tidying
[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 #ifndef DISABLE_MAL_KAV
195 /* Routine to check whether a system is big- or little-endian.
196 Ripped from http://www.faqs.org/faqs/graphics/fileformats-faq/part4/section-7.html
197 Needed for proper kavdaemon implementation. Sigh. */
198 # define BIG_MY_ENDIAN 0
199 # define LITTLE_MY_ENDIAN 1
200 static int test_byte_order(void);
201 static inline int
202 test_byte_order()
203 {
204 short int word = 0x0001;
205 char *byte = CS &word;
206 return(byte[0] ? LITTLE_MY_ENDIAN : BIG_MY_ENDIAN);
207 }
208 #endif
209
210 BOOL malware_ok = FALSE;
211
212 /* Gross hacks for the -bmalware option; perhaps we should just create
213 the scan directory normally for that case, but look into rigging up the
214 needed header variables if not already set on the command-line? */
215 extern int spool_mbox_ok;
216 extern uschar spooled_message_id[MESSAGE_ID_LENGTH+1];
217
218
219 /* Some (currently avast only) use backslash escaped whitespace,
220 this function undoes these escapes */
221
222 static inline void
223 unescape(uschar *p)
224 {
225 uschar *p0;
226 for (; *p; ++p)
227 if (*p == '\\' && (isspace(p[1]) || p[1] == '\\'))
228 for (p0 = p; *p0; ++p0) *p0 = p0[1];
229 }
230
231 /* --- malware_*_defer --- */
232 static inline int
233 malware_panic_defer(const uschar * str)
234 {
235 log_write(0, LOG_MAIN|LOG_PANIC, "malware acl condition: %s", str);
236 return DEFER;
237 }
238 static inline int
239 malware_log_defer(const uschar * str)
240 {
241 log_write(0, LOG_MAIN, "malware acl condition: %s", str);
242 return DEFER;
243 }
244 /* --- m_*_defer --- */
245 static inline int
246 m_panic_defer(struct scan * scanent, const uschar * hostport,
247 const uschar * str)
248 {
249 return malware_panic_defer(string_sprintf("%s %s : %s",
250 scanent->name, hostport ? hostport : CUS"", str));
251 }
252 static inline int
253 m_log_defer(struct scan * scanent, const uschar * hostport,
254 const uschar * str)
255 {
256 return malware_log_defer(string_sprintf("%s %s : %s",
257 scanent->name, hostport ? hostport : CUS"", str));
258 }
259 /* --- m_*_defer_3 */
260 static inline int
261 m_panic_defer_3(struct scan * scanent, const uschar * hostport,
262 const uschar * str, int fd_to_close)
263 {
264 (void) close(fd_to_close);
265 return m_panic_defer(scanent, hostport, str);
266 }
267
268 /*************************************************/
269
270 #ifndef DISABLE_MAL_CLAM
271 /* Only used by the Clamav code, which is working from a list of servers and
272 uses the returned in_addr to get a second connection to the same system.
273 */
274 static inline int
275 m_tcpsocket(const uschar * hostname, unsigned int port,
276 host_item * host, uschar ** errstr, const blob * fastopen_blob)
277 {
278 return ip_connectedsocket(SOCK_STREAM, hostname, port, port, 5,
279 host, errstr, fastopen_blob);
280 }
281 #endif
282
283 static int
284 m_sock_send(int sock, uschar * buf, int cnt, uschar ** errstr)
285 {
286 if (send(sock, buf, cnt, 0) < 0)
287 {
288 int err = errno;
289 (void)close(sock);
290 *errstr = string_sprintf("unable to send to socket (%s): %s",
291 buf, strerror(err));
292 return -1;
293 }
294 return sock;
295 }
296
297 static const pcre *
298 m_pcre_compile(const uschar * re, uschar ** errstr)
299 {
300 const uschar * rerror;
301 int roffset;
302 const pcre * cre;
303
304 cre = pcre_compile(CS re, PCRE_COPT, (const char **)&rerror, &roffset, NULL);
305 if (!cre)
306 *errstr= string_sprintf("regular expression error in '%s': %s at offset %d",
307 re, rerror, roffset);
308 return cre;
309 }
310
311 uschar *
312 m_pcre_exec(const pcre * cre, uschar * text)
313 {
314 int ovector[10*3];
315 int i = pcre_exec(cre, NULL, CS text, Ustrlen(text), 0, 0,
316 ovector, nelem(ovector));
317 uschar * substr = NULL;
318 if (i >= 2) /* Got it */
319 pcre_get_substring(CS text, ovector, i, 1, (const char **) &substr);
320 return substr;
321 }
322
323 static const pcre *
324 m_pcre_nextinlist(const uschar ** list, int * sep,
325 char * listerr, uschar ** errstr)
326 {
327 const uschar * list_ele;
328 const pcre * cre = NULL;
329
330 if (!(list_ele = string_nextinlist(list, sep, NULL, 0)))
331 *errstr = US listerr;
332 else
333 {
334 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "RE: ",
335 string_printing(list_ele));
336 cre = m_pcre_compile(CUS list_ele, errstr);
337 }
338 return cre;
339 }
340
341 /*
342 Simple though inefficient wrapper for reading a line. Drop CRs and the
343 trailing newline. Can return early on buffer full. Null-terminate.
