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/config.h>
  11 #include <linux/ip_mp_alg.h>
  12 #include <net/flow.h>
  13 #include <net/route.h>
  14
  15 struct fib_nh;
  16
  17 struct ip_mp_alg_ops {
  18         void    (*mp_alg_select_route)(const struct flowi *flp,
  19                                        struct rtable *rth, struct rtable **rp);
  20         void    (*mp_alg_flush)(void);
  21         void    (*mp_alg_set_nhinfo)(__u32 network, __u32 netmask,
  22                                      unsigned char prefixlen,
  23                                      const struct fib_nh *nh);
  24         void    (*mp_alg_remove)(struct rtable *rth);
  25 };
  26
  27 extern int multipath_alg_register(struct ip_mp_alg_ops *, enum ip_mp_alg);
  28 extern void multipath_alg_unregister(struct ip_mp_alg_ops *, enum ip_mp_alg);
  29
  30 extern struct ip_mp_alg_ops *ip_mp_alg_table[];
  31
  32 static inline int multipath_select_route(const struct flowi *flp,
  33                                          struct rtable *rth,
  34                                          struct rtable **rp)
  35 {
  36 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
  37         struct ip_mp_alg_ops *ops = ip_mp_alg_table[rth->rt_multipath_alg];
  38
  39         /* mp_alg_select_route _MUST_ be implemented */
  40         if (ops && (rth->u.dst.flags & DST_BALANCED)) {
  41                 ops->mp_alg_select_route(flp, rth, rp);
  42                 return 1;
  43         }
  44 #endif
  45         return 0;
  46 }
  47
  48 static inline void multipath_flush(void)
  49 {
  50 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
  51         int i;
  52
  53         for (i = IP_MP_ALG_NONE; i <= IP_MP_ALG_MAX; i++) {
  54                 struct ip_mp_alg_ops *ops = ip_mp_alg_table[i];
  55
  56                 if (ops && ops->mp_alg_flush)
  57                         ops->mp_alg_flush();
  58         }
  59 #endif
  60 }
  61
  62 static inline void multipath_set_nhinfo(struct rtable *rth,
  63                                         __u32 network, __u32 netmask,
  64                                         unsigned char prefixlen,
  65                                         const struct fib_nh *nh)
  66 {
  67 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
  68         struct ip_mp_alg_ops *ops = ip_mp_alg_table[rth->rt_multipath_alg];
  69
  70         if (ops && ops->mp_alg_set_nhinfo)
  71                 ops->mp_alg_set_nhinfo(network, netmask, prefixlen, nh);
  72 #endif
  73 }
  74
  75 static inline void multipath_remove(struct rtable *rth)
  76 {
  77 #ifdef CONFIG_IP_ROUTE_MULTIPATH_CACHED
  78         struct ip_mp_alg_ops *ops = ip_mp_alg_table[rth->rt_multipath_alg];
  79
  80         if (ops && ops->mp_alg_remove &&
  81             (rth->u.dst.flags & DST_BALANCED))
  82                 ops->mp_alg_remove(rth);
  83 #endif
  84 }
  85
  86 static inline int multipath_comparekeys(const struct flowi *flp1,
  87                                         const struct flowi *flp2)
  88 {
  89         return flp1->fl4_dst == flp2->fl4_dst &&
  90                 flp1->fl4_src == flp2->fl4_src &&
  91                 flp1->oif == flp2->oif &&
  92 #ifdef CONFIG_IP_ROUTE_FWMARK
  93                 flp1->fl4_fwmark == flp2->fl4_fwmark &&
  94 #endif
  95                 !((flp1->fl4_tos ^ flp2->fl4_tos) &
  96                   (IPTOS_RT_MASK | RTO_ONLINK));
  97 }
  98
  99 #endif /* _NET_IP_MP_ALG_H */