aboutsummaryrefslogtreecommitdiffstats
path: root/netlink/librtnl/rtnl.c
blob: fa316177aaf8f4ed29359f70cfba580d8ccff640 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
/*
 * 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.
 */

#define _GNU_SOURCE
#include <sched.h>

#include <librtnl/rtnl.h>
#include <librtnl/netns.h>

#include <vlib/vlib.h>
#include <vlib/unix/unix.h>
#include <vppinfra/error.h>

#include <sys/socket.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <float.h>
#include <fcntl.h>

#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>

#undef DBL_MAX
#define DBL_MAX 1000000000.0

typedef enum {
  RTNL_E_OPEN,
  RTNL_E_CLOSE,
  RTNL_E_READ,
} rtnl_event_t;

typedef enum {
  RTNL_S_INIT,
  RTNL_S_SYNC,
  RTNL_S_READY,
} rtnl_state_t;

typedef enum {
  RTNL_SS_OPENING,
  RTNL_SS_LINK,
  RTNL_SS_ADDR,
  RTNL_SS_ROUTE4,
  RTNL_SS_ROUTE6,
  RTNL_SS_NEIGH,
} rtnl_sync_state_t;

typedef struct {
  rtnl_stream_t stream;
  rtnl_state_t state;
  rtnl_sync_state_t sync_state;
  int ns_fd;
  int rtnl_socket;
  u32 unix_index;
  u32 rtnl_seq;
  f64 timeout;
} rtnl_ns_t;

typedef struct {
  f64 now;
  rtnl_ns_t *streams;
} rtnl_main_t;

static rtnl_main_t rtnl_main;
static vlib_node_registration_t rtnl_process_node;

#define RTNL_BUFFSIZ 16384
#define RTNL_DUMP_TIMEOUT 1

u8 *format_rtnl_nsname2path(u8 *s, va_list *args)
{
  char *nsname = va_arg(*args, char *);
  if (!nsname || !strlen(nsname)) {
    return format(s, "/proc/self/ns/net");
  } else if (strpbrk(nsname, "/") != NULL) {
    return format(s, "%s", nsname);
  } else {
    return format(s, "/var/run/netns/%s", nsname);
  }
}

static_always_inline void
rtnl_schedule_timeout(rtnl_ns_t *ns, f64 when)
{
  ns->timeout = when;
}

static_always_inline void
rtnl_cancel_timeout(rtnl_ns_t *ns)
{
  ns->timeout = DBL_MAX;
}

static clib_error_t *rtnl_read_cb(struct clib_file * f)
{
  rtnl_main_t *rm = &rtnl_main;
  vlib_main_t *vm = vlib_get_main();
  rtnl_ns_t *ns = &rm->streams[f->private_data];
  vlib_process_signal_event(vm, rtnl_process_node.index, RTNL_E_READ, (uword)(ns - rm->streams));
  return 0;
}

int rtnl_dump_request(rtnl_ns_t *ns, int type, void *req, size_t len)
{
  struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
  struct nlmsghdr nlh = {
      .nlmsg_len = NLMSG_LENGTH(len),
      .nlmsg_type = type,
      .nlmsg_flags = NLM_F_DUMP|NLM_F_REQUEST,
      .nlmsg_pid = 0,
      .nlmsg_seq = ++ns->rtnl_seq,
  };
  struct iovec iov[2] = {
      { .iov_base = &nlh, .iov_len = sizeof(nlh) },
      { .iov_base = req, .iov_len = len }
  };
  struct msghdr msg = {
      .msg_name = &nladdr,
      .msg_namelen =  sizeof(nladdr),
      .msg_iov = iov,
      .msg_iovlen = 2,
  };
  if(sendmsg(ns->rtnl_socket, &msg, 0) < 0)
    return -1;
  return 0;
}

static void rtnl_socket_close(rtnl_ns_t *ns)
{
  clib_file_del(&file_main, &file_main.file_pool[ns->unix_index]);
  close(ns->rtnl_socket);
}

struct rtnl_thread_exec {
  int fd;
  void *(*fn)(void *);
  void *arg;
  void **ret;
};

static void *rtnl_exec_in_thread_fn(void *p)
{
  struct rtnl_thread_exec *ex = (struct rtnl_thread_exec *) p;
  if (setns(ex->fd, 0))
    return (void *) ((uword) (-errno));

