Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/netinet/siftr.c
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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/hash.h> 68 #include <sys/kernel.h> 69 #include <sys/kthread.h> 70 #include <sys/lock.h> 71 #include <sys/mbuf.h> 72 #include <sys/module.h> 73 #include <sys/mutex.h> 74 #include <sys/pcpu.h> 75 #include <sys/proc.h> 76 #include <sys/sbuf.h> 77 #include <sys/smp.h> 78 #include <sys/socket.h> 79 #include <sys/socketvar.h> 80 #include <sys/sysctl.h> 81 #include <sys/unistd.h> 82 83 #include <net/if.h> 84 #include <net/pfil.h> 85 86 #include <netinet/in.h> 87 #include <netinet/in_pcb.h> 88 #include <netinet/in_systm.h> 89 #include <netinet/in_var.h> 90 #include <netinet/ip.h> 91 #include <netinet/tcp_var.h> 92 93 #ifdef SIFTR_IPV6 94 #include <netinet/ip6.h> 95 #include <netinet6/in6_pcb.h> 96 #endif /* SIFTR_IPV6 */ 97 98 #include <machine/in_cksum.h> 99 100 /* 101 * Three digit version number refers to X.Y.Z where: 102 * X is the major version number 103 * Y is bumped to mark backwards incompatible changes 104 * Z is bumped to mark backwards compatible changes 105 */ 106 #define V_MAJOR 1 107 #define V_BACKBREAK 2 108 #define V_BACKCOMPAT 4 109 #define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT)) 110 #define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \ 111 __XSTRING(V_BACKCOMPAT) 112 113 #define HOOK 0 114 #define UNHOOK 1 115 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536 116 #define SYS_NAME "FreeBSD" 117 #define PACKET_TAG_SIFTR 100 118 #define PACKET_COOKIE_SIFTR 21749576 119 #define SIFTR_LOG_FILE_MODE 0644 120 #define SIFTR_DISABLE 0 121 #define SIFTR_ENABLE 1 122 123 /* 124 * Hard upper limit on the length of log messages. Bump this up if you add new 125 * data fields such that the line length could exceed the below value. 126 */ 127 #define MAX_LOG_MSG_LEN 200 128 /* XXX: Make this a sysctl tunable. */ 129 #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN) 130 131 /* 132 * 1 byte for IP version 133 * IPv4: src/dst IP (4+4) + src/dst port (2+2) = 12 bytes 134 * IPv6: src/dst IP (16+16) + src/dst port (2+2) = 36 bytes 135 */ 136 #ifdef SIFTR_IPV6 137 #define FLOW_KEY_LEN 37 138 #else 139 #define FLOW_KEY_LEN 13 140 #endif 141 142 #ifdef SIFTR_IPV6 143 #define SIFTR_IPMODE 6 144 #else 145 #define SIFTR_IPMODE 4 146 #endif 147 148 /* useful macros */ 149 #define CAST_PTR_INT(X) (*((int*)(X))) 150 151 #define UPPER_SHORT(X) (((X) & 0xFFFF0000) >> 16) 152 #define LOWER_SHORT(X) ((X) & 0x0000FFFF) 153 154 #define FIRST_OCTET(X) (((X) & 0xFF000000) >> 24) 155 #define SECOND_OCTET(X) (((X) & 0x00FF0000) >> 16) 156 #define THIRD_OCTET(X) (((X) & 0x0000FF00) >> 8) 157 #define FOURTH_OCTET(X) ((X) & 0x000000FF) 158 159 static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR"); 160 static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode", 161 "SIFTR pkt_node struct"); 162 static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode", 163 "SIFTR flow_hash_node struct"); 164 165 /* Used as links in the pkt manager queue. */ 166 struct pkt_node { 167 /* Timestamp of pkt as noted in the pfil hook. */ 168 struct timeval tval; 169 /* Direction pkt is travelling; either PFIL_IN or PFIL_OUT. */ 170 uint8_t direction; 171 /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */ 172 uint8_t ipver; 173 /* Hash of the pkt which triggered the log message. */ 174 uint32_t hash; 175 /* Local/foreign IP address. */ 176 #ifdef SIFTR_IPV6 177 uint32_t ip_laddr[4]; 178 uint32_t ip_faddr[4]; 179 #else 180 uint8_t ip_laddr[4]; 181 uint8_t ip_faddr[4]; 182 #endif 183 /* Local TCP port. */ 184 uint16_t tcp_localport; 185 /* Foreign TCP port. */ 186 uint16_t tcp_foreignport; 187 /* Congestion Window (bytes). */ 188 u_long snd_cwnd; 189 /* Sending Window (bytes). */ 190 u_long snd_wnd; 191 /* Receive Window (bytes). */ 192 u_long rcv_wnd; 193 /* Unused (was: Bandwidth Controlled Window (bytes)). */ 194 u_long snd_bwnd; 195 /* Slow Start Threshold (bytes). */ 196 u_long snd_ssthresh; 197 /* Current state of the TCP FSM. */ 198 int conn_state; 199 /* Max Segment Size (bytes). */ 200 u_int max_seg_size; 201 /* 202 * Smoothed RTT stored as found in the TCP control block 203 * in units of (TCP_RTT_SCALE*hz). 204 */ 205 int smoothed_rtt; 206 /* Is SACK enabled? */ 207 u_char sack_enabled; 208 /* Window scaling for snd window. */ 209 u_char snd_scale; 210 /* Window scaling for recv window. */ 211 u_char rcv_scale; 212 /* TCP control block flags. */ 213 u_int flags; 214 /* Retransmit timeout length. */ 215 int rxt_length; 216 /* Size of the TCP send buffer in bytes. */ 217 u_int snd_buf_hiwater; 218 /* Current num bytes in the send socket buffer. */ 219 u_int snd_buf_cc; 220 /* Size of the TCP receive buffer in bytes. */ 221 u_int rcv_buf_hiwater; 222 /* Current num bytes in the receive socket buffer. */ 223 u_int rcv_buf_cc; 224 /* Number of bytes inflight that we are waiting on ACKs for. */ 225 u_int sent_inflight_bytes; 226 /* Number of segments currently in the reassembly queue. */ 227 int t_segqlen; 228 /* Flowid for the connection. */ 229 u_int flowid; 230 /* Flow type for the connection. */ 231 u_int flowtype; 232 /* Link to next pkt_node in the list. */ 233 STAILQ_ENTRY(pkt_node) nodes; 234 }; 235 236 struct flow_hash_node 237 { 238 uint16_t counter; 239 uint8_t key[FLOW_KEY_LEN]; 240 LIST_ENTRY(flow_hash_node) nodes; 241 }; 242 243 struct siftr_stats 244 { 245 /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */ 246 uint64_t n_in; 247 uint64_t n_out; 248 /* # pkts skipped due to failed malloc calls. */ 249 uint32_t nskip_in_malloc; 250 uint32_t nskip_out_malloc; 251 /* # pkts