Function crypto_cursor_advance

freebsd/opencrypto/criov.c:274–337

SDT_PROBE_DEFINE2(opencrypto, criov, cursor_advance, vmpage, "struct crypto_buffer_cursor*", "size_t");

void
crypto_cursor_advance(struct crypto_buffer_cursor *cc, size_t amount)
{
	size_t remain;

	switch (cc->cc_type) {
	case CRYPTO_BUF_CONTIG:
		MPASS(cc->cc_buf_len >= amount);
		cc->cc_buf += amount;
		cc->cc_buf_len -= amount;
		break;
	case CRYPTO_BUF_MBUF:
		for (;;) {
			remain = cc->cc_mbuf->m_len - cc->cc_offset;
			if (amount < remain) {
				cc->cc_offset += amount;
				break;
			}
			amount -= remain;
			cc->cc_mbuf = cc->cc_mbuf->m_next;
			cc->cc_offset = 0;
			if (amount == 0)
				break;
		}
		break;
	case CRYPTO_BUF_VMPAGE:
		for (;;) {
			SDT_PROBE2(opencrypto, criov, cursor_advance, vmpage,
			    cc, amount);
			remain = MIN(PAGE_SIZE - cc->cc_offset, cc->cc_buf_len);
			if (amount < remain) {
				cc->cc_buf_len -= amount;
				cc->cc_offset += amount;
				break;
			}
			cc->cc_buf_len -= remain;
			amount -= remain;
			cc->cc_vmpage++;
			cc->cc_offset = 0;
			if (amount == 0 || cc->cc_buf_len == 0)
				break;
		}
		break;
	case CRYPTO_BUF_UIO:
		for (;;) {
			remain = cc->cc_iov->iov_len - cc->cc_offset;
			if (amount < remain) {
				cc->cc_offset += amount;
				break;
			}
			amount -= remain;
			cc->cc_iov++;
			cc->cc_offset = 0;
			if (amount == 0)
				break;
		}
		break;
	default: