1 /*
2  * Copyright (c) 2016 Fabien Siron <fabien.siron@epita.fr>
3  * Copyright (c) 2017 JingPiao Chen <chenjingpiao@gmail.com>
4  * Copyright (c) 2016-2018 The strace developers.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include "defs.h"
31 #include <endian.h>
32 #include "netlink.h"
33 #include "nlattr.h"
34 #include <netinet/in.h>
35 #include <arpa/inet.h>
36 #include <linux/sock_diag.h>
37 #include "static_assert.h"
38 
39 #include "xlat/netlink_sk_meminfo_indices.h"
40 
41 static bool
fetch_nlattr(struct tcb * const tcp,struct nlattr * const nlattr,const kernel_ulong_t addr,const unsigned int len,const bool in_array)42 fetch_nlattr(struct tcb *const tcp, struct nlattr *const nlattr,
43 	     const kernel_ulong_t addr, const unsigned int len,
44 	     const bool in_array)
45 {
46 	if (len < sizeof(struct nlattr)) {
47 		printstr_ex(tcp, addr, len, QUOTE_FORCE_HEX);
48 		return false;
49 	}
50 
51 	if (tfetch_obj(tcp, addr, nlattr))
52 		return true;
53 
54 	if (in_array) {
55 		tprints("...");
56 		printaddr_comment(addr);
57 	} else {
58 		printaddr(addr);
59 	}
60 
61 	return false;
62 }
63 
64 static void
print_nlattr(const struct nlattr * const nla,const struct xlat * const table,const char * const dflt)65 print_nlattr(const struct nlattr *const nla,
66 	     const struct xlat *const table,
67 	     const char *const dflt)
68 {
69 	static_assert(NLA_TYPE_MASK == ~(NLA_F_NESTED | NLA_F_NET_BYTEORDER),
70 		      "wrong NLA_TYPE_MASK");
71 
72 	tprintf("{nla_len=%u, nla_type=", nla->nla_len);
73 	if (nla->nla_type & NLA_F_NESTED) {
74 		print_xlat(NLA_F_NESTED);
75 		tprints("|");
76 	}
77 	if (nla->nla_type & NLA_F_NET_BYTEORDER) {
78 		print_xlat(NLA_F_NET_BYTEORDER);
79 		tprints("|");
80 	}
81 	printxval(table, nla->nla_type & NLA_TYPE_MASK, dflt);
82 	tprints("}");
83 }
84 
85 static void
decode_nlattr_with_data(struct tcb * const tcp,const struct nlattr * const nla,const kernel_ulong_t addr,const unsigned int len,const struct xlat * const table,const char * const dflt,const nla_decoder_t * const decoders,const unsigned int size,const void * const opaque_data)86 decode_nlattr_with_data(struct tcb *const tcp,
87 			const struct nlattr *const nla,
88 			const kernel_ulong_t addr,
89 			const unsigned int len,
90 			const struct xlat *const table,
91 			const char *const dflt,
92 			const nla_decoder_t *const decoders,
93 			const unsigned int size,
94 			const void *const opaque_data)
95 {
96 	const unsigned int nla_len = MIN(nla->nla_len, len);
97 
98 	if (nla_len > NLA_HDRLEN)
99 		tprints("{");
100 
101 	print_nlattr(nla, table, dflt);
102 
103 	if (nla_len > NLA_HDRLEN) {
104 		const unsigned int idx =
105 			size ? nla->nla_type & NLA_TYPE_MASK : 0;
106 
107 		tprints(", ");
108 		if (!decoders
109 		    || (size && idx >= size)
110 		    || !decoders[idx]
111 		    || !decoders[idx](
112 				tcp, addr + NLA_HDRLEN,
113 				nla_len - NLA_HDRLEN,
114 				size ? opaque_data
115 				     : (const void *) (uintptr_t) nla->nla_type)
116 		    )
117 			printstr_ex(tcp, addr + NLA_HDRLEN,
118 				    nla_len - NLA_HDRLEN, QUOTE_FORCE_HEX);
119 		tprints("}");
120 	}
121 }
122 
123 void
decode_nlattr(struct tcb * const tcp,kernel_ulong_t addr,unsigned int len,const struct xlat * const table,const char * const dflt,const nla_decoder_t * const decoders,const unsigned int size,const void * const opaque_data)124 decode_nlattr(struct tcb *const tcp,
125 	      kernel_ulong_t addr,
126 	      unsigned int len,
127 	      const struct xlat *const table,
128 	      const char *const dflt,
129 	      const nla_decoder_t *const decoders,
