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 <netinet/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 2 116 #define V_BACKCOMPAT 4 117 #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 200 136 /* 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 u_long snd_cwnd; 198 /* Sending Window (bytes). */ 199 u_long snd_wnd; 200 /* Receive Window (bytes). */ 201 u_long rcv_wnd; 202 /* Unused (was: Bandwidth Controlled Window (bytes)). */ 203 u_long snd_bwnd; 204 /* Slow Start Threshold (bytes). */ 205 u_long 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 /* 211 * Smoothed RTT stored as found in the TCP control block 212 * in units of (TCP_RTT_SCALE*hz). 213 */ 214 int smoothed_rtt; 215 /* Is SACK enabled? */ 216 u_char sack_enabled; 217 /* Window scaling for snd window. */ 218 u_char snd_scale; 219 /* Window scaling for recv window. */ 220 u_char rcv_scale; 221 /* TCP control block flags. */ 222 u_int flags; 223 /* Retransmit timeout length. */ 224 int rxt_length; 225 /* Size of the TCP send buffer in bytes. */ 226 u_int snd_buf_hiwater; 227 /* Current num bytes in the send socket buffer. */ 228 u_int snd_buf_cc; 229 /* Size of the TCP receive buffer in bytes. */ 230 u_int rcv_buf_hiwater; 231 /* Current num bytes in the receive socket buffer. */ 232 u_int rcv_buf_cc; 233 /* Number of bytes inflight that we are waiting on ACKs for. */ 234 u_int sent_inflight_bytes; 235 /* Number of segments currently in the reassembly queue. */ 236 int t_segqlen; 237 /* Flowid for the connection. */ 238 u_int flowid; 239 /* Flow type for the connection. */ 240 u_int flowtype; 241 /* Link to next pkt_node in the list. */ 242 STAILQ_ENTRY(pkt_node) nodes; 243 }; 244 245 struct flow_hash_node 246 { 247 uint16_t counter; 248 uint8_t key[FLOW_KEY_LEN]; 249 LIST_ENTRY(flow_hash_node) nodes; 250 }; 251 252 struct siftr_stats 253 { 254 /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */ 255 uint64_t n_in; 256 uint64_t n_out; 257 /* # pkts skipped due to failed malloc calls. */ 258 uint32_t nskip_in_malloc; 259 uint32_t nskip_out_malloc; 260 /* # pkts skipped due to failed mtx acquisition. */ 261 uint32_t nskip_in_mtx; 262 uint32_t nskip_out_mtx; 263 /* # pkts skipped due to failed inpcb lookups. */ 264 uint32_t nskip_in_inpcb; 265 uint32_t nskip_out_inpcb; 266 /* # pkts skipped due to failed tcpcb lookups. */ 267 uint32_t nskip_in_tcpcb; 268 uint32_t nskip_out_tcpcb; 269 /* # pkts skipped due to stack reinjection. */ 270 uint32_t nskip_in_dejavu; 271 uint32_t nskip_out_dejavu; 272 }; 273 274 DPCPU_DEFINE_STATIC(struct siftr_stats, ss); 275 276 static volatile unsigned int siftr_exit_pkt_manager_thread = 0; 277 static unsigned int siftr_enabled = 0; 278 static unsigned int siftr_pkts_per_log = 1; 279 static unsigned int siftr_generate_hashes = 0; 280 static uint16_t siftr_port_filter = 0; 281 /* static unsigned int siftr_binary_log = 0; */ 282 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log"; 283 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log"; 284 static u_long siftr_hashmask; 285 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue); 286 LIST_HEAD(listhead, flow_hash_node) *counter_hash; 287 static int wait_for_pkt; 288 static struct alq *siftr_alq = NULL; 289 static struct mtx siftr_pkt_queue_mtx; 290 static struct mtx siftr_pkt_mgr_mtx; 291 static struct thread *siftr_pkt_manager_thr = NULL; 292 static char direction[2] = {'i','o'}; 293 294 /* Required function prototypes. */ 295 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS); 296 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS); 297 298 299 /* Declare the net.inet.siftr sysctl tree and populate it. */ 300 301 SYSCTL_DECL(_net_inet_siftr); 302 303 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL, 304 "siftr related settings"); 305 306 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, 307 CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 308 &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU", 309 "switch siftr module operations on/off"); 310 311 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, 312 CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &siftr_logfile_shadow, 313 sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler, "A", 314 "file to save siftr log messages to"); 315 316 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW, 317 &siftr_pkts_per_log, 1, 318 "number of packets between generating a log message"); 319 320 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW, 321 &siftr_generate_hashes, 0, 322 "enable packet hash generation"); 323 324 SYSCTL_U16(_net_inet_siftr, OID_AUTO, port_filter, CTLFLAG_RW, 325 &siftr_port_filter, 0, 326 "enable packet filter on a TCP port"); 327 328 /* XXX: TODO 329 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW, 330 &siftr_binary_log, 0, 331 "write log files in binary instead of ascii"); 332 */ 333 334 335 /* Begin functions. */ 336 337 static void 338 siftr_process_pkt(struct pkt_node * pkt_node) 339 { 340 struct flow_hash_node *hash_node; 341 struct listhead *counter_list; 342 struct siftr_stats *ss; 343 struct ale *log_buf; 344 uint8_t key[FLOW_KEY_LEN]; 345 uint8_t found_match, key_offset; 346 347 hash_node = NULL; 348 ss = DPCPU_PTR(ss); 349 found_match = 0; 350 key_offset = 1; 351 352 /* 353 * Create the key that will be used to create a hash index 354 * into our hash table. Our key