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