28d00fe4 |
1 | /* |
2 | * Pseudo-tty backend for pterm. |
28d00fe4 |
3 | */ |
4 | |
74aca06d |
5 | #define _GNU_SOURCE |
054d8535 |
6 | |
1709795f |
7 | #include <stdio.h> |
8 | #include <stdlib.h> |
054d8535 |
9 | #include <string.h> |
10 | #include <unistd.h> |
a0e16eb1 |
11 | #include <signal.h> |
2916fa14 |
12 | #include <assert.h> |
054d8535 |
13 | #include <fcntl.h> |
88e6b9ca |
14 | #include <termios.h> |
be4f86de |
15 | #include <grp.h> |
755a6d84 |
16 | #include <utmp.h> |
17 | #include <pwd.h> |
18 | #include <time.h> |
a0e16eb1 |
19 | #include <sys/types.h> |
d4e1d591 |
20 | #include <sys/stat.h> |
a0e16eb1 |
21 | #include <sys/wait.h> |
88e6b9ca |
22 | #include <sys/ioctl.h> |
0f33f9d1 |
23 | #include <errno.h> |
1709795f |
24 | |
25 | #include "putty.h" |
d6fa1947 |
26 | #include "tree234.h" |
1709795f |
27 | |
0b1df797 |
28 | #ifndef OMIT_UTMP |
bea25c48 |
29 | #include <utmpx.h> |
30 | #endif |
31 | |
1709795f |
32 | #ifndef FALSE |
33 | #define FALSE 0 |
34 | #endif |
35 | #ifndef TRUE |
36 | #define TRUE 1 |
37 | #endif |
38 | |
bea25c48 |
39 | /* updwtmpx() needs the name of the wtmp file. Try to find it. */ |
40 | #ifndef WTMPX_FILE |
41 | #ifdef _PATH_WTMPX |
42 | #define WTMPX_FILE _PATH_WTMPX |
43 | #else |
44 | #define WTMPX_FILE "/var/log/wtmpx" |
755a6d84 |
45 | #endif |
755a6d84 |
46 | #endif |
bea25c48 |
47 | |
755a6d84 |
48 | #ifndef LASTLOG_FILE |
49 | #ifdef _PATH_LASTLOG |
50 | #define LASTLOG_FILE _PATH_LASTLOG |
51 | #else |
52 | #define LASTLOG_FILE "/var/log/lastlog" |
53 | #endif |
54 | #endif |
55 | |
f51dc031 |
56 | /* |
57 | * Set up a default for vaguely sane systems. The idea is that if |
58 | * OMIT_UTMP is not defined, then at least one of the symbols which |
59 | * enable particular forms of utmp processing should be, if only so |
60 | * that a link error can warn you that you should have defined |
61 | * OMIT_UTMP if you didn't want any. Currently HAVE_PUTUTLINE is |
62 | * the only such symbol. |
63 | */ |
64 | #ifndef OMIT_UTMP |
65 | #if !defined HAVE_PUTUTLINE |
66 | #define HAVE_PUTUTLINE |
67 | #endif |
68 | #endif |
69 | |
d6fa1947 |
70 | typedef struct pty_tag *Pty; |
71 | |
72 | /* |
73 | * The pty_signal_pipe, along with the SIGCHLD handler, must be |
74 | * process-global rather than session-specific. |
75 | */ |
76 | static int pty_signal_pipe[2] = { -1, -1 }; /* obviously bogus initial val */ |
77 | |
78 | struct pty_tag { |
79 | Config cfg; |
80 | int master_fd, slave_fd; |
81 | void *frontend; |
82 | char name[FILENAME_MAX]; |
83 | int child_pid; |
84 | int term_width, term_height; |
85 | int child_dead, finished; |
86 | int exit_code; |
2916fa14 |
87 | bufchain output_data; |
d6fa1947 |
88 | }; |
89 | |
90 | /* |
91 | * We store our pty backends in a tree sorted by master fd, so that |
92 | * when we get an uxsel notification we know which backend instance |
93 | * is the owner of the pty that caused it. |
94 | */ |
95 | static int pty_compare_by_fd(void *av, void *bv) |
96 | { |
97 | Pty a = (Pty)av; |
98 | Pty b = (Pty)bv; |
99 | |
100 | if (a->master_fd < b->master_fd) |
101 | return -1; |
102 | else if (a->master_fd > b->master_fd) |
103 | return +1; |
104 | return 0; |
105 | } |
106 | |
107 | static int pty_find_by_fd(void *av, void *bv) |
108 | { |
109 | int a = *(int *)av; |
110 | Pty b = (Pty)bv; |
111 | |
112 | if (a < b->master_fd) |
113 | return -1; |
114 | else if (a > b->master_fd) |
115 | return +1; |
116 | return 0; |
117 | } |
054d8535 |
118 | |
d6fa1947 |
119 | static tree234 *ptys_by_fd = NULL; |
120 | |
121 | /* |
122 | * We also have a tree sorted by child pid, so that when we wait() |
123 | * in response to the signal we know which backend instance is the |
124 | * owner of the process that caused the signal. |
125 | */ |
126 | static int pty_compare_by_pid(void *av, void *bv) |
127 | { |
128 | Pty a = (Pty)av; |
129 | Pty b = (Pty)bv; |
130 | |
131 | if (a->child_pid < b->child_pid) |
132 | return -1; |
133 | else if (a->child_pid > b->child_pid) |
134 | return +1; |
135 | return 0; |
136 | } |
137 | |
138 | static int pty_find_by_pid(void *av, void *bv) |
139 | { |
140 | int a = *(int *)av; |
141 | Pty b = (Pty)bv; |
142 | |
143 | if (a < b->child_pid) |
144 | return -1; |
145 | else if (a > b->child_pid) |
146 | return +1; |
147 | return 0; |
148 | } |
149 | |
150 | static tree234 *ptys_by_pid = NULL; |
151 | |
152 | /* |
153 | * If we are using pty_pre_init(), it will need to have already |
154 | * allocated a pty structure, which we must then return from |
155 | * pty_init() rather than allocating a new one. Here we store that |
