usr.sbin/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  * $FreeBSD: src/usr.sbin/pw/edgroup.c,v 1.8 1999/08/28 01:19:16 peter Exp $
  27  * $DragonFly: src/usr.sbin/pw/edgroup.c,v 1.2 2003/06/17 04:30:01 dillon Exp $
  28  */
  29
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <unistd.h>
  34 #include <stdarg.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 int
  57 editgroups(char *name, char **groups)
  58 {
  59         int             rc = 0;
  60         int             infd;
  61         char            groupfile[MAXPATHLEN];
  62         char            grouptmp[MAXPATHLEN];
  63
  64         strncpy(groupfile, getgrpath(_GROUP), MAXPATHLEN - 5);
  65         groupfile[MAXPATHLEN - 5] = '\0';
  66         strcpy(grouptmp, groupfile);
  67         strcat(grouptmp, ".new");
  68
  69         if ((infd = open(groupfile, O_RDWR | O_CREAT, 0644)) != -1) {
  70                 FILE           *infp;
  71
  72                 if ((infp = fdopen(infd, "r+")) == NULL)
  73                         close(infd);
  74                 else {
  75                         int             outfd;
  76
  77                         if ((outfd = open(grouptmp, O_RDWR | O_CREAT | O_TRUNC | O_EXLOCK, 0644)) != -1) {
  78                                 FILE           *outfp;
  79
  80                                 if ((outfp = fdopen(outfd, "w+")) == NULL)
  81                                         close(outfd);
  82                                 else {
  83                                         int             linelen = PWBUFSZ;
  84                                         int             outlen =  PWBUFSZ;
  85                                         int             memlen = 200; /* Arbitrary */
  86                                         char           *line = malloc(linelen);
  87                                         char           *outl = malloc(outlen);
  88                                         char          **mems = malloc(memlen * sizeof(char *));
  89                                         int             namlen = strlen(name);
  90
  91                                         if (line == NULL || outl == NULL || mems == NULL) {
  92                                             mem_abort:
  93                                                 rc = 0;
  94                                         } else {
  95                                                 while (fgets(line, linelen, infp) != NULL) {
  96                                                         char           *p;
  97                                                         int             l;
  98
  99                                                         while ((p = strchr(line, '\n')) == NULL)
 100                                                         {
 101                                                                 if (extendline(&line, &linelen, linelen + PWBUFSZ) == -1) {
 102                                                                         goto mem_abort;
 103                                                                 }
 104                                                                 l = strlen(line);
 105                                                                 if (fgets(line + l, linelen - l, infp) == NULL)
 106                                                                         break;  /* No newline terminator on last line */
 107                                                         }
 108                                                         l = strlen(line) + namlen + 1;
 109                                                         if (extendline(&outl, &outlen, l) == -1) {
 110                                                                 goto mem_abort;
 111                                                         }
 112                                                         if (*line == '#')
 113                                                                 strcpy(outl, line);
 114                                                         else if (*line == '\n')
 115                                                                 *outl = '\0';
 116                                                         else {
 117                                                                 int             i,
 118                                                                                 mno = 0;
 119                                                                 char           *cp = line;
 120                                                                 char const     *sep = ":\n";
 121                                                                 struct group    grp;
 122
 123                                                                 memset(&grp, 0, sizeof grp);
 124                                                                 for (i = 0; (p = strsep(&cp, sep)) != NULL; i++) {
 125                                                                         switch (i) {
 126                                                                         case 0: /* Group name */
 127                                                                                 grp.gr_name = p;
 128                                                                                 break;
 129                                                                         case 1: /* Group password */
 130                                                                                 grp.gr_passwd = p;
 131                                                                                 break;
 132                                                                         case 2: /* Group id */
 133                                                                                 grp.gr_gid = atoi(p);
 134                                                                                 break;
 135                                                                         case 3: /* Member list */
 136                                                                                 cp = p;
 137                                                                                 sep = ",\n";
 138                                                                                 break;
 139                                                                         default:        /* Individual members */
 140                                                                                 if (*p) {
 141                                                                                         if (extendarray(&mems, &memlen, mno + 2) == -1) {
 142                                                                                                 goto mem_abort;
 143                                                                                         }
 144                                                                                         mems[mno++] = p;
 145                                                                                 }
 146                                                                                 break;
 147                                                                         }
 148                                                                 }
 149                                                                 if (i < 2)      /* Bail out - insufficient fields */
 150                                                                         continue;
 151
 152                                                                 grp.gr_mem = mems;
 153                                                                 for (i = mno; i < memlen; i++)
 154                                                                         mems[i] = NULL;
 155
 156                                                                 /*
 157                                                                  * Delete from group, or add to group?
 158                                                                  */
 159                                                                 if (groups == NULL || isingroup(grp.gr_name, groups) == -1) {   /* Delete */
 160                                                                         int             idx;
 161
 162                                                                         while ((idx = isingroup(name, mems)) != -1) {
 163                                                                                 for (i = idx; i < (memlen - 1); i++)
 164                                                                                         mems[i] = mems[i + 1];
 165                                                                                 mems[i] = NULL;
 166                                                                                 --mno;
 167                                                                         }
 168                                                                         /*
 169                                                                          * Special case - deleting user and group may be user's own
 170                                                                          */
 171                                                                         if (groups == NULL && mems[0] == NULL && strcmp(name, grp.gr_name) == 0) {
 172                                                                                 /*
 173                                                                                  * First, make _sure_ we don't have other members
 174                                                                                  */
 175                                                                                 struct passwd  *pwd;
 176
 177                                                                                 SETPWENT();
 178                                                                                 while ((pwd = GETPWENT()) != NULL && (gid_t)pwd->pw_gid != (gid_t)grp.gr_gid);
 179                                                                                 ENDPWENT();
 180                                                                                 if (pwd == NULL)        /* No members at all */
 181                                                                                         continue;       /* Drop the group */
 182                                                                         }
 183                                                                 } else if (isingroup(name, mems) == -1) {
 184                                                                         if (extendarray(&mems, &memlen, mno + 2) == -1) {
 185                                                                                 goto mem_abort;
 186                                                                         }
 187                                                                         grp.gr_mem = mems;    /* May have realloced() */
 188                                                                         mems[mno++] = name;
 189                                                                         mems[mno  ] = NULL;
 190                                                                 }
 191                                                                 fmtgrentry(&outl, &outlen, &grp, PWF_GROUP);
 192                                                         }
 193                                                         fputs(outl, outfp);
 194                                                 }
 195                                                 if (fflush(outfp) != EOF) {
 196                                                         rc = 1;
 197
 198                                                         /*
 199                                                          * Copy data back into the original file and truncate
 200                                                          */
 201                                                         rewind(infp);
 202                                                         rewind(outfp);
 203                                                         while (fgets(outl, outlen, outfp) != NULL)
 204                                                                 fputs(outl, infp);
 205
 206                                                         /*
 207                                                          * This is a gross hack, but we may have corrupted the
 208                                                          * original file. Unfortunately, it will lose preservation
 209                                                          * of the inode.
 210                                                          */
 211                                                         if (fflush(infp) == EOF || ferror(infp))
 212                                                                 rc = rename(grouptmp, groupfile) == 0;
 213                                                         else
 214                                                                 ftruncate(infd, ftell(infp));
 215                                                 }
 216                                         }
 217                                         free(mems);
 218                                         free(outl);
 219                                         free(line);
 220                                         fclose(outfp);
 221                                 }
 222                                 remove(grouptmp);
 223                         }
 224                         fclose(infp);
 225                 }
 226         }
 227         return rc;
 228 }