From: roopa <roopa@cumulusnetworks•com>
To: "Eric W. Biederman" <ebiederm@xmission•com>
Cc: David Miller <davem@davemloft•net>,
netdev@vger•kernel.org,
Stephen Hemminger <stephen@networkplumber•org>,
santiago@crfreenet•org, Simon Horman <horms@verge•net.au>
Subject: Re: [PATCH net-next 4/7] mpls: Basic support for adding and removing routes
Date: Wed, 04 Mar 2015 16:30:44 -0800 [thread overview]
Message-ID: <54F7A3B4.2050308@cumulusnetworks.com> (raw)
In-Reply-To: <87h9u0lctq.fsf@x220.int.ebiederm.org>
On 3/4/15, 12:36 PM, Eric W. Biederman wrote:
> roopa <roopa@cumulusnetworks•com> writes:
>
>> On 3/3/15, 5:12 PM, Eric W. Biederman wrote:
>>> mpls_route_add and mpls_route_del implement the basic logic for adding
>>> and removing Next Hop Label Forwarding Entries from the MPLS input
>>> label map. The addition and subtraction is done in a way that is
>>> consistent with how the existing routing table in Linux are
>>> maintained. Thus all of the work to deal with NLM_F_APPEND,
>>> NLM_F_EXCL, NLM_F_REPLACE, and NLM_F_CREATE.
>>>
>>> Cases that are not clearly defined such as changing the interpretation
>>> of the mpls reserved labels is not allowed.
>>>
>>> Because it seems like the right thing to do adding an MPLS route without
>>> specifying an input label and allowing the kernel to pick a free label
>>> table entry is supported. The implementation is currently less than optimal
>>> but that can be changed.
>>>
>>> As I don't have anything else to test with only ethernet and the loopback
>>> device are the only two device types currently supported for forwarding
>>> MPLS over.
>>>
>>> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission•com>
>>> ---
>>> net/mpls/af_mpls.c | 133 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>>> 1 file changed, 133 insertions(+)
>>>
>>> diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
>>> index b097125dfa33..e432f092f2fb 100644
>>> --- a/net/mpls/af_mpls.c
>>> +++ b/net/mpls/af_mpls.c
>>> @@ -16,6 +16,7 @@
>>> #include <net/netns/generic.h>
>>> #include "internal.h"
>>> +#define LABEL_NOT_SPECIFIED (1<<20)
>>> #define MAX_NEW_LABELS 2
>>> /* This maximum ha length copied from the definition of struct
>>> neighbour */
>>> @@ -211,6 +212,19 @@ static struct packet_type mpls_packet_type __read_mostly = {
>>> .func = mpls_forward,
>>> };
>>> +struct mpls_route_config {
>>> + u32 rc_protocol;
>>> + u32 rc_ifindex;
>>> + u16 rc_via_family;
>>> + u16 rc_via_alen;
>>> + u8 rc_via[MAX_VIA_ALEN];
>>> + u32 rc_label;
>>> + u32 rc_output_labels;
>>> + u32 rc_output_label[MAX_NEW_LABELS];
>>> + u32 rc_nlflags;
>>> + struct nl_info rc_nlinfo;
>>> +};
>>> +
>>> static struct mpls_route *mpls_rt_alloc(size_t alen)
>>> {
>>> struct mpls_route *rt;
>>> @@ -245,6 +259,125 @@ static void mpls_route_update(struct net *net, unsigned index,
>>> mpls_rt_free(old);
>>> }
>>> +static unsigned find_free_label(struct net *net)
>>> +{
>>> + unsigned index;
>>> + for (index = 16; index < net->mpls.platform_labels; index++) {
>>> + if (!net->mpls.platform_label[index])
>>> + return index;
>>> + }
>>> + return LABEL_NOT_SPECIFIED;
>>> +}
>>> +
>>> +static int mpls_route_add(struct mpls_route_config *cfg)
>>> +{
>>> + struct net *net = cfg->rc_nlinfo.nl_net;
>>> + struct net_device *dev = NULL;
>>> + struct mpls_route *rt, *old;
>>> + unsigned index;
>>> + int i;
>>> + int err = -EINVAL;
>>> +
>>> + index = cfg->rc_label;
>>> +
>>> + /* If a label was not specified during insert pick one */
>>> + if ((index == LABEL_NOT_SPECIFIED) &&
>>> + (cfg->rc_nlflags & NLM_F_CREATE)) {
>>> + index = find_free_label(net);
>>> + }
>>> +
>>> + /* The first 16 labels are reserved, and may not be set */
>>> + if (index < 16)
>>> + goto errout;
>>> +
>>> + /* The full 20 bit range may not be supported. */
>>> + if (index >= net->mpls.platform_labels)
>>> + goto errout;
>>> +
>>> + /* Ensure only a supported number of labels are present */
>>> + if (cfg->rc_output_labels > MAX_NEW_LABELS)
>>> + goto errout;
>>> +
>>> + err = -ENODEV;
>>> + dev = dev_get_by_index(net, cfg->rc_ifindex);
>>> + if (!dev)
>>> + goto errout;
>>> +
>>> + /* For now just support ethernet devices */
>>> + err = -EINVAL;
>>> + if ((dev->type != ARPHRD_ETHER) && (dev->type != ARPHRD_LOOPBACK))
>>> + goto errout;
>>> +
>>> + err = -EINVAL;
>>> + if ((cfg->rc_via_family == AF_PACKET) &&
>>> + (dev->addr_len != cfg->rc_via_alen))
>>> + goto errout;
>>> +
>>> + /* Append makes no sense with mpls */
>>> + err = -EINVAL;
>> minor nit: should this be -ENOTSUPP in that case ? (NLM_F_REPLACE and NLM_F_APPEND are
>> really operations. But, one can argue that they are an attribute of the msg and hence -EINVAL might be ok).
