1/* $NetBSD: kadm_conn.c,v 1.2 2017/01/28 21:31:44 christos Exp $ */ 2 3/* 4 * Copyright (c) 2000 - 2004 Kungliga Tekniska H��gskolan 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 41extern int daemon_child; 42 43struct kadm_port { 44 char *port; 45 unsigned short def_port; 46 struct kadm_port *next; 47} *kadm_ports; 48 49static void 50add_kadm_port(krb5_context contextp, const char *service, unsigned int port) 51{ 52 struct kadm_port *p; 53 p = malloc(sizeof(*p)); 54 if(p == NULL) { 55 krb5_warnx(contextp, "failed to allocate %lu bytes\n", 56 (unsigned long)sizeof(*p)); 57 return; 58 } 59 60 p->port = strdup(service); 61 p->def_port = port; 62 63 p->next = kadm_ports; 64 kadm_ports = p; 65} 66 67static void 68add_standard_ports (krb5_context contextp) 69{ 70 add_kadm_port(contextp, "kerberos-adm", 749); 71} 72 73/* 74 * parse the set of space-delimited ports in `str' and add them. 75 * "+" => all the standard ones 76 * otherwise it's port|service[/protocol] 77 */ 78 79void 80parse_ports(krb5_context contextp, const char *str) 81{ 82 char p[128]; 83 84 while(strsep_copy(&str, " \t", p, sizeof(p)) != -1) { 85 if(strcmp(p, "+") == 0) 86 add_standard_ports(contextp); 87 else 88 add_kadm_port(contextp, p, 0); 89 } 90} 91 92static pid_t pgrp; 93sig_atomic_t term_flag, doing_useful_work; 94 95static RETSIGTYPE 96sigchld(int sig) 97{ 98 int status; 99 /* 100 * waitpid() is async safe. will return -1 or 0 on no more zombie 101 * children 102 */ 103 while ((waitpid(-1, &status, WNOHANG)) > 0) 104 ; 105 SIGRETURN(0); 106} 107 108static RETSIGTYPE 109terminate(int sig) 110{ 111 if(getpid() == pgrp) { 112 /* parent */ 113 term_flag = 1; 114 signal(sig, SIG_IGN); 115 killpg(pgrp, sig); 116 } else { 117 /* child */ 118 if(doing_useful_work) 119 term_flag = 1; 120 else 121 exit(0); 122 } 123 SIGRETURN(0); 124} 125 126static int 127spawn_child(krb5_context contextp, int *socks, 128 unsigned int num_socks, int this_sock) 129{ 130 int e; 131 size_t i; 132 struct sockaddr_storage __ss; 133 struct sockaddr *sa = (struct sockaddr *)&__ss; 134 socklen_t sa_size = sizeof(__ss); 135 krb5_socket_t s; 136 pid_t pid; 137 krb5_address addr; 138 char buf[128]; 139 size_t buf_len; 140 141 s = accept(socks[this_sock], sa, &sa_size); 142 if(rk_IS_BAD_SOCKET(s)) { 143 krb5_warn(contextp, rk_SOCK_ERRNO, "accept"); 144 return 1; 145 } 146 e = krb5_sockaddr2address(contextp, sa, &addr); 147 if(e) 148 krb5_warn(contextp, e, "krb5_sockaddr2address"); 149 else { 150 e = krb5_print_address (&addr, buf, sizeof(buf), 151 &buf_len); 152 if(e) 153 krb5_warn(contextp, e, "krb5_print_address"); 154 else 155 krb5_warnx(contextp, "connection from %s", buf); 156 krb5_free_address(contextp, &addr); 157 } 158 159 pid = fork(); 160 if(pid == 0) { 161 for(i = 0; i < num_socks; i++) 162 rk_closesocket(socks[i]); 163 dup2(s, STDIN_FILENO); 164 dup2(s, STDOUT_FILENO); 165 if(s != STDIN_FILENO && s != STDOUT_FILENO) 166 rk_closesocket(s); 167 return 0; 168 } else { 169 rk_closesocket(s); 170 } 171 return 1; 172} 173 174static void 175wait_for_connection(krb5_context contextp, 176 krb5_socket_t *socks, unsigned int num_socks) 177{ 178 unsigned int