1/*
2 * Copyright (c) 2000 - 2004 Kungliga Tekniska H�gskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include "kadmin_locl.h"
35#ifdef HAVE_SYS_WAIT_H
36#include <sys/wait.h>
37#endif
38
39RCSID("$Id: kadm_conn.c 16007 2005-09-01 18:49:57Z lha $");
40
41struct kadm_port {
42    char *port;
43    unsigned short def_port;
44    struct kadm_port *next;
45} *kadm_ports;
46
47static void
48add_kadm_port(krb5_context context, const char *service, unsigned int port)
49{
50    struct kadm_port *p;
51    p = malloc(sizeof(*p));
52    if(p == NULL) {
53	krb5_warnx(context, "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
65static void
66add_standard_ports (krb5_context context)
67{
68    add_kadm_port(context, "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
77void
78parse_ports(krb5_context context, 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(context);
85	else
86	    add_kadm_port(context, p, 0);
87    }
88}
89
90static pid_t pgrp;
91sig_atomic_t term_flag, doing_useful_work;
92
93static RETSIGTYPE
94sigchld(int sig)
95{
96    int status;
97    waitpid(-1, &status, 0);
98    SIGRETURN(0);
99}
100
101static RETSIGTYPE
102terminate(int sig)
103{
104    if(getpid() == pgrp) {
105	/* parent */
106	term_flag = 1;
107	signal(sig, SIG_IGN);
108	killpg(pgrp, sig);
109    } else {
110	/* child */
111	if(doing_useful_work)
112	    term_flag = 1;
113	else
114	    exit(0);
115    }
116    SIGRETURN(0);
117}
118
119static int
120spawn_child(krb5_context context, int *socks, int num_socks, int this_sock)
121{
122    int e, i;
123    struct sockaddr_storage __ss;
124    struct sockaddr *sa = (struct sockaddr *)&__ss;
125    socklen_t sa_size = sizeof(__ss);
126    int s;
127    pid_t pid;
128    krb5_address addr;
129    char buf[128];
130    size_t buf_len;
131
132    s = accept(socks[this_sock], sa, &sa_size);
133    if(s < 0) {
134	krb5_warn(context, errno, "accept");
135	return 1;
136    }
137    e = krb5_sockaddr2address(context, sa, &addr);
138    if(e)
139	krb5_warn(context, e, "krb5_sockaddr2address");
140    else {
141	e = krb5_print_address (&addr, buf, sizeof(buf),
142				&buf_len);
143	if(e)
144	    krb5_warn(context, e, "krb5_print_address");
145	else
146	    krb5_warnx(context, "connection from %s", buf);
147	krb5_free_address(context, &addr);
148    }
149
150    pid = fork();
151    if(pid == 0) {
152	for(i = 0; i < num_socks; i++)
153	    close(socks[i]);
154	dup2(s, STDIN_FILENO);
155	dup2(s, STDOUT_FILENO);
156	if(s != STDIN_FILENO && s != STDOUT_FILENO)
157	    close(s);
158	return 0;
159    } else {
160	close(s);
161    }
162    return 1;
163}
164
165static int
166wait_for_connection(krb5_context context,
167		    int *socks, int num_socks)
168{
169    int i, e;
170    fd_set orig_read_set, read_set;
171    int max_fd = -1;
172
173    FD_ZERO(&orig_read_set);
174
175    for(i = 0; i < num_socks; i++) {
176	if (socks[i] >= FD_SETSIZE)
177	    errx (1, "fd too large");
178	FD_SET(socks[i], &orig_read_set);
179	max_fd = max(max_fd, socks[i]);
180    }
181
182    pgrp = getpid();
183
184    if(setpgid(0, pgrp) < 0)
185	err(1, "setpgid");
186
187    signal(SIGTERM, terminate);
188    signal(SIGINT, terminate);
189    signal(SIGCHLD, sigchld);
190
191    while (term_flag == 0) {
192	read_set = orig_read_set;
193	e = select(max_fd + 1, &read_set, NULL, NULL, NULL);
194	if(e < 0) {
195	    if(errno != EINTR)
196		krb5_warn(context, errno, "select");
197	} else if(e == 0)
198	    krb5_warnx(context, "select returned 0");
199	else {
200	    for(i = 0; i < num_socks; i++) {
201		if(FD_ISSET(socks[i], &read_set))
202		    if(spawn_child(context, socks, num_socks, i) == 0)
203			return 0;
204	    }
205	}
206    }
207    signal(SIGCHLD, SIG_IGN);
208    while(1) {
209	int status;
210	pid_t pid;
211	pid = waitpid(-1, &status, 0);
212	if(pid == -1 && errno == ECHILD)
213	    break;
214    }
215    exit(0);
216}
217
218
219int
220start_server(krb5_context context)
221{
222    int e;
223    struct kadm_port *p;
224
225    int *socks = NULL, *tmp;
226    int num_socks = 0;
227    int i;
228
229    for(p = kadm_ports; p; p = p->next) {
230	struct addrinfo hints, *ai, *ap;
231	char portstr[32];
232	memset (&hints, 0, sizeof(hints));
233	hints.ai_flags    = AI_PASSIVE;
234	hints.ai_socktype = SOCK_STREAM;
235
236	e = getaddrinfo(NULL, p->port, &hints, &ai);
237	if(e) {
238	    snprintf(portstr, sizeof(portstr), "%u", p->def_port);
239	    e = getaddrinfo(NULL, portstr, &hints, &ai);
240	}
241
242	if(e) {
243	    krb5_warn(context, krb5_eai_to_heim_errno(e, errno),
244		      "%s", portstr);
245	    continue;
246	}
247	i = 0;
248	for(ap = ai; ap; ap = ap->ai_next)
249	    i++;
250	tmp = realloc(socks, (num_socks + i) * sizeof(*socks));
251	if(tmp == NULL) {
252	    krb5_warnx(context, "failed to reallocate %lu bytes",
253		       (unsigned long)(num_socks + i) * sizeof(*socks));
254	    continue;
255	}
256	socks = tmp;
257	for(ap = ai; ap; ap = ap->ai_next) {
258	    int s = socket(ap->ai_family, ap->ai_socktype, ap->ai_protocol);
259	    if(s < 0) {
260		krb5_warn(context, errno, "socket");
261		continue;
262	    }
263
264	    socket_set_reuseaddr(s, 1);
265	    socket_set_ipv6only(s, 1);
266
267	    if (bind (s, ap->ai_addr, ap->ai_addrlen) < 0) {
268		krb5_warn(context, errno, "bind");
269		close(s);
270		continue;
271	    }
272	    if (listen (s, SOMAXCONN) < 0) {
273		krb5_warn(context, errno, "listen");
274		close(s);
275		continue;
276	    }
277	    socks[num_socks++] = s;
278	}
279	freeaddrinfo (ai);
280    }
281    if(num_socks == 0)
282	krb5_errx(context, 1, "no sockets to listen to - exiting");
283    return wait_for_connection(context, socks, num_socks);
284}
285