Try to minimise the amount of buffers allocated and copied by clients when building a message attribute that is a concatenation of other buffers, such as an IE sequence. --- ell/genl.c | 32 ++++++++++++++++++++++++++++++++ ell/genl.h | 2 ++ 2 files changed, 34 insertions(+) diff --git a/ell/genl.c b/ell/genl.c index 85e447a..c522ae7 100644 --- a/ell/genl.c +++ b/ell/genl.c @@ -793,6 +793,38 @@ LIB_EXPORT bool l_genl_msg_append_attr(struct l_genl_msg *msg, uint16_t type, return true; } +LIB_EXPORT bool l_genl_msg_append_attrv(struct l_genl_msg *msg, uint16_t type, + struct iovec *iov, size_t iov_len) +{ + struct nlattr *nla; + size_t len = 0; + unsigned int i; + + if (unlikely(!msg)) + return false; + + for (i = 0; i < iov_len; i++) + len += iov[i].iov_len; + + if (msg->len + NLA_HDRLEN + NLA_ALIGN(len) > msg->size) + return false; + + nla = msg->data + msg->len; + nla->nla_len = NLA_HDRLEN + len; + nla->nla_type = type; + + msg->len += NLA_HDRLEN; + + for (i = 0; i < iov_len; i++, iov++) { + memcpy(msg->data + msg->len, iov->iov_base, iov->iov_len); + msg->len += iov->iov_len; + } + + msg->len += NLA_ALIGN(len) - len; + + return true; +} + LIB_EXPORT bool l_genl_msg_enter_nested(struct l_genl_msg *msg, uint16_t type) { struct nlattr *nla; diff --git a/ell/genl.h b/ell/genl.h index 5b37d55..fe188d9 100644 --- a/ell/genl.h +++ b/ell/genl.h @@ -71,6 +71,8 @@ int l_genl_msg_get_error(struct l_genl_msg *msg); bool l_genl_msg_append_attr(struct l_genl_msg *msg, uint16_t type, uint16_t len, const void *data); +bool l_genl_msg_append_attrv(struct l_genl_msg *msg, uint16_t type, + struct iovec *iov, size_t iov_len); bool l_genl_msg_enter_nested(struct l_genl_msg *msg, uint16_t type); bool l_genl_msg_leave_nested(struct l_genl_msg *msg); -- 2.7.4