sys/netinet/siftr.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2007-2009
   5  *      Swinburne University of Technology, Melbourne, Australia.
   6  * Copyright (c) 2009-2010, The FreeBSD Foundation
   7  * All rights reserved.
   8  *
   9  * Portions of this software were developed at the Centre for Advanced
  10  * Internet Architectures, Swinburne University of Technology, Melbourne,
  11  * Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 /******************************************************
  36  * Statistical Information For TCP Research (SIFTR)
  37  *
  38  * A FreeBSD kernel module that adds very basic intrumentation to the
  39  * TCP stack, allowing internal stats to be recorded to a log file
  40  * for experimental, debugging and performance analysis purposes.
  41  *
  42  * SIFTR was first released in 2007 by James Healy and Lawrence Stewart whilst
  43  * working on the NewTCP research project at Swinburne University of
  44  * Technology's Centre for Advanced Internet Architectures, Melbourne,
  45  * Australia, which was made possible in part by a grant from the Cisco
  46  * University Research Program Fund at Community Foundation Silicon Valley.
  47  * More details are available at:
  48  *   http://caia.swin.edu.au/urp/newtcp/
  49  *
  50  * Work on SIFTR v1.2.x was sponsored by the FreeBSD Foundation as part of
  51  * the "Enhancing the FreeBSD TCP Implementation" project 2008-2009.
  52  * More details are available at:
  53  *   http://www.freebsdfoundation.org/
  54  *   http://caia.swin.edu.au/freebsd/etcp09/
  55  *
  56  * Lawrence Stewart is the current maintainer, and all contact regarding
  57  * SIFTR should be directed to him via email: lastewart@swin.edu.au
  58  *
  59  * Initial release date: June 2007
  60  * Most recent update: September 2010
  61  ******************************************************/
  62
  63 #include <sys/cdefs.h>
  64 __FBSDID("$FreeBSD$");
  65
  66 #include <sys/param.h>
  67 #include <sys/alq.h>
  68 #include <sys/errno.h>
  69 #include <sys/eventhandler.h>
  70 #include <sys/hash.h>
  71 #include <sys/kernel.h>
  72 #include <sys/kthread.h>
  73 #include <sys/lock.h>
  74 #include <sys/mbuf.h>
  75 #include <sys/module.h>
  76 #include <sys/mutex.h>
  77 #include <sys/pcpu.h>
  78 #include <sys/proc.h>
  79 #include <sys/sbuf.h>
  80 #include <sys/sdt.h>
  81 #include <sys/smp.h>
  82 #include <sys/socket.h>
  83 #include <sys/socketvar.h>
  84 #include <sys/sysctl.h>
  85 #include <sys/unistd.h>
  86
  87 #include <net/if.h>
  88 #include <net/if_var.h>
  89 #include <net/pfil.h>
  90
  91 #include <netinet/in.h>
  92 #include <netinet/in_kdtrace.h>
  93 #include <netinet/in_pcb.h>
  94 #include <netinet/in_systm.h>
  95 #include <netinet/in_var.h>
  96 #include <netinet/ip.h>
  97 #include <netinet/ip_var.h>
  98 #include <netinet/tcp_var.h>
  99
 100 #ifdef SIFTR_IPV6
 101 #include <netinet/ip6.h>
 102 #include <netinet/ip6_var.h>
 103 #include <netinet6/in6_pcb.h>
 104 #endif /* SIFTR_IPV6 */
 105
 106 #include <machine/in_cksum.h>
 107
 108 /*
 109  * Three digit version number refers to X.Y.Z where:
 110  * X is the major version number
 111  * Y is bumped to mark backwards incompatible changes
 112  * Z is bumped to mark backwards compatible changes
 113  */
 114 #define V_MAJOR         1
 115 #define V_BACKBREAK     2
 116 #define V_BACKCOMPAT    4
 117 #define MODVERSION      __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT))
 118 #define MODVERSION_STR  __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \
 119     __XSTRING(V_BACKCOMPAT)
 120
 121 #define HOOK 0
 122 #define UNHOOK 1
 123 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536
 124 #define SYS_NAME "FreeBSD"
 125 #define PACKET_TAG_SIFTR 100
 126 #define PACKET_COOKIE_SIFTR 21749576
 127 #define SIFTR_LOG_FILE_MODE 0644
 128 #define SIFTR_DISABLE 0
 129 #define SIFTR_ENABLE 1
 130
 131 /*
 132  * Hard upper limit on the length of log messages. Bump this up if you add new
 133  * data fields such that the line length could exceed the below value.
 134  */
 135 #define MAX_LOG_MSG_LEN 200
 136 /* XXX: Make this a sysctl tunable. */
 137 #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN)
 138
 139 /*
 140  * 1 byte for IP version
 141  * IPv4: src/dst IP (4+4) + src/dst port (2+2) = 12 bytes
 142  * IPv6: src/dst IP (16+16) + src/dst port (2+2) = 36 bytes
 143  */
 144 #ifdef SIFTR_IPV6
 145 #define FLOW_KEY_LEN 37
 146 #else
 147 #define FLOW_KEY_LEN 13
 148 #endif
 149
 150 #ifdef SIFTR_IPV6
 151 #define SIFTR_IPMODE 6
 152 #else
 153 #define SIFTR_IPMODE 4
 154 #endif
 155
 156 /* useful macros */
 157 #define UPPER_SHORT(X)  (((X) & 0xFFFF0000) >> 16)
 158 #define LOWER_SHORT(X)  ((X) & 0x0000FFFF)
 159
 160 #define FIRST_OCTET(X)  (((X) & 0xFF000000) >> 24)
 161 #define SECOND_OCTET(X) (((X) & 0x00FF0000) >> 16)
 162 #define THIRD_OCTET(X)  (((X) & 0x0000FF00) >> 8)
 163 #define FOURTH_OCTET(X) ((X) & 0x000000FF)
 164
 165 static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR");
 166 static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode",
 167     "SIFTR pkt_node struct");
 168 static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode",
 169     "SIFTR flow_hash_node struct");
 170
 171 /* Used as links in the pkt manager queue. */
 172 struct pkt_node {
 173         /* Timestamp of pkt as noted in the pfil hook. */
 174         struct timeval          tval;
 175         /* Direction pkt is travelling. */
 176         enum {
 177                 DIR_IN = 0,
 178                 DIR_OUT = 1,
 179         }                       direction;
 180         /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */
 181         uint8_t                 ipver;
 182         /* Hash of the pkt which triggered the log message. */
 183         uint32_t                hash;
 184         /* Local/foreign IP address. */
 185 #ifdef SIFTR_IPV6
 186         uint32_t                ip_laddr[4];
 187         uint32_t                ip_faddr[4];
 188 #else
 189         uint8_t                 ip_laddr[4];
 190         uint8_t                 ip_faddr[4];
 191 #endif
 192         /* Local TCP port. */
 193         uint16_t                tcp_localport;
 194         /* Foreign TCP port. */
 195         uint16_t                tcp_foreignport;
 196         /* Congestion Window (bytes). */
 197         u_long                  snd_cwnd;
 198         /* Sending Window (bytes). */
 199         u_long                  snd_wnd;
 200         /* Receive Window (bytes). */
 201         u_long                  rcv_wnd;
 202         /* Unused (was: Bandwidth Controlled Window (bytes)). */
 203         u_long                  snd_bwnd;
 204         /* Slow Start Threshold (bytes). */
 205         u_long                  snd_ssthresh;
 206         /* Current state of the TCP FSM. */
 207         int                     conn_state;
 208         /* Max Segment Size (bytes). */
 209         u_int                   max_seg_size;
 210         /*
 211          * Smoothed RTT stored as found in the TCP control block
 212          * in units of (TCP_RTT_SCALE*hz).
