[NETLINK]: Do precise netlink message allocations where possible

Account for the netlink message header size directly in nlmsg_new()
instead of relying on the caller calculate it correctly.

Replaces error handling of message construction functions when
constructing notifications with bug traps since a failure implies
a bug in calculating the size of the skb.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 6641162..e61e1e1 100644 (file)
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -174,6 +174,7 @@ int netlink_sendskb(struct sock *sk, struct sk_buff *skb, int protocol);
  */
 #define NLMSG_GOODORDER 0
 #define NLMSG_GOODSIZE (SKB_MAX_ORDER(0, NLMSG_GOODORDER))
+#define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)
 
 
 struct netlink_callback

diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h
index e4ba781..bc3c264 100644 (file)
--- a/include/net/fib_rules.h
+++ b/include/net/fib_rules.h
@@ -52,6 +52,7 @@ struct fib_rules_ops
                                        struct nlmsghdr *,
                                        struct fib_rule_hdr *);
        u32                     (*default_pref)(void);
+       size_t                  (*nlmsg_payload)(struct fib_rule *);
 
        int                     nlgroup;
        struct nla_policy       *policy;

diff --git a/include/net/netlink.h b/include/net/netlink.h
index ce5cba1..3002133 100644 (file)
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -500,14 +500,15 @@ static inline struct nlmsghdr *nlmsg_put_answer(struct sk_buff *skb,
 
 /**
  * nlmsg_new - Allocate a new netlink message
- * @size: maximum size of message
+ * @payload: size of the message payload
  * @flags: the type of memory to allocate.
  *
- * Use NLMSG_GOODSIZE if size isn't know and you need a good default size.
+ * Use NLMSG_DEFAULT_SIZE if the size of the payload isn't known
+ * and a good default is needed.
  */
-static inline struct sk_buff *nlmsg_new(int size, gfp_t flags)
+static inline struct sk_buff *nlmsg_new(size_t payload, gfp_t flags)
 {
-       return alloc_skb(size, flags);
+       return alloc_skb(nlmsg_total_size(payload), flags);
 }
 
 /**

diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index f45c5e7..4f3f0e4 100644 (file)
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -77,8 +77,7 @@ static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp,
        /*
         * If new attributes are added, please revisit this allocation
         */
-       size = nlmsg_total_size(genlmsg_total_size(size));
-       skb = nlmsg_new(size, GFP_KERNEL);
+       skb = nlmsg_new(genlmsg_total_size(size), GFP_KERNEL);
        if (!skb)
                return -ENOMEM;
 

diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 8f66119..15d6efb 100644 (file)
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -15,6 +15,18 @@
 #include <net/netlink.h>
 #include "br_private.h"
 
+static inline size_t br_nlmsg_size(void)
+{
+       return NLMSG_ALIGN(sizeof(struct ifinfomsg))
+              + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
+              + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
+              + nla_total_size(4) /* IFLA_MASTER */
+              + nla_total_size(4) /* IFLA_MTU */
+              + nla_total_size(4) /* IFLA_LINK */
+              + nla_total_size(1) /* IFLA_OPERSTATE */
+              + nla_total_size(1); /* IFLA_PROTINFO */
+}
+
 /*
  * Create one netlink message for one interface
  * Contains port and master info as well as carrier and bridge state.
@@ -77,19 +89,16 @@ rtattr_failure:
 void br_ifinfo_notify(int event, struct net_bridge_port *port)
 {
        struct sk_buff *skb;
-       int payload = sizeof(struct ifinfomsg) + 128;
        int err = -ENOBUFS;
 
        pr_debug("bridge notify event=%d\n", event);
-       skb = nlmsg_new(nlmsg_total_size(payload), GFP_ATOMIC);
+       skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC);
        if (skb == NULL)
                goto errout;
 
        err = br_fill_ifinfo(skb, port, 0, 0, event, 0);
-       if (err < 0) {
-               kfree_skb(skb);
-               goto errout;
-       }
+       /* failure implies BUG in br_nlmsg_size() */
+       BUG_ON(err < 0);
 
        err = rtnl_notify(skb, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
 errout:

diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 4148e27..1df6cd4 100644 (file)
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -306,6 +306,22 @@ errout:
        return err;
 }
 
