Mailing List Archive

[NETLINK]: Introduce nested and byteorder flag to netlink attribute
This change allows the generic attribute interface to be used within
the netfilter subsystem where this flag was initially introduced.

The byte-order flag is yet unused, it's intended use is to
allow automatic byte order convertions for all atomic types.

Signed-off-by: Thomas Graf <tgraf@suug.ch>

Index: net-2.6.24/include/linux/netlink.h
===================================================================
--- net-2.6.24.orig/include/linux/netlink.h 2007-09-12 13:29:49.000000000 +0200
+++ net-2.6.24/include/linux/netlink.h 2007-09-12 13:59:41.000000000 +0200
@@ -129,6 +129,20 @@
__u16 nla_type;
};

+/*
+ * nla_type (16 bits)
+ * +---+---+-------------------------------+
+ * | N | O | Attribute Type |
+ * +---+---+-------------------------------+
+ * N := Carries nested attributes
+ * O := Payload stored in network byte order
+ *
+ * Note: The N and O flag are mutually exclusive.
+ */
+#define NLA_F_NESTED (1 << 15)
+#define NLA_F_NET_BYTEORDER (1 << 14)
+#define NLA_TYPE_MASK ~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)
+
#define NLA_ALIGNTO 4
#define NLA_ALIGN(len) (((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
#define NLA_HDRLEN ((int) NLA_ALIGN(sizeof(struct nlattr)))
Index: net-2.6.24/include/net/netlink.h
===================================================================
--- net-2.6.24.orig/include/net/netlink.h 2007-09-12 13:29:50.000000000 +0200
+++ net-2.6.24/include/net/netlink.h 2007-09-12 14:17:56.000000000 +0200
@@ -667,6 +667,15 @@
}

/**
+ * nla_type - attribute type
+ * @nla: netlink attribute
+ */
+static inline int nla_type(const struct nlattr *nla)
+{
+ return nla->nla_type & NLA_TYPE_MASK;
+}
+
+/**
* nla_data - head of payload
* @nla: netlink attribute
*/
Index: net-2.6.24/net/ipv4/fib_frontend.c
===================================================================
--- net-2.6.24.orig/net/ipv4/fib_frontend.c 2007-09-12 13:29:51.000000000 +0200
+++ net-2.6.24/net/ipv4/fib_frontend.c 2007-09-12 13:59:41.000000000 +0200
@@ -487,7 +487,7 @@
}

nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
- switch (attr->nla_type) {
+ switch (nla_type(attr)) {
case RTA_DST:
cfg->fc_dst = nla_get_be32(attr);
break;
Index: net-2.6.24/net/ipv4/fib_semantics.c
===================================================================
--- net-2.6.24.orig/net/ipv4/fib_semantics.c 2007-09-12 13:29:51.000000000 +0200
+++ net-2.6.24/net/ipv4/fib_semantics.c 2007-09-12 13:59:41.000000000 +0200
@@ -743,7 +743,7 @@
int remaining;

nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
- int type = nla->nla_type;
+ int type = nla_type(nla);

if (type) {
if (type > RTAX_MAX)
Index: net-2.6.24/net/ipv6/route.c
===================================================================
--- net-2.6.24.orig/net/ipv6/route.c 2007-09-12 13:29:51.000000000 +0200
+++ net-2.6.24/net/ipv6/route.c 2007-09-12 13:59:41.000000000 +0200
@@ -1278,7 +1278,7 @@
int remaining;

nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
- int type = nla->nla_type;
+ int type = nla_type(nla);

if (type) {
if (type > RTAX_MAX) {
Index: net-2.6.24/net/netlabel/netlabel_cipso_v4.c
===================================================================
--- net-2.6.24.orig/net/netlabel/netlabel_cipso_v4.c 2007-09-12 13:29:51.000000000 +0200
+++ net-2.6.24/net/netlabel/netlabel_cipso_v4.c 2007-09-12 13:59:41.000000000 +0200
@@ -130,7 +130,7 @@
return -EINVAL;

