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1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  *
9  * Trivial file transfer protocol server.
10  *
11  * This code includes many modifications by Jim Guyton <guyton@rand-unix>
12  *
13  * This source file was started based on netkit-tftpd 0.17
14  * Heavily modified for curl's test suite
15  */
16 
17 /*
18  * Copyright (c) 1983, 2016 Regents of the University of California.
19  * All rights reserved.
20  *
21  * Redistribution and use in source and binary forms, with or without
22  * modification, are permitted provided that the following conditions
23  * are met:
24  * 1. Redistributions of source code must retain the above copyright
25  *    notice, this list of conditions and the following disclaimer.
26  * 2. Redistributions in binary form must reproduce the above copyright
27  *    notice, this list of conditions and the following disclaimer in the
28  *    documentation and/or other materials provided with the distribution.
29  * 3. All advertising materials mentioning features or use of this software
30  *    must display the following acknowledgement:
31  *      This product includes software developed by the University of
32  *      California, Berkeley and its contributors.
33  * 4. Neither the name of the University nor the names of its contributors
34  *    may be used to endorse or promote products derived from this software
35  *    without specific prior written permission.
36  *
37  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
38  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
39  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
40  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
41  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
42  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
43  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
45  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
46  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47  * SUCH DAMAGE.
48  */
49 
50 #include "server_setup.h"
51 
52 #ifdef HAVE_SYS_IOCTL_H
53 #include <sys/ioctl.h>
54 #endif
55 #ifdef HAVE_SIGNAL_H
56 #include <signal.h>
57 #endif
58 #ifdef HAVE_FCNTL_H
59 #include <fcntl.h>
60 #endif
61 #ifdef HAVE_NETINET_IN_H
62 #include <netinet/in.h>
63 #endif
64 #ifdef HAVE_ARPA_INET_H
65 #include <arpa/inet.h>
66 #endif
67 #ifdef HAVE_ARPA_TFTP_H
68 #include <arpa/tftp.h>
69 #else
70 #include "tftp.h"
71 #endif
72 #ifdef HAVE_NETDB_H
73 #include <netdb.h>
74 #endif
75 #ifdef HAVE_SYS_FILIO_H
76 /* FIONREAD on Solaris 7 */
77 #include <sys/filio.h>
78 #endif
79 
80 #include <setjmp.h>
81 
82 #ifdef HAVE_PWD_H
83 #include <pwd.h>
84 #endif
85 
86 #define ENABLE_CURLX_PRINTF
87 /* make the curlx header define all printf() functions to use the curlx_*
88    versions instead */
89 #include "curlx.h" /* from the private lib dir */
90 #include "getpart.h"
91 #include "util.h"
92 #include "server_sockaddr.h"
93 
94 /* include memdebug.h last */
95 #include "memdebug.h"
96 
97 /*****************************************************************************
98 *                      STRUCT DECLARATIONS AND DEFINES                       *
99 *****************************************************************************/
100 
101 #ifndef PKTSIZE
102 #define PKTSIZE (SEGSIZE + 4)  /* SEGSIZE defined in arpa/tftp.h */
103 #endif
104 
105 struct testcase {
106   char *buffer;   /* holds the file data to send to the client */
107   size_t bufsize; /* size of the data in buffer */
108   char *rptr;     /* read pointer into the buffer */
109   size_t rcount;  /* amount of data left to read of the file */
110   long testno;    /* test case number */
111   int ofile;      /* file descriptor for output file when uploading to us */
112 
113   int writedelay; /* number of seconds between each packet */
114 };
115 
116 struct formats {
117   const char *f_mode;
118   int f_convert;
119 };
120 
121 struct errmsg {
122   int e_code;
123   const char *e_msg;
124 };
125 
126 typedef union {
127   struct tftphdr hdr;
128   char storage[PKTSIZE];
129 } tftphdr_storage_t;
130 
131 /*
132  * bf.counter values in range [-1 .. SEGSIZE] represents size of data in the
133  * bf.buf buffer. Additionally it can also hold flags BF_ALLOC or BF_FREE.
134  */
135 
136 struct bf {
137   int counter;            /* size of data in buffer, or flag */
138   tftphdr_storage_t buf;  /* room for data packet */
139 };
140 
141 #define BF_ALLOC -3       /* alloc'd but not yet filled */
142 #define BF_FREE  -2       /* free */
143 
144 #define opcode_RRQ   1
145 #define opcode_WRQ   2
146 #define opcode_DATA  3
147 #define opcode_ACK   4
148 #define opcode_ERROR 5
149 
150 #define TIMEOUT      5
151 
152 #undef MIN
153 #define MIN(x,y) ((x)<(y)?(x):(y))
154 
155 #ifndef DEFAULT_LOGFILE
156 #define DEFAULT_LOGFILE "log/tftpd.log"
157 #endif
158 
159 #define REQUEST_DUMP  "log/server.input"
160 
161 #define DEFAULT_PORT 8999 /* UDP */
162 
163 /*****************************************************************************
164 *                              GLOBAL VARIABLES                              *
165 *****************************************************************************/
166 
167 static struct errmsg errmsgs[] = {
168   { EUNDEF,       "Undefined error code" },
169   { ENOTFOUND,    "File not found" },
