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Diffstat (limited to 'nsock/src/engine_kqueue.c')
-rw-r--r-- | nsock/src/engine_kqueue.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/nsock/src/engine_kqueue.c b/nsock/src/engine_kqueue.c new file mode 100644 index 0000000..aa992bb --- /dev/null +++ b/nsock/src/engine_kqueue.c @@ -0,0 +1,368 @@ +/*************************************************************************** + * engine_kqueue.c -- BSD kqueue(2) based IO engine. * + * * + ***********************IMPORTANT NSOCK LICENSE TERMS*********************** + * + * The nsock parallel socket event library is (C) 1999-2023 Nmap Software 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, Nmap Software LLC may be willing to sell alternative + * licenses (contact sales@nmap.com ). + * + * As a special exception to the GPL terms, Nmap Software 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. + * + * 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. By sending these changes to Fyodor or one of the Insecure.Org + * development mailing lists, or checking them into the Nmap source code + * repository, it is understood (unless you specify otherwise) that you are + * offering the Nmap Project (Nmap Software LLC) the unlimited, non-exclusive + * right to reuse, modify, and relicense the code. Nmap will always be available + * Open Source, but this is important because the inability to relicense code + * has caused devastating problems for other Free Software projects (such as KDE + * and NASM). We also occasionally relicense the code to third parties as + * discussed above. If you wish to specify special license conditions of your + * contributions, just say so when you send them. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + * FOR A PARTICULAR PURPOSE. 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 <sys/types.h> +#include <sys/event.h> +#include <sys/time.h> +#include <errno.h> + +#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(struct npool *nsp); +static void kqueue_destroy(struct npool *nsp); +static int kqueue_iod_register(struct npool *nsp, struct niod *iod, struct nevent *nse, int ev); +static int kqueue_iod_unregister(struct npool *nsp, struct niod *iod); +static int kqueue_iod_modify(struct npool *nsp, struct niod *iod, struct nevent *nse, int ev_set, int ev_clr); +static int kqueue_loop(struct npool *nsp, int msec_timeout); + +extern struct io_operations posix_io_operations; + +/* ---- ENGINE DEFINITION ---- */ +struct io_engine engine_kqueue = { + "kqueue", + kqueue_init, + kqueue_destroy, + kqueue_iod_register, + kqueue_iod_unregister, + kqueue_iod_modify, + kqueue_loop, + &posix_io_operations +}; + + +/* --- INTERNAL PROTOTYPES --- */ +static void iterate_through_event_lists(struct npool *nsp, int evcount); + +/* defined in nsock_core.c */ +void process_iod_events(struct npool *nsp, struct niod *nsi, int ev); +void process_event(struct npool *nsp, gh_list_t *evlist, struct nevent *nse, int ev); +void process_expired_events(struct npool *nsp); +#if HAVE_PCAP +#ifndef PCAP_CAN_DO_SELECT +int pcap_read_on_nonselect(struct npool *nsp); +#endif +#endif + +/* defined in nsock_event.c */ +void update_first_events(struct nevent *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(struct npool *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(struct npool *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(struct npool *nsp, struct niod *iod, struct nevent *nse, 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, nse, ev, EV_NONE); + + if (nsock_iod_get_sd(iod) > kinfo->maxfd) + kinfo->maxfd = nsock_iod_get_sd(iod); + + return 1; +} + +int kqueue_iod_unregister(struct npool *nsp, struct niod *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, NULL, EV_NONE, EV_READ|EV_WRITE); + IOD_PROPCLR(iod, IOD_REGISTERED); + + if (nsock_iod_get_sd(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(struct npool *nsp, struct niod *iod, struct nevent *nse, 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], nsock_iod_get_sd(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], nsock_iod_get_sd(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(struct npool *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 { + struct nevent *nse; + + nsock_log_debug_all("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("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(struct niod *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(struct npool *nsp, int evcount) { + int n; + struct kqueue_engine_info *kinfo = (struct kqueue_engine_info *)nsp->engine_data; + struct niod *nsi; + + for (n = 0; n < evcount; n++) { + struct kevent *kev = &kinfo->events[n]; + + nsi = (struct niod *)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 = (struct niod *)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 */ + |