+static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
+                                        struct fib_rule *rule)
+{
+       size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
+                        + nla_total_size(IFNAMSIZ) /* FRA_IFNAME */
+                        + nla_total_size(4) /* FRA_PRIORITY */
+                        + nla_total_size(4) /* FRA_TABLE */
+                        + nla_total_size(4) /* FRA_FWMARK */
+                        + nla_total_size(4); /* FRA_FWMASK */
+
+       if (ops->nlmsg_payload)
+               payload += ops->nlmsg_payload(rule);
+
+       return payload;
+}
+
 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
                            u32 pid, u32 seq, int type, int flags,
                            struct fib_rules_ops *ops)
@@ -384,15 +400,13 @@ static void notify_rule_change(int event, struct fib_rule *rule,
        struct sk_buff *skb;
        int err = -ENOBUFS;
 
-       skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+       skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
        if (skb == NULL)
                goto errout;
 
        err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
-       if (err < 0) {
-               kfree_skb(skb);
-               goto errout;
-       }
+       /* failure implies BUG in fib_rule_nlmsg_size() */
+       BUG_ON(err < 0);
 
        err = rtnl_notify(skb, pid, ops->nlgroup, nlh, GFP_KERNEL);
 errout:

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index b4b4783..0e097ba 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2410,20 +2410,27 @@ static struct file_operations neigh_stat_seq_fops = {
 #endif /* CONFIG_PROC_FS */
 
 #ifdef CONFIG_ARPD
+static inline size_t neigh_nlmsg_size(void)
+{
+       return NLMSG_ALIGN(sizeof(struct ndmsg))
+              + nla_total_size(MAX_ADDR_LEN) /* NDA_DST */
+              + nla_total_size(MAX_ADDR_LEN) /* NDA_LLADDR */
+              + nla_total_size(sizeof(struct nda_cacheinfo))
+              + nla_total_size(4); /* NDA_PROBES */
+}
+
 static void __neigh_notify(struct neighbour *n, int type, int flags)
 {
        struct sk_buff *skb;
        int err = -ENOBUFS;
 
-       skb = nlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
+       skb = nlmsg_new(neigh_nlmsg_size(), GFP_ATOMIC);
        if (skb == NULL)
                goto errout;
 
        err = neigh_fill_info(skb, n, 0, 0, type, flags);
-       if (err < 0) {
-               kfree_skb(skb);
-               goto errout;
-       }
+       /* failure implies BUG in neigh_nlmsg_size() */
+       BUG_ON(err < 0);
 
        err = rtnl_notify(skb, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
 errout:

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 02f3c79..50d6cb4 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -273,6 +273,25 @@ static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
        a->tx_compressed = b->tx_compressed;
 };
 
+static inline size_t if_nlmsg_size(int iwbuflen)
+{
+       return NLMSG_ALIGN(sizeof(struct ifinfomsg))
+              + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
+              + nla_total_size(IFNAMSIZ) /* IFLA_QDISC */
+              + nla_total_size(sizeof(struct rtnl_link_ifmap))
+              + nla_total_size(sizeof(struct rtnl_link_stats))
+              + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
+              + nla_total_size(MAX_ADDR_LEN) /* IFLA_BROADCAST */
+              + nla_total_size(4) /* IFLA_TXQLEN */
+              + nla_total_size(4) /* IFLA_WEIGHT */
+              + nla_total_size(4) /* IFLA_MTU */
+              + nla_total_size(4) /* IFLA_LINK */
+              + nla_total_size(4) /* IFLA_MASTER */
+              + nla_total_size(1) /* IFLA_OPERSTATE */
+              + nla_total_size(1) /* IFLA_LINKMODE */
+              + nla_total_size(iwbuflen);
+}
+
 static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
                            void *iwbuf, int iwbuflen, int type, u32 pid,
                            u32 seq, u32 change, unsigned int flags)
@@ -558,7 +577,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
        struct sk_buff *nskb;
        char *iw_buf = NULL, *iw = NULL;
        int iw_buf_len = 0;
-       int err, payload;
+       int err;
 
        err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
        if (err < 0)
@@ -587,9 +606,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
        }
 #endif /* CONFIG_NET_WIRELESS_RTNETLINK */
 
