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[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 2017
8 */
9
10 /* Code for calling virus (malware) scanners. Called from acl.c. */
11
12 #include "exim.h"
13 #ifdef WITH_CONTENT_SCAN
14
15 typedef enum {M_FPROTD, M_DRWEB, M_AVES, M_FSEC, M_KAVD, M_CMDL,
16 M_SOPHIE, M_CLAMD, M_SOCK, M_MKSD, M_AVAST, M_FPROT6D} scanner_t;
17 typedef enum {MC_NONE, MC_TCP, MC_UNIX, MC_STRM} contype_t;
18 static struct scan
19 {
20 scanner_t scancode;
21 const uschar * name;
22 const uschar * options_default;
23 contype_t conn;
24 } m_scans[] =
25 {
26 { M_FPROTD, US"f-protd", US"localhost 10200-10204", MC_TCP },
27 { M_DRWEB, US"drweb", US"/usr/local/drweb/run/drwebd.sock", MC_STRM },
28 { M_AVES, US"aveserver", US"/var/run/aveserver", MC_UNIX },
29 { M_FSEC, US"fsecure", US"/var/run/.fsav", MC_UNIX },
30 { M_KAVD, US"kavdaemon", US"/var/run/AvpCtl", MC_UNIX },
31 { M_CMDL, US"cmdline", NULL, MC_NONE },
32 { M_SOPHIE, US"sophie", US"/var/run/sophie", MC_UNIX },
33 { M_CLAMD, US"clamd", US"/tmp/clamd", MC_NONE },
34 { M_SOCK, US"sock", US"/tmp/malware.sock", MC_STRM },
35 { M_MKSD, US"mksd", NULL, MC_NONE },
36 { M_AVAST, US"avast", US"/var/run/avast/scan.sock", MC_STRM },
37 { M_FPROT6D, US"f-prot6d", US"localhost 10200", MC_TCP },
38 { -1, NULL, NULL, MC_NONE } /* end-marker */
39 };
40
41 /* The maximum number of clamd servers that are supported in the configuration */
42 #define MAX_CLAMD_SERVERS 32
43 #define MAX_CLAMD_SERVERS_S "32"
44
45 typedef struct clamd_address {
46 uschar * hostspec;
47 unsigned tcp_port;
48 unsigned retry;
49 } clamd_address;
50
51 #ifndef nelements
52 # define nelements(arr) (sizeof(arr) / sizeof(arr[0]))
53 #endif
54
55
56 #define MALWARE_TIMEOUT 120 /* default timeout, seconds */
57
58
59 #define DRWEBD_SCAN_CMD (1) /* scan file, buffer or diskfile */
60 #define DRWEBD_RETURN_VIRUSES (1<<0) /* ask daemon return to us viruses names from report */
61 #define DRWEBD_IS_MAIL (1<<19) /* say to daemon that format is "archive MAIL" */
62
63 #define DERR_READ_ERR (1<<0) /* read error */
64 #define DERR_NOMEMORY (1<<2) /* no memory */
65 #define DERR_TIMEOUT (1<<9) /* scan timeout has run out */
66 #define DERR_BAD_CALL (1<<15) /* wrong command */
67
68
69 static const uschar * malware_regex_default = US ".+";
70 static const pcre * malware_default_re = NULL;
71
72 static const uschar * drweb_re_str = US "infected\\swith\\s*(.+?)$";
73 static const pcre * drweb_re = NULL;
74
75 static const uschar * fsec_re_str = US "\\S{0,5}INFECTED\\t[^\\t]*\\t([^\\t]+)\\t\\S*$";
76 static const pcre * fsec_re = NULL;
77
78 static const uschar * kav_re_sus_str = US "suspicion:\\s*(.+?)\\s*$";
79 static const uschar * kav_re_inf_str = US "infected:\\s*(.+?)\\s*$";
80 static const pcre * kav_re_sus = NULL;
81 static const pcre * kav_re_inf = NULL;
82
83 static const uschar * ava_re_clean_str = US "(?!\\\\)\\t\\[\\+\\]";
84 static const uschar * ava_re_virus_str = US "(?!\\\\)\\t\\[L\\]\\d\\.\\d\\t\\d\\s(.*)";
85 static const pcre * ava_re_clean = NULL;
86 static const pcre * ava_re_virus = NULL;
87
88 static const uschar * fprot6d_re_error_str = US "^\\d+\\s<(.+?)>$";
89 static const uschar * fprot6d_re_virus_str = US "^\\d+\\s<infected:\\s+(.+?)>\\s+.+$";
90 static const pcre * fprot6d_re_error = NULL;
91 static const pcre * fprot6d_re_virus = NULL;
92
93
94
95 /******************************************************************************/
96
97 /* Routine to check whether a system is big- or little-endian.
