/*- * Copyright (c) 2007-2009, Centre for Advanced Internet Architectures * Swinburne University of Technology, Melbourne, Australia * (CRICOS number 00111D). * Copyright (c) 2009-2010, The FreeBSD Foundation * All rights reserved. * * Portions of this software were developed at the Centre for Advanced * Internet Architectures, Swinburne University of Technology, Melbourne, * Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /****************************************************** * Statistical Information For TCP Research (SIFTR) * * A FreeBSD kernel module that adds very basic intrumentation to the * TCP stack, allowing internal stats to be recorded to a log file * for experimental, debugging and performance analysis purposes. * * SIFTR was first released in 2007 by James Healy and Lawrence Stewart whilst * working on the NewTCP research project at Swinburne University's Centre for * Advanced Internet Architectures, Melbourne, Australia, which was made * possible in part by a grant from the Cisco University Research Program Fund * at Community Foundation Silicon Valley. More details are available at: * http://caia.swin.edu.au/urp/newtcp/ * * Work on SIFTR v1.2.x was sponsored by the FreeBSD Foundation as part of * the "Enhancing the FreeBSD TCP Implementation" project 2008-2009. * More details are available at: * http://www.freebsdfoundation.org/ * http://caia.swin.edu.au/freebsd/etcp09/ * * Lawrence Stewart is the current maintainer, and all contact regarding * SIFTR should be directed to him via email: lastewart@swin.edu.au * * Initial release date: June 2007 * Most recent update: June 2010 ******************************************************/ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef SIFTR_IPV6 #include #include #endif /* SIFTR_IPV6 */ #include /* * Three digit version number refers to X.Y.Z where: * X is the major version number * Y is bumped to mark backwards incompatible changes * Z is bumped to mark backwards compatible changes */ #define V_MAJOR 1 #define V_BACKBREAK 2 #define V_BACKCOMPAT 3 #define MODVERSION __CONCAT(V_MAJOR, __CONCAT(V_BACKBREAK, V_BACKCOMPAT)) #define MODVERSION_STR __XSTRING(V_MAJOR) "." __XSTRING(V_BACKBREAK) "." \ __XSTRING(V_BACKCOMPAT) #define HOOK 0 #define UNHOOK 1 #define SIFTR_EXPECTED_MAX_TCP_FLOWS 65536 #define SYS_NAME "FreeBSD" #define PACKET_TAG_SIFTR 100 #define PACKET_COOKIE_SIFTR 21749576 #define SIFTR_LOG_FILE_MODE 0644 #define SIFTR_DISABLE 0 #define SIFTR_ENABLE 1 /* * Hard upper limit on the length of log messages. Bump this up if you add new * data fields such that the line length could exceed the below value. */ #define MAX_LOG_MSG_LEN 200 /* XXX: Make this a sysctl tunable. */ #define SIFTR_ALQ_BUFLEN (1000*MAX_LOG_MSG_LEN) /* * 1 byte for IP version * IPv4: src/dst IP (4+4) + src/dst port (2+2) = 12 bytes * IPv6: src/dst IP (16+16) + src/dst port (2+2) = 36 bytes */ #ifdef SIFTR_IPV6 #define FLOW_KEY_LEN 37 #else #define FLOW_KEY_LEN 13 #endif #ifdef SIFTR_IPV6 #define SIFTR_IPMODE 6 #else #define SIFTR_IPMODE 4 #endif /* useful macros */ #define CAST_PTR_INT(X) (*((int*)(X))) #define UPPER_SHORT(X) (((X) & 0xFFFF0000) >> 16) #define LOWER_SHORT(X) ((X) & 0x0000FFFF) #define FIRST_OCTET(X) (((X) & 0xFF000000) >> 24) #define SECOND_OCTET(X) (((X) & 0x00FF0000) >> 16) #define THIRD_OCTET(X) (((X) & 0x0000FF00) >> 8) #define FOURTH_OCTET(X) ((X) & 0x000000FF) MALLOC_DECLARE(M_SIFTR); MALLOC_DEFINE(M_SIFTR, "siftr", "dynamic memory used by SIFTR"); MALLOC_DECLARE(M_SIFTR_PKTNODE); MALLOC_DEFINE(M_SIFTR_PKTNODE, "siftr_pktnode", "SIFTR pkt_node struct"); MALLOC_DECLARE(M_SIFTR_HASHNODE); MALLOC_DEFINE(M_SIFTR_HASHNODE, "siftr_hashnode", "SIFTR flow_hash_node struct"); /* Used as links in the pkt manager queue. */ struct pkt_node { /* Timestamp of pkt as noted in the pfil hook. */ struct timeval tval; /* Direction pkt is travelling; either PFIL_IN or PFIL_OUT. */ uint8_t direction; /* IP version pkt_node relates to; either INP_IPV4 or INP_IPV6. */ uint8_t ipver; /* Hash of the pkt which triggered the log message. */ uint32_t hash; /* Local/foreign IP address. */ #ifdef SIFTR_IPV6 uint32_t ip_laddr[4]; uint32_t ip_faddr[4]; #else uint8_t ip_laddr[4]; uint8_t ip_faddr[4]; #endif /* Local TCP port. */ uint16_t tcp_localport; /* Foreign TCP port. */ uint16_t tcp_foreignport; /* Congestion Window (bytes). */ u_long snd_cwnd; /* Sending Window (bytes). */ u_long snd_wnd; /* Receive Window (bytes). */ u_long rcv_wnd; /* Unused (was: Bandwidth Controlled Window (bytes)). */ u_long snd_bwnd; /* Slow Start Threshold (bytes). */ u_long snd_ssthresh; /* Current state of the TCP FSM. */ int conn_state; /* Max Segment Size (bytes). */ u_int max_seg_size; /* * Smoothed RTT stored as found in the TCP control block * in units of (TCP_RTT_SCALE*hz). */ int smoothed_rtt; /* Is SACK enabled? */ u_char sack_enabled; /* Window scaling for snd window. */ u_char