--- Hi Marcel, Quickly, as an RFC, does this look better? For building message I think either one uses l_genl_msg or l_genl_msg_builder. Thus I changed l_genl_msg_builder_new(): it creates the l_genl_msg by itself. Only when one calls l_genl_msg_builder_finalize(), he will get a reference on the message. Such reference l_genl_family_send() will unref, or that he will in case of error. Does that look saner? At least it avoids the user to call l_genl_msg_new() and again l_genl_msg_builder() afterwards. I think it's better to separate properly both. I kept the queue for the nested of nested etc... I still want your opinion: either a queue or a fixed depth of nested of nested ? or we don't care? (I think we do care). ell/genl.c | 118 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ell/genl.h | 19 ++++++++++ 2 files changed, 137 insertions(+) diff --git a/ell/genl.c b/ell/genl.c index 1b1afab..460d078 100644 --- a/ell/genl.c +++ b/ell/genl.c @@ -115,6 +115,12 @@ struct l_genl_family { unsigned int nlctrl_cmd; }; +struct l_genl_msg_builder { + struct l_genl_msg *message; + struct l_queue *nests; + struct nlattr *last_nested; +}; + static void destroy_request(void *data) { struct genl_request *request = data; @@ -1280,3 +1286,115 @@ LIB_EXPORT bool l_genl_family_unregister(struct l_genl_family *family, return true; } + +LIB_EXPORT struct l_genl_msg_builder *l_genl_msg_builder_new(uint8_t cmd, + uint32_t size) +{ + struct l_genl_msg_builder *ret; + + ret = l_new(struct l_genl_msg_builder, 1); + ret->message = l_genl_msg_new_sized(cmd, size); + + return ret; +} + +static inline void builder_message_realign(struct l_genl_msg_builder *builder) +{ + if (!builder->last_nested) + return; + + if (!builder->nests) + builder->message->len = NLA_ALIGN(builder->message->len); + + builder->last_nested = NULL; +} + +LIB_EXPORT bool l_genl_msg_builder_append_attr( + struct l_genl_msg_builder *builder, + uint16_t type, uint16_t len, + const void *data) +{ + if (unlikely(!builder)) + return false; + + builder_message_realign(builder); + + return l_genl_msg_append_attr(builder->message, type, len, data); +} + +LIB_EXPORT bool l_genl_msg_builder_enter_nested( + struct l_genl_msg_builder *builder, + uint16_t type) +{ + struct nlattr *nla; + + if (unlikely(!builder)) + return false; + + if (!builder->nests) { + builder->nests = l_queue_new(); + if (!builder->nests) + return false; + } + + builder_message_realign(builder); + + nla = builder->message->data + builder->message->len; + nla->nla_len = NLA_HDRLEN; + nla->nla_type = type; + + if (!l_genl_msg_append_attr(builder->message, type, 0, NULL)) + return false; + + return l_queue_push_head(builder->nests, nla); +} + +LIB_EXPORT bool l_genl_msg_builder_leave_nested( + struct l_genl_msg_builder *builder) +{ + struct nlattr *nla; + uint32_t len; + + if (unlikely(!builder) || unlikely(!builder->nests)) + return false; + + nla = l_queue_pop_head(builder->nests); + if (!nla) + return false; + + if (l_queue_isempty(builder->nests)) { + l_queue_destroy(builder->nests, NULL); + builder->nests = NULL; + } + + len = builder->message->len - ((void *)nla - builder->message->data); + if (len <= NLA_HDRLEN) + return false; + + nla->nla_len = len; + + builder->last_nested = nla; + + return true; +} + +LIB_EXPORT void l_genl_msg_builder_destroy(struct l_genl_msg_builder *builder) +{ + if (unlikely(!builder)) + return; + + l_queue_destroy(builder->nests, NULL); + l_genl_msg_unref(builder->message); + l_free(builder); +} + +LIB_EXPORT struct l_genl_msg *l_genl_msg_builder_finalize( + struct l_genl_msg_builder *builder) +{ + if (unlikely(!builder) || unlikely(builder->nests)) + return NULL; + + builder_message_realign(builder); + + return l_genl_msg_ref(builder->message); +} diff --git a/ell/genl.h b/ell/genl.h index c628b8c..773682a 100644 --- a/ell/genl.h +++ b/ell/genl.h @@ -112,6 +112,25 @@ unsigned int l_genl_family_register(struct l_genl_family *family, void *user_data, l_genl_destroy_func_t destroy); bool l_genl_family_unregister(struct l_genl_family *family, unsigned int id); +struct l_genl_msg_builder; + +struct l_genl_msg_builder *l_genl_msg_builder_new(uint8_t cmd, + uint32_t size); + +bool l_genl_msg_builder_append_attr(struct l_genl_msg_builder *builder, + uint16_t type, uint16_t len, + const void *data); + +bool l_genl_msg_builder_enter_nested(struct l_genl_msg_builder *builder, + uint16_t type); + +bool l_genl_msg_builder_leave_nested(struct l_genl_msg_builder *builder); + +void l_genl_msg_builder_destroy(struct l_genl_msg_builder *builder); + +struct l_genl_msg *l_genl_msg_builder_finalize( + struct l_genl_msg_builder *builder); + #ifdef __cplusplus } #endif -- 2.0.5