170   { EACCESS,      "Access violation" },
171   { ENOSPACE,     "Disk full or allocation exceeded" },
172   { EBADOP,       "Illegal TFTP operation" },
173   { EBADID,       "Unknown transfer ID" },
174   { EEXISTS,      "File already exists" },
175   { ENOUSER,      "No such user" },
176   { -1,           0 }
177 };
178 
179 static struct formats formata[] = {
180   { "netascii",   1 },
181   { "octet",      0 },
182   { NULL,         0 }
183 };
184 
185 static struct bf bfs[2];
186 
187 static int nextone;     /* index of next buffer to use */
188 static int current;     /* index of buffer in use */
189 
190                            /* control flags for crlf conversions */
191 static int newline = 0;    /* fillbuf: in middle of newline expansion */
192 static int prevchar = -1;  /* putbuf: previous char (cr check) */
193 
194 static tftphdr_storage_t buf;
195 static tftphdr_storage_t ackbuf;
196 
197 static srvr_sockaddr_union_t from;
198 static curl_socklen_t fromlen;
199 
200 static curl_socket_t peer = CURL_SOCKET_BAD;
201 
202 static int timeout;
203 static int maxtimeout = 5 * TIMEOUT;
204 
205 #ifdef ENABLE_IPV6
206 static bool use_ipv6 = FALSE;
207 #endif
208 static const char *ipv_inuse = "IPv4";
209 
210 const  char *serverlogfile = DEFAULT_LOGFILE;
211 static char *pidname= (char *)".tftpd.pid";
212 static int serverlogslocked = 0;
213 static int wrotepidfile = 0;
214 
215 #ifdef HAVE_SIGSETJMP
216 static sigjmp_buf timeoutbuf;
217 #endif
218 
219 #if defined(HAVE_ALARM) && defined(SIGALRM)
220 static int rexmtval = TIMEOUT;
221 #endif
222 
223 /* do-nothing macro replacement for systems which lack siginterrupt() */
224 
225 #ifndef HAVE_SIGINTERRUPT
226 #define siginterrupt(x,y) do {} while(0)
227 #endif
228 
229 /* vars used to keep around previous signal handlers */
230 
231 typedef RETSIGTYPE (*SIGHANDLER_T)(int);
232 
233 #ifdef SIGHUP
234 static SIGHANDLER_T old_sighup_handler  = SIG_ERR;
235 #endif
236 
237 #ifdef SIGPIPE
238 static SIGHANDLER_T old_sigpipe_handler = SIG_ERR;
239 #endif
240 
241 #ifdef SIGINT
242 static SIGHANDLER_T old_sigint_handler  = SIG_ERR;
243 #endif
244 
245 #ifdef SIGTERM
246 static SIGHANDLER_T old_sigterm_handler = SIG_ERR;
247 #endif
248 
249 #if defined(SIGBREAK) && defined(WIN32)
250 static SIGHANDLER_T old_sigbreak_handler = SIG_ERR;
251 #endif
252 
253 /* var which if set indicates that the program should finish execution */
254 
255 SIG_ATOMIC_T got_exit_signal = 0;
256 
257 /* if next is set indicates the first signal handled in exit_signal_handler */
258 
259 static volatile int exit_signal = 0;
260 
261 /*****************************************************************************
262 *                            FUNCTION PROTOTYPES                             *
263 *****************************************************************************/
264 
265 static struct tftphdr *rw_init(int);
266 
267 static struct tftphdr *w_init(void);
268 
269 static struct tftphdr *r_init(void);
270 
271 static void read_ahead(struct testcase *test, int convert);
272 
273 static ssize_t write_behind(struct testcase *test, int convert);
274 
275 static int synchnet(curl_socket_t);
276 
277 static int do_tftp(struct testcase *test, struct tftphdr *tp, ssize_t size);
278 
279 static int validate_access(struct testcase *test, const char *fname, int mode);
280 
281 static void sendtftp(struct testcase *test, struct formats *pf);
282 
283 static void recvtftp(struct testcase *test, struct formats *pf);
284 
285 static void nak(int error);
286 
287 #if defined(HAVE_ALARM) && defined(SIGALRM)
288 
289 static void mysignal(int sig, void (*handler)(int));
290 
291 static void timer(int signum);
292 
293 static void justtimeout(int signum);
294 
295 #endif /* HAVE_ALARM && SIGALRM */
296 
297 static RETSIGTYPE exit_signal_handler(int signum);
298 
299 static void install_signal_handlers(void);
300 
301 static void restore_signal_handlers(void);
302 
303 /*****************************************************************************
304 *                          FUNCTION IMPLEMENTATIONS                          *
305 *****************************************************************************/
306 
307 #if defined(HAVE_ALARM) && defined(SIGALRM)
308 
309 /*
310  * Like signal(), but with well-defined semantics.
311  */
mysignal(int sig,void (* handler)(int))312 static void mysignal(int sig, void (*handler)(int))
313 {
314   struct sigaction sa;
315   memset(&sa, 0, sizeof(sa));
316   sa.sa_handler = handler;
317   sigaction(sig, &sa, NULL);
318 }
319 
timer(int signum)320 static void timer(int signum)
321 {
322   (void)signum;
323 
324   logmsg("alarm!");
325 
326   timeout += rexmtval;
327   if(timeout >= maxtimeout) {
328     if(wrotepidfile) {
329       wrotepidfile = 0;
330       unlink(pidname);
331     }
332     if(serverlogslocked) {
333       serverlogslocked = 0;
334       clear_advisor_read_lock(SERVERLOGS_LOCK);
335     }
336     exit(1);
337   }
338 #ifdef HAVE_SIGSETJMP
339   siglongjmp(timeoutbuf, 1);
340 #endif
341 }
342 
justtimeout(int signum)343 static void justtimeout(int signum)
344 {
345   (void)signum;
346 }
347 
348 #endif /* HAVE_ALARM && SIGALRM */
349 
350 /* signal handler that will be triggered to indicate that the program
351   should finish its execution in a controlled manner as soon as possible.
