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