Commit | Line | Data |
---|---|---|
ec7f5095 BJ |
1 | #include <signal.h> |
2 | #include <sys/types.h> | |
3 | #include <utmp.h> | |
4 | #include <setjmp.h> | |
5 | ||
6 | #define LINSIZ sizeof(wtmp.ut_line) | |
7 | #define TABSIZ 100 | |
8 | #define ALL p = &itab[0]; p < &itab[TABSIZ]; p++ | |
9 | #define EVER ;; | |
10 | #define SCPYN(a, b) strncpy(a, b, sizeof(a)) | |
11 | #define SCMPN(a, b) strncmp(a, b, sizeof(a)) | |
12 | ||
13 | char shell[] = "/bin/sh"; | |
14 | char getty[] = "/etc/getty.vm"; | |
15 | char minus[] = "-"; | |
16 | char runc[] = "/etc/rc"; | |
17 | char ifile[] = "/etc/ttys"; | |
18 | char utmp[] = "/etc/utmp"; | |
19 | char wtmpf[] = "/usr/adm/wtmp"; | |
20 | char ctty[] = "/dev/console"; | |
21 | char dev[] = "/dev/"; | |
22 | ||
23 | struct utmp wtmp; | |
24 | struct | |
25 | { | |
26 | char line[LINSIZ]; | |
27 | char comn; | |
28 | char flag; | |
29 | } line; | |
30 | struct tab | |
31 | { | |
32 | char line[LINSIZ]; | |
33 | char comn; | |
34 | char xflag; | |
35 | int pid; | |
36 | } itab[TABSIZ]; | |
37 | ||
38 | int fi; | |
39 | int mergflag; | |
40 | char tty[20]; | |
41 | jmp_buf sjbuf; | |
42 | ||
43 | int reset(); | |
44 | char *strcpy(), *strcat(); | |
45 | long lseek(); | |
46 | ||
47 | main() | |
48 | { | |
49 | setjmp(sjbuf); | |
50 | signal(SIGTERM, reset); | |
51 | for(EVER) { | |
52 | shutdown(); | |
53 | single(); | |
54 | runcom(); | |
55 | merge(); | |
56 | multiple(); | |
57 | } | |
58 | } | |
59 | ||
60 | shutdown() | |
61 | { | |
62 | register i; | |
63 | register struct tab *p; | |
64 | ||
65 | close(creat(utmp, 0644)); | |
66 | signal(SIGHUP, SIG_IGN); | |
67 | for(ALL) { | |
68 | term(p); | |
69 | p->line[0] = 0; | |
70 | } | |
71 | signal(SIGALRM, reset); | |
72 | alarm(60); | |
73 | for(i=0; i<5; i++) | |
74 | kill(-1, SIGKILL); | |
75 | while(wait((int *)0) != -1) | |
76 | ; | |
77 | alarm(0); | |
78 | signal(SIGALRM, SIG_DFL); | |
79 | for(i=0; i<10; i++) | |
80 | close(i); | |
81 | } | |
82 | ||
83 | single() | |
84 | { | |
85 | register pid; | |
86 | ||
87 | pid = fork(); | |
88 | if(pid == 0) { | |
89 | /* | |
90 | alarm(300); | |
91 | */ | |
92 | signal(SIGTERM, SIG_DFL); | |
93 | signal(SIGHUP, SIG_DFL); | |
94 | signal(SIGALRM, SIG_DFL); | |
95 | open(ctty, 2); | |
96 | dup(0); | |
97 | dup(0); | |
98 | execl(shell, minus, (char *)0); | |
99 | exit(0); | |
100 | } | |
101 | while(wait((int *)0) != pid) | |
102 | ; | |
103 | } | |
104 | ||
105 | runcom() | |
106 | { | |
107 | register pid, f; | |
108 | ||
109 | pid = fork(); | |
110 | if(pid == 0) { | |
111 | open("/", 0); | |
112 | dup(0); | |
113 | dup(0); | |
114 | execl(shell, shell, runc, (char *)0); | |
115 | exit(0); | |
116 | } | |
117 | while(wait((int *)0) != pid) | |
118 | ; | |
119 | f = open(wtmpf, 1); | |
120 | if (f >= 0) { | |
121 | lseek(f, 0L, 2); | |
122 | SCPYN(wtmp.ut_line, "~"); | |
123 | SCPYN(wtmp.ut_name, ""); | |
124 | time(&wtmp.ut_time); | |
125 | write(f, (char *)&wtmp, sizeof(wtmp)); | |
126 | close(f); | |
127 | } | |
128 | } | |
129 | ||
130 | setmerge() | |
131 | { | |
132 | ||
133 | mergflag = 1; | |
134 | } | |
135 | ||
136 | multiple() | |
137 | { | |
138 | register struct tab *p; | |
139 | register pid; | |
140 | ||
141 | loop: | |
142 | mergflag = 0; | |
143 | signal(SIGHUP, setmerge); | |
144 | for(EVER) { | |
145 | pid = wait((int *)0); | |
146 | if(mergflag) { | |
147 | merge(); | |
148 | goto loop; | |
149 | } | |
150 | if(pid == -1) | |
151 | return; | |
152 | for(ALL) | |
153 | if(p->pid == pid || p->pid == -1) { | |
154 | rmut(p); | |
155 | dfork(p); | |
156 | } | |
157 | } | |
158 | } | |
159 | ||
160 | term(p) | |
