ddnuke: add random data options

diff --git a/ddnuke.c b/ddnuke.c
index 94691b34d96b8dfa0cef8b74f861fc5d8093809c..03ac78958fdac7daa83bd1645c172b9dc2ffbc53 100644 (file)
--- 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); \
@@ -66,32 +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);
-
-       if (lseek(fd, offset, SEEK_SET) != offset)
-               errp("lseek(%"PRIu64"u) failed", offset);
+       static char mem[1024 * 1024];
+       memset(mem, pattern, sizeof(mem));
+       if (pattern)
+               printf("Writing 0x%X to the output\n", pattern);
 
        unsigned long long speed = 0;
        struct timespec stime, etime, itime;
@@ -102,12 +82,13 @@ 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)) {
+               if (ret != sizeof(mem)) {
                        printf("\nread() returned %zi (wanted %zu)\n%'llu MB/s over entire run\n",
-                               ret, sizeof(zero), mbps(&itime, &etime, pos));
-                       return 0;
+                               ret, sizeof(mem), mbps(&itime, &etime, pos));
+                       return;
                }
 
                printf("%'llu bytes %u%% (%'llu MB/s)%20s\r", (unsigned long long)pos,
@@ -122,5 +103,60 @@ 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:"
+               " -o <offset>   Position to start writing\n"
+               " -r            Write random garbage to the device\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);
+
+       if (lseek(fd, offset, SEEK_SET) != offset)
+               errp("lseek(%"PRIu64"u) failed", offset);
+
+       nuke(fd, offset, max_size, 0x00);
+       if (random) {
+               nuke(fd, offset, max_size, 0xaa);
+               nuke(fd, offset, max_size, 0x55);
+       }
+
+       return EX_OK;
 }