1 /* vi: set sw=4 ts=4: */
2 /*
3 * Mini hostname implementation for busybox
4 *
5 * Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
6 *
7 * Adjusted by Erik Andersen <andersen@codepoet.org> to remove
8 * use of long options and GNU getopt. Improved the usage info.
9 *
10 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
11 */
12 //config:config HOSTNAME
13 //config: bool "hostname (5.5 kb)"
14 //config: default y
15 //config: help
16 //config: Show or set the system's host name.
17 //config:
18 //config:config DNSDOMAINNAME
19 //config: bool "dnsdomainname (3.6 kb)"
20 //config: default y
21 //config: help
22 //config: Alias to "hostname -d".
23
24 // APPLET_NOEXEC:name main location suid_type help
25 //applet:IF_DNSDOMAINNAME(APPLET_NOEXEC(dnsdomainname, hostname, BB_DIR_BIN, BB_SUID_DROP, dnsdomainname))
26 //applet:IF_HOSTNAME( APPLET_NOEXEC(hostname, hostname, BB_DIR_BIN, BB_SUID_DROP, hostname ))
27
28 //kbuild: lib-$(CONFIG_HOSTNAME) += hostname.o
29 //kbuild: lib-$(CONFIG_DNSDOMAINNAME) += hostname.o
30
31 //usage:#define hostname_trivial_usage
32 //usage: "[-sidf] [HOSTNAME | -F FILE]"
33 //usage:#define hostname_full_usage "\n\n"
34 //usage: "Show or set hostname or DNS domain name\n"
35 //usage: "\n -s Short"
36 //usage: "\n -i Addresses for the hostname"
37 //usage: "\n -d DNS domain name"
38 //usage: "\n -f Fully qualified domain name"
39 //usage: "\n -F FILE Use FILE's content as hostname"
40 //usage:
41 //usage:#define hostname_example_usage
42 //usage: "$ hostname\n"
43 //usage: "sage\n"
44 //usage:
45 //usage:#define dnsdomainname_trivial_usage NOUSAGE_STR
46 //usage:#define dnsdomainname_full_usage ""
47
48 #include "libbb.h"
49
do_sethostname(char * s,int isfile)50 static void do_sethostname(char *s, int isfile)
51 {
52 // if (!s)
53 // return;
54 if (isfile) {
55 parser_t *parser = config_open2(s, xfopen_for_read);
56 while (config_read(parser, &s, 1, 1, "# \t", PARSE_NORMAL & ~PARSE_GREEDY)) {
57 do_sethostname(s, 0);
58 }
59 if (ENABLE_FEATURE_CLEAN_UP)
60 config_close(parser);
61 } else if (sethostname(s, strlen(s))) {
62 // if (errno == EPERM)
63 // bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
64 bb_simple_perror_msg_and_die("sethostname");
65 }
66 }
67
68 /* Manpage circa 2009:
69 *
70 * hostname [-v] [-a] [--alias] [-d] [--domain] [-f] [--fqdn] [--long]
71 * [-i] [--ip-address] [-s] [--short] [-y] [--yp] [--nis]
72 *
73 * hostname [-v] [-F filename] [--file filename] / [hostname]
74 *
75 * domainname [-v] [-F filename] [--file filename] / [name]
76 * { bbox: not supported }
77 *
78 * nodename [-v] [-F filename] [--file filename] / [name]
79 * { bbox: not supported }
80 *
81 * dnsdomainname [-v]
82 * { bbox: supported: Linux kernel build needs this }
83 * nisdomainname [-v]
84 * { bbox: not supported }
85 * ypdomainname [-v]
86 * { bbox: not supported }
87 *
88 * -a, --alias
89 * Display the alias name of the host (if used).
90 * { bbox: not supported }
91 * -d, --domain
92 * Display the name of the DNS domain. Don't use the command
93 * domainname to get the DNS domain name because it will show the
94 * NIS domain name and not the DNS domain name. Use dnsdomainname
95 * instead.
