fileupd.c revision 30259
120253Sjoerg/*- 220302Sjoerg * Copyright (C) 1996 320302Sjoerg * David L. Nugent. All rights reserved. 420253Sjoerg * 520253Sjoerg * Redistribution and use in source and binary forms, with or without 620253Sjoerg * modification, are permitted provided that the following conditions 720253Sjoerg * are met: 820253Sjoerg * 1. Redistributions of source code must retain the above copyright 920302Sjoerg * notice, this list of conditions and the following disclaimer. 1020253Sjoerg * 2. Redistributions in binary form must reproduce the above copyright 1120253Sjoerg * notice, this list of conditions and the following disclaimer in the 1220253Sjoerg * documentation and/or other materials provided with the distribution. 1320253Sjoerg * 1420302Sjoerg * THIS SOFTWARE IS PROVIDED BY DAVID L. NUGENT AND CONTRIBUTORS ``AS IS'' AND 1520253Sjoerg * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1620253Sjoerg * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1720302Sjoerg * ARE DISCLAIMED. IN NO EVENT SHALL DAVID L. NUGENT OR CONTRIBUTORS BE LIABLE 1820253Sjoerg * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1920253Sjoerg * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2020253Sjoerg * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2120253Sjoerg * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2220253Sjoerg * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2320253Sjoerg * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2420253Sjoerg * SUCH DAMAGE. 2520253Sjoerg */ 2620253Sjoerg 2730259Scharnier#ifndef lint 2830259Scharnierstatic const char rcsid[] = 2930259Scharnier "$Id$"; 3030259Scharnier#endif /* not lint */ 3130259Scharnier 3220253Sjoerg#include <stdio.h> 3320253Sjoerg#include <fcntl.h> 3420253Sjoerg#include <stdlib.h> 3520253Sjoerg#include <string.h> 3620253Sjoerg#include <sys/types.h> 3720253Sjoerg#include <sys/stat.h> 3820253Sjoerg#include <sys/param.h> 3920253Sjoerg#include <errno.h> 4020253Sjoerg#include <unistd.h> 4120253Sjoerg 4220253Sjoerg#include "pwupd.h" 4320253Sjoerg 4420253Sjoergint 4520747Sdavidnextendline(char **buf, int * buflen, int needed) 4620747Sdavidn{ 4720747Sdavidn if (needed > *buflen) { 4820747Sdavidn char *tmp = realloc(*buf, needed); 4920747Sdavidn if (tmp == NULL) 5020747Sdavidn return -1; 5120747Sdavidn *buf = tmp; 5220747Sdavidn *buflen = needed; 5320747Sdavidn } 5420747Sdavidn return *buflen; 5520747Sdavidn} 5620747Sdavidn 5720747Sdavidnint 5820747Sdavidnextendarray(char ***buf, int * buflen, int needed) 5920747Sdavidn{ 6020747Sdavidn if (needed > *buflen) { 6120747Sdavidn char **tmp = realloc(*buf, needed * sizeof(char *)); 6220747Sdavidn if (tmp == NULL) 6320747Sdavidn return -1; 6420747Sdavidn *buf = tmp; 6520747Sdavidn *buflen = needed; 6620747Sdavidn } 6720747Sdavidn return *buflen; 6820747Sdavidn} 6920747Sdavidn 7020747Sdavidn 7120747Sdavidnint 7220253Sjoergfileupdate(char const * filename, mode_t fmode, char const * newline, char const * prefix, int pfxlen, int updmode) 7320253Sjoerg{ 7420253Sjoerg int rc = 0; 7520253Sjoerg 7620253Sjoerg if (pfxlen <= 1) 7720253Sjoerg errno = EINVAL; 7820253Sjoerg else { 7920253Sjoerg int infd = open(filename, O_RDWR | O_CREAT | O_EXLOCK, fmode); 8020253Sjoerg 8120253Sjoerg if (infd != -1) { 8220253Sjoerg FILE *infp = fdopen(infd, "r+"); 8320253Sjoerg 8420253Sjoerg if (infp == NULL) 8520253Sjoerg close(infd); 8620253Sjoerg else { 8720253Sjoerg int outfd; 8820253Sjoerg char file[MAXPATHLEN]; 