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