 213          */
 214         int                     smoothed_rtt;
 215         /* Is SACK enabled? */
 216         u_char                  sack_enabled;
 217         /* Window scaling for snd window. */
 218         u_char                  snd_scale;
 219         /* Window scaling for recv window. */
 220         u_char                  rcv_scale;
 221         /* TCP control block flags. */
 222         u_int                   flags;
 223         /* Retransmit timeout length. */
 224         int                     rxt_length;
 225         /* Size of the TCP send buffer in bytes. */
 226         u_int                   snd_buf_hiwater;
 227         /* Current num bytes in the send socket buffer. */
 228         u_int                   snd_buf_cc;
 229         /* Size of the TCP receive buffer in bytes. */
 230         u_int                   rcv_buf_hiwater;
 231         /* Current num bytes in the receive socket buffer. */
 232         u_int                   rcv_buf_cc;
 233         /* Number of bytes inflight that we are waiting on ACKs for. */
 234         u_int                   sent_inflight_bytes;
 235         /* Number of segments currently in the reassembly queue. */
 236         int                     t_segqlen;
 237         /* Flowid for the connection. */
 238         u_int                   flowid;
 239         /* Flow type for the connection. */
 240         u_int                   flowtype;
 241         /* Link to next pkt_node in the list. */
 242         STAILQ_ENTRY(pkt_node)  nodes;
 243 };
 244
 245 struct flow_hash_node
 246 {
 247         uint16_t counter;
 248         uint8_t key[FLOW_KEY_LEN];
 249         LIST_ENTRY(flow_hash_node) nodes;
 250 };
 251
 252 struct siftr_stats
 253 {
 254         /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */
 255         uint64_t n_in;
 256         uint64_t n_out;
 257         /* # pkts skipped due to failed malloc calls. */
 258         uint32_t nskip_in_malloc;
 259         uint32_t nskip_out_malloc;
 260         /* # pkts skipped due to failed mtx acquisition. */
 261         uint32_t nskip_in_mtx;
 262         uint32_t nskip_out_mtx;
 263         /* # pkts skipped due to failed inpcb lookups. */
 264         uint32_t nskip_in_inpcb;
 265         uint32_t nskip_out_inpcb;
 266         /* # pkts skipped due to failed tcpcb lookups. */
 267         uint32_t nskip_in_tcpcb;
 268         uint32_t nskip_out_tcpcb;
 269         /* # pkts skipped due to stack reinjection. */
 270         uint32_t nskip_in_dejavu;
 271         uint32_t nskip_out_dejavu;
 272 };
 273
 274 DPCPU_DEFINE_STATIC(struct siftr_stats, ss);
 275
 276 static volatile unsigned int siftr_exit_pkt_manager_thread = 0;
 277 static unsigned int siftr_enabled = 0;
 278 static unsigned int siftr_pkts_per_log = 1;
 279 static unsigned int siftr_generate_hashes = 0;
 280 static uint16_t     siftr_port_filter = 0;
 281 /* static unsigned int siftr_binary_log = 0; */
 282 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log";
 283 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log";
 284 static u_long siftr_hashmask;
 285 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue);
 286 LIST_HEAD(listhead, flow_hash_node) *counter_hash;
 287 static int wait_for_pkt;
 288 static struct alq *siftr_alq = NULL;
 289 static struct mtx siftr_pkt_queue_mtx;
 290 static struct mtx siftr_pkt_mgr_mtx;
 291 static struct thread *siftr_pkt_manager_thr = NULL;
 292 static char direction[2] = {'i','o'};
 293
 294 /* Required function prototypes. */
 295 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS);
 296 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS);
 297
 298
 299 /* Declare the net.inet.siftr sysctl tree and populate it. */
 300
 301 SYSCTL_DECL(_net_inet_siftr);
 302
 303 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
 304     "siftr related settings");
 305
 306 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled,
 307     CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
 308     &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU",
 309     "switch siftr module operations on/off");
 310
 311 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile,
 312     CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &siftr_logfile_shadow,
 313     sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler, "A",
 314     "file to save siftr log messages to");
 315
 316 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW,
 317     &siftr_pkts_per_log, 1,
 318     "number of packets between generating a log message");
 319
 320 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW,
 321     &siftr_generate_hashes, 0,
 322     "enable packet hash generation");
 323
 324 SYSCTL_U16(_net_inet_siftr, OID_AUTO, port_filter, CTLFLAG_RW,
 325     &siftr_port_filter, 0,
 326     "enable packet filter on a TCP port");
 327
 328 /* XXX: TODO
 329 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW,
 330     &siftr_binary_log, 0,
 331     "write log files in binary instead of ascii");
 332 */
 333
 334
 335 /* Begin functions. */
 336
 337 static void
 338 siftr_process_pkt(struct pkt_node * pkt_node)
 339 {
 340         struct flow_hash_node *hash_node;
 341         struct listhead *counter_list;
 342         struct siftr_stats *ss;
 343         struct ale *log_buf;
 344         uint8_t key[FLOW_KEY_LEN];
 345         uint8_t found_match, key_offset;
 346
 347         hash_node = NULL;
 348         ss = DPCPU_PTR(ss);
 349         found_match = 0;
 350         key_offset = 1;
 351
 352         /*
 353          * Create the key that will be used to create a hash index
 354          * into our hash table. Our key consists of:
 355          * ipversion, localip, localport, foreignip, foreignport
 356          */
 357         key[0] = pkt_node->ipver;
 358         memcpy(key + key_offset, &pkt_node->ip_laddr,
 359             sizeof(pkt_node->ip_laddr));
 360         key_offset += sizeof(pkt_node->ip_laddr);
 361         memcpy(key + key_offset, &pkt_node->tcp_localport,
 362             sizeof(pkt_node->tcp_localport));
 363         key_offset += sizeof(pkt_node->tcp_localport);
 364         memcpy(key + key_offset, &pkt_node->ip_faddr,
 365             sizeof(pkt_node->ip_faddr));
 366         key_offset += sizeof(pkt_node->ip_faddr);
 367         memcpy(key + key_offset, &pkt_node->tcp_foreignport,
 368             sizeof(pkt_node->tcp_foreignport));
 369
 370         counter_list = counter_hash +
 371             (hash32_buf(key, sizeof(key), 0) & siftr_hashmask);
 372
 373         /*
 374          * If the list is not empty i.e. the hash index has
 375          * been used by another flow previously.
 376          */
 377         if (LIST_FIRST(counter_list) != NULL) {
 378                 /*
 379                  * Loop through the hash nodes in the list.
 380                  * There should normally only be 1 hash node in the list,
 381                  * except if there have been collisions at the hash index
 382                  * computed by hash32_buf().
 383                  */
 384                 LIST_FOREACH(hash_node, counter_list, nodes) {
 385                         /*
 386                          * Check if the key for the pkt we are currently
 387                          * processing is the same as the key stored in the
 388                          * hash node we are currently processing.
 389                          * If they are the same, then we've found the
 390                          * hash node that stores the counter for the flow
 391                          * the pkt belongs to.
