path: root/networking/udhcp/dumpleases.c (plain)
blob: d83344a8da4898d1ee0b8bac5ee4a096114ec303

1	/* vi: set sw=4 ts=4: */
2	/*
3	* Licensed under GPLv2 or later, see file LICENSE in this source tree.
4	*/
5	//applet:IF_DUMPLEASES(APPLET(dumpleases, BB_DIR_USR_BIN, BB_SUID_DROP))
6
7	//kbuild:lib-$(CONFIG_DUMPLEASES) += dumpleases.o
8
9	//usage:#define dumpleases_trivial_usage
10	//usage: "[-r|-a] [-d] [-f LEASEFILE]"
11	//usage:#define dumpleases_full_usage "\n\n"
12	//usage: "Display DHCP leases granted by udhcpd\n"
13	//usage: IF_LONG_OPTS(
14	//usage: "\n -f,--file=FILE Lease file"
15	//usage: "\n -r,--remaining Show remaining time"
16	//usage: "\n -a,--absolute Show expiration time"
17	//usage: "\n -d,--decimal Show time in seconds"
18	//usage: )
19	//usage: IF_NOT_LONG_OPTS(
20	//usage: "\n -f FILE Lease file"
21	//usage: "\n -r Show remaining time"
22	//usage: "\n -a Show expiration time"
23	//usage: "\n -d Show time in seconds"
24	//usage: )
25
26	#include "common.h"
27	#include "dhcpd.h"
28	#include "unicode.h"
29
30	int dumpleases_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
31	int dumpleases_main(int argc UNUSED_PARAM, char **argv)
32	{
33	int fd;
34	int i;
35	unsigned opt;
36	int64_t written_at, curr;
37	const char *file = LEASES_FILE;
38	struct dyn_lease lease;
39
40	enum {
41	OPT_a = 0x1, // -a
42	OPT_r = 0x2, // -r
43	OPT_f = 0x4, // -f
44	OPT_d = 0x8, // -d
45	};
46	#if ENABLE_LONG_OPTS
47	static const char dumpleases_longopts[] ALIGN1 =
48	"absolute\0" No_argument "a"
49	"remaining\0" No_argument "r"
50	"file\0" Required_argument "f"
51	"decimal\0" No_argument "d"
52	;
53
54	applet_long_options = dumpleases_longopts;
55	#endif
56	init_unicode();
57
58	opt_complementary = "=0:a--r:r--a";
59	opt = getopt32(argv, "arf:d", &file);
60
61	fd = xopen(file, O_RDONLY);
62
63	/* "123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 */
64	/* "00:00:00:00:00:00 255.255.255.255 ABCDEFGHIJKLMNOPQRS Wed Jun 30 21:49:08 1993" */
65	printf("Mac %-14s" "IP %-13s" "Host %-15s" "Expires %s\n",
66	"Address", "Address", "Name",
67	(opt & OPT_a) ? "at" : "in"
68	);
69
70	xread(fd, &written_at, sizeof(written_at));
71	written_at = SWAP_BE64(written_at);
72	curr = time(NULL);
73	if (curr < written_at)
74	written_at = curr; /* lease file from future! :) */
75
76	while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
77	struct in_addr addr;
78	int64_t expires_abs;
79
80	const char *fmt = ":%02x" + 1;
81	for (i = 0; i < 6; i++) {
82	printf(fmt, lease.lease_mac[i]);
83	fmt = ":%02x";
84	}
85	addr.s_addr = lease.lease_nip;
86	#if ENABLE_UNICODE_SUPPORT
87	{
88	char *uni_name = unicode_conv_to_printable_fixedwidth(/*NULL,*/ lease.hostname, 19);
89	printf(" %-16s%s ", inet_ntoa(addr), uni_name);
90	free(uni_name);
91	}
92	#else
93	/* actually, 15+1 and 19+1, +1 is a space between columns */
94	/* lease.hostname is char[20] and is always NUL terminated */
95	printf(" %-16s%-20s", inet_ntoa(addr), lease.hostname);
96	#endif
97	expires_abs = ntohl(lease.expires) + written_at;
98	if (expires_abs <= curr) {
99	puts("expired");
100	continue;
101	}
102	if (opt & OPT_d) {
103	/* -d: decimal time */
104	if (!(opt & OPT_a))
105	expires_abs -= curr;
106	printf("%llu\n", (unsigned long long) expires_abs);
107	continue;
108	}
109	if (!(opt & OPT_a)) { /* no -a */
110	unsigned d, h, m;
111	unsigned expires = expires_abs - curr;
112	d = expires / (24*60*60); expires %= (24*60*60);
113	h = expires / (60*60); expires %= (60*60);
114	m = expires / 60; expires %= 60;
115	if (d)
116	printf("%u days ", d);
117	printf("%02u:%02u:%02u\n", h, m, (unsigned)expires);
118	} else { /* -a */
119	time_t t = expires_abs;
120	fputs(ctime(&t), stdout);
121	}
122	}
123	/* close(fd); */
124
125	return 0;
126	}
127