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/tcp_var.h> 98 99 #ifdef SIFTR_IPV6 100 #include <netinet/ip6.h> 101 #include <netinet6/in6_pcb.h> 102 #endif /* SIFTR_IPV6 */ 103 104 #include <machine/in_cksum.h> 105 106 /* 107 * Three digit version number refers to X.Y.Z where: 108 * X is the major version number 109 * Y is bumped to mark backwards incompatible changes 110 * Z is bumped to mark backwards compatible changes 111 */ 112 #define V_MAJOR 1 113 #define V_BACKBREAK 2 114 #define V_BACKCOMPAT 4 115 #define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT)) 116 #define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \ 117 __XSTRING(V_BACKCOMPAT) 118 119 #define HOOK 0 120 #define UNHOOK 1 121 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536 122 #define SYS_NAME "FreeBSD" 123 #define PACKET_TAG_SIFTR 100 124 #define PACKET_COOKIE_SIFTR 21749576 125 #define SIFTR_LOG_FILE_MODE 0644 126 #define SIFTR_DISABLE 0 127 #define SIFTR_ENABLE 1 128 129 /* 130 * Hard upper limit on the length of log messages. Bump this up if you add new 131 * data fields such that the line length could exceed the below value. 132 */ 133 #define MAX_LOG_MSG_LEN 200 134 /* XXX: Make this a sysctl tunable. */ 135 #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN) 136 137 /* 138 * 1 byte for IP version 139 * IPv4: src/dst IP (4+4) + src/dst port (2+2) = 12 bytes 140 * IPv6: src/dst IP (16+16) + src/dst port (2+2) = 36 bytes 141 */ 142 #ifdef SIFTR_IPV6 143 #define FLOW_KEY_LEN 37 144 #else 145 #define FLOW_KEY_LEN 13 146 #endif 147 148 #ifdef SIFTR_IPV6 149 #define SIFTR_IPMODE 6 150 #else 151 #define SIFTR_IPMODE 4 152 #endif 153 154 /* useful macros */ 155 #define CAST_PTR_INT(X) (*((int*)(X))) 156 157 #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; either PFIL_IN or PFIL_OUT. */ 176 uint8_t direction; 177 /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */ 178 uint8_t ipver; 179 /* Hash of the pkt which triggered the log message. */ 180 uint32_t hash; 181 /* Local/foreign IP address. */ 182 #ifdef SIFTR_IPV6 183 uint32_t ip_laddr[4]; 184 uint32_t ip_faddr[4]; 185 #else 186 uint8_t ip_laddr[4]; 187 uint8_t ip_faddr[4]; 188 #endif 189 /* Local TCP port. */ 190 uint16_t tcp_localport; 191 /* Foreign TCP port. */ 192 uint16_t tcp_foreignport; 193 /* Congestion Window (bytes). */ 194 u_long snd_cwnd; 195 /* Sending Window (bytes). */ 196 u_long snd_wnd; 197 /* Receive Window (bytes). */ 198 u_long rcv_wnd; 199 /* Unused (was: Bandwidth Controlled Window (bytes)). */ 200 u_long snd_bwnd; 201 /* Slow Start Threshold (bytes). */ 202 u_long snd_ssthresh; 203 /* Current state of the TCP FSM. */ 204 int conn_state; 205 /* Max Segment Size (bytes). */ 206 u_int max_seg_size; 207 /* 208 * Smoothed RTT stored as found in the TCP control block 209 * in units of (TCP_RTT_SCALE*hz). 210 */ 211 int smoothed_rtt; 212 /* Is SACK enabled? */ 213 u_char sack_enabled; 214 /* Window scaling for snd window. */ 215 u_char snd_scale; 216 /* Window scaling for recv window. */ 217 u_char rcv_scale; 218 /* TCP control block flags. */ 219 u_int flags; 220 /* Retransmit timeout length. */ 221 int rxt_length; 222 /* Size of the TCP send buffer in bytes. */ 223 u_int snd_buf_hiwater; 224 /* Current num bytes in the send socket buffer. */ 225 u_int snd_buf_cc; 226 /* Size of the TCP receive buffer in bytes. */ 227 u_int rcv_buf_hiwater; 228 /* Current num bytes in the receive socket buffer. */ 229 u_int rcv_buf_cc; 230 /* Number of bytes inflight that we are waiting on ACKs for. */ 231 u_int sent_inflight_bytes; 232 /* Number of segments currently in the reassembly queue. */ 233 int t_segqlen; 234 /* Flowid for the connection. */ 235 u_int flowid; 236 /* Flow type for the connection. */ 237 u_int flowtype; 238 /* Link to next pkt_node in the list. */ 239 STAILQ_ENTRY(pkt_node) nodes; 240 }; 241 242 struct flow_hash_node 243 { 244 uint16_t counter; 245 uint8_t key[FLOW_KEY_LEN]; 246 LIST_ENTRY(flow_hash_node) nodes; 247 }; 248 249 struct siftr_stats 250 { 251 /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */ 252 uint64_t n_in; 253 uint64_t n_out; 254 /* # pkts skipped due to failed malloc calls. */ 255 uint32_t nskip_in_malloc; 256 uint32_t nskip_out_malloc; 257 /* # pkts skipped due to failed mtx acquisition. */ 258 uint32_t nskip_in_mtx; 259 uint32_t nskip_out_mtx; 260 /* # pkts skipped due to failed inpcb lookups. */ 261 uint32_t nskip_in_inpcb; 262 uint32_t nskip_out_inpcb; 263 /* # pkts skipped due to failed tcpcb lookups. */ 264 uint32_t nskip_in_tcpcb; 265 uint32_t nskip_out_tcpcb; 266 /* # pkts skipped due to stack reinjection. */ 267 uint32_t nskip_in_dejavu; 268 uint32_t nskip_out_dejavu; 269 }; 270 271 static DPCPU_DEFINE(struct siftr_stats, ss); 272 273 static volatile unsigned int siftr_exit_pkt_manager_thread = 0; 274 static unsigned int siftr_enabled = 0; 275 static unsigned int siftr_pkts_per_log = 1; 276 static unsigned int siftr_generate_hashes = 0; 277 /* static unsigned int siftr_binary_log = 0; */ 278 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log"; 279 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log"; 280 static u_long siftr_hashmask; 281 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue); 282 LIST_HEAD(listhead, flow_hash_node) *counter_hash; 283 static int wait_for_pkt; 284 static struct alq *siftr_alq = NULL; 285 static struct mtx siftr_pkt_queue_mtx; 286 static struct mtx siftr_pkt_mgr_mtx; 287 static struct thread *siftr_pkt_manager_thr = NULL; 288 /* 289 * pfil.h defines PFIL_IN as 1 and PFIL_OUT as 2, 290 * which we use as an index into this array. 