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/tcp_var.h>
  98
  99 #ifdef SIFTR_IPV6
 100 #include <netinet/ip6.h>
 101 #include <netinet6/in6_pcb.h>
 102 #endif /* SIFTR_IPV6 */
 103
 104 #include <machine/in_cksum.h>
 105
 106 /*
 107  * Three digit version number refers to X.Y.Z where:
 108  * X is the major version number
 109  * Y is bumped to mark backwards incompatible changes
 110  * Z is bumped to mark backwards compatible changes
 111  */
 112 #define V_MAJOR         1
 113 #define V_BACKBREAK     2
 114 #define V_BACKCOMPAT    4
 115 #define MODVERSION      __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT))
 116 #define MODVERSION_STR  __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \
 117     __XSTRING(V_BACKCOMPAT)
 118
 119 #define HOOK 0
 120 #define UNHOOK 1
 121 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536
 122 #define SYS_NAME "FreeBSD"
 123 #define PACKET_TAG_SIFTR 100
 124 #define PACKET_COOKIE_SIFTR 21749576
 125 #define SIFTR_LOG_FILE_MODE 0644
 126 #define SIFTR_DISABLE 0
 127 #define SIFTR_ENABLE 1
 128
 129 /*
 130  * Hard upper limit on the length of log messages. Bump this up if you add new
 131  * data fields such that the line length could exceed the below value.
 132  */
 133 #define MAX_LOG_MSG_LEN 200
 134 /* XXX: Make this a sysctl tunable. */
 135 #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN)
 136
 137 /*
 138  * 1 byte for IP version
 139  * IPv4: src/dst IP (4+4) + src/dst port (2+2) = 12 bytes
 140  * IPv6: src/dst IP (16+16) + src/dst port (2+2) = 36 bytes
 141  */
 142 #ifdef SIFTR_IPV6
 143 #define FLOW_KEY_LEN 37
 144 #else
 145 #define FLOW_KEY_LEN 13
 146 #endif
 147
 148 #ifdef SIFTR_IPV6
 149 #define SIFTR_IPMODE 6
 150 #else
 151 #define SIFTR_IPMODE 4
 152 #endif
 153
 154 /* useful macros */
 155 #define CAST_PTR_INT(X) (*((int*)(X)))
 156
 157 #define UPPER_SHORT(X)  (((X) & 0xFFFF0000) >> 16)
 158 #define LOWER_SHORT(X)  ((X) & 0x0000FFFF)
 159
 160 #define FIRST_OCTET(X)  (((X) & 0xFF000000) >> 24)
 161 #define SECOND_OCTET(X) (((X) & 0x00FF0000) >> 16)
 162 #define THIRD_OCTET(X)  (((X) & 0x0000FF00) >> 8)
 163 #define FOURTH_OCTET(X) ((X) & 0x000000FF)
 164
 165 static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR");
 166 static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode",
 167     "SIFTR pkt_node struct");
 168 static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode",
 169     "SIFTR flow_hash_node struct");
 170
 171 /* Used as links in the pkt manager queue. */
 172 struct pkt_node {
 173         /* Timestamp of pkt as noted in the pfil hook. */
 174         struct timeval          tval;
 175         /* Direction pkt is travelling; either PFIL_IN or PFIL_OUT. */
 176         uint8_t                 direction;
 177         /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */
 178         uint8_t                 ipver;
 179         /* Hash of the pkt which triggered the log message. */
 180         uint32_t                hash;
 181         /* Local/foreign IP address. */
 182 #ifdef SIFTR_IPV6
 183         uint32_t                ip_laddr[4];
 184         uint32_t                ip_faddr[4];
 185 #else
 186         uint8_t                 ip_laddr[4];
 187         uint8_t                 ip_faddr[4];
 188 #endif
 189         /* Local TCP port. */
 190         uint16_t                tcp_localport;
 191         /* Foreign TCP port. */
 192         uint16_t                tcp_foreignport;
 193         /* Congestion Window (bytes). */
 194         u_long                  snd_cwnd;
 195         /* Sending Window (bytes). */
 196         u_long                  snd_wnd;
 197         /* Receive Window (bytes). */
 198         u_long                  rcv_wnd;
 199         /* Unused (was: Bandwidth Controlled Window (bytes)). */
 200         u_long                  snd_bwnd;
 201         /* Slow Start Threshold (bytes). */
 202         u_long                  snd_ssthresh;
 203         /* Current state of the TCP FSM. */
 204         int                     conn_state;
 205         /* Max Segment Size (bytes). */
 206         u_int                   max_seg_size;
 207         /*
 208          * Smoothed RTT stored as found in the TCP control block
 209          * in units of (TCP_RTT_SCALE*hz).
 210          */
 211         int                     smoothed_rtt;
 212         /* Is SACK enabled? */
 213         u_char                  sack_enabled;
 214         /* Window scaling for snd window. */
 215         u_char                  snd_scale;
 216         /* Window scaling for recv window. */
 217         u_char                  rcv_scale;
 218         /* TCP control block flags. */
 219         u_int                   flags;
 220         /* Retransmit timeout length. */
 221         int                     rxt_length;
 222         /* Size of the TCP send buffer in bytes. */
 223         u_int                   snd_buf_hiwater;
 224         /* Current num bytes in the send socket buffer. */
 225         u_int                   snd_buf_cc;
 226         /* Size of the TCP receive buffer in bytes. */
 227         u_int                   rcv_buf_hiwater;
 228         /* Current num bytes in the receive socket buffer. */
 229         u_int                   rcv_buf_cc;
 230         /* Number of bytes inflight that we are waiting on ACKs for. */
 231         u_int                   sent_inflight_bytes;
 232         /* Number of segments currently in the reassembly queue. */
 233         int                     t_segqlen;
 234         /* Flowid for the connection. */
 235         u_int                   flowid;
 236         /* Flow type for the connection. */
 237         u_int                   flowtype;
 238         /* Link to next pkt_node in the list. */
 239         STAILQ_ENTRY(pkt_node)  nodes;
 240 };
 241
 242 struct flow_hash_node
 243 {
 244         uint16_t counter;
 245         uint8_t key[FLOW_KEY_LEN];
 246         LIST_ENTRY(flow_hash_node) nodes;
 247 };
 248
 249 struct siftr_stats
 250 {
 251         /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */
 252         uint64_t n_in;
 253         uint64_t n_out;
 254         /* # pkts skipped due to failed malloc calls. */
 255         uint32_t nskip_in_malloc;
 256         uint32_t nskip_out_malloc;
 257         /* # pkts skipped due to failed mtx acquisition. */
 258         uint32_t nskip_in_mtx;
 259         uint32_t nskip_out_mtx;
 260         /* # pkts skipped due to failed inpcb lookups. */
 261         uint32_t nskip_in_inpcb;
 262         uint32_t nskip_out_inpcb;
 263         /* # pkts skipped due to failed tcpcb lookups. */
 264         uint32_t nskip_in_tcpcb;
 265         uint32_t nskip_out_tcpcb;
 266         /* # pkts skipped due to stack reinjection. */
 267         uint32_t nskip_in_dejavu;
 268         uint32_t nskip_out_dejavu;
 269 };
 270
 271 DPCPU_DEFINE_STATIC(struct siftr_stats, ss);
 272
 273 static volatile unsigned int siftr_exit_pkt_manager_thread = 0;
 274 static unsigned int siftr_enabled = 0;
 275 static unsigned int siftr_pkts_per_log = 1;
 276 static unsigned int siftr_generate_hashes = 0;
 277 /* static unsigned int siftr_binary_log = 0; */
 278 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log";
 279 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log";
 280 static u_long siftr_hashmask;
 281 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue);
 282 LIST_HEAD(listhead, flow_hash_node) *counter_hash;
 283 static int wait_for_pkt;
 284 static struct alq *siftr_alq = NULL;
 285 static struct mtx siftr_pkt_queue_mtx;
 286 static struct mtx siftr_pkt_mgr_mtx;
 287 static struct thread *siftr_pkt_manager_thr = NULL;
 288 /*
 289  * pfil.h defines PFIL_IN as 1 and PFIL_OUT as 2,
 290  * which we use as an index into this array.
