1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1997 Brian Somers <brian@Awfulhak.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD: stable/11/usr.sbin/pppctl/pppctl.c 330449 2018-03-05 07:26:05Z eadler $");
31
32#include <sys/types.h>
33
34#include <sys/socket.h>
35#include <netinet/in.h>
36#include <arpa/inet.h>
37#include <sys/un.h>
38#include <netdb.h>
39
40#include <sys/time.h>
41#include <err.h>
42#include <errno.h>
43#include <histedit.h>
44#include <semaphore.h>
45#include <pthread.h>
46#include <setjmp.h>
47#include <signal.h>
48#include <stdio.h>
49#include <stdlib.h>
50#include <string.h>
51#include <time.h>
52#include <unistd.h>
53
54#define LINELEN 2048
55
56/* Data passed to the threads we create */
57struct thread_data {
58    EditLine *edit;		/* libedit stuff */
59    History *hist;		/* libedit stuff */
60    pthread_t trm;		/* Terminal thread (for pthread_kill()) */
61    int ppp;			/* ppp descriptor */
62};
63
64/* Flags passed to Receive() */
65#define REC_PASSWD  (1)		/* Handle a password request from ppp */
66#define REC_SHOW    (2)		/* Show everything except prompts */
67#define REC_VERBOSE (4)		/* Show everything */
68
69static char *passwd;
70static char *prompt;		/* Tell libedit what the current prompt is */
71static int data = -1;		/* setjmp() has been done when data != -1 */
72static jmp_buf pppdead;		/* Jump the Terminal thread out of el_gets() */
73static int timetogo;		/* Tell the Monitor thread to exit */
74static sem_t sem_select;	/* select() co-ordination between threads */
75static int TimedOut;		/* Set if our connect() timed out */
76static int want_sem_post;	/* Need to let the Monitor thread in ? */
77
78/*
79 * How to use pppctl...
80 */
81static int
82usage()
83{
84    fprintf(stderr, "usage: pppctl [-v] [-t n] [-p passwd] "
85            "Port|LocalSock [command[;command]...]\n");
86    fprintf(stderr, "              -v tells pppctl to output all"
87            " conversation\n");
88    fprintf(stderr, "              -t n specifies a timeout of n"
89            " seconds when connecting (default 2)\n");
90    fprintf(stderr, "              -p passwd specifies your password\n");
91    exit(1);
92}
93
94/*
95 * Handle the SIGALRM received due to a connect() timeout.
96 */
97static void
98Timeout(int Sig)
99{
100    TimedOut = 1;
101}
102
103/*
104 * A callback routine for libedit to find out what the current prompt is.
105 * All the work is done in Receive() below.
106 */
107static char *
108GetPrompt(EditLine *e)
109{
110    if (prompt == NULL)
111        prompt = "";
112    return prompt;
113}
114
115/*
116 * Receive data from the ppp descriptor.
117 * We also handle password prompts here (if asked via the `display' arg)
118 * and buffer what our prompt looks like (via the `prompt' global).
