Commit b5ab4466 authored by Ramon Nou's avatar Ramon Nou
Browse files

Syscall Wrapper

parent f5e19305

src/client/hooks.cpp

+72 −53
Original line number Diff line number Diff line
@@ -56,6 +56,19 @@ with_errno(int ret) { 


} // namespace



template <class... Args>

inline long

syscall_no_intercept_wrapper(long syscall_number, Args... args) {

    long result;

    int error;

    result = syscall_no_intercept(syscall_number, args...);

    error = syscall_error_code(result);

    if(error != 0) {

        return -error;

    }

    return result;

}



namespace gkfs::hook {



int
@@ -103,7 +116,7 @@ hook_close(int fd) { 
        return 0;

    }



    return syscall_no_intercept(SYS_close, fd);

    return syscall_no_intercept_wrapper(SYS_close, fd);

}



int
@@ -116,7 +129,8 @@ hook_stat(const char* path, struct stat* buf) { 
    if(CTX->relativize_path(path, rel_path, false)) {

        return with_errno(gkfs::syscall::gkfs_stat(rel_path, buf));

    }

    return syscall_no_intercept(SYS_stat, rel_path.c_str(), buf);



    return syscall_no_intercept_wrapper(SYS_stat, rel_path.c_str(), buf);

}



#ifdef STATX_TYPE
@@ -167,7 +181,8 @@ hook_lstat(const char* path, struct stat* buf) { 
    if(CTX->relativize_path(path, rel_path)) {

        return with_errno(gkfs::syscall::gkfs_stat(rel_path, buf));

    }

    return syscall_no_intercept(SYS_lstat, rel_path.c_str(), buf);

    return syscall_no_intercept_wrapper(SYS_lstat, rel_path.c_str(), buf);

    ;

}



int
@@ -179,7 +194,7 @@ hook_fstat(unsigned int fd, struct stat* buf) { 
        auto path = CTX->file_map()->get(fd)->path();

        return with_errno(gkfs::syscall::gkfs_stat(path, buf));

    }

    return syscall_no_intercept(SYS_fstat, fd, buf);

    return syscall_no_intercept_wrapper(SYS_fstat, fd, buf);

}



int
@@ -197,12 +212,12 @@ hook_fstatat(int dirfd, const char* cpath, struct stat* buf, int flags) { 
    auto rstatus = CTX->relativize_fd_path(dirfd, cpath, resolved);

    switch(rstatus) {

        case gkfs::preload::RelativizeStatus::fd_unknown:

            return syscall_no_intercept(SYS_newfstatat, dirfd, cpath, buf,

                                        flags);

            return syscall_no_intercept_wrapper(SYS_newfstatat, dirfd, cpath,

                                                buf, flags);



        case gkfs::preload::RelativizeStatus::external:

            return syscall_no_intercept(SYS_newfstatat, dirfd, resolved.c_str(),

                                        buf, flags);

            return syscall_no_intercept_wrapper(SYS_newfstatat, dirfd,

                                                resolved.c_str(), buf, flags);



        case gkfs::preload::RelativizeStatus::fd_not_a_dir:

            return -ENOTDIR;
@@ -225,7 +240,7 @@ hook_read(unsigned int fd, void* buf, size_t count) { 
    if(CTX->file_map()->exist(fd)) {

        return with_errno(gkfs::syscall::gkfs_read(fd, buf, count));

    }

    return syscall_no_intercept(SYS_read, fd, buf, count);

    return syscall_no_intercept_wrapper(SYS_read, fd, buf, count);

}



int
@@ -239,7 +254,7 @@ hook_pread(unsigned int fd, char* buf, size_t count, loff_t pos) { 
    }

    /* Since kernel 2.6: pread() became pread64(), and pwrite() became

     * pwrite64(). */

    return syscall_no_intercept(SYS_pread64, fd, buf, count, pos);

    return syscall_no_intercept_wrapper(SYS_pread64, fd, buf, count, pos);

