zebra/zebra_dplane.h

   1 /*
   2  * Zebra dataplane layer api interfaces.
   3  * Copyright (c) 2018 Volta Networks, Inc.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; see the file COPYING; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 #ifndef _ZEBRA_DPLANE_H
  21 #define _ZEBRA_DPLANE_H 1
  22
  23 #include "lib/zebra.h"
  24 #include "lib/prefix.h"
  25 #include "lib/nexthop.h"
  26 #include "lib/nexthop_group.h"
  27 #include "lib/openbsd-queue.h"
  28 #include "zebra/zebra_ns.h"
  29 #include "zebra/rib.h"
  30 #include "zebra/zserv.h"
  31
  32 /* Key netlink info from zebra ns */
  33 struct zebra_dplane_info {
  34         ns_id_t ns_id;
  35
  36 #if defined(HAVE_NETLINK)
  37         struct nlsock nls;
  38         bool is_cmd;
  39 #endif
  40 };
  41
  42 /* Utility to fill in zns info from main zns struct */
  43 static inline void
  44 zebra_dplane_info_from_zns(struct zebra_dplane_info *zns_info,
  45                            const struct zebra_ns *zns, bool is_cmd)
  46 {
  47         zns_info->ns_id = zns->ns_id;
  48
  49 #if defined(HAVE_NETLINK)
  50         zns_info->is_cmd = is_cmd;
  51         if (is_cmd) {
  52                 zns_info->nls = zns->netlink_cmd;
  53         } else {
  54                 zns_info->nls = zns->netlink;
  55         }
  56 #endif /* NETLINK */
  57 }
  58
  59 /*
  60  * Result codes used when returning status back to the main zebra context.
  61  */
  62
  63 /*
  64  * Philosophy Note:
  65  *
  66  * Flags being SET/UNSET do not belong in the South Bound
  67  * Interface.  This Setting belongs at the calling level
  68  * because we can and will have multiple different interfaces
  69  * and we will have potentially multiple different
  70  * modules/filters to call.  As such Setting/Unsetting
  71  * success failure should be handled by the caller.
  72  */
  73 enum zebra_dplane_status {
  74         ZEBRA_DPLANE_STATUS_NONE = 0,
  75         ZEBRA_DPLANE_INSTALL_SUCCESS,
  76         ZEBRA_DPLANE_INSTALL_FAILURE,
  77         ZEBRA_DPLANE_DELETE_SUCCESS,
  78         ZEBRA_DPLANE_DELETE_FAILURE,
  79
  80 };
  81
  82 enum zebra_dplane_result {
  83         ZEBRA_DPLANE_REQUEST_QUEUED,
  84         ZEBRA_DPLANE_REQUEST_SUCCESS,
  85         ZEBRA_DPLANE_REQUEST_FAILURE,
  86 };
  87
  88 /*
  89  * API between the zebra dataplane system and the main zebra processing
  90  * context.
  91  */
  92
  93 /*
  94  * Enqueue a route install or update for the dataplane.
  95  */
  96 enum dplane_op_e {
  97         DPLANE_OP_NONE = 0,
  98
  99         /* Route update */
 100         DPLANE_OP_ROUTE_INSTALL,
 101         DPLANE_OP_ROUTE_UPDATE,
 102         DPLANE_OP_ROUTE_DELETE,
 103
 104 };
 105
 106 /*
 107  * The dataplane context struct is used to exchange info between the main zebra
 108  * context and the dataplane module(s). If these are two independent pthreads,
 109  * they cannot share existing global data structures safely.
 110  */
 111
 112 /* Define a tailq list type for context blocks. The list is exposed/public,
 113  * but the internal linkage in the context struct is private, so there
 114  * are accessor apis that support enqueue and dequeue.
 115  */
 116 TAILQ_HEAD(dplane_ctx_q, zebra_dplane_ctx);
 117
 118 /* Return a dataplane results context block after use; the caller's pointer will
 119  * be cleared.
 120  */
 121 void dplane_ctx_fini(struct zebra_dplane_ctx **pctx);
 122
 123 /* Enqueue a context block to caller's tailq. This exists so that the
 124  * context struct can remain opaque.
 125  */
 126 void dplane_ctx_enqueue_tail(struct dplane_ctx_q *q,
 127                              const struct zebra_dplane_ctx *ctx);
 128
 129 /* Append a list of context blocks to another list - again, just keeping
 130  * the context struct opaque.
 131  */
 132 void dplane_ctx_list_append(struct dplane_ctx_q *to_list,
 133                             struct dplane_ctx_q *from_list);
 134
 135 /* Dequeue a context block from the head of caller's tailq */
 136 struct zebra_dplane_ctx *dplane_ctx_dequeue(struct dplane_ctx_q *q);
 137
 138 /*
 139  * Accessors for information from the context object
 140  */
 141 enum zebra_dplane_result dplane_ctx_get_status(
 142         const struct zebra_dplane_ctx *ctx);
 143 void dplane_ctx_set_status(struct zebra_dplane_ctx *ctx,
 144                            enum zebra_dplane_result status);
 145 const char *dplane_res2str(enum zebra_dplane_result res);
 146
 147 enum dplane_op_e dplane_ctx_get_op(const struct zebra_dplane_ctx *ctx);
 148 const char *dplane_op2str(enum dplane_op_e op);
 149
 150 const struct prefix *dplane_ctx_get_dest(const struct zebra_dplane_ctx *ctx);
 151
 152 /* Retrieve last/current provider id */
 153 uint32_t dplane_ctx_get_provider(const struct zebra_dplane_ctx *ctx);
 154
 155 /* Providers running before the kernel can control whether a kernel
 156  * update should be done.
