ipv6 mcast: Introduce include/net/mld.h for MLD definitions.

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

2 files changed, 115 insertions, 95 deletions

diff --git a/include/net/mld.h b/include/net/mld.h
new file mode 100644
index 000000000000..467143cd4e2f
--- /dev/null
+++ b/include/net/mld.h
@@ -0,0 +1,75 @@
+#ifndef LINUX_MLD_H
+#define LINUX_MLD_H
+
+#include <linux/in6.h>
+#include <linux/icmpv6.h>
+
+/* MLDv1 Query/Report/Done */
+struct mld_msg {
+        struct icmp6hdr         mld_hdr;
+        struct in6_addr         mld_mca;
+};
+
+#define mld_type                mld_hdr.icmp6_type
+#define mld_code                mld_hdr.icmp6_code
+#define mld_cksum               mld_hdr.icmp6_cksum
+#define mld_maxdelay            mld_hdr.icmp6_maxdelay
+#define mld_reserved            mld_hdr.icmp6_dataun.un_data16[1]
+
+/* Multicast Listener Discovery version 2 headers */
+/* MLDv2 Report */
+struct mld2_grec {
+        __u8            grec_type;
+        __u8            grec_auxwords;
+        __be16          grec_nsrcs;
+        struct in6_addr grec_mca;
+        struct in6_addr grec_src[0];
+};
+
+struct mld2_report {
+        struct icmp6hdr         mld2r_hdr;
+        struct mld2_grec        mld2r_grec[0];
+};
+
+#define mld2r_type              mld2r_hdr.icmp6_type
+#define mld2r_resv1             mld2r_hdr.icmp6_code
+#define mld2r_cksum             mld2r_hdr.icmp6_cksum
+#define mld2r_resv2             mld2r_hdr.icmp6_dataun.un_data16[0]
+#define mld2r_ngrec             mld2r_hdr.icmp6_dataun.un_data16[1]
+
+/* MLDv2 Query */
+struct mld2_query {
+        struct icmp6hdr         mld2q_hdr;
+        struct in6_addr         mld2q_mca;
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+        __u8                    mld2q_qrv:3,
+                                mld2q_suppress:1,
+                                mld2q_resv2:4;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+        __u8                    mld2q_resv2:4,
+                                mld2q_suppress:1,
+                                mld2q_qrv:3;
+#else
+#error "Please fix <asm/byteorder.h>"
+#endif
+        __u8                    mld2q_qqic;
+        __be16                  mld2q_nsrcs;
+        struct in6_addr         mld2q_srcs[0];
+};
+
+#define mld2q_type              mld2q_hdr.icmp6_type
+#define mld2q_code              mld2q_hdr.icmp6_code
+#define mld2q_cksum             mld2q_hdr.icmp6_cksum
+#define mld2q_mrc               mld2q_hdr.icmp6_maxdelay
+#define mld2q_resv1             mld2q_hdr.icmp6_dataun.un_data16[1]
+
+/* Max Response Code */
+#define MLDV2_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value))
+#define MLDV2_EXP(thresh, nbmant, nbexp, value) \
+        ((value) < (thresh) ? (value) : \
+        ((MLDV2_MASK(value, nbmant) | (1<<(nbmant))) << \
+        (MLDV2_MASK((value) >> (nbmant), nbexp) + (nbexp))))
+
+#define MLDV2_MRC(value) MLDV2_EXP(0x8000, 12, 3, value)
+
+#endif
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 62ed08213d91..006aee683a0f 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -44,6 +44,7 @@
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
+#include <net/mld.h>
 
 #include <linux/netfilter.h>
 #include <linux/netfilter_ipv6.h>
@@ -71,54 +72,11 @@
 #define MDBG(x)
 #endif
 
