1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2007-2009 5 * Swinburne University of Technology, Melbourne, Australia. 6 * Copyright (c) 2009-2010, The FreeBSD Foundation 7 * All rights reserved. 8 * 9 * Portions of this software were developed at the Centre for Advanced 10 * Internet Architectures, Swinburne University of Technology, Melbourne, 11 * Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 /****************************************************** 36 * Statistical Information For TCP Research (SIFTR) 37 * 38 * A FreeBSD kernel module that adds very basic intrumentation to the 39 * TCP stack, allowing internal stats to be recorded to a log file 40 * for experimental, debugging and performance analysis purposes. 41 * 42 * SIFTR was first released in 2007 by James Healy and Lawrence Stewart whilst 43 * working on the NewTCP research project at Swinburne University of 44 * Technology's Centre for Advanced Internet Architectures, Melbourne, 45 * Australia, which was made possible in part by a grant from the Cisco 46 * University Research Program Fund at Community Foundation Silicon Valley. 47 * More details are available at: 48 * http://caia.swin.edu.au/urp/newtcp/ 49 * 50 * Work on SIFTR v1.2.x was sponsored by the FreeBSD Foundation as part of 51 * the "Enhancing the FreeBSD TCP Implementation" project 2008-2009. 52 * More details are available at: 53 * http://www.freebsdfoundation.org/ 54 * http://caia.swin.edu.au/freebsd/etcp09/ 55 * 56 * Lawrence Stewart is the current maintainer, and all contact regarding 57 * SIFTR should be directed to him via email: lastewart@swin.edu.au 58 * 59 * Initial release date: June 2007 60 * Most recent update: September 2010 61 ******************************************************/ 62 63 #include <sys/cdefs.h> 64 __FBSDID("$FreeBSD$"); 65 66 #include <sys/param.h> 67 #include <sys/alq.h> 68 #include <sys/errno.h> 69 #include <sys/eventhandler.h> 70 #include <sys/hash.h> 71 #include <sys/kernel.h> 72 #include <sys/kthread.h> 73 #include <sys/lock.h> 74 #include <sys/mbuf.h> 75 #include <sys/module.h> 76 #include <sys/mutex.h> 77 #include <sys/pcpu.h> 78 #include <sys/proc.h> 79 #include <sys/sbuf.h> 80 #include <sys/sdt.h> 81 #include <sys/smp.h> 82 #include <sys/socket.h> 83 #include <sys/socketvar.h> 84 #include <sys/sysctl.h> 85 #include <sys/unistd.h> 86 87 #include <net/if.h> 88 #include <net/if_var.h> 89 #include <net/pfil.h> 90 91 #include <netinet/in.h> 92 #include <netinet/in_kdtrace.h> 93 #include <netinet/in_pcb.h> 94 #include <netinet/in_systm.h> 95 #include <netinet/in_var.h> 96 #include <netinet/ip.h> 97 #include <netinet/ip_var.h> 98 #include <netinet/tcp_var.h> 99 100 #ifdef SIFTR_IPV6 101 #include <netinet/ip6.h> 102 #include <netinet6/ip6_var.h> 103 #include <netinet6/in6_pcb.h> 104 #endif /* SIFTR_IPV6 */ 105 106 #include <machine/in_cksum.h> 107 108 /* 109 * Three digit version number refers to X.Y.Z where: 110 * X is the major version number 111 * Y is bumped to mark backwards incompatible changes 112 * Z is bumped to mark backwards compatible changes 113 */ 114 #define V_MAJOR 1 115 #define V_BACKBREAK 3 116 #define V_BACKCOMPAT 0 117 #define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT)) 118 #define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \ 119 __XSTRING(V_BACKCOMPAT) 120 121 #define HOOK 0 122 #define UNHOOK 1 123 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536 124 #define SYS_NAME "FreeBSD" 125 #define PACKET_TAG_SIFTR 100 126 #define PACKET_COOKIE_SIFTR 21749576 127 #define SIFTR_LOG_FILE_MODE 0644 128 #define SIFTR_DISABLE 0 129 #define SIFTR_ENABLE 1 130 131 /* 132 * Hard upper limit on the length of log messages. Bump this up if you add new 133 * data fields such that the line length could exceed the below value. 134 */ 135 #define MAX_LOG_MSG_LEN 300 136 /* XXX: Make this a sysctl tunable. */ 137 #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN) 138 139 /* 140 * 1 byte for IP version 141 * IPv4: src/dst IP (4+4) + src/dst port (2+2) = 12 bytes 142 * IPv6: src/dst IP (16+16) + src/dst port (2+2) = 36 bytes 143 */ 144 #ifdef SIFTR_IPV6 145 #define FLOW_KEY_LEN 37 146 #else 147 #define FLOW_KEY_LEN 13 148 #endif 149 150 #ifdef SIFTR_IPV6 151 #define SIFTR_IPMODE 6 152 #else 153 #define SIFTR_IPMODE 4 154 #endif 155 156 /* useful macros */ 157 #define UPPER_SHORT(X) (((X) & 0xFFFF0000) >> 16) 158 #define LOWER_SHORT(X) ((X) & 0x0000FFFF) 159 160 #define FIRST_OCTET(X) (((X) & 0xFF000000) >> 24) 161 #define SECOND_OCTET(X) (((X) & 0x00FF0000) >> 16) 162 #define THIRD_OCTET(X) (((X) & 0x0000FF00) >> 8) 163 #define FOURTH_OCTET(X) ((X) & 0x000000FF) 164 165 static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR"); 166 static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode", 167 "SIFTR pkt_node struct"); 168 static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode", 169 "SIFTR flow_hash_node struct"); 170 171 /* Used as links in the pkt manager queue. */ 172 struct pkt_node { 173 /* Timestamp of pkt as noted in the pfil hook. */ 174 struct timeval tval; 175 /* Direction pkt is travelling. */ 176 enum { 177 DIR_IN = 0, 178 DIR_OUT = 1, 179 } direction; 180 /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */ 181 uint8_t ipver; 182 /* Hash of the pkt which triggered the log message. */ 183 uint32_t hash; 184 /* Local/foreign IP address. */ 185 #ifdef SIFTR_IPV6 186 uint32_t ip_laddr[4]; 187 uint32_t ip_faddr[4]; 188 #else 189 uint8_t ip_laddr[4]; 190 uint8_t ip_faddr[4]; 191 #endif 192 /* Local TCP port. */ 193 uint16_t tcp_localport; 194 /* Foreign TCP port. */ 195 uint16_t tcp_foreignport; 196 /* Congestion Window (bytes). */ 197 uint32_t snd_cwnd; 198 /* Sending Window (bytes). */ 199 uint32_t snd_wnd; 200 /* Receive Window (bytes). */ 201 uint32_t rcv_wnd; 202 /* More tcpcb flags storage */ 203 uint32_t t_flags2; 204 /* Slow Start Threshold (bytes). */ 205 uint32_t snd_ssthresh; 206 /* Current