-       payload = NLMSG_ALIGN(sizeof(struct ifinfomsg) +
-                             nla_total_size(iw_buf_len));
-       nskb = nlmsg_new(nlmsg_total_size(payload), GFP_KERNEL);
+       nskb = nlmsg_new(if_nlmsg_size(iw_buf_len), GFP_KERNEL);
        if (nskb == NULL) {
                err = -ENOBUFS;
                goto errout;
@@ -597,10 +614,8 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
 
        err = rtnl_fill_ifinfo(nskb, dev, iw, iw_buf_len, RTM_NEWLINK,
                               NETLINK_CB(skb).pid, nlh->nlmsg_seq, 0, 0);
-       if (err <= 0) {
-               kfree_skb(nskb);
-               goto errout;
-       }
+       /* failure impilies BUG in if_nlmsg_size or wireless_rtnetlink_get */
+       BUG_ON(err < 0);
 
        err = rtnl_unicast(nskb, NETLINK_CB(skb).pid);
 errout:
@@ -639,15 +654,13 @@ void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
        struct sk_buff *skb;
        int err = -ENOBUFS;
 
-       skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+       skb = nlmsg_new(if_nlmsg_size(0), GFP_KERNEL);
        if (skb == NULL)
                goto errout;
 
        err = rtnl_fill_ifinfo(skb, dev, NULL, 0, type, 0, 0, change, 0);
-       if (err < 0) {
-               kfree_skb(skb);
-               goto errout;
-       }
+       /* failure implies BUG in if_nlmsg_size() */
+       BUG_ON(err < 0);
 
        err = rtnl_notify(skb, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
 errout:

diff --git a/net/decnet/dn_rules.c b/net/decnet/dn_rules.c
index e32d0c3..b7dfd04 100644 (file)
--- a/net/decnet/dn_rules.c
+++ b/net/decnet/dn_rules.c
@@ -241,6 +241,12 @@ static u32 dn_fib_rule_default_pref(void)
        return 0;
 }
 
+static size_t dn_fib_rule_nlmsg_payload(struct fib_rule *rule)
+{
+       return nla_total_size(2) /* dst */
+              + nla_total_size(2); /* src */
+}
+
 int dn_fib_dump_rules(struct sk_buff *skb, struct netlink_callback *cb)
 {
        return fib_rules_dump(skb, cb, AF_DECnet);

diff --git a/net/decnet/dn_table.c b/net/decnet/dn_table.c
index 317904b..e74b744 100644 (file)
--- a/net/decnet/dn_table.c
+++ b/net/decnet/dn_table.c
@@ -263,6 +263,32 @@ static int dn_fib_nh_match(struct rtmsg *r, struct nlmsghdr *nlh, struct dn_kern
        return 0;
 }
 
+static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
+{
+       size_t payload = NLMSG_ALIGN(struct rtmsg)
+                        + nla_total_size(4) /* RTA_TABLE */
+                        + nla_total_size(2) /* RTA_DST */
+                        + nla_total_size(4); /* RTA_PRIORITY */
+
+       /* space for nested metrics */
+       payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
+
+       if (fi->fib_nhs) {
+               /* Also handles the special case fib_nhs == 1 */
+
+               /* each nexthop is packed in an attribute */
+               size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
+
+               /* may contain a gateway attribute */
+               nhsize += nla_total_size(4);
+
+               /* all nexthops are packed in a nested attribute */
+               payload += nla_total_size(fi->fib_nhs * nhsize);
+       }
+
+       return payload;
+}
+
 static int dn_fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
                         u32 tb_id, u8 type, u8 scope, void *dst, int dst_len,
                         struct dn_fib_info *fi, unsigned int flags)
@@ -335,17 +361,15 @@ static void dn_rtmsg_fib(int event, struct dn_fib_node *f, int z, u32 tb_id,
         u32 pid = req ? req->pid : 0;
        int err = -ENOBUFS;
 
-        skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+        skb = nlmsg_new(dn_fib_nlmsg_size(DN_FIB_INFO(f), GFP_KERNEL));
         if (skb == NULL)
                goto errout;
 
         err = dn_fib_dump_info(skb, pid, nlh->nlmsg_seq, event, tb_id,
                               f->fn_type, f->fn_scope, &f->fn_key, z,
                               DN_FIB_INFO(f), 0);
-       if (err < 0) {
-                kfree_skb(skb);
-               goto errout;
-        }
+       /* failure implies BUG in dn_fib_nlmsg_size() */
+       BUG_ON(err < 0);
 
        err = rtnl_notify(skb, pid, RTNLGRP_DECnet_ROUTE, nlh, GFP_KERNEL);
 errout:

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 7602c79..f38cbba 100644 (file)
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1120,6 +1120,16 @@ static struct notifier_block ip_netdev_notifier = {
        .notifier_call =inetdev_event,
 };
 
