1 /* $OpenBSD: dispatch.c,v 1.32 2019/01/19 21:33:13 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 <sys/types.h> 27 28 #include <signal.h> 29 #include <stdarg.h> 30 31 #include "ssh2.h" 32 #include "log.h" 33 #include "dispatch.h" 34 #include "packet.h" 35 #include "compat.h" 36 #include "ssherr.h" 37 38 int 39 dispatch_protocol_error(int type, u_int32_t seq, struct ssh *ssh) 40 { 41 int r; 42 43 logit("dispatch_protocol_error: type %d seq %u", type, seq); 44 if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 || 45 (r = sshpkt_put_u32(ssh, seq)) != 0 || 46 (r = sshpkt_send(ssh)) != 0 || 47 (r = ssh_packet_write_wait(ssh)) != 0) 48 sshpkt_fatal(ssh, r, "%s", __func__); 49 return 0; 50 } 51 52 int 53 dispatch_protocol_ignore(int type, u_int32_t seq, struct ssh *ssh) 54 { 55 logit("dispatch_protocol_ignore: type %d seq %u", type, seq); 56 return 0; 57 } 58 59 void 60 ssh_dispatch_init(struct ssh *ssh, dispatch_fn *dflt) 61 { 62 u_int i; 63 for (i = 0; i < DISPATCH_MAX; i++) 64 ssh->dispatch[i] = dflt; 65 } 66 67 void 68 ssh_dispatch_range(struct ssh *ssh, u_int from, u_int to, dispatch_fn *fn) 69 { 70 u_int i; 71 72 for (i = from; i <= to; i++) { 73 if (i >= DISPATCH_MAX) 74 break; 75 ssh->dispatch[i] = fn; 76 } 77 } 78 79 void 80 ssh_dispatch_set(struct ssh *ssh, int type, dispatch_fn *fn) 81 { 82 ssh->dispatch[type] = fn; 83 } 84 85 int 86 ssh_dispatch_run(struct ssh *ssh, int mode, volatile sig_atomic_t *done) 87 { 88 int r; 89 u_char type; 90 u_int32_t seqnr; 91 92 for (;;) { 93 if (mode == DISPATCH_BLOCK) { 94 r = ssh_packet_read_seqnr(ssh, &type, &seqnr); 95 if (r != 0) 96 return r; 97 } else { 98 r = ssh_packet_read_poll_seqnr(ssh, &type, &seqnr); 99 if (r != 0) 100 return r; 101 if (type == SSH_MSG_NONE) 102 return 0; 103 } 104 if (type > 0 && type < DISPATCH_MAX && 105 ssh->dispatch[type] != NULL) { 106 if (ssh->dispatch_skip_packets) { 107 debug2("skipped packet (type %u)", type); 108 ssh->dispatch_skip_packets--; 109 continue; 110 } 111 r = (*ssh->dispatch[type])(type, seqnr, ssh); 112 if (r != 0) 113 return r; 114 } else { 115 r = sshpkt_disconnect(ssh, 116 "protocol error: rcvd type %d", type); 117 if (r != 0) 118 return r; 119 return SSH_ERR_DISCONNECTED; 120 } 121 if (done != NULL && *done) 122 return 0; 123 } 124 } 125 126 void 127 ssh_dispatch_run_fatal(struct ssh *ssh, int mode, volatile sig_atomic_t *done) 128 { 129 int r; 130 131 if ((r = ssh_dispatch_run(ssh, mode, done)) != 0) 132 sshpkt_fatal(ssh, r, "%s", __func__); 133 } 134