1 /***************************************************************************
2 * nsock_pool.c -- This contains the functions that deal with creating, *
3 * destroying, and otherwise manipulating nsock_pools (and their internal *
4 * struct npool representation). An nsock_pool aggregates and manages events *
5 * and i/o descriptors *
6 * *
7 ***********************IMPORTANT NSOCK LICENSE TERMS***********************
8 * *
9 * The nsock parallel socket event library is (C) 1999-2020 Insecure.Com *
10 * LLC This library is free software; you may redistribute and/or *
11 * modify it under the terms of the GNU General Public License as *
12 * published by the Free Software Foundation; Version 2. This guarantees *
13 * your right to use, modify, and redistribute this software under certain *
14 * conditions. If this license is unacceptable to you, Insecure.Com LLC *
15 * may be willing to sell alternative licenses (contact *
16 * sales@insecure.com ). *
17 * *
18 * As a special exception to the GPL terms, Insecure.Com LLC grants *
19 * permission to link the code of this program with any version of the *
20 * OpenSSL library which is distributed under a license identical to that *
21 * listed in the included docs/licenses/OpenSSL.txt file, and distribute *
22 * linked combinations including the two. You must obey the GNU GPL in all *
23 * respects for all of the code used other than OpenSSL. If you modify *
24 * this file, you may extend this exception to your version of the file, *
25 * but you are not obligated to do so. *
26 * *
27 * If you received these files with a written license agreement stating *
28 * terms other than the (GPL) terms above, then that alternative license *
29 * agreement takes precedence over this comment. *
30 * *
31 * Source is provided to this software because we believe users have a *
32 * right to know exactly what a program is going to do before they run it. *
33 * This also allows you to audit the software for security holes. *
34 * *
35 * Source code also allows you to port Nmap to new platforms, fix bugs, *
36 * and add new features. You are highly encouraged to send your changes *
37 * to the dev@nmap.org mailing list for possible incorporation into the *
38 * main distribution. By sending these changes to Fyodor or one of the *
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43 * code. Nmap will always be available Open Source, but this is important *
44 * because the inability to relicense code has caused devastating problems *
45 * for other Free Software projects (such as KDE and NASM). We also *
46 * occasionally relicense the code to third parties as discussed above. *
47 * If you wish to specify special license conditions of your *
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49 * *
50 * This program is distributed in the hope that it will be useful, but *
51 * WITHOUT ANY WARRANTY; without even the implied warranty of *
52 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
53 * General Public License v2.0 for more details *
54 * (http://www.gnu.org/licenses/gpl-2.0.html). *
55 * *
56 ***************************************************************************/
57
58 /* $Id: nsock_pool.c 38071 2020-10-02 05:02:05Z fyodor $ */
59
60 #include "nsock_internal.h"
61 #include "nsock_log.h"
62 #include "gh_list.h"
63 #include "netutils.h"
64
65 #include <string.h>
66 #ifdef HAVE_SYS_TIME_H
67 #include <sys/time.h>
68 #endif
69 #ifdef HAVE_UNISTD_H
70 #include <unistd.h>
71 #endif
72 #include <signal.h>
73
74 #if HAVE_SYS_RESOURCE_H
75 #include <sys/resource.h>
76 #endif
77
