midfavila/sbase
1
0
Fork 0
Code Issues Pull Requests Projects Releases 1 Wiki Activity

tar: improve file status handling on extract

Browse Source 
by re-ordering when chmod/chown is done, only a list of directories (not
all files) need be kept for fixing mtime.

this also fixes an issue where set-user-id files in a tar may not work. chmod
is done before chown and before the file is written. if ownership changes, or
the file is being written as a normal user, the setuid bit would be cleared.

also fixes ownership of symbolic links. previously a chown() was called,
which would change the ownership of the link target. lchown() is now
used for symbolic links.

renamed all ent, ent* functions to dir* as it better describes what they
do.

use timespec/utimensat instead of timeval/utimes to get AT_SYMLINK_NOFOLLOW
This commit is contained in:
Brad Barden 2015-11-18 20:50:50 -06:00 committed by sin
parent 85a9254d3a
commit 211c565b3d
1 changed files with 40 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
tar.c
View File

@ -48,12 +48,12 @@ struct header {
char prefix[155];
};
static struct ent {
static struct dirtime {
char *name;
time_t mtime;
} *ents;
} *dirtimes;
static size_t entslen;
static size_t dirtimeslen;
static int tarfd;
static ino_t tarinode;
@ -72,20 +72,20 @@ static const char *filtertools[] = {
};
static void
pushent(char *name, time_t mtime)
pushdirtime(char *name, time_t mtime)
{
ents = reallocarray(ents, entslen + 1, sizeof(*ents));
ents[entslen].name = strdup(name);
ents[entslen].mtime = mtime;
entslen++;
dirtimes = reallocarray(dirtimes, dirtimeslen + 1, sizeof(*dirtimes));
dirtimes[dirtimeslen].name = strdup(name);
dirtimes[dirtimeslen].mtime = mtime;
dirtimeslen++;
}
static struct ent *
popent(void)
static struct dirtime *
popdirtime(void)
{
if (entslen) {
entslen--;
return &ents[entslen];
if (dirtimeslen) {
dirtimeslen--;
return &dirtimes[dirtimeslen];
}
return NULL;
}
@ -254,6 +254,7 @@ unarchive(char *fname, ssize_t l, char b[BLKSIZ])
long mode, major, minor, type, mtime, uid, gid;
struct header *h = (struct header *)b;
int fd = -1;
struct timespec times[2];
if (!mflag && ((mtime = strtol(h->mtime, &p, 8)) < 0 || *p != '\0'))
eprintf("strtol %s: invalid number\n", h->mtime);
@ -273,8 +274,6 @@ unarchive(char *fname, ssize_t l, char b[BLKSIZ])
fd = open(fname, O_WRONLY | O_TRUNC | O_CREAT, 0600);
if (fd < 0)
eprintf("open %s:", fname);
if (fchmod(fd, mode) < 0)
eprintf("fchmod %s:", fname);
break;
case HARDLINK:
case SYMLINK:
@ -290,6 +289,7 @@ unarchive(char *fname, ssize_t l, char b[BLKSIZ])
eprintf("strtol %s: invalid number\n", h->mode);
if (mkdir(fname, (mode_t)mode) < 0 && errno != EEXIST)
eprintf("mkdir %s:", fname);
pushdirtime(fname, mtime);
break;
case CHARDEV:
case BLOCKDEV:
@ -317,8 +317,6 @@ unarchive(char *fname, ssize_t l, char b[BLKSIZ])
eprintf("strtol %s: invalid number\n", h->uid);
if ((gid = strtol(h->gid, &p, 8)) < 0 || *p != '\0')
eprintf("strtol %s: invalid number\n", h->gid);
if (!getuid() && chown(fname, uid, gid))
weprintf("chown %s:", fname);
if (fd != -1) {
for (; l > 0; l -= BLKSIZ)
@ -327,7 +325,20 @@ unarchive(char *fname, ssize_t l, char b[BLKSIZ])
close(fd);
}
pushent(fname, mtime);
times[0].tv_sec = times[1].tv_sec = mtime;
times[0].tv_nsec = times[1].tv_nsec = 0;
if (!mflag && utimensat(AT_FDCWD, fname, times, AT_SYMLINK_NOFOLLOW) < 0)
weprintf("utimensat %s:\n", fname);
if (h->type == SYMLINK) {
if (!getuid() && lchown(fname, uid, gid))
weprintf("lchown %s:\n", fname);
} else {
if (!getuid() && chown(fname, uid, gid))
weprintf("chown %s:\n", fname);
if (chmod(fname, mode) < 0)
eprintf("fchmod %s:\n", fname);
}
return 0;
}
@ -420,9 +431,9 @@ static void
xt(int argc, char *argv[], int mode)
{
char b[BLKSIZ], fname[256 + 1], *p;
struct timeval times[2];
struct timespec times[2];
struct header *h = (struct header *)b;
struct ent *ent;
struct dirtime *dirtime;
long size;
int i, n;
int (*fn)(char *, ssize_t, char[BLKSIZ]) = (mode == 'x') ? unarchive : print;
@ -463,16 +474,16 @@ xt(int argc, char *argv[], int mode)
puts(fname);
}
if (!mflag) {
while ((ent = popent())) {
times[0].tv_sec = times[1].tv_sec = ent->mtime;
times[0].tv_usec = times[1].tv_usec = 0;
if (utimes(ent->name, times) < 0)
weprintf("utimes %s:", ent->name);
free(ent->name);
if (mode == 'x' && !mflag) {
while ((dirtime = popdirtime())) {
times[0].tv_sec = times[1].tv_sec = dirtime->mtime;
times[0].tv_nsec = times[1].tv_nsec = 0;
if (utimensat(AT_FDCWD, dirtime->name, times, 0) < 0)
eprintf("utimensat %s:", fname);
free(dirtime->name);
}
free(ents);
ents = NULL;
free(dirtimes);
dirtimes = NULL;
}
}