1 /*
2 * Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
3 * Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
4 * Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
5 * Copyright (c) 1996-2000 Wichert Akkerman <wichert@cistron.nl>
6 * Copyright (c) 2005-2016 Dmitry V. Levin <ldv@altlinux.org>
7 * Copyright (c) 2016-2018 The strace developers.
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. The name of the author may not be used to endorse or promote products
19 * derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #include "defs.h"
34 #include "print_fields.h"
35 #include "msghdr.h"
36 #include <limits.h>
37 #include <arpa/inet.h>
38 #include <netinet/in.h>
39
40 #include "xlat/msg_flags.h"
41 #include "xlat/scmvals.h"
42 #include "xlat/ip_cmsg_types.h"
43
44 #ifndef current_wordsize
45 struct cmsghdr32 {
46 uint32_t cmsg_len;
47 int cmsg_level;
48 int cmsg_type;
49 };
50 #endif
51
52 typedef union {
53 char *ptr;
54 struct cmsghdr *cmsg;
55 #ifndef current_wordsize
56 struct cmsghdr32 *cmsg32;
57 #endif
58 } union_cmsghdr;
59
60 static void
print_scm_rights(struct tcb * tcp,const void * cmsg_data,const unsigned int data_len)61 print_scm_rights(struct tcb *tcp, const void *cmsg_data,
62 const unsigned int data_len)
63 {
64 const int *fds = cmsg_data;
65 const unsigned int nfds = data_len / sizeof(*fds);
66 unsigned int i;
67
68 tprints("[");
69
70 for (i = 0; i < nfds; ++i) {
71 if (i)
72 tprints(", ");
73 if (abbrev(tcp) && i >= max_strlen) {
74 tprints("...");
75 break;
76 }
77 printfd(tcp, fds[i]);
78 }
79
80 tprints("]");
81 }
82
83 static void
print_scm_creds(struct tcb * tcp,const void * cmsg_data,const unsigned int data_len)84 print_scm_creds(struct tcb *tcp, const void *cmsg_data,
85 const unsigned int data_len)
86 {
87 const struct ucred *uc = cmsg_data;
88
89 PRINT_FIELD_U("{", *uc, pid);
90 PRINT_FIELD_UID(", ", *uc, uid);
91 PRINT_FIELD_UID(", ", *uc, gid);
92 tprints("}");
93 }
94
95 static void
print_scm_security(struct tcb * tcp,const void * cmsg_data,const unsigned int data_len)96 print_scm_security(struct tcb *tcp, const void *cmsg_data,
97 const unsigned int data_len)
98 {
99 print_quoted_string(cmsg_data, data_len, 0);
100 }
101
102 static void
print_scm_timestamp(struct tcb * tcp,const void * cmsg_data,const unsigned int data_len)103 print_scm_timestamp(struct tcb *tcp, const void *cmsg_data,
104 const unsigned int data_len)
105 {
106 print_struct_timeval_data_size(cmsg_data, data_len);
107 }
108
109 static void
print_scm_timestampns(struct tcb * tcp,const void * cmsg_data,const unsigned int data_len)110 print_scm_timestampns(struct tcb *tcp, const void *cmsg_data,
111 const unsigned int data_len)
112 {
113 print_struct_timespec_data_size(cmsg_data, data_len);
114 }
115
116 static void
print_scm_timestamping(struct tcb * tcp,const void * cmsg_data,const unsigned int data_len)117 print_scm_timestamping(struct tcb *tcp, const void *cmsg_data,
118 const unsigned int data_len)
119 {
120 print_struct_timespec_array_data_size(cmsg_data, 3, data_len);
121 }
122
123 static void
print_cmsg_ip_pktinfo(struct tcb * tcp,const void * cmsg_data,const unsigned int data_len)124 print_cmsg_ip_pktinfo(struct tcb *tcp, const void *cmsg_data,
125 const unsigned int data_len)
126 {
127 const struct in_pktinfo *info = cmsg_data;
128
129 PRINT_FIELD_IFINDEX("{", *info, ipi_ifindex);
130 PRINT_FIELD_INET4_ADDR(", ", *info, ipi_spec_dst);
131 PRINT_FIELD_INET4_ADDR(", ", *info, ipi_addr);
132 tprints("}");
133 }
134
135 static void