skipped due to failed mtx acquisition. */ 252 uint32_t nskip_in_mtx; 253 uint32_t nskip_out_mtx; 254 /* # pkts skipped due to failed inpcb lookups. */ 255 uint32_t nskip_in_inpcb; 256 uint32_t nskip_out_inpcb; 257 /* # pkts skipped due to failed tcpcb lookups. */ 258 uint32_t nskip_in_tcpcb; 259 uint32_t nskip_out_tcpcb; 260 /* # pkts skipped due to stack reinjection. */ 261 uint32_t nskip_in_dejavu; 262 uint32_t nskip_out_dejavu; 263 }; 264 265 static DPCPU_DEFINE(struct siftr_stats, ss); 266 267 static volatile unsigned int siftr_exit_pkt_manager_thread = 0; 268 static unsigned int siftr_enabled = 0; 269 static unsigned int siftr_pkts_per_log = 1; 270 static unsigned int siftr_generate_hashes = 0; 271 /* static unsigned int siftr_binary_log = 0; */ 272 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log"; 273 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log"; 274 static u_long siftr_hashmask; 275 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue); 276 LIST_HEAD(listhead, flow_hash_node) *counter_hash; 277 static int wait_for_pkt; 278 static struct alq *siftr_alq = NULL; 279 static struct mtx siftr_pkt_queue_mtx; 280 static struct mtx siftr_pkt_mgr_mtx; 281 static struct thread *siftr_pkt_manager_thr = NULL; 282 /* 283 * pfil.h defines PFIL_IN as 1 and PFIL_OUT as 2, 284 * which we use as an index into this array. 285 */ 286 static char direction[3] = {'\0', 'i','o'}; 287 288 /* Required function prototypes. */ 289 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS); 290 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS); 291 292 293 /* Declare the net.inet.siftr sysctl tree and populate it. */ 294 295 SYSCTL_DECL(_net_inet_siftr); 296 297 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW, NULL, 298 "siftr related settings"); 299 300 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, CTLTYPE_UINT|CTLFLAG_RW, 301 &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU", 302 "switch siftr module operations on/off"); 303 304 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, CTLTYPE_STRING|CTLFLAG_RW, 305 &siftr_logfile_shadow, sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler, 306 "A", "file to save siftr log messages to"); 307 308 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW, 309 &siftr_pkts_per_log, 1, 310 "number of packets between generating a log message"); 311 312 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW, 313 &siftr_generate_hashes, 0, 314 "enable packet hash generation"); 315 316 /* XXX: TODO 317 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW, 318 &siftr_binary_log, 0, 319 "write log files in binary instead of ascii"); 320 */ 321 322 323 /* Begin functions. */ 324 325 static void 326 siftr_process_pkt(struct pkt_node * pkt_node) 327 { 328 struct flow_hash_node *hash_node; 329 struct listhead *counter_list; 330 struct siftr_stats *ss; 331 struct ale *log_buf; 332 uint8_t key[FLOW_KEY_LEN]; 333 uint8_t found_match, key_offset; 334 335 hash_node = NULL; 336 ss = DPCPU_PTR(ss); 337 found_match = 0; 338 key_offset = 1; 339 340 /* 341 * Create the key that will be used to create a hash index 342 * into our hash table. Our key consists of: 343 * ipversion, localip, localport, foreignip, foreignport 344 */ 345 key[0] = pkt_node->ipver; 346 memcpy(key + key_offset, &pkt_node->ip_laddr, 347 sizeof(pkt_node->ip_laddr)); 348 key_offset += sizeof(pkt_node->ip_laddr); 349 memcpy(key + key_offset, &pkt_node->tcp_localport, 350 sizeof(pkt_node->tcp_localport)); 351 key_offset += sizeof(pkt_node->tcp_localport); 352 memcpy(key + key_offset, &pkt_node->ip_faddr, 353 sizeof(pkt_node->ip_faddr)); 354 key_offset += sizeof(pkt_node->ip_faddr); 355 memcpy(key + key_offset, &pkt_node->tcp_foreignport, 356 sizeof(pkt_node->tcp_foreignport)); 357 358 counter_list = counter_hash + 359 (hash32_buf(key, sizeof(key), 0) & siftr_hashmask); 360 361 /* 362 * If the list is not empty i.e. the hash index has 363 * been used by another flow previously. 364 */ 365 if (LIST_FIRST(counter_list) != NULL) { 366 /* 367 * Loop through the hash nodes in the list. 368 * There should normally only be 1 hash node in the list, 369 * except if there have been collisions at the hash index 370 * computed by hash32_buf(). 371 */ 372 LIST_FOREACH(hash_node, counter_list, nodes) { 373 /* 374 * Check if the key for the pkt we are currently 375 * processing is the same as the key stored in the 376 * hash node we are currently processing. 377 * If they are the same, then we've found the 378 * hash node that stores the counter for the flow 379 * the pkt belongs to. 380 */ 381 if (memcmp(hash_node->key, key, sizeof(key)) == 0) { 382 found_match = 1; 383 break; 384 } 385 } 386 } 387 388 /* If this flow hash hasn't been seen before or we have a collision. */ 389 if (hash_node == NULL || !found_match) { 390 /* Create a new hash node to store the flow's counter. */ 391 hash_node = malloc(sizeof(struct flow_hash_node), 392 M_SIFTR_HASHNODE, M_WAITOK); 393 394 if (hash_node != NULL) { 395 /* Initialise our new hash node list entry. */ 396 hash_node->counter = 0; 397 memcpy(hash_node->key, key, sizeof(key)); 398 LIST_INSERT_HEAD(counter_list, hash_node, nodes); 399 } else { 400 /* Malloc failed. */ 401 if (pkt_node->direction == PFIL_IN) 402 ss->nskip_in_malloc++; 403 else 404 ss->nskip_out_malloc++; 405 406 return; 407 } 408 } else if (siftr_pkts_per_log > 1) { 409 /* 410 * Taking the remainder of the counter divided 411 * by the current value of siftr_pkts_per_log 412 * and storing that in counter provides a neat 413 * way to modulate the frequency of log 414 * messages being written to the log file. 415 */ 416 hash_node->counter = (hash_node->counter + 1) % 417 siftr_pkts_per_log; 418 419 /* 420 * If we have not seen enough packets since the last time 421 * we wrote a log message for this connection, return. 