ARC: better diagnostics for keyfile issues
[exim.git] / src / src / malware.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2003 - 2015
6 * License: GPL
7 * Copyright (c) The Exim Maintainers 2015 - 2018
8 */
9
10 /* Code for calling virus (malware) scanners. Called from acl.c. */
11
12 #include "exim.h"
13 #ifdef WITH_CONTENT_SCAN /* entire file */
14
15 typedef enum {
16 #ifndef DISABLE_MAL_FFROTD
17 M_FPROTD,
18 #endif
19 #ifndef DISABLE_MAL_FFROT6D
20 M_FPROT6D,
21 #endif
22 #ifndef DISABLE_MAL_DRWEB
23 M_DRWEB,
24 #endif
25 #ifndef DISABLE_MAL_AVE
26 M_AVES,
27 #endif
28 #ifndef DISABLE_MAL_FSECURE
29 M_FSEC,
30 #endif
31 #ifndef DISABLE_MAL_KAV
32 M_KAVD,
33 #endif
34 #ifndef DISABLE_MAL_SOPHIE
35 M_SOPHIE,
36 #endif
37 #ifndef DISABLE_MAL_CLAM
38 M_CLAMD,
39 #endif
40 #ifndef DISABLE_MAL_MKS
41 M_MKSD,
42 #endif
43 #ifndef DISABLE_MAL_AVAST
44 M_AVAST,
45 #endif
46 #ifndef DISABLE_MAL_SOCK
47 M_SOCK,
48 #endif
49 #ifndef DISABLE_MAL_CMDLINE
50 M_CMDL,
51 #endif
52 } scanner_t;
53 typedef enum {MC_NONE, MC_TCP, MC_UNIX, MC_STRM} contype_t;
54 static struct scan
55 {
56 scanner_t scancode;
57 const uschar * name;
58 const uschar * options_default;
59 contype_t conn;
60 } m_scans[] =
61 {
62 #ifndef DISABLE_MAL_FFROTD
63 { M_FPROTD, US"f-protd", US"localhost 10200-10204", MC_TCP },
64 #endif
65 #ifndef DISABLE_MAL_FFROT6D
66 { M_FPROT6D, US"f-prot6d", US"localhost 10200", MC_TCP },
67 #endif
68 #ifndef DISABLE_MAL_DRWEB
69 { M_DRWEB, US"drweb", US"/usr/local/drweb/run/drwebd.sock", MC_STRM },
70 #endif
71 #ifndef DISABLE_MAL_AVE
72 { M_AVES, US"aveserver", US"/var/run/aveserver", MC_UNIX },
73 #endif
74 #ifndef DISABLE_MAL_FSECURE
75 { M_FSEC, US"fsecure", US"/var/run/.fsav", MC_UNIX },
76 #endif
77 #ifndef DISABLE_MAL_KAV
78 { M_KAVD, US"kavdaemon", US"/var/run/AvpCtl", MC_UNIX },
79 #endif
80 #ifndef DISABLE_MAL_SOPHIE
81 { M_SOPHIE, US"sophie", US"/var/run/sophie", MC_UNIX },
82 #endif
83 #ifndef DISABLE_MAL_CLAM
84 { M_CLAMD, US"clamd", US"/tmp/clamd", MC_NONE },
85 #endif
86 #ifndef DISABLE_MAL_MKS
87 { M_MKSD, US"mksd", NULL, MC_NONE },
88 #endif
89 #ifndef DISABLE_MAL_AVAST
90 { M_AVAST, US"avast", US"/var/run/avast/scan.sock", MC_STRM },
91 #endif
92 #ifndef DISABLE_MAL_SOCK
93 { M_SOCK, US"sock", US"/tmp/malware.sock", MC_STRM },
94 #endif
95 #ifndef DISABLE_MAL_CMDLINE
96 { M_CMDL, US"cmdline", NULL, MC_NONE },
97 #endif
98 { -1, NULL, NULL, MC_NONE } /* end-marker */
99 };
100
101 /******************************************************************************/
102 # ifdef MACRO_PREDEF /* build solely to predefine macros */
103
104 # include "macro_predef.h"
105
106 void
107 features_malware(void)
108 {
109 const struct scan * sc;
110 const uschar * s;
111 uschar * t;
112 uschar buf[64];
113
114 spf(buf, sizeof(buf), US"_HAVE_MALWARE_");
115
116 for (sc = m_scans; sc->scancode != -1; sc++)
117 {
118 for(s = sc->name, t = buf+14; *s; s++) if (*s != '-') *t++ = toupper(*s);
119 *t = '\0';
120 builtin_macro_create(buf);
121 }
122 }
123
124 /******************************************************************************/
125 # else /*!MACRO_PREDEF, main build*/
126
127
128 #define MALWARE_TIMEOUT 120 /* default timeout, seconds */
129
130 static const uschar * malware_regex_default = US ".+";
131 static const pcre * malware_default_re = NULL;
132
133
134
135 #ifndef DISABLE_MAL_CLAM
136 /* The maximum number of clamd servers that are supported in the configuration */
137 # define MAX_CLAMD_SERVERS 32
138 # define MAX_CLAMD_SERVERS_S "32"
139
140 typedef struct clamd_address {
141 uschar * hostspec;
142 unsigned tcp_port;
143 unsigned retry;
144 } clamd_address;
145 #endif
146
147
148 #ifndef DISABLE_MAL_DRWEB
149 # define DRWEBD_SCAN_CMD (1) /* scan file, buffer or diskfile */
150 # define DRWEBD_RETURN_VIRUSES (1<<0) /* ask daemon return to us viruses names from report */
151 # define DRWEBD_IS_MAIL (1<<19) /* say to daemon that format is "archive MAIL" */
152
153 # define DERR_READ_ERR (1<<0) /* read error */
154 # define DERR_NOMEMORY (1<<2) /* no memory */
155 # define DERR_TIMEOUT (1<<9) /* scan timeout has run out */
156 # define DERR_BAD_CALL (1<<15) /* wrong command */
157
158 static const uschar * drweb_re_str = US "infected\\swith\\s*(.+?)$";
159 static const pcre * drweb_re = NULL;
160 #endif
161
162 #ifndef DISABLE_MAL_FSECURE
163 static const uschar * fsec_re_str = US "\\S{0,5}INFECTED\\t[^\\t]*\\t([^\\t]+)\\t\\S*$";
164 static const pcre * fsec_re = NULL;
165 #endif
166
167 #ifndef DISABLE_MAL_KAV
168 static const uschar * kav_re_sus_str = US "suspicion:\\s*(.+?)\\s*$";
169 static const uschar * kav_re_inf_str = US "infected:\\s*(.+?)\\s*$";
170 static const pcre * kav_re_sus = NULL;
171 static const pcre * kav_re_inf = NULL;
172 #endif
173
174 #ifndef DISABLE_MAL_AVAST
175 static const uschar * ava_re_clean_str = US "(?!\\\\)\\t\\[\\+\\]";
176 static const uschar * ava_re_virus_str = US "(?!\\\\)\\t\\[L\\]\\d+\\.0\\t0\\s(.*)";
177 static const uschar * ava_re_error_str = US "(?!\\\\)\\t\\[E\\]\\d+\\.0\\tError\\s\\d+\\s(.*)";
178 static const pcre * ava_re_clean = NULL;
179 static const pcre * ava_re_virus = NULL;
180 static const pcre * ava_re_error = NULL;
181 #endif
182
183 #ifndef DISABLE_MAL_FFROT6D
184 static const uschar * fprot6d_re_error_str = US "^\\d+\\s<(.+?)>$";
185 static const uschar * fprot6d_re_virus_str = US "^\\d+\\s<infected:\\s+(.+?)>\\s+.+$";
186 static const pcre * fprot6d_re_error = NULL;
187 static const pcre * fprot6d_re_virus = NULL;
188 #endif
189
190
191
192 /******************************************************************************/
193
194 /* Routine to check whether a system is big- or little-endian.
195 Ripped from http://www.faqs.org/faqs/graphics/fileformats-faq/part4/section-7.html
196 Needed for proper kavdaemon implementation. Sigh. */
197 #define BIG_MY_ENDIAN 0
198 #define LITTLE_MY_ENDIAN 1
199 static int test_byte_order(void);
200 static inline int
201 test_byte_order()
202 {
203 short int word = 0x0001;
204 char *byte = CS &word;
205 return(byte[0] ? LITTLE_MY_ENDIAN : BIG_MY_ENDIAN);
206 }
207
208 BOOL malware_ok = FALSE;
209
210 /* Gross hacks for the -bmalware option; perhaps we should just create
211 the scan directory normally for that case, but look into rigging up the
212 needed header variables if not already set on the command-line? */
213 extern int spool_mbox_ok;
214 extern uschar spooled_message_id[MESSAGE_ID_LENGTH+1];
215
216
217 /* Some (currently avast only) use backslash escaped whitespace,
218 this function undoes these escapes */
219
220 static inline void
221 unescape(uschar *p)
222 {
223 uschar *p0;
224 for (; *p; ++p)
225 if (*p == '\\' && (isspace(p[1]) || p[1] == '\\'))
226 for (p0 = p; *p0; ++p0) *p0 = p0[1];
227 }
228
229 /* --- malware_*_defer --- */
230 static inline int
231 malware_panic_defer(const uschar * str)
232 {
233 log_write(0, LOG_MAIN|LOG_PANIC, "malware acl condition: %s", str);
234 return DEFER;
235 }
236 static inline int
237 malware_log_defer(const uschar * str)
238 {
239 log_write(0, LOG_MAIN, "malware acl condition: %s", str);
240 return DEFER;
241 }
242 /* --- m_*_defer --- */
243 static inline int
244 m_panic_defer(struct scan * scanent, const uschar * hostport,
245 const uschar * str)
246 {
247 return malware_panic_defer(string_sprintf("%s %s : %s",
248 scanent->name, hostport ? hostport : CUS"", str));
249 }
250 static inline int
251 m_log_defer(struct scan * scanent, const uschar * hostport,
252 const uschar * str)
253 {
254 return malware_log_defer(string_sprintf("%s %s : %s",
255 scanent->name, hostport ? hostport : CUS"", str));
256 }
257 /* --- m_*_defer_3 */
258 static inline int
259 m_panic_defer_3(struct scan * scanent, const uschar * hostport,
260 const uschar * str, int fd_to_close)
261 {
262 (void) close(fd_to_close);
263 return m_panic_defer(scanent, hostport, str);
264 }
265 static inline int
266 m_log_defer_3(struct scan * scanent, const uschar * hostport,
267 const uschar * str, int fd_to_close)
268 {
269 (void) close(fd_to_close);
270 return m_log_defer(scanent, hostport, str);
271 }
272
273 /*************************************************/
274
275 #ifndef DISABLE_MAL_CLAM
276 /* Only used by the Clamav code, which is working from a list of servers and
277 uses the returned in_addr to get a second connection to the same system.