-/*
- *  These header formats should be in a separate include file, but icmpv6.h
- *  doesn't have in6_addr defined in all cases, there is no __u128, and no
- *  other files reference these.
- *
- *                      +-DLS 4/14/03
- */
-
-/* Multicast Listener Discovery version 2 headers */
-
-struct mld2_grec {
-        __u8            grec_type;
-        __u8            grec_auxwords;
-        __be16          grec_nsrcs;
-        struct in6_addr grec_mca;
-        struct in6_addr grec_src[0];
-};
-
-struct mld2_report {
-        __u8    type;
-        __u8    resv1;
-        __sum16 csum;
-        __be16  resv2;
-        __be16  ngrec;
-        struct mld2_grec grec[0];
-};
-
-struct mld2_query {
-        __u8 type;
-        __u8 code;
-        __sum16 csum;
-        __be16 mrc;
-        __be16 resv1;
-        struct in6_addr mca;
-#if defined(__LITTLE_ENDIAN_BITFIELD)
-        __u8 qrv:3,
-             suppress:1,
-             resv2:4;
-#elif defined(__BIG_ENDIAN_BITFIELD)
-        __u8 resv2:4,
-             suppress:1,
-             qrv:3;
-#else
-#error "Please fix <asm/byteorder.h>"
-#endif
-        __u8 qqic;
-        __be16 nsrcs;
-        struct in6_addr srcs[0];
+/* Ensure that we have struct in6_addr aligned on 32bit word. */
+static void *__mld2_query_bugs[] __attribute__((__unused__)) = {
+        BUILD_BUG_ON_NULL(offsetof(struct mld2_query, mld2q_srcs) % 4),
+        BUILD_BUG_ON_NULL(offsetof(struct mld2_report, mld2r_grec) % 4),
+        BUILD_BUG_ON_NULL(offsetof(struct mld2_grec, grec_mca) % 4)
 };
 
 static struct in6_addr mld2_all_mcr = MLD2_ALL_MCR_INIT;
@@ -157,14 +115,6 @@ static int ip6_mc_leave_src(struct sock *sk, struct ipv6_mc_socklist *iml,
                 ((idev)->mc_v1_seen && \
                 time_before(jiffies, (idev)->mc_v1_seen)))
 
-#define MLDV2_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value))
-#define MLDV2_EXP(thresh, nbmant, nbexp, value) \
-        ((value) < (thresh) ? (value) : \
-        ((MLDV2_MASK(value, nbmant) | (1<<(nbmant))) << \
-        (MLDV2_MASK((value) >> (nbmant), nbexp) + (nbexp))))
-
-#define MLDV2_MRC(value) MLDV2_EXP(0x8000, 12, 3, value)
-
 #define IPV6_MLD_MAX_MSF        64
 
 int sysctl_mld_max_msf __read_mostly = IPV6_MLD_MAX_MSF;
@@ -1161,7 +1111,7 @@ int igmp6_event_query(struct sk_buff *skb)
         struct in6_addr *group;
         unsigned long max_delay;
         struct inet6_dev *idev;
-        struct icmp6hdr *hdr;
+        struct mld_msg *mld;
         int group_type;
         int mark = 0;
         int len;
@@ -1182,8 +1132,8 @@ int igmp6_event_query(struct sk_buff *skb)
         if (idev == NULL)
                 return 0;
 
-        hdr = icmp6_hdr(skb);
-        group = (struct in6_addr *) (hdr + 1);
+        mld = (struct mld_msg *)icmp6_hdr(skb);
+        group = &mld->mld_mca;
         group_type = ipv6_addr_type(group);
 
         if (group_type != IPV6_ADDR_ANY &&
@@ -1197,7 +1147,7 @@ int igmp6_event_query(struct sk_buff *skb)
                 /* MLDv1 router present */
 
                 /* Translate milliseconds to jiffies */
-                max_delay = (ntohs(hdr->icmp6_maxdelay)*HZ)/1000;
+                max_delay = (ntohs(mld->mld_maxdelay)*HZ)/1000;
 
