blob: 203aa6f9daed76721b4214150fc952d87bf06135 [file] [log] [blame]
/*-
* Copyright (c) 2003-2007 Tim Kientzle
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "bsdtar_platform.h"
__FBSDID("$FreeBSD: src/usr.bin/tar/util.c,v 1.23 2008/12/15 06:00:25 kientzle Exp $");
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h> /* Linux doesn't define mode_t, etc. in sys/stat.h. */
#endif
#include <ctype.h>
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_IO_H
#include <io.h>
#endif
#ifdef HAVE_STDARG_H
#include <stdarg.h>
#endif
#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_WCTYPE_H
#include <wctype.h>
#else
/* If we don't have wctype, we need to hack up some version of iswprint(). */
#define iswprint isprint
#endif
#include "bsdtar.h"
#include "err.h"
#include "passphrase.h"
static size_t bsdtar_expand_char(char *, size_t, char);
static const char *strip_components(const char *path, int elements);
#if defined(_WIN32) && !defined(__CYGWIN__)
#define read _read
#endif
/* TODO: Hack up a version of mbtowc for platforms with no wide
* character support at all. I think the following might suffice,
* but it needs careful testing.
* #if !HAVE_MBTOWC
* #define mbtowc(wcp, p, n) ((*wcp = *p), 1)
* #endif
*/
/*
* Print a string, taking care with any non-printable characters.
*
* Note that we use a stack-allocated buffer to receive the formatted
* string if we can. This is partly performance (avoiding a call to
* malloc()), partly out of expedience (we have to call vsnprintf()
* before malloc() anyway to find out how big a buffer we need; we may
* as well point that first call at a small local buffer in case it
* works), but mostly for safety (so we can use this to print messages
* about out-of-memory conditions).
*/
void
safe_fprintf(FILE *f, const char *fmt, ...)
{
char fmtbuff_stack[256]; /* Place to format the printf() string. */
char outbuff[256]; /* Buffer for outgoing characters. */
char *fmtbuff_heap; /* If fmtbuff_stack is too small, we use malloc */
char *fmtbuff; /* Pointer to fmtbuff_stack or fmtbuff_heap. */
int fmtbuff_length;
int length, n;
va_list ap;
const char *p;
unsigned i;
wchar_t wc;
char try_wc;
/* Use a stack-allocated buffer if we can, for speed and safety. */
fmtbuff_heap = NULL;
fmtbuff_length = sizeof(fmtbuff_stack);
fmtbuff = fmtbuff_stack;
/* Try formatting into the stack buffer. */
va_start(ap, fmt);
length = vsnprintf(fmtbuff, fmtbuff_length, fmt, ap);
va_end(ap);
/* If the result was too large, allocate a buffer on the heap. */
while (length < 0 || length >= fmtbuff_length) {
if (length >= fmtbuff_length)
fmtbuff_length = length+1;
else if (fmtbuff_length < 8192)
fmtbuff_length *= 2;
else if (fmtbuff_length < 1000000)
fmtbuff_length += fmtbuff_length / 4;
else {
length = fmtbuff_length;
fmtbuff_heap[length-1] = '\0';
break;
}
free(fmtbuff_heap);
fmtbuff_heap = malloc(fmtbuff_length);
/* Reformat the result into the heap buffer if we can. */
if (fmtbuff_heap != NULL) {
fmtbuff = fmtbuff_heap;
va_start(ap, fmt);
length = vsnprintf(fmtbuff, fmtbuff_length, fmt, ap);
va_end(ap);
} else {
/* Leave fmtbuff pointing to the truncated
* string in fmtbuff_stack. */
length = sizeof(fmtbuff_stack) - 1;
break;
}
}
/* Note: mbrtowc() has a cleaner API, but mbtowc() seems a bit
* more portable, so we use that here instead. */
if (mbtowc(NULL, NULL, 1) == -1) { /* Reset the shift state. */
/* mbtowc() should never fail in practice, but
* handle the theoretical error anyway. */
free(fmtbuff_heap);
return;
}
/* Write data, expanding unprintable characters. */
p = fmtbuff;
i = 0;
try_wc = 1;
while (*p != '\0') {
/* Convert to wide char, test if the wide
* char is printable in the current locale. */
if (try_wc && (n = mbtowc(&wc, p, length)) != -1) {
length -= n;
if (iswprint(wc) && wc != L'\\') {
/* Printable, copy the bytes through. */
while (n-- > 0)
outbuff[i++] = *p++;
} else {
/* Not printable, format the bytes. */
while (n-- > 0)
i += (unsigned)bsdtar_expand_char(
outbuff, i, *p++);
}
} else {
/* After any conversion failure, don't bother
* trying to convert the rest. */
i += (unsigned)bsdtar_expand_char(outbuff, i, *p++);
try_wc = 0;
}
/* If our output buffer is full, dump it and keep going. */
if (i > (sizeof(outbuff) - 20)) {
outbuff[i] = '\0';
fprintf(f, "%s", outbuff);
i = 0;
}
}
outbuff[i] = '\0';
fprintf(f, "%s", outbuff);
/* If we allocated a heap-based formatting buffer, free it now. */
free(fmtbuff_heap);
}
/*
* Render an arbitrary sequence of bytes into printable ASCII characters.
