Explicit definition structures of route attributes

Changes in internal API:

* Every route attribute must be defined as struct ea_class somewhere.
* Registration of route attributes known at startup must be done by
  ea_register_init() from protocol build functions.
* Every attribute has now its symbol registered in a global symbol table
  defined as SYM_ATTRIBUTE
* All attribute ID's are dynamically allocated.
* Attribute value custom formatting hook is defined in the ea_class.
* Attribute names are the same for display and filters, always prefixed
  by protocol name.

Also added some unit testing code for filters with route attributes.

1 files changed, 119 insertions, 78 deletions

diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c
index 81e02b4c..23d41b56 100644
--- a/sysdep/linux/netlink.c
+++ b/sysdep/linux/netlink.c
@@ -26,6 +26,7 @@
 #include "lib/socket.h"
 #include "lib/string.h"
 #include "lib/hash.h"
+#include "lib/macro.h"
 #include "conf/conf.h"
 
 #include <asm/types.h>
@@ -122,6 +123,101 @@ struct nl_parse_state
 };
 
 /*
+ *	Netlink eattr definitions
+ */
+
+#define KRT_METRICS_MAX		ARRAY_SIZE(ea_krt_metrics)
+#define KRT_FEATURES_MAX	4
+
+static void krt_bitfield_format(const eattr *e, byte *buf, uint buflen);
+
+static struct ea_class
+  ea_krt_prefsrc = {
+    .name = "krt_prefsrc",
+    .type = T_IP,
+  },
+  ea_krt_realm = {
+    .name = "krt_realm",
+    .type = T_INT,
+  },
+  ea_krt_scope = {
+    .name = "krt_scope",
+    .type = T_INT,
+  };
+
+static struct ea_class ea_krt_metrics[] = {
+  [RTAX_LOCK] = {
+    .name = "krt_lock",
+    .type = T_INT,
+    .format = krt_bitfield_format,
+  },
+  [RTAX_FEATURES] = {
+    .name = "krt_features",
+    .type = T_INT,
+    .format = krt_bitfield_format,
+  },
+#define KRT_METRIC_INT(_rtax, _name)	[_rtax] = { .name = _name, .type = T_INT }
+  KRT_METRIC_INT(RTAX_MTU, "krt_mtu"),
+  KRT_METRIC_INT(RTAX_WINDOW, "krt_window"),
+  KRT_METRIC_INT(RTAX_RTT, "krt_rtt"),
+  KRT_METRIC_INT(RTAX_RTTVAR, "krt_rttvar"),
+  KRT_METRIC_INT(RTAX_SSTHRESH, "krt_sstresh"),
+  KRT_METRIC_INT(RTAX_CWND, "krt_cwnd"),
+  KRT_METRIC_INT(RTAX_ADVMSS, "krt_advmss"),
+  KRT_METRIC_INT(RTAX_REORDERING, "krt_reordering"),
+  KRT_METRIC_INT(RTAX_HOPLIMIT, "krt_hoplimit"),
+  KRT_METRIC_INT(RTAX_INITCWND, "krt_initcwnd"),
+  KRT_METRIC_INT(RTAX_RTO_MIN, "krt_rto_min"),
+  KRT_METRIC_INT(RTAX_INITRWND, "krt_initrwnd"),
+  KRT_METRIC_INT(RTAX_QUICKACK, "krt_quickack"),
+#undef KRT_METRIC_INT
+};
+
+static const char *krt_metrics_names[KRT_METRICS_MAX] = {
+  NULL, "lock", "mtu", "window", "rtt", "rttvar", "sstresh", "cwnd", "advmss",
+  "reordering", "hoplimit", "initcwnd", "features", "rto_min", "initrwnd", "quickack"
+};
+
+static const char *krt_features_names[KRT_FEATURES_MAX] = {
+  "ecn", NULL, NULL, "allfrag"
+};
+
+static void
+krt_bitfield_format(const eattr *a, byte *buf, uint buflen)
+{
+  if (a->id == ea_krt_metrics[RTAX_LOCK].id)
+    ea_format_bitfield(a, buf, buflen, krt_metrics_names, 2, KRT_METRICS_MAX);
+  else if (a->id == ea_krt_metrics[RTAX_FEATURES].id)
+    ea_format_bitfield(a, buf, buflen, krt_features_names, 0, KRT_FEATURES_MAX);
+}
+
+static void
+nl_ea_register(void)
+{
+  EA_REGISTER_ALL(
+      &ea_krt_prefsrc,
+      &ea_krt_realm,
+      &ea_krt_scope
+      );
+
+  for (uint i = 0; i < KRT_METRICS_MAX; i++)
+  {
+    if (!ea_krt_metrics[i].name)
+      ea_krt_metrics[i] = (struct ea_class) {
+	.name = mb_sprintf(&root_pool, "krt_metric_%d", i),
+	.type = T_INT,
+      };
+
+    ea_register_init(&ea_krt_metrics[i]);
+  }
+
+  for (uint i = 1; i < KRT_METRICS_MAX; i++)
+    ASSERT_DIE(ea_krt_metrics[i].id == ea_krt_metrics[0].id + i);
+}
+
+
+
+/*
  *	Synchronous Netlink interface
  */
 
