[IPV6] MROUTE: Support multicast forwarding.

Based on ancient patch by Mickael Hoerdt
<hoerdt@clarinet.u-strasbg.fr>, which is available at
<http://www-r2.u-strasbg.fr/~hoerdt/dev/linux_ipv6_mforwarding/patch-linux-ipv6-mforwarding-0.1a>.

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

3 files changed, 233 insertions, 0 deletions

diff --git a/include/linux/Kbuild b/include/linux/Kbuild
index 84736acb4b99..29ab9b95d376 100644
--- a/include/linux/Kbuild
+++ b/include/linux/Kbuild
@@ -261,6 +261,7 @@ unifdef-y += mempolicy.h
 unifdef-y += mii.h
 unifdef-y += mman.h
 unifdef-y += mroute.h
+unifdef-y += mroute6.h
 unifdef-y += msdos_fs.h
 unifdef-y += msg.h
 unifdef-y += nbd.h
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index b90d3d461d4e..f53e4764fc05 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -160,6 +160,9 @@ struct ipv6_devconf {
 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
         __s32           optimistic_dad;
 #endif
+#ifdef CONFIG_IPV6_MROUTE
+        __s32           mc_forwarding;
+#endif
         void            *sysctl;
 };
 
@@ -190,6 +193,7 @@ enum {
         DEVCONF_PROXY_NDP,
         DEVCONF_OPTIMISTIC_DAD,
         DEVCONF_ACCEPT_SOURCE_ROUTE,
+        DEVCONF_MC_FORWARDING,
         DEVCONF_MAX
 };
 
@@ -230,6 +234,7 @@ struct inet6_skb_parm {
 #endif
 
 #define IP6SKB_XFRM_TRANSFORMED 1
+#define IP6SKB_FORWARDED        2
 };
 