*/
static size_t
bsdtar_expand_char(char *buff, size_t offset, char c)
{
size_t i = offset;
if (isprint((unsigned char)c) && c != '\\')
buff[i++] = c;
else {
buff[i++] = '\\';
switch (c) {
case '\a': buff[i++] = 'a'; break;
case '\b': buff[i++] = 'b'; break;
case '\f': buff[i++] = 'f'; break;
case '\n': buff[i++] = 'n'; break;
#if '\r' != '\n'
/* On some platforms, \n and \r are the same. */
case '\r': buff[i++] = 'r'; break;
#endif
case '\t': buff[i++] = 't'; break;
case '\v': buff[i++] = 'v'; break;
case '\\': buff[i++] = '\\'; break;
default:
sprintf(buff + i, "%03o", 0xFF & (int)c);
i += 3;
}
}
return (i - offset);
}
int
yes(const char *fmt, ...)
{
char buff[32];
char *p;
ssize_t l;
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, " (y/N)? ");
fflush(stderr);
l = read(2, buff, sizeof(buff) - 1);
if (l < 0) {
fprintf(stderr, "Keyboard read failed\n");
exit(1);
}
if (l == 0)
return (0);
buff[l] = 0;
for (p = buff; *p != '\0'; p++) {
if (isspace((unsigned char)*p))
continue;
switch(*p) {
case 'y': case 'Y':
return (1);
case 'n': case 'N':
return (0);
default:
return (0);
}
}
return (0);
}
/*-
* The logic here for -C <dir> attempts to avoid
* chdir() as long as possible. For example:
* "-C /foo -C /bar file" needs chdir("/bar") but not chdir("/foo")
* "-C /foo -C bar file" needs chdir("/foo/bar")
* "-C /foo -C bar /file1" does not need chdir()
* "-C /foo -C bar /file1 file2" needs chdir("/foo/bar") before file2
*
* The only correct way to handle this is to record a "pending" chdir
* request and combine multiple requests intelligently until we
* need to process a non-absolute file. set_chdir() adds the new dir
* to the pending list; do_chdir() actually executes any pending chdir.
*
* This way, programs that build tar command lines don't have to worry
* about -C with non-existent directories; such requests will only
* fail if the directory must be accessed.
*
*/
void
set_chdir(struct bsdtar *bsdtar, const char *newdir)
{
#if defined(_WIN32) && !defined(__CYGWIN__)
if (newdir[0] == '/' || newdir[0] == '\\' ||
/* Detect this type, for example, "C:\" or "C:/" */
(((newdir[0] >= 'a' && newdir[0] <= 'z') ||
(newdir[0] >= 'A' && newdir[0] <= 'Z')) &&
newdir[1] == ':' && (newdir[2] == '/' || newdir[2] == '\\'))) {
#else
if (newdir[0] == '/') {
#endif
/* The -C /foo -C /bar case; dump first one. */
free(bsdtar->pending_chdir);
bsdtar->pending_chdir = NULL;
}
if (bsdtar->pending_chdir == NULL)
/* Easy case: no previously-saved dir. */
bsdtar->pending_chdir = strdup(newdir);
else {
/* The -C /foo -C bar case; concatenate */
char *old_pending = bsdtar->pending_chdir;
size_t old_len = strlen(old_pending);
bsdtar->pending_chdir = malloc(old_len + strlen(newdir) + 2);
if (old_pending[old_len - 1] == '/')
old_pending[old_len - 1] = '\0';
if (bsdtar->pending_chdir != NULL)
sprintf(bsdtar->pending_chdir, "%s/%s",
old_pending, newdir);
free(old_pending);
}
if (bsdtar->pending_chdir == NULL)
lafe_errc(1, errno, "No memory");
}
void
do_chdir(struct bsdtar *bsdtar)
{
if (bsdtar->pending_chdir == NULL)
return;
if (chdir(bsdtar->pending_chdir) != 0) {
