sys/netinet/siftr.c

   1 /*-
   2  * Copyright (c) 2007-2009
   3  *      Swinburne University of Technology, Melbourne, Australia.
   4  * Copyright (c) 2009-2010, The FreeBSD Foundation
   5  * All rights reserved.
   6  *
   7  * Portions of this software were developed at the Centre for Advanced
   8  * Internet Architectures, Swinburne University of Technology, Melbourne,
   9  * Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /******************************************************
  34  * Statistical Information For TCP Research (SIFTR)
  35  *
  36  * A FreeBSD kernel module that adds very basic intrumentation to the
  37  * TCP stack, allowing internal stats to be recorded to a log file
  38  * for experimental, debugging and performance analysis purposes.
  39  *
  40  * SIFTR was first released in 2007 by James Healy and Lawrence Stewart whilst
  41  * working on the NewTCP research project at Swinburne University of
  42  * Technology's Centre for Advanced Internet Architectures, Melbourne,
  43  * Australia, which was made possible in part by a grant from the Cisco
  44  * University Research Program Fund at Community Foundation Silicon Valley.
  45  * More details are available at:
  46  *   http://caia.swin.edu.au/urp/newtcp/
  47  *
  48  * Work on SIFTR v1.2.x was sponsored by the FreeBSD Foundation as part of
  49  * the "Enhancing the FreeBSD TCP Implementation" project 2008-2009.
  50  * More details are available at:
  51  *   http://www.freebsdfoundation.org/
  52  *   http://caia.swin.edu.au/freebsd/etcp09/
  53  *
  54  * Lawrence Stewart is the current maintainer, and all contact regarding
  55  * SIFTR should be directed to him via email: lastewart@swin.edu.au
  56  *
  57  * Initial release date: June 2007
  58  * Most recent update: September 2010
  59  ******************************************************/
  60
  61 #include <sys/cdefs.h>
  62 __FBSDID("$FreeBSD$");
  63
  64 #include <sys/param.h>
  65 #include <sys/alq.h>
  66 #include <sys/errno.h>
  67 #include <sys/eventhandler.h>
  68 #include <sys/hash.h>
  69 #include <sys/kernel.h>
  70 #include <sys/kthread.h>
  71 #include <sys/lock.h>
  72 #include <sys/mbuf.h>
  73 #include <sys/module.h>
  74 #include <sys/mutex.h>
  75 #include <sys/pcpu.h>
  76 #include <sys/proc.h>
  77 #include <sys/sbuf.h>
  78 #include <sys/sdt.h>
  79 #include <sys/smp.h>
  80 #include <sys/socket.h>
  81 #include <sys/socketvar.h>
  82 #include <sys/sysctl.h>
  83 #include <sys/unistd.h>
  84
  85 #include <net/if.h>
  86 #include <net/if_var.h>
  87 #include <net/pfil.h>
  88
  89 #include <netinet/in.h>
  90 #include <netinet/in_kdtrace.h>
  91 #include <netinet/in_pcb.h>
  92 #include <netinet/in_systm.h>
  93 #include <netinet/in_var.h>
  94 #include <netinet/ip.h>
  95 #include <netinet/tcp_var.h>
  96
  97 #ifdef SIFTR_IPV6
  98 #include <netinet/ip6.h>
  99 #include <netinet6/in6_pcb.h>
 100 #endif /* SIFTR_IPV6 */
 101
 102 #include <machine/in_cksum.h>
 103
 104 /*
 105  * Three digit version number refers to X.Y.Z where:
 106  * X is the major version number
 107  * Y is bumped to mark backwards incompatible changes
 108  * Z is bumped to mark backwards compatible changes
 109  */
 110 #define V_MAJOR         1
 111 #define V_BACKBREAK     2
 112 #define V_BACKCOMPAT    4
 113 #define MODVERSION      __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT))
 114 #define MODVERSION_STR  __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \
 115     __XSTRING(V_BACKCOMPAT)
 116
 117 #define HOOK 0
 118 #define UNHOOK 1
 119 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536
 120 #define SYS_NAME "FreeBSD"
 121 #define PACKET_TAG_SIFTR 100
 122 #define PACKET_COOKIE_SIFTR 21749576
 123 #define SIFTR_LOG_FILE_MODE 0644
 124 #define SIFTR_DISABLE 0
 125 #define SIFTR_ENABLE 1
 126
 127 /*
 128  * Hard upper limit on the length of log messages. Bump this up if you add new
 129  * data fields such that the line length could exceed the below value.
 130  */
 131 #define MAX_LOG_MSG_LEN 200
 132 /* XXX: Make this a sysctl tunable. */
 133 #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN)
 134
 135 /*
 136  * 1 byte for IP version
 137  * IPv4: src/dst IP (4+4) + src/dst port (2+2) = 12 bytes
 138  * IPv6: src/dst IP (16+16) + src/dst port (2+2) = 36 bytes
 139  */
 140 #ifdef SIFTR_IPV6
 141 #define FLOW_KEY_LEN 37
 142 #else
 143 #define FLOW_KEY_LEN 13
 144 #endif
 145
 146 #ifdef SIFTR_IPV6
 147 #define SIFTR_IPMODE 6
 148 #else
 149 #define SIFTR_IPMODE 4
 150 #endif
 151
 152 /* useful macros */
 153 #define UPPER_SHORT(X)  (((X) & 0xFFFF0000) >> 16)
 154 #define LOWER_SHORT(X)  ((X) & 0x0000FFFF)
 155
 156 #define FIRST_OCTET(X)  (((X) & 0xFF000000) >> 24)
 157 #define SECOND_OCTET(X) (((X) & 0x00FF0000) >> 16)
 158 #define THIRD_OCTET(X)  (((X) & 0x0000FF00) >> 8)
 159 #define FOURTH_OCTET(X) ((X) & 0x000000FF)
 160
 161 static MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR");
 162 static MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode",
 163     "SIFTR pkt_node struct");
 164 static MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode",
 165     "SIFTR flow_hash_node struct");
 166
 167 /* Used as links in the pkt manager queue. */
 168 struct pkt_node {
 169         /* Timestamp of pkt as noted in the pfil hook. */
 170         struct timeval          tval;
 171         /* Direction pkt is travelling; either PFIL_IN or PFIL_OUT. */
 172         uint8_t                 direction;
 173         /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */
 174         uint8_t                 ipver;
 175         /* Hash of the pkt which triggered the log message. */
 176         uint32_t                hash;
 177         /* Local/foreign IP address. */
 178 #ifdef SIFTR_IPV6
 179         uint32_t                ip_laddr[4];
 180         uint32_t                ip_faddr[4];
 181 #else
 182         uint8_t                 ip_laddr[4];
 183         uint8_t                 ip_faddr[4];
 184 #endif
 185         /* Local TCP port. */
 186         uint16_t                tcp_localport;
 187         /* Foreign TCP port. */
 188         uint16_t                tcp_foreignport;
 189         /* Congestion Window (bytes). */
 190         u_long                  snd_cwnd;
 191         /* Sending Window (bytes). */
 192         u_long                  snd_wnd;
 193         /* Receive Window (bytes). */
 194         u_long                  rcv_wnd;
 195         /* Unused (was: Bandwidth Controlled Window (bytes)). */
 196         u_long                  snd_bwnd;
 197         /* Slow Start Threshold (bytes). */
 198         u_long                  snd_ssthresh;
 199         /* Current state of the TCP FSM. */
 200         int                     conn_state;
 201         /* Max Segment Size (bytes). */
 202         u_int                   max_seg_size;
 203         /*
 204          * Smoothed RTT stored as found in the TCP control block
 205          * in units of (TCP_RTT_SCALE*hz).
