From 29b721217b7beb4137d2e96fcc2797e9b9705df5 Mon Sep 17 00:00:00 2001
From: Maria Matejka <mq@ucw.cz>
Date: Wed, 18 Dec 2024 12:24:49 +0100
Subject: [PATCH] CLI: v2 compatibility mode for attribute name display

---
 doc/bird.sgml        | 21 +++++++++++++++------
 nest/cli.c           |  2 ++
 nest/cli.h           |  2 ++
 nest/rt-attr.c       | 25 ++++++++++++++++++++++++-
 sysdep/unix/config.Y |  1 +
 5 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/doc/bird.sgml b/doc/bird.sgml
index 09f711a9..2d9d57f4 100644
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -1293,16 +1293,25 @@ connects to it. If changed on the command line by the <tt/-s/ option,
 BIRD or the CLI tool connects there instead.
 
 <p>It's also possible to configure additional remote control sockets in the
-configuration file by <cf/cli "name";/ and you can open how many
+configuration file by <cf/cli "name" { <m/options/ };/ and you can open how many
 sockets you wish. There are no checks whether the user configured the same
 socket multiple times and BIRD may behave weirdly if this happens. On shutdown,
 the additional sockets get removed immediately and only the main socket stays
-until the very end.
+until the very end. If there are no options, the braces may be omitted.
 
-<p>The remote control socket can be also set as restricted by
-<cf/cli "name" { restrict; };/ instead of sending the <cf/restrict/ command
-after connecting. The user may still overload the daemon by requesting insanely
-complex filters so you shouldn't expose this socket to public anyway.
+<p>Options:
+
+<descrip>
+	<tag><label id="cli-conf-restrict">restrict</tag>
+	Set the socket to be restricted as if the user always sent the
+	<cf/restrict/ command after connecting. The user may still overload
+	the daemon by requesting insanely complex filters so you shouldn't
+	expose this socket to public even if restricted.
+
+	<tag><label id="cli-conf-v2mode">v2mode</tag>
+	Display the names of route attributes the same way as BIRD 2 does.
+	This is a compatibility option for easier transition from BIRD 2 to BIRD 3.
+</descrip>
 
 <sect>Usage
 <label id="remote-control-usage">
diff --git a/nest/cli.c b/nest/cli.c
index 3b8e6f46..da2ecea3 100644
--- a/nest/cli.c
+++ b/nest/cli.c
@@ -287,6 +287,8 @@ cli_new(struct birdsock *sock, struct cli_config *cf)
   if (cf->restricted)
     c->restricted = 1;
 
+  c->v2mode = cf->v2mode;
+
   ev_schedule(c->event);
   return c;
 }
diff --git a/nest/cli.h b/nest/cli.h
index d86ec380..4be3f390 100644
--- a/nest/cli.h
+++ b/nest/cli.h
@@ -44,6 +44,7 @@ typedef struct cli {
   struct config *main_config;		/* Main config currently in use */
   int last_reply;
   int restricted;			/* CLI is restricted to read-only commands */
+  bool v2mode;				/* CLI outputs are mimicking BIRD 2 */
   struct timeformat *tf;		/* Time format override */
   struct linpool *parser_pool;		/* Pool used during parsing */
   uint log_mask;			/* Mask of allowed message levels */
@@ -63,6 +64,7 @@ struct cli_config {
   struct config *config;
   uint uid, gid, mode;
   _Bool restricted;
+  _Bool v2mode;
 };
 #include "lib/tlists.h"
 
diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index a0f7d571..0dd1311f 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -1347,7 +1347,30 @@ ea_show(struct cli *c, const eattr *e)
 	  bsprintf(pos, "<type %02x>", e->type);
       }
 
-  cli_printf(c, -1012, "\t%s: %s", cls->name, buf);
+  const char *name = cls->name;
+  char v2n[64];
+
+  if (c->v2mode && !cls->conf)
+    if (strcmp(cls->name, "bgp_path") == 0)
+      name = "BGP.as_path";
+    else
+    {
+      strncpy(v2n, name, sizeof v2n - 1);
+      for (char *p = &v2n[0]; *p; p++)
+	if (*p == '_')
+	{
+	  *p = '.';
+	  break;
+	}
+	else
+	{
+	  ASSERT_DIE((*p >= 'a') && (*p <= 'z'));
+	  *p -= 'a' - 'A';
+	}
+      name = &v2n;
+    }
+
+  cli_printf(c, -1012, "\t%s: %s", name, buf);
 }
 
 static void
diff --git a/sysdep/unix/config.Y b/sysdep/unix/config.Y
index 42d78c6f..5d161985 100644
--- a/sysdep/unix/config.Y
+++ b/sysdep/unix/config.Y
@@ -143,6 +143,7 @@ cli_opts_begin: {
 cli_opts_block:
   /* EMPTY */ |
   cli_opts_block RESTRICT { this_cli_config->restricted = 1; }
+  cli_opts_block V2 MODE { this_cli_config->v2mode = 1; }
 ;
 
 conf: THREADS expr {