crypto/openssh/dispatch.c

   1 /* $OpenBSD: dispatch.c,v 1.27 2015/05/01 07:10:01 djm Exp $ */
   2 /*
   3  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "includes.h"
  27
  28 #include <sys/types.h>
  29
  30 #include <signal.h>
  31 #include <stdarg.h>
  32
  33 #include "ssh1.h"
  34 #include "ssh2.h"
  35 #include "log.h"
  36 #include "dispatch.h"
  37 #include "packet.h"
  38 #include "compat.h"
  39 #include "ssherr.h"
  40
  41 int
  42 dispatch_protocol_error(int type, u_int32_t seq, void *ctx)
  43 {
  44         struct ssh *ssh = active_state; /* XXX */
  45         int r;
  46
  47         logit("dispatch_protocol_error: type %d seq %u", type, seq);
  48         if (!compat20)
  49                 fatal("protocol error");
  50         if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 ||
  51             (r = sshpkt_put_u32(ssh, seq)) != 0 ||
  52             (r = sshpkt_send(ssh)) != 0 ||
  53             (r = ssh_packet_write_wait(ssh)) != 0)
  54                 sshpkt_fatal(ssh, __func__, r);
  55         return 0;
  56 }
  57
  58 int
  59 dispatch_protocol_ignore(int type, u_int32_t seq, void *ssh)
  60 {
  61         logit("dispatch_protocol_ignore: type %d seq %u", type, seq);
  62         return 0;
  63 }
  64
  65 void
  66 ssh_dispatch_init(struct ssh *ssh, dispatch_fn *dflt)
  67 {
  68         u_int i;
  69         for (i = 0; i < DISPATCH_MAX; i++)
  70                 ssh->dispatch[i] = dflt;
  71 }
  72
  73 void
  74 ssh_dispatch_range(struct ssh *ssh, u_int from, u_int to, dispatch_fn *fn)
  75 {
  76         u_int i;
  77
  78         for (i = from; i <= to; i++) {
  79                 if (i >= DISPATCH_MAX)
  80                         break;
  81                 ssh->dispatch[i] = fn;
  82         }
  83 }
  84
  85 void
  86 ssh_dispatch_set(struct ssh *ssh, int type, dispatch_fn *fn)
  87 {
  88         ssh->dispatch[type] = fn;
  89 }
  90
  91 int
  92 ssh_dispatch_run(struct ssh *ssh, int mode, volatile sig_atomic_t *done,
  93     void *ctxt)
  94 {
  95         int r;
  96         u_char type;
  97         u_int32_t seqnr;
  98
  99         for (;;) {
 100                 if (mode == DISPATCH_BLOCK) {
 101                         r = ssh_packet_read_seqnr(ssh, &type, &seqnr);
 102                         if (r != 0)
 103                                 return r;
 104                 } else {
 105                         r = ssh_packet_read_poll_seqnr(ssh, &type, &seqnr);
 106                         if (r != 0)
 107                                 return r;
 108                         if (type == SSH_MSG_NONE)
 109                                 return 0;
 110                 }
 111                 if (type > 0 && type < DISPATCH_MAX &&
 112                     ssh->dispatch[type] != NULL) {
 113                         if (ssh->dispatch_skip_packets) {
 114                                 debug2("skipped packet (type %u)", type);
 115                                 ssh->dispatch_skip_packets--;
 116                                 continue;
 117                         }
 118                         /* XXX 'ssh' will replace 'ctxt' later */
 119                         r = (*ssh->dispatch[type])(type, seqnr, ctxt);
 120                         if (r != 0)
 121                                 return r;
 122                 } else {
 123                         r = sshpkt_disconnect(ssh,
 124                             "protocol error: rcvd type %d", type);
 125                         if (r != 0)
 126                                 return r;
 127                         return SSH_ERR_DISCONNECTED;
 128                 }
 129                 if (done != NULL && *done)
 130                         return 0;
 131         }
 132 }
 133
 134 void
 135 ssh_dispatch_run_fatal(struct ssh *ssh, int mode, volatile sig_atomic_t *done,
 136     void *ctxt)
 137 {
 138         int r;
 139
 140         if ((r = ssh_dispatch_run(ssh, mode, done, ctxt)) != 0)
 141                 sshpkt_fatal(ssh, __func__, r);
 142 }