 206          */
 207         int                     smoothed_rtt;
 208         /* Is SACK enabled? */
 209         u_char                  sack_enabled;
 210         /* Window scaling for snd window. */
 211         u_char                  snd_scale;
 212         /* Window scaling for recv window. */
 213         u_char                  rcv_scale;
 214         /* TCP control block flags. */
 215         u_int                   flags;
 216         /* Retransmit timeout length. */
 217         int                     rxt_length;
 218         /* Size of the TCP send buffer in bytes. */
 219         u_int                   snd_buf_hiwater;
 220         /* Current num bytes in the send socket buffer. */
 221         u_int                   snd_buf_cc;
 222         /* Size of the TCP receive buffer in bytes. */
 223         u_int                   rcv_buf_hiwater;
 224         /* Current num bytes in the receive socket buffer. */
 225         u_int                   rcv_buf_cc;
 226         /* Number of bytes inflight that we are waiting on ACKs for. */
 227         u_int                   sent_inflight_bytes;
 228         /* Number of segments currently in the reassembly queue. */
 229         int                     t_segqlen;
 230         /* Flowid for the connection. */
 231         u_int                   flowid;
 232         /* Flow type for the connection. */
 233         u_int                   flowtype;
 234         /* Link to next pkt_node in the list. */
 235         STAILQ_ENTRY(pkt_node)  nodes;
 236 };
 237
 238 struct flow_hash_node
 239 {
 240         uint16_t counter;
 241         uint8_t key[FLOW_KEY_LEN];
 242         LIST_ENTRY(flow_hash_node) nodes;
 243 };
 244
 245 struct siftr_stats
 246 {
 247         /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */
 248         uint64_t n_in;
 249         uint64_t n_out;
 250         /* # pkts skipped due to failed malloc calls. */
 251         uint32_t nskip_in_malloc;
 252         uint32_t nskip_out_malloc;
 253         /* # pkts skipped due to failed mtx acquisition. */
 254         uint32_t nskip_in_mtx;
 255         uint32_t nskip_out_mtx;
 256         /* # pkts skipped due to failed inpcb lookups. */
 257         uint32_t nskip_in_inpcb;
 258         uint32_t nskip_out_inpcb;
 259         /* # pkts skipped due to failed tcpcb lookups. */
 260         uint32_t nskip_in_tcpcb;
 261         uint32_t nskip_out_tcpcb;
 262         /* # pkts skipped due to stack reinjection. */
 263         uint32_t nskip_in_dejavu;
 264         uint32_t nskip_out_dejavu;
 265 };
 266
 267 static DPCPU_DEFINE(struct siftr_stats, ss);
 268
 269 static volatile unsigned int siftr_exit_pkt_manager_thread = 0;
 270 static unsigned int siftr_enabled = 0;
 271 static unsigned int siftr_pkts_per_log = 1;
 272 static unsigned int siftr_generate_hashes = 0;
 273 /* static unsigned int siftr_binary_log = 0; */
 274 static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log";
 275 static char siftr_logfile_shadow[PATH_MAX] = "/var/log/siftr.log";
 276 static u_long siftr_hashmask;
 277 STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue);
 278 LIST_HEAD(listhead, flow_hash_node) *counter_hash;
 279 static int wait_for_pkt;
 280 static struct alq *siftr_alq = NULL;
 281 static struct mtx siftr_pkt_queue_mtx;
 282 static struct mtx siftr_pkt_mgr_mtx;
 283 static struct thread *siftr_pkt_manager_thr = NULL;
 284 /*
 285  * pfil.h defines PFIL_IN as 1 and PFIL_OUT as 2,
 286  * which we use as an index into this array.
 287  */
 288 static char direction[3] = {'\0', 'i','o'};
 289
 290 /* Required function prototypes. */
 291 static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS);
 292 static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS);
 293
 294
 295 /* Declare the net.inet.siftr sysctl tree and populate it. */
 296
 297 SYSCTL_DECL(_net_inet_siftr);
 298
 299 SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW, NULL,
 300     "siftr related settings");
 301
 302 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, CTLTYPE_UINT|CTLFLAG_RW,
 303     &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU",
 304     "switch siftr module operations on/off");
 305
 306 SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, CTLTYPE_STRING|CTLFLAG_RW,
 307     &siftr_logfile_shadow, sizeof(siftr_logfile_shadow), &siftr_sysctl_logfile_name_handler,
 308     "A", "file to save siftr log messages to");
 309
 310 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW,
 311     &siftr_pkts_per_log, 1,
 312     "number of packets between generating a log message");
 313
 314 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW,
 315     &siftr_generate_hashes, 0,
 316     "enable packet hash generation");
 317
 318 /* XXX: TODO
 319 SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW,
 320     &siftr_binary_log, 0,
 321     "write log files in binary instead of ascii");
 322 */
 323
 324
 325 /* Begin functions. */
 326
 327 static void
 328 siftr_process_pkt(struct pkt_node * pkt_node)
 329 {
 330         struct flow_hash_node *hash_node;
 331         struct listhead *counter_list;
 332         struct siftr_stats *ss;
 333         struct ale *log_buf;
 334         uint8_t key[FLOW_KEY_LEN];
 335         uint8_t found_match, key_offset;
 336
 337         hash_node = NULL;
 338         ss = DPCPU_PTR(ss);
 339         found_match = 0;
 340         key_offset = 1;
 341
 342         /*
 343          * Create the key that will be used to create a hash index
 344          * into our hash table. Our key consists of:
 345          * ipversion, localip, localport, foreignip, foreignport
 346          */
 347         key[0] = pkt_node->ipver;
 348         memcpy(key + key_offset, &pkt_node->ip_laddr,
 349             sizeof(pkt_node->ip_laddr));
 350         key_offset += sizeof(pkt_node->ip_laddr);
 351         memcpy(key + key_offset, &pkt_node->tcp_localport,
 352             sizeof(pkt_node->tcp_localport));
 353         key_offset += sizeof(pkt_node->tcp_localport);
 354         memcpy(key + key_offset, &pkt_node->ip_faddr,
 355             sizeof(pkt_node->ip_faddr));
 356         key_offset += sizeof(pkt_node->ip_faddr);
 357         memcpy(key + key_offset, &pkt_node->tcp_foreignport,
 358             sizeof(pkt_node->tcp_foreignport));
 359
 360         counter_list = counter_hash +
 361             (hash32_buf(key, sizeof(key), 0) & siftr_hashmask);
 362
 363         /*
 364          * If the list is not empty i.e. the hash index has
 365          * been used by another flow previously.
 366          */
 367         if (LIST_FIRST(counter_list) != NULL) {
 368                 /*
 369                  * Loop through the hash nodes in the list.
 370                  * There should normally only be 1 hash node in the list,
 371                  * except if there have been collisions at the hash index
 372                  * computed by hash32_buf().
 373                  */
 374                 LIST_FOREACH(hash_node, counter_list, nodes) {
 375                         /*
 376                          * Check if the key for the pkt we are currently
 377                          * processing is the same as the key stored in the
 378                          * hash node we are currently processing.