278 */
279 static inline int
280 m_tcpsocket(const uschar * hostname, unsigned int port,
281 host_item * host, uschar ** errstr, const blob * fastopen_blob)
282 {
283 return ip_connectedsocket(SOCK_STREAM, hostname, port, port, 5,
284 host, errstr, fastopen_blob);
285 }
286 #endif
287
288 static int
289 m_sock_send(int sock, uschar * buf, int cnt, uschar ** errstr)
290 {
291 if (send(sock, buf, cnt, 0) < 0)
292 {
293 int err = errno;
294 (void)close(sock);
295 *errstr = string_sprintf("unable to send to socket (%s): %s",
296 buf, strerror(err));
297 return -1;
298 }
299 return sock;
300 }
301
302 static const pcre *
303 m_pcre_compile(const uschar * re, uschar ** errstr)
304 {
305 const uschar * rerror;
306 int roffset;
307 const pcre * cre;
308
309 cre = pcre_compile(CS re, PCRE_COPT, (const char **)&rerror, &roffset, NULL);
310 if (!cre)
311 *errstr= string_sprintf("regular expression error in '%s': %s at offset %d",
312 re, rerror, roffset);
313 return cre;
314 }
315
316 uschar *
317 m_pcre_exec(const pcre * cre, uschar * text)
318 {
319 int ovector[10*3];
320 int i = pcre_exec(cre, NULL, CS text, Ustrlen(text), 0, 0,
321 ovector, nelem(ovector));
322 uschar * substr = NULL;
323 if (i >= 2) /* Got it */
324 pcre_get_substring(CS text, ovector, i, 1, (const char **) &substr);
325 return substr;
326 }
327
328 static const pcre *
329 m_pcre_nextinlist(const uschar ** list, int * sep,
330 char * listerr, uschar ** errstr)
331 {
332 const uschar * list_ele;
333 const pcre * cre = NULL;
334
335 if (!(list_ele = string_nextinlist(list, sep, NULL, 0)))
336 *errstr = US listerr;
337 else
338 {
339 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "RE: ",
340 string_printing(list_ele));
341 cre = m_pcre_compile(CUS list_ele, errstr);
342 }
343 return cre;
344 }
345
346 /*
347 Simple though inefficient wrapper for reading a line. Drop CRs and the
348 trailing newline. Can return early on buffer full. Null-terminate.
349 Apply initial timeout if no data ready.
350
351 Return: number of chars - zero for an empty line
352 -1 on EOF
353 -2 on timeout or error
354 */
355 static int
356 recv_line(int fd, uschar * buffer, int bsize, int tmo)
357 {
358 uschar * p = buffer;
359 ssize_t rcv;
360 BOOL ok = FALSE;
361
362 if (!fd_ready(fd, tmo-time(NULL)))
363 return -2;
364
365 /*XXX tmo handling assumes we always get a whole line */
366 /* read until \n */
367 errno = 0;
368 while ((rcv = read(fd, p, 1)) > 0)
369 {
370 ok = TRUE;
371 if (p-buffer > bsize-2) break;
372 if (*p == '\n') break;
373 if (*p != '\r') p++;
374 }
375 if (!ok)
376 {
377 DEBUG(D_acl) debug_printf_indent("Malware scan: read %s (%s)\n",
378 rcv==0 ? "EOF" : "error", strerror(errno));
379 return rcv==0 ? -1 : -2;
380 }
381 *p = '\0';
382
383 DEBUG(D_acl) debug_printf_indent("Malware scan: read '%s'\n", buffer);
384 return p - buffer;
385 }
386
387 /* return TRUE iff size as requested */
388 static BOOL
389 recv_len(int sock, void * buf, int size, int tmo)
390 {
391 return fd_ready(sock, tmo-time(NULL))
392 ? recv(sock, buf, size, 0) == size
393 : FALSE;
394 }
395
396
397
398 #ifndef DISABLE_MAL_MKS
399 /* ============= private routines for the "mksd" scanner type ============== */
400
401 # include <sys/uio.h>
402
403 static inline int
404 mksd_writev (int sock, struct iovec * iov, int iovcnt)
405 {
406 int i;
407
408 for (;;)
409 {
410 do
411 i = writev (sock, iov, iovcnt);
412 while (i < 0 && errno == EINTR);
413 if (i <= 0)
414 {
415 (void) malware_panic_defer(
416 US"unable to write to mksd UNIX socket (/var/run/mksd/socket)");
417 return -1;
418 }
419 for (;;) /* check for short write */
420 if (i >= iov->iov_len)
421 {
422 if (--iovcnt == 0)
423 return 0;
424 i -= iov->iov_len;
425 iov++;
426 }
427 else
428 {
429 iov->iov_len -= i;
430 iov->iov_base = CS iov->iov_base + i;
431 break;
432 }
433 }
434 }
435
436 static inline int
437 mksd_read_lines (int sock, uschar *av_buffer, int av_buffer_size, int tmo)
438 {
439 int offset = 0;
440 int i;
441
442 do
443 {
444 i = ip_recv(sock, av_buffer+offset, av_buffer_size-offset, tmo-time(NULL));
445 if (i <= 0)
446 {
447 (void) malware_panic_defer(US"unable to read from mksd UNIX socket (/var/run/mksd/socket)");
448 return -1;
449 }
450
451 offset += i;
452 /* offset == av_buffer_size -> buffer full */
453 if (offset == av_buffer_size)
454 {
455 (void) malware_panic_defer(US"malformed reply received from mksd");
456 return -1;
457 }
458 } while (av_buffer[offset-1] != '\n');
459
460 av_buffer[offset] = '\0';
461 return offset;
462 }
463
464 static inline int
465 mksd_parse_line(struct scan * scanent, char * line)
466 {
467 char *p;
468
469 switch (*line)
470 {
471 case 'O': /* OK */
472 return OK;
473
474 case 'E':
475 case 'A': /* ERR */
476 if ((p = strchr (line, '\n')) != NULL)
477 *p = '\0';
478 return m_panic_defer(scanent, NULL,
479 string_sprintf("scanner failed: %s", line));
480
481 default: /* VIR */
482 if ((p = strchr (line, '\n')) != NULL)
483 {
484 *p = '\0';
485 if ( p-line > 5
486 && line[3] == ' '
487 && (p = strchr(line+4, ' ')) != NULL
488 && p-line > 4
489 )
490 {
491 *p = '\0';
492 malware_name = string_copy(US line+4);
493 return OK;
494 }
495 }
496 return m_panic_defer(scanent, NULL,
497 string_sprintf("malformed reply received: %s", line));
498 }
499 }
500
501 static int
502 mksd_scan_packed(struct scan * scanent, int sock, const uschar * scan_filename,
503 int tmo)
504 {
505 struct iovec iov[3];
506 const char *cmd = "MSQ\n";
507 uschar av_buffer[1024];
508
509 iov[0].iov_base = (void *) cmd;
510 iov[0].iov_len = 3;
511 iov[1].iov_base = (void *) scan_filename;
512 iov[1].iov_len = Ustrlen(scan_filename);
513 iov[2].iov_base = (void *) (cmd + 3);
514 iov[2].iov_len = 1;
515
516 if (mksd_writev (sock, iov, 3) < 0)
517 return DEFER;
518
519 if (mksd_read_lines (sock, av_buffer, sizeof (av_buffer), tmo) < 0)
520 return DEFER;
521
522 return mksd_parse_line (scanent, CS av_buffer);
523 }
524 #endif /* MKSD */
525
526
527 #ifndef DISABLE_MAL_CLAM
528 static int
529 clamd_option(clamd_address * cd, const uschar * optstr, int * subsep)
530 {
531 uschar * s;
532
533 cd->retry = 0;
534 while ((s = string_nextinlist(&optstr, subsep, NULL, 0)))
535 if (Ustrncmp(s, "retry=", 6) == 0)
536 {
537 int sec = readconf_readtime((s += 6), '\0', FALSE);
538 if (sec < 0)
539 return FAIL;
540 cd->retry = sec;
541 }
542 else
543 return FAIL;
544 return OK;
545 }
546 #endif
547
548
549
550 /*************************************************
551 * Scan content for malware *
552 *************************************************/
553
554 /* This is an internal interface for scanning an email; the normal interface
555 is via malware(), or there's malware_in_file() used for testing/debugging.
556
557 Arguments:
558 malware_re match condition for "malware="
