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