On Fri, 2009-08-14 at 10:20 -0500, Chuck Kuecker wrote: > Hi, Kieran, > > My impression was that dns_gethostbyname() would return ERR_OK if it did > not encounter anything fatal, but would actually set up the DNS query > for transmission in the background, so that dns_gethostbyname() returns > immediately, and would only have good information if the resolution was > already in the DNS tables.
Take a look at the source. If it already knows the answer it fills it in and returns ERR_OK. Otherwise it will work asynchronously and call the specified callback when it knows the answer (or error, or timeout). > Since I am booting the processor every time I > need to resolve DNS, I can't expect a previously resolved IP to be in > memory. So then it will always work asynchronously. > The callback always gets called sometime after dns_gethostbyname() is > called. I use the argument parameter to let me know which URL I have > been working with. In case of a DNS failure, I need to abort further > processing. So if you get an error in your callback set some global state that you check before doing any processing, and abort the further processing if that state is set. Kieran _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