8920253Sjoerg 9020253Sjoerg strcpy(file, filename); 9120253Sjoerg strcat(file, ".new"); 9220253Sjoerg outfd = open(file, O_RDWR | O_CREAT | O_TRUNC | O_EXLOCK, fmode); 9320253Sjoerg if (outfd != -1) { 9420253Sjoerg FILE *outfp = fdopen(outfd, "w+"); 9520253Sjoerg 9620253Sjoerg if (outfp == NULL) 9720253Sjoerg close(outfd); 9820253Sjoerg else { 9920253Sjoerg int updated = UPD_CREATE; 10020747Sdavidn int linesize = PWBUFSZ; 10120747Sdavidn char *line = malloc(linesize); 10220253Sjoerg 10320747Sdavidn nextline: 10420747Sdavidn while (fgets(line, linesize, infp) != NULL) { 10520253Sjoerg char *p = strchr(line, '\n'); 10620253Sjoerg 10720747Sdavidn while ((p = strchr(line, '\n')) == NULL) { 10820747Sdavidn int l; 10920747Sdavidn if (extendline(&line, &linesize, linesize + PWBUFSZ) == -1) { 11020747Sdavidn int ch; 11120747Sdavidn fputs(line, outfp); 11220747Sdavidn while ((ch = fgetc(infp)) != EOF) { 11320747Sdavidn fputc(ch, outfp); 11420747Sdavidn if (ch == '\n') 11520747Sdavidn break; 11620747Sdavidn } 11720747Sdavidn goto nextline; 11820253Sjoerg } 11920747Sdavidn l = strlen(line); 12020747Sdavidn if (fgets(line + l, linesize - l, infp) == NULL) 12120747Sdavidn break; 12220253Sjoerg } 12320253Sjoerg if (*line != '#' && *line != '\n') { 12420253Sjoerg if (!updated && strncmp(line, prefix, pfxlen) == 0) { 12520253Sjoerg updated = updmode == UPD_REPLACE ? UPD_REPLACE : UPD_DELETE; 12620253Sjoerg 12720253Sjoerg /* 12820253Sjoerg * Only actually write changes if updating 12920253Sjoerg */ 13020253Sjoerg if (updmode == UPD_REPLACE) 13120253Sjoerg strcpy(line, newline); 13220253Sjoerg else if (updmode == UPD_DELETE) 13320253Sjoerg continue; 13420253Sjoerg } 13520253Sjoerg } 13620253Sjoerg fputs(line, outfp); 13720253Sjoerg } 13820253Sjoerg 13920253Sjoerg /* 14020253Sjoerg * Now, we need to decide what to do: If we are in 14120253Sjoerg * update mode, and no record was updated, then error If 14220253Sjoerg * we are in insert mode, and record already exists, 14320253Sjoerg * then error 14420253Sjoerg */ 14520253Sjoerg if (updmode != updated) 14620253Sjoerg errno = (updmode == UPD_CREATE) ? EEXIST : ENOENT; 14720253Sjoerg else { 14820253Sjoerg 14920253Sjoerg /* 15020253Sjoerg * If adding a new record, append it to the end 15120253Sjoerg */ 15220253Sjoerg if (updmode == UPD_CREATE) 15320253Sjoerg fputs(newline, outfp); 15420253Sjoerg 15520253Sjoerg /* 15620253Sjoerg * Flush the file and check for the result 15720253Sjoerg */ 15820253Sjoerg rc = fflush(outfp) != EOF; 15920253Sjoerg if (rc) { 16020253Sjoerg 16120253Sjoerg /* 16220253Sjoerg * Copy data back into the 16320253Sjoerg * original file and truncate 16420253Sjoerg */ 16520253Sjoerg rewind(infp); 16620253Sjoerg rewind(outfp); 16720747Sdavidn while (fgets(line, linesize, outfp) != NULL) 16820253Sjoerg fputs(line, infp); 16920253Sjoerg 17020253Sjoerg /* 17120253Sjoerg * This is a gross hack, but we may have 17220253Sjoerg * corrupted the original file 17320253Sjoerg * Unfortunately, it will lose the inode. 17420253Sjoerg */ 17520253Sjoerg if (fflush(infp) == EOF || ferror(infp)) 17620253Sjoerg rc = rename(file, filename) == 0; 17720253Sjoerg else 17820253Sjoerg ftruncate(infd, ftell(infp)); 17920253Sjoerg } 18020253Sjoerg } 18120747Sdavidn free(line); 18220253Sjoerg fclose(outfp); 18320253Sjoerg } 18420253Sjoerg remove(file); 18520253Sjoerg } 18620253Sjoerg fclose(infp); 18720253Sjoerg } 18820253Sjoerg } 18920253Sjoerg } 19020253Sjoerg return rc; 19120253Sjoerg} 192