+static inline size_t inet_nlmsg_size(void)
+{
+       return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
+              + nla_total_size(4) /* IFA_ADDRESS */
+              + nla_total_size(4) /* IFA_LOCAL */
+              + nla_total_size(4) /* IFA_BROADCAST */
+              + nla_total_size(4) /* IFA_ANYCAST */
+              + nla_total_size(IFNAMSIZ); /* IFA_LABEL */
+}
+
 static int inet_fill_ifaddr(struct sk_buff *skb, struct in_ifaddr *ifa,
                            u32 pid, u32 seq, int event, unsigned int flags)
 {
@@ -1208,15 +1218,13 @@ static void rtmsg_ifa(int event, struct in_ifaddr* ifa, struct nlmsghdr *nlh,
        u32 seq = nlh ? nlh->nlmsg_seq : 0;
        int err = -ENOBUFS;
 
-       skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+       skb = nlmsg_new(inet_nlmsg_size(), GFP_KERNEL);
        if (skb == NULL)
                goto errout;
 
        err = inet_fill_ifaddr(skb, ifa, pid, seq, event, 0);
-       if (err < 0) {
-               kfree_skb(skb);
-               goto errout;
-       }
+       /* failure implies BUG in inet_nlmsg_size() */
+       BUG_ON(err < 0);
 
        err = rtnl_notify(skb, pid, RTNLGRP_IPV4_IFADDR, nlh, GFP_KERNEL);
 errout:

diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
index fd4a8cd..b837c33 100644 (file)
--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -299,6 +299,13 @@ static u32 fib4_rule_default_pref(void)
        return 0;
 }
 
+static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
+{
+       return nla_total_size(4) /* dst */
+              + nla_total_size(4) /* src */
+              + nla_total_size(4); /* flow */
+}
+
 static struct fib_rules_ops fib4_rules_ops = {
        .family         = AF_INET,
        .rule_size      = sizeof(struct fib4_rule),
@@ -308,6 +315,7 @@ static struct fib_rules_ops fib4_rules_ops = {
        .compare        = fib4_rule_compare,
        .fill           = fib4_rule_fill,
        .default_pref   = fib4_rule_default_pref,
+       .nlmsg_payload  = fib4_rule_nlmsg_payload,
        .nlgroup        = RTNLGRP_IPV4_RULE,
        .policy         = fib4_rule_policy,
        .rules_list     = &fib4_rules,

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 884d176..e63b8a9 100644 (file)
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -273,25 +273,49 @@ int ip_fib_check_default(__be32 gw, struct net_device *dev)
        return -1;
 }
 
+static inline size_t fib_nlmsg_size(struct fib_info *fi)
+{
+       size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
+                        + nla_total_size(4) /* RTA_TABLE */
+                        + nla_total_size(4) /* RTA_DST */
+                        + nla_total_size(4) /* RTA_PRIORITY */
+                        + nla_total_size(4); /* RTA_PREFSRC */
+
+       /* space for nested metrics */
+       payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
+
+       if (fi->fib_nhs) {
+               /* Also handles the special case fib_nhs == 1 */
+
+               /* each nexthop is packed in an attribute */
+               size_t nhsize = nla_total_size(sizeof(struct rtnexthop));
+
+               /* may contain flow and gateway attribute */
+               nhsize += 2 * nla_total_size(4);
+
+               /* all nexthops are packed in a nested attribute */
+               payload += nla_total_size(fi->fib_nhs * nhsize);
+       }
+
+       return payload;
+}
+
 void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
               int dst_len, u32 tb_id, struct nl_info *info)
 {
        struct sk_buff *skb;
-       int payload = sizeof(struct rtmsg) + 256;
        u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
        int err = -ENOBUFS;
 
-       skb = nlmsg_new(nlmsg_total_size(payload), GFP_KERNEL);
+       skb = nlmsg_new(fib_nlmsg_size(fa->fa_info), GFP_KERNEL);
        if (skb == NULL)
                goto errout;
 
        err = fib_dump_info(skb, info->pid, seq, event, tb_id,
                            fa->fa_type, fa->fa_scope, key, dst_len,
                            fa->fa_tos, fa->fa_info, 0);
-       if (err < 0) {
-               kfree_skb(skb);
-               goto errout;
-       }
+       /* failure implies BUG in fib_nlmsg_size() */
+       BUG_ON(err < 0);
 
        err = rtnl_notify(skb, info->pid, RTNLGRP_IPV4_ROUTE,
                          info->nlh, GFP_KERNEL);