state of the TCP FSM. */ 207 int conn_state; 208 /* Max Segment Size (bytes). */ 209 u_int max_seg_size; 210 /* Smoothed RTT (usecs). */ 211 uint32_t srtt; 212 /* Is SACK enabled? */ 213 u_char sack_enabled; 214 /* Window scaling for snd window. */ 215 u_char snd_scale; 216 /* Window scaling for recv window. */ 217 u_char rcv_scale; 218 /* TCP control block flags. */ 219 u_int flags; 220 /* Retransmission timeout (usec). */ 221 uint32_t rto; 222 /* Size of the TCP send buffer in bytes. */ 223 u_int snd_buf_hiwater; 224 /* Current num bytes in the send socket buffer. */ 225 u_int snd_buf_cc; 226 /* Size of the TCP receive buffer in bytes. */ 227 u_int rcv_buf_hiwater; 228 /* Current num bytes in the receive socket buffer. */ 229 u_int rcv_buf_cc; 230 /* Number of bytes inflight that we are waiting on ACKs for. */ 231 u_int sent_inflight_bytes; 232 /* Number of segments currently in the reassembly queue. */ 233 int t_segqlen; 234 /* Flowid for the connection. */ 235 u_int flowid; 236 /* Flow type for the connection. */ 237 u_int flowtype; 238 /* Link to next pkt_node in the list. */ 239 STAILQ_ENTRY(pkt_node) nodes; 240 }; 241 242 struct flow_hash_node 243 { 244 uint16_t counter; 245 uint8_t key[FLOW_KEY_LEN]; 246 LIST_ENTRY(flow_hash_node) nodes; 247 }; 248 249 struct siftr_stats 250 { 251 /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */ 252 uint64_t n_in; 253 uint64_t n_out; 254 /* # pkts skipped due to failed malloc calls. */ 255 uint32_t nskip_in_malloc; 256 uint32_t nskip_out_malloc; 257 /* # pkts skipped due to failed inpcb lookups. */ 258 uint32_t nskip_in_inpcb; 259 uint32_t nskip_out_inpcb; 260 /* # pkts skipped due to failed tcpcb lookups. */ 261 uint32_t nskip_in_tcpcb; 262 uint32_t nskip_out_tcpcb; 263 /* # pkts skipped due to stack reinjection. */ 264 uint32_t nskip_in_dejavu; 265 uint32_t nskip_out_dejavu; 266 }; 267 268 DPCPU_DEFINE_STATIC(struct siftr_stats, ss); 269 270 static volatile unsigned int siftr_exit_pkt_manager_thread = 0; 271 static unsigned int siftr_enabled = 0; 272 static unsigned int siftr_pkts_per_log = 1; 273 static unsigned int siftr_generate_hashes = 0; 274 static uint16_t siftr_port_filter = 0; 275 /* static unsigned int siftr_binary_log = 0; */ 276 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log"; 277 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log"; 278 static u_long siftr_hashmask; 279 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue); 280 LIST_HEAD(listhead, flow_hash_node) *counter_hash; 281 static int wait_for_pkt; 282 static struct alq *siftr_alq = NULL; 283 static struct mtx siftr_pkt_queue_mtx; 284 static struct mtx siftr_pkt_mgr_mtx; 285 static struct thread *siftr_pkt_manager_thr = NULL; 286 static char direction[2] = {'i','o'}; 287 288 /* Required function prototypes. */ 289 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS); 290 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS); 291 292 /* Declare the net.inet.siftr sysctl tree and populate it. */ 293 294 SYSCTL_DECL(_net_inet_siftr); 295 296 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 297 "siftr related settings"); 298 299 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, 300 CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 301 &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU", 302 "switch siftr module operations on/off"); 303 304 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, 305 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &siftr_logfile_shadow, 306 sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler, "A", 307 "file to save siftr log messages to"); 308 309 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW, 310 &siftr_pkts_per_log, 1, 311 "number of packets between generating a log message"); 312 313 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW, 314 &siftr_generate_hashes, 0, 315 "enable packet hash generation"); 316 317 SYSCTL_U16(_net_inet_siftr, OID_AUTO, port_filter, CTLFLAG_RW, 318 &siftr_port_filter, 0, 319 "enable packet filter on a TCP port"); 320 321 /* XXX: TODO 322 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW, 323 &siftr_binary_log, 0, 324 "write log files in binary instead of ascii"); 325 */ 326 327 /* Begin functions. */ 328 329 static void 330 siftr_process_pkt(struct pkt_node * pkt_node) 331 { 332 struct flow_hash_node *hash_node; 333 struct listhead *counter_list; 334 struct siftr_stats *ss; 335 struct ale *log_buf; 336 uint8_t key[FLOW_KEY_LEN]; 337 uint8_t found_match, key_offset; 338 339 hash_node = NULL; 340 ss = DPCPU_PTR(ss); 341 found_match = 0; 342 key_offset = 1; 343 344 /* 345 * Create the key that will be used to create a hash index 346 * into our hash table. Our key consists of: 347 * ipversion, localip, localport, foreignip, foreignport 348 */ 349 key[0] = pkt_node->ipver; 350 memcpy(key + key_offset, &pkt_node->ip_laddr, 351 sizeof(pkt_node->ip_laddr)); 352 key_offset += sizeof(pkt_node->ip_laddr); 353 memcpy(key + key_offset, &pkt_node->tcp_localport, 354 sizeof(pkt_node->tcp_localport)); 355 key_offset += sizeof(pkt_node->tcp_localport); 356 memcpy(key + key_offset, &pkt_node->ip_faddr, 357 sizeof(pkt_node->ip_faddr)); 358 key_offset += sizeof(pkt_node->ip_faddr); 359 memcpy(key + key_offset, &pkt_node->tcp_foreignport, 360 sizeof(pkt_node->tcp_foreignport)); 361 362 counter_list = counter_hash + 363 (hash32_buf(key, sizeof(key), 0) & siftr_hashmask); 364 365 /* 366 * If the list is not empty i.e. the hash index has 367 * been used by another flow previously. 368 */ 369 if (LIST_FIRST(counter_list) != NULL) { 370 /* 371 * Loop through the hash nodes in the list. 372 * There should normally only be 1 hash node in the list, 373 * except if there have been collisions at the hash index 374 * computed by hash32_buf(). 375 */ 376 LIST_FOREACH(hash_node, counter_list, nodes) { 377 /* 378 * Check if the key for the pkt we are currently 379 * processing is the same as the key stored in the 380 * hash node we are currently processing. 