consists of: 355 * ipversion, localip, localport, foreignip, foreignport 356 */ 357 key[0] = pkt_node->ipver; 358 memcpy(key + key_offset, &pkt_node->ip_laddr, 359 sizeof(pkt_node->ip_laddr)); 360 key_offset += sizeof(pkt_node->ip_laddr); 361 memcpy(key + key_offset, &pkt_node->tcp_localport, 362 sizeof(pkt_node->tcp_localport)); 363 key_offset += sizeof(pkt_node->tcp_localport); 364 memcpy(key + key_offset, &pkt_node->ip_faddr, 365 sizeof(pkt_node->ip_faddr)); 366 key_offset += sizeof(pkt_node->ip_faddr); 367 memcpy(key + key_offset, &pkt_node->tcp_foreignport, 368 sizeof(pkt_node->tcp_foreignport)); 369 370 counter_list = counter_hash + 371 (hash32_buf(key, sizeof(key), 0) & siftr_hashmask); 372 373 /* 374 * If the list is not empty i.e. the hash index has 375 * been used by another flow previously. 376 */ 377 if (LIST_FIRST(counter_list) != NULL) { 378 /* 379 * Loop through the hash nodes in the list. 380 * There should normally only be 1 hash node in the list, 381 * except if there have been collisions at the hash index 382 * computed by hash32_buf(). 383 */ 384 LIST_FOREACH(hash_node, counter_list, nodes) { 385 /* 386 * Check if the key for the pkt we are currently 387 * processing is the same as the key stored in the 388 * hash node we are currently processing. 389 * If they are the same, then we've found the 390 * hash node that stores the counter for the flow 391 * the pkt belongs to. 392 */ 393 if (memcmp(hash_node->key, key, sizeof(key)) == 0) { 394 found_match = 1; 395 break; 396 } 397 } 398 } 399 400 /* If this flow hash hasn't been seen before or we have a collision. */ 401 if (hash_node == NULL || !found_match) { 402 /* Create a new hash node to store the flow's counter. */ 403 hash_node = malloc(sizeof(struct flow_hash_node), 404 M_SIFTR_HASHNODE, M_WAITOK); 405 406 if (hash_node != NULL) { 407 /* Initialise our new hash node list entry. */ 408 hash_node->counter = 0; 409 memcpy(hash_node->key, key, sizeof(key)); 410 LIST_INSERT_HEAD(counter_list, hash_node, nodes); 411 } else { 412 /* Malloc failed. */ 413 if (pkt_node->direction == DIR_IN) 414 ss->nskip_in_malloc++; 415 else 416 ss->nskip_out_malloc++; 417 418 return; 419 } 420 } else if (siftr_pkts_per_log > 1) { 421 /* 422 * Taking the remainder of the counter divided 423 * by the current value of siftr_pkts_per_log 424 * and storing that in counter provides a neat 425 * way to modulate the frequency of log 426 * messages being written to the log file. 427 */ 428 hash_node->counter = (hash_node->counter + 1) % 429 siftr_pkts_per_log; 430 431 /* 432 * If we have not seen enough packets since the last time 433 * we wrote a log message for this connection, return. 434 */ 435 if (hash_node->counter > 0) 436 return; 437 } 438 439 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK); 440 441 if (log_buf == NULL) 442 return; /* Should only happen if the ALQ is shutting down. */ 443 444 #ifdef SIFTR_IPV6 445 pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]); 446 pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]); 447 448 if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */ 449 pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]); 450 pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]); 451 pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]); 452 pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]); 453 pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]); 454 pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]); 455 456 /* Construct an IPv6 log message. */ 457 log_buf->ae_bytesused = snprintf(log_buf->ae_data, 458 MAX_LOG_MSG_LEN, 459 "%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:" 460 "%x:%x:%x:%x:%x,%u,%ld,%ld,%ld,%ld,%ld,%u,%u,%u,%u,%u,%u," 461 "%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n", 462 direction[pkt_node->direction], 463 pkt_node->hash, 464 pkt_node->tval.tv_sec, 465 pkt_node->tval.tv_usec, 466 UPPER_SHORT(pkt_node->ip_laddr[0]), 467 LOWER_SHORT(pkt_node->ip_laddr[0]), 468 UPPER_SHORT(pkt_node->ip_laddr[1]), 469 LOWER_SHORT(pkt_node->ip_laddr[1]), 470 UPPER_SHORT(pkt_node->ip_laddr[2]), 471 LOWER_SHORT(pkt_node->ip_laddr[2]), 472 UPPER_SHORT(pkt_node->ip_laddr[3]), 473 LOWER_SHORT(pkt_node->ip_laddr[3]), 474 ntohs(pkt_node->tcp_localport), 475 UPPER_SHORT(pkt_node->ip_faddr[0]), 476 LOWER_SHORT(pkt_node->ip_faddr[0]), 477 UPPER_SHORT(pkt_node->ip_faddr[1]), 478 LOWER_SHORT(pkt_node->ip_faddr[1]), 479 UPPER_SHORT(pkt_node->ip_faddr[2]), 480 LOWER_SHORT(pkt_node->ip_faddr[2]), 481 UPPER_SHORT(pkt_node->ip_faddr[3]), 482 LOWER_SHORT(pkt_node->ip_faddr[3]), 483 ntohs(pkt_node->tcp_foreignport), 484 pkt_node->snd_ssthresh, 485 pkt_node->snd_cwnd, 486 pkt_node->snd_bwnd, 487 pkt_node->snd_wnd, 488 pkt_node->rcv_wnd, 489 pkt_node->snd_scale, 490 pkt_node->rcv_scale, 491 pkt_node->conn_state, 492 pkt_node->max_seg_size, 493 pkt_node->smoothed_rtt, 494 pkt_node->sack_enabled, 495 pkt_node->flags, 496 pkt_node->rxt_length, 497 pkt_node->snd_buf_hiwater, 498 pkt_node->snd_buf_cc, 499 pkt_node->rcv_buf_hiwater, 500 pkt_node->rcv_buf_cc, 501 pkt_node->sent_inflight_bytes, 502 pkt_node->t_segqlen, 503 pkt_node->flowid, 504 pkt_node->flowtype); 505 } else { /* IPv4 packet */ 506 pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]); 507 pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]); 508 pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]); 