1 /* 2 * Copyright (C) 2003 Sean Chittenden <seanc@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/types.h> 31 #include <sys/param.h> 32 33 #include <ctype.h> 34 #include <err.h> 35 #include <errno.h> 36 #include <stdlib.h> 37 #include <stdio.h> 38 #include <string.h> 39 #include <unistd.h> 40 41 #include "randomize_fd.h" 42 43 static struct rand_node *rand_root; 44 static struct rand_node *rand_tail; 45 46 static struct rand_node * 47 rand_node_allocate(void) 48 { 49 struct rand_node *n; 50 51 n = (struct rand_node *)malloc(sizeof(struct rand_node)); 52 if (n == NULL) 53 err(1, "malloc"); 54 55 n->len = 0; 56 n->cp = NULL; 57 n->next = NULL; 58 return(n); 59 } 60 61 static void 62 rand_node_free(struct rand_node *n) 63 { 64 if (n != NULL) { 65 if (n->cp != NULL) 66 free(n->cp); 67 68 free(n); 69 } 70 } 71 72 static void 73 rand_node_free_rec(struct rand_node *n) 74 { 75 if (n != NULL) { 76 if (n->next != NULL) 77 rand_node_free_rec(n->next); 78 79 rand_node_free(n); 80 } 81 } 82 83 static void 84 rand_node_append(struct rand_node *n) 85 { 86 if (rand_root == NULL) 87 rand_root = rand_tail = n; 88 else { 89 rand_tail->next = n; 90 rand_tail = n; 91 } 92 } 93 94 int 95 randomize_fd(int fd, int type, int unique, double denom) 96 { 97 u_char *buf; 98 u_int slen; 99 u_long i, j, numnode, selected; 100 struct rand_node *n, *prev; 101 int bufleft, eof, fndstr, ret; 102 size_t bufc, buflen; 103 ssize_t len; 104 105 rand_root = rand_tail = NULL; 106 bufc = i = 0; 107 bufleft = eof = fndstr = numnode = 0; 108 109 if (type == RANDOM_TYPE_UNSET) 110 type = RANDOM_TYPE_LINES; 111 112 buflen = sizeof(u_char) * MAXBSIZE; 113 buf = (u_char *)malloc(buflen); 114 if (buf == NULL) 115 err(1, "malloc"); 116 117 while (!eof) { 118 /* Check to see if we have bits in the buffer */ 119 if (bufleft == 0) { 120 len = read(fd, buf, buflen); 121 if (len == -1) 122 err(1, "read"); 123 else if (len == 0) { 124 eof++; 125 break; 126 } else if ((size_t)len < buflen) 127 buflen = (size_t)len; 128 129 bufleft = (int)len; 130 } 131 132 /* Look for a newline */ 133 for (i = bufc; i <= buflen && bufleft >= 0; i++, bufleft--) { 134 if (i == buflen) { 135 if (fndstr) { 136 if (!eof) { 137 memmove(buf, &buf[bufc], i - bufc); 138 i -= bufc; 139 bufc = 0; 140 len = read(fd, &buf[i], buflen - i); 141 if (len == -1) 142 err(1, "read"); 143 else if (len == 0) { 144 eof++; 145 break; 146 } else if (len < (ssize_t)(buflen - i)) 147 buflen = i + (size_t)len; 148 149 bufleft = (int)len; 150 fndstr = 0; 151 } 152 } else { 153 buflen *= 2; 154 buf = (u_char *)realloc(buf, buflen); 155 if (buf == NULL) 156 err(1, "realloc"); 157 158 if (!eof) { 159 len = read(fd, &buf[i], buflen - i); 160 if (len == -1) 161 err(1, "read"); 162 else if (len == 0) { 163 eof++; 164 break; 165 } else if (len < (ssize_t)(buflen - i)) 166 buflen = i + (size_t)len; 167 168 bufleft = (int)len; 169 } 170 171 } 172 } 173 174 if ((type == RANDOM_TYPE_LINES && buf[i] == '\n') || 175 (type == RANDOM_TYPE_WORDS && isspace(buf[i])) || 176 (eof && i == buflen - 1)) { 177 make_token: 178 if (numnode == RANDOM_MAX_PLUS1) { 179 errno = EFBIG; 180 err(1, "too many delimiters"); 181 } 182 numnode++; 183 n = rand_node_allocate(); 184 if (-1 != (int)i) { 185 slen = i - (u_long)bufc; 186 n->len = slen + 2; 187 n->cp = (u_char *)malloc(slen + 2); 188 if (n->cp == NULL) 189 err(1, "malloc"); 190 191 memmove(n->cp, &buf[bufc], slen); 192 n->cp[slen] = buf[i]; 193 n->cp[slen + 1] = '\0'; 194 bufc = i + 1; 195 } 196 rand_node_append(n); 197 fndstr = 1; 198 } 199 } 200 } 201 202 /* Necessary evil to compensate for files that don't end with a newline */ 203 if (bufc != i) { 204 i--; 205 goto make_token; 206 } 207 208 (void)close(fd); 209 210 free(buf); 211 212 for (i = numnode; i > 0; i--) { 213 selected = random() % numnode; 214 215 for (j = 0, prev = n = rand_root; n != NULL; j++, prev = n, n = n->next) { 216 if (j == selected) { 217 if (n->cp == NULL) 218 break; 219 220 if ((int)(denom * random() / 221 RANDOM_MAX_PLUS1) == 0) { 222 ret = printf("%.*s", 223 (int)n->len - 1, n->cp); 224 if (ret < 0) 225 err(1, "printf"); 226 } 227 if (unique) { 228 if (n == rand_root) 229 rand_root = n->next; 230 if (n == rand_tail) 231 rand_tail = prev; 232 233 prev->next = n->next; 234 rand_node_free(n); 235 numnode--; 236 } 237 break; 238 } 239 } 240 } 241 242 fflush(stdout); 243 244 if (!unique) 245 rand_node_free_rec(rand_root); 246 247 return(0); 248 } 249