[IPV6] NDISC: Unify main process of sending ND messages.

Because ndisc_send_na(), ndisc_send_ns() and ndisc_send_rs()
are almost identical, so let's unify their common part.

With gcc (GCC) 3.3.5 (Debian 1:3.3.5-13) on i386,
	Before:
	   text	   data	    bss	    dec	    hex	filename
	  14689	    364	     24	  15077	   3ae5	net/ipv6/ndisc.o
	After:
	   text	   data	    bss	    dec	    hex	filename
	  12317	    364	     24	  12705	   31a1	net/ipv6/ndisc.o

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

1 files changed, 84 insertions, 199 deletions

diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 4ee1216f8018..d8b36451bada 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -427,38 +427,23 @@ static inline void ndisc_flow_init(struct flowi *fl, u8 type,
         security_sk_classify_flow(ndisc_socket->sk, fl);
 }
 
-static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
-                   struct in6_addr *daddr, struct in6_addr *solicited_addr,
-                   int router, int solicited, int override, int inc_opt)
+static void __ndisc_send(struct net_device *dev,
+                         struct neighbour *neigh,
+                         struct in6_addr *daddr, struct in6_addr *saddr,
+                         struct icmp6hdr *icmp6h, struct in6_addr *target,
+                         int llinfo, int icmp6_mib_outnd)
 {
-        struct in6_addr tmpaddr;
-        struct inet6_ifaddr *ifp;
-        struct inet6_dev *idev;
         struct flowi fl;
-        struct dst_entry* dst;
+        struct dst_entry *dst;
         struct sock *sk = ndisc_socket->sk;
-        struct in6_addr *src_addr;
-        struct nd_msg *msg;
-        int len;
         struct sk_buff *skb;
+        struct icmp6hdr *hdr;
+        struct inet6_dev *idev;
+        int len;
         int err;
+        u8 *opt;
 
-        len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
-
-        /* for anycast or proxy, solicited_addr != src_addr */
-        ifp = ipv6_get_ifaddr(solicited_addr, dev, 1);
-        if (ifp) {
-                src_addr = solicited_addr;
-                if (ifp->flags & IFA_F_OPTIMISTIC)
-                        override = 0;
-                in6_ifa_put(ifp);
-        } else {
-                if (ipv6_dev_get_saddr(dev, daddr, &tmpaddr))
-                        return;
-                src_addr = &tmpaddr;
-        }
-
-        ndisc_flow_init(&fl, NDISC_NEIGHBOUR_ADVERTISEMENT, src_addr, daddr,
+        ndisc_flow_init(&fl, icmp6h->icmp6_type, saddr, daddr,
                         dev->ifindex);
 
         dst = ndisc_dst_alloc(dev, neigh, daddr, ip6_output);
@@ -469,61 +454,57 @@ static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
         if (err < 0)
                 return;
 
-        if (inc_opt) {
-                if (dev->addr_len)
-                        len += ndisc_opt_addr_space(dev);
-                else
-                        inc_opt = 0;
-        }
+        if (!dev->addr_len)
+                llinfo = 0;
+
+        len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
+        if (llinfo)
+                len += ndisc_opt_addr_space(dev);
 
         skb = sock_alloc_send_skb(sk,
                                   (MAX_HEADER + sizeof(struct ipv6hdr) +
                                    len + LL_RESERVED_SPACE(dev)),
                                   1, &err);
-
-        if (skb == NULL) {
+        if (!skb) {
                 ND_PRINTK0(KERN_ERR
-                           "ICMPv6 NA: %s() failed to allocate an skb.\n",
+                           "ICMPv6 ND: %s() failed to allocate an skb.\n",
                            __FUNCTION__);
                 dst_release(dst);
                 return;
         }
 
         skb_reserve(skb, LL_RESERVED_SPACE(dev));
-        ip6_nd_hdr(sk, skb, dev, src_addr, daddr, IPPROTO_ICMPV6, len);
+        ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
 
         skb->transport_header = skb->tail;
         skb_put(skb, len);
-        msg = (struct nd_msg *)skb_transport_header(skb);
 
-        msg->icmph.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT;
-        msg->icmph.icmp6_code = 0;
-        msg->icmph.icmp6_cksum = 0;
+        hdr = (struct icmp6hdr *)skb_transport_header(skb);
+        memcpy(hdr, icmp6h, sizeof(*hdr));
 
-        msg->icmph.icmp6_unused = 0;
-        msg->icmph.icmp6_router    = router;
-        msg->icmph.icmp6_solicited = solicited;
-        msg->icmph.icmp6_override  = override;
-
-        /* Set the target address. */
-        ipv6_addr_copy(&msg->target, solicited_addr);
+        opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
+        if (target) {
+                ipv6_addr_copy((struct in6_addr *)opt, target);
+                opt += sizeof(*target);
+        }
 