@@ -734,7 +830,7 @@ static void
 nl_add_multipath(struct nlmsghdr *h, uint bufsize, struct nexthop *nh, int af, ea_list *eattrs)
 {
   struct rtattr *a = nl_open_attr(h, bufsize, RTA_MULTIPATH);
-  eattr *flow = ea_find(eattrs, EA_KRT_REALM);
+  eattr *flow = ea_find(eattrs, &ea_krt_realm);
 
   for (; nh; nh = nh->next)
   {
@@ -1399,7 +1495,7 @@ nl_send_route(struct krt_proto *p, rte *e, int op, int dest, struct nexthop *nh)
     priority = 0;
   else if (KRT_CF->sys.metric)
     priority = KRT_CF->sys.metric;
-  else if ((op != NL_OP_DELETE) && (ea = ea_find(eattrs, EA_KRT_METRIC)))
+  else if ((op != NL_OP_DELETE) && (ea = ea_find(eattrs, &ea_krt_metric)))
     priority = ea->u.data;
 
   if (priority)
@@ -1412,15 +1508,15 @@ nl_send_route(struct krt_proto *p, rte *e, int op, int dest, struct nexthop *nh)
   /* Default scope is LINK for device routes, UNIVERSE otherwise */
   if (p->af == AF_MPLS)
     r->r.rtm_scope = RT_SCOPE_UNIVERSE;
-  else if (ea = ea_find(eattrs, EA_KRT_SCOPE))
+  else if (ea = ea_find(eattrs, &ea_krt_scope))
     r->r.rtm_scope = ea->u.data;
   else
     r->r.rtm_scope = (dest == RTD_UNICAST && ipa_zero(nh->gw)) ? RT_SCOPE_LINK : RT_SCOPE_UNIVERSE;
 
-  if (ea = ea_find(eattrs, EA_KRT_PREFSRC))
+  if (ea = ea_find(eattrs, &ea_krt_prefsrc))
     nl_add_attr_ipa(&r->h, rsize, RTA_PREFSRC, *(ip_addr *)ea->u.ptr->data);
 
-  if (ea = ea_find(eattrs, EA_KRT_REALM))
+  if (ea = ea_find(eattrs, &ea_krt_realm))
     nl_add_attr_u32(&r->h, rsize, RTA_FLOW, ea->u.data);
 
 
@@ -1428,9 +1524,9 @@ nl_send_route(struct krt_proto *p, rte *e, int op, int dest, struct nexthop *nh)
   metrics[0] = 0;
 
   struct ea_walk_state ews = { .eattrs = eattrs };
-  while (ea = ea_walk(&ews, EA_KRT_METRICS, KRT_METRICS_MAX))
+  while (ea = ea_walk(&ews, ea_krt_metrics[0].id, KRT_METRICS_MAX))
   {
-    int id = ea->id - EA_KRT_METRICS;
+    int id = ea->id - ea_krt_metrics[0].id;
     metrics[0] |= 1 << id;
     metrics[id] = ea->u.data;
   }
@@ -1581,21 +1677,15 @@ nl_announce_route(struct nl_parse_state *s)
   rte *e = rte_get_temp(s->attrs, s->proto->p.main_source);
   e->net = s->net;
 
-  EA_LOCAL_LIST(2) ea0 = {
+  EA_LOCAL_LIST(2) ea = {
     .l = { .count = 2, .next = e->attrs->eattrs },
-    .a[0] = (eattr) {
-      .id = EA_KRT_SOURCE,
-      .type = T_INT,
-      .u.data = s->krt_proto,
-    },
-    .a[1] = (eattr) {
-      .id = EA_KRT_METRIC,
-      .type = T_INT,
-      .u.data = s->krt_metric,
+    .a = {
+      EA_LITERAL_EMBEDDED(&ea_krt_source, 0, s->krt_proto),
+      EA_LITERAL_EMBEDDED(&ea_krt_metric, 0, s->krt_metric),
     },
   };
 
