Re: [lnf-log RFC PATCH 2/2] utils: take a example from libmnl and use nflog_nlmsg_parse

[Ken-ichirou MATSUZAWA <chamaken@gmail.com>]

 Thank you for comment.

On Tue, Aug 18, 2015 at 08:04:22AM +0200, Pablo Neira Ayuso wrote:
> I suggest you use and implement the following new helper functions for
> libnetfilter_log:
> 
> struct nlmsghdr *
> nfnl_nlmsg_put_header(char *buf, uint8_t type, uint8_t cmd, uint16_t qnum);
> 
> int nfnl_attr_put_cfg_mode(struct nlmsghdr *nlh, struct nfulnl_msg_config_mode *mode);
> int nfnl_attr_put_cfg_cmd(struct nlmsghdr *nlh, struct nfulnl_msg_config_cmd *cmd);

Would you confirm the functions for nlmsg building which you suggested
to add because it's a little different from you suggested. I am worried
about it's in accodance with your intention.

In addition, I added NFLOG_DATA_SIZE as is, the size of struct
nflog_data. This enables to preallocate buffer, and I added
functions which initialize a buffer based on this.

Would you see it again?

Changes from previous:
  * introduce nlmsg three build functions:
    struct nlmsghdr *
      nfnl_nlmsg_put_header(char *buf, uint8_t type, uint8_t family, uint16_t qnum);
    int nfnl_attr_put_cfg_mode(struct nlmsghdr *nlh, struct nfulnl_msg_config_mode *mode);
    int nfnl_attr_put_cfg_cmd(struct nlmsghdr *nlh, struct nfulnl_msg_config_cmd *cmd);
    
  * introduce NFLOG_DATA_SIZE macro and use it at allocate functions.
  * update utils/nf-log to fit with the above.