344 Apply initial timeout if no data ready.
345
346 Return: number of chars - zero for an empty line
347 -1 on EOF
348 -2 on timeout or error
349 */
350 static int
351 recv_line(int fd, uschar * buffer, int bsize, int tmo)
352 {
353 uschar * p = buffer;
354 ssize_t rcv;
355 BOOL ok = FALSE;
356
357 if (!fd_ready(fd, tmo-time(NULL)))
358 return -2;
359
360 /*XXX tmo handling assumes we always get a whole line */
361 /* read until \n */
362 errno = 0;
363 while ((rcv = read(fd, p, 1)) > 0)
364 {
365 ok = TRUE;
366 if (p-buffer > bsize-2) break;
367 if (*p == '\n') break;
368 if (*p != '\r') p++;
369 }
370 if (!ok)
371 {
372 DEBUG(D_acl) debug_printf_indent("Malware scan: read %s (%s)\n",
373 rcv==0 ? "EOF" : "error", strerror(errno));
374 return rcv==0 ? -1 : -2;
375 }
376 *p = '\0';
377
378 DEBUG(D_acl) debug_printf_indent("Malware scan: read '%s'\n", buffer);
379 return p - buffer;
380 }
381
382 /* return TRUE iff size as requested */
383 static BOOL
384 recv_len(int sock, void * buf, int size, int tmo)
385 {
386 return fd_ready(sock, tmo-time(NULL))
387 ? recv(sock, buf, size, 0) == size
388 : FALSE;
389 }
390
391
392
393 #ifndef DISABLE_MAL_MKS
394 /* ============= private routines for the "mksd" scanner type ============== */
395
396 # include <sys/uio.h>
397
398 static inline int
399 mksd_writev (int sock, struct iovec * iov, int iovcnt)
400 {
401 int i;
402
403 for (;;)
404 {
405 do
406 i = writev (sock, iov, iovcnt);
407 while (i < 0 && errno == EINTR);
408 if (i <= 0)
409 {
410 (void) malware_panic_defer(
411 US"unable to write to mksd UNIX socket (/var/run/mksd/socket)");
412 return -1;
413 }
414 for (;;) /* check for short write */
415 if (i >= iov->iov_len)
416 {
417 if (--iovcnt == 0)
418 return 0;
419 i -= iov->iov_len;
420 iov++;
421 }
422 else
423 {
424 iov->iov_len -= i;
425 iov->iov_base = CS iov->iov_base + i;
426 break;
427 }
428 }
429 }
430
431 static inline int
432 mksd_read_lines (int sock, uschar *av_buffer, int av_buffer_size, int tmo)
433 {
434 client_conn_ctx cctx = {.sock = sock};
435 int offset = 0;
436 int i;
437
438 do
439 {
440 i = ip_recv(&cctx, av_buffer+offset, av_buffer_size-offset, tmo-time(NULL));
441 if (i <= 0)
442 {
443 (void) malware_panic_defer(US"unable to read from mksd UNIX socket (/var/run/mksd/socket)");
444 return -1;
445 }
446
447 offset += i;
448 /* offset == av_buffer_size -> buffer full */
449 if (offset == av_buffer_size)
450 {
451 (void) malware_panic_defer(US"malformed reply received from mksd");
452 return -1;
453 }
454 } while (av_buffer[offset-1] != '\n');
455
456 av_buffer[offset] = '\0';
457 return offset;
458 }
459
460 static inline int
461 mksd_parse_line(struct scan * scanent, char * line)
462 {
463 char *p;
464
465 switch (*line)
466 {
467 case 'O': /* OK */
468 return OK;
469
470 case 'E':
471 case 'A': /* ERR */
472 if ((p = strchr (line, '\n')) != NULL)
473 *p = '\0';
474 return m_panic_defer(scanent, NULL,
475 string_sprintf("scanner failed: %s", line));
476
477 default: /* VIR */
478 if ((p = strchr (line, '\n')) != NULL)
479 {
480 *p = '\0';
481 if ( p-line > 5
482 && line[3] == ' '
483 && (p = strchr(line+4, ' ')) != NULL
484 && p-line > 4
485 )
486 {
487 *p = '\0';
488 malware_name = string_copy(US line+4);
489 return OK;
490 }
491 }
492 return m_panic_defer(scanent, NULL,
493 string_sprintf("malformed reply received: %s", line));
494 }
495 }
496
497 static int
498 mksd_scan_packed(struct scan * scanent, int sock, const uschar * scan_filename,
499 int tmo)
500 {
501 struct iovec iov[3];
502 const char *cmd = "MSQ\n";
503 uschar av_buffer[1024];
504
505 iov[0].iov_base = (void *) cmd;
506 iov[0].iov_len = 3;
507 iov[1].iov_base = (void *) scan_filename;
508 iov[1].iov_len = Ustrlen(scan_filename);
509 iov[2].iov_base = (void *) (cmd + 3);
510 iov[2].iov_len = 1;
511
512 if (mksd_writev (sock, iov, 3) < 0)
513 return DEFER;
514
515 if (mksd_read_lines (sock, av_buffer, sizeof (av_buffer), tmo) < 0)
516 return DEFER;
517
518 return mksd_parse_line (scanent, CS av_buffer);
519 }
520 #endif /* MKSD */
521
522
523 #ifndef DISABLE_MAL_CLAM
524 static int
525 clamd_option(clamd_address * cd, const uschar * optstr, int * subsep)
526 {
527 uschar * s;
528
529 cd->retry = 0;
530 while ((s = string_nextinlist(&optstr, subsep, NULL, 0)))
531 if (Ustrncmp(s, "retry=", 6) == 0)
532 {
533 int sec = readconf_readtime((s += 6), '\0', FALSE);
534 if (sec < 0)
535 return FAIL;
536 cd->retry = sec;
537 }
538 else
539 return FAIL;
540 return OK;
541 }
542 #endif
543
544
545
546 /*************************************************
547 * Scan content for malware *
548 *************************************************/
549
550 /* This is an internal interface for scanning an email; the normal interface
551 is via malware(), or there's malware_in_file() used for testing/debugging.