-  e->attrs->eattrs = &ea0.l;
+  e->attrs->eattrs = &ea.l;
 
   if (s->scan)
     krt_got_route(s->proto, e, s->krt_src);
@@ -1867,20 +1957,20 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
 
   if (i->rtm_scope != def_scope)
     ea_set_attr(&ra->eattrs,
-	EA_LITERAL_EMBEDDED(EA_KRT_SCOPE, T_INT, 0, i->rtm_scope));
+	EA_LITERAL_EMBEDDED(&ea_krt_scope, 0, i->rtm_scope));
 
   if (a[RTA_PREFSRC])
-    {
-      ip_addr ps = rta_get_ipa(a[RTA_PREFSRC]);
+  {
+    ip_addr ps = rta_get_ipa(a[RTA_PREFSRC]);
 
-      ea_set_attr(&ra->eattrs,
-	  EA_LITERAL_STORE_ADATA(EA_KRT_PREFSRC, T_IP, 0, &ps, sizeof(ps)));
-    }
+    ea_set_attr(&ra->eattrs,
+	EA_LITERAL_STORE_ADATA(&ea_krt_prefsrc, 0, &ps, sizeof(ps)));
+  }
 
   /* Can be set per-route or per-nexthop */
   if (s->rta_flow)
     ea_set_attr(&ra->eattrs,
-	EA_LITERAL_EMBEDDED(EA_KRT_REALM, T_INT, 0, s->rta_flow));
+	EA_LITERAL_EMBEDDED(&ea_krt_realm, 0, s->rta_flow));
 
   if (a[RTA_METRICS])
     {
@@ -1891,11 +1981,10 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
 	  return;
 	}
 
-      for (int t = 1; t < KRT_METRICS_MAX; t++)
+      for (uint t = 1; t < KRT_METRICS_MAX; t++)
 	if (metrics[0] & (1 << t))
 	  ea_set_attr(&ra->eattrs,
-	      EA_LITERAL_EMBEDDED(EA_CODE(PROTOCOL_KERNEL, KRT_METRICS_OFFSET + t),
-		T_INT, 0, metrics[t]));
+	      EA_LITERAL_EMBEDDED(&ea_krt_metrics[t], 0, metrics[t]));
     }
 
   /*
@@ -2133,6 +2222,8 @@ krt_sys_io_init(void)
 {
   nl_linpool = lp_new_default(krt_pool);
   HASH_INIT(nl_table_map, krt_pool, 6);
+
+  nl_ea_register();
 }
 
 int
@@ -2186,56 +2277,6 @@ krt_sys_copy_config(struct krt_config *d, struct krt_config *s)
   d->sys.metric = s->sys.metric;
 }
 
-static const char *krt_metrics_names[KRT_METRICS_MAX] = {
-  NULL, "lock", "mtu", "window", "rtt", "rttvar", "sstresh", "cwnd", "advmss",
-  "reordering", "hoplimit", "initcwnd", "features", "rto_min", "initrwnd", "quickack"
-};
-
-static const char *krt_features_names[KRT_FEATURES_MAX] = {
-  "ecn", NULL, NULL, "allfrag"
-};
-
-int
-krt_sys_get_attr(const eattr *a, byte *buf, int buflen UNUSED)
-{
-  switch (a->id)
-  {
-  case EA_KRT_PREFSRC:
-    bsprintf(buf, "prefsrc");
-    return GA_NAME;
-
-  case EA_KRT_REALM:
-    bsprintf(buf, "realm");
-    return GA_NAME;
-
-  case EA_KRT_SCOPE:
-    bsprintf(buf, "scope");
-    return GA_NAME;
-
-  case EA_KRT_LOCK:
-    buf += bsprintf(buf, "lock:");
-    ea_format_bitfield(a, buf, buflen, krt_metrics_names, 2, KRT_METRICS_MAX);
-    return GA_FULL;
-
-  case EA_KRT_FEATURES:
-    buf += bsprintf(buf, "features:");
-    ea_format_bitfield(a, buf, buflen, krt_features_names, 0, KRT_FEATURES_MAX);
-    return GA_FULL;
-
-  default:;
-    int id = (int)EA_ID(a->id) - KRT_METRICS_OFFSET;
-    if (id > 0 && id < KRT_METRICS_MAX)
-    {
-      bsprintf(buf, "%s", krt_metrics_names[id]);
-      return GA_NAME;
-    }
-
-    return GA_UNKNOWN;
-  }
-}
-
-
-
 void
 kif_sys_start(struct kif_proto *p UNUSED)
 {