 392                          */
 393                         if (memcmp(hash_node->key, key, sizeof(key)) == 0) {
 394                                 found_match = 1;
 395                                 break;
 396                         }
 397                 }
 398         }
 399
 400         /* If this flow hash hasn't been seen before or we have a collision. */
 401         if (hash_node == NULL || !found_match) {
 402                 /* Create a new hash node to store the flow's counter. */
 403                 hash_node = malloc(sizeof(struct flow_hash_node),
 404                     M_SIFTR_HASHNODE, M_WAITOK);
 405
 406                 if (hash_node != NULL) {
 407                         /* Initialise our new hash node list entry. */
 408                         hash_node->counter = 0;
 409                         memcpy(hash_node->key, key, sizeof(key));
 410                         LIST_INSERT_HEAD(counter_list, hash_node, nodes);
 411                 } else {
 412                         /* Malloc failed. */
 413                         if (pkt_node->direction == DIR_IN)
 414                                 ss->nskip_in_malloc++;
 415                         else
 416                                 ss->nskip_out_malloc++;
 417
 418                         return;
 419                 }
 420         } else if (siftr_pkts_per_log > 1) {
 421                 /*
 422                  * Taking the remainder of the counter divided
 423                  * by the current value of siftr_pkts_per_log
 424                  * and storing that in counter provides a neat
 425                  * way to modulate the frequency of log
 426                  * messages being written to the log file.
 427                  */
 428                 hash_node->counter = (hash_node->counter + 1) %
 429                     siftr_pkts_per_log;
 430
 431                 /*
 432                  * If we have not seen enough packets since the last time
 433                  * we wrote a log message for this connection, return.
 434                  */
 435                 if (hash_node->counter > 0)
 436                         return;
 437         }
 438
 439         log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK);
 440
 441         if (log_buf == NULL)
 442                 return; /* Should only happen if the ALQ is shutting down. */
 443
 444 #ifdef SIFTR_IPV6
 445         pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]);
 446         pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]);
 447
 448         if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */
 449                 pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]);
 450                 pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]);
 451                 pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]);
 452                 pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]);
 453                 pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]);
 454                 pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]);
 455
 456                 /* Construct an IPv6 log message. */
 457                 log_buf->ae_bytesused = snprintf(log_buf->ae_data,
 458                     MAX_LOG_MSG_LEN,
 459                     "%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:"
 460                     "%x:%x:%x:%x:%x,%u,%ld,%ld,%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,"
 461                     "%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n",
 462                     direction[pkt_node->direction],
 463                     pkt_node->hash,
 464                     pkt_node->tval.tv_sec,
 465                     pkt_node->tval.tv_usec,
 466                     UPPER_SHORT(pkt_node->ip_laddr[0]),
 467                     LOWER_SHORT(pkt_node->ip_laddr[0]),
 468                     UPPER_SHORT(pkt_node->ip_laddr[1]),
 469                     LOWER_SHORT(pkt_node->ip_laddr[1]),
 470                     UPPER_SHORT(pkt_node->ip_laddr[2]),
 471                     LOWER_SHORT(pkt_node->ip_laddr[2]),
 472                     UPPER_SHORT(pkt_node->ip_laddr[3]),
 473                     LOWER_SHORT(pkt_node->ip_laddr[3]),
 474                     ntohs(pkt_node->tcp_localport),
 475                     UPPER_SHORT(pkt_node->ip_faddr[0]),
 476                     LOWER_SHORT(pkt_node->ip_faddr[0]),
 477                     UPPER_SHORT(pkt_node->ip_faddr[1]),
 478                     LOWER_SHORT(pkt_node->ip_faddr[1]),
 479                     UPPER_SHORT(pkt_node->ip_faddr[2]),
 480                     LOWER_SHORT(pkt_node->ip_faddr[2]),
 481                     UPPER_SHORT(pkt_node->ip_faddr[3]),
 482                     LOWER_SHORT(pkt_node->ip_faddr[3]),
 483                     ntohs(pkt_node->tcp_foreignport),
 484                     pkt_node->snd_ssthresh,
 485                     pkt_node->snd_cwnd,
 486                     pkt_node->snd_bwnd,
 487                     pkt_node->snd_wnd,
 488                     pkt_node->rcv_wnd,
 489                     pkt_node->snd_scale,
 490                     pkt_node->rcv_scale,
 491                     pkt_node->conn_state,
 492                     pkt_node->max_seg_size,
 493                     pkt_node->smoothed_rtt,
 494                     pkt_node->sack_enabled,
 495                     pkt_node->flags,
 496                     pkt_node->rxt_length,
 497                     pkt_node->snd_buf_hiwater,
 498                     pkt_node->snd_buf_cc,
 499                     pkt_node->rcv_buf_hiwater,
 500                     pkt_node->rcv_buf_cc,
 501                     pkt_node->sent_inflight_bytes,
 502                     pkt_node->t_segqlen,
 503                     pkt_node->flowid,
 504                     pkt_node->flowtype);
 505         } else { /* IPv4 packet */
 506                 pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]);
 507                 pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]);
 508                 pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]);
 509                 pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]);
 510                 pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]);
 511                 pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]);
 512                 pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]);
 513                 pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]);
 514 #endif /* SIFTR_IPV6 */
 515
 516                 /* Construct an IPv4 log message. */
 517                 log_buf->ae_bytesused = snprintf(log_buf->ae_data,
 518                     MAX_LOG_MSG_LEN,
 519                     "%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%ld,%ld,"
 520                     "%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n",
 521                     direction[pkt_node->direction],
 522                     pkt_node->hash,
 523                     (intmax_t)pkt_node->tval.tv_sec,
 524                     pkt_node->tval.tv_usec,
 525                     pkt_node->ip_laddr[0],
 526                     pkt_node->ip_laddr[1],
 527                     pkt_node->ip_laddr[2],
 528                     pkt_node->ip_laddr[3],
 529                     ntohs(pkt_node->tcp_localport),
 530                     pkt_node->ip_faddr[0],
 531                     pkt_node->ip_faddr[1],
 532                     pkt_node->ip_faddr[2],
 533                     pkt_node->ip_faddr[3],
 534                     ntohs(pkt_node->tcp_foreignport),
 535                     pkt_node->snd_ssthresh,
 536                     pkt_node->snd_cwnd,
 537                     pkt_node->snd_bwnd,
 538                     pkt_node->snd_wnd,
 539                     pkt_node->rcv_wnd,
 540                     pkt_node->snd_scale,
 541                     pkt_node->rcv_scale,
 542                     pkt_node->conn_state,
 543                     pkt_node->max_seg_size,
 544                     pkt_node->smoothed_rtt,
 545                     pkt_node->sack_enabled,
 546                     pkt_node->flags,
 547                     pkt_node->rxt_length,
 548                     pkt_node->snd_buf_hiwater,
 549                     pkt_node->snd_buf_cc,
 550                     pkt_node->rcv_buf_hiwater,
 551                     pkt_node->rcv_buf_cc,
 552                     pkt_node->sent_inflight_bytes,
 553                     pkt_node->t_segqlen,
 554                     pkt_node->flowid,
 555                     pkt_node->flowtype);
 556 #ifdef SIFTR_IPV6
 557         }
 558 #endif
 559
 560         alq_post_flags(siftr_alq, log_buf, 0);
 561 }
 562
 563
 564 static void
 565 siftr_pkt_manager_thread(void *arg)
 566 {
 567         STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue =
 568             STAILQ_HEAD_INITIALIZER(tmp_pkt_queue);
 569         struct pkt_node *pkt_node, *pkt_node_temp;
 570         uint8_t draining;
 571
 572         draining = 2;
 573
 574         mtx_lock(&siftr_pkt_mgr_mtx);
 575
 576         /* draining == 0 when queue has been flushed and it's safe to exit. */
 577         while (draining) {
 578                 /*
 579                  * Sleep until we are signalled to wake because thread has
 580                  * been told to exit or until 1 tick has passed.