509 pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]); 510 pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]); 511 pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]); 512 pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]); 513 pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]); 514 #endif /* SIFTR_IPV6 */ 515 516 /* Construct an IPv4 log message. */ 517 log_buf->ae_bytesused = snprintf(log_buf->ae_data, 518 MAX_LOG_MSG_LEN, 519 "%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%ld,%ld," 520 "%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n", 521 direction[pkt_node->direction], 522 pkt_node->hash, 523 (intmax_t)pkt_node->tval.tv_sec, 524 pkt_node->tval.tv_usec, 525 pkt_node->ip_laddr[0], 526 pkt_node->ip_laddr[1], 527 pkt_node->ip_laddr[2], 528 pkt_node->ip_laddr[3], 529 ntohs(pkt_node->tcp_localport), 530 pkt_node->ip_faddr[0], 531 pkt_node->ip_faddr[1], 532 pkt_node->ip_faddr[2], 533 pkt_node->ip_faddr[3], 534 ntohs(pkt_node->tcp_foreignport), 535 pkt_node->snd_ssthresh, 536 pkt_node->snd_cwnd, 537 pkt_node->snd_bwnd, 538 pkt_node->snd_wnd, 539 pkt_node->rcv_wnd, 540 pkt_node->snd_scale, 541 pkt_node->rcv_scale, 542 pkt_node->conn_state, 543 pkt_node->max_seg_size, 544 pkt_node->smoothed_rtt, 545 pkt_node->sack_enabled, 546 pkt_node->flags, 547 pkt_node->rxt_length, 548 pkt_node->snd_buf_hiwater, 549 pkt_node->snd_buf_cc, 550 pkt_node->rcv_buf_hiwater, 551 pkt_node->rcv_buf_cc, 552 pkt_node->sent_inflight_bytes, 553 pkt_node->t_segqlen, 554 pkt_node->flowid, 555 pkt_node->flowtype); 556 #ifdef SIFTR_IPV6 557 } 558 #endif 559 560 alq_post_flags(siftr_alq, log_buf, 0); 561 } 562 563 564 static void 565 siftr_pkt_manager_thread(void *arg) 566 { 567 STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue = 568 STAILQ_HEAD_INITIALIZER(tmp_pkt_queue); 569 struct pkt_node *pkt_node, *pkt_node_temp; 570 uint8_t draining; 571 572 draining = 2; 573 574 mtx_lock(&siftr_pkt_mgr_mtx); 575 576 /* draining == 0 when queue has been flushed and it's safe to exit. */ 577 while (draining) { 578 /* 579 * Sleep until we are signalled to wake because thread has 580 * been told to exit or until 1 tick has passed. 581 */ 582 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait", 583 1); 584 585 /* Gain exclusive access to the pkt_node queue. */ 586 mtx_lock(&siftr_pkt_queue_mtx); 587 588 /* 589 * Move pkt_queue to tmp_pkt_queue, which leaves 590 * pkt_queue empty and ready to receive more pkt_nodes. 591 */ 592 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue); 593 594 /* 595 * We've finished making changes to the list. Unlock it 596 * so the pfil hooks can continue queuing pkt_nodes. 597 */ 598 mtx_unlock(&siftr_pkt_queue_mtx); 599 600 /* 601 * We can't hold a mutex whilst calling siftr_process_pkt 602 * because ALQ might sleep waiting for buffer space. 603 */ 604 mtx_unlock(&siftr_pkt_mgr_mtx); 605 606 /* Flush all pkt_nodes to the log file. */ 607 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes, 608 pkt_node_temp) { 609 siftr_process_pkt(pkt_node); 610 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes); 611 free(pkt_node, M_SIFTR_PKTNODE); 612 } 613 614 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue), 615 ("SIFTR tmp_pkt_queue not empty after flush")); 616 617 mtx_lock(&siftr_pkt_mgr_mtx); 618 619 /* 620 * If siftr_exit_pkt_manager_thread gets set during the window 621 * where we are draining the tmp_pkt_queue above, there might 622 * still be pkts in pkt_queue that need to be drained. 623 * Allow one further iteration to occur after 624 * siftr_exit_pkt_manager_thread has been set to ensure 625 * pkt_queue is completely empty before we kill the thread. 626 * 627 * siftr_exit_pkt_manager_thread is set only after the pfil 628 * hooks have been removed, so only 1 extra iteration 629 * is needed to drain the queue. 630 */ 631 if (siftr_exit_pkt_manager_thread) 632 draining--; 633 } 634 635 mtx_unlock(&siftr_pkt_mgr_mtx); 636 637 /* Calls wakeup on this thread's struct thread ptr. */ 638 kthread_exit(); 639 } 640 641 642 static uint32_t 643 hash_pkt(struct mbuf *m, uint32_t offset) 644 { 645 uint32_t hash; 646 647 hash = 0; 648 649 while (m != NULL && offset > m->m_len) { 650 /* 651 * The IP packet payload does not start in this mbuf, so 652 * need to figure out which mbuf it starts in and what offset 653 * into the mbuf's data region the payload starts at. 654 */ 655 offset -= m->m_len; 656 m = m->m_next; 657 } 658 659 while (m != NULL) { 660 /* Ensure there is data in the mbuf */ 661 if ((m->m_len - offset) > 0) 662 hash = hash32_buf(m->m_data + offset, 663 m->m_len - offset, hash); 664 665 m = m->m_next; 666 offset = 0; 667 } 668 669 return (hash); 670 } 671 672 673 /* 674 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that 675 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return. 676 * Return value >0 means the caller should skip processing this mbuf. 677 */ 678 static inline int 679 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss) 680 { 681 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL) 682 != NULL) { 683 if (dir == PFIL_IN) 684 ss->nskip_in_dejavu++; 685 else 686 ss->nskip_out_dejavu++; 687 688 return (1); 689 } else { 690 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR, 691 PACKET_TAG_SIFTR, 0, M_NOWAIT); 692 if (tag == NULL) { 693 if (dir == PFIL_IN) 694 ss->nskip_in_malloc++; 695 else 696 ss->nskip_out_malloc++; 697 698 return (1); 699 } 700 701 m_tag_prepend(m, tag); 702 } 703 704 return (0); 705 } 706 707 708 /* 709 * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL 710 * otherwise. 