156 | * structure between allocation and use. |
157 | * |
158 | * Note that although most of this module is entirely capable of |
159 | * handling multiple ptys in a single process, pty_pre_init() is |
160 | * fundamentally _dependent_ on there being at most one pty per |
161 | * process, so the normal static-data constraints don't apply. |
162 | * |
163 | * Likewise, since utmp is only used via pty_pre_init, it too must |
164 | * be single-instance, so we can declare utmp-related variables |
165 | * here. |
166 | */ |
167 | static Pty single_pty = NULL; |
74aca06d |
168 | |
d4e1d591 |
169 | #ifndef OMIT_UTMP |
170 | static int pty_utmp_helper_pid, pty_utmp_helper_pipe; |
d6fa1947 |
171 | static int pty_stamped_utmp; |
bea25c48 |
172 | static struct utmpx utmp_entry; |
d6fa1947 |
173 | #endif |
174 | |
175 | /* |
176 | * pty_argv is a grievous hack to allow a proper argv to be passed |
177 | * through from the Unix command line. Again, it doesn't really |
178 | * make sense outside a one-pty-per-process setup. |
179 | */ |
180 | char **pty_argv; |
d6fa1947 |
181 | |
182 | static void pty_close(Pty pty); |
2916fa14 |
183 | static void pty_try_write(Pty pty); |
d4e1d591 |
184 | |
d6fa1947 |
185 | #ifndef OMIT_UTMP |
95c47834 |
186 | static void setup_utmp(char *ttyname, char *location) |
755a6d84 |
187 | { |
755a6d84 |
188 | #ifdef HAVE_LASTLOG |
189 | struct lastlog lastlog_entry; |
190 | FILE *lastlog; |
191 | #endif |
192 | struct passwd *pw; |
bea25c48 |
193 | struct timeval tv; |
755a6d84 |
194 | |
195 | pw = getpwuid(getuid()); |
196 | memset(&utmp_entry, 0, sizeof(utmp_entry)); |
197 | utmp_entry.ut_type = USER_PROCESS; |
198 | utmp_entry.ut_pid = getpid(); |
199 | strncpy(utmp_entry.ut_line, ttyname+5, lenof(utmp_entry.ut_line)); |
200 | strncpy(utmp_entry.ut_id, ttyname+8, lenof(utmp_entry.ut_id)); |
201 | strncpy(utmp_entry.ut_user, pw->pw_name, lenof(utmp_entry.ut_user)); |
202 | strncpy(utmp_entry.ut_host, location, lenof(utmp_entry.ut_host)); |
bea25c48 |
203 | /* |
204 | * Apparently there are some architectures where (struct |
205 | * utmpx).ut_tv is not essentially struct timeval (e.g. Linux |
206 | * amd64). Hence the temporary. |
207 | */ |
208 | gettimeofday(&tv, NULL); |
209 | utmp_entry.ut_tv.tv_sec = tv.tv_sec; |
210 | utmp_entry.ut_tv.tv_usec = tv.tv_usec; |
755a6d84 |
211 | |
bea25c48 |
212 | setutxent(); |
213 | pututxline(&utmp_entry); |
214 | endutxent(); |
215 | |
216 | updwtmpx(WTMPX_FILE, &utmp_entry); |
755a6d84 |
217 | |
218 | #ifdef HAVE_LASTLOG |
219 | memset(&lastlog_entry, 0, sizeof(lastlog_entry)); |
220 | strncpy(lastlog_entry.ll_line, ttyname+5, lenof(lastlog_entry.ll_line)); |
221 | strncpy(lastlog_entry.ll_host, location, lenof(lastlog_entry.ll_host)); |
222 | time(&lastlog_entry.ll_time); |
223 | if ((lastlog = fopen(LASTLOG_FILE, "r+")) != NULL) { |
224 | fseek(lastlog, sizeof(lastlog_entry) * getuid(), SEEK_SET); |
225 | fwrite(&lastlog_entry, 1, sizeof(lastlog_entry), lastlog); |
226 | fclose(lastlog); |
227 | } |
228 | #endif |
229 | |
f51dc031 |
230 | pty_stamped_utmp = 1; |
231 | |
755a6d84 |
232 | } |
233 | |
234 | static void cleanup_utmp(void) |
235 | { |
bea25c48 |
236 | struct timeval tv; |
755a6d84 |
237 | |
95c47834 |
238 | if (!pty_stamped_utmp) |
f51dc031 |
239 | return; |
240 | |
755a6d84 |
241 | utmp_entry.ut_type = DEAD_PROCESS; |
242 | memset(utmp_entry.ut_user, 0, lenof(utmp_entry.ut_user)); |
bea25c48 |
243 | gettimeofday(&tv, NULL); |
244 | utmp_entry.ut_tv.tv_sec = tv.tv_sec; |
245 | utmp_entry.ut_tv.tv_usec = tv.tv_usec; |
755a6d84 |
246 | |
bea25c48 |
247 | updwtmpx(WTMPX_FILE, &utmp_entry); |
755a6d84 |
248 | |
249 | memset(utmp_entry.ut_line, 0, lenof(utmp_entry.ut_line)); |
bea25c48 |
250 | utmp_entry.ut_tv.tv_sec = 0; |
251 | utmp_entry.ut_tv.tv_usec = 0; |
755a6d84 |
252 | |
bea25c48 |
253 | setutxent(); |
254 | pututxline(&utmp_entry); |
255 | endutxent(); |
755a6d84 |
256 | |
f51dc031 |
257 | pty_stamped_utmp = 0; /* ensure we never double-cleanup */ |
755a6d84 |
258 | } |
d4e1d591 |
259 | #endif |
755a6d84 |
260 | |
a0e16eb1 |
261 | static void sigchld_handler(int signum) |
262 | { |
74aca06d |
263 | write(pty_signal_pipe[1], "x", 1); |
a0e16eb1 |
264 | } |
265 | |
d4e1d591 |
266 | #ifndef OMIT_UTMP |
755a6d84 |
267 | static void fatal_sig_handler(int signum) |
268 | { |
0f33f9d1 |
269 | putty_signal(signum, SIG_DFL); |
755a6d84 |
270 | cleanup_utmp(); |
271 | setuid(getuid()); |
272 | raise(signum); |
273 | } |
d4e1d591 |
274 | #endif |
755a6d84 |
275 | |
d6fa1947 |
