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("$FreeBSD$");
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    char temp[sizeof(Buffer)];
125    struct timeval t;
126    int Result;
127    char *last;
128    fd_set f;
129    int len;
130    int err;
131
132    FD_ZERO(&f);
133    FD_SET(fd, &f);
134    t.tv_sec = 0;
135    t.tv_usec = 100000;
136    prompt = Buffer;
137    len = 0;
138
139    while (Result = read(fd, Buffer+len, sizeof(Buffer)-len-1), Result != -1) {
140        if (Result == 0) {
141            Result = -1;
142            break;
143        }
144        len += Result;
145        Buffer[len] = '\0';
146        if (len > 2 && !strcmp(Buffer+len-2, "> ")) {
147            prompt = strrchr(Buffer, '\n');
148            if (display & (REC_SHOW|REC_VERBOSE)) {
149                if (display & REC_VERBOSE)
150                    last = Buffer+len-1;
151                else
152                    last = prompt;
153                if (last) {
154                    last++;
155                    write(STDOUT_FILENO, Buffer, last-Buffer);
156                }
157            }
158            prompt = prompt == NULL ? Buffer : prompt+1;
159            for (last = Buffer+len-2; last > Buffer && *last != ' '; last--)
160                ;
161            if (last > Buffer+3 && !strncmp(last-3, " on", 3)) {
162                 /* a password is required ! */
163                 if (display & REC_PASSWD) {
164                    /* password time */
165                    if (!passwd)
166                        passwd = getpass("Password: ");
167                    sprintf(Buffer, "passwd %s\n", passwd);
168                    memset(passwd, '\0', strlen(passwd));
169                    if (display & REC_VERBOSE)
170                        write(STDOUT_FILENO, Buffer, strlen(Buffer));
171                    write(fd, Buffer, strlen(Buffer));
172                    memset(Buffer, '\0', strlen(Buffer));
173                    return Receive(fd, display & ~REC_PASSWD);
174                }
175                Result = 1;
176            } else
177                Result = 0;
178            break;
179        } else
180            prompt = "";
181        if (len == sizeof Buffer - 1) {
182            int flush;
183            if ((last = strrchr(Buffer, '\n')) == NULL)
184                /* Yeuch - this is one mother of a line ! */
185                flush = sizeof Buffer / 2;
186            else
187                flush = last - Buffer + 1;
188            write(STDOUT_FILENO, Buffer, flush);
189	    strcpy(temp, Buffer + flush);
190	    strcpy(Buffer, temp);
191            len -= flush;
192        }
193        if ((Result = select(fd + 1, &f, NULL, NULL, &t)) <= 0) {
194            err = Result == -1 ? errno : 0;
195            if (len)
196                write(STDOUT_FILENO, Buffer, len);
197            if (err == EINTR)
198                continue;
199            break;
200        }
201    }
202
203    return Result;
204}
205
206/*
207 * Handle being told by the Monitor thread that there's data to be read
208 * on the ppp descriptor.
209 *
210 * Note, this is a signal handler - be careful of what we do !
211 */
212static void
213InputHandler(int sig)
214{
215    static char buf[LINELEN];
216    struct timeval t;
217    int len;
218    fd_set f;
219
220    if (data != -1) {
221        FD_ZERO(&f);
222        FD_SET(data, &f);
223        t.tv_sec = t.tv_usec = 0;
224
225        if (select(data + 1, &f, NULL, NULL, &t) > 0) {
226            len = read(data, buf, sizeof buf);
227
228            if (len > 0)
229                write(STDOUT_FILENO, buf, len);
230            else if (data != -1)
231                longjmp(pppdead, -1);
232        }
233
234        sem_post(&sem_select);
235    } else
236        /* Don't let the Monitor thread in 'till we've set ``data'' up again */
237        want_sem_post = 1;
238}
239
240/*
241 * This is a simple wrapper for el_gets(), allowing our SIGUSR1 signal
242 * handler (above) to take effect only after we've done a setjmp().
243 *
244 * We don't want it to do anything outside of here as we're going to
245 * service the ppp descriptor anyway.
246 */
247static const char *
248SmartGets(EditLine *e, int *count, int fd)
249{
250    const char *result;
251
252    if (setjmp(pppdead))
253        result = NULL;
254    else {
255        data = fd;
256        if (want_sem_post)
257            /* Let the Monitor thread in again */
258            sem_post(&sem_select);
259        result = el_gets(e, count);
260    }
261
262    data = -1;
263
264    return result;
265}
266
267/*
268 * The Terminal thread entry point.
