xref: /freebsd/sys/netgraph/ng_vlan_rotate.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2019-2021 IKS Service GmbH
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * Author: Lutz Donnerhacke <lutz@donnerhacke.de>
28  */
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/mbuf.h>
34 #include <sys/malloc.h>
35 #include <sys/ctype.h>
36 #include <sys/errno.h>
37 #include <sys/syslog.h>
38 #include <sys/types.h>
39 #include <sys/counter.h>
40 
41 #include <net/ethernet.h>
42 
43 #include <netgraph/ng_message.h>
44 #include <netgraph/ng_parse.h>
45 #include <netgraph/ng_vlan_rotate.h>
46 #include <netgraph/netgraph.h>
47 
48 /*
49  * This section contains the netgraph method declarations for the
50  * sample node. These methods define the netgraph 'type'.
51  */
52 
53 static ng_constructor_t ng_vlanrotate_constructor;
54 static ng_rcvmsg_t ng_vlanrotate_rcvmsg;
55 static ng_shutdown_t ng_vlanrotate_shutdown;
56 static ng_newhook_t ng_vlanrotate_newhook;
57 static ng_rcvdata_t ng_vlanrotate_rcvdata;
58 static ng_disconnect_t ng_vlanrotate_disconnect;
59 
60 /* Parse type for struct ng_vlanrotate_conf */
61 static const struct ng_parse_struct_field ng_vlanrotate_conf_fields[] = {
62 	{"rot", &ng_parse_int8_type},
63 	{"min", &ng_parse_uint8_type},
64 	{"max", &ng_parse_uint8_type},
65 	{NULL}
66 };
67 static const struct ng_parse_type ng_vlanrotate_conf_type = {
68 	&ng_parse_struct_type,
69 	&ng_vlanrotate_conf_fields
70 };
71 
72 /* Parse type for struct ng_vlanrotate_stat */
73 static struct ng_parse_fixedarray_info ng_vlanrotate_stat_hist_info = {
74 	&ng_parse_uint64_type,
75 	NG_VLANROTATE_MAX_VLANS
76 };
77 static struct ng_parse_type ng_vlanrotate_stat_hist = {
78 	&ng_parse_fixedarray_type,
79 	&ng_vlanrotate_stat_hist_info
80 };
81 static const struct ng_parse_struct_field ng_vlanrotate_stat_fields[] = {
82 	{"drops", &ng_parse_uint64_type},
83 	{"excessive", &ng_parse_uint64_type},
84 	{"incomplete", &ng_parse_uint64_type},
85 	{"histogram", &ng_vlanrotate_stat_hist},
86 	{NULL}
87 };
88 static struct ng_parse_type ng_vlanrotate_stat_type = {
89 	&ng_parse_struct_type,
90 	&ng_vlanrotate_stat_fields
91 };
92 
93 
94 /* List of commands and how to convert arguments to/from ASCII */
95 static const struct ng_cmdlist ng_vlanrotate_cmdlist[] = {
96 	{
97 		NGM_VLANROTATE_COOKIE,
98 		NGM_VLANROTATE_GET_CONF,
99 		"getconf",
100 		NULL,
101 		&ng_vlanrotate_conf_type,
102 	},
103 	{
104 		NGM_VLANROTATE_COOKIE,
105 		NGM_VLANROTATE_SET_CONF,
106 		"setconf",
107 		&ng_vlanrotate_conf_type,
108 		NULL
109 	},
110 	{
111 		NGM_VLANROTATE_COOKIE,
112 		NGM_VLANROTATE_GET_STAT,
113 		"getstat",
114 		NULL,
115 		&ng_vlanrotate_stat_type
116 	},
117 	{
118 		NGM_VLANROTATE_COOKIE,
119 		NGM_VLANROTATE_CLR_STAT,
120 		"clrstat",
121 		NULL,
122 		&ng_vlanrotate_stat_type
123 	},
124 	{
125 		NGM_VLANROTATE_COOKIE,
126 		NGM_VLANROTATE_GETCLR_STAT,
127 		"getclrstat",
128 		NULL,
129 		&ng_vlanrotate_stat_type
130 	},
131 	{0}
132 };
133 
134 /* Netgraph node type descriptor */
135 static struct ng_type typestruct = {
136 	.version = NG_ABI_VERSION,
137 	.name = NG_VLANROTATE_NODE_TYPE,
138 	.constructor = ng_vlanrotate_constructor,
139 	.rcvmsg = ng_vlanrotate_rcvmsg,
140 	.shutdown = ng_vlanrotate_shutdown,
141 	.newhook = ng_vlanrotate_newhook,
142 	.rcvdata = ng_vlanrotate_rcvdata,
143 	.disconnect = ng_vlanrotate_disconnect,
144 	.cmdlist = ng_vlanrotate_cmdlist,
145 };
146 NETGRAPH_INIT(vlanrotate, &typestruct);
147 
148 struct ng_vlanrotate_kernel_stats {
149 	counter_u64_t	drops, excessive, incomplete;
150 	counter_u64_t	histogram[NG_VLANROTATE_MAX_VLANS];
151 };
152 
153 /* Information we store for each node */
154 struct vlanrotate {
155 	hook_p		original_hook;
156 	hook_p		ordered_hook;
157 	hook_p		excessive_hook;
158 	hook_p		incomplete_hook;
159 	struct ng_vlanrotate_conf conf;
160 	struct ng_vlanrotate_kernel_stats stats;
161 };
162 typedef struct vlanrotate *vlanrotate_p;
163 
164 /*
165  * Set up the private data structure.