snd_scale; /* Window scaling for recv window. */ u_char rcv_scale; /* TCP control block flags. */ u_int flags; /* Retransmit timeout length. */ int rxt_length; /* Size of the TCP send buffer in bytes. */ u_int snd_buf_hiwater; /* Current num bytes in the send socket buffer. */ u_int snd_buf_cc; /* Size of the TCP receive buffer in bytes. */ u_int rcv_buf_hiwater; /* Current num bytes in the receive socket buffer. */ u_int rcv_buf_cc; /* Number of bytes inflight that we are waiting on ACKs for. */ u_int sent_inflight_bytes; /* Link to next pkt_node in the list. */ STAILQ_ENTRY(pkt_node) nodes; }; struct flow_hash_node { uint16_t counter; uint8_t key[FLOW_KEY_LEN]; LIST_ENTRY(flow_hash_node) nodes; }; struct siftr_stats { /* # TCP pkts seen by the SIFTR PFIL hooks, including any skipped. */ uint64_t n_in; uint64_t n_out; /* # pkts skipped due to failed malloc calls. */ uint32_t nskip_in_malloc; uint32_t nskip_out_malloc; /* # pkts skipped due to failed mtx acquisition. */ uint32_t nskip_in_mtx; uint32_t nskip_out_mtx; /* # pkts skipped due to failed inpcb lookups. */ uint32_t nskip_in_inpcb; uint32_t nskip_out_inpcb; /* # pkts skipped due to failed tcpcb lookups. */ uint32_t nskip_in_tcpcb; uint32_t nskip_out_tcpcb; /* # pkts skipped due to stack reinjection. */ uint32_t nskip_in_dejavu; uint32_t nskip_out_dejavu; }; static DPCPU_DEFINE(struct siftr_stats, ss); static volatile unsigned int siftr_exit_pkt_manager_thread = 0; static unsigned int siftr_enabled = 0; static unsigned int siftr_pkts_per_log = 1; static unsigned int siftr_generate_hashes = 0; /* static unsigned int siftr_binary_log = 0; */ static char siftr_logfile[PATH_MAX] = "/var/log/siftr.log"; static u_long siftr_hashmask; STAILQ_HEAD(pkthead, pkt_node) pkt_queue = STAILQ_HEAD_INITIALIZER(pkt_queue); LIST_HEAD(listhead, flow_hash_node) *counter_hash; static int wait_for_pkt; static struct alq *siftr_alq = NULL; static struct mtx siftr_pkt_queue_mtx; static struct mtx siftr_pkt_mgr_mtx; static struct thread *siftr_pkt_manager_thr = NULL; /* * pfil.h defines PFIL_IN as 1 and PFIL_OUT as 2, * which we use as an index into this array. */ static char direction[3] = {'\0', 'i','o'}; /* Required function prototypes. */ static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS); static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS); /* Declare the net.inet.siftr sysctl tree and populate it. */ SYSCTL_DECL(_net_inet_siftr); SYSCTL_NODE(_net_inet, OID_AUTO, siftr, CTLFLAG_RW, NULL, "siftr related settings"); SYSCTL_PROC(_net_inet_siftr, OID_AUTO, enabled, CTLTYPE_UINT|CTLFLAG_RW, &siftr_enabled, 0, &siftr_sysctl_enabled_handler, "IU", "switch siftr module operations on/off"); SYSCTL_PROC(_net_inet_siftr, OID_AUTO, logfile, CTLTYPE_STRING|CTLFLAG_RW, &siftr_logfile, sizeof(siftr_logfile), &siftr_sysctl_logfile_name_handler, "A", "file to save siftr log messages to"); SYSCTL_UINT(_net_inet_siftr, OID_AUTO, ppl, CTLFLAG_RW, &siftr_pkts_per_log, 1, "number of packets between generating a log message"); SYSCTL_UINT(_net_inet_siftr, OID_AUTO, genhashes, CTLFLAG_RW, &siftr_generate_hashes, 0, "enable packet hash generation"); /* XXX: TODO SYSCTL_UINT(_net_inet_siftr, OID_AUTO, binary, CTLFLAG_RW, &siftr_binary_log, 0, "write log files in binary instead of ascii"); */ /* Begin functions. */ static void siftr_process_pkt(struct pkt_node * pkt_node) { struct flow_hash_node *hash_node; struct listhead *counter_list; struct siftr_stats *ss; struct ale *log_buf; uint8_t key[FLOW_KEY_LEN]; uint8_t found_match, key_offset; hash_node = NULL; ss = DPCPU_PTR(ss); found_match = 0; key_offset = 1; /* * Create the key that will be used to create a hash index * into our hash table. Our key consists of: * ipversion, localip, localport, foreignip, foreignport */ key[0] = pkt_node->ipver; memcpy(key + key_offset, &pkt_node->ip_laddr, sizeof(pkt_node->ip_laddr)); key_offset += sizeof(pkt_node->ip_laddr); memcpy(key + key_offset, &pkt_node->tcp_localport, sizeof(pkt_node->tcp_localport)); key_offset += sizeof(pkt_node->tcp_localport); memcpy(key + key_offset, &pkt_node->ip_faddr, sizeof(pkt_node->ip_faddr)); key_offset += sizeof(pkt_node->ip_faddr); memcpy(key + key_offset, &pkt_node->tcp_foreignport, sizeof(pkt_node->tcp_foreignport)); counter_list = counter_hash + (hash32_buf(key, sizeof(key), 0) & siftr_hashmask); /* * If the list is not empty i.e. the hash index has * been used by another flow previously. */ if (LIST_FIRST(counter_list) != NULL) { /* * Loop through the hash nodes in the list. * There should normally only be 1 hash node in the list, * except if there have been collisions at the hash index * computed by hash32_buf(). */ LIST_FOREACH(hash_node, counter_list, nodes) { /* * Check if the key for the pkt we are currently * processing is the same as the key stored in the * hash node we are currently processing. * If they are the same, then we've found the * hash node that