352   The first time this is called it will set got_exit_signal to one and
353   store in exit_signal the signal that triggered its execution. */
354 
exit_signal_handler(int signum)355 static RETSIGTYPE exit_signal_handler(int signum)
356 {
357   int old_errno = errno;
358   if(got_exit_signal == 0) {
359     got_exit_signal = 1;
360     exit_signal = signum;
361   }
362   (void)signal(signum, exit_signal_handler);
363   errno = old_errno;
364 }
365 
install_signal_handlers(void)366 static void install_signal_handlers(void)
367 {
368 #ifdef SIGHUP
369   /* ignore SIGHUP signal */
370   if((old_sighup_handler = signal(SIGHUP, SIG_IGN)) == SIG_ERR)
371     logmsg("cannot install SIGHUP handler: %s", strerror(errno));
372 #endif
373 #ifdef SIGPIPE
374   /* ignore SIGPIPE signal */
375   if((old_sigpipe_handler = signal(SIGPIPE, SIG_IGN)) == SIG_ERR)
376     logmsg("cannot install SIGPIPE handler: %s", strerror(errno));
377 #endif
378 #ifdef SIGINT
379   /* handle SIGINT signal with our exit_signal_handler */
380   if((old_sigint_handler = signal(SIGINT, exit_signal_handler)) == SIG_ERR)
381     logmsg("cannot install SIGINT handler: %s", strerror(errno));
382   else
383     siginterrupt(SIGINT, 1);
384 #endif
385 #ifdef SIGTERM
386   /* handle SIGTERM signal with our exit_signal_handler */
387   if((old_sigterm_handler = signal(SIGTERM, exit_signal_handler)) == SIG_ERR)
388     logmsg("cannot install SIGTERM handler: %s", strerror(errno));
389   else
390     siginterrupt(SIGTERM, 1);
391 #endif
392 #if defined(SIGBREAK) && defined(WIN32)
393   /* handle SIGBREAK signal with our exit_signal_handler */
394   if((old_sigbreak_handler = signal(SIGBREAK, exit_signal_handler)) == SIG_ERR)
395     logmsg("cannot install SIGBREAK handler: %s", strerror(errno));
396   else
397     siginterrupt(SIGBREAK, 1);
398 #endif
399 }
400 
restore_signal_handlers(void)401 static void restore_signal_handlers(void)
402 {
403 #ifdef SIGHUP
404   if(SIG_ERR != old_sighup_handler)
405     (void)signal(SIGHUP, old_sighup_handler);
406 #endif
407 #ifdef SIGPIPE
408   if(SIG_ERR != old_sigpipe_handler)
409     (void)signal(SIGPIPE, old_sigpipe_handler);
410 #endif
411 #ifdef SIGINT
412   if(SIG_ERR != old_sigint_handler)
413     (void)signal(SIGINT, old_sigint_handler);
414 #endif
415 #ifdef SIGTERM
416   if(SIG_ERR != old_sigterm_handler)
417     (void)signal(SIGTERM, old_sigterm_handler);
418 #endif
419 #if defined(SIGBREAK) && defined(WIN32)
420   if(SIG_ERR != old_sigbreak_handler)
421     (void)signal(SIGBREAK, old_sigbreak_handler);
422 #endif
423 }
424 
425 /*
426  * init for either read-ahead or write-behind.
427  * zero for write-behind, one for read-head.
428  */
rw_init(int x)429 static struct tftphdr *rw_init(int x)
430 {
431   newline = 0;                    /* init crlf flag */
432   prevchar = -1;
433   bfs[0].counter =  BF_ALLOC;     /* pass out the first buffer */
434   current = 0;
435   bfs[1].counter = BF_FREE;
436   nextone = x;                    /* ahead or behind? */
437   return &bfs[0].buf.hdr;
438 }
439 
w_init(void)440 static struct tftphdr *w_init(void)
441 {
442   return rw_init(0); /* write-behind */
443 }
444 
r_init(void)445 static struct tftphdr *r_init(void)
446 {
447   return rw_init(1); /* read-ahead */
448 }
449 
450 /* Have emptied current buffer by sending to net and getting ack.
451    Free it and return next buffer filled with data.
452  */
readit(struct testcase * test,struct tftphdr ** dpp,int convert)453 static int readit(struct testcase *test, struct tftphdr **dpp,
454                   int convert /* if true, convert to ascii */)
455 {
456   struct bf *b;
457 
458   bfs[current].counter = BF_FREE; /* free old one */
459   current = !current;             /* "incr" current */
460 
461   b = &bfs[current];              /* look at new buffer */
462   if(b->counter == BF_FREE)      /* if it's empty */
463     read_ahead(test, convert);    /* fill it */
464 
465   *dpp = &b->buf.hdr;             /* set caller's ptr */
466   return b->counter;
467 }
468 
469 /*
470  * fill the input buffer, doing ascii conversions if requested
471  * conversions are  lf -> cr, lf  and cr -> cr, nul
472  */
read_ahead(struct testcase * test,int convert)473 static void read_ahead(struct testcase *test,
474                        int convert /* if true, convert to ascii */)
475 {
476   int i;
477   char *p;
478   int c;
479   struct bf *b;
480   struct tftphdr *dp;
481 
482   b = &bfs[nextone];              /* look at "next" buffer */
483   if(b->counter != BF_FREE)      /* nop if not free */
484     return;
485   nextone = !nextone;             /* "incr" next buffer ptr */
486 
487   dp = &b->buf.hdr;
488 
489   if(convert == 0) {
490     /* The former file reading code did this:
491        b->counter = read(fileno(file), dp->th_data, SEGSIZE); */
492     size_t copy_n = MIN(SEGSIZE, test->rcount);
493     memcpy(dp->th_data, test->rptr, copy_n);
494 
495     /* decrease amount, advance pointer */
496     test->rcount -= copy_n;
497     test->rptr += copy_n;
498     b->counter = (int)copy_n;
499     return;
500   }
501 
502   p = dp->th_data;
503   for(i = 0 ; i < SEGSIZE; i++) {
504     if(newline) {
505       if(prevchar == '\n')
506         c = '\n';       /* lf to cr,lf */
507       else
508         c = '\0';       /* cr to cr,nul */
509       newline = 0;
510     }
511     else {
512       if(test->rcount) {
513         c=test->rptr[0];
514         test->rptr++;
515         test->rcount--;
516       }
517       else
518         break;
519       if(c == '\n' || c == '\r') {
520         prevchar = c;
521         c = '\r';
522         newline = 1;
523       }
524     }
525     *p++ = (char)c;
526   }
527   b->counter = (int)(p - dp->th_data);
528 }
529 
530 /* Update count associated with the buffer, get new buffer from the queue.
