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From: ebiederm@xmission•com (Eric W. Biederman)
To: Daniel Lezcano <daniel.lezcano@free•fr>
Cc: Pavel Emelyanov <xemul@parallels•com>,
	Sukadev Bhattiprolu <sukadev@linux•vnet.ibm.com>,
	Serge Hallyn <serue@us•ibm.com>,
	Linux Netdev List <netdev@vger•kernel.org>,
	containers@lists•linux-foundation.org,
	Netfilter Development Mailinglist
	<netfilter-devel@vger•kernel.org>,
	Ben Greear <greearb@candelatech•com>
Subject: Re: [RFC][PATCH] ns: Syscalls for better namespace sharing control.
Date: Mon, 08 Mar 2010 00:32:49 -0800	[thread overview]
Message-ID: <m1fx4bxlfy.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <4B92C886.9020507@free.fr> (Daniel Lezcano's message of "Sat\, 06 Mar 2010 22\:26\:30 +0100")


I have take an snapshot of my development tree and placed it at.


git://git.kernel.org/pub/scm/linux/people/ebiederm/linux-2.6.33-nsfd-v5.git


>> I am going to explore a bit more.  Given that nsfd is using the same
>> permission checks as a proc file, I think I can just make it a proc
>> file.  Something like "/proc/<pid>/ns/net".  With a little luck that
>> won't suck too badly.
>>   
> Ah ! yes. Good idea.

It is a hair more code to use proc files but nothing worth counting.

Probably the biggest thing I am aware of right now in my development
tree is in getting uids to pass properly between unix domain sockets
I would up writing this cred_to_ucred function.

Serge can you take a look and check my logic, and do you have
any idea of where we should place something like pid_vnr but
for the uid namespace?

void cred_to_ucred(struct pid *pid, const struct cred *cred,
		   struct ucred *ucred)
{
	ucred->pid = pid_vnr(pid);
	ucred->uid = ucred->gid = -1;
	if (cred) {
		struct user_namespace *cred_ns = cred->user->user_ns;
		struct user_namespace *current_ns = current_user_ns();
		struct user_namespace *tmp;

		if (likely(cred_ns == current_ns)) {
			ucred->uid = cred->euid;
			ucred->gid = cred->egid;
		} else {
			/* Is cred in a child user namespace */
			tmp = cred_ns;
			do {
				tmp = tmp->creator->user_ns;
				if (tmp == current_ns) {
					ucred->uid = tmp->creator->uid;
					ucred->gid = overflowgid;
					return;
				}
			} while (tmp != &init_user_ns);

			/* Is cred the creator of my user namespace,
			 * or the creator of one of it's parents?
			 */
			for( tmp = current_ns; tmp != &init_user_ns;
			     tmp = tmp->creator->user_ns) {
				if (cred->user == tmp->creator) {
					ucred->uid = 0;
					ucred->gid = 0;
					return;
				}
			}

			/* No user namespace relationship so no mapping */
			ucred->uid = overflowuid;
			ucred->gid = overflowgid;
		}
	}
}

Eric

  reply	other threads:[~2010-03-08  8:32 UTC|newest]

