1 /*- 2 * Copyright (c) 2007-2009 3 * Swinburne University of Technology, Melbourne, Australia. 4 * Copyright (c) 2009-2010, The FreeBSD Foundation 5 * All rights reserved. 6 * 7 * Portions of this software were developed at the Centre for Advanced 8 * Internet Architectures, Swinburne University of Technology, Melbourne, 9 * Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /****************************************************** 34 * Statistical Information For TCP Research (SIFTR) 35 * 36 * A FreeBSD kernel module that adds very basic intrumentation to the 37 * TCP stack, allowing internal stats to be recorded to a log file 38 * for experimental, debugging and performance analysis purposes. 39 * 40 * SIFTR was first released in 2007 by James Healy and Lawrence Stewart whilst 41 * working on the NewTCP research project at Swinburne University of 42 * Technology's Centre for Advanced Internet Architectures, Melbourne, 43 * Australia, which was made possible in part by a grant from the Cisco 44 * University Research Program Fund at Community Foundation Silicon Valley. 45 * More details are available at: 46 * http://caia.swin.edu.au/urp/newtcp/ 47 * 48 * Work on SIFTR v1.2.x was sponsored by the FreeBSD Foundation as part of 49 * the "Enhancing the FreeBSD TCP Implementation" project 2008-2009. 50 * More details are available at: 51 * http://www.freebsdfoundation.org/ 52 * http://caia.swin.edu.au/freebsd/etcp09/ 53 * 54 * Lawrence Stewart is the current maintainer, and all contact regarding 55 * SIFTR should be directed to him via email: lastewart@swin.edu.au 56 * 57 * Initial release date: June 2007 58 * Most recent update: September 2010 59 ******************************************************/ 60 61 #include <sys/cdefs.h> 62 __FBSDID("$FreeBSD$"); 63 64 #include <sys/param.h> 65 #include <sys/alq.h> 66 #include <sys/errno.h> 67 #include <sys/eventhandler.h> 68 #include <sys/hash.h> 69 #include <sys/kernel.h> 70 #include <sys/kthread.h> 71 #include <sys/lock.h> 72 #include <sys/mbuf.h> 73 #include <sys/module.h> 74 #include <sys/mutex.h> 75 #include <sys/pcpu.h> 76 #include <sys/proc.h> 77 #include <sys/sbuf.h> 78 #include <sys/sdt.h> 79 #include <sys/smp.h> 80 #include <sys/socket.h> 81 #include <sys/socketvar.h> 82 #include <sys/sysctl.h> 83 #include <sys/unistd.h> 84 85 #include <net/if.h> 86 #include <net/if_var.h> 87 #include <net/pfil.h> 88 89 #include <netinet/in.h> 90 #include <netinet/in_kdtrace.h> 91 #include <netinet/in_pcb.h> 92 #include <netinet/in_systm.h> 93 #include <netinet/in_var.h> 94 #include <netinet/ip.h> 95 #include <netinet/tcp_var.h> 96 97 #ifdef SIFTR_IPV6 98 #include <netinet/ip6.h> 99 #include <netinet6/in6_pcb.h> 100 #endif /* SIFTR_IPV6 */ 101 102 #include <machine/in_cksum.h> 103 104 /* 105 * Three digit version number refers to X.Y.Z where: 106 * X is the major version number 107 * Y is bumped to mark backwards incompatible changes 108 * Z is bumped to mark backwards compatible changes 109 */ 110 #define V_MAJOR 1 111 #define V_BACKBREAK 2 112 #define V_BACKCOMPAT 4 113 #define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT)) 114 #define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \ 115 __XSTRING(V_BACKCOMPAT) 116 117 #define HOOK 0 118 #define UNHOOK 1 119 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536 120 #define SYS_NAME "FreeBSD" 121 #define PACKET_TAG_SIFTR 100 122 #define PACKET_COOKIE_SIFTR 21749576 123 #define SIFTR_LOG_FILE_MODE 0644 124 #define SIFTR_DISABLE 0 125 #define SIFTR_ENABLE 1 126 127 /* 128 * Hard upper limit on the length of log messages. Bump this up if you add new 129 * data fields such that the line length could exceed the below value. 130 */ 131 #define MAX_LOG_MSG_LEN 200 132 /* XXX: Make this a sysctl tunable. */ 133 #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN) 134 135 /* 136 * 1 byte for IP version 137 * IPv4: src/dst IP (4+4) + src/dst port (2+2) = 12 bytes 138 * IPv6: src/dst IP (16+16) + src/dst port (2+2) = 36 bytes 139 */ 140 #ifdef SIFTR_IPV6 141 #define FLOW_KEY_LEN 37 142 #else 143 #define FLOW_KEY_LEN 13 144 #endif 145 146 #ifdef SIFTR_IPV6 147 #define SIFTR_IPMODE 6 148 #else 149 #define SIFTR_IPMODE 4 150 #endif 151 152 /* useful macros */ 153 #define CAST_PTR_INT(X) (*((int*)(X))) 154 155 #define UPPER_SHORT(X) (((X) & 0xFFFF0000) >> 16) 156 #define LOWER_SHORT(X) ((X) & 0x0000FFFF) 157 158 #define FIRST_OCTET(X) (((X) & 0xFF000000) >> 24) 159 #define SECOND_OCTET(X) (((X) & 0x00FF0000) >> 16) 160 #define THIRD_OCTET(X) (((X) & 0x0000FF00) >> 8) 161 #define FOURTH_OCTET(X) ((X) & 0x000000FF) 162 163 static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR"); 164 static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode", 165 "SIFTR pkt_node struct"); 166 static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode", 167 "SIFTR flow_hash_node struct"); 168 169 /* Used as links in the pkt manager queue. */ 170 struct pkt_node { 171 /* Timestamp of pkt as noted in the pfil hook. */ 172 struct timeval tval; 173 /* Direction pkt is travelling; either PFIL_IN or PFIL_OUT. */ 174 uint8_t direction; 175 /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */ 176 uint8_t ipver; 177 /* Hash of the pkt which triggered the log message. */ 178 uint32_t hash; 179 /* Local/foreign IP address. */ 180 #ifdef SIFTR_IPV6 181 uint32_t ip_laddr[4]; 182 uint32_t ip_faddr[4]; 183 #else 184 uint8_t ip_laddr[4]; 185 uint8_t ip_faddr[4]; 186 #endif 187 /* Local TCP port. */ 188 uint16_t tcp_localport; 189 /* Foreign TCP port. */ 190 uint16_t tcp_foreignport; 191 /* Congestion Window (bytes). */ 192 u_long snd_cwnd; 193 /* Sending Window (bytes). */ 194 u_long snd_wnd; 195 /* Receive Window (bytes). */ 196 u_long rcv_wnd; 197 /* Unused (was: Bandwidth Controlled Window (bytes)). */ 198 u_long snd_bwnd; 199 /* Slow Start Threshold (bytes). */ 200 u_long snd_ssthresh; 201 /* Current state of the TCP FSM. */ 202 int conn_state; 203 /* Max Segment Size (bytes). */ 204 u_int max_seg_size; 205 /* 206 * Smoothed RTT stored as found in the TCP control block 207 * in units of (TCP_RTT_SCALE*hz). 