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-rw-r--r--nsock/src/nsock_event.c538
1 files changed, 538 insertions, 0 deletions
diff --git a/nsock/src/nsock_event.c b/nsock/src/nsock_event.c
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+++ b/nsock/src/nsock_event.c
@@ -0,0 +1,538 @@
+/***************************************************************************
+ * nsock_event.c -- Functions dealing with nsock_events (and their *
+ * struct nevent internal representation. An event is created when you do *
+ * various calls (for reading, writing, connecting, timers, etc) and is *
+ * provided back to you in the callback when the call completes or *
+ * fails. It is automatically destroyed after the callback returns *
+ * *
+ ***********************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).
+ *
+ ***************************************************************************/
+
+/* $Id$ */
+
+#include "nsock_internal.h"
+#include "nsock_log.h"
+#include "gh_list.h"
+
+#if HAVE_PCAP
+#include "nsock_pcap.h"
+#endif
+
+#include <string.h>
+
+extern struct timeval nsock_tod;
+
+/* Find the type of an event that spawned a callback */
+enum nse_type nse_type(nsock_event nse) {
+ struct nevent *me = (struct nevent *)nse;
+ return me->type;
+}
+
+enum nse_status nse_status(nsock_event nse) {
+ struct nevent *me = (struct nevent *)nse;
+ return me->status;
+}
+
+int nse_eof(nsock_event nse) {
+ struct nevent *me = (struct nevent *)nse;
+ return me->eof;
+}
+
+/* Obtains the nsock_iod (see below) associated with the event. Note that
+ * some events (such as timers) don't have an nsock_iod associated with them */
+nsock_iod nse_iod(nsock_event ms_event) {
+ struct nevent *nse = (struct nevent *)ms_event;
+ return (nsock_iod) nse->iod;
+}
+
+/* This next function returns the errno style error code -- which is only valid
+ * if the status is NSE_STATUS_ERROR */
+int nse_errorcode(nsock_event nse) {
+ struct nevent *me = (struct nevent *)nse;
+ return me->errnum;
+}
+
+/* Every event has an ID which will be unique throughout the program's execution
+ * unless you use (literally) billions of them */
+nsock_event_id nse_id(nsock_event nse) {
+ struct nevent *me = (struct nevent *)nse;
+ return me->id;
+}
+
+/* If you did a read request, and the result was STATUS_SUCCESS, this function
+ * provides the buffer that was read in as well as the number of chars read.
+ * The buffer should not be modified or free'd */
+char *nse_readbuf(nsock_event nse, int *nbytes) {
+ struct nevent *me = (struct nevent *)nse;
+
+ if (nbytes)
+ *nbytes = fs_length(&(me->iobuf));
+ return fs_str(&(me->iobuf));
+}
+
+static void first_ev_next(struct nevent *nse, gh_lnode_t **first, int nodeq2) {
+ if (!first || !*first)
+ return;
+
+ if (&nse->nodeq_io == *first || &nse->nodeq_pcap == *first) {
+ gh_lnode_t *next;
+
+ next = gh_lnode_next(*first);
+ if (next) {
+ struct nevent *newevent;
+
+ if (nodeq2)
+ newevent = lnode_nevent2(next);
+ else
+ newevent = lnode_nevent(next);
+
+ if (newevent->iod == nse->iod)
+ *first = next;
+ else
+ *first = NULL;
+ } else {
+ *first = NULL;
+ }
+ }
+}
+
+void update_first_events(struct nevent *nse) {
+ switch (get_event_id_type(nse->id)) {
+ case NSE_TYPE_CONNECT:
+ case NSE_TYPE_CONNECT_SSL:
+ first_ev_next(nse, &nse->iod->first_connect, 0);
+ break;
+
+ case NSE_TYPE_READ:
+ first_ev_next(nse, &nse->iod->first_read, 0);
+ break;
+
+ case NSE_TYPE_WRITE:
+ first_ev_next(nse, &nse->iod->first_write, 0);
+ break;
+
+#if HAVE_PCAP
+ case NSE_TYPE_PCAP_READ:
+ first_ev_next(nse, &nse->iod->first_read, 0);
+ first_ev_next(nse, &nse->iod->first_pcap_read, 1);
+ break;
+#endif
+
+ case NSE_TYPE_TIMER:
+ /* nothing to do */
+ break;
+
+ default:
+ fatal("Bogus event type in update_first_events");
+ break;
+ }
+}
+
+/* Cancel an event (such as a timer or read request). If notify is nonzero, the
+ * requester will be sent an event CANCELLED status back to the given handler.