                 switchback = (idev->mc_qrv + 1) * max_delay;
                 idev->mc_v1_seen = jiffies + switchback;
@@ -1216,14 +1166,14 @@ int igmp6_event_query(struct sk_buff *skb)
                         return -EINVAL;
                 }
                 mlh2 = (struct mld2_query *)skb_transport_header(skb);
-                max_delay = (MLDV2_MRC(ntohs(mlh2->mrc))*HZ)/1000;
+                max_delay = (MLDV2_MRC(ntohs(mlh2->mld2q_mrc))*HZ)/1000;
                 if (!max_delay)
                         max_delay = 1;
                 idev->mc_maxdelay = max_delay;
-                if (mlh2->qrv)
-                        idev->mc_qrv = mlh2->qrv;
+                if (mlh2->mld2q_qrv)
+                        idev->mc_qrv = mlh2->mld2q_qrv;
                 if (group_type == IPV6_ADDR_ANY) { /* general query */
-                        if (mlh2->nsrcs) {
+                        if (mlh2->mld2q_nsrcs) {
                                 in6_dev_put(idev);
                                 return -EINVAL; /* no sources allowed */
                         }
@@ -1232,9 +1182,9 @@ int igmp6_event_query(struct sk_buff *skb)
                         return 0;
                 }
                 /* mark sources to include, if group & source-specific */
-                if (mlh2->nsrcs != 0) {
+                if (mlh2->mld2q_nsrcs != 0) {
                         if (!pskb_may_pull(skb, srcs_offset +
-                            ntohs(mlh2->nsrcs) * sizeof(struct in6_addr))) {
+                            ntohs(mlh2->mld2q_nsrcs) * sizeof(struct in6_addr))) {
                                 in6_dev_put(idev);
                                 return -EINVAL;
                         }
@@ -1270,7 +1220,7 @@ int igmp6_event_query(struct sk_buff *skb)
                                         ma->mca_flags &= ~MAF_GSQUERY;
                         }
                         if (!(ma->mca_flags & MAF_GSQUERY) ||
-                            mld_marksources(ma, ntohs(mlh2->nsrcs), mlh2->srcs))
+                            mld_marksources(ma, ntohs(mlh2->mld2q_nsrcs), mlh2->mld2q_srcs))
                                 igmp6_group_queried(ma, max_delay);
                         spin_unlock_bh(&ma->mca_lock);
                         break;
@@ -1286,9 +1236,8 @@ int igmp6_event_query(struct sk_buff *skb)
 int igmp6_event_report(struct sk_buff *skb)
 {
         struct ifmcaddr6 *ma;
-        struct in6_addr *addrp;
         struct inet6_dev *idev;
-        struct icmp6hdr *hdr;
+        struct mld_msg *mld;
         int addr_type;
 
         /* Our own report looped back. Ignore it. */
@@ -1300,10 +1249,10 @@ int igmp6_event_report(struct sk_buff *skb)
             skb->pkt_type != PACKET_BROADCAST)
                 return 0;
 
-        if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
+        if (!pskb_may_pull(skb, sizeof(*mld) - sizeof(struct icmp6hdr)))
                 return -EINVAL;
 
-        hdr = icmp6_hdr(skb);
+        mld = (struct mld_msg *)icmp6_hdr(skb);
 
         /* Drop reports with not link local source */
         addr_type = ipv6_addr_type(&ipv6_hdr(skb)->saddr);
@@ -1311,8 +1260,6 @@ int igmp6_event_report(struct sk_buff *skb)
             !(addr_type&IPV6_ADDR_LINKLOCAL))
                 return -EINVAL;
 
-        addrp = (struct in6_addr *) (hdr + 1);
-
         idev = in6_dev_get(skb->dev);
         if (idev == NULL)
                 return -ENODEV;
@@ -1323,7 +1270,7 @@ int igmp6_event_report(struct sk_buff *skb)
 
         read_lock_bh(&idev->lock);
         for (ma = idev->mc_list; ma; ma=ma->next) {
-                if (ipv6_addr_equal(&ma->mca_addr, addrp)) {
+                if (ipv6_addr_equal(&ma->mca_addr, &mld->mld_mca)) {
                         spin_lock(&ma->mca_lock);
                         if (del_timer(&ma->mca_timer))
                                 atomic_dec(&ma->mca_refcnt);
@@ -1432,11 +1379,11 @@ static struct sk_buff *mld_newpack(struct net_device *dev, int size)
         skb_set_transport_header(skb, skb_tail_pointer(skb) - skb->data);
         skb_put(skb, sizeof(*pmr));
         pmr = (struct mld2_report *)skb_transport_header(skb);
-        pmr->type = ICMPV6_MLD2_REPORT;
-        pmr->resv1 = 0;
-        pmr->csum = 0;
-        pmr->resv2 = 0;
-        pmr->ngrec = 0;
+        pmr->mld2r_type = ICMPV6_MLD2_REPORT;
+        pmr->mld2r_resv1 = 0;
+        pmr->mld2r_cksum = 0;
+        pmr->mld2r_resv2 = 0;
+        pmr->mld2r_ngrec = 0;
         return skb;
 }
 
