| Message ID | 20130628152652.GA4247@fedora-17-guest.blr.amer.dell.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Fri, 2013-06-28 at 20:57 +0530, Narendra_K@Dell.com wrote: [...] > --- a/include/linux/netdevice.h > +++ b/include/linux/netdevice.h > @@ -1062,6 +1062,14 @@ struct net_device_ops { > bool new_carrier); > }; > > +/* This structure holds a universally unique identifier to > + * identify the physical port used by a netdevice > + */ > +struct port_identifier { > + unsigned char port_id[MAX_ADDR_LEN]; > + unsigned port_id_len; Was this meant to be unsigned (int) or unsigned char? The length is typed as unsigned char in show_phys_port(). > +}; [...] > --- a/net/core/net-sysfs.c > +++ b/net/core/net-sysfs.c > @@ -334,6 +334,27 @@ static ssize_t store_group(struct device *dev, struct device_attribute *attr, > return netdev_store(dev, attr, buf, len, change_group); > } > > +static ssize_t show_phys_port(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct net_device *net = to_net_dev(dev); > + ssize_t ret = -EINVAL; > + unsigned char len; > + > + read_lock(&dev_base_lock); > + if (dev_isalive(net)) { > + len = net->phys_port.port_id_len; > + if (!len) { > + read_unlock(&dev_base_lock); > + return 0; > + } I would write this as: if (!len) ret = 0; else so that the same exit path is used in all three cases. Ben. > + ret = sysfs_format_mac(buf, net->phys_port.port_id, len); > + } > + read_unlock(&dev_base_lock); > + > + return ret; > +} [...]
On Tue, Jul 02, 2013 at 01:42:22AM +0530, Ben Hutchings wrote: > > On Fri, 2013-06-28 at 20:57 +0530, Narendra_K@Dell.com wrote: > [...] > > --- a/include/linux/netdevice.h > > +++ b/include/linux/netdevice.h > > @@ -1062,6 +1062,14 @@ struct net_device_ops { > > bool new_carrier); > > }; > > > > +/* This structure holds a universally unique identifier to > > + * identify the physical port used by a netdevice > > + */ > > +struct port_identifier { > > + unsigned char port_id[MAX_ADDR_LEN]; > > + unsigned port_id_len; > > Was this meant to be unsigned (int) or unsigned char? The length is > typed as unsigned char in show_phys_port(). Sorry, this change was by mistake. It is unsigned char. I will change it in the next version of the patch. Thank you for pointing out this. > > > +}; > [...] > > --- a/net/core/net-sysfs.c > > +++ b/net/core/net-sysfs.c > > @@ -334,6 +334,27 @@ static ssize_t store_group(struct device *dev, struct > device_attribute *attr, > > return netdev_store(dev, attr, buf, len, change_group); > > } > > > > +static ssize_t show_phys_port(struct device *dev, > > + struct device_attribute *attr, char *buf) > > +{ > > + struct net_device *net = to_net_dev(dev); > > + ssize_t ret = -EINVAL; > > + unsigned char len; > > + > > + read_lock(&dev_base_lock); > > + if (dev_isalive(net)) { > > + len = net->phys_port.port_id_len; > > + if (!len) { > > + read_unlock(&dev_base_lock); > > + return 0; > > + } > > I would write this as: > if (!len) > ret = 0; > else > so that the same exit path is used in all three cases. Ok. I will make this change in the next version of the patch. I will submit the next version when net-next opens. > > Ben. > > > + ret = sysfs_format_mac(buf, net->phys_port.port_id, len); > > + } > > + read_unlock(&dev_base_lock); > > + > > + return ret; > > +} > [...] > > -- > Ben Hutchings, Staff Engineer, Solarflare > Not speaking for my employer; that's the marketing department's job. > They asked us to note that Solarflare product names are trademarked. > >
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 09b4188..ddb14ef 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1062,6 +1062,14 @@ struct net_device_ops { bool new_carrier); }; +/* This structure holds a universally unique identifier to + * identify the physical port used by a netdevice + */ +struct port_identifier { + unsigned char port_id[MAX_ADDR_LEN]; + unsigned port_id_len; +}; + /* * The DEVICE structure. * Actually, this whole structure is a big mistake. It mixes I/O @@ -1181,6 +1189,11 @@ struct net_device { * that share the same link * layer address */ + struct port_identifier phys_port; /* Universally unique physical + * port