1/* $OpenBSD: roaming_common.c,v 1.8 2010/01/12 00:59:29 djm Exp $ */
2/*
3 * Copyright (c) 2004-2009 AppGate Network Security AB
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#include "includes.h"
19
20#include <sys/types.h>
21#include <sys/socket.h>
22#include <sys/uio.h>
23
24#include <errno.h>
25#ifdef HAVE_INTTYPES_H
26#include <inttypes.h>
27#endif
28#include <stdarg.h>
29#include <string.h>
30#include <unistd.h>
31
32#include "atomicio.h"
33#include "log.h"
34#include "packet.h"
35#include "xmalloc.h"
36#include "cipher.h"
37#include "buffer.h"
38#include "roaming.h"
39
40static size_t out_buf_size = 0;
41static char *out_buf = NULL;
42static size_t out_start;
43static size_t out_last;
44
45static u_int64_t write_bytes = 0;
46static u_int64_t read_bytes = 0;
47
48int roaming_enabled = 0;
49int resume_in_progress = 0;
50
51int
52get_snd_buf_size()
53{
54	int fd = packet_get_connection_out();
55	int optval;
56	socklen_t optvallen = sizeof(optval);
57
58	if (getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &optval, &optvallen) != 0)
59		optval = DEFAULT_ROAMBUF;
60	return optval;
61}
62
63int
64get_recv_buf_size()
65{
66	int fd = packet_get_connection_in();
67	int optval;
68	socklen_t optvallen = sizeof(optval);
69
70	if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &optval, &optvallen) != 0)
71		optval = DEFAULT_ROAMBUF;
72	return optval;
73}
74
75void
76set_out_buffer_size(size_t size)
77{
78	/*
79	 * The buffer size can only be set once and the buffer will live
80	 * as long as the session lives.
81	 */
82	if (out_buf == NULL) {
83		out_buf_size = size;
84		out_buf = xmalloc(size);
85		out_start = 0;
86		out_last = 0;
87	}
88}
89
90u_int64_t
91get_recv_bytes(void)
92{
93	return read_bytes;
94}
95
96void
97add_recv_bytes(u_int64_t num)
98{
99	read_bytes += num;
100}
101
102u_int64_t
103get_sent_bytes(void)
104{
105	return write_bytes;
106}
107
108void
109roam_set_bytes(u_int64_t sent, u_int64_t recvd)
110{
111	read_bytes = recvd;
112	write_bytes = sent;
113}
114
115static void
116buf_append(const char *buf, size_t count)
117{
118	if (count > out_buf_size) {
119		buf += count - out_buf_size;
120		count = out_buf_size;
121	}
122	if (count < out_buf_size - out_last) {
123		memcpy(out_buf + out_last, buf, count);
124		if (out_start > out_last)
125			out_start += count;
126		out_last += count;
127	} else {
128		/* data will wrap */
129		size_t chunk = out_buf_size - out_last;
130		memcpy(out_buf + out_last, buf, chunk);
131		memcpy(out_buf, buf + chunk, count - chunk);
132		out_last = count - chunk;
133		out_start = out_last + 1;
134	}
135}
136
137ssize_t
138roaming_write(int fd, const void *buf, size_t count, int *cont)
139{
140	ssize_t ret;
141
142	ret = write(fd, buf, count);
143	if (ret > 0 && !resume_in_progress) {
144		write_bytes += ret;
145		if (out_buf_size > 0)
146			buf_append(buf, ret);
147	}
148	if (out_buf_size > 0 &&
149	    (ret == 0 || (ret == -1 && errno == EPIPE))) {
150		if (wait_for_roaming_reconnect() != 0) {
151			ret = 0;
152			*cont = 1;
153		} else {
154			ret = -1;
155			errno = EAGAIN;
156		}
157	}
158	return ret;
159}
160
161ssize_t
162roaming_read(int fd, void *buf, size_t count, int *cont)
163{
164	ssize_t ret = read(fd, buf, count);
165	if (ret > 0) {
166		if (!resume_in_progress) {
167			read_bytes += ret;
168		}
169	} else if (out_buf_size > 0 &&
170	    (ret == 0 || (ret == -1 && (errno == ECONNRESET
171	    || errno == ECONNABORTED || errno == ETIMEDOUT
172	    || errno == EHOSTUNREACH)))) {
173		debug("roaming_read failed for %d  ret=%ld  errno=%d",
174		    fd, (long)ret, errno);
175		ret = 0;
176		if (wait_for_roaming_reconnect() == 0)
177			*cont = 1;
178	}
179	return ret;
180}
181
182size_t
183roaming_atomicio(ssize_t(*f)(int, void*, size_t), int fd, void *buf,
184    size_t count)
185{
186	size_t ret = atomicio(f, fd, buf, count);
187
188	if (f == vwrite && ret > 0 && !resume_in_progress) {
189		write_bytes += ret;
190	} else if (f == read && ret > 0 && !resume_in_progress) {
191		read_bytes += ret;
192	}
193	return ret;
194}
195
196void
197resend_bytes(int fd, u_int64_t *offset)
198{
199	size_t available, needed;
200
201	if (out_start < out_last)
202		available = out_last - out_start;
203	else
204		available = out_buf_size;
205	needed = write_bytes - *offset;
206	debug3("resend_bytes: resend %lu bytes from %llu",
207	    (unsigned long)needed, (unsigned long long)*offset);
208	if (needed > available)
209		fatal("Needed to resend more data than in the cache");
210	if (out_last < needed) {
211		int chunkend = needed - out_last;
212		atomicio(vwrite, fd, out_buf + out_buf_size - chunkend,
213		    chunkend);
214		atomicio(vwrite, fd, out_buf, out_last);
215	} else {
216		atomicio(vwrite, fd, out_buf + (out_last - needed), needed);
217	}
218}
219
220/*
221 * Caclulate a new key after a reconnect
222 */
223void
224calculate_new_key(u_int64_t *key, u_int64_t cookie, u_int64_t challenge)
225{
226	const EVP_MD *md = EVP_sha1();
227	EVP_MD_CTX ctx;
228	char hash[EVP_MAX_MD_SIZE];
229	Buffer b;
230
231	buffer_init(&b);
232	buffer_put_int64(&b, *key);
233	buffer_put_int64(&b, cookie);
234	buffer_put_int64(&b, challenge);
235
236	EVP_DigestInit(&ctx, md);
237	EVP_DigestUpdate(&ctx, buffer_ptr(&b), buffer_len(&b));
238	EVP_DigestFinal(&ctx, hash, NULL);
239
240	buffer_clear(&b);
241	buffer_append(&b, hash, EVP_MD_size(md));
242	*key = buffer_get_int64(&b);
243	buffer_free(&b);
244}
245