}



int
@@ -251,7 +266,7 @@ hook_readv(unsigned long fd, const struct iovec* iov, unsigned long iovcnt) { 
    if(CTX->file_map()->exist(fd)) {

        return with_errno(gkfs::syscall::gkfs_readv(fd, iov, iovcnt));

    }

    return syscall_no_intercept(SYS_readv, fd, iov, iovcnt);

    return syscall_no_intercept_wrapper(SYS_readv, fd, iov, iovcnt);

}



int
@@ -267,7 +282,7 @@ hook_preadv(unsigned long fd, const struct iovec* iov, unsigned long iovcnt, 
    if(CTX->file_map()->exist(fd)) {

        return with_errno(gkfs::syscall::gkfs_preadv(fd, iov, iovcnt, pos_l));

    }

    return syscall_no_intercept(SYS_preadv, fd, iov, iovcnt, pos_l);

    return syscall_no_intercept_wrapper(SYS_preadv, fd, iov, iovcnt, pos_l);

}



int
@@ -279,7 +294,7 @@ hook_write(unsigned int fd, const char* buf, size_t count) { 
    if(CTX->file_map()->exist(fd)) {

        return with_errno(gkfs::syscall::gkfs_write(fd, buf, count));

    }

    return syscall_no_intercept(SYS_write, fd, buf, count);

    return syscall_no_intercept_wrapper(SYS_write, fd, buf, count);

}



int
@@ -293,7 +308,7 @@ hook_pwrite(unsigned int fd, const char* buf, size_t count, loff_t pos) { 
    }

    /* Since kernel 2.6: pread() became pread64(), and pwrite() became

     * pwrite64(). */

    return syscall_no_intercept(SYS_pwrite64, fd, buf, count, pos);

    return syscall_no_intercept_wrapper(SYS_pwrite64, fd, buf, count, pos);

}



int
@@ -305,7 +320,7 @@ hook_writev(unsigned long fd, const struct iovec* iov, unsigned long iovcnt) { 
    if(CTX->file_map()->exist(fd)) {

        return with_errno(gkfs::syscall::gkfs_writev(fd, iov, iovcnt));

    }

    return syscall_no_intercept(SYS_writev, fd, iov, iovcnt);

    return syscall_no_intercept_wrapper(SYS_writev, fd, iov, iovcnt);

}



int
@@ -321,7 +336,7 @@ hook_pwritev(unsigned long fd, const struct iovec* iov, unsigned long iovcnt, 
    if(CTX->file_map()->exist(fd)) {

        return with_errno(gkfs::syscall::gkfs_pwritev(fd, iov, iovcnt, pos_l));

    }

    return syscall_no_intercept(SYS_pwritev, fd, iov, iovcnt, pos_l);

    return syscall_no_intercept_wrapper(SYS_pwritev, fd, iov, iovcnt, pos_l);

}



int
@@ -339,11 +354,12 @@ hook_unlinkat(int dirfd, const char* cpath, int flags) { 
    auto rstatus = CTX->relativize_fd_path(dirfd, cpath, resolved, false);

    switch(rstatus) {

        case gkfs::preload::RelativizeStatus::fd_unknown:

            return syscall_no_intercept(SYS_unlinkat, dirfd, cpath, flags);

            return syscall_no_intercept_wrapper(SYS_unlinkat, dirfd, cpath,

                                                flags);



        case gkfs::preload::RelativizeStatus::external:

            return syscall_no_intercept(SYS_unlinkat, dirfd, resolved.c_str(),

                                        flags);

            return syscall_no_intercept_wrapper(SYS_unlinkat, dirfd,

                                                resolved.c_str(), flags);



        case gkfs::preload::RelativizeStatus::fd_not_a_dir:

            return -ENOTDIR;
@@ -378,11 +394,11 @@ hook_symlinkat(const char* oldname, int newdfd, const char* newname) { 
            CTX->relativize_fd_path(newdfd, newname, newname_resolved, false);

    switch(rstatus) {

        case gkfs::preload::RelativizeStatus::fd_unknown:

            return syscall_no_intercept(SYS_symlinkat, oldname, newdfd,

            return syscall_no_intercept_wrapper(SYS_symlinkat, oldname, newdfd,

                                                newname);



        case gkfs::preload::RelativizeStatus::external:

            return syscall_no_intercept(SYS_symlinkat, oldname, newdfd,

            return syscall_no_intercept_wrapper(SYS_symlinkat, oldname, newdfd,

                                                newname_resolved.c_str());



        case gkfs::preload::RelativizeStatus::fd_not_a_dir:
@@ -412,7 +428,7 @@ hook_access(const char* path, int mask) { 
        }

        return ret;

    }

    return syscall_no_intercept(SYS_access, rel_path.c_str(), mask);

    return syscall_no_intercept_wrapper(SYS_access, rel_path.c_str(), mask);

}



int
@@ -425,11 +441,12 @@ hook_faccessat(int dirfd, const char* cpath, int mode) { 
    auto rstatus = CTX->relativize_fd_path(dirfd, cpath, resolved);

    switch(rstatus) {

        case gkfs::preload::RelativizeStatus::fd_unknown:

            return syscall_no_intercept(SYS_faccessat, dirfd, cpath, mode);

            return syscall_no_intercept_wrapper(SYS_faccessat, dirfd, cpath,

                                                mode);



        case gkfs::preload::RelativizeStatus::external:

            return syscall_no_intercept(SYS_faccessat, dirfd, resolved.c_str(),

                                        mode);

            return syscall_no_intercept_wrapper(SYS_faccessat, dirfd,

                                                resolved.c_str(), mode);



        case gkfs::preload::RelativizeStatus::fd_not_a_dir:

            return -ENOTDIR;
@@ -460,7 +477,7 @@ hook_lseek(unsigned int fd, off_t offset, unsigned int whence) { 
        LOG(DEBUG, "{}() returning {}", __func__, off_ret);

        return off_ret;

    }

    return syscall_no_intercept(SYS_lseek, fd, offset, whence);

    return syscall_no_intercept_wrapper(SYS_lseek, fd, offset, whence);

}



int
@@ -472,7 +489,7 @@ hook_truncate(const char* path, long length) { 
    if(CTX->relativize_path(path, rel_path)) {

        return with_errno(gkfs::syscall::gkfs_truncate(rel_path, length));

    }

    return syscall_no_intercept(SYS_truncate, rel_path.c_str(), length);

    return syscall_no_intercept_wrapper(SYS_truncate, rel_path.c_str(), length);

}



int
@@ -484,7 +501,7 @@ hook_ftruncate(unsigned int fd, unsigned long length) { 
        auto path = CTX->file_map()->get(fd)->path();

        return with_errno(gkfs::syscall::gkfs_truncate(path, length));

    }

    return syscall_no_intercept(SYS_ftruncate, fd, length);

    return syscall_no_intercept_wrapper(SYS_ftruncate, fd, length);

}



int
@@ -495,7 +512,7 @@ hook_dup(unsigned int fd) { 
    if(CTX->file_map()->exist(fd)) {

        return with_errno(gkfs::syscall::gkfs_dup(fd));

    }

    return syscall_no_intercept(SYS_dup, fd);

    return syscall_no_intercept_wrapper(SYS_dup, fd);

}



int
@@ -506,7 +523,7 @@ hook_dup2(unsigned int oldfd, unsigned int newfd) { 
    if(CTX->file_map()->exist(oldfd)) {

        return with_errno(gkfs::syscall::gkfs_dup2(oldfd, newfd));

    }

    return syscall_no_intercept(SYS_dup2, oldfd, newfd);

    return syscall_no_intercept_wrapper(SYS_dup2, oldfd, newfd);

}



int
@@ -521,7 +538,7 @@ hook_dup3(unsigned int oldfd, unsigned int newfd, int flags) { 
        LOG(WARNING, "{}() Not supported", __func__);

        return -ENOTSUP;