130 	      const unsigned int size,
131 	      const void *const opaque_data)
132 {
133 	struct nlattr nla;
134 	bool is_array = false;
135 	unsigned int elt;
136 
137 	if (decoders && !size && opaque_data)
138 		error_func_msg("[xlat %p, dflt \"%s\", decoders %p] "
139 			       "size is zero (going to pass nla_type as "
140 			       "decoder argument), but opaque data (%p) is not "
141 			       "- will be ignored",
142 			       table, dflt, decoders, opaque_data);
143 
144 	for (elt = 0; fetch_nlattr(tcp, &nla, addr, len, is_array); elt++) {
145 		if (abbrev(tcp) && elt == max_strlen) {
146 			tprints("...");
147 			break;
148 		}
149 
150 		const unsigned int nla_len = NLA_ALIGN(nla.nla_len);
151 		kernel_ulong_t next_addr = 0;
152 		unsigned int next_len = 0;
153 
154 		if (nla.nla_len >= NLA_HDRLEN) {
155 			next_len = (len >= nla_len) ? len - nla_len : 0;
156 
157 			if (next_len && addr + nla_len > addr)
158 				next_addr = addr + nla_len;
159 		}
160 
161 		if (!is_array && next_addr) {
162 			tprints("[");
163 			is_array = true;
164 		}
165 
166 		decode_nlattr_with_data(tcp, &nla, addr, len, table, dflt,
167 					decoders, size, opaque_data);
168 
169 		if (!next_addr)
170 			break;
171 
172 		tprints(", ");
173 		addr = next_addr;
174 		len = next_len;
175 	}
176 
177 	if (is_array) {
178 		tprints("]");
179 	}
180 }
181 
182 bool
decode_nla_str(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)183 decode_nla_str(struct tcb *const tcp,
184 	       const kernel_ulong_t addr,
185 	       const unsigned int len,
186 	       const void *const opaque_data)
187 {
188 	printstr_ex(tcp, addr, len, QUOTE_0_TERMINATED);
189 
190 	return true;
191 }
192 
193 bool
decode_nla_strn(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)194 decode_nla_strn(struct tcb *const tcp,
195 		const kernel_ulong_t addr,
196 		const unsigned int len,
197 		const void *const opaque_data)
198 {
199 	printstrn(tcp, addr, len);
200 
201 	return true;
202 }
203 
204 bool
decode_nla_meminfo(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)205 decode_nla_meminfo(struct tcb *const tcp,
206 		   const kernel_ulong_t addr,
207 		   const unsigned int len,
208 		   const void *const opaque_data)
209 {
210 	uint32_t mem;
211 	const size_t nmemb = len / sizeof(mem);
212 
213 	if (!nmemb)
214 		return false;
215 
216 	unsigned int count = 0;
217 	print_array_ex(tcp, addr, nmemb, &mem, sizeof(mem),
218 		       tfetch_mem, print_uint32_array_member, &count,
219 		       PAF_PRINT_INDICES | PAF_INDEX_XLAT_VALUE_INDEXED
220 			| XLAT_STYLE_FMT_U,
221 		       ARRSZ_PAIR(netlink_sk_meminfo_indices),
222 		       "SK_MEMINFO_???");
223 
224 	return true;
225 }
226 
227 bool
decode_nla_fd(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)228 decode_nla_fd(struct tcb *const tcp,
229 	      const kernel_ulong_t addr,
230 	      const unsigned int len,
231 	      const void *const opaque_data)
232 {
233 	int fd;
234 
235 	if (len < sizeof(fd))
236 		return false;
237 	else if (!umove_or_printaddr(tcp, addr, &fd))
238 		printfd(tcp, fd);
239 
240 	return true;
241 }
242 
243 bool
decode_nla_uid(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)244 decode_nla_uid(struct tcb *const tcp,
245 	       const kernel_ulong_t addr,
246 	       const unsigned int len,
247 	       const void *const opaque_data)
248 {
249 	uint32_t uid;
250 
251 	if (len < sizeof(uid))
252 		return false;
253 	else if (!umove_or_printaddr(tcp, addr, &uid))
254 		printuid("", uid);
255 
256 	return true;
257 }
258 
259 bool