559 scan_filename the file holding the email to be scanned, if we're faking
560 this up for the -bmalware test, else NULL
561 timeout if nonzero, non-default timeoutl
562
563 Returns: Exim message processing code (OK, FAIL, DEFER, ...)
564 where true means malware was found (condition applies)
565 */
566 static int
567 malware_internal(const uschar * malware_re, const uschar * scan_filename,
568 int timeout)
569 {
570 int sep = 0;
571 const uschar *av_scanner_work = av_scanner;
572 uschar *scanner_name;
573 unsigned long mbox_size;
574 FILE *mbox_file;
575 const pcre *re;
576 uschar * errstr;
577 struct scan * scanent;
578 const uschar * scanner_options;
579 int sock = -1;
580 time_t tmo;
581 uschar * eml_filename, * eml_dir;
582
583 if (!malware_re)
584 return FAIL; /* empty means "don't match anything" */
585
586 /* Ensure the eml mbox file is spooled up */
587
588 if (!(mbox_file = spool_mbox(&mbox_size, scan_filename, &eml_filename)))
589 return malware_panic_defer(US"error while creating mbox spool file");
590
591 /* None of our current scanners need the mbox file as a stream (they use
592 the name), so we can close it right away. Get the directory too. */
593
594 (void) fclose(mbox_file);
595 eml_dir = string_copyn(eml_filename, Ustrrchr(eml_filename, '/') - eml_filename);
596
597 /* parse 1st option */
598 if (strcmpic(malware_re, US"false") == 0 || Ustrcmp(malware_re,"0") == 0)
599 return FAIL; /* explicitly no matching */
600
601 /* special cases (match anything except empty) */
602 if ( strcmpic(malware_re,US"true") == 0
603 || Ustrcmp(malware_re,"*") == 0
604 || Ustrcmp(malware_re,"1") == 0
605 )
606 {
607 if ( !malware_default_re
608 && !(malware_default_re = m_pcre_compile(malware_regex_default, &errstr)))
609 return malware_panic_defer(errstr);
610 malware_re = malware_regex_default;
611 re = malware_default_re;
612 }
613
614 /* compile the regex, see if it works */
615 else if (!(re = m_pcre_compile(malware_re, &errstr)))
616 return malware_panic_defer(errstr);
617
618 /* if av_scanner starts with a dollar, expand it first */
619 if (*av_scanner == '$')
620 {
621 if (!(av_scanner_work = expand_string(av_scanner)))
622 return malware_panic_defer(
623 string_sprintf("av_scanner starts with $, but expansion failed: %s",
624 expand_string_message));
625
626 DEBUG(D_acl)
627 debug_printf_indent("Expanded av_scanner global: %s\n", av_scanner_work);
628 /* disable result caching in this case */
629 malware_name = NULL;
630 malware_ok = FALSE;
631 }
632
633 /* Do not scan twice (unless av_scanner is dynamic). */
634 if (!malware_ok)
635 {
636 /* find the scanner type from the av_scanner option */
637 if (!(scanner_name = string_nextinlist(&av_scanner_work, &sep, NULL, 0)))
638 return malware_panic_defer(US"av_scanner configuration variable is empty");
639 if (!timeout) timeout = MALWARE_TIMEOUT;
640 tmo = time(NULL) + timeout;
641
642 for (scanent = m_scans; ; scanent++)
643 {
644 if (!scanent->name)
645 return malware_panic_defer(string_sprintf("unknown scanner type '%s'",
646 scanner_name));
647 if (strcmpic(scanner_name, US scanent->name) != 0)
648 continue;
649 DEBUG(D_acl) debug_printf_indent("Malware scan: %s tmo=%s\n",
650 scanner_name, readconf_printtime(timeout));
651
652 if (!(scanner_options = string_nextinlist(&av_scanner_work, &sep, NULL, 0)))
653 scanner_options = scanent->options_default;
654 if (scanent->conn == MC_NONE)
655 break;
656
657 DEBUG(D_acl) debug_printf_indent("%15s%10s%s\n", "", "socket: ", scanner_options);
658 switch(scanent->conn)
659 {
660 case MC_TCP: sock = ip_tcpsocket(scanner_options, &errstr, 5); break;
661 case MC_UNIX: sock = ip_unixsocket(scanner_options, &errstr); break;
662 case MC_STRM: sock = ip_streamsocket(scanner_options, &errstr, 5); break;
663 default: /* compiler quietening */ break;
664 }
665 if (sock < 0)
666 return m_panic_defer(scanent, CUS callout_address, errstr);
667 break;
668 }
669
670 switch (scanent->scancode)
671 {
672 #ifndef DISABLE_MAL_FFROTD
673 case M_FPROTD: /* "f-protd" scanner type -------------------------------- */
674 {
675 uschar *fp_scan_option;
676 unsigned int detected=0, par_count=0;
677 uschar * scanrequest;
678 uschar buf[32768], *strhelper, *strhelper2;
679 uschar * malware_name_internal = NULL;
680 int len;
681
682 scanrequest = string_sprintf("GET %s", eml_filename);
683
684 while ((fp_scan_option = string_nextinlist(&av_scanner_work, &sep,
685 NULL, 0)))
686 {
687 scanrequest = string_sprintf("%s%s%s", scanrequest,
688 par_count ? "%20" : "?", fp_scan_option);
689 par_count++;
690 }
691 scanrequest = string_sprintf("%s HTTP/1.0\r\n\r\n", scanrequest);
692 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s: %s\n",
693 scanner_name, scanrequest);
694
695 /* send scan request */
696 if (m_sock_send(sock, scanrequest, Ustrlen(scanrequest)+1, &errstr) < 0)
697 return m_panic_defer(scanent, CUS callout_address, errstr);
698
699 while ((len = recv_line(sock, buf, sizeof(buf), tmo)) >= 0)
700 if (len > 0)
701 {
702 if (Ustrstr(buf, US"<detected type=\"") != NULL)
703 detected = 1;
704 else if (detected && (strhelper = Ustrstr(buf, US"<name>")))
705 {
706 if ((strhelper2 = Ustrstr(buf, US"</name>")) != NULL)
707 {
708 *strhelper2 = '\0';
709 malware_name_internal = string_copy(strhelper+6);
710 }
711 }
712 else if (Ustrstr(buf, US"<summary code=\""))
713 {
714 malware_name = Ustrstr(buf, US"<summary code=\"11\">")
715 ? malware_name_internal : NULL;
716 break;
717 }
718 }
719 if (len < -1)
720 {
721 (void)close(sock);
722 return DEFER;
723 }
724 break;
725 } /* f-protd */
726 #endif
727
728 #ifndef DISABLE_MAL_FFROT6D
729 case M_FPROT6D: /* "f-prot6d" scanner type ----------------------------------- */
730 {
731 int bread;
732 uschar * e;
733 uschar * linebuffer;
734 uschar * scanrequest;
735 uschar av_buffer[1024];
736
737 if ((!fprot6d_re_virus && !(fprot6d_re_virus = m_pcre_compile(fprot6d_re_virus_str, &errstr)))
738 || (!fprot6d_re_error && !(fprot6d_re_error = m_pcre_compile(fprot6d_re_error_str, &errstr))))
739 return malware_panic_defer(errstr);
740
741 scanrequest = string_sprintf("SCAN FILE %s\n", eml_filename);
742 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s: %s\n",
743 scanner_name, scanrequest);
744
745 if (m_sock_send(sock, scanrequest, Ustrlen(scanrequest), &errstr) < 0)
746 return m_panic_defer(scanent, CUS callout_address, errstr);
747
748 bread = ip_recv(sock, av_buffer, sizeof(av_buffer), tmo-time(NULL));
749
750 if (bread <= 0)
751 return m_panic_defer_3(scanent, CUS callout_address,
752 string_sprintf("unable to read from socket (%s)", strerror(errno)),
753 sock);
754
755 if (bread == sizeof(av_buffer))
756 return m_panic_defer_3(scanent, CUS callout_address,
757 US"buffer too small", sock);
758
759 av_buffer[bread] = '\0';
760 linebuffer = string_copy(av_buffer);
761
762 m_sock_send(sock, US"QUIT\n", 5, 0);
763
764 if ((e = m_pcre_exec(fprot6d_re_error, linebuffer)))
765 return m_panic_defer_3(scanent, CUS callout_address,
766 string_sprintf("scanner reported error (%s)", e), sock);
767
768 if (!(malware_name = m_pcre_exec(fprot6d_re_virus, linebuffer)))
769 malware_name = NULL;
770
771 break;
772 } /* f-prot6d */
773 #endif
774
775 #ifndef DISABLE_MAL_DRWEB
776 case M_DRWEB: /* "drweb" scanner type ----------------------------------- */
777 /* v0.1 - added support for tcp sockets */
778 /* v0.0 - initial release -- support for unix sockets */
779 {
780 int result;
781 off_t fsize;
782 unsigned int fsize_uint;
783 uschar * tmpbuf, *drweb_fbuf;
784 int drweb_rc, drweb_cmd, drweb_flags = 0x0000, drweb_fd,
785 drweb_vnum, drweb_slen, drweb_fin = 0x0000;
786
787 /* prepare variables */
788 drweb_cmd = htonl(DRWEBD_SCAN_CMD);
789 drweb_flags = htonl(DRWEBD_RETURN_VIRUSES | DRWEBD_IS_MAIL);
790
791 if (*scanner_options != '/')
792 {
793 /* calc file size */
794 if ((drweb_fd = open(CCS eml_filename, O_RDONLY)) == -1)
795 return m_panic_defer_3(scanent, NULL,
796 string_sprintf("can't open spool file %s: %s",
797 eml_filename, strerror(errno)),
798 sock);
799
800 if ((fsize = lseek(drweb_fd, 0, SEEK_END)) == -1)
801 {
802 int err;
803 badseek: err = errno;
804 (void)close(drweb_fd);
805 return m_panic_defer_3(scanent, NULL,
806 string_sprintf("can't seek spool file %s: %s",
807 eml_filename, strerror(err)),
808 sock);
809 }
810 fsize_uint = (unsigned int) fsize;
811 if ((off_t)fsize_uint != fsize)
812 {
813 (void)close(drweb_fd);
814 return m_panic_defer_3(scanent, NULL,
815 string_sprintf("seeking spool file %s, size overflow",
816 eml_filename),
817 sock);
818 }
819 drweb_slen = htonl(fsize);
820 if (lseek(drweb_fd, 0, SEEK_SET) < 0)
821 goto badseek;
822
823 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s remote scan [%s]\n",
824 scanner_name, scanner_options);
825
826 /* send scan request */
827 if ((send(sock, &drweb_cmd, sizeof(drweb_cmd), 0) < 0) ||
828 (send(sock, &drweb_flags, sizeof(drweb_flags), 0) < 0) ||
829 (send(sock, &drweb_fin, sizeof(drweb_fin), 0) < 0) ||
830 (send(sock, &drweb_slen, sizeof(drweb_slen), 0) < 0))
831 {
832 (void)close(drweb_fd);
833 return m_panic_defer_3(scanent, CUS callout_address, string_sprintf(
834 "unable to send commands to socket (%s)", scanner_options),
835 sock);
836 }
837
838 if (!(drweb_fbuf = US malloc(fsize_uint)))
839 {
840 (void)close(drweb_fd);
841 return m_panic_defer_3(scanent, NULL,
842 string_sprintf("unable to allocate memory %u for file (%s)",
843 fsize_uint, eml_filename),
844 sock);
845 }
846
847 if ((result = read (drweb_fd, drweb_fbuf, fsize)) == -1)
848 {
849 int err = errno;
850 (void)close(drweb_fd);
851 free(drweb_fbuf);
852 return m_panic_defer_3(scanent, NULL,
853 string_sprintf("can't read spool file %s: %s",
854 eml_filename, strerror(err)),
855 sock);
856 }
857 (void)close(drweb_fd);
858
859 /* send file body to socket */
860 if (send(sock, drweb_fbuf, fsize, 0) < 0)
861 {
862 free(drweb_fbuf);
863 return m_panic_defer_3(scanent, CUS callout_address, string_sprintf(
864 "unable to send file body to socket (%s)", scanner_options),
865 sock);
866 }
867 }
868 else
869 {
870 drweb_slen = htonl(Ustrlen(eml_filename));
871
872 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s local scan [%s]\n",
873 scanner_name, scanner_options);
874
875 /* send scan request */
876 if ((send(sock, &drweb_cmd, sizeof(drweb_cmd), 0) < 0) ||
877 (send(sock, &drweb_flags, sizeof(drweb_flags), 0) < 0) ||
878 (send(sock, &drweb_slen, sizeof(drweb_slen), 0) < 0) ||
879 (send(sock, eml_filename, Ustrlen(eml_filename), 0) < 0) ||
880 (send(sock, &drweb_fin, sizeof(drweb_fin), 0) < 0))
881 return m_panic_defer_3(scanent, CUS callout_address, string_sprintf(
882 "unable to send commands to socket (%s)", scanner_options),
883 sock);
884 }
885
886 /* wait for result */
887 if (!recv_len(sock, &drweb_rc, sizeof(drweb_rc), tmo))
888 return m_panic_defer_3(scanent, CUS callout_address,
889 US"unable to read return code", sock);
890 drweb_rc = ntohl(drweb_rc);
891
892 if (!recv_len(sock, &drweb_vnum, sizeof(drweb_vnum), tmo))
893 return m_panic_defer_3(scanent, CUS callout_address,
894 US"unable to read the number of viruses", sock);
895 drweb_vnum = ntohl(drweb_vnum);
896
897 /* "virus(es) found" if virus number is > 0 */
898 if (drweb_vnum)
899 {
900 int i;
901 gstring * g = NULL;
902
903 /* setup default virus name */
904 malware_name = US"unknown";
905
906 /* set up match regex */
907 if (!drweb_re)
908 drweb_re = m_pcre_compile(drweb_re_str, &errstr);
909
910 /* read and concatenate virus names into one string */
911 for (i = 0; i < drweb_vnum; i++)
912 {
913 int ovector[10*3];
914
915 /* read the size of report */
916 if (!recv_len(sock, &drweb_slen, sizeof(drweb_slen), tmo))
917 return m_panic_defer_3(scanent, CUS callout_address,
918 US"cannot read report size", sock);
919 drweb_slen = ntohl(drweb_slen);
920 tmpbuf = store_get(drweb_slen);
921
922 /* read report body */
923 if (!recv_len(sock, tmpbuf, drweb_slen, tmo))
924 return m_panic_defer_3(scanent, CUS callout_address,
925 US"cannot read report string", sock);
926 tmpbuf[drweb_slen] = '\0';
927
928 /* try matcher on the line, grab substring */
929 result = pcre_exec(drweb_re, NULL, CS tmpbuf, Ustrlen(tmpbuf), 0, 0,
930 ovector, nelem(ovector));
931 if (result >= 2)
932 {
933 const char * pre_malware_nb;
934
935 pcre_get_substring(CS tmpbuf, ovector, result, 1, &pre_malware_nb);
936
937 if (i==0) /* the first name we just copy to malware_name */
938 g = string_cat(NULL, US pre_malware_nb);
939
940 /*XXX could be string_append_listele? */
941 else /* concatenate each new virus name to previous */
942 g = string_append(g, 2, "/", pre_malware_nb);
943
944 pcre_free_substring(pre_malware_nb);
945 }
946 }
947 malware_name = string_from_gstring(g);
948 }
949 else
950 {
951 const char *drweb_s = NULL;
952
953 if (drweb_rc & DERR_READ_ERR) drweb_s = "read error";
954 if (drweb_rc & DERR_NOMEMORY) drweb_s = "no memory";
955 if (drweb_rc & DERR_TIMEOUT) drweb_s = "timeout";
956 if (drweb_rc & DERR_BAD_CALL) drweb_s = "wrong command";
957 /* retcodes DERR_SYMLINK, DERR_NO_REGFILE, DERR_SKIPPED.