711 */ 712 static inline struct inpcb * 713 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport, 714 uint16_t dport, int dir, struct siftr_stats *ss) 715 { 716 struct inpcb *inp; 717 718 /* We need the tcbinfo lock. */ 719 INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo); 720 721 if (dir == PFIL_IN) 722 inp = (ipver == INP_IPV4 ? 723 in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst, 724 dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 725 : 726 #ifdef SIFTR_IPV6 727 in6_pcblookup(&V_tcbinfo, 728 &((struct ip6_hdr *)ip)->ip6_src, sport, 729 &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB, 730 m->m_pkthdr.rcvif) 731 #else 732 NULL 733 #endif 734 ); 735 736 else 737 inp = (ipver == INP_IPV4 ? 738 in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src, 739 sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 740 : 741 #ifdef SIFTR_IPV6 742 in6_pcblookup(&V_tcbinfo, 743 &((struct ip6_hdr *)ip)->ip6_dst, dport, 744 &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB, 745 m->m_pkthdr.rcvif) 746 #else 747 NULL 748 #endif 749 ); 750 751 /* If we can't find the inpcb, bail. */ 752 if (inp == NULL) { 753 if (dir == PFIL_IN) 754 ss->nskip_in_inpcb++; 755 else 756 ss->nskip_out_inpcb++; 757 } 758 759 return (inp); 760 } 761 762 763 static inline void 764 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp, 765 int ipver, int dir, int inp_locally_locked) 766 { 767 #ifdef SIFTR_IPV6 768 if (ipver == INP_IPV4) { 769 pn->ip_laddr[3] = inp->inp_laddr.s_addr; 770 pn->ip_faddr[3] = inp->inp_faddr.s_addr; 771 #else 772 *((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr; 773 *((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr; 774 #endif 775 #ifdef SIFTR_IPV6 776 } else { 777 pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0]; 778 pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1]; 779 pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2]; 780 pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3]; 781 pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0]; 782 pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1]; 783 pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2]; 784 pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3]; 785 } 786 #endif 787 pn->tcp_localport = inp->inp_lport; 788 pn->tcp_foreignport = inp->inp_fport; 789 pn->snd_cwnd = tp->snd_cwnd; 790 pn->snd_wnd = tp->snd_wnd; 791 pn->rcv_wnd = tp->rcv_wnd; 792 pn->snd_bwnd = 0; /* Unused, kept for compat. */ 793 pn->snd_ssthresh = tp->snd_ssthresh; 794 pn->snd_scale = tp->snd_scale; 795 pn->rcv_scale = tp->rcv_scale; 796 pn->conn_state = tp->t_state; 797 pn->max_seg_size = tp->t_maxseg; 798 pn->smoothed_rtt = tp->t_srtt; 799 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0; 800 pn->flags = tp->t_flags; 801 pn->rxt_length = tp->t_rxtcur; 802 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat; 803 pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd); 804 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat; 805 pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv); 806 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una; 807 pn->t_segqlen = tp->t_segqlen; 808 pn->flowid = inp->inp_flowid; 809 pn->flowtype = inp->inp_flowtype; 810 811 /* We've finished accessing the tcb so release the lock. */ 812 if (inp_locally_locked) 813 INP_RUNLOCK(inp); 814 815 pn->ipver = ipver; 816 pn->direction = (dir == PFIL_IN ? DIR_IN : DIR_OUT); 817 818 /* 819 * Significantly more accurate than using getmicrotime(), but slower! 820 * Gives true microsecond resolution at the expense of a hit to 821 * maximum pps throughput processing when SIFTR is loaded and enabled. 822 */ 823 microtime(&pn->tval); 824 TCP_PROBE1(siftr, &pn); 825 826 } 827 828 829 /* 830 * pfil hook that is called for each IPv4 packet making its way through the 831 * stack in either direction. 832 * The pfil subsystem holds a non-sleepable mutex somewhere when 833 * calling our hook function, so we can't sleep at all. 834 * It's very important to use the M_NOWAIT flag with all function calls 835 * that support it so that they won't sleep, otherwise you get a panic. 836 */ 837 static pfil_return_t 838 siftr_chkpkt(struct mbuf **m, struct ifnet *ifp, int flags, 839 void *ruleset __unused, struct inpcb *inp) 840 { 841 struct pkt_node *pn; 842 struct ip *ip; 843 struct tcphdr *th; 844 struct tcpcb *tp; 845 struct siftr_stats *ss; 846 unsigned int ip_hl; 847 int inp_locally_locked, dir; 848 849 inp_locally_locked = 0; 850 dir = PFIL_DIR(flags); 851 ss = DPCPU_PTR(ss); 852 853 /* 854 * m_pullup is not required here because ip_{input|output} 855 * already do the heavy lifting for us. 856 */ 857 858 ip = mtod(*m, struct ip *); 859 860 /* Only continue processing if the packet is TCP. */ 861 if (ip->ip_p != IPPROTO_TCP) 862 goto ret; 863 864 /* 865 * If a kernel subsystem reinjects packets into the stack, our pfil 866 * hook will be called multiple times for the same packet. 867 * Make sure we only process unique packets. 