276 | static int pty_open_slave(Pty pty) |
270d2e8d |
277 | { |
d6fa1947 |
278 | if (pty->slave_fd < 0) |
279 | pty->slave_fd = open(pty->name, O_RDWR); |
270d2e8d |
280 | |
d6fa1947 |
281 | return pty->slave_fd; |
270d2e8d |
282 | } |
283 | |
d6fa1947 |
284 | static void pty_open_master(Pty pty) |
1709795f |
285 | { |
be4f86de |
286 | #ifdef BSD_PTYS |
95c47834 |
287 | const char chars1[] = "pqrstuvwxyz"; |
288 | const char chars2[] = "0123456789abcdef"; |
289 | const char *p1, *p2; |
290 | char master_name[20]; |
291 | struct group *gp; |
292 | |
293 | for (p1 = chars1; *p1; p1++) |
294 | for (p2 = chars2; *p2; p2++) { |
295 | sprintf(master_name, "/dev/pty%c%c", *p1, *p2); |
d6fa1947 |
296 | pty->master_fd = open(master_name, O_RDWR); |
297 | if (pty->master_fd >= 0) { |
95c47834 |
298 | if (geteuid() == 0 || |
270d2e8d |
299 | access(master_name, R_OK | W_OK) == 0) { |
300 | /* |
301 | * We must also check at this point that we are |
302 | * able to open the slave side of the pty. We |
303 | * wouldn't want to allocate the wrong master, |
304 | * get all the way down to forking, and _then_ |
305 | * find we're unable to open the slave. |
306 | */ |
d6fa1947 |
307 | strcpy(pty->name, master_name); |
308 | pty->name[5] = 't'; /* /dev/ptyXX -> /dev/ttyXX */ |
270d2e8d |
309 | |
d6fa1947 |
310 | if (pty_open_slave(pty) >= 0 && |
311 | access(pty->name, R_OK | W_OK) == 0) |
270d2e8d |
312 | goto got_one; |
d6fa1947 |
313 | if (pty->slave_fd > 0) |
314 | close(pty->slave_fd); |
315 | pty->slave_fd = -1; |
270d2e8d |
316 | } |
d6fa1947 |
317 | close(pty->master_fd); |
be4f86de |
318 | } |
95c47834 |
319 | } |
be4f86de |
320 | |
95c47834 |
321 | /* If we get here, we couldn't get a tty at all. */ |
322 | fprintf(stderr, "pterm: unable to open a pseudo-terminal device\n"); |
323 | exit(1); |
be4f86de |
324 | |
95c47834 |
325 | got_one: |
95c47834 |
326 | |
327 | /* We need to chown/chmod the /dev/ttyXX device. */ |
328 | gp = getgrnam("tty"); |
d6fa1947 |
329 | chown(pty->name, getuid(), gp ? gp->gr_gid : -1); |
330 | chmod(pty->name, 0600); |
be4f86de |
331 | #else |
d6fa1947 |
332 | pty->master_fd = open("/dev/ptmx", O_RDWR); |
054d8535 |
333 | |
d6fa1947 |
334 | if (pty->master_fd < 0) { |
054d8535 |
335 | perror("/dev/ptmx: open"); |
336 | exit(1); |
337 | } |
338 | |
d6fa1947 |
339 | if (grantpt(pty->master_fd) < 0) { |
054d8535 |
340 | perror("grantpt"); |
341 | exit(1); |
342 | } |
343 | |
d6fa1947 |
344 | if (unlockpt(pty->master_fd) < 0) { |
054d8535 |
345 | perror("unlockpt"); |
346 | exit(1); |
347 | } |
348 | |
d6fa1947 |
349 | pty->name[FILENAME_MAX-1] = '\0'; |
350 | strncpy(pty->name, ptsname(pty->master_fd), FILENAME_MAX-1); |
be4f86de |
351 | #endif |
d6fa1947 |
352 | |
2916fa14 |
353 | { |
354 | /* |
355 | * Set the pty master into non-blocking mode. |
356 | */ |
357 | int i = 1; |
358 | ioctl(pty->master_fd, FIONBIO, &i); |
359 | } |
360 | |
d6fa1947 |
361 | if (!ptys_by_fd) |
362 | ptys_by_fd = newtree234(pty_compare_by_fd); |
363 | add234(ptys_by_fd, pty); |
95c47834 |
364 | } |
054d8535 |
365 | |
95c47834 |
366 | /* |
367 | * Pre-initialisation. This is here to get around the fact that GTK |
368 | * doesn't like being run in setuid/setgid programs (probably |
369 | * sensibly). So before we initialise GTK - and therefore before we |
370 | * even process the command line - we check to see if we're running |
371 | * set[ug]id. If so, we open our pty master _now_, chown it as |
372 | * necessary, and drop privileges. We can always close it again |
373 | * later. If we're potentially going to be doing utmp as well, we |
374 | * also fork off a utmp helper process and communicate with it by |
375 | * means of a pipe; the utmp helper will keep privileges in order |
376 | * to clean up utmp when we exit (i.e. when its end of our pipe |
377 | * closes). |
378 | */ |
379 | void pty_pre_init(void) |
380 | { |
d6fa1947 |
381 | Pty pty; |
382 | |
d4e1d591 |
383 | #ifndef OMIT_UTMP |
95c47834 |
384 | pid_t pid; |
385 | int pipefd[2]; |
d4e1d591 |
386 | #endif |
95c47834 |
387 | |
d6fa1947 |
388 | pty = single_pty = snew(struct pty_tag); |
2916fa14 |
389 | bufchain_init(&pty->output_data); |
d6fa1947 |
390 | |
0f33f9d1 |
391 | /* set the child signal handler straight away; it needs to be set |
392 | * before we ever fork. */ |
393 | putty_signal(SIGCHLD, sigchld_handler); |
d6fa1947 |
394 | pty->master_fd = pty->slave_fd = -1; |
395 | #ifndef OMIT_UTMP |
396 | pty_stamped_utmp = FALSE; |
397 | #endif |
95c47834 |
398 | |
399 | if (geteuid() != getuid() || getegid() != getgid()) { |
d6fa1947 |