291 */ 292 static char direction[3] = {'\0', '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, NULL, 304 "siftr related settings"); 305 306 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, CTLTYPE_UINT|CTLFLAG_RW, 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, CTLTYPE_STRING|CTLFLAG_RW, 311 &siftr_logfile_shadow, sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler, 312 "A", "file to save siftr log messages to"); 313 314 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW, 315 &siftr_pkts_per_log, 1, 316 "number of packets between generating a log message"); 317 318 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW, 319 &siftr_generate_hashes, 0, 320 "enable packet hash generation"); 321 322 /* XXX: TODO 323 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW, 324 &siftr_binary_log, 0, 325 "write log files in binary instead of ascii"); 326 */ 327 328 329 /* Begin functions. */ 330 331 static void 332 siftr_process_pkt(struct pkt_node * pkt_node) 333 { 334 struct flow_hash_node *hash_node; 335 struct listhead *counter_list; 336 struct siftr_stats *ss; 337 struct ale *log_buf; 338 uint8_t key[FLOW_KEY_LEN]; 339 uint8_t found_match, key_offset; 340 341 hash_node = NULL; 342 ss = DPCPU_PTR(ss); 343 found_match = 0; 344 key_offset = 1; 345 346 /* 347 * Create the key that will be used to create a hash index 348 * into our hash table. Our key consists of: 349 * ipversion, localip, localport, foreignip, foreignport 350 */ 351 key[0] = pkt_node->ipver; 352 memcpy(key + key_offset, &pkt_node->ip_laddr, 353 sizeof(pkt_node->ip_laddr)); 354 key_offset += sizeof(pkt_node->ip_laddr); 355 memcpy(key + key_offset, &pkt_node->tcp_localport, 356 sizeof(pkt_node->tcp_localport)); 357 key_offset += sizeof(pkt_node->tcp_localport); 358 memcpy(key + key_offset, &pkt_node->ip_faddr, 359 sizeof(pkt_node->ip_faddr)); 360 key_offset += sizeof(pkt_node->ip_faddr); 361 memcpy(key + key_offset, &pkt_node->tcp_foreignport, 362 sizeof(pkt_node->tcp_foreignport)); 363 364 counter_list = counter_hash + 365 (hash32_buf(key, sizeof(key), 0) & siftr_hashmask); 366 367 /* 368 * If the list is not empty i.e. the hash index has 369 * been used by another flow previously. 370 */ 371 if (LIST_FIRST(counter_list) != NULL) { 372 /* 373 * Loop through the hash nodes in the list. 374 * There should normally only be 1 hash node in the list, 375 * except if there have been collisions at the hash index 376 * computed by hash32_buf(). 377 */ 378 LIST_FOREACH(hash_node, counter_list, nodes) { 379 /* 380 * Check if the key for the pkt we are currently 381 * processing is the same as the key stored in the 382 * hash node we are currently processing. 383 * If they are the same, then we've found the 384 * hash node that stores the counter for the flow 385 * the pkt belongs to. 386 */ 387 if (memcmp(hash_node->key, key, sizeof(key)) == 0) { 388 found_match = 1; 389 break; 390 } 391 } 392 } 393 394 /* If this flow hash hasn't been seen before or we have a collision. */ 395 if (hash_node == NULL || !found_match) { 396 /* Create a new hash node to store the flow's counter. */ 397 hash_node = malloc(sizeof(struct flow_hash_node), 398 M_SIFTR_HASHNODE, M_WAITOK); 399 400 if (hash_node != NULL) { 401 /* Initialise our new hash node list entry. */ 402 hash_node->counter = 0; 403 memcpy(hash_node->key, key, sizeof(key)); 404 LIST_INSERT_HEAD(counter_list, hash_node, nodes); 405 } else { 406 /* Malloc failed. */ 407 if (pkt_node->direction == PFIL_IN) 408 ss->nskip_in_malloc++; 409 else 410 ss->nskip_out_malloc++; 411 412 return; 413 } 414 } else if (siftr_pkts_per_log > 1) { 415 /* 416 * Taking the remainder of the counter divided 417 * by the current value of siftr_pkts_per_log 418 * and storing that in counter provides a neat 419 * way to modulate the frequency of log 420 * messages being written to the log file. 421 */ 422 hash_node->counter = (hash_node->counter + 1) % 423 siftr_pkts_per_log; 424 425 /* 426 * If we have not seen enough packets since the last time 427 * we wrote a log message for this connection, return. 428 */ 429 if (hash_node->counter > 0) 430 return; 431 } 432 433 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK); 434 435 if (log_buf == NULL) 436 return; /* Should only happen if the ALQ is shutting down. */ 437 438 #ifdef SIFTR_IPV6 439 pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]); 440 pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]); 441 442 if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */ 443 pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]); 444 pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]); 445 pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]); 446 pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]); 447 pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]); 448 pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]); 449 450 /* Construct an IPv6 log message. */ 451 log_buf->ae_bytesused = snprintf(log_buf->ae_data, 