nla_for_each_nested(nla, info->attrs[NLBL_CIPSOV4_A_TAGLST], nla_rem)
- if (nla->nla_type == NLBL_CIPSOV4_A_TAG) {
+ if (nla_type(nla) == NLBL_CIPSOV4_A_TAG) {
if (iter >= CIPSO_V4_TAG_MAXCNT)
return -EINVAL;
doi_def->tags[iter++] = nla_get_u8(nla);
@@ -192,13 +192,13 @@
nla_for_each_nested(nla_a,
info->attrs[NLBL_CIPSOV4_A_MLSLVLLST],
nla_a_rem)
- if (nla_a->nla_type == NLBL_CIPSOV4_A_MLSLVL) {
+ if (nla_type(nla_a) == NLBL_CIPSOV4_A_MLSLVL) {
if (nla_validate_nested(nla_a,
NLBL_CIPSOV4_A_MAX,
netlbl_cipsov4_genl_policy) != 0)
goto add_std_failure;
nla_for_each_nested(nla_b, nla_a, nla_b_rem)
- switch (nla_b->nla_type) {
+ switch (nla_type(nla_b)) {
case NLBL_CIPSOV4_A_MLSLVLLOC:
if (nla_get_u32(nla_b) >
CIPSO_V4_MAX_LOC_LVLS)
@@ -240,7 +240,7 @@
nla_for_each_nested(nla_a,
info->attrs[NLBL_CIPSOV4_A_MLSLVLLST],
nla_a_rem)
- if (nla_a->nla_type == NLBL_CIPSOV4_A_MLSLVL) {
+ if (nla_type(nla_a) == NLBL_CIPSOV4_A_MLSLVL) {
struct nlattr *lvl_loc;
struct nlattr *lvl_rem;

@@ -265,13 +265,13 @@
nla_for_each_nested(nla_a,
info->attrs[NLBL_CIPSOV4_A_MLSCATLST],
nla_a_rem)
- if (nla_a->nla_type == NLBL_CIPSOV4_A_MLSCAT) {
+ if (nla_type(nla_a) == NLBL_CIPSOV4_A_MLSCAT) {
if (nla_validate_nested(nla_a,
NLBL_CIPSOV4_A_MAX,
netlbl_cipsov4_genl_policy) != 0)
goto add_std_failure;
nla_for_each_nested(nla_b, nla_a, nla_b_rem)
- switch (nla_b->nla_type) {
+ switch (nla_type(nla_b)) {
case NLBL_CIPSOV4_A_MLSCATLOC:
if (nla_get_u32(nla_b) >
CIPSO_V4_MAX_LOC_CATS)
@@ -315,7 +315,7 @@
nla_for_each_nested(nla_a,
info->attrs[NLBL_CIPSOV4_A_MLSCATLST],
nla_a_rem)
- if (nla_a->nla_type == NLBL_CIPSOV4_A_MLSCAT) {
+ if (nla_type(nla_a) == NLBL_CIPSOV4_A_MLSCAT) {
struct nlattr *cat_loc;
struct nlattr *cat_rem;

Index: net-2.6.24/net/netlink/attr.c
===================================================================
--- net-2.6.24.orig/net/netlink/attr.c 2007-09-12 13:29:51.000000000 +0200
+++ net-2.6.24/net/netlink/attr.c 2007-09-12 14:10:51.000000000 +0200
@@ -27,12 +27,12 @@
const struct nla_policy *policy)
{
const struct nla_policy *pt;
- int minlen = 0, attrlen = nla_len(nla);
+ int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla);

- if (nla->nla_type <= 0 || nla->nla_type > maxtype)
+ if (type <= 0 || type > maxtype)
return 0;

- pt = &policy[nla->nla_type];
+ pt = &policy[type];

BUG_ON(pt->type > NLA_TYPE_MAX);

@@ -149,7 +149,7 @@
memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));

nla_for_each_attr(nla, head, len, rem) {
- u16 type = nla->nla_type;
+ u16 type = nla_type(nla);

if (type > 0 && type <= maxtype) {
if (policy) {
@@ -185,7 +185,7 @@
int rem;

nla_for_each_attr(nla, head, len, rem)
- if (nla->nla_type == attrtype)
+ if (nla_type(nla) == attrtype)
return nla;

return NULL;