[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>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index d2843ae..e638256 100644 (file)
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -131,6 +131,20 @@ struct nlattr
        __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)))

diff --git a/include/net/netlink.h b/include/net/netlink.h
index d7b824b..695e613 100644 (file)
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -666,6 +666,15 @@ static inline int nla_padlen(int payload)
        return nla_total_size(payload) - nla_attr_size(payload);
 }
 
+/**
+ * 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

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index df17aab..f823ca3 100644 (file)
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -487,7 +487,7 @@ static int rtm_to_fib_config(struct sk_buff *skb, struct nlmsghdr *nlh,
        }
 
        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;

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index d30fb68..1351a26 100644 (file)
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -743,7 +743,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg)
                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)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 5bdd9d4..104070e 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1279,7 +1279,7 @@ install_route:
                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) {

diff --git a/net/netlabel/netlabel_cipso_v4.c b/net/netlabel/netlabel_cipso_v4.c
index c060e3f..ba0ca8d 100644 (file)
--- a/net/netlabel/netlabel_cipso_v4.c
+++ b/net/netlabel/netlabel_cipso_v4.c
@@ -130,7 +130,7 @@ static int netlbl_cipsov4_add_common(struct genl_info *info,
                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 @@ static int netlbl_cipsov4_add_std(struct genl_info *info)
        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 @@ static int netlbl_cipsov4_add_std(struct genl_info *info)
        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 @@ static int netlbl_cipsov4_add_std(struct genl_info *info)
                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 @@ static int netlbl_cipsov4_add_std(struct genl_info *info)
                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;
 

diff --git a/net/netlink/attr.c b/net/netlink/attr.c
index e4d7bed..ec39d12 100644 (file)
--- a/net/netlink/attr.c
+++ b/net/netlink/attr.c
@@ -27,12 +27,12 @@ static int validate_nla(struct nlattr *nla, int maxtype,
                        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 @@ int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len,
        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 @@ struct nlattr *nla_find(struct nlattr *head, int len, int attrtype)
        int rem;
 
        nla_for_each_attr(nla, head, len, rem)
-               if (nla->nla_type == attrtype)
+               if (nla_type(nla) == attrtype)
                        return nla;
 
        return NULL;