400 | pty_open_master(pty); |
39baeaa4 |
401 | } |
402 | |
95c47834 |
403 | #ifndef OMIT_UTMP |
39baeaa4 |
404 | /* |
95c47834 |
405 | * Fork off the utmp helper. |
755a6d84 |
406 | */ |
95c47834 |
407 | if (pipe(pipefd) < 0) { |
408 | perror("pterm: pipe"); |
409 | exit(1); |
410 | } |
411 | pid = fork(); |
412 | if (pid < 0) { |
413 | perror("pterm: fork"); |
414 | exit(1); |
415 | } else if (pid == 0) { |
416 | char display[128], buffer[128]; |
417 | int dlen, ret; |
418 | |
419 | close(pipefd[1]); |
420 | /* |
421 | * Now sit here until we receive a display name from the |
422 | * other end of the pipe, and then stamp utmp. Unstamp utmp |
423 | * again, and exit, when the pipe closes. |
424 | */ |
425 | |
426 | dlen = 0; |
427 | while (1) { |
428 | |
429 | ret = read(pipefd[0], buffer, lenof(buffer)); |
430 | if (ret <= 0) { |
431 | cleanup_utmp(); |
0f33f9d1 |
432 | _exit(0); |
95c47834 |
433 | } else if (!pty_stamped_utmp) { |
434 | if (dlen < lenof(display)) |
435 | memcpy(display+dlen, buffer, |
436 | min(ret, lenof(display)-dlen)); |
437 | if (buffer[ret-1] == '\0') { |
438 | /* |
439 | * Now we have a display name. NUL-terminate |
440 | * it, and stamp utmp. |
441 | */ |
442 | display[lenof(display)-1] = '\0'; |
443 | /* |
444 | * Trap as many fatal signals as we can in the |
445 | * hope of having the best possible chance to |
446 | * clean up utmp before termination. We are |
447 | * unfortunately unprotected against SIGKILL, |
448 | * but that's life. |
449 | */ |
0f33f9d1 |
450 | putty_signal(SIGHUP, fatal_sig_handler); |
451 | putty_signal(SIGINT, fatal_sig_handler); |
452 | putty_signal(SIGQUIT, fatal_sig_handler); |
453 | putty_signal(SIGILL, fatal_sig_handler); |
454 | putty_signal(SIGABRT, fatal_sig_handler); |
455 | putty_signal(SIGFPE, fatal_sig_handler); |
456 | putty_signal(SIGPIPE, fatal_sig_handler); |
457 | putty_signal(SIGALRM, fatal_sig_handler); |
458 | putty_signal(SIGTERM, fatal_sig_handler); |
459 | putty_signal(SIGSEGV, fatal_sig_handler); |
460 | putty_signal(SIGUSR1, fatal_sig_handler); |
461 | putty_signal(SIGUSR2, fatal_sig_handler); |
755a6d84 |
462 | #ifdef SIGBUS |
0f33f9d1 |
463 | putty_signal(SIGBUS, fatal_sig_handler); |
755a6d84 |
464 | #endif |
465 | #ifdef SIGPOLL |
0f33f9d1 |
466 | putty_signal(SIGPOLL, fatal_sig_handler); |
755a6d84 |
467 | #endif |
468 | #ifdef SIGPROF |
0f33f9d1 |
469 | putty_signal(SIGPROF, fatal_sig_handler); |
755a6d84 |
470 | #endif |
471 | #ifdef SIGSYS |
0f33f9d1 |
472 | putty_signal(SIGSYS, fatal_sig_handler); |
755a6d84 |
473 | #endif |
474 | #ifdef SIGTRAP |
0f33f9d1 |
475 | putty_signal(SIGTRAP, fatal_sig_handler); |
755a6d84 |
476 | #endif |
477 | #ifdef SIGVTALRM |
0f33f9d1 |
478 | putty_signal(SIGVTALRM, fatal_sig_handler); |
755a6d84 |
479 | #endif |
480 | #ifdef SIGXCPU |
0f33f9d1 |
481 | putty_signal(SIGXCPU, fatal_sig_handler); |
755a6d84 |
482 | #endif |
483 | #ifdef SIGXFSZ |
0f33f9d1 |
484 | putty_signal(SIGXFSZ, fatal_sig_handler); |
755a6d84 |
485 | #endif |
486 | #ifdef SIGIO |
0f33f9d1 |
487 | putty_signal(SIGIO, fatal_sig_handler); |
95c47834 |
488 | #endif |
d6fa1947 |
489 | setup_utmp(pty->name, display); |
95c47834 |
490 | } |
491 | } |
492 | } |
493 | } else { |
494 | close(pipefd[0]); |
495 | pty_utmp_helper_pid = pid; |
496 | pty_utmp_helper_pipe = pipefd[1]; |
497 | } |
755a6d84 |
498 | #endif |
95c47834 |
499 | |
500 | /* Drop privs. */ |
501 | { |
95c47834 |
502 | #ifndef HAVE_NO_SETRESUID |
d4e1d591 |
503 | int gid = getgid(), uid = getuid(); |
95c47834 |
504 | int setresgid(gid_t, gid_t, gid_t); |
505 | int setresuid(uid_t, uid_t, uid_t); |
506 | setresgid(gid, gid, gid); |
507 | setresuid(uid, uid, uid); |
508 | #else |
509 | setgid(getgid()); |
510 | setuid(getuid()); |
511 | #endif |
512 | } |
513 | } |
514 | |
d6fa1947 |
515 | int pty_real_select_result(Pty pty, int event, int status) |
74aca06d |
516 | { |
517 | char buf[4096]; |
518 | int ret; |
519 | int finished = FALSE; |
520 | |
d6fa1947 |
521 | if (event < 0) { |
74aca06d |
522 | /* |
d6fa1947 |
523 | * We've been called because our child process did |
524 | * something. `status' tells us what. |
74aca06d |
525 | */ |
d6fa1947 |
526 | if ((WIFEXITED(status) || WIFSIGNALED(status))) { |
74aca06d |
527 | /* |
d6fa1947 |
528 | * The primary child process died. We could keep |
529 | * the terminal open for remaining subprocesses to |
530 | * output to, but conventional wisdom seems to feel |
531 | * that that's the Wrong Thing for an xterm-alike, |
532 | * so we bail out now (though we don't necessarily |