 157  */
 158 void dplane_ctx_set_skip_kernel(struct zebra_dplane_ctx *ctx);
 159 bool dplane_ctx_is_skip_kernel(const struct zebra_dplane_ctx *ctx);
 160
 161 /* Source prefix is a little special - use convention to return NULL
 162  * to mean "no src prefix"
 163  */
 164 const struct prefix *dplane_ctx_get_src(const struct zebra_dplane_ctx *ctx);
 165
 166 bool dplane_ctx_is_update(const struct zebra_dplane_ctx *ctx);
 167 uint32_t dplane_ctx_get_seq(const struct zebra_dplane_ctx *ctx);
 168 uint32_t dplane_ctx_get_old_seq(const struct zebra_dplane_ctx *ctx);
 169 vrf_id_t dplane_ctx_get_vrf(const struct zebra_dplane_ctx *ctx);
 170 int dplane_ctx_get_type(const struct zebra_dplane_ctx *ctx);
 171 int dplane_ctx_get_old_type(const struct zebra_dplane_ctx *ctx);
 172 afi_t dplane_ctx_get_afi(const struct zebra_dplane_ctx *ctx);
 173 safi_t dplane_ctx_get_safi(const struct zebra_dplane_ctx *ctx);
 174 uint32_t dplane_ctx_get_table(const struct zebra_dplane_ctx *ctx);
 175 route_tag_t dplane_ctx_get_tag(const struct zebra_dplane_ctx *ctx);
 176 route_tag_t dplane_ctx_get_old_tag(const struct zebra_dplane_ctx *ctx);
 177 uint16_t dplane_ctx_get_instance(const struct zebra_dplane_ctx *ctx);
 178 uint16_t dplane_ctx_get_old_instance(const struct zebra_dplane_ctx *ctx);
 179 uint32_t dplane_ctx_get_metric(const struct zebra_dplane_ctx *ctx);
 180 uint32_t dplane_ctx_get_old_metric(const struct zebra_dplane_ctx *ctx);
 181 uint32_t dplane_ctx_get_mtu(const struct zebra_dplane_ctx *ctx);
 182 uint32_t dplane_ctx_get_nh_mtu(const struct zebra_dplane_ctx *ctx);
 183 uint8_t dplane_ctx_get_distance(const struct zebra_dplane_ctx *ctx);
 184 uint8_t dplane_ctx_get_old_distance(const struct zebra_dplane_ctx *ctx);
 185
 186 const struct nexthop_group *dplane_ctx_get_ng(
 187         const struct zebra_dplane_ctx *ctx);
 188 const struct nexthop_group *dplane_ctx_get_old_ng(
 189         const struct zebra_dplane_ctx *ctx);
 190
 191 const struct zebra_dplane_info *dplane_ctx_get_ns(
 192         const struct zebra_dplane_ctx *ctx);
 193
 194 /* Indicates zebra shutdown/exit is in progress. Some operations may be
 195  * simplified or skipped during shutdown processing.
 196  */
 197 bool dplane_is_in_shutdown(void);
 198
 199 /*
 200  * Enqueue route change operations for the dataplane.
 201  */
 202 enum zebra_dplane_result dplane_route_add(struct route_node *rn,
 203                                           struct route_entry *re);
 204
 205 enum zebra_dplane_result dplane_route_update(struct route_node *rn,
 206                                              struct route_entry *re,
 207                                              struct route_entry *old_re);
 208
 209 enum zebra_dplane_result dplane_route_delete(struct route_node *rn,
 210                                              struct route_entry *re);
 211
 212 /* Retrieve the limit on the number of pending, unprocessed updates. */
 213 uint32_t dplane_get_in_queue_limit(void);
 214
 215 /* Configure limit on the number of pending, queued updates. If 'unset', reset
 216  * to default value.
 217  */
 218 void dplane_set_in_queue_limit(uint32_t limit, bool set);
 219
 220 /* Retrieve the current queue depth of incoming, unprocessed updates */
 221 uint32_t dplane_get_in_queue_len(void);
 222
 223 /*
 224  * Vty/cli apis
 225  */
 226 int dplane_show_helper(struct vty *vty, bool detailed);
 227 int dplane_show_provs_helper(struct vty *vty, bool detailed);
 228
 229
 230 /*
 231  * Dataplane providers: modules that process or consume dataplane events.
 232  */
 233
 234 struct zebra_dplane_provider;
 235
 236 /* Support string name for a dataplane provider */
 237 #define DPLANE_PROVIDER_NAMELEN 64
 238
 239 /* Priority or ordering values for providers. The idea is that there may be
 240  * some pre-processing, followed by an external or remote dataplane,
 241  * followed by the kernel, followed by some post-processing step (such as
 242  * the fpm output stream.)
