lib/encode.c

   1 /*
   2 **  Copyright 1998-2003 University of Illinois Board of Trustees
   3 **  Copyright 1998-2003 Mark D. Roth
   4 **  All rights reserved.
   5 **
   6 **  encode.c - libtar code to encode tar header blocks
   7 **
   8 **  Mark D. Roth <roth@uiuc.edu>
   9 **  Campus Information Technologies and Educational Services
  10 **  University of Illinois at Urbana-Champaign
  11 */
  12
  13 #include <internal.h>
  14
  15 #include <stdio.h>
  16 #include <pwd.h>
  17 #include <grp.h>
  18 #include <sys/types.h>
  19
  20 #ifdef STDC_HEADERS
  21 # include <string.h>
  22 # include <stdlib.h>
  23 #endif
  24
  25
  26 /* magic, version, and checksum */
  27 void
  28 th_finish(TAR *t)
  29 {
  30         int i, sum = 0;
  31
  32         if (t->options & TAR_GNU)
  33         {
  34                 /* we're aiming for this result, but must do it in
  35                  * two calls to avoid FORTIFY segfaults on some Linux
  36                  * systems:
  37                  *      strncpy(t->th_buf.magic, "ustar  ", 8);
  38                  */
  39                 strncpy(t->th_buf.magic, "ustar ", 6);
  40                 strncpy(t->th_buf.version, " ", 2);
  41         }
  42         else
  43         {
  44                 strncpy(t->th_buf.version, TVERSION, TVERSLEN);
  45                 strncpy(t->th_buf.magic, TMAGIC, TMAGLEN);
  46         }
  47
  48         for (i = 0; i < T_BLOCKSIZE; i++)
  49                 sum += ((char *)(&(t->th_buf)))[i];
  50         for (i = 0; i < 8; i++)
  51                 sum += (' ' - t->th_buf.chksum[i]);
  52         int_to_oct(sum, t->th_buf.chksum, 8);
  53 }
  54
  55
  56 /* map a file mode to a typeflag */
  57 void
  58 th_set_type(TAR *t, mode_t mode)
  59 {
  60         if (S_ISLNK(mode))
  61                 t->th_buf.typeflag = SYMTYPE;
  62         if (S_ISREG(mode))
  63                 t->th_buf.typeflag = REGTYPE;
  64         if (S_ISDIR(mode))
  65                 t->th_buf.typeflag = DIRTYPE;
  66         if (S_ISCHR(mode))
  67                 t->th_buf.typeflag = CHRTYPE;
  68         if (S_ISBLK(mode))
  69                 t->th_buf.typeflag = BLKTYPE;
  70         if (S_ISFIFO(mode) || S_ISSOCK(mode))
  71                 t->th_buf.typeflag = FIFOTYPE;
  72 }
  73
  74
  75 /* encode file path */
  76 void
  77 th_set_path(TAR *t, char *pathname)
  78 {
  79         char suffix[2] = "";
  80         char *tmp;
  81
  82 #ifdef DEBUG
  83         printf("in th_set_path(th, pathname=\"%s\")\n", pathname);
  84 #endif
  85
  86         if (t->th_buf.gnu_longname != NULL)
  87                 free(t->th_buf.gnu_longname);
  88         t->th_buf.gnu_longname = NULL;
  89
  90         if (pathname[strlen(pathname) - 1] != '/' && TH_ISDIR(t))
  91                 strcpy(suffix, "/");
  92
  93         if (strlen(pathname) > T_NAMELEN-1 && (t->options & TAR_GNU))
  94         {
  95                 /* GNU-style long name */
  96                 t->th_buf.gnu_longname = strdup(pathname);
  97                 strncpy(t->th_buf.name, t->th_buf.gnu_longname, T_NAMELEN);
  98         }
  99         else if (strlen(pathname) > T_NAMELEN)
 100         {
 101                 /* POSIX-style prefix field */
 102                 tmp = strchr(&(pathname[strlen(pathname) - T_NAMELEN - 1]), '/');
 103                 if (tmp == NULL)
 104                 {