531    Calls write_behind only if next buffer not available.
532  */
writeit(struct testcase * test,struct tftphdr * volatile * dpp,int ct,int convert)533 static int writeit(struct testcase *test, struct tftphdr * volatile *dpp,
534                    int ct, int convert)
535 {
536   bfs[current].counter = ct;      /* set size of data to write */
537   current = !current;             /* switch to other buffer */
538   if(bfs[current].counter != BF_FREE)     /* if not free */
539     write_behind(test, convert);     /* flush it */
540   bfs[current].counter = BF_ALLOC;        /* mark as alloc'd */
541   *dpp =  &bfs[current].buf.hdr;
542   return ct;                      /* this is a lie of course */
543 }
544 
545 /*
546  * Output a buffer to a file, converting from netascii if requested.
547  * CR, NUL -> CR  and CR, LF => LF.
548  * Note spec is undefined if we get CR as last byte of file or a
549  * CR followed by anything else.  In this case we leave it alone.
550  */
write_behind(struct testcase * test,int convert)551 static ssize_t write_behind(struct testcase *test, int convert)
552 {
553   char *writebuf;
554   int count;
555   int ct;
556   char *p;
557   int c;                          /* current character */
558   struct bf *b;
559   struct tftphdr *dp;
560 
561   b = &bfs[nextone];
562   if(b->counter < -1)            /* anything to flush? */
563     return 0;                     /* just nop if nothing to do */
564 
565   if(!test->ofile) {
566     char outfile[256];
567     snprintf(outfile, sizeof(outfile), "log/upload.%ld", test->testno);
568 #ifdef WIN32
569     test->ofile=open(outfile, O_CREAT|O_RDWR|O_BINARY, 0777);
570 #else
571     test->ofile=open(outfile, O_CREAT|O_RDWR, 0777);
572 #endif
573     if(test->ofile == -1) {
574       logmsg("Couldn't create and/or open file %s for upload!", outfile);
575       return -1; /* failure! */
576     }
577   }
578 
579   count = b->counter;             /* remember byte count */
580   b->counter = BF_FREE;           /* reset flag */
581   dp = &b->buf.hdr;
582   nextone = !nextone;             /* incr for next time */
583   writebuf = dp->th_data;
584 
585   if(count <= 0)
586     return -1;                    /* nak logic? */
587 
588   if(convert == 0)
589     return write(test->ofile, writebuf, count);
590 
591   p = writebuf;
592   ct = count;
593   while(ct--) {                   /* loop over the buffer */
594     c = *p++;                     /* pick up a character */
595     if(prevchar == '\r') {        /* if prev char was cr */
596       if(c == '\n')               /* if have cr,lf then just */
597         lseek(test->ofile, -1, SEEK_CUR); /* smash lf on top of the cr */
598       else
599         if(c == '\0')             /* if have cr,nul then */
600           goto skipit;            /* just skip over the putc */
601       /* else just fall through and allow it */
602     }
603     /* formerly
604        putc(c, file); */
605     if(1 != write(test->ofile, &c, 1))
606       break;
607     skipit:
608     prevchar = c;
609   }
610   return count;
611 }
612 
613 /* When an error has occurred, it is possible that the two sides are out of
614  * synch.  Ie: that what I think is the other side's response to packet N is
615  * really their response to packet N-1.
616  *
617  * So, to try to prevent that, we flush all the input queued up for us on the
618  * network connection on our host.
619  *
620  * We return the number of packets we flushed (mostly for reporting when trace
621  * is active).
622  */
623 
synchnet(curl_socket_t f)624 static int synchnet(curl_socket_t f /* socket to flush */)
625 {
626 
627 #if defined(HAVE_IOCTLSOCKET)
628   unsigned long i;
629 #else
630   int i;
631 #endif
632   int j = 0;
633   char rbuf[PKTSIZE];
634   srvr_sockaddr_union_t fromaddr;
635   curl_socklen_t fromaddrlen;
636 
637   for(;;) {
638 #if defined(HAVE_IOCTLSOCKET)
639     (void) ioctlsocket(f, FIONREAD, &i);
640 #else
641     (void) ioctl(f, FIONREAD, &i);
642 #endif
643     if(i) {
644       j++;
645 #ifdef ENABLE_IPV6
646       if(!use_ipv6)
647 #endif
648         fromaddrlen = sizeof(fromaddr.sa4);
649 #ifdef ENABLE_IPV6
650       else
651         fromaddrlen = sizeof(fromaddr.sa6);
652 #endif
653       (void) recvfrom(f, rbuf, sizeof(rbuf), 0,
654                       &fromaddr.sa, &fromaddrlen);
655     }
656     else
657       break;
658   }
659   return j;
660 }
661 
main(int argc,char ** argv)662 int main(int argc, char **argv)
663 {
664   srvr_sockaddr_union_t me;
665   struct tftphdr *tp;
666   ssize_t n = 0;
667   int arg = 1;
668   unsigned short port = DEFAULT_PORT;
669   curl_socket_t sock = CURL_SOCKET_BAD;
670   int flag;
671   int rc;
672   int error;
673   long pid;
674   struct testcase test;
675   int result = 0;
676 
677   memset(&test, 0, sizeof(test));
678 
679   while(argc>arg) {
680     if(!strcmp("--version", argv[arg])) {
681       printf("tftpd IPv4%s\n",
682 #ifdef ENABLE_IPV6
683              "/IPv6"
684 #else
685              ""
686 #endif
687              );
688       return 0;
689     }
690     else if(!strcmp("--pidfile", argv[arg])) {
691       arg++;
692       if(argc>arg)
693         pidname = argv[arg++];
694     }
695     else if(!strcmp("--logfile", argv[arg])) {
696       arg++;
697       if(argc>arg)
698         serverlogfile = argv[arg++];
699     }
700     else if(!strcmp("--ipv4", argv[arg])) {
701 #ifdef ENABLE_IPV6
702       ipv_inuse = "IPv4";
703       use_ipv6 = FALSE;
704 #endif
705       arg++;
706     }
707     else if(!strcmp("--ipv6", argv[arg])) {
708 #ifdef ENABLE_IPV6
709       ipv_inuse = "IPv6";
710       use_ipv6 = TRUE;
711 #endif
712       arg++;
713     }
714     else if(!strcmp("--port", argv[arg])) {
715       arg++;
716       if(argc>arg) {
717         char *endptr;