78 extern struct timeval nsock_tod;
79
80 /* To use this library, the first thing they must do is create a pool
81 * so we do the initialization during the first pool creation */
82 static int nsocklib_initialized = 0;
83
84
85 /* defined in nsock_engines.h */
86 struct io_engine *get_io_engine(void);
87
88 /* ---- INTERNAL FUNCTIONS PROTOTYPES ---- */
89 static void nsock_library_initialize(void);
90 /* --------------------------------------- */
91
92
93 /* This next function returns the errno style error code -- which is only
94 * valid if the status NSOCK_LOOP_ERROR was returned by nsock_loop() */
nsock_pool_get_error(nsock_pool nsp)95 int nsock_pool_get_error(nsock_pool nsp) {
96 struct npool *mt = (struct npool *)nsp;
97 return mt->errnum;
98 }
99
100 /* Sometimes it is useful to store a pointer to information inside
101 * the NSP so you can retrieve it during a callback. */
nsock_pool_set_udata(nsock_pool nsp,void * data)102 void nsock_pool_set_udata(nsock_pool nsp, void *data) {
103 struct npool *mt = (struct npool *)nsp;
104 mt->userdata = data;
105 }
106
107 /* And the define above wouldn't make much sense if we didn't have a way
108 * to retrieve that data ... */
nsock_pool_get_udata(nsock_pool nsp)109 void *nsock_pool_get_udata(nsock_pool nsp) {
110 struct npool *mt = (struct npool *)nsp;
111 return mt->userdata;
112 }
113
114 /* Turns on or off broadcast support on new sockets. Default is off (0, false)
115 * set in nsock_pool_new(). Any non-zero (true) value sets SO_BROADCAST on all new
116 * sockets (value of optval will be used directly in the setsockopt() call */
nsock_pool_set_broadcast(nsock_pool nsp,int optval)117 void nsock_pool_set_broadcast(nsock_pool nsp, int optval) {
118 struct npool *mt = (struct npool *)nsp;
119 mt->broadcast = optval;
120 }
121
122 /* Sets the name of the interface for new sockets to bind to. */
nsock_pool_set_device(nsock_pool nsp,const char * device)123 void nsock_pool_set_device(nsock_pool nsp, const char *device) {
124 struct npool *mt = (struct npool *)nsp;
125 mt->device = device;
126 }
127
expirable_cmp(gh_hnode_t * n1,gh_hnode_t * n2)128 static int expirable_cmp(gh_hnode_t *n1, gh_hnode_t *n2) {
129 struct nevent *nse1;
130 struct nevent *nse2;
131
132 nse1 = container_of(n1, struct nevent, expire);
133 nse2 = container_of(n2, struct nevent, expire);
134
135 return (TIMEVAL_BEFORE(nse1->timeout, nse2->timeout)) ? 1 : 0;
136 }
137
138 /* And here is how you create an nsock_pool. This allocates, initializes, and
139 * returns an nsock_pool event aggregator. In the case of error, NULL will be
140 * returned. If you do not wish to immediately associate any userdata, pass in
141 * NULL. */
nsock_pool_new(void * userdata)142 nsock_pool nsock_pool_new(void *userdata) {
143 struct npool *nsp;
144
145 /* initialize the library in not already done */
146 if (!nsocklib_initialized) {
147 nsock_library_initialize();
148 nsocklib_initialized = 1;
149 }
150
151 nsp = (struct npool *)safe_malloc(sizeof(*nsp));
152 memset(nsp, 0, sizeof(*nsp));
153
154 gettimeofday(&nsock_tod, NULL);
155
156 nsp->userdata = userdata;
157
158 nsp->engine = get_io_engine();
159 nsock_engine_init(nsp);
160
161 /* initialize IO events lists */
162 gh_list_init(&nsp->connect_events);
163 gh_list_init(&nsp->read_events);
164 gh_list_init(&nsp->write_events);
165 #if HAVE_PCAP
166 gh_list_init(&nsp->pcap_read_events);
167 #endif
168
169 /* initialize timer heap */
170 gh_heap_init(&nsp->expirables, expirable_cmp);
171
172 /* initialize the list of IODs */
173 gh_list_init(&nsp->active_iods);
174
