pw/edgroup.c

   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  *      $Id$
  27  */
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <unistd.h>
  33 #include <stdarg.h>
  34 #include <errno.h>
  35 #include <sys/types.h>
  36 #include <sys/stat.h>
  37 #include <pwd.h>
  38 #include <grp.h>
  39 #include <fcntl.h>
  40 #include <sys/param.h>
  41 #include <ctype.h>
  42
  43 #include "pwupd.h"
  44
  45 static int
  46 isingroup(char const * name, char **mem)
  47 {
  48         int             i;
  49
  50         for (i = 0; mem[i] != NULL; i++)
  51                 if (strcmp(name, mem[i]) == 0)
  52                         return i;
  53         return -1;
  54 }
  55
  56 static char     groupfile[] = _PATH_GROUP;
  57 static char     grouptmp[] = _PATH_GROUP ".new";
  58
  59 int
  60 editgroups(char *name, char **groups)
  61 {
  62         int             rc = 0;
  63         int             infd;
  64
  65         if ((infd = open(groupfile, O_RDWR | O_CREAT | O_EXLOCK, 0644)) != -1) {
  66                 FILE           *infp;
  67
  68                 if ((infp = fdopen(infd, "r+")) == NULL)
  69                         close(infd);
  70                 else {
  71                         int             outfd;
  72
  73                         if ((outfd = open(grouptmp, O_RDWR | O_CREAT | O_TRUNC | O_EXLOCK, 0644)) != -1) {
  74                                 FILE           *outfp;
  75
  76                                 if ((outfp = fdopen(outfd, "w+")) == NULL)
  77                                         close(outfd);
  78                                 else {
  79                                         int             linelen = PWBUFSZ;
  80                                         int             outlen =  PWBUFSZ;
  81                                         int             memlen = 200; /* Arbitrary */
  82                                         char           *line = malloc(linelen);
  83                                         char           *outl = malloc(outlen);
  84                                         char          **mems = malloc(memlen * sizeof(char *));
  85                                         int             namlen = strlen(name);
  86
  87                                         if (line == NULL || outl == NULL || mems == NULL) {
  88                                             mem_abort:
  89                                                 rc = 0;
  90                                         } else {
  91                                                 while (fgets(line, linelen, infp) != NULL) {
  92                                                         char           *p;
  93                                                         int             l;
  94
  95                                                         while ((p = strchr(line, '\n')) == NULL)
  96                                                         {
  97                                                                 if (extendline(&line, &linelen, linelen + PWBUFSZ) == -1) {
  98                                                                         goto mem_abort;
  99                                                                 }
 100                                                                 l = strlen(line);
 101                                                                 if (fgets(line + l, linelen - l, infp) == NULL)
 102                                                                         break;  /* No newline terminator on last line */
 103                                                         }
 104                                                         l = strlen(line) + namlen + 1;
 105                                                         if (extendline(&outl, &outlen, l) == -1) {
 106                                                                 goto mem_abort;
 107                                                         }
 108                                                         if (*line == '#')
 109                                                                 strcpy(outl, line);
 110                                                         else if (*line == '\n')
 111                                                                 *outl = '\0';
 112                                                         else {
 113                                                                 int             i,
 114                                                                                 mno = 0;
 115                                                                 char           *cp = line;
 116                                                                 char const     *sep = ":\n";
 117                                                                 struct group    grp;
 118
 119                                                                 memset(&grp, 0, sizeof grp);
 120                                                                 for (i = 0; (p = strsep(&cp, sep)) != NULL; i++) {
 121                                                                         switch (i) {
 122                                                                         case 0: /* Group name */
 123                                                                                 grp.gr_name = p;
 124                                                                                 break;
 125                                                                         case 1: /* Group password */
 126                                                                                 grp.gr_passwd = p;
 127                                                                                 break;
 128                                                                         case 2: /* Group id */
 129                                                                                 grp.gr_gid = atoi(p);
 130                                                                                 break;
 131                                                                         case 3: /* Member list */
 132                                                                                 cp = p;
 133                                                                                 sep = ",\n";
 134                                                                                 break;
 135                                                                         default:        /* Individual members */
 136                                                                                 if (*p) {
 137                                                                                         if (extendarray(&mems, &memlen, mno + 2) == -1) {
 138                                                                                                 goto mem_abort;
 139                                                                                         }
 140                                                                                         mems[mno++] = p;
 141                                                                                 }
 142                                                                                 break;
 143                                                                         }
 144                                                                 }
 145                                                                 if (i < 2)      /* Bail out - insufficient fields */
 146                                                                         continue;
 147
 148                                                                 grp.gr_mem = mems;
 149                                                                 for (i = mno; i < memlen; i++)
 150                                                                         mems[i] = NULL;
 151
 152                                                                 /*
 153                                                                  * Delete from group, or add to group?
