2 * This file is part of vbig.
3 * Copyright (C) 2011 Richard Kettlewell
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
32 // Command line options
33 const struct option opts[] = {
34 { "seed", required_argument, 0, 's' },
35 { "both", no_argument, 0, 'b' },
36 { "verify", no_argument, 0, 'v' },
37 { "create", no_argument, 0, 'c' },
38 { "flush", no_argument, 0, 'f' },
39 { "entire", no_argument, 0, 'e' },
40 { "help", no_argument, 0, 'h' },
41 { "version", no_argument, 0, 'V' },
45 // Display help message
46 static void help(void) {
47 printf("vbig - create or verify a large but pseudo-random file\n"
50 " vbig [--seed SEED] --verify|--create PATH [SIZE]\n"
53 " --seed, -s Specify random seed\n"
54 " --verify, -v Verify that PATH contains the expected contents\n"
55 " --create, -c Create PATH with psuedo-random contents\n"
56 " --flush, -f Flush cache\n"
57 " --entire, -e Write until full; read until EOF\n"
58 " --help, -h Display usage message\n"
59 " --version, -V Display version string\n");
62 // Possible modes of operation
69 // Report an error and exit
70 static void fatal(int errno_value, const char *fmt, ...) {
72 fprintf(stderr, "ERROR: ");
74 vfprintf(stderr, fmt, ap);
77 fprintf(stderr, ": %s", strerror(errno_value));
82 // Evict whatever FP points to from RAM
83 static void flushCache(FILE *fp) {
84 // drop_caches only evicts clean pages, so first the target file is
86 if(fsync(fileno(fp)) < 0)
87 fatal(errno, "fsync");
88 #if defined DROP_CACHE_FILE
90 if((fd = open(DROP_CACHE_FILE, O_WRONLY, 0)) < 0)
91 fatal(errno, "%s", DROP_CACHE_FILE);
92 if(write(fd, "3\n", 2) < 0)
93 fatal(errno, "%s", DROP_CACHE_FILE);
95 #elif defined PURGE_COMMAND
97 if((rc = system(PURGE_COMMAND)) < 0)
98 fatal(errno, "executing %s", PURGE_COMMAND);
100 if(WIFSIGNALED(rc)) {
101 fprintf(stderr, "%s%s\n",
102 strsignal(WTERMSIG(rc)),
103 WCOREDUMP(rc) ? " (core dumped)" : "");
104 exit(WTERMSIG(rc) + 128);
106 exit(WEXITSTATUS(rc));
111 static long long execute(mode_type mode, bool entire, const char *show);
113 static const char default_seed[] = "hexapodia as the key insight";
114 static const void *seed;
115 static size_t seedlen;
116 static const char *path;
117 static bool entireopt = false;
118 static bool flush = false;
119 static long long size;
121 int main(int argc, char **argv) {
122 mode_type mode = BOTH;
124 while((n = getopt_long(argc, argv, "+s:vcefhV", opts, 0)) >= 0) {
126 case 's': seed = optarg; seedlen = strlen(optarg); break;
127 case 'b': mode = BOTH; break;
128 case 'v': mode = VERIFY; break;
129 case 'c': mode = CREATE; break;
130 case 'e': entireopt = true; break;
131 case 'f': flush = true; break;
132 case 'h': help(); exit(0);
133 case 'V': puts(VERSION); exit(0);
135 fatal(0, "unknown option");
141 fatal(0, "excess arguments");
142 if(argc == 1 && mode == BOTH)
146 fatal(0, "with --entire, size should not be specified");
148 if(argc < (mode == VERIFY ? 1 : 2))
149 fatal(0, "insufficient arguments");
153 seedlen = sizeof(default_seed)-1;
159 size = strtoll(argv[1], &end, 10);
161 fatal(errno, "invalid size");
163 fatal(0, "invalid size");
164 if(!strcmp(end, "K"))
166 else if(!strcmp(end, "M"))
168 else if(!strcmp(end, "G"))
169 size *= 1024 * 1024 * 1024;
171 fatal(0, "invalid size");
172 } else if(entireopt) {
173 size = LONG_LONG_MAX;
176 if(stat(path, &sb) < 0)
177 fatal(errno, "stat %s", path);
180 const char *show = entireopt ? (mode == CREATE ? "written" : "verified") : 0;
182 size = execute(CREATE, entireopt, 0);
183 execute(VERIFY, false, show);
185 execute(mode, entireopt, show);
190 static long long execute(mode_type mode, bool entire, const char *show) {
191 Arcfour rng((const char*)seed, seedlen);
192 FILE *fp = fopen(path, mode == VERIFY ? "rb" : "wb");
194 fatal(errno, "%s", path);
195 if(mode == VERIFY && flush)
197 if(mode == CREATE && entire)
198 setvbuf(fp, 0, _IONBF, 0);
199 char generated[4096], input[4096];
200 long long remain = size;
201 static const size_t rc4drop = 3072; // en.wikipedia.org/wiki/RC4#Security
202 assert(rc4drop <= sizeof(generated));
203 rng.stream(generated, rc4drop);
205 size_t bytesGenerated = (remain > (ssize_t)sizeof generated
208 rng.stream(generated, bytesGenerated);
210 size_t bytesWritten = fwrite(generated, 1, bytesGenerated, fp);
212 if(!entire || errno != ENOSPC)
213 fatal(errno, "%s", path);
214 remain -= bytesWritten;
217 assert(bytesWritten == bytesGenerated);
219 size_t bytesRead = fread(input, 1, bytesGenerated, fp);
221 fatal(errno, "%s", path);
222 if(memcmp(generated, input, bytesRead)) {
223 for(size_t n = 0; n < bytesRead; ++n)
224 if(generated[n] != input[n])
225 fatal(0, "%s corrupted at %lld/%lld bytes (expected %d got %d)",
226 path, size - remain + n, size,
227 (unsigned char)generated[n], (unsigned char)input[n]);
229 if(bytesRead < bytesGenerated) {
235 fatal(0, "%s: truncated at %lld/%lld bytes",
236 path, (size - remain + bytesRead), size);
239 remain -= bytesGenerated;
241 if(mode == VERIFY && !entire && getc(fp) != EOF)
242 fatal(0, "%s: extended beyond %lld bytes",
244 if(mode == CREATE && flush) {
246 fatal(errno, "%s", path);
250 fatal(errno, "%s", path);
251 long long done = size - remain;
253 printf("%lld bytes (%lldM, %lldG) %s\n",
254 done, done >> 20, done >> 30,
256 if(ferror(stdout) || fflush(stdout))
257 fatal(errno, "flush stdout");