include/net/ip_mp_alg.h

   1 /* ip_mp_alg.h: IPV4 multipath algorithm support.
   2  *
   3  * Copyright (C) 2004, 2005 Einar Lueck <elueck@de.ibm.com>
   4  * Copyright (C) 2005 David S. Miller <davem@davemloft.net>
   5  */
   6
   7 #ifndef _NET_IP_MP_ALG_H
   8 #define _NET_IP_MP_ALG_H
   9
  10 #include <linux/ip_mp_alg.h>
  11 #include <net/flow.h>
  12 #include <net/route.h>
  13
  14 struct fib_nh;
  15
  16 struct ip_mp_alg_ops {
  17         void    (*mp_alg_select_route)(const struct flowi *flp,
  18                                        struct rtable *rth, struct rtable **rp);
  19         void    (*mp_alg_flush)(void);
  20         void    (*mp_alg_set_nhinfo)(__be32 network, __be32 netmask,
  21                                      unsigned char prefixlen,
  22                                      const struct fib_nh *nh);
  23         void    (*mp_alg_remove)(struct rtable *rth);
  24 };
  25
  26 extern int multipath_alg_register(struct ip_mp_alg_ops *, enum ip_mp_alg);
  27 extern void multipath_alg_unregister(struct ip_mp_alg_ops *, enum ip_mp_alg);
  28
  29 extern struct ip_mp_alg_ops *ip_mp_alg_table[];
  30
  31 static inline int multipath_select_route(const struct flowi *flp,
  32                                          struct rtable *rth,
  33                                          struct rtable **rp)
  34 {
  35 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
  36         struct ip_mp_alg_ops *ops = ip_mp_alg_table[rth->rt_multipath_alg];
  37
  38         /* mp_alg_select_route _MUST_ be implemented */
  39         if (ops && (rth->u.dst.flags & DST_BALANCED)) {
  40                 ops->mp_alg_select_route(flp, rth, rp);
  41                 return 1;
  42         }
  43 #endif
  44         return 0;
  45 }
  46
  47 static inline void multipath_flush(void)
  48 {
  49 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
  50         int i;
  51
  52         for (i = IP_MP_ALG_NONE; i <= IP_MP_ALG_MAX; i++) {
  53                 struct ip_mp_alg_ops *ops = ip_mp_alg_table[i];
  54
  55                 if (ops && ops->mp_alg_flush)
  56                         ops->mp_alg_flush();
  57         }
  58 #endif
  59 }
  60
  61 static inline void multipath_set_nhinfo(struct rtable *rth,
  62                                         __be32 network, __be32 netmask,
  63                                         unsigned char prefixlen,
  64                                         const struct fib_nh *nh)
  65 {
  66 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
  67         struct ip_mp_alg_ops *ops = ip_mp_alg_table[rth->rt_multipath_alg];
  68
  69         if (ops && ops->mp_alg_set_nhinfo)
  70                 ops->mp_alg_set_nhinfo(network, netmask, prefixlen, nh);
  71 #endif
  72 }
  73
  74 static inline void multipath_remove(struct rtable *rth)
  75 {
  76 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
  77         struct ip_mp_alg_ops *ops = ip_mp_alg_table[rth->rt_multipath_alg];
  78
  79         if (ops && ops->mp_alg_remove &&
  80             (rth->u.dst.flags & DST_BALANCED))
  81                 ops->mp_alg_remove(rth);
  82 #endif
  83 }
  84
  85 static inline int multipath_comparekeys(const struct flowi *flp1,
  86                                         const struct flowi *flp2)
  87 {
  88         return flp1->fl4_dst == flp2->fl4_dst &&
  89                 flp1->fl4_src == flp2->fl4_src &&
  90                 flp1->oif == flp2->oif &&
  91                 flp1->mark == flp2->mark &&
  92                 !((flp1->fl4_tos ^ flp2->fl4_tos) &
  93                   (IPTOS_RT_MASK | RTO_ONLINK));
  94 }
  95
  96 #endif /* _NET_IP_MP_ALG_H */