208 */ 209 int smoothed_rtt; 210 /* Is SACK enabled? */ 211 u_char sack_enabled; 212 /* Window scaling for snd window. */ 213 u_char snd_scale; 214 /* Window scaling for recv window. */ 215 u_char rcv_scale; 216 /* TCP control block flags. */ 217 u_int flags; 218 /* Retransmit timeout length. */ 219 int rxt_length; 220 /* Size of the TCP send buffer in bytes. */ 221 u_int snd_buf_hiwater; 222 /* Current num bytes in the send socket buffer. */ 223 u_int snd_buf_cc; 224 /* Size of the TCP receive buffer in bytes. */ 225 u_int rcv_buf_hiwater; 226 /* Current num bytes in the receive socket buffer. */ 227 u_int rcv_buf_cc; 228 /* Number of bytes inflight that we are waiting on ACKs for. */ 229 u_int sent_inflight_bytes; 230 /* Number of segments currently in the reassembly queue. */ 231 int t_segqlen; 232 /* Flowid for the connection. */ 233 u_int flowid; 234 /* Flow type for the connection. */ 235 u_int flowtype; 236 /* Link to next pkt_node in the list. */ 237 STAILQ_ENTRY(pkt_node) nodes; 238 }; 239 240 struct flow_hash_node 241 { 242 uint16_t counter; 243 uint8_t key[FLOW_KEY_LEN]; 244 LIST_ENTRY(flow_hash_node) nodes; 245 }; 246 247 struct siftr_stats 248 { 249 /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */ 250 uint64_t n_in; 251 uint64_t n_out; 252 /* # pkts skipped due to failed malloc calls. */ 253 uint32_t nskip_in_malloc; 254 uint32_t nskip_out_malloc; 255 /* # pkts skipped due to failed mtx acquisition. */ 256 uint32_t nskip_in_mtx; 257 uint32_t nskip_out_mtx; 258 /* # pkts skipped due to failed inpcb lookups. */ 259 uint32_t nskip_in_inpcb; 260 uint32_t nskip_out_inpcb; 261 /* # pkts skipped due to failed tcpcb lookups. */ 262 uint32_t nskip_in_tcpcb; 263 uint32_t nskip_out_tcpcb; 264 /* # pkts skipped due to stack reinjection. */ 265 uint32_t nskip_in_dejavu; 266 uint32_t nskip_out_dejavu; 267 }; 268 269 static DPCPU_DEFINE(struct siftr_stats, ss); 270 271 static volatile unsigned int siftr_exit_pkt_manager_thread = 0; 272 static unsigned int siftr_enabled = 0; 273 static unsigned int siftr_pkts_per_log = 1; 274 static unsigned int siftr_generate_hashes = 0; 275 /* static unsigned int siftr_binary_log = 0; */ 276 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log"; 277 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log"; 278 static u_long siftr_hashmask; 279 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue); 280 LIST_HEAD(listhead, flow_hash_node) *counter_hash; 281 static int wait_for_pkt; 282 static struct alq *siftr_alq = NULL; 283 static struct mtx siftr_pkt_queue_mtx; 284 static struct mtx siftr_pkt_mgr_mtx; 285 static struct thread *siftr_pkt_manager_thr = NULL; 286 /* 287 * pfil.h defines PFIL_IN as 1 and PFIL_OUT as 2, 288 * which we use as an index into this array. 289 */ 290 static char direction[3] = {'\0', 'i','o'}; 291 292 /* Required function prototypes. */ 293 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS); 294 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS); 295 296 297 /* Declare the net.inet.siftr sysctl tree and populate it. */ 298 299 SYSCTL_DECL(_net_inet_siftr); 300 301 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW, NULL, 302 "siftr related settings"); 303 304 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, CTLTYPE_UINT|CTLFLAG_RW, 305 &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU", 306 "switch siftr module operations on/off"); 307 308 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, CTLTYPE_STRING|CTLFLAG_RW, 309 &siftr_logfile_shadow, sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler, 310 "A", "file to save siftr log messages to"); 311 312 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW, 313 &siftr_pkts_per_log, 1, 314 "number of packets between generating a log message"); 315 316 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW, 317 &siftr_generate_hashes, 0, 318 "enable packet hash generation"); 319 320 /* XXX: TODO 321 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW, 322 &siftr_binary_log, 0, 323 "write log files in binary instead of ascii"); 324 */ 325 326 327 /* Begin functions. */ 328 329 static void 330 siftr_process_pkt(struct pkt_node * pkt_node) 331 { 332 struct flow_hash_node *hash_node; 333 struct listhead *counter_list; 334 struct siftr_stats *ss; 335 struct ale *log_buf; 336 uint8_t key[FLOW_KEY_LEN]; 337 uint8_t found_match, key_offset; 338 339 hash_node = NULL; 340 ss = DPCPU_PTR(ss); 341 found_match = 0; 342 key_offset = 1; 343 344 /* 345 * Create the key that will be used to create a hash index 346 * into our hash table. Our key consists of: 347 * ipversion, localip, localport, foreignip, foreignport 348 */ 349 key[0] = pkt_node->ipver; 350 memcpy(key + key_offset, &pkt_node->ip_laddr, 351 sizeof(pkt_node->ip_laddr)); 352 key_offset += sizeof(pkt_node->ip_laddr); 353 memcpy(key + key_offset, &pkt_node->tcp_localport, 354 sizeof(pkt_node->tcp_localport)); 355 key_offset += sizeof(pkt_node->tcp_localport); 356 memcpy(key + key_offset, &pkt_node->ip_faddr, 357 sizeof(pkt_node->ip_faddr)); 358 key_offset += sizeof(pkt_node->ip_faddr); 359 memcpy(key + key_offset, &pkt_node->tcp_foreignport, 360 sizeof(pkt_node->tcp_foreignport)); 361 362 counter_list = counter_hash + 363 (hash32_buf(key, sizeof(key), 0) & siftr_hashmask); 364 365 /* 366 * If the list is not empty i.e. the hash index has 367 * been used by another flow previously. 368 */ 369 if (LIST_FIRST(counter_list) != NULL) { 370 /* 371 * Loop through the hash nodes in the list. 372 * There should normally only be 1 hash node in the list, 373 * except if there have been collisions at the hash index 374 * computed by hash32_buf(). 