 379                          * If they are the same, then we've found the
 380                          * hash node that stores the counter for the flow
 381                          * the pkt belongs to.
 382                          */
 383                         if (memcmp(hash_node->key, key, sizeof(key)) == 0) {
 384                                 found_match = 1;
 385                                 break;
 386                         }
 387                 }
 388         }
 389
 390         /* If this flow hash hasn't been seen before or we have a collision. */
 391         if (hash_node == NULL || !found_match) {
 392                 /* Create a new hash node to store the flow's counter. */
 393                 hash_node = malloc(sizeof(struct flow_hash_node),
 394                     M_SIFTR_HASHNODE, M_WAITOK);
 395
 396                 if (hash_node != NULL) {
 397                         /* Initialise our new hash node list entry. */
 398                         hash_node->counter = 0;
 399                         memcpy(hash_node->key, key, sizeof(key));
 400                         LIST_INSERT_HEAD(counter_list, hash_node, nodes);
 401                 } else {
 402                         /* Malloc failed. */
 403                         if (pkt_node->direction == PFIL_IN)
 404                                 ss->nskip_in_malloc++;
 405                         else
 406                                 ss->nskip_out_malloc++;
 407
 408                         return;
 409                 }
 410         } else if (siftr_pkts_per_log > 1) {
 411                 /*
 412                  * Taking the remainder of the counter divided
 413                  * by the current value of siftr_pkts_per_log
 414                  * and storing that in counter provides a neat
 415                  * way to modulate the frequency of log
 416                  * messages being written to the log file.
 417                  */
 418                 hash_node->counter = (hash_node->counter + 1) %
 419                     siftr_pkts_per_log;
 420
 421                 /*
 422                  * If we have not seen enough packets since the last time
 423                  * we wrote a log message for this connection, return.
 424                  */
 425                 if (hash_node->counter > 0)
 426                         return;
 427         }
 428
 429         log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK);
 430
 431         if (log_buf == NULL)
 432                 return; /* Should only happen if the ALQ is shutting down. */
 433
 434 #ifdef SIFTR_IPV6
 435         pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]);
 436         pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]);
 437
 438         if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */
 439                 pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]);
 440                 pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]);
 441                 pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]);
 442                 pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]);
 443                 pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]);
 444                 pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]);
 445
 446                 /* Construct an IPv6 log message. */
 447                 log_buf->ae_bytesused = snprintf(log_buf->ae_data,
 448                     MAX_LOG_MSG_LEN,
 449                     "%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:"
 450                     "%x:%x:%x:%x:%x,%u,%ld,%ld,%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,"
 451                     "%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n",
 452                     direction[pkt_node->direction],
 453                     pkt_node->hash,
 454                     pkt_node->tval.tv_sec,
 455                     pkt_node->tval.tv_usec,
 456                     UPPER_SHORT(pkt_node->ip_laddr[0]),
 457                     LOWER_SHORT(pkt_node->ip_laddr[0]),
 458                     UPPER_SHORT(pkt_node->ip_laddr[1]),
 459                     LOWER_SHORT(pkt_node->ip_laddr[1]),
 460                     UPPER_SHORT(pkt_node->ip_laddr[2]),
 461                     LOWER_SHORT(pkt_node->ip_laddr[2]),
 462                     UPPER_SHORT(pkt_node->ip_laddr[3]),
 463                     LOWER_SHORT(pkt_node->ip_laddr[3]),
 464                     ntohs(pkt_node->tcp_localport),
 465                     UPPER_SHORT(pkt_node->ip_faddr[0]),
 466                     LOWER_SHORT(pkt_node->ip_faddr[0]),
 467                     UPPER_SHORT(pkt_node->ip_faddr[1]),
 468                     LOWER_SHORT(pkt_node->ip_faddr[1]),
 469                     UPPER_SHORT(pkt_node->ip_faddr[2]),
 470                     LOWER_SHORT(pkt_node->ip_faddr[2]),
 471                     UPPER_SHORT(pkt_node->ip_faddr[3]),
 472                     LOWER_SHORT(pkt_node->ip_faddr[3]),
 473                     ntohs(pkt_node->tcp_foreignport),
 474                     pkt_node->snd_ssthresh,
 475                     pkt_node->snd_cwnd,
 476                     pkt_node->snd_bwnd,
 477                     pkt_node->snd_wnd,
 478                     pkt_node->rcv_wnd,
 479                     pkt_node->snd_scale,
 480                     pkt_node->rcv_scale,
 481                     pkt_node->conn_state,
 482                     pkt_node->max_seg_size,
 483                     pkt_node->smoothed_rtt,
 484                     pkt_node->sack_enabled,
 485                     pkt_node->flags,
 486                     pkt_node->rxt_length,
 487                     pkt_node->snd_buf_hiwater,
 488                     pkt_node->snd_buf_cc,
 489                     pkt_node->rcv_buf_hiwater,
 490                     pkt_node->rcv_buf_cc,
 491                     pkt_node->sent_inflight_bytes,
 492                     pkt_node->t_segqlen,
 493                     pkt_node->flowid,
 494                     pkt_node->flowtype);
 495         } else { /* IPv4 packet */
 496                 pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]);
 497                 pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]);
 498                 pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]);
 499                 pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]);
 500                 pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]);
 501                 pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]);
 502                 pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]);
 503                 pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]);
 504 #endif /* SIFTR_IPV6 */
 505
 506                 /* Construct an IPv4 log message. */
 507                 log_buf->ae_bytesused = snprintf(log_buf->ae_data,
 508                     MAX_LOG_MSG_LEN,
 509                     "%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%ld,%ld,"
 510                     "%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,%u,%d,%u,%u,%u,%u,%u,%u,%u,%u\n",
 511                     direction[pkt_node->direction],
 512                     pkt_node->hash,
 513                     (intmax_t)pkt_node->tval.tv_sec,
 514                     pkt_node->tval.tv_usec,
 515                     pkt_node->ip_laddr[0],
 516                     pkt_node->ip_laddr[1],
 517                     pkt_node->ip_laddr[2],
 518                     pkt_node->ip_laddr[3],
 519                     ntohs(pkt_node->tcp_localport),
 520                     pkt_node->ip_faddr[0],
 521                     pkt_node->ip_faddr[1],
 522                     pkt_node->ip_faddr[2],
 523                     pkt_node->ip_faddr[3],
 524                     ntohs(pkt_node->tcp_foreignport),
 525                     pkt_node->snd_ssthresh,
 526                     pkt_node->snd_cwnd,
 527                     pkt_node->snd_bwnd,
 528                     pkt_node->snd_wnd,
 529                     pkt_node->rcv_wnd,
 530                     pkt_node->snd_scale,
 531                     pkt_node->rcv_scale,
 532                     pkt_node->conn_state,
 533                     pkt_node->max_seg_size,
 534                     pkt_node->smoothed_rtt,
 535                     pkt_node->sack_enabled,
 536                     pkt_node->flags,
 537                     pkt_node->rxt_length,
 538                     pkt_node->snd_buf_hiwater,
 539                     pkt_node->snd_buf_cc,
 540                     pkt_node->rcv_buf_hiwater,
 541                     pkt_node->rcv_buf_cc,
 542                     pkt_node->sent_inflight_bytes,
 543                     pkt_node->t_segqlen,
 544                     pkt_node->flowid,
 545                     pkt_node->flowtype);
 546 #ifdef SIFTR_IPV6
 547         }
 548 #endif
 549
 550         alq_post_flags(siftr_alq, log_buf, 0);
 551 }
 552
 553
 554 static void
 555 siftr_pkt_manager_thread(void *arg)
 556 {
 557         STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue =
 558             STAILQ_HEAD_INITIALIZER(tmp_pkt_queue);
 559         struct pkt_node *pkt_node, *pkt_node_temp;
 560         uint8_t draining;
 561
 562         draining = 2;
 563
 564         mtx_lock(&siftr_pkt_mgr_mtx);
 565
 566         /* draining == 0 when queue has been flushed and it's safe to exit. */
 567         while (draining) {
 568                 /*
 569                  * Sleep until we are signalled to wake because thread has
 570                  * been told to exit or until 1 tick has passed.
