/*-

* Copyright (c) 2015-2019 Juan Romero Pardines.

* Copyright (c) 2020 Duncan Overbruck <mail@duncano.de>.

* 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 ``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 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.

*/

/*-

* xbps_path_clean is based on the go filepath.Clean function:

* - https://github.com/golang/go/blob/cfe2ab42/src/path/filepath/path.go#L88

*

* Copyright (c) 2009 The Go Authors. All rights reserved.

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions are

* met:

*

* * Redistributions of source code must retain the above copyright

* notice, this list of conditions and the following disclaimer.

* * 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.

* * Neither the name of Google Inc. nor the names of its

* contributors may be used to endorse or promote products derived from

* this software without specific prior written permission.

*

* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

* "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 COPYRIGHT

* OWNER OR CONTRIBUTORS 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 <errno.h>

#include <limits.h>

#include <stdlib.h>

#include <string.h>

#include "xbps_api_impl.h"

ssize_t

xbps_path_clean(char *dst)

{

char buf[PATH_MAX];

const char *p = buf;

const char *dotdot = dst;

char *d = dst;

bool rooted = *dst == '/';

if (xbps_strlcpy(buf, dst, sizeof buf) >= sizeof buf)

return -1;

if (rooted) {

*d++ = '/';

p++;

dotdot++;

}

for (; *p;) {

switch (*p) {

/* empty path element */

case '/': p++; break;

case '.':

if (p[1] == '\0' || p[1] == '/') {

/* . element */

p++;

continue;

} else if (p[1] == '.' && (p[2] == '\0' || p[2] == '/')) {

p += 2;

/* .. element */

if (d > dotdot) {

/* can backtrack */

d--;

for (; d > dotdot && *d != '/'; d--)

;

} else if (!rooted) {

/* cannot backtrack, but not rooted,

* append .. element. */

if (d > dst)

*d++ = '/';

*d++ = '.';

*d++ = '.';

dotdot = d;

}

continue;

}

/* normal path element starting with . */

/* FALLTHROUGH */

default:

if (d > dst+(rooted ? 1 : 0))

*d++ = '/';

for (; *p && *p != '/'; p++)

*d++ = *p;

}

}

/* Turn empty string into "." */

if (d == dst)

*d++ = '.';

*d = '\0';

return (d-dst);

}

ssize_t

xbps_path_rel(char *dst, size_t dstlen, const char *from, const char *to)

{

char frombuf[PATH_MAX], tobuf[PATH_MAX];

const char *fromp = frombuf, *top = tobuf, *suffix = tobuf;

size_t len = 0;

int up = -1;

*dst = '\0';

if (xbps_strlcpy(frombuf, from, sizeof frombuf) >= sizeof frombuf ||

xbps_strlcpy(tobuf, to, sizeof tobuf) >= sizeof tobuf)

return -1;

if (xbps_path_clean(frombuf) == -1 || xbps_path_clean(tobuf) == -1)

return -1;

for (; *fromp == *top && *to; fromp++, top++)

if (*top == '/')

suffix = top;

for (up = -1, fromp--; fromp && *fromp; fromp = strchr(fromp+1, '/'), up++)

;

while (up--) {

for (const char *x = "../"; *x; x++) {

if (len+1 < dstlen)

dst[len] = *x;

len++;

}

}

if (*suffix != '\0') {

for (suffix += 1; *suffix; suffix++) {

if (len+1 < dstlen)

dst[len] = *suffix;

len++;

}

}

dst[len < dstlen ? len : dstlen - 1] = '\0';

return len;

}

static ssize_t

xbps_path_vjoin(char *dst, size_t dstlen, va_list ap)

{

size_t len = 0;

const char *val;

*dst = '\0';

if ((val = va_arg(ap, const char *)) == NULL)

return 0;

for (;;) {

size_t n;

if ((n = xbps_strlcat(dst+len, val, dstlen-len)) >= dstlen-len)

goto err;

len += n;

if ((val = va_arg(ap, const char *)) == NULL)

break;

if (len > 0 && dst[len-1] != '/') {

if (len+1 > dstlen)

goto err;

dst[len] = '/';

dst[len+1] = '\0';

len++;

}

if (len > 0 && *val == '/')

val++;

}

return (ssize_t)len < 0 ? -1 : (ssize_t)len;

err:

errno = ENOBUFS;

return -1;

}

ssize_t

xbps_path_join(char *dst, size_t dstlen, ...)

{

ssize_t len;

va_list ap;

va_start(ap, dstlen);

len = xbps_path_vjoin(dst, dstlen, ap);

va_end(ap);

return len;

}

ssize_t

xbps_path_append(char *dst, size_t dstlen, const char *suffix)

{

size_t len = strlen(dst);

if (*suffix == '\0')

goto out;

if (*dst == '\0') {

if ((len = xbps_strlcpy(dst, suffix, dstlen)) >= dstlen)

goto err;

goto out;

}

if (dst[len-1] != '/' && len+1 < dstlen) {

dst[len] = '/';

dst[len+1] = '\0';

}

if (*suffix == '/')

suffix++;

if ((len = xbps_strlcat(dst, suffix, dstlen)) >= dstlen)

goto err;

out:

return (ssize_t)len < 0 ? -1 : (ssize_t)len;

err:

errno = ENOBUFS;

return -1;

}

ssize_t

xbps_path_prepend(char *dst, size_t dstlen, const char *prefix)

{

size_t len, prelen;

char *p = dst;

len = strlen(dst);

if (*prefix == '\0')

goto out;

if (*dst == '\0') {

if ((len = xbps_strlcpy(dst, prefix, dstlen)) >= dstlen)

goto err;

goto out;

}

prelen = strlen(prefix);

if (prefix[prelen-1] == '/')

prelen--;

if (*dst == '/') {

len--;

p++;

}

/* prefix + '/' + dst + '\0' */

if (len+prelen+2 > dstlen)

goto err;

memmove(dst+prelen+1, p, len);

len += prelen+1;

dst[prelen] = '/';

memcpy(dst, prefix, prelen);

dst[len] = '\0';

out:

return (ssize_t)len < 0 ? -1 : (ssize_t)len;

err:

errno = ENOBUFS;

return -1;

}