1/* $OpenBSD: roaming_common.c,v 1.12 2014/01/09 23:20:00 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#include "digest.h"
40
41static size_t out_buf_size = 0;
42static char *out_buf = NULL;
43static size_t out_start;
44static size_t out_last;
45
46static u_int64_t write_bytes = 0;
47static u_int64_t read_bytes = 0;
48
49int roaming_enabled = 0;
50int resume_in_progress = 0;
51
52int
53get_snd_buf_size(void)
54{
55	int fd = packet_get_connection_out();
56	int optval;
57	socklen_t optvallen = sizeof(optval);
58
59	if (getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &optval, &optvallen) != 0)
60		optval = DEFAULT_ROAMBUF;
61	return optval;
62}
63
64int
65get_recv_buf_size(void)
66{
67	int fd = packet_get_connection_in();
68	int optval;
69	socklen_t optvallen = sizeof(optval);
70
71	if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &optval, &optvallen) != 0)
72		optval = DEFAULT_ROAMBUF;
73	return optval;
74}
75
76void
77set_out_buffer_size(size_t size)
78{
79	if (size == 0 || size > MAX_ROAMBUF)
80		fatal("%s: bad buffer size %lu", __func__, (u_long)size);
81	/*
82	 * The buffer size can only be set once and the buffer will live
83	 * as long as the session lives.
84	 */
85	if (out_buf == NULL) {
86		out_buf_size = size;
87		out_buf = xmalloc(size);
88		out_start = 0;
89		out_last = 0;
90	}
91}
92
93u_int64_t
94get_recv_bytes(void)
95{
96	return read_bytes;
97}
98
99void
100add_recv_bytes(u_int64_t num)
101{
102	read_bytes += num;
103}
104
105u_int64_t
106get_sent_bytes(void)
107{
108	return write_bytes;
109}
110
111void
112roam_set_bytes(u_int64_t sent, u_int64_t recvd)
113{
114	read_bytes = recvd;
115	write_bytes = sent;
116}
117
118static void
119buf_append(const char *buf, size_t count)
120{
121	if (count > out_buf_size) {
122		buf += count - out_buf_size;
123		count = out_buf_size;
124	}
125	if (count < out_buf_size - out_last) {
126		memcpy(out_buf + out_last, buf, count);
127		if (out_start > out_last)
128			out_start += count;
129		out_last += count;
130	} else {
131		/* data will wrap */
132		size_t chunk = out_buf_size - out_last;
133		memcpy(out_buf + out_last, buf, chunk);
134		memcpy(out_buf, buf + chunk, count - chunk);
135		out_last = count - chunk;
136		out_start = out_last + 1;
137	}
138}
139
140ssize_t
141roaming_write(int fd, const void *buf, size_t count, int *cont)
142{
143	ssize_t ret;
144
145	ret = write(fd, buf, count);
146	if (ret > 0 && !resume_in_progress) {
147		write_bytes += ret;
148		if (out_buf_size > 0)
149			buf_append(buf, ret);
150	}
151	if (out_buf_size > 0 &&
152	    (ret == 0 || (ret == -1 && errno == EPIPE))) {
153		if (wait_for_roaming_reconnect() != 0) {
154			ret = 0;
155			*cont = 1;
156		} else {
157			ret = -1;
158			errno = EAGAIN;
159		}
160	}
161	return ret;
162}
163
164ssize_t
165roaming_read(int fd, void *buf, size_t count, int *cont)
166{
167	ssize_t ret = read(fd, buf, count);
168	if (ret > 0) {
169		if (!resume_in_progress) {
170			read_bytes += ret;
171		}
172	} else if (out_buf_size > 0 &&
173	    (ret == 0 || (ret == -1 && (errno == ECONNRESET
174	    || errno == ECONNABORTED || errno == ETIMEDOUT
175	    || errno == EHOSTUNREACH)))) {
176		debug("roaming_read failed for %d  ret=%ld  errno=%d",
177		    fd, (long)ret, errno);
178		ret = 0;
179		if (wait_for_roaming_reconnect() == 0)
180			*cont = 1;
181	}
182	return ret;
183}
184
185size_t
186roaming_atomicio(ssize_t(*f)(int, void*, size_t), int fd, void *buf,
187    size_t count)
188{
189	size_t ret = atomicio(f, fd, buf, count);
190
191	if (f == vwrite && ret > 0 && !resume_in_progress) {
192		write_bytes += ret;
193	} else if (f == read && ret > 0 && !resume_in_progress) {
194		read_bytes += ret;
195	}
196	return ret;
197}
198
199void
200resend_bytes(int fd, u_int64_t *offset)
201{
202	size_t available, needed;
203
204	if (out_start < out_last)
205		available = out_last - out_start;
206	else
207		available = out_buf_size;
208	needed = write_bytes - *offset;
209	debug3("resend_bytes: resend %lu bytes from %llu",
210	    (unsigned long)needed, (unsigned long long)*offset);
211	if (needed > available)
212		fatal("Needed to resend more data than in the cache");
213	if (out_last < needed) {
214		int chunkend = needed - out_last;
215		atomicio(vwrite, fd, out_buf + out_buf_size - chunkend,
216		    chunkend);
217		atomicio(vwrite, fd, out_buf, out_last);
218	} else {
219		atomicio(vwrite, fd, out_buf + (out_last - needed), needed);
220	}
221}
222
223/*
224 * Caclulate a new key after a reconnect
225 */
226void
227calculate_new_key(u_int64_t *key, u_int64_t cookie, u_int64_t challenge)
228{
229	u_char hash[SSH_DIGEST_MAX_LENGTH];
230	Buffer b;
231
232	buffer_init(&b);
233	buffer_put_int64(&b, *key);
234	buffer_put_int64(&b, cookie);
235	buffer_put_int64(&b, challenge);
236
237	if (ssh_digest_buffer(SSH_DIGEST_SHA1, &b, hash, sizeof(hash)) != 0)
238		fatal("%s: digest_buffer failed", __func__);
239
240	buffer_clear(&b);
241	buffer_append(&b, hash, ssh_digest_bytes(SSH_DIGEST_SHA1));
242	*key = buffer_get_int64(&b);
243	buffer_free(&b);
244}
245