#include <getopt.h>
#include <unistd.h>
#include <fcntl.h>
+#include <limits.h>
+#include <assert.h>
+#include <sys/stat.h>
#include "Arcfour.h"
+#define DEFAULT_SEED_LENGTH 2048;
+
// Command line options
const struct option opts[] = {
{ "seed", required_argument, 0, 's' },
+ { "seed-file", required_argument, 0, 'S' },
+ { "seed-length", required_argument, 0, 'L' },
+ { "both", no_argument, 0, 'b' },
{ "verify", no_argument, 0, 'v' },
{ "create", no_argument, 0, 'c' },
{ "flush", no_argument, 0, 'f' },
+ { "entire", no_argument, 0, 'e' },
{ "help", no_argument, 0, 'h' },
{ "version", no_argument, 0, 'V' },
{ 0, 0, 0, 0 },
printf("vbig - create or verify a large but pseudo-random file\n"
"\n"
"Usage:\n"
- " vbig [--seed SEED] --verify|--create PATH SIZE\n"
+ " vbig [--seed SEED] --verify|--create PATH [SIZE]\n"
"\n"
"Options:\n"
- " --seed, -s Specify random seed\n"
- " --verify, -v Verify that PATH contains the expected contents\n"
- " --create, -c Create PATH with psuedo-random contents\n"
- " --flush, -f Flush cache\n"
- " --help, -h Display usage message\n"
- " --version, -V Display version string\n");
+ " --seed, -s Specify random seed as string\n"
+ " --seed-file, -S Read random seed from (start of) this file\n"
+ " --seed-length, -L Set (maximum) seed length to read from file\n"
+ " --verify, -v Verify that PATH contains the expected contents\n"
+ " --create, -c Create PATH with psuedo-random contents\n"
+ " --flush, -f Flush cache\n"
+ " --entire, -e Write until full; read until EOF\n"
+ " --help, -h Display usage message\n"
+ " --version, -V Display version string\n");
}
// Possible modes of operation
enum mode_type {
- NONE,
VERIFY,
- CREATE
+ CREATE,
+ BOTH
};
// Report an error and exit
#endif
}
+static long long execute(mode_type mode, bool entire, const char *show);
+
+static const char default_seed[] = "hexapodia as the key insight";
+static void *seed;
+static size_t seedlen;
+static const char *seedpath;
+static const char *path;
+static bool entireopt = false;
+static bool flush = false;
+static long long size;
+
int main(int argc, char **argv) {
- const char *seed = "hexapodia as the key insight";
- mode_type mode = NONE;
- bool flush = false;
+ mode_type mode = BOTH;
int n;
- while((n = getopt_long(argc, argv, "+s:vcfhV", opts, 0)) >= 0) {
+ char *ep;
+ while((n = getopt_long(argc, argv, "+s:S:L:vcefhV", opts, 0)) >= 0) {
switch(n) {
- case 's': seed = optarg; break;
+ case 's': seed = optarg; seedlen = strlen(optarg); break;
+ case 'S': seedpath = optarg; break;
+ case 'L':
+ seedlen = strtoul(optarg,&ep,0);
+ if(ep==optarg || *ep) fatal(0, "bad number for -S");
+ break;
+ case 'b': mode = BOTH; break;
case 'v': mode = VERIFY; break;
case 'c': mode = CREATE; break;
+ case 'e': entireopt = true; break;
case 'f': flush = true; break;
case 'h': help(); exit(0);
case 'V': puts(VERSION); exit(0);
}
argc -= optind;
argv += optind;
- if(mode == NONE) {
- fatal(0, "must specify one of --verify or --create");
- exit(1);
+ if(argc > 2)
+ fatal(0, "excess arguments");
+ if(argc == 1 && mode == BOTH)
+ entireopt = true;
+ if(entireopt) {
+ if(argc != 1)
+ fatal(0, "with --entire, size should not be specified");
+ } else {
+ if(argc < (mode == VERIFY ? 1 : 2))
+ fatal(0, "insufficient arguments");
+ }
+ if(seed && seedpath)
+ fatal(0, "both --seed and --seed-file specified");
+ if(mode == BOTH && !seed && !seedpath) {
+#ifdef HAVE_RANDOM_DEVICE
+ seedpath = RANDOM_DEVICE;
+#else
+ fatal(0, "no --seed or --seed-file specified in --both mode"
+ " and random device not supported on this system");
+#endif
+ }
+ if(seedpath) {
+ if(!seedlen)
+ seedlen = DEFAULT_SEED_LENGTH;
+ FILE *seedfile = fopen(seedpath, "rb");
+ if(!seedfile)
+ fatal(errno, "%s", seedpath);
+ seed = malloc(seedlen);
+ if(!seed)
+ fatal(errno, "allocate seed");
+ seedlen = fread(seed, 1, seedlen, seedfile);
+ if(ferror(seedfile))
+ fatal(errno, "read %s", seedpath);
+ fclose(seedfile);
}