 #define IP6CB(skb)      ((struct inet6_skb_parm*)((skb)->cb))
diff --git a/include/linux/mroute6.h b/include/linux/mroute6.h
new file mode 100644
index 000000000000..b92190304e0b
--- /dev/null
+++ b/include/linux/mroute6.h
@@ -0,0 +1,227 @@
+#ifndef __LINUX_MROUTE6_H
+#define __LINUX_MROUTE6_H
+
+#include <linux/types.h>
+#include <linux/sockios.h>
+
+/*
+ *      Based on the MROUTING 3.5 defines primarily to keep
+ *      source compatibility with BSD.
+ *
+ *      See the pim6sd code for the original history.
+ *
+ *      Protocol Independent Multicast (PIM) data structures included
+ *      Carlos Picoto (cap@di.fc.ul.pt)
+ *
+ */
+
+#define MRT6_BASE       200
+#define MRT6_INIT       (MRT6_BASE)     /* Activate the kernel mroute code      */
+#define MRT6_DONE       (MRT6_BASE+1)   /* Shutdown the kernel mroute           */
+#define MRT6_ADD_MIF    (MRT6_BASE+2)   /* Add a virtual interface              */
+#define MRT6_DEL_MIF    (MRT6_BASE+3)   /* Delete a virtual interface           */
+#define MRT6_ADD_MFC    (MRT6_BASE+4)   /* Add a multicast forwarding entry     */
+#define MRT6_DEL_MFC    (MRT6_BASE+5)   /* Delete a multicast forwarding entry  */
+#define MRT6_VERSION    (MRT6_BASE+6)   /* Get the kernel multicast version     */
+
+#define SIOCGETMIFCNT_IN6       SIOCPROTOPRIVATE        /* IP protocol privates */
+#define SIOCGETSGCNT_IN6        (SIOCPROTOPRIVATE+1)
+#define SIOCGETRPF      (SIOCPROTOPRIVATE+2)
+
+#define MAXMIFS         32
+typedef unsigned long mifbitmap_t;      /* User mode code depends on this lot */
+typedef unsigned short mifi_t;
+#define ALL_MIFS        ((mifi_t)(-1))
+
+#ifndef IF_SETSIZE
+#define IF_SETSIZE      256
+#endif
+
+typedef __u32           if_mask;
+#define NIFBITS (sizeof(if_mask) * 8)        /* bits per mask */
+
+#if !defined(__KERNEL__) && !defined(DIV_ROUND_UP)
+#define DIV_ROUND_UP(x,y)       (((x) + ((y) - 1)) / (y))
+#endif
+
+typedef struct if_set {
+        if_mask ifs_bits[DIV_ROUND_UP(IF_SETSIZE, NIFBITS)];
+} if_set;
+
+#define IF_SET(n, p)    ((p)->ifs_bits[(n)/NIFBITS] |= (1 << ((n) % NIFBITS)))
+#define IF_CLR(n, p)    ((p)->ifs_bits[(n)/NIFBITS] &= ~(1 << ((n) % NIFBITS)))
+#define IF_ISSET(n, p)  ((p)->ifs_bits[(n)/NIFBITS] & (1 << ((n) % NIFBITS)))
+#define IF_COPY(f, t)   bcopy(f, t, sizeof(*(f)))
+#define IF_ZERO(p)      bzero(p, sizeof(*(p)))
+
+/*
+ *      Passed by mrouted for an MRT_ADD_MIF - again we use the
+ *      mrouted 3.6 structures for compatibility
+ */
+
+struct mif6ctl {
+        mifi_t  mif6c_mifi;             /* Index of MIF */
+        unsigned char mif6c_flags;      /* MIFF_ flags */
+        unsigned char vifc_threshold;   /* ttl limit */
+        u_short  mif6c_pifi;            /* the index of the physical IF */
+        unsigned int vifc_rate_limit;   /* Rate limiter values (NI) */
+};
+
+#define MIFF_REGISTER   0x1     /* register vif */
+
+/*
+ *      Cache manipulation structures for mrouted and PIMd
+ */
+
+struct mf6cctl
+{
+        struct sockaddr_in6 mf6cc_origin;               /* Origin of mcast      */
+        struct sockaddr_in6 mf6cc_mcastgrp;             /* Group in question    */
+        mifi_t  mf6cc_parent;                   /* Where it arrived     */
+        struct if_set mf6cc_ifset;              /* Where it is going */
+};
+
+/*
+ *      Group count retrieval for pim6sd
+ */
+
+struct sioc_sg_req6
+{
+        struct sockaddr_in6 src;
+        struct sockaddr_in6 grp;
+        unsigned long pktcnt;
+        unsigned long bytecnt;
+        unsigned long wrong_if;
+};
+
+/*
+ *      To get vif packet counts
+ */
+
+struct sioc_mif_req6
+{
+        mifi_t  mifi;           /* Which iface */
+        unsigned long icount;   /* In packets */
+        unsigned long ocount;   /* Out packets */
+        unsigned long ibytes;   /* In bytes */
+        unsigned long obytes;   /* Out bytes */
+};
+
+/*
+ *      That's all usermode folks
+ */
+
+#ifdef __KERNEL__
+
+#include <linux/skbuff.h>       /* for struct sk_buff_head */
+
+struct net_device;
+struct inet6_dev *ipv6_find_idev(struct net_device *dev);
+
+#ifdef CONFIG_IPV6_MROUTE
+static inline int ip6_mroute_opt(int opt)
+{
+        return (opt >= MRT6_BASE) && (opt <= MRT6_BASE + 10);
+}
+#else
+static inline int ip6_mroute_opt(int opt)
+{
+        return 0;
+}
+#endif
+
+struct sock;
+
+extern int ip6_mroute_setsockopt(struct sock *, int, char __user *, int);
+extern int ip6_mroute_getsockopt(struct sock *, int, char __user *, int __user *);
+extern int ip6_mr_input(struct sk_buff *skb);
+extern int ip6mr_ioctl(struct sock *sk, int cmd, void __user *arg);
+extern void ip6_mr_init(void);
+
+struct mif_device
+{
+        struct net_device       *dev;                   /* Device we are using */
+        unsigned long   bytes_in,bytes_out;
+        unsigned long   pkt_in,pkt_out;         /* Statistics                   */
+        unsigned long   rate_limit;             /* Traffic shaping (NI)         */
+        unsigned char   threshold;              /* TTL threshold                */
+        unsigned short  flags;                  /* Control flags                */
+        int             link;                   /* Physical interface index     */
+};
+
+#define VIFF_STATIC 0x8000
+
+struct mfc6_cache
+{
+        struct mfc6_cache *next;                /* Next entry on cache line     */
+        struct in6_addr mf6c_mcastgrp;                  /* Group the entry belongs to   */
+        struct in6_addr mf6c_origin;                    /* Source of packet             */
+        mifi_t mf6c_parent;                     /* Source interface             */
+        int mfc_flags;                          /* Flags on line                */
+
+        union {
+                struct {
+                        unsigned long expires;
+                        struct sk_buff_head unresolved; /* Unresolved buffers           */
+                } unres;
+                struct {
+                        unsigned long last_assert;
+                        int minvif;
+                        int maxvif;
+                        unsigned long bytes;
+                        unsigned long pkt;
+                        unsigned long wrong_if;
+                        unsigned char ttls[MAXMIFS];    /* TTL thresholds               */
+                } res;
+        } mfc_un;
+};
+
+#define MFC_STATIC              1
+#define MFC_NOTIFY              2
+
+#define MFC6_LINES              64
+
+#define MFC6_HASH(a, g) (((__force u32)(a)->s6_addr32[0] ^ \
+                          (__force u32)(a)->s6_addr32[1] ^ \
+                          (__force u32)(a)->s6_addr32[2] ^ \
+                          (__force u32)(a)->s6_addr32[3] ^ \
+                          (__force u32)(g)->s6_addr32[0] ^ \
+                          (__force u32)(g)->s6_addr32[1] ^ \
+                          (__force u32)(g)->s6_addr32[2] ^ \
+                          (__force u32)(g)->s6_addr32[3]) % MFC6_LINES)
+
+#define MFC_ASSERT_THRESH (3*HZ)                /* Maximal freq. of asserts */
+
+#endif
+
+#ifdef __KERNEL__
+struct rtmsg;
+extern int ip6mr_get_route(struct sk_buff *skb, struct rtmsg *rtm, int nowait);
+
+#ifdef CONFIG_IPV6_MROUTE
+extern struct sock *mroute6_socket;
+extern int ip6mr_sk_done(struct sock *sk);
+#else
+#define mroute6_socket NULL
+static inline int ip6mr_sk_done(struct sock *sk) { return 0; }
+#endif
+#endif
+
+/*
+ * Structure used to communicate from kernel to multicast router.
+ * We'll overlay the structure onto an MLD header (not an IPv6 heder like igmpmsg{}
+ * used for IPv4 implementation). This is because this structure will be passed via an
+ * IPv6 raw socket, on wich an application will only receiver the payload i.e the data after
+ * the IPv6 header and all the extension headers. (See section 3 of RFC 3542)
+ */
+
+struct mrt6msg {
+#define MRT6MSG_NOCACHE         1
+        __u8            im6_mbz;                /* must be zero            */
+        __u8            im6_msgtype;            /* what type of message    */
+        __u16           im6_mif;                /* mif rec'd on            */
+        __u32           im6_pad;                /* padding for 64 bit arch */
+        struct in6_addr im6_src, im6_dst;
+};
+
+#endif