Thread overview: 94+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-14 14:05 RFC: netfilter: nf_conntrack: add support for "conntrack zones" Patrick McHardy
2010-01-14 15:05 ` jamal
2010-01-14 15:37   ` Patrick McHardy
2010-01-14 17:33     ` jamal
2010-01-15 10:15       ` Patrick McHardy
2010-01-15 15:19         ` jamal
2010-02-22 20:46           ` Eric W. Biederman
2010-02-22 21:55             ` jamal
2010-02-22 23:17               ` Eric W. Biederman
     [not found]                 ` <m1wry46es9.fsf-+imSwln9KH6u2/kzUuoCbdi2O/JbrIOy@public.gmane.org>
2010-02-23 13:27                   ` jamal
2010-02-23 14:07                     ` Eric W. Biederman
2010-02-23 14:20                       ` jamal
2010-02-23 20:00                         ` Eric W. Biederman
2010-02-23 23:09                           ` jamal
2010-02-24  1:43                             ` Eric W. Biederman
2010-02-25 20:57                             ` [RFC][PATCH] ns: Syscalls for better namespace sharing control Eric W. Biederman
2010-02-25 21:31                               ` Daniel Lezcano
2010-02-25 21:49                                 ` Eric W. Biederman
2010-02-25 22:13                                   ` Daniel Lezcano
2010-02-25 22:31                                     ` Eric W. Biederman
2010-02-26 20:35                                   ` Eric W. Biederman
2010-02-25 21:46                               ` Matt Helsley
2010-02-25 21:54                                 ` Eric W. Biederman
2010-02-26  0:53                                 ` Eric W. Biederman
2010-02-26  1:09                               ` Matt Helsley
2010-02-26  1:26                                 ` Eric W. Biederman
2010-02-26  3:15                               ` [RFC][PATCH] ns: Syscalls for better namespace sharing control. v2 Eric W. Biederman
     [not found]                                 ` <m18wagy9f3.fsf_-_-+imSwln9KH6u2/kzUuoCbdi2O/JbrIOy@public.gmane.org>
2010-03-03 20:29                                   ` Jonathan Corbet
2010-03-03 20:50                                     ` Eric W. Biederman
     [not found]                               ` <m1pr3t2fvl.fsf_-_-+imSwln9KH6u2/kzUuoCbdi2O/JbrIOy@public.gmane.org>
2010-02-26 21:13                                 ` [RFC][PATCH] ns: Syscalls for better namespace sharing control Pavel Emelyanov
2010-02-26 21:24                                   ` Eric W. Biederman
2010-02-26 21:34                                     ` Pavel Emelyanov
2010-02-26 21:42                                       ` Eric W. Biederman
2010-02-26 21:58                                         ` Oren Laadan
2010-02-26 22:16                                           ` Eric W. Biederman
2010-02-26 22:52                                             ` Oren Laadan
2010-02-26 23:13                                               ` Eric W. Biederman
2010-02-27  8:30                                         ` Pavel Emelyanov
2010-02-27  9:04                                           ` Eric W. Biederman
     [not found]                                             ` <m1mxyvrqvk.fsf-+imSwln9KH6u2/kzUuoCbdi2O/JbrIOy@public.gmane.org>
2010-02-27  9:21                                               ` Pavel Emelyanov
2010-02-27  9:42                                                 ` Eric W. Biederman
2010-02-27 16:16                                                   ` Pavel Emelyanov
2010-02-27 19:08                                                     ` Eric W. Biederman
2010-02-27 19:29                                                       ` Pavel Emelyanov
2010-02-27 19:44                                                         ` Eric W. Biederman
2010-02-28 22:05                                                           ` Daniel Lezcano
2010-03-01 19:24                                                             ` Eric W. Biederman
2010-03-01 21:42                                                             ` Eric W. Biederman
2010-03-02 13:10                                                               ` Cedric Le Goater
2010-03-02 15:03                                                             ` Pavel Emelyanov
2010-03-02 15:14                                                               ` Jan Engelhardt
2010-03-02 21:45                                                                 ` Eric W. Biederman
2010-03-02 21:19                                                               ` Sukadev Bhattiprolu
2010-03-02 22:13                                                                 ` Eric W. Biederman
2010-03-03  0:07                                                                   ` Sukadev Bhattiprolu
2010-03-03  0:46                                                                     ` Eric W. Biederman
2010-03-03 15:38                                                                       ` Serge E. Hallyn
2010-03-03 19:47                                                                         ` Eric W. Biederman
2010-03-04 21:45                                                                           ` Eric W. Biederman
2010-03-04 22:55                                                                             ` Jan Engelhardt
2010-03-03 16:50                                                                       ` Pavel Emelyanov
2010-03-03 20:16                                                                         ` Eric W. Biederman
2010-03-05 19:18                                                                           ` Pavel Emelyanov
2010-03-05 20:26                                                                             ` Eric W. Biederman
2010-03-06 14:47                                                                               ` Daniel Lezcano
     [not found]                                                                                 ` <4B926B1B.5070207-GANU6spQydw@public.gmane.org>
2010-03-06 20:48                                                                                   ` Eric W. Biederman
     [not found]                                                                                     ` <m1aaulyy5c.fsf-+imSwln9KH6u2/kzUuoCbdi2O/JbrIOy@public.gmane.org>
2010-03-06 21:26                                                                                       ` Daniel Lezcano
2010-03-08  8:32                                                                                         ` Eric W. Biederman [this message]
2010-03-08 16:54                                                                                           ` Daniel Lezcano
2010-03-08 17:29                                                                                             ` Eric W. Biederman
2010-03-08 19:57                                                                                               ` Daniel Lezcano
2010-03-08 20:24                                                                                                 ` Eric W. Biederman
2010-03-08 20:42                                                                                                   ` Daniel Lezcano
2010-03-08 20:47                                                                                                     ` Eric W. Biederman
2010-03-08 21:12                                                                                                       ` Daniel Lezcano
2010-03-08 21:25                                                                                                         ` Eric W. Biederman
2010-03-08 21:49                                                                                                           ` Serge E. Hallyn
2010-03-08 22:24                                                                                                             ` Eric W. Biederman
2010-03-09 10:03                                                                                                           ` Daniel Lezcano
2010-03-09 10:13                                                                                                             ` Eric W. Biederman
2010-03-09 10:26                                                                                                               ` Daniel Lezcano
2010-03-10 21:16                                                                                                           ` Daniel Lezcano
2010-03-08 17:07                                                                                           ` Serge E. Hallyn
2010-03-08 17:35                                                                                             ` Eric W. Biederman
2010-03-08 17:47                                                                                               ` Serge E. Hallyn
2010-03-03 20:59                                                             ` Oren Laadan
2010-03-03 21:05                                                               ` Eric W. Biederman
     [not found]                                     ` <m1bpfbwuze.fsf-+imSwln9KH6u2/kzUuoCbdi2O/JbrIOy@public.gmane.org>
2010-02-26 21:35                                       ` Pavel Emelyanov
2010-02-26 21:49                                         ` Eric W. Biederman
2010-02-23 23:49                           ` RFC: netfilter: nf_conntrack: add support for "conntrack zones" Matt Helsley
2010-02-24  1:32                             ` Eric W. Biederman
2010-02-24  1:39                               ` Serge E. Hallyn
2010-01-14 18:32   ` Ben Greear
2010-01-15 15:03     ` jamal

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