1 /*
2 * em_meta.c Metadata Ematch
3 *
4 * This program is free software; you can distribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Thomas Graf <tgraf@suug.ch>
10 */
11
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <unistd.h>
15 #include <syslog.h>
16 #include <fcntl.h>
17 #include <sys/socket.h>
18 #include <netinet/in.h>
19 #include <arpa/inet.h>
20 #include <string.h>
21 #include <errno.h>
22
23 #include "m_ematch.h"
24 #include <linux/tc_ematch/tc_em_meta.h>
25
26 extern struct ematch_util meta_ematch_util;
27
meta_print_usage(FILE * fd)28 static void meta_print_usage(FILE *fd)
29 {
30 fprintf(fd,
31 "Usage: meta(OBJECT { eq | lt | gt } OBJECT)\n" \
32 "where: OBJECT := { META_ID | VALUE }\n" \
33 " META_ID := id [ shift SHIFT ] [ mask MASK ]\n" \
34 "\n" \
35 "Example: meta(nf_mark gt 24)\n" \
36 " meta(indev shift 1 eq \"ppp\")\n" \
37 " meta(tcindex mask 0xf0 eq 0xf0)\n" \
38 "\n" \
39 "For a list of meta identifiers, use meta(list).\n");
40 }
41
42 struct meta_entry {
43 int id;
44 char * kind;
45 char * mask;
46 char * desc;
47 } meta_table[] = {
48 #define TCF_META_ID_SECTION 0
49 #define __A(id, name, mask, desc) { TCF_META_ID_##id, name, mask, desc }
50 __A(SECTION, "Generic", "", ""),
51 __A(RANDOM, "random", "i",
52 "Random value (32 bit)"),
53 __A(LOADAVG_0, "loadavg_1", "i",
54 "Load average in last minute"),
55 __A(LOADAVG_1, "loadavg_5", "i",
56 "Load average in last 5 minutes"),
57 __A(LOADAVG_2, "loadavg_15", "i",
58 "Load average in last 15 minutes"),
59
60 __A(SECTION, "Interfaces", "", ""),
61 __A(DEV, "dev", "iv",
62 "Device the packet is on"),
63 __A(SECTION, "Packet attributes", "", ""),
64 __A(PRIORITY, "priority", "i",
65 "Priority of packet"),
66 __A(PROTOCOL, "protocol", "i",
67 "Link layer protocol"),
68 __A(PKTTYPE, "pkt_type", "i",
69 "Packet type (uni|multi|broad|...)cast"),
70 __A(PKTLEN, "pkt_len", "i",
71 "Length of packet"),
72 __A(DATALEN, "data_len", "i",
73 "Length of data in packet"),
74 __A(MACLEN, "mac_len", "i",
75 "Length of link layer header"),
76
77 __A(SECTION, "Netfilter", "", ""),
78 __A(NFMARK, "nf_mark", "i",
79 "Netfilter mark"),
80 __A(NFMARK, "fwmark", "i",
81 "Alias for nf_mark"),
82
83 __A(SECTION, "Traffic Control", "", ""),
84 __A(TCINDEX, "tc_index", "i", "TC Index"),
85 __A(SECTION, "Routing", "", ""),
86 __A(RTCLASSID, "rt_classid", "i",
87 "Routing ClassID (cls_route)"),
88 __A(RTIIF, "rt_iif", "i",
89 "Incoming interface index"),
90 __A(VLAN_TAG, "vlan", "i", "Vlan tag"),
91
92 __A(SECTION, "Sockets", "", ""),
93 __A(SK_FAMILY, "sk_family", "i", "Address family"),
94 __A(SK_STATE, "sk_state", "i", "State"),
95 __A(SK_REUSE, "sk_reuse", "i", "Reuse Flag"),
96 __A(SK_BOUND_IF, "sk_bind_if", "iv", "Bound interface"),
97 __A(SK_REFCNT, "sk_refcnt", "i", "Reference counter"),
98 __A(SK_SHUTDOWN, "sk_shutdown", "i", "Shutdown mask"),
99 __A(SK_PROTO, "sk_proto", "i", "Protocol"),
100 __A(SK_TYPE, "sk_type", "i", "Type"),