422 */ 423 if (hash_node->counter > 0) 424 return; 425 } 426 427 log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK); 428 429 if (log_buf == NULL) 430 return; /* Should only happen if the ALQ is shutting down. */ 431 432 #ifdef SIFTR_IPV6 433 pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]); 434 pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]); 435 436 if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */ 437 pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]); 438 pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]); 439 pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]); 440 pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]); 441 pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]); 442 pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]); 443 444 /* Construct an IPv6 log message. */ 445 log_buf->ae_bytesused = snprintf(log_buf->ae_data, 446 MAX_LOG_MSG_LEN, 447 "%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:" 448 "%x:%x:%x:%x:%x,%u,%ld,%ld,%ld,%ld,%ld,%u,%u,%u,%u,%u,%u," 449 "%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n", 450 direction[pkt_node->direction], 451 pkt_node->hash, 452 pkt_node->tval.tv_sec, 453 pkt_node->tval.tv_usec, 454 UPPER_SHORT(pkt_node->ip_laddr[0]), 455 LOWER_SHORT(pkt_node->ip_laddr[0]), 456 UPPER_SHORT(pkt_node->ip_laddr[1]), 457 LOWER_SHORT(pkt_node->ip_laddr[1]), 458 UPPER_SHORT(pkt_node->ip_laddr[2]), 459 LOWER_SHORT(pkt_node->ip_laddr[2]), 460 UPPER_SHORT(pkt_node->ip_laddr[3]), 461 LOWER_SHORT(pkt_node->ip_laddr[3]), 462 ntohs(pkt_node->tcp_localport), 463 UPPER_SHORT(pkt_node->ip_faddr[0]), 464 LOWER_SHORT(pkt_node->ip_faddr[0]), 465 UPPER_SHORT(pkt_node->ip_faddr[1]), 466 LOWER_SHORT(pkt_node->ip_faddr[1]), 467 UPPER_SHORT(pkt_node->ip_faddr[2]), 468 LOWER_SHORT(pkt_node->ip_faddr[2]), 469 UPPER_SHORT(pkt_node->ip_faddr[3]), 470 LOWER_SHORT(pkt_node->ip_faddr[3]), 471 ntohs(pkt_node->tcp_foreignport), 472 pkt_node->snd_ssthresh, 473 pkt_node->snd_cwnd, 474 pkt_node->snd_bwnd, 475 pkt_node->snd_wnd, 476 pkt_node->rcv_wnd, 477 pkt_node->snd_scale, 478 pkt_node->rcv_scale, 479 pkt_node->conn_state, 480 pkt_node->max_seg_size, 481 pkt_node->smoothed_rtt, 482 pkt_node->sack_enabled, 483 pkt_node->flags, 484 pkt_node->rxt_length, 485 pkt_node->snd_buf_hiwater, 486 pkt_node->snd_buf_cc, 487 pkt_node->rcv_buf_hiwater, 488 pkt_node->rcv_buf_cc, 489 pkt_node->sent_inflight_bytes, 490 pkt_node->t_segqlen, 491 pkt_node->flowid, 492 pkt_node->flowtype); 493 } else { /* IPv4 packet */ 494 pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]); 495 pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]); 496 pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]); 497 pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]); 498 pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]); 499 pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]); 500 pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]); 501 pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]); 502 #endif /* SIFTR_IPV6 */ 503 504 /* Construct an IPv4 log message. */ 505 log_buf->ae_bytesused = snprintf(log_buf->ae_data, 506 MAX_LOG_MSG_LEN, 507 "%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%ld,%ld," 508 "%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n", 509 direction[pkt_node->direction], 510 pkt_node->hash, 511 (intmax_t)pkt_node->tval.tv_sec, 512 pkt_node->tval.tv_usec, 513 pkt_node->ip_laddr[0], 514 pkt_node->ip_laddr[1], 515 pkt_node->ip_laddr[2], 516 pkt_node->ip_laddr[3], 517 ntohs(pkt_node->tcp_localport), 518 pkt_node->ip_faddr[0], 519 pkt_node->ip_faddr[1], 520 pkt_node->ip_faddr[2], 521 pkt_node->ip_faddr[3], 522 ntohs(pkt_node->tcp_foreignport), 523 pkt_node->snd_ssthresh, 524 pkt_node->snd_cwnd, 525 pkt_node->snd_bwnd, 526 pkt_node->snd_wnd, 527 pkt_node->rcv_wnd, 528 pkt_node->snd_scale, 529 pkt_node->rcv_scale, 530 pkt_node->conn_state, 531 pkt_node->max_seg_size, 532 pkt_node->smoothed_rtt, 533 pkt_node->sack_enabled, 534 pkt_node->flags, 535 pkt_node->rxt_length, 536 pkt_node->snd_buf_hiwater, 537 pkt_node->snd_buf_cc, 538 pkt_node->rcv_buf_hiwater, 539 pkt_node->rcv_buf_cc, 540 pkt_node->sent_inflight_bytes, 541 pkt_node->t_segqlen, 542 pkt_node->flowid, 543 pkt_node->flowtype); 544 #ifdef SIFTR_IPV6 545 } 546 #endif 547 548 alq_post_flags(siftr_alq, log_buf, 0); 549 } 550 551 552 static void 553 siftr_pkt_manager_thread(void *arg) 554 { 555 STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue = 556 STAILQ_HEAD_INITIALIZER(tmp_pkt_queue); 557 struct pkt_node *pkt_node, *pkt_node_temp; 558 uint8_t draining; 559 560 draining = 2; 561 562 mtx_lock(&siftr_pkt_mgr_mtx); 563 564 /* draining == 0 when queue has been flushed and it's safe to exit. */ 565 while (draining) { 566 /* 567 * Sleep until we are signalled to wake because thread has 568 * been told to exit or until 1 tick has passed. 569 */ 570 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait", 571 1); 572 573 /* Gain exclusive access to the pkt_node queue. */ 574 mtx_lock(&siftr_pkt_queue_mtx); 575 576 /* 577 * Move pkt_queue to tmp_pkt_queue, which leaves 578 * pkt_queue empty and ready to receive more pkt_nodes. 579 */ 580 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue); 581 582 /* 583 * We've finished making changes to the list. Unlock it 584 * so the pfil hooks can continue queuing pkt_nodes. 585 */ 586 mtx_unlock(&siftr_pkt_queue_mtx); 587 588 /* 589 * We can't hold a mutex whilst calling siftr_process_pkt 590 * because ALQ might sleep waiting for buffer space. 