 571                  */
 572                 mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait",
 573                     1);
 574
 575                 /* Gain exclusive access to the pkt_node queue. */
 576                 mtx_lock(&siftr_pkt_queue_mtx);
 577
 578                 /*
 579                  * Move pkt_queue to tmp_pkt_queue, which leaves
 580                  * pkt_queue empty and ready to receive more pkt_nodes.
 581                  */
 582                 STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue);
 583
 584                 /*
 585                  * We've finished making changes to the list. Unlock it
 586                  * so the pfil hooks can continue queuing pkt_nodes.
 587                  */
 588                 mtx_unlock(&siftr_pkt_queue_mtx);
 589
 590                 /*
 591                  * We can't hold a mutex whilst calling siftr_process_pkt
 592                  * because ALQ might sleep waiting for buffer space.
 593                  */
 594                 mtx_unlock(&siftr_pkt_mgr_mtx);
 595
 596                 /* Flush all pkt_nodes to the log file. */
 597                 STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes,
 598                     pkt_node_temp) {
 599                         siftr_process_pkt(pkt_node);
 600                         STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes);
 601                         free(pkt_node, M_SIFTR_PKTNODE);
 602                 }
 603
 604                 KASSERT(STAILQ_EMPTY(&tmp_pkt_queue),
 605                     ("SIFTR tmp_pkt_queue not empty after flush"));
 606
 607                 mtx_lock(&siftr_pkt_mgr_mtx);
 608
 609                 /*
 610                  * If siftr_exit_pkt_manager_thread gets set during the window
 611                  * where we are draining the tmp_pkt_queue above, there might
 612                  * still be pkts in pkt_queue that need to be drained.
 613                  * Allow one further iteration to occur after
 614                  * siftr_exit_pkt_manager_thread has been set to ensure
 615                  * pkt_queue is completely empty before we kill the thread.
 616                  *
 617                  * siftr_exit_pkt_manager_thread is set only after the pfil
 618                  * hooks have been removed, so only 1 extra iteration
 619                  * is needed to drain the queue.
 620                  */
 621                 if (siftr_exit_pkt_manager_thread)
 622                         draining--;
 623         }
 624
 625         mtx_unlock(&siftr_pkt_mgr_mtx);
 626
 627         /* Calls wakeup on this thread's struct thread ptr. */
 628         kthread_exit();
 629 }
 630
 631
 632 static uint32_t
 633 hash_pkt(struct mbuf *m, uint32_t offset)
 634 {
 635         uint32_t hash;
 636
 637         hash = 0;
 638
 639         while (m != NULL && offset > m->m_len) {
 640                 /*
 641                  * The IP packet payload does not start in this mbuf, so
 642                  * need to figure out which mbuf it starts in and what offset
 643                  * into the mbuf's data region the payload starts at.
 644                  */
 645                 offset -= m->m_len;
 646                 m = m->m_next;
 647         }
 648
 649         while (m != NULL) {
 650                 /* Ensure there is data in the mbuf */
 651                 if ((m->m_len - offset) > 0)
 652                         hash = hash32_buf(m->m_data + offset,
 653                             m->m_len - offset, hash);
 654
 655                 m = m->m_next;
 656                 offset = 0;
 657         }
 658
 659         return (hash);
 660 }
 661
 662
 663 /*
 664  * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that
 665  * it's a reinjected packet and return. If it doesn't, tag the mbuf and return.
 666  * Return value >0 means the caller should skip processing this mbuf.
 667  */
 668 static inline int
 669 siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss)
 670 {
 671         if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL)
 672             != NULL) {
 673                 if (dir == PFIL_IN)
 674                         ss->nskip_in_dejavu++;
 675                 else
 676                         ss->nskip_out_dejavu++;
 677
 678                 return (1);
 679         } else {
 680                 struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR,
 681                     PACKET_TAG_SIFTR, 0, M_NOWAIT);
 682                 if (tag == NULL) {
 683                         if (dir == PFIL_IN)
 684                                 ss->nskip_in_malloc++;
 685                         else
 686                                 ss->nskip_out_malloc++;
 687
 688                         return (1);
 689                 }
 690
 691                 m_tag_prepend(m, tag);
 692         }
 693
 694         return (0);
 695 }
 696
 697
 698 /*
 699  * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL
 700  * otherwise.
 701  */
 702 static inline struct inpcb *
 703 siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport,
 704     uint16_t dport, int dir, struct siftr_stats *ss)
 705 {
 706         struct inpcb *inp;
 707
 708         /* We need the tcbinfo lock. */
 709         INP_INFO_UNLOCK_ASSERT(&V_tcbinfo);
 710
 711         if (dir == PFIL_IN)
 712                 inp = (ipver == INP_IPV4 ?
 713                     in_pcblookup(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst,
 714                     dport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
 715                     :
 716 #ifdef SIFTR_IPV6
 717                     in6_pcblookup(&V_tcbinfo,
 718                     &((struct ip6_hdr *)ip)->ip6_src, sport,
 719                     &((struct ip6_hdr *)ip)->ip6_dst, dport, INPLOOKUP_RLOCKPCB,
 720                     m->m_pkthdr.rcvif)
 721 #else
 722                     NULL
 723 #endif
 724                     );
 725
 726         else
 727                 inp = (ipver == INP_IPV4 ?