    }

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

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

}



int
@@ -533,7 +550,7 @@ hook_getdents(unsigned int fd, struct linux_dirent* dirp, unsigned int count) { 
    if(CTX->file_map()->exist(fd)) {

        return with_errno(gkfs::syscall::gkfs_getdents(fd, dirp, count));

    }

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

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

}
@@ -547,7 +564,7 @@ hook_getdents64(unsigned int fd, struct linux_dirent64* dirp, 
    if(CTX->file_map()->exist(fd)) {

        return with_errno(gkfs::syscall::gkfs_getdents64(fd, dirp, count));

    }

    return syscall_no_intercept(SYS_getdents64, fd, dirp, count);

    return syscall_no_intercept_wrapper(SYS_getdents64, fd, dirp, count);

}
@@ -561,11 +578,12 @@ hook_mkdirat(int dirfd, const char* cpath, mode_t mode) { 
    auto rstatus = CTX->relativize_fd_path(dirfd, cpath, resolved);

    switch(rstatus) {

        case gkfs::preload::RelativizeStatus::external:

            return syscall_no_intercept(SYS_mkdirat, dirfd, resolved.c_str(),

                                        mode);

            return syscall_no_intercept_wrapper(SYS_mkdirat, dirfd,

                                                resolved.c_str(), mode);



        case gkfs::preload::RelativizeStatus::fd_unknown:

            return syscall_no_intercept(SYS_mkdirat, dirfd, cpath, mode);

            return syscall_no_intercept_wrapper(SYS_mkdirat, dirfd, cpath,

                                                mode);



        case gkfs::preload::RelativizeStatus::fd_not_a_dir:

            return -ENOTDIR;
@@ -590,11 +608,12 @@ hook_fchmodat(int dirfd, const char* cpath, mode_t mode) { 
    auto rstatus = CTX->relativize_fd_path(dirfd, cpath, resolved);

    switch(rstatus) {

        case gkfs::preload::RelativizeStatus::fd_unknown:

            return syscall_no_intercept(SYS_fchmodat, dirfd, cpath, mode);

            return syscall_no_intercept_wrapper(SYS_fchmodat, dirfd, cpath,

                                                mode);



        case gkfs::preload::RelativizeStatus::external:

            return syscall_no_intercept(SYS_fchmodat, dirfd, resolved.c_str(),

                                        mode);

            return syscall_no_intercept_wrapper(SYS_fchmodat, dirfd,

                                                resolved.c_str(), mode);



        case gkfs::preload::RelativizeStatus::fd_not_a_dir:

            return -ENOTDIR;
@@ -618,7 +637,7 @@ hook_fchmod(unsigned int fd, mode_t mode) { 
        LOG(WARNING, "{}() operation not supported", __func__);

        return -ENOTSUP;

    }

    return syscall_no_intercept(SYS_fchmod, fd, mode);

    return syscall_no_intercept_wrapper(SYS_fchmod, fd, mode);

}



int
@@ -681,7 +700,7 @@ hook_fchdir(unsigned int fd) { 
            return -(se.code().value());

        }

    } else {

        long ret = syscall_no_intercept(SYS_fchdir, fd);

        long ret = syscall_no_intercept_wrapper(SYS_fchdir, fd);

        if(ret < 0) {

            throw std::system_error(

                    syscall_error_code(ret), std::system_category(),
@@ -719,12 +738,12 @@ hook_readlinkat(int dirfd, const char* cpath, char* buf, int bufsiz) { 
    auto rstatus = CTX->relativize_fd_path(dirfd, cpath, resolved, false);

    switch(rstatus) {

        case gkfs::preload::RelativizeStatus::fd_unknown:

            return syscall_no_intercept(SYS_readlinkat, dirfd, cpath, buf,

                                        bufsiz);

            return syscall_no_intercept_wrapper(SYS_readlinkat, dirfd, cpath,

                                                buf, bufsiz);



        case gkfs::preload::RelativizeStatus::external:

            return syscall_no_intercept(SYS_readlinkat, dirfd, resolved.c_str(),

                                        buf, bufsiz);

            return syscall_no_intercept_wrapper(SYS_readlinkat, dirfd,

                                                resolved.c_str(), buf, bufsiz);



        case gkfs::preload::RelativizeStatus::fd_not_a_dir:

            return -ENOTDIR;
@@ -746,7 +765,7 @@ hook_fcntl(unsigned int fd, unsigned int cmd, unsigned long arg) { 
        arg);