161 | register struct tab *p; | |
162 | { | |
163 | ||
164 | if(p->pid != 0) { | |
165 | rmut(p); | |
166 | kill(p->pid, SIGKILL); | |
167 | } | |
168 | p->pid = 0; | |
169 | } | |
170 | ||
171 | rline() | |
172 | { | |
173 | register c, i; | |
174 | ||
175 | loop: | |
176 | c = get(); | |
177 | if(c < 0) | |
178 | return(0); | |
179 | if(c == 0) | |
180 | goto loop; | |
181 | line.flag = c; | |
182 | c = get(); | |
183 | if(c <= 0) | |
184 | goto loop; | |
185 | line.comn = c; | |
186 | SCPYN(line.line, ""); | |
187 | for (i=0; i<LINSIZ; i++) { | |
188 | c = get(); | |
189 | if(c <= 0) | |
190 | break; | |
191 | line.line[i] = c; | |
192 | } | |
193 | while(c > 0) | |
194 | c = get(); | |
195 | if(line.line[0] == 0) | |
196 | goto loop; | |
197 | if(line.flag == '0') | |
198 | goto loop; | |
199 | strcpy(tty, dev); | |
200 | strncat(tty, line.line, LINSIZ); | |
201 | if(access(tty, 06) < 0) | |
202 | goto loop; | |
203 | return(1); | |
204 | } | |
205 | ||
206 | get() | |
207 | { | |
208 | char b; | |
209 | ||
210 | if(read(fi, &b, 1) != 1) | |
211 | return(-1); | |
212 | if(b == '\n') | |
213 | return(0); | |
214 | return(b); | |
215 | } | |
216 | ||
217 | #define FOUND 1 | |
218 | #define CHANGE 2 | |
219 | ||
220 | merge() | |
221 | { | |
222 | register struct tab *p; | |
223 | ||
224 | fi = open(ifile, 0); | |
225 | if(fi < 0) | |
226 | return; | |
227 | for(ALL) | |
228 | p->xflag = 0; | |
229 | while(rline()) { | |
230 | for(ALL) { | |
231 | if (SCMPN(p->line, line.line)) | |
232 | continue; | |
233 | p->xflag |= FOUND; | |
234 | if(line.comn != p->comn) { | |
235 | p->xflag |= CHANGE; | |
236 | p->comn = line.comn; | |
237 | } | |
238 | goto contin1; | |
239 | } | |
240 | for(ALL) { | |
241 | if(p->line[0] != 0) | |
242 | continue; | |
243 | SCPYN(p->line, line.line); | |
244 | p->xflag |= FOUND|CHANGE; | |
245 | p->comn = line.comn; | |
246 | goto contin1; | |
247 | } | |
248 | contin1: | |
249 | ; | |
250 | } | |
251 | close(fi); | |
252 | for(ALL) { | |
253 | if((p->xflag&FOUND) == 0) { | |
254 | term(p); | |
255 | p->line[0] = 0; | |
256 | } | |
257 | if((p->xflag&CHANGE) != 0) { | |
258 | term(p); | |
259 | dfork(p); | |
260 | } | |
261 | } | |
262 | } | |
263 | ||
264 | dfork(p) | |
265 | struct tab *p; | |
266 | { | |
267 | register pid; | |
268 | ||
269 | pid = fork(); | |
270 | if(pid == 0) { | |
271 | signal(SIGTERM, SIG_DFL); | |
272 | signal(SIGHUP, SIG_DFL); | |
273 | strcpy(tty, dev); | |
274 | strncat(tty, p->line, LINSIZ); | |
275 | chown(tty, 0, 0); | |
276 | chmod(tty, 0622); | |
277 | open(tty, 2); | |
278 | dup(0); | |
279 | dup(0); | |
280 | tty[0] = p->comn; | |
281 | tty[1] = 0; | |
282 | execl(getty, minus, tty, (char *)0); | |
283 | exit(0); | |
284 | } | |
285 | p->pid = pid; | |
286 | } | |
287 | ||
288 | rmut(p) | |
289 | register struct tab *p; | |
290 | { | |
291 | register f; | |
292 | ||
293 | f = open(utmp, 2); | |
294 | if(f >= 0) { | |
295 | while(read(f, (char *)&wtmp, sizeof(wtmp)) == sizeof(wtmp)) { | |
296 | if (SCMPN(wtmp.ut_line, p->line)) | |
297 | continue; | |
298 | lseek(f, -(long)sizeof(wtmp), 1); | |
299 | SCPYN(wtmp.ut_name, ""); | |
300 | time(&wtmp.ut_time); | |
301 | write(f, (char *)&wtmp, sizeof(wtmp)); | |
302 | } | |
303 | close(f); | |
304 | } | |
305 | f = open(wtmpf, 1); | |
306 | if (f >= 0) { | |
307 | SCPYN(wtmp.ut_line, p->line); | |
308 | SCPYN(wtmp.ut_name, ""); | |
309 | time(&wtmp.ut_time); | |
310 | lseek(f, (long)0, 2); | |
311 | write(f, (char *)&wtmp, sizeof(wtmp)); | |
312 | close(f); | |
313 | } | |
314 | } | |
315 | ||
316 | reset() | |
317 | { | |
318 | longjmp(sjbuf, 1); | |
319 | } | |
320 | ||
321 |