- if(argc != 2) {
- fatal(0, "must specify a path and size");
- exit(1);
+ if (!seed) {
+ seed = (void*)default_seed;
+ seedlen = sizeof(default_seed)-1;
}
- const char *path = argv[0];
- errno = 0;
- char *end;
- long long size = strtoll(argv[1], &end, 10);
- if(errno) {
- fatal(errno, "invalid size");
- exit(1);
+ path = argv[0];
+ if(argc > 1) {
+ errno = 0;
+ char *end;
+ size = strtoll(argv[1], &end, 10);
+ if(errno)
+ fatal(errno, "invalid size");
+ if(end == argv[1])
+ fatal(0, "invalid size");
+ if(!strcmp(end, "K"))
+ size *= 1024;
+ else if(!strcmp(end, "M"))
+ size *= 1024 * 1024;
+ else if(!strcmp(end, "G"))
+ size *= 1024 * 1024 * 1024;
+ else if(*end)
+ fatal(0, "invalid size");
+ } else if(entireopt) {
+ size = LONG_LONG_MAX;
+ } else {
+ struct stat sb;
+ if(stat(path, &sb) < 0)
+ fatal(errno, "stat %s", path);
+ size = sb.st_size;
}
- if(end == argv[1]) {
- fatal(0, "invalid size");
- exit(1);
+ const char *show = entireopt ? (mode == CREATE ? "written" : "verified") : 0;
+ if(mode == BOTH) {
+ size = execute(CREATE, entireopt, 0);
+ execute(VERIFY, false, show);
+ } else {
+ execute(mode, entireopt, show);
}
- if(!strcmp(end, "K"))
- size *= 1024;
- else if(!strcmp(end, "M"))
- size *= 1024 * 1024;
- else if(!strcmp(end, "G"))
- size *= 1024 * 1024 * 1024;
- else if(*end) {
- fatal(0, "invalid size");
- exit(1);
- }
- Arcfour rng(seed, strlen(seed));
+ return 0;
+}
+
+static long long execute(mode_type mode, bool entire, const char *show) {
+ Arcfour rng((const char*)seed, seedlen);
FILE *fp = fopen(path, mode == VERIFY ? "rb" : "wb");
- if(!fp) {
+ if(!fp)
fatal(errno, "%s", path);
- exit(1);
- }
if(mode == VERIFY && flush)
flushCache(fp);
+ if(mode == CREATE && entire)
+ setvbuf(fp, 0, _IONBF, 0);
char generated[4096], input[4096];
long long remain = size;
+ static const size_t rc4drop = 3072; // en.wikipedia.org/wiki/RC4#Security
+ assert(rc4drop <= sizeof(generated));
+ rng.stream(generated, rc4drop);
while(remain > 0) {
size_t bytesGenerated = (remain > (ssize_t)sizeof generated
? sizeof generated
: remain);
rng.stream(generated, bytesGenerated);
if(mode == CREATE) {
- fwrite(generated, 1, bytesGenerated, fp);
+ size_t bytesWritten = fwrite(generated, 1, bytesGenerated, fp);
if(ferror(fp)) {
- fatal(errno, "%s", path);
- exit(1);
+ if(!entire || errno != ENOSPC)
+ fatal(errno, "%s", path);
+ remain -= bytesWritten;
+ break;
}
+ assert(bytesWritten == bytesGenerated);
} else {
size_t bytesRead = fread(input, 1, bytesGenerated, fp);
- if(ferror(fp)) {
+ if(ferror(fp))
fatal(errno, "%s", path);
- exit(1);
+ if(memcmp(generated, input, bytesRead)) {
+ for(size_t n = 0; n < bytesRead; ++n)
+ if(generated[n] != input[n])
+ fatal(0, "%s corrupted at %lld/%lld bytes (expected %d got %d)",
+ path, size - remain + n, size,
+ (unsigned char)generated[n], (unsigned char)input[n]);
}
if(bytesRead < bytesGenerated) {
+ if(entire) {
+ assert(feof(fp));
+ remain -= bytesRead;
+ break;
+ }
fatal(0, "%s: truncated at %lld/%lld bytes",
path, (size - remain + bytesRead), size);
- exit(1);
- }
- if(memcmp(generated, input, bytesGenerated)) {
- for(size_t n = 0; n < bytesGenerated; ++n)
- if(generated[n] != input[n]){
- fatal(0, "%s corrupted at %lld/%lld bytes (expected %d got %d)",
- path, size - remain + n, size,
- (unsigned char)generated[n], (unsigned char)input[n]);
- exit(1);
- }
}
}
remain -= bytesGenerated;
}
- if(mode == VERIFY && getc(fp) != EOF) {
+ if(mode == VERIFY && !entire && getc(fp) != EOF)
fatal(0, "%s: extended beyond %lld bytes",
path, size);
- exit(1);
- }
if(mode == CREATE && flush) {
if(fflush(fp) < 0)
fatal(errno, "%s", path);
flushCache(fp);
}
- if(fclose(fp) < 0) {
+ if(fclose(fp) < 0)
fatal(errno, "%s", path);
- exit(1);
+ long long done = size - remain;
+ if(show) {
+ printf("%lld bytes (%lldM, %lldG) %s\n",
+ done, done >> 20, done >> 30,
+ show);
+ if(ferror(stdout) || fflush(stdout))
+ fatal(errno, "flush stdout");
}
- return 0;
+ return done;
}