381 * If they are the same, then we've found the 382 * hash node that stores the counter for the flow 383 * the pkt belongs to. 384 */ 385 if (memcmp(hash_node->key, key, sizeof(key)) == 0) { 386 found_match = 1; 387 break; 388 } 389 } 390 } 391 392 /* If this flow hash hasn't been seen before or we have a collision. */ 393 if (hash_node == NULL || !found_match) { 394 /* Create a new hash node to store the flow's counter. */ 395 hash_node = malloc(sizeof(struct flow_hash_node), 396 M_SIFTR_HASHNODE, M_WAITOK); 397 398 if (hash_node != NULL) { 399 /* Initialise our new hash node list entry. */ 400 hash_node->counter = 0; 401 memcpy(hash_node->key, key, sizeof(key)); 402 LIST_INSERT_HEAD(counter_list, hash_node, nodes); 403 } else { 404 /* Malloc failed. */ 405 if (pkt_node->direction == DIR_IN) 406 ss->nskip_in_malloc++; 407 else 408 ss->nskip_out_malloc++; 409 410 return; 411 } 412 } else if (siftr_pkts_per_log > 1) { 413 /* 414 * Taking the remainder of the counter divided 415 * by the current value of siftr_pkts_per_log 416 * and storing that in counter provides a neat 417 * way to modulate the frequency of log 418 * messages being written to the log file. 419 */ 420 hash_node->counter = (hash_node->counter + 1) % 421 siftr_pkts_per_log; 422 423 /* 424 * If we have not seen enough packets since the last time 425 * we wrote a log message for this connection, return. 426 */ 427 if (hash_node->counter > 0) 428 return; 429 } 430 431 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK); 432 433 if (log_buf == NULL) 434 return; /* Should only happen if the ALQ is shutting down. */ 435 436 #ifdef SIFTR_IPV6 437 pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]); 438 pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]); 439 440 if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */ 441 pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]); 442 pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]); 443 pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]); 444 pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]); 445 pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]); 446 pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]); 447 448 /* Construct an IPv6 log message. */ 449 log_buf->ae_bytesused = snprintf(log_buf->ae_data, 450 MAX_LOG_MSG_LEN, 451 "%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:" 452 "%x:%x:%x:%x:%x,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u," 453 "%u,%u,%u,%u,%u,%u,%u,%u,%u,%u\n", 454 direction[pkt_node->direction], 455 pkt_node->hash, 456 pkt_node->tval.tv_sec, 457 pkt_node->tval.tv_usec, 458 UPPER_SHORT(pkt_node->ip_laddr[0]), 459 LOWER_SHORT(pkt_node->ip_laddr[0]), 460 UPPER_SHORT(pkt_node->ip_laddr[1]), 461 LOWER_SHORT(pkt_node->ip_laddr[1]), 462 UPPER_SHORT(pkt_node->ip_laddr[2]), 463 LOWER_SHORT(pkt_node->ip_laddr[2]), 464 UPPER_SHORT(pkt_node->ip_laddr[3]), 465 LOWER_SHORT(pkt_node->ip_laddr[3]), 466 ntohs(pkt_node->tcp_localport), 467 UPPER_SHORT(pkt_node->ip_faddr[0]), 468 LOWER_SHORT(pkt_node->ip_faddr[0]), 469 UPPER_SHORT(pkt_node->ip_faddr[1]), 470 LOWER_SHORT(pkt_node->ip_faddr[1]), 471 UPPER_SHORT(pkt_node->ip_faddr[2]), 472 LOWER_SHORT(pkt_node->ip_faddr[2]), 473 UPPER_SHORT(pkt_node->ip_faddr[3]), 474 LOWER_SHORT(pkt_node->ip_faddr[3]), 475 ntohs(pkt_node->tcp_foreignport), 476 pkt_node->snd_ssthresh, 477 pkt_node->snd_cwnd, 478 pkt_node->t_flags2, 479 pkt_node->snd_wnd, 480 pkt_node->rcv_wnd, 481 pkt_node->snd_scale, 482 pkt_node->rcv_scale, 483 pkt_node->conn_state, 484 pkt_node->max_seg_size, 485 pkt_node->srtt, 486 pkt_node->sack_enabled, 487 pkt_node->flags, 488 pkt_node->rto, 489 pkt_node->snd_buf_hiwater, 490 pkt_node->snd_buf_cc, 491 pkt_node->rcv_buf_hiwater, 492 pkt_node->rcv_buf_cc, 493 pkt_node->sent_inflight_bytes, 494 pkt_node->t_segqlen, 495 pkt_node->flowid, 496 pkt_node->flowtype); 497 } else { /* IPv4 packet */ 498 pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]); 499 pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]); 500 pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]); 501 pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]); 502 pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]); 503 pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]); 504 pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]); 505 pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]); 506 #endif /* SIFTR_IPV6 */ 507 508 /* Construct an IPv4 log message. */ 509 log_buf->ae_bytesused = snprintf(log_buf->ae_data, 510 MAX_LOG_MSG_LEN, 511 "%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%u,%u," 512 "%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u\n", 513 direction[pkt_node->direction], 514 pkt_node->hash, 515 (intmax_t)pkt_node->tval.tv_sec, 516 pkt_node->tval.tv_usec, 517 pkt_node->ip_laddr[0], 518 pkt_node->ip_laddr[1], 519 pkt_node->ip_laddr[2], 520 pkt_node->ip_laddr[3], 521 ntohs(pkt_node->tcp_localport), 522 pkt_node->ip_faddr[0], 523 pkt_node->ip_faddr[1], 524 pkt_node->ip_faddr[2], 525 pkt_node->ip_faddr[3], 526 ntohs(pkt_node->tcp_foreignport), 527 pkt_node->snd_ssthresh, 528 pkt_node->snd_cwnd, 529 pkt_node->t_flags2, 530 pkt_node->snd_wnd, 531 pkt_node->rcv_wnd, 532 pkt_node->snd_scale, 533 pkt_node->rcv_scale, 534 pkt_node->conn_state, 535 pkt_node->max_seg_size, 536 pkt_node->srtt, 537 pkt_node->sack_enabled, 538 pkt_node->flags, 539 pkt_node->rto, 540 pkt_node->snd_buf_hiwater, 541 pkt_node->snd_buf_cc, 542 pkt_node->rcv_buf_hiwater, 543 pkt_node->rcv_buf_cc, 544 pkt_node->sent_inflight_bytes, 545 pkt_node->t_segqlen, 546 pkt_node->flowid, 547 pkt_node->flowtype); 548 #ifdef SIFTR_IPV6 549 } 550 #endif 551 552 alq_post_flags(siftr_alq, log_buf, 0); 553 } 554 555 static void 556 siftr_pkt_manager_thread(void *arg) 557 { 558 STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue = 559 STAILQ_HEAD_INITIALIZER(tmp_pkt_queue); 560 struct pkt_node *pkt_node, *pkt_node_temp; 561 uint8_t draining; 562 563 draining = 2; 564 565 mtx_lock(&siftr_pkt_mgr_mtx); 566 567 /* draining == 0 when queue has been flushed and it's safe to exit. */ 568 while (draining) { 569 /* 570 * Sleep until we are signalled to wake because thread has 571 * been told to exit or until 1 tick has passed. 