Hello,
I noticed today if you pass a string with spaces to set_servers_csv, like:
"127.0.0.1 , 200.0.0.1"
It will take the first server as "127.0.0.1 " (note the space), it will notice it's not a valid IP and fail. So far so good.
However, nservers for the channel will stay set to -1, so when ares_send is called, this will be executed:
query->server_info = ares_malloc(channel->nservers *
sizeof(query->server_info[0]));
The negative value will be misinterpreted to a huge number since argument is size_t and we agree things smell really bad from here. In practice, such a mem allocation fails and we return ENOMEM (which is also misleading), but it's a very incorrect behaviour.
I was thinking on just adding a check at the beginning of ares_send() to exit if nservers is <= 0.
Do you guys agree with the approach? If that’s the case, which error do you suggest to return? No one really matches, I’d say ARES_ENOTFOUND, but that implies we tried to contact the server…
Thanks!
. .:|:.:|:. Francisco Sedano | CCIE 14859, Tech Lead Software Engineering | CSG Enterprise Access and Services Group (EASG)
Received on 2018-03-10