linux-brain/net/bridge/br_netlink_tunnel.c
Michal Kubecek ae0be8de9a netlink: make nla_nest_start() add NLA_F_NESTED flag
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.

Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().

Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:

@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)

@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27 17:03:44 -04:00

299 lines
7.0 KiB
C

/*
* Bridge per vlan tunnel port dst_metadata netlink control interface
*
* Authors:
* Roopa Prabhu <roopa@cumulusnetworks.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/etherdevice.h>
#include <net/rtnetlink.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <uapi/linux/if_bridge.h>
#include <net/dst_metadata.h>
#include "br_private.h"
#include "br_private_tunnel.h"
static size_t __get_vlan_tinfo_size(void)
{
return nla_total_size(0) + /* nest IFLA_BRIDGE_VLAN_TUNNEL_INFO */
nla_total_size(sizeof(u32)) + /* IFLA_BRIDGE_VLAN_TUNNEL_ID */
nla_total_size(sizeof(u16)) + /* IFLA_BRIDGE_VLAN_TUNNEL_VID */
nla_total_size(sizeof(u16)); /* IFLA_BRIDGE_VLAN_TUNNEL_FLAGS */
}
static bool vlan_tunid_inrange(struct net_bridge_vlan *v_curr,
struct net_bridge_vlan *v_last)
{
__be32 tunid_curr = tunnel_id_to_key32(v_curr->tinfo.tunnel_id);
__be32 tunid_last = tunnel_id_to_key32(v_last->tinfo.tunnel_id);
return (be32_to_cpu(tunid_curr) - be32_to_cpu(tunid_last)) == 1;
}
static int __get_num_vlan_tunnel_infos(struct net_bridge_vlan_group *vg)
{
struct net_bridge_vlan *v, *vtbegin = NULL, *vtend = NULL;
int num_tinfos = 0;
/* Count number of vlan infos */
list_for_each_entry_rcu(v, &vg->vlan_list, vlist) {
/* only a context, bridge vlan not activated */
if (!br_vlan_should_use(v) || !v->tinfo.tunnel_id)
continue;
if (!vtbegin) {
goto initvars;
} else if ((v->vid - vtend->vid) == 1 &&
vlan_tunid_inrange(v, vtend)) {
vtend = v;
continue;
} else {
if ((vtend->vid - vtbegin->vid) > 0)
num_tinfos += 2;
else
num_tinfos += 1;
}
initvars:
vtbegin = v;
vtend = v;
}
if (vtbegin && vtend) {
if ((vtend->vid - vtbegin->vid) > 0)
num_tinfos += 2;
else
num_tinfos += 1;
}
return num_tinfos;
}
int br_get_vlan_tunnel_info_size(struct net_bridge_vlan_group *vg)
{
int num_tinfos;
if (!vg)
return 0;
rcu_read_lock();
num_tinfos = __get_num_vlan_tunnel_infos(vg);
rcu_read_unlock();
return num_tinfos * __get_vlan_tinfo_size();
}
static int br_fill_vlan_tinfo(struct sk_buff *skb, u16 vid,
__be64 tunnel_id, u16 flags)
{
__be32 tid = tunnel_id_to_key32(tunnel_id);
struct nlattr *tmap;
tmap = nla_nest_start_noflag(skb, IFLA_BRIDGE_VLAN_TUNNEL_INFO);
if (!tmap)
return -EMSGSIZE;
if (nla_put_u32(skb, IFLA_BRIDGE_VLAN_TUNNEL_ID,
be32_to_cpu(tid)))
goto nla_put_failure;
if (nla_put_u16(skb, IFLA_BRIDGE_VLAN_TUNNEL_VID,
vid))
goto nla_put_failure;
if (nla_put_u16(skb, IFLA_BRIDGE_VLAN_TUNNEL_FLAGS,
flags))
goto nla_put_failure;
nla_nest_end(skb, tmap);
return 0;
nla_put_failure:
nla_nest_cancel(skb, tmap);
return -EMSGSIZE;
}
static int br_fill_vlan_tinfo_range(struct sk_buff *skb,
struct net_bridge_vlan *vtbegin,
struct net_bridge_vlan *vtend)
{
int err;
if (vtend && (vtend->vid - vtbegin->vid) > 0) {
/* add range to skb */
err = br_fill_vlan_tinfo(skb, vtbegin->vid,
vtbegin->tinfo.tunnel_id,
BRIDGE_VLAN_INFO_RANGE_BEGIN);
if (err)
return err;
err = br_fill_vlan_tinfo(skb, vtend->vid,
vtend->tinfo.tunnel_id,
BRIDGE_VLAN_INFO_RANGE_END);
