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/*
Copyright (c) 2016, Antonio SJ Musumeci <trapexit@spawn.link>
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.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "config.hpp"
#include "errno.hpp"
#include "fs_clonepath.hpp"
#include "fs_link.hpp"
#include "fs_lstat.hpp"
#include "fs_path.hpp"
#include "fuse_getattr.hpp"
#include "fuse_symlink.hpp"
#include "ghc/filesystem.hpp"
#include "ugid.hpp"
#include "fuse.h"
#include <string>
#include <vector>
using std::string;
using std::vector;
namespace gfs = ghc::filesystem;
namespace error
{
static
inline
int
calc(const int rv_,
const int prev_,
const int cur_)
{
if(rv_ == -1)
{
if(prev_ == 0)
return 0;
return cur_;
}
return 0;
}
}
namespace l
{
static
int
link_create_path_loop(const StrVec &oldbasepaths_,
const string &newbasepath_,
const char *oldfusepath_,
const char *newfusepath_,
const string &newfusedirpath_)
{
int rv;
int error;
string oldfullpath;
string newfullpath;
error = -1;
for(auto &oldbasepath : oldbasepaths_)
{
oldfullpath = fs::path::make(oldbasepath,oldfusepath_);
newfullpath = fs::path::make(oldbasepath,newfusepath_);
rv = fs::link(oldfullpath,newfullpath);
if((rv == -1) && (errno == ENOENT))
{
rv = fs::clonepath_as_root(newbasepath_,oldbasepath,newfusedirpath_);
if(rv == 0)
rv = fs::link(oldfullpath,newfullpath);
}
error = error::calc(rv,error,errno);
}
return -error;
}
static
int
link_create_path(const Policy::Search &searchFunc_,
const Policy::Action &actionFunc_,
const Branches &branches_,
const char *oldfusepath_,
const char *newfusepath_)
{
int rv;
string newfusedirpath;
StrVec oldbasepaths;
StrVec newbasepaths;
rv = actionFunc_(branches_,oldfusepath_,&oldbasepaths);
if(rv == -1)
return -errno;
newfusedirpath = fs::path::dirname(newfusepath_);
rv = searchFunc_(branches_,newfusedirpath,&newbasepaths);
if(rv == -1)
return -errno;
return l::link_create_path_loop(oldbasepaths,newbasepaths[0],
oldfusepath_,newfusepath_,
newfusedirpath);
}
static
int
link_preserve_path_core(const string &oldbasepath_,
const char *oldfusepath_,
const char *newfusepath_,
struct stat *st_,
const int error_)
{
int rv;
string oldfullpath;
string newfullpath;
oldfullpath = fs::path::make(oldbasepath_,oldfusepath_);
newfullpath = fs::path::make(oldbasepath_,newfusepath_);
rv = fs::link(oldfullpath,newfullpath);
if((rv == -1) && (errno == ENOENT))
errno = EXDEV;
if((rv == 0) && (st_->st_ino == 0))
rv = fs::lstat(oldfullpath,st_);
return error::calc(rv,error_,errno);
}
static
int
link_preserve_path_loop(const StrVec &oldbasepaths_,
const char *oldfusepath_,
const char *newfusepath_,
struct stat *st_)
{
int error;
error = -1;
for(auto &oldbasepath : oldbasepaths_)
{
error = l::link_preserve_path_core(oldbasepath,
oldfusepath_,
newfusepath_,
st_,
error);
}
return -error;
}
static
int
link_preserve_path(const Policy::Action &actionFunc_,
const Branches &branches_,
const char *oldfusepath_,
const char *newfusepath_,
struct stat *st_)
{
int rv;
StrVec oldbasepaths;
rv = actionFunc_(branches_,oldfusepath_,&oldbasepaths);
if(rv == -1)
return -errno;
return l::link_preserve_path_loop(oldbasepaths,
oldfusepath_,
newfusepath_,
st_);
}
static
int
link(Config::Read &cfg_,
const char *oldpath_,
const char *newpath_,
struct stat *st_)
{
if(cfg_->func.create.policy.path_preserving() && !cfg_->ignorepponrename)
return l::link_preserve_path(cfg_->func.link.policy,
cfg_->branches,
oldpath_,
newpath_,
st_);
return l::link_create_path(cfg_->func.getattr.policy,
cfg_->func.link.policy,
cfg_->branches,
oldpath_,
newpath_);
}
static
int
link(Config::Read &cfg_,
const char *oldpath_,
const char *newpath_,
struct stat *st_,
fuse_timeouts_t *timeouts_)
{
int rv;
rv = l::link(cfg_,oldpath_,newpath_,st_);
if(rv < 0)
return rv;
return FUSE::getattr(newpath_,st_,timeouts_);
}
static
int
link_exdev_rel_symlink(const char *oldpath_,
const char *newpath_,
struct stat *st_,
fuse_timeouts_t *timeouts_)
{
int rv;
gfs::path target(oldpath_);
gfs::path linkpath(newpath_);
target = target.lexically_relative(linkpath.parent_path());
rv = FUSE::symlink(target.c_str(),linkpath.c_str());
if(rv == 0)
rv = FUSE::getattr(oldpath_,st_,timeouts_);
// Disable caching since we created a symlink but should be a regular.