533 | * _close_ the window, depending on the state of |
534 | * Close On Exit). This would be easy enough to |
535 | * change or make configurable if necessary. |
74aca06d |
536 | */ |
d6fa1947 |
537 | pty->exit_code = status; |
538 | pty->child_dead = TRUE; |
539 | del234(ptys_by_pid, pty); |
74aca06d |
540 | finished = TRUE; |
74aca06d |
541 | } |
d6fa1947 |
542 | } else { |
543 | if (event == 1) { |
74aca06d |
544 | |
d6fa1947 |
545 | ret = read(pty->master_fd, buf, sizeof(buf)); |
74aca06d |
546 | |
d6fa1947 |
547 | /* |
548 | * Clean termination condition is that either ret == 0, or ret |
549 | * < 0 and errno == EIO. Not sure why the latter, but it seems |
550 | * to happen. Boo. |
551 | */ |
552 | if (ret == 0 || (ret < 0 && errno == EIO)) { |
74aca06d |
553 | /* |
d6fa1947 |
554 | * We assume a clean exit if the pty has closed but the |
555 | * actual child process hasn't. The only way I can |
556 | * imagine this happening is if it detaches itself from |
557 | * the pty and goes daemonic - in which case the |
558 | * expected usage model would precisely _not_ be for |
559 | * the pterm window to hang around! |
74aca06d |
560 | */ |
74aca06d |
561 | finished = TRUE; |
d6fa1947 |
562 | if (!pty->child_dead) |
563 | pty->exit_code = 0; |
564 | } else if (ret < 0) { |
565 | perror("read pty master"); |
566 | exit(1); |
567 | } else if (ret > 0) { |
568 | from_backend(pty->frontend, 0, buf, ret); |
74aca06d |
569 | } |
2916fa14 |
570 | } else if (event == 2) { |
571 | /* |
572 | * Attempt to send data down the pty. |
573 | */ |
574 | pty_try_write(pty); |
575 | } |
74aca06d |
576 | } |
577 | |
d6fa1947 |
578 | if (finished && !pty->finished) { |
579 | uxsel_del(pty->master_fd); |
580 | pty_close(pty); |
581 | pty->master_fd = -1; |
74aca06d |
582 | |
d6fa1947 |
583 | pty->finished = TRUE; |
74aca06d |
584 | |
585 | /* |
586 | * This is a slight layering-violation sort of hack: only |
587 | * if we're not closing on exit (COE is set to Never, or to |
588 | * Only On Clean and it wasn't a clean exit) do we output a |
589 | * `terminated' message. |
590 | */ |
d6fa1947 |
591 | if (pty->cfg.close_on_exit == FORCE_OFF || |
592 | (pty->cfg.close_on_exit == AUTO && pty->exit_code != 0)) { |
74aca06d |
593 | char message[512]; |
d6fa1947 |
594 | if (WIFEXITED(pty->exit_code)) |
74aca06d |
595 | sprintf(message, "\r\n[pterm: process terminated with exit" |
d6fa1947 |
596 | " code %d]\r\n", WEXITSTATUS(pty->exit_code)); |
597 | else if (WIFSIGNALED(pty->exit_code)) |
74aca06d |
598 | #ifdef HAVE_NO_STRSIGNAL |
599 | sprintf(message, "\r\n[pterm: process terminated on signal" |
d6fa1947 |
600 | " %d]\r\n", WTERMSIG(pty->exit_code)); |
74aca06d |
601 | #else |
602 | sprintf(message, "\r\n[pterm: process terminated on signal" |
d6fa1947 |
603 | " %d (%.400s)]\r\n", WTERMSIG(pty->exit_code), |
604 | strsignal(WTERMSIG(pty->exit_code))); |
74aca06d |
605 | #endif |
d6fa1947 |
606 | from_backend(pty->frontend, 0, message, strlen(message)); |
74aca06d |
607 | } |
39934deb |
608 | |
d6fa1947 |
609 | notify_remote_exit(pty->frontend); |
74aca06d |
610 | } |
d6fa1947 |
611 | |
74aca06d |
612 | return !finished; |
613 | } |
614 | |
d6fa1947 |
615 | int pty_select_result(int fd, int event) |
74aca06d |
616 | { |
d6fa1947 |
617 | int ret = TRUE; |
618 | Pty pty; |
619 | |
620 | if (fd == pty_signal_pipe[0]) { |
621 | pid_t pid; |
622 | int ipid; |
623 | int status; |
624 | char c[1]; |
625 | |
626 | read(pty_signal_pipe[0], c, 1); /* ignore its value; it'll be `x' */ |
627 | |
628 | do { |
629 | pid = waitpid(-1, &status, WNOHANG); |
630 | |
631 | ipid = pid; |
632 | pty = find234(ptys_by_pid, &pid, pty_find_by_pid); |
633 | |
634 | if (pty) |
635 | ret = ret && pty_real_select_result(pty, -1, status); |
636 | } while (pid > 0); |
637 | } else { |
638 | pty = find234(ptys_by_fd, &fd, pty_find_by_fd); |
639 | |
640 | if (pty) |
641 | ret = ret && pty_real_select_result(pty, event, 0); |
642 | } |
643 | |
644 | return ret; |
645 | } |
646 | |
647 | static void pty_uxsel_setup(Pty pty) |
648 | { |
2916fa14 |
649 | int rwx; |
650 | |
651 | rwx = 1; /* always want to read from pty */ |
652 | if (bufchain_size(&pty->output_data)) |
653 | rwx |= 2; /* might also want to write to it */ |
654 | uxsel_set(pty->master_fd, rwx, pty_select_result); |
d6fa1947 |
655 | |
656 | /* |
657 | * In principle this only needs calling once for all pty |
658 | * backend instances, but it's simplest just to call it every |
659 | * time; uxsel won't mind. |
660 | */ |
74aca06d |
661 | uxsel_set(pty_signal_pipe[0], 1, pty_select_result); |
662 | } |
663 | |
