On 8/31/2011 11:46 AM, Stephen Smalley wrote: > On Wed, 2011-08-31 at 08:43 -0700, Casey Schaufler wrote: >> On 8/31/2011 1:36 AM, rongqing.li@xxxxxxxxxxxxx wrote: >>> From: Roy.Li <rongqing.li@xxxxxxxxxxxxx> >>> >>> Define security_sk_getsecctx to return the security >>> context of a sock. >> So, what is the intended use of the information >> coming from this hook? If I wanted to write the >> Smack hook, which of the "contexts" would I want >> to return? There are potentially three. If I know >> what the caller is looking for, I can (hopefully) >> select the correct information. > The initial use case is for netstat -Z so that it can reliably show the > security context of the socket rather than inferring it from the owning > process, which can be inaccurate for security-aware applications. > > In your situation, when in != out, which would you rather see in netstat > -Z output? Alternatively, if you want them both, perhaps you could > combine in and out into a single string that is returned, similar to > what you proposed for handling multiple xattrs with inode_getsecctx()? > If we want to use secctx consistently within the kernel, and I personally think that is a good idea, I would have to chose the SMACK64IPIN (label checked on packet delivery) value. Putting both the SMACK64IPOUT and SMACK64IPIN "contexts" into the secctx would violate the architectural notion that a secctx is the textual representation of a value used to make access control decisions. It would mean that calling security_secctx_to_secid() with the value returned by security_sk_getsecctx would be invalid. Note that this is different from the mechanism I had suggested for handling secctx in the multiple LSM case, as the composed string would map to a single secid which would in turn map back to that same composed string. If, on the other hand, what netstat -Z is out to show is all of the LSM base information about the socket a compound string might make sense, it just would not be a secctx, it would be an informational string of some other flavor. -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@xxxxxxxxxxxxx with the words "unsubscribe selinux" without quotes as the message.