98 Ripped from http://www.faqs.org/faqs/graphics/fileformats-faq/part4/section-7.html
99 Needed for proper kavdaemon implementation. Sigh. */
100 #define BIG_MY_ENDIAN 0
101 #define LITTLE_MY_ENDIAN 1
102 static int test_byte_order(void);
103 static inline int
104 test_byte_order()
105 {
106 short int word = 0x0001;
107 char *byte = CS &word;
108 return(byte[0] ? LITTLE_MY_ENDIAN : BIG_MY_ENDIAN);
109 }
110
111 BOOL malware_ok = FALSE;
112
113 /* Gross hacks for the -bmalware option; perhaps we should just create
114 the scan directory normally for that case, but look into rigging up the
115 needed header variables if not already set on the command-line? */
116 extern int spool_mbox_ok;
117 extern uschar spooled_message_id[MESSAGE_ID_LENGTH+1];
118
119
120
121 static inline int
122 malware_errlog_defer(const uschar * str)
123 {
124 log_write(0, LOG_MAIN|LOG_PANIC, "malware acl condition: %s", str);
125 return DEFER;
126 }
127
128 static int
129 m_errlog_defer(struct scan * scanent, const uschar * hostport,
130 const uschar * str)
131 {
132 return malware_errlog_defer(string_sprintf("%s %s : %s",
133 scanent->name, hostport ? hostport : CUS"", str));
134 }
135 static int
136 m_errlog_defer_3(struct scan * scanent, const uschar * hostport,
137 const uschar * str, int fd_to_close)
138 {
139 (void) close(fd_to_close);
140 return m_errlog_defer(scanent, hostport, str);
141 }
142
143 /*************************************************/
144
145 /* Only used by the Clamav code, which is working from a list of servers and
146 uses the returned in_addr to get a second connection to the same system.
147 */
148 static inline int
149 m_tcpsocket(const uschar * hostname, unsigned int port,
150 host_item * host, uschar ** errstr, const blob * fastopen_blob)
151 {
152 return ip_connectedsocket(SOCK_STREAM, hostname, port, port, 5,
153 host, errstr, fastopen_blob);
154 }
155
156 static int
157 m_sock_send(int sock, uschar * buf, int cnt, uschar ** errstr)
158 {
159 if (send(sock, buf, cnt, 0) < 0)
160 {
161 int err = errno;
162 (void)close(sock);
163 *errstr = string_sprintf("unable to send to socket (%s): %s",
164 buf, strerror(err));
165 return -1;
166 }
167 return sock;
168 }
169
170 static const pcre *
171 m_pcre_compile(const uschar * re, uschar ** errstr)
172 {
173 const uschar * rerror;
174 int roffset;
175 const pcre * cre;
176
177 cre = pcre_compile(CS re, PCRE_COPT, (const char **)&rerror, &roffset, NULL);
178 if (!cre)
179 *errstr= string_sprintf("regular expression error in '%s': %s at offset %d",
180 re, rerror, roffset);
181 return cre;
182 }
183
184 uschar *
185 m_pcre_exec(const pcre * cre, uschar * text)
186 {
187 int ovector[10*3];
188 int i = pcre_exec(cre, NULL, CS text, Ustrlen(text), 0, 0,
189 ovector, nelements(ovector));
190 uschar * substr = NULL;
191 if (i >= 2) /* Got it */
192 pcre_get_substring(CS text, ovector, i, 1, (const char **) &substr);
193 return substr;
194 }
195
196 static const pcre *
197 m_pcre_nextinlist(const uschar ** list, int * sep,
198 char * listerr, uschar ** errstr)
199 {
200 const uschar * list_ele;
201 const pcre * cre = NULL;
202
203 if (!(list_ele = string_nextinlist(list, sep, NULL, 0)))
204 *errstr = US listerr;
205 else
206 {
207 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "RE: ",
208 string_printing(list_ele));
209 cre = m_pcre_compile(CUS list_ele, errstr);
210 }
211 return cre;
212 }
213
214 /*
215 Simple though inefficient wrapper for reading a line. Drop CRs and the
216 trailing newline. Can return early on buffer full. Null-terminate.