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 6a98f68..967ea32 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3098,10 +3098,9 @@ static inline int rt_scope(int ifa_scope)
 
 static inline int inet6_ifaddr_msgsize(void)
 {
-       return nlmsg_total_size(sizeof(struct ifaddrmsg) +
-                               nla_total_size(16) +
-                               nla_total_size(sizeof(struct ifa_cacheinfo)) +
-                               128);
+       return NLMSG_ALIGN(sizeof(struct ifaddrmsg))
+              + nla_total_size(16) /* IFA_ADDRESS */
+              + nla_total_size(sizeof(struct ifa_cacheinfo));
 }
 
 static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
@@ -3329,10 +3328,8 @@ static int inet6_rtm_getaddr(struct sk_buff *in_skb, struct nlmsghdr* nlh,
 
        err = inet6_fill_ifaddr(skb, ifa, NETLINK_CB(in_skb).pid,
                                nlh->nlmsg_seq, RTM_NEWADDR, 0);
-       if (err < 0) {
-               kfree_skb(skb);
-               goto errout_ifa;
-       }
+       /* failure implies BUG in inet6_ifaddr_msgsize() */
+       BUG_ON(err < 0);
 
        err = rtnl_unicast(skb, NETLINK_CB(in_skb).pid);
 errout_ifa:
@@ -3351,10 +3348,8 @@ static void inet6_ifa_notify(int event, struct inet6_ifaddr *ifa)
                goto errout;
 
        err = inet6_fill_ifaddr(skb, ifa, 0, 0, event, 0);
-       if (err < 0) {
-               kfree_skb(skb);
-               goto errout;
-       }
+       /* failure implies BUG in inet6_ifaddr_msgsize() */
+       BUG_ON(err < 0);
 
        err = rtnl_notify(skb, 0, RTNLGRP_IPV6_IFADDR, NULL, GFP_ATOMIC);
 errout:
@@ -3397,16 +3392,19 @@ static void inline ipv6_store_devconf(struct ipv6_devconf *cnf,
        array[DEVCONF_PROXY_NDP] = cnf->proxy_ndp;
 }
 
-/* Maximum length of ifinfomsg attributes */
-#define INET6_IFINFO_RTA_SPACE \
-               RTA_SPACE(IFNAMSIZ) /* IFNAME */ + \
-               RTA_SPACE(MAX_ADDR_LEN) /* ADDRESS */ + \
-               RTA_SPACE(sizeof(u32)) /* MTU */ + \
-               RTA_SPACE(sizeof(int)) /* LINK */ + \
-               RTA_SPACE(0) /* PROTINFO */ + \
-               RTA_SPACE(sizeof(u32)) /* FLAGS */ + \
-               RTA_SPACE(sizeof(struct ifla_cacheinfo)) /* CACHEINFO */ + \
-               RTA_SPACE(sizeof(__s32[DEVCONF_MAX])) /* CONF */
+static inline size_t inet6_if_nlmsg_size(void)
+{
+       return NLMSG_ALIGN(sizeof(struct ifinfomsg))
+              + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
+              + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
+              + nla_total_size(4) /* IFLA_MTU */
+              + nla_total_size(4) /* IFLA_LINK */
+              + nla_total_size( /* IFLA_PROTINFO */
+                       nla_total_size(4) /* IFLA_INET6_FLAGS */
+                       + nla_total_size(sizeof(struct ifla_cacheinfo))
+                       + nla_total_size(DEVCONF_MAX * 4) /* IFLA_INET6_CONF */
+                );
+}
 
 static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev, 
                             u32 pid, u32 seq, int event, unsigned int flags)
@@ -3501,18 +3499,15 @@ static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 void inet6_ifinfo_notify(int event, struct inet6_dev *idev)
 {
        struct sk_buff *skb;
-       int payload = sizeof(struct ifinfomsg) + INET6_IFINFO_RTA_SPACE;
        int err = -ENOBUFS;
        