958 * DERR_TOO_BIG, DERR_TOO_COMPRESSED, DERR_SPAM,
959 * DERR_CRC_ERROR, DERR_READSOCKET, DERR_WRITE_ERR
960 * and others are ignored */
961 if (drweb_s)
962 return m_panic_defer_3(scanent, CUS callout_address,
963 string_sprintf("drweb daemon retcode 0x%x (%s)", drweb_rc, drweb_s),
964 sock);
965
966 /* no virus found */
967 malware_name = NULL;
968 }
969 break;
970 } /* drweb */
971 #endif
972
973 #ifndef DISABLE_MAL_AVE
974 case M_AVES: /* "aveserver" scanner type -------------------------------- */
975 {
976 uschar buf[32768];
977 int result;
978
979 /* read aveserver's greeting and see if it is ready (2xx greeting) */
980 buf[0] = 0;
981 recv_line(sock, buf, sizeof(buf), tmo);
982
983 if (buf[0] != '2') /* aveserver is having problems */
984 return m_panic_defer_3(scanent, CUS callout_address,
985 string_sprintf("unavailable (Responded: %s).",
986 ((buf[0] != 0) ? buf : US "nothing") ),
987 sock);
988
989 /* prepare our command */
990 (void)string_format(buf, sizeof(buf), "SCAN bPQRSTUW %s\r\n",
991 eml_filename);
992
993 /* and send it */
994 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s %s\n",
995 scanner_name, buf);
996 if (m_sock_send(sock, buf, Ustrlen(buf), &errstr) < 0)
997 return m_panic_defer(scanent, CUS callout_address, errstr);
998
999 malware_name = NULL;
1000 result = 0;
1001 /* read response lines, find malware name and final response */
1002 while (recv_line(sock, buf, sizeof(buf), tmo) > 0)
1003 {
1004 if (buf[0] == '2')
1005 break;
1006 if (buf[0] == '5') /* aveserver is having problems */
1007 {
1008 result = m_panic_defer(scanent, CUS callout_address,
1009 string_sprintf("unable to scan file %s (Responded: %s).",
1010 eml_filename, buf));
1011 break;
1012 }
1013 if (Ustrncmp(buf,"322",3) == 0)
1014 {
1015 uschar *p = Ustrchr(&buf[4], ' ');
1016 *p = '\0';
1017 malware_name = string_copy(&buf[4]);
1018 }
1019 }
1020
1021 if (m_sock_send(sock, US"quit\r\n", 6, &errstr) < 0)
1022 return m_panic_defer(scanent, CUS callout_address, errstr);
1023
1024 /* read aveserver's greeting and see if it is ready (2xx greeting) */
1025 buf[0] = 0;
1026 recv_line(sock, buf, sizeof(buf), tmo);
1027
1028 if (buf[0] != '2') /* aveserver is having problems */
1029 return m_panic_defer_3(scanent, CUS callout_address,
1030 string_sprintf("unable to quit dialogue (Responded: %s).",
1031 ((buf[0] != 0) ? buf : US "nothing") ),
1032 sock);
1033
1034 if (result == DEFER)
1035 {
1036 (void)close(sock);
1037 return DEFER;
1038 }
1039 break;
1040 } /* aveserver */
1041 #endif
1042
1043 #ifndef DISABLE_MAL_FSECURE
1044 case M_FSEC: /* "fsecure" scanner type ---------------------------------- */
1045 {
1046 int i, j, bread = 0;
1047 uschar * file_name;
1048 uschar av_buffer[1024];
1049 static uschar *cmdopt[] = { US"CONFIGURE\tARCHIVE\t1\n",
1050 US"CONFIGURE\tTIMEOUT\t0\n",
1051 US"CONFIGURE\tMAXARCH\t5\n",
1052 US"CONFIGURE\tMIME\t1\n" };
1053
1054 malware_name = NULL;
1055
1056 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n",
1057 scanner_name, scanner_options);
1058 /* pass options */
1059 memset(av_buffer, 0, sizeof(av_buffer));
1060 for (i = 0; i != nelem(cmdopt); i++)
1061 {
1062
1063 if (m_sock_send(sock, cmdopt[i], Ustrlen(cmdopt[i]), &errstr) < 0)
1064 return m_panic_defer(scanent, CUS callout_address, errstr);
1065
1066 bread = ip_recv(sock, av_buffer, sizeof(av_buffer), tmo-time(NULL));
1067 if (bread > 0) av_buffer[bread]='\0';
1068 if (bread < 0)
1069 return m_panic_defer_3(scanent, CUS callout_address,
1070 string_sprintf("unable to read answer %d (%s)", i, strerror(errno)),
1071 sock);
1072 for (j = 0; j < bread; j++)
1073 if (av_buffer[j] == '\r' || av_buffer[j] == '\n')
1074 av_buffer[j] ='@';
1075 }
1076
1077 /* pass the mailfile to fsecure */
1078 file_name = string_sprintf("SCAN\t%s\n", eml_filename);
1079
1080 if (m_sock_send(sock, file_name, Ustrlen(file_name), &errstr) < 0)
1081 return m_panic_defer(scanent, CUS callout_address, errstr);
1082
1083 /* set up match */
1084 /* todo also SUSPICION\t */
1085 if (!fsec_re)
1086 fsec_re = m_pcre_compile(fsec_re_str, &errstr);
1087
1088 /* read report, linewise. Apply a timeout as the Fsecure daemon
1089 sometimes wants an answer to "PING" but they won't tell us what */
1090 {
1091 uschar * p = av_buffer;
1092 uschar * q;
1093
1094 for (;;)
1095 {
1096 errno = ETIMEDOUT;
1097 i = av_buffer+sizeof(av_buffer)-p;
1098 if ((bread= ip_recv(sock, p, i-1, tmo-time(NULL))) < 0)
1099 return m_panic_defer_3(scanent, CUS callout_address,
1100 string_sprintf("unable to read result (%s)", strerror(errno)),
1101 sock);
1102
1103 for (p[bread] = '\0'; (q = Ustrchr(p, '\n')); p = q+1)
1104 {
1105 *q = '\0';
1106
1107 /* Really search for virus again? */
1108 if (!malware_name)
1109 /* try matcher on the line, grab substring */
1110 malware_name = m_pcre_exec(fsec_re, p);
1111
1112 if (Ustrstr(p, "OK\tScan ok."))
1113 goto fsec_found;
1114 }
1115
1116 /* copy down the trailing partial line then read another chunk */
1117 i = av_buffer+sizeof(av_buffer)-p;
1118 memmove(av_buffer, p, i);
1119 p = av_buffer+i;
1120 }
1121 }
1122
1123 fsec_found:
1124 break;
1125 } /* fsecure */
1126 #endif
1127
1128 #ifndef DISABLE_MAL_KAV
1129 case M_KAVD: /* "kavdaemon" scanner type -------------------------------- */
1130 {
1131 time_t t;
1132 uschar tmpbuf[1024];
1133 uschar * scanrequest;
1134 int kav_rc;
1135 unsigned long kav_reportlen;
1136 int bread;
1137 const pcre *kav_re;
1138 uschar *p;
1139
1140 /* get current date and time, build scan request */
1141 time(&t);
1142 /* pdp note: before the eml_filename parameter, this scanned the
1143 directory; not finding documentation, so we'll strip off the directory.
