[Nexthop][fboss2-dev] fboss2 bgp policy prefix-list entry subcommand

cmake/CliFboss2.cmake

@@ -984,6 +984,8 @@ add_library(fboss2_config_lib
   fboss/cli/fboss2/commands/config/protocol/bgp/policy/prefix-list/BgpPrefixListCliUtils.h
   fboss/cli/fboss2/commands/config/protocol/bgp/policy/prefix-list/CmdConfigProtocolBgpPolicyPrefixList.cpp
   fboss/cli/fboss2/commands/config/protocol/bgp/policy/prefix-list/CmdConfigProtocolBgpPolicyPrefixList.h
+  fboss/cli/fboss2/commands/config/protocol/bgp/policy/prefix-list/entry/CmdConfigProtocolBgpPolicyPrefixListEntry.cpp
+  fboss/cli/fboss2/commands/config/protocol/bgp/policy/prefix-list/entry/CmdConfigProtocolBgpPolicyPrefixListEntry.h
   fboss/cli/fboss2/commands/config/ptp/CmdConfigPtp.cpp
   fboss/cli/fboss2/commands/config/ptp/CmdConfigPtp.h
   fboss/cli/fboss2/commands/config/ptp/transparent_clock/CmdConfigPtpTransparentClock.cpp

cmake/CliFboss2TestConfig.cmake

@@ -17,6 +17,7 @@ add_executable(fboss2_cmd_config_test
   fboss/cli/fboss2/test/config/CmdConfigBgpPolicyAsPathListTest.cpp
   fboss/cli/fboss2/test/config/CmdConfigBgpPolicyCommunityListTest.cpp
   fboss/cli/fboss2/test/config/CmdConfigBgpPolicyPrefixListTest.cpp
+  fboss/cli/fboss2/test/config/CmdConfigBgpPolicyPrefixListEntryTest.cpp
   fboss/cli/fboss2/test/config/CmdConfigCoppTest.cpp
   fboss/cli/fboss2/test/config/CmdConfigDataPlaneTrafficPolicyTest.cpp
   fboss/cli/fboss2/test/config/CmdConfigDhcpTest.cpp

cmake/CliFboss2TestIntegrationTest.cmake

@@ -21,6 +21,7 @@ add_executable(fboss2_integration_test
   fboss/cli/fboss2/test/integration_test/ConfigBgpPolicyAsPathListTest.cpp
   fboss/cli/fboss2/test/integration_test/ConfigBgpPolicyCommunityListTest.cpp
   fboss/cli/fboss2/test/integration_test/ConfigBgpPolicyPrefixListTest.cpp
+  fboss/cli/fboss2/test/integration_test/ConfigBgpPolicyPrefixListEntryTest.cpp
   fboss/cli/fboss2/test/integration_test/ConfigBgpSessionTest.cpp
   fboss/cli/fboss2/test/integration_test/ConfigConcurrentSessionsTest.cpp
   fboss/cli/fboss2/test/integration_test/ConfigHostnameTest.cpp

fboss/cli/fboss2/BUCK

@@ -1218,6 +1218,7 @@ cpp_library(
         "commands/config/protocol/bgp/policy/as-path-list/CmdConfigProtocolBgpPolicyAsPathList.cpp",
         "commands/config/protocol/bgp/policy/community-list/CmdConfigProtocolBgpPolicyCommunityList.cpp",
         "commands/config/protocol/bgp/policy/prefix-list/CmdConfigProtocolBgpPolicyPrefixList.cpp",
+        "commands/config/protocol/bgp/policy/prefix-list/entry/CmdConfigProtocolBgpPolicyPrefixListEntry.cpp",
         "commands/config/protocol/static/CmdConfigProtocolStatic.cpp",
         "commands/config/protocol/static/route/add/CmdConfigProtocolStaticRouteAdd.cpp",
         "commands/config/ptp/CmdConfigPtp.cpp",
@@ -1370,6 +1371,7 @@ cpp_library(
         "commands/config/protocol/bgp/policy/community-list/CmdConfigProtocolBgpPolicyCommunityList.h",
         "commands/config/protocol/bgp/policy/prefix-list/BgpPrefixListCliUtils.h",
         "commands/config/protocol/bgp/policy/prefix-list/CmdConfigProtocolBgpPolicyPrefixList.h",
+        "commands/config/protocol/bgp/policy/prefix-list/entry/CmdConfigProtocolBgpPolicyPrefixListEntry.h",
         "commands/config/protocol/static/CmdConfigProtocolStatic.h",
         "commands/config/protocol/static/route/StaticRouteUtils.h",
         "commands/config/protocol/static/route/add/CmdConfigProtocolStaticRouteAdd.h",