166  */
167 static int
168 ng_vlanrotate_constructor(node_p node)
169 {
170 	int i;
171 
172 	vlanrotate_p vrp = malloc(sizeof(*vrp), M_NETGRAPH, M_WAITOK | M_ZERO);
173 
174 	vrp->conf.max = NG_VLANROTATE_MAX_VLANS;
175 
176 	vrp->stats.drops = counter_u64_alloc(M_WAITOK);
177 	vrp->stats.excessive = counter_u64_alloc(M_WAITOK);
178 	vrp->stats.incomplete = counter_u64_alloc(M_WAITOK);
179 	for (i = 0; i < NG_VLANROTATE_MAX_VLANS; i++)
180 		vrp->stats.histogram[i] = counter_u64_alloc(M_WAITOK);
181 
182 	NG_NODE_SET_PRIVATE(node, vrp);
183 	return (0);
184 }
185 
186 /*
187  * Give our ok for a hook to be added.
188  */
189 static int
190 ng_vlanrotate_newhook(node_p node, hook_p hook, const char *name)
191 {
192 	const vlanrotate_p vrp = NG_NODE_PRIVATE(node);
193 	hook_p *dst = NULL;
194 
195 	if (strcmp(name, NG_VLANROTATE_HOOK_ORDERED) == 0) {
196 		dst = &vrp->ordered_hook;
197 	} else if (strcmp(name, NG_VLANROTATE_HOOK_ORIGINAL) == 0) {
198 		dst = &vrp->original_hook;
199 	} else if (strcmp(name, NG_VLANROTATE_HOOK_EXCESSIVE) == 0) {
200 		dst = &vrp->excessive_hook;
201 	} else if (strcmp(name, NG_VLANROTATE_HOOK_INCOMPLETE) == 0) {
202 		dst = &vrp->incomplete_hook;
203 	} else
204 		return (EINVAL);	/* not a hook we know about */
205 
206 	if (*dst != NULL)
207 		return (EADDRINUSE);	/* don't override */
208 
209 	*dst = hook;
210 	return (0);
211 }
212 
213 /*
214  * Get a netgraph control message.
215  * A response is not required.
216  */
217 static int
218 ng_vlanrotate_rcvmsg(node_p node, item_p item, hook_p lasthook)
219 {
220 	const vlanrotate_p vrp = NG_NODE_PRIVATE(node);
221 	struct ng_mesg *resp = NULL;
222 	struct ng_mesg *msg;
223 	struct ng_vlanrotate_conf *pcf;
224 	int error = 0;
225 
226 	NGI_GET_MSG(item, msg);
227 	/* Deal with message according to cookie and command */
228 	switch (msg->header.typecookie) {
229 	case NGM_VLANROTATE_COOKIE:
230 		switch (msg->header.cmd) {
231 		case NGM_VLANROTATE_GET_CONF:
232 			NG_MKRESPONSE(resp, msg, sizeof(vrp->conf), M_NOWAIT);
233 			if (!resp) {
234 				error = ENOMEM;
235 				break;
236 			}
237 			*((struct ng_vlanrotate_conf *)resp->data) = vrp->conf;
238 			break;
239 		case NGM_VLANROTATE_SET_CONF:
240 			if (msg->header.arglen != sizeof(*pcf)) {
241 				error = EINVAL;
242 				break;
243 			}
244 
245 			pcf = (struct ng_vlanrotate_conf *)msg->data;
246 
247 			if (pcf->max == 0)	/* keep current value */
248 				pcf->max = vrp->conf.max;
249 
250 			if ((pcf->max > NG_VLANROTATE_MAX_VLANS) ||
251 			    (pcf->min > pcf->max) ||
252 			    (abs(pcf->rot) >= pcf->max)) {
253 				error = EINVAL;
254 				break;
255 			}
256 
257 			vrp->conf = *pcf;
258 			break;
259 		case NGM_VLANROTATE_GET_STAT:
260 		case NGM_VLANROTATE_GETCLR_STAT:
261 		{
262 			struct ng_vlanrotate_stat *p;
263 			int i;
264 
265 			NG_MKRESPONSE(resp, msg, sizeof(*p), M_NOWAIT);
266 			if (!resp) {
267 				error = ENOMEM;
268 				break;
269 			}
270 			p = (struct ng_vlanrotate_stat *)resp->data;
271 			p->drops = counter_u64_fetch(vrp->stats.drops);
272 			p->excessive = counter_u64_fetch(vrp->stats.excessive);
273 			p->incomplete = counter_u64_fetch(vrp->stats.incomplete);
