Discovered that the DHCP server on a TrendNet router (unknown model)
provides a zero-length option 12 (Host Name) in the DHCP ACK message. This
has the effect of causing udhcpc to drop the rest of the options, including
option 51 (IP Address Lease Time), 3 (Router), and 6 (Domain Name Server),
most importantly leaving the OpenWrt device with no default gateway.
The TrendNet behavior violates RFC 2132, which in Section 3.14 declares that
option 12 has a minimum length of 1 octet. It is perhaps not a cosmic coincidence
that I found this behavior on Pi Day.
This patch allows zero length options without bailing out, by simply skipping them.
function old new delta
udhcp_scan_options 183 172 -11
Signed-off-by: Russell Senior <russell@personaltelco.net>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
There are cases where binding to source IP and
destination IP is insufficient to guarantee sane
xmit netdev.
One case where this can fail is when
route-matching netdev carrier is down (cable
unplugged, wifi disconnected), or the netdev is
admin down. Then all the IP based bindings (bind()
+ connect()) will seemingly succeed but the actual
packet can go out through a default gw path.
Depending on the network this happens on
it can create issues or false alarms. It can
also leak some subnet info across networks that
shouldn't be routed.
As such better be safe than sorry and bind to a
netdev to be sure it's used for xmit.
function old new delta
udhcp_send_kernel_packet 293 336 +43
send_packet 182 188 +6
bcast_or_ucast 37 43 +6
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/0 up/down: 55/0) Total: 55 bytes
Signed-off-by: Michal Kazior <michal@plume.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
"error: taking address of packed member of 'struct ip_udp_dhcp_packet'
may result in an unaligned pointer value" here:
udhcp_dump_packet(&packet.data);
and in other places.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
PLATFORM_LINUX is a hidden configuration option which is disabled by
default and enabled at over a hundred locations for features that are
deemed to be Linux specific.
The only effect of PLATFORM_LINUX is to control compilation of
libbb/match_fstype.c. This file is only needed by mount and umount.
Remove all references to PLATFORM_LINUX and compile match_fstype.c
if mount or umount is enabled.
Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Duplicate options are currently overridden (only the last option is kept).
This leads to unexpected behavior when using long options.
The patch adds support for long options in compliance with RFC 3396.
Fixes#13136.
function old new delta
udhcp_run_script 601 725 +124
optitem_unset_env_and_free - 38 +38
putenvp 46 59 +13
static.xmalloc_optname_optval 718 717 -1
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/1 up/down: 175/-1) Total: 174 bytes
Signed-off-by: Martin Lewis <martin.lewis.x84@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
dname_dec: now iterates over the packet only once.
convert_dname: remove redundant checks and code shrink.
While testing I've noticed that some of the tests didn't compile
properly, so I fixed them.
function old new delta
dname_dec 286 267 -19
dname_enc 166 143 -23
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-42) Total: -42 bytes
Signed-off-by: Martin Lewis <martin.lewis.x84@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
fill_envp now iterates over the packet only once instead of a few hundred times
using the new option scanner.
function old new delta
udhcp_scan_options - 189 +189
putenvp - 46 +46
init_scan_state - 22 +22
udhcp_get_option 227 104 -123
udhcp_run_script 835 601 -234
------------------------------------------------------------------------------
(add/remove: 3/0 grow/shrink: 0/2 up/down: 257/-357) Total: -100 bytes
Signed-off-by: Martin Lewis <martin.lewis.x84@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Added an option scanner to udhcp to enable iteration over packet options.
Signed-off-by: Martin Lewis <martin.lewis.x84@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Incorporated valid_domain_label into good_hostname to simplify the implementation.
function old new delta
static.xmalloc_optname_optval 973 958 -15
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-15) Total: -15 bytes
text data bss dec hex filename
993144 16915 1872 1011931 f70db busybox_old
993129 16915 1872 1011916 f70cc busybox_unstripped
Signed-off-by: Martin Lewis <martin.lewis.x84@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
The following caused udhcpc to segfault:
busybox udhcpc -i lo -s /dev/null -x 0x3d:
function old new delta
udhcp_str2optset 629 641 +12
Signed-off-by: Michal Kazior <michal@plume.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Back in 2007, commit 0c97c9d437 ("'simple' error message functions by
Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower
overhead call to bb_perror_msg() when only a string was being printed
with no parameters. This saves space for some CPU architectures because
it avoids the overhead of a call to a variadic function. However there
has never been a simple version of bb_error_msg(), and since 2007 many
new calls to bb_perror_msg() have been added that only take a single
parameter and so could have been using bb_simple_perror_message().
This changeset introduces 'simple' versions of bb_info_msg(),
bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and
bb_herror_msg_and_die(), and replaces all calls that only take a
single parameter, or use something like ("%s", arg), with calls to the
corresponding 'simple' version.
Since it is likely that single parameter calls to the variadic functions
may be accidentally reintroduced in the future a new debugging config
option WARN_SIMPLE_MSG has been introduced. This uses some macro magic
which will cause any such calls to generate a warning, but this is
turned off by default to avoid use of the unpleasant macros in normal
circumstances.
This is a large changeset due to the number of calls that have been
replaced. The only files that contain changes other than simple
substitution of function calls are libbb.h, libbb/herror_msg.c,
libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c,
networking/udhcp/common.h and util-linux/mdev.c additonal macros have
been added for logging so that single parameter and multiple parameter
logging variants exist.
The amount of space saved varies considerably by architecture, and was
found to be as follows (for 'defconfig' using GCC 7.4):
Arm: -92 bytes
MIPS: -52 bytes
PPC: -1836 bytes
x86_64: -938 bytes
Note that for the MIPS architecture only an exception had to be made
disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h)
because it made these files larger on MIPS.
Signed-off-by: James Byrne <james.byrne@origamienergy.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Resolved a TODO by adding support for gateway_nip parameter.
function old new delta
udhcp_run_script 792 835 +43
Signed-off-by: Martin Lewis <martin.lewis.x84@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Between Busybox 1.24.2 and 1.25.0 the bb_info_msg() function was
eliminated and calls to it changed to be bb_error_msg(). The downside of
this is that daemons now log all messages to syslog at the LOG_ERR level
which makes it hard to filter errors from informational messages.
This change optionally re-introduces bb_info_msg(), controlled by a new
option FEATURE_SYSLOG_INFO, restores all the calls to bb_info_msg() that
were removed (only in applets that set logmode to LOGMODE_SYSLOG or
LOGMODE_BOTH), and also changes informational messages in ifplugd and
ntpd.
The code size change of this is as follows (using 'defconfig' on x86_64
with gcc 7.3.0-27ubuntu1~18.04)
function old new delta
bb_info_msg - 182 +182
bb_vinfo_msg - 27 +27
static.log7 194 198 +4
log8 190 191 +1
log5 190 191 +1
crondlog 45 - -45
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 3/0 up/down: 215/-45) Total: 170 bytes
If you don't care about everything being logged at LOG_ERR level
then when FEATURE_SYSLOG_INFO is disabled Busybox actually gets smaller:
function old new delta
static.log7 194 200 +6
log8 190 193 +3
log5 190 193 +3
syslog_level 1 - -1
bb_verror_msg 583 581 -2
crondlog 45 - -45
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 3/1 up/down: 12/-48) Total: -36 bytes
Signed-off-by: James Byrne <james.byrne@origamienergy.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