 291  */
 292 static char direction[3] = {'\0', 'i','o'};
 293
 294 /* Required function prototypes. */
 295 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS);
 296 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS);
 297
 298
 299 /* Declare the net.inet.siftr sysctl tree and populate it. */
 300
 301 SYSCTL_DECL(_net_inet_siftr);
 302
 303 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW, NULL,
 304     "siftr related settings");
 305
 306 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, CTLTYPE_UINT|CTLFLAG_RW,
 307     &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU",
 308     "switch siftr module operations on/off");
 309
 310 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, CTLTYPE_STRING|CTLFLAG_RW,
 311     &siftr_logfile_shadow, sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler,
 312     "A", "file to save siftr log messages to");
 313
 314 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW,
 315     &siftr_pkts_per_log, 1,
 316     "number of packets between generating a log message");
 317
 318 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW,
 319     &siftr_generate_hashes, 0,
 320     "enable packet hash generation");
 321
 322 /* XXX: TODO
 323 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW,
 324     &siftr_binary_log, 0,
 325     "write log files in binary instead of ascii");
 326 */
 327
 328
 329 /* Begin functions. */
 330
 331 static void
 332 siftr_process_pkt(struct pkt_node * pkt_node)
 333 {
 334         struct flow_hash_node *hash_node;
 335         struct listhead *counter_list;
 336         struct siftr_stats *ss;
 337         struct ale *log_buf;
 338         uint8_t key[FLOW_KEY_LEN];
 339         uint8_t found_match, key_offset;
 340
 341         hash_node = NULL;
 342         ss = DPCPU_PTR(ss);
 343         found_match = 0;
 344         key_offset = 1;
 345
 346         /*
 347          * Create the key that will be used to create a hash index
 348          * into our hash table. Our key consists of:
 349          * ipversion, localip, localport, foreignip, foreignport
 350          */
 351         key[0] = pkt_node->ipver;
 352         memcpy(key + key_offset, &pkt_node->ip_laddr,
 353             sizeof(pkt_node->ip_laddr));
 354         key_offset += sizeof(pkt_node->ip_laddr);
 355         memcpy(key + key_offset, &pkt_node->tcp_localport,
 356             sizeof(pkt_node->tcp_localport));
 357         key_offset += sizeof(pkt_node->tcp_localport);
 358         memcpy(key + key_offset, &pkt_node->ip_faddr,
 359             sizeof(pkt_node->ip_faddr));
 360         key_offset += sizeof(pkt_node->ip_faddr);
 361         memcpy(key + key_offset, &pkt_node->tcp_foreignport,
 362             sizeof(pkt_node->tcp_foreignport));
 363
 364         counter_list = counter_hash +
 365             (hash32_buf(key, sizeof(key), 0) & siftr_hashmask);
 366
 367         /*
 368          * If the list is not empty i.e. the hash index has
 369          * been used by another flow previously.
 370          */
 371         if (LIST_FIRST(counter_list) != NULL) {
 372                 /*
 373                  * Loop through the hash nodes in the list.
 374                  * There should normally only be 1 hash node in the list,
 375                  * except if there have been collisions at the hash index
 376                  * computed by hash32_buf().
 377                  */
 378                 LIST_FOREACH(hash_node, counter_list, nodes) {
 379                         /*
 380                          * Check if the key for the pkt we are currently
 381                          * processing is the same as the key stored in the
 382                          * hash node we are currently processing.
 383                          * If they are the same, then we've found the
 384                          * hash node that stores the counter for the flow
 385                          * the pkt belongs to.
 386                          */
 387                         if (memcmp(hash_node->key, key, sizeof(key)) == 0) {
 388                                 found_match = 1;
 389                                 break;
 390                         }
 391                 }
 392         }
 393
 394         /* If this flow hash hasn't been seen before or we have a collision. */
 395         if (hash_node == NULL || !found_match) {
 396                 /* Create a new hash node to store the flow's counter. */
 397                 hash_node = malloc(sizeof(struct flow_hash_node),
 398                     M_SIFTR_HASHNODE, M_WAITOK);
 399
 400                 if (hash_node != NULL) {
 401                         /* Initialise our new hash node list entry. */
 402                         hash_node->counter = 0;
 403                         memcpy(hash_node->key, key, sizeof(key));
 404                         LIST_INSERT_HEAD(counter_list, hash_node, nodes);
 405                 } else {
 406                         /* Malloc failed. */
 407                         if (pkt_node->direction == PFIL_IN)
 408                                 ss->nskip_in_malloc++;
 409                         else
 410                                 ss->nskip_out_malloc++;
 411
 412                         return;
 413                 }
 414         } else if (siftr_pkts_per_log > 1) {
 415                 /*
 416                  * Taking the remainder of the counter divided
 417                  * by the current value of siftr_pkts_per_log
 418                  * and storing that in counter provides a neat
 419                  * way to modulate the frequency of log
 420                  * messages being written to the log file.
 421                  */
 422                 hash_node->counter = (hash_node->counter + 1) %
 423                     siftr_pkts_per_log;
 424
 425                 /*
 426                  * If we have not seen enough packets since the last time
 427                  * we wrote a log message for this connection, return.