stores the counter for the flow * the pkt belongs to. */ if (memcmp(hash_node->key, key, sizeof(key)) == 0) { found_match = 1; break; } } } /* If this flow hash hasn't been seen before or we have a collision. */ if (hash_node == NULL || !found_match) { /* Create a new hash node to store the flow's counter. */ hash_node = malloc(sizeof(struct flow_hash_node), M_SIFTR_HASHNODE, M_WAITOK); if (hash_node != NULL) { /* Initialise our new hash node list entry. */ hash_node->counter = 0; memcpy(hash_node->key, key, sizeof(key)); LIST_INSERT_HEAD(counter_list, hash_node, nodes); } else { /* Malloc failed. */ if (pkt_node->direction == PFIL_IN) ss->nskip_in_malloc++; else ss->nskip_out_malloc++; return; } } else if (siftr_pkts_per_log > 1) { /* * Taking the remainder of the counter divided * by the current value of siftr_pkts_per_log * and storing that in counter provides a neat * way to modulate the frequency of log * messages being written to the log file. */ hash_node->counter = (hash_node->counter + 1) % siftr_pkts_per_log; /* * If we have not seen enough packets since the last time * we wrote a log message for this connection, return. */ if (hash_node->counter > 0) return; } log_buf = alq_getn(siftr_alq, MAX_LOG_MSG_LEN, ALQ_WAITOK); if (log_buf == NULL) return; /* Should only happen if the ALQ is shutting down. */ #ifdef SIFTR_IPV6 pkt_node->ip_laddr[3] = ntohl(pkt_node->ip_laddr[3]); pkt_node->ip_faddr[3] = ntohl(pkt_node->ip_faddr[3]); if (pkt_node->ipver == INP_IPV6) { /* IPv6 packet */ pkt_node->ip_laddr[0] = ntohl(pkt_node->ip_laddr[0]); pkt_node->ip_laddr[1] = ntohl(pkt_node->ip_laddr[1]); pkt_node->ip_laddr[2] = ntohl(pkt_node->ip_laddr[2]); pkt_node->ip_faddr[0] = ntohl(pkt_node->ip_faddr[0]); pkt_node->ip_faddr[1] = ntohl(pkt_node->ip_faddr[1]); pkt_node->ip_faddr[2] = ntohl(pkt_node->ip_faddr[2]); /* Construct an IPv6 log message. */ log_buf->ae_bytesused = snprintf(log_buf->ae_data, MAX_LOG_MSG_LEN, "%c,0x%08x,%zd.%06ld,%x:%x:%x:%x:%x:%x:%x:%x,%u,%x:%x:%x:" "%x:%x:%x:%x:%x,%u,%ld,%ld,%ld,%ld,%ld,%u,%u,%u,%u,%u,%u," "%u,%d,%u,%u,%u,%u,%u\n", direction[pkt_node->direction], pkt_node->hash, pkt_node->tval.tv_sec, pkt_node->tval.tv_usec, UPPER_SHORT(pkt_node->ip_laddr[0]), LOWER_SHORT(pkt_node->ip_laddr[0]), UPPER_SHORT(pkt_node->ip_laddr[1]), LOWER_SHORT(pkt_node->ip_laddr[1]), UPPER_SHORT(pkt_node->ip_laddr[2]), LOWER_SHORT(pkt_node->ip_laddr[2]), UPPER_SHORT(pkt_node->ip_laddr[3]), LOWER_SHORT(pkt_node->ip_laddr[3]), ntohs(pkt_node->tcp_localport), UPPER_SHORT(pkt_node->ip_faddr[0]), LOWER_SHORT(pkt_node->ip_faddr[0]), UPPER_SHORT(pkt_node->ip_faddr[1]), LOWER_SHORT(pkt_node->ip_faddr[1]), UPPER_SHORT(pkt_node->ip_faddr[2]), LOWER_SHORT(pkt_node->ip_faddr[2]), UPPER_SHORT(pkt_node->ip_faddr[3]), LOWER_SHORT(pkt_node->ip_faddr[3]), ntohs(pkt_node->tcp_foreignport), pkt_node->snd_ssthresh, pkt_node->snd_cwnd, pkt_node->snd_bwnd, pkt_node->snd_wnd, pkt_node->rcv_wnd, pkt_node->snd_scale, pkt_node->rcv_scale, pkt_node->conn_state, pkt_node->max_seg_size, pkt_node->smoothed_rtt, pkt_node->sack_enabled, pkt_node->flags, pkt_node->rxt_length, pkt_node->snd_buf_hiwater, pkt_node->snd_buf_cc, pkt_node->rcv_buf_hiwater, pkt_node->rcv_buf_cc, pkt_node->sent_inflight_bytes); } else { /* IPv4 packet */ pkt_node->ip_laddr[0] = FIRST_OCTET(pkt_node->ip_laddr[3]); pkt_node->ip_laddr[1] = SECOND_OCTET(pkt_node->ip_laddr[3]); pkt_node->ip_laddr[2] = THIRD_OCTET(pkt_node->ip_laddr[3]); pkt_node->ip_laddr[3] = FOURTH_OCTET(pkt_node->ip_laddr[3]); pkt_node->ip_faddr[0] = FIRST_OCTET(pkt_node->ip_faddr[3]); pkt_node->ip_faddr[1] = SECOND_OCTET(pkt_node->ip_faddr[3]); pkt_node->ip_faddr[2] = THIRD_OCTET(pkt_node->ip_faddr[3]); pkt_node->ip_faddr[3] = FOURTH_OCTET(pkt_node->ip_faddr[3]); #endif /* SIFTR_IPV6 */ /* Construct an IPv4 log message. */ log_buf->ae_bytesused = snprintf(log_buf->ae_data, MAX_LOG_MSG_LEN, "%c,0x%08x,%jd.%06ld,%u.%u.%u.%u,%u,%u.%u.%u.%u,%u,%ld,%ld," "%ld,%ld,%ld,%u,%u,%u,%u,%u,%u,%u,%d,%u,%u,%u,%u,%u\n", direction[pkt_node->direction], pkt_node->hash, (intmax_t)pkt_node->tval.tv_sec, pkt_node->tval.tv_usec, pkt_node->ip_laddr[0], pkt_node->ip_laddr[1], pkt_node->ip_laddr[2], pkt_node->ip_laddr[3], ntohs(pkt_node->tcp_localport), pkt_node->ip_faddr[0], pkt_node->ip_faddr[1], pkt_node->ip_faddr[2], pkt_node->ip_faddr[3], ntohs(pkt_node->tcp_foreignport), pkt_node->snd_ssthresh, pkt_node->snd_cwnd, pkt_node->snd_bwnd, pkt_node->snd_wnd, pkt_node->rcv_wnd, pkt_node->snd_scale, pkt_node->rcv_scale, pkt_node->conn_state, pkt_node->max_seg_size, pkt_node->smoothed_rtt, pkt_node->sack_enabled, pkt_node->flags, pkt_node->rxt_length, pkt_node->snd_buf_hiwater, pkt_node->snd_buf_cc, pkt_node->rcv_buf_hiwater, pkt_node->rcv_buf_cc, pkt_node->sent_inflight_bytes); #ifdef SIFTR_IPV6 } #endif alq_post_flags(siftr_alq, log_buf, 0); } static void siftr_pkt_manager_thread(void *arg) { STAILQ_HEAD(pkthead, pkt_node) tmp_pkt_queue = STAILQ_HEAD_INITIALIZER(tmp_pkt_queue); struct pkt_node *pkt_node, *pkt_node_temp; uint8_t draining; draining = 2; mtx_lock(&siftr_pkt_mgr_mtx); /* draining == 0 when queue has been flushed and it's safe to exit. */ while (draining) { /* * Sleep until we are signalled to wake because thread has * been told to exit or until 1 tick has passed. */ mtx_sleep(&wait_for_pkt, &siftr_pkt_mgr_mtx, PWAIT, "pktwait", 1); /* Gain exclusive access to the pkt_node queue. */ mtx_lock(&siftr_pkt_queue_mtx); /* * Move pkt_queue to tmp_pkt_queue, which leaves * pkt_queue empty and ready to receive more pkt_nodes. */ STAILQ_CONCAT(&tmp_pkt_queue, &pkt_queue); /* * We've finished making changes to the list. Unlock it * so the pfil hooks can continue queuing pkt_nodes. */ mtx_unlock(&siftr_pkt_queue_mtx); /* * We can't hold a mutex whilst calling siftr_process_pkt * because ALQ might sleep waiting for buffer space. */ mtx_unlock(&siftr_pkt_mgr_mtx); /* Flush all pkt_nodes to the log file. */ STAILQ_FOREACH_SAFE(pkt_node, &tmp_pkt_queue, nodes, pkt_node_temp) { siftr_process_pkt(pkt_node); STAILQ_REMOVE_HEAD(&tmp_pkt_queue, nodes); free(pkt_node, M_SIFTR_PKTNODE); } KASSERT(STAILQ_EMPTY(&tmp_pkt_queue), ("SIFTR tmp_pkt_queue not empty after flush")); mtx_lock(&siftr_pkt_mgr_mtx); /* * If siftr_exit_pkt_manager_thread gets set during the window * where we are draining the tmp_pkt_queue above, there might * still be pkts in pkt_queue that need to be drained. * Allow one further iteration to occur after * siftr_exit_pkt_manager_thread has been set to ensure * pkt_queue is completely empty before we kill the thread. * * siftr_exit_pkt_manager_thread is set only after the pfil * hooks have been removed, so only 1 extra iteration * is needed to drain the queue. */ if (siftr_exit_pkt_manager_thread) draining--; } mtx_unlock(&siftr_pkt_mgr_mtx); /* Calls wakeup on this thread's struct thread ptr. */ kthread_exit(); } static uint32_t hash_pkt(struct mbuf *m, uint32_t offset) { uint32_t hash; hash = 0; while (m != NULL && offset > m->m_len) { /* * The IP packet payload does not start in this mbuf, so * need to figure out which mbuf it starts in and what offset * into the mbuf's data region the payload starts at. */ offset -= m->m_len; m = m->m_next; } while (m != NULL) { /* Ensure there is data in the mbuf */ if ((m->m_len - offset) > 0) hash = hash32_buf(m->m_data + offset, m->m_len - offset, hash); m = m->m_next; offset = 0; } return (hash); } /* * Check if a given mbuf has the SIFTR mbuf tag. If it does, log the fact that * it's a reinjected packet and return. If it doesn't, tag the mbuf and return. * Return value >0 means the caller should skip processing this mbuf. */ static inline int siftr_chkreinject(struct mbuf *m, int dir, struct siftr_stats *ss) { if (m_tag_locate(m, PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, NULL) != NULL) { if (dir == PFIL_IN) ss->nskip_in_dejavu++; else ss->nskip_out_dejavu++; return (1); } else { struct m_tag *tag = m_tag_alloc(PACKET_COOKIE_SIFTR, PACKET_TAG_SIFTR, 0, M_NOWAIT); if (tag == NULL) { if (dir == PFIL_IN) ss->nskip_in_malloc++; else ss->nskip_out_malloc++; return (1); } m_tag_prepend(m, tag); } return (0); } /* * Look up an inpcb for a packet. Return the inpcb pointer if found, or NULL * otherwise. */ static inline struct inpcb * siftr_findinpcb(int ipver, struct ip *ip, struct mbuf *m, uint16_t sport, uint16_t dport, int dir, struct siftr_stats *ss) { struct inpcb *inp; /* We need the tcbinfo lock. */ INP_INFO_UNLOCK_ASSERT(&V_tcbinfo); INP_INFO_RLOCK(&V_tcbinfo); if (dir == PFIL_IN) inp = (ipver == INP_IPV4 ? in_pcblookup_hash(&V_tcbinfo, ip->ip_src, sport, ip->ip_dst, dport, 0, m->m_pkthdr.rcvif) : #ifdef SIFTR_IPV6 in6_pcblookup_hash(&V_tcbinfo, &((struct ip6_hdr *)ip)->ip6_src, sport, &((struct ip6_hdr *)ip)->ip6_dst, dport, 0, m->m_pkthdr.rcvif) #else NULL #endif ); else inp = (ipver == INP_IPV4 ? in_pcblookup_hash(&V_tcbinfo, ip->ip_dst, dport, ip->ip_src, sport, 0, m->m_pkthdr.rcvif) : #ifdef SIFTR_IPV6 in6_pcblookup_hash(&V_tcbinfo, &((struct ip6_hdr *)ip)->ip6_dst, dport, &((struct ip6_hdr *)ip)->ip6_src, sport, 0, m->m_pkthdr.rcvif) #else NULL #endif ); /* If we can't find the inpcb, bail. */ if (inp == NULL) { if (dir == PFIL_IN) ss->nskip_in_inpcb++; else ss->nskip_out_inpcb++; INP_INFO_RUNLOCK(&V_tcbinfo); } else { /* Acquire the inpcb lock. */ INP_UNLOCK_ASSERT(inp); INP_RLOCK(inp); INP_INFO_RUNLOCK(&V_tcbinfo); } return (inp); } static inline void siftr_siftdata(struct pkt_node *pn, struct inpcb *inp, struct tcpcb *tp, int ipver, int dir, int inp_locally_locked) { #ifdef SIFTR_IPV6 if (ipver == INP_IPV4) { pn->ip_laddr[3] = inp->inp_laddr.s_addr; pn->ip_faddr[3] = inp->inp_faddr.s_addr; #else *((uint32_t *)pn->ip_laddr) = inp->inp_laddr.s_addr; *((uint32_t *)pn->ip_faddr) = inp->inp_faddr.s_addr; #endif #ifdef SIFTR_IPV6 } else { pn->ip_laddr[0] = inp->in6p_laddr.s6_addr32[0]; pn->ip_laddr[1] = inp->in6p_laddr.s6_addr32[1]; pn->ip_laddr[2] = inp->in6p_laddr.s6_addr32[2]; pn->ip_laddr[3] = inp->in6p_laddr.s6_addr32[3]; pn->ip_faddr[0] = inp->in6p_faddr.s6_addr32[0]; pn->ip_faddr[1] = inp->in6p_faddr.s6_addr32[1]; pn->ip_faddr[2] = inp->in6p_faddr.s6_addr32[2]; pn->ip_faddr[3] = inp->in6p_faddr.s6_addr32[3]; } #endif pn->tcp_localport = inp->inp_lport; pn->tcp_foreignport = inp->inp_fport; pn->snd_cwnd = tp->snd_cwnd; pn->snd_wnd = tp->snd_wnd; pn->rcv_wnd = tp->rcv_wnd; pn->snd_bwnd = 0; /* Unused, kept for compat. */ pn->snd_ssthresh = tp->snd_ssthresh; pn->snd_scale = tp->snd_scale; pn->rcv_scale = tp->rcv_scale; pn->conn_state = tp->t_state; pn->max_seg_size = tp->t_maxseg; pn->smoothed_rtt = tp->t_srtt; pn->sack_enabled = (tp->t_flags & TF_SACK_PERMIT) != 0; pn->flags = tp->t_flags; pn->rxt_length = tp->t_rxtcur; pn->snd_buf_hiwater = inp->inp_socket->so_snd.sb_hiwat; pn->snd_buf_cc = inp->inp_socket->so_snd.sb_cc; pn->rcv_buf_hiwater = inp->inp_socket->so_rcv.sb_hiwat; pn->rcv_buf_cc = inp->inp_socket->so_rcv.sb_cc; pn->sent_inflight_bytes = tp->snd_max - tp->snd_una; /* We've finished accessing the tcb so release the lock. */ if (inp_locally_locked) INP_RUNLOCK(inp); pn->ipver = ipver; pn->direction = dir; /* * Significantly more accurate than using getmicrotime(), but slower! * Gives true microsecond resolution at the expense of a hit to * maximum pps throughput processing when SIFTR is loaded and enabled. */ microtime(&pn->tval); } /* * pfil hook that is called for each IPv4 packet making its way through the * stack in either direction. * The pfil subsystem holds a non-sleepable mutex somewhere when * calling our hook function, so we can't sleep at all. * It's very important to use the M_NOWAIT flag with all function calls * that support it so that they won't sleep, otherwise you get a panic. */ static int siftr_chkpkt(void *arg, struct mbuf **m, struct ifnet *ifp, int dir, struct inpcb *inp) { struct pkt_node *pn; struct ip *ip; struct tcphdr *th; struct tcpcb *tp; struct siftr_stats *ss; unsigned int ip_hl; int inp_locally_locked; inp_locally_locked = 0; ss = DPCPU_PTR(ss); /* * m_pullup is not required here because ip_{input|output} * already do the heavy lifting for us. */ ip = mtod(*m, struct ip *); /* Only continue processing if the packet is TCP. */ if (ip->ip_p != IPPROTO_TCP) goto ret; /* * If a kernel subsystem reinjects packets into the stack, our pfil * hook will be called multiple times for the same packet. * Make sure we only process unique packets. */ if (siftr_chkreinject(*m, dir, ss)) goto ret; if (dir == PFIL_IN) ss->n_in++; else ss->n_out++; /* * Create a tcphdr struct starting at the correct offset * in the IP packet. ip->ip_hl gives the ip header length * in 4-byte words, so multiply it to get the size in bytes. */ ip_hl = (ip->ip_hl << 2); th = (struct tcphdr *)((caddr_t)ip + ip_hl); /* * If the pfil hooks don't provide a pointer to the * inpcb, we need to find it ourselves and lock it. */ if (!inp) { /* Find the corresponding inpcb for this pkt. */ inp = siftr_findinpcb(INP_IPV4, ip, *m, th->th_sport, th->th_dport, dir, ss); if (inp == NULL) goto ret; else inp_locally_locked = 1; } INP_LOCK_ASSERT(inp); /* Find the TCP control block that corresponds with this packet */ tp = intotcpcb(inp); /* * If we can't find the TCP control block (happens occasionaly for a * packet sent during the shutdown phase of a TCP connection), * or we're in the timewait state, bail */ if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) { if (dir == PFIL_IN) ss->nskip_in_tcpcb++; else ss->nskip_out_tcpcb++; goto inp_unlock; } pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); if (pn == NULL) { if (dir == PFIL_IN) ss->nskip_in_malloc++; else ss->nskip_out_malloc++; goto inp_unlock; } siftr_siftdata(pn, inp, tp, INP_IPV4, dir, inp_locally_locked); if (siftr_generate_hashes) { if ((*m)->m_pkthdr.csum_flags & CSUM_TCP) { /* * For outbound packets, the TCP checksum isn't * calculated yet. This is a problem for our packet * hashing as the receiver will calc a different hash * to ours if we don't include the correct TCP checksum * in the bytes being hashed. To work around this * problem, we manually calc the TCP checksum here in * software. We unset the CSUM_TCP flag so the lower * layers don't recalc it. */ (*m)->m_pkthdr.csum_flags &= ~CSUM_TCP; /* * Calculate the TCP checksum in software and assign * to correct TCP header field, which will follow the * packet mbuf down the stack. The trick here is that * tcp_output() sets th->th_sum to the checksum of the * pseudo header for us already. Because of the nature * of the checksumming algorithm, we can sum over the * entire IP payload (i.e. TCP header and data), which * will include the already calculated pseduo header * checksum, thus giving us the complete TCP checksum. * * To put it in simple terms, if