print_cmsg_uint(struct tcb * tcp,const void * cmsg_data,const unsigned int data_len)136 print_cmsg_uint(struct tcb *tcp, const void *cmsg_data,
137 const unsigned int data_len)
138 {
139 const unsigned int *p = cmsg_data;
140
141 tprintf("[%u]", *p);
142 }
143
144 static void
print_cmsg_uint8_t(struct tcb * tcp,const void * cmsg_data,const unsigned int data_len)145 print_cmsg_uint8_t(struct tcb *tcp, const void *cmsg_data,
146 const unsigned int data_len)
147 {
148 const uint8_t *p = cmsg_data;
149
150 tprintf("[%#x]", *p);
151 }
152
153 static void
print_cmsg_ip_opts(struct tcb * tcp,const void * cmsg_data,const unsigned int data_len)154 print_cmsg_ip_opts(struct tcb *tcp, const void *cmsg_data,
155 const unsigned int data_len)
156 {
157 const unsigned char *opts = cmsg_data;
158 unsigned int i;
159
160 tprints("[");
161 for (i = 0; i < data_len; ++i) {
162 if (i)
163 tprints(", ");
164 if (abbrev(tcp) && i >= max_strlen) {
165 tprints("...");
166 break;
167 }
168 tprintf("0x%02x", opts[i]);
169 }
170 tprints("]");
171 }
172
173 struct sock_ee {
174 uint32_t ee_errno;
175 uint8_t ee_origin;
176 uint8_t ee_type;
177 uint8_t ee_code;
178 uint8_t ee_pad;
179 uint32_t ee_info;
180 uint32_t ee_data;
181 struct sockaddr_in offender;
182 };
183
184 static void
print_cmsg_ip_recverr(struct tcb * tcp,const void * cmsg_data,const unsigned int data_len)185 print_cmsg_ip_recverr(struct tcb *tcp, const void *cmsg_data,
186 const unsigned int data_len)
187 {
188 const struct sock_ee *const err = cmsg_data;
189
190 PRINT_FIELD_U("{", *err, ee_errno);
191 PRINT_FIELD_U(", ", *err, ee_origin);
192 PRINT_FIELD_U(", ", *err, ee_type);
193 PRINT_FIELD_U(", ", *err, ee_code);
194 PRINT_FIELD_U(", ", *err, ee_info);
195 PRINT_FIELD_U(", ", *err, ee_data);
196 PRINT_FIELD_SOCKADDR(", ", *err, offender);
197 tprints("}");
198 }
199
200 static void
print_cmsg_ip_origdstaddr(struct tcb * tcp,const void * cmsg_data,const unsigned int data_len)201 print_cmsg_ip_origdstaddr(struct tcb *tcp, const void *cmsg_data,
202 const unsigned int data_len)
203 {
204 const unsigned int addr_len =
205 data_len > sizeof(struct sockaddr_storage)
206 ? sizeof(struct sockaddr_storage) : data_len;
207
208 print_sockaddr(cmsg_data, addr_len);
209 }
210
211 typedef void (* const cmsg_printer)(struct tcb *, const void *, unsigned int);
212
213 static const struct {
214 const cmsg_printer printer;
215 const unsigned int min_len;
216 } cmsg_socket_printers[] = {
217 [SCM_RIGHTS] = { print_scm_rights, sizeof(int) },
218 [SCM_CREDENTIALS] = { print_scm_creds, sizeof(struct ucred) },
219 [SCM_SECURITY] = { print_scm_security, 1 },
220 [SCM_TIMESTAMP] = { print_scm_timestamp, 1 },
221 [SCM_TIMESTAMPNS] = { print_scm_timestampns, 1 },
222 [SCM_TIMESTAMPING] = { print_scm_timestamping, 1 }
223 }, cmsg_ip_printers[] = {
224 [IP_PKTINFO] = { print_cmsg_ip_pktinfo, sizeof(struct in_pktinfo) },
225 [IP_TTL] = { print_cmsg_uint, sizeof(unsigned int) },
226 [IP_TOS] = { print_cmsg_uint8_t, 1 },
227 [IP_RECVOPTS] = { print_cmsg_ip_opts, 1 },
228 [IP_RETOPTS] = { print_cmsg_ip_opts, 1 },
229 [IP_RECVERR] = { print_cmsg_ip_recverr, sizeof(struct sock_ee) },
230 [IP_ORIGDSTADDR] = { print_cmsg_ip_origdstaddr, sizeof(struct sockaddr_in) },
231 [IP_CHECKSUM] = { print_cmsg_uint, sizeof(unsigned int) },
232 [SCM_SECURITY] = { print_scm_security, 1 }
233 };
234
235 static void
print_cmsg_type_data(struct tcb * tcp,const int cmsg_level,const int cmsg_type,const void * cmsg_data,const unsigned int data_len)236 print_cmsg_type_data(struct tcb *tcp, const int cmsg_level, const int cmsg_type,