718         unsigned long ulnum = strtoul(argv[arg], &endptr, 10);
719         if((endptr != argv[arg] + strlen(argv[arg])) ||
720            (ulnum < 1025UL) || (ulnum > 65535UL)) {
721           fprintf(stderr, "tftpd: invalid --port argument (%s)\n",
722                   argv[arg]);
723           return 0;
724         }
725         port = curlx_ultous(ulnum);
726         arg++;
727       }
728     }
729     else if(!strcmp("--srcdir", argv[arg])) {
730       arg++;
731       if(argc>arg) {
732         path = argv[arg];
733         arg++;
734       }
735     }
736     else {
737       puts("Usage: tftpd [option]\n"
738            " --version\n"
739            " --logfile [file]\n"
740            " --pidfile [file]\n"
741            " --ipv4\n"
742            " --ipv6\n"
743            " --port [port]\n"
744            " --srcdir [path]");
745       return 0;
746     }
747   }
748 
749 #ifdef WIN32
750   win32_init();
751   atexit(win32_cleanup);
752 #endif
753 
754   install_signal_handlers();
755 
756   pid = (long)getpid();
757 
758 #ifdef ENABLE_IPV6
759   if(!use_ipv6)
760 #endif
761     sock = socket(AF_INET, SOCK_DGRAM, 0);
762 #ifdef ENABLE_IPV6
763   else
764     sock = socket(AF_INET6, SOCK_DGRAM, 0);
765 #endif
766 
767   if(CURL_SOCKET_BAD == sock) {
768     error = SOCKERRNO;
769     logmsg("Error creating socket: (%d) %s",
770            error, strerror(error));
771     result = 1;
772     goto tftpd_cleanup;
773   }
774 
775   flag = 1;
776   if(0 != setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
777             (void *)&flag, sizeof(flag))) {
778     error = SOCKERRNO;
779     logmsg("setsockopt(SO_REUSEADDR) failed with error: (%d) %s",
780            error, strerror(error));
781     result = 1;
782     goto tftpd_cleanup;
783   }
784 
785 #ifdef ENABLE_IPV6
786   if(!use_ipv6) {
787 #endif
788     memset(&me.sa4, 0, sizeof(me.sa4));
789     me.sa4.sin_family = AF_INET;
790     me.sa4.sin_addr.s_addr = INADDR_ANY;
791     me.sa4.sin_port = htons(port);
792     rc = bind(sock, &me.sa, sizeof(me.sa4));
793 #ifdef ENABLE_IPV6
794   }
795   else {
796     memset(&me.sa6, 0, sizeof(me.sa6));
797     me.sa6.sin6_family = AF_INET6;
798     me.sa6.sin6_addr = in6addr_any;
799     me.sa6.sin6_port = htons(port);
800     rc = bind(sock, &me.sa, sizeof(me.sa6));
801   }
802 #endif /* ENABLE_IPV6 */
803   if(0 != rc) {
804     error = SOCKERRNO;
805     logmsg("Error binding socket on port %hu: (%d) %s",
806            port, error, strerror(error));
807     result = 1;
808     goto tftpd_cleanup;
809   }
810 
811   wrotepidfile = write_pidfile(pidname);
812   if(!wrotepidfile) {
813     result = 1;
814     goto tftpd_cleanup;
815   }
816 
817   logmsg("Running %s version on port UDP/%d", ipv_inuse, (int)port);
818 
819   for(;;) {
820     fromlen = sizeof(from);
821 #ifdef ENABLE_IPV6
822     if(!use_ipv6)
823 #endif
824       fromlen = sizeof(from.sa4);
825 #ifdef ENABLE_IPV6
826     else
827       fromlen = sizeof(from.sa6);
828 #endif
829     n = (ssize_t)recvfrom(sock, &buf.storage[0], sizeof(buf.storage), 0,
830                           &from.sa, &fromlen);
831     if(got_exit_signal)
832       break;
833     if(n < 0) {
834       logmsg("recvfrom");
835       result = 3;
836       break;
837     }
838 
839     set_advisor_read_lock(SERVERLOGS_LOCK);
840     serverlogslocked = 1;
841 
842 #ifdef ENABLE_IPV6
843     if(!use_ipv6) {
844 #endif
845       from.sa4.sin_family = AF_INET;
846       peer = socket(AF_INET, SOCK_DGRAM, 0);
847       if(CURL_SOCKET_BAD == peer) {
848         logmsg("socket");
849         result = 2;
850         break;
851       }
852       if(connect(peer, &from.sa, sizeof(from.sa4)) < 0) {
853         logmsg("connect: fail");
854         result = 1;
855         break;
856       }
857 #ifdef ENABLE_IPV6
858     }
859     else {
860       from.sa6.sin6_family = AF_INET6;
861       peer = socket(AF_INET6, SOCK_DGRAM, 0);
862       if(CURL_SOCKET_BAD == peer) {
863         logmsg("socket");
864         result = 2;
865         break;
866       }
867       if(connect(peer, &from.sa, sizeof(from.sa6)) < 0) {
868         logmsg("connect: fail");
869         result = 1;
870         break;
871       }
872     }
873 #endif
874 
875     maxtimeout = 5*TIMEOUT;
876 
877     tp = &buf.hdr;
878     tp->th_opcode = ntohs(tp->th_opcode);
879     if(tp->th_opcode == opcode_RRQ || tp->th_opcode == opcode_WRQ) {
880       memset(&test, 0, sizeof(test));
881       if(do_tftp(&test, tp, n) < 0)
882         break;
883       free(test.buffer);
884     }
885     sclose(peer);
886     peer = CURL_SOCKET_BAD;
887 
888     if(test.ofile > 0) {
889       close(test.ofile);
890       test.ofile = 0;
891     }
892 
893     if(got_exit_signal)
894       break;
895 
896     if(serverlogslocked) {
897       serverlogslocked = 0;
898       clear_advisor_read_lock(SERVERLOGS_LOCK);
899     }
900 
901     logmsg("end of one transfer");
902 
903   }
904 
905 tftpd_cleanup:
906 
907   if(test.ofile > 0)
908     close(test.ofile);
909 
910   if((peer != sock) && (peer != CURL_SOCKET_BAD))
911     sclose(peer);
912 
913   if(sock != CURL_SOCKET_BAD)
914     sclose(sock);
915 
916   if(got_exit_signal)
917     logmsg("signalled to die");
918 
919   if(wrotepidfile)
920     unlink(pidname);
921 
922   if(serverlogslocked) {
923     serverlogslocked = 0;
924     clear_advisor_read_lock(SERVERLOGS_LOCK);
925   }
926 
927   restore_signal_handlers();
928 
929   if(got_exit_signal) {
930     logmsg("========> %s tftpd (port: %d pid: %ld) exits with signal (%d)",
931            ipv_inuse, (int)port, pid, exit_signal);
932     /*
933      * To properly set the return status of the process we
934      * must raise the same signal SIGINT or SIGTERM that we
935      * caught and let the old handler take care of it.