timeouts_->attr = 0;
timeouts_->entry = 0;
return rv;
}
static
int
link_exdev_abs_base_symlink(const Policy::Search &openPolicy_,
const Branches::CPtr &branches_,
const char *oldpath_,
const char *newpath_,
struct stat *st_,
fuse_timeouts_t *timeouts_)
{
int rv;
StrVec basepaths;
std::string target;
rv = openPolicy_(branches_,oldpath_,&basepaths);
if(rv == -1)
return -errno;
target = fs::path::make(basepaths[0],oldpath_);
rv = FUSE::symlink(target.c_str(),newpath_);
if(rv == 0)
rv = FUSE::getattr(oldpath_,st_,timeouts_);
// Disable caching since we created a symlink but should be a regular.
timeouts_->attr = 0;
timeouts_->entry = 0;
return rv;
}
static
int
link_exdev_abs_pool_symlink(const std::string &mount_,
const char *oldpath_,
const char *newpath_,
struct stat *st_,
fuse_timeouts_t *timeouts_)
{
int rv;
StrVec basepaths;
std::string target;
target = fs::path::make(mount_,oldpath_);
rv = FUSE::symlink(target.c_str(),newpath_);
if(rv == 0)
rv = FUSE::getattr(oldpath_,st_,timeouts_);
// Disable caching since we created a symlink but should be a regular.
timeouts_->attr = 0;
timeouts_->entry = 0;
return rv;
}
static
int
link_exdev(Config::Read &cfg_,
const char *oldpath_,
const char *newpath_,
struct stat *st_,
fuse_timeouts_t *timeouts_)
{
switch(cfg_->link_exdev)
{
case LinkEXDEV::ENUM::PASSTHROUGH:
return -EXDEV;
case LinkEXDEV::ENUM::REL_SYMLINK:
return l::link_exdev_rel_symlink(oldpath_,
newpath_,
st_,
timeouts_);
case LinkEXDEV::ENUM::ABS_BASE_SYMLINK:
return l::link_exdev_abs_base_symlink(cfg_->func.open.policy,
cfg_->branches,
oldpath_,
newpath_,
st_,
timeouts_);
case LinkEXDEV::ENUM::ABS_POOL_SYMLINK:
return l::link_exdev_abs_pool_symlink(cfg_->mountpoint,
oldpath_,
newpath_,
st_,
timeouts_);
}
return -EXDEV;
}
}
namespace FUSE
{
int
link(const char *oldpath_,
const char *newpath_,
struct stat *st_,
fuse_timeouts_t *timeouts_)
{
int rv;
Config::Read cfg;
const fuse_context *fc = fuse_get_context();
const ugid::Set ugid(fc->uid,fc->gid);
rv = l::link(cfg,oldpath_,newpath_,st_,timeouts_);
if(rv == -EXDEV)
rv = l::link_exdev(cfg,oldpath_,newpath_,st_,timeouts_);
return rv;
}
}