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openvswitch: Fix mask generation for nested attributes. 

Masks were added to OVS flows in a way that was backwards compatible
with userspace programs that did not generate masks. As a result, it is
possible that we may receive flows that do not have a mask and we need
to synthesize one.

Generating a mask requires iterating over attributes and descending into
nested attributes. For each level we need to know the size to generate the
correct mask. We do this with a linked table of attribute types.

Although the logic to handle these nested attributes was there in concept,
there are a number of bugs in practice. Examples include incomplete links
between tables, variable length attributes being treated as nested and
missing sanity checks.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
steinar/wifi_calib_4_9_kernel
Jesse Gross 2015-09-11 18:38:28 -07:00 committed by David S. Miller
parent 892aa01df2
commit 982b527004
1 changed files with 59 additions and 23 deletions
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82
net/openvswitch/flow_netlink.c
View File

@ -57,6 +57,7 @@ struct ovs_len_tbl {
};
#define OVS_ATTR_NESTED -1
#define OVS_ATTR_VARIABLE -2
static void update_range(struct sw_flow_match *match,
size_t offset, size_t size, bool is_mask)
@ -304,6 +305,10 @@ size_t ovs_key_attr_size(void)
+ nla_total_size(28); /* OVS_KEY_ATTR_ND */
}
static const struct ovs_len_tbl ovs_vxlan_ext_key_lens[OVS_VXLAN_EXT_MAX + 1] = {
[OVS_VXLAN_EXT_GBP] = { .len = sizeof(u32) },
};
static const struct ovs_len_tbl ovs_tunnel_key_lens[OVS_TUNNEL_KEY_ATTR_MAX + 1] = {
[OVS_TUNNEL_KEY_ATTR_ID] = { .len = sizeof(u64) },
[OVS_TUNNEL_KEY_ATTR_IPV4_SRC] = { .len = sizeof(u32) },
@ -315,8 +320,9 @@ static const struct ovs_len_tbl ovs_tunnel_key_lens[OVS_TUNNEL_KEY_ATTR_MAX + 1]
[OVS_TUNNEL_KEY_ATTR_TP_SRC] = { .len = sizeof(u16) },
[OVS_TUNNEL_KEY_ATTR_TP_DST] = { .len = sizeof(u16) },
[OVS_TUNNEL_KEY_ATTR_OAM] = { .len = 0 },
[OVS_TUNNEL_KEY_ATTR_GENEVE_OPTS] = { .len = OVS_ATTR_NESTED },
[OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS] = { .len = OVS_ATTR_NESTED },
[OVS_TUNNEL_KEY_ATTR_GENEVE_OPTS] = { .len = OVS_ATTR_VARIABLE },
[OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS] = { .len = OVS_ATTR_NESTED,
.next = ovs_vxlan_ext_key_lens },
};
/* The size of the argument for each %OVS_KEY_ATTR_* Netlink attribute. */
@ -349,6 +355,13 @@ static const struct ovs_len_tbl ovs_key_lens[OVS_KEY_ATTR_MAX + 1] = {
[OVS_KEY_ATTR_CT_LABEL] = { .len = sizeof(struct ovs_key_ct_label) },
};
static bool check_attr_len(unsigned int attr_len, unsigned int expected_len)
{
return expected_len == attr_len ||
expected_len == OVS_ATTR_NESTED ||
expected_len == OVS_ATTR_VARIABLE;
}
static bool is_all_zero(const u8 *fp, size_t size)
{
int i;
@ -388,7 +401,7 @@ static int __parse_flow_nlattrs(const struct nlattr *attr,
}
expected_len = ovs_key_lens[type].len;
