crypto/openssh/roaming_common.c

   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
  41 static size_t out_buf_size = 0;
  42 static char *out_buf = NULL;
  43 static size_t out_start;
  44 static size_t out_last;
  45
  46 static u_int64_t write_bytes = 0;
  47 static u_int64_t read_bytes = 0;
  48
  49 int roaming_enabled = 0;
  50 int resume_in_progress = 0;
  51
  52 int
  53 get_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
  64 int
  65 get_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
  76 void
  77 set_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
  93 u_int64_t
  94 get_recv_bytes(void)
  95 {
  96         return read_bytes;
  97 }
  98
  99 void
 100 add_recv_bytes(u_int64_t num)
 101 {
 102         read_bytes += num;
 103 }
 104
 105 u_int64_t
 106 get_sent_bytes(void)
 107 {
 108         return write_bytes;
 109 }
 110
 111 void
 112 roam_set_bytes(u_int64_t sent, u_int64_t recvd)
 113 {
 114         read_bytes = recvd;
 115         write_bytes = sent;
 116 }
 117
 118 static void
 119 buf_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
 140 ssize_t
 141 roaming_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
 164 ssize_t
 165 roaming_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
 185 size_t
 186 roaming_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
 199 void
 200 resend_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  */
 226 void
 227 calculate_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 }