-        if (inc_opt)
-                ndisc_fill_addr_option(msg->opt, ND_OPT_TARGET_LL_ADDR, dev->dev_addr,
+        if (llinfo)
+                ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
                                        dev->addr_len, dev->type);
 
-        /* checksum */
-        msg->icmph.icmp6_cksum = csum_ipv6_magic(src_addr, daddr, len,
-                                                 IPPROTO_ICMPV6,
-                                                 csum_partial((__u8 *) msg,
-                                                              len, 0));
+        hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
+                                           IPPROTO_ICMPV6,
+                                           csum_partial((__u8 *) hdr,
+                                                        len, 0));
 
         skb->dst = dst;
+
         idev = in6_dev_get(dst->dev);
         IP6_INC_STATS(idev, IPSTATS_MIB_OUTREQUESTS);
+
         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
         if (!err) {
-                ICMP6_INC_STATS(idev, ICMP6_MIB_OUTNEIGHBORADVERTISEMENTS);
+                ICMP6_INC_STATS(idev, icmp6_mib_outnd);
                 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
         }
 
@@ -531,20 +512,48 @@ static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
                 in6_dev_put(idev);
 }
 
+static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh,
+                   struct in6_addr *daddr, struct in6_addr *solicited_addr,
+                   int router, int solicited, int override, int inc_opt)
+{
+        struct in6_addr tmpaddr;
+        struct inet6_ifaddr *ifp;
+        struct in6_addr *src_addr;
+        struct icmp6hdr icmp6h = {
+                .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT,
+        };
+
+        /* for anycast or proxy, solicited_addr != src_addr */
+        ifp = ipv6_get_ifaddr(solicited_addr, dev, 1);
+        if (ifp) {
+                src_addr = solicited_addr;
+                if (ifp->flags & IFA_F_OPTIMISTIC)
+                        override = 0;
+                in6_ifa_put(ifp);
+        } else {
+                if (ipv6_dev_get_saddr(dev, daddr, &tmpaddr))
+                        return;
+                src_addr = &tmpaddr;
+        }
+
+        icmp6h.icmp6_router = router;
+        icmp6h.icmp6_solicited = solicited;
+        icmp6h.icmp6_override = override;
+
+        __ndisc_send(dev, neigh, daddr, src_addr,
+                     &icmp6h, solicited_addr,
+                     inc_opt ? ND_OPT_TARGET_LL_ADDR : 0,
+                     ICMP6_MIB_OUTNEIGHBORADVERTISEMENTS);
+}
+
 void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
                    struct in6_addr *solicit,
                    struct in6_addr *daddr, struct in6_addr *saddr)
 {
-        struct flowi fl;
-        struct dst_entry* dst;
-        struct inet6_dev *idev;
-        struct sock *sk = ndisc_socket->sk;
-        struct sk_buff *skb;
-        struct nd_msg *msg;
         struct in6_addr addr_buf;
-        int len;
-        int err;
-        int send_llinfo;
+        struct icmp6hdr icmp6h = {
+                .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION,
+        };
 
         if (saddr == NULL) {
                 if (ipv6_get_lladdr(dev, &addr_buf,
@@ -553,86 +562,19 @@ void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh,
                 saddr = &addr_buf;
         }
 
