118 lines
2.9 KiB
C
118 lines
2.9 KiB
C
#include "dev_hidraw.h"
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#define MAX_PATH_LEN 512
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static const char *const hidraw_path = "/dev/";
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static bool hidraw_matches(
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const hidraw_filters_t *const in_filters,
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dev_hidraw_t *const in_dev
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) {
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if (in_dev->info.product != in_filters->pid) {
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return false;
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} else if (in_dev->info.vendor != in_filters->vid) {
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return false;
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} else if (in_dev->rdesc.size != in_filters->rdesc_size) {
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return false;
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}
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return true;
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}
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static int dev_hidraw_new_from_fd(int fd, dev_hidraw_t **const out_dev) {
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int res = -EINVAL;
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*out_dev = malloc(sizeof(dev_hidraw_t));
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if (out_dev == NULL) {
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fprintf(stderr, "Cannot allocate memory for hidraw device\n");
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res = -ENOMEM;
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goto dev_hidraw_new_from_fd_err;
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}
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(*out_dev)->fd = fd;
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memset(&(*out_dev)->info, 0, sizeof(struct hidraw_devinfo));
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memset(&(*out_dev)->rdesc, 0, sizeof(struct hidraw_report_descriptor));
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res = ioctl((*out_dev)->fd, HIDIOCGRAWINFO, &(*out_dev)->info);
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if (res < 0) {
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fprintf(stderr, "Error getting device info: %d\n", errno);
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goto dev_hidraw_new_from_fd_err;
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}
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res = ioctl(fd, HIDIOCGRDESC, &(*out_dev)->rdesc);
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if (res < 0) {
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perror("Error getting Report Descriptor");
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goto dev_hidraw_new_from_fd_err;
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}
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dev_hidraw_new_from_fd_err:
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if (res < 0) {
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free(*out_dev);
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*out_dev = NULL;
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}
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return res;
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}
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int dev_hidraw_open(
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const hidraw_filters_t *const in_filters,
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dev_hidraw_t **const out_dev
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) {
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int res = -ENOENT;
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char path[MAX_PATH_LEN] = "\0";
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DIR *d;
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struct dirent *dir;
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d = opendir(hidraw_path);
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if (d) {
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while ((dir = readdir(d)) != NULL) {
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if (strstr(dir->d_name, "hidraw") == NULL) {
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continue;
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}
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snprintf(path, MAX_PATH_LEN - 1, "%s%s", hidraw_path, dir->d_name);
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//printf("Testing for device %s\n", path);
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// try to open the device, if it cannot be opened to go the next
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int fd = open(path, O_RDWR);
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if (fd < 0) {
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//fprintf(stderr, "Cannot open %s, device skipped.\n", path);
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continue;
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}
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const int hidraw_open_res = dev_hidraw_new_from_fd(fd, out_dev);
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if (hidraw_open_res != 0) {
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close(fd);
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continue;
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}
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if (!hidraw_matches(in_filters, *out_dev)) {
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dev_hidraw_close(*out_dev);
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continue;
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}
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// the device has been found
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res = 0;
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break;
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}
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closedir(d);
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}
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dev_hidraw_open_err:
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return res;
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}
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void dev_hidraw_close(dev_hidraw_t *const inout_dev) {
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close(inout_dev->fd);
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free(inout_dev);
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}
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int dev_hidraw_get_fd(const dev_hidraw_t* in_dev) {
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if (in_dev == NULL) {
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return -EINVAL;
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}
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return in_dev->fd;
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}
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