if (err)
return err;
} else {
err = br_fill_vlan_tinfo(skb, vtbegin->vid,
vtbegin->tinfo.tunnel_id,
0);
if (err)
return err;
}
return 0;
}
int br_fill_vlan_tunnel_info(struct sk_buff *skb,
struct net_bridge_vlan_group *vg)
{
struct net_bridge_vlan *vtbegin = NULL;
struct net_bridge_vlan *vtend = NULL;
struct net_bridge_vlan *v;
int err;
/* Count number of vlan infos */
list_for_each_entry_rcu(v, &vg->vlan_list, vlist) {
/* only a context, bridge vlan not activated */
if (!br_vlan_should_use(v))
continue;
if (!v->tinfo.tunnel_dst)
continue;
if (!vtbegin) {
goto initvars;
} else if ((v->vid - vtend->vid) == 1 &&
vlan_tunid_inrange(v, vtend)) {
vtend = v;
continue;
} else {
err = br_fill_vlan_tinfo_range(skb, vtbegin, vtend);
if (err)
return err;
}
initvars:
vtbegin = v;
vtend = v;
}
if (vtbegin) {
err = br_fill_vlan_tinfo_range(skb, vtbegin, vtend);
if (err)
return err;
}
return 0;
}
static const struct nla_policy vlan_tunnel_policy[IFLA_BRIDGE_VLAN_TUNNEL_MAX + 1] = {
[IFLA_BRIDGE_VLAN_TUNNEL_ID] = { .type = NLA_U32 },
[IFLA_BRIDGE_VLAN_TUNNEL_VID] = { .type = NLA_U16 },
[IFLA_BRIDGE_VLAN_TUNNEL_FLAGS] = { .type = NLA_U16 },
};
static int br_vlan_tunnel_info(struct net_bridge_port *p, int cmd,
u16 vid, u32 tun_id, bool *changed)
{
int err = 0;
if (!p)
return -EINVAL;
switch (cmd) {
case RTM_SETLINK:
err = nbp_vlan_tunnel_info_add(p, vid, tun_id);
if (!err)
*changed = true;
break;
case RTM_DELLINK:
if (!nbp_vlan_tunnel_info_delete(p, vid))
*changed = true;
break;
}
return err;
}
int br_parse_vlan_tunnel_info(struct nlattr *attr,
struct vtunnel_info *tinfo)
{
struct nlattr *tb[IFLA_BRIDGE_VLAN_TUNNEL_MAX + 1];
u32 tun_id;
u16 vid, flags = 0;
int err;
memset(tinfo, 0, sizeof(*tinfo));
err = nla_parse_nested(tb, IFLA_BRIDGE_VLAN_TUNNEL_MAX, attr,
vlan_tunnel_policy, NULL);
if (err < 0)
return err;
if (!tb[IFLA_BRIDGE_VLAN_TUNNEL_ID] ||
!tb[IFLA_BRIDGE_VLAN_TUNNEL_VID])
return -EINVAL;
tun_id = nla_get_u32(tb[IFLA_BRIDGE_VLAN_TUNNEL_ID]);
vid = nla_get_u16(tb[IFLA_BRIDGE_VLAN_TUNNEL_VID]);
if (vid >= VLAN_VID_MASK)
return -ERANGE;
if (tb[IFLA_BRIDGE_VLAN_TUNNEL_FLAGS])
flags = nla_get_u16(tb[IFLA_BRIDGE_VLAN_TUNNEL_FLAGS]);
tinfo->tunid = tun_id;
tinfo->vid = vid;
tinfo->flags = flags;
return 0;
}
int br_process_vlan_tunnel_info(struct net_bridge *br,
struct net_bridge_port *p, int cmd,
struct vtunnel_info *tinfo_curr,
struct vtunnel_info *tinfo_last,
bool *changed)
{
int err;
if (tinfo_curr->flags & BRIDGE_VLAN_INFO_RANGE_BEGIN) {
if (tinfo_last->flags & BRIDGE_VLAN_INFO_RANGE_BEGIN)
return -EINVAL;
memcpy(tinfo_last, tinfo_curr, sizeof(struct vtunnel_info));
} else if (tinfo_curr->flags & BRIDGE_VLAN_INFO_RANGE_END) {
int t, v;
if (!(tinfo_last->flags & BRIDGE_VLAN_INFO_RANGE_BEGIN))
return -EINVAL;
if ((tinfo_curr->vid - tinfo_last->vid) !=
(tinfo_curr->tunid - tinfo_last->tunid))
return -EINVAL;
t = tinfo_last->tunid;
for (v = tinfo_last->vid; v <= tinfo_curr->vid; v++) {
err = br_vlan_tunnel_info(p, cmd, v, t, changed);
if (err)
return err;
t++;
}
memset(tinfo_last, 0, sizeof(struct vtunnel_info));
memset(tinfo_curr, 0, sizeof(struct vtunnel_info));
} else {
if (tinfo_last->flags)
return -EINVAL;
err = br_vlan_tunnel_info(p, cmd, tinfo_curr->vid,
tinfo_curr->tunid, changed);
if (err)
return err;
memset(tinfo_last, 0, sizeof(struct vtunnel_info));
memset(tinfo_curr, 0, sizeof(struct vtunnel_info));
}
return 0;
}