pkgconf/libpkgconf/path.c

331 lines
7.8 KiB
C

/*
* path.c
* filesystem path management
*
* Copyright (c) 2016 pkgconf authors (see AUTHORS).
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* This software is provided 'as is' and without any warranty, express or
* implied. In no event shall the authors be liable for any damages arising
* from the use of this software.
*/
#include <libpkgconf/stdinc.h>
#include <libpkgconf/libpkgconf.h>
#include <libpkgconf/config.h>
#if defined(HAVE_CYGWIN_CONV_PATH) && defined(__MSYS__)
# include <sys/cygwin.h>
#endif
#if defined(HAVE_SYS_STAT_H) && ! defined(_WIN32)
# include <sys/stat.h>
# define PKGCONF_CACHE_INODES
#endif
static bool
#ifdef PKGCONF_CACHE_INODES
path_list_contains_entry(const char *text, pkgconf_list_t *dirlist, struct stat *st)
#else
path_list_contains_entry(const char *text, pkgconf_list_t *dirlist)
#endif
{
pkgconf_node_t *n;
PKGCONF_FOREACH_LIST_ENTRY(dirlist->head, n)
{
pkgconf_path_t *pn = n->data;
#ifdef PKGCONF_CACHE_INODES
if (pn->handle_device == (void *)(intptr_t)st->st_dev && pn->handle_path == (void *)(intptr_t)st->st_ino)
return true;
#endif
if (!strcmp(text, pn->path))
return true;
}
return false;
}
/*
* !doc
*
* libpkgconf `path` module
* ========================
*
* The `path` module provides functions for manipulating lists of paths in a cross-platform manner. Notably,
* it is used by the `pkgconf client` to parse the ``PKG_CONFIG_PATH``, ``PKG_CONFIG_LIBDIR`` and related environment
* variables.
*/
/*
* !doc
*
* .. c:function:: void pkgconf_path_add(const char *text, pkgconf_list_t *dirlist)
*
* Adds a path node to a path list. If the path is already in the list, do nothing.
*
* :param char* text: The path text to add as a path node.
* :param pkgconf_list_t* dirlist: The path list to add the path node to.
* :param bool filter: Whether to perform duplicate filtering.
* :return: nothing
*/
void
pkgconf_path_add(const char *text, pkgconf_list_t *dirlist, bool filter)
{
pkgconf_path_t *node;
char path[PKGCONF_ITEM_SIZE];
pkgconf_strlcpy(path, text, sizeof path);
pkgconf_path_relocate(path, sizeof path);
#ifdef PKGCONF_CACHE_INODES
struct stat st;
if (filter)
{
if (lstat(path, &st) == -1)
return;
if (S_ISLNK(st.st_mode))
{
char linkdest[PKGCONF_ITEM_SIZE];
ssize_t len;
memset(linkdest, '\0', sizeof linkdest);
len = readlink(path, linkdest, sizeof linkdest);
if (len != -1 && (size_t)len < sizeof(linkdest) &&
stat(linkdest, &st) == -1)
return;
}
if (path_list_contains_entry(path, dirlist, &st))
return;
}
#else
if (filter && path_list_contains_entry(path, dirlist))
return;
#endif
node = calloc(sizeof(pkgconf_path_t), 1);
node->path = strdup(path);
#ifdef PKGCONF_CACHE_INODES
if (filter) {
node->handle_path = (void *)(intptr_t) st.st_ino;
node->handle_device = (void *)(intptr_t) st.st_dev;
}
#endif
pkgconf_node_insert_tail(&node->lnode, node, dirlist);
}
/*
* !doc
*
* .. c:function:: size_t pkgconf_path_split(const char *text, pkgconf_list_t *dirlist)
*
* Splits a given text input and inserts paths into a path list.
*
* :param char* text: The path text to split and add as path nodes.
* :param pkgconf_list_t* dirlist: The path list to have the path nodes added to.
* :param bool filter: Whether to perform duplicate filtering.
* :return: number of path nodes added to the path list
* :rtype: size_t
*/
size_t
pkgconf_path_split(const char *text, pkgconf_list_t *dirlist, bool filter)
{
size_t count = 0;
char *workbuf, *p, *iter;
if (text == NULL)
return 0;
iter = workbuf = strdup(text);
while ((p = strtok(iter, PKG_CONFIG_PATH_SEP_S)) != NULL)
{
pkgconf_path_add(p, dirlist, filter);
count++, iter = NULL;
}
free(workbuf);
return count;
}
/*
* !doc
*
* .. c:function:: size_t pkgconf_path_build_from_environ(const char *envvarname, const char *fallback, pkgconf_list_t *dirlist)
*
* Adds the paths specified in an environment variable to a path list. If the environment variable is not set,
* an optional default set of paths is added.