 728                     in_pcblookup(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src,
 729                     sport, INPLOOKUP_RLOCKPCB, m->m_pkthdr.rcvif)
 730                     :
 731 #ifdef SIFTR_IPV6
 732                     in6_pcblookup(&V_tcbinfo,
 733                     &((struct ip6_hdr *)ip)->ip6_dst, dport,
 734                     &((struct ip6_hdr *)ip)->ip6_src, sport, INPLOOKUP_RLOCKPCB,
 735                     m->m_pkthdr.rcvif)
 736 #else
 737                     NULL
 738 #endif
 739                     );
 740
 741         /* If we can't find the inpcb, bail. */
 742         if (inp == NULL) {
 743                 if (dir == PFIL_IN)
 744                         ss->nskip_in_inpcb++;
 745                 else
 746                         ss->nskip_out_inpcb++;
 747         }
 748
 749         return (inp);
 750 }
 751
 752
 753 static inline void
 754 siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp,
 755     int ipver, int dir, int inp_locally_locked)
 756 {
 757 #ifdef SIFTR_IPV6
 758         if (ipver == INP_IPV4) {
 759                 pn->ip_laddr[3] = inp->inp_laddr.s_addr;
 760                 pn->ip_faddr[3] = inp->inp_faddr.s_addr;
 761 #else
 762                 *((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr;
 763                 *((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr;
 764 #endif
 765 #ifdef SIFTR_IPV6
 766         } else {
 767                 pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0];
 768                 pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1];
 769                 pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2];
 770                 pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3];
 771                 pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0];
 772                 pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1];
 773                 pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2];
 774                 pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3];
 775         }
 776 #endif
 777         pn->tcp_localport = inp->inp_lport;
 778         pn->tcp_foreignport = inp->inp_fport;
 779         pn->snd_cwnd = tp->snd_cwnd;
 780         pn->snd_wnd = tp->snd_wnd;
 781         pn->rcv_wnd = tp->rcv_wnd;
 782         pn->snd_bwnd = 0;               /* Unused, kept for compat. */
 783         pn->snd_ssthresh = tp->snd_ssthresh;
 784         pn->snd_scale = tp->snd_scale;
 785         pn->rcv_scale = tp->rcv_scale;
 786         pn->conn_state = tp->t_state;
 787         pn->max_seg_size = tp->t_maxseg;
 788         pn->smoothed_rtt = tp->t_srtt;
 789         pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0;
 790         pn->flags = tp->t_flags;
 791         pn->rxt_length = tp->t_rxtcur;
 792         pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat;
 793         pn->snd_buf_cc = sbused(&inp->inp_socket->so_snd);
 794         pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat;
 795         pn->rcv_buf_cc = sbused(&inp->inp_socket->so_rcv);
 796         pn->sent_inflight_bytes = tp->snd_max - tp->snd_una;
 797         pn->t_segqlen = tp->t_segqlen;
 798         pn->flowid = inp->inp_flowid;
 799         pn->flowtype = inp->inp_flowtype;
 800
 801         /* We've finished accessing the tcb so release the lock. */
 802         if (inp_locally_locked)
 803                 INP_RUNLOCK(inp);
 804
 805         pn->ipver = ipver;
 806         pn->direction = dir;
 807
 808         /*
 809          * Significantly more accurate than using getmicrotime(), but slower!
 810          * Gives true microsecond resolution at the expense of a hit to
 811          * maximum pps throughput processing when SIFTR is loaded and enabled.
 812          */
 813         microtime(&pn->tval);
 814         TCP_PROBE1(siftr, &pn);
 815
 816 }
 817
 818
 819 /*
 820  * pfil hook that is called for each IPv4 packet making its way through the
 821  * stack in either direction.
 822  * The pfil subsystem holds a non-sleepable mutex somewhere when
 823  * calling our hook function, so we can't sleep at all.
 824  * It's very important to use the M_NOWAIT flag with all function calls
 825  * that support it so that they won't sleep, otherwise you get a panic.
 826  */
 827 static int
 828 siftr_chkpkt(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
 829     struct inpcb *inp)
 830 {
 831         struct pkt_node *pn;
 832         struct ip *ip;
 833         struct tcphdr *th;
 834         struct tcpcb *tp;
 835         struct siftr_stats *ss;
 836         unsigned int ip_hl;
 837         int inp_locally_locked;
 838
 839         inp_locally_locked = 0;
 840         ss = DPCPU_PTR(ss);
 841
 842         /*
 843          * m_pullup is not required here because ip_{input|output}
 844          * already do the heavy lifting for us.
 845          */
 846
 847         ip = mtod(*m, struct ip *);
 848
 849         /* Only continue processing if the packet is TCP. */
 850         if (ip->ip_p != IPPROTO_TCP)
 851                 goto ret;
 852
 853         /*
 854          * If a kernel subsystem reinjects packets into the stack, our pfil
 855          * hook will be called multiple times for the same packet.
 856          * Make sure we only process unique packets.
 857          */
 858         if (siftr_chkreinject(*m, dir, ss))
 859                 goto ret;
 860
 861         if (dir == PFIL_IN)
 862                 ss->n_in++;
 863         else
 864                 ss->n_out++;
 865
 866         /*
 867          * Create a tcphdr struct starting at the correct offset
 868          * in the IP packet. ip->ip_hl gives the ip header length
 869          * in 4-byte words, so multiply it to get the size in bytes.
 870          */
 871         ip_hl = (ip->ip_hl << 2);
 872         th = (struct tcphdr *)((caddr_t)ip + ip_hl);
 873
 874         /*
 875          * If the pfil hooks don't provide a pointer to the
 876          * inpcb, we need to find it ourselves and lock it.
 877          */
 878         if (!inp) {
 879                 /* Find the corresponding inpcb for this pkt. */
 880                 inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport,
 881                     th->th_dport, dir, ss);
 882
 883                 if (inp == NULL)
 884                         goto ret;
 885                 else
 886                         inp_locally_locked = 1;
 887         }
 888
 889         INP_LOCK_ASSERT(inp);
 890
 891         /* Find the TCP control block that corresponds with this packet */
 892         tp = intotcpcb(inp);
 893
 894         /*
 895          * If we can't find the TCP control block (happens occasionaly for a
 896          * packet sent during the shutdown phase of a TCP connection),
 897          * or we're in the timewait state, bail
 898          */
 899         if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
 900                 if (dir == PFIL_IN)
 901                         ss->nskip_in_tcpcb++;
 902                 else
 903                         ss->nskip_out_tcpcb++;
 904
 905                 goto inp_unlock;
 906         }
 907
 908         pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
 909
 910         if (pn == NULL) {
 911                 if (dir == PFIL_IN)
 912                         ss->nskip_in_malloc++;
 913                 else
 914                         ss->nskip_out_malloc++;
 915
 916                 goto inp_unlock;
 917         }
 918
 919         siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked);
 920
 921         if (siftr_generate_hashes) {
 922                 if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) {
 923                         /*
 924                          * For outbound packets, the TCP checksum isn't
 925                          * calculated yet. This is a problem for our packet
 926                          * hashing as the receiver will calc a different hash
 927                          * to ours if we don't include the correct TCP checksum
 928                          * in the bytes being hashed. To work around this
 929                          * problem, we manually calc the TCP checksum here in
 930                          * software. We unset the CSUM_TCP flag so the lower
 931                          * layers don't recalc it.
 932                          */
 933                         (*m)->m_pkthdr.csum_flags &= ~CSUM_TCP;
 934
 935                         /*
 936                          * Calculate the TCP checksum in software and assign
 937                          * to correct TCP header field, which will follow the
 938                          * packet mbuf down the stack. The trick here is that
 939                          * tcp_output() sets th->th_sum to the checksum of the
 940                          * pseudo header for us already. Because of the nature
 941                          * of the checksumming algorithm, we can sum over the
 942                          * entire IP payload (i.e. TCP header and data), which
 943                          * will include the already calculated pseduo header
 944                          * checksum, thus giving us the complete TCP checksum.
 945                          *
 946                          * To put it in simple terms, if checksum(1,2,3,4)=10,
 947                          * then checksum(1,2,3,4,5) == checksum(10,5).
 948                          * This property is what allows us to "cheat" and
 949                          * checksum only the IP payload which has the TCP
 950                          * th_sum field populated with the pseudo header's
 951                          * checksum, and not need to futz around checksumming
 952                          * pseudo header bytes and TCP header/data in one hit.
 953                          * Refer to RFC 1071 for more info.