95c47834 |
664 | /* |
665 | * Called to set up the pty. |
666 | * |
667 | * Returns an error message, or NULL on success. |
668 | * |
669 | * Also places the canonical host name into `realhost'. It must be |
670 | * freed by the caller. |
671 | */ |
cbe2d68f |
672 | static const char *pty_init(void *frontend, void **backend_handle, Config *cfg, |
79bf227b |
673 | char *host, int port, char **realhost, int nodelay, |
674 | int keepalive) |
95c47834 |
675 | { |
676 | int slavefd; |
677 | pid_t pid, pgrp; |
c13772b1 |
678 | #ifndef NOT_X_WINDOWS /* for Mac OS X native compilation */ |
7af753e6 |
679 | long windowid; |
c13772b1 |
680 | #endif |
d6fa1947 |
681 | Pty pty; |
95c47834 |
682 | |
d6fa1947 |
683 | if (single_pty) { |
684 | pty = single_pty; |
685 | } else { |
686 | pty = snew(struct pty_tag); |
687 | pty->master_fd = pty->slave_fd = -1; |
688 | #ifndef OMIT_UTMP |
689 | pty_stamped_utmp = FALSE; |
690 | #endif |
691 | } |
692 | |
693 | pty->frontend = frontend; |
28d00fe4 |
694 | *backend_handle = NULL; /* we can't sensibly use this, sadly */ |
695 | |
d6fa1947 |
696 | pty->cfg = *cfg; /* structure copy */ |
697 | pty->term_width = cfg->width; |
698 | pty->term_height = cfg->height; |
f278d6f8 |
699 | |
d6fa1947 |
700 | if (pty->master_fd < 0) |
701 | pty_open_master(pty); |
95c47834 |
702 | |
703 | /* |
704 | * Set the backspace character to be whichever of ^H and ^? is |
705 | * specified by bksp_is_delete. |
706 | */ |
707 | { |
708 | struct termios attrs; |
d6fa1947 |
709 | tcgetattr(pty->master_fd, &attrs); |
86916870 |
710 | attrs.c_cc[VERASE] = cfg->bksp_is_delete ? '\177' : '\010'; |
d6fa1947 |
711 | tcsetattr(pty->master_fd, TCSANOW, &attrs); |
95c47834 |
712 | } |
713 | |
d4e1d591 |
714 | #ifndef OMIT_UTMP |
95c47834 |
715 | /* |
716 | * Stamp utmp (that is, tell the utmp helper process to do so), |
717 | * or not. |
718 | */ |
58dcb876 |
719 | if (!cfg->stamp_utmp) { |
95c47834 |
720 | close(pty_utmp_helper_pipe); /* just let the child process die */ |
58dcb876 |
721 | pty_utmp_helper_pipe = -1; |
722 | } else { |
d6fa1947 |
723 | char *location = get_x_display(pty->frontend); |
95c47834 |
724 | int len = strlen(location)+1, pos = 0; /* +1 to include NUL */ |
725 | while (pos < len) { |
726 | int ret = write(pty_utmp_helper_pipe, location+pos, len - pos); |
727 | if (ret < 0) { |
728 | perror("pterm: writing to utmp helper process"); |
729 | close(pty_utmp_helper_pipe); /* arrgh, just give up */ |
58dcb876 |
730 | pty_utmp_helper_pipe = -1; |
95c47834 |
731 | break; |
732 | } |
733 | pos += ret; |
734 | } |
735 | } |
d4e1d591 |
736 | #endif |
755a6d84 |
737 | |
c13772b1 |
738 | #ifndef NOT_X_WINDOWS /* for Mac OS X native compilation */ |
d6fa1947 |
739 | windowid = get_windowid(pty->frontend); |
c13772b1 |
740 | #endif |
7af753e6 |
741 | |
755a6d84 |
742 | /* |
054d8535 |
743 | * Fork and execute the command. |
744 | */ |
745 | pid = fork(); |
746 | if (pid < 0) { |
747 | perror("fork"); |
88e6b9ca |
748 | exit(1); |
054d8535 |
749 | } |
750 | |
751 | if (pid == 0) { |
752 | int i; |
753 | /* |
754 | * We are the child. |
755 | */ |
d37c2d81 |
756 | |
d6fa1947 |
757 | slavefd = pty_open_slave(pty); |
d37c2d81 |
758 | if (slavefd < 0) { |
759 | perror("slave pty: open"); |
0f33f9d1 |
760 | _exit(1); |
d37c2d81 |
761 | } |
762 | |
d6fa1947 |
763 | close(pty->master_fd); |
054d8535 |
764 | fcntl(slavefd, F_SETFD, 0); /* don't close on exec */ |
765 | dup2(slavefd, 0); |
766 | dup2(slavefd, 1); |
767 | dup2(slavefd, 2); |
768 | setsid(); |
bbaa7993 |
769 | #ifdef TIOCSCTTY |
d37c2d81 |
770 | ioctl(slavefd, TIOCSCTTY, 1); |
bbaa7993 |
771 | #endif |
d37c2d81 |
772 | pgrp = getpid(); |
773 | tcsetpgrp(slavefd, pgrp); |
ea0716c6 |
774 | setpgid(pgrp, pgrp); |
d6fa1947 |
775 | close(open(pty->name, O_WRONLY, 0)); |
ea0716c6 |
776 | setpgid(pgrp, pgrp); |
054d8535 |
777 | /* Close everything _else_, for tidiness. */ |
778 | for (i = 3; i < 1024; i++) |
779 | close(i); |
fe9548aa |
780 | { |
30d1257c |
781 | char *term_env_var = dupprintf("TERM=%s", cfg->termtype); |
fe9548aa |
782 | putenv(term_env_var); |
30d1257c |
783 | /* We mustn't free term_env_var, as putenv links it into the |
784 | * environment in place. |
785 | */ |
fe9548aa |
786 | } |
c13772b1 |
787 | #ifndef NOT_X_WINDOWS /* for Mac OS X native compilation */ |
7af753e6 |
788 | { |
30d1257c |
789 | char *windowid_env_var = dupprintf("WINDOWID=%ld", windowid); |
7af753e6 |
790 | putenv(windowid_env_var); |
30d1257c |
791 | /* We mustn't free windowid_env_var, as putenv links it into the |
792 | * environment in place. |