237 const void *cmsg_data, const unsigned int data_len)
238 {
239 const unsigned int utype = cmsg_type;
240 switch (cmsg_level) {
241 case SOL_SOCKET:
242 printxval(scmvals, cmsg_type, "SCM_???");
243 if (utype < ARRAY_SIZE(cmsg_socket_printers)
244 && cmsg_socket_printers[utype].printer
245 && data_len >= cmsg_socket_printers[utype].min_len) {
246 tprints(", cmsg_data=");
247 cmsg_socket_printers[utype].printer(tcp, cmsg_data, data_len);
248 }
249 break;
250 case SOL_IP:
251 printxval(ip_cmsg_types, cmsg_type, "IP_???");
252 if (utype < ARRAY_SIZE(cmsg_ip_printers)
253 && cmsg_ip_printers[utype].printer
254 && data_len >= cmsg_ip_printers[utype].min_len) {
255 tprints(", cmsg_data=");
256 cmsg_ip_printers[utype].printer(tcp, cmsg_data, data_len);
257 }
258 break;
259 default:
260 tprintf("%#x", cmsg_type);
261 }
262 }
263
264 static unsigned int
get_optmem_max(struct tcb * tcp)265 get_optmem_max(struct tcb *tcp)
266 {
267 static int optmem_max;
268
269 if (!optmem_max) {
270 if (read_int_from_file(tcp, "/proc/sys/net/core/optmem_max",
271 &optmem_max) || optmem_max <= 0) {
272 optmem_max = sizeof(long long) * (2 * IOV_MAX + 512);
273 } else {
274 optmem_max = (optmem_max + sizeof(long long) - 1)
275 & ~(sizeof(long long) - 1);
276 }
277 }
278
279 return optmem_max;
280 }
281
282 static void
decode_msg_control(struct tcb * const tcp,const kernel_ulong_t addr,const kernel_ulong_t in_control_len)283 decode_msg_control(struct tcb *const tcp, const kernel_ulong_t addr,
284 const kernel_ulong_t in_control_len)
285 {
286 if (!in_control_len)
287 return;
288 tprints(", msg_control=");
289
290 const unsigned int cmsg_size =
291 #ifndef current_wordsize
292 (current_wordsize < sizeof(long)) ? sizeof(struct cmsghdr32) :
293 #endif
294 sizeof(struct cmsghdr);
295
296 unsigned int control_len = in_control_len > get_optmem_max(tcp)
297 ? get_optmem_max(tcp) : in_control_len;
298 unsigned int buf_len = control_len;
299 char *buf = buf_len < cmsg_size ? NULL : malloc(buf_len);
300 if (!buf || umoven(tcp, addr, buf_len, buf) < 0) {
301 printaddr(addr);
302 free(buf);
303 return;
304 }
305
306 union_cmsghdr u = { .ptr = buf };
307
308 tprints("[");
309 while (buf_len >= cmsg_size) {
310 const kernel_ulong_t cmsg_len =
311 #ifndef current_wordsize
312 (current_wordsize < sizeof(long)) ? u.cmsg32->cmsg_len :
313 #endif
314 u.cmsg->cmsg_len;
315 const int cmsg_level =
316 #ifndef current_wordsize
317 (current_wordsize < sizeof(long)) ? u.cmsg32->cmsg_level :
318 #endif
319 u.cmsg->cmsg_level;
320 const int cmsg_type =
321 #ifndef current_wordsize
322 (current_wordsize < sizeof(long)) ? u.cmsg32->cmsg_type :
323 #endif
324 u.cmsg->cmsg_type;
325
326 if (u.ptr != buf)
327 tprints(", ");
328 tprintf("{cmsg_len=%" PRI_klu ", cmsg_level=", cmsg_len);
329 printxval(socketlayers, cmsg_level, "SOL_???");
330 tprints(", cmsg_type=");
331
332 kernel_ulong_t len = cmsg_len > buf_len ? buf_len : cmsg_len;
333
334 print_cmsg_type_data(tcp, cmsg_level, cmsg_type,
335 (const void *) (u.ptr + cmsg_size),
336 len > cmsg_size ? len - cmsg_size : 0);
337 tprints("}");
338
339 if (len < cmsg_size) {
340 buf_len -= cmsg_size;
341 break;
342 }
343 len = (cmsg_len + current_wordsize - 1) &
344 ~((kernel_ulong_t) current_wordsize - 1);
345 if (len >= buf_len) {
346 buf_len = 0;
347 break;
348 }
349 u.ptr += len;
350 buf_len -= len;
351 }
352 if (buf_len) {
353 tprints(", ...");
354 printaddr_comment(addr + (control_len - buf_len));
355 } else if (control_len < in_control_len) {
356 tprints(", ...");
357 }