452 MAX_LOG_MSG_LEN, 453 "%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:" 454 "%x:%x:%x:%x:%x,%u,%ld,%ld,%ld,%ld,%ld,%u,%u,%u,%u,%u,%u," 455 "%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n", 456 direction[pkt_node->direction], 457 pkt_node->hash, 458 pkt_node->tval.tv_sec, 459 pkt_node->tval.tv_usec, 460 UPPER_SHORT(pkt_node->ip_laddr[0]), 461 LOWER_SHORT(pkt_node->ip_laddr[0]), 462 UPPER_SHORT(pkt_node->ip_laddr[1]), 463 LOWER_SHORT(pkt_node->ip_laddr[1]), 464 UPPER_SHORT(pkt_node->ip_laddr[2]), 465 LOWER_SHORT(pkt_node->ip_laddr[2]), 466 UPPER_SHORT(pkt_node->ip_laddr[3]), 467 LOWER_SHORT(pkt_node->ip_laddr[3]), 468 ntohs(pkt_node->tcp_localport), 469 UPPER_SHORT(pkt_node->ip_faddr[0]), 470 LOWER_SHORT(pkt_node->ip_faddr[0]), 471 UPPER_SHORT(pkt_node->ip_faddr[1]), 472 LOWER_SHORT(pkt_node->ip_faddr[1]), 473 UPPER_SHORT(pkt_node->ip_faddr[2]), 474 LOWER_SHORT(pkt_node->ip_faddr[2]), 475 UPPER_SHORT(pkt_node->ip_faddr[3]), 476 LOWER_SHORT(pkt_node->ip_faddr[3]), 477 ntohs(pkt_node->tcp_foreignport), 478 pkt_node->snd_ssthresh, 479 pkt_node->snd_cwnd, 480 pkt_node->snd_bwnd, 481 pkt_node->snd_wnd, 482 pkt_node->rcv_wnd, 483 pkt_node->snd_scale, 484 pkt_node->rcv_scale, 485 pkt_node->conn_state, 486 pkt_node->max_seg_size, 487 pkt_node->smoothed_rtt, 488 pkt_node->sack_enabled, 489 pkt_node->flags, 490 pkt_node->rxt_length, 491 pkt_node->snd_buf_hiwater, 492 pkt_node->snd_buf_cc, 493 pkt_node->rcv_buf_hiwater, 494 pkt_node->rcv_buf_cc, 495 pkt_node->sent_inflight_bytes, 496 pkt_node->t_segqlen, 497 pkt_node->flowid, 498 pkt_node->flowtype); 499 } else { /* IPv4 packet */ 500 pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]); 501 pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]); 502 pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]); 503 pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]); 504 pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]); 505 pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]); 506 pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]); 507 pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]); 508 #endif /* SIFTR_IPV6 */ 509 510 /* Construct an IPv4 log message. */ 511 log_buf->ae_bytesused = snprintf(log_buf->ae_data, 512 MAX_LOG_MSG_LEN, 513 "%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%ld,%ld," 514 "%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n", 515 direction[pkt_node->direction], 516 pkt_node->hash, 517 (intmax_t)pkt_node->tval.tv_sec, 518 pkt_node->tval.tv_usec, 519 pkt_node->ip_laddr[0], 520 pkt_node->ip_laddr[1], 521 pkt_node->ip_laddr[2], 522 pkt_node->ip_laddr[3], 523 ntohs(pkt_node->tcp_localport), 524 pkt_node->ip_faddr[0], 525 pkt_node->ip_faddr[1], 526 pkt_node->ip_faddr[2], 527 pkt_node->ip_faddr[3], 528 ntohs(pkt_node->tcp_foreignport), 529 pkt_node->snd_ssthresh, 530 pkt_node->snd_cwnd, 531 pkt_node->snd_bwnd, 532 pkt_node->snd_wnd, 533 pkt_node->rcv_wnd, 534 pkt_node->snd_scale, 535 pkt_node->rcv_scale, 536 pkt_node->conn_state, 537 pkt_node->max_seg_size, 538 pkt_node->smoothed_rtt, 539 pkt_node->sack_enabled, 540 pkt_node->flags, 541 pkt_node->rxt_length, 542 pkt_node->snd_buf_hiwater, 543 pkt_node->snd_buf_cc, 544 pkt_node->rcv_buf_hiwater, 545 pkt_node->rcv_buf_cc, 546 pkt_node->sent_inflight_bytes, 547 pkt_node->t_segqlen, 548 pkt_node->flowid, 549 pkt_node->flowtype); 550 #ifdef SIFTR_IPV6 551 } 552 #endif 553 554 alq_post_flags(siftr_alq, log_buf, 0); 555 } 556 557 558 static void 559 siftr_pkt_manager_thread(void *arg) 560 { 561 STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue = 562 STAILQ_HEAD_INITIALIZER(tmp_pkt_queue); 563 struct pkt_node *pkt_node, *pkt_node_temp; 564 uint8_t draining; 565 566 draining = 2; 567 568 mtx_lock(&siftr_pkt_mgr_mtx); 569 570 /* draining == 0 when queue has been flushed and it's safe to exit. */ 571 while (draining) { 572 /* 573 * Sleep until we are signalled to wake because thread has 574 * been told to exit or until 1 tick has passed. 575 */ 576 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait", 577 1); 578 579 /* Gain exclusive access to the pkt_node queue. */ 580 mtx_lock(&siftr_pkt_queue_mtx); 581 582 /* 583 * Move pkt_queue to tmp_pkt_queue, which leaves 584 * pkt_queue empty and ready to receive more pkt_nodes. 585 */ 586 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue); 587 588 /* 589 * We've finished making changes to the list. Unlock it 590 * so the pfil hooks can continue queuing pkt_nodes. 591 */ 592 mtx_unlock(&siftr_pkt_queue_mtx); 593 594 /* 595 * We can't hold a mutex whilst calling siftr_process_pkt 596 * because ALQ might sleep waiting for buffer space. 597 */ 598 mtx_unlock(&siftr_pkt_mgr_mtx); 599 600 /* Flush all pkt_nodes to the log file. */ 601 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes, 602 pkt_node_temp) { 603 siftr_process_pkt(pkt_node); 604 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes); 605 free(pkt_node, M_SIFTR_PKTNODE); 606 } 607 608 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue), 609 ("SIFTR tmp_pkt_queue not empty after flush")); 610 611 mtx_lock(&siftr_pkt_mgr_mtx); 612 613 /* 614 * If siftr_exit_pkt_manager_thread gets set during the window 615 * where we are draining the tmp_pkt_queue above, there might 616 * still be pkts in pkt_queue that need to be drained. 