#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <getopt.h>

void usage(void)
{
	printf ("Usage: rawread [-s read size -n loop count -d raw device].\n");
	printf ("-s N, where N is the size of the raw read (def=128K).\n");
	printf ("-n N, where N is the number times to read (def=128).\n");
	printf ("-d N, where N is the raw device number (def=1).\n");
}

int main (int argc, char *argv[])
{
	int rc, i, c, rawdev, numreads;
	int recordsize = 65536*2;
	int loopcount  = 128;
	int device = 1;
	char *p;
	char rawname[] = "/dev/raw/raw1\0\0\0";

	while ((c = getopt(argc, argv, "d:s:n:?")) != -1) {
		switch (c) {
			case 'n': loopcount = atoi(optarg); break;
			case 's': recordsize = atoi(optarg); break;
			case 'd': device = atoi(optarg); break;
			case '?':
			default:  usage(); return(1);
		}
	}

	/* raw io read size must be sector aligned */
	if (recordsize & (512-1)) {
		printf("-s %d parm is not sector size aligned\n", recordsize);
		return(1);
	}

	/* loopcount must be positive */
	if (loopcount < 1) {
		printf("-n %d parm must be > 0\n", loopcount);
		return(1);
	}

	/* check if default raw device overridden */
	if (device != 1) {
		if (device < 1 || device > 256) {
			printf("-d %d parm must be > 0 and < 257\n", device);
			return(1);
		}
		sprintf(&rawname[12], "%d", device);
	}

	if ((p = (char*)malloc(recordsize+512)) == NULL) {
		perror("malloc of read buffer");
		return(0);
	}

	/* raw io read buffer must be sector aligned */
	p += (512-1);
	p = (char*) ((unsigned long)p & ~(512-1));

	/* touch each page, do not want page faults for test */
	for (i = 0; i < (recordsize >> 9) ; i++) {
		char * pp = p;
		*pp = 1;
		pp += 512;
	}

	rawdev = open(rawname,O_RDONLY);
	if (rawdev != -1) {

		numreads = loopcount; 

		/* loop and read from raw device */
		while (loopcount) {
			rc = read(rawdev, p, recordsize);
			if (rc == -1) {
				perror("raw read failed");
				return(1);
			}
			loopcount--;
		};
		printf("%d reads of %d bytes from %s (%d) OK\n", numreads, recordsize, rawname, numreads*recordsize);
	} else {
		printf("%s\n", rawname);
		perror("fopen failed on raw device");
		return(1);
	}
	return(0);
}