119 */
120static int
121Receive(int fd, int display)
122{
123    static char Buffer[LINELEN];
124    struct timeval t;
125    int Result;
126    char *last;
127    fd_set f;
128    int len;
129    int err;
130
131    FD_ZERO(&f);
132    FD_SET(fd, &f);
133    t.tv_sec = 0;
134    t.tv_usec = 100000;
135    prompt = Buffer;
136    len = 0;
137
138    while (Result = read(fd, Buffer+len, sizeof(Buffer)-len-1), Result != -1) {
139        if (Result == 0) {
140            Result = -1;
141            break;
142        }
143        len += Result;
144        Buffer[len] = '\0';
145        if (len > 2 && !strcmp(Buffer+len-2, "> ")) {
146            prompt = strrchr(Buffer, '\n');
147            if (display & (REC_SHOW|REC_VERBOSE)) {
148                if (display & REC_VERBOSE)
149                    last = Buffer+len-1;
150                else
151                    last = prompt;
152                if (last) {
153                    last++;
154                    write(STDOUT_FILENO, Buffer, last-Buffer);
155                }
156            }
157            prompt = prompt == NULL ? Buffer : prompt+1;
158            for (last = Buffer+len-2; last > Buffer && *last != ' '; last--)
159                ;
160            if (last > Buffer+3 && !strncmp(last-3, " on", 3)) {
161                 /* a password is required ! */
162                 if (display & REC_PASSWD) {
163                    /* password time */
164                    if (!passwd)
165                        passwd = getpass("Password: ");
166                    sprintf(Buffer, "passwd %s\n", passwd);
167                    memset(passwd, '\0', strlen(passwd));
168                    if (display & REC_VERBOSE)
169                        write(STDOUT_FILENO, Buffer, strlen(Buffer));
170                    write(fd, Buffer, strlen(Buffer));
171                    memset(Buffer, '\0', strlen(Buffer));
172                    return Receive(fd, display & ~REC_PASSWD);
173                }
174                Result = 1;
175            } else
176                Result = 0;
177            break;
178        } else
179            prompt = "";
180        if (len == sizeof Buffer - 1) {
181            int flush;
182            if ((last = strrchr(Buffer, '\n')) == NULL)
183                /* Yeuch - this is one mother of a line ! */
184                flush = sizeof Buffer / 2;
185            else
186                flush = last - Buffer + 1;
187            write(STDOUT_FILENO, Buffer, flush);
188            strcpy(Buffer, Buffer + flush);
189            len -= flush;
190        }
191        if ((Result = select(fd + 1, &f, NULL, NULL, &t)) <= 0) {
192            err = Result == -1 ? errno : 0;
193            if (len)
194                write(STDOUT_FILENO, Buffer, len);
195            if (err == EINTR)
196                continue;
197            break;
198        }
199    }
200
201    return Result;
202}
203
204/*
205 * Handle being told by the Monitor thread that there's data to be read
206 * on the ppp descriptor.
207 *
208 * Note, this is a signal handler - be careful of what we do !
209 */
210static void
211InputHandler(int sig)
212{
213    static char buf[LINELEN];
214    struct timeval t;
215    int len;
216    fd_set f;
217
218    if (data != -1) {
219        FD_ZERO(&f);
220        FD_SET(data, &f);
221        t.tv_sec = t.tv_usec = 0;
222
223        if (select(data + 1, &f, NULL, NULL, &t) > 0) {
224            len = read(data, buf, sizeof buf);
225
226            if (len > 0)
227                write(STDOUT_FILENO, buf, len);
228            else if (data != -1)
229                longjmp(pppdead, -1);
230        }
231
232        sem_post(&sem_select);
233    } else
234        /* Don't let the Monitor thread in 'till we've set ``data'' up again */
235        want_sem_post = 1;
236}
237
238/*
239 * This is a simple wrapper for el_gets(), allowing our SIGUSR1 signal
240 * handler (above) to take effect only after we've done a setjmp().
241 *
242 * We don't want it to do anything outside of here as we're going to
243 * service the ppp descriptor anyway.
244 */
245static const char *
246SmartGets(EditLine *e, int *count, int fd)
247{
248    const char *result;
249
250    if (setjmp(pppdead))
251        result = NULL;
252    else {
253        data = fd;
254        if (want_sem_post)
255            /* Let the Monitor thread in again */
256            sem_post(&sem_select);
257        result = el_gets(e, count);
258    }
259
260    data = -1;
261
262    return result;
263}
264
265/*
266 * The Terminal thread entry point.
267 *
268 * The bulk of the interactive work is done here.  We read the terminal,
269 * write the results to our ppp descriptor and read the results back.
270 *
271 * While reading the terminal (using el_gets()), it's possible to take
272 * a SIGUSR1 from the Monitor thread, telling us that the ppp descriptor
273 * has some data.  The data is read and displayed by the signal handler
274 * itself.
275 */
276static void *
277Terminal(void *v)
278{
279    struct sigaction act, oact;
280    struct thread_data *td;
281    const char *l;
282    int len;
283#ifndef __OpenBSD__
284    HistEvent hev = { 0, "" };
285#endif
286
287    act.sa_handler = InputHandler;
288    sigemptyset(&act.sa_mask);
289    act.sa_flags = SA_RESTART;
290    sigaction(SIGUSR1, &act, &oact);
291
292    td = (struct thread_data *)v;
293    want_sem_post = 1;
294
295    while ((l = SmartGets(td->edit, &len, td->ppp))) {
296        if (len > 1)
297#ifdef __OpenBSD__
298            history(td->hist, H_ENTER, l);
299#else
300            history(td->hist, &hev, H_ENTER, l);
301#endif
302        write(td->ppp, l, len);
303        if (Receive(td->ppp, REC_SHOW) != 0)
304            break;
305    }
306
307    return NULL;
308}
309
310/*
311 * The Monitor thread entry point.