1144 The side-effect is that the test framework scanning may end up in
1145 scanning more than was requested, but for the normal interface, this is
1146 fine. */
1147
1148 strftime(CS tmpbuf, sizeof(tmpbuf), "%d %b %H:%M:%S", localtime(&t));
1149 scanrequest = string_sprintf("<0>%s:%s", CS tmpbuf, eml_filename);
1150 p = Ustrrchr(scanrequest, '/');
1151 if (p)
1152 *p = '\0';
1153
1154 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n",
1155 scanner_name, scanner_options);
1156
1157 /* send scan request */
1158 if (m_sock_send(sock, scanrequest, Ustrlen(scanrequest)+1, &errstr) < 0)
1159 return m_panic_defer(scanent, CUS callout_address, errstr);
1160
1161 /* wait for result */
1162 if (!recv_len(sock, tmpbuf, 2, tmo))
1163 return m_panic_defer_3(scanent, CUS callout_address,
1164 US"unable to read 2 bytes from socket.", sock);
1165
1166 /* get errorcode from one nibble */
1167 kav_rc = tmpbuf[ test_byte_order()==LITTLE_MY_ENDIAN ? 0 : 1 ] & 0x0F;
1168 switch(kav_rc)
1169 {
1170 case 5: case 6: /* improper kavdaemon configuration */
1171 return m_panic_defer_3(scanent, CUS callout_address,
1172 US"please reconfigure kavdaemon to NOT disinfect or remove infected files.",
1173 sock);
1174 case 1:
1175 return m_panic_defer_3(scanent, CUS callout_address,
1176 US"reported 'scanning not completed' (code 1).", sock);
1177 case 7:
1178 return m_panic_defer_3(scanent, CUS callout_address,
1179 US"reported 'kavdaemon damaged' (code 7).", sock);
1180 }
1181
1182 /* code 8 is not handled, since it is ambiguous. It appears mostly on
1183 bounces where part of a file has been cut off */
1184
1185 /* "virus found" return codes (2-4) */
1186 if (kav_rc > 1 && kav_rc < 5)
1187 {
1188 int report_flag = 0;
1189
1190 /* setup default virus name */
1191 malware_name = US"unknown";
1192
1193 report_flag = tmpbuf[ test_byte_order() == LITTLE_MY_ENDIAN ? 1 : 0 ];
1194
1195 /* read the report, if available */
1196 if (report_flag == 1)
1197 {
1198 /* read report size */
1199 if (!recv_len(sock, &kav_reportlen, 4, tmo))
1200 return m_panic_defer_3(scanent, CUS callout_address,
1201 US"cannot read report size", sock);
1202
1203 /* it's possible that avp returns av_buffer[1] == 1 but the
1204 reportsize is 0 (!?) */
1205 if (kav_reportlen > 0)
1206 {
1207 /* set up match regex, depends on retcode */
1208 if (kav_rc == 3)
1209 {
1210 if (!kav_re_sus) kav_re_sus = m_pcre_compile(kav_re_sus_str, &errstr);
1211 kav_re = kav_re_sus;
1212 }
1213 else
1214 {
1215 if (!kav_re_inf) kav_re_inf = m_pcre_compile(kav_re_inf_str, &errstr);
1216 kav_re = kav_re_inf;
1217 }
1218
1219 /* read report, linewise. Using size from stream to read amount of data
1220 from same stream is safe enough. */
1221 /* coverity[tainted_data] */
1222 while (kav_reportlen > 0)
1223 {
1224 if ((bread = recv_line(sock, tmpbuf, sizeof(tmpbuf), tmo)) < 0)
1225 break;
1226 kav_reportlen -= bread+1;
1227
1228 /* try matcher on the line, grab substring */
1229 if ((malware_name = m_pcre_exec(kav_re, tmpbuf)))
1230 break;
1231 }
1232 }
1233 }
1234 }
1235 else /* no virus found */
1236 malware_name = NULL;
1237
1238 break;
1239 }
1240 #endif
1241
1242 #ifndef DISABLE_MAL_CMDLINE
1243 case M_CMDL: /* "cmdline" scanner type ---------------------------------- */
1244 {
1245 const uschar *cmdline_scanner = scanner_options;
1246 const pcre *cmdline_trigger_re;
1247 const pcre *cmdline_regex_re;
1248 uschar * file_name;
1249 uschar * commandline;
1250 void (*eximsigchld)(int);
1251 void (*eximsigpipe)(int);
1252 FILE *scanner_out = NULL;
1253 int scanner_fd;
1254 FILE *scanner_record = NULL;
1255 uschar linebuffer[32767];
1256 int rcnt;
1257 int trigger = 0;
1258 uschar *p;
1259
1260 if (!cmdline_scanner)
1261 return m_panic_defer(scanent, NULL, errstr);
1262
1263 /* find scanner output trigger */
1264 cmdline_trigger_re = m_pcre_nextinlist(&av_scanner_work, &sep,
1265 "missing trigger specification", &errstr);
1266 if (!cmdline_trigger_re)
1267 return m_panic_defer(scanent, NULL, errstr);
1268
1269 /* find scanner name regex */
1270 cmdline_regex_re = m_pcre_nextinlist(&av_scanner_work, &sep,
1271 "missing virus name regex specification", &errstr);
1272 if (!cmdline_regex_re)
1273 return m_panic_defer(scanent, NULL, errstr);
1274
1275 /* prepare scanner call; despite the naming, file_name holds a directory
1276 name which is documented as the value given to %s. */
1277
1278 file_name = string_copy(eml_filename);
1279 p = Ustrrchr(file_name, '/');
1280 if (p)
1281 *p = '\0';
1282 commandline = string_sprintf(CS cmdline_scanner, file_name);
1283
1284 /* redirect STDERR too */
1285 commandline = string_sprintf("%s 2>&1", commandline);
1286
1287 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n",
1288 scanner_name, commandline);
1289
1290 /* store exims signal handlers */
1291 eximsigchld = signal(SIGCHLD,SIG_DFL);
1292 eximsigpipe = signal(SIGPIPE,SIG_DFL);
1293
1294 if (!(scanner_out = popen(CS commandline,"r")))
1295 {
1296 int err = errno;
1297 signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
1298 return m_panic_defer(scanent, NULL,
1299 string_sprintf("call (%s) failed: %s.", commandline, strerror(err)));
1300 }
1301 scanner_fd = fileno(scanner_out);
1302
1303 file_name = string_sprintf("%s/%s_scanner_output", eml_dir, message_id);
1304
1305 if (!(scanner_record = modefopen(file_name, "wb", SPOOL_MODE)))
1306 {
1307 int err = errno;
1308 (void) pclose(scanner_out);
1309 signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
1310 return m_panic_defer(scanent, NULL, string_sprintf(
1311 "opening scanner output file (%s) failed: %s.",
1312 file_name, strerror(err)));
1313 }
1314
1315 /* look for trigger while recording output */
1316 while ((rcnt = recv_line(scanner_fd, linebuffer,
1317 sizeof(linebuffer), tmo)))
1318 {
1319 if (rcnt < 0)
1320 {
1321 int err = errno;
1322 if (rcnt == -1)
1323 break;
1324 (void) pclose(scanner_out);
1325 signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
1326 return m_panic_defer(scanent, NULL, string_sprintf(
1327 "unable to read from scanner (%s): %s",
1328 commandline, strerror(err)));
1329 }
1330
1331 if (Ustrlen(linebuffer) > fwrite(linebuffer, 1, Ustrlen(linebuffer), scanner_record))
1332 {
1333 /* short write */
1334 (void) pclose(scanner_out);
1335 signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
1336 return m_panic_defer(scanent, NULL, string_sprintf(
1337 "short write on scanner output file (%s).", file_name));
1338 }
1339 putc('\n', scanner_record);
1340 /* try trigger match */
1341 if ( !trigger
1342 && regex_match_and_setup(cmdline_trigger_re, linebuffer, 0, -1)
1343 )
1344 trigger = 1;
1345 }
1346
1347 (void)fclose(scanner_record);
1348 sep = pclose(scanner_out);
1349 signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
1350 if (sep != 0)
1351 return m_panic_defer(scanent, NULL,
1352 sep == -1
1353 ? string_sprintf("running scanner failed: %s", strerror(sep))
1354 : string_sprintf("scanner returned error code: %d", sep));
1355
1356 if (trigger)
1357 {
1358 uschar * s;
1359 /* setup default virus name */
1360 malware_name = US"unknown";
1361
1362 /* re-open the scanner output file, look for name match */
1363 scanner_record = fopen(CS file_name, "rb");
1364 while (fgets(CS linebuffer, sizeof(linebuffer), scanner_record))
1365 {
1366 /* try match */
1367 if ((s = m_pcre_exec(cmdline_regex_re, linebuffer)))
1368 malware_name = s;
1369 }
1370 (void)fclose(scanner_record);
1371 }
1372 else /* no virus found */
1373 malware_name = NULL;
1374 break;
1375 } /* cmdline */
1376 #endif
1377
1378 #ifndef DISABLE_MAL_SOPHIE
1379 case M_SOPHIE: /* "sophie" scanner type --------------------------------- */
1380 {
1381 int bread = 0;
1382 uschar *p;
1383 uschar * file_name;
1384 uschar av_buffer[1024];
1385
1386 /* pass the scan directory to sophie */
1387 file_name = string_copy(eml_filename);
1388 if ((p = Ustrrchr(file_name, '/')))
1389 *p = '\0';
1390
1391 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n",
1392 scanner_name, scanner_options);
1393
1394 if ( write(sock, file_name, Ustrlen(file_name)) < 0
1395 || write(sock, "\n", 1) != 1
1396 )
1397 return m_panic_defer_3(scanent, CUS callout_address,
1398 string_sprintf("unable to write to UNIX socket (%s)", scanner_options),
1399 sock);
1400
1401 /* wait for result */
1402 memset(av_buffer, 0, sizeof(av_buffer));
1403 if ((bread = ip_recv(sock, av_buffer, sizeof(av_buffer), tmo-time(NULL))) <= 0)
1404 return m_panic_defer_3(scanent, CUS callout_address,
1405 string_sprintf("unable to read from UNIX socket (%s)", scanner_options),
1406 sock);
1407
1408 /* infected ? */
1409 if (av_buffer[0] == '1') {
1410 uschar * s = Ustrchr(av_buffer, '\n');
1411 if (s)
1412 *s = '\0';
1413 malware_name = string_copy(&av_buffer[2]);
1414 }
1415 else if (!strncmp(CS av_buffer, "-1", 2))
1416 return m_panic_defer_3(scanent, CUS callout_address,
1417 US"scanner reported error", sock);
1418 else /* all ok, no virus */
1419 malware_name = NULL;
1420
1421 break;
1422 }
1423 #endif
1424
1425 #ifndef DISABLE_MAL_CLAM
1426 case M_CLAMD: /* "clamd" scanner type ----------------------------------- */
1427 {
1428 /* This code was originally contributed by David Saez */
1429 /* There are three scanning methods available to us:
1430 * (1) Use the SCAN command, pointing to a file in the filesystem
1431 * (2) Use the STREAM command, send the data on a separate port
1432 * (3) Use the zINSTREAM command, send the data inline
1433 * The zINSTREAM command was introduced with ClamAV 0.95, which marked
1434 * STREAM deprecated; see: http://wiki.clamav.net/bin/view/Main/UpgradeNotes095
1435 * In Exim, we use SCAN if using a Unix-domain socket or explicitly told that
1436 * the TCP-connected daemon is actually local; otherwise we use zINSTREAM
1437 * See Exim bug 926 for details. */
1438
1439 uschar *p, *vname, *result_tag;
1440 int bread=0;
1441 uschar av_buffer[1024];
1442 uschar *hostname = US"";
1443 host_item connhost;
1444 uschar *clamav_fbuf;
1445 int clam_fd, result;
1446 off_t fsize;
1447 unsigned int fsize_uint;
1448 BOOL use_scan_command = FALSE;
1449 clamd_address * cv[MAX_CLAMD_SERVERS];
1450 int num_servers = 0;
1451 uint32_t send_size, send_final_zeroblock;
1452 blob cmd_str;
1453
1454 /*XXX if unixdomain socket, only one server supported. Needs fixing;
