openssh-portable/roaming_common.c

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/* $OpenBSD: roaming_common.c,v 1.11 2013/11/03 10:37:19 djm Exp $ */
/*
* Copyright (c) 2004-2009 AppGate Network Security AB
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "includes.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <errno.h>
#ifdef HAVE_INTTYPES_H
#include <inttypes.h>
#endif
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include "atomicio.h"
#include "log.h"
#include "packet.h"
#include "xmalloc.h"
#include "cipher.h"
#include "buffer.h"
#include "roaming.h"
static size_t out_buf_size = 0;
static char *out_buf = NULL;
static size_t out_start;
static size_t out_last;
static u_int64_t write_bytes = 0;
static u_int64_t read_bytes = 0;
int roaming_enabled = 0;
int resume_in_progress = 0;
int
get_snd_buf_size(void)
{
int fd = packet_get_connection_out();
int optval;
socklen_t optvallen = sizeof(optval);
if (getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &optval, &optvallen) != 0)
optval = DEFAULT_ROAMBUF;
return optval;
}
int
get_recv_buf_size(void)
{
int fd = packet_get_connection_in();
int optval;
socklen_t optvallen = sizeof(optval);
if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &optval, &optvallen) != 0)
optval = DEFAULT_ROAMBUF;
return optval;
}
void
set_out_buffer_size(size_t size)
{
if (size == 0 || size > MAX_ROAMBUF)
fatal("%s: bad buffer size %lu", __func__, (u_long)size);
/*
* The buffer size can only be set once and the buffer will live
* as long as the session lives.
*/
if (out_buf == NULL) {
out_buf_size = size;
out_buf = xmalloc(size);
out_start = 0;
out_last = 0;
}
}
u_int64_t
get_recv_bytes(void)
{
return read_bytes;
}
void
add_recv_bytes(u_int64_t num)
{
read_bytes += num;
}
u_int64_t
get_sent_bytes(void)
{
return write_bytes;
}
void
roam_set_bytes(u_int64_t sent, u_int64_t recvd)
{
read_bytes = recvd;
write_bytes = sent;
}
static void
buf_append(const char *buf, size_t count)
{
if (count > out_buf_size) {
buf += count - out_buf_size;
count = out_buf_size;
}
if (count < out_buf_size - out_last) {
memcpy(out_buf + out_last, buf, count);
if (out_start > out_last)
out_start += count;
out_last += count;
} else {
/* data will wrap */
size_t chunk = out_buf_size - out_last;
memcpy(out_buf + out_last, buf, chunk);
memcpy(out_buf, buf + chunk, count - chunk);
out_last = count - chunk;
out_start = out_last + 1;
}
}
ssize_t
roaming_write(int fd, const void *buf, size_t count, int *cont)
{
ssize_t ret;
ret = write(fd, buf, count);
if (ret > 0 && !resume_in_progress) {
write_bytes += ret;
if (out_buf_size > 0)
buf_append(buf, ret);
}
if (out_buf_size > 0 &&
(ret == 0 || (ret == -1 && errno == EPIPE))) {
if (wait_for_roaming_reconnect() != 0) {
ret = 0;
*cont = 1;
} else {
ret = -1;
errno = EAGAIN;
}
}
return ret;
}
ssize_t
roaming_read(int fd, void *buf, size_t count, int *cont)
{
ssize_t ret = read(fd, buf, count);
if (ret > 0) {
if (!resume_in_progress) {
read_bytes += ret;
}
} else if (out_buf_size > 0 &&
(ret == 0 || (ret == -1 && (errno == ECONNRESET
|| errno == ECONNABORTED || errno == ETIMEDOUT
|| errno == EHOSTUNREACH)))) {
debug("roaming_read failed for %d ret=%ld errno=%d",
fd, (long)ret, errno);
ret = 0;
if (wait_for_roaming_reconnect() == 0)
*cont = 1;
}
return ret;
}
size_t
roaming_atomicio(ssize_t(*f)(int, void*, size_t), int fd, void *buf,
size_t count)
{
size_t ret = atomicio(f, fd, buf, count);
if (f == vwrite && ret > 0 && !resume_in_progress) {
write_bytes += ret;
} else if (f == read && ret > 0 && !resume_in_progress) {
read_bytes += ret;
}
return ret;
}
void
resend_bytes(int fd, u_int64_t *offset)
{
size_t available, needed;
if (out_start < out_last)
available = out_last - out_start;
else
available = out_buf_size;
needed = write_bytes - *offset;
debug3("resend_bytes: resend %lu bytes from %llu",
(unsigned long)needed, (unsigned long long)*offset);
if (needed > available)
fatal("Needed to resend more data than in the cache");
if (out_last < needed) {
int chunkend = needed - out_last;
atomicio(vwrite, fd, out_buf + out_buf_size - chunkend,
chunkend);
atomicio(vwrite, fd, out_buf, out_last);
} else {
atomicio(vwrite, fd, out_buf + (out_last - needed), needed);
}
}
/*
* Caclulate a new key after a reconnect
*/
void
calculate_new_key(u_int64_t *key, u_int64_t cookie, u_int64_t challenge)
{
const EVP_MD *md = EVP_sha1();
EVP_MD_CTX ctx;
u_char hash[EVP_MAX_MD_SIZE];
Buffer b;
buffer_init(&b);
buffer_put_int64(&b, *key);
buffer_put_int64(&b, cookie);
buffer_put_int64(&b, challenge);
EVP_DigestInit(&ctx, md);
EVP_DigestUpdate(&ctx, buffer_ptr(&b), buffer_len(&b));
EVP_DigestFinal(&ctx, hash, NULL);
buffer_clear(&b);
buffer_append(&b, hash, EVP_MD_size(md));
*key = buffer_get_int64(&b);
buffer_free(&b);
}