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10#include "libbb.h"
11#include <utmp.h>
12
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14
15
16#ifndef SHUTDOWN_TIME
17# define SHUTDOWN_TIME 254
18#endif
19
20#define HEADER_FORMAT "%-8.8s %-12.12s %-*.*s %-16.16s %-7.7s %s\n"
21#define HEADER_LINE "USER", "TTY", \
22 INET_ADDRSTRLEN, INET_ADDRSTRLEN, "HOST", "LOGIN", " TIME", ""
23#define HEADER_LINE_WIDE "USER", "TTY", \
24 INET6_ADDRSTRLEN, INET6_ADDRSTRLEN, "HOST", "LOGIN", " TIME", ""
25
26enum {
27 NORMAL,
28 LOGGED,
29 DOWN,
30 REBOOT,
31 CRASH,
32 GONE
33};
34
35enum {
36 LAST_OPT_W = (1 << 0),
37 LAST_OPT_f = (1 << 1),
38 LAST_OPT_H = (1 << 2),
39};
40
41#define show_wide (option_mask32 & LAST_OPT_W)
42
43static void show_entry(struct utmp *ut, int state, time_t dur_secs)
44{
45 unsigned days, hours, mins;
46 char duration[32];
47 char login_time[17];
48 char logout_time[8];
49 const char *logout_str;
50 const char *duration_str;
51 time_t tmp;
52
53
54
55 tmp = ut->ut_tv.tv_sec;
56 safe_strncpy(login_time, ctime(&tmp), 17);
57 snprintf(logout_time, 8, "- %s", ctime(&dur_secs) + 11);
58
59 dur_secs = MAX(dur_secs - (time_t)ut->ut_tv.tv_sec, (time_t)0);
60
61 mins = dur_secs / 60;
62 days = mins / (24*60);
63 mins = mins % (24*60);
64 hours = mins / 60;
65 mins = mins % 60;
66
67
68 sprintf(duration, "(%u+%02u:%02u)", days, hours, mins);
69
70
71
72
73 logout_str = logout_time;
74 duration_str = duration;
75 switch (state) {
76 case NORMAL:
77 break;
78 case LOGGED:
79 logout_str = " still";
80 duration_str = "logged in";
81 break;
82 case DOWN:
83 logout_str = "- down ";
84 break;
85 case REBOOT:
86 break;
87 case CRASH:
88 logout_str = "- crash";
89 break;
90 case GONE:
91 logout_str = " gone";
92 duration_str = "- no logout";
93 break;
94 }
95
96 printf(HEADER_FORMAT,
97 ut->ut_user,
98 ut->ut_line,
99 show_wide ? INET6_ADDRSTRLEN : INET_ADDRSTRLEN,
100 show_wide ? INET6_ADDRSTRLEN : INET_ADDRSTRLEN,
101 ut->ut_host,
102 login_time,
103 logout_str,
104 duration_str);
105}
106
107static int get_ut_type(struct utmp *ut)
108{
109 if (ut->ut_line[0] == '~') {
110 if (strcmp(ut->ut_user, "shutdown") == 0) {
111 return SHUTDOWN_TIME;
112 }
113 if (strcmp(ut->ut_user, "reboot") == 0) {
114 return BOOT_TIME;
115 }
116 if (strcmp(ut->ut_user, "runlevel") == 0) {
117 return RUN_LVL;
118 }
119 return ut->ut_type;
120 }
121
122 if (ut->ut_user[0] == 0) {
123 return DEAD_PROCESS;
124 }
125
126 if ((ut->ut_type != DEAD_PROCESS)
127 && (strcmp(ut->ut_user, "LOGIN") != 0)
128 && ut->ut_user[0]
129 && ut->ut_line[0]
130 ) {
131 ut->ut_type = USER_PROCESS;
132 }
133
134 if (strcmp(ut->ut_user, "date") == 0) {
135 if (ut->ut_line[0] == '|') {
136 return OLD_TIME;
137 }
138 if (ut->ut_line[0] == '{') {
139 return NEW_TIME;
140 }
141 }
142 return ut->ut_type;
143}
144
145static int is_runlevel_shutdown(struct utmp *ut)
146{
147 if (((ut->ut_pid & 255) == '0') || ((ut->ut_pid & 255) == '6')) {
148 return 1;
149 }