if (nla_len(nla) != expected_len && expected_len != OVS_ATTR_NESTED) {
if (!check_attr_len(nla_len(nla), expected_len)) {
OVS_NLERR(log, "Key %d has unexpected len %d expected %d",
type, nla_len(nla), expected_len);
return -EINVAL;
@ -473,29 +486,50 @@ static int genev_tun_opt_from_nlattr(const struct nlattr *a,
return 0;
}
static const struct nla_policy vxlan_opt_policy[OVS_VXLAN_EXT_MAX + 1] = {
[OVS_VXLAN_EXT_GBP] = { .type = NLA_U32 },
};
static int vxlan_tun_opt_from_nlattr(const struct nlattr *a,
static int vxlan_tun_opt_from_nlattr(const struct nlattr *attr,
struct sw_flow_match *match, bool is_mask,
bool log)
{
struct nlattr *tb[OVS_VXLAN_EXT_MAX+1];
struct nlattr *a;
int rem;
unsigned long opt_key_offset;
struct vxlan_metadata opts;
int err;
BUILD_BUG_ON(sizeof(opts) > sizeof(match->key->tun_opts));
err = nla_parse_nested(tb, OVS_VXLAN_EXT_MAX, a, vxlan_opt_policy);
if (err < 0)
return err;
memset(&opts, 0, sizeof(opts));
nla_for_each_nested(a, attr, rem) {
int type = nla_type(a);
if (tb[OVS_VXLAN_EXT_GBP])
opts.gbp = nla_get_u32(tb[OVS_VXLAN_EXT_GBP]);
if (type > OVS_VXLAN_EXT_MAX) {
OVS_NLERR(log, "VXLAN extension %d out of range max %d",
type, OVS_VXLAN_EXT_MAX);
return -EINVAL;
}
if (!check_attr_len(nla_len(a),
ovs_vxlan_ext_key_lens[type].len)) {
OVS_NLERR(log, "VXLAN extension %d has unexpected len %d expected %d",
type, nla_len(a),
ovs_vxlan_ext_key_lens[type].len);
return -EINVAL;
}
switch (type) {
case OVS_VXLAN_EXT_GBP:
opts.gbp = nla_get_u32(a);
break;
default:
OVS_NLERR(log, "Unknown VXLAN extension attribute %d",
type);
return -EINVAL;
}
}
if (rem) {
OVS_NLERR(log, "VXLAN extension message has %d unknown bytes.",
rem);
return -EINVAL;
}
if (!is_mask)
SW_FLOW_KEY_PUT(match, tun_opts_len, sizeof(opts), false);
@ -528,8 +562,8 @@ static int ipv4_tun_from_nlattr(const struct nlattr *attr,
return -EINVAL;
}
if (ovs_tunnel_key_lens[type].len != nla_len(a) &&
ovs_tunnel_key_lens[type].len != OVS_ATTR_NESTED) {
if (!check_attr_len(nla_len(a),
ovs_tunnel_key_lens[type].len)) {
OVS_NLERR(log, "Tunnel attr %d has unexpected len %d expected %d",
type, nla_len(a), ovs_tunnel_key_lens[type].len);
return -EINVAL;
@ -1052,10 +1086,13 @@ static void nlattr_set(struct nlattr *attr, u8 val,
/* The nlattr stream should already have been validated */
nla_for_each_nested(nla, attr, rem) {
if (tbl && tbl[nla_type(nla)].len == OVS_ATTR_NESTED)
nlattr_set(nla, val, tbl[nla_type(nla)].next);
else
if (tbl[nla_type(nla)].len == OVS_ATTR_NESTED) {
if (tbl[nla_type(nla)].next)
tbl = tbl[nla_type(nla)].next;
nlattr_set(nla, val, tbl);
} else {
memset(nla_data(nla), val, nla_len(nla));
}
}
}
@ -1922,8 +1959,7 @@ static int validate_set(const struct nlattr *a,
key_len /= 2;
if (key_type > OVS_KEY_ATTR_MAX ||
(ovs_key_lens[key_type].len != key_len &&
ovs_key_lens[key_type].len != OVS_ATTR_NESTED))
!check_attr_len(key_len, ovs_key_lens[key_type].len))
return -EINVAL;
if (masked && !validate_masked(nla_data(ovs_key), key_len))