1 /* vi: set sw=4 ts=4: */
2 /*
3 * (sysvinit like) last implementation
4 *
5 * Copyright (C) 2008 by Patricia Muscalu <patricia.muscalu@axis.com>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8 */
9
10 #include "libbb.h"
11
12 /* NB: ut_name and ut_user are the same field, use only one name (ut_user)
13 * to reduce confusion */
14
15 #ifndef SHUTDOWN_TIME
16 # define SHUTDOWN_TIME 254
17 #endif
18
19 #define HEADER_FORMAT "%-8.8s %-12.12s %-*.*s %-16.16s %-7.7s %s\n"
20 #define HEADER_LINE "USER", "TTY", \
21 INET_ADDRSTRLEN, INET_ADDRSTRLEN, "HOST", "LOGIN", " TIME", ""
22 #define HEADER_LINE_WIDE "USER", "TTY", \
23 INET6_ADDRSTRLEN, INET6_ADDRSTRLEN, "HOST", "LOGIN", " TIME", ""
24
25 #if !defined __UT_LINESIZE && defined UT_LINESIZE
26 # define __UT_LINESIZE UT_LINESIZE
27 #endif
28
29 enum {
30 NORMAL,
31 LOGGED,
32 DOWN,
33 REBOOT,
34 CRASH,
35 GONE
36 };
37
38 enum {
39 LAST_OPT_W = (1 << 0), /* -W wide */
40 LAST_OPT_f = (1 << 1), /* -f input file */
41 LAST_OPT_H = (1 << 2), /* -H header */
42 };
43
44 #define show_wide (option_mask32 & LAST_OPT_W)
45
show_entry(struct utmpx * ut,int state,time_t dur_secs)46 static void show_entry(struct utmpx *ut, int state, time_t dur_secs)
47 {
48 unsigned days, hours, mins;
49 char duration[sizeof("(%u+02:02)") + sizeof(int)*3];
50 char login_time[17];
51 char logout_time[8];
52 const char *logout_str;
53 const char *duration_str;
54 time_t tmp;
55
56 /* manpages say ut_tv.tv_sec *is* time_t,
57 * but some systems have it wrong */
58 tmp = ut->ut_tv.tv_sec;
59 safe_strncpy(login_time, ctime(&tmp), 17);
60 tmp = dur_secs;
61 snprintf(logout_time, 8, "- %s", ctime(&tmp) + 11);
62
63 dur_secs = MAX(dur_secs - (time_t)ut->ut_tv.tv_sec, (time_t)0);
64 /* unsigned int is easier to divide than time_t (which may be signed long) */
65 mins = dur_secs / 60;
66 days = mins / (24*60);
67 mins = mins % (24*60);
68 hours = mins / 60;
69 mins = mins % 60;
70
71 // if (days) {
72 sprintf(duration, "(%u+%02u:%02u)", days, hours, mins);
73 // } else {
74 // sprintf(duration, " (%02u:%02u)", hours, mins);
75 // }
76
77 logout_str = logout_time;
78 duration_str = duration;
79 switch (state) {
80 case NORMAL:
81 break;
82 case LOGGED:
83 logout_str = " still";
84 duration_str = "logged in";
85 break;
86 case DOWN:
87 logout_str = "- down ";
88 break;
89 case REBOOT:
90 break;
91 case CRASH:
92 logout_str = "- crash";
93 break;
94 case GONE:
95 logout_str = " gone";
96 duration_str = "- no logout";
97 break;
98 }
99
100 printf(HEADER_FORMAT,
101 ut->ut_user,
102 ut->ut_line,
103 show_wide ? INET6_ADDRSTRLEN : INET_ADDRSTRLEN,
104 show_wide ? INET6_ADDRSTRLEN : INET_ADDRSTRLEN,
105 ut->ut_host,
106 login_time,
107 logout_str,
108 duration_str);
109 }
110
get_ut_type(struct utmpx * ut)111 static int get_ut_type(struct utmpx *ut)
112 {
113 if (ut->ut_line[0] == '~') {
114 if (strcmp(ut->ut_user, "shutdown") == 0) {
115 return SHUTDOWN_TIME;
116 }
117 if (strcmp(ut->ut_user, "reboot") == 0) {
118 return BOOT_TIME;
119 }
120 if (strcmp(ut->ut_user, "runlevel") == 0) {
121 return RUN_LVL;
122 }
123 return ut->ut_type;
124 }
125
126 if (ut->ut_user[0] == 0) {
127 return DEAD_PROCESS;
128 }
129
130 if ((ut->ut_type != DEAD_PROCESS)
131 && (strcmp(ut->ut_user, "LOGIN") != 0)
132 && ut->ut_user[0]
133 && ut->ut_line[0]
134 ) {
135 ut->ut_type = USER_PROCESS;
136 }
137
138 if (strcmp(ut->ut_user, "date") == 0) {
139 if (ut->ut_line[0] == '|') {
140 return OLD_TIME;
141 }
142 if (ut->ut_line[0] == '{') {
143 return NEW_TIME;
144 }
145 }
146 return ut->ut_type;
147 }