150
151 return 0;
152}
153
154int last_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
155int last_main(int argc UNUSED_PARAM, char **argv)
156{
157 struct utmp ut;
158 const char *filename = _PATH_WTMP;
159 llist_t *zlist;
160 off_t pos;
161 time_t start_time;
162 time_t boot_time;
163 time_t down_time;
164 int file;
165 unsigned opt;
166 smallint going_down;
167 smallint boot_down;
168
169 opt = getopt32(argv, "Wf:" , &filename);
170#ifdef BUT_UTIL_LINUX_LAST_HAS_NO_SUCH_OPT
171 if (opt & LAST_OPT_H) {
172
173 if (opt & LAST_OPT_W) {
174 printf(HEADER_FORMAT, HEADER_LINE_WIDE);
175 } else {
176 printf(HEADER_FORMAT, HEADER_LINE);
177 }
178 }
179#endif
180
181 file = xopen(filename, O_RDONLY);
182 {
183
184 struct stat st;
185 fstat(file, &st);
186 start_time = st.st_ctime;
187 }
188
189 time(&down_time);
190 going_down = 0;
191 boot_down = NORMAL;
192 zlist = NULL;
193 boot_time = 0;
194
195 pos = xlseek(file, 0, SEEK_END) / sizeof(ut) * sizeof(ut);
196 for (;;) {
197 pos -= (off_t)sizeof(ut);
198 if (pos < 0) {
199
200
201 break;
202 }
203 xlseek(file, pos, SEEK_SET);
204 xread(file, &ut, sizeof(ut));
205
206
207 start_time = ut.ut_tv.tv_sec;
208
209 switch (get_ut_type(&ut)) {
210 case SHUTDOWN_TIME:
211 down_time = ut.ut_tv.tv_sec;
212 boot_down = DOWN;
213 going_down = 1;
214 break;
215 case RUN_LVL:
216 if (is_runlevel_shutdown(&ut)) {
217 down_time = ut.ut_tv.tv_sec;
218 going_down = 1;
219 boot_down = DOWN;
220 }
221 break;
222 case BOOT_TIME:
223 strcpy(ut.ut_line, "system boot");
224 show_entry(&ut, REBOOT, down_time);
225 boot_down = CRASH;
226 going_down = 1;
227 break;
228 case DEAD_PROCESS:
229 if (!ut.ut_line[0]) {
230 break;
231 }
232
233 llist_add_to(&zlist, memcpy(xmalloc(sizeof(ut)), &ut, sizeof(ut)));
234 break;
235 case USER_PROCESS: {
236 int show;
237
238 if (!ut.ut_line[0]) {
239 break;
240 }
241
242 show = 1;
243 {
244 llist_t *el, *next;
245 for (el = zlist; el; el = next) {
246 struct utmp *up = (struct utmp *)el->data;
247 next = el->link;
248 if (strncmp(up->ut_line, ut.ut_line, UT_LINESIZE) == 0) {
249 if (show) {
250 show_entry(&ut, NORMAL, up->ut_tv.tv_sec);
251 show = 0;
252 }
253 llist_unlink(&zlist, el);
254 free(el->data);
255 free(el);
256 }
257 }
258 }
259
260 if (show) {
261 int state = boot_down;
262
263 if (boot_time == 0) {
264 state = LOGGED;
265
266 if ((ut.ut_pid > 0)
267 && (kill(ut.ut_pid, 0) != 0)
268 && (errno == ESRCH)) {
269 state = GONE;
270 }
271 }
272 show_entry(&ut, state, boot_time);
273 }
274
275 llist_add_to(&zlist, memcpy(xmalloc(sizeof(ut)), &ut, sizeof(ut)));
276 break;
277 }
278 }
279
280 if (going_down) {
281 boot_time = ut.ut_tv.tv_sec;
282 llist_free(zlist, free);
283 zlist = NULL;
284 going_down = 0;
285 }
286 }
287
288 if (ENABLE_FEATURE_CLEAN_UP) {
289 llist_free(zlist, free);
290 }
291
292 printf("\nwtmp begins %s", ctime(&start_time));
293
294 if (ENABLE_FEATURE_CLEAN_UP)
295 close(file);
296 fflush_stdout_and_exit(EXIT_SUCCESS);
297}
298
