linux/net/core
David Herrmann f5dd3d0c96 net: introduce SO_BINDTOIFINDEX sockopt
This introduces a new generic SOL_SOCKET-level socket option called
SO_BINDTOIFINDEX. It behaves similar to SO_BINDTODEVICE, but takes a
network interface index as argument, rather than the network interface
name.

User-space often refers to network-interfaces via their index, but has
to temporarily resolve it to a name for a call into SO_BINDTODEVICE.
This might pose problems when the network-device is renamed
asynchronously by other parts of the system. When this happens, the
SO_BINDTODEVICE might either fail, or worse, it might bind to the wrong
device.

In most cases user-space only ever operates on devices which they
either manage themselves, or otherwise have a guarantee that the device
name will not change (e.g., devices that are UP cannot be renamed).
However, particularly in libraries this guarantee is non-obvious and it
would be nice if that race-condition would simply not exist. It would
make it easier for those libraries to operate even in situations where
the device-name might change under the hood.

A real use-case that we recently hit is trying to start the network
stack early in the initrd but make it survive into the real system.
Existing distributions rename network-interfaces during the transition
from initrd into the real system. This, obviously, cannot affect
devices that are up and running (unless you also consider moving them
between network-namespaces). However, the network manager now has to
make sure its management engine for dormant devices will not run in
parallel to these renames. Particularly, when you offload operations
like DHCP into separate processes, these might setup their sockets
early, and thus have to resolve the device-name possibly running into
this race-condition.

By avoiding a call to resolve the device-name, we no longer depend on
the name and can run network setup of dormant devices in parallel to
the transition off the initrd. The SO_BINDTOIFINDEX ioctl plugs this
race.

Reviewed-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-17 14:55:51 -08:00
..
Makefile bpf, sockmap: convert to generic sk_msg interface 2018-10-15 12:23:19 -07:00
datagram.c for-4.21/block-20181221 2018-12-28 13:19:59 -08:00
dev.c jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
dev_addr_lists.c net: dev: Issue NETDEV_PRE_CHANGEADDR 2018-12-13 18:41:38 -08:00
dev_ioctl.c net: dev: Add extack argument to dev_set_mac_address() 2018-12-13 18:41:38 -08:00
devlink.c devlink: Add 'fw_load_policy' generic parameter 2018-12-03 13:55:43 -08:00
drop_monitor.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
dst.c netfilter: nf_tables: add tunnel support 2018-08-03 21:12:12 +02:00
dst_cache.c net: core: dst_cache_set_ip6: Rename 'addr' parameter to 'saddr' for consistency 2018-03-05 12:52:45 -05:00
ethtool.c ethtool: check the return value of get_regs_len 2018-12-28 21:24:56 -08:00
failover.c net: Introduce generic failover module 2018-05-28 22:59:54 -04:00
fib_notifier.c net: Fix fib notifer to return errno 2018-03-29 14:10:30 -04:00
fib_rules.c net/fib_rules: Update fib_nl_dumprule for strict data checking 2018-10-08 10:39:05 -07:00
filter.c bpf: correctly set initial window on active Fast Open sender 2019-01-09 15:17:46 -08:00
flow_dissector.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-20 11:53:36 -08:00
gen_estimator.c net: core: protect rate estimator statistics pointer with lock 2018-08-11 12:37:10 -07:00
gen_stats.c net/core: make function ___gnet_stats_copy_basic() static 2018-09-28 10:25:11 -07:00
gro_cells.c gro_cell: add napi_disable in gro_cells_destroy 2018-12-19 15:50:02 -08:00
hwbm.c
link_watch.c net: linkwatch: add check for netdevice being present to linkwatch_do_dev 2018-09-19 21:06:46 -07:00
lwt_bpf.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-08-07 11:02:05 -07:00
lwtunnel.c ipv6: sr: define core operations for seg6local lightweight tunnel 2017-08-07 14:16:22 -07:00
neighbour.c net/core/neighbour: tell kmemleak about hash tables 2019-01-10 09:34:51 -05:00
net-procfs.c proc: introduce proc_create_net{,_data} 2018-05-16 07:24:30 +02:00
net-sysfs.c net: core: dev: Add extack argument to dev_change_flags() 2018-12-06 13:26:07 -08:00
net-sysfs.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
net-traces.c net/ipv6: Udate fib6_table_lookup tracepoint 2018-05-24 23:01:15 -04:00
net_namespace.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-24 16:19:56 -08:00
netclassid_cgroup.c cgroup, netclassid: add a preemption point to write_classid 2018-10-23 12:58:17 -07:00
netevent.c
netpoll.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-12-27 13:04:52 -08:00
netprio_cgroup.c net: remove duplicate includes 2017-12-13 13:18:46 -05:00
page_pool.c net/page_pool: Fix inconsistent lock state warning 2018-07-19 23:23:01 -07:00
pktgen.c pktgen: Fix fall-through annotation 2018-09-13 15:36:41 -07:00
ptp_classifier.c
request_sock.c ipv4: Namespaceify tcp_max_syn_backlog knob 2016-12-29 11:38:31 -05:00
rtnetlink.c net: rtnetlink: address is mandatory for rtnl_fdb_get 2018-12-30 11:35:36 -08:00
scm.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/user.h> 2017-03-02 08:42:29 +01:00
secure_seq.c infiniband: i40iw, nes: don't use wall time for TCP sequence numbers 2018-07-11 12:10:19 -06:00
skbuff.c net, skbuff: do not prefer skb allocation fails early 2019-01-04 12:53:16 -08:00
skmsg.c Optimize sk_msg_clone() by data merge to end dst sg entry 2019-01-17 11:42:26 -08:00
sock.c net: introduce SO_BINDTOIFINDEX sockopt 2019-01-17 14:55:51 -08:00
sock_diag.c net: sock_diag: Fix spectre v1 gadget in __sock_diag_cmd() 2018-08-14 10:01:24 -07:00
sock_map.c bpf: skmsg, fix psock create on existing kcm/tls port 2018-10-20 00:40:45 +02:00
sock_reuseport.c sctp: add sock_reuseport for the sock in __sctp_hash_endpoint 2018-11-12 09:09:51 -08:00
stream.c tcp: reduce POLLOUT events caused by TCP_NOTSENT_LOWAT 2018-12-04 21:21:18 -08:00
sysctl_net_core.c bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K 2018-12-11 19:12:21 -08:00
timestamping.c
tso.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
utils.c net: Remove some unneeded semicolon 2018-08-04 13:05:39 -07:00
xdp.c xdp: remove redundant variable 'headroom' 2018-09-01 01:35:53 +02:00