Verified Commit 42201011 authored by Tommaso Tocci's avatar Tommaso Tocci
Browse files

intercept getdents

parent 42111273

ifs/include/preload/adafs_functions.hpp

+3 −1
Original line number Diff line number Diff line
@@ -69,7 +69,9 @@ ssize_t adafs_read(int fd, void* buf, size_t count); 


int adafs_opendir(const std::string& path);



struct dirent * adafs_readdir(int fd);

int getdents(unsigned int fd,

             struct linux_dirent *dirp,

             unsigned int count);



int adafs_rmdir(const std::string& path);

ifs/include/preload/hooks.hpp

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ int hook_lseek(unsigned int fd, off_t offset, unsigned int whence); 
int hook_dup(unsigned int fd);

int hook_dup2(unsigned int oldfd, unsigned int newfd);

int hook_dup3(unsigned int oldfd, unsigned int newfd, int flags);

int hook_getdents(unsigned int fd, struct linux_dirent *dirp, unsigned int count);





#endif

ifs/include/preload/open_dir.hpp

+11 −14
Original line number Diff line number Diff line
@@ -10,28 +10,25 @@ 
#include <preload/open_file_map.hpp>





class OpenDir: public OpenFile {

    private:



class DirEntry {

    private:

        std::string name_;

        FileType type_;

    public:

                std::string name;

                FileType type;



        DirEntry(const std::string& name, const FileType type);

        const std::string& name();

        FileType type();

};



class OpenDir: public OpenFile {

    private:

        std::vector<DirEntry> entries;

        struct dirent dirent_;

        bool is_dirent_valid;



        void update_dirent(unsigned int pos);





    public:

        OpenDir(const std::string& path);

        void add(const std::string& name, const FileType& type);

        struct dirent * readdir();

        const DirEntry& getdent(unsigned int pos);

        size_t size();

};

ifs/src/preload/adafs_functions.cpp

+62 −8
Original line number Diff line number Diff line
@@ -8,6 +8,20 @@ 
#include <preload/rpc/ld_rpc_data_ws.hpp>

#include <preload/open_dir.hpp>



#include <dirent.h>





#define __ALIGN_KERNEL_MASK(x, mask)	(((x) + (mask)) & ~(mask))

#define __ALIGN_KERNEL(x, a)		    __ALIGN_KERNEL_MASK(x, (typeof(x))(a) - 1)

#define ALIGN(x, a)                     __ALIGN_KERNEL((x), (a))



struct linux_dirent {

    unsigned long	d_ino;

    unsigned long	d_off;

    unsigned short	d_reclen;

    char		d_name[1];

};



using namespace std;



int adafs_open(const std::string& path, mode_t mode, int flags) {
@@ -469,15 +483,55 @@ int adafs_rmdir(const std::string& path) { 
    return rpc_send_rm_node(path, true);

}



struct dirent * adafs_readdir(int fd){

    CTX->log()->trace("{}() called on fd: {}", __func__, fd);

    auto open_file = CTX->file_map()->get(fd);

    assert(open_file != nullptr);

    auto open_dir = static_pointer_cast<OpenDir>(open_file);

    if(!open_dir){



int getdents(unsigned int fd,

             struct linux_dirent *dirp,

             unsigned int count) {

    CTX->log()->trace("{}() called on fd: {}, count {}", __func__, fd, count);

    auto open_dir = CTX->file_map()->get_dir(fd);

    if(open_dir == nullptr){

        //Cast did not succeeded: open_file is a regular file

        errno = EBADF;

        return nullptr;

        return -1;

    }



    auto pos = open_dir->pos();

    if (pos >= open_dir->size()) {

        return 0;

    }



    unsigned int written = 0;

    struct linux_dirent * current_dirp = nullptr;

    while(pos < open_dir->size()) {

        DirEntry de = open_dir->getdent(pos);

        auto total_size = ALIGN(offsetof(struct linux_dirent, d_name) +

                de.name().size() + 3, sizeof(long));

        if (total_size > (count - written)) {

            //no enough space left on user buffer to insert next dirent

            break;

        }

        current_dirp = reinterpret_cast<struct linux_dirent *>(

                        reinterpret_cast<char*>(dirp) + written);

        current_dirp->d_ino = std::hash<std::string>()(

                open_dir->path() + "/" + de.name());



        current_dirp->d_reclen = total_size;



        *(reinterpret_cast<char*>(current_dirp) + total_size - 1) =

            ((de.type() == FileType::regular)? DT_REG : DT_DIR);



        CTX->log()->trace("{}() name {}: {}", __func__, pos, de.name());

        std::strcpy(&(current_dirp->d_name[0]), de.name().c_str());

        ++pos;

        current_dirp->d_off = pos;

        written += total_size;

    }



    if (written == 0) {

        errno = EINVAL;

        return -1;

    }

    return open_dir->readdir();



    open_dir->pos(pos);

    return written;

}
 
 No newline at end of file

ifs/src/preload/hooks.cpp

+8 −0
Original line number Diff line number Diff line
@@ -168,3 +168,11 @@ int hook_dup3(unsigned int oldfd, unsigned int newfd, int flags) { 
    }

    return syscall_no_intercept(SYS_dup3, oldfd, newfd, flags);

}



int hook_getdents(unsigned int fd, struct linux_dirent *dirp, unsigned int count) {

    CTX->log()->trace("{}() called with fd {}, count {}", __func__, fd, count);

    if (CTX->file_map()->exist(fd)) {

        return with_errno(getdents(fd, dirp, count));

    }

    return syscall_no_intercept(SYS_getdents, fd, dirp, count);

}