-        ndisc_flow_init(&fl, NDISC_NEIGHBOUR_SOLICITATION, saddr, daddr,
-                        dev->ifindex);
-
-        dst = ndisc_dst_alloc(dev, neigh, daddr, ip6_output);
-        if (!dst)
-                return;
-
-        err = xfrm_lookup(&dst, &fl, NULL, 0);
-        if (err < 0)
-                return;
-
-        len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
-        send_llinfo = dev->addr_len && !ipv6_addr_any(saddr);
-        if (send_llinfo)
-                len += ndisc_opt_addr_space(dev);
-
-        skb = sock_alloc_send_skb(sk,
-                                  (MAX_HEADER + sizeof(struct ipv6hdr) +
-                                   len + LL_RESERVED_SPACE(dev)),
-                                  1, &err);
-        if (skb == NULL) {
-                ND_PRINTK0(KERN_ERR
-                           "ICMPv6 NA: %s() failed to allocate an skb.\n",
-                           __FUNCTION__);
-                dst_release(dst);
-                return;
-        }
-
-        skb_reserve(skb, LL_RESERVED_SPACE(dev));
-        ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
-
-        skb->transport_header = skb->tail;
-        skb_put(skb, len);
-        msg = (struct nd_msg *)skb_transport_header(skb);
-        msg->icmph.icmp6_type = NDISC_NEIGHBOUR_SOLICITATION;
-        msg->icmph.icmp6_code = 0;
-        msg->icmph.icmp6_cksum = 0;
-        msg->icmph.icmp6_unused = 0;
-
-        /* Set the target address. */
-        ipv6_addr_copy(&msg->target, solicit);
-
-        if (send_llinfo)
-                ndisc_fill_addr_option(msg->opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr,
-                                       dev->addr_len, dev->type);
-
-        /* checksum */
-        msg->icmph.icmp6_cksum = csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
-                                                 daddr, len,
-                                                 IPPROTO_ICMPV6,
-                                                 csum_partial((__u8 *) msg,
-                                                              len, 0));
-        /* send it! */
-        skb->dst = dst;
-        idev = in6_dev_get(dst->dev);
-        IP6_INC_STATS(idev, IPSTATS_MIB_OUTREQUESTS);
-        err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
-        if (!err) {
-                ICMP6_INC_STATS(idev, ICMP6_MIB_OUTNEIGHBORSOLICITS);
-                ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
-        }
-
-        if (likely(idev != NULL))
-                in6_dev_put(idev);
+        __ndisc_send(dev, neigh, daddr, saddr,
+                     &icmp6h, solicit,
+                     !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0,
+                     ICMP6_MIB_OUTNEIGHBORSOLICITS);
 }
 
 void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
                    struct in6_addr *daddr)
 {
-        struct flowi fl;
-        struct dst_entry* dst;
-        struct inet6_dev *idev;
-        struct sock *sk = ndisc_socket->sk;
-        struct sk_buff *skb;
-        struct icmp6hdr *hdr;
-        __u8 * opt;
+        struct icmp6hdr icmp6h = {
+                .icmp6_type = NDISC_ROUTER_SOLICITATION,
+        };
         int send_sllao = dev->addr_len;
-        int len;
-        int err;
-
 
 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
         /*
@@ -655,67 +597,10 @@ void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr,
                 }
         }
 #endif
-        ndisc_flow_init(&fl, NDISC_ROUTER_SOLICITATION, saddr, daddr,
-                        dev->ifindex);
-
-        dst = ndisc_dst_alloc(dev, NULL, daddr, ip6_output);
-        if (!dst)
-                return;
-
-        err = xfrm_lookup(&dst, &fl, NULL, 0);
-        if (err < 0)
-                return;
-
-        len = sizeof(struct icmp6hdr);
-        if (send_sllao)
-                len += ndisc_opt_addr_space(dev);
-
-        skb = sock_alloc_send_skb(sk,
-                                  (MAX_HEADER + sizeof(struct ipv6hdr) +
-                                   len + LL_RESERVED_SPACE(dev)),
-                                  1, &err);
-        if (skb == NULL) {
-                ND_PRINTK0(KERN_ERR
-                           "ICMPv6 RS: %s() failed to allocate an skb.\n",
-                           __FUNCTION__);
-                dst_release(dst);
-                return;
-        }
-
-        skb_reserve(skb, LL_RESERVED_SPACE(dev));
-        ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
-
-        skb->transport_header = skb->tail;
-        skb_put(skb, len);
-        hdr = icmp6_hdr(skb);
-        hdr->icmp6_type = NDISC_ROUTER_SOLICITATION;
-        hdr->icmp6_code = 0;
-        hdr->icmp6_cksum = 0;
-        hdr->icmp6_unused = 0;
-
-        opt = (u8*) (hdr + 1);
-
-        if (send_sllao)
-                ndisc_fill_addr_option(opt, ND_OPT_SOURCE_LL_ADDR, dev->dev_addr,
-                                       dev->addr_len, dev->type);
-
-        /* checksum */
-        hdr->icmp6_cksum = csum_ipv6_magic(&ipv6_hdr(skb)->saddr, daddr, len,
-                                           IPPROTO_ICMPV6,
-                                           csum_partial((__u8 *) hdr, len, 0));
-
-        /* send it! */
-        skb->dst = dst;
-        idev = in6_dev_get(dst->dev);
-        IP6_INC_STATS(idev, IPSTATS_MIB_OUTREQUESTS);
-        err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output);
-        if (!err) {
-                ICMP6_INC_STATS(idev, ICMP6_MIB_OUTROUTERSOLICITS);
-                ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
-        }
-
-        if (likely(idev != NULL))
-                in6_dev_put(idev);
+        __ndisc_send(dev, NULL, daddr, saddr,
+                     &icmp6h, NULL,
+                     send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0,
+                     ICMP6_MIB_OUTROUTERSOLICITS);
 }