>> I did not find any other such case for consistency check.
> Yes. IPv4 implements NLM_F_APPEND and IPv6 ignores it.
>
> I will add a patch to change the error code.
Thanks.
>
> Do you happen to know what NLM_F_APPEND means? I couldn't figure out
> when glancing through the IPv4 code.
>
> NLM_F_REPLACE seems obvious. Though it seems to have exactly the
> oposite meaning of NLM_F_EXCL. Which seems to make NLM_F_EXCL
> redundant.
>
> My hunch is that there are meanings here that apply when you are doing
> longest prefix matching that don't quite apply when you are are doing
> exact match routing.
NLM_F_APPEND only affects the position where the new fib_alias gets added
(fib_insert_alias). A new fib_alias is always added at the front and
NLM_F_APPEND makes it
go to the tail AFAICT (This is fib_aliases for the same prefix or fib_info)
Thanks,
Roopa
next prev parent reply other threads:[~2015-03-05 0:30 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-25 17:09 [PATCH net-next 0/8] Basic MPLS support Eric W. Biederman
2015-02-25 17:13 ` [PATCH net-next 1/8] mpls: Refactor how the mpls module is built Eric W. Biederman
2015-02-26 2:05 ` Simon Horman
2015-02-26 2:15 ` Eric W. Biederman
2015-02-26 2:28 ` Simon Horman
2015-02-25 17:14 ` [PATCH net-next 2/8] mpls: Basic routing support Eric W. Biederman
2015-02-25 17:15 ` [PATCH net-next 3/8] mpls: Add a sysctl to control the size of the mpls label table Eric W. Biederman
2015-02-25 17:16 ` [PATCH net-next 4/8] mpls: Basic support for adding and removing routes Eric W. Biederman
2015-02-25 17:16 ` [PATCH net-next 5/8] mpls: Functions for reading and wrinting mpls labels over netlink Eric W. Biederman
2015-02-25 17:17 ` [PATCH net-next 6/8] mpls: Netlink commands to add, remove, and dump routes Eric W. Biederman
2015-02-25 17:18 ` [PATCH net-next 8/8] ipmpls: Basic device for injecting packets into an mpls tunnel Eric W. Biederman
2015-03-05 9:17 ` Vivek Venkatraman
2015-03-05 14:00 ` Eric W. Biederman
2015-03-05 16:25 ` Vivek Venkatraman
2015-03-05 19:52 ` Eric W. Biederman
2015-03-06 6:05 ` Vivek Venkatraman
2015-03-07 10:36 ` Robert Shearman
2015-03-07 21:12 ` Eric W. Biederman
2015-02-25 17:19 ` [PATCH net-next 7/8] mpls: Multicast route table change notifications Eric W. Biederman
2015-02-26 7:21 ` roopa
2015-02-26 14:03 ` Eric W. Biederman
2015-02-26 15:12 ` roopa
2015-03-05 1:56 ` Andy Gospodarek
2015-02-25 17:37 ` [PATCH iproute2] mpls: Add basic mpls support to iproute Eric W. Biederman
2015-02-26 6:58 ` [PATCH net-next 0/8] Basic MPLS support roopa
2015-02-27 21:21 ` David Miller
2015-02-28 0:58 ` Eric W. Biederman
2015-03-02 0:05 ` Shrijeet Mukherjee
2015-03-02 4:03 ` David Miller
2015-03-02 5:10 ` Eric W. Biederman
2015-03-02 5:53 ` David Miller
2015-03-02 5:59 ` [PATCH net-next 0/15] Neighbour table and ax25 cleanups Eric W. Biederman
2015-03-02 5:59 ` [PATCH net-next 01/15] ax25: In ax25_rebuild_header add missing kfree_skb Eric W. Biederman
2015-03-02 6:01 ` [PATCH net-next 02/15] rose: Set the destination address in rose_header Eric W. Biederman
2015-03-02 6:02 ` [PATCH net-next 03/15] rose: Transmit packets in rose_xmit not rose_rebuild_header Eric W. Biederman
2015-03-02 6:03 ` [PATCH net-next 04/15] ax25/kiss: Replace ax_header_ops with ax25_header_ops Eric W. Biederman
2015-03-02 6:03 ` [PATCH net-next 05/15] ax25/6pack: Replace sp_header_ops " Eric W. Biederman
2015-03-02 6:04 ` [PATCH net-next 06/15] ax25: Make ax25_header and ax25_rebuild_header static Eric W. Biederman