 154                                                                  */
 155                                                                 if (groups == NULL || isingroup(grp.gr_name, groups) == -1) {   /* Delete */
 156                                                                         int             idx;
 157
 158                                                                         while ((idx = isingroup(name, mems)) != -1) {
 159                                                                                 for (i = idx; i < (memlen - 1); i++)
 160                                                                                         mems[i] = mems[i + 1];
 161                                                                                 mems[i] = NULL;
 162                                                                                 --mno;
 163                                                                         }
 164                                                                         /*
 165                                                                          * Special case - deleting user and group may be user's own
 166                                                                          */
 167                                                                         if (groups == NULL && mems[0] == NULL && strcmp(name, grp.gr_name) == 0) {
 168                                                                                 /*
 169                                                                                  * First, make _sure_ we don't have other members
 170                                                                                  */
 171                                                                                 struct passwd  *pwd;
 172
 173                                                                                 setpwent();
 174                                                                                 while ((pwd = getpwent()) != NULL && pwd->pw_gid != grp.gr_gid);
 175                                                                                 endpwent();
 176                                                                                 if (pwd == NULL)        /* No members at all */
 177                                                                                         continue;       /* Drop the group */
 178                                                                         }
 179                                                                 } else if (isingroup(name, mems) == -1) {
 180                                                                         if (extendarray(&mems, &memlen, mno + 2) == -1) {
 181                                                                                 goto mem_abort;
 182                                                                         }
 183                                                                         grp.gr_mem = mems;    /* May have realloced() */
 184                                                                         mems[mno++] = name;
 185                                                                         mems[mno  ] = NULL;
 186                                                                 }
 187                                                                 fmtgrentry(&outl, &outlen, &grp, PWF_GROUP);
 188                                                         }
 189                                                         fputs(outl, outfp);
 190                                                 }
 191                                                 if (fflush(outfp) != EOF) {
 192                                                         rc = 1;
 193
 194                                                         /*
 195                                                          * Copy data back into the original file and truncate
 196                                                          */
 197                                                         rewind(infp);
 198                                                         rewind(outfp);
 199                                                         while (fgets(outl, outlen, outfp) != NULL)
 200                                                                 fputs(outl, infp);
 201
 202                                                         /*
 203                                                          * This is a gross hack, but we may have corrupted the
 204                                                          * original file. Unfortunately, it will lose preservation
 205                                                          * of the inode.
 206                                                          */
 207                                                         if (fflush(infp) == EOF || ferror(infp))
 208                                                                 rc = rename(grouptmp, groupfile) == 0;
 209                                                         else
 210                                                                 ftruncate(infd, ftell(infp));
 211                                                 }
 212                                         }
 213                                         free(mems);
 214                                         free(outl);
 215                                         free(line);
 216                                         fclose(outfp);
 217                                 }
 218                                 remove(grouptmp);
 219                         }
 220                         fclose(infp);
 221                 }
 222         }
 223         return rc;
 224 }