552
553 Arguments:
554 malware_re match condition for "malware="
555 scan_filename the file holding the email to be scanned, if we're faking
556 this up for the -bmalware test, else NULL
557 timeout if nonzero, non-default timeoutl
558
559 Returns: Exim message processing code (OK, FAIL, DEFER, ...)
560 where true means malware was found (condition applies)
561 */
562 static int
563 malware_internal(const uschar * malware_re, const uschar * scan_filename,
564 int timeout)
565 {
566 int sep = 0;
567 const uschar *av_scanner_work = av_scanner;
568 uschar *scanner_name;
569 unsigned long mbox_size;
570 FILE *mbox_file;
571 const pcre *re;
572 uschar * errstr;
573 struct scan * scanent;
574 const uschar * scanner_options;
575 client_conn_ctx malware_daemon_ctx = {.sock = -1};
576 time_t tmo;
577 uschar * eml_filename, * eml_dir;
578
579 if (!malware_re)
580 return FAIL; /* empty means "don't match anything" */
581
582 /* Ensure the eml mbox file is spooled up */
583
584 if (!(mbox_file = spool_mbox(&mbox_size, scan_filename, &eml_filename)))
585 return malware_panic_defer(US"error while creating mbox spool file");
586
587 /* None of our current scanners need the mbox file as a stream (they use
588 the name), so we can close it right away. Get the directory too. */
589
590 (void) fclose(mbox_file);
591 eml_dir = string_copyn(eml_filename, Ustrrchr(eml_filename, '/') - eml_filename);
592
593 /* parse 1st option */
594 if (strcmpic(malware_re, US"false") == 0 || Ustrcmp(malware_re,"0") == 0)
595 return FAIL; /* explicitly no matching */
596
597 /* special cases (match anything except empty) */
598 if ( strcmpic(malware_re,US"true") == 0
599 || Ustrcmp(malware_re,"*") == 0
600 || Ustrcmp(malware_re,"1") == 0
601 )
602 {
603 if ( !malware_default_re
604 && !(malware_default_re = m_pcre_compile(malware_regex_default, &errstr)))
605 return malware_panic_defer(errstr);
606 malware_re = malware_regex_default;
607 re = malware_default_re;
608 }
609
610 /* compile the regex, see if it works */
611 else if (!(re = m_pcre_compile(malware_re, &errstr)))
612 return malware_panic_defer(errstr);
613
614 /* if av_scanner starts with a dollar, expand it first */
615 if (*av_scanner == '$')
616 {
617 if (!(av_scanner_work = expand_string(av_scanner)))
618 return malware_panic_defer(
619 string_sprintf("av_scanner starts with $, but expansion failed: %s",
620 expand_string_message));
621
622 DEBUG(D_acl)
623 debug_printf_indent("Expanded av_scanner global: %s\n", av_scanner_work);
624 /* disable result caching in this case */
625 malware_name = NULL;
626 malware_ok = FALSE;
627 }
628
629 /* Do not scan twice (unless av_scanner is dynamic). */
630 if (!malware_ok)
631 {
632 /* find the scanner type from the av_scanner option */
633 if (!(scanner_name = string_nextinlist(&av_scanner_work, &sep, NULL, 0)))
634 return malware_panic_defer(US"av_scanner configuration variable is empty");
635 if (!timeout) timeout = MALWARE_TIMEOUT;
636 tmo = time(NULL) + timeout;
637
638 for (scanent = m_scans; ; scanent++)
639 {
640 if (!scanent->name)
641 return malware_panic_defer(string_sprintf("unknown scanner type '%s'",
642 scanner_name));
643 if (strcmpic(scanner_name, US scanent->name) != 0)
644 continue;
645 DEBUG(D_acl) debug_printf_indent("Malware scan: %s tmo=%s\n",
646 scanner_name, readconf_printtime(timeout));
647
648 if (!(scanner_options = string_nextinlist(&av_scanner_work, &sep, NULL, 0)))
649 scanner_options = scanent->options_default;
650 if (scanent->conn == MC_NONE)
651 break;
652
653 DEBUG(D_acl) debug_printf_indent("%15s%10s%s\n", "", "socket: ", scanner_options);
654 switch(scanent->conn)
655 {
656 case MC_TCP:
657 malware_daemon_ctx.sock = ip_tcpsocket(scanner_options, &errstr, 5); break;
658 case MC_UNIX:
659 malware_daemon_ctx.sock = ip_unixsocket(scanner_options, &errstr); break;
660 case MC_STRM:
661 malware_daemon_ctx.sock = ip_streamsocket(scanner_options, &errstr, 5); break;
662 default:
663 /* compiler quietening */ break;
664 }
665 if (malware_daemon_ctx.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(malware_daemon_ctx.sock, scanrequest, Ustrlen(scanrequest)+1, &errstr) < 0)
697 return m_panic_defer(scanent, CUS callout_address, errstr);
698
699 while ((len = recv_line(malware_daemon_ctx.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(malware_daemon_ctx.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(malware_daemon_ctx.sock, scanrequest, Ustrlen(scanrequest), &errstr) < 0)
746 return m_panic_defer(scanent, CUS callout_address, errstr);
747
748 bread = ip_recv(&malware_daemon_ctx, 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 malware_daemon_ctx.sock);
754
755 if (bread == sizeof(av_buffer))
756 return m_panic_defer_3(scanent, CUS callout_address,
757 US"buffer too small", malware_daemon_ctx.sock);
758
759 av_buffer[bread] = '\0';
760 linebuffer = string_copy(av_buffer);
761
762 m_sock_send(malware_daemon_ctx.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), malware_daemon_ctx.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 malware_daemon_ctx.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 malware_daemon_ctx.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 malware_daemon_ctx.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(malware_daemon_ctx.sock, &drweb_cmd, sizeof(drweb_cmd), 0) < 0) ||
828 (send(malware_daemon_ctx.sock, &drweb_flags, sizeof(drweb_flags), 0) < 0) ||
829 (send(malware_daemon_ctx.sock, &drweb_fin, sizeof(drweb_fin), 0) < 0) ||
830 (send(malware_daemon_ctx.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 malware_daemon_ctx.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 malware_daemon_ctx.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 malware_daemon_ctx.sock);
856 }
857 (void)close(drweb_fd);
858
859 /* send file body to socket */
