Verified Commit d79c4910 authored by Tommaso Tocci's avatar Tommaso Tocci
Browse files

fix fstat

parent e62d4a33

ifs/include/preload/hooks.hpp

+2 −1
Original line number Diff line number Diff line
@@ -8,7 +8,8 @@ int hook_openat(int dirfd, const char *cpath, int flags, mode_t mode); 
int hook_close(int fd);

int hook_stat(const char* path, struct stat* buf);

int hook_lstat(const char* path, struct stat* buf);

int hook_fstat(unsigned int, struct stat* buf);

int hook_fstat(unsigned int fd, struct stat* buf);

int hook_fstatat(int dirfd, const char * cpath, struct stat * buf, int flags);

int hook_read(unsigned int fd, void* buf, size_t count);

int hook_write(unsigned int fd, void* buf, size_t count);

int hook_writev(unsigned long fd, const struct iovec * iov, unsigned long iovcnt);

ifs/src/preload/hooks.cpp

+46 −0
Original line number Diff line number Diff line
@@ -100,6 +100,52 @@ int hook_fstat(unsigned int fd, struct stat* buf) { 
    return syscall_no_intercept(SYS_fstat, fd, buf);

}



int hook_fstatat(int dirfd, const char * cpath, struct stat * buf, int flags) {

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

        CTX->log()->error("{}() path is invalid", __func__);

        return -EINVAL;

    }



    CTX->log()->trace("{}() called with path '{}' and fd {}", __func__, cpath, dirfd);



    if(flags & AT_EMPTY_PATH) {

        CTX->log()->error("{}() AT_EMPTY_PATH flag not supported", __func__);

        return -ENOTSUP;

    }



    std::string resolved;



    if(cpath[0] != PSP) {

        // cpath is relative

        //TODO handle the case in which dirfd is AT_FDCWD

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

            //TODO relative cpath could still lead to our FS

            return syscall_no_intercept(SYS_newfstatat, dirfd, cpath, buf, flags);

        }



        auto dir = CTX->file_map()->get_dir(dirfd);

        if(dir == nullptr) {

            CTX->log()->error("{}() dirfd is not a directory ", __func__);

            return -ENOTDIR;

        }



        std::string path = CTX->mountdir();

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

        path.push_back(PSP);

        path.append(cpath);

        if(resolve_path(path, resolved)) {

            return with_errno(adafs_stat(resolved, buf));

        }

    } else {

        // Path is absolute



        if (CTX->relativize_path(cpath, resolved)) {

            return with_errno(adafs_stat(resolved, buf));

        }

    }

    return syscall_no_intercept(SYS_newfstatat, dirfd, resolved.c_str(), buf, flags);

}



int hook_read(unsigned int fd, void* buf, size_t count) {

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

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

ifs/src/preload/intercept.cpp

+7 −0
Original line number Diff line number Diff line
@@ -56,6 +56,13 @@ static inline int hook(long syscall_number, 
                            reinterpret_cast<struct stat*>(arg1));

        break;



    case SYS_newfstatat:

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

                              reinterpret_cast<const char*>(arg1),

                              reinterpret_cast<struct stat *>(arg2),

                              static_cast<int>(arg3));

        break;



    case SYS_read:

        *result = hook_read(static_cast<unsigned int>(arg0),

                            reinterpret_cast<void*>(arg1),