ozerocdoff.c

udev是一种工具

		        fprintf(outlog, "Found attached driver: %s\n", buffer);
		}
	        ret = usb_detach_kernel_driver_np(usb_hd, 0);
		if (ret != 0) {
		        if(!quiet) fprintf(errlog, "ERROR: unsuccessful kernel driver detaching\n");
			(void)usb_close(usb_hd);
			exit(5);
		}
	} else {
	        /* hopefully no default kernel driver yet running, send only a warning */
	        if(!quiet) fprintf(errlog, "WARNING: No kernel driver attached found\n");
	}
	ret = usb_claim_interface(usb_hd, 0);
	if (ret != 0) {
		if(!quiet) fprintf(errlog, "ERROR: could not claim interface\n");
		(void)usb_close(usb_hd);
		exit(6);
	}
	  

	/* findout the Message and Response Endpoint */	
        int MessageEndpoint=search_message_endp(usb_dev);
	int ResponseEndpoint=search_response_endp(usb_dev);
	if (MessageEndpoint == 0) {
		if(!quiet) fprintf(errlog, "ERROR: could not detremine Endpoint addresses\n");
		(void)usb_close(usb_hd);
		exit(6);
	}
	if (debug) {
	        fprintf(outlog,"MessageEndpoint:  0x%x\n", MessageEndpoint);
		fprintf(outlog,"ResponseEndpoint:  0x%x \n", ResponseEndpoint);
	}


	/* preparation to send rezero string */
       	(void)usb_clear_halt(usb_hd, MessageEndpoint); //ResponseEndpoint
        ret = usb_set_altinterface(usb_hd, 0);
	if (ret != 0) {
	        if (warno) {
		        if(!quiet) fprintf(errlog, "WARNING: unsuccessful set alternative interface\n");
		} else {
		        if(!quiet) fprintf(errlog, "ERROR: unsuccessful set alternative interface\n");
			(void)usb_release_interface(usb_hd, 0);
			(void)usb_close(usb_hd);
		        exit(7);
		}
	}


	/* usb mass storage setting time (needed by some WWAN modems) */
	sleep(1);

	if (!test) {
	        /* send rezero string */
	        ret = usb_bulk_write(usb_hd, MessageEndpoint, (char *)MessageContent, sizeof(MessageContent), 1000);
	        if (ret < 0) {
	                if (warno) {
			        if(!quiet) fprintf(errlog, "WARNING: unsuccessful write rezero string\n");
			} else {
			        if(!quiet) fprintf(errlog, "ERROR: unsuccessful write rezero string\n");
				(void)usb_release_interface(usb_hd, 0);
				(void)usb_close(usb_hd);
				exit(8);
			}
		} else {
		        if (debug) fprintf(outlog, "Have successfully send ZERO-CD disabling command\n");
		}
		/* needed by some WWAN modems) */
		if (ResponseEndpoint != 0) {
		        ret = usb_bulk_read(usb_hd, ResponseEndpoint, buffer, BUFFER_SIZE, 1000);
			if (ret < 0 ) {
			        if(!quiet) fprintf(errlog, "WARNING: unsuccessful read response message\n");
			}
		}
	}


	/* close device */
	ret = usb_close(usb_hd);
	if (ret < 0) {
	        if (warno) {
		        if(!quiet) fprintf(errlog, "WARNING: closeing failed\n");
		} else {
		        if(!quiet) fprintf(errlog, "ERROR: closeing failed\n");
			(void)usb_release_interface(usb_hd, 0);
			exit(9);
		}
	}	


	/* search again to check result. Note that still the search is needed by some WWAN modems! */
	for (count = 5; (count>0) && (usb_dev != NULL); count--) {
       	        sleep(1);
		(void)usb_find_devices();
		usb_dev = search_devices(TARGET_VENDOR, TargetProduct, "");
	}
	if (usb_dev != NULL) {
	        if (warno) {
		        if(!quiet) fprintf(errlog, "WARNING: Zero-CD device still found\n");
		} else {
		        if(!quiet) fprintf(errlog, "ERROR: Zero-CD device still found\n");
			(void)usb_release_interface(usb_hd, 0);
			exit(10);
		}
	} else {
	        if (debug) fprintf(outlog, "Checked successfully ZERO-CD disabled\n");
		else if(!quiet) fprintf(outlog, "Successfully ZERO-CD disabled\n");
	}



	/* relese device */
	(void)usb_release_interface(usb_hd, 0);
	return 0;
}


/**
 * release_usb_device
 * need for the signal handler to ensure proper usb port close and release
 *
 * input param : just a dumy paramter
 * return      : nothting
 */
void release_usb_device(int param) {
	(void)usb_release_interface(usb_hd, 0);
	(void)usb_close(usb_hd);
}