868 */ 869 if (siftr_chkreinject(*m, dir, ss)) 870 goto ret; 871 872 if (dir == PFIL_IN) 873 ss->n_in++; 874 else 875 ss->n_out++; 876 877 /* 878 * Create a tcphdr struct starting at the correct offset 879 * in the IP packet. ip->ip_hl gives the ip header length 880 * in 4-byte words, so multiply it to get the size in bytes. 881 */ 882 ip_hl = (ip->ip_hl << 2); 883 th = (struct tcphdr *)((caddr_t)ip + ip_hl); 884 885 /* 886 * If the pfil hooks don't provide a pointer to the 887 * inpcb, we need to find it ourselves and lock it. 888 */ 889 if (!inp) { 890 /* Find the corresponding inpcb for this pkt. */ 891 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport, 892 th->th_dport, dir, ss); 893 894 if (inp == NULL) 895 goto ret; 896 else 897 inp_locally_locked = 1; 898 } 899 900 INP_LOCK_ASSERT(inp); 901 902 /* Find the TCP control block that corresponds with this packet */ 903 tp = intotcpcb(inp); 904 905 /* 906 * If we can't find the TCP control block (happens occasionaly for a 907 * packet sent during the shutdown phase of a TCP connection), 908 * or we're in the timewait state, bail 909 */ 910 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) { 911 if (dir == PFIL_IN) 912 ss->nskip_in_tcpcb++; 913 else 914 ss->nskip_out_tcpcb++; 915 916 goto inp_unlock; 917 } 918 919 /* 920 * Only pkts selected by the tcp port filter 921 * can be inserted into the pkt_queue 922 */ 923 if ((siftr_port_filter != 0) && 924 (siftr_port_filter != ntohs(inp->inp_lport)) && 925 (siftr_port_filter != ntohs(inp->inp_fport))) { 926 goto inp_unlock; 927 } 928 929 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 930 931 if (pn == NULL) { 932 if (dir == PFIL_IN) 933 ss->nskip_in_malloc++; 934 else 935 ss->nskip_out_malloc++; 936 937 goto inp_unlock; 938 } 939 940 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked); 941 942 if (siftr_generate_hashes) { 943 if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) { 944 /* 945 * For outbound packets, the TCP checksum isn't 946 * calculated yet. This is a problem for our packet 947 * hashing as the receiver will calc a different hash 948 * to ours if we don't include the correct TCP checksum 949 * in the bytes being hashed. To work around this 950 * problem, we manually calc the TCP checksum here in 951 * software. We unset the CSUM_TCP flag so the lower 952 * layers don't recalc it. 953 */ 954 (*m)->m_pkthdr.csum_flags &= ~CSUM_TCP; 955 956 /* 957 * Calculate the TCP checksum in software and assign 958 * to correct TCP header field, which will follow the 959 * packet mbuf down the stack. The trick here is that 960 * tcp_output() sets th->th_sum to the checksum of the 961 * pseudo header for us already. Because of the nature 962 * of the checksumming algorithm, we can sum over the 963 * entire IP payload (i.e. TCP header and data), which 964 * will include the already calculated pseduo header 965 * checksum, thus giving us the complete TCP checksum. 966 * 967 * To put it in simple terms, if checksum(1,2,3,4)=10, 968 * then checksum(1,2,3,4,5) == checksum(10,5). 969 * This property is what allows us to "cheat" and 970 * checksum only the IP payload which has the TCP 971 * th_sum field populated with the pseudo header's 972 * checksum, and not need to futz around checksumming 973 * pseudo header bytes and TCP header/data in one hit. 974 * Refer to RFC 1071 for more info. 975 * 976 * NB: in_cksum_skip(struct mbuf *m, int len, int skip) 977 * in_cksum_skip 2nd argument is NOT the number of 978 * bytes to read from the mbuf at "skip" bytes offset 979 * from the start of the mbuf (very counter intuitive!). 980 * The number of bytes to read is calculated internally 981 * by the function as len-skip i.e. to sum over the IP 982 * payload (TCP header + data) bytes, it is INCORRECT 983 * to call the function like this: 984 * in_cksum_skip(at, ip->ip_len - offset, offset) 985 * Rather, it should be called like this: 986 * in_cksum_skip(at, ip->ip_len, offset) 987 * which means read "ip->ip_len - offset" bytes from 988 * the mbuf cluster "at" at offset "offset" bytes from 989 * the beginning of the "at" mbuf's data pointer. 990 */ 991 th->th_sum = in_cksum_skip(*m, ntohs(ip->ip_len), 992 ip_hl); 993 } 994 995 /* 996 * XXX: Having to calculate the checksum in software and then 997 * hash over all bytes is really inefficient. Would be nice to 998 * find a way to create the hash and checksum in the same pass 999 * over the bytes. 1000 */ 1001 pn->hash = hash_pkt(*m, ip_hl); 1002 } 1003 1004 mtx_lock(&siftr_pkt_queue_mtx); 1005 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 1006 mtx_unlock(&siftr_pkt_queue_mtx); 1007 goto ret; 1008 1009 inp_unlock: 1010 if (inp_locally_locked) 1011 INP_RUNLOCK(inp); 1012 1013 ret: 1014 return (PFIL_PASS); 1015 } 1016 1017 1018 #ifdef SIFTR_IPV6 1019 static int 1020 siftr_chkpkt6(struct mbuf **m, struct ifnet *ifp, int flags, struct inpcb *inp) 1021 { 1022 struct pkt_node *pn; 1023 struct ip6_hdr *ip6; 1024 struct tcphdr *th; 1025 struct tcpcb *tp; 1026 struct siftr_stats *ss; 1027 unsigned int ip6_hl; 1028 int inp_locally_locked, dir; 1029 1030 inp_locally_locked = 0; 1031 dir = PFIL_DIR(flags); 1032 ss = DPCPU_PTR(ss); 1033 1034 /* 1035 * m_pullup is not required here because ip6_{input|output} 1036 * already do the heavy lifting for us. 1037 */ 1038 1039 ip6 = mtod(*m, struct ip6_hdr *); 1040 1041 /* 1042 * Only continue processing if the packet is TCP 1043 * XXX: We should follow the next header fields 1044 * as shown on Pg 6 RFC 2460, but right now we'll 1045 * only check pkts that have no extension headers. 