*
* :param char* envvarname: The environment variable to look up.
* :param char* fallback: The fallback paths to use if the environment variable is not set.
* :param pkgconf_list_t* dirlist: The path list to add the path nodes to.
* :param bool filter: Whether to perform duplicate filtering.
* :return: number of path nodes added to the path list
* :rtype: size_t
*/
size_t
pkgconf_path_build_from_environ(const char *envvarname, const char *fallback, pkgconf_list_t *dirlist, bool filter)
{
const char *data;
data = getenv(envvarname);
if (data != NULL)
return pkgconf_path_split(data, dirlist, filter);
if (fallback != NULL)
return pkgconf_path_split(fallback, dirlist, filter);
/* no fallback and no environment variable, thusly no nodes added */
return 0;
}
/*
* !doc
*
* .. c:function:: bool pkgconf_path_match_list(const char *path, const pkgconf_list_t *dirlist)
*
* Checks whether a path has a matching prefix in a path list.
*
* :param char* path: The path to check against a path list.
* :param pkgconf_list_t* dirlist: The path list to check the path against.
* :return: true if the path list has a matching prefix, otherwise false
* :rtype: bool
*/
bool
pkgconf_path_match_list(const char *path, const pkgconf_list_t *dirlist)
{
pkgconf_node_t *n = NULL;
char relocated[PKGCONF_ITEM_SIZE];
const char *cpath = path;
pkgconf_strlcpy(relocated, path, sizeof relocated);
if (pkgconf_path_relocate(relocated, sizeof relocated))
cpath = relocated;
PKGCONF_FOREACH_LIST_ENTRY(dirlist->head, n)
{
pkgconf_path_t *pnode = n->data;
if (!strcmp(pnode->path, cpath))
return true;
}
return false;
}
/*
* !doc
*
* .. c:function:: void pkgconf_path_free(pkgconf_list_t *dirlist)
*
* Releases any path nodes attached to the given path list.
*
* :param pkgconf_list_t* dirlist: The path list to clean up.
* :return: nothing
*/
void
pkgconf_path_free(pkgconf_list_t *dirlist)
{
pkgconf_node_t *n, *tn;
PKGCONF_FOREACH_LIST_ENTRY_SAFE(dirlist->head, tn, n)
{
pkgconf_path_t *pnode = n->data;
free(pnode->path);
free(pnode);
}
}
static char *
normpath(const char *path)
{
if (!path)
return NULL;
char *copy = strdup(path);
if (NULL == copy)
return NULL;
char *ptr = copy;
for (int ii = 0; copy[ii]; ii++)
{
*ptr++ = path[ii];
if ('/' == path[ii])
{
ii++;
while ('/' == path[ii])
ii++;
ii--;
}
}
*ptr = '\0';
return copy;
}
/*
* !doc
*
* .. c:function:: bool pkgconf_path_relocate(char *buf, size_t buflen)
*
* Relocates a path, possibly calling normpath() or cygwin_conv_path() on it.
*
* :param char* buf: The path to relocate.
* :param size_t buflen: The buffer length the path is contained in.
* :return: true on success, false on error
* :rtype: bool
*/
bool
pkgconf_path_relocate(char *buf, size_t buflen)
{
#if defined(HAVE_CYGWIN_CONV_PATH) && defined(__MSYS__)
ssize_t size;
char *tmpbuf, *ti;
size = cygwin_conv_path(CCP_POSIX_TO_WIN_A, buf, NULL, 0);
if (size < 0 || (size_t) size > buflen)
return false;
tmpbuf = malloc(size);
if (cygwin_conv_path(CCP_POSIX_TO_WIN_A, buf, tmpbuf, size))
return false;
pkgconf_strlcpy(buf, tmpbuf, buflen);
free(tmpbuf);
/* rewrite any backslash arguments for best compatibility */
for (ti = buf; *ti != '\0'; ti++)
{
if (*ti == '\\')
*ti = '/';
}
#else
char *tmpbuf;
if ((tmpbuf = normpath(buf)) != NULL)
{
size_t tmpbuflen = strlen(tmpbuf);
if (tmpbuflen > buflen)
{
free(tmpbuf);
return false;
}
pkgconf_strlcpy(buf, tmpbuf, buflen);
free(tmpbuf);
}
#endif
return true;
}