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

        return syscall_no_intercept(SYS_fcntl, fd, cmd, arg);

        return syscall_no_intercept_wrapper(SYS_fcntl, fd, cmd, arg);

    }

    int ret;

    switch(cmd) {
@@ -864,8 +883,8 @@ hook_renameat(int olddfd, const char* oldname, int newdfd, const char* newname, 
            return -EINVAL;

    }



    return syscall_no_intercept(SYS_renameat2, olddfd, oldpath_pass, newdfd,

                                newpath_pass, flags);

    return syscall_no_intercept_wrapper(SYS_renameat2, olddfd, oldpath_pass,

                                        newdfd, newpath_pass, flags);

}



int
@@ -878,7 +897,7 @@ hook_statfs(const char* path, struct statfs* buf) { 
    if(CTX->relativize_path(path, rel_path)) {

        return with_errno(gkfs::syscall::gkfs_statfs(buf));

    }

    return syscall_no_intercept(SYS_statfs, rel_path.c_str(), buf);

    return syscall_no_intercept_wrapper(SYS_statfs, rel_path.c_str(), buf);

}



int
@@ -889,7 +908,7 @@ hook_fstatfs(unsigned int fd, struct statfs* buf) { 
    if(CTX->file_map()->exist(fd)) {

        return with_errno(gkfs::syscall::gkfs_statfs(buf));

    }

    return syscall_no_intercept(SYS_fstatfs, fd, buf);

    return syscall_no_intercept_wrapper(SYS_fstatfs, fd, buf);

}



/* The function should broadcast a flush message (pmem_persist i.e.) if the
@@ -904,7 +923,7 @@ hook_fsync(unsigned int fd) { 
        return 0;

    }



    return syscall_no_intercept(SYS_fsync, fd);

    return syscall_no_intercept_wrapper(SYS_fsync, fd);

}



} // namespace gkfs::hook

src/client/intercept.cpp

+40 −13
Original line number Diff line number Diff line
@@ -84,6 +84,7 @@ hook_internal(long syscall_number, long arg0, long arg1, long arg2, long arg3, 
    const long args[gkfs::syscall::MAX_ARGS] = {arg0, arg1, arg2,

                                                arg3, arg4, arg5};

#endif

    int syserror = 0;



    LOG(SYSCALL,

        gkfs::syscall::from_internal_code | gkfs::syscall::to_hook |
@@ -96,9 +97,12 @@ hook_internal(long syscall_number, long arg0, long arg1, long arg2, long arg3, 
            *result = syscall_no_intercept(

                    syscall_number, reinterpret_cast<char*>(arg0),

                    static_cast<int>(arg1), static_cast<mode_t>(arg2));

            syserror = syscall_error_code(*result);



            if(*result >= 0) {

            if(syserror == 0) {

                *result = CTX->register_internal_fd(*result);

            } else {

                *result = -syserror;

            }



            break;
@@ -107,9 +111,12 @@ hook_internal(long syscall_number, long arg0, long arg1, long arg2, long arg3, 
            *result = syscall_no_intercept(

                    syscall_number, reinterpret_cast<const char*>(arg0),

                    O_WRONLY | O_CREAT | O_TRUNC, static_cast<mode_t>(arg1));

            syserror = syscall_error_code(*result);



            if(*result >= 0) {

            if(syserror == 0) {

                *result = CTX->register_internal_fd(*result);

            } else {

                *result = -syserror;