375 */ 376 LIST_FOREACH(hash_node, counter_list, nodes) { 377 /* 378 * Check if the key for the pkt we are currently 379 * processing is the same as the key stored in the 380 * hash node we are currently processing. 381 * If they are the same, then we've found the 382 * hash node that stores the counter for the flow 383 * the pkt belongs to. 384 */ 385 if (memcmp(hash_node->key, key, sizeof(key)) == 0) { 386 found_match = 1; 387 break; 388 } 389 } 390 } 391 392 /* If this flow hash hasn't been seen before or we have a collision. */ 393 if (hash_node == NULL || !found_match) { 394 /* Create a new hash node to store the flow's counter. */ 395 hash_node = malloc(sizeof(struct flow_hash_node), 396 M_SIFTR_HASHNODE, M_WAITOK); 397 398 if (hash_node != NULL) { 399 /* Initialise our new hash node list entry. */ 400 hash_node->counter = 0; 401 memcpy(hash_node->key, key, sizeof(key)); 402 LIST_INSERT_HEAD(counter_list, hash_node, nodes); 403 } else { 404 /* Malloc failed. */ 405 if (pkt_node->direction == PFIL_IN) 406 ss->nskip_in_malloc++; 407 else 408 ss->nskip_out_malloc++; 409 410 return; 411 } 412 } else if (siftr_pkts_per_log > 1) { 413 /* 414 * Taking the remainder of the counter divided 415 * by the current value of siftr_pkts_per_log 416 * and storing that in counter provides a neat 417 * way to modulate the frequency of log 418 * messages being written to the log file. 419 */ 420 hash_node->counter = (hash_node->counter + 1) % 421 siftr_pkts_per_log; 422 423 /* 424 * If we have not seen enough packets since the last time 425 * we wrote a log message for this connection, return. 426 */ 427 if (hash_node->counter > 0) 428 return; 429 } 430 431 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK); 432 433 if (log_buf == NULL) 434 return; /* Should only happen if the ALQ is shutting down. */ 435 436 #ifdef SIFTR_IPV6 437 pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]); 438 pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]); 439 440 if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */ 441 pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]); 442 pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]); 443 pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]); 444 pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]); 445 pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]); 446 pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]); 447 448 /* Construct an IPv6 log message. */ 449 log_buf->ae_bytesused = snprintf(log_buf->ae_data, 450 MAX_LOG_MSG_LEN, 451 "%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:" 452 "%x:%x:%x:%x:%x,%u,%ld,%ld,%ld,%ld,%ld,%u,%u,%u,%u,%u,%u," 453 "%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n", 454 direction[pkt_node->direction], 455 pkt_node->hash, 456 pkt_node->tval.tv_sec, 457 pkt_node->tval.tv_usec, 458 UPPER_SHORT(pkt_node->ip_laddr[0]), 459 LOWER_SHORT(pkt_node->ip_laddr[0]), 460 UPPER_SHORT(pkt_node->ip_laddr[1]), 461 LOWER_SHORT(pkt_node->ip_laddr[1]), 462 UPPER_SHORT(pkt_node->ip_laddr[2]), 463 LOWER_SHORT(pkt_node->ip_laddr[2]), 464 UPPER_SHORT(pkt_node->ip_laddr[3]), 465 LOWER_SHORT(pkt_node->ip_laddr[3]), 466 ntohs(pkt_node->tcp_localport), 467 UPPER_SHORT(pkt_node->ip_faddr[0]), 468 LOWER_SHORT(pkt_node->ip_faddr[0]), 469 UPPER_SHORT(pkt_node->ip_faddr[1]), 470 LOWER_SHORT(pkt_node->ip_faddr[1]), 471 UPPER_SHORT(pkt_node->ip_faddr[2]), 472 LOWER_SHORT(pkt_node->ip_faddr[2]), 473 UPPER_SHORT(pkt_node->ip_faddr[3]), 474 LOWER_SHORT(pkt_node->ip_faddr[3]), 475 ntohs(pkt_node->tcp_foreignport), 476 pkt_node->snd_ssthresh, 477 pkt_node->snd_cwnd, 478 pkt_node->snd_bwnd, 479 pkt_node->snd_wnd, 480 pkt_node->rcv_wnd, 481 pkt_node->snd_scale, 482 pkt_node->rcv_scale, 483 pkt_node->conn_state, 484 pkt_node->max_seg_size, 485 pkt_node->smoothed_rtt, 486 pkt_node->sack_enabled, 487 pkt_node->flags, 488 pkt_node->rxt_length, 489 pkt_node->snd_buf_hiwater, 490 pkt_node->snd_buf_cc, 491 pkt_node->rcv_buf_hiwater, 492 pkt_node->rcv_buf_cc, 493 pkt_node->sent_inflight_bytes, 494 pkt_node->t_segqlen, 495 pkt_node->flowid, 496 pkt_node->flowtype); 497 } else { /* IPv4 packet */ 498 pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]); 499 pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]); 500 pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]); 501 pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]); 502 pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]); 503 pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]); 504 pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]); 505 pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]); 506 #endif /* SIFTR_IPV6 */ 507 508 /* Construct an IPv4 log message. */ 509 log_buf->ae_bytesused = snprintf(log_buf->ae_data, 510 MAX_LOG_MSG_LEN, 511 "%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%ld,%ld," 512 "%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n", 513 direction[pkt_node->direction], 514 pkt_node->hash, 515 (intmax_t)pkt_node->tval.tv_sec, 516 pkt_node->tval.tv_usec, 517 pkt_node->ip_laddr[0], 518 pkt_node->ip_laddr[1], 519 pkt_node->ip_laddr[2], 520 pkt_node->ip_laddr[3], 521 ntohs(pkt_node->tcp_localport), 522 pkt_node->ip_faddr[0], 523 pkt_node->ip_faddr[1], 524 pkt_node->ip_faddr[2], 525 pkt_node->ip_faddr[3], 526 ntohs(pkt_node->tcp_foreignport), 527 pkt_node->snd_ssthresh, 528 pkt_node->snd_cwnd, 529 pkt_node->snd_bwnd, 530 pkt_node->snd_wnd, 531 pkt_node->rcv_wnd, 532 pkt_node->snd_scale, 533 pkt_node->rcv_scale, 534 pkt_node->conn_state, 535 pkt_node->max_seg_size, 536 pkt_node->smoothed_rtt, 537 pkt_node->sack_enabled, 538 pkt_node->flags, 539 pkt_node->rxt_length, 540 pkt_node->snd_buf_hiwater, 541 pkt_node->snd_buf_cc, 542 pkt_node->rcv_buf_hiwater, 543 pkt_node->rcv_buf_cc, 544 pkt_node->sent_inflight_bytes, 545 pkt_node->t_segqlen, 546 pkt_node->flowid, 547 pkt_node->flowtype); 548 #ifdef SIFTR_IPV6 549 } 550 #endif 551 552 alq_post_flags(siftr_alq, log_buf, 0); 553 } 554 555 556 static void 557 siftr_pkt_manager_thread(void *arg) 558 { 559 STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue = 560 STAILQ_HEAD_INITIALIZER(tmp_pkt_queue); 561 struct pkt_node *pkt_node, *pkt_node_temp; 562 uint8_t draining; 563 564 draining = 2; 565 566 mtx_lock(&siftr_pkt_mgr_mtx); 567 568 /* draining == 0 when queue has been flushed and it's safe to exit. */ 569 while (draining) { 570 /* 571 * Sleep until we are signalled to wake because thread has 572 * been told to exit or until 1 tick has passed. 