  *ex->ret = ex->fn(ex->arg);
  return NULL;
}

static int rtnl_exec_in_namespace_byfd(int fd, void *(*fn)(void *), void *arg, void **ret)
{
  pthread_t thread;
  void *thread_ret;
  struct rtnl_thread_exec ex = {
      .fd = fd,
      .fn = fn,
      .arg = arg,
      .ret = ret
  };
  if(pthread_create(&thread, NULL, rtnl_exec_in_thread_fn, &ex))
    return -errno;

  if(pthread_join(thread, &thread_ret))
    return -errno;

  if (thread_ret)
    return (int) ((uword)thread_ret);

  return 0;
}

int rtnl_exec_in_namespace(u32 stream_index, void *(*fn)(void *), void *arg, void **ret)
{
  rtnl_main_t *rm = &rtnl_main;
  if (pool_is_free_index(rm->streams, stream_index))
    return -EBADR;

  rtnl_ns_t *ns = pool_elt_at_index(rm->streams, stream_index);
  return rtnl_exec_in_namespace_byfd(ns->ns_fd, fn, arg, ret);
}

int rtnl_exec_in_namespace_by_name(char *nsname, void *(*fn)(void *), void *arg, void **ret)
{
  int fd;
  u8 *s = format((u8 *)0, "%U", format_rtnl_nsname2path, nsname);

  if ((fd = open((char *)s, O_RDONLY)) < 0) {
    vec_free(s);
    return -errno;
  }

  int r = rtnl_exec_in_namespace_byfd(fd, fn, arg, ret);
  vec_free(s);
  close(fd);
  return r;
}

/* this function is run by the second thread */
static void *rtnl_thread_fn(void *p)
{
  rtnl_ns_t *ns = (rtnl_ns_t *) p;
  if (setns(ns->ns_fd, 0)) {
    clib_warning("setns(%d, %d) error %d", ns->ns_fd, CLONE_NEWNET, errno);
    return (void *) -1;
  }

  if ((ns->rtnl_socket = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) == -1) {
    clib_warning("Cannot open socket");
    return (void *) -2;
  }

  return NULL;
}

static int rtnl_socket_open(rtnl_ns_t *ns)
{
  rtnl_main_t *rm = &rtnl_main;
  pthread_t thread;
  void *thread_ret;
  if(pthread_create(&thread, NULL, rtnl_thread_fn, ns)) {
    clib_warning("Can't create opening thread");
    return -1;
  }

  if(pthread_join(thread, &thread_ret)) {
    clib_warning("Can't join opening thread");
    return -2;
  }

  if (thread_ret) {
    clib_warning("Could not open netlink socket");
    return -3;
  }

  struct sockaddr_nl addr = {
      .nl_family = AF_NETLINK,
      .nl_pad = 0,
      .nl_pid = 0,
      .nl_groups =
           RTMGRP_LINK | RTMGRP_IPV6_IFADDR | RTMGRP_IPV4_IFADDR |
           RTMGRP_IPV4_ROUTE | RTMGRP_IPV6_ROUTE | RTMGRP_NEIGH |
           RTMGRP_NOTIFY,
  };

  if (bind(ns->rtnl_socket, (struct sockaddr*) &addr, sizeof(addr))) {
    close(ns->rtnl_socket);
    return -3;
  }

  clib_file_t template = {0};
  template.read_function = rtnl_read_cb;
  template.file_descriptor = ns->rtnl_socket;
  template.private_data = (uword) (ns - rm->streams);
  ns->unix_index = clib_file_add (&file_main, &template);
  return 0;
}

static int
rtnl_rcv_error(rtnl_ns_t *ns, struct nlmsghdr *hdr, int *error)
{
  struct nlmsgerr *err = NLMSG_DATA(hdr);
  size_t datalen = hdr->nlmsg_len - NLMSG_ALIGN(sizeof(*hdr));
  if(datalen < sizeof(*err))
    return -1;

  *error = err->error;
  return 0;
}

static void
rtnl_sync_reset(rtnl_ns_t *ns)
{
  if (ns->sync_state == RTNL_SS_OPENING)
    return;

