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4ef48614 WJ |
1 | /* |
2 | * Copyright (c) 1986, 1987, 1992 Daniel D. Lanciani. | |
3 | * All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
13 | * 3. All advertising materials mentioning features or use of this software | |
14 | * must display the following acknowledgement: | |
15 | * This product includes software developed by | |
16 | * Daniel D. Lanciani. | |
17 | * 4. The name of the author may not | |
18 | * be used to endorse or promote products derived from this software | |
19 | * without specific prior written permission. | |
20 | * | |
21 | * THIS SOFTWARE IS PROVIDED BY Daniel D. Lanciani ``AS IS'' AND | |
22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
24 | * ARE DISCLAIMED. IN NO EVENT SHALL Daniel D. Lanciani BE LIABLE | |
25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
31 | * SUCH DAMAGE. | |
32 | */ | |
33 | ||
34 | ||
35 | #include <sys/types.h> | |
36 | #include <sys/errno.h> | |
37 | #include <sys/signal.h> | |
38 | #include <sys/wait.h> | |
39 | #include <setjmp.h> | |
40 | #include <ttyent.h> | |
41 | #include <unistd.h> | |
42 | ||
43 | #define NTTY 32 /* max ttys */ | |
44 | #define NARG 16 /* max args to login/getty */ | |
45 | ||
46 | /* internal flags */ | |
47 | #define TTY_SEEN 0x8000 | |
48 | #define TTY_DIFF 0x4000 | |
49 | #define TTY_LOGIN 0x2000 | |
50 | ||
51 | /* non-standard tty_logout: rerun login/getty with -o switch to clean line */ | |
52 | #ifndef TTY_LOGOUT | |
53 | #define TTY_LOGOUT 0x1000 | |
54 | #endif | |
55 | ||
56 | /* non-standard tty_open: open device for login/getty */ | |
57 | #ifndef TTY_OPEN | |
58 | #define TTY_OPEN 0x0800 | |
59 | #endif | |
60 | ||
61 | #define isspace(c) ((c) == ' ' || (c) == '\t') | |
62 | ||
63 | struct ttytab { | |
64 | char *tt_name; | |
65 | char *tt_getty; | |
66 | char *tt_type; | |
67 | int tt_status; | |
68 | int tt_pid; | |
69 | } ttytab[NTTY], *ttytabend = ttytab; | |
70 | int drain, sflag; | |
71 | char arg[128], nam[64], term[64], *env[] = { term, 0 }; | |
72 | jmp_buf single, reread; | |
73 | char *Reboot = "autoboot"; | |
74 | ||
75 | char *newstring(), *malloc(); | |
76 | extern int errno; | |
77 | ||
78 | /* signal state of child process */ | |
79 | #define SIGNALSFORCHILD \ | |
80 | signal(SIGHUP, SIG_DFL); signal(SIGINT, SIG_DFL); \ | |
81 | signal(SIGTERM, SIG_DFL); signal(SIGALRM, SIG_DFL); \ | |
82 | signal(SIGTSTP, SIG_DFL); signal(SIGCHLD, SIG_DFL); \ | |
83 | signal(SIGTTIN, SIG_DFL); signal(SIGTTOU, SIG_DFL); | |
84 | ||
85 | /* SIGHUP: reread /etc/ttys */ | |
86 | void | |
87 | shup(sig) | |
88 | { | |
89 | longjmp(reread, 1); | |
90 | } | |
91 | ||
92 | /* SIGALRM: abort wait and go single user */ | |
93 | void | |
94 | salrm(sig) | |
95 | { | |
96 | signal(SIGALRM, SIG_DFL); | |
97 | warn("process hung"); | |
98 | longjmp(single, 1); | |
99 | } | |
100 | ||
101 | /* SIGTERM: go single user */ | |