617 * Allow one further iteration to occur after 618 * siftr_exit_pkt_manager_thread has been set to ensure 619 * pkt_queue is completely empty before we kill the thread. 620 * 621 * siftr_exit_pkt_manager_thread is set only after the pfil 622 * hooks have been removed, so only 1 extra iteration 623 * is needed to drain the queue. 624 */ 625 if (siftr_exit_pkt_manager_thread) 626 draining--; 627 } 628 629 mtx_unlock(&siftr_pkt_mgr_mtx); 630 631 /* Calls wakeup on this thread's struct thread ptr. */ 632 kthread_exit(); 633 } 634 635 636 static uint32_t 637 hash_pkt(struct mbuf *m, uint32_t offset) 638 { 639 uint32_t hash; 640 641 hash = 0; 642 643 while (m != NULL && offset > m->m_len) { 644 /* 645 * The IP packet payload does not start in this mbuf, so 646 * need to figure out which mbuf it starts in and what offset 647 * into the mbuf's data region the payload starts at. 648 */ 649 offset -= m->m_len; 650 m = m->m_next; 651 } 652 653 while (m != NULL) { 654 /* Ensure there is data in the mbuf */ 655 if ((m->m_len - offset) > 0) 656 hash = hash32_buf(m->m_data + offset, 657 m->m_len - offset, hash); 658 659 m = m->m_next; 660 offset = 0; 661 } 662 663 return (hash); 664 } 665 666 667 /* 668 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that 669 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return. 670 * Return value >0 means the caller should skip processing this mbuf. 671 */ 672 static inline int 673 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss) 674 { 675 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL) 676 != NULL) { 677 if (dir == PFIL_IN) 678 ss->nskip_in_dejavu++; 679 else 680 ss->nskip_out_dejavu++; 681 682 return (1); 683 } else { 684 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR, 685 PACKET_TAG_SIFTR, 0, M_NOWAIT); 686 if (tag == NULL) { 687 if (dir == PFIL_IN) 688 ss->nskip_in_malloc++; 689 else 690 ss->nskip_out_malloc++; 691 692 return (1); 693 } 694 695 m_tag_prepend(m, tag); 696 } 697 698 return (0); 699 } 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_UNLOCK_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 } 755 756 757 static inline void 758 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp, 759 int ipver, int dir, int inp_locally_locked) 760 { 761 #ifdef SIFTR_IPV6 762 if (ipver == INP_IPV4) { 763 pn->ip_laddr[3] = inp->inp_laddr.s_addr; 764 pn->ip_faddr[3] = inp->inp_faddr.s_addr; 765 #else 766 *((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr; 767 *((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr; 768 #endif 769 #ifdef SIFTR_IPV6 770 } else { 771 pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0]; 772 pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1]; 773 pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2]; 774 pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3]; 775 pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0]; 776 pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1]; 777 pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2]; 778 pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3]; 779 } 780 #endif 781 pn->tcp_localport = inp->inp_lport; 782 pn->tcp_foreignport = inp->inp_fport; 783 pn->snd_cwnd = tp->snd_cwnd; 784 pn->snd_wnd = tp->snd_wnd; 785 pn->rcv_wnd = tp->rcv_wnd; 786 pn->snd_bwnd = 0; /* Unused, kept for compat. */ 787 pn->snd_ssthresh = tp->snd_ssthresh; 788 pn->snd_scale = tp->snd_scale; 789 pn->rcv_scale = tp->rcv_scale; 790 pn->conn_state = tp->t_state; 791 pn->max_seg_size = tp->t_maxseg; 792 pn->smoothed_rtt = tp->t_srtt; 793 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0; 794 pn->flags = tp->t_flags; 795 pn->rxt_length = tp->t_rxtcur; 796 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat; 797 pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd); 798 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat; 799 pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv); 800 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una; 801 pn->t_segqlen = tp->t_segqlen; 802 pn->flowid = inp->inp_flowid; 803 pn->flowtype = inp->inp_flowtype; 804 805 /* We've finished accessing the tcb so release the lock. */ 806 if (inp_locally_locked) 807 INP_RUNLOCK(inp); 808 809 pn->ipver = ipver; 810 pn->direction = dir; 811 812 /* 813 * Significantly more accurate than using getmicrotime(), but slower! 814 * Gives true microsecond resolution at the expense of a hit to 815 * maximum pps throughput processing when SIFTR is loaded and enabled. 816 */ 817 microtime(&pn->tval); 818 TCP_PROBE1(siftr, &pn); 819 820 } 821 822 823 /* 824 * pfil hook that is called for each IPv4 packet making its way through the 825 * stack in either direction. 826 * The pfil subsystem holds a non-sleepable mutex somewhere when 827 * calling our hook function, so we can't sleep at all. 828 * It's very important to use the M_NOWAIT flag with all function calls 829 * that support it so that they won't sleep, otherwise you get a panic. 