Messages in this thread | | | From | Sergey Ryazanov <> | Date | Wed, 20 Oct 2021 23:02:17 +0300 | Subject | Re: Retrieving the network namespace of a socket |
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On Wed, Oct 20, 2021 at 7:34 PM Sargun Dhillon <sargun@sargun.me> wrote: > On Wed, Oct 20, 2021 at 05:03:56PM +0300, Sergey Ryazanov wrote: >> On Wed, Oct 20, 2021 at 12:57 PM Sargun Dhillon <sargun@sargun.me> wrote: >>> I'm working on a problem where I need to determine which network namespace a >>> given socket is in. I can currently bruteforce this by using INET_DIAG, and >>> enumerating namespaces and working backwards. >> >> Namespace is not a per-socket, but a per-process attribute. So each >> socket of a process belongs to the same namespace. >> > > Could you elaborate what kind of problem you are trying to solve? >> Maybe there is a more simple solution. for it. > > That's not entirely true. See the folowing code: > > int main() { > int fd1, fd2; > fd1 = socket(AF_INET, SOCK_STREAM, 0); > assert(fd1 >= 0); > assert(unshare(CLONE_NEWNET) == 0); > fd2 = socket(AF_INET, SOCK_STREAM, 0); > assert(fd2 >= 0); > } > > fd1 and fd2 have different sock_net.
Ouch, I totally missed this case. Thank you for reminding me.
-- Sergey
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