bss_dgram.c revision 160815 
1/* crypto/bio/bio_dgram.c */
2/*
3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
5 */
6/* ====================================================================
7 * Copyright (c) 1999-2005 The OpenSSL Project.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in
18 *    the documentation and/or other materials provided with the
19 *    distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 *    software must display the following acknowledgment:
23 *    "This product includes software developed by the OpenSSL Project
24 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 *    endorse or promote products derived from this software without
28 *    prior written permission. For written permission, please contact
29 *    openssl-core@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 *    nor may "OpenSSL" appear in their names without prior written
33 *    permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 *    acknowledgment:
37 *    "This product includes software developed by the OpenSSL Project
38 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com).  This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59
60#ifndef OPENSSL_NO_DGRAM
61
62#include <stdio.h>
63#include <errno.h>
64#define USE_SOCKETS
65#include "cryptlib.h"
66
67#include <openssl/bio.h>
68
69#define IP_MTU      14 /* linux is lame */
70
71#ifdef WATT32
72#define sock_write SockWrite  /* Watt-32 uses same names */
73#define sock_read  SockRead
74#define sock_puts  SockPuts
75#endif
76
77static int dgram_write(BIO *h, const char *buf, int num);
78static int dgram_read(BIO *h, char *buf, int size);
79static int dgram_puts(BIO *h, const char *str);
80static long dgram_ctrl(BIO *h, int cmd, long arg1, void *arg2);
81static int dgram_new(BIO *h);
82static int dgram_free(BIO *data);
83static int dgram_clear(BIO *bio);
84
85int BIO_dgram_should_retry(int s);
86
87static BIO_METHOD methods_dgramp=
88	{
89	BIO_TYPE_DGRAM,
90	"datagram socket",
91	dgram_write,
92	dgram_read,
93	dgram_puts,
94	NULL, /* dgram_gets, */
95	dgram_ctrl,
96	dgram_new,
97	dgram_free,
98	NULL,
99	};
100
101typedef struct bio_dgram_data_st
102	{
103	struct sockaddr peer;
104	unsigned int connected;
105	unsigned int _errno;
106	unsigned int mtu;
107	} bio_dgram_data;
108
109BIO_METHOD *BIO_s_datagram(void)
110	{
111	return(&methods_dgramp);
112	}
113
114BIO *BIO_new_dgram(int fd, int close_flag)
115	{
116	BIO *ret;
117
118	ret=BIO_new(BIO_s_datagram());
119	if (ret == NULL) return(NULL);
120	BIO_set_fd(ret,fd,close_flag);
121	return(ret);
122	}
123
124static int dgram_new(BIO *bi)
125	{
126	bio_dgram_data *data = NULL;
127
128	bi->init=0;
129	bi->num=0;
130	data = OPENSSL_malloc(sizeof(bio_dgram_data));
131	if (data == NULL)
132		return 0;
133	memset(data, 0x00, sizeof(bio_dgram_data));
134    bi->ptr = data;
135
136	bi->flags=0;
137	return(1);
138	}
139
140static int dgram_free(BIO *a)
141	{
142	bio_dgram_data *data;
143
144	if (a == NULL) return(0);
145	if ( ! dgram_clear(a))
146		return 0;
147
148	data = (bio_dgram_data *)a->ptr;
149	if(data != NULL) OPENSSL_free(data);
150
151	return(1);
152	}
153
154static int dgram_clear(BIO *a)
155	{
156	if (a == NULL) return(0);
157	if (a->shutdown)
158		{
159		if (a->init)
160			{
161			SHUTDOWN2(a->num);
162			}
163		a->init=0;
164		a->flags=0;
165		}
166	return(1);
167	}
168
169static int dgram_read(BIO *b, char *out, int outl)
170	{
171	int ret=0;
172	bio_dgram_data *data = (bio_dgram_data *)b->ptr;
173
174	struct sockaddr peer;
175	int peerlen = sizeof(peer);
176
177	if (out != NULL)
178		{
179		clear_socket_error();
180		memset(&peer, 0x00, peerlen);
181		/* Last arg in recvfrom is signed on some platforms and
182		 * unsigned on others. It is of type socklen_t on some
183		 * but this is not universal. Cast to (void *) to avoid
184		 * compiler warnings.