+ * But in some cases there is no need to do this (like if the function deleting
+ * it is the one which created it), in which case 0 can be passed to skip the
+ * step. This function returns zero if the event is not found, nonzero
+ * otherwise. */
+int nsock_event_cancel(nsock_pool ms_pool, nsock_event_id id, int notify) {
+ struct npool *nsp = (struct npool *)ms_pool;
+ enum nse_type type;
+ unsigned int i;
+ gh_list_t *event_list = NULL, *event_list2 = NULL;
+ gh_lnode_t *current, *next;
+ struct nevent *nse = NULL;
+
+ assert(nsp);
+
+ type = get_event_id_type(id);
+ nsock_log_info("Event #%li (type %s) cancelled", id, nse_type2str(type));
+
+ /* First we figure out what list it is in */
+ switch (type) {
+ case NSE_TYPE_CONNECT:
+ case NSE_TYPE_CONNECT_SSL:
+ event_list = &nsp->connect_events;
+ break;
+
+ case NSE_TYPE_READ:
+ event_list = &nsp->read_events;
+ break;
+
+ case NSE_TYPE_WRITE:
+ event_list = &nsp->write_events;
+ break;
+
+ case NSE_TYPE_TIMER:
+ for (i = 0; i < gh_heap_count(&nsp->expirables); i++) {
+ gh_hnode_t *hnode;
+
+ hnode = gh_heap_find(&nsp->expirables, i);
+ nse = container_of(hnode, struct nevent, expire);
+ if (nse->id == id)
+ return nevent_delete(nsp, nse, NULL, NULL, notify);
+ }
+ return 0;
+
+#if HAVE_PCAP
+ case NSE_TYPE_PCAP_READ:
+ event_list = &nsp->read_events;
+ event_list2 = &nsp->pcap_read_events;
+ break;
+#endif
+
+ default:
+ fatal("Bogus event type in nsock_event_cancel"); break;
+ }
+
+ /* Now we try to find the event in the list */
+ for (current = gh_list_first_elem(event_list); current != NULL; current = next) {
+ next = gh_lnode_next(current);
+ nse = lnode_nevent(current);
+ if (nse->id == id)
+ break;
+ }
+
+ if (current == NULL && event_list2) {
+ event_list = event_list2;
+ for (current = gh_list_first_elem(event_list); current != NULL; current = next) {
+ next = gh_lnode_next(current);
+ nse = lnode_nevent2(current);
+ if (nse->id == id)
+ break;
+ }
+ }
+ if (current == NULL)
+ return 0;
+
+ return nevent_delete(nsp, nse, event_list, current, notify);
+}
+
+/* An internal function for cancelling an event when you already have a pointer
+ * to the struct nevent (use nsock_event_cancel if you just have an ID). The
+ * event_list passed in should correspond to the type of the event. For example,
+ * with NSE_TYPE_READ, you would pass in &nsp->read_events;. elem is the list
+ * element in event_list which holds the event. Pass a nonzero for notify if
+ * you want the program owning the event to be notified that it has been
+ * cancelled */
+int nevent_delete(struct npool *nsp, struct nevent *nse, gh_list_t *event_list,
+ gh_lnode_t *elem, int notify) {
+ if (nse->event_done) {
+ /* This event has already been marked for death somewhere else -- it will be
+ * gone soon (and if we try to kill it now all hell will break loose due to
+ * reentrancy. */
+ return 0;
+ }
+
+ nsock_log_info("%s on event #%li (type %s)", __func__, nse->id,
+ nse_type2str(nse->type));
+
+ /* Now that we found the event... we go through the motions of cleanly
+ * cancelling it */
+ switch (nse->type) {
+ case NSE_TYPE_CONNECT:
+ case NSE_TYPE_CONNECT_SSL:
+ handle_connect_result(nsp, nse, NSE_STATUS_CANCELLED);
+ break;
+
+ case NSE_TYPE_READ:
+ handle_read_result(nsp, nse, NSE_STATUS_CANCELLED);
+ break;
+
+ case NSE_TYPE_WRITE:
+ handle_write_result(nsp, nse, NSE_STATUS_CANCELLED);
+ break;
+
+ case NSE_TYPE_TIMER:
+ handle_timer_result(nsp, nse, NSE_STATUS_CANCELLED);
+ break;
+
+#if HAVE_PCAP
+ case NSE_TYPE_PCAP_READ:
+ handle_pcap_read_result(nsp, nse, NSE_STATUS_CANCELLED);
+ break;
+#endif
+
+ default:
+ fatal("Invalid nsock event type (%d)", nse->type);
+ }
+
+ assert(nse->event_done);
+
+ if (nse->timeout.tv_sec)
