fib: Decouple source from priority and behaviour

Type: feature

the fib_source_t enum alone no longer defines the priority and
behaviour, instead each source must be allocated these attributes.
This allows the creation of other sources by the plugins (and
soon over the API).

Signed-off-by: Neale Ranns <nranns@cisco.com>
Change-Id: I890ee820fbc16079ee417ea1fbc163192806e853

1 files changed, 222 insertions, 0 deletions

diff --git a/src/vnet/fib/fib_source.c b/src/vnet/fib/fib_source.c
new file mode 100644
index 00000000000..0aeecae545f
--- /dev/null
+++ b/src/vnet/fib/fib_source.c
@@ -0,0 +1,222 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vnet/fib/fib_source.h>
+
+static const char *fib_source_names[] = FIB_SOURCES;
+static const char *fib_source_behaviour_names[] = FIB_SOURCE_BEHAVIOURS;
+
+static fib_source_t fib_source_id = FIB_SOURCE_LAST+1;
+
+typedef struct fib_source_prio_t_
+{
+    fib_source_priority_t fsp_class;
+    fib_source_priority_t fsp_slot;
+} fib_source_prio_t;
+
+/**
+ * for each client requested priority count the number pf uses of
+ * that prio so we can asign is usage a slot number, and therefore
+ * each request will have a unique value.
+ */
+STATIC_ASSERT_SIZEOF(fib_source_priority_t, 1);
+static fib_source_priority_t fib_source_prio_by_class[0x100];
+
+typedef struct fib_source_reg_t_
+{
+    fib_source_t fsr_source;
+    const char *fsr_name;
+    fib_source_behaviour_t fsr_behaviour;
+    fib_source_prio_t fsr_prio;
+} fib_source_reg_t;
+
+static fib_source_reg_t *fib_source_regs;
+
+
+u16
+fib_source_get_prio (fib_source_t src)
+{
+    ASSERT(vec_len(fib_source_regs) > src);
+
+    return (((u16)fib_source_regs[src].fsr_prio.fsp_class << 8) |
+            fib_source_regs[src].fsr_prio.fsp_slot);
+}
+
+fib_source_behaviour_t
+fib_source_get_behaviour (fib_source_t src)
+{
+    ASSERT(vec_len(fib_source_regs) > src);
+
+    return (fib_source_regs[src].fsr_behaviour);
+}
+
+u8 *
+format_fib_source (u8 *s, va_list *a)
+{
+    fib_source_t src = va_arg(*a, int);
+
+    ASSERT(vec_len(fib_source_regs) > src);
+
+    return (format(s, "%s", fib_source_regs[src].fsr_name));
+}
+
+fib_source_priority_cmp_t
+fib_source_cmp (fib_source_t s1,
+                fib_source_t s2)
+{
+    if (fib_source_get_prio(s1) <
+        fib_source_get_prio(s2))
+    {
+        return (FIB_SOURCE_CMP_BETTER);
+    }
+    else if (fib_source_get_prio(s1) >
+             fib_source_get_prio(s2))
+    {
+        return (FIB_SOURCE_CMP_WORSE);
+    }
+    return (FIB_SOURCE_CMP_EQUAL);
+}
+
+static void
+fib_source_reg_init (fib_source_t src,
+                     const char *name,
+                     fib_source_priority_t prio,
+                     fib_source_behaviour_t bh)
+{
+    fib_source_priority_t slot;
+    fib_source_reg_t *fsr;
+
+    /*
+     * ensure we assign a unique priority to each request
+     * otherwise different source will be treated like ECMP
+     */
+    slot = fib_source_prio_by_class[prio]++;
+
+    vec_validate(fib_source_regs, src);
+
+    fsr = &fib_source_regs[src];
+    fsr->fsr_source = src;
+    fsr->fsr_name = strdup(name);
+    fsr->fsr_prio.fsp_class = prio;
+    fsr->fsr_prio.fsp_slot = slot;
+    fsr->fsr_behaviour = bh;
+}
+
+fib_source_t
+fib_source_allocate (const char *name,
+                     fib_source_priority_t prio,
+                     fib_source_behaviour_t bh)
+{
+    fib_source_t src;
+
+    // max value range
+    ASSERT(fib_source_id < 255);
+    if (fib_source_id == 255)
+        return (FIB_SOURCE_INVALID);
+
+    src = fib_source_id++;
+
+    fib_source_reg_init(src, name, prio, bh);
+
+    return (src);
+}
+
+void
+fib_source_register (fib_source_t src,
+                     fib_source_priority_t prio,
+                     fib_source_behaviour_t bh)
+{
+    fib_source_reg_init(src, fib_source_names[src], prio, bh);
+}
+
+static u8 *
+format_fib_source_reg (u8 *s, va_list *a)
+{
+    fib_source_reg_t *fsr = va_arg(*a, fib_source_reg_t*);
+
+    s = format(s, "[%d] %U prio:%d.%d behaviour:%s",
+               fsr->fsr_source,
+               format_fib_source, fsr->fsr_source,
+               fsr->fsr_prio.fsp_class, fsr->fsr_prio.fsp_slot,
+               fib_source_behaviour_names[fsr->fsr_behaviour]);
+
+    return (s);
+}
+
+static int
+fib_source_reg_cmp_for_sort (void * v1,
+                             void * v2)
+{
+    fib_source_reg_t *fsr1 = v1, *fsr2 = v2;
+
+    return (fib_source_get_prio(fsr1->fsr_source) -
+            fib_source_get_prio(fsr2->fsr_source));
+}
+
+void
+fib_source_walk (fib_source_walk_t fn,
+                 void *ctx)
+{
+    fib_source_reg_t *fsr;
+
+    vec_foreach(fsr, fib_source_regs)
+    {
+        if (WALK_STOP == fn(fsr->fsr_source,
+                            fsr->fsr_name,
+                            fsr->fsr_prio.fsp_class,
+                            fsr->fsr_behaviour,
+                            ctx))
+            break;
+    }
+}
+
+static clib_error_t *
+fib_source_show (vlib_main_t * vm,
+		 unformat_input_t * input,
+		 vlib_cli_command_t * cmd)
+{
+    fib_source_reg_t *fsr, *fsrs;
+
+    fsrs = vec_dup(fib_source_regs);
+
+    while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+    {
+	if (unformat (input, "prio")   ||
+	    unformat (input, "priority"))
+            vec_sort_with_function(fsrs, fib_source_reg_cmp_for_sort);
+    }
+    vec_foreach(fsr, fsrs)
+    {
+        vlib_cli_output(vm, "%U", format_fib_source_reg, fsr);
+    }
+    vec_free(fsrs);
+
+    return (NULL);
+}
+
+VLIB_CLI_COMMAND (show_fib_sources, static) = {
+    .path = "show fib source",
+    .function = fib_source_show,
+    .short_help = "show fib source [prio]",
+};
+
+
+void
+fib_source_module_init (void)
+{
+#define _(s,p,b) fib_source_register(s,p,b);
+    foreach_fib_source
+#undef _
+}