <sys/select.h>
29 #include <net/if.h>
30 #include <linux/can.h>
31 #include <linux/can/raw.h>
32 #else
33 #error "This driver can only be built on Linux systems"
34 #endif
35
36 #include "can_native_posix_linux_socketcan.h"
37
38 #ifndef CANFD_FDF
39 /* Linux kernels before v5.14 do not define CANFD_FDF */
40 #define CANFD_FDF 0x04
41 #endif /* CANFD_FDF */
42
linux_socketcan_iface_open(const char * if_name)43 int linux_socketcan_iface_open(const char *if_name)
44 {
45 struct sockaddr_can addr;
46 struct ifreq ifr;
47 int fd, opt, ret = -EINVAL;
48
49 fd = socket(PF_CAN, SOCK_RAW, CAN_RAW);
50 if (fd < 0) {
51 return -errno;
52 }
53
54 (void)memset(&ifr, 0, sizeof(ifr));
55 (void)memset(&addr, 0, sizeof(addr));
56
57 strncpy(ifr.ifr_name, if_name, IFNAMSIZ);
58
59 ret = ioctl(fd, SIOCGIFINDEX, (void *)&ifr);
60 if (ret < 0) {
61 close(fd);
62 return -errno;
63 }
64
65 addr.can_ifindex = ifr.ifr_ifindex;
66 addr.can_family = PF_CAN;
67
68 ret = bind(fd, (struct sockaddr *)&addr, sizeof(addr));
69 if (ret < 0) {
70 close(fd);
71 return -errno;
72 }
73
74 /* this option must always be enabled in order to receive TX confirmations */
75 opt = 1;
76 ret = setsockopt(fd, SOL_CAN_RAW, CAN_RAW_RECV_OWN_MSGS, &opt, sizeof(opt));
77 if (ret < 0) {
78 close(fd);
79 return -errno;
80 }
81
82 return fd;
83 }
84
linux_socketcan_iface_close(int fd)85 int linux_socketcan_iface_close(int fd)
86 {
87 return close(fd);
88 }
89
linux_socketcan_poll_data(int fd)90 int linux_socketcan_poll_data(int fd)
91 {
92 struct timeval timeout;
93 fd_set rset;
94 int ret;
95
96 FD_ZERO(&rset);
97
98 FD_SET(fd, &rset);
99
100 timeout.tv_sec = 0;
101 timeout.tv_usec = 0;
102
103 ret = select(fd + 1, &rset, NULL, NULL, &timeout);
104 if (ret < 0 && errno != EINTR) {
105 return -errno;
106 } else if (ret > 0) {
107 if (FD_ISSET(fd, &rset)) {
108 return 0;
109 }
110 }
111
112 return -EAGAIN;
113 }
114
linux_socketcan_read_data(int fd,void * buf,size_t buf_len,bool * msg_confirm)115 ssize_t linux_socketcan_read_data(int fd, void *buf, size_t buf_len, bool *msg_confirm)
116 {
117 struct canfd_frame *frame = (struct canfd_frame *)buf;
118 struct msghdr msg = {0};
119
120 struct iovec iov = {
121 .iov_base = buf,
122 .iov_len = buf_len,
123 };
124 msg.msg_iov = &iov;
125 msg.msg_iovlen = 1;
126
127 int ret = recvmsg(fd, &msg, MSG_WAITALL);
128
129 if (msg_confirm != NULL) {
130 *msg_confirm = (msg.msg_flags & MSG_CONFIRM) != 0;
131 }
132
133 /* Make sure to set the flags for all frames received via the Linux API.
134 *
135 * Zephyr relies on defined flags field of the SocketCAN data for both FD and classical CAN
136 * frames. In Linux the flags field is undefined for legacy frames.
137 */
138 if (ret == CANFD_MTU) {
139 frame->flags |= CANFD_FDF;
140 } else if (ret == CAN_MTU) {
141 frame->flags = 0;
142 }
143
144 return ret;
145 }
146
linux_socketcan_write_data(int fd,void * buf,size_t buf_len)147 ssize_t linux_socketcan_write_data(int fd, void *buf, size_t buf_len)
148 {
149 return write(fd, buf, buf_len);
150 }
151
linux_socketcan_setsockopt(int fd,int level,int optname,const void * optval,socklen_t optlen)152 int linux_socketcan_setsockopt(int fd, int level, int optname,
153 const void *optval, socklen_t optlen)
154 {
155 return setsockopt(fd, level, optname, optval, optlen);
156 }
157
linux_socketcan_getsockopt(int fd,int level,int optname,void * optval,socklen_t * optlen)158 int linux_socketcan_getsockopt(int fd, int level, int optname,
159 void *optval, socklen_t *optlen)
160 {
161 return getsockopt(fd, level, optname, optval, optlen);
162 }
163
linux_socketcan_set_mode_fd(int fd,bool mode_fd)164 int linux_socketcan_set_mode_fd(int fd, bool mode_fd)
165 {
166 int opt = mode_fd ? 1 : 0;
167
168 return setsockopt(fd, SOL_CAN_RAW, CAN_RAW_FD_FRAMES, &opt, sizeof(opt));
169 }
170