573 */ 574 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait", 575 1); 576 577 /* Gain exclusive access to the pkt_node queue. */ 578 mtx_lock(&siftr_pkt_queue_mtx); 579 580 /* 581 * Move pkt_queue to tmp_pkt_queue, which leaves 582 * pkt_queue empty and ready to receive more pkt_nodes. 583 */ 584 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue); 585 586 /* 587 * We've finished making changes to the list. Unlock it 588 * so the pfil hooks can continue queuing pkt_nodes. 589 */ 590 mtx_unlock(&siftr_pkt_queue_mtx); 591 592 /* 593 * We can't hold a mutex whilst calling siftr_process_pkt 594 * because ALQ might sleep waiting for buffer space. 595 */ 596 mtx_unlock(&siftr_pkt_mgr_mtx); 597 598 /* Flush all pkt_nodes to the log file. */ 599 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes, 600 pkt_node_temp) { 601 siftr_process_pkt(pkt_node); 602 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes); 603 free(pkt_node, M_SIFTR_PKTNODE); 604 } 605 606 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue), 607 ("SIFTR tmp_pkt_queue not empty after flush")); 608 609 mtx_lock(&siftr_pkt_mgr_mtx); 610 611 /* 612 * If siftr_exit_pkt_manager_thread gets set during the window 613 * where we are draining the tmp_pkt_queue above, there might 614 * still be pkts in pkt_queue that need to be drained. 615 * Allow one further iteration to occur after 616 * siftr_exit_pkt_manager_thread has been set to ensure 617 * pkt_queue is completely empty before we kill the thread. 618 * 619 * siftr_exit_pkt_manager_thread is set only after the pfil 620 * hooks have been removed, so only 1 extra iteration 621 * is needed to drain the queue. 622 */ 623 if (siftr_exit_pkt_manager_thread) 624 draining--; 625 } 626 627 mtx_unlock(&siftr_pkt_mgr_mtx); 628 629 /* Calls wakeup on this thread's struct thread ptr. */ 630 kthread_exit(); 631 } 632 633 634 static uint32_t 635 hash_pkt(struct mbuf *m, uint32_t offset) 636 { 637 uint32_t hash; 638 639 hash = 0; 640 641 while (m != NULL && offset > m->m_len) { 642 /* 643 * The IP packet payload does not start in this mbuf, so 644 * need to figure out which mbuf it starts in and what offset 645 * into the mbuf's data region the payload starts at. 646 */ 647 offset -= m->m_len; 648 m = m->m_next; 649 } 650 651 while (m != NULL) { 652 /* Ensure there is data in the mbuf */ 653 if ((m->m_len - offset) > 0) 654 hash = hash32_buf(m->m_data + offset, 655 m->m_len - offset, hash); 656 657 m = m->m_next; 658 offset = 0; 659 } 660 661 return (hash); 662 } 663 664 665 /* 666 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that 667 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return. 668 * Return value >0 means the caller should skip processing this mbuf. 669 */ 670 static inline int 671 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss) 672 { 673 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL) 674 != NULL) { 675 if (dir == PFIL_IN) 676 ss->nskip_in_dejavu++; 677 else 678 ss->nskip_out_dejavu++; 679 680 return (1); 681 } else { 682 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR, 683 PACKET_TAG_SIFTR, 0, M_NOWAIT); 684 if (tag == NULL) { 685 if (dir == PFIL_IN) 686 ss->nskip_in_malloc++; 687 else 688 ss->nskip_out_malloc++; 689 690 return (1); 691 } 692 693 m_tag_prepend(m, tag); 694 } 695 696 return (0); 697 } 698 699 700 /* 701 * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL 702 * otherwise. 703 */ 704 static inline struct inpcb * 705 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport, 706 uint16_t dport, int dir, struct siftr_stats *ss) 707 { 708 struct inpcb *inp; 709 710 /* We need the tcbinfo lock. */ 711 INP_INFO_UNLOCK_ASSERT(&V_tcbinfo); 712 713 if (dir == PFIL_IN) 714 inp = (ipver == INP_IPV4 ? 715 in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst, 716 dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 717 : 718 #ifdef SIFTR_IPV6 719 in6_pcblookup(&V_tcbinfo, 720 &((struct ip6_hdr *)ip)->ip6_src, sport, 721 &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB, 722 m->m_pkthdr.rcvif) 723 #else 724 NULL 725 #endif 726 ); 727 728 else 729 inp = (ipver == INP_IPV4 ? 730 in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src, 731 sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 732 : 733 #ifdef SIFTR_IPV6 734 in6_pcblookup(&V_tcbinfo, 735 &((struct ip6_hdr *)ip)->ip6_dst, dport, 736 &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB, 737 m->m_pkthdr.rcvif) 738 #else 739 NULL 740 #endif 741 ); 742 743 /* If we can't find the inpcb, bail. */ 744 if (inp == NULL) { 745 if (dir == PFIL_IN) 746 ss->nskip_in_inpcb++; 747 else 748 ss->nskip_out_inpcb++; 749 } 750 751 return (inp); 752 } 753 754 755 static inline void 756 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp, 757 int ipver, int dir, int inp_locally_locked) 758 { 759 #ifdef SIFTR_IPV6 760 if (ipver == INP_IPV4) { 761 pn->ip_laddr[3] = inp->inp_laddr.s_addr; 762 pn->ip_faddr[3] = inp->inp_faddr.s_addr; 763 #else 764 *((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr; 765 *((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr; 766 #endif 767 #ifdef