 243  */
 244 enum dplane_provider_prio {
 245         DPLANE_PRIO_NONE = 0,
 246         DPLANE_PRIO_PREPROCESS,
 247         DPLANE_PRIO_PRE_KERNEL,
 248         DPLANE_PRIO_KERNEL,
 249         DPLANE_PRIO_POSTPROCESS,
 250         DPLANE_PRIO_LAST
 251 };
 252
 253 /* Provider's entry-point for incoming work, called in the context of the
 254  * dataplane pthread. The dataplane pthread enqueues any new work to the
 255  * provider's 'inbound' queue, then calls the callback. The dataplane
 256  * then checks the provider's outbound queue.
 257  */
 258 typedef int (*dplane_provider_process_fp)(struct zebra_dplane_provider *prov);
 259
 260 /* Provider's entry-point for shutdown and cleanup. Called with 'early'
 261  * during shutdown, to indicate that the dataplane subsystem is allowing
 262  * work to move through the providers and finish. When called without 'early',
 263  * the provider should release all resources (if it has any allocated).
 264  */
 265 typedef int (*dplane_provider_fini_fp)(struct zebra_dplane_provider *prov,
 266                                        bool early);
 267
 268 /* Flags values used during provider registration. */
 269 #define DPLANE_PROV_FLAGS_DEFAULT  0x0
 270
 271 /* Provider will be spawning its own worker thread */
 272 #define DPLANE_PROV_FLAG_THREADED  0x1
 273
 274
 275 /* Provider registration: ordering or priority value, callbacks, and optional
 276  * opaque data value.
 277  */
 278 int dplane_provider_register(const char *name,
 279                              enum dplane_provider_prio prio,
 280                              int flags,
 281                              dplane_provider_process_fp fp,
 282                              dplane_provider_fini_fp fini_fp,
 283                              void *data);
 284
 285 /* Accessors for provider attributes */
 286 const char *dplane_provider_get_name(const struct zebra_dplane_provider *prov);
 287 uint32_t dplane_provider_get_id(const struct zebra_dplane_provider *prov);
 288 void *dplane_provider_get_data(const struct zebra_dplane_provider *prov);
 289 bool dplane_provider_is_threaded(const struct zebra_dplane_provider *prov);
 290
 291 /* Lock/unlock a provider's mutex - iff the provider was registered with
 292  * the THREADED flag.
 293  */
 294 void dplane_provider_lock(struct zebra_dplane_provider *prov);
 295 void dplane_provider_unlock(struct zebra_dplane_provider *prov);
 296
 297 /* Obtain thread_master for dataplane thread */
 298 struct thread_master *dplane_get_thread_master(void);
 299
 300 /* Providers should (generally) limit number of updates per work cycle */
 301 int dplane_provider_get_work_limit(const struct zebra_dplane_provider *prov);
 302
 303 /* Provider api to signal that work/events are available
 304  * for the dataplane pthread.
 305  */
 306 int dplane_provider_work_ready(void);
 307
 308 /* Dequeue, maintain associated counter and locking */
 309 struct zebra_dplane_ctx *dplane_provider_dequeue_in_ctx(
 310         struct zebra_dplane_provider *prov);
 311
 312 /* Dequeue work to a list, maintain counter and locking, return count */
 313 int dplane_provider_dequeue_in_list(struct zebra_dplane_provider *prov,
 314                                     struct dplane_ctx_q *listp);
 315
 316 /* Enqueue, maintain associated counter and locking */
 317 void dplane_provider_enqueue_out_ctx(struct zebra_dplane_provider *prov,
 318                                      struct zebra_dplane_ctx *ctx);
 319
 320 /*
 321  * Zebra registers a results callback with the dataplane. The callback is
 322  * called in the dataplane pthread context, so the expectation is that the
 323  * context is queued for the zebra main pthread or that processing
 324  * is very limited.
 325  */
 326 typedef int (*dplane_results_fp)(struct zebra_dplane_ctx *ctx);
 327
 328 int dplane_results_register(dplane_results_fp fp);
 329
 330 /*
 331  * Initialize the dataplane modules at zebra startup. This is currently called
 332  * by the rib module.
 333  */
 334 void zebra_dplane_init(void);
 335
 336 /*
 337  * Start the dataplane pthread. This step needs to be run later than the
 338  * 'init' step, in case zebra has fork-ed.
 339  */
 340 void zebra_dplane_start(void);
 341
 342 /* Finalize/cleanup apis, one called early as shutdown is starting,
 343  * one called late at the end of zebra shutdown, and then one called
 344  * from the zebra main pthread to stop the dplane pthread and
 345  * free all resources.
 346  *
 347  * Zebra expects to try to clean up all vrfs and all routes during
 348  * shutdown, so the dplane must be available until very late.
 349  */
 350 void zebra_dplane_pre_finish(void);
 351 void zebra_dplane_finish(void);
 352 void zebra_dplane_shutdown(void);
 353
 354 #endif  /* _ZEBRA_DPLANE_H */