96 * -f, --fqdn, --long
97 * Display the FQDN (Fully Qualified Domain Name). A FQDN consists
98 * of a short host name and the DNS domain name. Unless you are
99 * using bind or NIS for host lookups you can change the FQDN and
100 * the DNS domain name (which is part of the FQDN) in the
101 * /etc/hosts file.
102 * -i, --ip-address
103 * Display the IP address(es) of the host.
104 * -s, --short
105 * Display the short host name. This is the host name cut at the
106 * first dot.
107 * -v, --verbose
108 * Be verbose and tell what's going on.
109 * { bbox: supported but ignored }
110 * -y, --yp, --nis
111 * Display the NIS domain name. If a parameter is given (or --file
112 * name ) then root can also set a new NIS domain.
113 * { bbox: not supported }
114 * -F, --file filename
115 * Read the host name from the specified file. Comments (lines
116 * starting with a '#') are ignored.
117 */
118 int hostname_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
hostname_main(int argc UNUSED_PARAM,char ** argv)119 int hostname_main(int argc UNUSED_PARAM, char **argv)
120 {
121 enum {
122 OPT_d = 0x1,
123 OPT_f = 0x2,
124 OPT_i = 0x4,
125 OPT_s = 0x8,
126 OPT_F = 0x10,
127 OPT_dfi = 0x7,
128 };
129
130 unsigned opts;
131 char *buf;
132 char *hostname_str;
133
134 /* dnsdomainname from net-tools 1.60, hostname 1.100 (2001-04-14),
135 * supports hostname's options too (not just -v as manpage says) */
136 opts = getopt32(argv, "dfisF:v", &hostname_str,
137 "domain\0" No_argument "d"
138 "fqdn\0" No_argument "f"
139 //Enable if seen in active use in some distro:
140 // "long\0" No_argument "f"
141 // "ip-address\0" No_argument "i"
142 // "short\0" No_argument "s"
143 // "verbose\0" No_argument "v"
144 "file\0" No_argument "F"
145 );
146 argv += optind;
147 buf = safe_gethostname();
148 if (ENABLE_DNSDOMAINNAME) {
149 if (!ENABLE_HOSTNAME || applet_name[0] == 'd') {
150 /* dnsdomainname */
151 opts = OPT_d;
152 }
153 }
154
155 if (opts & OPT_dfi) {
156 /* Cases when we need full hostname (or its part) */
157 struct hostent *hp;
158 char *p;
159
160 hp = xgethostbyname(buf);
161 p = strchrnul(hp->h_name, '.');
162 if (opts & OPT_f) {
163 puts(hp->h_name);
164 } else if (opts & OPT_s) {
165 *p = '\0';
166 puts(hp->h_name);
167 } else if (opts & OPT_d) {
168 if (*p)
169 puts(p + 1);
170 } else /*if (opts & OPT_i)*/ {
171 if (hp->h_length == sizeof(struct in_addr)) {
172 struct in_addr **h_addr_list = (struct in_addr **)hp->h_addr_list;
173 while (*h_addr_list) {
174 printf(h_addr_list[1] ? "%s " : "%s", inet_ntoa(**h_addr_list));
175 h_addr_list++;
176 }
177 bb_putchar('\n');
178 }
179 }
180 } else if (opts & OPT_s) {
181 strchrnul(buf, '.')[0] = '\0';
182 puts(buf);
183 } else if (opts & OPT_F) {
184 /* Set the hostname */
185 do_sethostname(hostname_str, 1);
186 } else if (argv[0]) {
187 /* Set the hostname */
188 do_sethostname(argv[0], 0);
189 } else {
190 /* Just print the current hostname */
191 puts(buf);
192 }
193
194 if (ENABLE_FEATURE_CLEAN_UP)
195 free(buf);
196 return EXIT_SUCCESS;
197 }
198