102 | void | |
103 | sterm(sig) | |
104 | { | |
105 | register struct ttytab *tt; | |
106 | ||
107 | if (!Reboot) { | |
108 | for(tt = ttytab; tt < ttytabend; tt++) { | |
109 | free(tt->tt_name); | |
110 | free(tt->tt_getty); | |
111 | free(tt->tt_type); | |
112 | } | |
113 | ttytabend = ttytab; | |
114 | kill(-1, SIGKILL); | |
115 | kill(-1, SIGCONT); | |
116 | signal(SIGALRM, salrm); | |
117 | alarm(30); | |
118 | while(wait((int *)0) > 0); | |
119 | alarm(0); | |
120 | signal(SIGALRM, SIG_DFL); | |
121 | longjmp(single, 1); | |
122 | } | |
123 | } | |
124 | ||
125 | /* SIGTSTP: drain system */ | |
126 | void | |
127 | ststp(sig) | |
128 | { | |
129 | drain = 1; | |
130 | } | |
131 | ||
132 | /* init [-s] [-f] */ | |
133 | ||
134 | main(argc, argv) | |
135 | char **argv; | |
136 | { | |
137 | register int pid; | |
138 | register struct ttytab *tt; | |
139 | struct ttyent *ty; | |
140 | int status; | |
141 | long mask = sigblock(sigmask(SIGHUP) | sigmask(SIGTERM)); | |
142 | ||
143 | /* did some idiot try to run us? */ | |
144 | if(getpid() != 1) { | |
145 | writes(2,"init: sorry, system daemon, runnable only by system\n"); | |
146 | exit(0xff); | |
147 | } | |
148 | ||
149 | /* allocate a session for init */ | |
150 | (void) setsid(); | |
151 | ||
152 | /* protect against signals, listen for outside requests */ | |
153 | signal(SIGHUP, shup); | |
154 | signal(SIGTSTP, ststp); | |
155 | ||
156 | signal (SIGTTIN, SIG_IGN); | |
157 | signal (SIGTTOU, SIG_IGN); | |
158 | signal (SIGCHLD, SIG_IGN); | |
159 | signal (SIGINT, SIG_IGN); | |
160 | ||
161 | /* handle arguments, if any */ | |
162 | if(argc > 1) | |
163 | if(!strcmp(argv[1], "-s")) | |
164 | sflag++; | |
165 | else if(!strcmp(argv[1], "-f")) | |
166 | Reboot = 0; | |
167 | top: | |
168 | /* Single user mode? */ | |
169 | if(sflag) { | |
170 | sflag = 0; | |
171 | status = 1; | |
172 | } else { | |
173 | /* otherwise, execute /etc/rc */ | |
174 | if (access("/etc/rc", F_OK) == 0) { | |
175 | ||
176 | signal(SIGTERM, SIG_IGN); /* XXX */ | |
177 | if((pid = fork()) < 0) | |
178 | fatal("fork"); | |
179 | else if(!pid) { | |
180 | /* signals, to default state */ | |
181 | SIGNALSFORCHILD; | |
182 | ||
183 | /* clean off console */ | |
184 | revoke("/dev/console"); | |
185 | ||
186 | /* create a shell */ | |
187 | login_tty(open("/dev/console", 2)); | |
188 | execl("/bin/sh", "sh", "/etc/rc", Reboot, (char *)0); | |
189 | _exit(127); | |
190 | } | |
191 | while(wait(&status) != pid); | |
192 | ||
193 | /* if we are about to be rebooted, then wait for it */ | |
194 | if (WIFSIGNALED(status) && WTERMSIG(status) == SIGKILL) | |
195 | pause(); | |
196 | } else { status = 1; sflag = 1; goto top; } | |
197 | } | |
198 | signal(SIGTERM, sterm); | |
199 | Reboot = 0; | |
200 | ||
201 | /* do single user shell on console */ | |
202 | if (setjmp(single) || status) { | |
203 | if((pid = fork()) < 0) | |
204 | fatal("fork"); | |
205 | else if(!pid) { | |