fboss/cli/fboss2/CmdListConfig.cpp

@@ -46,6 +46,7 @@
 #include "fboss/cli/fboss2/commands/config/protocol/bgp/policy/as-path-list/CmdConfigProtocolBgpPolicyAsPathList.h"
 #include "fboss/cli/fboss2/commands/config/protocol/bgp/policy/community-list/CmdConfigProtocolBgpPolicyCommunityList.h"
 #include "fboss/cli/fboss2/commands/config/protocol/bgp/policy/prefix-list/CmdConfigProtocolBgpPolicyPrefixList.h"
+#include "fboss/cli/fboss2/commands/config/protocol/bgp/policy/prefix-list/entry/CmdConfigProtocolBgpPolicyPrefixListEntry.h"
 #include "fboss/cli/fboss2/commands/config/protocol/static/CmdConfigProtocolStatic.h"
 #include "fboss/cli/fboss2/commands/config/protocol/static/route/add/CmdConfigProtocolStaticRouteAdd.h"
 #include "fboss/cli/fboss2/commands/config/ptp/CmdConfigPtp.h"
@@ -457,6 +458,18 @@ const CommandTree& kConfigCommandTree() {
                                    CmdConfigProtocolBgpPolicyPrefixList>,
                                argRegistrar<
                                    CmdConfigProtocolBgpPolicyPrefixListTraits>,
+                               {{
+                                   "prefix",
+                                   "Configure a prefix-list entry: "
+                                   "<prefix/len> [<attribute> <value> ...] "
+                                   "(communities, description, match-logic, "
+                                   "max-allowed-subnet-count, "
+                                   "prefix-len-range, regex)",
+                                   commandHandler<
+                                       CmdConfigProtocolBgpPolicyPrefixListEntry>,
+                                   argRegistrar<
+                                       CmdConfigProtocolBgpPolicyPrefixListEntryTraits>,
+                               }},
                            }},
                       },
                   },
@@ -824,7 +837,8 @@ const CommandTree& kConfigCommandTree() {
                      },
                      {
                          "prefix-list",
-                         "Delete a BGP prefix-list: <name>",
+                         "Delete a BGP prefix-list, or one of its "
+                         "entries: <name> [prefix <prefix/len>]",
                          commandHandler<CmdDeleteProtocolBgpPolicyPrefixList>,
                          argRegistrar<
                              CmdDeleteProtocolBgpPolicyPrefixListTraits>,

fboss/cli/fboss2/commands/config/protocol/bgp/policy/prefix-list/BgpPrefixListCliUtils.h

@@ -10,6 +10,7 @@
 
 #pragma once
 
+#include <folly/IPAddress.h>
 #include <algorithm>
 #include <string>
 
@@ -22,10 +23,11 @@
 
 /**
  * Lookup/create helpers for the prefix-list CLI family, shared between the
- * list-level dispatcher (CmdConfigProtocolBgpPolicyPrefixList) and its delete
- * counterpart. A PrefixList is keyed by name. Entry helpers arrive with the
- * entry subcommand, which decides the entry's identity (bgpd rejects a
- * PrefixListEntry carrying seq_num).
+ * list-level dispatcher (CmdConfigProtocolBgpPolicyPrefixList), the prefix
+ * subcommand (CmdConfigProtocolBgpPolicyPrefixListEntry), and the delete
+ * counterparts. A PrefixList is keyed by name; a PrefixListEntry (in
+ * prefixes[]) is keyed by base_prefix, the only identity bgpd keeps (it
+ * merges entries by prefix and rejects seq_num).
  */
 namespace facebook::fboss::bgpcli {
 
@@ -60,4 +62,39 @@ inline bgp::routing_policy::PrefixList& findOrCreatePrefixList(
   return list;
 }
 
+// A prefix with an explicit /len, as every entry key must be. folly fills in
+// a default mask for a bare address, so the slash is checked separately. The
+// string is stored as typed, not normalized.
+inline bool isPrefixWithLength(const std::string& s) {
+  return s.find('/') != std::string::npos &&
+      !folly::IPAddress::tryCreateNetwork(s).hasError();
+}
+
+inline bool prefixListEntryExists(
+    const bgp::routing_policy::PrefixList& list,
+    const std::string& basePrefix) {
+  const auto& entries = *list.prefixes();
+  return std::any_of(entries.begin(), entries.end(), [&](const auto& entry) {
+    return *entry.base_prefix() == basePrefix;
+  });
+}
+
+// Find the entry keyed by base_prefix within a list's prefixes[], creating it
+// if absent. bgpd merges entries that share a base_prefix, so one entry per
+// prefix is the only shape the CLI needs to address.
+inline bgp::routing_policy::PrefixListEntry& findOrCreatePrefixListEntry(
+    bgp::routing_policy::PrefixList& list,
+    const std::string& basePrefix) {
+  auto& entries = *list.prefixes();
+  for (auto& entry : entries) {
+    if (*entry.base_prefix() == basePrefix) {
+      return entry;
+    }
+  }
+  entries.emplace_back();
+  auto& entry = entries.back();
+  entry.base_prefix() = basePrefix;
+  return entry;
+}
+
 } // namespace facebook::fboss::bgpcli

fboss/cli/fboss2/commands/config/protocol/bgp/policy/prefix-list/CmdConfigProtocolBgpPolicyPrefixList.h

@@ -61,7 +61,7 @@ struct CmdConfigProtocolBgpPolicyPrefixListTraits : public WriteCommandTraits {
   using ParentCmd = CmdConfigProtocolBgpPolicy;
   static void addCliArg(CLI::App& cmd, std::vector<std::string>& args) {
     // No positionals_at_end() here: CLI11 must stay free to classify the
-    // `entry` token as this command's subcommand rather than swallowing it
+    // `prefix` token as this command's subcommand rather than swallowing it
     // into args. See CmdConfigProtocolBgpPolicyAsPathListTraits.
     cmd.add_option("args", args, "<name> [<attribute> <value> ...]");
   }