1/*- 2 * Copyright (C) 1996 3 * David L. Nugent. 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 DAVID L. NUGENT 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 DAVID L. NUGENT 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#ifndef lint 28static const char rcsid[] = 29 "$FreeBSD$"; 30#endif /* not lint */ 31 32#include <stdio.h> 33#include <fcntl.h> 34#include <stdlib.h> 35#include <string.h> 36#include <sys/types.h> 37#include <sys/stat.h> 38#include <sys/param.h> 39#include <errno.h> 40#include <unistd.h> 41 42#include "pwupd.h" 43 44int 45extendline(char **buf, int * buflen, int needed) 46{ 47 if (needed > *buflen) { 48 char *tmp = realloc(*buf, needed); 49 if (tmp == NULL) 50 return -1; 51 *buf = tmp; 52 *buflen = needed; 53 } 54 return *buflen; 55} 56 57int 58extendarray(char ***buf, int * buflen, int needed) 59{ 60 if (needed > *buflen) { 61 char **tmp = realloc(*buf, needed * sizeof(char *)); 62 if (tmp == NULL) 63 return -1; 64 *buf = tmp; 65 *buflen = needed; 66 } 67 return *buflen; 68} 69 70 71int 72fileupdate(char const * filename, mode_t fmode, char const * newline, char const * prefix, int pfxlen, int updmode) 73{ 74 int rc = 0; 75 76 if (pfxlen <= 1) 77 rc = EINVAL; 78 else { 79 int infd = open(filename, O_RDWR | O_CREAT | O_EXLOCK, fmode); 80 81 if (infd == -1) 82 rc = errno; 83 else { 84 FILE *infp = fdopen(infd, "r+"); 85 86 if (infp == NULL) { 87 rc = errno; /* Assumes fopen(3) sets errno from open(2) */ 88 close(infd); 89 } else { 90 int outfd; 91 char file[MAXPATHLEN]; 92 93 strcpy(file, filename); 94 strcat(file, ".new"); 95 outfd = open(file, O_RDWR | O_CREAT | O_TRUNC, fmode); 96 if (outfd == -1) 97 rc = errno; 98 else { 99 FILE *outfp = fdopen(outfd, "w+"); 100 101 if (outfp == NULL) { 102 rc = errno; 103 close(outfd); 104 } else { 105 int updated = UPD_CREATE; 106 int linesize = PWBUFSZ; 107 char *line = malloc(linesize); 108 109 nextline: 110 while (fgets(line, linesize, infp) != NULL) { 111 char *p = strchr(line, '\n'); 112 113 while ((p = strchr(line, '\n')) == NULL) { 114 int l; 115 if (extendline(&line, &linesize, linesize + PWBUFSZ) == -1) { 116 int ch; 117 fputs(line, outfp); 118 while ((ch = fgetc(infp)) != EOF) { 119 fputc(ch, outfp); 120 if (ch == '\n') 121 break; 122 } 123 goto nextline; 124 } 125 l = strlen(line); 126 if (fgets(line + l, linesize - l, infp) == NULL) 127 break; 128 } 129 if (*line != '#' && *line != '\n') { 130 if (!updated && strncmp(line, prefix, pfxlen) == 0) { 131 updated = updmode == UPD_REPLACE ? UPD_REPLACE : UPD_DELETE; 132 133 /* 134 * Only actually write changes if updating 135 */ 136 if (updmode == UPD_REPLACE) 137 strcpy(line, newline); 138 else if (updmode == UPD_DELETE) 139 continue; 140 } 141 } 142 fputs(line, outfp); 143 } 144 145 /* 146 * Now, we need to decide what to do: If we are in 147 * update mode, and no record was updated, then error If 148 * we are in insert mode, and record already exists, 149 * then error 150 */ 151 if (updmode != updated) 152 /* -1 return means: 153 * update,delete=no user entry 154 * create=entry exists 155 */ 156 rc = -1; 157 else { 158 159 /* 160 * If adding a new record, append it to the end 161 */ 162 if (updmode == UPD_CREATE) 163 fputs(newline, outfp); 164 165 /* 166 * Flush the file and check for the result 167 */ 168 if (fflush(outfp) == EOF) 169 rc = errno; /* Failed to update */ 170 else { 171 /* 172 * Copy data back into the 173 * original file and truncate 174 */ 175 rewind(infp); 176 rewind(outfp); 177 while (fgets(line, linesize, outfp) != NULL) 178 fputs(line, infp); 179 180 /* 181 * If there was a problem with copying 182 * we will just rename 'file.new' 183 * to 'file'. 184 * This is a gross hack, but we may have 185 * corrupted the original file 186 */ 187 if (fflush(infp) == EOF || ferror(infp)) 188 rename(file, filename); 189 else 190 ftruncate(infd, ftell(infp)); 191 } 192 } 193 free(line); 194 fclose(outfp); 195 } 196 remove(file); 197 } 198 fclose(infp); 199 } 200 } 201 } 202 return rc; 203} 204