1455 there's no reason we should not mix local and remote servers */
1456
1457 if (*scanner_options == '/')
1458 {
1459 clamd_address * cd;
1460 const uschar * sublist;
1461 int subsep = ' ';
1462
1463 /* Local file; so we def want to use_scan_command and don't want to try
1464 * passing IP/port combinations */
1465 use_scan_command = TRUE;
1466 cd = (clamd_address *) store_get(sizeof(clamd_address));
1467
1468 /* extract socket-path part */
1469 sublist = scanner_options;
1470 cd->hostspec = string_nextinlist(&sublist, &subsep, NULL, 0);
1471
1472 /* parse options */
1473 if (clamd_option(cd, sublist, &subsep) != OK)
1474 return m_panic_defer(scanent, NULL,
1475 string_sprintf("bad option '%s'", scanner_options));
1476 cv[0] = cd;
1477 }
1478 else
1479 {
1480 /* Go through the rest of the list of host/port and construct an array
1481 * of servers to try. The first one is the bit we just passed from
1482 * scanner_options so process that first and then scan the remainder of
1483 * the address buffer */
1484 do
1485 {
1486 clamd_address * cd;
1487 const uschar * sublist;
1488 int subsep = ' ';
1489 uschar * s;
1490
1491 /* The 'local' option means use the SCAN command over the network
1492 * socket (ie common file storage in use) */
1493 /*XXX we could accept this also as a local option? */
1494 if (strcmpic(scanner_options, US"local") == 0)
1495 {
1496 use_scan_command = TRUE;
1497 continue;
1498 }
1499
1500 cd = (clamd_address *) store_get(sizeof(clamd_address));
1501
1502 /* extract host and port part */
1503 sublist = scanner_options;
1504 if (!(cd->hostspec = string_nextinlist(&sublist, &subsep, NULL, 0)))
1505 {
1506 (void) m_panic_defer(scanent, NULL,
1507 string_sprintf("missing address: '%s'", scanner_options));
1508 continue;
1509 }
1510 if (!(s = string_nextinlist(&sublist, &subsep, NULL, 0)))
1511 {
1512 (void) m_panic_defer(scanent, NULL,
1513 string_sprintf("missing port: '%s'", scanner_options));
1514 continue;
1515 }
1516 cd->tcp_port = atoi(CS s);
1517
1518 /* parse options */
1519 /*XXX should these options be common over scanner types? */
1520 if (clamd_option(cd, sublist, &subsep) != OK)
1521 return m_panic_defer(scanent, NULL,
1522 string_sprintf("bad option '%s'", scanner_options));
1523
1524 cv[num_servers++] = cd;
1525 if (num_servers >= MAX_CLAMD_SERVERS)
1526 {
1527 (void) m_panic_defer(scanent, NULL,
1528 US"More than " MAX_CLAMD_SERVERS_S " clamd servers "
1529 "specified; only using the first " MAX_CLAMD_SERVERS_S );
1530 break;
1531 }
1532 } while ((scanner_options = string_nextinlist(&av_scanner_work, &sep,
1533 NULL, 0)));
1534
1535 /* check if we have at least one server */
1536 if (!num_servers)
1537 return m_panic_defer(scanent, NULL,
1538 US"no useable server addresses in malware configuration option.");
1539 }
1540
1541 /* See the discussion of response formats below to see why we really
1542 don't like colons in filenames when passing filenames to ClamAV. */
1543 if (use_scan_command && Ustrchr(eml_filename, ':'))
1544 return m_panic_defer(scanent, NULL,
1545 string_sprintf("local/SCAN mode incompatible with" \
1546 " : in path to email filename [%s]", eml_filename));
1547
1548 /* Set up the very first data we will be sending */
1549 if (!use_scan_command)
1550 { cmd_str.data = US"zINSTREAM"; cmd_str.len = 10; }
1551 else
1552 {
1553 cmd_str.data = string_sprintf("SCAN %s\n", eml_filename);
1554 cmd_str.len = Ustrlen(cmd_str.data);
1555 }
1556
1557 /* We have some network servers specified */
1558 if (num_servers)
1559 {
1560 /* Confirmed in ClamAV source (0.95.3) that the TCPAddr option of clamd
1561 * only supports AF_INET, but we should probably be looking to the
1562 * future and rewriting this to be protocol-independent anyway. */
1563
1564 while (num_servers > 0)
1565 {
1566 int i = random_number(num_servers);
1567 clamd_address * cd = cv[i];
1568
1569 DEBUG(D_acl) debug_printf_indent("trying server name %s, port %u\n",
1570 cd->hostspec, cd->tcp_port);
1571
1572 /* Lookup the host. This is to ensure that we connect to the same IP
1573 * on both connections (as one host could resolve to multiple ips) */
1574 for (;;)
1575 {
1576 if ((sock = m_tcpsocket(cd->hostspec, cd->tcp_port,
1577 &connhost, &errstr, &cmd_str)) >= 0)
1578 {
1579 /* Connection successfully established with a server */
1580 hostname = cd->hostspec;
1581 cmd_str.len = 0;
1582 break;
1583 }
1584 if (cd->retry <= 0) break;
1585 while (cd->retry > 0) cd->retry = sleep(cd->retry);
1586 }
1587 if (sock >= 0)
1588 break;
1589
1590 (void) m_panic_defer(scanent, CUS callout_address, errstr);
1591
1592 /* Remove the server from the list. XXX We should free the memory */
1593 num_servers--;
1594 for (; i < num_servers; i++)
1595 cv[i] = cv[i+1];
1596 }
1597
1598 if (num_servers == 0)
1599 return m_panic_defer(scanent, NULL, US"all servers failed");
1600 }
1601 else
1602 for (;;)
1603 {
1604 if ((sock = ip_unixsocket(cv[0]->hostspec, &errstr)) >= 0)
1605 {
1606 hostname = cv[0]->hostspec;
1607 break;
1608 }
1609 if (cv[0]->retry <= 0)
1610 return m_panic_defer(scanent, CUS callout_address, errstr);
1611 while (cv[0]->retry > 0) cv[0]->retry = sleep(cv[0]->retry);
1612 }
1613
1614 /* have socket in variable "sock"; command to use is semi-independent of
1615 * the socket protocol. We use SCAN if is local (either Unix/local
1616 * domain socket, or explicitly told local) else we stream the data.
1617 * How we stream the data depends upon how we were built. */
1618
1619 if (!use_scan_command)
1620 {
1621 /* New protocol: "zINSTREAM\n" followed by a sequence of <length><data>
1622 chunks, <n> a 4-byte number (network order), terminated by a zero-length
1623 chunk. */
1624
1625 DEBUG(D_acl) debug_printf_indent(
1626 "Malware scan: issuing %s new-style remote scan (zINSTREAM)\n",
1627 scanner_name);
1628
1629 /* Pass the string to ClamAV (10 = "zINSTREAM\0"), if not already sent */
1630 if (cmd_str.len)
1631 if (send(sock, cmd_str.data, cmd_str.len, 0) < 0)
1632 return m_panic_defer_3(scanent, CUS hostname,
1633 string_sprintf("unable to send zINSTREAM to socket (%s)",
1634 strerror(errno)),
1635 sock);
1636
1637 /* calc file size */
1638 if ((clam_fd = open(CS eml_filename, O_RDONLY)) < 0)
1639 {
1640 int err = errno;
1641 return m_panic_defer_3(scanent, NULL,
1642 string_sprintf("can't open spool file %s: %s",
1643 eml_filename, strerror(err)),
1644 sock);
1645 }
1646 if ((fsize = lseek(clam_fd, 0, SEEK_END)) < 0)
1647 {
1648 int err;
1649 b_seek: err = errno;
1650 (void)close(clam_fd);
1651 return m_panic_defer_3(scanent, NULL,
1652 string_sprintf("can't seek spool file %s: %s",
1653 eml_filename, strerror(err)),
1654 sock);
1655 }
1656 fsize_uint = (unsigned int) fsize;
1657 if ((off_t)fsize_uint != fsize)
1658 {
1659 (void)close(clam_fd);
1660 return m_panic_defer_3(scanent, NULL,
1661 string_sprintf("seeking spool file %s, size overflow",
1662 eml_filename),
1663 sock);
1664 }
1665 if (lseek(clam_fd, 0, SEEK_SET) < 0)
1666 goto b_seek;
1667
1668 if (!(clamav_fbuf = US malloc(fsize_uint)))
1669 {
1670 (void)close(clam_fd);
1671 return m_panic_defer_3(scanent, NULL,
1672 string_sprintf("unable to allocate memory %u for file (%s)",
1673 fsize_uint, eml_filename),
1674 sock);
1675 }
1676
1677 if ((result = read(clam_fd, clamav_fbuf, fsize_uint)) < 0)
1678 {
1679 int err = errno;
1680 free(clamav_fbuf); (void)close(clam_fd);
1681 return m_panic_defer_3(scanent, NULL,
1682 string_sprintf("can't read spool file %s: %s",
1683 eml_filename, strerror(err)),
1684 sock);
1685 }
1686 (void)close(clam_fd);
1687
1688 /* send file body to socket */
1689 send_size = htonl(fsize_uint);
1690 send_final_zeroblock = 0;
1691 if ((send(sock, &send_size, sizeof(send_size), 0) < 0) ||
1692 (send(sock, clamav_fbuf, fsize_uint, 0) < 0) ||
1693 (send(sock, &send_final_zeroblock, sizeof(send_final_zeroblock), 0) < 0))
1694 {
1695 free(clamav_fbuf);
1696 return m_panic_defer_3(scanent, NULL,
1697 string_sprintf("unable to send file body to socket (%s)", hostname),
1698 sock);
1699 }
1700
1701 free(clamav_fbuf);
1702 }
1703 else
1704 { /* use scan command */
1705 /* Send a SCAN command pointing to a filename; then in the then in the
1706 * scan-method-neutral part, read the response back */
1707
1708 /* ================================================================= */
1709
1710 /* Prior to the reworking post-Exim-4.72, this scanned a directory,
1711 which dates to when ClamAV needed us to break apart the email into the
1712 MIME parts (eg, with the now deprecated demime condition coming first).
1713 Some time back, ClamAV gained the ability to deconstruct the emails, so
1714 doing this would actually have resulted in the mail attachments being
1715 scanned twice, in the broken out files and from the original .eml.
1716 Since ClamAV now handles emails (and has for quite some time) we can
1717 just use the email file itself. */
1718 /* Pass the string to ClamAV (7 = "SCAN \n" + \0), if not already sent */
1719
1720 DEBUG(D_acl) debug_printf_indent(
1721 "Malware scan: issuing %s local-path scan [%s]\n",
1722 scanner_name, scanner_options);
1723
1724 if (cmd_str.len)
1725 if (send(sock, cmd_str.data, cmd_str.len, 0) < 0)
1726 return m_panic_defer_3(scanent, CUS callout_address,
1727 string_sprintf("unable to write to socket (%s)", strerror(errno)),
1728 sock);
1729
1730 /* Do not shut down the socket for writing; a user report noted that
1731 * clamd 0.70 does not react well to this. */
1732 }
1733 /* Commands have been sent, no matter which scan method or connection
1734 * type we're using; now just read the result, independent of method. */
1735
1736 /* Read the result */
1737 memset(av_buffer, 0, sizeof(av_buffer));
1738 bread = ip_recv(sock, av_buffer, sizeof(av_buffer), tmo-time(NULL));
1739 (void)close(sock);
1740 sock = -1;
1741
1742 if (bread <= 0)
1743 return m_panic_defer(scanent, CUS callout_address,
1744 string_sprintf("unable to read from socket (%s)",
1745 errno == 0 ? "EOF" : strerror(errno)));
1746
1747 if (bread == sizeof(av_buffer))
1748 return m_panic_defer(scanent, CUS callout_address,
1749 US"buffer too small");
1750 /* We're now assured of a NULL at the end of av_buffer */
1751
1752 /* Check the result. ClamAV returns one of two result formats.