            }



            break;
@@ -119,19 +126,24 @@ hook_internal(long syscall_number, long arg0, long arg1, long arg2, long arg3, 
                    syscall_number, static_cast<int>(arg0),

                    reinterpret_cast<const char*>(arg1), static_cast<int>(arg2),

                    static_cast<mode_t>(arg3));

            syserror = syscall_error_code(*result);



            if(*result >= 0) {

            if(syserror == 0) {

                *result = CTX->register_internal_fd(*result);

            } else {

                *result = -syserror;

            }



            break;



        case SYS_epoll_create:

            *result = syscall_no_intercept(syscall_number,

                                           static_cast<int>(arg0));

            syserror = syscall_error_code(*result);



            if(*result >= 0) {

            if(syserror == 0) {

                *result = CTX->register_internal_fd(*result);

            } else {

                *result = -syserror;

            }



            break;
@@ -139,9 +151,12 @@ hook_internal(long syscall_number, long arg0, long arg1, long arg2, long arg3, 
        case SYS_epoll_create1:

            *result = syscall_no_intercept(syscall_number,

                                           static_cast<int>(arg0));

            syserror = syscall_error_code(*result);



            if(*result >= 0) {

            if(syserror == 0) {

                *result = CTX->register_internal_fd(*result);

            } else {

                *result = -syserror;

            }



            break;
@@ -149,8 +164,9 @@ hook_internal(long syscall_number, long arg0, long arg1, long arg2, long arg3, 
        case SYS_dup:

            *result = syscall_no_intercept(syscall_number,

                                           static_cast<unsigned int>(arg0));

            syserror = syscall_error_code(*result);



            if(*result >= 0) {

            if(syserror == 0) {

                *result = CTX->register_internal_fd(*result);

            }
@@ -160,8 +176,9 @@ hook_internal(long syscall_number, long arg0, long arg1, long arg2, long arg3, 
            *result = syscall_no_intercept(syscall_number,

                                           static_cast<unsigned int>(arg0),

                                           static_cast<unsigned int>(arg1));

            syserror = syscall_error_code(*result);



            if(*result >= 0) {

            if(syserror == 0) {

                *result = CTX->register_internal_fd(*result);

            }
@@ -172,7 +189,11 @@ hook_internal(long syscall_number, long arg0, long arg1, long arg2, long arg3, 
                    syscall_number, static_cast<unsigned int>(arg0),

                    static_cast<unsigned int>(arg1), static_cast<int>(arg2));



            if(*result >= 0) {

            syserror = syscall_error_code(*result);



            if(syserror == 0) {





                *result = CTX->register_internal_fd(*result);

            }
@@ -370,18 +391,24 @@ hook_internal(long syscall_number, long arg0, long arg1, long arg2, long arg3, 
            *result =

                    syscall_no_intercept(syscall_number, static_cast<int>(arg0),

                                         static_cast<int>(arg1), arg2);

            syserror = syscall_error_code(*result);



            if(*result >= 0 && (static_cast<int>(arg1) == F_DUPFD ||

            if(syserror == 0) {





                if((static_cast<int>(arg1) == F_DUPFD ||

                    static_cast<int>(arg1) == F_DUPFD_CLOEXEC)) {

                    *result = CTX->register_internal_fd(*result);

                }

            }

            break;



        case SYS_close:

            *result = syscall_no_intercept(syscall_number,

                                           static_cast<int>(arg0));

            syserror = syscall_error_code(*result);



            if(*result == 0) {

            if(syserror == 0) {

                CTX->unregister_internal_fd(arg0);

            }

            break;

src/client/preload_context.cpp

+2 −2
Original line number Diff line number Diff line
@@ -395,8 +395,8 @@ PreloadContext::protect_user_fds() { 


    const auto fd_is_open = [](int fd) -> bool {

        const int ret = ::syscall_no_intercept(SYS_fcntl, fd, F_GETFD);

        return ::syscall_error_code(ret) == 0 ||

               ::syscall_error_code(ret) != EBADF;

        const int error = ::syscall_error_code(ret);

        return error == 0 || error != EBADF;

    };



    for(int fd = 0; fd < MAX_USER_FDS; ++fd) {