312 *
313 * This thread simply monitors our ppp descriptor.  When there's something
314 * to read, a SIGUSR1 is sent to the Terminal thread.
315 *
316 * sem_select() is used by the Terminal thread to keep us from sending
317 * flurries of SIGUSR1s, and is used from the main thread to wake us up
318 * when it's time to exit.
319 */
320static void *
321Monitor(void *v)
322{
323    struct thread_data *td;
324    fd_set f;
325    int ret;
326
327    td = (struct thread_data *)v;
328    FD_ZERO(&f);
329    FD_SET(td->ppp, &f);
330
331    sem_wait(&sem_select);
332    while (!timetogo)
333        if ((ret = select(td->ppp + 1, &f, NULL, NULL, NULL)) > 0) {
334            pthread_kill(td->trm, SIGUSR1);
335            sem_wait(&sem_select);
336        }
337
338    return NULL;
339}
340
341static const char *
342sockaddr_ntop(const struct sockaddr *sa)
343{
344    const void *addr;
345    static char addrbuf[INET6_ADDRSTRLEN];
346
347    switch (sa->sa_family) {
348    case AF_INET:
349	addr = &((const struct sockaddr_in *)sa)->sin_addr;
350	break;
351    case AF_UNIX:
352	addr = &((const struct sockaddr_un *)sa)->sun_path;
353	break;
354    case AF_INET6:
355	addr = &((const struct sockaddr_in6 *)sa)->sin6_addr;
356	break;
357    default:
358	return NULL;
359    }
360    inet_ntop(sa->sa_family, addr, addrbuf, sizeof(addrbuf));
361    return addrbuf;
362}
363
364/*
365 * Connect to ppp using either a local domain socket or a tcp socket.
366 *
367 * If we're given arguments, process them and quit, otherwise create two
368 * threads to handle interactive mode.
369 */
370int
371main(int argc, char **argv)
372{
373    struct sockaddr_un ifsun;
374    int n, arg, fd, len, verbose, save_errno, hide1, hide1off, hide2;
375    unsigned TimeoutVal;
376    char *DoneWord = "x", *next, *start;
377    struct sigaction act, oact;
378    void *thread_ret;
379    pthread_t mon;
380    char Command[LINELEN];
381    char Buffer[LINELEN];
382
383    verbose = 0;
384    TimeoutVal = 2;
385    hide1 = hide1off = hide2 = 0;
386
387    for (arg = 1; arg < argc; arg++)
388        if (*argv[arg] == '-') {
389            for (start = argv[arg] + 1; *start; start++)
390                switch (*start) {
391                    case 't':
392                        TimeoutVal = (unsigned)atoi
393                            (start[1] ? start + 1 : argv[++arg]);
394                        start = DoneWord;
395                        break;
396
397                    case 'v':
398                        verbose = REC_VERBOSE;
399                        break;
400
401                    case 'p':
402                        if (start[1]) {
403                          hide1 = arg;
404                          hide1off = start - argv[arg];
405                          passwd = start + 1;
406                        } else {
407                          hide1 = arg;
408                          hide1off = start - argv[arg];
409                          passwd = argv[++arg];
410                          hide2 = arg;
411                        }
412                        start = DoneWord;
413                        break;
414
415                    default:
416                        usage();
417                }
418        }
419        else
420            break;
421
422
423    if (argc < arg + 1)
424        usage();
425
426    if (hide1) {
427      char title[1024];
428      int pos, harg;
429
430      for (harg = pos = 0; harg < argc; harg++)
431        if (harg == 0 || harg != hide2) {
432          if (harg == 0 || harg != hide1)
433            n = snprintf(title + pos, sizeof title - pos, "%s%s",
434                            harg ? " " : "", argv[harg]);
435          else if (hide1off > 1)
436            n = snprintf(title + pos, sizeof title - pos, " %.*s",
437                            hide1off, argv[harg]);
438          else
439            n = 0;
440          if (n < 0 || n >= sizeof title - pos)
441            break;