274 			for (i = 0; i < NG_VLANROTATE_MAX_VLANS; i++)
275 				p->histogram[i] = counter_u64_fetch(vrp->stats.histogram[i]);
276 			if (msg->header.cmd != NGM_VLANROTATE_GETCLR_STAT)
277 				break;
278 		}
279 		case NGM_VLANROTATE_CLR_STAT:
280 		{
281 			int i;
282 
283 			counter_u64_zero(vrp->stats.drops);
284 			counter_u64_zero(vrp->stats.excessive);
285 			counter_u64_zero(vrp->stats.incomplete);
286 			for (i = 0; i < NG_VLANROTATE_MAX_VLANS; i++)
287 				counter_u64_zero(vrp->stats.histogram[i]);
288 			break;
289 		}
290 		default:
291 			error = EINVAL;	/* unknown command */
292 			break;
293 		}
294 		break;
295 	default:
296 		error = EINVAL;	/* unknown cookie type */
297 		break;
298 	}
299 
300 	/* Take care of synchronous response, if any */
301 	NG_RESPOND_MSG(error, node, item, resp);
302 	/* Free the message and return */
303 	NG_FREE_MSG(msg);
304 	return (error);
305 }
306 
307 /*
308  * Receive data, and do rotate the vlans as desired.
309  *
310  * Rotating is quite complicated if the rotation offset and the number
311  * of vlans are not relativly prime. In this case multiple slices need
312  * to be rotated separately.
313  *
314  * Rotation can be additive or subtractive. Some examples:
315  *  01234   5 vlans given
316  *  -----
317  *  34012  +2 rotate
318  *  12340  +4 rotate
319  *  12340  -1 rotate
320  *
321  * First some helper functions ...
322  */
323 
324 struct ether_vlan_stack_entry {
325 	uint16_t	proto;
326 	uint16_t	tag;
327 }		__packed;
328 
329 struct ether_vlan_stack_header {
330 	uint8_t		dst[ETHER_ADDR_LEN];
331 	uint8_t		src[ETHER_ADDR_LEN];
332 	struct ether_vlan_stack_entry vlan_stack[1];
333 }		__packed;
334 
335 static int
336 ng_vlanrotate_gcd(int a, int b)
337 {
338 	if (b == 0)
339 		return a;
340 	else
341 		return ng_vlanrotate_gcd(b, a % b);
342 }
343 
344 static void
345 ng_vlanrotate_rotate(struct ether_vlan_stack_entry arr[], int d, int n)
346 {
347 	int		i, j, k;
348 	struct ether_vlan_stack_entry temp;
349 
350 	/* for each commensurable slice */
351 	for (i = ng_vlanrotate_gcd(d, n); i-- > 0;) {
352 		/* rotate left aka downwards */
353 		temp = arr[i];
354 		j = i;
355 
356 		while (1) {
357 			k = j + d;
358 			if (k >= n)
359 				k = k - n;
360 			if (k == i)
361 				break;
362 			arr[j] = arr[k];
363 			j = k;
364 		}
365 
366 		arr[j] = temp;
367 	}
368 }
369 
370 static int
371 ng_vlanrotate_rcvdata(hook_p hook, item_p item)
372 {
373 	const vlanrotate_p vrp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
374 	struct ether_vlan_stack_header *evsh;
375 	struct mbuf *m = NULL;
376 	hook_p	dst_hook;
377 	int8_t	rotate;
378 	int8_t	vlans = 0;
379 	int	error = ENOSYS;
380 
381 	NGI_GET_M(item, m);
382 
383 	if (hook == vrp->ordered_hook) {
384 		rotate = +vrp->conf.rot;
385 		dst_hook = vrp->original_hook;
386 	} else if (hook == vrp->original_hook) {
387 		rotate = -vrp->conf.rot;
388 		dst_hook = vrp->ordered_hook;
389 	} else {
390 		dst_hook = vrp->original_hook;
391 		goto send;	/* everything else goes out unmodified */
392 	}
393 
394 	if (dst_hook == NULL) {
395 		error = ENETDOWN;
396 		goto fail;