860 if (send(malware_daemon_ctx.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 malware_daemon_ctx.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(malware_daemon_ctx.sock, &drweb_cmd, sizeof(drweb_cmd), 0) < 0) ||
877 (send(malware_daemon_ctx.sock, &drweb_flags, sizeof(drweb_flags), 0) < 0) ||
878 (send(malware_daemon_ctx.sock, &drweb_slen, sizeof(drweb_slen), 0) < 0) ||
879 (send(malware_daemon_ctx.sock, eml_filename, Ustrlen(eml_filename), 0) < 0) ||
880 (send(malware_daemon_ctx.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 malware_daemon_ctx.sock);
884 }
885
886 /* wait for result */
887 if (!recv_len(malware_daemon_ctx.sock, &drweb_rc, sizeof(drweb_rc), tmo))
888 return m_panic_defer_3(scanent, CUS callout_address,
889 US"unable to read return code", malware_daemon_ctx.sock);
890 drweb_rc = ntohl(drweb_rc);
891
892 if (!recv_len(malware_daemon_ctx.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", malware_daemon_ctx.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(malware_daemon_ctx.sock, &drweb_slen, sizeof(drweb_slen), tmo))
917 return m_panic_defer_3(scanent, CUS callout_address,
918 US"cannot read report size", malware_daemon_ctx.sock);
919 drweb_slen = ntohl(drweb_slen);
920 tmpbuf = store_get(drweb_slen);
921
922 /* read report body */
923 if (!recv_len(malware_daemon_ctx.sock, tmpbuf, drweb_slen, tmo))
924 return m_panic_defer_3(scanent, CUS callout_address,
925 US"cannot read report string", malware_daemon_ctx.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 malware_daemon_ctx.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(malware_daemon_ctx.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 malware_daemon_ctx.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(malware_daemon_ctx.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(malware_daemon_ctx.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(malware_daemon_ctx.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(malware_daemon_ctx.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 malware_daemon_ctx.sock);
1033
1034 if (result == DEFER)
1035 {
1036 (void)close(malware_daemon_ctx.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(malware_daemon_ctx.sock, cmdopt[i], Ustrlen(cmdopt[i]), &errstr) < 0)
1064 return m_panic_defer(scanent, CUS callout_address, errstr);
1065
1066 bread = ip_recv(&malware_daemon_ctx, 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 malware_daemon_ctx.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(malware_daemon_ctx.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(&malware_daemon_ctx, 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 malware_daemon_ctx.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(malware_daemon_ctx.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(malware_daemon_ctx.sock, tmpbuf, 2, tmo))
1163 return m_panic_defer_3(scanent, CUS callout_address,
1164 US"unable to read 2 bytes from socket.", malware_daemon_ctx.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 malware_daemon_ctx.sock);
1174 case 1:
1175 return m_panic_defer_3(scanent, CUS callout_address,
1176 US"reported 'scanning not completed' (code 1).", malware_daemon_ctx.sock);
1177 case 7:
1178 return m_panic_defer_3(scanent, CUS callout_address,
1179 US"reported 'kavdaemon damaged' (code 7).", malware_daemon_ctx.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(malware_daemon_ctx.sock, &kav_reportlen, 4, tmo))
1200 return m_panic_defer_3(scanent, CUS callout_address,
1201 US"cannot read report size", malware_daemon_ctx.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(malware_daemon_ctx.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(malware_daemon_ctx.sock, file_name, Ustrlen(file_name)) < 0
1395 || write(malware_daemon_ctx.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 malware_daemon_ctx.sock);
1400
1401 /* wait for result */
1402 memset(av_buffer, 0, sizeof(av_buffer));
1403 if ((bread = ip_recv(&malware_daemon_ctx, 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 malware_daemon_ctx.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", malware_daemon_ctx.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 ((malware_daemon_ctx.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 (malware_daemon_ctx.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 ((malware_daemon_ctx.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(malware_daemon_ctx.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 malware_daemon_ctx.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 malware_daemon_ctx.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 malware_daemon_ctx.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 malware_daemon_ctx.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 malware_daemon_ctx.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 malware_daemon_ctx.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(malware_daemon_ctx.sock, &send_size, sizeof(send_size), 0) < 0) ||
1692 (send(malware_daemon_ctx.sock, clamav_fbuf, fsize_uint, 0) < 0) ||
1693 (send(malware_daemon_ctx.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 malware_daemon_ctx.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(malware_daemon_ctx.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 malware_daemon_ctx.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(&malware_daemon_ctx, av_buffer, sizeof(av_buffer), tmo-time(NULL));
1739 (void)close(malware_daemon_ctx.sock);
1740 malware_daemon_ctx.sock = -1;
1741 malware_daemon_ctx.tls_ctx = NULL;
1742
1743 if (bread <= 0)
1744 return m_panic_defer(scanent, CUS callout_address,
1745 string_sprintf("unable to read from socket (%s)",
1746 errno == 0 ? "EOF" : strerror(errno)));
1747
1748 if (bread == sizeof(av_buffer))
1749 return m_panic_defer(scanent, CUS callout_address,
1750 US"buffer too small");
1751 /* We're now assured of a NULL at the end of av_buffer */
1752
1753 /* Check the result. ClamAV returns one of two result formats.