442          pos += n;
443        }
444#ifdef __FreeBSD__
445      setproctitle("-%s", title);
446#else
447      setproctitle("%s", title);
448#endif
449    }
450
451    if (*argv[arg] == '/') {
452        memset(&ifsun, '\0', sizeof ifsun);
453        ifsun.sun_len = strlen(argv[arg]);
454        if (ifsun.sun_len > sizeof ifsun.sun_path - 1) {
455            warnx("%s: path too long", argv[arg]);
456            return 1;
457        }
458        ifsun.sun_family = AF_LOCAL;
459        strcpy(ifsun.sun_path, argv[arg]);
460
461        if (fd = socket(AF_LOCAL, SOCK_STREAM, 0), fd < 0) {
462            warnx("cannot create local domain socket");
463            return 2;
464        }
465	if (connect(fd, (struct sockaddr *)&ifsun, sizeof(ifsun)) < 0) {
466	    if (errno)
467		warn("cannot connect to socket %s", argv[arg]);
468	    else
469		warnx("cannot connect to socket %s", argv[arg]);
470	    close(fd);
471	    return 3;
472	}
473    } else {
474        char *addr, *p, *port;
475	const char *caddr;
476	struct addrinfo hints, *res, *pai;
477        int gai;
478	char local[] = "localhost";
479
480	addr = argv[arg];
481	if (addr[strspn(addr, "0123456789")] == '\0') {
482	    /* port on local machine */
483	    port = addr;
484	    addr = local;
485	} else if (*addr == '[') {
486	    /* [addr]:port */
487	    if ((p = strchr(addr, ']')) == NULL) {
488		warnx("%s: mismatched '['", addr);
489		return 1;
490	    }
491	    addr++;
492	    *p++ = '\0';
493	    if (*p != ':') {
494		warnx("%s: missing port", addr);
495		return 1;
496	    }
497	    port = ++p;
498	} else {
499	    /* addr:port */
500	    p = addr + strcspn(addr, ":");
501	    if (*p != ':') {
502		warnx("%s: missing port", addr);
503		return 1;
504	    }
505	    *p++ = '\0';
506	    port = p;
507	}
508	memset(&hints, 0, sizeof(hints));
509	hints.ai_socktype = SOCK_STREAM;
510	gai = getaddrinfo(addr, port, &hints, &res);
511	if (gai != 0) {
512	    warnx("%s: %s", addr, gai_strerror(gai));
513	    return 1;
514	}
515	for (pai = res; pai != NULL; pai = pai->ai_next) {
516	    if (fd = socket(pai->ai_family, pai->ai_socktype,
517		pai->ai_protocol), fd < 0) {
518		warnx("cannot create socket");
519		continue;
520	    }
521	    TimedOut = 0;
522	    if (TimeoutVal) {
523		act.sa_handler = Timeout;
524		sigemptyset(&act.sa_mask);
525		act.sa_flags = 0;
526		sigaction(SIGALRM, &act, &oact);
527		alarm(TimeoutVal);
528	    }
529	    if (connect(fd, pai->ai_addr, pai->ai_addrlen) == 0)
530		break;
531	    if (TimeoutVal) {
532		save_errno = errno;
533		alarm(0);
534		sigaction(SIGALRM, &oact, 0);
535		errno = save_errno;
536	    }
537	    caddr = sockaddr_ntop(pai->ai_addr);
538	    if (caddr == NULL)
539		caddr = argv[arg];
540	    if (TimedOut)
541		warnx("timeout: cannot connect to %s", caddr);
542	    else {
543		if (errno)
544		    warn("cannot connect to %s", caddr);
545		else
546		    warnx("cannot connect to %s", caddr);
547	    }
548	    close(fd);
549	}
550	freeaddrinfo(res);
551	if (pai == NULL)
552	    return 1;
553	if (TimeoutVal) {
554	    alarm(0);
555	    sigaction(SIGALRM, &oact, 0);
556	}
557    }
558
559    len = 0;
560    Command[sizeof(Command)-1] = '\0';
561    for (arg++; arg < argc; arg++) {
562        if (len && len < sizeof(Command)-1)
563            strcpy(Command+len++, " ");
564        strncpy(Command+len, argv[arg], sizeof(Command)-len-1);
565        len += strlen(Command+len);
566    }
567
568    switch (Receive(fd, verbose | REC_PASSWD)) {
569        case 1:
570            fprintf(stderr, "Password incorrect\n");
571            break;
572
573        case 0:
574            passwd = NULL;
575            if (len == 0) {
576                struct thread_data td;
577                const char *env;
578                int size;
579#ifndef __OpenBSD__
580                HistEvent hev = { 0, "" };
581#endif
582
583                td.hist = history_init();
584                if ((env = getenv("EL_SIZE"))) {
585                    size = atoi(env);