 581                  */
 582                 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait",
 583                     1);
 584
 585                 /* Gain exclusive access to the pkt_node queue. */
 586                 mtx_lock(&siftr_pkt_queue_mtx);
 587
 588                 /*
 589                  * Move pkt_queue to tmp_pkt_queue, which leaves
 590                  * pkt_queue empty and ready to receive more pkt_nodes.
 591                  */
 592                 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue);
 593
 594                 /*
 595                  * We've finished making changes to the list. Unlock it
 596                  * so the pfil hooks can continue queuing pkt_nodes.
 597                  */
 598                 mtx_unlock(&siftr_pkt_queue_mtx);
 599
 600                 /*
 601                  * We can't hold a mutex whilst calling siftr_process_pkt
 602                  * because ALQ might sleep waiting for buffer space.
 603                  */
 604                 mtx_unlock(&siftr_pkt_mgr_mtx);
 605
 606                 /* Flush all pkt_nodes to the log file. */
 607                 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes,
 608                     pkt_node_temp) {
 609                         siftr_process_pkt(pkt_node);
 610                         STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes);
 611                         free(pkt_node, M_SIFTR_PKTNODE);
 612                 }
 613
 614                 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue),
 615                     ("SIFTR tmp_pkt_queue not empty after flush"));
 616
 617                 mtx_lock(&siftr_pkt_mgr_mtx);
 618
 619                 /*
 620                  * If siftr_exit_pkt_manager_thread gets set during the window
 621                  * where we are draining the tmp_pkt_queue above, there might
 622                  * still be pkts in pkt_queue that need to be drained.
 623                  * Allow one further iteration to occur after
 624                  * siftr_exit_pkt_manager_thread has been set to ensure
 625                  * pkt_queue is completely empty before we kill the thread.
 626                  *
 627                  * siftr_exit_pkt_manager_thread is set only after the pfil
 628                  * hooks have been removed, so only 1 extra iteration
 629                  * is needed to drain the queue.
 630                  */
 631                 if (siftr_exit_pkt_manager_thread)
 632                         draining--;
 633         }
 634
 635         mtx_unlock(&siftr_pkt_mgr_mtx);
 636
 637         /* Calls wakeup on this thread's struct thread ptr. */
 638         kthread_exit();
 639 }
 640
 641
 642 static uint32_t
 643 hash_pkt(struct mbuf *m, uint32_t offset)
 644 {
 645         uint32_t hash;
 646
 647         hash = 0;
 648
 649         while (m != NULL && offset > m->m_len) {
 650                 /*
 651                  * The IP packet payload does not start in this mbuf, so
 652                  * need to figure out which mbuf it starts in and what offset
 653                  * into the mbuf's data region the payload starts at.
 654                  */
 655                 offset -= m->m_len;
 656                 m = m->m_next;
 657         }
 658
 659         while (m != NULL) {
 660                 /* Ensure there is data in the mbuf */
 661                 if ((m->m_len - offset) > 0)
 662                         hash = hash32_buf(m->m_data + offset,
 663                             m->m_len - offset, hash);
 664
 665                 m = m->m_next;
 666                 offset = 0;
 667         }
 668
 669         return (hash);
 670 }
 671
 672
 673 /*
 674  * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that
 675  * it's a reinjected packet and return. If it doesn't, tag the mbuf and return.
 676  * Return value >0 means the caller should skip processing this mbuf.
 677  */
 678 static inline int
 679 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss)
 680 {
 681         if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL)
 682             != NULL) {
 683                 if (dir == PFIL_IN)
 684                         ss->nskip_in_dejavu++;
 685                 else
 686                         ss->nskip_out_dejavu++;
 687
 688                 return (1);
 689         } else {
 690                 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR,
 691                     PACKET_TAG_SIFTR, 0, M_NOWAIT);
 692                 if (tag == NULL) {
 693                         if (dir == PFIL_IN)
 694                                 ss->nskip_in_malloc++;
 695                         else
 696                                 ss->nskip_out_malloc++;
 697
 698                         return (1);
 699                 }
 700
 701                 m_tag_prepend(m, tag);
 702         }
 703
 704         return (0);
 705 }
 706
 707
 708 /*
 709  * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL
 710  * otherwise.
 711  */
 712 static inline struct inpcb *
 713 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport,
 714     uint16_t dport, int dir, struct siftr_stats *ss)
 715 {
 716         struct inpcb *inp;
 717
 718         /* We need the tcbinfo lock. */
 719         INP_INFO_WUNLOCK_ASSERT(&V_tcbinfo);
 720
 721         if (dir == PFIL_IN)
 722                 inp = (ipver == INP_IPV4 ?
 723                     in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst,
 724                     dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
 725                     :
 726 #ifdef SIFTR_IPV6
 727                     in6_pcblookup(&V_tcbinfo,
 728                     &((struct ip6_hdr *)ip)->ip6_src, sport,
 729                     &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB,
 730                     m->m_pkthdr.rcvif)
 731 #else
 732                     NULL
 733 #endif
 734                     );
 735
 736         else
 737                 inp = (ipver == INP_IPV4 ?
 738                     in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src,
 739                     sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
 740                     :
 741 #ifdef SIFTR_IPV6
 742                     in6_pcblookup(&V_tcbinfo,
 743                     &((struct ip6_hdr *)ip)->ip6_dst, dport,
 744                     &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB,
 745                     m->m_pkthdr.rcvif)
 746 #else
 747                     NULL
 748 #endif
 749                     );
 750
 751         /* If we can't find the inpcb, bail. */
 752         if (inp == NULL) {
 753                 if (dir == PFIL_IN)
 754                         ss->nskip_in_inpcb++;
 755                 else
 756                         ss->nskip_out_inpcb++;
 757         }
 758
 759         return (inp);
 760 }
 761
 762
 763 static inline void
 764 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp,
 765     int ipver, int dir, int inp_locally_locked)
 766 {
 767 #ifdef SIFTR_IPV6
 768         if (ipver == INP_IPV4) {
 769                 pn->ip_laddr[3] = inp->inp_laddr.s_addr;
 770                 pn->ip_faddr[3] = inp->inp_faddr.s_addr;
 771 #else
 772                 *((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr;
 773                 *((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr;
 774 #endif
 775 #ifdef SIFTR_IPV6
 776         } else {
 777                 pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0];
 778                 pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1];
 779                 pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2];
 780                 pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3];
 781                 pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0];
 782                 pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1];
 783                 pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2];
 784                 pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3];
 785         }
 786 #endif
 787         pn->tcp_localport = inp->inp_lport;
 788         pn->tcp_foreignport = inp->inp_fport;
 789         pn->snd_cwnd = tp->snd_cwnd;
 790         pn->snd_wnd = tp->snd_wnd;
 791         pn->rcv_wnd = tp->rcv_wnd;
 792         pn->snd_bwnd = 0;               /* Unused, kept for compat. */
 793         pn->snd_ssthresh = tp->snd_ssthresh;
 794         pn->snd_scale = tp->snd_scale;
 795         pn->rcv_scale = tp->rcv_scale;
 796         pn->conn_state = tp->t_state;
 797         pn->max_seg_size = tp->t_maxseg;
 798         pn->smoothed_rtt = tp->t_srtt;
 799         pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0;
 800         pn->flags = tp->t_flags;
 801         pn->rxt_length = tp->t_rxtcur;
 802         pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat;
 803         pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd);
 804         pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat;
 805         pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv);
 806         pn->sent_inflight_bytes = tp->snd_max - tp->snd_una;
 807         pn->t_segqlen = tp->t_segqlen;
 808         pn->flowid = inp->inp_flowid;
 809         pn->flowtype = inp->inp_flowtype;
 810
 811         /* We've finished accessing the tcb so release the lock. */
 812         if (inp_locally_locked)
 813                 INP_RUNLOCK(inp);
 814
 815         pn->ipver = ipver;
 816         pn->direction = (dir == PFIL_IN ? DIR_IN : DIR_OUT);
 817
 818         /*
 819          * Significantly more accurate than using getmicrotime(), but slower!