936      */
937     raise(exit_signal);
938   }
939 
940   logmsg("========> tftpd quits");
941   return result;
942 }
943 
944 /*
945  * Handle initial connection protocol.
946  */
do_tftp(struct testcase * test,struct tftphdr * tp,ssize_t size)947 static int do_tftp(struct testcase *test, struct tftphdr *tp, ssize_t size)
948 {
949   char *cp;
950   int first = 1, ecode;
951   struct formats *pf;
952   char *filename, *mode = NULL;
953   int error;
954   FILE *server;
955 #ifdef USE_WINSOCK
956   DWORD recvtimeout, recvtimeoutbak;
957 #endif
958   char *option = (char *)"mode"; /* mode is implicit */
959   int toggle = 1;
960 
961   /* Open request dump file. */
962   server = fopen(REQUEST_DUMP, "ab");
963   if(!server) {
964     error = errno;
965     logmsg("fopen() failed with error: %d %s", error, strerror(error));
966     logmsg("Error opening file: %s", REQUEST_DUMP);
967     return -1;
968   }
969 
970   /* store input protocol */
971   fprintf(server, "opcode: %x\n", tp->th_opcode);
972 
973   cp = (char *)&tp->th_stuff;
974   filename = cp;
975   do {
976     bool endofit = true;
977     while(cp < &buf.storage[size]) {
978       if(*cp == '\0') {
979         endofit = false;
980         break;
981       }
982       cp++;
983     }
984     if(endofit)
985       /* no more options */
986       break;
987 
988     /* before increasing pointer, make sure it is still within the legal
989        space */
990     if((cp+1) < &buf.storage[size]) {
991       ++cp;
992       if(first) {
993         /* store the mode since we need it later */
994         mode = cp;
995         first = 0;
996       }
997       if(toggle)
998         /* name/value pair: */
999         fprintf(server, "%s: %s\n", option, cp);
1000       else {
1001         /* store the name pointer */
1002         option = cp;
1003       }
1004       toggle ^= 1;
1005     }
1006     else
1007       /* No more options */
1008       break;
1009   } while(1);
1010 
1011   if(*cp) {
1012     nak(EBADOP);
1013     fclose(server);
1014     return 3;
1015   }
1016 
1017   /* store input protocol */
1018   fprintf(server, "filename: %s\n", filename);
1019 
1020   for(cp = mode; cp && *cp; cp++)
1021     if(ISUPPER(*cp))
1022       *cp = (char)tolower((int)*cp);
1023 
1024   /* store input protocol */
1025   fclose(server);
1026 
1027   for(pf = formata; pf->f_mode; pf++)
1028     if(strcmp(pf->f_mode, mode) == 0)
1029       break;
1030   if(!pf->f_mode) {
1031     nak(EBADOP);
1032     return 2;
1033   }
1034   ecode = validate_access(test, filename, tp->th_opcode);
1035   if(ecode) {
1036     nak(ecode);
1037     return 1;
1038   }
1039 
1040 #ifdef USE_WINSOCK
1041   recvtimeout = sizeof(recvtimeoutbak);
1042   getsockopt(peer, SOL_SOCKET, SO_RCVTIMEO,
1043              (char *)&recvtimeoutbak, (int *)&recvtimeout);
1044   recvtimeout = TIMEOUT*1000;
1045   setsockopt(peer, SOL_SOCKET, SO_RCVTIMEO,
1046              (const char *)&recvtimeout, sizeof(recvtimeout));
1047 #endif
1048 
1049   if(tp->th_opcode == opcode_WRQ)
1050     recvtftp(test, pf);
1051   else
1052     sendtftp(test, pf);
1053 
1054 #ifdef USE_WINSOCK
1055   recvtimeout = recvtimeoutbak;
1056   setsockopt(peer, SOL_SOCKET, SO_RCVTIMEO,
1057              (const char *)&recvtimeout, sizeof(recvtimeout));
1058 #endif
1059 
1060   return 0;
1061 }
1062 
1063 /* Based on the testno, parse the correct server commands. */
parse_servercmd(struct testcase * req)1064 static int parse_servercmd(struct testcase *req)
1065 {
1066   FILE *stream;
1067   char *filename;
1068   int error;
1069 
1070   filename = test2file(req->testno);
1071 
1072   stream=fopen(filename, "rb");
1073   if(!stream) {
1074     error = errno;
1075     logmsg("fopen() failed with error: %d %s", error, strerror(error));
1076     logmsg("  [1] Error opening file: %s", filename);
1077     logmsg("  Couldn't open test file %ld", req->testno);
1078     return 1; /* done */
1079   }
1080   else {
1081     char *orgcmd = NULL;
1082     char *cmd = NULL;
1083     size_t cmdsize = 0;
1084     int num=0;
1085 
1086     /* get the custom server control "commands" */
1087     error = getpart(&orgcmd, &cmdsize, "reply", "servercmd", stream);
1088     fclose(stream);
1089     if(error) {
1090       logmsg("getpart() failed with error: %d", error);
1091       return 1; /* done */
1092     }
1093 
1094     cmd = orgcmd;
1095     while(cmd && cmdsize) {
1096       char *check;
1097       if(1 == sscanf(cmd, "writedelay: %d", &num)) {
1098         logmsg("instructed to delay %d secs between packets", num);
1099         req->writedelay = num;
1100       }
1101       else {
1102         logmsg("Unknown <servercmd> instruction found: %s", cmd);
1103       }
1104       /* try to deal with CRLF or just LF */
1105       check = strchr(cmd, '\r');
1106       if(!check)
1107         check = strchr(cmd, '\n');
1108 
1109       if(check) {
1110         /* get to the letter following the newline */
1111         while((*check == '\r') || (*check == '\n'))
1112           check++;
1113 
1114         if(!*check)
1115           /* if we reached a zero, get out */
1116           break;
1117         cmd = check;
1118       }
1119       else
1120         break;
1121     }
1122     free(orgcmd);
1123   }
1124 
1125   return 0; /* OK! */
1126 }
1127 
1128 
1129 /*
1130  * Validate file access.