1753 In the basic mode, the response is of the form:
1754 infected: -> "<filename>: <virusname> FOUND"
1755 not-infected: -> "<filename>: OK"
1756 error: -> "<filename>: <errcode> ERROR
1757 If the ExtendedDetectionInfo option has been turned on, then we get:
1758 "<filename>: <virusname>(<virushash>:<virussize>) FOUND"
1759 for the infected case. Compare:
1760 /tmp/eicar.com: Eicar-Test-Signature FOUND
1761 /tmp/eicar.com: Eicar-Test-Signature(44d88612fea8a8f36de82e1278abb02f:68) FOUND
1762
1763 In the streaming case, clamd uses the filename "stream" which you should
1764 be able to verify with { ktrace clamdscan --stream /tmp/eicar.com }. (The
1765 client app will replace "stream" with the original filename before returning
1766 results to stdout, but the trace shows the data).
1767
1768 We will assume that the pathname passed to clamd from Exim does not contain
1769 a colon. We will have whined loudly above if the eml_filename does (and we're
1770 passing a filename to clamd). */
1771
1772 if (!(*av_buffer))
1773 return m_panic_defer(scanent, CUS callout_address,
1774 US"ClamAV returned null");
1775
1776 /* strip newline at the end (won't be present for zINSTREAM)
1777 (also any trailing whitespace, which shouldn't exist, but we depend upon
1778 this below, so double-check) */
1779 p = av_buffer + Ustrlen(av_buffer) - 1;
1780 if (*p == '\n') *p = '\0';
1781
1782 DEBUG(D_acl) debug_printf_indent("Malware response: %s\n", av_buffer);
1783
1784 while (isspace(*--p) && (p > av_buffer))
1785 *p = '\0';
1786 if (*p) ++p;
1787
1788 /* colon in returned output? */
1789 if(!(p = Ustrchr(av_buffer,':')))
1790 return m_panic_defer(scanent, CUS callout_address, string_sprintf(
1791 "ClamAV returned malformed result (missing colon): %s",
1792 av_buffer));
1793
1794 /* strip filename */
1795 while (*p && isspace(*++p)) /**/;
1796 vname = p;
1797
1798 /* It would be bad to encounter a virus with "FOUND" in part of the name,
1799 but we should at least be resistant to it. */
1800 p = Ustrrchr(vname, ' ');
1801 result_tag = p ? p+1 : vname;
1802
1803 if (Ustrcmp(result_tag, "FOUND") == 0)
1804 {
1805 /* p should still be the whitespace before the result_tag */
1806 while (isspace(*p)) --p;
1807 *++p = '\0';
1808 /* Strip off the extended information too, which will be in parens
1809 after the virus name, with no intervening whitespace. */
1810 if (*--p == ')')
1811 {
1812 /* "(hash:size)", so previous '(' will do; if not found, we have
1813 a curious virus name, but not an error. */
1814 p = Ustrrchr(vname, '(');
1815 if (p)
1816 *p = '\0';
1817 }
1818 malware_name = string_copy(vname);
1819 DEBUG(D_acl) debug_printf_indent("Malware found, name \"%s\"\n", malware_name);
1820
1821 }
1822 else if (Ustrcmp(result_tag, "ERROR") == 0)
1823 return m_panic_defer(scanent, CUS callout_address,
1824 string_sprintf("ClamAV returned: %s", av_buffer));
1825
1826 else if (Ustrcmp(result_tag, "OK") == 0)
1827 {
1828 /* Everything should be OK */
1829 malware_name = NULL;
1830 DEBUG(D_acl) debug_printf_indent("Malware not found\n");
1831
1832 }
1833 else
1834 return m_panic_defer(scanent, CUS callout_address,
1835 string_sprintf("unparseable response from ClamAV: {%s}", av_buffer));
1836
1837 break;
1838 } /* clamd */
1839 #endif
1840
1841 #ifndef DISABLE_MAL_SOCK
1842 case M_SOCK: /* "sock" scanner type ------------------------------------- */
1843 /* This code was derived by Martin Poole from the clamd code contributed
1844 by David Saez and the cmdline code
1845 */
1846 {
1847 int bread;
1848 uschar * commandline;
1849 uschar av_buffer[1024];
1850 uschar * linebuffer;
1851 uschar * sockline_scanner;
1852 uschar sockline_scanner_default[] = "%s\n";
1853 const pcre *sockline_trig_re;
1854 const pcre *sockline_name_re;
1855
1856 /* find scanner command line */
1857 if ( (sockline_scanner = string_nextinlist(&av_scanner_work, &sep,
1858 NULL, 0))
1859 && *sockline_scanner
1860 )
1861 { /* check for no expansions apart from one %s */
1862 uschar * s = Ustrchr(sockline_scanner, '%');
1863 if (s++)
1864 if ((*s != 's' && *s != '%') || Ustrchr(s+1, '%'))
1865 return m_panic_defer_3(scanent, NULL,
1866 US"unsafe sock scanner call spec", sock);
1867 }
1868 else
1869 sockline_scanner = sockline_scanner_default;
1870 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "cmdline: ",
1871 string_printing(sockline_scanner));
1872
1873 /* find scanner output trigger */
1874 sockline_trig_re = m_pcre_nextinlist(&av_scanner_work, &sep,
1875 "missing trigger specification", &errstr);
1876 if (!sockline_trig_re)
1877 return m_panic_defer_3(scanent, NULL, errstr, sock);
1878
1879 /* find virus name regex */
1880 sockline_name_re = m_pcre_nextinlist(&av_scanner_work, &sep,
1881 "missing virus name regex specification", &errstr);
1882 if (!sockline_name_re)
1883 return m_panic_defer_3(scanent, NULL, errstr, sock);
1884
1885 /* prepare scanner call - security depends on expansions check above */
1886 commandline = string_sprintf( CS sockline_scanner, CS eml_filename);
1887 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "expanded: ",
1888 string_printing(commandline));
1889
1890 /* Pass the command string to the socket */
1891 if (m_sock_send(sock, commandline, Ustrlen(commandline), &errstr) < 0)
1892 return m_panic_defer(scanent, CUS callout_address, errstr);
1893
1894 /* Read the result */
1895 bread = ip_recv(sock, av_buffer, sizeof(av_buffer), tmo-time(NULL));
1896
1897 if (bread <= 0)
1898 return m_panic_defer_3(scanent, CUS callout_address,
1899 string_sprintf("unable to read from socket (%s)", strerror(errno)),
1900 sock);
1901
1902 if (bread == sizeof(av_buffer))
1903 return m_panic_defer_3(scanent, CUS callout_address,
1904 US"buffer too small", sock);
1905 av_buffer[bread] = '\0';
1906 linebuffer = string_copy(av_buffer);
1907 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "answer: ",
1908 string_printing(linebuffer));
1909
1910 /* try trigger match */
1911 if (regex_match_and_setup(sockline_trig_re, linebuffer, 0, -1))
1912 {
1913 if (!(malware_name = m_pcre_exec(sockline_name_re, av_buffer)))
1914 malware_name = US "unknown";
1915 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "name: ",
1916 string_printing(malware_name));
1917 }
1918 else /* no virus found */
1919 malware_name = NULL;
1920 break;
1921 }
1922 #endif
1923
1924 #ifndef DISABLE_MAL_MKS
1925 case M_MKSD: /* "mksd" scanner type ------------------------------------- */
1926 {
1927 char *mksd_options_end;
1928 int mksd_maxproc = 1; /* default, if no option supplied */
1929 int retval;
1930
1931 if (scanner_options)
1932 {
1933 mksd_maxproc = (int)strtol(CS scanner_options, &mksd_options_end, 10);
1934 if ( *scanner_options == '\0'
1935 || *mksd_options_end != '\0'
1936 || mksd_maxproc < 1
1937 || mksd_maxproc > 32
1938 )
1939 return m_panic_defer(scanent, CUS callout_address,
1940 string_sprintf("invalid option '%s'", scanner_options));
1941 }
1942
1943 if((sock = ip_unixsocket(US "/var/run/mksd/socket", &errstr)) < 0)
1944 return m_panic_defer(scanent, CUS callout_address, errstr);
1945
1946 malware_name = NULL;
1947
1948 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan\n", scanner_name);
1949
1950 if ((retval = mksd_scan_packed(scanent, sock, eml_filename, tmo)) != OK)
1951 {
1952 close (sock);
1953 return retval;
1954 }
1955 break;
1956 }
1957 #endif
1958
1959 #ifndef DISABLE_MAL_AVAST
1960 case M_AVAST: /* "avast" scanner type ----------------------------------- */
1961 {
1962 uschar buf[1024];
1963 uschar * scanrequest;
1964 enum {AVA_HELO, AVA_OPT, AVA_RSP, AVA_DONE} avast_stage;
1965 int nread;
1966 uschar * error_message = NULL;
1967 BOOL more_data = FALSE;
1968 BOOL strict = TRUE;
1969
1970 /* According to Martin Tuma @avast the protocol uses "escaped
1971 whitespace", that is, every embedded whitespace is backslash
1972 escaped, as well as backslash is protected by backslash.
1973 The returned lines contain the name of the scanned file, a tab
1974 and the [ ] marker.
1975 [+] - not infected
1976 [L] - infected
1977 [E] - some error occured
1978 Such marker follows the first non-escaped TAB. For more information
1979 see avast-protocol(5)
1980
1981 We observed two cases:
1982 -> SCAN /file
1983 <- /file [E]0.0 Error 13 Permission denied
1984 <- 451 SCAN Engine error 13 permission denied
1985
1986 -> SCAN /file
1987 <- /file… [E]3.0 Error 41120 The file is a decompression bomb
1988 <- /file… [+]2.0
1989 <- /file… [+]2.0 0 Eicar Test Virus!!!
1990 <- 200 SCAN OK
1991
1992 If the scanner returns 4xx, DEFER is a good decision, combined
1993 with a panic log entry, to get the admin's attention.
1994
1995 If the scanner returns 200, we reject it as malware, if found any,
1996 or, in case of an error, we set the malware message to the error
1997 string.
1998
1999 Some of the >= 42000 errors are message related - usually some
2000 broken archives etc, but some of them are e.g. license related.