 820          * Gives true microsecond resolution at the expense of a hit to
 821          * maximum pps throughput processing when SIFTR is loaded and enabled.
 822          */
 823         microtime(&pn->tval);
 824         TCP_PROBE1(siftr, &pn);
 825
 826 }
 827
 828
 829 /*
 830  * pfil hook that is called for each IPv4 packet making its way through the
 831  * stack in either direction.
 832  * The pfil subsystem holds a non-sleepable mutex somewhere when
 833  * calling our hook function, so we can't sleep at all.
 834  * It's very important to use the M_NOWAIT flag with all function calls
 835  * that support it so that they won't sleep, otherwise you get a panic.
 836  */
 837 static pfil_return_t
 838 siftr_chkpkt(struct mbuf **m, struct ifnet *ifp, int flags,
 839     void *ruleset __unused, struct inpcb *inp)
 840 {
 841         struct pkt_node *pn;
 842         struct ip *ip;
 843         struct tcphdr *th;
 844         struct tcpcb *tp;
 845         struct siftr_stats *ss;
 846         unsigned int ip_hl;
 847         int inp_locally_locked, dir;
 848
 849         inp_locally_locked = 0;
 850         dir = PFIL_DIR(flags);
 851         ss = DPCPU_PTR(ss);
 852
 853         /*
 854          * m_pullup is not required here because ip_{input|output}
 855          * already do the heavy lifting for us.
 856          */
 857
 858         ip = mtod(*m, struct ip *);
 859
 860         /* Only continue processing if the packet is TCP. */
 861         if (ip->ip_p != IPPROTO_TCP)
 862                 goto ret;
 863
 864         /*
 865          * If a kernel subsystem reinjects packets into the stack, our pfil
 866          * hook will be called multiple times for the same packet.
 867          * Make sure we only process unique packets.
 868          */
 869         if (siftr_chkreinject(*m, dir, ss))
 870                 goto ret;
 871
 872         if (dir == PFIL_IN)
 873                 ss->n_in++;
 874         else
 875                 ss->n_out++;
 876
 877         /*
 878          * Create a tcphdr struct starting at the correct offset
 879          * in the IP packet. ip->ip_hl gives the ip header length
 880          * in 4-byte words, so multiply it to get the size in bytes.
 881          */
 882         ip_hl = (ip->ip_hl << 2);
 883         th = (struct tcphdr *)((caddr_t)ip + ip_hl);
 884
 885         /*
 886          * If the pfil hooks don't provide a pointer to the
 887          * inpcb, we need to find it ourselves and lock it.
 888          */
 889         if (!inp) {
 890                 /* Find the corresponding inpcb for this pkt. */
 891                 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport,
 892                     th->th_dport, dir, ss);
 893
 894                 if (inp == NULL)
 895                         goto ret;
 896                 else
 897                         inp_locally_locked = 1;
 898         }
 899
 900         INP_LOCK_ASSERT(inp);
 901
 902         /* Find the TCP control block that corresponds with this packet */
 903         tp = intotcpcb(inp);
 904
 905         /*
 906          * If we can't find the TCP control block (happens occasionaly for a
 907          * packet sent during the shutdown phase of a TCP connection),
 908          * or we're in the timewait state, bail
 909          */
 910         if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
 911                 if (dir == PFIL_IN)
 912                         ss->nskip_in_tcpcb++;
 913                 else
 914                         ss->nskip_out_tcpcb++;
 915
 916                 goto inp_unlock;
 917         }
 918
 919         /*
 920          * Only pkts selected by the tcp port filter
 921          * can be inserted into the pkt_queue
 922          */
 923         if ((siftr_port_filter != 0) &&
 924             (siftr_port_filter != ntohs(inp->inp_lport)) &&
 925             (siftr_port_filter != ntohs(inp->inp_fport))) {
 926                 goto inp_unlock;
 927         }
 928
 929         pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
 930
 931         if (pn == NULL) {
 932                 if (dir == PFIL_IN)
 933                         ss->nskip_in_malloc++;
 934                 else
 935                         ss->nskip_out_malloc++;
 936
 937                 goto inp_unlock;
 938         }
 939
 940         siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked);
 941
 942         if (siftr_generate_hashes) {
 943                 if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) {
 944                         /*
 945                          * For outbound packets, the TCP checksum isn't
 946                          * calculated yet. This is a problem for our packet
 947                          * hashing as the receiver will calc a different hash
 948                          * to ours if we don't include the correct TCP checksum
 949                          * in the bytes being hashed. To work around this
 950                          * problem, we manually calc the TCP checksum here in
 951                          * software. We unset the CSUM_TCP flag so the lower
 952                          * layers don't recalc it.
 953                          */
 954                         (*m)->m_pkthdr.csum_flags &= ~CSUM_TCP;
 955
 956                         /*
 957                          * Calculate the TCP checksum in software and assign
 958                          * to correct TCP header field, which will follow the
 959                          * packet mbuf down the stack. The trick here is that
 960                          * tcp_output() sets th->th_sum to the checksum of the
 961                          * pseudo header for us already. Because of the nature
 962                          * of the checksumming algorithm, we can sum over the
 963                          * entire IP payload (i.e. TCP header and data), which
 964                          * will include the already calculated pseduo header
 965                          * checksum, thus giving us the complete TCP checksum.
 966                          *
 967                          * To put it in simple terms, if checksum(1,2,3,4)=10,
 968                          * then checksum(1,2,3,4,5) == checksum(10,5).
 969                          * This property is what allows us to "cheat" and
 970                          * checksum only the IP payload which has the TCP
 971                          * th_sum field populated with the pseudo header's
 972                          * checksum, and not need to futz around checksumming
 973                          * pseudo header bytes and TCP header/data in one hit.
 974                          * Refer to RFC 1071 for more info.
 975                          *
 976                          * NB: in_cksum_skip(struct mbuf *m, int len, int skip)
 977                          * in_cksum_skip 2nd argument is NOT the number of
 978                          * bytes to read from the mbuf at "skip" bytes offset
 979                          * from the start of the mbuf (very counter intuitive!).
 980                          * The number of bytes to read is calculated internally
 981                          * by the function as len-skip i.e. to sum over the IP
 982                          * payload (TCP header + data) bytes, it is INCORRECT
 983                          * to call the function like this:
 984                          * in_cksum_skip(at, ip->ip_len - offset, offset)
 985                          * Rather, it should be called like this:
 986                          * in_cksum_skip(at, ip->ip_len, offset)
 987                          * which means read "ip->ip_len - offset" bytes from
 988                          * the mbuf cluster "at" at offset "offset" bytes from
 989                          * the beginning of the "at" mbuf's data pointer.