decode_nla_gid(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)260 decode_nla_gid(struct tcb *const tcp,
261 	       const kernel_ulong_t addr,
262 	       const unsigned int len,
263 	       const void *const opaque_data)
264 {
265 	return decode_nla_uid(tcp, addr, len, opaque_data);
266 }
267 
268 bool
decode_nla_ifindex(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)269 decode_nla_ifindex(struct tcb *const tcp,
270 	       const kernel_ulong_t addr,
271 	       const unsigned int len,
272 	       const void *const opaque_data)
273 {
274 	uint32_t ifindex;
275 
276 	if (len < sizeof(ifindex))
277 		return false;
278 	else if (!umove_or_printaddr(tcp, addr, &ifindex))
279 		print_ifindex(ifindex);
280 
281 	return true;
282 }
283 
284 bool
decode_nla_xval(struct tcb * const tcp,const kernel_ulong_t addr,unsigned int len,const void * const opaque_data)285 decode_nla_xval(struct tcb *const tcp,
286 		const kernel_ulong_t addr,
287 		unsigned int len,
288 		const void *const opaque_data)
289 {
290 	const struct decode_nla_xlat_opts * const opts = opaque_data;
291 	union {
292 		uint64_t val;
293 		uint8_t  bytes[sizeof(uint64_t)];
294 	} data = { .val = 0 };
295 
296 	if (len > sizeof(data) || len < opts->size)
297 		return false;
298 
299 	if (opts->size)
300 		len = MIN(len, opts->size);
301 
302 	const size_t bytes_offs = is_bigendian ? sizeof(data) - len : 0;
303 
304 	if (!umoven_or_printaddr(tcp, addr, len, data.bytes + bytes_offs)) {
305 		if (opts->process_fn)
306 			data.val = opts->process_fn(data.val);
307 		if (opts->prefix)
308 			tprints(opts->prefix);
309 		printxval_dispatch_ex(opts->xlat, opts->xlat_size, data.val,
310 				      opts->dflt, opts->xt, opts->style);
311 		if (opts->suffix)
312 			tprints(opts->suffix);
313 	}
314 
315 	return true;
316 }
317 
318 static uint64_t
process_host_order(uint64_t val)319 process_host_order(uint64_t val)
320 {
321 	return ntohs(val);
322 }
323 
324 bool
decode_nla_ether_proto(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)325 decode_nla_ether_proto(struct tcb *const tcp,
326 		       const kernel_ulong_t addr,
327 		       const unsigned int len,
328 		       const void *const opaque_data)
329 {
330 	const struct decode_nla_xlat_opts opts = {
331 		.xlat = ethernet_protocols,
332 		.xlat_size = ethernet_protocols_size,
333 		.dflt = "ETHER_P_???",
334 		.xt = XT_SORTED,
335 		.prefix = "htons(",
336 		.suffix = ")",
337 		.size = 2,
338 		.process_fn = process_host_order,
339 	};
340 
341 	return decode_nla_xval(tcp, addr, len, &opts);
342 }
343 
344 bool
decode_nla_ip_proto(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)345 decode_nla_ip_proto(struct tcb *const tcp,
346 		    const kernel_ulong_t addr,
347 		    const unsigned int len,
348 		    const void *const opaque_data)
349 {
350 	const struct decode_nla_xlat_opts opts = {
351 		.xlat = inet_protocols,
352 		.xlat_size = inet_protocols_size,
353 		.xt = XT_SORTED,
354 		.dflt = "IPPROTO_???",
355 		.size = 1,
356 	};
357 
358 	return decode_nla_xval(tcp, addr, len, &opts);
359 }
360 
361 bool
decode_nla_in_addr(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)362 decode_nla_in_addr(struct tcb *const tcp,
363 		   const kernel_ulong_t addr,
364 		   const unsigned int len,
365 		   const void *const opaque_data)
366 {
367 	struct in_addr in;
368 
369 	if (len < sizeof(in))
370 		return false;
371 	else if (!umove_or_printaddr(tcp, addr, &in))
372 		print_inet_addr(AF_INET, &in, sizeof(in), NULL);
373 
374 	return true;
375 }
376 
377 bool
decode_nla_in6_addr(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)378 decode_nla_in6_addr(struct tcb *const tcp,