101 __A(SK_RCVBUF, "sk_rcvbuf", "i", "Receive buffer size"),
102 __A(SK_RMEM_ALLOC, "sk_rmem", "i", "RMEM"),
103 __A(SK_WMEM_ALLOC, "sk_wmem", "i", "WMEM"),
104 __A(SK_OMEM_ALLOC, "sk_omem", "i", "OMEM"),
105 __A(SK_WMEM_QUEUED, "sk_wmem_queue","i", "WMEM queue"),
106 __A(SK_SND_QLEN, "sk_snd_queue", "i", "Send queue length"),
107 __A(SK_RCV_QLEN, "sk_rcv_queue", "i", "Receive queue length"),
108 __A(SK_ERR_QLEN, "sk_err_queue", "i", "Error queue length"),
109 __A(SK_FORWARD_ALLOCS, "sk_fwd_alloc", "i", "Forward allocations"),
110 __A(SK_SNDBUF, "sk_sndbuf", "i", "Send buffer size"),
111 #undef __A
112 };
113
map_type(char k)114 static inline int map_type(char k)
115 {
116 switch (k) {
117 case 'i': return TCF_META_TYPE_INT;
118 case 'v': return TCF_META_TYPE_VAR;
119 }
120
121 fprintf(stderr, "BUG: Unknown map character '%c'\n", k);
122 return INT_MAX;
123 }
124
lookup_meta_entry(struct bstr * kind)125 static struct meta_entry * lookup_meta_entry(struct bstr *kind)
126 {
127 int i;
128
129 for (i = 0; i < (sizeof(meta_table)/sizeof(meta_table[0])); i++)
130 if (!bstrcmp(kind, meta_table[i].kind) &&
131 meta_table[i].id != 0)
132 return &meta_table[i];
133
134 return NULL;
135 }
136
lookup_meta_entry_byid(int id)137 static struct meta_entry * lookup_meta_entry_byid(int id)
138 {
139 int i;
140
141 for (i = 0; i < (sizeof(meta_table)/sizeof(meta_table[0])); i++)
142 if (meta_table[i].id == id)
143 return &meta_table[i];
144
145 return NULL;
146 }
147
dump_value(struct nlmsghdr * n,int tlv,unsigned long val,struct tcf_meta_val * hdr)148 static inline void dump_value(struct nlmsghdr *n, int tlv, unsigned long val,
149 struct tcf_meta_val *hdr)
150 {
151 __u32 t;
152
153 switch (TCF_META_TYPE(hdr->kind)) {
154 case TCF_META_TYPE_INT:
155 t = val;
156 addattr_l(n, MAX_MSG, tlv, &t, sizeof(t));
157 break;
158
159 case TCF_META_TYPE_VAR:
160 if (TCF_META_ID(hdr->kind) == TCF_META_ID_VALUE) {
161 struct bstr *a = (struct bstr *) val;
162 addattr_l(n, MAX_MSG, tlv, a->data, a->len);
163 }
164 break;
165 }
166 }
167
is_compatible(struct tcf_meta_val * what,struct tcf_meta_val * needed)168 static inline int is_compatible(struct tcf_meta_val *what,
169 struct tcf_meta_val *needed)
170 {
171 char *p;
172 struct meta_entry *entry;
173
174 entry = lookup_meta_entry_byid(TCF_META_ID(what->kind));
175
176 if (entry == NULL)
177 return 0;
178
179 for (p = entry->mask; p; p++)
180 if (map_type(*p) == TCF_META_TYPE(needed->kind))
181 return 1;
182
183 return 0;
184 }
185
list_meta_ids(FILE * fd)186 static void list_meta_ids(FILE *fd)
187 {
188 int i;
189
190 fprintf(fd,
191 "--------------------------------------------------------\n" \
192 " ID Type Description\n" \
193 "--------------------------------------------------------");
194
195 for (i = 0; i < (sizeof(meta_table)/sizeof(meta_table[0])); i++) {
196 if (meta_table[i].id == TCF_META_ID_SECTION) {
197 fprintf(fd, "\n%s:\n", meta_table[i].kind);
