1 /* $OpenBSD: dispatch.c,v 1.31 2017/05/31 07:00:13 markus 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 "ssh2.h" 34 #include "log.h" 35 #include "dispatch.h" 36 #include "packet.h" 37 #include "compat.h" 38 #include "ssherr.h" 39 40 int 41 dispatch_protocol_error(int type, u_int32_t seq, struct ssh *ssh) 42 { 43 int r; 44 45 logit("dispatch_protocol_error: type %d seq %u", type, seq); 46 if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 || 47 (r = sshpkt_put_u32(ssh, seq)) != 0 || 48 (r = sshpkt_send(ssh)) != 0 || 49 (r = ssh_packet_write_wait(ssh)) != 0) 50 sshpkt_fatal(ssh, __func__, r); 51 return 0; 52 } 53 54 int 55 dispatch_protocol_ignore(int type, u_int32_t seq, struct ssh *ssh) 56 { 57 logit("dispatch_protocol_ignore: type %d seq %u", type, seq); 58 return 0; 59 } 60 61 void 62 ssh_dispatch_init(struct ssh *ssh, dispatch_fn *dflt) 63 { 64 u_int i; 65 for (i = 0; i < DISPATCH_MAX; i++) 66 ssh->dispatch[i] = dflt; 67 } 68 69 void 70 ssh_dispatch_range(struct ssh *ssh, u_int from, u_int to, dispatch_fn *fn) 71 { 72 u_int i; 73 74 for (i = from; i <= to; i++) { 75 if (i >= DISPATCH_MAX) 76 break; 77 ssh->dispatch[i] = fn; 78 } 79 } 80 81 void 82 ssh_dispatch_set(struct ssh *ssh, int type, dispatch_fn *fn) 83 { 84 ssh->dispatch[type] = fn; 85 } 86 87 int 88 ssh_dispatch_run(struct ssh *ssh, int mode, volatile sig_atomic_t *done) 89 { 90 int r; 91 u_char type; 92 u_int32_t seqnr; 93 94 for (;;) { 95 if (mode == DISPATCH_BLOCK) { 96 r = ssh_packet_read_seqnr(ssh, &type, &seqnr); 97 if (r != 0) 98 return r; 99 } else { 100 r = ssh_packet_read_poll_seqnr(ssh, &type, &seqnr); 101 if (r != 0) 102 return r; 103 if (type == SSH_MSG_NONE) 104 return 0; 105 } 106 if (type > 0 && type < DISPATCH_MAX && 107 ssh->dispatch[type] != NULL) { 108 if (ssh->dispatch_skip_packets) { 109 debug2("skipped packet (type %u)", type); 110 ssh->dispatch_skip_packets--; 111 continue; 112 } 113 r = (*ssh->dispatch[type])(type, seqnr, ssh); 114 if (r != 0) 115 return r; 116 } else { 117 r = sshpkt_disconnect(ssh, 118 "protocol error: rcvd type %d", type); 119 if (r != 0) 120 return r; 121 return SSH_ERR_DISCONNECTED; 122 } 123 if (done != NULL && *done) 124 return 0; 125 } 126 } 127 128 void 129 ssh_dispatch_run_fatal(struct ssh *ssh, int mode, volatile sig_atomic_t *done) 130 { 131 int r; 132 133 if ((r = ssh_dispatch_run(ssh, mode, done)) != 0) 134 sshpkt_fatal(ssh, __func__, r); 135 } 136