572 */ 573 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait", 574 1); 575 576 /* Gain exclusive access to the pkt_node queue. */ 577 mtx_lock(&siftr_pkt_queue_mtx); 578 579 /* 580 * Move pkt_queue to tmp_pkt_queue, which leaves 581 * pkt_queue empty and ready to receive more pkt_nodes. 582 */ 583 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue); 584 585 /* 586 * We've finished making changes to the list. Unlock it 587 * so the pfil hooks can continue queuing pkt_nodes. 588 */ 589 mtx_unlock(&siftr_pkt_queue_mtx); 590 591 /* 592 * We can't hold a mutex whilst calling siftr_process_pkt 593 * because ALQ might sleep waiting for buffer space. 594 */ 595 mtx_unlock(&siftr_pkt_mgr_mtx); 596 597 /* Flush all pkt_nodes to the log file. */ 598 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes, 599 pkt_node_temp) { 600 siftr_process_pkt(pkt_node); 601 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes); 602 free(pkt_node, M_SIFTR_PKTNODE); 603 } 604 605 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue), 606 ("SIFTR tmp_pkt_queue not empty after flush")); 607 608 mtx_lock(&siftr_pkt_mgr_mtx); 609 610 /* 611 * If siftr_exit_pkt_manager_thread gets set during the window 612 * where we are draining the tmp_pkt_queue above, there might 613 * still be pkts in pkt_queue that need to be drained. 614 * Allow one further iteration to occur after 615 * siftr_exit_pkt_manager_thread has been set to ensure 616 * pkt_queue is completely empty before we kill the thread. 617 * 618 * siftr_exit_pkt_manager_thread is set only after the pfil 619 * hooks have been removed, so only 1 extra iteration 620 * is needed to drain the queue. 621 */ 622 if (siftr_exit_pkt_manager_thread) 623 draining--; 624 } 625 626 mtx_unlock(&siftr_pkt_mgr_mtx); 627 628 /* Calls wakeup on this thread's struct thread ptr. */ 629 kthread_exit(); 630 } 631 632 static uint32_t 633 hash_pkt(struct mbuf *m, uint32_t offset) 634 { 635 uint32_t hash; 636 637 hash = 0; 638 639 while (m != NULL && offset > m->m_len) { 640 /* 641 * The IP packet payload does not start in this mbuf, so 642 * need to figure out which mbuf it starts in and what offset 643 * into the mbuf's data region the payload starts at. 644 */ 645 offset -= m->m_len; 646 m = m->m_next; 647 } 648 649 while (m != NULL) { 650 /* Ensure there is data in the mbuf */ 651 if ((m->m_len - offset) > 0) 652 hash = hash32_buf(m->m_data + offset, 653 m->m_len - offset, hash); 654 655 m = m->m_next; 656 offset = 0; 657 } 658 659 return (hash); 660 } 661 662 /* 663 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that 664 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return. 665 * Return value >0 means the caller should skip processing this mbuf. 666 */ 667 static inline int 668 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss) 669 { 670 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL) 671 != NULL) { 672 if (dir == PFIL_IN) 673 ss->nskip_in_dejavu++; 674 else 675 ss->nskip_out_dejavu++; 676 677 return (1); 678 } else { 679 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR, 680 PACKET_TAG_SIFTR, 0, M_NOWAIT); 681 if (tag == NULL) { 682 if (dir == PFIL_IN) 683 ss->nskip_in_malloc++; 684 else 685 ss->nskip_out_malloc++; 686 687 return (1); 688 } 689 690 m_tag_prepend(m, tag); 691 } 692 693 return (0); 694 } 695 696 /* 697 * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL 698 * otherwise. 699 */ 700 static inline struct inpcb * 701 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport, 702 uint16_t dport, int dir, struct siftr_stats *ss) 703 { 704 struct inpcb *inp; 705 706 /* We need the tcbinfo lock. */ 707 INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo); 708 709 if (dir == PFIL_IN) 710 inp = (ipver == INP_IPV4 ? 711 in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst, 712 dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 713 : 714 #ifdef SIFTR_IPV6 715 in6_pcblookup(&V_tcbinfo, 716 &((struct ip6_hdr *)ip)->ip6_src, sport, 717 &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB, 718 m->m_pkthdr.rcvif) 719 #else 720 NULL 721 #endif 722 ); 723 724 else 725 inp = (ipver == INP_IPV4 ? 726 in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src, 727 sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 728 : 729 #ifdef SIFTR_IPV6 730 in6_pcblookup(&V_tcbinfo, 731 &((struct ip6_hdr *)ip)->ip6_dst, dport, 732 &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB, 733 m->m_pkthdr.rcvif) 734 #else 735 NULL 736 #endif 737 ); 738 739 /* If we can't find the inpcb, bail. */ 740 if (inp == NULL) { 741 if (dir == PFIL_IN) 742 ss->nskip_in_inpcb++; 743 else 744 ss->nskip_out_inpcb++; 745 } 746 747 return (inp); 748 } 749 750 static inline void 751 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp, 752 int ipver, int dir, int inp_locally_locked) 753 { 754 #ifdef SIFTR_IPV6 755 if (ipver == INP_IPV4) { 756 pn->ip_laddr[3] = inp->inp_laddr.s_addr; 757 pn->ip_faddr[3] = inp->inp_faddr.s_addr; 758 #else 759 *((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr; 760 *((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr; 761 #endif 762 #ifdef SIFTR_IPV6 763 } else { 764 pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0]; 765 pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1]; 766 pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2]; 767 pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3]; 768 pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0]; 769 pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1]; 770 pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2]; 771 pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3]; 772 } 773 #endif 774 pn->tcp_localport = inp->inp_lport; 775 pn->tcp_foreignport = inp->inp_fport; 776 pn->snd_cwnd = tp->snd_cwnd; 777 pn->snd_wnd = tp->snd_wnd; 778 pn->rcv_wnd = tp->rcv_wnd; 779 pn->t_flags2 = tp->t_flags2; 780 pn->snd_ssthresh = tp->snd_ssthresh; 781 pn->snd_scale = tp->snd_scale; 782 pn->rcv_scale = tp->rcv_scale; 783 pn->conn_state = tp->t_state; 784 pn->max_seg_size = tp->t_maxseg; 785 pn->srtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT; 786 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0; 787 pn->flags = tp->t_flags; 788 pn->rto = tp->t_rxtcur * tick; 789 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat; 790 pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd); 791 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat; 792 pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv); 793 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una; 794 pn->t_segqlen = tp->t_segqlen; 795 pn->flowid = inp->inp_flowid; 796 pn->flowtype = inp->inp_flowtype; 797 798 /* We've finished accessing the tcb so release the lock. */ 799 if (inp_locally_locked) 800 INP_RUNLOCK(inp); 801 802 pn->ipver = ipver; 803 pn->direction = (dir == PFIL_IN ? DIR_IN : DIR_OUT); 804 805 /* 806 * Significantly more accurate than using getmicrotime(), but slower! 807 * Gives true microsecond resolution at the expense of a hit to 808 * maximum pps throughput processing when SIFTR is loaded and enabled. 809 */ 810 microtime(&pn->tval); 811 TCP_PROBE1(siftr, &pn); 812 813 } 814 815 /* 816 * pfil hook that is called for each IPv4 packet making its way through the 817 * stack in either direction. 818 * The pfil subsystem holds a non-sleepable mutex somewhere when 819 * calling our hook function, so we can't sleep at all. 820 * It's very important to use the M_NOWAIT flag with all function calls 821 * that support it so that they won't sleep, otherwise you get a panic. 822 */ 823 static pfil_return_t 824 siftr_chkpkt(struct mbuf **m, struct ifnet *ifp, int flags, 825 void *ruleset __unused, struct inpcb *inp) 826 { 827 struct pkt_node *pn; 828 struct ip *ip; 829 struct tcphdr *th; 830 struct tcpcb *tp; 831 struct siftr_stats *ss; 832 unsigned int ip_hl; 833 int inp_locally_locked, dir; 834 835 inp_locally_locked = 0; 836 dir = PFIL_DIR(flags); 837 ss = DPCPU_PTR(ss); 838 839 /* 840 * m_pullup is not required here because ip_{input|output} 841 * already do the heavy lifting for us. 842 */ 843 844 ip = mtod(*m, struct ip *); 845 846 /* Only continue processing if the packet is TCP. */ 847 if (ip->ip_p != IPPROTO_TCP) 848 goto ret; 849 850 /* 851 * Create a tcphdr struct starting at the correct offset 852 * in the IP packet. ip->ip_hl gives the ip header length 853 * in 4-byte words, so multiply it to get the size in bytes. 854 */ 855 ip_hl = (ip->ip_hl << 2); 856 th = (struct tcphdr *)((caddr_t)ip + ip_hl); 857 858 /* 859 * Only pkts selected by the tcp port filter 860 * can be inserted into the pkt_queue 861 */ 862 if ((siftr_port_filter != 0) && 863 (siftr_port_filter != ntohs(th->th_sport)) && 864 (siftr_port_filter != ntohs(th->th_dport))) { 865 goto ret; 866 } 867 868 /* 869 * If a kernel subsystem reinjects packets into the stack, our pfil 870 * hook will be called multiple times for the same packet. 871 * Make sure we only process unique packets. 872 */ 873 if (siftr_chkreinject(*m, dir, ss)) 874 goto ret; 875 876 if (dir == PFIL_IN) 877 ss->n_in++; 878 else 879 ss->n_out++; 880 881 /* 882 * If the pfil hooks don't provide a pointer to the 883 * inpcb, we need to find it ourselves and lock it. 884 */ 885 if (!inp) { 886 /* Find the corresponding inpcb for this pkt. */ 887 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport, 888 th->th_dport, dir, ss); 889 890 if (inp == NULL) 891 goto ret; 892 else 893 inp_locally_locked = 1; 894 } 895 896 INP_LOCK_ASSERT(inp); 897 898 /* Find the TCP control block that corresponds with this packet */ 899 tp = intotcpcb(inp); 900 901 /* 902 * If we can't find the TCP control block (happens occasionaly for a 903 * packet sent during the shutdown phase of a TCP connection), bail 904 */ 905 if (tp == NULL) { 906 if (dir == PFIL_IN) 907 ss->nskip_in_tcpcb++; 908 else 909 ss->nskip_out_tcpcb++; 910 911 goto inp_unlock; 912 } 913 914 915 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 916 917 if (pn == NULL) { 918 if (dir == PFIL_IN) 919 ss->nskip_in_malloc++; 920 else 921 ss->nskip_out_malloc++; 922 923 goto inp_unlock; 924 } 925 926 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked); 927 928 if (siftr_generate_hashes) { 929 if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) { 930 /* 931 * For outbound packets, the TCP checksum isn't 932 * calculated yet. This is a problem for our packet 933 * hashing as the receiver will calc a different hash 934 * to ours if we don't include the correct TCP checksum 935 * in the bytes being hashed. To work around this 936 * problem, we manually calc the TCP checksum here in 937 * software. We unset the CSUM_TCP flag so the lower 938 * layers don't recalc it. 939 */ 940 (*m)->m_pkthdr.csum_flags &= ~CSUM_TCP; 941 942 /* 943 * Calculate the TCP checksum in software and assign 944 * to correct TCP header field, which will follow the 945 * packet mbuf down the stack. The trick here is that 946 * tcp_output() sets th->th_sum to the checksum of the 947 * pseudo header for us already. Because of the nature 948 * of the checksumming algorithm, we can sum over the 949 * entire IP payload (i.e. TCP header and data), which 950 * will include the already calculated pseduo header 951 * checksum, thus giving us the complete TCP checksum. 952 * 953 * To put it in simple terms, if checksum(1,2,3,4)=10, 954 * then checksum(1,2,3,4,5) == checksum(10,5). 