pinephone-keyboard/usb-flasher/common.c

206 lines
4.1 KiB
C
Raw Normal View History

2021-06-17 14:50:06 +02:00
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <time.h>
#include <sys/poll.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <sys/types.h>
#include <dirent.h>
#include <getopt.h>
#include <linux/usbdevice_fs.h>
static bool verbose;
#define debug(args...) { if (verbose) printf(args); }
static void syscall_error(int is_err, const char* fmt, ...)
{
va_list ap;
if (!is_err)
return;
fprintf(stderr, "ERROR: ");
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, ": %s\n", strerror(errno));
exit(1);
}
static void error(const char* fmt, ...)
{
va_list ap;
fprintf(stderr, "ERROR: ");
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, "\n");
exit(1);
}
static bool read_file(const char* path, char* buf, size_t size)
{
int fd;
ssize_t ret;
fd = open(path, O_RDONLY);
if (fd < 0)
return false;
ret = read(fd, buf, size);
close(fd);
if (ret < 0)
return false;
if (ret < size) {
buf[ret] = 0;
return true;
} else {
buf[size - 1] = 0;
return false;
}
}
static int open_usb_dev(uint16_t vid, uint16_t pid)
{
char path[256], buf[256];
struct dirent *e;
unsigned e_vid, e_pid, bus, dev;
int fd = -1, ret;
DIR* d;
d = opendir("/sys/bus/usb/devices");
syscall_error(d == NULL, "opendir(/sys/bus/usb/devices) failed");
while (true) {
errno = 0;
e = readdir(d);
syscall_error(e == NULL && errno, "readdir(/sys/bus/usb/devices) failed");
if (!e)
break;
if (!strcmp(e->d_name, ".") || !strcmp(e->d_name, ".."))
continue;
snprintf(path, sizeof path,
"/sys/bus/usb/devices/%s/idVendor", e->d_name);
if (!read_file(path, buf, sizeof buf))
continue;
ret = sscanf(buf, "%x", &e_vid);
if (ret != 1)
error("Failed to parse %s", path);
snprintf(path, sizeof path,
"/sys/bus/usb/devices/%s/idProduct", e->d_name);
if (!read_file(path, buf, sizeof buf))
continue;
ret = sscanf(buf, "%x", &e_pid);
if (ret != 1)
error("Failed to parse %s", path);
if (e_vid == vid && e_pid == pid) {
snprintf(path, sizeof path,
"/sys/bus/usb/devices/%s/busnum", e->d_name);
if (!read_file(path, buf, sizeof buf))
error("Failed to read %s", path);
ret = sscanf(buf, "%u", &bus);
if (ret != 1)
error("Failed to parse %s", path);
snprintf(path, sizeof path,
"/sys/bus/usb/devices/%s/devnum", e->d_name);
if (!read_file(path, buf, sizeof buf))
error("Failed to read %s", path);
ret = sscanf(buf, "%u", &dev);
if (ret != 1)
error("Failed to parse %s", path);
snprintf(path, sizeof path,
"/dev/bus/usb/%03u/%03u", bus, dev);
debug("Found %04x:%04x at %s\n", e_vid, e_pid, path);
fd = open(path, O_RDWR);
syscall_error(fd < 0, "open(%s) failed", path);
break;
}
}
errno = ENOENT;
closedir(d);
return fd;
}
static int handle_urb(int usb_fd, struct usbdevfs_urb* urb, int timeout)
{
int ret;
struct usbdevfs_urb* reaped_urb;
int retries = 0;
retry:
ret = ioctl(usb_fd, USBDEVFS_SUBMITURB, urb);
if (ret < 0)
return ret;
struct pollfd fd = {
.fd = usb_fd,
.events = POLLOUT,
};
ret = poll(&fd, 1, timeout);
if (ret <= 0) {
if (ret == 0)
errno = ETIMEDOUT;
int save_errno = errno;
// on timeout or other poll error, we need to discard and reap the submitted URB
ret = ioctl(usb_fd, USBDEVFS_DISCARDURB, urb);
// even if discard fails, URB may still be reapable, we need to try reaping anyway
ret = ioctl(usb_fd, USBDEVFS_REAPURBNDELAY, &reaped_urb);
// reap must immediately succeed, otherwise this is fatal
syscall_error(ret < 0, "USBDEVFS_REAPURBNDELAY failed");
errno = save_errno;
return -1;
}
// hopefully POLLERR means we get some error immediately on reap
ret = ioctl(usb_fd, USBDEVFS_REAPURB, &reaped_urb);
if (ret < 0)
return ret;
// EPROTO errors are recoverable
if (urb->status == -71 && retries < 3) {
retries++;
goto retry;
}
if (urb->status != 0) {
errno = -urb->status;
return -1;
}
return 0;
}