lib/route/cls/ematch/cmp.c

   1 /*
   2  * lib/route/cls/ematch/cmp.c   Simple packet data comparison ematch
   3  *
   4  *      This library is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU Lesser General Public
   6  *      License as published by the Free Software Foundation version 2.1
   7  *      of the License.
   8  *
   9  * Copyright (c) 2008-2009 Thomas Graf <tgraf@suug.ch>
  10  */
  11
  12 /**
  13  * @ingroup ematch
  14  * @defgroup em_cmp Simple packet data comparison
  15  *
  16  * @{
  17  */
  18
  19 #include <netlink-local.h>
  20 #include <netlink-tc.h>
  21 #include <netlink/netlink.h>
  22 #include <netlink/route/cls/ematch.h>
  23 #include <linux/tc_ematch/tc_em_cmp.h>
  24
  25 void rtnl_ematch_cmp_set(struct rtnl_ematch *ematch,
  26                          struct tcf_em_cmp *cfg)
  27 {
  28         memcpy(rtnl_ematch_data(ematch), cfg, sizeof(*cfg));
  29 }
  30
  31 struct tcf_em_cmp *rtnl_ematch_cmp_get(struct rtnl_ematch *ematch)
  32 {
  33         return rtnl_ematch_data(ematch);
  34 }
  35
  36 static const char *align_txt(struct tcf_em_cmp *cmp)
  37 {
  38         switch (cmp->align) {
  39         case TCF_EM_ALIGN_U8:
  40                 return "u8";
  41         case TCF_EM_ALIGN_U16:
  42                 return (cmp->flags & TCF_EM_CMP_TRANS) ? "h16" : "u16";
  43         case TCF_EM_ALIGN_U32:
  44                 return (cmp->flags & TCF_EM_CMP_TRANS) ? "h32" : "u32";
  45         default:
  46                 return (cmp->flags & TCF_EM_CMP_TRANS) ? "h?" : "u?";
  47         }
  48 }
  49
  50 static const char *layer_txt(struct tcf_em_cmp *cmp)
  51 {
  52         switch (cmp->layer) {
  53         case TCF_LAYER_LINK:
  54                 return "link";
  55         case TCF_LAYER_NETWORK:
  56                 return "network";
  57         case TCF_LAYER_TRANSPORT:
  58                 return "transport";
  59         default:
  60                 return "?";
  61         }
  62 }
  63
  64 static const char *relation_txt(struct tcf_em_cmp *cmp)
  65 {
  66         switch (cmp->opnd) {
  67         case TCF_EM_OPND_EQ:
  68                 return "eq";
  69         case TCF_EM_OPND_LT:
  70                 return "lt";
  71         case TCF_EM_OPND_GT:
  72                 return "gt";
  73         default:
  74                 return "?";
  75         }
  76 }
  77
  78 static int cmp_parse(struct rtnl_ematch *m, void *data, size_t len)
  79 {
  80         memcpy(rtnl_ematch_data(m), data, len);
  81
  82         return 0;
  83 }
  84
  85 static void cmp_dump(struct rtnl_ematch *m, struct nl_dump_params *p)
  86 {
  87         struct tcf_em_cmp *cmp = rtnl_ematch_data(m);
  88
  89         nl_dump(p, "%s at %s+%u ",
  90                 align_txt(cmp), layer_txt(cmp), cmp->off);
  91
  92         if (cmp->mask)
  93                 nl_dump(p, "& 0x%x ", cmp->mask);
  94
  95         nl_dump(p, "%s %u", relation_txt(cmp), cmp->val);
  96 }
  97
  98 static struct rtnl_ematch_ops cmp_ops = {
  99         .eo_kind        = TCF_EM_CMP,
 100         .eo_name        = "cmp",
 101         .eo_datalen     = sizeof(struct tcf_em_cmp),
 102         .eo_parse       = cmp_parse,
 103         .eo_dump        = cmp_dump,
 104 };
 105
 106 static void __init cmp_init(void)
 107 {
 108         rtnl_ematch_register(&cmp_ops);
 109 }
 110
 111 static void __exit cmp_exit(void)
 112 {
 113         rtnl_ematch_unregister(&cmp_ops);
 114 }
 115
 116 /** @} */