Verified Commit 58360b32 authored by Tommaso Tocci's avatar Tommaso Tocci
Browse files

relativize path support fd descriptor logic 

relativize path now accepts a file descriptor.

If fd is AT_FDCWD relative path need to be considered with respect to
the current working directory. Otherwise the path is relative to the
directory with the given file descriptor
parent 50b0a755

ifs/include/preload/preload_context.hpp

+10 −1
Original line number Diff line number Diff line
@@ -36,6 +36,12 @@ struct FsConfig { 
    std::string rpc_port;

};



enum class RelativizeStatus {

    internal,

    external,

    fd_unknown,

    fd_not_a_dir

};



class PreloadContext {

    private:
@@ -74,8 +80,11 @@ class PreloadContext { 
    void cwd(const std::string& path);

    const std::string& cwd() const;



    bool relativize_path(const char * raw_path, std::string& relative_path) const;

    RelativizeStatus relativize_fd_path(int dirfd,

                                        const char * raw_path,

                                        std::string& relative_path) const;



    bool relativize_path(const char * raw_path, std::string& relative_path) const;

    const std::shared_ptr<OpenFileMap>& file_map() const;



    void distributor(std::shared_ptr<Distributor> distributor);

ifs/src/preload/preload_context.cpp

+46 −3
Original line number Diff line number Diff line 
#include <preload/preload_context.hpp>



#include <preload/open_file_map.hpp>

#include <preload/open_dir.hpp>

#include <preload/resolve.hpp>

#include <global/path_util.hpp>

#include <cassert>
@@ -53,15 +54,57 @@ const std::string& PreloadContext::cwd() const { 
    return cwd_;

}



bool PreloadContext::relativize_path(const char * raw_path, std::string& relative_path) const {

RelativizeStatus PreloadContext::relativize_fd_path(int dirfd,

                                                    const char * raw_path,

                                                    std::string& relative_path) const {



    // Relativize path should be called only after the library constructor has been executed

    assert(initialized_);

    // If we run the constructor we also already setup the mountdir

    assert(!mountdir_.empty());



    if(raw_path == nullptr || raw_path[0] == '\0') {

        return false;

    // We assume raw path is valid

    assert(raw_path != nullptr);



    std::string path;



    if (raw_path[0] != PSP) {

        // path is relative

        if (dirfd == AT_FDCWD) {

            // path is relative to cwd

            path = prepend_path(cwd_, raw_path);

        } else {

            if (!ofm_->exist(dirfd)) {

                return RelativizeStatus::fd_unknown;

            }

            // path is relative to fd

            auto dir = ofm_->get_dir(dirfd);

            if (dir == nullptr) {

                return RelativizeStatus::fd_not_a_dir;

            }

            path = mountdir_;

            path.append(dir->path());

            path.push_back(PSP);

            path.append(raw_path);

        }

    } else {

        path = raw_path;

    }



    if (resolve_path(path, relative_path)) {

        return RelativizeStatus::internal;

    }

    return RelativizeStatus::external;

}



bool PreloadContext::relativize_path(const char * raw_path, std::string& relative_path) const {

    // Relativize path should be called only after the library constructor has been executed

    assert(initialized_);

    // If we run the constructor we also already setup the mountdir

    assert(!mountdir_.empty());



    // We assume raw path is valid

    assert(raw_path != nullptr);



    std::string path;