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>
A padding to align a message should not only be added between
different attributes of a netlink message, but also at the end of the
message to pad it to the correct size.
Without this patch the following command does not work and returns an
error code:
ip link add type nlmon
Without this ip from busybox sends this:
sendmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000},
msg_namelen=12, msg_iov=[{iov_base={{len=45, ...},
"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\20\0\22\0\t\0\1nlmon"}, iov_len=45}],
msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 45
return value: 2
The normal ip utile from iproute2 sends this:
sendmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000},
msg_namelen=12, msg_iov=[{iov_base={{len=48, ...},
"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\20\0\22\0\t\0\1nlmon\0\0\0"}, iov_len=48}],
msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 48
return value: 0
With this patch ip from busybox sends this:
sendmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000},
msg_namelen=12, msg_iov=[{iov_base={{len=48, ...},
"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\20\0\22\0\t\0\1nlmon\0\0\0"}, iov_len=48}],
msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 48
return value: 0
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Use designated initializers for struct msghdr.
The struct layout is non-portable and musl libc does not match what busybox expects.
Signed-off-by: Szabolcs Nagy <nsz@port70.net>
Tested-by: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
libbb: make get_sock_lsa use only one getsockaddr syscall, not two
function old new delta
get_sock_lsa 72 101 +29
do_iplink 1151 1137 -14
arping_main 1585 1569 -16
dolisten 789 755 -34
xrtnl_open 161 94 -67
Hello,
Last November a bug was found in iproute. CAN-2003-0856 has more information.
Basically, netlink packets can come from any user. If a program performs action
based on netlink packets, they must be examined to make sure they came from the
place they are expected (the kernel).
Attached is a patch against pre8. Please apply this before releasing 1.00 final.
All users of busy box may be vulnerable to local attacks without it.
Best Regards,
Steve Grubb
I'm building BusyBox using a development kit for MontaVista Hardhat Linux
(PPC) -- which, at least in this instance, is based around kernel 2.2.14.
I've had to massage a few files in networking/libiproute/ to make it
compile. Specifically:
(1) Added a #include <sys/uio.h> for the iovec structure in
libnetlink.c,
(2) Put ifdefs in ll_types.c and ll_proto.c around various
constants (ETH_P_xxx and ARPHRD_xxx) that weren't defined,
(3) Make do_changename() in iplink.c require a kernel >=
2.4.0 -- the ifr structure in my environment doesn't
have the ifr_name attribute. I've assumed this is
a kernel dependency -- let me know if I ought to be
checking something else.
In the absence of the correct kernel, do_changename()
always returns 0.
Attached is a patch against the current CVS that will make these changes.
-- Lars
