linux_dsm_epyc7002/arch/sparc/include/uapi/asm/socket.h
David Herrmann 28b5ba2aa0 net: introduce SO_PEERGROUPS getsockopt
This adds the new getsockopt(2) option SO_PEERGROUPS on SOL_SOCKET to
retrieve the auxiliary groups of the remote peer. It is designed to
naturally extend SO_PEERCRED. That is, the underlying data is from the
same credentials. Regarding its syntax, it is based on SO_PEERSEC. That
is, if the provided buffer is too small, ERANGE is returned and @optlen
is updated. Otherwise, the information is copied, @optlen is set to the
actual size, and 0 is returned.

While SO_PEERCRED (and thus `struct ucred') already returns the primary
group, it lacks the auxiliary group vector. However, nearly all access
controls (including kernel side VFS and SYSVIPC, but also user-space
polkit, DBus, ...) consider the entire set of groups, rather than just
the primary group. But this is currently not possible with pure
SO_PEERCRED. Instead, user-space has to work around this and query the
system database for the auxiliary groups of a UID retrieved via
SO_PEERCRED.

Unfortunately, there is no race-free way to query the auxiliary groups
of the PID/UID retrieved via SO_PEERCRED. Hence, the current user-space
solution is to use getgrouplist(3p), which itself falls back to NSS and
whatever is configured in nsswitch.conf(3). This effectively checks
which groups we *would* assign to the user if it logged in *now*. On
normal systems it is as easy as reading /etc/group, but with NSS it can
resort to quering network databases (eg., LDAP), using IPC or network
communication.

Long story short: Whenever we want to use auxiliary groups for access
checks on IPC, we need further IPC to talk to the user/group databases,
rather than just relying on SO_PEERCRED and the incoming socket. This
is unfortunate, and might even result in dead-locks if the database
query uses the same IPC as the original request.

So far, those recursions / dead-locks have been avoided by using
primitive IPC for all crucial NSS modules. However, we want to avoid
re-inventing the wheel for each NSS module that might be involved in
user/group queries. Hence, we would preferably make DBus (and other IPC
that supports access-management based on groups) work without resorting
to the user/group database. This new SO_PEERGROUPS ioctl would allow us
to make dbus-daemon work without ever calling into NSS.

Cc: Michal Sekletar <msekleta@redhat.com>
Cc: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-21 11:38:41 -04:00

107 lines
2.3 KiB
C

#ifndef _ASM_SOCKET_H
#define _ASM_SOCKET_H
#include <asm/sockios.h>
/* For setsockopt(2) */
#define SOL_SOCKET 0xffff
#define SO_DEBUG 0x0001
#define SO_PASSCRED 0x0002
#define SO_REUSEADDR 0x0004
#define SO_KEEPALIVE 0x0008
#define SO_DONTROUTE 0x0010
#define SO_BROADCAST 0x0020
#define SO_PEERCRED 0x0040
#define SO_LINGER 0x0080
#define SO_OOBINLINE 0x0100
#define SO_REUSEPORT 0x0200
#define SO_BSDCOMPAT 0x0400
#define SO_RCVLOWAT 0x0800
#define SO_SNDLOWAT 0x1000
#define SO_RCVTIMEO 0x2000
#define SO_SNDTIMEO 0x4000
#define SO_ACCEPTCONN 0x8000
#define SO_SNDBUF 0x1001
#define SO_RCVBUF 0x1002
#define SO_SNDBUFFORCE 0x100a
#define SO_RCVBUFFORCE 0x100b
#define SO_ERROR 0x1007
#define SO_TYPE 0x1008
#define SO_PROTOCOL 0x1028
#define SO_DOMAIN 0x1029
/* Linux specific, keep the same. */
#define SO_NO_CHECK 0x000b
#define SO_PRIORITY 0x000c
#define SO_BINDTODEVICE 0x000d
#define SO_ATTACH_FILTER 0x001a
#define SO_DETACH_FILTER 0x001b
#define SO_GET_FILTER SO_ATTACH_FILTER
#define SO_PEERNAME 0x001c
#define SO_TIMESTAMP 0x001d
#define SCM_TIMESTAMP SO_TIMESTAMP
#define SO_PEERSEC 0x001e
#define SO_PASSSEC 0x001f
#define SO_TIMESTAMPNS 0x0021
#define SCM_TIMESTAMPNS SO_TIMESTAMPNS
#define SO_MARK 0x0022
#define SO_TIMESTAMPING 0x0023
#define SCM_TIMESTAMPING SO_TIMESTAMPING
#define SO_RXQ_OVFL 0x0024
#define SO_WIFI_STATUS 0x0025
#define SCM_WIFI_STATUS SO_WIFI_STATUS
#define SO_PEEK_OFF 0x0026
/* Instruct lower device to use last 4-bytes of skb data as FCS */
#define SO_NOFCS 0x0027
#define SO_LOCK_FILTER 0x0028
#define SO_SELECT_ERR_QUEUE 0x0029
#define SO_BUSY_POLL 0x0030
#define SO_MAX_PACING_RATE 0x0031
#define SO_BPF_EXTENSIONS 0x0032
#define SO_INCOMING_CPU 0x0033
#define SO_ATTACH_BPF 0x0034
#define SO_DETACH_BPF SO_DETACH_FILTER
#define SO_ATTACH_REUSEPORT_CBPF 0x0035
#define SO_ATTACH_REUSEPORT_EBPF 0x0036
#define SO_CNX_ADVICE 0x0037
#define SCM_TIMESTAMPING_OPT_STATS 0x0038
#define SO_MEMINFO 0x0039
#define SO_INCOMING_NAPI_ID 0x003a
#define SO_COOKIE 0x003b
#define SCM_TIMESTAMPING_PKTINFO 0x003c
#define SO_PEERGROUPS 0x003d
/* Security levels - as per NRL IPv6 - don't actually do anything */
#define SO_SECURITY_AUTHENTICATION 0x5001
#define SO_SECURITY_ENCRYPTION_TRANSPORT 0x5002
#define SO_SECURITY_ENCRYPTION_NETWORK 0x5004
#endif /* _ASM_SOCKET_H */