jtag: drivers: provide initial support for usb path filtering

[openocd.git] / src / jtag / drivers / jtag_usb_common.c

diff --git a/src/jtag/drivers/jtag_usb_common.c b/src/jtag/drivers/jtag_usb_common.c
new file mode 100644 (file)
index 0000000..637e6c7
--- /dev/null
+++ b/src/jtag/drivers/jtag_usb_common.c
@@ -0,0 +1,85 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0+
+ * Copyright (c) 2018 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
+ */
+
+#include <helper/log.h>
+
+#include "jtag_usb_common.h"
+
+static char *jtag_usb_location;
+/*
+ * 1 char: bus
+ * 2 * 7 chars: max 7 ports
+ * 1 char: test for overflow
+ * ------
+ * 16 chars
+ */
+#define JTAG_USB_MAX_LOCATION_LENGHT   16
+
+void jtag_usb_set_location(const char *location)
+{
+       if (strnlen(location, JTAG_USB_MAX_LOCATION_LENGHT) ==
+           JTAG_USB_MAX_LOCATION_LENGHT)
+               LOG_WARNING("usb location string is too long!!\n");
+
+       if (jtag_usb_location)
+               free(jtag_usb_location);
+
+       jtag_usb_location = strndup(location, JTAG_USB_MAX_LOCATION_LENGHT);
+}
+
+const char *jtag_usb_get_location(void)
+{
+       return jtag_usb_location;
+}
+
+bool jtag_usb_location_equal(uint8_t dev_bus, uint8_t *port_path,
+                            size_t path_len)
+{
+       size_t path_step, string_lengh;
+       char *ptr, *loc;
+       bool equal = false;
+
+       /* strtok need non const char */
+       loc = strndup(jtag_usb_get_location(), JTAG_USB_MAX_LOCATION_LENGHT);
+       string_lengh = strnlen(loc, JTAG_USB_MAX_LOCATION_LENGHT);
+
+       ptr = strtok(loc, "-");
+       if (ptr == NULL) {
+               LOG_WARNING("no '-' in usb path\n");
+               goto done;
+       }
+
+       string_lengh -= 1;
+       /* check bus mismatch */
+       if (atoi(ptr) != dev_bus)
+               goto done;
+
+       path_step = 0;
+       while (path_step < path_len) {
+               ptr = strtok(NULL, ".");
+
+               /* no more tokens in path */
+               if (ptr == NULL)
+                       break;
+
+               /* path mismatch at some step */
+               if (path_step < path_len && atoi(ptr) != port_path[path_step])
+                       break;
+
+               path_step++;
+               string_lengh -= 2;
+       };
+
+       /* walked the full path, all elements match */
+       if (path_step == path_len && !string_lengh)
+               equal = true;
+       else
+               LOG_WARNING("excluded by device path option: %s\n",
+                           jtag_usb_get_location());
+
+done:
+       free(loc);
+       return equal;
+}