 428                  */
 429                 if (hash_node->counter > 0)
 430                         return;
 431         }
 432
 433         log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK);
 434
 435         if (log_buf == NULL)
 436                 return; /* Should only happen if the ALQ is shutting down. */
 437
 438 #ifdef SIFTR_IPV6
 439         pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]);
 440         pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]);
 441
 442         if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */
 443                 pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]);
 444                 pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]);
 445                 pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]);
 446                 pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]);
 447                 pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]);
 448                 pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]);
 449
 450                 /* Construct an IPv6 log message. */
 451                 log_buf->ae_bytesused = snprintf(log_buf->ae_data,
 452                     MAX_LOG_MSG_LEN,
 453                     "%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:"
 454                     "%x:%x:%x:%x:%x,%u,%ld,%ld,%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,"
 455                     "%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n",
 456                     direction[pkt_node->direction],
 457                     pkt_node->hash,
 458                     pkt_node->tval.tv_sec,
 459                     pkt_node->tval.tv_usec,
 460                     UPPER_SHORT(pkt_node->ip_laddr[0]),
 461                     LOWER_SHORT(pkt_node->ip_laddr[0]),
 462                     UPPER_SHORT(pkt_node->ip_laddr[1]),
 463                     LOWER_SHORT(pkt_node->ip_laddr[1]),
 464                     UPPER_SHORT(pkt_node->ip_laddr[2]),
 465                     LOWER_SHORT(pkt_node->ip_laddr[2]),
 466                     UPPER_SHORT(pkt_node->ip_laddr[3]),
 467                     LOWER_SHORT(pkt_node->ip_laddr[3]),
 468                     ntohs(pkt_node->tcp_localport),
 469                     UPPER_SHORT(pkt_node->ip_faddr[0]),
 470                     LOWER_SHORT(pkt_node->ip_faddr[0]),
 471                     UPPER_SHORT(pkt_node->ip_faddr[1]),
 472                     LOWER_SHORT(pkt_node->ip_faddr[1]),
 473                     UPPER_SHORT(pkt_node->ip_faddr[2]),
 474                     LOWER_SHORT(pkt_node->ip_faddr[2]),
 475                     UPPER_SHORT(pkt_node->ip_faddr[3]),
 476                     LOWER_SHORT(pkt_node->ip_faddr[3]),
 477                     ntohs(pkt_node->tcp_foreignport),
 478                     pkt_node->snd_ssthresh,
 479                     pkt_node->snd_cwnd,
 480                     pkt_node->snd_bwnd,
 481                     pkt_node->snd_wnd,
 482                     pkt_node->rcv_wnd,
 483                     pkt_node->snd_scale,
 484                     pkt_node->rcv_scale,
 485                     pkt_node->conn_state,
 486                     pkt_node->max_seg_size,
 487                     pkt_node->smoothed_rtt,
 488                     pkt_node->sack_enabled,
 489                     pkt_node->flags,
 490                     pkt_node->rxt_length,
 491                     pkt_node->snd_buf_hiwater,
 492                     pkt_node->snd_buf_cc,
 493                     pkt_node->rcv_buf_hiwater,
 494                     pkt_node->rcv_buf_cc,
 495                     pkt_node->sent_inflight_bytes,
 496                     pkt_node->t_segqlen,
 497                     pkt_node->flowid,
 498                     pkt_node->flowtype);
 499         } else { /* IPv4 packet */
 500                 pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]);
 501                 pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]);
 502                 pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]);
 503                 pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]);
 504                 pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]);
 505                 pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]);
 506                 pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]);
 507                 pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]);
 508 #endif /* SIFTR_IPV6 */
 509
 510                 /* Construct an IPv4 log message. */
 511                 log_buf->ae_bytesused = snprintf(log_buf->ae_data,
 512                     MAX_LOG_MSG_LEN,
 513                     "%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%ld,%ld,"
 514                     "%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n",
 515                     direction[pkt_node->direction],
 516                     pkt_node->hash,
 517                     (intmax_t)pkt_node->tval.tv_sec,
 518                     pkt_node->tval.tv_usec,
 519                     pkt_node->ip_laddr[0],
 520                     pkt_node->ip_laddr[1],
 521                     pkt_node->ip_laddr[2],
 522                     pkt_node->ip_laddr[3],
 523                     ntohs(pkt_node->tcp_localport),
 524                     pkt_node->ip_faddr[0],
 525                     pkt_node->ip_faddr[1],
 526                     pkt_node->ip_faddr[2],
 527                     pkt_node->ip_faddr[3],
 528                     ntohs(pkt_node->tcp_foreignport),
 529                     pkt_node->snd_ssthresh,
 530                     pkt_node->snd_cwnd,
 531                     pkt_node->snd_bwnd,
 532                     pkt_node->snd_wnd,
 533                     pkt_node->rcv_wnd,
 534                     pkt_node->snd_scale,
 535                     pkt_node->rcv_scale,
 536                     pkt_node->conn_state,
 537                     pkt_node->max_seg_size,
 538                     pkt_node->smoothed_rtt,
 539                     pkt_node->sack_enabled,
 540                     pkt_node->flags,
 541                     pkt_node->rxt_length,
 542                     pkt_node->snd_buf_hiwater,
 543                     pkt_node->snd_buf_cc,
 544                     pkt_node->rcv_buf_hiwater,
 545                     pkt_node->rcv_buf_cc,
 546                     pkt_node->sent_inflight_bytes,
 547                     pkt_node->t_segqlen,
 548                     pkt_node->flowid,
 549                     pkt_node->flowtype);
 550 #ifdef SIFTR_IPV6
 551         }
 552 #endif
 553
 554         alq_post_flags(siftr_alq, log_buf, 0);
 555 }
 556
 557
 558 static void
 559 siftr_pkt_manager_thread(void *arg)
 560 {
 561         STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue =
 562             STAILQ_HEAD_INITIALIZER(tmp_pkt_queue);
 563         struct pkt_node *pkt_node, *pkt_node_temp;
 564         uint8_t draining;
 565
 566         draining = 2;
 567
 568         mtx_lock(&siftr_pkt_mgr_mtx);
 569
 570         /* draining == 0 when queue has been flushed and it's safe to exit. */
 571         while (draining) {
 572                 /*
 573                  * Sleep until we are signalled to wake because thread has
 574                  * been told to exit or until 1 tick has passed.
 575                  */
 576                 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait",
 577                     1);
 578
 579                 /* Gain exclusive access to the pkt_node queue. */
 580                 mtx_lock(&siftr_pkt_queue_mtx);
 581
 582                 /*
 583                  * Move pkt_queue to tmp_pkt_queue, which leaves
 584                  * pkt_queue empty and ready to receive more pkt_nodes.
 585                  */
 586                 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue);
 587
 588                 /*
 589                  * We've finished making changes to the list. Unlock it
 590                  * so the pfil hooks can continue queuing pkt_nodes.
 591                  */
 592                 mtx_unlock(&siftr_pkt_queue_mtx);
 593
 594                 /*
 595                  * We can't hold a mutex whilst calling siftr_process_pkt
 596                  * because ALQ might sleep waiting for buffer space.
