dunnel

 1#include <dtls.h>
 2#include <dtls_debug.h>
 3#include <string.h>
 4#include <unistd.h>
 5#include <string.h>
 6#include <errno.h>
 7
 8#include <sys/types.h>
 9#include <sys/socket.h>
10
11#include "dat.h"
12#include "fns.h"
13
14static int
15dwrite(struct dtls_context_t *ctx, session_t *sess, uint8 *data, size_t len)
16{
17	struct dctx *dctx;
18
19	dctx = dtls_get_app_data(ctx);
20	return sendto(dctx->dfd, data, len, MSG_DONTWAIT,
21		&sess->addr.sa, sess->size);
22}
23
24static int
25dread(struct dtls_context_t *ctx, session_t *sess, uint8 *data, size_t len)
26{
27	(void)sess;
28	struct dctx *dctx;
29
30	dctx = dtls_get_app_data(ctx);
31	if (smode) {
32		/* in server mode connect(3) is called on the UDP socket up
33		 * on creation thus we don't need to specify an address. */
34		if (send(dctx->ufd, data, len, MSG_DONTWAIT) == -1)
35			dtls_alert("send failed in dread: %s\n", strerror(errno));
36	} else {
37		/* in client mode csess should contain the address of
38		 * the client from which we last received a datagram. */
39		if (csess.size <= 0) {
40			dtls_alert("Didn't receive a datagram from a client yet, "
41				"discarding received DTLS message\n");
42			return 0;
43		}
44
45		if (sendto(dctx->ufd, data, len, MSG_DONTWAIT,
46				&csess.addr.sa, csess.size) == -1)
47			dtls_alert("sendto failed in dread: %s\n", strerror(errno));
48	}
49
50	/* I have no idea why this function prototype has a return value
51	 * `tests/dtls-client.c` returns 0 here so lets do that as well. */
52	return 0;
53}
54
55static int
56dpsk(struct dtls_context_t *ctx, const session_t *sess, dtls_credentials_type_t type,
57	const unsigned char *id, size_t ilen, unsigned char *res, size_t rlen)
58{
59	(void)sess;
60	void *ptr;
61	size_t len;
62	struct dctx *dctx;
63
64	dctx = dtls_get_app_data(ctx);
65	switch (type) {
66	case DTLS_PSK_HINT:
67	case DTLS_PSK_IDENTITY:
68		ptr = dctx->id;
69		len = strlen((char*)dctx->id);
70		break;
71	case DTLS_PSK_KEY:
72		ptr = dctx->key;
73		len = strlen((char*)dctx->key);
74
75		if (xmemcmp((void*)id, ilen, dctx->id, len)) {
76			dtls_warn("Received request for unknown ID\n");
77			return dtls_alert_fatal_create(DTLS_ALERT_ILLEGAL_PARAMETER);
78		}
79		break;
80	default:
81		dtls_warn("Unsupported request type: %d\n", type);
82		break;
83	}
84
85	if (len > rlen) {
86		dtls_warn("Buffer to small for request type: %d\n", type);
87		return dtls_alert_fatal_create(DTLS_ALERT_INTERNAL_ERROR);
88	}
89
90	memcpy(res, ptr, len);
91	return len;
92}
93
94dtls_handler_t dtlscb = {
95	.write = dwrite,
96	.read  = dread,
97	.event = NULL,
98	.get_psk_info = dpsk
99};