SIFTR_IPV6 768 } else { 769 pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0]; 770 pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1]; 771 pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2]; 772 pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3]; 773 pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0]; 774 pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1]; 775 pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2]; 776 pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3]; 777 } 778 #endif 779 pn->tcp_localport = inp->inp_lport; 780 pn->tcp_foreignport = inp->inp_fport; 781 pn->snd_cwnd = tp->snd_cwnd; 782 pn->snd_wnd = tp->snd_wnd; 783 pn->rcv_wnd = tp->rcv_wnd; 784 pn->snd_bwnd = 0; /* Unused, kept for compat. */ 785 pn->snd_ssthresh = tp->snd_ssthresh; 786 pn->snd_scale = tp->snd_scale; 787 pn->rcv_scale = tp->rcv_scale; 788 pn->conn_state = tp->t_state; 789 pn->max_seg_size = tp->t_maxseg; 790 pn->smoothed_rtt = tp->t_srtt; 791 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0; 792 pn->flags = tp->t_flags; 793 pn->rxt_length = tp->t_rxtcur; 794 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat; 795 pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd); 796 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat; 797 pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv); 798 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una; 799 pn->t_segqlen = tp->t_segqlen; 800 pn->flowid = inp->inp_flowid; 801 pn->flowtype = inp->inp_flowtype; 802 803 /* We've finished accessing the tcb so release the lock. */ 804 if (inp_locally_locked) 805 INP_RUNLOCK(inp); 806 807 pn->ipver = ipver; 808 pn->direction = dir; 809 810 /* 811 * Significantly more accurate than using getmicrotime(), but slower! 812 * Gives true microsecond resolution at the expense of a hit to 813 * maximum pps throughput processing when SIFTR is loaded and enabled. 814 */ 815 microtime(&pn->tval); 816 TCP_PROBE1(siftr, &pn); 817 818 } 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 int 830 siftr_chkpkt(void *arg, struct mbuf **m, struct ifnet *ifp, int dir, 831 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; 840 841 inp_locally_locked = 0; 842 ss = DPCPU_PTR(ss); 843 844 /* 845 * m_pullup is not required here because ip_{input|output} 846 * already do the heavy lifting for us. 847 */ 848 849 ip = mtod(*m, struct ip *); 850 851 /* Only continue processing if the packet is TCP. */ 852 if (ip->ip_p != IPPROTO_TCP) 853 goto ret; 854 855 /* 856 * If a kernel subsystem reinjects packets into the stack, our pfil 857 * hook will be called multiple times for the same packet. 858 * Make sure we only process unique packets. 859 */ 860 if (siftr_chkreinject(*m, dir, ss)) 861 goto ret; 862 863 if (dir == PFIL_IN) 864 ss->n_in++; 865 else 866 ss->n_out++; 867 868 /* 869 * Create a tcphdr struct starting at the correct offset 870 * in the IP packet. ip->ip_hl gives the ip header length 871 * in 4-byte words, so multiply it to get the size in bytes. 872 */ 873 ip_hl = (ip->ip_hl << 2); 874 th = (struct tcphdr *)((caddr_t)ip + ip_hl); 875 876 /* 877 * If the pfil hooks don't provide a pointer to the 878 * inpcb, we need to find it ourselves and lock it. 879 */ 880 if (!inp) { 881 /* Find the corresponding inpcb for this pkt. */ 882 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport, 883 th->th_dport, dir, ss); 884 885 if (inp == NULL) 886 goto ret; 887 else 888 inp_locally_locked = 1; 889 } 890 891 INP_LOCK_ASSERT(inp); 892 893 /* Find the TCP control block that corresponds with this packet */ 894 tp = intotcpcb(inp); 895 896 /* 897 * If we can't find the TCP control block (happens occasionaly for a 898 * packet sent during the shutdown phase of a TCP connection), 899 * or we're in the timewait state, bail 900 */ 901 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) { 902 if (dir == PFIL_IN) 903 ss->nskip_in_tcpcb++; 904 else 905 ss->nskip_out_tcpcb++; 906 907 goto inp_unlock; 908 } 909 910 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 911 912 if (pn == NULL) { 913 if (dir == PFIL_IN) 914 ss->nskip_in_malloc++; 915 else 916 ss->nskip_out_malloc++; 917 918 goto inp_unlock; 919 } 920 921 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked); 922 923 if (siftr_generate_hashes) { 924 if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) { 925 /* 926 * For outbound packets, the TCP checksum isn't 927 * calculated yet. This is a problem for our packet 928 * hashing as the receiver will calc a different hash 929 * to ours if we don't include the correct TCP checksum 930 * in the bytes being hashed. To work around this 931 * problem, we manually calc the TCP checksum here in 932 * software. We unset the CSUM_TCP flag so the lower 933 * layers don't recalc it. 934 */ 935 (*m)->m_pkthdr.csum_flags &= ~CSUM_TCP; 936 937 /* 938 * Calculate the TCP checksum in software and assign 939 * to correct TCP header field, which will follow the 940 * packet mbuf down the stack. The trick here is that 941 * tcp_output() sets th->th_sum to the checksum of the 942 * pseudo header for us already. Because of the nature 943 * of the checksumming algorithm, we can sum over the 944 * entire IP payload (i.e. TCP header and data), which 945 * will include the already calculated pseduo header 946 * checksum, thus giving us the complete TCP checksum. 947 * 948 * To put it in simple terms, if checksum(1,2,3,4)=10, 949 * then checksum(1,2,3,4,5) == checksum(10,5). 950 * This property is what allows us to "cheat" and 951 * checksum only the IP payload which has the TCP 952 * th_sum field populated with the pseudo header's 953 * checksum, and not need to futz around checksumming 954 * pseudo header bytes and TCP header/data in one hit. 955 * Refer to RFC 1071 for more info. 956 * 957 * NB: in_cksum_skip(struct mbuf *m, int len, int skip) 958 * in_cksum_skip 2nd argument is NOT the number of 959 * bytes to read from the mbuf at "skip" bytes offset 960 * from the start of the mbuf (very counter intuitive!). 