269 *
270 * The bulk of the interactive work is done here.  We read the terminal,
271 * write the results to our ppp descriptor and read the results back.
272 *
273 * While reading the terminal (using el_gets()), it's possible to take
274 * a SIGUSR1 from the Monitor thread, telling us that the ppp descriptor
275 * has some data.  The data is read and displayed by the signal handler
276 * itself.
277 */
278static void *
279Terminal(void *v)
280{
281    struct sigaction act, oact;
282    struct thread_data *td;
283    const char *l;
284    int len;
285#ifndef __OpenBSD__
286    HistEvent hev = { 0, "" };
287#endif
288
289    act.sa_handler = InputHandler;
290    sigemptyset(&act.sa_mask);
291    act.sa_flags = SA_RESTART;
292    sigaction(SIGUSR1, &act, &oact);
293
294    td = (struct thread_data *)v;
295    want_sem_post = 1;
296
297    while ((l = SmartGets(td->edit, &len, td->ppp))) {
298        if (len > 1)
299#ifdef __OpenBSD__
300            history(td->hist, H_ENTER, l);
301#else
302            history(td->hist, &hev, H_ENTER, l);
303#endif
304        write(td->ppp, l, len);
305        if (Receive(td->ppp, REC_SHOW) != 0)
306            break;
307    }
308
309    return NULL;
310}
311
312/*
313 * The Monitor thread entry point.
314 *
315 * This thread simply monitors our ppp descriptor.  When there's something
316 * to read, a SIGUSR1 is sent to the Terminal thread.
317 *
318 * sem_select() is used by the Terminal thread to keep us from sending
319 * flurries of SIGUSR1s, and is used from the main thread to wake us up
320 * when it's time to exit.
321 */
322static void *
323Monitor(void *v)
324{
325    struct thread_data *td;
326    fd_set f;
327    int ret;
328
329    td = (struct thread_data *)v;
330    FD_ZERO(&f);
331    FD_SET(td->ppp, &f);
332
333    sem_wait(&sem_select);
334    while (!timetogo)
335        if ((ret = select(td->ppp + 1, &f, NULL, NULL, NULL)) > 0) {
336            pthread_kill(td->trm, SIGUSR1);
337            sem_wait(&sem_select);
338        }
339
340    return NULL;
341}
342
343static const char *
344sockaddr_ntop(const struct sockaddr *sa)
345{
346    const void *addr;
347    static char addrbuf[INET6_ADDRSTRLEN];
348
349    switch (sa->sa_family) {
350    case AF_INET:
351	addr = &((const struct sockaddr_in *)sa)->sin_addr;
352	break;
353    case AF_UNIX:
354	addr = &((const struct sockaddr_un *)sa)->sun_path;
355	break;
356    case AF_INET6:
357	addr = &((const struct sockaddr_in6 *)sa)->sin6_addr;
358	break;
359    default:
360	return NULL;
361    }
362    inet_ntop(sa->sa_family, addr, addrbuf, sizeof(addrbuf));
363    return addrbuf;
364}
365
366/*
367 * Connect to ppp using either a local domain socket or a tcp socket.
368 *
369 * If we're given arguments, process them and quit, otherwise create two
370 * threads to handle interactive mode.