793 | */ |
7af753e6 |
794 | } |
c13772b1 |
795 | #endif |
73feed4f |
796 | { |
797 | char *e = cfg->environmt; |
798 | char *var, *varend, *val, *varval; |
799 | while (*e) { |
800 | var = e; |
801 | while (*e && *e != '\t') e++; |
802 | varend = e; |
803 | if (*e == '\t') e++; |
804 | val = e; |
805 | while (*e) e++; |
806 | e++; |
807 | |
808 | varval = dupprintf("%.*s=%s", varend-var, var, val); |
809 | putenv(varval); |
810 | /* |
811 | * We must not free varval, since putenv links it |
812 | * into the environment _in place_. Weird, but |
813 | * there we go. Memory usage will be rationalised |
814 | * as soon as we exec anyway. |
815 | */ |
816 | } |
817 | } |
818 | |
8bf5c419 |
819 | /* |
820 | * SIGINT and SIGQUIT may have been set to ignored by our |
821 | * parent, particularly by things like sh -c 'pterm &' and |
15b5d988 |
822 | * some window managers. SIGCHLD, meanwhile, was blocked |
823 | * during pt_main() startup. Reverse all this for our child |
824 | * process. |
8bf5c419 |
825 | */ |
0f33f9d1 |
826 | putty_signal(SIGINT, SIG_DFL); |
827 | putty_signal(SIGQUIT, SIG_DFL); |
15b5d988 |
828 | block_signal(SIGCHLD, 0); |
6169c758 |
829 | if (pty_argv) |
830 | execvp(pty_argv[0], pty_argv); |
c8ee61b9 |
831 | else { |
832 | char *shell = getenv("SHELL"); |
833 | char *shellname; |
86916870 |
834 | if (cfg->login_shell) { |
c8ee61b9 |
835 | char *p = strrchr(shell, '/'); |
3d88e64d |
836 | shellname = snewn(2+strlen(shell), char); |
c8ee61b9 |
837 | p = p ? p+1 : shell; |
838 | sprintf(shellname, "-%s", p); |
839 | } else |
840 | shellname = shell; |
30264db9 |
841 | execl(getenv("SHELL"), shellname, (void *)NULL); |
c8ee61b9 |
842 | } |
843 | |
054d8535 |
844 | /* |
845 | * If we're here, exec has gone badly foom. |
846 | */ |
847 | perror("exec"); |
0f33f9d1 |
848 | _exit(127); |
054d8535 |
849 | } else { |
d6fa1947 |
850 | pty->child_pid = pid; |
851 | pty->child_dead = FALSE; |
852 | pty->finished = FALSE; |
853 | if (pty->slave_fd > 0) |
854 | close(pty->slave_fd); |
855 | if (!ptys_by_pid) |
856 | ptys_by_pid = newtree234(pty_compare_by_pid); |
857 | add234(ptys_by_pid, pty); |
270d2e8d |
858 | } |
054d8535 |
859 | |
d6fa1947 |
860 | if (pty_signal_pipe[0] < 0 && pipe(pty_signal_pipe) < 0) { |
74aca06d |
861 | perror("pipe"); |
862 | exit(1); |
863 | } |
d6fa1947 |
864 | pty_uxsel_setup(pty); |
865 | |
866 | *backend_handle = pty; |
74aca06d |
867 | |
5617c1e6 |
868 | *realhost = dupprintf("\0"); |
869 | |
1709795f |
870 | return NULL; |
871 | } |
872 | |
86916870 |
873 | static void pty_reconfig(void *handle, Config *cfg) |
874 | { |
d6fa1947 |
875 | Pty pty = (Pty)handle; |
6b0eeb4e |
876 | /* |
877 | * We don't have much need to reconfigure this backend, but |
878 | * unfortunately we do need to pick up the setting of Close On |
879 | * Exit so we know whether to give a `terminated' message. |
880 | */ |
d6fa1947 |
881 | pty->cfg = *cfg; /* structure copy */ |
86916870 |
882 | } |
883 | |
884 | /* |
6b0eeb4e |
885 | * Stub routine (never called in pterm). |
cb60dcb3 |
886 | */ |
887 | static void pty_free(void *handle) |
888 | { |
d6fa1947 |
889 | Pty pty = (Pty)handle; |
890 | |
891 | /* Either of these may fail `not found'. That's fine with us. */ |
892 | del234(ptys_by_pid, pty); |
893 | del234(ptys_by_fd, pty); |
894 | |
895 | sfree(pty); |
cb60dcb3 |
896 | } |
897 | |
2916fa14 |
898 | static void pty_try_write(Pty pty) |
899 | { |
900 | void *data; |
901 | int len, ret; |
902 | |
903 | assert(pty->master_fd >= 0); |
904 | |
905 | while (bufchain_size(&pty->output_data) > 0) { |
906 | bufchain_prefix(&pty->output_data, &data, &len); |
907 | ret = write(pty->master_fd, data, len); |
908 | |
909 | if (ret < 0 && (errno == EWOULDBLOCK)) { |
910 | /* |
911 | * We've sent all we can for the moment. |
912 | */ |
913 | break; |
914 | } |
915 | if (ret < 0) { |
916 | perror("write pty master"); |
917 | exit(1); |
918 | } |
919 | bufchain_consume(&pty->output_data, ret); |
920 | } |
921 | |
922 | pty_uxsel_setup(pty); |
923 | } |
924 | |
cb60dcb3 |
925 | /* |
1709795f |
926 | * Called to send data down the pty. |
927 | */ |
28d00fe4 |
928 | static int pty_send(void *handle, char *buf, int len) |
1709795f |
929 | { |
d6fa1947 |
930 | Pty pty = (Pty)handle; |
931 | |
932 | if (pty->master_fd < 0) |
2916fa14 |
933 | return 0; /* ignore all writes if fd closed */ |
90cfd8f4 |
934 | |
2916fa14 |
935 | bufchain_add(&pty->output_data, buf, len); |
936 | pty_try_write(pty); |
937 | |
938 | return bufchain_size(&pty->output_data); |
1709795f |
939 | } |
940 | |