-       skb = nlmsg_new(nlmsg_total_size(payload), GFP_ATOMIC);
+       skb = nlmsg_new(inet6_if_nlmsg_size(), GFP_ATOMIC);
        if (skb == NULL)
                goto errout;
 
        err = inet6_fill_ifinfo(skb, idev, 0, 0, event, 0);
-       if (err < 0) {
-               kfree_skb(skb);
-               goto errout;
-       }
+       /* failure implies BUG in inet6_if_nlmsg_size() */
+       BUG_ON(err < 0);
 
        err = rtnl_notify(skb, 0, RTNLGRP_IPV6_IFADDR, NULL, GFP_ATOMIC);
 errout:
@@ -3520,10 +3515,12 @@ errout:
                rtnl_set_sk_err(RTNLGRP_IPV6_IFADDR, err);
 }
 
-/* Maximum length of prefix_cacheinfo attributes */
-#define INET6_PREFIX_RTA_SPACE \
-               RTA_SPACE(sizeof(((struct prefix_info *)NULL)->prefix)) /* ADDRESS */ + \
-               RTA_SPACE(sizeof(struct prefix_cacheinfo)) /* CACHEINFO */
+static inline size_t inet6_prefix_nlmsg_size(void)
+{
+       return NLMSG_ALIGN(sizeof(struct prefixmsg))
+              + nla_total_size(sizeof(struct in6_addr))
+              + nla_total_size(sizeof(struct prefix_cacheinfo));
+}
 
 static int inet6_fill_prefix(struct sk_buff *skb, struct inet6_dev *idev,
                        struct prefix_info *pinfo, u32 pid, u32 seq, 
@@ -3569,18 +3566,15 @@ static void inet6_prefix_notify(int event, struct inet6_dev *idev,
                         struct prefix_info *pinfo)
 {
        struct sk_buff *skb;
-       int payload = sizeof(struct prefixmsg) + INET6_PREFIX_RTA_SPACE;
        int err = -ENOBUFS;
 
-       skb = nlmsg_new(nlmsg_total_size(payload), GFP_ATOMIC);
+       skb = nlmsg_new(inet6_prefix_nlmsg_size(), GFP_ATOMIC);
        if (skb == NULL)
                goto errout;
 
        err = inet6_fill_prefix(skb, idev, pinfo, 0, 0, event, 0);
-       if (err < 0) {
-               kfree_skb(skb);
-               goto errout;
-       }
+       /* failure implies BUG in inet6_prefix_nlmsg_size() */
+       BUG_ON(err < 0);
 
        err = rtnl_notify(skb, 0, RTNLGRP_IPV6_PREFIX, NULL, GFP_ATOMIC);
 errout:

diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index 25804cb..d587dde 100644 (file)
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -232,6 +232,12 @@ static u32 fib6_rule_default_pref(void)
        return 0x3FFF;
 }
 
+static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
+{
+       return nla_total_size(16) /* dst */
+              + nla_total_size(16); /* src */
+}
+
 static struct fib_rules_ops fib6_rules_ops = {
        .family                 = AF_INET6,
        .rule_size              = sizeof(struct fib6_rule),
@@ -241,6 +247,7 @@ static struct fib_rules_ops fib6_rules_ops = {
        .compare                = fib6_rule_compare,
        .fill                   = fib6_rule_fill,
        .default_pref           = fib6_rule_default_pref,
+       .nlmsg_payload          = fib6_rule_nlmsg_payload,
        .nlgroup                = RTNLGRP_IPV6_RULE,
        .policy                 = fib6_rule_policy,
        .rules_list             = &fib6_rules,

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 0ad07c9..a6472cb 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2006,6 +2006,20 @@ int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
        return ip6_route_add(&cfg);
 }
 
+static inline size_t rt6_nlmsg_size(void)
+{
+       return NLMSG_ALIGN(sizeof(struct rtmsg))
+              + nla_total_size(16) /* RTA_SRC */
+              + nla_total_size(16) /* RTA_DST */
+              + nla_total_size(16) /* RTA_GATEWAY */
+              + nla_total_size(16) /* RTA_PREFSRC */
+              + nla_total_size(4) /* RTA_TABLE */
+              + nla_total_size(4) /* RTA_IIF */
+              + nla_total_size(4) /* RTA_OIF */
+              + nla_total_size(4) /* RTA_PRIORITY */
+              + nla_total_size(sizeof(struct rta_cacheinfo));
+}
+
 static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt,
                         struct in6_addr *dst, struct in6_addr *src,
                         int iif, int type, u32 pid, u32 seq,
@@ -2200,7 +2214,6 @@ void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info)
        struct sk_buff *skb;
        u32 pid = 0, seq = 0;
        struct nlmsghdr *nlh = NULL;
-       int payload = sizeof(struct rtmsg) + 256;
        int err = -ENOBUFS;
 
        if (info) {
@@ -2210,15 +2223,13 @@ void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info)
                        seq = nlh->nlmsg_seq;
        }
 