1131  */
validate_access(struct testcase * test,const char * filename,int mode)1132 static int validate_access(struct testcase *test,
1133                            const char *filename, int mode)
1134 {
1135   char *ptr;
1136   long testno, partno;
1137   int error;
1138   char partbuf[80]="data";
1139 
1140   logmsg("trying to get file: %s mode %x", filename, mode);
1141 
1142   if(!strncmp("verifiedserver", filename, 14)) {
1143     char weare[128];
1144     size_t count = snprintf(weare, sizeof(weare),
1145                             "WE ROOLZ: %ld\r\n", (long)getpid());
1146 
1147     logmsg("Are-we-friendly question received");
1148     test->buffer = strdup(weare);
1149     test->rptr = test->buffer; /* set read pointer */
1150     test->bufsize = count;    /* set total count */
1151     test->rcount = count;     /* set data left to read */
1152     return 0; /* fine */
1153   }
1154 
1155   /* find the last slash */
1156   ptr = strrchr(filename, '/');
1157 
1158   if(ptr) {
1159     char *file;
1160 
1161     ptr++; /* skip the slash */
1162 
1163     /* skip all non-numericals following the slash */
1164     while(*ptr && !ISDIGIT(*ptr))
1165       ptr++;
1166 
1167     /* get the number */
1168     testno = strtol(ptr, &ptr, 10);
1169 
1170     if(testno > 10000) {
1171       partno = testno % 10000;
1172       testno /= 10000;
1173     }
1174     else
1175       partno = 0;
1176 
1177 
1178     logmsg("requested test number %ld part %ld", testno, partno);
1179 
1180     test->testno = testno;
1181 
1182     (void)parse_servercmd(test);
1183 
1184     file = test2file(testno);
1185 
1186     if(0 != partno)
1187       snprintf(partbuf, sizeof(partbuf), "data%ld", partno);
1188 
1189     if(file) {
1190       FILE *stream=fopen(file, "rb");
1191       if(!stream) {
1192         error = errno;
1193         logmsg("fopen() failed with error: %d %s", error, strerror(error));
1194         logmsg("Error opening file: %s", file);
1195         logmsg("Couldn't open test file: %s", file);
1196         return EACCESS;
1197       }
1198       else {
1199         size_t count;
1200         error = getpart(&test->buffer, &count, "reply", partbuf, stream);
1201         fclose(stream);
1202         if(error) {
1203           logmsg("getpart() failed with error: %d", error);
1204           return EACCESS;
1205         }
1206         if(test->buffer) {
1207           test->rptr = test->buffer; /* set read pointer */
1208           test->bufsize = count;    /* set total count */
1209           test->rcount = count;     /* set data left to read */
1210         }
1211         else
1212           return EACCESS;
1213       }
1214 
1215     }
1216     else
1217       return EACCESS;
1218   }
1219   else {
1220     logmsg("no slash found in path");
1221     return EACCESS; /* failure */
1222   }
1223 
1224   logmsg("file opened and all is good");
1225   return 0;
1226 }
1227 
1228 /*
1229  * Send the requested file.
1230  */
sendtftp(struct testcase * test,struct formats * pf)1231 static void sendtftp(struct testcase *test, struct formats *pf)
1232 {
1233   int size;
1234   ssize_t n;
1235   /* These are volatile to live through a siglongjmp */
1236   volatile unsigned short sendblock; /* block count */
1237   struct tftphdr * volatile sdp = r_init(); /* data buffer */
1238   struct tftphdr * const sap = &ackbuf.hdr; /* ack buffer */
1239 
1240   sendblock = 1;
1241 #if defined(HAVE_ALARM) && defined(SIGALRM)
1242   mysignal(SIGALRM, timer);
1243 #endif
1244   do {
1245     size = readit(test, (struct tftphdr **)&sdp, pf->f_convert);
1246     if(size < 0) {
1247       nak(errno + 100);
1248       return;
1249     }
1250     sdp->th_opcode = htons((unsigned short)opcode_DATA);
1251     sdp->th_block = htons(sendblock);
1252     timeout = 0;
1253 #ifdef HAVE_SIGSETJMP
1254     (void) sigsetjmp(timeoutbuf, 1);
1255 #endif
1256     if(test->writedelay) {
1257       logmsg("Pausing %d seconds before %d bytes", test->writedelay,
1258              size);
1259       wait_ms(1000*test->writedelay);
1260     }
1261 
1262     send_data:
1263     if(swrite(peer, sdp, size + 4) != size + 4) {
1264       logmsg("write");
1265       return;
1266     }
1267     read_ahead(test, pf->f_convert);
1268     for(;;) {
1269 #ifdef HAVE_ALARM
1270       alarm(rexmtval);        /* read the ack */
1271 #endif
1272       n = sread(peer, &ackbuf.storage[0], sizeof(ackbuf.storage));
1273 #ifdef HAVE_ALARM
1274       alarm(0);
1275 #endif
1276       if(got_exit_signal)
1277         return;
1278       if(n < 0) {
1279         logmsg("read: fail");
1280         return;
1281       }
1282       sap->th_opcode = ntohs((unsigned short)sap->th_opcode);
1283       sap->th_block = ntohs(sap->th_block);
1284 
1285       if(sap->th_opcode == opcode_ERROR) {
1286         logmsg("got ERROR");
1287         return;
1288       }
1289 
1290       if(sap->th_opcode == opcode_ACK) {
1291         if(sap->th_block == sendblock) {
1292           break;
1293         }
1294         /* Re-synchronize with the other side */
1295         (void) synchnet(peer);
1296         if(sap->th_block == (sendblock-1)) {
1297           goto send_data;
1298         }
1299       }
1300 
1301     }
1302     sendblock++;
1303   } while(size == SEGSIZE);
1304 }
1305 
1306 /*
1307  * Receive a file.
