diff options
Diffstat (limited to 'iov.h')
| -rw-r--r-- | iov.h | 58 |
1 files changed, 44 insertions, 14 deletions
@@ -70,38 +70,68 @@ struct iov_tail { #define IOV_TAIL(iov_, cnt_, off_) \ (struct iov_tail){ .iov = (iov_), .cnt = (cnt_), .off = (off_) } +/** + * IOV_TAIL_FROM_BUF() - Create a new IOV tail from a buffer + * @buf_: Buffer address to use in the iovec + * @len_: Buffer size + * @off_: Byte offset in the buffer where the tail begins + */ +#define IOV_TAIL_FROM_BUF(buf_, len_, off_) \ + IOV_TAIL((&(const struct iovec){ .iov_base = (buf_), \ + .iov_len = (len_) }), \ + 1, \ + (off_)) + bool iov_tail_prune(struct iov_tail *tail); size_t iov_tail_size(struct iov_tail *tail); -void *iov_peek_header_(struct iov_tail *tail, size_t len, size_t align); -void *iov_remove_header_(struct iov_tail *tail, size_t len, size_t align); +bool iov_drop_header(struct iov_tail *tail, size_t len); +void *iov_peek_header_(struct iov_tail *tail, void *v, size_t len, size_t align); +void *iov_remove_header_(struct iov_tail *tail, void *v, size_t len, size_t align); +ssize_t iov_tail_clone(struct iovec *dst_iov, size_t dst_iov_cnt, + struct iov_tail *tail); /** * IOV_PEEK_HEADER() - Get typed pointer to a header from an IOV tail * @tail_: IOV tail to get header from - * @type_: Data type of the header + * @var_: Temporary buffer of the type of the header to use if + * the memory in the iovec array is not contiguous. * * @tail_ may be pruned, but will represent the same bytes as before. * - * Returns: Pointer of type (@type_ *) located at the start of @tail_, NULL if - * we can't get a contiguous and aligned pointer. + * Return: pointer of type (@type_ *) located at the start of @tail_ + * or to @var_ if iovec memory is not contiguous, NULL if + * that overruns the iovec. */ -#define IOV_PEEK_HEADER(tail_, type_) \ - ((type_ *)(iov_peek_header_((tail_), \ - sizeof(type_), __alignof__(type_)))) + +#define IOV_PEEK_HEADER(tail_, var_) \ + ((__typeof__(var_) *)(iov_peek_header_((tail_), &(var_), \ + sizeof(var_), \ + __alignof__(var_)))) /** * IOV_REMOVE_HEADER() - Remove and return typed header from an IOV tail * @tail_: IOV tail to remove header from (modified) - * @type_: Data type of the header to remove + * @var_: Temporary buffer of the type of the header to use if + * the memory in the iovec array is not contiguous. * * On success, @tail_ is updated so that it longer includes the bytes of the * returned header. * - * Returns: Pointer of type (@type_ *) located at the old start of @tail_, NULL - * if we can't get a contiguous and aligned pointer. + * Return: pointer of type (@type_ *) located at the start of @tail_ + * or to @var_ if iovec memory is not contiguous, NULL if + * that overruns the iovec. + */ + +#define IOV_REMOVE_HEADER(tail_, var_) \ + ((__typeof__(var_) *)(iov_remove_header_((tail_), &(var_), \ + sizeof(var_), __alignof__(var_)))) + +/** IOV_DROP_HEADER() - Remove a typed header from an IOV tail + * @tail_: IOV tail to remove header from (modified) + * @type_: Data type of the header to remove + * + * Return: true if the tail still contains any bytes, otherwise false */ -#define IOV_REMOVE_HEADER(tail_, type_) \ - ((type_ *)(iov_remove_header_((tail_), \ - sizeof(type_), __alignof__(type_)))) +#define IOV_DROP_HEADER(tail_, type_) iov_drop_header((tail_), sizeof(type_)) #endif /* IOVEC_H */ |