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