 105                         printf("!!! '/' not found in \"%s\"\n", pathname);
 106                         return;
 107                 }
 108                 snprintf(t->th_buf.name, 100, "%s%s", &(tmp[1]), suffix);
 109                 snprintf(t->th_buf.prefix,
 110                          ((tmp - pathname + 1) <
 111                           155 ? (tmp - pathname + 1) : 155), "%s", pathname);
 112         }
 113         else
 114                 /* classic tar format */
 115                 snprintf(t->th_buf.name, 100, "%s%s", pathname, suffix);
 116
 117 #ifdef DEBUG
 118         puts("returning from th_set_path()...");
 119 #endif
 120 }
 121
 122
 123 /* encode link path */
 124 void
 125 th_set_link(TAR *t, char *linkname)
 126 {
 127 #ifdef DEBUG
 128         printf("==> th_set_link(th, linkname=\"%s\")\n", linkname);
 129 #endif
 130
 131         if (strlen(linkname) > T_NAMELEN-1 && (t->options & TAR_GNU))
 132         {
 133                 /* GNU longlink format */
 134                 t->th_buf.gnu_longlink = strdup(linkname);
 135                 strcpy(t->th_buf.linkname, "././@LongLink");
 136         }
 137         else
 138         {
 139                 /* classic tar format */
 140                 strlcpy(t->th_buf.linkname, linkname,
 141                         sizeof(t->th_buf.linkname));
 142                 if (t->th_buf.gnu_longlink != NULL)
 143                         free(t->th_buf.gnu_longlink);
 144                 t->th_buf.gnu_longlink = NULL;
 145         }
 146 }
 147
 148
 149 /* encode device info */
 150 void
 151 th_set_device(TAR *t, dev_t device)
 152 {
 153 #ifdef DEBUG
 154         printf("th_set_device(): major = %d, minor = %d\n",
 155                major(device), minor(device));
 156 #endif
 157         int_to_oct(major(device), t->th_buf.devmajor, 8);
 158         int_to_oct(minor(device), t->th_buf.devminor, 8);
 159 }
 160
 161
 162 /* encode user info */
 163 void
 164 th_set_user(TAR *t, uid_t uid)
 165 {
 166         struct passwd *pw;
 167
 168         pw = getpwuid(uid);
 169         if (pw != NULL)
 170                 strlcpy(t->th_buf.uname, pw->pw_name, sizeof(t->th_buf.uname));
 171
 172         int_to_oct(uid, t->th_buf.uid, 8);
 173 }
 174
 175
 176 /* encode group info */
 177 void
 178 th_set_group(TAR *t, gid_t gid)
 179 {
 180         struct group *gr;
 181
 182         gr = getgrgid(gid);
 183         if (gr != NULL)
 184                 strlcpy(t->th_buf.gname, gr->gr_name, sizeof(t->th_buf.gname));
 185
 186         int_to_oct(gid, t->th_buf.gid, 8);
 187 }
 188
 189
 190 /* encode file mode */
 191 void
 192 th_set_mode(TAR *t, mode_t fmode)
 193 {
 194         if (S_ISSOCK(fmode))
 195         {
 196                 fmode &= ~S_IFSOCK;
 197                 fmode |= S_IFIFO;
 198         }
 199         int_to_oct(fmode, (t)->th_buf.mode, 8);
 200 }
 201
 202
 203 void
 204 th_set_from_stat(TAR *t, struct stat *s)
 205 {
 206         th_set_type(t, s->st_mode);
 207         if (S_ISCHR(s->st_mode) || S_ISBLK(s->st_mode))
 208                 th_set_device(t, s->st_rdev);
 209         th_set_user(t, s->st_uid);
 210         th_set_group(t, s->st_gid);
 211         th_set_mode(t, s->st_mode);
 212         th_set_mtime(t, s->st_mtime);
 213         if (S_ISREG(s->st_mode))
 214                 th_set_size(t, s->st_size);
 215         else
 216                 th_set_size(t, 0);
 217 }
 218
 219