961 * The number of bytes to read is calculated internally 962 * by the function as len-skip i.e. to sum over the IP 963 * payload (TCP header + data) bytes, it is INCORRECT 964 * to call the function like this: 965 * in_cksum_skip(at, ip->ip_len - offset, offset) 966 * Rather, it should be called like this: 967 * in_cksum_skip(at, ip->ip_len, offset) 968 * which means read "ip->ip_len - offset" bytes from 969 * the mbuf cluster "at" at offset "offset" bytes from 970 * the beginning of the "at" mbuf's data pointer. 971 */ 972 th->th_sum = in_cksum_skip(*m, ntohs(ip->ip_len), 973 ip_hl); 974 } 975 976 /* 977 * XXX: Having to calculate the checksum in software and then 978 * hash over all bytes is really inefficient. Would be nice to 979 * find a way to create the hash and checksum in the same pass 980 * over the bytes. 981 */ 982 pn->hash = hash_pkt(*m, ip_hl); 983 } 984 985 mtx_lock(&siftr_pkt_queue_mtx); 986 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 987 mtx_unlock(&siftr_pkt_queue_mtx); 988 goto ret; 989 990 inp_unlock: 991 if (inp_locally_locked) 992 INP_RUNLOCK(inp); 993 994 ret: 995 /* Returning 0 ensures pfil will not discard the pkt */ 996 return (0); 997 } 998 999 1000 #ifdef SIFTR_IPV6 1001 static int 1002 siftr_chkpkt6(void *arg, struct mbuf **m, struct ifnet *ifp, int dir, 1003 struct inpcb *inp) 1004 { 1005 struct pkt_node *pn; 1006 struct ip6_hdr *ip6; 1007 struct tcphdr *th; 1008 struct tcpcb *tp; 1009 struct siftr_stats *ss; 1010 unsigned int ip6_hl; 1011 int inp_locally_locked; 1012 1013 inp_locally_locked = 0; 1014 ss = DPCPU_PTR(ss); 1015 1016 /* 1017 * m_pullup is not required here because ip6_{input|output} 1018 * already do the heavy lifting for us. 1019 */ 1020 1021 ip6 = mtod(*m, struct ip6_hdr *); 1022 1023 /* 1024 * Only continue processing if the packet is TCP 1025 * XXX: We should follow the next header fields 1026 * as shown on Pg 6 RFC 2460, but right now we'll 1027 * only check pkts that have no extension headers. 1028 */ 1029 if (ip6->ip6_nxt != IPPROTO_TCP) 1030 goto ret6; 1031 1032 /* 1033 * If a kernel subsystem reinjects packets into the stack, our pfil 1034 * hook will be called multiple times for the same packet. 1035 * Make sure we only process unique packets. 1036 */ 1037 if (siftr_chkreinject(*m, dir, ss)) 1038 goto ret6; 1039 1040 if (dir == PFIL_IN) 1041 ss->n_in++; 1042 else 1043 ss->n_out++; 1044 1045 ip6_hl = sizeof(struct ip6_hdr); 1046 1047 /* 1048 * Create a tcphdr struct starting at the correct offset 1049 * in the ipv6 packet. ip->ip_hl gives the ip header length 1050 * in 4-byte words, so multiply it to get the size in bytes. 1051 */ 1052 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl); 1053 1054 /* 1055 * For inbound packets, the pfil hooks don't provide a pointer to the 1056 * inpcb, so we need to find it ourselves and lock it. 1057 */ 1058 if (!inp) { 1059 /* Find the corresponding inpcb for this pkt. */ 1060 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m, 1061 th->th_sport, th->th_dport, dir, ss); 1062 1063 if (inp == NULL) 1064 goto ret6; 1065 else 1066 inp_locally_locked = 1; 1067 } 1068 1069 /* Find the TCP control block that corresponds with this packet. */ 1070 tp = intotcpcb(inp); 1071 1072 /* 1073 * If we can't find the TCP control block (happens occasionaly for a 1074 * packet sent during the shutdown phase of a TCP connection), 1075 * or we're in the timewait state, bail. 1076 */ 1077 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) { 1078 if (dir == PFIL_IN) 1079 ss->nskip_in_tcpcb++; 1080 else 1081 ss->nskip_out_tcpcb++; 1082 1083 goto inp_unlock6; 1084 } 1085 1086 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 1087 1088 if (pn == NULL) { 1089 if (dir == PFIL_IN) 1090 ss->nskip_in_malloc++; 1091 else 1092 ss->nskip_out_malloc++; 1093 1094 goto inp_unlock6; 1095 } 1096 1097 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked); 1098 1099 /* XXX: Figure out how to generate hashes for IPv6 packets. */ 1100 1101 mtx_lock(&siftr_pkt_queue_mtx); 1102 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 1103 mtx_unlock(&siftr_pkt_queue_mtx); 1104 goto ret6; 1105 1106 inp_unlock6: 1107 if (inp_locally_locked) 1108 INP_RUNLOCK(inp); 1109 1110 ret6: 1111 /* Returning 0 ensures pfil will not discard the pkt. */ 1112 return (0); 1113 } 1114 #endif /* #ifdef SIFTR_IPV6 */ 1115 1116 1117 static int 1118 siftr_pfil(int action) 1119 { 1120 struct pfil_head *pfh_inet; 1121 #ifdef SIFTR_IPV6 1122 struct pfil_head *pfh_inet6; 1123 #endif 1124 VNET_ITERATOR_DECL(vnet_iter); 1125 1126 VNET_LIST_RLOCK(); 1127 VNET_FOREACH(vnet_iter) { 1128 CURVNET_SET(vnet_iter); 1129 pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET); 1130 #ifdef SIFTR_IPV6 1131 pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6); 1132 #endif 1133 1134 if (action == HOOK) { 1135 pfil_add_hook(siftr_chkpkt, NULL, 1136 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet); 1137 #ifdef SIFTR_IPV6 1138 pfil_add_hook(siftr_chkpkt6, NULL, 1139 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6); 1140 #endif 1141 } else if (action == UNHOOK) { 1142 pfil_remove_hook(siftr_chkpkt, NULL, 1143 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet); 1144 #ifdef SIFTR_IPV6 1145 pfil_remove_hook(siftr_chkpkt6, NULL, 1146 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6); 1147 #endif 1148 } 1149 CURVNET_RESTORE(); 1150 } 1151 VNET_LIST_RUNLOCK(); 1152 1153 return (0); 1154 } 1155 1156 1157 static int 1158 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS) 1159 { 1160 struct alq *new_alq; 1161 int error; 1162 1163 error = sysctl_handle_string(oidp, arg1, arg2, req); 1164 1165 /* Check for error or same filename */ 1166 if (error != 0 || req->newptr == NULL || 1167 strncmp(siftr_logfile, arg1, arg2) == 0) 1168 goto done; 1169 1170 /* Filname changed */ 1171 error = alq_open(&new_alq, arg1, curthread->td_ucred, 1172 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1173 if (error != 0) 1174 goto done; 1175 1176 /* 1177 * If disabled, siftr_alq == NULL so we simply close 1178 * the alq as we've proved it can be opened. 