 990                          */
 991                         th->th_sum = in_cksum_skip(*m, ntohs(ip->ip_len),
 992                             ip_hl);
 993                 }
 994
 995                 /*
 996                  * XXX: Having to calculate the checksum in software and then
 997                  * hash over all bytes is really inefficient. Would be nice to
 998                  * find a way to create the hash and checksum in the same pass
 999                  * over the bytes.
1000                  */
1001                 pn->hash = hash_pkt(*m, ip_hl);
1002         }
1003
1004         mtx_lock(&siftr_pkt_queue_mtx);
1005         STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
1006         mtx_unlock(&siftr_pkt_queue_mtx);
1007         goto ret;
1008
1009 inp_unlock:
1010         if (inp_locally_locked)
1011                 INP_RUNLOCK(inp);
1012
1013 ret:
1014         return (PFIL_PASS);
1015 }
1016
1017
1018 #ifdef SIFTR_IPV6
1019 static int
1020 siftr_chkpkt6(struct mbuf **m, struct ifnet *ifp, int flags, struct inpcb *inp)
1021 {
1022         struct pkt_node *pn;
1023         struct ip6_hdr *ip6;
1024         struct tcphdr *th;
1025         struct tcpcb *tp;
1026         struct siftr_stats *ss;
1027         unsigned int ip6_hl;
1028         int inp_locally_locked, dir;
1029
1030         inp_locally_locked = 0;
1031         dir = PFIL_DIR(flags);
1032         ss = DPCPU_PTR(ss);
1033
1034         /*
1035          * m_pullup is not required here because ip6_{input|output}
1036          * already do the heavy lifting for us.
1037          */
1038
1039         ip6 = mtod(*m, struct ip6_hdr *);
1040
1041         /*
1042          * Only continue processing if the packet is TCP
1043          * XXX: We should follow the next header fields
1044          * as shown on Pg 6 RFC 2460, but right now we'll
1045          * only check pkts that have no extension headers.
1046          */
1047         if (ip6->ip6_nxt != IPPROTO_TCP)
1048                 goto ret6;
1049
1050         /*
1051          * If a kernel subsystem reinjects packets into the stack, our pfil
1052          * hook will be called multiple times for the same packet.
1053          * Make sure we only process unique packets.
1054          */
1055         if (siftr_chkreinject(*m, dir, ss))
1056                 goto ret6;
1057
1058         if (dir == PFIL_IN)
1059                 ss->n_in++;
1060         else
1061                 ss->n_out++;
1062
1063         ip6_hl = sizeof(struct ip6_hdr);
1064
1065         /*
1066          * Create a tcphdr struct starting at the correct offset
1067          * in the ipv6 packet. ip->ip_hl gives the ip header length
1068          * in 4-byte words, so multiply it to get the size in bytes.
1069          */
1070         th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl);
1071
1072         /*
1073          * For inbound packets, the pfil hooks don't provide a pointer to the
1074          * inpcb, so we need to find it ourselves and lock it.
1075          */
1076         if (!inp) {
1077                 /* Find the corresponding inpcb for this pkt. */
1078                 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m,
1079                     th->th_sport, th->th_dport, dir, ss);
1080
1081                 if (inp == NULL)
1082                         goto ret6;
1083                 else
1084                         inp_locally_locked = 1;
1085         }
1086
1087         /* Find the TCP control block that corresponds with this packet. */
1088         tp = intotcpcb(inp);
1089
1090         /*
1091          * If we can't find the TCP control block (happens occasionaly for a
1092          * packet sent during the shutdown phase of a TCP connection),
1093          * or we're in the timewait state, bail.
1094          */
1095         if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
1096                 if (dir == PFIL_IN)
1097                         ss->nskip_in_tcpcb++;
1098                 else
1099                         ss->nskip_out_tcpcb++;
1100
1101                 goto inp_unlock6;
1102         }
1103
1104         /*
1105          * Only pkts selected by the tcp port filter
1106          * can be inserted into the pkt_queue
1107          */
1108         if ((siftr_port_filter != 0) &&
1109             (siftr_port_filter != ntohs(inp->inp_lport)) &&
1110             (siftr_port_filter != ntohs(inp->inp_fport))) {
1111                 goto inp_unlock6;
1112         }
1113
1114         pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
1115
1116         if (pn == NULL) {
1117                 if (dir == PFIL_IN)
1118                         ss->nskip_in_malloc++;
1119                 else
1120                         ss->nskip_out_malloc++;
1121
1122                 goto inp_unlock6;
1123         }
1124
1125         siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked);
1126
1127         /* XXX: Figure out how to generate hashes for IPv6 packets. */
1128
1129         mtx_lock(&siftr_pkt_queue_mtx);
1130         STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
1131         mtx_unlock(&siftr_pkt_queue_mtx);
1132         goto ret6;
1133
1134 inp_unlock6:
1135         if (inp_locally_locked)
1136                 INP_RUNLOCK(inp);
1137
1138 ret6:
1139         /* Returning 0 ensures pfil will not discard the pkt. */
1140         return (0);
1141 }
1142 #endif /* #ifdef SIFTR_IPV6 */
1143
1144 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet_hook);
1145 #define V_siftr_inet_hook       VNET(siftr_inet_hook)
1146 #ifdef INET6
1147 VNET_DEFINE_STATIC(pfil_hook_t, siftr_inet6_hook);
1148 #define V_siftr_inet6_hook      VNET(siftr_inet6_hook)
1149 #endif
1150 static int
1151 siftr_pfil(int action)
1152 {
1153         struct pfil_hook_args pha;
1154         struct pfil_link_args pla;
1155
1156         pha.pa_version = PFIL_VERSION;
1157         pha.pa_flags = PFIL_IN | PFIL_OUT;
1158         pha.pa_modname = "siftr";
1159         pha.pa_ruleset = NULL;
1160         pha.pa_rulname = "default";
1161
1162         pla.pa_version = PFIL_VERSION;
1163         pla.pa_flags = PFIL_IN | PFIL_OUT |
1164             PFIL_HEADPTR | PFIL_HOOKPTR;
1165
1166         VNET_ITERATOR_DECL(vnet_iter);
1167
1168         VNET_LIST_RLOCK();
1169         VNET_FOREACH(vnet_iter) {
1170                 CURVNET_SET(vnet_iter);
1171
1172                 if (action == HOOK) {
1173                         pha.pa_func = siftr_chkpkt;
1174                         pha.pa_type = PFIL_TYPE_IP4;
1175                         V_siftr_inet_hook = pfil_add_hook(&pha);
1176                         pla.pa_hook = V_siftr_inet_hook;
1177                         pla.pa_head = V_inet_pfil_head;
1178                         (void)pfil_link(&pla);
1179 #ifdef SIFTR_IPV6
1180                         pha.pa_func = siftr_chkpkt6;
1181                         pha.pa_type = PFIL_TYPE_IP6;
1182                         V_siftr_inet6_hook = pfil_add_hook(&pha);
1183                         pla.pa_hook = V_siftr_inet6_hook;
1184                         pla.pa_head = V_inet6_pfil_head;
1185                         (void)pfil_link(&pla);
1186 #endif
1187                 } else if (action == UNHOOK) {
1188                         pfil_remove_hook(V_siftr_inet_hook);
1189 #ifdef SIFTR_IPV6
1190                         pfil_remove_hook(V_siftr_inet6_hook);
1191 #endif
1192                 }
1193                 CURVNET_RESTORE();
1194         }
1195         VNET_LIST_RUNLOCK();
1196
1197         return (0);
1198 }
1199
1200
1201 static int
1202 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS)
1203 {
1204         struct alq *new_alq;
1205         int error;
1206
1207         error = sysctl_handle_string(oidp, arg1, arg2, req);
1208
1209         /* Check for error or same filename */
1210         if (error != 0 || req->newptr == NULL ||
1211             strncmp(siftr_logfile, arg1, arg2) == 0)
1212                 goto done;
1213
1214         /* Filname changed */
1215         error = alq_open(&new_alq, arg1, curthread->td_ucred,
1216             SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1217         if (error != 0)
1218                 goto done;
1219
1220         /*
1221          * If disabled, siftr_alq == NULL so we simply close
1222          * the alq as we've proved it can be opened.
