Verified Commit f782a743 authored by Tommaso Tocci's avatar Tommaso Tocci
Browse files

intercept renameat

parent d6c78bdb

ifs/include/preload/hooks.hpp

+2 −0
Original line number Diff line number Diff line
@@ -36,6 +36,8 @@ int hook_fchdir(unsigned int fd); 
int hook_getcwd(char * buf, unsigned long size);

int hook_readlinkat(int dirfd, const char * cpath, char * buf, int bufsiz);

int hook_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg);

int hook_renameat(int olddfd, const char * oldname, int newdfd, const char * newname,

                  unsigned int flags);





#endif

ifs/src/preload/hooks.cpp

+58 −0
Original line number Diff line number Diff line
@@ -555,3 +555,61 @@ int hook_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg) { 
            return -ENOTSUP;

    }

}



int hook_renameat(int olddfd, const char * oldname,

                  int newdfd, const char * newname,

                  unsigned int flags) {



    CTX->log()->trace("{}() called with olddfd {}, oldname: '{}', newfd {}, newname '{}', flags {}",

                      __func__, olddfd, oldname, newdfd, newname, flags);



    const char * oldpath_pass;

    std::string oldpath_resolved;

    auto oldpath_status = CTX->relativize_fd_path(olddfd, oldname, oldpath_resolved);

    switch(oldpath_status) {

        case RelativizeStatus::fd_unknown:

            oldpath_pass = oldname;

            break;



        case RelativizeStatus::external:

            oldpath_pass = oldpath_resolved.c_str();

            break;



        case RelativizeStatus::fd_not_a_dir:

            return -ENOTDIR;



        case RelativizeStatus::internal:

            CTX->log()->warn("{}() not supported", __func__);

            return -ENOTSUP;



        default:

            CTX->log()->error("{}() relativize status unknown", __func__);

            return -EINVAL;

    }



    const char * newpath_pass;

    std::string newpath_resolved;

    auto newpath_status = CTX->relativize_fd_path(newdfd, newname, newpath_resolved);

    switch(newpath_status) {

        case RelativizeStatus::fd_unknown:

            newpath_pass = newname;

            break;



        case RelativizeStatus::external:

            newpath_pass = newpath_resolved.c_str();

            break;



        case RelativizeStatus::fd_not_a_dir:

            return -ENOTDIR;



        case RelativizeStatus::internal:

            CTX->log()->warn("{}() not supported", __func__);

            return -ENOTSUP;



        default:

            CTX->log()->error("{}() relativize status unknown", __func__);

            return -EINVAL;

    }



   return syscall_no_intercept(SYS_renameat2, olddfd, oldpath_pass, newdfd, newpath_pass, flags);

}

ifs/src/preload/intercept.cpp

+24 −0
Original line number Diff line number Diff line
@@ -242,6 +242,30 @@ static inline int hook(long syscall_number, 
                             static_cast<unsigned long>(arg2));

        break;



    case SYS_rename:

        *result = hook_renameat(AT_FDCWD,

                                reinterpret_cast<const char *>(arg0),

                                AT_FDCWD,

                                reinterpret_cast<const char *>(arg1),

                                0);

        break;



    case SYS_renameat:

        *result = hook_renameat(static_cast<int>(arg0),

                                reinterpret_cast<const char *>(arg1),

                                static_cast<int>(arg2),

                                reinterpret_cast<const char *>(arg3),

                                0);

        break;



    case SYS_renameat2:

        *result = hook_renameat(static_cast<int>(arg0),

                                reinterpret_cast<const char *>(arg1),

                                static_cast<int>(arg2),

                                reinterpret_cast<const char *>(arg3),

                                static_cast<unsigned int>(arg4));

        break;

    

    default:

        /*

         * Ignore any other syscalls