 597                  */
 598                 mtx_unlock(&siftr_pkt_mgr_mtx);
 599
 600                 /* Flush all pkt_nodes to the log file. */
 601                 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes,
 602                     pkt_node_temp) {
 603                         siftr_process_pkt(pkt_node);
 604                         STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes);
 605                         free(pkt_node, M_SIFTR_PKTNODE);
 606                 }
 607
 608                 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue),
 609                     ("SIFTR tmp_pkt_queue not empty after flush"));
 610
 611                 mtx_lock(&siftr_pkt_mgr_mtx);
 612
 613                 /*
 614                  * If siftr_exit_pkt_manager_thread gets set during the window
 615                  * where we are draining the tmp_pkt_queue above, there might
 616                  * still be pkts in pkt_queue that need to be drained.
 617                  * Allow one further iteration to occur after
 618                  * siftr_exit_pkt_manager_thread has been set to ensure
 619                  * pkt_queue is completely empty before we kill the thread.
 620                  *
 621                  * siftr_exit_pkt_manager_thread is set only after the pfil
 622                  * hooks have been removed, so only 1 extra iteration
 623                  * is needed to drain the queue.
 624                  */
 625                 if (siftr_exit_pkt_manager_thread)
 626                         draining--;
 627         }
 628
 629         mtx_unlock(&siftr_pkt_mgr_mtx);
 630
 631         /* Calls wakeup on this thread's struct thread ptr. */
 632         kthread_exit();
 633 }
 634
 635
 636 static uint32_t
 637 hash_pkt(struct mbuf *m, uint32_t offset)
 638 {
 639         uint32_t hash;
 640
 641         hash = 0;
 642
 643         while (m != NULL && offset > m->m_len) {
 644                 /*
 645                  * The IP packet payload does not start in this mbuf, so
 646                  * need to figure out which mbuf it starts in and what offset
 647                  * into the mbuf's data region the payload starts at.
 648                  */
 649                 offset -= m->m_len;
 650                 m = m->m_next;
 651         }
 652
 653         while (m != NULL) {
 654                 /* Ensure there is data in the mbuf */
 655                 if ((m->m_len - offset) > 0)
 656                         hash = hash32_buf(m->m_data + offset,
 657                             m->m_len - offset, hash);
 658
 659                 m = m->m_next;
 660                 offset = 0;
 661         }
 662
 663         return (hash);
 664 }
 665
 666
 667 /*
 668  * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that
 669  * it's a reinjected packet and return. If it doesn't, tag the mbuf and return.
 670  * Return value >0 means the caller should skip processing this mbuf.
 671  */
 672 static inline int
 673 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss)
 674 {
 675         if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL)
 676             != NULL) {
 677                 if (dir == PFIL_IN)
 678                         ss->nskip_in_dejavu++;
 679                 else
 680                         ss->nskip_out_dejavu++;
 681
 682                 return (1);
 683         } else {
 684                 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR,
 685                     PACKET_TAG_SIFTR, 0, M_NOWAIT);
 686                 if (tag == NULL) {
 687                         if (dir == PFIL_IN)
 688                                 ss->nskip_in_malloc++;
 689                         else
 690                                 ss->nskip_out_malloc++;
 691
 692                         return (1);
 693                 }
 694
 695                 m_tag_prepend(m, tag);
 696         }
 697
 698         return (0);
 699 }
 700
 701
 702 /*
 703  * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL
 704  * otherwise.
 705  */
 706 static inline struct inpcb *
 707 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport,
 708     uint16_t dport, int dir, struct siftr_stats *ss)
 709 {
 710         struct inpcb *inp;
 711
 712         /* We need the tcbinfo lock. */
 713         INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);
 714
 715         if (dir == PFIL_IN)
 716                 inp = (ipver == INP_IPV4 ?
 717                     in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst,
 718                     dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
 719                     :
 720 #ifdef SIFTR_IPV6
 721                     in6_pcblookup(&V_tcbinfo,
 722                     &((struct ip6_hdr *)ip)->ip6_src, sport,
 723                     &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB,
 724                     m->m_pkthdr.rcvif)
 725 #else
 726                     NULL
 727 #endif
 728                     );
 729
 730         else
 731                 inp = (ipver == INP_IPV4 ?
 732                     in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src,
 733                     sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
 734                     :
 735 #ifdef SIFTR_IPV6
 736                     in6_pcblookup(&V_tcbinfo,
 737                     &((struct ip6_hdr *)ip)->ip6_dst, dport,
 738                     &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB,
 739                     m->m_pkthdr.rcvif)
 740 #else
 741                     NULL
 742 #endif
 743                     );
 744
 745         /* If we can't find the inpcb, bail. */
 746         if (inp == NULL) {
 747                 if (dir == PFIL_IN)
 748                         ss->nskip_in_inpcb++;
 749                 else
 750                         ss->nskip_out_inpcb++;
 751         }
 752
 753         return (inp);
 754 }
 755
 756
 757 static inline void
 758 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp,
 759     int ipver, int dir, int inp_locally_locked)
 760 {
 761 #ifdef SIFTR_IPV6
 762         if (ipver == INP_IPV4) {
 763                 pn->ip_laddr[3] = inp->inp_laddr.s_addr;
 764                 pn->ip_faddr[3] = inp->inp_faddr.s_addr;
 765 #else
 766                 *((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr;
 767                 *((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr;
 768 #endif
 769 #ifdef SIFTR_IPV6
 770         } else {
 771                 pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0];
 772                 pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1];
 773                 pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2];
 774                 pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3];
 775                 pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0];
 776                 pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1];
 777                 pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2];
 778                 pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3];
 779         }
 780 #endif
 781         pn->tcp_localport = inp->inp_lport;
 782         pn->tcp_foreignport = inp->inp_fport;
 783         pn->snd_cwnd = tp->snd_cwnd;
 784         pn->snd_wnd = tp->snd_wnd;
 785         pn->rcv_wnd = tp->rcv_wnd;
 786         pn->snd_bwnd = 0;               /* Unused, kept for compat. */
 787         pn->snd_ssthresh = tp->snd_ssthresh;
 788         pn->snd_scale = tp->snd_scale;
 789         pn->rcv_scale = tp->rcv_scale;
 790         pn->conn_state = tp->t_state;
 791         pn->max_seg_size = tp->t_maxseg;
 792         pn->smoothed_rtt = tp->t_srtt;
 793         pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0;
 794         pn->flags = tp->t_flags;
 795         pn->rxt_length = tp->t_rxtcur;
 796         pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat;
 797         pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd);
 798         pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat;
 799         pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv);
 800         pn->sent_inflight_bytes = tp->snd_max - tp->snd_una;
 801         pn->t_segqlen = tp->t_segqlen;
 802         pn->flowid = inp->inp_flowid;
 803         pn->flowtype = inp->inp_flowtype;
 804
 805         /* We've finished accessing the tcb so release the lock. */
 806         if (inp_locally_locked)
 807                 INP_RUNLOCK(inp);
 808
 809         pn->ipver = ipver;
 810         pn->direction = dir;
 811
 812         /*
 813          * Significantly more accurate than using getmicrotime(), but slower!