checksum(1,2,3,4)=10, * then checksum(1,2,3,4,5) == checksum(10,5). * This property is what allows us to "cheat" and * checksum only the IP payload which has the TCP * th_sum field populated with the pseudo header's * checksum, and not need to futz around checksumming * pseudo header bytes and TCP header/data in one hit. * Refer to RFC 1071 for more info. * * NB: in_cksum_skip(struct mbuf *m, int len, int skip) * in_cksum_skip 2nd argument is NOT the number of * bytes to read from the mbuf at "skip" bytes offset * from the start of the mbuf (very counter intuitive!). * The number of bytes to read is calculated internally * by the function as len-skip i.e. to sum over the IP * payload (TCP header + data) bytes, it is INCORRECT * to call the function like this: * in_cksum_skip(at, ip->ip_len - offset, offset) * Rather, it should be called like this: * in_cksum_skip(at, ip->ip_len, offset) * which means read "ip->ip_len - offset" bytes from * the mbuf cluster "at" at offset "offset" bytes from * the beginning of the "at" mbuf's data pointer. */ th->th_sum = in_cksum_skip(*m, ip->ip_len, ip_hl); } /* * XXX: Having to calculate the checksum in software and then * hash over all bytes is really inefficient. Would be nice to * find a way to create the hash and checksum in the same pass * over the bytes. */ pn->hash = hash_pkt(*m, ip_hl); } mtx_lock(&siftr_pkt_queue_mtx); STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); mtx_unlock(&siftr_pkt_queue_mtx); goto ret; inp_unlock: if (inp_locally_locked) INP_RUNLOCK(inp); ret: /* Returning 0 ensures pfil will not discard the pkt */ return (0); } #ifdef SIFTR_IPV6 static int siftr_chkpkt6(void *arg, struct mbuf **m, struct ifnet *ifp, int dir, struct inpcb *inp) { struct pkt_node *pn; struct ip6_hdr *ip6; struct tcphdr *th; struct tcpcb *tp; struct siftr_stats *ss; unsigned int ip6_hl; int inp_locally_locked; inp_locally_locked = 0; ss = DPCPU_PTR(ss); /* * m_pullup is not required here because ip6_{input|output} * already do the heavy lifting for us. */ ip6 = mtod(*m, struct ip6_hdr *); /* * Only continue processing if the packet is TCP * XXX: We should follow the next header fields * as shown on Pg 6 RFC 2460, but right now we'll * only check pkts that have no extension headers. */ if (ip6->ip6_nxt != IPPROTO_TCP) goto ret6; /* * If a kernel subsystem reinjects packets into the stack, our pfil * hook will be called multiple times for the same packet. * Make sure we only process unique packets. */ if (siftr_chkreinject(*m, dir, ss)) goto ret6; if (dir == PFIL_IN) ss->n_in++; else ss->n_out++; ip6_hl = sizeof(struct ip6_hdr); /* * Create a tcphdr struct starting at the correct offset * in the ipv6 packet. ip->ip_hl gives the ip header length * in 4-byte words, so multiply it to get the size in bytes. */ th = (struct tcphdr *)((caddr_t)ip6 + ip6_hl); /* * For inbound packets, the pfil hooks don't provide a pointer to the * inpcb, so we need to find it ourselves and lock it. */ if (!inp) { /* Find the corresponding inpcb for this pkt. */ inp = siftr_findinpcb(INP_IPV6, (struct ip *)ip6, *m, th->th_sport, th->th_dport, dir, ss); if (inp == NULL) goto ret6; else inp_locally_locked = 1; } /* Find the TCP control block that corresponds with this packet. */ tp = intotcpcb(inp); /* * If we can't find the TCP control block (happens occasionaly for a * packet sent during the shutdown phase of a TCP connection), * or we're in the timewait state, bail. */ if (tp == NULL || inp->inp_flags & INP_TIMEWAIT) { if (dir == PFIL_IN) ss->nskip_in_tcpcb++; else ss->nskip_out_tcpcb++; goto inp_unlock6; } pn = malloc(sizeof(struct pkt_node), M_SIFTR_PKTNODE, M_NOWAIT|M_ZERO); if (pn == NULL) { if (dir == PFIL_IN) ss->nskip_in_malloc++; else ss->nskip_out_malloc++; goto inp_unlock6; } siftr_siftdata(pn, inp, tp, INP_IPV6, dir, inp_locally_locked); /* XXX: Figure out how to generate hashes for IPv6 packets. */ mtx_lock(&siftr_pkt_queue_mtx); STAILQ_INSERT_TAIL(&pkt_queue, pn, nodes); mtx_unlock(&siftr_pkt_queue_mtx); goto ret6; inp_unlock6: if (inp_locally_locked) INP_RUNLOCK(inp); ret6: /* Returning 0 ensures pfil will not discard the pkt. */ return (0); } #endif /* #ifdef SIFTR_IPV6 */ static int siftr_pfil(int action) { struct pfil_head *pfh_inet = pfil_head_get(PFIL_TYPE_AF, AF_INET); #ifdef SIFTR_IPV6 struct pfil_head *pfh_inet6 = pfil_head_get(PFIL_TYPE_AF, AF_INET6); #endif if (action == HOOK) { pfil_add_hook(siftr_chkpkt, NULL, PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet); #ifdef SIFTR_IPV6 pfil_add_hook(siftr_chkpkt6, NULL, PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6); #endif } else if (action == UNHOOK) { pfil_remove_hook(siftr_chkpkt, NULL, PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet); #ifdef SIFTR_IPV6 pfil_remove_hook(siftr_chkpkt6, NULL, PFIL_IN | PFIL_OUT | PFIL_WAITOK, pfh_inet6); #endif } return (0); } static int siftr_sysctl_logfile_name_handler(SYSCTL_HANDLER_ARGS) { struct