397 	}
398 
399 	/* count the vlans */
400 	for (vlans = 0; vlans <= NG_VLANROTATE_MAX_VLANS; vlans++) {
401 		size_t expected_len = sizeof(struct ether_vlan_stack_header)
402 		    + vlans * sizeof(struct ether_vlan_stack_entry);
403 
404 		if (m->m_len < expected_len) {
405 			m = m_pullup(m, expected_len);
406 			if (m == NULL) {
407 				error = EINVAL;
408 				goto fail;
409 			}
410 		}
411 
412 		evsh = mtod(m, struct ether_vlan_stack_header *);
413 		switch (ntohs(evsh->vlan_stack[vlans].proto)) {
414 		case ETHERTYPE_VLAN:
415 		case ETHERTYPE_QINQ:
416 		case ETHERTYPE_8021Q9100:
417 		case ETHERTYPE_8021Q9200:
418 		case ETHERTYPE_8021Q9300:
419 			break;
420 		default:
421 			goto out;
422 		}
423 	}
424 out:
425 	if ((vlans > vrp->conf.max) || (vlans >= NG_VLANROTATE_MAX_VLANS)) {
426 		counter_u64_add(vrp->stats.excessive, 1);
427 		dst_hook = vrp->excessive_hook;
428 		goto send;
429 	}
430 
431 	if ((vlans < vrp->conf.min) || (vlans <= abs(rotate))) {
432 		counter_u64_add(vrp->stats.incomplete, 1);
433 		dst_hook = vrp->incomplete_hook;
434 		goto send;
435 	}
436 	counter_u64_add(vrp->stats.histogram[vlans], 1);
437 
438 	/* rotating upwards always (using modular arithmetics) */
439 	if (rotate == 0) {
440 		/* nothing to do */
441 	} else if (rotate > 0) {
442 		ng_vlanrotate_rotate(evsh->vlan_stack, rotate, vlans);
443 	} else {
444 		ng_vlanrotate_rotate(evsh->vlan_stack, vlans + rotate, vlans);
445 	}
446 
447 send:
448 	if (dst_hook == NULL)
449 		goto fail;
450 	NG_FWD_NEW_DATA(error, item, dst_hook, m);
451 	return 0;
452 
453 fail:
454 	counter_u64_add(vrp->stats.drops, 1);
455 	if (m != NULL)
456 		m_freem(m);
457 	NG_FREE_ITEM(item);
458 	return (error);
459 }
460 
461 /*
462  * Do local shutdown processing..
463  * All our links and the name have already been removed.
464  */
465 static int
466 ng_vlanrotate_shutdown(node_p node)
467 {
468 	const		vlanrotate_p vrp = NG_NODE_PRIVATE(node);
469 	int i;
470 
471 	NG_NODE_SET_PRIVATE(node, NULL);
472 
473 	counter_u64_free(vrp->stats.drops);
474 	counter_u64_free(vrp->stats.excessive);
475 	counter_u64_free(vrp->stats.incomplete);
476 	for (i = 0; i < NG_VLANROTATE_MAX_VLANS; i++)
477 		counter_u64_free(vrp->stats.histogram[i]);
478 
479 	free(vrp, M_NETGRAPH);
480 
481 	NG_NODE_UNREF(node);
482 	return (0);
483 }
484 
485 /*
486  * Hook disconnection
487  * For this type, removal of the last link destroys the node
488  */
489 static int
490 ng_vlanrotate_disconnect(hook_p hook)
491 {
492 	const		vlanrotate_p vrp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
493 
494 	if (vrp->original_hook == hook)
495 		vrp->original_hook = NULL;
496 	if (vrp->ordered_hook == hook)
497 		vrp->ordered_hook = NULL;
498 	if (vrp->excessive_hook == hook)
499 		vrp->excessive_hook = NULL;
500 	if (vrp->incomplete_hook == hook)
501 		vrp->incomplete_hook = NULL;
502 
503 	/* during shutdown the node is invalid, don't shutdown twice */
504 	if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) &&
505 	    (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
506 		ng_rmnode_self(NG_HOOK_NODE(hook));
507 	return (0);
508 }
509