955 * This property is what allows us to "cheat" and 956 * checksum only the IP payload which has the TCP 957 * th_sum field populated with the pseudo header's 958 * checksum, and not need to futz around checksumming 959 * pseudo header bytes and TCP header/data in one hit. 960 * Refer to RFC 1071 for more info. 961 * 962 * NB: in_cksum_skip(struct mbuf *m, int len, int skip) 963 * in_cksum_skip 2nd argument is NOT the number of 964 * bytes to read from the mbuf at "skip" bytes offset 965 * from the start of the mbuf (very counter intuitive!). 966 * The number of bytes to read is calculated internally 967 * by the function as len-skip i.e. to sum over the IP 968 * payload (TCP header + data) bytes, it is INCORRECT 969 * to call the function like this: 970 * in_cksum_skip(at, ip->ip_len - offset, offset) 971 * Rather, it should be called like this: 972 * in_cksum_skip(at, ip->ip_len, offset) 973 * which means read "ip->ip_len - offset" bytes from 974 * the mbuf cluster "at" at offset "offset" bytes from 975 * the beginning of the "at" mbuf's data pointer. 976 */ 977 th->th_sum = in_cksum_skip(*m, ntohs(ip->ip_len), 978 ip_hl); 979 } 980 981 /* 982 * XXX: Having to calculate the checksum in software and then 983 * hash over all bytes is really inefficient. Would be nice to 984 * find a way to create the hash and checksum in the same pass 985 * over the bytes. 986 */ 987 pn->hash = hash_pkt(*m, ip_hl); 988 } 989 990 mtx_lock(&siftr_pkt_queue_mtx); 991 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 992 mtx_unlock(&siftr_pkt_queue_mtx); 993 goto ret; 994 995 inp_unlock: 996 if (inp_locally_locked) 997 INP_RUNLOCK(inp); 998 999 ret: 1000 return (PFIL_PASS); 1001 } 1002 1003 #ifdef SIFTR_IPV6 1004 static pfil_return_t 1005 siftr_chkpkt6(struct mbuf **m, struct ifnet *ifp, int flags, 1006 void *ruleset __unused, struct inpcb *inp) 1007 { 1008 struct pkt_node *pn; 1009 struct ip6_hdr *ip6; 1010 struct tcphdr *th; 1011 struct tcpcb *tp; 1012 struct siftr_stats *ss; 1013 unsigned int ip6_hl; 1014 int inp_locally_locked, dir; 1015 1016 inp_locally_locked = 0; 1017 dir = PFIL_DIR(flags); 1018 ss = DPCPU_PTR(ss); 1019 1020 /* 1021 * m_pullup is not required here because ip6_{input|output} 1022 * already do the heavy lifting for us. 1023 */ 1024 1025 ip6 = mtod(*m, struct ip6_hdr *); 1026 1027 /* 1028 * Only continue processing if the packet is TCP 1029 * XXX: We should follow the next header fields 1030 * as shown on Pg 6 RFC 2460, but right now we'll 1031 * only check pkts that have no extension headers. 1032 */ 1033 if (ip6->ip6_nxt != IPPROTO_TCP) 1034 goto ret6; 1035 1036 /* 1037 * Create a tcphdr struct starting at the correct offset 1038 * in the ipv6 packet. 1039 */ 1040 ip6_hl = sizeof(struct ip6_hdr); 1041 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl); 1042 1043 /* 1044 * Only pkts selected by the tcp port filter 1045 * can be inserted into the pkt_queue 1046 */ 1047 if ((siftr_port_filter != 0) && 1048 (siftr_port_filter != ntohs(th->th_sport)) && 1049 (siftr_port_filter != ntohs(th->th_dport))) { 1050 goto ret6; 1051 } 1052 1053 /* 1054 * If a kernel subsystem reinjects packets into the stack, our pfil 1055 * hook will be called multiple times for the same packet. 1056 * Make sure we only process unique packets. 1057 */ 1058 if (siftr_chkreinject(*m, dir, ss)) 1059 goto ret6; 1060 1061 if (dir == PFIL_IN) 1062 ss->n_in++; 1063 else 1064 ss->n_out++; 1065 1066 /* 1067 * For inbound packets, the pfil hooks don't provide a pointer to the 1068 * inpcb, so we need to find it ourselves and lock it. 1069 */ 1070 if (!inp) { 1071 /* Find the corresponding inpcb for this pkt. */ 1072 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m, 1073 th->th_sport, th->th_dport, dir, ss); 1074 1075 if (inp == NULL) 1076 goto ret6; 1077 else 1078 inp_locally_locked = 1; 1079 } 1080 1081 /* Find the TCP control block that corresponds with this packet. */ 1082 tp = intotcpcb(inp); 1083 1084 /* 1085 * If we can't find the TCP control block (happens occasionaly for a 1086 * packet sent during the shutdown phase of a TCP connection), bail 1087 */ 1088 if (tp == NULL) { 1089 if (dir == PFIL_IN) 1090 ss->nskip_in_tcpcb++; 1091 else 1092 ss->nskip_out_tcpcb++; 1093 1094 goto inp_unlock6; 1095 } 1096 1097 1098 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 1099 1100 if (pn == NULL) { 1101 if (dir == PFIL_IN) 1102 ss->nskip_in_malloc++; 1103 else 1104 ss->nskip_out_malloc++; 1105 1106 goto inp_unlock6; 1107 } 1108 1109 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked); 1110 1111 /* XXX: Figure out how to generate hashes for IPv6 packets. */ 1112 1113 mtx_lock(&siftr_pkt_queue_mtx); 1114 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 1115 mtx_unlock(&siftr_pkt_queue_mtx); 1116 goto ret6; 1117 1118 inp_unlock6: 1119 if (inp_locally_locked) 1120 INP_RUNLOCK(inp); 1121 1122 ret6: 1123 return (PFIL_PASS); 1124 } 1125 #endif /* #ifdef SIFTR_IPV6 */ 1126 1127 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet_hook); 1128 #define V_siftr_inet_hook VNET(siftr_inet_hook) 1129 #ifdef SIFTR_IPV6 1130 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet6_hook); 1131 #define V_siftr_inet6_hook VNET(siftr_inet6_hook) 1132 #endif 1133 static int 1134 siftr_pfil(int action) 1135 { 1136 struct pfil_hook_args pha = { 1137 .pa_version = PFIL_VERSION, 1138 .pa_flags = PFIL_IN | PFIL_OUT, 1139 .pa_modname = "siftr", 1140 .pa_rulname = "default", 1141 }; 1142 struct pfil_link_args pla = { 1143 .pa_version = PFIL_VERSION, 1144 .pa_flags = PFIL_IN | PFIL_OUT | PFIL_HEADPTR | PFIL_HOOKPTR, 1145 }; 1146 1147 VNET_ITERATOR_DECL(vnet_iter); 1148 1149 VNET_LIST_RLOCK(); 1150 VNET_FOREACH(vnet_iter) { 1151 CURVNET_SET(vnet_iter); 1152 1153 if (action == HOOK) { 1154 pha.pa_mbuf_chk = siftr_chkpkt; 1155 pha.pa_type = PFIL_TYPE_IP4; 1156 V_siftr_inet_hook = pfil_add_hook(&pha); 1157 pla.pa_hook = V_siftr_inet_hook; 1158 pla.pa_head = V_inet_pfil_head; 1159 (void)pfil_link(&pla); 1160 #ifdef SIFTR_IPV6 1161 pha.pa_mbuf_chk = siftr_chkpkt6; 1162 pha.pa_type = PFIL_TYPE_IP6; 