591 */ 592 mtx_unlock(&siftr_pkt_mgr_mtx); 593 594 /* Flush all pkt_nodes to the log file. */ 595 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes, 596 pkt_node_temp) { 597 siftr_process_pkt(pkt_node); 598 STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes); 599 free(pkt_node, M_SIFTR_PKTNODE); 600 } 601 602 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue), 603 ("SIFTR tmp_pkt_queue not empty after flush")); 604 605 mtx_lock(&siftr_pkt_mgr_mtx); 606 607 /* 608 * If siftr_exit_pkt_manager_thread gets set during the window 609 * where we are draining the tmp_pkt_queue above, there might 610 * still be pkts in pkt_queue that need to be drained. 611 * Allow one further iteration to occur after 612 * siftr_exit_pkt_manager_thread has been set to ensure 613 * pkt_queue is completely empty before we kill the thread. 614 * 615 * siftr_exit_pkt_manager_thread is set only after the pfil 616 * hooks have been removed, so only 1 extra iteration 617 * is needed to drain the queue. 618 */ 619 if (siftr_exit_pkt_manager_thread) 620 draining--; 621 } 622 623 mtx_unlock(&siftr_pkt_mgr_mtx); 624 625 /* Calls wakeup on this thread's struct thread ptr. */ 626 kthread_exit(); 627 } 628 629 630 static uint32_t 631 hash_pkt(struct mbuf *m, uint32_t offset) 632 { 633 uint32_t hash; 634 635 hash = 0; 636 637 while (m != NULL && offset > m->m_len) { 638 /* 639 * The IP packet payload does not start in this mbuf, so 640 * need to figure out which mbuf it starts in and what offset 641 * into the mbuf's data region the payload starts at. 642 */ 643 offset -= m->m_len; 644 m = m->m_next; 645 } 646 647 while (m != NULL) { 648 /* Ensure there is data in the mbuf */ 649 if ((m->m_len - offset) > 0) 650 hash = hash32_buf(m->m_data + offset, 651 m->m_len - offset, hash); 652 653 m = m->m_next; 654 offset = 0; 655 } 656 657 return (hash); 658 } 659 660 661 /* 662 * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that 663 * it's a reinjected packet and return. If it doesn't, tag the mbuf and return. 664 * Return value >0 means the caller should skip processing this mbuf. 665 */ 666 static inline int 667 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss) 668 { 669 if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL) 670 != NULL) { 671 if (dir == PFIL_IN) 672 ss->nskip_in_dejavu++; 673 else 674 ss->nskip_out_dejavu++; 675 676 return (1); 677 } else { 678 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR, 679 PACKET_TAG_SIFTR, 0, M_NOWAIT); 680 if (tag == NULL) { 681 if (dir == PFIL_IN) 682 ss->nskip_in_malloc++; 683 else 684 ss->nskip_out_malloc++; 685 686 return (1); 687 } 688 689 m_tag_prepend(m, tag); 690 } 691 692 return (0); 693 } 694 695 696 /* 697 * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL 698 * otherwise. 699 */ 700 static inline struct inpcb * 701 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport, 702 uint16_t dport, int dir, struct siftr_stats *ss) 703 { 704 struct inpcb *inp; 705 706 /* We need the tcbinfo lock. */ 707 INP_INFO_UNLOCK_ASSERT(&V_tcbinfo); 708 709 if (dir == PFIL_IN) 710 inp = (ipver == INP_IPV4 ? 711 in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst, 712 dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 713 : 714 #ifdef SIFTR_IPV6 715 in6_pcblookup(&V_tcbinfo, 716 &((struct ip6_hdr *)ip)->ip6_src, sport, 717 &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB, 718 m->m_pkthdr.rcvif) 719 #else 720 NULL 721 #endif 722 ); 723 724 else 725 inp = (ipver == INP_IPV4 ? 726 in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src, 727 sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif) 728 : 729 #ifdef SIFTR_IPV6 730 in6_pcblookup(&V_tcbinfo, 731 &((struct ip6_hdr *)ip)->ip6_dst, dport, 732 &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB, 733 m->m_pkthdr.rcvif) 734 #else 735 NULL 736 #endif 737 ); 738 739 /* If we can't find the inpcb, bail. */ 740 if (inp == NULL) { 741 if (dir == PFIL_IN) 742 ss->nskip_in_inpcb++; 743 else 744 ss->nskip_out_inpcb++; 745 } 746 747 return (inp); 748 } 749 750 751 static inline void 752 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp, 753 int ipver, int dir, int inp_locally_locked) 754 { 755 #ifdef SIFTR_IPV6 756 if (ipver == INP_IPV4) { 757 pn->ip_laddr[3] = inp->inp_laddr.s_addr; 758 pn->ip_faddr[3] = inp->inp_faddr.s_addr; 759 #else 760 *((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr; 761 *((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr; 762 #endif 763 #ifdef SIFTR_IPV6 764 } else { 765 pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0]; 766 pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1]; 767 pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2]; 768 pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3]; 769 pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0]; 770 pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1]; 771 pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2]; 772 pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3]; 773 } 774 #endif 775 pn->tcp_localport = inp->inp_lport; 776 pn->tcp_foreignport = inp->inp_fport; 777 pn->snd_cwnd = tp->snd_cwnd; 778 pn->snd_wnd = tp->snd_wnd; 779 pn->rcv_wnd = tp->rcv_wnd; 780 pn->snd_bwnd = 0; /* Unused, kept for compat. */ 781 pn->snd_ssthresh = tp->snd_ssthresh; 782 pn->snd_scale = tp->snd_scale; 783 pn->rcv_scale = tp->rcv_scale; 784 pn->conn_state = tp->t_state; 785 pn->max_seg_size = tp->t_maxseg; 786 pn->smoothed_rtt = tp->t_srtt; 787 pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0; 788 pn->flags = tp->t_flags; 789 pn->rxt_length = tp->t_rxtcur; 790 pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat; 791 pn->snd_buf_cc = inp->inp_socket->so_snd.sb_cc; 792 pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat; 793 pn->rcv_buf_cc = inp->inp_socket->so_rcv.sb_cc; 794 pn->sent_inflight_bytes = tp->snd_max - tp->snd_una; 795 pn->t_segqlen = tp->t_segqlen; 796 pn->flowid = inp->inp_flowid; 797 pn->flowtype = inp->inp_flowtype; 798 799 /* We've finished accessing the tcb so release the lock. */ 800 if (inp_locally_locked) 801 INP_RUNLOCK(inp); 802 803 pn->ipver = ipver; 804 pn->direction = dir; 805 806 /* 807 * Significantly more accurate than using getmicrotime(), but slower! 