185		 */
186		ret=recvfrom(b->num,out,outl,0,&peer,(void *)&peerlen);
187
188		if ( ! data->connected  && ret > 0)
189			BIO_ctrl(b, BIO_CTRL_DGRAM_CONNECT, 0, &peer);
190
191		BIO_clear_retry_flags(b);
192		if (ret <= 0)
193			{
194			if (BIO_dgram_should_retry(ret))
195				{
196				BIO_set_retry_read(b);
197				data->_errno = get_last_socket_error();
198				}
199			}
200		}
201	return(ret);
202	}
203
204static int dgram_write(BIO *b, const char *in, int inl)
205	{
206	int ret;
207	bio_dgram_data *data = (bio_dgram_data *)b->ptr;
208	clear_socket_error();
209
210    if ( data->connected )
211        ret=send(b->num,in,inl,0);
212    else
213        ret=sendto(b->num, in, inl, 0, &data->peer, sizeof(data->peer));
214
215	BIO_clear_retry_flags(b);
216	if (ret <= 0)
217		{
218		if (BIO_sock_should_retry(ret))
219			{
220			BIO_set_retry_write(b);
221			data->_errno = get_last_socket_error();
222
223#if 0 /* higher layers are responsible for querying MTU, if necessary */
224			if ( data->_errno == EMSGSIZE)
225				/* retrieve the new MTU */
226				BIO_ctrl(b, BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
227#endif
228			}
229		}
230	return(ret);
231	}
232
233static long dgram_ctrl(BIO *b, int cmd, long num, void *ptr)
234	{
235	long ret=1;
236	int *ip;
237	struct sockaddr *to = NULL;
238	bio_dgram_data *data = NULL;
239	long sockopt_val = 0;
240	unsigned int sockopt_len = 0;
241
242	data = (bio_dgram_data *)b->ptr;
243
244	switch (cmd)
245		{
246	case BIO_CTRL_RESET:
247		num=0;
248	case BIO_C_FILE_SEEK:
249		ret=0;
250		break;
251	case BIO_C_FILE_TELL:
252	case BIO_CTRL_INFO:
253		ret=0;
254		break;
255	case BIO_C_SET_FD:
256		dgram_clear(b);
257		b->num= *((int *)ptr);
258		b->shutdown=(int)num;
259		b->init=1;
260		break;
261	case BIO_C_GET_FD:
262		if (b->init)
263			{
264			ip=(int *)ptr;
265			if (ip != NULL) *ip=b->num;
266			ret=b->num;
267			}
268		else
269			ret= -1;
270		break;
271	case BIO_CTRL_GET_CLOSE:
272		ret=b->shutdown;
273		break;
274	case BIO_CTRL_SET_CLOSE:
275		b->shutdown=(int)num;
276		break;
277	case BIO_CTRL_PENDING:
278	case BIO_CTRL_WPENDING:
279		ret=0;
280		break;
281	case BIO_CTRL_DUP:
282	case BIO_CTRL_FLUSH:
283		ret=1;
284		break;
285	case BIO_CTRL_DGRAM_CONNECT:
286		to = (struct sockaddr *)ptr;
287#if 0
288		if (connect(b->num, to, sizeof(struct sockaddr)) < 0)
289			{ perror("connect"); ret = 0; }
290		else
291			{
292#endif
293			memcpy(&(data->peer),to, sizeof(struct sockaddr));
294#if 0
295			}
296#endif
297		break;
298		/* (Linux)kernel sets DF bit on outgoing IP packets */
299#ifdef IP_MTU_DISCOVER
300	case BIO_CTRL_DGRAM_MTU_DISCOVER:
301		sockopt_val = IP_PMTUDISC_DO;
302		if ((ret = setsockopt(b->num, IPPROTO_IP, IP_MTU_DISCOVER,
303			&sockopt_val, sizeof(sockopt_val))) < 0)
304			perror("setsockopt");
305		break;
306#endif
307	case BIO_CTRL_DGRAM_QUERY_MTU:
308         sockopt_len = sizeof(sockopt_val);
309		if ((ret = getsockopt(b->num, IPPROTO_IP, IP_MTU, (void *)&sockopt_val,
310			&sockopt_len)) < 0 || sockopt_val < 0)
311			{ ret = 0; }
312		else
313			{
314			data->mtu = sockopt_val;
315			ret = data->mtu;
316			}
317		break;
318	case BIO_CTRL_DGRAM_GET_MTU:
319		return data->mtu;
320		break;
321	case BIO_CTRL_DGRAM_SET_MTU:
322		data->mtu = num;
323		ret = num;
324		break;