830 */ 831 static int 832 siftr_chkpkt(void *arg, struct mbuf **m, struct ifnet *ifp, int dir, 833 struct inpcb *inp) 834 { 835 struct pkt_node *pn; 836 struct ip *ip; 837 struct tcphdr *th; 838 struct tcpcb *tp; 839 struct siftr_stats *ss; 840 unsigned int ip_hl; 841 int inp_locally_locked; 842 843 inp_locally_locked = 0; 844 ss = DPCPU_PTR(ss); 845 846 /* 847 * m_pullup is not required here because ip_{input|output} 848 * already do the heavy lifting for us. 849 */ 850 851 ip = mtod(*m, struct ip *); 852 853 /* Only continue processing if the packet is TCP. */ 854 if (ip->ip_p != IPPROTO_TCP) 855 goto ret; 856 857 /* 858 * If a kernel subsystem reinjects packets into the stack, our pfil 859 * hook will be called multiple times for the same packet. 860 * Make sure we only process unique packets. 861 */ 862 if (siftr_chkreinject(*m, dir, ss)) 863 goto ret; 864 865 if (dir == PFIL_IN) 866 ss->n_in++; 867 else 868 ss->n_out++; 869 870 /* 871 * Create a tcphdr struct starting at the correct offset 872 * in the IP packet. ip->ip_hl gives the ip header length 873 * in 4-byte words, so multiply it to get the size in bytes. 874 */ 875 ip_hl = (ip->ip_hl << 2); 876 th = (struct tcphdr *)((caddr_t)ip + ip_hl); 877 878 /* 879 * If the pfil hooks don't provide a pointer to the 880 * inpcb, we need to find it ourselves and lock it. 881 */ 882 if (!inp) { 883 /* Find the corresponding inpcb for this pkt. */ 884 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport, 885 th->th_dport, dir, ss); 886 887 if (inp == NULL) 888 goto ret; 889 else 890 inp_locally_locked = 1; 891 } 892 893 INP_LOCK_ASSERT(inp); 894 895 /* Find the TCP control block that corresponds with this packet */ 896 tp = intotcpcb(inp); 897 898 /* 899 * If we can't find the TCP control block (happens occasionaly for a 900 * packet sent during the shutdown phase of a TCP connection), 901 * or we're in the timewait state, bail 902 */ 903 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) { 904 if (dir == PFIL_IN) 905 ss->nskip_in_tcpcb++; 906 else 907 ss->nskip_out_tcpcb++; 908 909 goto inp_unlock; 910 } 911 912 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 913 914 if (pn == NULL) { 915 if (dir == PFIL_IN) 916 ss->nskip_in_malloc++; 917 else 918 ss->nskip_out_malloc++; 919 920 goto inp_unlock; 921 } 922 923 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked); 924 925 if (siftr_generate_hashes) { 926 if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) { 927 /* 928 * For outbound packets, the TCP checksum isn't 929 * calculated yet. This is a problem for our packet 930 * hashing as the receiver will calc a different hash 931 * to ours if we don't include the correct TCP checksum 932 * in the bytes being hashed. To work around this 933 * problem, we manually calc the TCP checksum here in 934 * software. We unset the CSUM_TCP flag so the lower 935 * layers don't recalc it. 936 */ 937 (*m)->m_pkthdr.csum_flags &= ~CSUM_TCP; 938 939 /* 940 * Calculate the TCP checksum in software and assign 941 * to correct TCP header field, which will follow the 942 * packet mbuf down the stack. The trick here is that 943 * tcp_output() sets th->th_sum to the checksum of the 944 * pseudo header for us already. Because of the nature 945 * of the checksumming algorithm, we can sum over the 946 * entire IP payload (i.e. TCP header and data), which 947 * will include the already calculated pseduo header 948 * checksum, thus giving us the complete TCP checksum. 949 * 950 * To put it in simple terms, if checksum(1,2,3,4)=10, 951 * then checksum(1,2,3,4,5) == checksum(10,5). 952 * This property is what allows us to "cheat" and 953 * checksum only the IP payload which has the TCP 954 * th_sum field populated with the pseudo header's 955 * checksum, and not need to futz around checksumming 956 * pseudo header bytes and TCP header/data in one hit. 957 * Refer to RFC 1071 for more info. 958 * 959 * NB: in_cksum_skip(struct mbuf *m, int len, int skip) 960 * in_cksum_skip 2nd argument is NOT the number of 961 * bytes to read from the mbuf at "skip" bytes offset 962 * from the start of the mbuf (very counter intuitive!). 963 * The number of bytes to read is calculated internally 964 * by the function as len-skip i.e. to sum over the IP 965 * payload (TCP header + data) bytes, it is INCORRECT 966 * to call the function like this: 967 * in_cksum_skip(at, ip->ip_len - offset, offset) 968 * Rather, it should be called like this: 969 * in_cksum_skip(at, ip->ip_len, offset) 970 * which means read "ip->ip_len - offset" bytes from 971 * the mbuf cluster "at" at offset "offset" bytes from 972 * the beginning of the "at" mbuf's data pointer. 973 */ 974 th->th_sum = in_cksum_skip(*m, ntohs(ip->ip_len), 975 ip_hl); 976 } 977 978 /* 979 * XXX: Having to calculate the checksum in software and then 980 * hash over all bytes is really inefficient. Would be nice to 981 * find a way to create the hash and checksum in the same pass 982 * over the bytes. 983 */ 984 pn->hash = hash_pkt(*m, ip_hl); 985 } 986 987 mtx_lock(&siftr_pkt_queue_mtx); 988 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 989 mtx_unlock(&siftr_pkt_queue_mtx); 990 goto ret; 991 992 inp_unlock: 993 if (inp_locally_locked) 994 INP_RUNLOCK(inp); 995 996 ret: 997 /* Returning 0 ensures pfil will not discard the pkt */ 998 return (0); 999 } 1000 1001 1002 #ifdef SIFTR_IPV6 1003 static int 1004 siftr_chkpkt6(void *arg, struct mbuf **m, struct ifnet *ifp, int dir, 1005 struct inpcb *inp) 1006 { 1007 struct pkt_node *pn; 1008 struct ip6_hdr *ip6; 1009 struct tcphdr *th; 1010 struct tcpcb *tp; 1011 struct siftr_stats *ss; 1012 unsigned int ip6_hl; 1013 int inp_locally_locked; 1014 1015 inp_locally_locked = 0; 1016 ss = DPCPU_PTR(ss); 1017 1018 /* 1019 * m_pullup is not required here because ip6_{input|output} 1020 * already do the heavy lifting for us. 1021 */ 1022 1023 ip6 = mtod(*m, struct ip6_hdr *); 1024 1025 /* 1026 * Only continue processing if the packet is TCP 1027 * XXX: We should follow the next header fields 1028 * as shown on Pg 6 RFC 2460, but right now we'll 1029 * only check pkts that have no extension headers. 