371 */
372int
373main(int argc, char **argv)
374{
375    struct sockaddr_un ifsun;
376    int n, arg, fd, len, verbose, save_errno, hide1, hide1off, hide2;
377    unsigned TimeoutVal;
378    char *DoneWord = "x", *next, *start;
379    struct sigaction act, oact;
380    void *thread_ret;
381    pthread_t mon;
382    char Command[LINELEN];
383    char Buffer[LINELEN];
384
385    verbose = 0;
386    TimeoutVal = 2;
387    hide1 = hide1off = hide2 = 0;
388
389    for (arg = 1; arg < argc; arg++)
390        if (*argv[arg] == '-') {
391            for (start = argv[arg] + 1; *start; start++)
392                switch (*start) {
393                    case 't':
394                        TimeoutVal = (unsigned)atoi
395                            (start[1] ? start + 1 : argv[++arg]);
396                        start = DoneWord;
397                        break;
398
399                    case 'v':
400                        verbose = REC_VERBOSE;
401                        break;
402
403                    case 'p':
404                        if (start[1]) {
405                          hide1 = arg;
406                          hide1off = start - argv[arg];
407                          passwd = start + 1;
408                        } else {
409                          hide1 = arg;
410                          hide1off = start - argv[arg];
411                          passwd = argv[++arg];
412                          hide2 = arg;
413                        }
414                        start = DoneWord;
415                        break;
416
417                    default:
418                        usage();
419                }
420        }
421        else
422            break;
423
424
425    if (argc < arg + 1)
426        usage();
427
428    if (hide1) {
429      char title[1024];
430      int pos, harg;
431
432      for (harg = pos = 0; harg < argc; harg++)
433        if (harg == 0 || harg != hide2) {
434          if (harg == 0 || harg != hide1)
435            n = snprintf(title + pos, sizeof title - pos, "%s%s",
436                            harg ? " " : "", argv[harg]);
437          else if (hide1off > 1)
438            n = snprintf(title + pos, sizeof title - pos, " %.*s",
439                            hide1off, argv[harg]);
440          else
441            n = 0;
442          if (n < 0 || n >= sizeof title - pos)
443            break;
444          pos += n;
445        }
446#ifdef __FreeBSD__
447      setproctitle("-%s", title);
448#else
449      setproctitle("%s", title);
450#endif
451    }
452
453    if (*argv[arg] == '/') {
454        memset(&ifsun, '\0', sizeof ifsun);
455        ifsun.sun_len = strlen(argv[arg]);
456        if (ifsun.sun_len > sizeof ifsun.sun_path - 1) {
457            warnx("%s: path too long", argv[arg]);
458            return 1;
459        }
460        ifsun.sun_family = AF_LOCAL;
461        strcpy(ifsun.sun_path, argv[arg]);
462
463        if (fd = socket(AF_LOCAL, SOCK_STREAM, 0), fd < 0) {
464            warnx("cannot create local domain socket");
465            return 2;
466        }
467	if (connect(fd, (struct sockaddr *)&ifsun, sizeof(ifsun)) < 0) {
468	    if (errno)
469		warn("cannot connect to socket %s", argv[arg]);
470	    else
471		warnx("cannot connect to socket %s", argv[arg]);
472	    close(fd);
473	    return 3;
474	}
475    } else {
476        char *addr, *p, *port;
477	const char *caddr;
478	struct addrinfo hints, *res, *pai;
479        int gai;
480	char local[] = "localhost";
481
482	addr = argv[arg];
483	if (addr[strspn(addr, "0123456789")] == '\0') {
484	    /* port on local machine */
485	    port = addr;
486	    addr = local;
487	} else if (*addr == '[') {
488	    /* [addr]:port */
489	    if ((p = strchr(addr, ']')) == NULL) {
490		warnx("%s: mismatched '['", addr);
491		return 1;
492	    }
493	    addr++;
494	    *p++ = '\0';
495	    if (*p != ':') {
496		warnx("%s: missing port", addr);
497		return 1;
498	    }
499	    port = ++p;
500	} else {
501	    /* addr:port */
502	    p = addr + strcspn(addr, ":");
503	    if (*p != ':') {
504		warnx("%s: missing port", addr);
505		return 1;
506	    }
507	    *p++ = '\0';
508	    port = p;
509	}
510	memset(&hints, 0, sizeof(hints));
511	hints.ai_socktype = SOCK_STREAM;
512	gai = getaddrinfo(addr, port, &hints, &res);
513	if (gai != 0) {
514	    warnx("%s: %s", addr, gai_strerror(gai));
515	    return 1;
516	}
517	for (pai = res; pai != NULL; pai = pai->ai_next) {
518	    if (fd = socket(pai->ai_family, pai->ai_socktype,
519		pai->ai_protocol), fd < 0) {
520		warnx("cannot create socket");
521		continue;
522	    }
523	    TimedOut = 0;
524	    if (TimeoutVal) {
525		act.sa_handler = Timeout;
526		sigemptyset(&act.sa_mask);
527		act.sa_flags = 0;
528		sigaction(SIGALRM, &act, &oact);
529		alarm(TimeoutVal);
530	    }
531	    if (connect(fd, pai->ai_addr, pai->ai_addrlen) == 0)
532		break;
533	    if (TimeoutVal) {
534		save_errno = errno;
535		alarm(0);
536		sigaction(SIGALRM, &oact, 0);
537		errno = save_errno;
538	    }
539	    caddr = sockaddr_ntop(pai->ai_addr);
540	    if (caddr == NULL)
541		caddr = argv[arg];
542	    if (TimedOut)
543		warnx("timeout: cannot connect to %s", caddr);