  rtnl_socket_close(ns);
  ns->sync_state = RTNL_SS_OPENING;
}

static void
rtnl_sync_done(rtnl_ns_t *ns)
{
  rtnl_main_t *rm = &rtnl_main;
  struct ifaddrmsg addrmsg;
  struct rtmsg rtmsg;
  struct ndmsg ndmsg;
  switch (ns->sync_state) {
    case RTNL_SS_OPENING:
      //Cannot happen here
      break;
    case RTNL_SS_LINK:
      memset(&addrmsg, 0, sizeof(addrmsg));
      addrmsg.ifa_family = AF_UNSPEC;
      if(rtnl_dump_request(ns, RTM_GETADDR, &addrmsg, sizeof(addrmsg))) {
        rtnl_sync_reset(ns);
        rtnl_schedule_timeout(ns, rm->now + 1);
        return;
      }
      rtnl_schedule_timeout(ns, rm->now + RTNL_DUMP_TIMEOUT);
      ns->sync_state = RTNL_SS_ADDR;
      break;
    case RTNL_SS_ADDR:
    case RTNL_SS_ROUTE4:
      memset(&rtmsg, 0, sizeof(rtmsg));
      rtmsg.rtm_family = (ns->sync_state == RTNL_SS_ADDR)?AF_INET:AF_INET6;
      rtmsg.rtm_table = RT_TABLE_UNSPEC;
      if(rtnl_dump_request(ns, RTM_GETROUTE, &rtmsg, sizeof(rtmsg))) {
        rtnl_sync_reset(ns);
        rtnl_schedule_timeout(ns, rm->now + 1);
        return;
      }
      rtnl_schedule_timeout(ns, rm->now + RTNL_DUMP_TIMEOUT);
      ns->sync_state = (ns->sync_state == RTNL_SS_ADDR)?RTNL_SS_ROUTE4:RTNL_SS_ROUTE6;
      break;
    case RTNL_SS_ROUTE6:
      memset(&ndmsg, 0, sizeof(ndmsg));
      ndmsg.ndm_family = AF_UNSPEC;
      if(rtnl_dump_request(ns, RTM_GETNEIGH, &ndmsg, sizeof(ndmsg))) {
        rtnl_sync_reset(ns);
        rtnl_schedule_timeout(ns, rm->now + 1);
        return;
      }
      rtnl_schedule_timeout(ns, rm->now + RTNL_DUMP_TIMEOUT);
      ns->sync_state = RTNL_SS_NEIGH;
      break;
    case RTNL_SS_NEIGH:
      ns->state = RTNL_S_READY;
      ns->sync_state = 0;
      rtnl_cancel_timeout(ns);
      break;
  }
}

static void
rtnl_sync_timeout(rtnl_ns_t *ns)
{
  rtnl_main_t *rm = &rtnl_main;
  struct ifinfomsg imsg = {};
  switch (ns->sync_state) {
    case RTNL_SS_OPENING:
      if (rtnl_socket_open(ns)) {
        rtnl_schedule_timeout(ns, rm->now + 10);
        return;
      }
      imsg.ifi_family = AF_UNSPEC;
      if (rtnl_dump_request(ns, RTM_GETLINK, &imsg, sizeof(imsg))) {
        rtnl_sync_reset(ns);
        rtnl_schedule_timeout(ns, rm->now + 10);
      }
      ns->sync_state = RTNL_SS_LINK;
      rtnl_schedule_timeout(ns, rm->now + 2);
      break;
    case RTNL_SS_LINK:
    case RTNL_SS_ADDR:
    case RTNL_SS_ROUTE4:
    case RTNL_SS_ROUTE6:
    case RTNL_SS_NEIGH:
      //Timeout happened while synchronizing
      rtnl_sync_reset(ns);
      rtnl_schedule_timeout(ns, rm->now + 1);
      break;
  }
}

static int
rtnl_ns_recv(rtnl_ns_t *ns, struct nlmsghdr *hdr)
{
  rtnl_main_t *rm = &rtnl_main;
  int ret, error = 0;

  if (ns->state == RTNL_S_SYNC &&
      ((hdr->nlmsg_flags & RTM_F_NOTIFY) ||
          (hdr->nlmsg_seq != (ns->rtnl_seq)))) {
    clib_warning("Received notification while in sync. Restart synchronization.");
    rtnl_sync_reset(ns);
    rtnl_schedule_timeout(ns, rm->now);
  }

  switch (hdr->nlmsg_type) {
    case NLMSG_DONE:
      rtnl_sync_done(ns);
      break;
    case NLMSG_ERROR:
      if((ret = rtnl_rcv_error(ns, hdr, &error)))
        return ret;
      break;
    case RTM_NEWROUTE:
    case RTM_DELROUTE:
    case RTM_NEWLINK:
    case RTM_DELLINK:
    case RTM_NEWADDR:
    case RTM_DELADDR:
    case RTM_NEWNEIGH:
    case RTM_DELNEIGH:
      if (ns->stream.recv_message)
        ns->stream.recv_message(hdr, ns->stream.opaque);
      break;
    default:
      clib_warning("Unknown rtnetlink type %d", hdr->nlmsg_type);
      break;
  }
  return 0;
}

static void
rtnl_process_open(rtnl_ns_t *ns)
{
  rtnl_main_t *rm = &rtnl_main;
  if (ns->state != RTNL_S_INIT)
    return;

  ns->state = RTNL_S_SYNC;
  ns->sync_state = RTNL_SS_OPENING;
  rtnl_schedule_timeout(ns, rm->now);
}

static void
rtnl_process_close(rtnl_ns_t *ns)
{
  rtnl_main_t *rm = &rtnl_main;
  if (ns->state == RTNL_S_INIT)
    return;