198 } else {
199 char *p = meta_table[i].mask;
200 char buf[64] = {0};
201
202 fprintf(fd, " %-16s ", meta_table[i].kind);
203
204 while (*p) {
205 int type = map_type(*p);
206
207 switch (type) {
208 case TCF_META_TYPE_INT:
209 strcat(buf, "INT");
210 break;
211
212 case TCF_META_TYPE_VAR:
213 strcat(buf, "VAR");
214 break;
215 }
216
217 if (*(++p))
218 strcat(buf, ",");
219 }
220
221 fprintf(fd, "%-10s %s\n", buf, meta_table[i].desc);
222 }
223 }
224
225 fprintf(fd,
226 "--------------------------------------------------------\n");
227 }
228
229 #undef TCF_META_ID_SECTION
230
231 #define PARSE_FAILURE ((void *) (-1))
232
233 #define PARSE_ERR(CARG, FMT, ARGS...) \
234 em_parse_error(EINVAL, args, CARG, &meta_ematch_util, FMT ,##ARGS)
235
can_adopt(struct tcf_meta_val * val)236 static inline int can_adopt(struct tcf_meta_val *val)
237 {
238 return !!TCF_META_ID(val->kind);
239 }
240
overwrite_type(struct tcf_meta_val * src,struct tcf_meta_val * dst)241 static inline int overwrite_type(struct tcf_meta_val *src,
242 struct tcf_meta_val *dst)
243 {
244 return (TCF_META_TYPE(dst->kind) << 12) | TCF_META_ID(src->kind);
245 }
246
247
248 static inline struct bstr *
parse_object(struct bstr * args,struct bstr * arg,struct tcf_meta_val * obj,unsigned long * dst,struct tcf_meta_val * left)249 parse_object(struct bstr *args, struct bstr *arg, struct tcf_meta_val *obj,
250 unsigned long *dst, struct tcf_meta_val *left)
251 {
252 struct meta_entry *entry;
253 unsigned long num;
254 struct bstr *a;
255
256 if (arg->quoted) {
257 obj->kind = TCF_META_TYPE_VAR << 12;
258 obj->kind |= TCF_META_ID_VALUE;
259 *dst = (unsigned long) arg;
260 return bstr_next(arg);
261 }
262
263 num = bstrtoul(arg);
264 if (num != ULONG_MAX) {
265 obj->kind = TCF_META_TYPE_INT << 12;
266 obj->kind |= TCF_META_ID_VALUE;
267 *dst = (unsigned long) num;
268 return bstr_next(arg);
269 }
270
271 entry = lookup_meta_entry(arg);
272
273 if (entry == NULL) {
274 PARSE_ERR(arg, "meta: unknown meta id\n");
275 return PARSE_FAILURE;
276 }
277
278 obj->kind = entry->id | (map_type(entry->mask[0]) << 12);
279
280 if (left) {
281 struct tcf_meta_val *right = obj;
282
283 if (TCF_META_TYPE(right->kind) == TCF_META_TYPE(left->kind))
284 goto compatible;
285
286 if (can_adopt(left) && !can_adopt(right)) {
287 if (is_compatible(left, right))
288 left->kind = overwrite_type(left, right);
289 else
290 goto not_compatible;
291 } else if (can_adopt(right) && !can_adopt(left)) {
292 if (is_compatible(right, left))
293 right->kind = overwrite_type(right, left);
294 else
295 goto not_compatible;
296 } else if (can_adopt(left) && can_adopt(right)) {
297 if (is_compatible(left, right))
298 left->kind = overwrite_type(left, right);
299 else if (is_compatible(right, left))
300 right->kind = overwrite_type(right, left);
301 else
302 goto not_compatible;
303 } else
304 goto not_compatible;
305 }
306
307 compatible:
308
309 a = bstr_next(arg);