1030 */ 1031 if (ip6->ip6_nxt != IPPROTO_TCP) 1032 goto ret6; 1033 1034 /* 1035 * If a kernel subsystem reinjects packets into the stack, our pfil 1036 * hook will be called multiple times for the same packet. 1037 * Make sure we only process unique packets. 1038 */ 1039 if (siftr_chkreinject(*m, dir, ss)) 1040 goto ret6; 1041 1042 if (dir == PFIL_IN) 1043 ss->n_in++; 1044 else 1045 ss->n_out++; 1046 1047 ip6_hl = sizeof(struct ip6_hdr); 1048 1049 /* 1050 * Create a tcphdr struct starting at the correct offset 1051 * in the ipv6 packet. ip->ip_hl gives the ip header length 1052 * in 4-byte words, so multiply it to get the size in bytes. 1053 */ 1054 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl); 1055 1056 /* 1057 * For inbound packets, the pfil hooks don't provide a pointer to the 1058 * inpcb, so we need to find it ourselves and lock it. 1059 */ 1060 if (!inp) { 1061 /* Find the corresponding inpcb for this pkt. */ 1062 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m, 1063 th->th_sport, th->th_dport, dir, ss); 1064 1065 if (inp == NULL) 1066 goto ret6; 1067 else 1068 inp_locally_locked = 1; 1069 } 1070 1071 /* Find the TCP control block that corresponds with this packet. */ 1072 tp = intotcpcb(inp); 1073 1074 /* 1075 * If we can't find the TCP control block (happens occasionaly for a 1076 * packet sent during the shutdown phase of a TCP connection), 1077 * or we're in the timewait state, bail. 1078 */ 1079 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) { 1080 if (dir == PFIL_IN) 1081 ss->nskip_in_tcpcb++; 1082 else 1083 ss->nskip_out_tcpcb++; 1084 1085 goto inp_unlock6; 1086 } 1087 1088 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 1089 1090 if (pn == NULL) { 1091 if (dir == PFIL_IN) 1092 ss->nskip_in_malloc++; 1093 else 1094 ss->nskip_out_malloc++; 1095 1096 goto inp_unlock6; 1097 } 1098 1099 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked); 1100 1101 /* XXX: Figure out how to generate hashes for IPv6 packets. */ 1102 1103 mtx_lock(&siftr_pkt_queue_mtx); 1104 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 1105 mtx_unlock(&siftr_pkt_queue_mtx); 1106 goto ret6; 1107 1108 inp_unlock6: 1109 if (inp_locally_locked) 1110 INP_RUNLOCK(inp); 1111 1112 ret6: 1113 /* Returning 0 ensures pfil will not discard the pkt. */ 1114 return (0); 1115 } 1116 #endif /* #ifdef SIFTR_IPV6 */ 1117 1118 1119 static int 1120 siftr_pfil(int action) 1121 { 1122 struct pfil_head *pfh_inet; 1123 #ifdef SIFTR_IPV6 1124 struct pfil_head *pfh_inet6; 1125 #endif 1126 VNET_ITERATOR_DECL(vnet_iter); 1127 1128 VNET_LIST_RLOCK(); 1129 VNET_FOREACH(vnet_iter) { 1130 CURVNET_SET(vnet_iter); 1131 pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET); 1132 #ifdef SIFTR_IPV6 1133 pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6); 1134 #endif 1135 1136 if (action == HOOK) { 1137 pfil_add_hook(siftr_chkpkt, NULL, 1138 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet); 1139 #ifdef SIFTR_IPV6 1140 pfil_add_hook(siftr_chkpkt6, NULL, 1141 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6); 1142 #endif 1143 } else if (action == UNHOOK) { 1144 pfil_remove_hook(siftr_chkpkt, NULL, 1145 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet); 1146 #ifdef SIFTR_IPV6 1147 pfil_remove_hook(siftr_chkpkt6, NULL, 1148 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6); 1149 #endif 1150 } 1151 CURVNET_RESTORE(); 1152 } 1153 VNET_LIST_RUNLOCK(); 1154 1155 return (0); 1156 } 1157 1158 1159 static int 1160 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS) 1161 { 1162 struct alq *new_alq; 1163 int error; 1164 1165 error = sysctl_handle_string(oidp, arg1, arg2, req); 1166 1167 /* Check for error or same filename */ 1168 if (error != 0 || req->newptr == NULL || 1169 strncmp(siftr_logfile, arg1, arg2) == 0) 1170 goto done; 1171 1172 /* Filname changed */ 1173 error = alq_open(&new_alq, arg1, curthread->td_ucred, 1174 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1175 if (error != 0) 1176 goto done; 1177 1178 /* 1179 * If disabled, siftr_alq == NULL so we simply close 1180 * the alq as we've proved it can be opened. 1181 * If enabled, close the existing alq and switch the old 1182 * for the new. 1183 */ 1184 if (siftr_alq == NULL) { 1185 alq_close(new_alq); 1186 } else { 1187 alq_close(siftr_alq); 1188 siftr_alq = new_alq; 1189 } 1190 1191 /* Update filename upon success */ 1192 strlcpy(siftr_logfile, arg1, arg2); 1193 done: 1194 return (error); 1195 } 1196 1197 static int 1198 siftr_manage_ops(uint8_t action) 1199 { 1200 struct siftr_stats totalss; 1201 struct timeval tval; 1202 struct flow_hash_node *counter, *tmp_counter; 1203 struct sbuf *s; 1204 int i, key_index, ret, error; 1205 uint32_t bytes_to_write, total_skipped_pkts; 1206 uint16_t lport, fport; 1207 uint8_t *key, ipver; 1208 1209 #ifdef SIFTR_IPV6 1210 uint32_t laddr[4]; 1211 uint32_t faddr[4]; 1212 #else 1213 uint8_t laddr[4]; 1214 uint8_t faddr[4]; 1215 #endif 1216 1217 error = 0; 1218 total_skipped_pkts = 0; 1219 1220 /* Init an autosizing sbuf that initially holds 200 chars. */ 1221 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL) 1222 return (-1); 1223 1224 if (action == SIFTR_ENABLE) { 1225 /* 1226 * Create our alq 1227 * XXX: We should abort if alq_open fails! 