 954                          *
 955                          * NB: in_cksum_skip(struct mbuf *m, int len, int skip)
 956                          * in_cksum_skip 2nd argument is NOT the number of
 957                          * bytes to read from the mbuf at "skip" bytes offset
 958                          * from the start of the mbuf (very counter intuitive!).
 959                          * The number of bytes to read is calculated internally
 960                          * by the function as len-skip i.e. to sum over the IP
 961                          * payload (TCP header + data) bytes, it is INCORRECT
 962                          * to call the function like this:
 963                          * in_cksum_skip(at, ip->ip_len - offset, offset)
 964                          * Rather, it should be called like this:
 965                          * in_cksum_skip(at, ip->ip_len, offset)
 966                          * which means read "ip->ip_len - offset" bytes from
 967                          * the mbuf cluster "at" at offset "offset" bytes from
 968                          * the beginning of the "at" mbuf's data pointer.
 969                          */
 970                         th->th_sum = in_cksum_skip(*m, ntohs(ip->ip_len),
 971                             ip_hl);
 972                 }
 973
 974                 /*
 975                  * XXX: Having to calculate the checksum in software and then
 976                  * hash over all bytes is really inefficient. Would be nice to
 977                  * find a way to create the hash and checksum in the same pass
 978                  * over the bytes.
 979                  */
 980                 pn->hash = hash_pkt(*m, ip_hl);
 981         }
 982
 983         mtx_lock(&siftr_pkt_queue_mtx);
 984         STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
 985         mtx_unlock(&siftr_pkt_queue_mtx);
 986         goto ret;
 987
 988 inp_unlock:
 989         if (inp_locally_locked)
 990                 INP_RUNLOCK(inp);
 991
 992 ret:
 993         /* Returning 0 ensures pfil will not discard the pkt */
 994         return (0);
 995 }
 996
 997
 998 #ifdef SIFTR_IPV6
 999 static int
1000 siftr_chkpkt6(void *arg, struct mbuf **m, struct ifnet *ifp, int dir,
1001     struct inpcb *inp)
1002 {
1003         struct pkt_node *pn;
1004         struct ip6_hdr *ip6;
1005         struct tcphdr *th;
1006         struct tcpcb *tp;
1007         struct siftr_stats *ss;
1008         unsigned int ip6_hl;
1009         int inp_locally_locked;
1010
1011         inp_locally_locked = 0;
1012         ss = DPCPU_PTR(ss);
1013
1014         /*
1015          * m_pullup is not required here because ip6_{input|output}
1016          * already do the heavy lifting for us.
1017          */
1018
1019         ip6 = mtod(*m, struct ip6_hdr *);
1020
1021         /*
1022          * Only continue processing if the packet is TCP
1023          * XXX: We should follow the next header fields
1024          * as shown on Pg 6 RFC 2460, but right now we'll
1025          * only check pkts that have no extension headers.
1026          */
1027         if (ip6->ip6_nxt != IPPROTO_TCP)
1028                 goto ret6;
1029
1030         /*
1031          * If a kernel subsystem reinjects packets into the stack, our pfil
1032          * hook will be called multiple times for the same packet.
1033          * Make sure we only process unique packets.
1034          */
1035         if (siftr_chkreinject(*m, dir, ss))
1036                 goto ret6;
1037
1038         if (dir == PFIL_IN)
1039                 ss->n_in++;
1040         else
1041                 ss->n_out++;
1042
1043         ip6_hl = sizeof(struct ip6_hdr);
1044
1045         /*
1046          * Create a tcphdr struct starting at the correct offset
1047          * in the ipv6 packet. ip->ip_hl gives the ip header length
1048          * in 4-byte words, so multiply it to get the size in bytes.
1049          */
1050         th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl);
1051
1052         /*
1053          * For inbound packets, the pfil hooks don't provide a pointer to the
1054          * inpcb, so we need to find it ourselves and lock it.
1055          */
1056         if (!inp) {
1057                 /* Find the corresponding inpcb for this pkt. */
1058                 inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m,
1059                     th->th_sport, th->th_dport, dir, ss);
1060
1061                 if (inp == NULL)
1062                         goto ret6;
1063                 else
1064                         inp_locally_locked = 1;
1065         }
1066
1067         /* Find the TCP control block that corresponds with this packet. */
1068         tp = intotcpcb(inp);
1069
1070         /*
1071          * If we can't find the TCP control block (happens occasionaly for a
1072          * packet sent during the shutdown phase of a TCP connection),
1073          * or we're in the timewait state, bail.
1074          */
1075         if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) {
1076                 if (dir == PFIL_IN)
1077                         ss->nskip_in_tcpcb++;
1078                 else
1079                         ss->nskip_out_tcpcb++;
1080
1081                 goto inp_unlock6;
1082         }
1083
1084         pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO);
1085
1086         if (pn == NULL) {
1087                 if (dir == PFIL_IN)
1088                         ss->nskip_in_malloc++;
1089                 else
1090                         ss->nskip_out_malloc++;
1091
1092                 goto inp_unlock6;
1093         }
1094
1095         siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked);
1096
1097         /* XXX: Figure out how to generate hashes for IPv6 packets. */
1098
1099         mtx_lock(&siftr_pkt_queue_mtx);
1100         STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes);
1101         mtx_unlock(&siftr_pkt_queue_mtx);
1102         goto ret6;
1103
1104 inp_unlock6:
1105         if (inp_locally_locked)
1106                 INP_RUNLOCK(inp);
1107
1108 ret6:
1109         /* Returning 0 ensures pfil will not discard the pkt. */
1110         return (0);
1111 }
1112 #endif /* #ifdef SIFTR_IPV6 */
1113
1114
1115 static int
1116 siftr_pfil(int action)
1117 {
1118         struct pfil_head *pfh_inet;
1119 #ifdef SIFTR_IPV6
1120         struct pfil_head *pfh_inet6;
1121 #endif
1122         VNET_ITERATOR_DECL(vnet_iter);
1123
1124         VNET_LIST_RLOCK();
1125         VNET_FOREACH(vnet_iter) {
1126                 CURVNET_SET(vnet_iter);
1127                 pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET);
1128 #ifdef SIFTR_IPV6
1129                 pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6);
1130 #endif
1131
1132                 if (action == HOOK) {
1133                         pfil_add_hook(siftr_chkpkt, NULL,
1134                             PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet);
1135 #ifdef SIFTR_IPV6
1136                         pfil_add_hook(siftr_chkpkt6, NULL,
1137                             PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6);
1138 #endif
1139                 } else if (action == UNHOOK) {
1140                         pfil_remove_hook(siftr_chkpkt, NULL,
1141                             PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet);
1142 #ifdef SIFTR_IPV6
1143                         pfil_remove_hook(siftr_chkpkt6, NULL,
1144                             PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6);
1145 #endif
1146                 }
1147                 CURVNET_RESTORE();
1148         }
1149         VNET_LIST_RUNLOCK();
1150
1151         return (0);
1152 }
1153
1154
1155 static int
1156 siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS)
1157 {
1158         struct alq *new_alq;
1159         int error;
1160
1161         error = sysctl_handle_string(oidp, arg1, arg2, req);
1162
1163         /* Check for error or same filename */
1164         if (error != 0 || req->newptr == NULL ||
1165             strncmp(siftr_logfile, arg1, arg2) == 0)
1166                 goto done;
1167
1168         /* Filname changed */
1169         error = alq_open(&new_alq, arg1, curthread->td_ucred,
1170             SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1171         if (error != 0)
1172                 goto done;
1173
1174         /*
1175          * If disabled, siftr_alq == NULL so we simply close
1176          * the alq as we've proved it can be opened.
