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authorUros Majstorovic <majstor@majstor.org>2021-08-27 02:01:29 +0200
committerUros Majstorovic <majstor@majstor.org>2021-08-27 02:01:29 +0200
commit6c4998209307cd84982bf056fafa3a3135667bb2 (patch)
tree3801722505109db67f8e99ffff153ed070465d9a /recipes-bsp/esp32spid/src/tun.c
parent33dec797ef8d0d556723bba7c2bd46c4b59f5bea (diff)
added esp32 spi daemon
Diffstat (limited to 'recipes-bsp/esp32spid/src/tun.c')
-rw-r--r--recipes-bsp/esp32spid/src/tun.c94
1 files changed, 94 insertions, 0 deletions
diff --git a/recipes-bsp/esp32spid/src/tun.c b/recipes-bsp/esp32spid/src/tun.c
new file mode 100644
index 0000000..d75edc4
--- /dev/null
+++ b/recipes-bsp/esp32spid/src/tun.c
@@ -0,0 +1,94 @@
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+
+#include <linux/if.h>
+#include <linux/if_tun.h>
+
+#include <pthread.h>
+
+#include "spi.h"
+#include "tun.h"
+
+static pthread_t read_thd;
+
+static int tun_fd;
+static char tun_name[IFNAMSIZ];
+
+static int tun_alloc(char *dev, int flags) {
+ struct ifreq ifr;
+ int fd, err;
+ char *clonedev = "/dev/net/tun";
+
+ /* Arguments taken by the function:
+ *
+ * char *dev: the name of an interface (or '\0'). MUST have enough
+ * space to hold the interface name if '\0' is passed
+ * int flags: interface flags (eg, IFF_TUN etc.)
+ */
+
+ fd = open(clonedev, O_RDWR);
+ if (fd < 0) {
+ return fd;
+ }
+
+ memset(&ifr, 0, sizeof(ifr));
+ ifr.ifr_flags = flags; /* IFF_TUN or IFF_TAP, plus maybe IFF_NO_PI */
+
+ if (*dev) {
+ /* if a device name was specified, put it in the structure; otherwise,
+ * the kernel will try to allocate the "next" device of the
+ * specified type */
+ strncpy(ifr.ifr_name, dev, IFNAMSIZ);
+ }
+
+ /* try to create the device */
+ err = ioctl(fd, TUNSETIFF, (void *) &ifr);
+ if (err < 0) {
+ close(fd);
+ return err;
+ }
+
+ /* if the operation was successful, write back the name of the
+ * interface to the variable "dev", so the caller can know
+ * it. Note that the caller MUST reserve space in *dev (see calling
+ * code below) */
+ strcpy(dev, ifr.ifr_name);
+
+ /* this is the special file descriptor that the caller will use to talk
+ * with the virtual interface */
+ return fd;
+}
+
+void *tun_read(void *arg) {
+ unsigned char *buffer;
+ int len;
+
+ while (1) {
+ buffer = spi_alloc();
+ if (buffer == NULL) continue;
+ len = read(tun_fd, buffer + SPI_SIZE_HDR, SPI_SIZE_BUF - SPI_SIZE_HDR);
+ if (len < 0) {
+ perror("tun read");
+ continue;
+ }
+ spi_xchg(SPI_MTYPE_TUN, buffer, len);
+ }
+}
+
+int tun_write(unsigned char *buffer, uint16_t len) {
+ return write(tun_fd, buffer, len);
+}
+
+int tun_init(void) {
+ int rv;
+
+ strcpy(tun_name, "tun0");
+ tun_fd = tun_alloc(tun_name, IFF_TUN | IFF_NO_PI);
+ if (tun_fd < 0) return TUN_ERR;
+
+ return TUN_OK;
+}