379 		    const kernel_ulong_t addr,
380 		    const unsigned int len,
381 		    const void *const opaque_data)
382 {
383 	struct in6_addr in6;
384 
385 	if (len < sizeof(in6))
386 		return false;
387 	else if (!umove_or_printaddr(tcp, addr, &in6))
388 		print_inet_addr(AF_INET6, &in6, sizeof(in6), NULL);
389 
390 	return true;
391 }
392 
393 bool
decode_nla_flags(struct tcb * const tcp,const kernel_ulong_t addr,unsigned int len,const void * const opaque_data)394 decode_nla_flags(struct tcb *const tcp,
395 		 const kernel_ulong_t addr,
396 		 unsigned int len,
397 		 const void *const opaque_data)
398 {
399 	const struct decode_nla_xlat_opts * const opts = opaque_data;
400 	union {
401 		uint64_t flags;
402 		uint8_t  bytes[sizeof(uint64_t)];
403 	} data = { .flags = 0 };
404 
405 	if (len > sizeof(data) || len < opts->size)
406 		return false;
407 
408 	if (opts->size)
409 		len = MIN(len, opts->size);
410 
411 	const size_t bytes_offs = is_bigendian ? sizeof(data) - len : 0;
412 
413 	if (opts->xt == XT_INDEXED)
414 		error_func_msg("indexed xlats are currently incompatible with "
415 			       "printflags");
416 
417 	if (!umoven_or_printaddr(tcp, addr, len, data.bytes + bytes_offs)) {
418 		if (opts->process_fn)
419 			data.flags = opts->process_fn(data.flags);
420 		if (opts->prefix)
421 			tprints(opts->prefix);
422 		printflags_ex(data.flags, opts->dflt, opts->style, opts->xlat,
423 			      NULL);
424 		if (opts->suffix)
425 			tprints(opts->suffix);
426 	}
427 
428 	return true;
429 }
430 
431 bool
decode_nla_be16(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)432 decode_nla_be16(struct tcb *const tcp,
433 		const kernel_ulong_t addr,
434 		const unsigned int len,
435 		const void *const opaque_data)
436 {
437 	uint16_t num;
438 
439 	if (len < sizeof(num))
440 		return false;
441 	else if (!umove_or_printaddr(tcp, addr, &num))
442 		tprintf("htons(%u)", ntohs(num));
443 
444 	return true;
445 }
446 
447 bool
decode_nla_be64(struct tcb * const tcp,const kernel_ulong_t addr,const unsigned int len,const void * const opaque_data)448 decode_nla_be64(struct tcb *const tcp,
449 		const kernel_ulong_t addr,
450 		const unsigned int len,
451 		const void *const opaque_data)
452 {
453 #if defined HAVE_BE64TOH || defined be64toh
454 	uint64_t num;
455 
456 	if (len < sizeof(num))
457 		return false;
458 	else if (!umove_or_printaddr(tcp, addr, &num))
459 		tprintf("htobe64(%" PRIu64 ")", be64toh(num));
460 
461 	return true;
462 #else
463 	return false;
464 #endif
465 }
466 
467 #define DECODE_NLA_INTEGER(name, type, fmt)		\
468 bool							\
469 decode_nla_ ## name(struct tcb *const tcp,		\
470 		    const kernel_ulong_t addr,		\
471 		    const unsigned int len,		\
472 		    const void *const opaque_data)	\
473 {							\
474 	type num;					\
475 							\
476 	if (len < sizeof(num))				\
477 		return false;				\
478 	if (!umove_or_printaddr(tcp, addr, &num))	\
479 		tprintf(fmt, num);			\
480 	return true;					\
481 }
482 
483 DECODE_NLA_INTEGER(x8, uint8_t, "%#" PRIx8)
484 DECODE_NLA_INTEGER(x16, uint16_t, "%#" PRIx16)
485 DECODE_NLA_INTEGER(x32, uint32_t, "%#" PRIx32)
486 DECODE_NLA_INTEGER(x64, uint64_t, "%#" PRIx64)
487 DECODE_NLA_INTEGER(u8, uint8_t, "%" PRIu8)
488 DECODE_NLA_INTEGER(u16, uint16_t, "%" PRIu16)
489 DECODE_NLA_INTEGER(u32, uint32_t, "%" PRIu32)
490 DECODE_NLA_INTEGER(u64, uint64_t, "%" PRIu64)
491 DECODE_NLA_INTEGER(s8, int8_t, "%" PRId8)
492 DECODE_NLA_INTEGER(s16, int16_t, "%" PRId16)
493 DECODE_NLA_INTEGER(s32, int32_t, "%" PRId32)
494 DECODE_NLA_INTEGER(s64, int64_t, "%" PRId64)
495