175 /* initialize caches */
176 gh_list_init(&nsp->free_iods);
177 gh_list_init(&nsp->free_events);
178
179 nsp->next_event_serial = 1;
180
181 nsp->device = NULL;
182
183 #if HAVE_OPENSSL
184 nsp->sslctx = NULL;
185 #endif
186
187 nsp->px_chain = NULL;
188
189 return (nsock_pool)nsp;
190 }
191
192 /* If nsock_pool_new returned success, you must free the nsp when you are done with it
193 * to conserve memory (and in some cases, sockets). After this call, nsp may no
194 * longer be used. Any pending events are sent an NSE_STATUS_KILL callback and
195 * all outstanding iods are deleted. */
nsock_pool_delete(nsock_pool ms_pool)196 void nsock_pool_delete(nsock_pool ms_pool) {
197 struct npool *nsp = (struct npool *)ms_pool;
198 struct nevent *nse;
199 struct niod *nsi;
200 int i;
201 gh_lnode_t *current, *next;
202 gh_list_t *event_lists[] = {
203 &nsp->connect_events,
204 &nsp->read_events,
205 &nsp->write_events,
206 #if HAVE_PCAP
207 &nsp->pcap_read_events,
208 #endif
209 NULL
210 };
211
212 assert(nsp);
213
214 /* First I go through all the events sending NSE_STATUS_KILL */
215 for (i = 0; event_lists[i] != NULL; i++) {
216 while (gh_list_count(event_lists[i]) > 0) {
217 gh_lnode_t *lnode = gh_list_pop(event_lists[i]);
218
219 assert(lnode);
220
221 #if HAVE_PCAP
222 if (event_lists[i] == &nsp->pcap_read_events)
223 nse = lnode_nevent2(lnode);
224 else
225 #endif
226 nse = lnode_nevent(lnode);
227
228 assert(nse);
229
230 nse->status = NSE_STATUS_KILL;
231 nsock_trace_handler_callback(nsp, nse);
232 nse->handler(nsp, nse, nse->userdata);
233
234 if (nse->iod) {
235 nse->iod->events_pending--;
236 assert(nse->iod->events_pending >= 0);
237 }
238 event_delete(nsp, nse);
239 }
240 gh_list_free(event_lists[i]);
241 }
242
243 /* Kill timers too, they're not in event lists */
244 while (gh_heap_count(&nsp->expirables) > 0) {
245 gh_hnode_t *hnode;
246
247 hnode = gh_heap_pop(&nsp->expirables);
248 nse = container_of(hnode, struct nevent, expire);
249
250 if (nse->type == NSE_TYPE_TIMER) {
251 nse->status = NSE_STATUS_KILL;
252 nsock_trace_handler_callback(nsp, nse);
253 nse->handler(nsp, nse, nse->userdata);
254 event_delete(nsp, nse);
255 gh_list_append(&nsp->free_events, &nse->nodeq_io);
256 }
257 }
258
259 gh_heap_free(&nsp->expirables);
260
261 /* foreach struct niod */
262 for (current = gh_list_first_elem(&nsp->active_iods);
263 current != NULL;
264 current = next) {
265 next = gh_lnode_next(current);
266 nsi = container_of(current, struct niod, nodeq);
267
268 nsock_iod_delete(nsi, NSOCK_PENDING_ERROR);
269
270 gh_list_remove(&nsp->active_iods, current);
271 gh_list_prepend(&nsp->free_iods, &nsi->nodeq);
272 }
273
274 /* Now we free all the memory in the free iod list */
275 while ((current = gh_list_pop(&nsp->free_iods))) {
276 nsi = container_of(current, struct niod, nodeq);
277 free(nsi);
278 }
279
280 while ((current = gh_list_pop(&nsp->free_events))) {
281 nse = lnode_nevent(current);
282 free(nse);
283 }
284
285 gh_list_free(&nsp->active_iods);
286 gh_list_free(&nsp->free_iods);
287 gh_list_free(&nsp->free_events);
288
289 nsock_engine_destroy(nsp);
290
291 #if HAVE_OPENSSL
292 if (nsp->sslctx != NULL)
293 SSL_CTX_free(nsp->sslctx);
294 #endif
295
296 free(nsp);
297 }
298
nsock_library_initialize(void)299 void nsock_library_initialize(void) {
300 #ifndef WIN32
301 rlim_t res;
302
303 /* We want to make darn sure the evil SIGPIPE is ignored */
304 signal(SIGPIPE, SIG_IGN);
305
306 /* And we're gonna need sockets -- LOTS of sockets ... */
307 res = maximize_fdlimit();
308 assert(res > 7);
309 #endif
310 return;
311 }
312
313