808 * Gives true microsecond resolution at the expense of a hit to 809 * maximum pps throughput processing when SIFTR is loaded and enabled. 810 */ 811 microtime(&pn->tval); 812 } 813 814 815 /* 816 * pfil hook that is called for each IPv4 packet making its way through the 817 * stack in either direction. 818 * The pfil subsystem holds a non-sleepable mutex somewhere when 819 * calling our hook function, so we can't sleep at all. 820 * It's very important to use the M_NOWAIT flag with all function calls 821 * that support it so that they won't sleep, otherwise you get a panic. 822 */ 823 static int 824 siftr_chkpkt(void *arg, struct mbuf **m, struct ifnet *ifp, int dir, 825 struct inpcb *inp) 826 { 827 struct pkt_node *pn; 828 struct ip *ip; 829 struct tcphdr *th; 830 struct tcpcb *tp; 831 struct siftr_stats *ss; 832 unsigned int ip_hl; 833 int inp_locally_locked; 834 835 inp_locally_locked = 0; 836 ss = DPCPU_PTR(ss); 837 838 /* 839 * m_pullup is not required here because ip_{input|output} 840 * already do the heavy lifting for us. 841 */ 842 843 ip = mtod(*m, struct ip *); 844 845 /* Only continue processing if the packet is TCP. */ 846 if (ip->ip_p != IPPROTO_TCP) 847 goto ret; 848 849 /* 850 * If a kernel subsystem reinjects packets into the stack, our pfil 851 * hook will be called multiple times for the same packet. 852 * Make sure we only process unique packets. 853 */ 854 if (siftr_chkreinject(*m, dir, ss)) 855 goto ret; 856 857 if (dir == PFIL_IN) 858 ss->n_in++; 859 else 860 ss->n_out++; 861 862 /* 863 * Create a tcphdr struct starting at the correct offset 864 * in the IP packet. ip->ip_hl gives the ip header length 865 * in 4-byte words, so multiply it to get the size in bytes. 866 */ 867 ip_hl = (ip->ip_hl << 2); 868 th = (struct tcphdr *)((caddr_t)ip + ip_hl); 869 870 /* 871 * If the pfil hooks don't provide a pointer to the 872 * inpcb, we need to find it ourselves and lock it. 873 */ 874 if (!inp) { 875 /* Find the corresponding inpcb for this pkt. */ 876 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport, 877 th->th_dport, dir, ss); 878 879 if (inp == NULL) 880 goto ret; 881 else 882 inp_locally_locked = 1; 883 } 884 885 INP_LOCK_ASSERT(inp); 886 887 /* Find the TCP control block that corresponds with this packet */ 888 tp = intotcpcb(inp); 889 890 /* 891 * If we can't find the TCP control block (happens occasionaly for a 892 * packet sent during the shutdown phase of a TCP connection), 893 * or we're in the timewait state, bail 894 */ 895 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) { 896 if (dir == PFIL_IN) 897 ss->nskip_in_tcpcb++; 898 else 899 ss->nskip_out_tcpcb++; 900 901 goto inp_unlock; 902 } 903 904 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 905 906 if (pn == NULL) { 907 if (dir == PFIL_IN) 908 ss->nskip_in_malloc++; 909 else 910 ss->nskip_out_malloc++; 911 912 goto inp_unlock; 913 } 914 915 siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked); 916 917 if (siftr_generate_hashes) { 918 if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) { 919 /* 920 * For outbound packets, the TCP checksum isn't 921 * calculated yet. This is a problem for our packet 922 * hashing as the receiver will calc a different hash 923 * to ours if we don't include the correct TCP checksum 924 * in the bytes being hashed. To work around this 925 * problem, we manually calc the TCP checksum here in 926 * software. We unset the CSUM_TCP flag so the lower 927 * layers don't recalc it. 928 */ 929 (*m)->m_pkthdr.csum_flags &= ~CSUM_TCP; 930 931 /* 932 * Calculate the TCP checksum in software and assign 933 * to correct TCP header field, which will follow the 934 * packet mbuf down the stack. The trick here is that 935 * tcp_output() sets th->th_sum to the checksum of the 936 * pseudo header for us already. Because of the nature 937 * of the checksumming algorithm, we can sum over the 938 * entire IP payload (i.e. TCP header and data), which 939 * will include the already calculated pseduo header 940 * checksum, thus giving us the complete TCP checksum. 941 * 942 * To put it in simple terms, if checksum(1,2,3,4)=10, 943 * then checksum(1,2,3,4,5) == checksum(10,5). 944 * This property is what allows us to "cheat" and 945 * checksum only the IP payload which has the TCP 946 * th_sum field populated with the pseudo header's 947 * checksum, and not need to futz around checksumming 948 * pseudo header bytes and TCP header/data in one hit. 949 * Refer to RFC 1071 for more info. 950 * 951 * NB: in_cksum_skip(struct mbuf *m, int len, int skip) 952 * in_cksum_skip 2nd argument is NOT the number of 953 * bytes to read from the mbuf at "skip" bytes offset 954 * from the start of the mbuf (very counter intuitive!). 955 * The number of bytes to read is calculated internally 956 * by the function as len-skip i.e. to sum over the IP 957 * payload (TCP header + data) bytes, it is INCORRECT 958 * to call the function like this: 959 * in_cksum_skip(at, ip->ip_len - offset, offset) 960 * Rather, it should be called like this: 961 * in_cksum_skip(at, ip->ip_len, offset) 962 * which means read "ip->ip_len - offset" bytes from 963 * the mbuf cluster "at" at offset "offset" bytes from 964 * the beginning of the "at" mbuf's data pointer. 