1754 In the basic mode, the response is of the form:
1755 infected: -> "<filename>: <virusname> FOUND"
1756 not-infected: -> "<filename>: OK"
1757 error: -> "<filename>: <errcode> ERROR
1758 If the ExtendedDetectionInfo option has been turned on, then we get:
1759 "<filename>: <virusname>(<virushash>:<virussize>) FOUND"
1760 for the infected case. Compare:
1761 /tmp/eicar.com: Eicar-Test-Signature FOUND
1762 /tmp/eicar.com: Eicar-Test-Signature(44d88612fea8a8f36de82e1278abb02f:68) FOUND
1763
1764 In the streaming case, clamd uses the filename "stream" which you should
1765 be able to verify with { ktrace clamdscan --stream /tmp/eicar.com }. (The
1766 client app will replace "stream" with the original filename before returning
1767 results to stdout, but the trace shows the data).
1768
1769 We will assume that the pathname passed to clamd from Exim does not contain
1770 a colon. We will have whined loudly above if the eml_filename does (and we're
1771 passing a filename to clamd). */
1772
1773 if (!(*av_buffer))
1774 return m_panic_defer(scanent, CUS callout_address,
1775 US"ClamAV returned null");
1776
1777 /* strip newline at the end (won't be present for zINSTREAM)
1778 (also any trailing whitespace, which shouldn't exist, but we depend upon
1779 this below, so double-check) */
1780 p = av_buffer + Ustrlen(av_buffer) - 1;
1781 if (*p == '\n') *p = '\0';
1782
1783 DEBUG(D_acl) debug_printf_indent("Malware response: %s\n", av_buffer);
1784
1785 while (isspace(*--p) && (p > av_buffer))
1786 *p = '\0';
1787 if (*p) ++p;
1788
1789 /* colon in returned output? */
1790 if(!(p = Ustrchr(av_buffer,':')))
1791 return m_panic_defer(scanent, CUS callout_address, string_sprintf(
1792 "ClamAV returned malformed result (missing colon): %s",
1793 av_buffer));
1794
1795 /* strip filename */
1796 while (*p && isspace(*++p)) /**/;
1797 vname = p;
1798
1799 /* It would be bad to encounter a virus with "FOUND" in part of the name,
1800 but we should at least be resistant to it. */
1801 p = Ustrrchr(vname, ' ');
1802 result_tag = p ? p+1 : vname;
1803
1804 if (Ustrcmp(result_tag, "FOUND") == 0)
1805 {
1806 /* p should still be the whitespace before the result_tag */
1807 while (isspace(*p)) --p;
1808 *++p = '\0';
1809 /* Strip off the extended information too, which will be in parens
1810 after the virus name, with no intervening whitespace. */
1811 if (*--p == ')')
1812 {
1813 /* "(hash:size)", so previous '(' will do; if not found, we have
1814 a curious virus name, but not an error. */
1815 p = Ustrrchr(vname, '(');
1816 if (p)
1817 *p = '\0';
1818 }
1819 malware_name = string_copy(vname);
1820 DEBUG(D_acl) debug_printf_indent("Malware found, name \"%s\"\n", malware_name);
1821
1822 }
1823 else if (Ustrcmp(result_tag, "ERROR") == 0)
1824 return m_panic_defer(scanent, CUS callout_address,
1825 string_sprintf("ClamAV returned: %s", av_buffer));
1826
1827 else if (Ustrcmp(result_tag, "OK") == 0)
1828 {
1829 /* Everything should be OK */
1830 malware_name = NULL;
1831 DEBUG(D_acl) debug_printf_indent("Malware not found\n");
1832
1833 }
1834 else
1835 return m_panic_defer(scanent, CUS callout_address,
1836 string_sprintf("unparseable response from ClamAV: {%s}", av_buffer));
1837
1838 break;
1839 } /* clamd */
1840 #endif
1841
1842 #ifndef DISABLE_MAL_SOCK
1843 case M_SOCK: /* "sock" scanner type ------------------------------------- */
1844 /* This code was derived by Martin Poole from the clamd code contributed
1845 by David Saez and the cmdline code
1846 */
1847 {
1848 int bread;
1849 uschar * commandline;
1850 uschar av_buffer[1024];
1851 uschar * linebuffer;
1852 uschar * sockline_scanner;
1853 uschar sockline_scanner_default[] = "%s\n";
1854 const pcre *sockline_trig_re;
1855 const pcre *sockline_name_re;
1856
1857 /* find scanner command line */
1858 if ( (sockline_scanner = string_nextinlist(&av_scanner_work, &sep,
1859 NULL, 0))
1860 && *sockline_scanner
1861 )
1862 { /* check for no expansions apart from one %s */
1863 uschar * s = Ustrchr(sockline_scanner, '%');
1864 if (s++)
1865 if ((*s != 's' && *s != '%') || Ustrchr(s+1, '%'))
1866 return m_panic_defer_3(scanent, NULL,
1867 US"unsafe sock scanner call spec", malware_daemon_ctx.sock);
1868 }
1869 else
1870 sockline_scanner = sockline_scanner_default;
1871 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "cmdline: ",
1872 string_printing(sockline_scanner));
1873
1874 /* find scanner output trigger */
1875 sockline_trig_re = m_pcre_nextinlist(&av_scanner_work, &sep,
1876 "missing trigger specification", &errstr);
