1 /* $OpenBSD: dispatch.c,v 1.33 2023/03/05 05:34:09 dtucker 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 "ssherr.h" 38 39 int 40 dispatch_protocol_error(int type, u_int32_t seq, struct ssh *ssh) 41 { 42 int r; 43 44 logit("dispatch_protocol_error: type %d seq %u", type, seq); 45 if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 || 46 (r = sshpkt_put_u32(ssh, seq)) != 0 || 47 (r = sshpkt_send(ssh)) != 0 || 48 (r = ssh_packet_write_wait(ssh)) != 0) 49 sshpkt_fatal(ssh, r, "%s", __func__); 50 return 0; 51 } 52 53 int 54 dispatch_protocol_ignore(int type, u_int32_t seq, struct ssh *ssh) 55 { 56 logit("dispatch_protocol_ignore: type %d seq %u", type, seq); 57 return 0; 58 } 59 60 void 61 ssh_dispatch_init(struct ssh *ssh, dispatch_fn *dflt) 62 { 63 u_int i; 64 for (i = 0; i < DISPATCH_MAX; i++) 65 ssh->dispatch[i] = dflt; 66 } 67 68 void 69 ssh_dispatch_range(struct ssh *ssh, u_int from, u_int to, dispatch_fn *fn) 70 { 71 u_int i; 72 73 for (i = from; i <= to; i++) { 74 if (i >= DISPATCH_MAX) 75 break; 76 ssh->dispatch[i] = fn; 77 } 78 } 79 80 void 81 ssh_dispatch_set(struct ssh *ssh, int type, dispatch_fn *fn) 82 { 83 ssh->dispatch[type] = fn; 84 } 85 86 int 87 ssh_dispatch_run(struct ssh *ssh, int mode, volatile sig_atomic_t *done) 88 { 89 int r; 90 u_char type; 91 u_int32_t seqnr; 92 93 for (;;) { 94 if (mode == DISPATCH_BLOCK) { 95 r = ssh_packet_read_seqnr(ssh, &type, &seqnr); 96 if (r != 0) 97 return r; 98 } else { 99 r = ssh_packet_read_poll_seqnr(ssh, &type, &seqnr); 100 if (r != 0) 101 return r; 102 if (type == SSH_MSG_NONE) 103 return 0; 104 } 105 if (type > 0 && type < DISPATCH_MAX && 106 ssh->dispatch[type] != NULL) { 107 if (ssh->dispatch_skip_packets) { 108 debug2("skipped packet (type %u)", type); 109 ssh->dispatch_skip_packets--; 110 continue; 111 } 112 r = (*ssh->dispatch[type])(type, seqnr, ssh); 113 if (r != 0) 114 return r; 115 } else { 116 r = sshpkt_disconnect(ssh, 117 "protocol error: rcvd type %d", type); 118 if (r != 0) 119 return r; 120 return SSH_ERR_DISCONNECTED; 121 } 122 if (done != NULL && *done) 123 return 0; 124 } 125 } 126 127 void 128 ssh_dispatch_run_fatal(struct ssh *ssh, int mode, volatile sig_atomic_t *done) 129 { 130 int r; 131 132 if ((r = ssh_dispatch_run(ssh, mode, done)) != 0) 133 sshpkt_fatal(ssh, r, "%s", __func__); 134 } 135