1179 * If enabled, close the existing alq and switch the old 1180 * for the new. 1181 */ 1182 if (siftr_alq == NULL) { 1183 alq_close(new_alq); 1184 } else { 1185 alq_close(siftr_alq); 1186 siftr_alq = new_alq; 1187 } 1188 1189 /* Update filename upon success */ 1190 strlcpy(siftr_logfile, arg1, arg2); 1191 done: 1192 return (error); 1193 } 1194 1195 static int 1196 siftr_manage_ops(uint8_t action) 1197 { 1198 struct siftr_stats totalss; 1199 struct timeval tval; 1200 struct flow_hash_node *counter, *tmp_counter; 1201 struct sbuf *s; 1202 int i, key_index, ret, error; 1203 uint32_t bytes_to_write, total_skipped_pkts; 1204 uint16_t lport, fport; 1205 uint8_t *key, ipver; 1206 1207 #ifdef SIFTR_IPV6 1208 uint32_t laddr[4]; 1209 uint32_t faddr[4]; 1210 #else 1211 uint8_t laddr[4]; 1212 uint8_t faddr[4]; 1213 #endif 1214 1215 error = 0; 1216 total_skipped_pkts = 0; 1217 1218 /* Init an autosizing sbuf that initially holds 200 chars. */ 1219 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL) 1220 return (-1); 1221 1222 if (action == SIFTR_ENABLE) { 1223 /* 1224 * Create our alq 1225 * XXX: We should abort if alq_open fails! 1226 */ 1227 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred, 1228 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1229 1230 STAILQ_INIT(&pkt_queue); 1231 1232 DPCPU_ZERO(ss); 1233 1234 siftr_exit_pkt_manager_thread = 0; 1235 1236 ret = kthread_add(&siftr_pkt_manager_thread, NULL, NULL, 1237 &siftr_pkt_manager_thr, RFNOWAIT, 0, 1238 "siftr_pkt_manager_thr"); 1239 1240 siftr_pfil(HOOK); 1241 1242 microtime(&tval); 1243 1244 sbuf_printf(s, 1245 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t" 1246 "siftrver=%s\thz=%u\ttcp_rtt_scale=%u\tsysname=%s\t" 1247 "sysver=%u\tipmode=%u\n", 1248 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, hz, 1249 TCP_RTT_SCALE, SYS_NAME, __FreeBSD_version, SIFTR_IPMODE); 1250 1251 sbuf_finish(s); 1252 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK); 1253 1254 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) { 1255 /* 1256 * Remove the pfil hook functions. All threads currently in 1257 * the hook functions are allowed to exit before siftr_pfil() 1258 * returns. 1259 */ 1260 siftr_pfil(UNHOOK); 1261 1262 /* This will block until the pkt manager thread unlocks it. */ 1263 mtx_lock(&siftr_pkt_mgr_mtx); 1264 1265 /* Tell the pkt manager thread that it should exit now. */ 1266 siftr_exit_pkt_manager_thread = 1; 1267 1268 /* 1269 * Wake the pkt_manager thread so it realises that 1270 * siftr_exit_pkt_manager_thread == 1 and exits gracefully. 1271 * The wakeup won't be delivered until we unlock 1272 * siftr_pkt_mgr_mtx so this isn't racy. 1273 */ 1274 wakeup(&wait_for_pkt); 1275 1276 /* Wait for the pkt_manager thread to exit. */ 1277 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT, 1278 "thrwait", 0); 1279 1280 siftr_pkt_manager_thr = NULL; 1281 mtx_unlock(&siftr_pkt_mgr_mtx); 1282 1283 totalss.n_in = DPCPU_VARSUM(ss, n_in); 1284 totalss.n_out = DPCPU_VARSUM(ss, n_out); 1285 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc); 1286 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc); 1287 totalss.nskip_in_mtx = DPCPU_VARSUM(ss, nskip_in_mtx); 1288 totalss.nskip_out_mtx = DPCPU_VARSUM(ss, nskip_out_mtx); 1289 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb); 1290 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb); 1291 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb); 1292 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb); 1293 1294 total_skipped_pkts = totalss.nskip_in_malloc + 1295 totalss.nskip_out_malloc + totalss.nskip_in_mtx + 1296 totalss.nskip_out_mtx + totalss.nskip_in_tcpcb + 1297 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb + 1298 totalss.nskip_out_inpcb; 1299 1300 microtime(&tval); 1301 1302 sbuf_printf(s, 1303 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t" 1304 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t" 1305 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t" 1306 "num_outbound_skipped_pkts_malloc=%u\t" 1307 "num_inbound_skipped_pkts_mtx=%u\t" 1308 "num_outbound_skipped_pkts_mtx=%u\t" 1309 "num_inbound_skipped_pkts_tcpcb=%u\t" 1310 "num_outbound_skipped_pkts_tcpcb=%u\t" 1311 "num_inbound_skipped_pkts_inpcb=%u\t" 1312 "num_outbound_skipped_pkts_inpcb=%u\t" 1313 "total_skipped_tcp_pkts=%u\tflow_list=", 1314 (intmax_t)tval.tv_sec, 1315 tval.tv_usec, 1316 (uintmax_t)totalss.n_in, 1317 (uintmax_t)totalss.n_out, 1318 (uintmax_t)(totalss.n_in + totalss.n_out), 1319 totalss.nskip_in_malloc, 1320 totalss.nskip_out_malloc, 1321 totalss.nskip_in_mtx, 1322 totalss.nskip_out_mtx, 1323 totalss.nskip_in_tcpcb, 1324 totalss.nskip_out_tcpcb, 1325 totalss.nskip_in_inpcb, 1326 totalss.nskip_out_inpcb, 1327 total_skipped_pkts); 1328 1329 /* 1330 * Iterate over the flow hash, printing a summary of each 1331 * flow seen and freeing any malloc'd memory. 1332 * The hash consists of an array of LISTs (man 3 queue). 