310
311 while(a) {
312 if (!bstrcmp(a, "shift")) {
313 unsigned long shift;
314
315 if (a->next == NULL) {
316 PARSE_ERR(a, "meta: missing argument");
317 return PARSE_FAILURE;
318 }
319 a = bstr_next(a);
320
321 shift = bstrtoul(a);
322 if (shift == ULONG_MAX) {
323 PARSE_ERR(a, "meta: invalid shift, must " \
324 "be numeric");
325 return PARSE_FAILURE;
326 }
327
328 obj->shift = (__u8) shift;
329 a = bstr_next(a);
330 } else if (!bstrcmp(a, "mask")) {
331 unsigned long mask;
332
333 if (a->next == NULL) {
334 PARSE_ERR(a, "meta: missing argument");
335 return PARSE_FAILURE;
336 }
337 a = bstr_next(a);
338
339 mask = bstrtoul(a);
340 if (mask == ULONG_MAX) {
341 PARSE_ERR(a, "meta: invalid mask, must be " \
342 "numeric");
343 return PARSE_FAILURE;
344 }
345 *dst = (unsigned long) mask;
346 a = bstr_next(a);
347 } else
348 break;
349 }
350
351 return a;
352
353 not_compatible:
354 PARSE_ERR(arg, "lvalue and rvalue are not compatible.");
355 return PARSE_FAILURE;
356 }
357
meta_parse_eopt(struct nlmsghdr * n,struct tcf_ematch_hdr * hdr,struct bstr * args)358 static int meta_parse_eopt(struct nlmsghdr *n, struct tcf_ematch_hdr *hdr,
359 struct bstr *args)
360 {
361 int opnd;
362 struct bstr *a;
363 struct tcf_meta_hdr meta_hdr;
364 unsigned long lvalue = 0, rvalue = 0;
365
366 memset(&meta_hdr, 0, sizeof(meta_hdr));
367
368 if (args == NULL)
369 return PARSE_ERR(args, "meta: missing arguments");
370
371 if (!bstrcmp(args, "list")) {
372 list_meta_ids(stderr);
373 return -1;
374 }
375
376 a = parse_object(args, args, &meta_hdr.left, &lvalue, NULL);
377 if (a == PARSE_FAILURE)
378 return -1;
379 else if (a == NULL)
380 return PARSE_ERR(args, "meta: missing operand");
381
382 if (!bstrcmp(a, "eq"))
383 opnd = TCF_EM_OPND_EQ;
384 else if (!bstrcmp(a, "gt"))
385 opnd = TCF_EM_OPND_GT;
386 else if (!bstrcmp(a, "lt"))
387 opnd = TCF_EM_OPND_LT;
388 else
389 return PARSE_ERR(a, "meta: invalid operand");
390
391 meta_hdr.left.op = (__u8) opnd;
392
393 if (a->next == NULL)
394 return PARSE_ERR(args, "meta: missing rvalue");
395 a = bstr_next(a);
396
397 a = parse_object(args, a, &meta_hdr.right, &rvalue, &meta_hdr.left);
398 if (a == PARSE_FAILURE)
399 return -1;
400 else if (a != NULL)
401 return PARSE_ERR(a, "meta: unexpected trailer");
402
403
404 addraw_l(n, MAX_MSG, hdr, sizeof(*hdr));
405
406 addattr_l(n, MAX_MSG, TCA_EM_META_HDR, &meta_hdr, sizeof(meta_hdr));
407
408 dump_value(n, TCA_EM_META_LVALUE, lvalue, &meta_hdr.left);
409 dump_value(n, TCA_EM_META_RVALUE, rvalue, &meta_hdr.right);
410
411 return 0;
412 }
413 #undef PARSE_ERR
414
print_binary(FILE * fd,unsigned char * str,int len)415 static inline void print_binary(FILE *fd, unsigned char *str, int len)
416 {
417 int i;
418
419 for (i = 0; i < len; i++)
420 if (!isprint(str[i]))
421 goto binary;
422
423 for (i = 0; i < len; i++)
424 fprintf(fd, "%c", str[i]);
425 return;
426
427 binary:
428 for (i = 0; i < len; i++)