1177          * If enabled, close the existing alq and switch the old
1178          * for the new.
1179          */
1180         if (siftr_alq == NULL) {
1181                 alq_close(new_alq);
1182         } else {
1183                 alq_close(siftr_alq);
1184                 siftr_alq = new_alq;
1185         }
1186
1187         /* Update filename upon success */
1188         strlcpy(siftr_logfile, arg1, arg2);
1189 done:
1190         return (error);
1191 }
1192
1193 static int
1194 siftr_manage_ops(uint8_t action)
1195 {
1196         struct siftr_stats totalss;
1197         struct timeval tval;
1198         struct flow_hash_node *counter, *tmp_counter;
1199         struct sbuf *s;
1200         int i, key_index, ret, error;
1201         uint32_t bytes_to_write, total_skipped_pkts;
1202         uint16_t lport, fport;
1203         uint8_t *key, ipver;
1204
1205 #ifdef SIFTR_IPV6
1206         uint32_t laddr[4];
1207         uint32_t faddr[4];
1208 #else
1209         uint8_t laddr[4];
1210         uint8_t faddr[4];
1211 #endif
1212
1213         error = 0;
1214         total_skipped_pkts = 0;
1215
1216         /* Init an autosizing sbuf that initially holds 200 chars. */
1217         if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL)
1218                 return (-1);
1219
1220         if (action == SIFTR_ENABLE && siftr_pkt_manager_thr == NULL) {
1221                 /*
1222                  * Create our alq
1223                  * XXX: We should abort if alq_open fails!
1224                  */
1225                 alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred,
1226                     SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0);
1227
1228                 STAILQ_INIT(&pkt_queue);
1229
1230                 DPCPU_ZERO(ss);
1231
1232                 siftr_exit_pkt_manager_thread = 0;
1233
1234                 ret = kthread_add(&siftr_pkt_manager_thread, NULL, NULL,
1235                     &siftr_pkt_manager_thr, RFNOWAIT, 0,
1236                     "siftr_pkt_manager_thr");
1237
1238                 siftr_pfil(HOOK);
1239
1240                 microtime(&tval);
1241
1242                 sbuf_printf(s,
1243                     "enable_time_secs=%jd\tenable_time_usecs=%06ld\t"
1244                     "siftrver=%s\thz=%u\ttcp_rtt_scale=%u\tsysname=%s\t"
1245                     "sysver=%u\tipmode=%u\n",
1246                     (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, hz,
1247                     TCP_RTT_SCALE, SYS_NAME, __FreeBSD_version, SIFTR_IPMODE);
1248
1249                 sbuf_finish(s);
1250                 alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK);
1251
1252         } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) {
1253                 /*
1254                  * Remove the pfil hook functions. All threads currently in
1255                  * the hook functions are allowed to exit before siftr_pfil()
1256                  * returns.
1257                  */
1258                 siftr_pfil(UNHOOK);
1259
1260                 /* This will block until the pkt manager thread unlocks it. */
1261                 mtx_lock(&siftr_pkt_mgr_mtx);
1262
1263                 /* Tell the pkt manager thread that it should exit now. */
1264                 siftr_exit_pkt_manager_thread = 1;
1265
1266                 /*
1267                  * Wake the pkt_manager thread so it realises that
1268                  * siftr_exit_pkt_manager_thread == 1 and exits gracefully.
1269                  * The wakeup won't be delivered until we unlock
1270                  * siftr_pkt_mgr_mtx so this isn't racy.
1271                  */
1272                 wakeup(&wait_for_pkt);
1273
1274                 /* Wait for the pkt_manager thread to exit. */
1275                 mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT,
1276                     "thrwait", 0);
1277
1278                 siftr_pkt_manager_thr = NULL;
1279                 mtx_unlock(&siftr_pkt_mgr_mtx);
1280
1281                 totalss.n_in = DPCPU_VARSUM(ss, n_in);
1282                 totalss.n_out = DPCPU_VARSUM(ss, n_out);
1283                 totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc);
1284                 totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc);
1285                 totalss.nskip_in_mtx = DPCPU_VARSUM(ss, nskip_in_mtx);
1286                 totalss.nskip_out_mtx = DPCPU_VARSUM(ss, nskip_out_mtx);
1287                 totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb);
1288                 totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb);
1289                 totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb);
1290                 totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb);
1291
1292                 total_skipped_pkts = totalss.nskip_in_malloc +
1293                     totalss.nskip_out_malloc + totalss.nskip_in_mtx +
1294                     totalss.nskip_out_mtx + totalss.nskip_in_tcpcb +
1295                     totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb +
1296                     totalss.nskip_out_inpcb;
1297
1298                 microtime(&tval);
1299
1300                 sbuf_printf(s,
1301                     "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t"
1302                     "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t"
1303                     "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t"
1304                     "num_outbound_skipped_pkts_malloc=%u\t"
1305                     "num_inbound_skipped_pkts_mtx=%u\t"
1306                     "num_outbound_skipped_pkts_mtx=%u\t"
1307                     "num_inbound_skipped_pkts_tcpcb=%u\t"
1308                     "num_outbound_skipped_pkts_tcpcb=%u\t"
1309                     "num_inbound_skipped_pkts_inpcb=%u\t"
1310                     "num_outbound_skipped_pkts_inpcb=%u\t"
1311                     "total_skipped_tcp_pkts=%u\tflow_list=",
1312                     (intmax_t)tval.tv_sec,
1313                     tval.tv_usec,
1314                     (uintmax_t)totalss.n_in,
1315                     (uintmax_t)totalss.n_out,
1316                     (uintmax_t)(totalss.n_in + totalss.n_out),
1317                     totalss.nskip_in_malloc,
1318                     totalss.nskip_out_malloc,
1319                     totalss.nskip_in_mtx,
1320                     totalss.nskip_out_mtx,
1321                     totalss.nskip_in_tcpcb,
1322                     totalss.nskip_out_tcpcb,
1323                     totalss.nskip_in_inpcb,
1324                     totalss.nskip_out_inpcb,
1325                     total_skipped_pkts);
1326
1327                 /*
1328                  * Iterate over the flow hash, printing a summary of each
1329                  * flow seen and freeing any malloc'd memory.
1330                  * The hash consists of an array of LISTs (man 3 queue).