148
is_runlevel_shutdown(struct utmpx * ut)149 static int is_runlevel_shutdown(struct utmpx *ut)
150 {
151 if (((ut->ut_pid & 255) == '0') || ((ut->ut_pid & 255) == '6')) {
152 return 1;
153 }
154
155 return 0;
156 }
157
158 int last_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
last_main(int argc UNUSED_PARAM,char ** argv)159 int last_main(int argc UNUSED_PARAM, char **argv)
160 {
161 struct utmpx ut;
162 const char *filename = _PATH_WTMP;
163 llist_t *zlist;
164 off_t pos;
165 time_t start_time;
166 time_t boot_time;
167 time_t down_time;
168 int file;
169 smallint going_down;
170 smallint boot_down;
171
172 /*opt =*/ getopt32(argv, "Wf:" /* "H" */, &filename);
173 #ifdef BUT_UTIL_LINUX_LAST_HAS_NO_SUCH_OPT
174 if (opt & LAST_OPT_H) {
175 /* Print header line */
176 if (opt & LAST_OPT_W) {
177 printf(HEADER_FORMAT, HEADER_LINE_WIDE);
178 } else {
179 printf(HEADER_FORMAT, HEADER_LINE);
180 }
181 }
182 #endif
183
184 file = xopen(filename, O_RDONLY);
185 {
186 /* in case the file is empty... */
187 struct stat st;
188 fstat(file, &st);
189 start_time = st.st_ctime;
190 }
191
192 time(&down_time);
193 going_down = 0;
194 boot_down = NORMAL; /* 0 */
195 zlist = NULL;
196 boot_time = 0;
197 /* get file size, rounding down to last full record */
198 pos = xlseek(file, 0, SEEK_END) / sizeof(ut) * sizeof(ut);
199 for (;;) {
200 pos -= (off_t)sizeof(ut);
201 if (pos < 0) {
202 /* Beyond the beginning of the file boundary =>
203 * the whole file has been read. */
204 break;
205 }
206 xlseek(file, pos, SEEK_SET);
207 xread(file, &ut, sizeof(ut));
208 /* rewritten by each record, eventially will have
209 * first record's ut_tv.tv_sec: */
210 start_time = ut.ut_tv.tv_sec;
211
212 switch (get_ut_type(&ut)) {
213 case SHUTDOWN_TIME:
214 down_time = ut.ut_tv.tv_sec;
215 boot_down = DOWN;
216 going_down = 1;
217 break;
218 case RUN_LVL:
219 if (is_runlevel_shutdown(&ut)) {
220 down_time = ut.ut_tv.tv_sec;
221 going_down = 1;
222 boot_down = DOWN;
223 }
224 break;
225 case BOOT_TIME:
226 strcpy(ut.ut_line, "system boot");
227 show_entry(&ut, REBOOT, down_time);
228 boot_down = CRASH;
229 going_down = 1;
230 break;
231 case DEAD_PROCESS:
232 if (!ut.ut_line[0]) {
233 break;
234 }
235 /* add_entry */
236 llist_add_to(&zlist, xmemdup(&ut, sizeof(ut)));
237 break;
238 case USER_PROCESS: {
239 int show;
240
241 if (!ut.ut_line[0]) {
242 break;
243 }
244 /* find_entry */
245 show = 1;
246 {
247 llist_t *el, *next;
248 for (el = zlist; el; el = next) {
249 struct utmpx *up = (struct utmpx *)el->data;
250 next = el->link;
251 if (strncmp(up->ut_line, ut.ut_line, __UT_LINESIZE) == 0) {
252 if (show) {
253 show_entry(&ut, NORMAL, up->ut_tv.tv_sec);
254 show = 0;
255 }
256 llist_unlink(&zlist, el);
257 free(el->data);
258 free(el);
259 }
260 }
261 }
262
263 if (show) {
264 int state = boot_down;
265
266 if (boot_time == 0) {
267 state = LOGGED;
268 /* Check if the process is alive */
269 if ((ut.ut_pid > 0)
270 && (kill(ut.ut_pid, 0) != 0)
271 && (errno == ESRCH)) {
272 state = GONE;
273 }
274 }
275 show_entry(&ut, state, boot_time);
276 }
277 /* add_entry */
278 llist_add_to(&zlist, xmemdup(&ut, sizeof(ut)));
279 break;
280 }
281 }
282
283 if (going_down) {
284 boot_time = ut.ut_tv.tv_sec;
285 llist_free(zlist, free);
286 zlist = NULL;
287 going_down = 0;
288 }
289 }
290
291 if (ENABLE_FEATURE_CLEAN_UP) {
292 llist_free(zlist, free);
293 }
294
295 printf("\nwtmp begins %s", ctime(&start_time));
296
297 if (ENABLE_FEATURE_CLEAN_UP)
298 close(file);
299 fflush_stdout_and_exit(EXIT_SUCCESS);
300 }
301