lafe_errc(1, 0, "could not chdir to '%s'\n",
bsdtar->pending_chdir);
}
free(bsdtar->pending_chdir);
bsdtar->pending_chdir = NULL;
}
static const char *
strip_components(const char *p, int elements)
{
/* Skip as many elements as necessary. */
while (elements > 0) {
switch (*p++) {
case '/':
#if defined(_WIN32) && !defined(__CYGWIN__)
case '\\': /* Support \ path sep on Windows ONLY. */
#endif
elements--;
break;
case '\0':
/* Path is too short, skip it. */
return (NULL);
}
}
/* Skip any / characters. This handles short paths that have
* additional / termination. This also handles the case where
* the logic above stops in the middle of a duplicate //
* sequence (which would otherwise get converted to an
* absolute path). */
for (;;) {
switch (*p) {
case '/':
#if defined(_WIN32) && !defined(__CYGWIN__)
case '\\': /* Support \ path sep on Windows ONLY. */
#endif
++p;
break;
case '\0':
return (NULL);
default:
return (p);
}
}
}
static void
warn_strip_leading_char(struct bsdtar *bsdtar, const char *c)
{
if (!bsdtar->warned_lead_slash) {
lafe_warnc(0,
"Removing leading '%c' from member names",
c[0]);
bsdtar->warned_lead_slash = 1;
}
}
static void
warn_strip_drive_letter(struct bsdtar *bsdtar)
{
if (!bsdtar->warned_lead_slash) {
lafe_warnc(0,
"Removing leading drive letter from "
"member names");
bsdtar->warned_lead_slash = 1;
}
}
/*
* Convert absolute path to non-absolute path by skipping leading
* absolute path prefixes.
*/
static const char*
strip_absolute_path(struct bsdtar *bsdtar, const char *p)
{
const char *rp;
/* Remove leading "//./" or "//?/" or "//?/UNC/"
* (absolute path prefixes used by Windows API) */
if ((p[0] == '/' || p[0] == '\\') &&
(p[1] == '/' || p[1] == '\\') &&
(p[2] == '.' || p[2] == '?') &&
(p[3] == '/' || p[3] == '\\'))
{
if (p[2] == '?' &&
(p[4] == 'U' || p[4] == 'u') &&
(p[5] == 'N' || p[5] == 'n') &&
(p[6] == 'C' || p[6] == 'c') &&
(p[7] == '/' || p[7] == '\\'))
p += 8;
else
p += 4;
warn_strip_drive_letter(bsdtar);
}
/* Remove multiple leading slashes and Windows drive letters. */
do {
rp = p;
if (((p[0] >= 'a' && p[0] <= 'z') ||
(p[0] >= 'A' && p[0] <= 'Z')) &&
p[1] == ':') {
p += 2;
warn_strip_drive_letter(bsdtar);
}
/* Remove leading "/../", "/./", "//", etc. */
while (p[0] == '/' || p[0] == '\\') {
if (p[1] == '.' &&
p[2] == '.' &&
(p[3] == '/' || p[3] == '\\')) {
p += 3; /* Remove "/..", leave "/" for next pass. */
} else if (p[1] == '.' &&
(p[2] == '/' || p[2] == '\\')) {
p += 2; /* Remove "/.", leave "/" for next pass. */
} else
p += 1; /* Remove "/". */
warn_strip_leading_char(bsdtar, rp);
}
} while (rp != p);
return (p);
}
/*
* Handle --strip-components and any future path-rewriting options.
* Returns non-zero if the pathname should not be extracted.
*
* Note: The rewrites are applied uniformly to pathnames and hardlink
* names but not to symlink bodies. This is deliberate: Symlink
* bodies are not necessarily filenames. Even when they are, they
* need to be interpreted relative to the directory containing them,
* so simple rewrites like this are rarely appropriate.
*
* TODO: Support pax-style regex path rewrites.