1046 */ 1047 if (ip6->ip6_nxt != IPPROTO_TCP) 1048 goto ret6; 1049 1050 /* 1051 * If a kernel subsystem reinjects packets into the stack, our pfil 1052 * hook will be called multiple times for the same packet. 1053 * Make sure we only process unique packets. 1054 */ 1055 if (siftr_chkreinject(*m, dir, ss)) 1056 goto ret6; 1057 1058 if (dir == PFIL_IN) 1059 ss->n_in++; 1060 else 1061 ss->n_out++; 1062 1063 ip6_hl = sizeof(struct ip6_hdr); 1064 1065 /* 1066 * Create a tcphdr struct starting at the correct offset 1067 * in the ipv6 packet. ip->ip_hl gives the ip header length 1068 * in 4-byte words, so multiply it to get the size in bytes. 1069 */ 1070 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl); 1071 1072 /* 1073 * For inbound packets, the pfil hooks don't provide a pointer to the 1074 * inpcb, so we need to find it ourselves and lock it. 1075 */ 1076 if (!inp) { 1077 /* Find the corresponding inpcb for this pkt. */ 1078 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m, 1079 th->th_sport, th->th_dport, dir, ss); 1080 1081 if (inp == NULL) 1082 goto ret6; 1083 else 1084 inp_locally_locked = 1; 1085 } 1086 1087 /* Find the TCP control block that corresponds with this packet. */ 1088 tp = intotcpcb(inp); 1089 1090 /* 1091 * If we can't find the TCP control block (happens occasionaly for a 1092 * packet sent during the shutdown phase of a TCP connection), 1093 * or we're in the timewait state, bail. 1094 */ 1095 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) { 1096 if (dir == PFIL_IN) 1097 ss->nskip_in_tcpcb++; 1098 else 1099 ss->nskip_out_tcpcb++; 1100 1101 goto inp_unlock6; 1102 } 1103 1104 /* 1105 * Only pkts selected by the tcp port filter 1106 * can be inserted into the pkt_queue 1107 */ 1108 if ((siftr_port_filter != 0) && 1109 (siftr_port_filter != ntohs(inp->inp_lport)) && 1110 (siftr_port_filter != ntohs(inp->inp_fport))) { 1111 goto inp_unlock6; 1112 } 1113 1114 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 1115 1116 if (pn == NULL) { 1117 if (dir == PFIL_IN) 1118 ss->nskip_in_malloc++; 1119 else 1120 ss->nskip_out_malloc++; 1121 1122 goto inp_unlock6; 1123 } 1124 1125 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked); 1126 1127 /* XXX: Figure out how to generate hashes for IPv6 packets. */ 1128 1129 mtx_lock(&siftr_pkt_queue_mtx); 1130 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 1131 mtx_unlock(&siftr_pkt_queue_mtx); 1132 goto ret6; 1133 1134 inp_unlock6: 1135 if (inp_locally_locked) 1136 INP_RUNLOCK(inp); 1137 1138 ret6: 1139 /* Returning 0 ensures pfil will not discard the pkt. */ 1140 return (0); 1141 } 1142 #endif /* #ifdef SIFTR_IPV6 */ 1143 1144 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet_hook); 1145 #define V_siftr_inet_hook VNET(siftr_inet_hook) 1146 #ifdef INET6 1147 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet6_hook); 1148 #define V_siftr_inet6_hook VNET(siftr_inet6_hook) 1149 #endif 1150 static int 1151 siftr_pfil(int action) 1152 { 1153 struct pfil_hook_args pha; 1154 struct pfil_link_args pla; 1155 1156 pha.pa_version = PFIL_VERSION; 1157 pha.pa_flags = PFIL_IN | PFIL_OUT; 1158 pha.pa_modname = "siftr"; 1159 pha.pa_ruleset = NULL; 1160 pha.pa_rulname = "default"; 1161 1162 pla.pa_version = PFIL_VERSION; 1163 pla.pa_flags = PFIL_IN | PFIL_OUT | 1164 PFIL_HEADPTR | PFIL_HOOKPTR; 1165 1166 VNET_ITERATOR_DECL(vnet_iter); 1167 1168 VNET_LIST_RLOCK(); 1169 VNET_FOREACH(vnet_iter) { 1170 CURVNET_SET(vnet_iter); 1171 1172 if (action == HOOK) { 1173 pha.pa_func = siftr_chkpkt; 1174 pha.pa_type = PFIL_TYPE_IP4; 1175 V_siftr_inet_hook = pfil_add_hook(&pha); 1176 pla.pa_hook = V_siftr_inet_hook; 1177 pla.pa_head = V_inet_pfil_head; 1178 (void)pfil_link(&pla); 1179 #ifdef SIFTR_IPV6 1180 pha.pa_func = siftr_chkpkt6; 1181 pha.pa_type = PFIL_TYPE_IP6; 1182 V_siftr_inet6_hook = pfil_add_hook(&pha); 1183 pla.pa_hook = V_siftr_inet6_hook; 1184 pla.pa_head = V_inet6_pfil_head; 1185 (void)pfil_link(&pla); 1186 #endif 1187 } else if (action == UNHOOK) { 1188 pfil_remove_hook(V_siftr_inet_hook); 1189 #ifdef SIFTR_IPV6 1190 pfil_remove_hook(V_siftr_inet6_hook); 1191 #endif 1192 } 1193 CURVNET_RESTORE(); 1194 } 1195 VNET_LIST_RUNLOCK(); 1196 1197 return (0); 1198 } 1199 1200 1201 static int 1202 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS) 1203 { 1204 struct alq *new_alq; 1205 int error; 1206 1207 error = sysctl_handle_string(oidp, arg1, arg2, req); 1208 1209 /* Check for error or same filename */ 1210 if (error != 0 || req->newptr == NULL || 1211 strncmp(siftr_logfile, arg1, arg2) == 0) 1212 goto done; 1213 1214 /* Filname changed */ 1215 error = alq_open(&new_alq, arg1, curthread->td_ucred, 1216 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1217 if (error != 0) 1218 goto done; 1219 1220 /* 1221 * If disabled, siftr_alq == NULL so we simply close 1222 * the alq as we've proved it can be opened. 