1331                  */
1332                 for (i = 0; i <= siftr_hashmask; i++) {
1333                         LIST_FOREACH_SAFE(counter, counter_hash + i, nodes,
1334                             tmp_counter) {
1335                                 key = counter->key;
1336                                 key_index = 1;
1337
1338                                 ipver = key[0];
1339
1340                                 memcpy(laddr, key + key_index, sizeof(laddr));
1341                                 key_index += sizeof(laddr);
1342                                 memcpy(&lport, key + key_index, sizeof(lport));
1343                                 key_index += sizeof(lport);
1344                                 memcpy(faddr, key + key_index, sizeof(faddr));
1345                                 key_index += sizeof(faddr);
1346                                 memcpy(&fport, key + key_index, sizeof(fport));
1347
1348 #ifdef SIFTR_IPV6
1349                                 laddr[3] = ntohl(laddr[3]);
1350                                 faddr[3] = ntohl(faddr[3]);
1351
1352                                 if (ipver == INP_IPV6) {
1353                                         laddr[0] = ntohl(laddr[0]);
1354                                         laddr[1] = ntohl(laddr[1]);
1355                                         laddr[2] = ntohl(laddr[2]);
1356                                         faddr[0] = ntohl(faddr[0]);
1357                                         faddr[1] = ntohl(faddr[1]);
1358                                         faddr[2] = ntohl(faddr[2]);
1359
1360                                         sbuf_printf(s,
1361                                             "%x:%x:%x:%x:%x:%x:%x:%x;%u-"
1362                                             "%x:%x:%x:%x:%x:%x:%x:%x;%u,",
1363                                             UPPER_SHORT(laddr[0]),
1364                                             LOWER_SHORT(laddr[0]),
1365                                             UPPER_SHORT(laddr[1]),
1366                                             LOWER_SHORT(laddr[1]),
1367                                             UPPER_SHORT(laddr[2]),
1368                                             LOWER_SHORT(laddr[2]),
1369                                             UPPER_SHORT(laddr[3]),
1370                                             LOWER_SHORT(laddr[3]),
1371                                             ntohs(lport),
1372                                             UPPER_SHORT(faddr[0]),
1373                                             LOWER_SHORT(faddr[0]),
1374                                             UPPER_SHORT(faddr[1]),
1375                                             LOWER_SHORT(faddr[1]),
1376                                             UPPER_SHORT(faddr[2]),
1377                                             LOWER_SHORT(faddr[2]),
1378                                             UPPER_SHORT(faddr[3]),
1379                                             LOWER_SHORT(faddr[3]),
1380                                             ntohs(fport));
1381                                 } else {
1382                                         laddr[0] = FIRST_OCTET(laddr[3]);
1383                                         laddr[1] = SECOND_OCTET(laddr[3]);
1384                                         laddr[2] = THIRD_OCTET(laddr[3]);
1385                                         laddr[3] = FOURTH_OCTET(laddr[3]);
1386                                         faddr[0] = FIRST_OCTET(faddr[3]);
1387                                         faddr[1] = SECOND_OCTET(faddr[3]);
1388                                         faddr[2] = THIRD_OCTET(faddr[3]);
1389                                         faddr[3] = FOURTH_OCTET(faddr[3]);
1390 #endif
1391                                         sbuf_printf(s,
1392                                             "%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,",
1393                                             laddr[0],
1394                                             laddr[1],
1395                                             laddr[2],
1396                                             laddr[3],
1397                                             ntohs(lport),
1398                                             faddr[0],
1399                                             faddr[1],
1400                                             faddr[2],
1401                                             faddr[3],
1402                                             ntohs(fport));
1403 #ifdef SIFTR_IPV6
1404                                 }
1405 #endif
1406
1407                                 free(counter, M_SIFTR_HASHNODE);
1408                         }
1409
1410                         LIST_INIT(counter_hash + i);
1411                 }
1412
1413                 sbuf_printf(s, "\n");
1414                 sbuf_finish(s);
1415
1416                 i = 0;
1417                 do {
1418                         bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i);
1419                         alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK);
1420                         i += bytes_to_write;
1421                 } while (i < sbuf_len(s));
1422
1423                 alq_close(siftr_alq);
1424                 siftr_alq = NULL;
1425         } else
1426                 error = EINVAL;
1427
1428         sbuf_delete(s);
1429
1430         /*
1431          * XXX: Should be using ret to check if any functions fail
1432          * and set error appropriately
1433          */
1434
1435         return (error);
1436 }
1437
1438
1439 static int
1440 siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS)
1441 {
1442         int error;
1443         uint32_t new;
1444
1445         new = siftr_enabled;
1446         error = sysctl_handle_int(oidp, &new, 0, req);
1447         if (error == 0 && req->newptr != NULL) {
1448                 if (new > 1)
1449                         return (EINVAL);
1450                 else if (new != siftr_enabled) {
1451                         if ((error = siftr_manage_ops(new)) == 0) {
1452                                 siftr_enabled = new;
1453                         } else {
1454                                 siftr_manage_ops(SIFTR_DISABLE);
1455                         }
1456                 }
1457         }
1458
1459         return (error);
1460 }
1461
1462
1463 static void
1464 siftr_shutdown_handler(void *arg)
1465 {
1466         if (siftr_enabled == 1) {
1467                 siftr_manage_ops(SIFTR_DISABLE);
1468         }
1469 }
1470
1471
1472 /*
1473  * Module is being unloaded or machine is shutting down. Take care of cleanup.
1474  */
1475 static int
1476 deinit_siftr(void)
1477 {
1478         /* Cleanup. */
1479         siftr_manage_ops(SIFTR_DISABLE);
1480         hashdestroy(counter_hash, M_SIFTR, siftr_hashmask);
1481         mtx_destroy(&siftr_pkt_queue_mtx);
1482         mtx_destroy(&siftr_pkt_mgr_mtx);
1483
1484         return (0);
1485 }
1486
1487
1488 /*
1489  * Module has just been loaded into the kernel.
1490  */
1491 static int
1492 init_siftr(void)
1493 {
1494         EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL,
1495             SHUTDOWN_PRI_FIRST);
1496
1497         /* Initialise our flow counter hash table. */
1498         counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR,
1499             &siftr_hashmask);
1500
1501         mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF);
1502         mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF);
1503
1504         /* Print message to the user's current terminal. */
1505         uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n"
1506             "          http://caia.swin.edu.au/urp/newtcp\n\n",
1507             MODVERSION_STR);
1508
1509         return (0);
1510 }
1511
1512
1513 /*
1514  * This is the function that is called to load and unload the module.
1515  * When the module is loaded, this function is called once with
1516  * "what" == MOD_LOAD
1517  * When the module is unloaded, this function is called twice with
1518  * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second
1519  * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command,
1520  * this function is called once with "what" = MOD_SHUTDOWN
1521  * When the system is shut down, the handler isn't called until the very end
1522  * of the shutdown sequence i.e. after the disks have been synced.
1523  */
1524 static int
1525 siftr_load_handler(module_t mod, int what, void *arg)
1526 {
1527         int ret;
1528
1529         switch (what) {
1530         case MOD_LOAD:
1531                 ret = init_siftr();
1532                 break;
1533
1534         case MOD_QUIESCE:
1535         case MOD_SHUTDOWN:
1536                 ret = deinit_siftr();
1537                 break;
1538
1539         case MOD_UNLOAD:
1540                 ret = 0;
1541                 break;
1542
1543         default:
1544                 ret = EINVAL;
1545                 break;
1546         }
1547
1548         return (ret);
1549 }
1550
1551
1552 static moduledata_t siftr_mod = {
1553         .name = "siftr",
1554         .evhand = siftr_load_handler,
1555 };
1556
1557 /*
1558  * Param 1: name of the kernel module
1559  * Param 2: moduledata_t struct containing info about the kernel module
1560  *          and the execution entry point for the module
1561  * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h
1562  *          Defines the module initialisation order
1563  * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h
1564  *          Defines the initialisation order of this kld relative to others
1565  *          within the same subsystem as defined by param 3
1566  */
1567 DECLARE_MODULE(siftr, siftr_mod, SI_SUB_LAST, SI_ORDER_ANY);
1568 MODULE_DEPEND(siftr, alq, 1, 1, 1);
1569 MODULE_VERSION(siftr, MODVERSION);