 814          * Gives true microsecond resolution at the expense of a hit to
 815          * maximum pps throughput processing when SIFTR is loaded and enabled.
 816          */
 817         microtime(&pn->tval);
 818         TCP_PROBE1(siftr, &pn);
 819
 820 }
 821
 822
 823 /*
 824  * pfil hook that is called for each IPv4 packet making its way through the
 825  * stack in either direction.
 826  * The pfil subsystem holds a non-sleepable mutex somewhere when
 827  * calling our hook function, so we can't sleep at all.
 828  * It's very important to use the M_NOWAIT flag with all function calls
 829  * that support it so that they won't sleep, otherwise you get a panic.
 830  */
 831 static int
 832 siftr_chkpkt(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
 833     struct inpcb *inp)
 834 {
 835         struct pkt_node *pn;
 836         struct ip *ip;
 837         struct tcphdr *th;
 838         struct tcpcb *tp;
 839         struct siftr_stats *ss;
 840         unsigned int ip_hl;
 841         int inp_locally_locked;
 842
 843         inp_locally_locked = 0;
 844         ss = DPCPU_PTR(ss);
 845
 846         /*
 847          * m_pullup is not required here because ip_{input|output}
 848          * already do the heavy lifting for us.
 849          */
 850
 851         ip = mtod(*m, struct ip *);
 852
 853         /* Only continue processing if the packet is TCP. */
 854         if (ip->ip_p != IPPROTO_TCP)
 855                 goto ret;
 856
 857         /*
 858          * If a kernel subsystem reinjects packets into the stack, our pfil
 859          * hook will be called multiple times for the same packet.
 860          * Make sure we only process unique packets.
 861          */
 862         if (siftr_chkreinject(*m, dir, ss))
 863                 goto ret;
 864
 865         if (dir == PFIL_IN)
 866                 ss->n_in++;
 867         else
 868                 ss->n_out++;
 869
 870         /*
 871          * Create a tcphdr struct starting at the correct offset
 872          * in the IP packet. ip->ip_hl gives the ip header length
 873          * in 4-byte words, so multiply it to get the size in bytes.
 874          */
 875         ip_hl = (ip->ip_hl << 2);
 876         th = (struct tcphdr *)((caddr_t)ip + ip_hl);
 877
 878         /*
 879          * If the pfil hooks don't provide a pointer to the
 880          * inpcb, we need to find it ourselves and lock it.
 881          */
 882         if (!inp) {
 883                 /* Find the corresponding inpcb for this pkt. */
 884                 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport,
 885                     th->th_dport, dir, ss);
 886
 887                 if (inp == NULL)
 888                         goto ret;
 889                 else
 890                         inp_locally_locked = 1;
 891         }
 892
 893         INP_LOCK_ASSERT(inp);
 894
 895         /* Find the TCP control block that corresponds with this packet */
 896         tp = intotcpcb(inp);
 897
 898         /*
 899          * If we can't find the TCP control block (happens occasionaly for a
 900          * packet sent during the shutdown phase of a TCP connection),
 901          * or we're in the timewait state, bail
 902          */
 903         if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
 904                 if (dir == PFIL_IN)
 905                         ss->nskip_in_tcpcb++;
 906                 else
 907                         ss->nskip_out_tcpcb++;
 908
 909                 goto inp_unlock;
 910         }
 911
 912         pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
 913
 914         if (pn == NULL) {
 915                 if (dir == PFIL_IN)
 916                         ss->nskip_in_malloc++;
 917                 else
 918                         ss->nskip_out_malloc++;
 919
 920                 goto inp_unlock;
 921         }
 922
 923         siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked);
 924
 925         if (siftr_generate_hashes) {
 926                 if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) {
 927                         /*
 928                          * For outbound packets, the TCP checksum isn't
 929                          * calculated yet. This is a problem for our packet
 930                          * hashing as the receiver will calc a different hash
 931                          * to ours if we don't include the correct TCP checksum
 932                          * in the bytes being hashed. To work around this
 933                          * problem, we manually calc the TCP checksum here in
 934                          * software. We unset the CSUM_TCP flag so the lower
 935                          * layers don't recalc it.
 936                          */
 937                         (*m)->m_pkthdr.csum_flags &= ~CSUM_TCP;
 938
 939                         /*
 940                          * Calculate the TCP checksum in software and assign
 941                          * to correct TCP header field, which will follow the
 942                          * packet mbuf down the stack. The trick here is that
 943                          * tcp_output() sets th->th_sum to the checksum of the
 944                          * pseudo header for us already. Because of the nature
 945                          * of the checksumming algorithm, we can sum over the
 946                          * entire IP payload (i.e. TCP header and data), which
 947                          * will include the already calculated pseduo header
 948                          * checksum, thus giving us the complete TCP checksum.
 949                          *
 950                          * To put it in simple terms, if checksum(1,2,3,4)=10,
 951                          * then checksum(1,2,3,4,5) == checksum(10,5).
 952                          * This property is what allows us to "cheat" and
 953                          * checksum only the IP payload which has the TCP
 954                          * th_sum field populated with the pseudo header's
 955                          * checksum, and not need to futz around checksumming
 956                          * pseudo header bytes and TCP header/data in one hit.
 957                          * Refer to RFC 1071 for more info.
 958                          *
 959                          * NB: in_cksum_skip(struct mbuf *m, int len, int skip)
 960                          * in_cksum_skip 2nd argument is NOT the number of
 961                          * bytes to read from the mbuf at "skip" bytes offset
 962                          * from the start of the mbuf (very counter intuitive!).
 963                          * The number of bytes to read is calculated internally
 964                          * by the function as len-skip i.e. to sum over the IP
 965                          * payload (TCP header + data) bytes, it is INCORRECT
 966                          * to call the function like this:
 967                          * in_cksum_skip(at, ip->ip_len - offset, offset)
 968                          * Rather, it should be called like this:
 969                          * in_cksum_skip(at, ip->ip_len, offset)
 970                          * which means read "ip->ip_len - offset" bytes from
 971                          * the mbuf cluster "at" at offset "offset" bytes from
 972                          * the beginning of the "at" mbuf's data pointer.
 973                          */
 974                         th->th_sum = in_cksum_skip(*m, ntohs(ip->ip_len),
 975                             ip_hl);
 976                 }
 977
 978                 /*
 979                  * XXX: Having to calculate the checksum in software and then
 980                  * hash over all bytes is really inefficient. Would be nice to
 981                  * find a way to create the hash and checksum in the same pass
 982                  * over the bytes.