i; 179 int e; 180 fd_set orig_read_set, read_set; 181 int status, max_fd = -1; 182 183 FD_ZERO(&orig_read_set); 184 185 for(i = 0; i < num_socks; i++) { 186#ifdef FD_SETSIZE 187 if (socks[i] >= FD_SETSIZE) 188 errx (1, "fd too large"); 189#endif 190 FD_SET(socks[i], &orig_read_set); 191 max_fd = max(max_fd, socks[i]); 192 } 193 194 pgrp = getpid(); 195 196 /* systemd may cause setpgid to fail with EPERM */ 197 if(setpgid(0, pgrp) < 0 && errno != EPERM) 198 err(1, "setpgid"); 199 200 signal(SIGTERM, terminate); 201 signal(SIGINT, terminate); 202 signal(SIGCHLD, sigchld); 203 204 while (term_flag == 0) { 205 read_set = orig_read_set; 206 e = select(max_fd + 1, &read_set, NULL, NULL, NULL); 207 if(rk_IS_SOCKET_ERROR(e)) { 208 if(rk_SOCK_ERRNO != EINTR) 209 krb5_warn(contextp, rk_SOCK_ERRNO, "select"); 210 } else if(e == 0) 211 krb5_warnx(contextp, "select returned 0"); 212 else { 213 for(i = 0; i < num_socks; i++) { 214 if(FD_ISSET(socks[i], &read_set)) 215 if(spawn_child(contextp, socks, num_socks, i) == 0) 216 return; 217 } 218 } 219 } 220 signal(SIGCHLD, SIG_IGN); 221 222 while ((waitpid(-1, &status, WNOHANG)) > 0) 223 ; 224 225 exit(0); 226} 227 228 229void 230start_server(krb5_context contextp, const char *port_str) 231{ 232 int e; 233 struct kadm_port *p; 234 235 krb5_socket_t *socks = NULL, *tmp; 236 unsigned int num_socks = 0; 237 int i; 238 239 if (port_str == NULL) 240 port_str = "+"; 241 242 parse_ports(contextp, port_str); 243 244 for(p = kadm_ports; p; p = p->next) { 245 struct addrinfo hints, *ai, *ap; 246 char portstr[32]; 247 memset (&hints, 0, sizeof(hints)); 248 hints.ai_flags = AI_PASSIVE; 249 hints.ai_socktype = SOCK_STREAM; 250 251 e = getaddrinfo(NULL, p->port, &hints, &ai); 252 if(e) { 253 snprintf(portstr, sizeof(portstr), "%u", p->def_port); 254 e = getaddrinfo(NULL, portstr, &hints, &ai); 255 } 256 257 if(e) { 258 krb5_warn(contextp, krb5_eai_to_heim_errno(e, errno), 259 "%s", portstr); 260 continue; 261 } 262 i = 0; 263 for(ap = ai; ap; ap = ap->ai_next) 264 i++; 265 tmp = realloc(socks, (num_socks + i) * sizeof(*socks)); 266 if(tmp == NULL) { 267 krb5_warnx(contextp, "failed to reallocate %lu bytes", 268 (unsigned long)(num_socks + i) * sizeof(*socks)); 269 freeaddrinfo(ai); 270 continue; 271 } 272 socks = tmp; 273 for(ap = ai; ap; ap = ap->ai_next) { 274 krb5_socket_t s = socket(ap->ai_family, ap->ai_socktype, ap->ai_protocol); 275 if(rk_IS_BAD_SOCKET(s)) { 276 krb5_warn(contextp, rk_SOCK_ERRNO, "socket"); 277 continue; 278 } 279 280 socket_set_reuseaddr(s, 1); 281 socket_set_ipv6only(s, 1); 282 283 if (rk_IS_SOCKET_ERROR(bind (s, ap->ai_addr, ap->ai_addrlen))) { 284 krb5_warn(contextp, rk_SOCK_ERRNO, "bind"); 285 rk_closesocket(s); 286 continue; 287 } 288 if (rk_IS_SOCKET_ERROR(listen (s, SOMAXCONN))) { 289 krb5_warn(contextp, rk_SOCK_ERRNO, "listen"); 290 rk_closesocket(s); 291 continue; 292 } 293 socks[num_socks++] = s; 294 } 295 freeaddrinfo (ai); 296 } 297 if(num_socks == 0) 298 krb5_errx(contextp, 1, "no sockets to listen to - exiting"); 299 300 roken_detach_finish(NULL, daemon_child); 301 302 wait_for_connection(contextp, socks, num_socks); 303 free(socks); 304} 305