358 tprints("]");
359 free(buf);
360 }
361
362 void
print_struct_msghdr(struct tcb * tcp,const struct msghdr * msg,const int * const p_user_msg_namelen,const kernel_ulong_t data_size)363 print_struct_msghdr(struct tcb *tcp, const struct msghdr *msg,
364 const int *const p_user_msg_namelen,
365 const kernel_ulong_t data_size)
366 {
367 const int msg_namelen =
368 p_user_msg_namelen && (int) msg->msg_namelen > *p_user_msg_namelen
369 ? *p_user_msg_namelen : (int) msg->msg_namelen;
370
371 tprints("{msg_name=");
372 const int family =
373 decode_sockaddr(tcp, ptr_to_kulong(msg->msg_name), msg_namelen);
374 const enum iov_decode decode =
375 (family == AF_NETLINK) ? IOV_DECODE_NETLINK : IOV_DECODE_STR;
376
377 tprints(", msg_namelen=");
378 if (p_user_msg_namelen && *p_user_msg_namelen != (int) msg->msg_namelen)
379 tprintf("%d->", *p_user_msg_namelen);
380 tprintf("%d", msg->msg_namelen);
381
382 tprints(", msg_iov=");
383 tprint_iov_upto(tcp, msg->msg_iovlen,
384 ptr_to_kulong(msg->msg_iov), decode, data_size);
385 PRINT_FIELD_U(", ", *msg, msg_iovlen);
386
387 decode_msg_control(tcp, ptr_to_kulong(msg->msg_control),
388 msg->msg_controllen);
389 PRINT_FIELD_U(", ", *msg, msg_controllen);
390
391 PRINT_FIELD_FLAGS(", ", *msg, msg_flags, msg_flags, "MSG_???");
392 tprints("}");
393 }
394
395 static bool
fetch_msghdr_namelen(struct tcb * const tcp,const kernel_ulong_t addr,int * const p_msg_namelen)396 fetch_msghdr_namelen(struct tcb *const tcp, const kernel_ulong_t addr,
397 int *const p_msg_namelen)
398 {
399 struct msghdr msg;
400
401 if (addr && verbose(tcp) && fetch_struct_msghdr(tcp, addr, &msg)) {
402 *p_msg_namelen = msg.msg_namelen;
403 return true;
404 } else {
405 return false;
406 }
407 }
408
409 static void
decode_msghdr(struct tcb * const tcp,const int * const p_user_msg_namelen,const kernel_ulong_t addr,const kernel_ulong_t data_size)410 decode_msghdr(struct tcb *const tcp, const int *const p_user_msg_namelen,
411 const kernel_ulong_t addr, const kernel_ulong_t data_size)
412 {
413 struct msghdr msg;
414
415 if (addr && verbose(tcp) && fetch_struct_msghdr(tcp, addr, &msg))
416 print_struct_msghdr(tcp, &msg, p_user_msg_namelen, data_size);
417 else
418 printaddr(addr);
419 }
420
421 void
dumpiov_in_msghdr(struct tcb * const tcp,const kernel_ulong_t addr,const kernel_ulong_t data_size)422 dumpiov_in_msghdr(struct tcb *const tcp, const kernel_ulong_t addr,
423 const kernel_ulong_t data_size)
424 {
425 struct msghdr msg;
426
427 if (fetch_struct_msghdr(tcp, addr, &msg)) {
428 dumpiov_upto(tcp, msg.msg_iovlen,
429 ptr_to_kulong(msg.msg_iov), data_size);
430 }
431 }
432
SYS_FUNC(sendmsg)433 SYS_FUNC(sendmsg)
434 {
435 printfd(tcp, tcp->u_arg[0]);
436 tprints(", ");
437 decode_msghdr(tcp, 0, tcp->u_arg[1], -1);
438 /* flags */
439 tprints(", ");
440 printflags(msg_flags, tcp->u_arg[2], "MSG_???");
441
442 return RVAL_DECODED;
443 }
444
SYS_FUNC(recvmsg)445 SYS_FUNC(recvmsg)
446 {
447 int msg_namelen;
448
449 if (entering(tcp)) {
450 printfd(tcp, tcp->u_arg[0]);
451 tprints(", ");
452 if (fetch_msghdr_namelen(tcp, tcp->u_arg[1], &msg_namelen)) {
453 set_tcb_priv_ulong(tcp, msg_namelen);
454 return 0;
455 }
456 printaddr(tcp->u_arg[1]);
457 } else {
458 msg_namelen = get_tcb_priv_ulong(tcp);
459
460 if (syserror(tcp))
461 tprintf("{msg_namelen=%d}", msg_namelen);
462 else
463 decode_msghdr(tcp, &msg_namelen, tcp->u_arg[1],
464 tcp->u_rval);
465 }
466
467 /* flags */
468 tprints(", ");
469 printflags(msg_flags, tcp->u_arg[2], "MSG_???");
470
471 return RVAL_DECODED;
472 }
473