1308  */
recvtftp(struct testcase * test,struct formats * pf)1309 static void recvtftp(struct testcase *test, struct formats *pf)
1310 {
1311   ssize_t n, size;
1312   /* These are volatile to live through a siglongjmp */
1313   volatile unsigned short recvblock; /* block count */
1314   struct tftphdr * volatile rdp;     /* data buffer */
1315   struct tftphdr *rap;      /* ack buffer */
1316 
1317   recvblock = 0;
1318   rdp = w_init();
1319 #if defined(HAVE_ALARM) && defined(SIGALRM)
1320   mysignal(SIGALRM, timer);
1321 #endif
1322   rap = &ackbuf.hdr;
1323   do {
1324     timeout = 0;
1325     rap->th_opcode = htons((unsigned short)opcode_ACK);
1326     rap->th_block = htons(recvblock);
1327     recvblock++;
1328 #ifdef HAVE_SIGSETJMP
1329     (void) sigsetjmp(timeoutbuf, 1);
1330 #endif
1331 send_ack:
1332     if(swrite(peer, &ackbuf.storage[0], 4) != 4) {
1333       logmsg("write: fail\n");
1334       goto abort;
1335     }
1336     write_behind(test, pf->f_convert);
1337     for(;;) {
1338 #ifdef HAVE_ALARM
1339       alarm(rexmtval);
1340 #endif
1341       n = sread(peer, rdp, PKTSIZE);
1342 #ifdef HAVE_ALARM
1343       alarm(0);
1344 #endif
1345       if(got_exit_signal)
1346         goto abort;
1347       if(n < 0) {                       /* really? */
1348         logmsg("read: fail\n");
1349         goto abort;
1350       }
1351       rdp->th_opcode = ntohs((unsigned short)rdp->th_opcode);
1352       rdp->th_block = ntohs(rdp->th_block);
1353       if(rdp->th_opcode == opcode_ERROR)
1354         goto abort;
1355       if(rdp->th_opcode == opcode_DATA) {
1356         if(rdp->th_block == recvblock) {
1357           break;                         /* normal */
1358         }
1359         /* Re-synchronize with the other side */
1360         (void) synchnet(peer);
1361         if(rdp->th_block == (recvblock-1))
1362           goto send_ack;                 /* rexmit */
1363       }
1364     }
1365 
1366     size = writeit(test, &rdp, (int)(n - 4), pf->f_convert);
1367     if(size != (n-4)) {                 /* ahem */
1368       if(size < 0)
1369         nak(errno + 100);
1370       else
1371         nak(ENOSPACE);
1372       goto abort;
1373     }
1374   } while(size == SEGSIZE);
1375   write_behind(test, pf->f_convert);
1376 
1377   rap->th_opcode = htons((unsigned short)opcode_ACK);  /* send the "final"
1378                                                           ack */
1379   rap->th_block = htons(recvblock);
1380   (void) swrite(peer, &ackbuf.storage[0], 4);
1381 #if defined(HAVE_ALARM) && defined(SIGALRM)
1382   mysignal(SIGALRM, justtimeout);        /* just abort read on timeout */
1383   alarm(rexmtval);
1384 #endif
1385   /* normally times out and quits */
1386   n = sread(peer, &buf.storage[0], sizeof(buf.storage));
1387 #ifdef HAVE_ALARM
1388   alarm(0);
1389 #endif
1390   if(got_exit_signal)
1391     goto abort;
1392   if(n >= 4 &&                               /* if read some data */
1393      rdp->th_opcode == opcode_DATA &&        /* and got a data block */
1394      recvblock == rdp->th_block) {           /* then my last ack was lost */
1395     (void) swrite(peer, &ackbuf.storage[0], 4);  /* resend final ack */
1396   }
1397 abort:
1398   return;
1399 }
1400 
1401 /*
1402  * Send a nak packet (error message).  Error code passed in is one of the
1403  * standard TFTP codes, or a Unix errno offset by 100.
1404  */
nak(int error)1405 static void nak(int error)
1406 {
1407   struct tftphdr *tp;
1408   int length;
1409   struct errmsg *pe;
1410 
1411   tp = &buf.hdr;
1412   tp->th_opcode = htons((unsigned short)opcode_ERROR);
1413   tp->th_code = htons((unsigned short)error);
1414   for(pe = errmsgs; pe->e_code >= 0; pe++)
1415     if(pe->e_code == error)
1416       break;
1417   if(pe->e_code < 0) {
1418     pe->e_msg = strerror(error - 100);
1419     tp->th_code = EUNDEF;   /* set 'undef' errorcode */
1420   }
1421   length = (int)strlen(pe->e_msg);
1422 
1423   /* we use memcpy() instead of strcpy() in order to avoid buffer overflow
1424    * report from glibc with FORTIFY_SOURCE */
1425   memcpy(tp->th_msg, pe->e_msg, length + 1);
1426   length += 5;
1427   if(swrite(peer, &buf.storage[0], length) != length)
1428     logmsg("nak: fail\n");
1429 }
1430