*/
int
edit_pathname(struct bsdtar *bsdtar, struct archive_entry *entry)
{
const char *name = archive_entry_pathname(entry);
const char *original_name = name;
const char *hardlinkname = archive_entry_hardlink(entry);
const char *original_hardlinkname = hardlinkname;
#if defined(HAVE_REGEX_H) || defined(HAVE_PCREPOSIX_H)
char *subst_name;
int r;
/* Apply user-specified substitution to pathname. */
r = apply_substitution(bsdtar, name, &subst_name, 0, 0);
if (r == -1) {
lafe_warnc(0, "Invalid substitution, skipping entry");
return 1;
}
if (r == 1) {
archive_entry_copy_pathname(entry, subst_name);
if (*subst_name == '\0') {
free(subst_name);
return -1;
} else
free(subst_name);
name = archive_entry_pathname(entry);
original_name = name;
}
/* Apply user-specified substitution to hardlink target. */
if (hardlinkname != NULL) {
r = apply_substitution(bsdtar, hardlinkname, &subst_name, 0, 1);
if (r == -1) {
lafe_warnc(0, "Invalid substitution, skipping entry");
return 1;
}
if (r == 1) {
archive_entry_copy_hardlink(entry, subst_name);
free(subst_name);
}
hardlinkname = archive_entry_hardlink(entry);
original_hardlinkname = hardlinkname;
}
/* Apply user-specified substitution to symlink body. */
if (archive_entry_symlink(entry) != NULL) {
r = apply_substitution(bsdtar, archive_entry_symlink(entry), &subst_name, 1, 0);
if (r == -1) {
lafe_warnc(0, "Invalid substitution, skipping entry");
return 1;
}
if (r == 1) {
archive_entry_copy_symlink(entry, subst_name);
free(subst_name);
}
}
#endif
/* Strip leading dir names as per --strip-components option. */
if (bsdtar->strip_components > 0) {
name = strip_components(name, bsdtar->strip_components);
if (name == NULL)
return (1);
if (hardlinkname != NULL) {
hardlinkname = strip_components(hardlinkname,
bsdtar->strip_components);
if (hardlinkname == NULL)
return (1);
}
}
if (!bsdtar->option_absolute_paths) {
/* By default, don't write or restore absolute pathnames. */
name = strip_absolute_path(bsdtar, name);
if (*name == '\0')
name = ".";
if (hardlinkname != NULL) {
hardlinkname = strip_absolute_path(bsdtar, hardlinkname);
if (*hardlinkname == '\0')
return (1);
}
} else {
/* Strip redundant leading '/' characters. */
while (name[0] == '/' && name[1] == '/')
name++;
}
/* Replace name in archive_entry. */
if (name != original_name) {
archive_entry_copy_pathname(entry, name);
}
if (hardlinkname != original_hardlinkname) {
archive_entry_copy_hardlink(entry, hardlinkname);
}
return (0);
}
/*
* It would be nice to just use printf() for formatting large numbers,
* but the compatibility problems are quite a headache. Hence the
* following simple utility function.
*/
const char *
tar_i64toa(int64_t n0)
{
static char buff[24];
uint64_t n = n0 < 0 ? -n0 : n0;
char *p = buff + sizeof(buff);
*--p = '\0';
do {
*--p = '0' + (int)(n % 10);
} while (n /= 10);
if (n0 < 0)
*--p = '-';
return p;
}
/*
* Like strcmp(), but try to be a little more aware of the fact that
* we're comparing two paths. Right now, it just handles leading
* "./" and trailing '/' specially, so that "a/b/" == "./a/b"
*
* TODO: Make this better, so that "./a//b/./c/" == "a/b/c"
* TODO: After this works, push it down into libarchive.
* TODO: Publish the path normalization routines in libarchive so
* that bsdtar can normalize paths and use fast strcmp() instead
* of this.
*
* Note: This is currently only used within write.c, so should
* not handle \ path separators.
*/
int
pathcmp(const char *a, const char *b)
{
/* Skip leading './' */
if (a[0] == '.' && a[1] == '/' && a[2] != '\0')
a += 2;
if (b[0] == '.' && b[1] == '/' && b[2] != '\0')
b += 2;
/* Find the first difference, or return (0) if none. */
while (*a == *b) {
if (*a == '\0')
return (0);
a++;
b++;
}
/*
* If one ends in '/' and the other one doesn't,
* they're the same.
*/
if (a[0] == '/' && a[1] == '\0' && b[0] == '\0')
return (0);
if (a[0] == '\0' && b[0] == '/' && b[1] == '\0')
return (0);
/* They're really different, return the correct sign. */
return (*(const unsigned char *)a - *(const unsigned char *)b);
}
#define PPBUFF_SIZE 1024
const char *
passphrase_callback(struct archive *a, void *_client_data)
{
struct bsdtar *bsdtar = (struct bsdtar *)_client_data;
(void)a; /* UNUSED */
if (bsdtar->ppbuff == NULL) {
bsdtar->ppbuff = malloc(PPBUFF_SIZE);
if (bsdtar->ppbuff == NULL)
lafe_errc(1, errno, "Out of memory");
}
return lafe_readpassphrase("Enter passphrase:",
bsdtar->ppbuff, PPBUFF_SIZE);
}
void
passphrase_free(char *ppbuff)
{
if (ppbuff != NULL) {
memset(ppbuff, 0, PPBUFF_SIZE);
free(ppbuff);
}
}