1163 V_siftr_inet6_hook = pfil_add_hook(&pha); 1164 pla.pa_hook = V_siftr_inet6_hook; 1165 pla.pa_head = V_inet6_pfil_head; 1166 (void)pfil_link(&pla); 1167 #endif 1168 } else if (action == UNHOOK) { 1169 pfil_remove_hook(V_siftr_inet_hook); 1170 #ifdef SIFTR_IPV6 1171 pfil_remove_hook(V_siftr_inet6_hook); 1172 #endif 1173 } 1174 CURVNET_RESTORE(); 1175 } 1176 VNET_LIST_RUNLOCK(); 1177 1178 return (0); 1179 } 1180 1181 static int 1182 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS) 1183 { 1184 struct alq *new_alq; 1185 int error; 1186 1187 error = sysctl_handle_string(oidp, arg1, arg2, req); 1188 1189 /* Check for error or same filename */ 1190 if (error != 0 || req->newptr == NULL || 1191 strncmp(siftr_logfile, arg1, arg2) == 0) 1192 goto done; 1193 1194 /* Filname changed */ 1195 error = alq_open(&new_alq, arg1, curthread->td_ucred, 1196 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1197 if (error != 0) 1198 goto done; 1199 1200 /* 1201 * If disabled, siftr_alq == NULL so we simply close 1202 * the alq as we've proved it can be opened. 1203 * If enabled, close the existing alq and switch the old 1204 * for the new. 1205 */ 1206 if (siftr_alq == NULL) { 1207 alq_close(new_alq); 1208 } else { 1209 alq_close(siftr_alq); 1210 siftr_alq = new_alq; 1211 } 1212 1213 /* Update filename upon success */ 1214 strlcpy(siftr_logfile, arg1, arg2); 1215 done: 1216 return (error); 1217 } 1218 1219 static int 1220 siftr_manage_ops(uint8_t action) 1221 { 1222 struct siftr_stats totalss; 1223 struct timeval tval; 1224 struct flow_hash_node *counter, *tmp_counter; 1225 struct sbuf *s; 1226 int i, key_index, error; 1227 uint32_t bytes_to_write, total_skipped_pkts; 1228 uint16_t lport, fport; 1229 uint8_t *key, ipver __unused; 1230 1231 #ifdef SIFTR_IPV6 1232 uint32_t laddr[4]; 1233 uint32_t faddr[4]; 1234 #else 1235 uint8_t laddr[4]; 1236 uint8_t faddr[4]; 1237 #endif 1238 1239 error = 0; 1240 total_skipped_pkts = 0; 1241 1242 /* Init an autosizing sbuf that initially holds 200 chars. */ 1243 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL) 1244 return (-1); 1245 1246 if (action == SIFTR_ENABLE && siftr_pkt_manager_thr == NULL) { 1247 /* 1248 * Create our alq 1249 * XXX: We should abort if alq_open fails! 1250 */ 1251 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred, 1252 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1253 1254 STAILQ_INIT(&pkt_queue); 1255 1256 DPCPU_ZERO(ss); 1257 1258 siftr_exit_pkt_manager_thread = 0; 1259 1260 kthread_add(&siftr_pkt_manager_thread, NULL, NULL, 1261 &siftr_pkt_manager_thr, RFNOWAIT, 0, 1262 "siftr_pkt_manager_thr"); 1263 1264 siftr_pfil(HOOK); 1265 1266 microtime(&tval); 1267 1268 sbuf_printf(s, 1269 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t" 1270 "siftrver=%s\tsysname=%s\tsysver=%u\tipmode=%u\n", 1271 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, 1272 SYS_NAME, __FreeBSD_version, SIFTR_IPMODE); 1273 1274 sbuf_finish(s); 1275 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK); 1276 1277 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) { 1278 /* 1279 * Remove the pfil hook functions. All threads currently in 1280 * the hook functions are allowed to exit before siftr_pfil() 1281 * returns. 1282 */ 1283 siftr_pfil(UNHOOK); 1284 1285 /* This will block until the pkt manager thread unlocks it. */ 1286 mtx_lock(&siftr_pkt_mgr_mtx); 1287 1288 /* Tell the pkt manager thread that it should exit now. */ 1289 siftr_exit_pkt_manager_thread = 1; 1290 1291 /* 1292 * Wake the pkt_manager thread so it realises that 1293 * siftr_exit_pkt_manager_thread == 1 and exits gracefully. 1294 * The wakeup won't be delivered until we unlock 1295 * siftr_pkt_mgr_mtx so this isn't racy. 1296 */ 1297 wakeup(&wait_for_pkt); 1298 1299 /* Wait for the pkt_manager thread to exit. */ 1300 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT, 1301 "thrwait", 0); 1302 1303 siftr_pkt_manager_thr = NULL; 1304 mtx_unlock(&siftr_pkt_mgr_mtx); 1305 1306 totalss.n_in = DPCPU_VARSUM(ss, n_in); 1307 totalss.n_out = DPCPU_VARSUM(ss, n_out); 1308 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc); 1309 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc); 1310 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb); 1311 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb); 1312 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb); 1313 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb); 1314 1315 total_skipped_pkts = totalss.nskip_in_malloc + 1316 totalss.nskip_out_malloc + totalss.nskip_in_tcpcb + 1317 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb + 1318 totalss.nskip_out_inpcb; 1319 1320 microtime(&tval); 1321 1322 sbuf_printf(s, 1323 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t" 1324 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t" 1325 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t" 1326 "num_outbound_skipped_pkts_malloc=%u\t" 1327 "num_inbound_skipped_pkts_tcpcb=%u\t" 1328 "num_outbound_skipped_pkts_tcpcb=%u\t" 1329 "num_inbound_skipped_pkts_inpcb=%u\t" 1330 "num_outbound_skipped_pkts_inpcb=%u\t" 1331 "total_skipped_tcp_pkts=%u\tflow_list=", 1332 (intmax_t)tval.tv_sec, 1333 tval.tv_usec, 1334 (uintmax_t)totalss.n_in, 1335 (uintmax_t)totalss.n_out, 1336 (uintmax_t)(totalss.n_in + totalss.n_out), 1337 totalss.nskip_in_malloc, 1338 totalss.nskip_out_malloc, 1339 totalss.nskip_in_tcpcb, 1340 totalss.nskip_out_tcpcb, 1341 totalss.nskip_in_inpcb, 1342 totalss.nskip_out_inpcb, 1343 total_skipped_pkts); 1344 1345 /* 1346 * Iterate over the flow hash, printing a summary of each 1347 * flow seen and freeing any malloc'd memory. 1348 * The hash consists of an array of LISTs (man 3 queue). 