325	case BIO_CTRL_DGRAM_SET_CONNECTED:
326		to = (struct sockaddr *)ptr;
327
328		if ( to != NULL)
329			{
330			data->connected = 1;
331			memcpy(&(data->peer),to, sizeof(struct sockaddr));
332			}
333		else
334			{
335			data->connected = 0;
336			memset(&(data->peer), 0x00, sizeof(struct sockaddr));
337			}
338		break;
339    case BIO_CTRL_DGRAM_SET_PEER:
340        to = (struct sockaddr *) ptr;
341
342        memcpy(&(data->peer), to, sizeof(struct sockaddr));
343        break;
344	case BIO_CTRL_DGRAM_SET_RECV_TIMEOUT:
345		if ( setsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO, ptr,
346			sizeof(struct timeval)) < 0)
347			{ perror("setsockopt");	ret = -1; }
348		break;
349	case BIO_CTRL_DGRAM_GET_RECV_TIMEOUT:
350		if ( getsockopt(b->num, SOL_SOCKET, SO_RCVTIMEO,
351			ptr, (void *)&ret) < 0)
352			{ perror("getsockopt"); ret = -1; }
353		break;
354	case BIO_CTRL_DGRAM_SET_SEND_TIMEOUT:
355		if ( setsockopt(b->num, SOL_SOCKET, SO_SNDTIMEO, ptr,
356			sizeof(struct timeval)) < 0)
357			{ perror("setsockopt");	ret = -1; }
358		break;
359	case BIO_CTRL_DGRAM_GET_SEND_TIMEOUT:
360		if ( getsockopt(b->num, SOL_SOCKET, SO_SNDTIMEO,
361			ptr, (void *)&ret) < 0)
362			{ perror("getsockopt"); ret = -1; }
363		break;
364	case BIO_CTRL_DGRAM_GET_SEND_TIMER_EXP:
365		/* fall-through */
366	case BIO_CTRL_DGRAM_GET_RECV_TIMER_EXP:
367		if ( data->_errno == EAGAIN)
368			{
369			ret = 1;
370			data->_errno = 0;
371			}
372		else
373			ret = 0;
374		break;
375#ifdef EMSGSIZE
376	case BIO_CTRL_DGRAM_MTU_EXCEEDED:
377		if ( data->_errno == EMSGSIZE)
378			{
379			ret = 1;
380			data->_errno = 0;
381			}
382		else
383			ret = 0;
384		break;
385#endif
386	default:
387		ret=0;
388		break;
389		}
390	return(ret);
391	}
392
393static int dgram_puts(BIO *bp, const char *str)
394	{
395	int n,ret;
396
397	n=strlen(str);
398	ret=dgram_write(bp,str,n);
399	return(ret);
400	}
401
402int BIO_dgram_should_retry(int i)
403	{
404	int err;
405
406	if ((i == 0) || (i == -1))
407		{
408		err=get_last_socket_error();
409
410#if defined(OPENSSL_SYS_WINDOWS) && 0 /* more microsoft stupidity? perhaps not? Ben 4/1/99 */
411		if ((i == -1) && (err == 0))
412			return(1);
413#endif
414
415		return(BIO_dgram_non_fatal_error(err));
416		}
417	return(0);
418	}
419
420int BIO_dgram_non_fatal_error(int err)
421	{
422	switch (err)
423		{
424#if defined(OPENSSL_SYS_WINDOWS)
425# if defined(WSAEWOULDBLOCK)
426	case WSAEWOULDBLOCK:
427# endif
428
429# if 0 /* This appears to always be an error */
430#  if defined(WSAENOTCONN)
431	case WSAENOTCONN:
432#  endif
433# endif
434#endif
435
436#ifdef EWOULDBLOCK
437# ifdef WSAEWOULDBLOCK
438#  if WSAEWOULDBLOCK != EWOULDBLOCK
439	case EWOULDBLOCK:
440#  endif
441# else
442	case EWOULDBLOCK:
443# endif
444#endif
445
446#if defined(ENOTCONN)
447	case ENOTCONN:
448#endif
449
450#ifdef EINTR
451	case EINTR:
452#endif
453
454#ifdef EAGAIN
455#if EWOULDBLOCK != EAGAIN
456	case EAGAIN:
457# endif
458#endif
459
460#ifdef EPROTO
461	case EPROTO:
462#endif
463
464#ifdef EINPROGRESS
465	case EINPROGRESS:
466#endif
467
468#ifdef EALREADY
469	case EALREADY:
470#endif
471
472/* DF bit set, and packet larger than MTU */
473#ifdef EMSGSIZE
474	case EMSGSIZE:
475#endif
476
477		return(1);
478		/* break; */
479	default:
480		break;
481		}
482	return(0);
483	}
484#endif
485