capabilities: added support for ambient capabilities.

This patch adds support for ambient capabilities in service files. The
idea with ambient capabilities is that the execed processes can run with
non-root user and get some inherited capabilities, without having any
need to add the capabilities to the executable file.

You need at least Linux 4.3 to use ambient capabilities. SecureBit
keep-caps is automatically added when you use ambient capabilities and
wish to change the user.

An example system service file might look like this:

[Unit]
Description=Service for testing caps

[Service]
ExecStart=/usr/bin/sleep 10000
User=nobody
AmbientCapabilities=CAP_NET_ADMIN CAP_NET_RAW

After starting the service it has these capabilities:

CapInh: 0000000000003000
CapPrm: 0000000000003000
CapEff: 0000000000003000
CapBnd: 0000003fffffffff
CapAmb: 0000000000003000

This commit is contained in:

Ismo Puustinen

2016-01-12 12:14:50 +02:00

parent a103496ca5

commit 755d4b67a4

8 changed files with 173 additions and 17 deletions

									
										src/core/execute.h
									
		+2
		
												View File
												
				@@ -157,6 +157,8 @@ struct ExecContext {

				        uint64_t capability_bounding_set;

				        uint64_t capability_ambient_set;

				        cap_t capabilities;

				        int secure_bits;