1223          * If enabled, close the existing alq and switch the old
1224          * for the new.
1225          */
1226         if (siftr_alq == NULL) {
1227                 alq_close(new_alq);
1228         } else {
1229                 alq_close(siftr_alq);
1230                 siftr_alq = new_alq;
1231         }
1232
1233         /* Update filename upon success */
1234         strlcpy(siftr_logfile, arg1, arg2);
1235 done:
1236         return (error);
1237 }
1238
1239 static int
1240 siftr_manage_ops(uint8_t action)
1241 {
1242         struct siftr_stats totalss;
1243         struct timeval tval;
1244         struct flow_hash_node *counter, *tmp_counter;
1245         struct sbuf *s;
1246         int i, key_index, error;
1247         uint32_t bytes_to_write, total_skipped_pkts;
1248         uint16_t lport, fport;
1249         uint8_t *key, ipver __unused;
1250
1251 #ifdef SIFTR_IPV6
1252         uint32_t laddr[4];
1253         uint32_t faddr[4];
1254 #else
1255         uint8_t laddr[4];
1256         uint8_t faddr[4];
1257 #endif
1258
1259         error = 0;
1260         total_skipped_pkts = 0;
1261
1262         /* Init an autosizing sbuf that initially holds 200 chars. */
1263         if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL)
1264                 return (-1);
1265
1266         if (action == SIFTR_ENABLE && siftr_pkt_manager_thr == NULL) {
1267                 /*
1268                  * Create our alq
1269                  * XXX: We should abort if alq_open fails!
1270                  */
1271                 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred,
1272                     SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1273
1274                 STAILQ_INIT(&pkt_queue);
1275
1276                 DPCPU_ZERO(ss);
1277
1278                 siftr_exit_pkt_manager_thread = 0;
1279
1280                 kthread_add(&siftr_pkt_manager_thread, NULL, NULL,
1281                     &siftr_pkt_manager_thr, RFNOWAIT, 0,
1282                     "siftr_pkt_manager_thr");
1283
1284                 siftr_pfil(HOOK);
1285
1286                 microtime(&tval);
1287
1288                 sbuf_printf(s,
1289                     "enable_time_secs=%jd\tenable_time_usecs=%06ld\t"
1290                     "siftrver=%s\thz=%u\ttcp_rtt_scale=%u\tsysname=%s\t"
1291                     "sysver=%u\tipmode=%u\n",
1292                     (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, hz,
1293                     TCP_RTT_SCALE, SYS_NAME, __FreeBSD_version, SIFTR_IPMODE);
1294
1295                 sbuf_finish(s);
1296                 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK);
1297
1298         } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) {
1299                 /*
1300                  * Remove the pfil hook functions. All threads currently in
1301                  * the hook functions are allowed to exit before siftr_pfil()
1302                  * returns.
1303                  */
1304                 siftr_pfil(UNHOOK);
1305
1306                 /* This will block until the pkt manager thread unlocks it. */
1307                 mtx_lock(&siftr_pkt_mgr_mtx);
1308
1309                 /* Tell the pkt manager thread that it should exit now. */
1310                 siftr_exit_pkt_manager_thread = 1;
1311
1312                 /*
1313                  * Wake the pkt_manager thread so it realises that
1314                  * siftr_exit_pkt_manager_thread == 1 and exits gracefully.
1315                  * The wakeup won't be delivered until we unlock
1316                  * siftr_pkt_mgr_mtx so this isn't racy.
1317                  */
1318                 wakeup(&wait_for_pkt);
1319
1320                 /* Wait for the pkt_manager thread to exit. */
1321                 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT,
1322                     "thrwait", 0);
1323
1324                 siftr_pkt_manager_thr = NULL;
1325                 mtx_unlock(&siftr_pkt_mgr_mtx);
1326
1327                 totalss.n_in = DPCPU_VARSUM(ss, n_in);
1328                 totalss.n_out = DPCPU_VARSUM(ss, n_out);
1329                 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc);
1330                 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc);
1331                 totalss.nskip_in_mtx = DPCPU_VARSUM(ss, nskip_in_mtx);
1332                 totalss.nskip_out_mtx = DPCPU_VARSUM(ss, nskip_out_mtx);
1333                 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb);
1334                 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb);
1335                 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb);
1336                 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb);
1337
1338                 total_skipped_pkts = totalss.nskip_in_malloc +
1339                     totalss.nskip_out_malloc + totalss.nskip_in_mtx +
1340                     totalss.nskip_out_mtx + totalss.nskip_in_tcpcb +
1341                     totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb +
1342                     totalss.nskip_out_inpcb;
1343
1344                 microtime(&tval);
1345
1346                 sbuf_printf(s,
1347                     "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t"
1348                     "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t"
1349                     "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t"
1350                     "num_outbound_skipped_pkts_malloc=%u\t"
1351                     "num_inbound_skipped_pkts_mtx=%u\t"
1352                     "num_outbound_skipped_pkts_mtx=%u\t"
1353                     "num_inbound_skipped_pkts_tcpcb=%u\t"
1354                     "num_outbound_skipped_pkts_tcpcb=%u\t"
1355                     "num_inbound_skipped_pkts_inpcb=%u\t"
1356                     "num_outbound_skipped_pkts_inpcb=%u\t"
1357                     "total_skipped_tcp_pkts=%u\tflow_list=",
1358                     (intmax_t)tval.tv_sec,
1359                     tval.tv_usec,
1360                     (uintmax_t)totalss.n_in,
1361                     (uintmax_t)totalss.n_out,
1362                     (uintmax_t)(totalss.n_in + totalss.n_out),
1363                     totalss.nskip_in_malloc,
1364                     totalss.nskip_out_malloc,
1365                     totalss.nskip_in_mtx,
1366                     totalss.nskip_out_mtx,
1367                     totalss.nskip_in_tcpcb,
1368                     totalss.nskip_out_tcpcb,
1369                     totalss.nskip_in_inpcb,
1370                     totalss.nskip_out_inpcb,
1371                     total_skipped_pkts);
1372
1373                 /*
1374                  * Iterate over the flow hash, printing a summary of each
1375                  * flow seen and freeing any malloc'd memory.
1376                  * The hash consists of an array of LISTs (man 3 queue).
