/*************************************************************************** * engine_kqueue.c -- BSD kqueue(2) based IO engine. * * * ***********************IMPORTANT NSOCK LICENSE TERMS*********************** * * * The nsock parallel socket event library is (C) 1999-2013 Insecure.Com * * LLC This library is free software; you may redistribute and/or * * modify it under the terms of the GNU General Public License as * * published by the Free Software Foundation; Version 2. This guarantees * * your right to use, modify, and redistribute this software under certain * * conditions. If this license is unacceptable to you, Insecure.Com LLC * * may be willing to sell alternative licenses (contact * * sales@insecure.com ). * * * * As a special exception to the GPL terms, Insecure.Com LLC grants * * permission to link the code of this program with any version of the * * OpenSSL library which is distributed under a license identical to that * * listed in the included docs/licenses/OpenSSL.txt file, and distribute * * linked combinations including the two. You must obey the GNU GPL in all * * respects for all of the code used other than OpenSSL. If you modify * * this file, you may extend this exception to your version of the file, * * but you are not obligated to do so. * * * * If you received these files with a written license agreement stating * * terms other than the (GPL) terms above, then that alternative license * * agreement takes precedence over this comment. * * * * Source is provided to this software because we believe users have a * * right to know exactly what a program is going to do before they run it. * * This also allows you to audit the software for security holes (none * * have been found so far). * * * * Source code also allows you to port Nmap to new platforms, fix bugs, * * and add new features. You are highly encouraged to send your changes * * to the dev@nmap.org mailing list for possible incorporation into the * * main distribution. 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See the GNU * * General Public License v2.0 for more details * * (http://www.gnu.org/licenses/gpl-2.0.html). * * * ***************************************************************************/ /* $Id$ */ #ifdef HAVE_CONFIG_H #include "nsock_config.h" #endif #if HAVE_KQUEUE #include #include #include #include #include "nsock_internal.h" #include "nsock_log.h" #if HAVE_PCAP #include "nsock_pcap.h" #endif #define INITIAL_EV_COUNT 128 /* --- ENGINE INTERFACE PROTOTYPES --- */ static int kqueue_init(mspool *nsp); static void kqueue_destroy(mspool *nsp); static int kqueue_iod_register(mspool *nsp, msiod *iod, int ev); static int kqueue_iod_unregister(mspool *nsp, msiod *iod); static int kqueue_iod_modify(mspool *nsp, msiod *iod, int ev_set, int ev_clr); static int kqueue_loop(mspool *nsp, int msec_timeout); /* ---- ENGINE DEFINITION ---- */ struct io_engine engine_kqueue = { "kqueue", kqueue_init, kqueue_destroy, kqueue_iod_register, kqueue_iod_unregister, kqueue_iod_modify, kqueue_loop }; /* --- INTERNAL PROTOTYPES --- */ static void iterate_through_event_lists(mspool *nsp, int evcount); /* defined in nsock_core.c */ void process_iod_events(mspool *nsp, msiod *nsi, int ev); void process_event(mspool *nsp, gh_list_t *evlist, msevent *nse, int ev); void process_expired_events(mspool *nsp); #if HAVE_PCAP #ifndef PCAP_CAN_DO_SELECT int pcap_read_on_nonselect(mspool *nsp); #endif #endif /* defined in nsock_event.c */ void update_first_events(msevent *nse); extern struct timeval nsock_tod; /* * Engine specific data structure */ struct kqueue_engine_info { int kqfd; int maxfd; size_t evlen; struct kevent *events; }; int kqueue_init(mspool *nsp) { struct kqueue_engine_info *kinfo; kinfo = (struct kqueue_engine_info *)safe_malloc(sizeof(struct kqueue_engine_info)); kinfo->kqfd = kqueue(); kinfo->maxfd = -1; kinfo->evlen = INITIAL_EV_COUNT; kinfo->events = (struct kevent *)safe_malloc(INITIAL_EV_COUNT * sizeof(struct kevent)); nsp->engine_data = (void *)kinfo; return 1; } void kqueue_destroy(mspool *nsp) { struct kqueue_engine_info *kinfo = (struct kqueue_engine_info *)nsp->engine_data; assert(kinfo != NULL); close(kinfo->kqfd); free(kinfo->events); free(kinfo); } int kqueue_iod_register(mspool *nsp, msiod *iod, int ev) { struct kqueue_engine_info *kinfo = (struct kqueue_engine_info *)nsp->engine_data; assert(!IOD_PROPGET(iod, IOD_REGISTERED)); IOD_PROPSET(iod, IOD_REGISTERED); iod->watched_events = EV_NONE; kqueue_iod_modify(nsp, iod, ev, EV_NONE); if (nsi_getsd(iod) > kinfo->maxfd) kinfo->maxfd = nsi_getsd(iod); return 1; } int kqueue_iod_unregister(mspool *nsp, msiod *iod) { struct kqueue_engine_info *kinfo = (struct kqueue_engine_info *)nsp->engine_data; /* some IODs can be unregistered here if they're associated to an event that was * immediately completed */ if (IOD_PROPGET(iod, IOD_REGISTERED)) { kqueue_iod_modify(nsp, iod, EV_NONE, EV_READ|EV_WRITE); IOD_PROPCLR(iod, IOD_REGISTERED); if (nsi_getsd(iod) == kinfo->maxfd) kinfo->maxfd--; } iod->watched_events = EV_NONE; return 1; } #define EV_SETFLAG(_set, _ev) (((_set) & (_ev)) ? (EV_ADD|EV_ENABLE) : (EV_ADD|EV_DISABLE)) int kqueue_iod_modify(mspool *nsp, msiod *iod, int ev_set, int ev_clr) { struct kevent kev[2]; int new_events, i; struct kqueue_engine_info *kinfo = (struct kqueue_engine_info *)nsp->engine_data; assert((ev_set & ev_clr) == 0); assert(IOD_PROPGET(iod, IOD_REGISTERED)); new_events = iod->watched_events; new_events |= ev_set; new_events &= ~ev_clr; if (new_events == iod->watched_events) return 1; /* nothing to do */ i = 0; if ((ev_set ^ ev_clr) & EV_READ) { EV_SET(&kev[i], nsi_getsd(iod), EVFILT_READ, EV_SETFLAG(ev_set, EV_READ), 0, 0, (void *)iod); i++; } if ((ev_set ^ ev_clr) & EV_WRITE) { EV_SET(&kev[i], nsi_getsd(iod), EVFILT_WRITE, EV_SETFLAG(ev_set, EV_WRITE), 0, 0, (void *)iod); i++; } if (i > 0 && kevent(kinfo->kqfd, kev, i, NULL, 0, NULL) < 0) fatal("Unable to update events for IOD #%lu: %s", iod->id, strerror(errno)); iod->watched_events = new_events; return 1; } int kqueue_loop(mspool *nsp, int msec_timeout) { int results_left = 0; int event_msecs; /* msecs before an event goes off */ int combined_msecs; struct timespec ts, *ts_p; int sock_err = 0; struct kqueue_engine_info *kinfo = (struct kqueue_engine_info *)nsp->engine_data; assert(msec_timeout >= -1); if (nsp->events_pending == 0) return 0; /* No need to wait on 0 events ... */ if (gh_list_count(&nsp->active_iods) > kinfo->evlen) { kinfo->evlen = gh_list_count(&nsp->active_iods) * 2; kinfo->events = (struct kevent *)safe_realloc(kinfo->events, kinfo->evlen * sizeof(struct kevent)); } do { msevent *nse; nsock_log_debug_all(nsp, "wait for events"); nse = next_expirable_event(nsp); if (!nse) event_msecs = -1; /* None of the events specified a timeout */ else event_msecs = MAX(0, TIMEVAL_MSEC_SUBTRACT(nse->timeout, nsock_tod)); #if HAVE_PCAP #ifndef PCAP_CAN_DO_SELECT /* Force a low timeout when capturing packets on systems where * the pcap descriptor is not select()able. */ if (gh_list_count(&nsp->pcap_read_events) > 0) if (event_msecs > PCAP_POLL_INTERVAL) event_msecs = PCAP_POLL_INTERVAL; #endif #endif /* We cast to unsigned because we want -1 to be very high (since it means no * timeout) */ combined_msecs = MIN((unsigned)event_msecs, (unsigned)msec_timeout); /* Set up the timeval pointer we will give to kevent() */ memset(&ts, 0, sizeof(struct timespec)); if (combined_msecs >= 0) { ts.tv_sec = combined_msecs / 1000; ts.tv_nsec = (combined_msecs % 1000) * 1000000L; ts_p = &ts; } else { ts_p = NULL; } #if HAVE_PCAP #ifndef PCAP_CAN_DO_SELECT /* do non-blocking read on pcap devices that doesn't support select() * If there is anything read, just leave this loop. */ if (pcap_read_on_nonselect(nsp)) { /* okay, something was read. */ } else #endif #endif { results_left = kevent(kinfo->kqfd, NULL, 0, kinfo->events, kinfo->evlen, ts_p); if (results_left == -1) sock_err = socket_errno(); } gettimeofday(&nsock_tod, NULL); /* Due to kevent delay */ } while (results_left == -1 && sock_err == EINTR); /* repeat only if signal occurred */ if (results_left == -1 && sock_err != EINTR) { nsock_log_error(nsp, "nsock_loop error %d: %s", sock_err, socket_strerror(sock_err)); nsp->errnum = sock_err; return -1; } iterate_through_event_lists(nsp, results_left); return 1; } /* ---- INTERNAL FUNCTIONS ---- */ static inline int get_evmask(msiod *nsi, const struct kevent *kev) { int evmask = EV_NONE; /* generate the corresponding event mask with nsock event flags */ if (kev->flags & EV_ERROR) { evmask |= EV_EXCEPT; if (kev->data == EPIPE && (nsi->watched_events & EV_READ)) evmask |= EV_READ; } else { switch (kev->filter) { case EVFILT_READ: evmask |= EV_READ; break; case EVFILT_WRITE: evmask |= EV_WRITE; break; default: fatal("Unsupported filter value: %d\n", (int)kev->filter); } } return evmask; } /* Iterate through all the event lists (such as connect_events, read_events, * timer_events, etc) and take action for those that have completed (due to * timeout, i/o, etc) */ void iterate_through_event_lists(mspool *nsp, int evcount) { int n; struct kqueue_engine_info *kinfo = (struct kqueue_engine_info *)nsp->engine_data; msiod *nsi; for (n = 0; n < evcount; n++) { struct kevent *kev = &kinfo->events[n]; nsi = (msiod *)kev->udata; /* process all the pending events for this IOD */ process_iod_events(nsp, nsi, get_evmask(nsi, kev)); IOD_PROPSET(nsi, IOD_PROCESSED); } for (n = 0; n < evcount; n++) { struct kevent *kev = &kinfo->events[n]; nsi = (msiod *)kev->udata; if (nsi->state == NSIOD_STATE_DELETED) { if (IOD_PROPGET(nsi, IOD_PROCESSED)) { IOD_PROPCLR(nsi, IOD_PROCESSED); gh_list_remove(&nsp->active_iods, &nsi->nodeq); gh_list_prepend(&nsp->free_iods, &nsi->nodeq); } } } /* iterate through timers and expired events */ process_expired_events(nsp); } #endif /* HAVE_KQUEUE */