d6fa1947 |
941 | static void pty_close(Pty pty) |
90cfd8f4 |
942 | { |
d6fa1947 |
943 | if (pty->master_fd >= 0) { |
944 | close(pty->master_fd); |
945 | pty->master_fd = -1; |
90cfd8f4 |
946 | } |
d4e1d591 |
947 | #ifndef OMIT_UTMP |
58dcb876 |
948 | if (pty_utmp_helper_pipe >= 0) { |
949 | close(pty_utmp_helper_pipe); /* this causes utmp to be cleaned up */ |
950 | pty_utmp_helper_pipe = -1; |
951 | } |
d4e1d591 |
952 | #endif |
90cfd8f4 |
953 | } |
954 | |
1709795f |
955 | /* |
956 | * Called to query the current socket sendability status. |
957 | */ |
28d00fe4 |
958 | static int pty_sendbuffer(void *handle) |
1709795f |
959 | { |
d6fa1947 |
960 | /* Pty pty = (Pty)handle; */ |
1709795f |
961 | return 0; |
962 | } |
963 | |
964 | /* |
965 | * Called to set the size of the window |
966 | */ |
28d00fe4 |
967 | static void pty_size(void *handle, int width, int height) |
1709795f |
968 | { |
d6fa1947 |
969 | Pty pty = (Pty)handle; |
88e6b9ca |
970 | struct winsize size; |
971 | |
d6fa1947 |
972 | pty->term_width = width; |
973 | pty->term_height = height; |
f278d6f8 |
974 | |
d6fa1947 |
975 | size.ws_row = (unsigned short)pty->term_height; |
976 | size.ws_col = (unsigned short)pty->term_width; |
977 | size.ws_xpixel = (unsigned short) pty->term_width * |
978 | font_dimension(pty->frontend, 0); |
979 | size.ws_ypixel = (unsigned short) pty->term_height * |
980 | font_dimension(pty->frontend, 1); |
981 | ioctl(pty->master_fd, TIOCSWINSZ, (void *)&size); |
1709795f |
982 | return; |
983 | } |
984 | |
985 | /* |
986 | * Send special codes. |
987 | */ |
28d00fe4 |
988 | static void pty_special(void *handle, Telnet_Special code) |
1709795f |
989 | { |
d6fa1947 |
990 | /* Pty pty = (Pty)handle; */ |
1709795f |
991 | /* Do nothing! */ |
992 | return; |
993 | } |
994 | |
125105d1 |
995 | /* |
996 | * Return a list of the special codes that make sense in this |
997 | * protocol. |
998 | */ |
999 | static const struct telnet_special *pty_get_specials(void *handle) |
1000 | { |
d6fa1947 |
1001 | /* Pty pty = (Pty)handle; */ |
125105d1 |
1002 | /* |
1003 | * Hmm. When I get round to having this actually usable, it |
1004 | * might be quite nice to have the ability to deliver a few |
1005 | * well chosen signals to the child process - SIGINT, SIGTERM, |
1006 | * SIGKILL at least. |
1007 | */ |
1008 | return NULL; |
1009 | } |
1010 | |
28d00fe4 |
1011 | static Socket pty_socket(void *handle) |
1709795f |
1012 | { |
d6fa1947 |
1013 | /* Pty pty = (Pty)handle; */ |
1709795f |
1014 | return NULL; /* shouldn't ever be needed */ |
1015 | } |
1016 | |
28d00fe4 |
1017 | static int pty_sendok(void *handle) |
1709795f |
1018 | { |
d6fa1947 |
1019 | /* Pty pty = (Pty)handle; */ |
1709795f |
1020 | return 1; |
1021 | } |
1022 | |
28d00fe4 |
1023 | static void pty_unthrottle(void *handle, int backlog) |
1709795f |
1024 | { |
d6fa1947 |
1025 | /* Pty pty = (Pty)handle; */ |
1709795f |
1026 | /* do nothing */ |
1027 | } |
1028 | |
28d00fe4 |
1029 | static int pty_ldisc(void *handle, int option) |
1709795f |
1030 | { |
d6fa1947 |
1031 | /* Pty pty = (Pty)handle; */ |
1709795f |
1032 | return 0; /* neither editing nor echoing */ |
1033 | } |
1034 | |
b9d7bcad |
1035 | static void pty_provide_ldisc(void *handle, void *ldisc) |
1036 | { |
d6fa1947 |
1037 | /* Pty pty = (Pty)handle; */ |
b9d7bcad |
1038 | /* This is a stub. */ |
1039 | } |
1040 | |
a8327734 |
1041 | static void pty_provide_logctx(void *handle, void *logctx) |
1042 | { |
d6fa1947 |
1043 | /* Pty pty = (Pty)handle; */ |
a8327734 |
1044 | /* This is a stub. */ |
1045 | } |
1046 | |
28d00fe4 |
1047 | static int pty_exitcode(void *handle) |
1709795f |
1048 | { |
d6fa1947 |
1049 | Pty pty = (Pty)handle; |
1050 | if (!pty->finished) |
90cfd8f4 |
1051 | return -1; /* not dead yet */ |
1052 | else |
d6fa1947 |
1053 | return pty->exit_code; |
1709795f |
1054 | } |
1055 | |
f89c3294 |
1056 | static int pty_cfg_info(void *handle) |
1057 | { |
d6fa1947 |
1058 | /* Pty pty = (Pty)handle; */ |
f89c3294 |
1059 | return 0; |
1060 | } |
1061 | |
1709795f |
1062 | Backend pty_backend = { |
1063 | pty_init, |
cb60dcb3 |
1064 | pty_free, |
86916870 |
1065 | pty_reconfig, |
1709795f |
1066 | pty_send, |
1067 | pty_sendbuffer, |
1068 | pty_size, |
1069 | pty_special, |
125105d1 |
1070 | pty_get_specials, |
1709795f |
1071 | pty_socket, |
1072 | pty_exitcode, |
1073 | pty_sendok, |
1074 | pty_ldisc, |
b9d7bcad |
1075 | pty_provide_ldisc, |
a8327734 |
1076 | pty_provide_logctx, |
1709795f |
1077 | pty_unthrottle, |
f89c3294 |
1078 | pty_cfg_info, |
1709795f |
1079 | 1 |
1080 | }; |