-       skb = nlmsg_new(nlmsg_total_size(payload), gfp_any());
+       skb = nlmsg_new(rt6_nlmsg_size(), gfp_any());
        if (skb == NULL)
                goto errout;
 
        err = rt6_fill_node(skb, rt, NULL, NULL, 0, event, pid, seq, 0, 0);
-       if (err < 0) {
-               kfree_skb(skb);
-               goto errout;
-       }
+       /* failure implies BUG in rt6_nlmsg_size() */
+       BUG_ON(err < 0);
 
        err = rtnl_notify(skb, pid, RTNLGRP_IPV6_ROUTE, nlh, gfp_any());
 errout:

diff --git a/net/netlabel/netlabel_cipso_v4.c b/net/netlabel/netlabel_cipso_v4.c
index a6ce1d6..f1788bd 100644 (file)
--- a/net/netlabel/netlabel_cipso_v4.c
+++ b/net/netlabel/netlabel_cipso_v4.c
@@ -452,7 +452,7 @@ static int netlbl_cipsov4_list(struct sk_buff *skb, struct genl_info *info)
        }
 
 list_start:
-       ans_skb = nlmsg_new(NLMSG_GOODSIZE * nlsze_mult, GFP_KERNEL);
+       ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE * nlsze_mult, GFP_KERNEL);
        if (ans_skb == NULL) {
                ret_val = -ENOMEM;
                goto list_failure;

diff --git a/net/netlabel/netlabel_mgmt.c b/net/netlabel/netlabel_mgmt.c
index 53c9079..c529622 100644 (file)
--- a/net/netlabel/netlabel_mgmt.c
+++ b/net/netlabel/netlabel_mgmt.c
@@ -356,7 +356,7 @@ static int netlbl_mgmt_listdef(struct sk_buff *skb, struct genl_info *info)
        void *data;
        struct netlbl_dom_map *entry;
 
-       ans_skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+       ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
        if (ans_skb == NULL)
                return -ENOMEM;
        data = netlbl_netlink_hdr_put(ans_skb,
@@ -492,7 +492,7 @@ static int netlbl_mgmt_version(struct sk_buff *skb, struct genl_info *info)
        struct sk_buff *ans_skb = NULL;
        void *data;
 
-       ans_skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+       ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
        if (ans_skb == NULL)
                return -ENOMEM;
        data = netlbl_netlink_hdr_put(ans_skb,

diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 1833ad2..219dcca 100644 (file)
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -138,7 +138,7 @@ static int netlbl_unlabel_list(struct sk_buff *skb, struct genl_info *info)
        struct sk_buff *ans_skb;
        void *data;
 
-       ans_skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+       ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
        if (ans_skb == NULL)
                goto list_failure;
        data = netlbl_netlink_hdr_put(ans_skb,

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index d527c89..f61d81b 100644 (file)
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1148,7 +1148,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
        if (len > sk->sk_sndbuf - 32)
                goto out;
        err = -ENOBUFS;
-       skb = nlmsg_new(len, GFP_KERNEL);
+       skb = alloc_skb(len, GFP_KERNEL);
        if (skb==NULL)
                goto out;
 
@@ -1435,14 +1435,13 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
        struct sk_buff *skb;
        struct nlmsghdr *rep;
        struct nlmsgerr *errmsg;
-       int size;
+       size_t payload = sizeof(*errmsg);
 
-       if (err == 0)
-               size = nlmsg_total_size(sizeof(*errmsg));
-       else
-               size = nlmsg_total_size(sizeof(*errmsg) + nlmsg_len(nlh));
+       /* error messages get the original request appened */
+       if (err)
+               payload += nlmsg_len(nlh);
 
-       skb = nlmsg_new(size, GFP_KERNEL);
+       skb = nlmsg_new(payload, GFP_KERNEL);
        if (!skb) {
                struct sock *sk;
 

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 49bc2db..70d60c8 100644 (file)
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -480,7 +480,7 @@ static struct sk_buff *ctrl_build_msg(struct genl_family *family, u32 pid,
        struct sk_buff *skb;
        int err;
 
-       skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+       skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
        if (skb == NULL)
                return ERR_PTR(-ENOBUFS);