@@ -1458,9 +1405,10 @@ static void mld_sendpack(struct sk_buff *skb)
         mldlen = skb->tail - skb->transport_header;
         pip6->payload_len = htons(payload_len);
 
-        pmr->csum = csum_ipv6_magic(&pip6->saddr, &pip6->daddr, mldlen,
-                IPPROTO_ICMPV6, csum_partial(skb_transport_header(skb),
-                                             mldlen, 0));
+        pmr->mld2r_cksum = csum_ipv6_magic(&pip6->saddr, &pip6->daddr, mldlen,
+                                           IPPROTO_ICMPV6,
+                                           csum_partial(skb_transport_header(skb),
+                                                        mldlen, 0));
 
         dst = icmp6_dst_alloc(skb->dev, NULL, &ipv6_hdr(skb)->daddr);
 
@@ -1521,7 +1469,7 @@ static struct sk_buff *add_grhead(struct sk_buff *skb, struct ifmcaddr6 *pmc,
         pgr->grec_nsrcs = 0;
         pgr->grec_mca = pmc->mca_addr;  /* structure copy */
         pmr = (struct mld2_report *)skb_transport_header(skb);
-        pmr->ngrec = htons(ntohs(pmr->ngrec)+1);
+        pmr->mld2r_ngrec = htons(ntohs(pmr->mld2r_ngrec)+1);
         *ppgr = pgr;
         return skb;
 }
@@ -1557,7 +1505,7 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ifmcaddr6 *pmc,
 
         /* EX and TO_EX get a fresh packet, if needed */
         if (truncate) {
-                if (pmr && pmr->ngrec &&
+                if (pmr && pmr->mld2r_ngrec &&
                     AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
                         if (skb)
                                 mld_sendpack(skb);
@@ -1770,9 +1718,8 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
         struct sock *sk = net->ipv6.igmp_sk;
         struct inet6_dev *idev;
         struct sk_buff *skb;
-        struct icmp6hdr *hdr;
+        struct mld_msg *hdr;
         const struct in6_addr *snd_addr, *saddr;
-        struct in6_addr *addrp;
         struct in6_addr addr_buf;
         int err, len, payload_len, full_len;
         u8 ra[8] = { IPPROTO_ICMPV6, 0,
@@ -1820,16 +1767,14 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
 
         memcpy(skb_put(skb, sizeof(ra)), ra, sizeof(ra));
 
-        hdr = (struct icmp6hdr *) skb_put(skb, sizeof(struct icmp6hdr));
-        memset(hdr, 0, sizeof(struct icmp6hdr));
-        hdr->icmp6_type = type;
+        hdr = (struct mld_msg *) skb_put(skb, sizeof(struct mld_msg));
+        memset(hdr, 0, sizeof(struct mld_msg));
+        hdr->mld_type = type;
+        ipv6_addr_copy(&hdr->mld_mca, addr);
 
-        addrp = (struct in6_addr *) skb_put(skb, sizeof(struct in6_addr));
-        ipv6_addr_copy(addrp, addr);
-
-        hdr->icmp6_cksum = csum_ipv6_magic(saddr, snd_addr, len,
-                                           IPPROTO_ICMPV6,
-                                           csum_partial(hdr, len, 0));
+        hdr->mld_cksum = csum_ipv6_magic(saddr, snd_addr, len,
+                                         IPPROTO_ICMPV6,
+                                         csum_partial(hdr, len, 0));
 
         idev = in6_dev_get(skb->dev);