1377                  */
1378                 for (i = 0; i <= siftr_hashmask; i++) {
1379                         LIST_FOREACH_SAFE(counter, counter_hash + i, nodes,
1380                             tmp_counter) {
1381                                 key = counter->key;
1382                                 key_index = 1;
1383
1384                                 ipver = key[0];
1385
1386                                 memcpy(laddr, key + key_index, sizeof(laddr));
1387                                 key_index += sizeof(laddr);
1388                                 memcpy(&lport, key + key_index, sizeof(lport));
1389                                 key_index += sizeof(lport);
1390                                 memcpy(faddr, key + key_index, sizeof(faddr));
1391                                 key_index += sizeof(faddr);
1392                                 memcpy(&fport, key + key_index, sizeof(fport));
1393
1394 #ifdef SIFTR_IPV6
1395                                 laddr[3] = ntohl(laddr[3]);
1396                                 faddr[3] = ntohl(faddr[3]);
1397
1398                                 if (ipver == INP_IPV6) {
1399                                         laddr[0] = ntohl(laddr[0]);
1400                                         laddr[1] = ntohl(laddr[1]);
1401                                         laddr[2] = ntohl(laddr[2]);
1402                                         faddr[0] = ntohl(faddr[0]);
1403                                         faddr[1] = ntohl(faddr[1]);
1404                                         faddr[2] = ntohl(faddr[2]);
1405
1406                                         sbuf_printf(s,
1407                                             "%x:%x:%x:%x:%x:%x:%x:%x;%u-"
1408                                             "%x:%x:%x:%x:%x:%x:%x:%x;%u,",
1409                                             UPPER_SHORT(laddr[0]),
1410                                             LOWER_SHORT(laddr[0]),
1411                                             UPPER_SHORT(laddr[1]),
1412                                             LOWER_SHORT(laddr[1]),
1413                                             UPPER_SHORT(laddr[2]),
1414                                             LOWER_SHORT(laddr[2]),
1415                                             UPPER_SHORT(laddr[3]),
1416                                             LOWER_SHORT(laddr[3]),
1417                                             ntohs(lport),
1418                                             UPPER_SHORT(faddr[0]),
1419                                             LOWER_SHORT(faddr[0]),
1420                                             UPPER_SHORT(faddr[1]),
1421                                             LOWER_SHORT(faddr[1]),
1422                                             UPPER_SHORT(faddr[2]),
1423                                             LOWER_SHORT(faddr[2]),
1424                                             UPPER_SHORT(faddr[3]),
1425                                             LOWER_SHORT(faddr[3]),
1426                                             ntohs(fport));
1427                                 } else {
1428                                         laddr[0] = FIRST_OCTET(laddr[3]);
1429                                         laddr[1] = SECOND_OCTET(laddr[3]);
1430                                         laddr[2] = THIRD_OCTET(laddr[3]);
1431                                         laddr[3] = FOURTH_OCTET(laddr[3]);
1432                                         faddr[0] = FIRST_OCTET(faddr[3]);
1433                                         faddr[1] = SECOND_OCTET(faddr[3]);
1434                                         faddr[2] = THIRD_OCTET(faddr[3]);
1435                                         faddr[3] = FOURTH_OCTET(faddr[3]);
1436 #endif
1437                                         sbuf_printf(s,
1438                                             "%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,",
1439                                             laddr[0],
1440                                             laddr[1],
1441                                             laddr[2],
1442                                             laddr[3],
1443                                             ntohs(lport),
1444                                             faddr[0],
1445                                             faddr[1],
1446                                             faddr[2],
1447                                             faddr[3],
1448                                             ntohs(fport));
1449 #ifdef SIFTR_IPV6
1450                                 }
1451 #endif
1452
1453                                 free(counter, M_SIFTR_HASHNODE);
1454                         }
1455
1456                         LIST_INIT(counter_hash + i);
1457                 }
1458
1459                 sbuf_printf(s, "\n");
1460                 sbuf_finish(s);
1461
1462                 i = 0;
1463                 do {
1464                         bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i);
1465                         alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK);
1466                         i += bytes_to_write;
1467                 } while (i < sbuf_len(s));
1468
1469                 alq_close(siftr_alq);
1470                 siftr_alq = NULL;
1471         } else
1472                 error = EINVAL;
1473
1474         sbuf_delete(s);
1475
1476         /*
1477          * XXX: Should be using ret to check if any functions fail
1478          * and set error appropriately
1479          */
1480
1481         return (error);
1482 }
1483
1484
1485 static int
1486 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS)
1487 {
1488         int error;
1489         uint32_t new;
1490
1491         new = siftr_enabled;
1492         error = sysctl_handle_int(oidp, &new, 0, req);
1493         if (error == 0 && req->newptr != NULL) {
1494                 if (new > 1)
1495                         return (EINVAL);
1496                 else if (new != siftr_enabled) {
1497                         if ((error = siftr_manage_ops(new)) == 0) {
1498                                 siftr_enabled = new;
1499                         } else {
1500                                 siftr_manage_ops(SIFTR_DISABLE);
1501                         }
1502                 }
1503         }
1504
1505         return (error);
1506 }
1507
1508
1509 static void
1510 siftr_shutdown_handler(void *arg)
1511 {
1512         if (siftr_enabled == 1) {
1513                 siftr_manage_ops(SIFTR_DISABLE);
1514         }
1515 }
1516
1517
1518 /*
1519  * Module is being unloaded or machine is shutting down. Take care of cleanup.
1520  */
1521 static int
1522 deinit_siftr(void)
1523 {
1524         /* Cleanup. */
1525         siftr_manage_ops(SIFTR_DISABLE);
1526         hashdestroy(counter_hash, M_SIFTR, siftr_hashmask);
1527         mtx_destroy(&siftr_pkt_queue_mtx);
1528         mtx_destroy(&siftr_pkt_mgr_mtx);
1529
1530         return (0);
1531 }
1532
1533
1534 /*
1535  * Module has just been loaded into the kernel.
1536  */
1537 static int
1538 init_siftr(void)
1539 {
1540         EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL,
1541             SHUTDOWN_PRI_FIRST);
1542
1543         /* Initialise our flow counter hash table. */
1544         counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR,
1545             &siftr_hashmask);
1546
1547         mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF);
1548         mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF);
1549
1550         /* Print message to the user's current terminal. */
1551         uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n"
1552             "          http://caia.swin.edu.au/urp/newtcp\n\n",
1553             MODVERSION_STR);
1554
1555         return (0);
1556 }
1557
1558
1559 /*
1560  * This is the function that is called to load and unload the module.
1561  * When the module is loaded, this function is called once with
1562  * "what" == MOD_LOAD
1563  * When the module is unloaded, this function is called twice with
1564  * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second
1565  * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command,
1566  * this function is called once with "what" = MOD_SHUTDOWN
1567  * When the system is shut down, the handler isn't called until the very end
1568  * of the shutdown sequence i.e. after the disks have been synced.
1569  */
1570 static int
1571 siftr_load_handler(module_t mod, int what, void *arg)
1572 {
1573         int ret;
1574
1575         switch (what) {
1576         case MOD_LOAD:
1577                 ret = init_siftr();
1578                 break;
1579
1580         case MOD_QUIESCE:
1581         case MOD_SHUTDOWN:
1582                 ret = deinit_siftr();
1583                 break;
1584
1585         case MOD_UNLOAD:
1586                 ret = 0;
1587                 break;
1588
1589         default:
1590                 ret = EINVAL;
1591                 break;
1592         }
1593
1594         return (ret);
1595 }
1596
1597
1598 static moduledata_t siftr_mod = {
1599         .name = "siftr",
1600         .evhand = siftr_load_handler,
1601 };
1602
1603 /*
1604  * Param 1: name of the kernel module
1605  * Param 2: moduledata_t struct containing info about the kernel module
1606  *          and the execution entry point for the module
1607  * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h
1608  *          Defines the module initialisation order
1609  * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h
1610  *          Defines the initialisation order of this kld relative to others
1611  *          within the same subsystem as defined by param 3
1612  */
1613 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY);
1614 MODULE_DEPEND(siftr, alq, 1, 1, 1);
1615 MODULE_VERSION(siftr, MODVERSION);