+ gh_heap_remove(&nsp->expirables, &nse->expire);
+
+ if (event_list) {
+ update_first_events(nse);
+ gh_list_remove(event_list, elem);
+ }
+
+ gh_list_append(&nsp->free_events, &nse->nodeq_io);
+
+ nsock_log_debug_all("NSE #%lu: Removing event from list", nse->id);
+
+#if HAVE_PCAP
+#if PCAP_BSD_SELECT_HACK
+ if (nse->type == NSE_TYPE_PCAP_READ) {
+ nsock_log_debug_all("PCAP NSE #%lu: CANCEL TEST pcap=%p read=%p curr=%p sd=%i",
+ nse->id, &nsp->pcap_read_events, &nsp->read_events,
+ event_list,((mspcap *)nse->iod->pcap)->pcap_desc);
+
+ /* If event occurred, and we're in BSD_HACK mode, then this event was added to
+ * two queues. read_event and pcap_read_event Of course we should
+ * destroy it only once. I assume we're now in read_event, so just unlink
+ * this event from pcap_read_event */
+ if (((mspcap *)nse->iod->pcap)->pcap_desc >= 0 && event_list == &nsp->read_events) {
+ /* event is done, list is read_events and we're in BSD_HACK mode. So unlink
+ * event from pcap_read_events */
+ gh_list_remove(&nsp->pcap_read_events, &nse->nodeq_pcap);
+ nsock_log_debug_all("PCAP NSE #%lu: Removing event from PCAP_READ_EVENTS", nse->id);
+ }
+
+ if (((mspcap *)nse->iod->pcap)->pcap_desc >= 0 && event_list == &nsp->pcap_read_events) {
+ /* event is done, list is read_events and we're in BSD_HACK mode.
+ * So unlink event from read_events */
+ gh_list_remove(&nsp->read_events, &nse->nodeq_io);
+
+ nsock_log_debug_all("PCAP NSE #%lu: Removing event from READ_EVENTS", nse->id);
+ }
+ }
+#endif
+#endif
+ event_dispatch_and_delete(nsp, nse, notify);
+ return 1;
+}
+
+/* Adjust various statistics, dispatches the event handler (if notify is
+ * nonzero) and then deletes the event. This function does NOT delete the event
+ * from any lists it might be on (eg nsp->read_list etc.) nse->event_done
+ * MUST be true when you call this */
+void event_dispatch_and_delete(struct npool *nsp, struct nevent *nse, int notify) {
+ assert(nsp);
+ assert(nse);
+
+ assert(nse->event_done);
+
+ nsp->events_pending--;
+ assert(nsp->events_pending >= 0);
+
+ if (nse->iod) {
+ nse->iod->events_pending--;
+ assert(nse->iod->events_pending >= 0);
+ }
+
+ if (notify) {
+ nsock_trace_handler_callback(nsp, nse);
+ nse->handler(nsp, nse, nse->userdata);
+ }
+
+ /* FIXME: We should be updating stats here ... */
+
+ /* Now we clobber the event ... */
+ event_delete(nsp, nse);
+}
+
+/* OK -- the idea is that we want the type included in the rightmost two bits
+ * and the serial number in the leftmost 30 or 62. But we also want to insure a
+ * correct wrap-around in the case of an obscene number of event. One
+ * definition of a "correct" wraparound is that it goes from the highest number
+ * back to one (not zero) because we don't want event numbers to ever be zero.
+ * */
+nsock_event_id get_new_event_id(struct npool *ms, enum nse_type type) {
+ int type_code = (int)type;
+ unsigned long serial = ms->next_event_serial++;
+ unsigned long max_serial_allowed;
+ int shiftbits;
+
+ assert(type < NSE_TYPE_MAX);
+
+ shiftbits = sizeof(nsock_event_id) * 8 - TYPE_CODE_NUM_BITS;
+ max_serial_allowed = ((unsigned long)1 << shiftbits) - 1;
+ if (serial == max_serial_allowed) {
+ /* then the next serial will be one because 0 is forbidden */
+ ms->next_event_serial = 1;
+ }
+
+ return (serial << TYPE_CODE_NUM_BITS) | type_code;
+}
+
+/* Take an event ID and return the type (NSE_TYPE_CONNECT, etc */
+enum nse_type get_event_id_type(nsock_event_id event_id) {
+ return (enum nse_type)((event_id & ((1 << TYPE_CODE_NUM_BITS) - 1)));
+}
+
+/* Create a new event structure -- must be deleted later with event_delete,
+ * unless it returns NULL (failure). NULL can be passed in for the struct niod
+ * and the userdata if not available */