2001 Once the license expires the engine starts returning errors for
2002 every scanning attempt. I¹ have the full list of the error codes
2003 but it is not a public API and is subject to change. It is hard
2004 for me to say what you should do in case of an engine error. You
2005 can have a “Treat * unscanned file as infection” policy or “Treat
2006 unscanned file as clean” policy. ¹) Jakub Bednar
2007
2008 */
2009
2010 if ( ( !ava_re_clean
2011 && !(ava_re_clean = m_pcre_compile(ava_re_clean_str, &errstr)))
2012 || ( !ava_re_virus
2013 && !(ava_re_virus = m_pcre_compile(ava_re_virus_str, &errstr)))
2014 || ( !ava_re_error
2015 && !(ava_re_error = m_pcre_compile(ava_re_error_str, &errstr)))
2016 )
2017 return malware_panic_defer(errstr);
2018
2019 /* wait for result */
2020 for (avast_stage = AVA_HELO;
2021 (nread = recv_line(sock, buf, sizeof(buf), tmo)) > 0;
2022 )
2023 {
2024 int slen = Ustrlen(buf);
2025 if (slen >= 1)
2026 {
2027
2028 /* Multi line responses are bracketed between 210 … and nnn … */
2029 if (Ustrncmp(buf, "210", 3) == 0)
2030 {
2031 more_data = 1;
2032 continue;
2033 }
2034 else if (more_data && isdigit(buf[0])) more_data = 0;
2035
2036 switch (avast_stage)
2037 {
2038 case AVA_HELO:
2039 if (more_data) continue;
2040 if (Ustrncmp(buf, "220", 3) != 0)
2041 goto endloop; /* require a 220 */
2042 goto sendreq;
2043
2044 case AVA_OPT:
2045 if (more_data) continue;
2046 if (Ustrncmp(buf, "200", 3) != 0)
2047 goto endloop; /* require a 200 */
2048
2049 sendreq:
2050 {
2051 int len;
2052 /* Check for another option to send. Newline-terminate it. */
2053 if ((scanrequest = string_nextinlist(&av_scanner_work, &sep,
2054 NULL, 0)))
2055 {
2056 if (Ustrcmp(scanrequest, "pass_unscanned") == 0)
2057 {
2058 DEBUG(D_acl) debug_printf_indent("pass unscanned files as clean\n");
2059 strict = FALSE;
2060 goto sendreq;
2061 }
2062 scanrequest = string_sprintf("%s\n", scanrequest);
2063 avast_stage = AVA_OPT; /* just sent option */
2064 DEBUG(D_acl) debug_printf_indent("send to avast OPTION: %s", scanrequest);
2065 }
2066 else
2067 {
2068 scanrequest = string_sprintf("SCAN %s\n", eml_dir);
2069 avast_stage = AVA_RSP; /* just sent command */
2070 DEBUG(D_acl) debug_printf_indent("send to avast REQUEST: SCAN %s\n", eml_dir);
2071 }
2072
2073 /* send config-cmd or scan-request to socket */
2074 len = Ustrlen(scanrequest);
2075 if (send(sock, scanrequest, len, 0) == -1)
2076 {
2077 scanrequest[len-1] = '\0';
2078 return m_panic_defer_3(scanent, CUS callout_address, string_sprintf(
2079 "unable to send request '%s' to socket (%s): %s",
2080 scanrequest, scanner_options, strerror(errno)), sock);
2081 }
2082 break;
2083 }
2084
2085 case AVA_RSP:
2086
2087 if (isdigit(buf[0])) /* We're done */
2088 goto endloop;
2089
2090 if (malware_name) /* Nothing else matters, just read on */
2091 break;
2092
2093 if (pcre_exec(ava_re_clean, NULL, CS buf, slen, 0, 0, NULL, 0) == 0)
2094 break;
2095
2096 if ((malware_name = m_pcre_exec(ava_re_virus, buf)))
2097 {
2098 unescape(malware_name);
2099 DEBUG(D_acl)
2100 debug_printf_indent("unescaped malware name: '%s'\n", malware_name);
2101 break;
2102 }
2103
2104 if (strict) /* treat scanner errors as malware */
2105 {
2106 if ((malware_name = m_pcre_exec(ava_re_error, buf)))
2107 {
2108 unescape(malware_name);
2109 DEBUG(D_acl)
2110 debug_printf_indent("unescaped error message: '%s'\n", malware_name);
2111 break;
2112 }
2113 }
2114 else if (pcre_exec(ava_re_error, NULL, CS buf, slen, 0, 0, NULL, 0) == 0)
2115 {
2116 log_write(0, LOG_MAIN, "internal scanner error (ignored): %s", buf);
2117 break;
2118 }
2119
2120 /* here also for any unexpected response from the scanner */
2121 DEBUG(D_acl) debug_printf("avast response not handled: '%s'\n", buf);
2122
2123 goto endloop;
2124
2125 default: log_write(0, LOG_PANIC, "%s:%d:%s: should not happen",
2126 __FILE__, __LINE__, __FUNCTION__);
2127 }
2128 }
2129 }
2130
2131 endloop:
2132
2133 if (nread == -1) error_message = US"EOF from scanner";
2134 else if (nread < 0) error_message = US"timeout from scanner";
2135 else if (nread == 0) error_message = US"got nothing from scanner";
2136 else if (buf[0] != '2') error_message = buf;
2137
2138 DEBUG(D_acl) debug_printf_indent("sent to avast QUIT\n");
2139 if (send(sock, "QUIT\n", 5, 0) == -1)
2140 return m_panic_defer_3(scanent, CUS callout_address,
2141 string_sprintf("unable to send quit request to socket (%s): %s",
2142 scanner_options, strerror(errno)), sock);
2143
2144 if (error_message)
2145 return m_panic_defer_3(scanent, CUS callout_address, error_message, sock);
2146
2147 }
2148 #endif
2149 } /* scanner type switch */
2150
2151 if (sock >= 0)
2152 (void) close (sock);
2153 malware_ok = TRUE; /* set "been here, done that" marker */
2154 }
2155
2156 /* match virus name against pattern (caseless ------->----------v) */
2157 if (malware_name && regex_match_and_setup(re, malware_name, 0, -1))
2158 {
2159 DEBUG(D_acl) debug_printf_indent(
2160 "Matched regex to malware [%s] [%s]\n", malware_re, malware_name);
2161 return OK;
2162 }
2163 else
2164 return FAIL;
2165 }
2166
2167
2168 /*************************************************
2169 * Scan an email for malware *
2170 *************************************************/
2171
2172 /* This is the normal interface for scanning an email, which doesn't need a
2173 filename; it's a wrapper around the malware_file function.
2174
2175 Arguments:
2176 malware_re match condition for "malware="
2177 timeout if nonzero, timeout in seconds
2178
2179 Returns: Exim message processing code (OK, FAIL, DEFER, ...)
2180 where true means malware was found (condition applies)
2181 */
2182 int
2183 malware(const uschar * malware_re, int timeout)
2184 {
2185 int ret = malware_internal(malware_re, NULL, timeout);
2186
2187 if (ret == DEFER) av_failed = TRUE;
2188 return ret;
2189 }
2190
2191
2192 /*************************************************
2193 * Scan a file for malware *
2194 *************************************************/
2195
2196 /* This is a test wrapper for scanning an email, which is not used in
2197 normal processing. Scan any file, using the Exim scanning interface.
2198 This function tampers with various global variables so is unsafe to use
2199 in any other context.
2200
2201 Arguments:
2202 eml_filename a file holding the message to be scanned
2203
2204 Returns: Exim message processing code (OK, FAIL, DEFER, ...)
2205 where true means malware was found (condition applies)
2206 */
2207 int
2208 malware_in_file(uschar *eml_filename)
2209 {
2210 uschar message_id_buf[64];
2211 int ret;
2212
2213 /* spool_mbox() assumes various parameters exist, when creating
2214 the relevant directory and the email within */
2215
2216 (void) string_format(message_id_buf, sizeof(message_id_buf),
2217 "dummy-%d", vaguely_random_number(INT_MAX));
2218 message_id = message_id_buf;
2219 sender_address = US"malware-sender@example.net";
2220 return_path = US"";
2221 recipients_list = NULL;
2222 receive_add_recipient(US"malware-victim@example.net", -1);
2223 enable_dollar_recipients = TRUE;
2224
2225 ret = malware_internal(US"*", eml_filename, 0);
2226
2227 Ustrncpy(spooled_message_id, message_id, sizeof(spooled_message_id));
2228 spool_mbox_ok = 1;
2229
2230 /* don't set no_mbox_unspool; at present, there's no way for it to become
2231 set, but if that changes, then it should apply to these tests too */
2232
2233 unspool_mbox();
2234
2235 /* silence static analysis tools */
2236 message_id = NULL;
2237
2238 return ret;
2239 }
2240
2241
2242 void
2243 malware_init(void)
2244 {
2245 if (!malware_default_re)
2246 malware_default_re = regex_must_compile(malware_regex_default, FALSE, TRUE);
2247
2248 #ifndef DISABLE_MAL_DRWEB
2249 if (!drweb_re)
2250 drweb_re = regex_must_compile(drweb_re_str, FALSE, TRUE);
2251 #endif
2252 #ifndef DISABLE_MAL_FSECURE
2253 if (!fsec_re)
2254 fsec_re = regex_must_compile(fsec_re_str, FALSE, TRUE);
2255 #endif
2256 #ifndef DISABLE_MAL_KAV
2257 if (!kav_re_sus)
2258 kav_re_sus = regex_must_compile(kav_re_sus_str, FALSE, TRUE);
2259 if (!kav_re_inf)
2260 kav_re_inf = regex_must_compile(kav_re_inf_str, FALSE, TRUE);
2261 #endif
2262 #ifndef DISABLE_MAL_AVAST
2263 if (!ava_re_clean)
2264 ava_re_clean = regex_must_compile(ava_re_clean_str, FALSE, TRUE);
2265 if (!ava_re_virus)
2266 ava_re_virus = regex_must_compile(ava_re_virus_str, FALSE, TRUE);
2267 if (!ava_re_error)
2268 ava_re_error = regex_must_compile(ava_re_error_str, FALSE, TRUE);
2269 #endif
2270 #ifndef DISABLE_MAL_FFROT6D
2271 if (!fprot6d_re_error)
2272 fprot6d_re_error = regex_must_compile(fprot6d_re_error_str, FALSE, TRUE);
2273 if (!fprot6d_re_virus)
2274 fprot6d_re_virus = regex_must_compile(fprot6d_re_virus_str, FALSE, TRUE);
2275 #endif
2276 }
2277
2278
2279 void
2280 malware_show_supported(FILE * f)
2281 {
2282 struct scan * sc;
2283 fprintf(f, "Malware:");
2284 for (sc = m_scans; sc->scancode != -1; sc++) fprintf(f, " %s", sc->name);
2285 fprintf(f, "\n");
2286 }
2287
2288
2289 # endif /*!MACRO_PREDEF*/
2290 #endif /*WITH_CONTENT_SCAN*/
2291 /*
2292 * vi: aw ai sw=2
2293 */