1/* $OpenBSD: roaming_common.c,v 1.10 2013/07/12 00:19:59 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	if (size == 0 || size > MAX_ROAMBUF)
79		fatal("%s: bad buffer size %lu", __func__, (u_long)size);
80	/*
81	 * The buffer size can only be set once and the buffer will live
82	 * as long as the session lives.
83	 */
84	if (out_buf == NULL) {
85		out_buf_size = size;
86		out_buf = xmalloc(size);
87		out_start = 0;
88		out_last = 0;
89	}
90}
91
92u_int64_t
93get_recv_bytes(void)
94{
95	return read_bytes;
96}
97
98void
99add_recv_bytes(u_int64_t num)
100{
101	read_bytes += num;
102}
103
104u_int64_t
105get_sent_bytes(void)
106{
107	return write_bytes;
108}
109
110void
111roam_set_bytes(u_int64_t sent, u_int64_t recvd)
112{
113	read_bytes = recvd;
114	write_bytes = sent;
115}
116
117static void
118buf_append(const char *buf, size_t count)
119{
120	if (count > out_buf_size) {
121		buf += count - out_buf_size;
122		count = out_buf_size;
123	}
124	if (count < out_buf_size - out_last) {
125		memcpy(out_buf + out_last, buf, count);
126		if (out_start > out_last)
127			out_start += count;
128		out_last += count;
129	} else {
130		/* data will wrap */
131		size_t chunk = out_buf_size - out_last;
132		memcpy(out_buf + out_last, buf, chunk);
133		memcpy(out_buf, buf + chunk, count - chunk);
134		out_last = count - chunk;
135		out_start = out_last + 1;
136	}
137}
138
139ssize_t
140roaming_write(int fd, const void *buf, size_t count, int *cont)
141{
142	ssize_t ret;
143
144	ret = write(fd, buf, count);
145	if (ret > 0 && !resume_in_progress) {
146		write_bytes += ret;
147		if (out_buf_size > 0)
148			buf_append(buf, ret);
149	}
150	if (out_buf_size > 0 &&
151	    (ret == 0 || (ret == -1 && errno == EPIPE))) {
152		if (wait_for_roaming_reconnect() != 0) {
153			ret = 0;
154			*cont = 1;
155		} else {
156			ret = -1;
157			errno = EAGAIN;
158		}
159	}
160	return ret;
161}
162
163ssize_t
164roaming_read(int fd, void *buf, size_t count, int *cont)
165{
166	ssize_t ret = read(fd, buf, count);
167	if (ret > 0) {
168		if (!resume_in_progress) {
169			read_bytes += ret;
170		}
171	} else if (out_buf_size > 0 &&
172	    (ret == 0 || (ret == -1 && (errno == ECONNRESET
173	    || errno == ECONNABORTED || errno == ETIMEDOUT
174	    || errno == EHOSTUNREACH)))) {
175		debug("roaming_read failed for %d  ret=%ld  errno=%d",
176		    fd, (long)ret, errno);
177		ret = 0;
178		if (wait_for_roaming_reconnect() == 0)
179			*cont = 1;
180	}
181	return ret;
182}
183
184size_t
185roaming_atomicio(ssize_t(*f)(int, void*, size_t), int fd, void *buf,
186    size_t count)
187{
188	size_t ret = atomicio(f, fd, buf, count);
189
190	if (f == vwrite && ret > 0 && !resume_in_progress) {
191		write_bytes += ret;
192	} else if (f == read && ret > 0 && !resume_in_progress) {
193		read_bytes += ret;
194	}
195	return ret;
196}
197
198void
199resend_bytes(int fd, u_int64_t *offset)
200{
201	size_t available, needed;
202
203	if (out_start < out_last)
204		available = out_last - out_start;
205	else
206		available = out_buf_size;
207	needed = write_bytes - *offset;
208	debug3("resend_bytes: resend %lu bytes from %llu",
209	    (unsigned long)needed, (unsigned long long)*offset);
210	if (needed > available)
211		fatal("Needed to resend more data than in the cache");
212	if (out_last < needed) {
213		int chunkend = needed - out_last;
214		atomicio(vwrite, fd, out_buf + out_buf_size - chunkend,
215		    chunkend);
216		atomicio(vwrite, fd, out_buf, out_last);
217	} else {
218		atomicio(vwrite, fd, out_buf + (out_last - needed), needed);
219	}
220}
221
222/*
223 * Caclulate a new key after a reconnect
224 */
225void
226calculate_new_key(u_int64_t *key, u_int64_t cookie, u_int64_t challenge)
227{
228	const EVP_MD *md = EVP_sha1();
229	EVP_MD_CTX ctx;
230	u_char hash[EVP_MAX_MD_SIZE];
231	Buffer b;
232
233	buffer_init(&b);
234	buffer_put_int64(&b, *key);
235	buffer_put_int64(&b, cookie);
236	buffer_put_int64(&b, challenge);
237
238	EVP_DigestInit(&ctx, md);
239	EVP_DigestUpdate(&ctx, buffer_ptr(&b), buffer_len(&b));
240	EVP_DigestFinal(&ctx, hash, NULL);
241
242	buffer_clear(&b);
243	buffer_append(&b, hash, EVP_MD_size(md));
244	*key = buffer_get_int64(&b);
245	buffer_free(&b);
246}
247