965 */ 966 th->th_sum = in_cksum_skip(*m, ntohs(ip->ip_len), 967 ip_hl); 968 } 969 970 /* 971 * XXX: Having to calculate the checksum in software and then 972 * hash over all bytes is really inefficient. Would be nice to 973 * find a way to create the hash and checksum in the same pass 974 * over the bytes. 975 */ 976 pn->hash = hash_pkt(*m, ip_hl); 977 } 978 979 mtx_lock(&siftr_pkt_queue_mtx); 980 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 981 mtx_unlock(&siftr_pkt_queue_mtx); 982 goto ret; 983 984 inp_unlock: 985 if (inp_locally_locked) 986 INP_RUNLOCK(inp); 987 988 ret: 989 /* Returning 0 ensures pfil will not discard the pkt */ 990 return (0); 991 } 992 993 994 #ifdef SIFTR_IPV6 995 static int 996 siftr_chkpkt6(void *arg, struct mbuf **m, struct ifnet *ifp, int dir, 997 struct inpcb *inp) 998 { 999 struct pkt_node *pn; 1000 struct ip6_hdr *ip6; 1001 struct tcphdr *th; 1002 struct tcpcb *tp; 1003 struct siftr_stats *ss; 1004 unsigned int ip6_hl; 1005 int inp_locally_locked; 1006 1007 inp_locally_locked = 0; 1008 ss = DPCPU_PTR(ss); 1009 1010 /* 1011 * m_pullup is not required here because ip6_{input|output} 1012 * already do the heavy lifting for us. 1013 */ 1014 1015 ip6 = mtod(*m, struct ip6_hdr *); 1016 1017 /* 1018 * Only continue processing if the packet is TCP 1019 * XXX: We should follow the next header fields 1020 * as shown on Pg 6 RFC 2460, but right now we'll 1021 * only check pkts that have no extension headers. 1022 */ 1023 if (ip6->ip6_nxt != IPPROTO_TCP) 1024 goto ret6; 1025 1026 /* 1027 * If a kernel subsystem reinjects packets into the stack, our pfil 1028 * hook will be called multiple times for the same packet. 1029 * Make sure we only process unique packets. 1030 */ 1031 if (siftr_chkreinject(*m, dir, ss)) 1032 goto ret6; 1033 1034 if (dir == PFIL_IN) 1035 ss->n_in++; 1036 else 1037 ss->n_out++; 1038 1039 ip6_hl = sizeof(struct ip6_hdr); 1040 1041 /* 1042 * Create a tcphdr struct starting at the correct offset 1043 * in the ipv6 packet. ip->ip_hl gives the ip header length 1044 * in 4-byte words, so multiply it to get the size in bytes. 1045 */ 1046 th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl); 1047 1048 /* 1049 * For inbound packets, the pfil hooks don't provide a pointer to the 1050 * inpcb, so we need to find it ourselves and lock it. 1051 */ 1052 if (!inp) { 1053 /* Find the corresponding inpcb for this pkt. */ 1054 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m, 1055 th->th_sport, th->th_dport, dir, ss); 1056 1057 if (inp == NULL) 1058 goto ret6; 1059 else 1060 inp_locally_locked = 1; 1061 } 1062 1063 /* Find the TCP control block that corresponds with this packet. */ 1064 tp = intotcpcb(inp); 1065 1066 /* 1067 * If we can't find the TCP control block (happens occasionaly for a 1068 * packet sent during the shutdown phase of a TCP connection), 1069 * or we're in the timewait state, bail. 1070 */ 1071 if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) { 1072 if (dir == PFIL_IN) 1073 ss->nskip_in_tcpcb++; 1074 else 1075 ss->nskip_out_tcpcb++; 1076 1077 goto inp_unlock6; 1078 } 1079 1080 pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); 1081 1082 if (pn == NULL) { 1083 if (dir == PFIL_IN) 1084 ss->nskip_in_malloc++; 1085 else 1086 ss->nskip_out_malloc++; 1087 1088 goto inp_unlock6; 1089 } 1090 1091 siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked); 1092 1093 /* XXX: Figure out how to generate hashes for IPv6 packets. */ 1094 1095 mtx_lock(&siftr_pkt_queue_mtx); 1096 STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); 1097 mtx_unlock(&siftr_pkt_queue_mtx); 1098 goto ret6; 1099 1100 inp_unlock6: 1101 if (inp_locally_locked) 1102 INP_RUNLOCK(inp); 1103 1104 ret6: 1105 /* Returning 0 ensures pfil will not discard the pkt. */ 1106 return (0); 1107 } 1108 #endif /* #ifdef SIFTR_IPV6 */ 1109 1110 1111 static int 1112 siftr_pfil(int action) 1113 { 1114 struct pfil_head *pfh_inet; 1115 #ifdef SIFTR_IPV6 1116 struct pfil_head *pfh_inet6; 1117 #endif 1118 VNET_ITERATOR_DECL(vnet_iter); 1119 1120 VNET_LIST_RLOCK(); 1121 VNET_FOREACH(vnet_iter) { 1122 CURVNET_SET(vnet_iter); 1123 pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET); 1124 #ifdef SIFTR_IPV6 1125 pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6); 1126 #endif 1127 1128 if (action == HOOK) { 1129 pfil_add_hook(siftr_chkpkt, NULL, 1130 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet); 1131 #ifdef SIFTR_IPV6 1132 pfil_add_hook(siftr_chkpkt6, NULL, 1133 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6); 1134 #endif 1135 } else if (action == UNHOOK) { 1136 pfil_remove_hook(siftr_chkpkt, NULL, 1137 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet); 1138 #ifdef SIFTR_IPV6 1139 pfil_remove_hook(siftr_chkpkt6, NULL, 1140 PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6); 1141 #endif 1142 } 1143 CURVNET_RESTORE(); 1144 } 1145 VNET_LIST_RUNLOCK(); 1146 1147 return (0); 1148 } 1149 1150 1151 static int 1152 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS) 1153 { 1154 struct alq *new_alq; 1155 int error; 1156 1157 error = sysctl_handle_string(oidp, arg1, arg2, req); 1158 1159 /* Check for error or same filename */ 1160 if (error != 0 || req->newptr == NULL || 1161 strncmp(siftr_logfile, arg1, arg2) == 0) 1162 goto done; 1163 1164 /* Filname changed */ 1165 error = alq_open(&new_alq, arg1, curthread->td_ucred, 1166 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1167 if (error != 0) 1168 goto done; 1169 1170 /* 1171 * If disabled, siftr_alq == NULL so we simply close 1172 * the alq as we've proved it can be opened. 