/**
 * strrcut
 * string help function, which cuts the string and returns the 
 * right boundary last 'n' characters from the given string 's' or
 * an empty string, if the given string length is shorter than 'n'
 *
 * input s  : const string
 * input n  : number of charaacters, which should be left on the 
 *            right side of the given string
 * return   : the result (shorten) strinf or empty string
 */
const char *strrcut(const char *s, int n) {
        if (strlen(s)>=n) {
	        return &(s[strlen(s)-n]);
	} else {
	        return "";
	}
}

/**
 * strrcmp
 * string help function, which is used to compare just the right
 * part of the given two strings. All other part is just cut away or
 * not be used for the comparision
 *
 * input s1 : const 1st string
 * input s2 : const 2nd string
 * return   : the strcmp return value of the shorted given strings
 */
int strrcmp(const char *s1, const char *s2) {
      if (strlen(s1)<=strlen(s2)) {
	      return strcmp(s1,strrcut(s2,strlen(s1)));
      } else {
	      return strcmp(strrcut(s1,strlen(s2)),s2);
      }
}


/** search_devices
 * search function of the vendor and device id. Optional the name can 
 * be used to compare the right part of found string of the usblib.
 *
 * input vendor  : USB vendor id
 * input product : USB product id
 * input name    : optional right part of the searched filename or just an empty string
 * return        : the found usb device structure, which matches the search
 */
struct usb_device* search_devices(int vendor, int product, const char * name) {
        struct usb_bus *bus;
    
	for (bus = usb_get_busses(); bus; bus = bus->next) {
		struct usb_device *dev;
		for (dev = bus->devices; dev; dev = dev->next) {
		        if (dev->descriptor.idVendor == vendor && dev->descriptor.idProduct == product) {
			        /* check number of Endpoints, class, subclass and protocol */
			        if (debug) {
				        fprintf(outlog, "Endpoints: %d  (2)\n", dev->config[0].interface[0].altsetting[0].bNumEndpoints);
					fprintf(outlog, "Class:     0x%x  (0x08)\n", dev->config[0].interface[0].altsetting[0].bInterfaceClass);
					fprintf(outlog, "SubClass:  0x%x  (0x06)\n", dev->config[0].interface[0].altsetting[0].bInterfaceSubClass);
					fprintf(outlog, "Protocol:  0x%x  (0x50)\n", dev->config[0].interface[0].altsetting[0].bInterfaceProtocol);
				}
				if (   (dev->config[0].interface[0].altsetting[0].bNumEndpoints == 2)
				    && (dev->config[0].interface[0].altsetting[0].bInterfaceClass == 0x08)
				    && (dev->config[0].interface[0].altsetting[0].bInterfaceSubClass == 0x06)
				    && (dev->config[0].interface[0].altsetting[0].bInterfaceProtocol == 0x50) ) {
				        if (debug) {
					        fprintf(outlog, "Found file name: '%s'\n", dev->filename);
						fprintf(outlog, "Required last chars of file name: '%s'\n", name);
					}
					if (strrcmp(name, dev->filename) == 0) {
					        if (debug) fprintf(outlog, "UMS interface found\n");
						return dev;
					} else {
					        if (debug) fprintf(outlog, "UMS interface found, but its wrong\n");
					}
				}
			}
		}
	}
	return NULL;
}

/**
 * search_message_endp
 * looks inside the USB descriptor stuff for the needed endpoint address. 
 * It searches explicit for an bulk output interface and returns the address
 * or even zero
 *
 * input dev : usb device structure
 * return    : endpoint address of 0, if it is no bulk output endpoint
 */
int search_message_endp(struct usb_device *dev) {
        if (  ((dev->config[0].interface[0].altsetting[0].endpoint[0].bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK)
	    &&((dev->config[0].interface[0].altsetting[0].endpoint[0].bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT)) {
	        return dev->config[0].interface[0].altsetting[0].endpoint[0].bEndpointAddress; 
	} else 
	        if (  ((dev->config[0].interface[0].altsetting[0].endpoint[1].bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK)
	            &&((dev->config[0].interface[0].altsetting[0].endpoint[1].bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT)) {
	                return dev->config[0].interface[0].altsetting[0].endpoint[1].bEndpointAddress;
	}
	return 0;
}

/**
 * search_response_endp
 * looks inside the USB descriptor stuff for the needed endpoint address. 
 * It searches explicit for an bulk input interface and returns the address
 * or even zero
 *
 * input dev : usb device structure
 * return    : endpoint address of 0, if it is no bulk input endpoint
 */
int search_response_endp(struct usb_device *dev) {
        if (  ((dev->config[0].interface[0].altsetting[0].endpoint[0].bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK)
	    &&((dev->config[0].interface[0].altsetting[0].endpoint[0].bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN)) {
	        return dev->config[0].interface[0].altsetting[0].endpoint[0].bEndpointAddress; 
	} else 
	        if (  ((dev->config[0].interface[0].altsetting[0].endpoint[1].bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK)
	            &&((dev->config[0].interface[0].altsetting[0].endpoint[1].bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN)) {
	                return dev->config[0].interface[0].altsetting[0].endpoint[1].bEndpointAddress;
	}
	return 0;
}