1228 */ 1229 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred, 1230 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1231 1232 STAILQ_INIT(&pkt_queue); 1233 1234 DPCPU_ZERO(ss); 1235 1236 siftr_exit_pkt_manager_thread = 0; 1237 1238 ret = kthread_add(&siftr_pkt_manager_thread, NULL, NULL, 1239 &siftr_pkt_manager_thr, RFNOWAIT, 0, 1240 "siftr_pkt_manager_thr"); 1241 1242 siftr_pfil(HOOK); 1243 1244 microtime(&tval); 1245 1246 sbuf_printf(s, 1247 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t" 1248 "siftrver=%s\thz=%u\ttcp_rtt_scale=%u\tsysname=%s\t" 1249 "sysver=%u\tipmode=%u\n", 1250 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, hz, 1251 TCP_RTT_SCALE, SYS_NAME, __FreeBSD_version, SIFTR_IPMODE); 1252 1253 sbuf_finish(s); 1254 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK); 1255 1256 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) { 1257 /* 1258 * Remove the pfil hook functions. All threads currently in 1259 * the hook functions are allowed to exit before siftr_pfil() 1260 * returns. 1261 */ 1262 siftr_pfil(UNHOOK); 1263 1264 /* This will block until the pkt manager thread unlocks it. */ 1265 mtx_lock(&siftr_pkt_mgr_mtx); 1266 1267 /* Tell the pkt manager thread that it should exit now. */ 1268 siftr_exit_pkt_manager_thread = 1; 1269 1270 /* 1271 * Wake the pkt_manager thread so it realises that 1272 * siftr_exit_pkt_manager_thread == 1 and exits gracefully. 1273 * The wakeup won't be delivered until we unlock 1274 * siftr_pkt_mgr_mtx so this isn't racy. 1275 */ 1276 wakeup(&wait_for_pkt); 1277 1278 /* Wait for the pkt_manager thread to exit. */ 1279 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT, 1280 "thrwait", 0); 1281 1282 siftr_pkt_manager_thr = NULL; 1283 mtx_unlock(&siftr_pkt_mgr_mtx); 1284 1285 totalss.n_in = DPCPU_VARSUM(ss, n_in); 1286 totalss.n_out = DPCPU_VARSUM(ss, n_out); 1287 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc); 1288 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc); 1289 totalss.nskip_in_mtx = DPCPU_VARSUM(ss, nskip_in_mtx); 1290 totalss.nskip_out_mtx = DPCPU_VARSUM(ss, nskip_out_mtx); 1291 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb); 1292 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb); 1293 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb); 1294 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb); 1295 1296 total_skipped_pkts = totalss.nskip_in_malloc + 1297 totalss.nskip_out_malloc + totalss.nskip_in_mtx + 1298 totalss.nskip_out_mtx + totalss.nskip_in_tcpcb + 1299 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb + 1300 totalss.nskip_out_inpcb; 1301 1302 microtime(&tval); 1303 1304 sbuf_printf(s, 1305 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t" 1306 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t" 1307 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t" 1308 "num_outbound_skipped_pkts_malloc=%u\t" 1309 "num_inbound_skipped_pkts_mtx=%u\t" 1310 "num_outbound_skipped_pkts_mtx=%u\t" 1311 "num_inbound_skipped_pkts_tcpcb=%u\t" 1312 "num_outbound_skipped_pkts_tcpcb=%u\t" 1313 "num_inbound_skipped_pkts_inpcb=%u\t" 1314 "num_outbound_skipped_pkts_inpcb=%u\t" 1315 "total_skipped_tcp_pkts=%u\tflow_list=", 1316 (intmax_t)tval.tv_sec, 1317 tval.tv_usec, 1318 (uintmax_t)totalss.n_in, 1319 (uintmax_t)totalss.n_out, 1320 (uintmax_t)(totalss.n_in + totalss.n_out), 1321 totalss.nskip_in_malloc, 1322 totalss.nskip_out_malloc, 1323 totalss.nskip_in_mtx, 1324 totalss.nskip_out_mtx, 1325 totalss.nskip_in_tcpcb, 1326 totalss.nskip_out_tcpcb, 1327 totalss.nskip_in_inpcb, 1328 totalss.nskip_out_inpcb, 1329 total_skipped_pkts); 1330 1331 /* 1332 * Iterate over the flow hash, printing a summary of each 1333 * flow seen and freeing any malloc'd memory. 1334 * The hash consists of an array of LISTs (man 3 queue). 1335 */ 1336 for (i = 0; i <= siftr_hashmask; i++) { 1337 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes, 1338 tmp_counter) { 1339 key = counter->key; 1340 key_index = 1; 1341 1342 ipver = key[0]; 1343 1344 memcpy(laddr, key + key_index, sizeof(laddr)); 1345 key_index += sizeof(laddr); 1346 memcpy(&lport, key + key_index, sizeof(lport)); 1347 key_index += sizeof(lport); 1348 memcpy(faddr, key + key_index, sizeof(faddr)); 1349 key_index += sizeof(faddr); 1350 memcpy(&fport, key + key_index, sizeof(fport)); 1351 1352 #ifdef SIFTR_IPV6 1353 laddr[3] = ntohl(laddr[3]); 1354 faddr[3] = ntohl(faddr[3]); 1355 1356 if (ipver == INP_IPV6) { 1357 laddr[0] = ntohl(laddr[0]); 1358 laddr[1] = ntohl(laddr[1]); 1359 laddr[2] = ntohl(laddr[2]); 1360 faddr[0] = ntohl(faddr[0]); 1361 faddr[1] = ntohl(faddr[1]); 1362 faddr[2] = ntohl(faddr[2]); 1363 1364 sbuf_printf(s, 1365 "%x:%x:%x:%x:%x:%x:%x:%x;%u-" 1366 "%x:%x:%x:%x:%x:%x:%x:%x;%u,", 1367 