 983                  */
 984                 pn->hash = hash_pkt(*m, ip_hl);
 985         }
 986
 987         mtx_lock(&siftr_pkt_queue_mtx);
 988         STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
 989         mtx_unlock(&siftr_pkt_queue_mtx);
 990         goto ret;
 991
 992 inp_unlock:
 993         if (inp_locally_locked)
 994                 INP_RUNLOCK(inp);
 995
 996 ret:
 997         /* Returning 0 ensures pfil will not discard the pkt */
 998         return (0);
 999 }
1000
1001
1002 #ifdef SIFTR_IPV6
1003 static int
1004 siftr_chkpkt6(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
1005     struct inpcb *inp)
1006 {
1007         struct pkt_node *pn;
1008         struct ip6_hdr *ip6;
1009         struct tcphdr *th;
1010         struct tcpcb *tp;
1011         struct siftr_stats *ss;
1012         unsigned int ip6_hl;
1013         int inp_locally_locked;
1014
1015         inp_locally_locked = 0;
1016         ss = DPCPU_PTR(ss);
1017
1018         /*
1019          * m_pullup is not required here because ip6_{input|output}
1020          * already do the heavy lifting for us.
1021          */
1022
1023         ip6 = mtod(*m, struct ip6_hdr *);
1024
1025         /*
1026          * Only continue processing if the packet is TCP
1027          * XXX: We should follow the next header fields
1028          * as shown on Pg 6 RFC 2460, but right now we'll
1029          * only check pkts that have no extension headers.
1030          */
1031         if (ip6->ip6_nxt != IPPROTO_TCP)
1032                 goto ret6;
1033
1034         /*
1035          * If a kernel subsystem reinjects packets into the stack, our pfil
1036          * hook will be called multiple times for the same packet.
1037          * Make sure we only process unique packets.
1038          */
1039         if (siftr_chkreinject(*m, dir, ss))
1040                 goto ret6;
1041
1042         if (dir == PFIL_IN)
1043                 ss->n_in++;
1044         else
1045                 ss->n_out++;
1046
1047         ip6_hl = sizeof(struct ip6_hdr);
1048
1049         /*
1050          * Create a tcphdr struct starting at the correct offset
1051          * in the ipv6 packet. ip->ip_hl gives the ip header length
1052          * in 4-byte words, so multiply it to get the size in bytes.
1053          */
1054         th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl);
1055
1056         /*
1057          * For inbound packets, the pfil hooks don't provide a pointer to the
1058          * inpcb, so we need to find it ourselves and lock it.
1059          */
1060         if (!inp) {
1061                 /* Find the corresponding inpcb for this pkt. */
1062                 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m,
1063                     th->th_sport, th->th_dport, dir, ss);
1064
1065                 if (inp == NULL)
1066                         goto ret6;
1067                 else
1068                         inp_locally_locked = 1;
1069         }
1070
1071         /* Find the TCP control block that corresponds with this packet. */
1072         tp = intotcpcb(inp);
1073
1074         /*
1075          * If we can't find the TCP control block (happens occasionaly for a
1076          * packet sent during the shutdown phase of a TCP connection),
1077          * or we're in the timewait state, bail.
1078          */
1079         if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
1080                 if (dir == PFIL_IN)
1081                         ss->nskip_in_tcpcb++;
1082                 else
1083                         ss->nskip_out_tcpcb++;
1084
1085                 goto inp_unlock6;
1086         }
1087
1088         pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
1089
1090         if (pn == NULL) {
1091                 if (dir == PFIL_IN)
1092                         ss->nskip_in_malloc++;
1093                 else
1094                         ss->nskip_out_malloc++;
1095
1096                 goto inp_unlock6;
1097         }
1098
1099         siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked);
1100
1101         /* XXX: Figure out how to generate hashes for IPv6 packets. */
1102
1103         mtx_lock(&siftr_pkt_queue_mtx);
1104         STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
1105         mtx_unlock(&siftr_pkt_queue_mtx);
1106         goto ret6;
1107
1108 inp_unlock6:
1109         if (inp_locally_locked)
1110                 INP_RUNLOCK(inp);
1111
1112 ret6:
1113         /* Returning 0 ensures pfil will not discard the pkt. */
1114         return (0);
1115 }
1116 #endif /* #ifdef SIFTR_IPV6 */
1117
1118
1119 static int
1120 siftr_pfil(int action)
1121 {
1122         struct pfil_head *pfh_inet;
1123 #ifdef SIFTR_IPV6
1124         struct pfil_head *pfh_inet6;
1125 #endif
1126         VNET_ITERATOR_DECL(vnet_iter);
1127
1128         VNET_LIST_RLOCK();
1129         VNET_FOREACH(vnet_iter) {
1130                 CURVNET_SET(vnet_iter);
1131                 pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
1132 #ifdef SIFTR_IPV6
1133                 pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
1134 #endif
1135
1136                 if (action == HOOK) {
1137                         pfil_add_hook(siftr_chkpkt, NULL,
1138                             PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet);
1139 #ifdef SIFTR_IPV6
1140                         pfil_add_hook(siftr_chkpkt6, NULL,
1141                             PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6);
1142 #endif
1143                 } else if (action == UNHOOK) {
1144                         pfil_remove_hook(siftr_chkpkt, NULL,
1145                             PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet);
1146 #ifdef SIFTR_IPV6
1147                         pfil_remove_hook(siftr_chkpkt6, NULL,
1148                             PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6);
1149 #endif
1150                 }
1151                 CURVNET_RESTORE();
1152         }
1153         VNET_LIST_RUNLOCK();
1154
1155         return (0);
1156 }
1157
1158
1159 static int
1160 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS)
1161 {
1162         struct alq *new_alq;
1163         int error;
1164
1165         error = sysctl_handle_string(oidp, arg1, arg2, req);
1166
1167         /* Check for error or same filename */
1168         if (error != 0 || req->newptr == NULL ||
1169             strncmp(siftr_logfile, arg1, arg2) == 0)
1170                 goto done;
1171
1172         /* Filname changed */
1173         error = alq_open(&new_alq, arg1, curthread->td_ucred,
1174             SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1175         if (error != 0)
1176                 goto done;
1177
1178         /*
1179          * If disabled, siftr_alq == NULL so we simply close
1180          * the alq as we've proved it can be opened.
1181          * If enabled, close the existing alq and switch the old
1182          * for the new.