identifier, MAC-48 or + * EUI-64 or 128 bit UUID, + * length is zero if not set + */ spinlock_t addr_list_lock; struct netdev_hw_addr_list uc; /* Unicast mac addresses */ struct netdev_hw_addr_list mc; /* Multicast mac addresses */ diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 981fed3..f151eab 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -334,6 +334,27 @@ static ssize_t store_group(struct device *dev, struct device_attribute *attr, return netdev_store(dev, attr, buf, len, change_group); } +static ssize_t show_phys_port(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct net_device *net = to_net_dev(dev); + ssize_t ret = -EINVAL; + unsigned char len; + + read_lock(&dev_base_lock); + if (dev_isalive(net)) { + len = net->phys_port.port_id_len; + if (!len) { + read_unlock(&dev_base_lock); + return 0; + } + ret = sysfs_format_mac(buf, net->phys_port.port_id, len); + } + read_unlock(&dev_base_lock); + + return ret; +} + static struct device_attribute net_class_attributes[] = { __ATTR(addr_assign_type, S_IRUGO, show_addr_assign_type, NULL), __ATTR(addr_len, S_IRUGO, show_addr_len, NULL), @@ -355,6 +376,7 @@ static struct device_attribute net_class_attributes[] = { __ATTR(tx_queue_len, S_IRUGO | S_IWUSR, show_tx_queue_len, store_tx_queue_len), __ATTR(netdev_group, S_IRUGO | S_IWUSR, show_group, store_group), + __ATTR(phys_port, S_IRUGO, show_phys_port, NULL), {} };
It is useful to know if network interfaces from NIC partitions 'map to/use the' same physical port. For example, when creating bonding in fault tolerance mode, if two network interfaces map to/use the same physical port, it might not have the desired result. This information is not available today in a standard format or it is not present. If this information can be made available in a generic way to user space, tools such as NetworkManager or Libteam or Wicked can make smarter bonding decisions (such as warn users when setting up configurations which will not have desired effect). The requirement is to have a generic interface using which kernel/drivers can provide information/hints to user space about the physical port number used by a network interface. The following options were explored - 1. 'dev_id' sysfs attribute: In addition to being used to differentiate between devices that share the same link layer address, it is being used to indicate the physical port number used by a network interface. As dev_id exists to differentiate between devices sharing the same link layer address, dev_id option is not selected. 2. Re-using 'if_port' field in 'struct net_device': if_port field exists to indicate the media type(please refer to netdevice.h). It seemed like it was also used to indicate the physical port number. As re-using 'if_port' might possibly break user space, this option is not selected. 3. Add a new field 'phys_port' to 'struct net_device' and export it to sysfs: The 'phys_port' will be a universally unique identifier, which would be a MAC-48 or EUI-64 or a 128 bit UUID value, but not restricted to these spaces. It will uniquely identify the physical port used by a network interface. The 'length' of the identifier will be zero if the field is not set for a network interface. This patch implements option 3. It creates a new sysfs attribute 'phys_port' - /sys/class/net/<interface name>/phys_port References: http://marc.info/?l=linux-netdev&m=136920998009209&w=2 References: http://marc.info/?l=linux-netdev&m=136992041432498&w=2 Signed-off-by: Narendra K <narendra_k@dell.com> --- Changes from RFC version: Suggestions from Ben Hutchings - 1. 'struct port_identifier' is changed to be generic instead of restricting it to MAC-48 or EUI-64 or 128 bit UUID. 2. Commit message updated to indicate point 1. 3. 'show_phys_port' function modified to handle zero length instead of returning -EINVAL 4. 'show_phys_port' function made generic to handle all lengths instead 6, 8 or 16 bytes. v0 -> v1: Added the missing locking in 'show_phys_port' function - suggested by John Fastabend. include/linux/netdevice.h | 13 +++++++++++++ net/core/net-sysfs.c | 22 ++++++++++++++++++++++ 2 files changed, 35 insertions(+)