1333 */ 1334 for (i = 0; i <= siftr_hashmask; i++) { 1335 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes, 1336 tmp_counter) { 1337 key = counter->key; 1338 key_index = 1; 1339 1340 ipver = key[0]; 1341 1342 memcpy(laddr, key + key_index, sizeof(laddr)); 1343 key_index += sizeof(laddr); 1344 memcpy(&lport, key + key_index, sizeof(lport)); 1345 key_index += sizeof(lport); 1346 memcpy(faddr, key + key_index, sizeof(faddr)); 1347 key_index += sizeof(faddr); 1348 memcpy(&fport, key + key_index, sizeof(fport)); 1349 1350 #ifdef SIFTR_IPV6 1351 laddr[3] = ntohl(laddr[3]); 1352 faddr[3] = ntohl(faddr[3]); 1353 1354 if (ipver == INP_IPV6) { 1355 laddr[0] = ntohl(laddr[0]); 1356 laddr[1] = ntohl(laddr[1]); 1357 laddr[2] = ntohl(laddr[2]); 1358 faddr[0] = ntohl(faddr[0]); 1359 faddr[1] = ntohl(faddr[1]); 1360 faddr[2] = ntohl(faddr[2]); 1361 1362 sbuf_printf(s, 1363 "%x:%x:%x:%x:%x:%x:%x:%x;%u-" 1364 "%x:%x:%x:%x:%x:%x:%x:%x;%u,", 1365 UPPER_SHORT(laddr[0]), 1366 LOWER_SHORT(laddr[0]), 1367 UPPER_SHORT(laddr[1]), 1368 LOWER_SHORT(laddr[1]), 1369 UPPER_SHORT(laddr[2]), 1370 LOWER_SHORT(laddr[2]), 1371 UPPER_SHORT(laddr[3]), 1372 LOWER_SHORT(laddr[3]), 1373 ntohs(lport), 1374 UPPER_SHORT(faddr[0]), 1375 LOWER_SHORT(faddr[0]), 1376 UPPER_SHORT(faddr[1]), 1377 LOWER_SHORT(faddr[1]), 1378 UPPER_SHORT(faddr[2]), 1379 LOWER_SHORT(faddr[2]), 1380 UPPER_SHORT(faddr[3]), 1381 LOWER_SHORT(faddr[3]), 1382 ntohs(fport)); 1383 } else { 1384 laddr[0] = FIRST_OCTET(laddr[3]); 1385 laddr[1] = SECOND_OCTET(laddr[3]); 1386 laddr[2] = THIRD_OCTET(laddr[3]); 1387 laddr[3] = FOURTH_OCTET(laddr[3]); 1388 faddr[0] = FIRST_OCTET(faddr[3]); 1389 faddr[1] = SECOND_OCTET(faddr[3]); 1390 faddr[2] = THIRD_OCTET(faddr[3]); 1391 faddr[3] = FOURTH_OCTET(faddr[3]); 1392 #endif 1393 sbuf_printf(s, 1394 "%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,", 1395 laddr[0], 1396 laddr[1], 1397 laddr[2], 1398 laddr[3], 1399 ntohs(lport), 1400 faddr[0], 1401 faddr[1], 1402 faddr[2], 1403 faddr[3], 1404 ntohs(fport)); 1405 #ifdef SIFTR_IPV6 1406 } 1407 #endif 1408 1409 free(counter, M_SIFTR_HASHNODE); 1410 } 1411 1412 LIST_INIT(counter_hash + i); 1413 } 1414 1415 sbuf_printf(s, "\n"); 1416 sbuf_finish(s); 1417 1418 i = 0; 1419 do { 1420 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i); 1421 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK); 1422 i += bytes_to_write; 1423 } while (i < sbuf_len(s)); 1424 1425 alq_close(siftr_alq); 1426 siftr_alq = NULL; 1427 } 1428 1429 sbuf_delete(s); 1430 1431 /* 1432 * XXX: Should be using ret to check if any functions fail 1433 * and set error appropriately 1434 */ 1435 1436 return (error); 1437 } 1438 1439 1440 static int 1441 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS) 1442 { 1443 if (req->newptr == NULL) 1444 goto skip; 1445 1446 /* If the value passed in isn't 0 or 1, return an error. */ 1447 if (CAST_PTR_INT(req->newptr) != 0 && CAST_PTR_INT(req->newptr) != 1) 1448 return (1); 1449 1450 /* If we are changing state (0 to 1 or 1 to 0). */ 1451 if (CAST_PTR_INT(req->newptr) != siftr_enabled ) 1452 if (siftr_manage_ops(CAST_PTR_INT(req->newptr))) { 1453 siftr_manage_ops(SIFTR_DISABLE); 1454 return (1); 1455 } 1456 1457 skip: 1458 return (sysctl_handle_int(oidp, arg1, arg2, req)); 1459 } 1460 1461 1462 static void 1463 siftr_shutdown_handler(void *arg) 1464 { 1465 siftr_manage_ops(SIFTR_DISABLE); 1466 } 1467 1468 1469 /* 1470 * Module is being unloaded or machine is shutting down. Take care of cleanup. 1471 */ 1472 static int 1473 deinit_siftr(void) 1474 { 1475 /* Cleanup. */ 1476 siftr_manage_ops(SIFTR_DISABLE); 1477 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask); 1478 mtx_destroy(&siftr_pkt_queue_mtx); 1479 mtx_destroy(&siftr_pkt_mgr_mtx); 1480 1481 return (0); 1482 } 1483 1484 1485 /* 1486 * Module has just been loaded into the kernel. 1487 */ 1488 static int 1489 init_siftr(void) 1490 { 1491 EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL, 1492 SHUTDOWN_PRI_FIRST); 1493 1494 /* Initialise our flow counter hash table. */ 1495 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR, 1496 &siftr_hashmask); 1497 1498 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF); 1499 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF); 1500 1501 /* Print message to the user's current terminal. */ 1502 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n" 1503 " http://caia.swin.edu.au/urp/newtcp\n\n", 1504 MODVERSION_STR); 1505 1506 return (0); 1507 } 1508 1509 1510 /* 1511 * This is the function that is called to load and unload the module. 1512 * When the module is loaded, this function is called once with 1513 * "what" == MOD_LOAD 1514 * When the module is unloaded, this function is called twice with 1515 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second 1516 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command, 1517 * this function is called once with "what" = MOD_SHUTDOWN 1518 * When the system is shut down, the handler isn't called until the very end 1519 * of the shutdown sequence i.e. after the disks have been synced. 1520 */ 1521 static int 1522 siftr_load_handler(module_t mod, int what, void *arg) 1523 { 1524 int ret; 1525 1526 switch (what) { 1527 case MOD_LOAD: 1528 ret = init_siftr(); 1529 break; 1530 1531 case MOD_QUIESCE: 1532 case MOD_SHUTDOWN: 1533 ret = deinit_siftr(); 1534 break; 1535 1536 case MOD_UNLOAD: 1537 ret = 0; 1538 break; 1539 1540 default: 1541 ret = EINVAL; 1542 break; 1543 } 1544 1545 return (ret); 1546 } 1547 1548 1549 static moduledata_t siftr_mod = { 1550 .name = "siftr", 1551 .evhand = siftr_load_handler, 1552 }; 1553 1554 /* 1555 * Param 1: name of the kernel module 1556 * Param 2: moduledata_t struct containing info about the kernel module 1557 * and the execution entry point for the module 1558 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h 1559 * Defines the module initialisation order 1560 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h 1561 * Defines the initialisation order of this kld relative to others 1562 * within the same subsystem as defined by param 3 1563 */ 1564 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_SMP, SI_ORDER_ANY); 1565 MODULE_DEPEND(siftr, alq, 1, 1, 1); 1566 MODULE_VERSION(siftr, MODVERSION); 1567