/*
** Copyright 1998-2003 University of Illinois Board of Trustees
** Copyright 1998-2003 Mark D. Roth
** All rights reserved.
**
** encode.c - libtar code to encode tar header blocks
**
** Mark D. Roth <roth@uiuc.edu>
** Campus Information Technologies and Educational Services
** University of Illinois at Urbana-Champaign
*/
#include <internal.h>
#include <stdio.h>
#include <pwd.h>
#include <grp.h>
#include <sys/types.h>
#include <sys/sysmacros.h>
#ifdef STDC_HEADERS
# include <string.h>
# include <stdlib.h>
#endif
/* magic, version, and checksum */
void
th_finish(TAR *t)
{
if (t->options & TAR_GNU)
{
/* we're aiming for this result, but must do it in
* two calls to avoid FORTIFY segfaults on some Linux
* systems:
* strncpy(t->th_buf.magic, "ustar ", 8);
*/
strncpy(t->th_buf.magic, "ustar ", 6);
strncpy(t->th_buf.version, " ", 2);
}
else
{
strncpy(t->th_buf.version, TVERSION, TVERSLEN);
strncpy(t->th_buf.magic, TMAGIC, TMAGLEN);
}
int_to_oct(th_crc_calc(t), t->th_buf.chksum, 8);
}
/* map a file mode to a typeflag */
void
th_set_type(TAR *t, mode_t mode)
{
if (S_ISLNK(mode))
t->th_buf.typeflag = SYMTYPE;
if (S_ISREG(mode))
t->th_buf.typeflag = REGTYPE;
if (S_ISDIR(mode))
t->th_buf.typeflag = DIRTYPE;
if (S_ISCHR(mode))
t->th_buf.typeflag = CHRTYPE;
if (S_ISBLK(mode))
t->th_buf.typeflag = BLKTYPE;
if (S_ISFIFO(mode) || S_ISSOCK(mode))
t->th_buf.typeflag = FIFOTYPE;
}
/* encode file path */
void
th_set_path(TAR *t, const char *pathname)
{
char suffix[2] = "";
char *tmp;
size_t pathname_len = strlen(pathname);
#ifdef DEBUG
printf("in th_set_path(th, pathname=\"%s\")\n", pathname);
#endif
if (t->th_buf.gnu_longname != NULL)
free(t->th_buf.gnu_longname);
t->th_buf.gnu_longname = NULL;
/* old archive compatibility (not needed for gnu): add trailing / to directories */
if (pathname[pathname_len - 1] != '/' && TH_ISDIR(t))
strcpy(suffix, "/");
if (pathname_len >= T_NAMELEN && (t->options & TAR_GNU))
{
/* GNU-style long name (no file name length limit) */
t->th_buf.gnu_longname = strdup(pathname);
strncpy(t->th_buf.name, t->th_buf.gnu_longname, T_NAMELEN);
}
else if (pathname_len >= T_NAMELEN)
{
/* POSIX-style prefix field:
* The maximum length of a file name is limited to 256 characters,
* provided that the file name can be split at a directory separator
* in two parts. The first part being at most 155 bytes long and
* the second part being at most 100 bytes long. So, in most cases
* the maximum file name length will be shorter than 256 characters.
*/
char tail_path[T_NAMELEN + 1];
tmp = strchr(&(pathname[pathname_len - T_NAMELEN]), '/');
if (tmp == NULL)
{
printf("!!! '/' not found in \"%s\"\n", pathname);
return;
}
snprintf(tail_path, T_NAMELEN + 1, "%s%s", &tmp[1], suffix);
strncpy(t->th_buf.name, tail_path, T_NAMELEN);
/*
* first part, max = 155 == sizeof(t->th_buf.prefix) , include NULL if it fits
* trailing '/' is added during decode: decode.c/th_get_pathname()
*/
if (tmp - pathname >= 155) {
strncpy(t->th_buf.prefix, pathname, 155);
} else {
snprintf(t->th_buf.prefix, (tmp - pathname + 1), "%s", pathname);
}
}
else {
/* any short name for all formats, or classic tar format (99 chars max) */
snprintf(t->th_buf.name, T_NAMELEN, "%s%s", pathname, suffix);
}
#ifdef DEBUG
puts("returning from th_set_path()...");
#endif
}
/* encode link path */
void
th_set_link(TAR *t, const char *linkname)
{
#ifdef DEBUG
printf("==> th_set_link(th, linkname=\"%s\")\n", linkname);
#endif
if (strlen(linkname) >= T_NAMELEN && (t->options & TAR_GNU))
{
/* --format=gnu: GNU-style long name (no file name length limit) */
t->th_buf.gnu_longlink = strdup(linkname);
strcpy(t->th_buf.linkname, "././@LongLink");
}
else if (strlen(linkname) >= T_NAMELEN)
{
/* --format=ustar: 100 chars max limit for symbolic links */
strncpy(t->th_buf.linkname, linkname, T_NAMELEN);
if (t->th_buf.gnu_longlink != NULL)
free(t->th_buf.gnu_longlink);
t->th_buf.gnu_longlink = NULL;
} else {
/* all short links or v7 tar format: The maximum length of a symbolic link name is limited to 99 characters */
snprintf(t->th_buf.linkname, T_NAMELEN, "%s", linkname);
if (t->th_buf.gnu_longlink != NULL)
free(t->th_buf.gnu_longlink);
t->th_buf.gnu_longlink = NULL;
}
}
/* encode device info */
void
th_set_device(TAR *t, dev_t device)
{
#ifdef DEBUG
printf("th_set_device(): major = %d, minor = %d\n",
major(device), minor(device));
#endif
int_to_oct(major(device), t->th_buf.devmajor, 8);
int_to_oct(minor(device), t->th_buf.devminor, 8);
}
/* encode user info */
void
th_set_user(TAR *t, uid_t uid)
{
struct passwd *pw;
if (!(t->options & TAR_USE_NUMERIC_ID)) {
pw = getpwuid(uid);
if (pw != NULL)
strlcpy(t->th_buf.uname, pw->pw_name, sizeof(t->th_buf.uname));
}
int_to_oct(uid, t->th_buf.uid, 8);
}
/* encode group info */
void
th_set_group(TAR *t, gid_t gid)
{
struct group *gr;
if (!(t->options & TAR_USE_NUMERIC_ID)) {
gr = getgrgid(gid);
if (gr != NULL)
strlcpy(t->th_buf.gname, gr->gr_name, sizeof(t->th_buf.gname));
}
int_to_oct(gid, t->th_buf.gid, 8);
}
/* encode file mode */
void
th_set_mode(TAR *t, mode_t fmode)
{
if (S_ISSOCK(fmode))
{
fmode &= ~S_IFSOCK;
fmode |= S_IFIFO;
}
int_to_oct(fmode, (t)->th_buf.mode, 8);
}
void
th_set_from_stat(TAR *t, struct stat *s)
{
th_set_type(t, s->st_mode);
if (S_ISCHR(s->st_mode) || S_ISBLK(s->st_mode))
th_set_device(t, s->st_rdev);
th_set_user(t, s->st_uid);
th_set_group(t, s->st_gid);
th_set_mode(t, s->st_mode);
th_set_mtime(t, s->st_mtime);
if (S_ISREG(s->st_mode))
th_set_size(t, s->st_size);
else
th_set_size(t, 0);
}