206 | /* signals, to default state */ | |
207 | SIGNALSFORCHILD; | |
208 | ||
209 | /* clean off console */ | |
210 | revoke("/dev/console"); | |
211 | ||
212 | /* do open and configuration of console */ | |
213 | login_tty(open("/dev/console", 2)); | |
214 | execl("/bin/sh", "-", (char *)0); | |
215 | _exit(127); | |
216 | } | |
217 | while(wait(&status) != pid) | |
218 | goto top; | |
219 | } | |
220 | ||
221 | /* multiuser mode, traipse through table */ | |
222 | setttyent(); | |
223 | for(tt = ttytab; (ty = getttyent()) && tt < &ttytab[NTTY]; tt++) { | |
224 | tt->tt_name = newstring(ty->ty_name); | |
225 | tt->tt_getty = newstring(ty->ty_getty); | |
226 | tt->tt_type = newstring(ty->ty_type); | |
227 | tt->tt_status = ty->ty_status; | |
228 | } | |
229 | ttytabend = tt; | |
230 | endttyent(); | |
231 | for(tt = ttytab; tt < ttytabend; getty(tt++)); | |
232 | ||
233 | /* if we receive a request to reread the table, come here */ | |
234 | if(setjmp(reread)) { | |
235 | ||
236 | /* first pass. find and clean the entries that have changed */ | |
237 | setttyent(); | |
238 | while(ty = getttyent()) { | |
239 | for(tt = ttytab; tt < ttytabend; tt++) | |
240 | if(!strcmp(tt->tt_name, ty->ty_name)) { | |
241 | /* if a process present, mark */ | |
242 | if((tt->tt_status & ~TTY_LOGIN) !=ty->ty_status) | |
243 | tt->tt_status = ty->ty_status |TTY_DIFF; | |
244 | if(strcmp(tt->tt_getty, ty->ty_getty)) { | |
245 | free(tt->tt_getty); | |
246 | tt->tt_getty = newstring(ty->ty_getty); | |
247 | tt->tt_status |= TTY_DIFF; | |
248 | } | |
249 | if(strcmp(tt->tt_type, ty->ty_type)) { | |
250 | free(tt->tt_type); | |
251 | tt->tt_type = newstring(ty->ty_type); | |
252 | tt->tt_status |= TTY_DIFF; | |
253 | } | |
254 | if(((tt->tt_status |= TTY_SEEN) & TTY_DIFF) | |
255 | && tt->tt_pid > 1) | |
256 | kill(tt->tt_pid, 9); | |
257 | break; | |
258 | } | |
259 | if(tt == ttytabend && tt < &ttytab[NTTY]) { | |
260 | tt->tt_name = newstring(ty->ty_name); | |
261 | tt->tt_getty = newstring(ty->ty_getty); | |
262 | tt->tt_type = newstring(ty->ty_type); | |
263 | tt->tt_status = ty->ty_status | | |
264 | TTY_SEEN | TTY_DIFF; | |
265 | ttytabend++; | |
266 | } | |
267 | } | |
268 | endttyent(); | |
269 | /* second pass. offer gettys on previously cleaned entries, | |
270 | and garbage collect "dead" entries */ | |
271 | for(tt = ttytab; tt < ttytabend; tt++) | |
272 | if(tt->tt_status & TTY_SEEN) { | |
273 | tt->tt_status &= ~TTY_SEEN; | |
274 | if(tt->tt_status & TTY_DIFF) { | |
275 | tt->tt_status &= ~TTY_DIFF; | |
276 | getty(tt); | |
277 | } | |
278 | } | |
279 | else { | |
280 | if(tt->tt_pid > 1) | |
281 | kill(tt->tt_pid, 9); | |
282 | free(tt->tt_name); | |
283 | free(tt->tt_getty); | |
284 | free(tt->tt_type); | |
285 | pid = tt - ttytab; | |
286 | for(tt++; tt < ttytabend; tt++) | |
287 | tt[-1] = *tt; | |
288 | ttytabend--; | |
289 | tt = &ttytab[pid]; | |
290 | } | |
291 | } | |
