openwrtv4/package/utils
Adi Shammout e4259bed3f busybox: udhcpc: no MSG_DONTROUTE when sending packet
This reverts a change made in Sep 2017 [1] which introduced
MSG_DONTROUTE flag to prevent udhcpc from reaching out to servers on a
different subnet. That change violates RFC2131 by forcing fully
configured clients, who got their configurations through an offer
relayed by a DHCP relay, from renewing through a unicast request
directly to the DHCP server, resulting in the client resorting to
boradcasting lease extension requests instead of unicasting them,
further breaking RFC2131.

The problem with MSG_DONTROUTE appears when talking to a properly
configured DHCP server that rejects non-compliant requests. Such server
will reject lease extension attempts sent via broadcast rather than
unicast, as is the case with Finnish ISPs Telia and DNA as well as
Estonian ISP Starman. Once the lease expires without renewal, udhcpc
enters init mode, taking down the interfaces with it, and thus causing
interruption on every lease expiry. On some ISPs (such as the ones
mentioned above) that can be once every 10-20 minutes. The interruptions
appear in the logs as such:
----
udhcpc: sending renew to x.x.x.x
udhcpc: send: Network unreachable
udhcpc: sending renew to 0.0.0.0
udhcpc: sending renew to 0.0.0.0
...
udhcpc: lease lost, entering init state
Interface 'wan' has lost the connection
Interface 'wan' is now down
Network alias 'eth0' link is down
udhcpc: sending select for y.y.y.y
udhcpc: lease of y.y.y.y obtained, lease time 1200
Network alias 'eth0' link is up
Interface 'wan' is now up
----

During lease extension, a fully configured client should be able to
reach out to the server from which it recieved the lease for extension,
regardless in which network it is; that's up to the gateway to find. [2]
This patch ensures that.

[1]
http://lists.busybox.net/pipermail/busybox-cvs/2017-September/037402.html
[2]
https://www.netmanias.com/en/post/techdocs/6000/dhcp-network-protocol/
understanding-dhcp-relay-agents

Signed-off-by: Adi Shammout <adi.shammout@outlook.com>
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com> [PKG_RELEASE increase]
2018-06-07 21:44:04 +02:00
..
adb adb: fix package description 2017-10-29 16:16:35 +01:00
admswconfig treewide: clean up download hashes 2016-12-16 22:39:22 +01:00
bsdiff bsdiff: Also pass down TARGET_CPPFLAGS 2017-03-01 17:19:50 -08:00
busybox busybox: udhcpc: no MSG_DONTROUTE when sending packet 2018-06-07 21:44:04 +02:00
bzip2 add PKG_CPE_ID ids to package and tools 2017-11-17 02:24:35 +01:00
ct-bugcheck merge: packages: update branding in core packages 2017-12-08 19:41:18 +01:00
e2fsprogs package/utils/e2fsprogs: update to 1.44.1 2018-03-31 16:30:27 +02:00
f2fs-tools package/utils/f2fs-tools: Update to 1.10.0 2018-04-03 23:26:45 +02:00
fbtest utils/fbtest: drop Build/Prepare rule in favor of default one 2016-10-15 11:36:51 +02:00
fritz-tools fritz_tffs_read: get tffs size from input file 2017-06-24 22:36:38 +02:00
fuse add PKG_CPE_ID ids to package and tools 2017-11-17 02:24:35 +01:00
jboot-tools firmware: add JBOOT based devices config extractor 2018-03-18 22:22:38 +01:00
jsonfilter jsonfilter: update to latest git HEAD 2018-03-14 18:48:23 +01:00
lua package/utils/lua: cleanup source mirrors 2018-04-18 23:59:32 +02:00
mdadm mdadm: fix parameter quoting 2017-10-27 03:26:37 +02:00
mtd-utils mtd-utils: activate --gc-sections 2018-04-28 15:29:22 +02:00
nvram packages: nvram: fix memory leak in _nvram_free 2017-11-15 21:11:23 +01:00
osafeloader packages: mark packages depending on a target as nonshared 2017-01-24 09:45:05 +01:00
oseama utils/oseama: drop Build/Prepare rule in favor of default one 2016-10-15 11:36:52 +02:00
otrx otrx: fix memory leak in otrx_create_append_zeros 2017-11-17 11:32:51 +01:00
px5g mbedtls: update to version 2.9.0 2018-05-22 20:47:20 +02:00
spidev_test utils/spidev_test: drop Build/Prepare rule in favor of default one 2016-10-15 11:36:52 +02:00
ugps treewide: replace LEDE_GIT with PROJECT_GIT 2018-01-10 21:27:32 +01:00
usbmode treewide: replace LEDE_GIT with PROJECT_GIT 2018-01-10 21:27:32 +01:00
usbreset utils/usbreset: drop Build/Prepare rule in favor of default one 2016-10-15 11:36:52 +02:00
usbutils usbutils: Update usb.ids file to latest 2017-11-22 20:45:07 +01:00
util-linux flock: enable alternatives support 2018-05-07 15:50:18 +08:00
xfsprogs xfsprogs: add xfs-admin util 2018-03-31 16:30:30 +02:00