1223 * If enabled, close the existing alq and switch the old 1224 * for the new. 1225 */ 1226 if (siftr_alq == NULL) { 1227 alq_close(new_alq); 1228 } else { 1229 alq_close(siftr_alq); 1230 siftr_alq = new_alq; 1231 } 1232 1233 /* Update filename upon success */ 1234 strlcpy(siftr_logfile, arg1, arg2); 1235 done: 1236 return (error); 1237 } 1238 1239 static int 1240 siftr_manage_ops(uint8_t action) 1241 { 1242 struct siftr_stats totalss; 1243 struct timeval tval; 1244 struct flow_hash_node *counter, *tmp_counter; 1245 struct sbuf *s; 1246 int i, key_index, error; 1247 uint32_t bytes_to_write, total_skipped_pkts; 1248 uint16_t lport, fport; 1249 uint8_t *key, ipver __unused; 1250 1251 #ifdef SIFTR_IPV6 1252 uint32_t laddr[4]; 1253 uint32_t faddr[4]; 1254 #else 1255 uint8_t laddr[4]; 1256 uint8_t faddr[4]; 1257 #endif 1258 1259 error = 0; 1260 total_skipped_pkts = 0; 1261 1262 /* Init an autosizing sbuf that initially holds 200 chars. */ 1263 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL) 1264 return (-1); 1265 1266 if (action == SIFTR_ENABLE && siftr_pkt_manager_thr == NULL) { 1267 /* 1268 * Create our alq 1269 * XXX: We should abort if alq_open fails! 1270 */ 1271 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred, 1272 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1273 1274 STAILQ_INIT(&pkt_queue); 1275 1276 DPCPU_ZERO(ss); 1277 1278 siftr_exit_pkt_manager_thread = 0; 1279 1280 kthread_add(&siftr_pkt_manager_thread, NULL, NULL, 1281 &siftr_pkt_manager_thr, RFNOWAIT, 0, 1282 "siftr_pkt_manager_thr"); 1283 1284 siftr_pfil(HOOK); 1285 1286 microtime(&tval); 1287 1288 sbuf_printf(s, 1289 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t" 1290 "siftrver=%s\thz=%u\ttcp_rtt_scale=%u\tsysname=%s\t" 1291 "sysver=%u\tipmode=%u\n", 1292 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, hz, 1293 TCP_RTT_SCALE, SYS_NAME, __FreeBSD_version, SIFTR_IPMODE); 1294 1295 sbuf_finish(s); 1296 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK); 1297 1298 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) { 1299 /* 1300 * Remove the pfil hook functions. All threads currently in 1301 * the hook functions are allowed to exit before siftr_pfil() 1302 * returns. 1303 */ 1304 siftr_pfil(UNHOOK); 1305 1306 /* This will block until the pkt manager thread unlocks it. */ 1307 mtx_lock(&siftr_pkt_mgr_mtx); 1308 1309 /* Tell the pkt manager thread that it should exit now. */ 1310 siftr_exit_pkt_manager_thread = 1; 1311 1312 /* 1313 * Wake the pkt_manager thread so it realises that 1314 * siftr_exit_pkt_manager_thread == 1 and exits gracefully. 1315 * The wakeup won't be delivered until we unlock 1316 * siftr_pkt_mgr_mtx so this isn't racy. 1317 */ 1318 wakeup(&wait_for_pkt); 1319 1320 /* Wait for the pkt_manager thread to exit. */ 1321 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT, 1322 "thrwait", 0); 1323 1324 siftr_pkt_manager_thr = NULL; 1325 mtx_unlock(&siftr_pkt_mgr_mtx); 1326 1327 totalss.n_in = DPCPU_VARSUM(ss, n_in); 1328 totalss.n_out = DPCPU_VARSUM(ss, n_out); 1329 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc); 1330 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc); 1331 totalss.nskip_in_mtx = DPCPU_VARSUM(ss, nskip_in_mtx); 1332 totalss.nskip_out_mtx = DPCPU_VARSUM(ss, nskip_out_mtx); 1333 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb); 1334 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb); 1335 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb); 1336 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb); 1337 1338 total_skipped_pkts = totalss.nskip_in_malloc + 1339 totalss.nskip_out_malloc + totalss.nskip_in_mtx + 1340 totalss.nskip_out_mtx + totalss.nskip_in_tcpcb + 1341 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb + 1342 totalss.nskip_out_inpcb; 1343 1344 microtime(&tval); 1345 1346 sbuf_printf(s, 1347 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t" 1348 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t" 1349 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t" 1350 "num_outbound_skipped_pkts_malloc=%u\t" 1351 "num_inbound_skipped_pkts_mtx=%u\t" 1352 "num_outbound_skipped_pkts_mtx=%u\t" 1353 "num_inbound_skipped_pkts_tcpcb=%u\t" 1354 "num_outbound_skipped_pkts_tcpcb=%u\t" 1355 "num_inbound_skipped_pkts_inpcb=%u\t" 1356 "num_outbound_skipped_pkts_inpcb=%u\t" 1357 "total_skipped_tcp_pkts=%u\tflow_list=", 1358 (intmax_t)tval.tv_sec, 1359 tval.tv_usec, 1360 (uintmax_t)totalss.n_in, 1361 (uintmax_t)totalss.n_out, 1362 (uintmax_t)(totalss.n_in + totalss.n_out), 1363 totalss.nskip_in_malloc, 1364 totalss.nskip_out_malloc, 1365 totalss.nskip_in_mtx, 1366 totalss.nskip_out_mtx, 1367 totalss.nskip_in_tcpcb, 1368 totalss.nskip_out_tcpcb, 1369 totalss.nskip_in_inpcb, 1370 totalss.nskip_out_inpcb, 1371 total_skipped_pkts); 1372 1373 /* 1374 * Iterate over the flow hash, printing a summary of each 1375 * flow seen and freeing any malloc'd memory. 1376 * The hash consists of an array of LISTs (man 3 queue). 1377 */ 1378 for (i = 0; i <= siftr_hashmask; i++) { 1379 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes, 1380 tmp_counter) { 1381 key = counter->key; 1382 key_index = 1; 1383 1384 ipver = key[0]; 1385 1386 memcpy(laddr, key + key_index, sizeof(laddr)); 1387 key_index += sizeof(laddr); 1388 memcpy(&lport, key + key_index, sizeof(lport)); 1389 key_index += sizeof(lport); 1390 memcpy(faddr, key + key_index, sizeof(faddr)); 1391 key_index += sizeof(faddr); 1392 memcpy(&fport, key + key_index, sizeof(fport)); 1393 1394 #ifdef SIFTR_IPV6 1395 laddr[3] = ntohl(laddr[3]); 1396 faddr[3] = ntohl(faddr[3]); 1397 1398 if (ipver == INP_IPV6) { 1399 laddr[0] = ntohl(laddr[0]); 1400 laddr[1] = ntohl(laddr[1]); 1401 laddr[2] = ntohl(laddr[2]); 1402 faddr[0] = ntohl(faddr[0]); 1403 faddr[1] = ntohl(faddr[1]); 1404 faddr[2] = ntohl(faddr[2]); 