1173 * If enabled, close the existing alq and switch the old 1174 * for the new. 1175 */ 1176 if (siftr_alq == NULL) { 1177 alq_close(new_alq); 1178 } else { 1179 alq_close(siftr_alq); 1180 siftr_alq = new_alq; 1181 } 1182 1183 /* Update filename upon success */ 1184 strlcpy(siftr_logfile, arg1, arg2); 1185 done: 1186 return (error); 1187 } 1188 1189 static int 1190 siftr_manage_ops(uint8_t action) 1191 { 1192 struct siftr_stats totalss; 1193 struct timeval tval; 1194 struct flow_hash_node *counter, *tmp_counter; 1195 struct sbuf *s; 1196 int i, key_index, ret, error; 1197 uint32_t bytes_to_write, total_skipped_pkts; 1198 uint16_t lport, fport; 1199 uint8_t *key, ipver; 1200 1201 #ifdef SIFTR_IPV6 1202 uint32_t laddr[4]; 1203 uint32_t faddr[4]; 1204 #else 1205 uint8_t laddr[4]; 1206 uint8_t faddr[4]; 1207 #endif 1208 1209 error = 0; 1210 total_skipped_pkts = 0; 1211 1212 /* Init an autosizing sbuf that initially holds 200 chars. */ 1213 if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL) 1214 return (-1); 1215 1216 if (action == SIFTR_ENABLE) { 1217 /* 1218 * Create our alq 1219 * XXX: We should abort if alq_open fails! 1220 */ 1221 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred, 1222 SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); 1223 1224 STAILQ_INIT(&pkt_queue); 1225 1226 DPCPU_ZERO(ss); 1227 1228 siftr_exit_pkt_manager_thread = 0; 1229 1230 ret = kthread_add(&siftr_pkt_manager_thread, NULL, NULL, 1231 &siftr_pkt_manager_thr, RFNOWAIT, 0, 1232 "siftr_pkt_manager_thr"); 1233 1234 siftr_pfil(HOOK); 1235 1236 microtime(&tval); 1237 1238 sbuf_printf(s, 1239 "enable_time_secs=%jd\tenable_time_usecs=%06ld\t" 1240 "siftrver=%s\thz=%u\ttcp_rtt_scale=%u\tsysname=%s\t" 1241 "sysver=%u\tipmode=%u\n", 1242 (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, hz, 1243 TCP_RTT_SCALE, SYS_NAME, __FreeBSD_version, SIFTR_IPMODE); 1244 1245 sbuf_finish(s); 1246 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK); 1247 1248 } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) { 1249 /* 1250 * Remove the pfil hook functions. All threads currently in 1251 * the hook functions are allowed to exit before siftr_pfil() 1252 * returns. 1253 */ 1254 siftr_pfil(UNHOOK); 1255 1256 /* This will block until the pkt manager thread unlocks it. */ 1257 mtx_lock(&siftr_pkt_mgr_mtx); 1258 1259 /* Tell the pkt manager thread that it should exit now. */ 1260 siftr_exit_pkt_manager_thread = 1; 1261 1262 /* 1263 * Wake the pkt_manager thread so it realises that 1264 * siftr_exit_pkt_manager_thread == 1 and exits gracefully. 1265 * The wakeup won't be delivered until we unlock 1266 * siftr_pkt_mgr_mtx so this isn't racy. 1267 */ 1268 wakeup(&wait_for_pkt); 1269 1270 /* Wait for the pkt_manager thread to exit. */ 1271 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT, 1272 "thrwait", 0); 1273 1274 siftr_pkt_manager_thr = NULL; 1275 mtx_unlock(&siftr_pkt_mgr_mtx); 1276 1277 totalss.n_in = DPCPU_VARSUM(ss, n_in); 1278 totalss.n_out = DPCPU_VARSUM(ss, n_out); 1279 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc); 1280 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc); 1281 totalss.nskip_in_mtx = DPCPU_VARSUM(ss, nskip_in_mtx); 1282 totalss.nskip_out_mtx = DPCPU_VARSUM(ss, nskip_out_mtx); 1283 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb); 1284 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb); 1285 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb); 1286 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb); 1287 1288 total_skipped_pkts = totalss.nskip_in_malloc + 1289 totalss.nskip_out_malloc + totalss.nskip_in_mtx + 1290 totalss.nskip_out_mtx + totalss.nskip_in_tcpcb + 1291 totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb + 1292 totalss.nskip_out_inpcb; 1293 1294 microtime(&tval); 1295 1296 sbuf_printf(s, 1297 "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t" 1298 "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t" 1299 "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t" 1300 "num_outbound_skipped_pkts_malloc=%u\t" 1301 "num_inbound_skipped_pkts_mtx=%u\t" 1302 "num_outbound_skipped_pkts_mtx=%u\t" 1303 "num_inbound_skipped_pkts_tcpcb=%u\t" 1304 "num_outbound_skipped_pkts_tcpcb=%u\t" 1305 "num_inbound_skipped_pkts_inpcb=%u\t" 1306 "num_outbound_skipped_pkts_inpcb=%u\t" 1307 "total_skipped_tcp_pkts=%u\tflow_list=", 1308 (intmax_t)tval.tv_sec, 1309 tval.tv_usec, 1310 (uintmax_t)totalss.n_in, 1311 (uintmax_t)totalss.n_out, 1312 (uintmax_t)(totalss.n_in + totalss.n_out), 1313 totalss.nskip_in_malloc, 1314 totalss.nskip_out_malloc, 1315 totalss.nskip_in_mtx, 1316 totalss.nskip_out_mtx, 1317 totalss.nskip_in_tcpcb, 1318 totalss.nskip_out_tcpcb, 1319 totalss.nskip_in_inpcb, 1320 totalss.nskip_out_inpcb, 1321 total_skipped_pkts); 1322 1323 /* 1324 * Iterate over the flow hash, printing a summary of each 1325 * flow seen and freeing any malloc'd memory. 1326 * The hash consists of an array of LISTs (man 3 queue). 