Alexandre Chataignon wrote: > This patch adds the possibility to enable a captive portal while connman is in > tethering mode by sending its own IP via the DNS proxy (which acts as a DNS > server more than a proxy in this case). > > I needed this usage for an IoT device, in which the tethering mode is in fact > a > hotspot mode. With a light http server and patched connman, it offers the > possibility to have a light and easy-to-use captive portal for example to > diagnostic device. > > The captive portal is enabled in settings file, via the key > Tethering.Captive=true (defaults to false) > > It has been used for 1 month on our devices without failures. > > Thanks for your reviews,
I'm interested in this concept. I applied your patch to ConnMan 1.30, and I've been testing it. In my testing with DNS queries using the Linux 'dig' utility, I found it returns malformed responses. That is because the 'dig' query includes an additional record (ARCOUNT=1), of type OPT (41). When your patch send_response_A() creates the response, it just uses the total length of the query (which includes the question and the additional record), but then sets the ARCOUNT=0, so that doesn't account for a query that contains additional records. So the response appears to have just one answer record of type "OPT", followed by an additional 16 bytes of junk. So the response is malformed for any query that includes more than one question, and more than zero additional records. I also note that this patch sends an A record response to any query, with a link to the query name. But it doesn't make sense to send an A record answer if the query wasn't an A record question. E.g. if the query is a PTR (reverse lookup) question for 216.58.220.110, it doesn't make sense to respond with an A record saying the IP address of 110.2200.58.216.in-addr.arpa is 192.168.1.1. So the patch would need to be improved as follows: * Check that the query first question is for an A record, and only send an A record if so. * Calculate the correct length of the query header and question record(s), in order to position the answer in the correct location in the response. * Calculate the correct total length of the response. * Consider whether an "OPT" or other additional record should be copied into the answer * Consider how to handle a query with more than one question. -- Craig McQueen _______________________________________________ connman mailing list [email protected] https://lists.connman.net/mailman/listinfo/connman
