mergerfs/src/fuse_readlink.cpp

135 lines
3.4 KiB
C++

/*
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_lstat.hpp"
#include "fs_path.hpp"
#include "fs_readlink.hpp"
#include "symlinkify.hpp"
#include "ugid.hpp"
#include "fuse.h"
#include <string.h>
using std::string;
namespace l
{
static
int
readlink_core_standard(const string &fullpath_,
char *buf_,
const size_t size_)
{
int rv;
rv = fs::readlink(fullpath_,buf_,size_);
if(rv == -1)
return -errno;
buf_[rv] = '\0';
return 0;
}
static
int
readlink_core_symlinkify(const string &fullpath_,
char *buf_,
const size_t size_,
const time_t symlinkify_timeout_)
{
int rv;
struct stat st;
rv = fs::lstat(fullpath_,&st);
if(rv == -1)
return -errno;
if(!symlinkify::can_be_symlink(st,symlinkify_timeout_))
return l::readlink_core_standard(fullpath_,buf_,size_);
strncpy(buf_,fullpath_.c_str(),size_);
return 0;
}
static
int
readlink_core(const string &basepath_,
const char *fusepath_,
char *buf_,
const size_t size_,
const bool symlinkify_,
const time_t symlinkify_timeout_)
{
string fullpath;
fullpath = fs::path::make(basepath_,fusepath_);
if(symlinkify_)
return l::readlink_core_symlinkify(fullpath,buf_,size_,symlinkify_timeout_);
return l::readlink_core_standard(fullpath,buf_,size_);
}
static
int
readlink(const Policy::Search &searchFunc_,
const Branches &branches_,
const char *fusepath_,
char *buf_,
const size_t size_,
const bool symlinkify_,
const time_t symlinkify_timeout_)
{
int rv;
StrVec basepaths;
rv = searchFunc_(branches_,fusepath_,&basepaths);
if(rv == -1)
return -errno;
return l::readlink_core(basepaths[0],fusepath_,buf_,size_,
symlinkify_,symlinkify_timeout_);
}
}
namespace FUSE
{
int
readlink(const char *fusepath_,
char *buf_,
size_t size_)
{
Config::Read cfg;
const fuse_context *fc = fuse_get_context();
const ugid::Set ugid(fc->uid,fc->gid);
return l::readlink(cfg->func.readlink.policy,
cfg->branches,
fusepath_,
buf_,
size_,
cfg->symlinkify,
cfg->symlinkify_timeout);
}
}