1327 */ 1328 for (i = 0; i <= siftr_hashmask; i++) { 1329 LIST_FOREACH_SAFE(counter, counter_hash + i, nodes, 1330 tmp_counter) { 1331 key = counter->key; 1332 key_index = 1; 1333 1334 ipver = key[0]; 1335 1336 memcpy(laddr, key + key_index, sizeof(laddr)); 1337 key_index += sizeof(laddr); 1338 memcpy(&lport, key + key_index, sizeof(lport)); 1339 key_index += sizeof(lport); 1340 memcpy(faddr, key + key_index, sizeof(faddr)); 1341 key_index += sizeof(faddr); 1342 memcpy(&fport, key + key_index, sizeof(fport)); 1343 1344 #ifdef SIFTR_IPV6 1345 laddr[3] = ntohl(laddr[3]); 1346 faddr[3] = ntohl(faddr[3]); 1347 1348 if (ipver == INP_IPV6) { 1349 laddr[0] = ntohl(laddr[0]); 1350 laddr[1] = ntohl(laddr[1]); 1351 laddr[2] = ntohl(laddr[2]); 1352 faddr[0] = ntohl(faddr[0]); 1353 faddr[1] = ntohl(faddr[1]); 1354 faddr[2] = ntohl(faddr[2]); 1355 1356 sbuf_printf(s, 1357 "%x:%x:%x:%x:%x:%x:%x:%x;%u-" 1358 "%x:%x:%x:%x:%x:%x:%x:%x;%u,", 1359 UPPER_SHORT(laddr[0]), 1360 LOWER_SHORT(laddr[0]), 1361 UPPER_SHORT(laddr[1]), 1362 LOWER_SHORT(laddr[1]), 1363 UPPER_SHORT(laddr[2]), 1364 LOWER_SHORT(laddr[2]), 1365 UPPER_SHORT(laddr[3]), 1366 LOWER_SHORT(laddr[3]), 1367 ntohs(lport), 1368 UPPER_SHORT(faddr[0]), 1369 LOWER_SHORT(faddr[0]), 1370 UPPER_SHORT(faddr[1]), 1371 LOWER_SHORT(faddr[1]), 1372 UPPER_SHORT(faddr[2]), 1373 LOWER_SHORT(faddr[2]), 1374 UPPER_SHORT(faddr[3]), 1375 LOWER_SHORT(faddr[3]), 1376 ntohs(fport)); 1377 } else { 1378 laddr[0] = FIRST_OCTET(laddr[3]); 1379 laddr[1] = SECOND_OCTET(laddr[3]); 1380 laddr[2] = THIRD_OCTET(laddr[3]); 1381 laddr[3] = FOURTH_OCTET(laddr[3]); 1382 faddr[0] = FIRST_OCTET(faddr[3]); 1383 faddr[1] = SECOND_OCTET(faddr[3]); 1384 faddr[2] = THIRD_OCTET(faddr[3]); 1385 faddr[3] = FOURTH_OCTET(faddr[3]); 1386 #endif 1387 sbuf_printf(s, 1388 "%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,", 1389 laddr[0], 1390 laddr[1], 1391 laddr[2], 1392 laddr[3], 1393 ntohs(lport), 1394 faddr[0], 1395 faddr[1], 1396 faddr[2], 1397 faddr[3], 1398 ntohs(fport)); 1399 #ifdef SIFTR_IPV6 1400 } 1401 #endif 1402 1403 free(counter, M_SIFTR_HASHNODE); 1404 } 1405 1406 LIST_INIT(counter_hash + i); 1407 } 1408 1409 sbuf_printf(s, "\n"); 1410 sbuf_finish(s); 1411 1412 i = 0; 1413 do { 1414 bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i); 1415 alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK); 1416 i += bytes_to_write; 1417 } while (i < sbuf_len(s)); 1418 1419 alq_close(siftr_alq); 1420 siftr_alq = NULL; 1421 } 1422 1423 sbuf_delete(s); 1424 1425 /* 1426 * XXX: Should be using ret to check if any functions fail 1427 * and set error appropriately 1428 */ 1429 1430 return (error); 1431 } 1432 1433 1434 static int 1435 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS) 1436 { 1437 if (req->newptr == NULL) 1438 goto skip; 1439 1440 /* If the value passed in isn't 0 or 1, return an error. */ 1441 if (CAST_PTR_INT(req->newptr) != 0 && CAST_PTR_INT(req->newptr) != 1) 1442 return (1); 1443 1444 /* If we are changing state (0 to 1 or 1 to 0). */ 1445 if (CAST_PTR_INT(req->newptr) != siftr_enabled ) 1446 if (siftr_manage_ops(CAST_PTR_INT(req->newptr))) { 1447 siftr_manage_ops(SIFTR_DISABLE); 1448 return (1); 1449 } 1450 1451 skip: 1452 return (sysctl_handle_int(oidp, arg1, arg2, req)); 1453 } 1454 1455 1456 static void 1457 siftr_shutdown_handler(void *arg) 1458 { 1459 siftr_manage_ops(SIFTR_DISABLE); 1460 } 1461 1462 1463 /* 1464 * Module is being unloaded or machine is shutting down. Take care of cleanup. 1465 */ 1466 static int 1467 deinit_siftr(void) 1468 { 1469 /* Cleanup. */ 1470 siftr_manage_ops(SIFTR_DISABLE); 1471 hashdestroy(counter_hash, M_SIFTR, siftr_hashmask); 1472 mtx_destroy(&siftr_pkt_queue_mtx); 1473 mtx_destroy(&siftr_pkt_mgr_mtx); 1474 1475 return (0); 1476 } 1477 1478 1479 /* 1480 * Module has just been loaded into the kernel. 1481 */ 1482 static int 1483 init_siftr(void) 1484 { 1485 EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL, 1486 SHUTDOWN_PRI_FIRST); 1487 1488 /* Initialise our flow counter hash table. */ 1489 counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR, 1490 &siftr_hashmask); 1491 1492 mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF); 1493 mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF); 1494 1495 /* Print message to the user's current terminal. */ 1496 uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n" 1497 " http://caia.swin.edu.au/urp/newtcp\n\n", 1498 MODVERSION_STR); 1499 1500 return (0); 1501 } 1502 1503 1504 /* 1505 * This is the function that is called to load and unload the module. 1506 * When the module is loaded, this function is called once with 1507 * "what" == MOD_LOAD 1508 * When the module is unloaded, this function is called twice with 1509 * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second 1510 * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command, 1511 * this function is called once with "what" = MOD_SHUTDOWN 1512 * When the system is shut down, the handler isn't called until the very end 1513 * of the shutdown sequence i.e. after the disks have been synced. 1514 */ 1515 static int 1516 siftr_load_handler(module_t mod, int what, void *arg) 1517 { 1518 int ret; 1519 1520 switch (what) { 1521 case MOD_LOAD: 1522 ret = init_siftr(); 1523 break; 1524 1525 case MOD_QUIESCE: 1526 case MOD_SHUTDOWN: 1527 ret = deinit_siftr(); 1528 break; 1529 1530 case MOD_UNLOAD: 1531 ret = 0; 1532 break; 1533 1534 default: 1535 ret = EINVAL; 1536 break; 1537 } 1538 1539 return (ret); 1540 } 1541 1542 1543 static moduledata_t siftr_mod = { 1544 .name = "siftr", 1545 .evhand = siftr_load_handler, 1546 }; 1547 1548 /* 1549 * Param 1: name of the kernel module 1550 * Param 2: moduledata_t struct containing info about the kernel module 1551 * and the execution entry point for the module 1552 * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h 1553 * Defines the module initialisation order 1554 * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h 1555 * Defines the initialisation order of this kld relative to others 1556 * within the same subsystem as defined by param 3 1557 */ 1558 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_SMP, SI_ORDER_ANY); 1559 MODULE_DEPEND(siftr, alq, 1, 1, 1); 1560 MODULE_VERSION(siftr, MODVERSION);
Cache object: ed8055902ce98b7423bd02c278677bb7
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