1405 1406 sbuf_printf(s, 1407 "%x:%x:%x:%x:%x:%x:%x:%x;%u-" 1408 "%x:%x:%x:%x:%x:%x:%x:%x;%u,", 1409 UPPER_SHORT(laddr[0]), 1410 LOWER_SHORT(laddr[0]), 1411 UPPER_SHORT(laddr[1]), 1412 LOWER_SHORT(laddr[1]), 1413 UPPER_SHORT(laddr[2]), 1414 LOWER_SHORT(laddr[2]), 1415 UPPER_SHORT(laddr[3]), 1416 LOWER_SHORT(laddr[3]), 1417 ntohs(lport), 1418 UPPER_SHORT(faddr[0]), 1419 LOWER_SHORT(faddr[0]), 1420 UPPER_SHORT(faddr[1]), 1421 LOWER_SHORT(faddr[1]), 1422 UPPER_SHORT(faddr[2]), 1423 LOWER_SHORT(faddr[2]), 1424 UPPER_SHORT(faddr[3]), 1425 LOWER_SHORT(faddr[3]), 1426 ntohs(fport)); 1427 } else { 1428 laddr[0] = FIRST_OCTET(laddr[3]); 1429 laddr[1] = SECOND_OCTET(laddr[3]); 1430 laddr[2] = THIRD_OCTET(laddr[3]); 1431 laddr[3] = FOURTH_OCTET(laddr[3]); 1432 faddr[0] = FIRST_OCTET(faddr[3]); 1433 faddr[1] = SECOND_OCTET(faddr[3]); 1434 faddr[2] = THIRD_OCTET(faddr[3]); 1435 faddr[3] = FOURTH_OCTET(faddr[3]); 1436 #endif 1437 sbuf_printf(s, 1438 "%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,", 1439 laddr[0], 1440 laddr[1], 1441 laddr[2], 1442 laddr[3], 1443 ntohs(lport), 1444 faddr[0], 1445 faddr[1], 1446 faddr[2], 1447 faddr[3], 1448 ntohs(fport)); 1449 #ifdef SIFTR_IPV6 1450 } 1451 #endif 1452 1453 free(counter, M_SIFTR_HASHNODE); 1454 } 1455 1456 LIST_INIT(counter_hash + i); 1457 } 1458 1459 sbuf_printf(s, "\n"); 1460 sbuf_finish(s); 1461 1462 i = 0; 1463 do { 1464 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i); 1465 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK); 1466 i += bytes_to_write; 1467 } while (i < sbuf_len(s)); 1468 1469 alq_close(siftr_alq); 1470 siftr_alq = NULL; 1471 } else 1472 error = EINVAL; 1473 1474 sbuf_delete(s); 1475 1476 /* 1477 * XXX: Should be using ret to check if any functions fail 1478 * and set error appropriately 1479 */ 1480 1481 return (error); 1482 } 1483 1484 1485 static int 1486 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS) 1487 { 1488 int error; 1489 uint32_t new; 1490 1491 new = siftr_enabled; 1492 error = sysctl_handle_int(oidp, &new, 0, req); 1493 if (error == 0 && req->newptr != NULL) { 1494 if (new > 1) 1495 return (EINVAL); 1496 else if (new != siftr_enabled) { 1497 if ((error = siftr_manage_ops(new)) == 0) { 1498 siftr_enabled = new; 1499 } else { 1500 siftr_manage_ops(SIFTR_DISABLE); 1501 } 1502 } 1503 } 1504 1505 return (error); 1506 } 1507 1508 1509 static void 1510 siftr_shutdown_handler(void *arg) 1511 { 1512 if (siftr_enabled == 1) { 1513 siftr_manage_ops(SIFTR_DISABLE); 1514 } 1515 } 1516 1517 1518 /* 1519 * Module is being unloaded or machine is shutting down. Take care of cleanup. 1520 */ 1521 static int 1522 deinit_siftr(void) 1523 { 1524 /* Cleanup. */ 1525 siftr_manage_ops(SIFTR_DISABLE); 1526 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask); 1527 mtx_destroy(&siftr_pkt_queue_mtx); 1528 mtx_destroy(&siftr_pkt_mgr_mtx); 1529 1530 return (0); 1531 } 1532 1533 1534 /* 1535 * Module has just been loaded into the kernel. 1536 */ 1537 static int 1538 init_siftr(void) 1539 { 1540 EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL, 1541 SHUTDOWN_PRI_FIRST); 1542 1543 /* Initialise our flow counter hash table. */ 1544 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR, 1545 &siftr_hashmask); 1546 1547 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF); 1548 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF); 1549 1550 /* Print message to the user's current terminal. */ 1551 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n" 1552 " http://caia.swin.edu.au/urp/newtcp\n\n", 1553 MODVERSION_STR); 1554 1555 return (0); 1556 } 1557 1558 1559 /* 1560 * This is the function that is called to load and unload the module. 1561 * When the module is loaded, this function is called once with 1562 * "what" == MOD_LOAD 1563 * When the module is unloaded, this function is called twice with 1564 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second 1565 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command, 1566 * this function is called once with "what" = MOD_SHUTDOWN 1567 * When the system is shut down, the handler isn't called until the very end 1568 * of the shutdown sequence i.e. after the disks have been synced. 1569 */ 1570 static int 1571 siftr_load_handler(module_t mod, int what, void *arg) 1572 { 1573 int ret; 1574 1575 switch (what) { 1576 case MOD_LOAD: 1577 ret = init_siftr(); 1578 break; 1579 1580 case MOD_QUIESCE: 1581 case MOD_SHUTDOWN: 1582 ret = deinit_siftr(); 1583 break; 1584 1585 case MOD_UNLOAD: 1586 ret = 0; 1587 break; 1588 1589 default: 1590 ret = EINVAL; 1591 break; 1592 } 1593 1594 return (ret); 1595 } 1596 1597 1598 static moduledata_t siftr_mod = { 1599 .name = "siftr", 1600 .evhand = siftr_load_handler, 1601 }; 1602 1603 /* 1604 * Param 1: name of the kernel module 1605 * Param 2: moduledata_t struct containing info about the kernel module 1606 * and the execution entry point for the module 1607 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h 1608 * Defines the module initialisation order 1609 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h 1610 * Defines the initialisation order of this kld relative to others 1611 * within the same subsystem as defined by param 3 1612 */ 1613 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY); 1614 MODULE_DEPEND(siftr, alq, 1, 1, 1); 1615 MODULE_VERSION(siftr, MODVERSION); 1616