From a9f1ac2dfdc3ab7421ea33ae977f7e078750e542 Mon Sep 17 00:00:00 2001
From: "Robin H. Johnson" <robbat2@gentoo.org>
Date: Thu, 11 Oct 2012 03:54:32 +0000
Subject: [PATCH] net/bonding: Sanity-check sysfs usage

If sysfs is not available, you might still be able to create bond
interfaces, but only in very specific configurations, and you must have
the ifenslave binary instead to call ioctls.

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
---
 net/bonding.sh | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/net/bonding.sh b/net/bonding.sh
index 67b0d9ba..7ea75085 100644
--- a/net/bonding.sh
+++ b/net/bonding.sh
@@ -5,6 +5,11 @@ bonding_depend()
 {
 	before interface macchanger
 	program /sbin/ifconfig /bin/ifconfig
+	# If you do not have sysfs, you MUST have this binary instead for ioctl
+	# Also you will loose some functionality that cannot be done via sysfs:
+	if [ ! -d /sys/class/net ]; then
+		program /sbin/ifenslave
+	fi
 }
 
 _config_vars="$_config_vars slaves"
@@ -38,6 +43,10 @@ bonding_pre_start()
 		fi
 	fi
 
+	if [ ! -d /sys/class/net ]; then
+		ewarn "sysfs is not available! You will be unable to create new bonds, or change dynamic parameters!"
+	fi
+
 	# We can create the interface name we like now, but this
 	# requires sysfs
 	if ! _exists && [ -d /sys/class/net ]; then
@@ -55,7 +64,7 @@ bonding_pre_start()
 
 	# Configure the bond mode, then we can reloop to ensure we configure
 	# All other options
-	for x in /sys/class/net/"${IFACE}"/bonding/mode; do
+	[ -d /sys/class/net ] && for x in /sys/class/net/"${IFACE}"/bonding/mode; do
 		[ -f "${x}" ] || continue
 		n=${x##*/}
 		eval s=\$${n}_${IFVAR}
@@ -66,7 +75,7 @@ bonding_pre_start()
 		fi
 	done
 	# Nice and dynamic for remaining options:)
-	for x in /sys/class/net/"${IFACE}"/bonding/*; do
+	[ -d /sys/class/net ] && for x in /sys/class/net/"${IFACE}"/bonding/*; do
 		[ -f "${x}" ] || continue
 		n=${x##*/}
 		eval s=\$${n}_${IFVAR}
@@ -154,7 +163,7 @@ bonding_pre_start()
 			fi
 		done
 	else
-		/sbin/ifenslave "${IFACE}" ${slaves} >/dev/null
+		ifenslave "${IFACE}" ${slaves} >/dev/null
 	fi
 	eend $?
 
@@ -187,7 +196,7 @@ bonding_stop()
 			echo -"${s}" > /sys/class/net/"${IFACE}"/bonding/slaves
 		done
 	else
-		/sbin/ifenslave -d "${IFACE}" ${slaves}
+		ifenslave -d "${IFACE}" ${slaves}
 	fi
 
 	# reset all slaves