+struct nevent *event_new(struct npool *nsp, enum nse_type type,
+ struct niod *iod, int timeout_msecs,
+ nsock_ev_handler handler, void *userdata) {
+ struct nevent *nse;
+ gh_lnode_t *lnode;
+
+ /* Bring us up to date for the timeout calculation. */
+ gettimeofday(&nsock_tod, NULL);
+
+ if (iod) {
+ iod->events_pending++;
+ assert(iod->state != NSIOD_STATE_DELETED);
+ }
+
+ /* First we check if one is available from the free list ... */
+ lnode = gh_list_pop(&nsp->free_events);
+ if (!lnode)
+ nse = (struct nevent *)safe_malloc(sizeof(*nse));
+ else
+ nse = lnode_nevent(lnode);
+
+ memset(nse, 0, sizeof(*nse));
+
+ nse->id = get_new_event_id(nsp, type);
+ nse->type = type;
+ nse->status = NSE_STATUS_NONE;
+ gh_hnode_invalidate(&nse->expire);
+#if HAVE_OPENSSL
+ nse->sslinfo.ssl_desire = SSL_ERROR_NONE;
+#endif
+
+ if (type == NSE_TYPE_READ || type == NSE_TYPE_WRITE)
+ filespace_init(&(nse->iobuf), 1024);
+
+#if HAVE_PCAP
+ if (type == NSE_TYPE_PCAP_READ) {
+ mspcap *mp;
+ int sz;
+
+ assert(iod != NULL);
+ mp = (mspcap *)iod->pcap;
+ assert(mp);
+
+ sz = mp->snaplen+1 + sizeof(nsock_pcap);
+ filespace_init(&(nse->iobuf), sz);
+ }
+#endif
+
+ if (timeout_msecs != -1) {
+ assert(timeout_msecs >= 0);
+ TIMEVAL_MSEC_ADD(nse->timeout, nsock_tod, timeout_msecs);
+ }
+
+ nse->iod = iod;
+ nse->handler = handler;
+ nse->userdata = userdata;
+
+ if (nse->iod == NULL)
+ nsock_log_debug("%s (IOD #NULL) (EID #%li)", __func__, nse->id);
+ else
+ nsock_log_debug("%s (IOD #%li) (EID #%li)", __func__, nse->iod->id,
+ nse->id);
+ return nse;
+}
+
+/* Free an struct nevent which was allocated with event_new, including all internal
+ * resources. Note -- we assume that nse->iod->events_pending (if it exists)
+ * has ALREADY been decremented (done during event_dispatch_and_delete) -- so
+ * remember to do this if you call event_delete() directly */
+void event_delete(struct npool *nsp, struct nevent *nse) {
+ if (nse->iod == NULL)
+ nsock_log_debug("%s (IOD #NULL) (EID #%li)", __func__, nse->id);
+ else
+ nsock_log_debug("%s (IOD #%li) (EID #%li)", __func__, nse->iod->id, nse->id);
+
+ /* First free the IOBuf inside it if necessary */
+ if (nse->type == NSE_TYPE_READ || nse->type == NSE_TYPE_WRITE) {
+ fs_free(&nse->iobuf);
+ }
+ #if HAVE_PCAP
+ if (nse->type == NSE_TYPE_PCAP_READ) {
+ fs_free(&nse->iobuf);
+ nsock_log_debug_all("PCAP removed %lu", nse->id);
+ }
+ #endif
+
+ /* Now we add the event back into the free pool */
+ nse->event_done = 1;
+}
+
+
+/* Takes an nse_type (as returned by nse_type() and returns a static string name
+ * that you can use for printing, etc. */
+const char *nse_type2str(enum nse_type type) {
+ switch (type) {
+ case NSE_TYPE_CONNECT: return "CONNECT";
+ case NSE_TYPE_CONNECT_SSL: return "SSL-CONNECT";
+ case NSE_TYPE_READ: return "READ";
+ case NSE_TYPE_WRITE: return "WRITE";
+ case NSE_TYPE_TIMER: return "TIMER";
+ case NSE_TYPE_PCAP_READ: return "READ-PCAP";
+ default:
+ return "UNKNOWN!";
+ }
+}
+
+/* Takes an nse_status (as returned by nse_status() and returns a static string
+ * name that you can use for printing, etc. */
+const char *nse_status2str(enum nse_status status) {
+ switch (status) {
+ case NSE_STATUS_NONE: return "NONE";
+ case NSE_STATUS_SUCCESS: return "SUCCESS";
+ case NSE_STATUS_ERROR: return "ERROR";
+ case NSE_STATUS_TIMEOUT: return "TIMEOUT";
+ case NSE_STATUS_CANCELLED: return "CANCELLED";
+ case NSE_STATUS_KILL: return "KILL";
+ case NSE_STATUS_EOF: return "EOF";
+ case NSE_STATUS_PROXYERROR: return "PROXY ERROR";
+ default:
+ return "UNKNOWN!";
+ }
+}
+
+int event_timedout(struct nevent *nse) {
+ if (nse->event_done)
+ return 0;
+
+ return (nse->timeout.tv_sec && !TIMEVAL_AFTER(nse->timeout, nsock_tod));
+}
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