1877 if (!sockline_trig_re)
1878 return m_panic_defer_3(scanent, NULL, errstr, malware_daemon_ctx.sock);
1879
1880 /* find virus name regex */
1881 sockline_name_re = m_pcre_nextinlist(&av_scanner_work, &sep,
1882 "missing virus name regex specification", &errstr);
1883 if (!sockline_name_re)
1884 return m_panic_defer_3(scanent, NULL, errstr, malware_daemon_ctx.sock);
1885
1886 /* prepare scanner call - security depends on expansions check above */
1887 commandline = string_sprintf( CS sockline_scanner, CS eml_filename);
1888 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "expanded: ",
1889 string_printing(commandline));
1890
1891 /* Pass the command string to the socket */
1892 if (m_sock_send(malware_daemon_ctx.sock, commandline, Ustrlen(commandline), &errstr) < 0)
1893 return m_panic_defer(scanent, CUS callout_address, errstr);
1894
1895 /* Read the result */
1896 bread = ip_recv(&malware_daemon_ctx, av_buffer, sizeof(av_buffer), tmo-time(NULL));
1897
1898 if (bread <= 0)
1899 return m_panic_defer_3(scanent, CUS callout_address,
1900 string_sprintf("unable to read from socket (%s)", strerror(errno)),
1901 malware_daemon_ctx.sock);
1902
1903 if (bread == sizeof(av_buffer))
1904 return m_panic_defer_3(scanent, CUS callout_address,
1905 US"buffer too small", malware_daemon_ctx.sock);
1906 av_buffer[bread] = '\0';
1907 linebuffer = string_copy(av_buffer);
1908 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "answer: ",
1909 string_printing(linebuffer));
1910
1911 /* try trigger match */
1912 if (regex_match_and_setup(sockline_trig_re, linebuffer, 0, -1))
1913 {
1914 if (!(malware_name = m_pcre_exec(sockline_name_re, av_buffer)))
1915 malware_name = US "unknown";
1916 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "name: ",
1917 string_printing(malware_name));
1918 }
1919 else /* no virus found */
1920 malware_name = NULL;
1921 break;
1922 }
1923 #endif
1924
1925 #ifndef DISABLE_MAL_MKS
1926 case M_MKSD: /* "mksd" scanner type ------------------------------------- */
1927 {
1928 char *mksd_options_end;
1929 int mksd_maxproc = 1; /* default, if no option supplied */
1930 int retval;
1931
1932 if (scanner_options)
1933 {
1934 mksd_maxproc = (int)strtol(CS scanner_options, &mksd_options_end, 10);
1935 if ( *scanner_options == '\0'
1936 || *mksd_options_end != '\0'
1937 || mksd_maxproc < 1
1938 || mksd_maxproc > 32
1939 )
1940 return m_panic_defer(scanent, CUS callout_address,
1941 string_sprintf("invalid option '%s'", scanner_options));
1942 }
1943
1944 if((malware_daemon_ctx.sock = ip_unixsocket(US "/var/run/mksd/socket", &errstr)) < 0)
1945 return m_panic_defer(scanent, CUS callout_address, errstr);
1946
1947 malware_name = NULL;
1948
1949 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan\n", scanner_name);
1950
1951 if ((retval = mksd_scan_packed(scanent, malware_daemon_ctx.sock, eml_filename, tmo)) != OK)
1952 {
1953 close (malware_daemon_ctx.sock);
1954 return retval;
1955 }
1956 break;
1957 }
1958 #endif
1959
1960 #ifndef DISABLE_MAL_AVAST
1961 case M_AVAST: /* "avast" scanner type ----------------------------------- */
1962 {
1963 uschar buf[1024];
1964 uschar * scanrequest;
1965 enum {AVA_HELO, AVA_OPT, AVA_RSP, AVA_DONE} avast_stage;
1966 int nread;
1967 uschar * error_message = NULL;
1968 BOOL more_data = FALSE;
1969 BOOL strict = TRUE;
1970
1971 /* According to Martin Tuma @avast the protocol uses "escaped
1972 whitespace", that is, every embedded whitespace is backslash
1973 escaped, as well as backslash is protected by backslash.
1974 The returned lines contain the name of the scanned file, a tab
1975 and the [ ] marker.
1976 [+] - not infected
1977 [L] - infected
1978 [E] - some error occured
1979 Such marker follows the first non-escaped TAB. For more information
1980 see avast-protocol(5)
1981
1982 We observed two cases:
1983 -> SCAN /file
1984 <- /file [E]0.0 Error 13 Permission denied
1985 <- 451 SCAN Engine error 13 permission denied
1986
1987 -> SCAN /file
1988 <- /file… [E]3.0 Error 41120 The file is a decompression bomb
1989 <- /file… [+]2.0
1990 <- /file… [+]2.0 0 Eicar Test Virus!!!
1991 <- 200 SCAN OK
1992
1993 If the scanner returns 4xx, DEFER is a good decision, combined
1994 with a panic log entry, to get the admin's attention.
1995
1996 If the scanner returns 200, we reject it as malware, if found any,
1997 or, in case of an error, we set the malware message to the error
1998 string.
1999
2000 Some of the >= 42000 errors are message related - usually some
2001 broken archives etc, but some of them are e.g. license related.
