Verified Commit 0d5c532e authored by Tommaso Tocci's avatar Tommaso Tocci
Browse files

intercept writev

parent e155dd60

ifs/include/preload/hooks.hpp

+3 −2
Original line number Diff line number Diff line
@@ -9,8 +9,9 @@ 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_read(int fd, void* buf, size_t count);

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

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);

int hook_unlink(const char* path);

int hook_access(const char* path, int mask);

int hook_lseek(unsigned int fd, off_t offset, unsigned int whence);

ifs/src/preload/hooks.cpp

+38 −12
Original line number Diff line number Diff line
@@ -100,30 +100,56 @@ int hook_fstat(unsigned int fd, struct stat* buf) { 
    return syscall_no_intercept(SYS_fstat, fd, buf);

}



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

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)) {

        auto ret = adafs_read(fd, buf, count);

        if(ret < 0) {

            return -errno;

        }

        return ret;

        return  with_errno(adafs_read(fd, buf, count));

    }

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

}



int hook_write(int fd, void* buf, size_t count) {

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

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

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

        auto ret = adafs_write(fd, buf, count);

        if(ret < 0) {

            return -errno;

        }

        return ret;

        return with_errno(adafs_write(fd, buf, count));

    }

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

}



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

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

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

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

        auto pos = adafs_fd->pos(); // retrieve the current offset

        ssize_t written = 0;

        ssize_t ret;

        for (unsigned long i = 0; i < iovcnt; ++i){

            auto count = (iov+i)->iov_len;

            if(count == 0) {

                continue;

            }

            auto buf = (iov+i)->iov_base;

            ret = adafs_pwrite_ws(fd, buf, count, pos);

            if(ret == -1) {

                break;

            }

            written += ret;

            pos += ret;



            if(static_cast<size_t>(ret) < count){

                break;

            }

        }



        if(written == 0){

            return -1;

        }

        adafs_fd->pos(pos);

        return written;

    }

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

}



int hook_unlink(const char* path) {

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

    std::string rel_path;

ifs/src/preload/intercept.cpp

+8 −2
Original line number Diff line number Diff line
@@ -57,17 +57,23 @@ static inline int hook(long syscall_number, 
        break;



    case SYS_read:

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

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

                            reinterpret_cast<void*>(arg1),

                            static_cast<size_t>(arg2));

        break;



    case SYS_write:

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

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

                             reinterpret_cast<void*>(arg1),

                             static_cast<size_t>(arg2));

        break;



    case SYS_writev:

        *result = hook_writev(static_cast<unsigned long>(arg0),

                              reinterpret_cast<const struct iovec *>(arg1),

                              static_cast<unsigned long>(arg2));

        break;



    case SYS_unlink:

        *result = hook_unlink(reinterpret_cast<char*>(arg0));

        break;