1183          */
1184         if (siftr_alq == NULL) {
1185                 alq_close(new_alq);
1186         } else {
1187                 alq_close(siftr_alq);
1188                 siftr_alq = new_alq;
1189         }
1190
1191         /* Update filename upon success */
1192         strlcpy(siftr_logfile, arg1, arg2);
1193 done:
1194         return (error);
1195 }
1196
1197 static int
1198 siftr_manage_ops(uint8_t action)
1199 {
1200         struct siftr_stats totalss;
1201         struct timeval tval;
1202         struct flow_hash_node *counter, *tmp_counter;
1203         struct sbuf *s;
1204         int i, key_index, error;
1205         uint32_t bytes_to_write, total_skipped_pkts;
1206         uint16_t lport, fport;
1207         uint8_t *key, ipver __unused;
1208
1209 #ifdef SIFTR_IPV6
1210         uint32_t laddr[4];
1211         uint32_t faddr[4];
1212 #else
1213         uint8_t laddr[4];
1214         uint8_t faddr[4];
1215 #endif
1216
1217         error = 0;
1218         total_skipped_pkts = 0;
1219
1220         /* Init an autosizing sbuf that initially holds 200 chars. */
1221         if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL)
1222                 return (-1);
1223
1224         if (action == SIFTR_ENABLE) {
1225                 /*
1226                  * Create our alq
1227                  * XXX: We should abort if alq_open fails!
1228                  */
1229                 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred,
1230                     SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1231
1232                 STAILQ_INIT(&pkt_queue);
1233
1234                 DPCPU_ZERO(ss);
1235
1236                 siftr_exit_pkt_manager_thread = 0;
1237
1238                 kthread_add(&siftr_pkt_manager_thread, NULL, NULL,
1239                     &siftr_pkt_manager_thr, RFNOWAIT, 0,
1240                     "siftr_pkt_manager_thr");
1241
1242                 siftr_pfil(HOOK);
1243
1244                 microtime(&tval);
1245
1246                 sbuf_printf(s,
1247                     "enable_time_secs=%jd\tenable_time_usecs=%06ld\t"
1248                     "siftrver=%s\thz=%u\ttcp_rtt_scale=%u\tsysname=%s\t"
1249                     "sysver=%u\tipmode=%u\n",
1250                     (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, hz,
1251                     TCP_RTT_SCALE, SYS_NAME, __FreeBSD_version, SIFTR_IPMODE);
1252
1253                 sbuf_finish(s);
1254                 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK);
1255
1256         } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) {
1257                 /*
1258                  * Remove the pfil hook functions. All threads currently in
1259                  * the hook functions are allowed to exit before siftr_pfil()
1260                  * returns.
1261                  */
1262                 siftr_pfil(UNHOOK);
1263
1264                 /* This will block until the pkt manager thread unlocks it. */
1265                 mtx_lock(&siftr_pkt_mgr_mtx);
1266
1267                 /* Tell the pkt manager thread that it should exit now. */
1268                 siftr_exit_pkt_manager_thread = 1;
1269
1270                 /*
1271                  * Wake the pkt_manager thread so it realises that
1272                  * siftr_exit_pkt_manager_thread == 1 and exits gracefully.
1273                  * The wakeup won't be delivered until we unlock
1274                  * siftr_pkt_mgr_mtx so this isn't racy.
1275                  */
1276                 wakeup(&wait_for_pkt);
1277
1278                 /* Wait for the pkt_manager thread to exit. */
1279                 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT,
1280                     "thrwait", 0);
1281
1282                 siftr_pkt_manager_thr = NULL;
1283                 mtx_unlock(&siftr_pkt_mgr_mtx);
1284
1285                 totalss.n_in = DPCPU_VARSUM(ss, n_in);
1286                 totalss.n_out = DPCPU_VARSUM(ss, n_out);
1287                 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc);
1288                 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc);
1289                 totalss.nskip_in_mtx = DPCPU_VARSUM(ss, nskip_in_mtx);
1290                 totalss.nskip_out_mtx = DPCPU_VARSUM(ss, nskip_out_mtx);
1291                 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb);
1292                 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb);
1293                 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb);
1294                 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb);
1295
1296                 total_skipped_pkts = totalss.nskip_in_malloc +
1297                     totalss.nskip_out_malloc + totalss.nskip_in_mtx +
1298                     totalss.nskip_out_mtx + totalss.nskip_in_tcpcb +
1299                     totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb +
1300                     totalss.nskip_out_inpcb;
1301
1302                 microtime(&tval);
1303
1304                 sbuf_printf(s,
1305                     "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t"
1306                     "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t"
1307                     "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t"
1308                     "num_outbound_skipped_pkts_malloc=%u\t"
1309                     "num_inbound_skipped_pkts_mtx=%u\t"
1310                     "num_outbound_skipped_pkts_mtx=%u\t"
1311                     "num_inbound_skipped_pkts_tcpcb=%u\t"
1312                     "num_outbound_skipped_pkts_tcpcb=%u\t"
1313                     "num_inbound_skipped_pkts_inpcb=%u\t"
1314                     "num_outbound_skipped_pkts_inpcb=%u\t"
1315                     "total_skipped_tcp_pkts=%u\tflow_list=",
1316                     (intmax_t)tval.tv_sec,
1317                     tval.tv_usec,
1318                     (uintmax_t)totalss.n_in,
1319                     (uintmax_t)totalss.n_out,
1320                     (uintmax_t)(totalss.n_in + totalss.n_out),
1321                     totalss.nskip_in_malloc,
1322                     totalss.nskip_out_malloc,
1323                     totalss.nskip_in_mtx,
1324                     totalss.nskip_out_mtx,
1325                     totalss.nskip_in_tcpcb,
1326                     totalss.nskip_out_tcpcb,
1327                     totalss.nskip_in_inpcb,
1328                     totalss.nskip_out_inpcb,
1329                     total_skipped_pkts);
1330
1331                 /*
1332                  * Iterate over the flow hash, printing a summary of each
1333                  * flow seen and freeing any malloc'd memory.
1334                  * The hash consists of an array of LISTs (man 3 queue).
