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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_lstat.hpp"
#include "fs_path.hpp"
#include "fs_inode.hpp"
#include "fs_symlink.hpp"
#include "fuse_getattr.hpp"
#include "ugid.hpp"
#include "fuse.h"
#include <string>
#include <sys/types.h>
#include <unistd.h>
using std::string;
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
symlink_loop_core(const string &newbasepath_,
const char *target_,
const char *linkpath_,
struct stat *st_,
const int error_)
{
int rv;
string fullnewpath;
fullnewpath = fs::path::make(newbasepath_,linkpath_);
rv = fs::symlink(target_,fullnewpath);
if((rv != -1) && (st_ != NULL) && (st_->st_ino == 0))
{
fs::lstat(fullnewpath,st_);
if(st_->st_ino != 0)
fs::inode::calc(linkpath_,st_);
}
return error::calc(rv,error_,errno);
}
static
int
symlink_loop(const string &existingpath_,
const StrVec &newbasepaths_,
const char *target_,
const char *linkpath_,
const string &newdirpath_,
struct stat *st_)
{
int rv;
int error;
error = -1;
for(size_t i = 0, ei = newbasepaths_.size(); i != ei; i++)
{
rv = fs::clonepath_as_root(existingpath_,newbasepaths_[i],newdirpath_);
if(rv == -1)
error = error::calc(rv,error,errno);
else
error = l::symlink_loop_core(newbasepaths_[i],
target_,
linkpath_,
st_,
error);
}
return -error;
}
static
int
symlink(const Policy::Search &searchFunc_,
const Policy::Create &createFunc_,
const Branches &branches_,
const char *target_,
const char *linkpath_,
struct stat *st_)
{
int rv;
string newdirpath;
StrVec newbasepaths;
StrVec existingpaths;
newdirpath = fs::path::dirname(linkpath_);
rv = searchFunc_(branches_,newdirpath,&existingpaths);
if(rv == -1)
return -errno;
rv = createFunc_(branches_,newdirpath,&newbasepaths);
if(rv == -1)
return -errno;
return l::symlink_loop(existingpaths[0],newbasepaths,
target_,linkpath_,newdirpath,st_);
}
}
namespace FUSE
{
int
symlink(const char *target_,
const char *linkpath_,
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::symlink(cfg->func.getattr.policy,
cfg->func.symlink.policy,
cfg->branches,
target_,
linkpath_,
st_);
if(rv == -EROFS)
{
Config::Write()->branches.find_and_set_mode_ro();
rv = l::symlink(cfg->func.getattr.policy,
cfg->func.symlink.policy,
cfg->branches,
target_,
linkpath_,
st_);
}
if(timeouts_ != NULL)
{
switch(cfg->follow_symlinks)
{
case FollowSymlinks::ENUM::NEVER:
timeouts_->entry = ((rv >= 0) ?
cfg->cache_entry :
cfg->cache_negative_entry);
timeouts_->attr = cfg->cache_attr;
break;
default:
timeouts_->entry = 0;
timeouts_->attr = 0;
break;
}
}
return rv;
}
}