kcapi_cipher_stream_op - Man Page

ssize_t kcapi_cipher_stream_op(struct kcapi_handle * handle, struct iovec * iov, size_t iovlen);

handle

iov

iovlen

This call can be called interleaved with kcapi_cipher_stream_update to fetch the processed data​.

This function may cause the caller to sleep if the kernel buffer holding the data is empty​. The process will be woken up once more data is sent by calling kcapi_cipher_stream_update​.

Note, when supplying buffers that are not multiple of block size, the buffers will only be filled up to the maximum number of full block sizes that fit into the buffer​.

The kernel supports multithreaded applications where one or more threads send data via the kcapi_cipher_stream_update function and another thread collects the processed data via kcapi_cipher_stream_op​. The kernel, however, will return data via kcapi_cipher_stream_op as soon as it has some data available​. For example, one thread sends 1000 bytes to be encrypted and another thread already waits for the ciphertext​. The kernel may send only, say, 500 bytes back to the waiting process during one kcapi_cipher_stream_op call​. In a subsequent calls to kcapi_cipher_stream_op more ciphertext is returned​. This implies that when the receiving thread shall collect all data there is, kcapi_cipher_stream_op must be called in a loop until all data is received​.

return number of bytes obtained from the kernel upon success; a negative errno-style error code if an error occurred

Stephan Mueller <​smueller@chronox.de​>