1335                  */
1336                 for (i = 0; i <= siftr_hashmask; i++) {
1337                         LIST_FOREACH_SAFE(counter, counter_hash + i, nodes,
1338                             tmp_counter) {
1339                                 key = counter->key;
1340                                 key_index = 1;
1341
1342                                 ipver = key[0];
1343
1344                                 memcpy(laddr, key + key_index, sizeof(laddr));
1345                                 key_index += sizeof(laddr);
1346                                 memcpy(&lport, key + key_index, sizeof(lport));
1347                                 key_index += sizeof(lport);
1348                                 memcpy(faddr, key + key_index, sizeof(faddr));
1349                                 key_index += sizeof(faddr);
1350                                 memcpy(&fport, key + key_index, sizeof(fport));
1351
1352 #ifdef SIFTR_IPV6
1353                                 laddr[3] = ntohl(laddr[3]);
1354                                 faddr[3] = ntohl(faddr[3]);
1355
1356                                 if (ipver == INP_IPV6) {
1357                                         laddr[0] = ntohl(laddr[0]);
1358                                         laddr[1] = ntohl(laddr[1]);
1359                                         laddr[2] = ntohl(laddr[2]);
1360                                         faddr[0] = ntohl(faddr[0]);
1361                                         faddr[1] = ntohl(faddr[1]);
1362                                         faddr[2] = ntohl(faddr[2]);
1363
1364                                         sbuf_printf(s,
1365                                             "%x:%x:%x:%x:%x:%x:%x:%x;%u-"
1366                                             "%x:%x:%x:%x:%x:%x:%x:%x;%u,",
1367                                             UPPER_SHORT(laddr[0]),
1368                                             LOWER_SHORT(laddr[0]),
1369                                             UPPER_SHORT(laddr[1]),
1370                                             LOWER_SHORT(laddr[1]),
1371                                             UPPER_SHORT(laddr[2]),
1372                                             LOWER_SHORT(laddr[2]),
1373                                             UPPER_SHORT(laddr[3]),
1374                                             LOWER_SHORT(laddr[3]),
1375                                             ntohs(lport),
1376                                             UPPER_SHORT(faddr[0]),
1377                                             LOWER_SHORT(faddr[0]),
1378                                             UPPER_SHORT(faddr[1]),
1379                                             LOWER_SHORT(faddr[1]),
1380                                             UPPER_SHORT(faddr[2]),
1381                                             LOWER_SHORT(faddr[2]),
1382                                             UPPER_SHORT(faddr[3]),
1383                                             LOWER_SHORT(faddr[3]),
1384                                             ntohs(fport));
1385                                 } else {
1386                                         laddr[0] = FIRST_OCTET(laddr[3]);
1387                                         laddr[1] = SECOND_OCTET(laddr[3]);
1388                                         laddr[2] = THIRD_OCTET(laddr[3]);
1389                                         laddr[3] = FOURTH_OCTET(laddr[3]);
1390                                         faddr[0] = FIRST_OCTET(faddr[3]);
1391                                         faddr[1] = SECOND_OCTET(faddr[3]);
1392                                         faddr[2] = THIRD_OCTET(faddr[3]);
1393                                         faddr[3] = FOURTH_OCTET(faddr[3]);
1394 #endif
1395                                         sbuf_printf(s,
1396                                             "%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,",
1397                                             laddr[0],
1398                                             laddr[1],
1399                                             laddr[2],
1400                                             laddr[3],
1401                                             ntohs(lport),
1402                                             faddr[0],
1403                                             faddr[1],
1404                                             faddr[2],
1405                                             faddr[3],
1406                                             ntohs(fport));
1407 #ifdef SIFTR_IPV6
1408                                 }
1409 #endif
1410
1411                                 free(counter, M_SIFTR_HASHNODE);
1412                         }
1413
1414                         LIST_INIT(counter_hash + i);
1415                 }
1416
1417                 sbuf_printf(s, "\n");
1418                 sbuf_finish(s);
1419
1420                 i = 0;
1421                 do {
1422                         bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i);
1423                         alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK);
1424                         i += bytes_to_write;
1425                 } while (i < sbuf_len(s));
1426
1427                 alq_close(siftr_alq);
1428                 siftr_alq = NULL;
1429         }
1430
1431         sbuf_delete(s);
1432
1433         /*
1434          * XXX: Should be using ret to check if any functions fail
1435          * and set error appropriately
1436          */
1437
1438         return (error);
1439 }
1440
1441
1442 static int
1443 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS)
1444 {
1445         if (req->newptr == NULL)
1446                 goto skip;
1447
1448         /* If the value passed in isn't 0 or 1, return an error. */
1449         if (CAST_PTR_INT(req->newptr) != 0 && CAST_PTR_INT(req->newptr) != 1)
1450                 return (1);
1451
1452         /* If we are changing state (0 to 1 or 1 to 0). */
1453         if (CAST_PTR_INT(req->newptr) != siftr_enabled )
1454                 if (siftr_manage_ops(CAST_PTR_INT(req->newptr))) {
1455                         siftr_manage_ops(SIFTR_DISABLE);
1456                         return (1);
1457                 }
1458
1459 skip:
1460         return (sysctl_handle_int(oidp, arg1, arg2, req));
1461 }
1462
1463
1464 static void
1465 siftr_shutdown_handler(void *arg)
1466 {
1467         siftr_manage_ops(SIFTR_DISABLE);
1468 }
1469
1470
1471 /*
1472  * Module is being unloaded or machine is shutting down. Take care of cleanup.
1473  */
1474 static int
1475 deinit_siftr(void)
1476 {
1477         /* Cleanup. */
1478         siftr_manage_ops(SIFTR_DISABLE);
1479         hashdestroy(counter_hash, M_SIFTR, siftr_hashmask);
1480         mtx_destroy(&siftr_pkt_queue_mtx);
1481         mtx_destroy(&siftr_pkt_mgr_mtx);
1482
1483         return (0);
1484 }
1485
1486
1487 /*
1488  * Module has just been loaded into the kernel.
1489  */
1490 static int
1491 init_siftr(void)
1492 {
1493         EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL,
1494             SHUTDOWN_PRI_FIRST);
1495
1496         /* Initialise our flow counter hash table. */
1497         counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR,
1498             &siftr_hashmask);
1499
1500         mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF);
1501         mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF);
1502
1503         /* Print message to the user's current terminal. */
1504         uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n"
1505             "          http://caia.swin.edu.au/urp/newtcp\n\n",
1506             MODVERSION_STR);
1507
1508         return (0);
1509 }
1510
1511
1512 /*
1513  * This is the function that is called to load and unload the module.
1514  * When the module is loaded, this function is called once with
1515  * "what" == MOD_LOAD
1516  * When the module is unloaded, this function is called twice with
1517  * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second
1518  * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command,
1519  * this function is called once with "what" = MOD_SHUTDOWN
1520  * When the system is shut down, the handler isn't called until the very end
1521  * of the shutdown sequence i.e. after the disks have been synced.
1522  */
1523 static int
1524 siftr_load_handler(module_t mod, int what, void *arg)
1525 {
1526         int ret;
1527
1528         switch (what) {
1529         case MOD_LOAD:
1530                 ret = init_siftr();
1531                 break;
1532
1533         case MOD_QUIESCE:
1534         case MOD_SHUTDOWN:
1535                 ret = deinit_siftr();
1536                 break;
1537
1538         case MOD_UNLOAD:
1539                 ret = 0;
1540                 break;
1541
1542         default:
1543                 ret = EINVAL;
1544                 break;
1545         }
1546
1547         return (ret);
1548 }
1549
1550
1551 static moduledata_t siftr_mod = {
1552         .name = "siftr",
1553         .evhand = siftr_load_handler,
1554 };
1555
1556 /*
1557  * Param 1: name of the kernel module
1558  * Param 2: moduledata_t struct containing info about the kernel module
1559  *          and the execution entry point for the module
1560  * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h
1561  *          Defines the module initialisation order
1562  * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h
1563  *          Defines the initialisation order of this kld relative to others
1564  *          within the same subsystem as defined by param 3
1565  */
1566 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY);
1567 MODULE_DEPEND(siftr, alq, 1, 1, 1);
1568 MODULE_VERSION(siftr, MODVERSION);