1 /* $NetBSD: kadm_conn.c,v 1.1.1.2 2014/04/24 12:45:27 pettai Exp $ */ 2 3 /* 4 * Copyright (c) 2000 - 2004 Kungliga Tekniska Högskolan 5 * (Royal Institute of Technology, Stockholm, Sweden). 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * 3. Neither the name of the Institute nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include "kadmin_locl.h" 37 #ifdef HAVE_SYS_WAIT_H 38 #include <sys/wait.h> 39 #endif 40 41 struct kadm_port { 42 char *port; 43 unsigned short def_port; 44 struct kadm_port *next; 45 } *kadm_ports; 46 47 static void 48 add_kadm_port(krb5_context contextp, const char *service, unsigned int port) 49 { 50 struct kadm_port *p; 51 p = malloc(sizeof(*p)); 52 if(p == NULL) { 53 krb5_warnx(contextp, "failed to allocate %lu bytes\n", 54 (unsigned long)sizeof(*p)); 55 return; 56 } 57 58 p->port = strdup(service); 59 p->def_port = port; 60 61 p->next = kadm_ports; 62 kadm_ports = p; 63 } 64 65 static void 66 add_standard_ports (krb5_context contextp) 67 { 68 add_kadm_port(contextp, "kerberos-adm", 749); 69 } 70 71 /* 72 * parse the set of space-delimited ports in `str' and add them. 73 * "+" => all the standard ones 74 * otherwise it's port|service[/protocol] 75 */ 76 77 void 78 parse_ports(krb5_context contextp, const char *str) 79 { 80 char p[128]; 81 82 while(strsep_copy(&str, " \t", p, sizeof(p)) != -1) { 83 if(strcmp(p, "+") == 0) 84 add_standard_ports(contextp); 85 else 86 add_kadm_port(contextp, p, 0); 87 } 88 } 89 90 static pid_t pgrp; 91 sig_atomic_t term_flag, doing_useful_work; 92 93 static RETSIGTYPE 94 sigchld(int sig) 95 { 96 int status; 97 /* 98 * waitpid() is async safe. will return -1 or 0 on no more zombie 99 * children 100 */ 101 while ((waitpid(-1, &status, WNOHANG)) > 0) 102 ; 103 SIGRETURN(0); 104 } 105 106 static RETSIGTYPE 107 terminate(int sig) 108 { 109 if(getpid() == pgrp) { 110 /* parent */ 111 term_flag = 1; 112 signal(sig, SIG_IGN); 113 killpg(pgrp, sig); 114 } else { 115 /* child */ 116 if(doing_useful_work) 117 term_flag = 1; 118 else 119 exit(0); 120 } 121 SIGRETURN(0); 122 } 123 124 static int 125 spawn_child(krb5_context contextp, int *socks, 126 unsigned int num_socks, int this_sock) 127 { 128 int e; 129 size_t i; 130 struct sockaddr_storage __ss; 131 struct sockaddr *sa = (struct sockaddr *)&__ss; 132 socklen_t sa_size = sizeof(__ss); 133 krb5_socket_t s; 134 pid_t pid; 135 krb5_address addr; 136 char buf[128]; 137 size_t buf_len; 138 139 s = accept(socks[this_sock], sa, &sa_size); 140 if(rk_IS_BAD_SOCKET(s)) { 141 krb5_warn(contextp, rk_SOCK_ERRNO, "accept"); 142 return 1; 143 } 144 e = krb5_sockaddr2address(contextp, sa, &addr); 145 if(e) 146 krb5_warn(contextp, e, "krb5_sockaddr2address"); 147 else { 148 e = krb5_print_address (&addr, buf, sizeof(buf), 149 &buf_len); 150 if(e) 151 krb5_warn(contextp, e, "krb5_print_address"); 152 else 153 krb5_warnx(contextp, "connection from %s", buf); 154 krb5_free_address(contextp, &addr); 155 } 156 157 pid = fork(); 158 if(pid == 0) { 159 for(i = 0; i < num_socks; i++) 160 rk_closesocket(socks[i]); 161 dup2(s, STDIN_FILENO); 162 dup2(s, STDOUT_FILENO); 163 if(s != STDIN_FILENO && s != STDOUT_FILENO) 164 rk_closesocket(s); 165 return 0; 166 } else { 167 rk_closesocket(s); 168 } 169 return 1; 170 } 171 172 static void 173 wait_for_connection(krb5_context contextp, 174 krb5_socket_t *socks, unsigned int num_socks) 175 { 176 unsigned int i; 177 int e; 178 fd_set orig_read_set, read_set; 179 int status, max_fd = -1; 180 181 FD_ZERO(&orig_read_set); 182 183 for(i = 0; i < num_socks; i++) { 184 #ifdef FD_SETSIZE 185 if (socks[i] >= FD_SETSIZE) 186 errx (1, "fd too large"); 187 #endif 188 FD_SET(socks[i], &orig_read_set); 189 max_fd = max(max_fd, socks[i]); 190 } 191 192 pgrp = getpid(); 193 194 if(setpgid(0, pgrp) < 0) 195 err(1, "setpgid"); 196 197 signal(SIGTERM, terminate); 198 signal(SIGINT, terminate); 199 signal(SIGCHLD, sigchld); 200 201 while (term_flag == 0) { 202 read_set = orig_read_set; 203 e = select(max_fd + 1, &read_set, NULL, NULL, NULL); 204 if(rk_IS_SOCKET_ERROR(e)) { 205 if(rk_SOCK_ERRNO != EINTR) 206 krb5_warn(contextp, rk_SOCK_ERRNO, "select"); 207 } else if(e == 0) 208 krb5_warnx(contextp, "select returned 0"); 209 else { 210 for(i = 0; i < num_socks; i++) { 211 if(FD_ISSET(socks[i], &read_set)) 212 if(spawn_child(contextp, socks, num_socks, i) == 0) 213 return; 214 } 215 } 216 } 217 signal(SIGCHLD, SIG_IGN); 218 219 while ((waitpid(-1, &status, WNOHANG)) > 0) 220 ; 221 222 exit(0); 223 } 224 225 226 void 227 start_server(krb5_context contextp, const char *port_str) 228 { 229 int e; 230 struct kadm_port *p; 231 232 krb5_socket_t *socks = NULL, *tmp; 233 unsigned int num_socks = 0; 234 int i; 235 236 if (port_str == NULL) 237 port_str = "+"; 238 239 parse_ports(contextp, port_str); 240 241 for(p = kadm_ports; p; p = p->next) { 242 struct addrinfo hints, *ai, *ap; 243 char portstr[32]; 244 memset (&hints, 0, sizeof(hints)); 245 hints.ai_flags = AI_PASSIVE; 246 hints.ai_socktype = SOCK_STREAM; 247 248 e = getaddrinfo(NULL, p->port, &hints, &ai); 249 if(e) { 250 snprintf(portstr, sizeof(portstr), "%u", p->def_port); 251 e = getaddrinfo(NULL, portstr, &hints, &ai); 252 } 253 254 if(e) { 255 krb5_warn(contextp, krb5_eai_to_heim_errno(e, errno), 256 "%s", portstr); 257 continue; 258 } 259 i = 0; 260 for(ap = ai; ap; ap = ap->ai_next) 261 i++; 262 tmp = realloc(socks, (num_socks + i) * sizeof(*socks)); 263 if(tmp == NULL) { 264 krb5_warnx(contextp, "failed to reallocate %lu bytes", 265 (unsigned long)(num_socks + i) * sizeof(*socks)); 266 continue; 267 } 268 socks = tmp; 269 for(ap = ai; ap; ap = ap->ai_next) { 270 krb5_socket_t s = socket(ap->ai_family, ap->ai_socktype, ap->ai_protocol); 271 if(rk_IS_BAD_SOCKET(s)) { 272 krb5_warn(contextp, rk_SOCK_ERRNO, "socket"); 273 continue; 274 } 275 276 socket_set_reuseaddr(s, 1); 277 socket_set_ipv6only(s, 1); 278 279 if (rk_IS_SOCKET_ERROR(bind (s, ap->ai_addr, ap->ai_addrlen))) { 280 krb5_warn(contextp, rk_SOCK_ERRNO, "bind"); 281 rk_closesocket(s); 282 continue; 283 } 284 if (rk_IS_SOCKET_ERROR(listen (s, SOMAXCONN))) { 285 krb5_warn(contextp, rk_SOCK_ERRNO, "listen"); 286 rk_closesocket(s); 287 continue; 288 } 289 socks[num_socks++] = s; 290 } 291 freeaddrinfo (ai); 292 } 293 if(num_socks == 0) 294 krb5_errx(contextp, 1, "no sockets to listen to - exiting"); 295 296 wait_for_connection(contextp, socks, num_socks); 297 } 298