544	    else {
545		if (errno)
546		    warn("cannot connect to %s", caddr);
547		else
548		    warnx("cannot connect to %s", caddr);
549	    }
550	    close(fd);
551	}
552	freeaddrinfo(res);
553	if (pai == NULL)
554	    return 1;
555	if (TimeoutVal) {
556	    alarm(0);
557	    sigaction(SIGALRM, &oact, 0);
558	}
559    }
560
561    len = 0;
562    Command[sizeof(Command)-1] = '\0';
563    for (arg++; arg < argc; arg++) {
564        if (len && len < sizeof(Command)-1)
565            strcpy(Command+len++, " ");
566        strncpy(Command+len, argv[arg], sizeof(Command)-len-1);
567        len += strlen(Command+len);
568    }
569
570    switch (Receive(fd, verbose | REC_PASSWD)) {
571        case 1:
572            fprintf(stderr, "Password incorrect\n");
573            break;
574
575        case 0:
576            passwd = NULL;
577            if (len == 0) {
578                struct thread_data td;
579                const char *env;
580                int size;
581#ifndef __OpenBSD__
582                HistEvent hev = { 0, "" };
583#endif
584
585                td.hist = history_init();
586                if ((env = getenv("EL_SIZE"))) {
587                    size = atoi(env);
588                    if (size < 0)
589                      size = 20;
590                } else
591                    size = 20;
592#ifdef __OpenBSD__
593                history(td.hist, H_EVENT, size);
594                td.edit = el_init("pppctl", stdin, stdout);
595#else
596                history(td.hist, &hev, H_SETSIZE, size);
597                td.edit = el_init("pppctl", stdin, stdout, stderr);
598#endif
599                el_source(td.edit, NULL);
600                el_set(td.edit, EL_PROMPT, GetPrompt);
601                if ((env = getenv("EL_EDITOR"))) {
602                    if (!strcmp(env, "vi"))
603                        el_set(td.edit, EL_EDITOR, "vi");
604                    else if (!strcmp(env, "emacs"))
605                        el_set(td.edit, EL_EDITOR, "emacs");
606                }
607                el_set(td.edit, EL_SIGNAL, 1);
608                el_set(td.edit, EL_HIST, history, (const char *)td.hist);
609
610                td.ppp = fd;
611                td.trm = NULL;
612
613                /*
614                 * We create two threads.  The Terminal thread does all the
615                 * work while the Monitor thread simply tells the Terminal
616                 * thread when ``fd'' becomes readable.  The telling is done
617                 * by sending a SIGUSR1 to the Terminal thread.  The
618                 * sem_select semaphore is used to prevent the monitor
619                 * thread from firing excessive signals at the Terminal
620                 * thread (it's abused for exit handling too - see below).
621                 *
622                 * The Terminal thread never uses td.trm !
623                 */
624                sem_init(&sem_select, 0, 0);
625
626                pthread_create(&td.trm, NULL, Terminal, &td);
627                pthread_create(&mon, NULL, Monitor, &td);
628
629                /* Wait for the terminal thread to finish */
630                pthread_join(td.trm, &thread_ret);
631                fprintf(stderr, "Connection closed\n");
632
633                /* Get rid of the monitor thread by abusing sem_select */
634                timetogo = 1;
635                close(fd);
636                fd = -1;
637                sem_post(&sem_select);
638                pthread_join(mon, &thread_ret);
639
640                /* Restore our terminal and release resources */
641                el_end(td.edit);
642                history_end(td.hist);
643                sem_destroy(&sem_select);
644            } else {
645                start = Command;
646                do {
647                    next = strchr(start, ';');
648                    while (*start == ' ' || *start == '\t')
649                        start++;
650                    if (next)
651                        *next = '\0';
652                    strcpy(Buffer, start);
653                    Buffer[sizeof(Buffer)-2] = '\0';
654                    strcat(Buffer, "\n");
655                    if (verbose)
656                        write(STDOUT_FILENO, Buffer, strlen(Buffer));
657                    write(fd, Buffer, strlen(Buffer));
658                    if (Receive(fd, verbose | REC_SHOW) != 0) {
659                        fprintf(stderr, "Connection closed\n");
660                        break;
661                    }
662                    if (next)
663                        start = ++next;
664                } while (next && *next);
665                if (verbose)
666                    write(STDOUT_FILENO, "quit\n", 5);
667                write(fd, "quit\n", 5);
668                while (Receive(fd, verbose | REC_SHOW) == 0)
669                    ;
670                if (verbose)
671                    puts("");
672            }
673            break;
674
675        default:
676            warnx("ppp is not responding");
677            break;
678    }
679
680    if (fd != -1)
681        close(fd);
682
683    return 0;
684}
685