alq *new_alq; int error; if (req->newptr == NULL) goto skip; /* If old filename and new filename are different. */ if (strncmp(siftr_logfile, (char *)req->newptr, PATH_MAX)) { error = alq_open(&new_alq, req->newptr, curthread->td_ucred, SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); /* Bail if unable to create new alq. */ if (error) return (1); /* * If disabled, siftr_alq == NULL so we simply close * the alq as we've proved it can be opened. * If enabled, close the existing alq and switch the old * for the new. */ if (siftr_alq == NULL) alq_close(new_alq); else { alq_close(siftr_alq); siftr_alq = new_alq; } } skip: return (sysctl_handle_string(oidp, arg1, arg2, req)); } static int siftr_manage_ops(uint8_t action) { struct siftr_stats totalss; struct timeval tval; struct flow_hash_node *counter, *tmp_counter; struct sbuf *s; int i, key_index, ret, error; uint32_t bytes_to_write, total_skipped_pkts; uint16_t lport, fport; uint8_t *key, ipver; #ifdef SIFTR_IPV6 uint32_t laddr[4]; uint32_t faddr[4]; #else uint8_t laddr[4]; uint8_t faddr[4]; #endif error = 0; total_skipped_pkts = 0; /* Init an autosizing sbuf that initially holds 200 chars. */ if ((s = sbuf_new(NULL, NULL, 200, SBUF_AUTOEXTEND)) == NULL) return (-1); if (action == SIFTR_ENABLE) { /* * Create our alq * XXX: We should abort if alq_open fails! */ alq_open(&siftr_alq, siftr_logfile, curthread->td_ucred, SIFTR_LOG_FILE_MODE, SIFTR_ALQ_BUFLEN, 0); STAILQ_INIT(&pkt_queue); DPCPU_ZERO(ss); siftr_exit_pkt_manager_thread = 0; ret = kthread_add(&siftr_pkt_manager_thread, NULL, NULL, &siftr_pkt_manager_thr, RFNOWAIT, 0, "siftr_pkt_manager_thr"); siftr_pfil(HOOK); microtime(&tval); sbuf_printf(s, "enable_time_secs=%jd\tenable_time_usecs=%06ld\t" "siftrver=%s\thz=%u\ttcp_rtt_scale=%u\tsysname=%s\t" "sysver=%u\tipmode=%u\n", (intmax_t)tval.tv_sec, tval.tv_usec, MODVERSION_STR, hz, TCP_RTT_SCALE, SYS_NAME, __FreeBSD_version, SIFTR_IPMODE); sbuf_finish(s); alq_writen(siftr_alq, sbuf_data(s), sbuf_len(s), ALQ_WAITOK); } else if (action == SIFTR_DISABLE && siftr_pkt_manager_thr != NULL) { /* * Remove the pfil hook functions. All threads currently in * the hook functions are allowed to exit before siftr_pfil() * returns. */ siftr_pfil(UNHOOK); /* This will block until the pkt manager thread unlocks it. */ mtx_lock(&siftr_pkt_mgr_mtx); /* Tell the pkt manager thread that it should exit now. */ siftr_exit_pkt_manager_thread = 1; /* * Wake the pkt_manager thread so it realises that * siftr_exit_pkt_manager_thread == 1 and exits gracefully. * The wakeup won't be delivered until we unlock * siftr_pkt_mgr_mtx so this isn't racy. */ wakeup(&wait_for_pkt); /* Wait for the pkt_manager thread to exit. */ mtx_sleep(siftr_pkt_manager_thr, &siftr_pkt_mgr_mtx, PWAIT, "thrwait", 0); siftr_pkt_manager_thr = NULL; mtx_unlock(&siftr_pkt_mgr_mtx); totalss.n_in = DPCPU_VARSUM(ss, n_in); totalss.n_out = DPCPU_VARSUM(ss, n_out); totalss.nskip_in_malloc = DPCPU_VARSUM(ss, nskip_in_malloc); totalss.nskip_out_malloc = DPCPU_VARSUM(ss, nskip_out_malloc); totalss.nskip_in_mtx = DPCPU_VARSUM(ss, nskip_in_mtx); totalss.nskip_out_mtx = DPCPU_VARSUM(ss, nskip_out_mtx); totalss.nskip_in_tcpcb = DPCPU_VARSUM(ss, nskip_in_tcpcb); totalss.nskip_out_tcpcb = DPCPU_VARSUM(ss, nskip_out_tcpcb); totalss.nskip_in_inpcb = DPCPU_VARSUM(ss, nskip_in_inpcb); totalss.nskip_out_inpcb = DPCPU_VARSUM(ss, nskip_out_inpcb); total_skipped_pkts = totalss.nskip_in_malloc + totalss.nskip_out_malloc + totalss.nskip_in_mtx + totalss.nskip_out_mtx + totalss.nskip_in_tcpcb + totalss.nskip_out_tcpcb + totalss.nskip_in_inpcb + totalss.nskip_out_inpcb; microtime(&tval); sbuf_printf(s, "disable_time_secs=%jd\tdisable_time_usecs=%06ld\t" "num_inbound_tcp_pkts=%ju\tnum_outbound_tcp_pkts=%ju\t" "total_tcp_pkts=%ju\tnum_inbound_skipped_pkts_malloc=%u\t" "num_outbound_skipped_pkts_malloc=%u\t" "num_inbound_skipped_pkts_mtx=%u\t" "num_outbound_skipped_pkts_mtx=%u\t" "num_inbound_skipped_pkts_tcpcb=%u\t" "num_outbound_skipped_pkts_tcpcb=%u\t" "num_inbound_skipped_pkts_inpcb=%u\t" "num_outbound_skipped_pkts_inpcb=%u\t" "total_skipped_tcp_pkts=%u\tflow_list=", (intmax_t)tval.tv_sec, tval.tv_usec, (uintmax_t)totalss.n_in, (uintmax_t)totalss.n_out, (uintmax_t)(totalss.n_in + totalss.n_out), totalss.nskip_in_malloc, totalss.nskip_out_malloc, totalss.nskip_in_mtx, totalss.nskip_out_mtx, totalss.nskip_in_tcpcb, totalss.nskip_out_tcpcb, totalss.nskip_in_inpcb, totalss.nskip_out_inpcb, total_skipped_pkts); /* * Iterate over the flow hash, printing a summary of each * flow seen and freeing any malloc'd memory. * The hash consists of an array of LISTs (man 3 queue). */ for (i = 0; i < siftr_hashmask; i++) { LIST_FOREACH_SAFE(counter, counter_hash + i, nodes, tmp_counter) { key = counter->key; key_index = 1; ipver = key[0]; memcpy(laddr, key + key_index, sizeof(laddr)); key_index += sizeof(laddr); memcpy(&lport, key + key_index, sizeof(lport)); key_index += sizeof(lport); memcpy(faddr, key + key_index, sizeof(faddr)); key_index += sizeof(faddr); memcpy(&fport, key + key_index, sizeof(fport)); #ifdef SIFTR_IPV6 laddr[3] = ntohl(laddr[3]); faddr[3] = ntohl(faddr[3]); if (ipver == INP_IPV6) { laddr[0] = ntohl(laddr[0]); laddr[1] = ntohl(laddr[1]); laddr[2] = ntohl(laddr[2]); faddr[0] = ntohl(faddr[0]); faddr[1] = ntohl(faddr[1]); faddr[2] = ntohl(faddr[2]); sbuf_printf(s, "%x:%x:%x:%x:%x:%x:%x:%x;%u-" "%x:%x:%x:%x:%x:%x:%x:%x;%u,", UPPER_SHORT(laddr[0]), LOWER_SHORT(laddr[0]), UPPER_SHORT(laddr[1]), LOWER_SHORT(laddr[1]), UPPER_SHORT(laddr[2]), LOWER_SHORT(laddr[2]), UPPER_SHORT(laddr[3]), LOWER_SHORT(laddr[3]), ntohs(lport), UPPER_SHORT(faddr[0]), LOWER_SHORT(faddr[0]), UPPER_SHORT(faddr[1]), LOWER_SHORT(faddr[1]), UPPER_SHORT(faddr[2]), LOWER_SHORT(faddr[2]), UPPER_SHORT(faddr[3]), LOWER_SHORT(faddr[3]), ntohs(fport)); } else { laddr[0] = FIRST_OCTET(laddr[3]); laddr[1] = SECOND_OCTET(laddr[3]); laddr[2] = THIRD_OCTET(laddr[3]); laddr[3] = FOURTH_OCTET(laddr[3]); faddr[0] = FIRST_OCTET(faddr[3]); faddr[1] = SECOND_OCTET(faddr[3]); faddr[2] = THIRD_OCTET(faddr[3]); faddr[3] = FOURTH_OCTET(faddr[3]); #endif sbuf_printf(s, "%u.%u.%u.%u;%u-%u.%u.%u.%u;%u,", laddr[0], laddr[1], laddr[2], laddr[3], ntohs(lport), faddr[0], faddr[1], faddr[2], faddr[3], ntohs(fport)); #ifdef SIFTR_IPV6 } #endif free(counter, M_SIFTR_HASHNODE); } LIST_INIT(counter_hash + i); } sbuf_printf(s, "\n"); sbuf_finish(s); i = 0; do { bytes_to_write = min(SIFTR_ALQ_BUFLEN, sbuf_len(s)-i); alq_writen(siftr_alq, sbuf_data(s)+i, bytes_to_write, ALQ_WAITOK); i += bytes_to_write; } while (i < sbuf_len(s)); alq_close(siftr_alq); siftr_alq = NULL; } sbuf_delete(s); /* * XXX: Should be using ret to check if any functions fail * and set error appropriately */ return (error); } static int siftr_sysctl_enabled_handler(SYSCTL_HANDLER_ARGS) { if (req->newptr == NULL) goto skip; /* If the value passed in isn't 0 or 1, return an error. */ if (CAST_PTR_INT(req->newptr) != 0 && CAST_PTR_INT(req->newptr) != 1) return (1); /* If we are changing state (0 to 1 or 1 to 0). */ if (CAST_PTR_INT(req->newptr) != siftr_enabled ) if (siftr_manage_ops(CAST_PTR_INT(req->newptr))) { siftr_manage_ops(SIFTR_DISABLE); return (1); } skip: return (sysctl_handle_int(oidp, arg1, arg2, req)); } static void siftr_shutdown_handler(void *arg) { siftr_manage_ops(SIFTR_DISABLE); } /* * Module is being unloaded or machine is shutting down. Take care of cleanup. */ static int deinit_siftr(void) { /* Cleanup. */ siftr_manage_ops(SIFTR_DISABLE); hashdestroy(counter_hash, M_SIFTR, siftr_hashmask); mtx_destroy(&siftr_pkt_queue_mtx); mtx_destroy(&siftr_pkt_mgr_mtx); return (0); } /* * Module has just been loaded into the kernel. */ static int init_siftr(void) { EVENTHANDLER_REGISTER(shutdown_pre_sync, siftr_shutdown_handler, NULL, SHUTDOWN_PRI_FIRST); /* Initialise our flow counter hash table. */ counter_hash = hashinit(SIFTR_EXPECTED_MAX_TCP_FLOWS, M_SIFTR, &siftr_hashmask); mtx_init(&siftr_pkt_queue_mtx, "siftr_pkt_queue_mtx", NULL, MTX_DEF); mtx_init(&siftr_pkt_mgr_mtx, "siftr_pkt_mgr_mtx", NULL, MTX_DEF); /* Print message to the user's current terminal. */ uprintf("\nStatistical Information For TCP Research (SIFTR) %s\n" " http://caia.swin.edu.au/urp/newtcp\n\n", MODVERSION_STR); return (0); } /* * This is the function that is called to load and unload the module. * When the module is loaded, this function is called once with * "what" == MOD_LOAD * When the module is unloaded, this function is called twice with * "what" = MOD_QUIESCE first, followed by "what" = MOD_UNLOAD second * When the system is shut down e.g. CTRL-ALT-DEL or using the shutdown command, * this function is called once with "what" = MOD_SHUTDOWN * When the system is shut down, the handler isn't called until the very end * of the shutdown sequence i.e. after the disks have been synced. */ static int siftr_load_handler(module_t mod, int what, void *arg) { int ret; switch (what) { case MOD_LOAD: ret = init_siftr(); break; case MOD_QUIESCE: case MOD_SHUTDOWN: ret = deinit_siftr(); break; case MOD_UNLOAD: ret = 0; break; default: ret = EINVAL; break; } return (ret); } static moduledata_t siftr_mod = { .name = "siftr", .evhand = siftr_load_handler, }; /* * Param 1: name of the kernel module * Param 2: moduledata_t struct containing info about the kernel module * and the execution entry point for the module * Param 3: From sysinit_sub_id enumeration in /usr/include/sys/kernel.h * Defines the module initialisation order * Param 4: From sysinit_elem_order enumeration in /usr/include/sys/kernel.h * Defines the initialisation order of this kld relative to others * within the same subsystem as defined by param 3 */ DECLARE_MODULE(siftr, siftr_mod, SI_SUB_SMP, SI_ORDER_ANY); MODULE_DEPEND(siftr, alq, 1, 1, 1); MODULE_VERSION(siftr, MODVERSION);