X-Git-Url: https://git.wh0rd.org/?a=blobdiff_plain;f=ddnuke.c;h=8e0abdbaaa5c371e1aab3a15eb0e41a738351310;hb=96e9a04aba0ce70ffa67d0afa2c80430c61dead9;hp=774830e82eb18efa852ed3636ddb01818079d0d0;hpb=e5e72e456dd1418b083e3feed94356231851f046;p=home.git

diff --git a/ddnuke.c b/ddnuke.c
index 774830e..8e0abdb 100644
--- a/ddnuke.c
+++ b/ddnuke.c
@@ -15,17 +15,17 @@
 #include <fcntl.h>
 #include <inttypes.h>
 #include <locale.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sysexits.h>
 #include <time.h>
 #include <unistd.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>
 #include <linux/fs.h>
 
-static const char zero[1024 * 1024];
-
 #define errp(msg, args...) \
 	do { \
 		printf("%s: " msg ": %m\n", program_invocation_short_name, ## args); \
@@ -66,29 +66,12 @@ static off_t get_size(int fd)
 	errp("unknown type of file");
 }
 
-int main(int argc, char *argv[])
+static void nuke(int fd, off_t offset, off_t max_size, unsigned char pattern)
 {
-	off_t offset = 0;
-	const char *file;
-
-	setlocale(LC_NUMERIC, "en_US");
-
-	switch (argc) {
-	case 3:
-		offset = atoll(argv[2]);
-	case 2:
-		file = argv[1];
-		break;
-	default:
-		puts("Usage: ddnuke <dev> [offset in bytes]");
-		return 1;
-	}
-
-	int fd = open(file, O_WRONLY);
-	if (fd == -1)
-		errp("open(%s) failed", file);
-
-	off_t max_size = get_size(fd);
+	static char mem[1024 * 1024];
+	memset(mem, pattern, sizeof(mem));
+	if (pattern)
+		printf("Writing 0x%X to the output\n", pattern);
 
 	if (lseek(fd, offset, SEEK_SET) != offset)
 		errp("lseek(%"PRIu64"u) failed", offset);
@@ -102,18 +85,20 @@ int main(int argc, char *argv[])
 	ssize_t ret;
 	int fsync_pos = 0;
 	while (pos < max_size) {
-		ret = write(fd, zero, sizeof(zero));
+		/* This will round up to sizeof(mem) ... */
+		ret = write(fd, mem, sizeof(mem));
 		pos += ret;
-		if (ret != sizeof(zero)) {
-			printf("\ngot back %zi (wanted %zu)\n%'llu MB/s over entire run\n",
-				ret, sizeof(zero), mbps(&itime, &etime, pos));
-			return 0;
+		if (ret != sizeof(mem)) {
+			if (pos != max_size)
+				printf("\nread() returned %zi (wanted %zu)\n%'llu MB/s over entire run\n",
+					ret, sizeof(mem), mbps(&itime, &etime, pos));
+			return;
 		}
 
 		printf("%'llu bytes %u%% (%'llu MB/s)%20s\r", (unsigned long long)pos,
 			(unsigned)((pos * 100) / max_size), speed, "");
 
-		if ((++fsync_pos % 16) == 0) {
+		if ((++fsync_pos % 32) == 0) {
 			speed = mbps(&stime, &etime, pos - last_pos);
 			last_pos = pos;
 			fflush(stdout);
@@ -122,5 +107,57 @@ int main(int argc, char *argv[])
 	}
 
 	printf("\n");
-	return 0;
+}
+
+static void usage(int status)
+{
+	fprintf(
+		status ? stderr : stdout,
+		"Usage: ddnuke [options] <dev>\n"
+		"\n"
+		"Options:\n"
+		" -o <offset>   Position to start writing\n"
+		" -r            Write three times: 0x00, then 0xaa, then 0x55\n"
+	);
+	exit(status);
+}
+
+int main(int argc, char *argv[])
+{
+	off_t offset = 0;
+	const char *file;
+	bool random = false;
+	int o;
+
+	setlocale(LC_NUMERIC, "en_US");
+
+	while ((o = getopt(argc, argv, "ho:r")) != -1) {
+		switch (o) {
+		case 'o':
+			offset = atoll(optarg);
+			break;
+		case 'r':
+			random = true;
+			break;
+		case 'h': usage(EX_OK);
+		default:  usage(EX_USAGE);
+		}
+	}
+	if (argc != optind + 1)
+		usage(EX_USAGE);
+	file = argv[optind];
+
+	int fd = open(file, O_WRONLY|O_CLOEXEC);
+	if (fd == -1)
+		errp("open(%s) failed", file);
+
+	off_t max_size = get_size(fd);
+
+	nuke(fd, offset, max_size, 0x00);
+	if (random) {
+		nuke(fd, offset, max_size, 0xaa);
+		nuke(fd, offset, max_size, 0x55);
+	}
+
+	return EX_OK;
 }