429 fprintf(fd, "%02x ", str[i]);
430
431 fprintf(fd, "\"");
432 for (i = 0; i < len; i++)
433 fprintf(fd, "%c", isprint(str[i]) ? str[i] : '.');
434 fprintf(fd, "\"");
435 }
436
print_value(FILE * fd,int type,struct rtattr * rta)437 static inline int print_value(FILE *fd, int type, struct rtattr *rta)
438 {
439 if (rta == NULL) {
440 fprintf(stderr, "Missing value TLV\n");
441 return -1;
442 }
443
444 switch(type) {
445 case TCF_META_TYPE_INT:
446 if (RTA_PAYLOAD(rta) < sizeof(__u32)) {
447 fprintf(stderr, "meta int type value TLV " \
448 "size mismatch.\n");
449 return -1;
450 }
451 fprintf(fd, "%d", rta_getattr_u32(rta));
452 break;
453
454 case TCF_META_TYPE_VAR:
455 print_binary(fd, RTA_DATA(rta), RTA_PAYLOAD(rta));
456 break;
457 }
458
459 return 0;
460 }
461
print_object(FILE * fd,struct tcf_meta_val * obj,struct rtattr * rta)462 static int print_object(FILE *fd, struct tcf_meta_val *obj, struct rtattr *rta)
463 {
464 int id = TCF_META_ID(obj->kind);
465 int type = TCF_META_TYPE(obj->kind);
466 struct meta_entry *entry;
467
468 if (id == TCF_META_ID_VALUE)
469 return print_value(fd, type, rta);
470
471 entry = lookup_meta_entry_byid(id);
472
473 if (entry == NULL)
474 fprintf(fd, "[unknown meta id %d]", id);
475 else
476 fprintf(fd, "%s", entry->kind);
477
478 if (obj->shift)
479 fprintf(fd, " shift %d", obj->shift);
480
481 switch (type) {
482 case TCF_META_TYPE_INT:
483 if (rta) {
484 if (RTA_PAYLOAD(rta) < sizeof(__u32))
485 goto size_mismatch;
486
487 fprintf(fd, " mask 0x%08x",
488 rta_getattr_u32(rta));
489 }
490 break;
491 }
492
493 return 0;
494
495 size_mismatch:
496 fprintf(stderr, "meta int type mask TLV size mismatch\n");
497 return -1;
498 }
499
500
meta_print_eopt(FILE * fd,struct tcf_ematch_hdr * hdr,void * data,int data_len)501 static int meta_print_eopt(FILE *fd, struct tcf_ematch_hdr *hdr, void *data,
502 int data_len)
503 {
504 struct rtattr *tb[TCA_EM_META_MAX+1];
505 struct tcf_meta_hdr *meta_hdr;
506
507 if (parse_rtattr(tb, TCA_EM_META_MAX, data, data_len) < 0)
508 return -1;
509
510 if (tb[TCA_EM_META_HDR] == NULL) {
511 fprintf(stderr, "Missing meta header\n");
512 return -1;
513 }
514
515 if (RTA_PAYLOAD(tb[TCA_EM_META_HDR]) < sizeof(*meta_hdr)) {
516 fprintf(stderr, "Meta header size mismatch\n");
517 return -1;
518 }
519
520 meta_hdr = RTA_DATA(tb[TCA_EM_META_HDR]);
521
522 if (print_object(fd, &meta_hdr->left, tb[TCA_EM_META_LVALUE]) < 0)
523 return -1;
524
525 switch (meta_hdr->left.op) {
526 case TCF_EM_OPND_EQ:
527 fprintf(fd, " eq ");
528 break;
529 case TCF_EM_OPND_LT:
530 fprintf(fd, " lt ");
531 break;
532 case TCF_EM_OPND_GT:
533 fprintf(fd, " gt ");
534 break;
535 }
536
537 return print_object(fd, &meta_hdr->right, tb[TCA_EM_META_RVALUE]);
538 }
539
540 struct ematch_util meta_ematch_util = {
541 .kind = "meta",
542 .kind_num = TCF_EM_META,
543 .parse_eopt = meta_parse_eopt,
544 .print_eopt = meta_print_eopt,
545 .print_usage = meta_print_usage
546 };
547