udhcp: cosmetic cleanups; one case of s/full_read/xread/
[oweals/busybox.git] / networking / udhcp / dumpleases.c
1 /* vi: set sw=4 ts=4: */
2 /*
3  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
4  */
5 #include "common.h"
6 #include "dhcpd.h"
7 #include "unicode.h"
8
9 #if BB_LITTLE_ENDIAN
10 static inline uint64_t hton64(uint64_t v)
11 {
12         return (((uint64_t)htonl(v)) << 32) | htonl(v >> 32);
13 }
14 #else
15 #define hton64(v) (v)
16 #endif
17 #define ntoh64(v) hton64(v)
18
19
20 int dumpleases_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
21 int dumpleases_main(int argc UNUSED_PARAM, char **argv)
22 {
23         int fd;
24         int i;
25         unsigned opt;
26         int64_t written_at, curr, expires_abs;
27         const char *file = LEASES_FILE;
28         struct dyn_lease lease;
29         struct in_addr addr;
30
31         enum {
32                 OPT_a   = 0x1,  // -a
33                 OPT_r   = 0x2,  // -r
34                 OPT_f   = 0x4,  // -f
35         };
36 #if ENABLE_LONG_OPTS
37         static const char dumpleases_longopts[] ALIGN1 =
38                 "absolute\0"  No_argument       "a"
39                 "remaining\0" No_argument       "r"
40                 "file\0"      Required_argument "f"
41                 ;
42
43         applet_long_options = dumpleases_longopts;
44 #endif
45         init_unicode();
46
47         opt_complementary = "=0:a--r:r--a";
48         opt = getopt32(argv, "arf:", &file);
49
50         fd = xopen(file, O_RDONLY);
51
52         printf("Mac Address       IP Address      Host Name           Expires %s\n", (opt & OPT_a) ? "at" : "in");
53         /*     "00:00:00:00:00:00 255.255.255.255 ABCDEFGHIJKLMNOPQRS Wed Jun 30 21:49:08 1993" */
54         /*     "123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 */
55
56         xread(fd, &written_at, sizeof(written_at));
57         written_at = ntoh64(written_at);
58         curr = time(NULL);
59         if (curr < written_at)
60                 written_at = curr; /* lease file from future! :) */
61
62         while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
63                 const char *fmt = ":%02x" + 1;
64                 for (i = 0; i < 6; i++) {
65                         printf(fmt, lease.lease_mac[i]);
66                         fmt = ":%02x";
67                 }
68                 addr.s_addr = lease.lease_nip;
69 #if ENABLE_FEATURE_ASSUME_UNICODE
70                 {
71                         char *uni_name = unicode_conv_to_printable_fixedwidth(NULL, lease.hostname, 19);
72                         printf(" %-16s%s ", inet_ntoa(addr), uni_name);
73                         free(uni_name);
74                 }
75 #else
76                 /* actually, 15+1 and 19+1, +1 is a space between columns */
77                 /* lease.hostname is char[20] and is always NUL terminated */
78                 printf(" %-16s%-20s", inet_ntoa(addr), lease.hostname);
79 #endif
80                 expires_abs = ntohl(lease.expires) + written_at;
81                 if (expires_abs <= curr) {
82                         puts("expired");
83                         continue;
84                 }
85                 if (!(opt & OPT_a)) { /* no -a */
86                         unsigned d, h, m;
87                         unsigned expires = expires_abs - curr;
88                         d = expires / (24*60*60); expires %= (24*60*60);
89                         h = expires / (60*60); expires %= (60*60);
90                         m = expires / 60; expires %= 60;
91                         if (d)
92                                 printf("%u days ", d);
93                         printf("%02u:%02u:%02u\n", h, m, (unsigned)expires);
94                 } else { /* -a */
95                         time_t t = expires_abs;
96                         fputs(ctime(&t), stdout);
97                 }
98         }
99         /* close(fd); */
100
101         return 0;
102 }