2002 Once the license expires the engine starts returning errors for
2003 every scanning attempt. I¹ have the full list of the error codes
2004 but it is not a public API and is subject to change. It is hard
2005 for me to say what you should do in case of an engine error. You
2006 can have a “Treat * unscanned file as infection” policy or “Treat
2007 unscanned file as clean” policy. ¹) Jakub Bednar
2008
2009 */
2010
2011 if ( ( !ava_re_clean
2012 && !(ava_re_clean = m_pcre_compile(ava_re_clean_str, &errstr)))
2013 || ( !ava_re_virus
2014 && !(ava_re_virus = m_pcre_compile(ava_re_virus_str, &errstr)))
2015 || ( !ava_re_error
2016 && !(ava_re_error = m_pcre_compile(ava_re_error_str, &errstr)))
2017 )
2018 return malware_panic_defer(errstr);
2019
2020 /* wait for result */
2021 for (avast_stage = AVA_HELO;
2022 (nread = recv_line(malware_daemon_ctx.sock, buf, sizeof(buf), tmo)) > 0;
2023 )
2024 {
2025 int slen = Ustrlen(buf);
2026 if (slen >= 1)
2027 {
2028
2029 /* Multi line responses are bracketed between 210 … and nnn … */
2030 if (Ustrncmp(buf, "210", 3) == 0)
2031 {
2032 more_data = 1;
2033 continue;
2034 }
2035 else if (more_data && isdigit(buf[0])) more_data = 0;
2036
2037 switch (avast_stage)
2038 {
2039 case AVA_HELO:
2040 if (more_data) continue;
2041 if (Ustrncmp(buf, "220", 3) != 0)
2042 goto endloop; /* require a 220 */
2043 goto sendreq;
2044
2045 case AVA_OPT:
2046 if (more_data) continue;
2047 if (Ustrncmp(buf, "200", 3) != 0)
2048 goto endloop; /* require a 200 */
2049
2050 sendreq:
2051 {
2052 int len;
2053 /* Check for another option to send. Newline-terminate it. */
2054 if ((scanrequest = string_nextinlist(&av_scanner_work, &sep,
2055 NULL, 0)))
2056 {
2057 if (Ustrcmp(scanrequest, "pass_unscanned") == 0)
2058 {
2059 DEBUG(D_acl) debug_printf_indent("pass unscanned files as clean\n");
2060 strict = FALSE;
2061 goto sendreq;
2062 }
2063 scanrequest = string_sprintf("%s\n", scanrequest);
2064 avast_stage = AVA_OPT; /* just sent option */
2065 DEBUG(D_acl) debug_printf_indent("send to avast OPTION: %s", scanrequest);
2066 }
2067 else
2068 {
2069 scanrequest = string_sprintf("SCAN %s\n", eml_dir);
2070 avast_stage = AVA_RSP; /* just sent command */
2071 DEBUG(D_acl) debug_printf_indent("send to avast REQUEST: SCAN %s\n", eml_dir);
2072 }
2073
2074 /* send config-cmd or scan-request to socket */
2075 len = Ustrlen(scanrequest);
2076 if (send(malware_daemon_ctx.sock, scanrequest, len, 0) == -1)
2077 {
2078 scanrequest[len-1] = '\0';
2079 return m_panic_defer_3(scanent, CUS callout_address, string_sprintf(
2080 "unable to send request '%s' to socket (%s): %s",
2081 scanrequest, scanner_options, strerror(errno)), malware_daemon_ctx.sock);
2082 }
2083 break;
2084 }
2085
2086 case AVA_RSP:
2087
2088 if (isdigit(buf[0])) /* We're done */
2089 goto endloop;
2090
2091 if (malware_name) /* Nothing else matters, just read on */
2092 break;
2093
2094 if (pcre_exec(ava_re_clean, NULL, CS buf, slen, 0, 0, NULL, 0) == 0)
2095 break;
2096
2097 if ((malware_name = m_pcre_exec(ava_re_virus, buf)))
2098 {
2099 unescape(malware_name);
2100 DEBUG(D_acl)
2101 debug_printf_indent("unescaped malware name: '%s'\n", malware_name);
2102 break;
2103 }
2104
2105 if (strict) /* treat scanner errors as malware */
2106 {
2107 if ((malware_name = m_pcre_exec(ava_re_error, buf)))
2108 {
2109 unescape(malware_name);
2110 DEBUG(D_acl)
2111 debug_printf_indent("unescaped error message: '%s'\n", malware_name);
2112 break;
2113 }
2114 }
2115 else if (pcre_exec(ava_re_error, NULL, CS buf, slen, 0, 0, NULL, 0) == 0)
2116 {
2117 log_write(0, LOG_MAIN, "internal scanner error (ignored): %s", buf);
2118 break;
2119 }
2120
2121 /* here also for any unexpected response from the scanner */
2122 DEBUG(D_acl) debug_printf("avast response not handled: '%s'\n", buf);
2123
2124 goto endloop;
2125
2126 default: log_write(0, LOG_PANIC, "%s:%d:%s: should not happen",
2127 __FILE__, __LINE__, __FUNCTION__);
2128 }
2129 }
2130 }
2131
2132 endloop:
2133
2134 if (nread == -1) error_message = US"EOF from scanner";
2135 else if (nread < 0) error_message = US"timeout from scanner";
2136 else if (nread == 0) error_message = US"got nothing from scanner";
2137 else if (buf[0] != '2') error_message = buf;
2138
2139 DEBUG(D_acl) debug_printf_indent("sent to avast QUIT\n");
2140 if (send(malware_daemon_ctx.sock, "QUIT\n", 5, 0) == -1)
2141 return m_panic_defer_3(scanent, CUS callout_address,
2142 string_sprintf("unable to send quit request to socket (%s): %s",
2143 scanner_options, strerror(errno)), malware_daemon_ctx.sock);
2144
2145 if (error_message)
2146 return m_panic_defer_3(scanent, CUS callout_address, error_message, malware_daemon_ctx.sock);
2147
2148 }
2149 #endif
2150 } /* scanner type switch */
2151
2152 if (malware_daemon_ctx.sock >= 0)
2153 (void) close (malware_daemon_ctx.sock);
2154 malware_ok = TRUE; /* set "been here, done that" marker */
2155 }
2156
2157 /* match virus name against pattern (caseless ------->----------v) */
2158 if (malware_name && regex_match_and_setup(re, malware_name, 0, -1))
2159 {
2160 DEBUG(D_acl) debug_printf_indent(
2161 "Matched regex to malware [%s] [%s]\n", malware_re, malware_name);
2162 return OK;
2163 }
2164 else
2165 return FAIL;
2166 }
2167
2168
2169 /*************************************************
2170 * Scan an email for malware *
2171 *************************************************/
2172
2173 /* This is the normal interface for scanning an email, which doesn't need a
2174 filename; it's a wrapper around the malware_file function.