2015-03-02 6:05 ` [PATCH net-next 07/15] ax25: Refactor to use private neighbour operations Eric W. Biederman
2015-03-02 6:06 ` [PATCH net-next 08/15] arp: Remove special case to give AX25 it's open arp operations Eric W. Biederman
2015-03-02 6:07 ` [PATCH net-next 09/15] neigh: Move neigh_compat_output into ax25_ip.c Eric W. Biederman
2015-03-02 6:08 ` [PATCH net-next 10/15] ax25: Stop calling/abusing dev_rebuild_header Eric W. Biederman
2015-03-02 6:09 ` [PATCH net-next 11/15] ax25: Stop depending on arp_find Eric W. Biederman
2015-03-02 6:11 ` [PATCH net-next 12/15] net: Kill dev_rebuild_header Eric W. Biederman
2015-03-02 6:12 ` [PATCH net-next 13/15] arp: Kill arp_find Eric W. Biederman
2015-03-02 6:13 ` [PATCH net-next 14/15] neigh: Don't require dst in neigh_hh_init Eric W. Biederman
2015-03-02 6:14 ` [PATCH net-next 15/15] neigh: Don't require a dst in neigh_resolve_output Eric W. Biederman
2015-03-02 21:44 ` [PATCH net-next 0/15] Neighbour table and ax25 cleanups David Miller
2015-03-03 15:41 ` [PATCH net-next] ax25: Stop using magic neighbour cache operations Eric W. Biederman
2015-03-03 19:45 ` David Miller
2015-03-03 20:22 ` Eric W. Biederman
2015-03-03 20:33 ` David Miller
2015-03-03 23:09 ` [PATCH net-next 0/2] Neighbour table prep for MPLS Eric W. Biederman
2015-03-03 23:10 ` [PATCH net-next 1/2] neigh: Factor out ___neigh_lookup_noref Eric W. Biederman
2015-03-04 14:53 ` Andy Gospodarek
2015-03-04 15:58 ` Eric W. Biederman
2015-03-04 16:30 ` Andy Gospodarek
2015-03-03 23:11 ` [PATCH net-next 2/2] neigh: Add helper function neigh_xmit Eric W. Biederman
2015-03-04 1:06 ` [PATCH net-next 0/7] Basic MPLS support take 2 Eric W. Biederman
2015-03-04 1:10 ` [PATCH net-next 1/7] mpls: Refactor how the mpls module is built Eric W. Biederman
2015-03-04 1:10 ` [PATCH net-next 2/7] mpls: Basic routing support Eric W. Biederman
2015-03-05 16:36 ` Vivek Venkatraman
2015-03-05 18:42 ` Eric W. Biederman
2015-03-04 1:11 ` [PATCH net-next 3/7] mpls: Add a sysctl to control the size of the mpls label table Eric W. Biederman
2015-03-05 9:45 ` Vivek Venkatraman
2015-03-05 13:22 ` Eric W. Biederman
2015-03-05 14:38 ` Eric W. Biederman
2015-03-05 16:49 ` Vivek Venkatraman
2015-03-04 1:12 ` [PATCH net-next 4/7] mpls: Basic support for adding and removing routes Eric W. Biederman
2015-03-04 8:13 ` roopa
2015-03-04 20:36 ` Eric W. Biederman
2015-03-05 0:30 ` roopa [this message]
2015-03-05 2:50 ` Bill Fink
2015-03-05 11:54 ` Eric W. Biederman
2015-03-05 19:10 ` Bill Fink
2015-03-04 1:13 ` [PATCH net-next 5/7] mpls: Functions for reading and wrinting mpls labels over netlink Eric W. Biederman
2015-03-04 1:13 ` [PATCH net-next 6/7] mpls: Netlink commands to add, remove, and dump routes Eric W. Biederman
2015-03-04 1:14 ` [PATCH net-next 7/7] mpls: Multicast route table change notifications Eric W. Biederman
2015-03-04 5:27 ` [PATCH net-next 0/7] Basic MPLS support take 2 David Miller
2015-03-04 6:13 ` Eric W. Biederman
2015-03-04 5:25 ` [PATCH net-next 0/2] Neighbour table prep for MPLS David Miller
2015-03-04 5:53 ` Eric W. Biederman
2015-03-04 14:56 ` Andy Gospodarek
2015-03-04 21:04 ` David Miller
2015-03-05 12:35 ` Eric W. Biederman
2015-03-05 10:14 ` [PATCH net-next] ax25: Stop using magic neighbour cache operations Steven Whitehouse
2015-03-06 20:44 ` Eric W. Biederman
2015-03-14 0:33 ` Steven Whitehouse
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