1 /* 2 * Copyright (c) 1991, 1992 Paul Kranenburg <pk (at) cs.few.eur.nl> 3 * Copyright (c) 1993 Branko Lankester <branko (at) hacktic.nl> 4 * Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs (at) world.std.com> 5 * Copyright (c) 1996-2000 Wichert Akkerman <wichert (at) cistron.nl> 6 * Copyright (c) 2005-2016 Dmitry V. Levin <ldv (at) altlinux.org> 7 * Copyright (c) 2016-2017 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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(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 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 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 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 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 } 432 433 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 } 444 445 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