1349 */ 1350 for (i = 0; i <= siftr_hashmask; i++) { 1351 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes, 1352 tmp_counter) { 1353 key = counter->key; 1354 key_index = 1; 1355 1356 ipver = key[0]; 1357 1358 memcpy(laddr, key + key_index, sizeof(laddr)); 1359 key_index += sizeof(laddr); 1360 memcpy(&lport, key + key_index, sizeof(lport)); 1361 key_index += sizeof(lport); 1362 memcpy(faddr, key + key_index, sizeof(faddr)); 1363 key_index += sizeof(faddr); 1364 memcpy(&fport, key + key_index, sizeof(fport)); 1365 1366 #ifdef SIFTR_IPV6 1367 laddr[3] = ntohl(laddr[3]); 1368 faddr[3] = ntohl(faddr[3]); 1369 1370 if (ipver == INP_IPV6) { 1371 laddr[0] = ntohl(laddr[0]); 1372 laddr[1] = ntohl(laddr[1]); 1373 laddr[2] = ntohl(laddr[2]); 1374 faddr[0] = ntohl(faddr[0]); 1375 faddr[1] = ntohl(faddr[1]); 1376 faddr[2] = ntohl(faddr[2]); 1377 1378 sbuf_printf(s, 1379 "%x:%x:%x:%x:%x:%x:%x:%x;%u-" 1380 "%x:%x:%x:%x:%x:%x:%x:%x;%u,", 1381 UPPER_SHORT(laddr[0]), 1382 LOWER_SHORT(laddr[0]), 1383 UPPER_SHORT(laddr[1]), 1384 LOWER_SHORT(laddr[1]), 1385 UPPER_SHORT(laddr[2]), 1386 LOWER_SHORT(laddr[2]), 1387 UPPER_SHORT(laddr[3]), 1388 LOWER_SHORT(laddr[3]), 1389 ntohs(lport), 1390 UPPER_SHORT(faddr[0]), 1391 LOWER_SHORT(faddr[0]), 1392 UPPER_SHORT(faddr[1]), 1393 LOWER_SHORT(faddr[1]), 1394 UPPER_SHORT(faddr[2]), 1395 LOWER_SHORT(faddr[2]), 1396 UPPER_SHORT(faddr[3]), 1397 LOWER_SHORT(faddr[3]), 1398 ntohs(fport)); 1399 } else { 1400 laddr[0] = FIRST_OCTET(laddr[3]); 1401 laddr[1] = SECOND_OCTET(laddr[3]); 1402 laddr[2] = THIRD_OCTET(laddr[3]); 1403 laddr[3] = FOURTH_OCTET(laddr[3]); 1404 faddr[0] = FIRST_OCTET(faddr[3]); 1405 faddr[1] = SECOND_OCTET(faddr[3]); 1406 faddr[2] = THIRD_OCTET(faddr[3]); 1407 faddr[3] = FOURTH_OCTET(faddr[3]); 1408 #endif 1409 sbuf_printf(s, 1410 "%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,", 1411 laddr[0], 1412 laddr[1], 1413 laddr[2], 1414 laddr[3], 1415 ntohs(lport), 1416 faddr[0], 1417 faddr[1], 1418 faddr[2], 1419 faddr[3], 1420 ntohs(fport)); 1421 #ifdef SIFTR_IPV6 1422 } 1423 #endif 1424 1425 free(counter, M_SIFTR_HASHNODE); 1426 } 1427 1428 LIST_INIT(counter_hash + i); 1429 } 1430 1431 sbuf_printf(s, "\n"); 1432 sbuf_finish(s); 1433 1434 i = 0; 1435 do { 1436 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i); 1437 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK); 1438 i += bytes_to_write; 1439 } while (i < sbuf_len(s)); 1440 1441 alq_close(siftr_alq); 1442 siftr_alq = NULL; 1443 } else 1444 error = EINVAL; 1445 1446 sbuf_delete(s); 1447 1448 /* 1449 * XXX: Should be using ret to check if any functions fail 1450 * and set error appropriately 1451 */ 1452 1453 return (error); 1454 } 1455 1456 static int 1457 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS) 1458 { 1459 int error; 1460 uint32_t new; 1461 1462 new = siftr_enabled; 1463 error = sysctl_handle_int(oidp, &new, 0, req); 1464 if (error == 0 && req->newptr != NULL) { 1465 if (new > 1) 1466 return (EINVAL); 1467 else if (new != siftr_enabled) { 1468 if ((error = siftr_manage_ops(new)) == 0) { 1469 siftr_enabled = new; 1470 } else { 1471 siftr_manage_ops(SIFTR_DISABLE); 1472 } 1473 } 1474 } 1475 1476 return (error); 1477 } 1478 1479 static void 1480 siftr_shutdown_handler(void *arg) 1481 { 1482 if (siftr_enabled == 1) { 1483 siftr_manage_ops(SIFTR_DISABLE); 1484 } 1485 } 1486 1487 /* 1488 * Module is being unloaded or machine is shutting down. Take care of cleanup. 1489 */ 1490 static int 1491 deinit_siftr(void) 1492 { 1493 /* Cleanup. */ 1494 siftr_manage_ops(SIFTR_DISABLE); 1495 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask); 1496 mtx_destroy(&siftr_pkt_queue_mtx); 1497 mtx_destroy(&siftr_pkt_mgr_mtx); 1498 1499 return (0); 1500 } 1501 1502 /* 1503 * Module has just been loaded into the kernel. 1504 */ 1505 static int 1506 init_siftr(void) 1507 { 1508 EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL, 1509 SHUTDOWN_PRI_FIRST); 1510 1511 /* Initialise our flow counter hash table. */ 1512 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR, 1513 &siftr_hashmask); 1514 1515 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF); 1516 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF); 1517 1518 /* Print message to the user's current terminal. */ 1519 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n" 1520 " http://caia.swin.edu.au/urp/newtcp\n\n", 1521 MODVERSION_STR); 1522 1523 return (0); 1524 } 1525 1526 /* 1527 * This is the function that is called to load and unload the module. 1528 * When the module is loaded, this function is called once with 1529 * "what" == MOD_LOAD 1530 * When the module is unloaded, this function is called twice with 1531 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second 1532 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command, 1533 * this function is called once with "what" = MOD_SHUTDOWN 1534 * When the system is shut down, the handler isn't called until the very end 1535 * of the shutdown sequence i.e. after the disks have been synced. 1536 */ 1537 static int 1538 siftr_load_handler(module_t mod, int what, void *arg) 1539 { 1540 int ret; 1541 1542 switch (what) { 1543 case MOD_LOAD: 1544 ret = init_siftr(); 1545 break; 1546 1547 case MOD_QUIESCE: 1548 case MOD_SHUTDOWN: 1549 ret = deinit_siftr(); 1550 break; 1551 1552 case MOD_UNLOAD: 1553 ret = 0; 1554 break; 1555 1556 default: 1557 ret = EINVAL; 1558 break; 1559 } 1560 1561 return (ret); 1562 } 1563 1564 static moduledata_t siftr_mod = { 1565 .name = "siftr", 1566 .evhand = siftr_load_handler, 1567 }; 1568 1569 /* 1570 * Param 1: name of the kernel module 1571 * Param 2: moduledata_t struct containing info about the kernel module 1572 * and the execution entry point for the module 1573 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h 1574 * Defines the module initialisation order 1575 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h 1576 * Defines the initialisation order of this kld relative to others 1577 * within the same subsystem as defined by param 3 1578 */ 1579 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY); 1580 MODULE_DEPEND(siftr, alq, 1, 1, 1); 1581 MODULE_VERSION(siftr, MODVERSION); 1582