busybox: backport the ifplugd-larger-buffer patch for kernel 3.9 and above

To use the busybox-ipflugd a larger buffer for netdev messages
is needed. This is orginal patch from

http://git.busybox.net/busybox/commit/networking/ifplugd.c?id=da331d779c19d7d5d4ef05152ee467d617913a01

which is needed until a new busybox version is released.

This commit only is only relevant to the dora release of poky.

* bump PRINC

recipes-core/busybox/busybox-1.21.1/ifplugd-use-a-larger-netlink-buffer.patch

@@ -0,0 +1,62 @@
+Upstream-Status: Backport
+Signed-off-by: Henning Heinold <henning@itconsulting-heinold.de>
+
+From da331d779c19d7d5d4ef05152ee467d617913a01 Mon Sep 17 00:00:00 2001
+From: Tito Ragusa <farmatito@tiscali.it>
+Date: Sun, 4 Aug 2013 18:08:40 +0200
+Subject: [PATCH 001/104] ifplugd: use a larger netlink buffer
+
+function                                             old     new   delta
+check_existence_through_netlink                      310     321     +11
+
+Signed-off-by: Tito Ragusa <farmatito@tiscali.it>
+Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
+---
+ networking/ifplugd.c |   14 ++++++++++----
+ 1 file changed, 10 insertions(+), 4 deletions(-)
+
+diff --git a/networking/ifplugd.c b/networking/ifplugd.c
+index 3cdc2c9..b578f4c 100644
+--- a/networking/ifplugd.c
++++ b/networking/ifplugd.c
+@@ -451,20 +451,24 @@ static smallint detect_link(void)
+ static NOINLINE int check_existence_through_netlink(void)
+ {
+ 	int iface_len;
+-	char replybuf[1024];
++	/* Buffer was 1K, but on linux-3.9.9 it was reported to be too small.
++	 * netlink.h: "limit to 8K to avoid MSG_TRUNC when PAGE_SIZE is very large".
++	 * Note: on error returns (-1) we exit, no need to free replybuf.
++	 */
++	enum { BUF_SIZE = 8 * 1024 };
++	char *replybuf = xmalloc(BUF_SIZE);
+ 
+ 	iface_len = strlen(G.iface);
+ 	while (1) {
+ 		struct nlmsghdr *mhdr;
+ 		ssize_t bytes;
+ 
+-		bytes = recv(netlink_fd, &replybuf, sizeof(replybuf), MSG_DONTWAIT);
++		bytes = recv(netlink_fd, replybuf, BUF_SIZE, MSG_DONTWAIT);
+ 		if (bytes < 0) {
+ 			if (errno == EAGAIN)
+-				return G.iface_exists;
++				goto ret;
+ 			if (errno == EINTR)
+ 				continue;
+-
+ 			bb_perror_msg("netlink: recv");
+ 			return -1;
+ 		}
+@@ -507,6 +511,8 @@ static NOINLINE int check_existence_through_netlink(void)
+ 		}
+ 	}
+ 
++ ret:
++	free(replybuf);
+ 	return G.iface_exists;
+ }
+ 
+-- 
+1.7.10.4
+

recipes-core/busybox/busybox_sysmocom.inc

@@ -1,6 +1,6 @@
 SYSMOCOM := "${@os.path.dirname(bb.data.getVar('FILE', d, True))}"
 FILESEXTRAPATHS_prepend := "${SYSMOCOM}/busybox-${SYSMOCOM_ORIG_PV}:${SYSMOCOM}/files:"
-PRINC = "19"
+PRINC = "20"
 
 SRC_URI += "file://busybox-ifplugd.sh \
             file://ifplugd.sh"

recipes-core/busybox/busybox_sysmocom_systemd.inc

@@ -2,3 +2,5 @@
 SYSMOCOM_D := "${@os.path.dirname(bb.data.getVar('FILE', d, True))}"
 FILESEXTRAPATHS_prepend := "${SYSMOCOM}/${PN}-systemd:${SYSMOCOM_D}/${PN}:"
 PRINC := "${@int(PRINC) + 2}"
+
+SRC_URI += "file://ifplugd-use-a-larger-netlink-buffer.patch"