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 <stdint.h> 38 #include <stdio.h> 39 #include <string.h> 40 #include <unistd.h> 41 42 #include "randomize_fd.h" 43 44 static struct rand_node *rand_root; 45 static struct rand_node *rand_tail; 46 47 static struct rand_node * 48 rand_node_allocate(void) 49 { 50 struct rand_node *n; 51 52 n = (struct rand_node *)malloc(sizeof(struct rand_node)); 53 if (n == NULL) 54 err(1, "malloc"); 55 56 n->len = 0; 57 n->cp = NULL; 58 n->next = NULL; 59 return(n); 60 } 61 62 static void 63 rand_node_free(struct rand_node *n) 64 { 65 if (n != NULL) { 66 if (n->cp != NULL) 67 free(n->cp); 68 69 free(n); 70 } 71 } 72 73 static void 74 rand_node_free_rec(struct rand_node *n) 75 { 76 if (n != NULL) { 77 if (n->next != NULL) 78 rand_node_free_rec(n->next); 79 80 rand_node_free(n); 81 } 82 } 83 84 static void 85 rand_node_append(struct rand_node *n) 86 { 87 if (rand_root == NULL) 88 rand_root = rand_tail = n; 89 else { 90 rand_tail->next = n; 91 rand_tail = n; 92 } 93 } 94 95 int 96 randomize_fd(int fd, int type, int unique, double denom) 97 { 98 u_char *buf; 99 u_int slen; 100 u_long i, j, numnode, selected; 101 struct rand_node *n, *prev; 102 int bufleft, eof, fndstr, ret; 103 size_t bufc, buflen; 104 ssize_t len; 105 106 rand_root = rand_tail = NULL; 107 bufc = i = 0; 108 bufleft = eof = fndstr = numnode = 0; 109 110 if (type == RANDOM_TYPE_UNSET) 111 type = RANDOM_TYPE_LINES; 112 113 buflen = sizeof(u_char) * MAXBSIZE; 114 buf = (u_char *)malloc(buflen); 115 if (buf == NULL) 116 err(1, "malloc"); 117 118 while (!eof) { 119 /* Check to see if we have bits in the buffer */ 120 if (bufleft == 0) { 121 len = read(fd, buf, buflen); 122 if (len == -1) 123 err(1, "read"); 124 else if (len == 0) { 125 eof++; 126 break; 127 } else if ((size_t)len < buflen) 128 buflen = (size_t)len; 129 130 bufleft = (int)len; 131 } 132 133 /* Look for a newline */ 134 for (i = bufc; i <= buflen && bufleft >= 0; i++, bufleft--) { 135 if (i == buflen) { 136 if (fndstr) { 137 if (!eof) { 138 memmove(buf, &buf[bufc], i - bufc); 139 i -= bufc; 140 bufc = 0; 141 len = read(fd, &buf[i], buflen - i); 142 if (len == -1) 143 err(1, "read"); 144 else if (len == 0) { 145 eof++; 146 break; 147 } else if (len < (ssize_t)(buflen - i)) 148 buflen = i + (size_t)len; 149 150 bufleft = (int)len; 151 fndstr = 0; 152 } 153 } else { 154 buflen *= 2; 155 buf = (u_char *)realloc(buf, buflen); 156 if (buf == NULL) 157 err(1, "realloc"); 158 159 if (!eof) { 160 len = read(fd, &buf[i], buflen - i); 161 if (len == -1) 162 err(1, "read"); 163 else if (len == 0) { 164 eof++; 165 break; 166 } else if (len < (ssize_t)(buflen - i)) 167 buflen = i + (size_t)len; 168 169 bufleft = (int)len; 170 } 171 172 } 173 } 174 175 if ((type == RANDOM_TYPE_LINES && buf[i] == '\n') || 176 (type == RANDOM_TYPE_WORDS && isspace(buf[i])) || 177 (eof && i == buflen - 1)) { 178 make_token: 179 if (numnode == UINT32_MAX - 1) { 180 errno = EFBIG; 181 err(1, "too many delimiters"); 182 } 183 numnode++; 184 n = rand_node_allocate(); 185 if (-1 != (int)i) { 186 slen = i - (u_long)bufc; 187 n->len = slen + 2; 188 n->cp = (u_char *)malloc(slen + 2); 189 if (n->cp == NULL) 190 err(1, "malloc"); 191 192 memmove(n->cp, &buf[bufc], slen); 193 n->cp[slen] = buf[i]; 194 n->cp[slen + 1] = '\0'; 195 bufc = i + 1; 196 } 197 rand_node_append(n); 198 fndstr = 1; 199 } 200 } 201 } 202 203 /* Necessary evil to compensate for files that don't end with a newline */ 204 if (bufc != i) { 205 i--; 206 goto make_token; 207 } 208 209 (void)close(fd); 210 211 free(buf); 212 213 for (i = numnode; i > 0; i--) { 214 selected = arc4random_uniform(numnode); 215 216 for (j = 0, prev = n = rand_root; n != NULL; j++, prev = n, n = n->next) { 217 if (j == selected) { 218 if (n->cp == NULL) 219 break; 220 221 if (arc4random_uniform(denom) == 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