292 | drain = 0; | |
293 | ||
294 | /* listen for terminating gettys and sessions, and process them */ | |
295 | while(1) { | |
296 | sigsetmask(mask); | |
297 | pid = wait(&status); | |
298 | sigblock(sigmask(SIGHUP) | sigmask(SIGTERM)); | |
299 | if(pid < 0) { | |
300 | sleep(5); | |
301 | continue; | |
302 | } | |
303 | for(tt = ttytab; tt < ttytabend; tt++) | |
304 | if(pid == tt->tt_pid) { | |
305 | if(drain && !(tt->tt_status & TTY_LOGIN)) { | |
306 | free(tt->tt_name); | |
307 | free(tt->tt_getty); | |
308 | free(tt->tt_type); | |
309 | for(tt++; tt < ttytabend; tt++) | |
310 | tt[-1] = *tt; | |
311 | ttytabend--; | |
312 | } | |
313 | else | |
314 | getty(tt); | |
315 | break; | |
316 | } | |
317 | } | |
318 | } | |
319 | ||
320 | /* process a getty for a "line". N.B. by having getty do open, init | |
321 | is not limited by filedescriptors for number of possible users */ | |
322 | getty(tt) | |
323 | struct ttytab *tt; | |
324 | { | |
325 | char *sargv[NARG]; | |
326 | register char *p = arg, **sp = sargv; | |
327 | ||
328 | if(!(tt->tt_status & TTY_ON)) { | |
329 | tt->tt_pid = -1; | |
330 | return; | |
331 | } | |
332 | if((tt->tt_pid = fork()) < 0) | |
333 | fatal("getty fork"); | |
334 | else if(tt->tt_pid) { | |
335 | if(tt->tt_status & TTY_LOGOUT) | |
336 | tt->tt_status ^= TTY_LOGIN; | |
337 | return; | |
338 | } | |
339 | signal(SIGHUP, SIG_DFL); | |
340 | signal(SIGTERM, SIG_DFL); | |
341 | signal(SIGTSTP, SIG_DFL); | |
342 | sigsetmask(0); | |
343 | strcpy(p, tt->tt_getty); | |
344 | while(sp < &sargv[NARG - 2]) { | |
345 | while(isspace(*p)) | |
346 | p++; | |
347 | if(!*p) | |
348 | break; | |
349 | *sp++ = p; | |
350 | while(!isspace(*p) && *p) | |
351 | p++; | |
352 | if(!*p) | |
353 | break; | |
354 | *p++ = 0; | |
355 | } | |
356 | strcpy(nam, tt->tt_name); | |
357 | *sp++ = nam; | |
358 | *sp = 0; | |
359 | p = *sargv; | |
360 | strcpy(term, "TERM="); | |
361 | strcat(term, tt->tt_type); | |
362 | execve(p, sargv, env); | |
363 | bad: | |
364 | sleep(30); | |
365 | fatal(tt->tt_name); | |
366 | } | |
367 | ||
368 | char * | |
369 | newstring(s) | |
370 | register char *s; | |
371 | { | |
372 | register char *n; | |
373 | ||
374 | if(!(n = malloc(strlen(s) + 1))) | |
375 | fatal("out of memory"); | |
376 | strcpy(n, s); | |
377 | return(n); | |
378 | } | |
379 | ||
380 | warn(s) | |
381 | char *s; | |
382 | { | |
383 | register int pid; | |
384 | int fd; | |
385 | ||
386 | fd = open("/dev/console", 2); | |
387 | writes(fd, "init WARNING: "); | |
388 | writes(fd, s); | |
389 | write(fd, "\n", 1); | |
390 | close(fd); | |
391 | } | |
392 | ||
393 | fatal(s) | |
394 | char *s; | |
395 | { | |
396 | login_tty(open("/dev/console", 2)); | |
397 | writes(2, "init FATAL error: "); | |
398 | perror(s); | |
399 | exit(1); | |
400 | /* panic: init died */ | |
401 | } | |
402 | ||
403 | writes(n, s) | |
404 | char *s; | |
405 | { | |
406 | write(n, s, strlen(s)); | |
407 | } |