UPPER_SHORT(laddr[0]), 1368 LOWER_SHORT(laddr[0]), 1369 UPPER_SHORT(laddr[1]), 1370 LOWER_SHORT(laddr[1]), 1371 UPPER_SHORT(laddr[2]), 1372 LOWER_SHORT(laddr[2]), 1373 UPPER_SHORT(laddr[3]), 1374 LOWER_SHORT(laddr[3]), 1375 ntohs(lport), 1376 UPPER_SHORT(faddr[0]), 1377 LOWER_SHORT(faddr[0]), 1378 UPPER_SHORT(faddr[1]), 1379 LOWER_SHORT(faddr[1]), 1380 UPPER_SHORT(faddr[2]), 1381 LOWER_SHORT(faddr[2]), 1382 UPPER_SHORT(faddr[3]), 1383 LOWER_SHORT(faddr[3]), 1384 ntohs(fport)); 1385 } else { 1386 laddr[0] = FIRST_OCTET(laddr[3]); 1387 laddr[1] = SECOND_OCTET(laddr[3]); 1388 laddr[2] = THIRD_OCTET(laddr[3]); 1389 laddr[3] = FOURTH_OCTET(laddr[3]); 1390 faddr[0] = FIRST_OCTET(faddr[3]); 1391 faddr[1] = SECOND_OCTET(faddr[3]); 1392 faddr[2] = THIRD_OCTET(faddr[3]); 1393 faddr[3] = FOURTH_OCTET(faddr[3]); 1394 #endif 1395 sbuf_printf(s, 1396 "%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,", 1397 laddr[0], 1398 laddr[1], 1399 laddr[2], 1400 laddr[3], 1401 ntohs(lport), 1402 faddr[0], 1403 faddr[1], 1404 faddr[2], 1405 faddr[3], 1406 ntohs(fport)); 1407 #ifdef SIFTR_IPV6 1408 } 1409 #endif 1410 1411 free(counter, M_SIFTR_HASHNODE); 1412 } 1413 1414 LIST_INIT(counter_hash + i); 1415 } 1416 1417 sbuf_printf(s, "\n"); 1418 sbuf_finish(s); 1419 1420 i = 0; 1421 do { 1422 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i); 1423 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK); 1424 i += bytes_to_write; 1425 } while (i < sbuf_len(s)); 1426 1427 alq_close(siftr_alq); 1428 siftr_alq = NULL; 1429 } 1430 1431 sbuf_delete(s); 1432 1433 /* 1434 * XXX: Should be using ret to check if any functions fail 1435 * and set error appropriately 1436 */ 1437 1438 return (error); 1439 } 1440 1441 1442 static int 1443 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS) 1444 { 1445 if (req->newptr == NULL) 1446 goto skip; 1447 1448 /* If the value passed in isn't 0 or 1, return an error. */ 1449 if (CAST_PTR_INT(req->newptr) != 0 && CAST_PTR_INT(req->newptr) != 1) 1450 return (1); 1451 1452 /* If we are changing state (0 to 1 or 1 to 0). */ 1453 if (CAST_PTR_INT(req->newptr) != siftr_enabled ) 1454 if (siftr_manage_ops(CAST_PTR_INT(req->newptr))) { 1455 siftr_manage_ops(SIFTR_DISABLE); 1456 return (1); 1457 } 1458 1459 skip: 1460 return (sysctl_handle_int(oidp, arg1, arg2, req)); 1461 } 1462 1463 1464 static void 1465 siftr_shutdown_handler(void *arg) 1466 { 1467 siftr_manage_ops(SIFTR_DISABLE); 1468 } 1469 1470 1471 /* 1472 * Module is being unloaded or machine is shutting down. Take care of cleanup. 1473 */ 1474 static int 1475 deinit_siftr(void) 1476 { 1477 /* Cleanup. */ 1478 siftr_manage_ops(SIFTR_DISABLE); 1479 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask); 1480 mtx_destroy(&siftr_pkt_queue_mtx); 1481 mtx_destroy(&siftr_pkt_mgr_mtx); 1482 1483 return (0); 1484 } 1485 1486 1487 /* 1488 * Module has just been loaded into the kernel. 1489 */ 1490 static int 1491 init_siftr(void) 1492 { 1493 EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL, 1494 SHUTDOWN_PRI_FIRST); 1495 1496 /* Initialise our flow counter hash table. */ 1497 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR, 1498 &siftr_hashmask); 1499 1500 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF); 1501 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF); 1502 1503 /* Print message to the user's current terminal. */ 1504 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n" 1505 " http://caia.swin.edu.au/urp/newtcp\n\n", 1506 MODVERSION_STR); 1507 1508 return (0); 1509 } 1510 1511 1512 /* 1513 * This is the function that is called to load and unload the module. 1514 * When the module is loaded, this function is called once with 1515 * "what" == MOD_LOAD 1516 * When the module is unloaded, this function is called twice with 1517 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second 1518 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command, 1519 * this function is called once with "what" = MOD_SHUTDOWN 1520 * When the system is shut down, the handler isn't called until the very end 1521 * of the shutdown sequence i.e. after the disks have been synced. 1522 */ 1523 static int 1524 siftr_load_handler(module_t mod, int what, void *arg) 1525 { 1526 int ret; 1527 1528 switch (what) { 1529 case MOD_LOAD: 1530 ret = init_siftr(); 1531 break; 1532 1533 case MOD_QUIESCE: 1534 case MOD_SHUTDOWN: 1535 ret = deinit_siftr(); 1536 break; 1537 1538 case MOD_UNLOAD: 1539 ret = 0; 1540 break; 1541 1542 default: 1543 ret = EINVAL; 1544 break; 1545 } 1546 1547 return (ret); 1548 } 1549 1550 1551 static moduledata_t siftr_mod = { 1552 .name = "siftr", 1553 .evhand = siftr_load_handler, 1554 }; 1555 1556 /* 1557 * Param 1: name of the kernel module 1558 * Param 2: moduledata_t struct containing info about the kernel module 1559 * and the execution entry point for the module 1560 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h 1561 * Defines the module initialisation order 1562 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h 1563 * Defines the initialisation order of this kld relative to others 1564 * within the same subsystem as defined by param 3 1565 */ 1566 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY); 1567 MODULE_DEPEND(siftr, alq, 1, 1, 1); 1568 MODULE_VERSION(siftr, MODVERSION); 1569