2175
2176 Arguments:
2177 malware_re match condition for "malware="
2178 timeout if nonzero, timeout in seconds
2179
2180 Returns: Exim message processing code (OK, FAIL, DEFER, ...)
2181 where true means malware was found (condition applies)
2182 */
2183 int
2184 malware(const uschar * malware_re, int timeout)
2185 {
2186 int ret = malware_internal(malware_re, NULL, timeout);
2187
2188 if (ret == DEFER) av_failed = TRUE;
2189 return ret;
2190 }
2191
2192
2193 /*************************************************
2194 * Scan a file for malware *
2195 *************************************************/
2196
2197 /* This is a test wrapper for scanning an email, which is not used in
2198 normal processing. Scan any file, using the Exim scanning interface.
2199 This function tampers with various global variables so is unsafe to use
2200 in any other context.
2201
2202 Arguments:
2203 eml_filename a file holding the message to be scanned
2204
2205 Returns: Exim message processing code (OK, FAIL, DEFER, ...)
2206 where true means malware was found (condition applies)
2207 */
2208 int
2209 malware_in_file(uschar *eml_filename)
2210 {
2211 uschar message_id_buf[64];
2212 int ret;
2213
2214 /* spool_mbox() assumes various parameters exist, when creating
2215 the relevant directory and the email within */
2216
2217 (void) string_format(message_id_buf, sizeof(message_id_buf),
2218 "dummy-%d", vaguely_random_number(INT_MAX));
2219 message_id = message_id_buf;
2220 sender_address = US"malware-sender@example.net";
2221 return_path = US"";
2222 recipients_list = NULL;
2223 receive_add_recipient(US"malware-victim@example.net", -1);
2224 f.enable_dollar_recipients = TRUE;
2225
2226 ret = malware_internal(US"*", eml_filename, 0);
2227
2228 Ustrncpy(spooled_message_id, message_id, sizeof(spooled_message_id));
2229 spool_mbox_ok = 1;
2230
2231 /* don't set no_mbox_unspool; at present, there's no way for it to become
2232 set, but if that changes, then it should apply to these tests too */
2233
2234 unspool_mbox();
2235
2236 /* silence static analysis tools */
2237 message_id = NULL;
2238
2239 return ret;
2240 }
2241
2242
2243 void
2244 malware_init(void)
2245 {
2246 if (!malware_default_re)
2247 malware_default_re = regex_must_compile(malware_regex_default, FALSE, TRUE);
2248
2249 #ifndef DISABLE_MAL_DRWEB
2250 if (!drweb_re)
2251 drweb_re = regex_must_compile(drweb_re_str, FALSE, TRUE);
2252 #endif
2253 #ifndef DISABLE_MAL_FSECURE
2254 if (!fsec_re)
2255 fsec_re = regex_must_compile(fsec_re_str, FALSE, TRUE);
2256 #endif
2257 #ifndef DISABLE_MAL_KAV
2258 if (!kav_re_sus)
2259 kav_re_sus = regex_must_compile(kav_re_sus_str, FALSE, TRUE);
2260 if (!kav_re_inf)
2261 kav_re_inf = regex_must_compile(kav_re_inf_str, FALSE, TRUE);
2262 #endif
2263 #ifndef DISABLE_MAL_AVAST
2264 if (!ava_re_clean)
2265 ava_re_clean = regex_must_compile(ava_re_clean_str, FALSE, TRUE);
2266 if (!ava_re_virus)
2267 ava_re_virus = regex_must_compile(ava_re_virus_str, FALSE, TRUE);
2268 if (!ava_re_error)
2269 ava_re_error = regex_must_compile(ava_re_error_str, FALSE, TRUE);
2270 #endif
2271 #ifndef DISABLE_MAL_FFROT6D
2272 if (!fprot6d_re_error)
2273 fprot6d_re_error = regex_must_compile(fprot6d_re_error_str, FALSE, TRUE);
2274 if (!fprot6d_re_virus)
2275 fprot6d_re_virus = regex_must_compile(fprot6d_re_virus_str, FALSE, TRUE);
2276 #endif
2277 }
2278
2279
2280 void
2281 malware_show_supported(FILE * f)
2282 {
2283 struct scan * sc;
2284 fprintf(f, "Malware:");
2285 for (sc = m_scans; sc->scancode != (scanner_t)-1; sc++) fprintf(f, " %s", sc->name);
2286 fprintf(f, "\n");
2287 }
2288
2289
2290 # endif /*!MACRO_PREDEF*/
2291 #endif /*WITH_CONTENT_SCAN*/
2292 /*
2293 * vi: aw ai sw=2
2294 */