  rtnl_socket_close(ns);
  close(ns->ns_fd);
  pool_put(rm->streams, ns);
}

static int
rtnl_process_read(rtnl_ns_t *ns)
{
  uint8_t buff[RTNL_BUFFSIZ];
  ssize_t len;
  struct nlmsghdr *hdr;
  while(1) {
    if((len = recv(ns->rtnl_socket, buff, RTNL_BUFFSIZ, MSG_DONTWAIT)) < 0) {
      if(errno != EAGAIN) {
        clib_warning("rtnetlink recv error (%d) [%s]: %s", ns->rtnl_socket, ns->stream.name, strerror(errno));
        return -1;
      }
      return 0;
    }

    for(hdr = (struct nlmsghdr *) buff;
        len > 0;
        len -= NLMSG_ALIGN(hdr->nlmsg_len),
            hdr = (struct nlmsghdr *) (((uint8_t *) hdr) + NLMSG_ALIGN(hdr->nlmsg_len))) {
      if((sizeof(*hdr) > (size_t)len) || (hdr->nlmsg_len > (size_t)len)) {
        clib_warning("rtnetlink buffer too small (%d Vs %d)", (int) hdr->nlmsg_len, (int) len);
        return -1;
      }
      if (rtnl_ns_recv(ns, hdr))
        return -1;
    }
  }
  return 0;
}

static void
rtnl_process_timeout(rtnl_ns_t *ns)
{
  switch (ns->state) {
    case RTNL_S_SYNC:
      rtnl_sync_timeout(ns);
      break;
    case RTNL_S_INIT:
    case RTNL_S_READY:
      clib_warning("Should not happen");
      break;
  }
}

static uword
rtnl_process (vlib_main_t * vm,
              vlib_node_runtime_t * node,
              vlib_frame_t * frame)
{
  rtnl_main_t *rm = &rtnl_main;
  uword event_type;
  uword *event_data = 0;
  rm->now = vlib_time_now(vm);
  f64 timeout = DBL_MAX;
  rtnl_ns_t *ns;

  //Setting up
  while (1) {
    vlib_process_wait_for_event_or_clock(vm, timeout - rm->now);
    event_type = vlib_process_get_events(vm, &event_data);
    rm->now = vlib_time_now(vm);

    if (event_type == ~0) { //Clock event or no event
      pool_foreach(ns, rm->streams, {
         if (ns->timeout < rm->now) {
           ns->timeout = DBL_MAX;
           rtnl_process_timeout(ns);
         }
      });
    } else {
      rtnl_ns_t *ns;
      uword *d;
      vec_foreach(d, event_data) {
        ns = &rm->streams[d[0]];
        switch (event_type)
        {
          case RTNL_E_CLOSE:
            rtnl_process_close(ns);
            break;
          case RTNL_E_OPEN:
            rtnl_process_open(ns);
            break;
          case RTNL_E_READ:
            rtnl_process_read(ns);
            break;
        }
      }
    }

    vec_reset_length (event_data);

    timeout = DBL_MAX;
    pool_foreach(ns, rm->streams, {
        if (ns->timeout < timeout)
          timeout = ns->timeout;
    });
  }
  return frame->n_vectors;
}

VLIB_REGISTER_NODE(rtnl_process_node, static) = {
    .function = rtnl_process,
    .name = "rtnl-process",
    .type = VLIB_NODE_TYPE_PROCESS,
};

u32
rtnl_stream_open(rtnl_stream_t *template)
{
  vlib_main_t *vm = vlib_get_main();
  rtnl_main_t *rm = &rtnl_main;
  rtnl_ns_t *ns;
  int fd;
  u8 *s = format((u8 *)0, "%U", format_rtnl_nsname2path, template->name);
  vec_add1(s, 0);

  if ((fd = open((char *)s, O_RDONLY)) < 0) {
    clib_unix_warning("open stream %s: ", s);
    vec_free(s);
    return ~0;
  }

  vec_free(s);
  pool_get(rm->streams, ns);
  ns->state = RTNL_S_INIT;
  ns->ns_fd = fd;
  ns->stream = *template;
  vlib_process_signal_event(vm, rtnl_process_node.index, RTNL_E_OPEN, (uword)(ns - rm->streams));
  return ns - rm->streams;
}

void
rtnl_stream_close(u32 stream_index)
{
  vlib_main_t *vm = vlib_get_main();
  rtnl_main_t *rm = &rtnl_main;
  ASSERT(!pool_is_free_index(rm->streams, stream_index));
  vlib_process_signal_event(vm, rtnl_process_node.index, RTNL_E_CLOSE, stream_index);
}

clib_error_t *
rtnl_init (vlib_main_t * vm)
{
  rtnl_main_t *rm = &rtnl_main;
  rm->streams = 0;
  return 0;
}

VLIB_INIT_FUNCTION (rtnl_init);