ndisc: Break down ndisc_build_skb() and build message directly.

Construct NS/NA/RS message directly using C99 compound literals.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 63 insertions, 59 deletions

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 79a56a7663b7..1c015665ce71 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -413,47 +413,6 @@ static void ip6_nd_hdr(struct sk_buff *skb,
         hdr->daddr = *daddr;
 }
 
-static struct sk_buff *ndisc_build_skb(struct net_device *dev,
-                                       const struct in6_addr *daddr,
-                                       const struct in6_addr *saddr,
-                                       struct icmp6hdr *icmp6h,
-                                       const struct in6_addr *target,
-                                       int llinfo)
-{
-        struct sk_buff *skb;
-        struct icmp6hdr *hdr;
-        int len;
-        int optlen = 0;
-        u8 *opt;
-
-        if (!dev->addr_len)
-                llinfo = 0;
-
-        len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
-        if (llinfo)
-                optlen += ndisc_opt_addr_space(dev);
-
-        skb = ndisc_alloc_skb(dev, len + optlen);
-        if (!skb)
-                return NULL;
-
-        skb_put(skb, len);
-
-        hdr = (struct icmp6hdr *)skb_transport_header(skb);
-        memcpy(hdr, icmp6h, sizeof(*hdr));
-
-        opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
-        if (target) {
-                *(struct in6_addr *)opt = *target;
-                opt += sizeof(*target);
-        }
-
-        if (llinfo)
-                ndisc_fill_addr_option(skb, llinfo, dev->dev_addr);
-
-        return skb;
-}
-
 static void ndisc_send_skb(struct sk_buff *skb,
                            const struct in6_addr *daddr,
                            const struct in6_addr *saddr)
@@ -512,9 +471,8 @@ static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
         struct in6_addr tmpaddr;
         struct inet6_ifaddr *ifp;
         const struct in6_addr *src_addr;
-        struct icmp6hdr icmp6h = {
-                .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
-        };
+        struct nd_msg *msg;
+        int optlen = 0;
 
         /* for anycast or proxy, solicited_addr != src_addr */
         ifp = ipv6_get_ifaddr(dev_net(dev), solicited_addr, dev, 1);
@@ -532,15 +490,31 @@ static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
                 src_addr = &tmpaddr;
         }
 
-        icmp6h.icmp6_router = router;
-        icmp6h.icmp6_solicited = solicited;
-        icmp6h.icmp6_override = override;
+        if (!dev->addr_len)
+                inc_opt = 0;
+        if (inc_opt)
+                optlen += ndisc_opt_addr_space(dev);
 
-        skb = ndisc_build_skb(dev, daddr, src_addr, &icmp6h, solicited_addr,
-                              inc_opt ? ND_OPT_TARGET_LL_ADDR : 0);
+        skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
         if (!skb)
                 return;
 
+        msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
+        *msg = (struct nd_msg) {
+                .icmph = {
+                        .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
+                        .icmp6_router = router,
+                        .icmp6_solicited = solicited,
+                        .icmp6_override = override,
+                },
+                .target = *solicited_addr,
+        };
+
+        if (inc_opt)
+                ndisc_fill_addr_option(skb, ND_OPT_TARGET_LL_ADDR,
+                                       dev->dev_addr);
+
+
         ndisc_send_skb(skb, daddr, src_addr);
 }
 
@@ -571,9 +545,9 @@ void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
 {
         struct sk_buff *skb;
         struct in6_addr addr_buf;
-        struct icmp6hdr icmp6h = {
-                .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
-        };
+        int inc_opt = dev->addr_len;
+        int optlen = 0;
+        struct nd_msg *msg;
 
         if (saddr == NULL) {
                 if (ipv6_get_lladdr(dev, &addr_buf,
@@ -582,11 +556,27 @@ void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
                 saddr = &addr_buf;
         }
 
-        skb = ndisc_build_skb(dev, daddr, saddr, &icmp6h, solicit,
-                              !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0);
+        if (ipv6_addr_any(saddr))
+                inc_opt = 0;
+        if (inc_opt)
+                optlen += ndisc_opt_addr_space(dev);
+
+        skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
         if (!skb)
                 return;
 
+        msg = (struct nd_msg *)skb_put(skb, sizeof(*msg));
+        *msg = (struct nd_msg) {
+                .icmph = {
+                        .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
+                },
+                .target = *solicit,
+        };
+
+        if (inc_opt)
+                ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
+                                       dev->dev_addr);
+
         ndisc_send_skb(skb, daddr, saddr);
 }
 
@@ -594,10 +584,9 @@ void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
                    const struct in6_addr *daddr)
 {
         struct sk_buff *skb;
-        struct icmp6hdr icmp6h = {
-                .icmp6_type = NDISC_ROUTER_SOLICITATION,
-        };
+        struct rs_msg *msg;
         int send_sllao = dev->addr_len;
+        int optlen = 0;
 
 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
         /*
@@ -621,11 +610,26 @@ void ndisc_send_rs(struct net_device *dev, const struct in6_addr *saddr,
                 }
         }
 #endif
-        skb = ndisc_build_skb(dev, daddr, saddr, &icmp6h, NULL,
-                              send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0);
+        if (!dev->addr_len)
+                send_sllao = 0;
+        if (send_sllao)
+                optlen += ndisc_opt_addr_space(dev);
+
+        skb = ndisc_alloc_skb(dev, sizeof(*msg) + optlen);
         if (!skb)
                 return;
 
+        msg = (struct rs_msg *)skb_put(skb, sizeof(*msg));
+        *msg = (struct rs_msg) {
+                .icmph = {
+                        .icmp6_type = NDISC_ROUTER_SOLICITATION,
+                },
+        };
+
+        if (send_sllao)
+                ndisc_fill_addr_option(skb, ND_OPT_SOURCE_LL_ADDR,
+                                       dev->dev_addr);
+
         ndisc_send_skb(skb, daddr, saddr);
 }