586                    if (size < 0)
587                      size = 20;
588                } else
589                    size = 20;
590#ifdef __OpenBSD__
591                history(td.hist, H_EVENT, size);
592                td.edit = el_init("pppctl", stdin, stdout);
593#else
594                history(td.hist, &hev, H_SETSIZE, size);
595                td.edit = el_init("pppctl", stdin, stdout, stderr);
596#endif
597                el_source(td.edit, NULL);
598                el_set(td.edit, EL_PROMPT, GetPrompt);
599                if ((env = getenv("EL_EDITOR"))) {
600                    if (!strcmp(env, "vi"))
601                        el_set(td.edit, EL_EDITOR, "vi");
602                    else if (!strcmp(env, "emacs"))
603                        el_set(td.edit, EL_EDITOR, "emacs");
604                }
605                el_set(td.edit, EL_SIGNAL, 1);
606                el_set(td.edit, EL_HIST, history, (const char *)td.hist);
607
608                td.ppp = fd;
609                td.trm = NULL;
610
611                /*
612                 * We create two threads.  The Terminal thread does all the
613                 * work while the Monitor thread simply tells the Terminal
614                 * thread when ``fd'' becomes readable.  The telling is done
615                 * by sending a SIGUSR1 to the Terminal thread.  The
616                 * sem_select semaphore is used to prevent the monitor
617                 * thread from firing excessive signals at the Terminal
618                 * thread (it's abused for exit handling too - see below).
619                 *
620                 * The Terminal thread never uses td.trm !
621                 */
622                sem_init(&sem_select, 0, 0);
623
624                pthread_create(&td.trm, NULL, Terminal, &td);
625                pthread_create(&mon, NULL, Monitor, &td);
626
627                /* Wait for the terminal thread to finish */
628                pthread_join(td.trm, &thread_ret);
629                fprintf(stderr, "Connection closed\n");
630
631                /* Get rid of the monitor thread by abusing sem_select */
632                timetogo = 1;
633                close(fd);
634                fd = -1;
635                sem_post(&sem_select);
636                pthread_join(mon, &thread_ret);
637
638                /* Restore our terminal and release resources */
639                el_end(td.edit);
640                history_end(td.hist);
641                sem_destroy(&sem_select);
642            } else {
643                start = Command;
644                do {
645                    next = strchr(start, ';');
646                    while (*start == ' ' || *start == '\t')
647                        start++;
648                    if (next)
649                        *next = '\0';
650                    strcpy(Buffer, start);
651                    Buffer[sizeof(Buffer)-2] = '\0';
652                    strcat(Buffer, "\n");
653                    if (verbose)
654                        write(STDOUT_FILENO, Buffer, strlen(Buffer));
655                    write(fd, Buffer, strlen(Buffer));
656                    if (Receive(fd, verbose | REC_SHOW) != 0) {
657                        fprintf(stderr, "Connection closed\n");
658                        break;
659                    }
660                    if (next)
661                        start = ++next;
662                } while (next && *next);
663                if (verbose)
664                    write(STDOUT_FILENO, "quit\n", 5);
665                write(fd, "quit\n", 5);
666                while (Receive(fd, verbose | REC_SHOW) == 0)
667                    ;
668                if (verbose)
669                    puts("");
670            }
671            break;
672
673        default:
674            warnx("ppp is not responding");
675            break;
676    }
677
678    if (fd != -1)
679        close(fd);
680
681    return 0;
682}
683