217 Apply initial timeout if no data ready.
218
219 Return: number of chars - zero for an empty line
220 -1 on EOF
221 -2 on timeout or error
222 */
223 static int
224 recv_line(int fd, uschar * buffer, int bsize, int tmo)
225 {
226 uschar * p = buffer;
227 ssize_t rcv;
228 BOOL ok = FALSE;
229
230 if (!fd_ready(fd, tmo-time(NULL)))
231 return -2;
232
233 /*XXX tmo handling assumes we always get a whole line */
234 /* read until \n */
235 errno = 0;
236 while ((rcv = read(fd, p, 1)) > 0)
237 {
238 ok = TRUE;
239 if (p-buffer > bsize-2) break;
240 if (*p == '\n') break;
241 if (*p != '\r') p++;
242 }
243 if (!ok)
244 {
245 DEBUG(D_acl) debug_printf_indent("Malware scan: read %s (%s)\n",
246 rcv==0 ? "EOF" : "error", strerror(errno));
247 return rcv==0 ? -1 : -2;
248 }
249 *p = '\0';
250
251 DEBUG(D_acl) debug_printf_indent("Malware scan: read '%s'\n", buffer);
252 return p - buffer;
253 }
254
255 /* return TRUE iff size as requested */
256 static BOOL
257 recv_len(int sock, void * buf, int size, int tmo)
258 {
259 return fd_ready(sock, tmo-time(NULL))
260 ? recv(sock, buf, size, 0) == size
261 : FALSE;
262 }
263
264
265
266 /* ============= private routines for the "mksd" scanner type ============== */
267
268 #include <sys/uio.h>
269
270 static inline int
271 mksd_writev (int sock, struct iovec * iov, int iovcnt)
272 {
273 int i;
274
275 for (;;)
276 {
277 do
278 i = writev (sock, iov, iovcnt);
279 while (i < 0 && errno == EINTR);
280 if (i <= 0)
281 {
282 (void) malware_errlog_defer(
283 US"unable to write to mksd UNIX socket (/var/run/mksd/socket)");
284 return -1;
285 }
286 for (;;) /* check for short write */
287 if (i >= iov->iov_len)
288 {
289 if (--iovcnt == 0)
290 return 0;
291 i -= iov->iov_len;
292 iov++;
293 }
294 else
295 {
296 iov->iov_len -= i;
297 iov->iov_base = CS iov->iov_base + i;
298 break;
299 }
300 }
301 }
302
303 static inline int
304 mksd_read_lines (int sock, uschar *av_buffer, int av_buffer_size, int tmo)
305 {
306 int offset = 0;
307 int i;
308
309 do
310 {
311 i = ip_recv(sock, av_buffer+offset, av_buffer_size-offset, tmo-time(NULL));
312 if (i <= 0)
313 {
314 (void) malware_errlog_defer(US"unable to read from mksd UNIX socket (/var/run/mksd/socket)");
315 return -1;
316 }
317
318 offset += i;
319 /* offset == av_buffer_size -> buffer full */
320 if (offset == av_buffer_size)
321 {
322 (void) malware_errlog_defer(US"malformed reply received from mksd");
323 return -1;
324 }
325 } while (av_buffer[offset-1] != '\n');
326
327 av_buffer[offset] = '\0';
328 return offset;
329 }
330
331 static inline int
332 mksd_parse_line(struct scan * scanent, char * line)
333 {
334 char *p;
335
336 switch (*line)
337 {
338 case 'O': /* OK */
339 return OK;
340
341 case 'E':
342 case 'A': /* ERR */
343 if ((p = strchr (line, '\n')) != NULL)
344 *p = '\0';
345 return m_errlog_defer(scanent, NULL,
346 string_sprintf("scanner failed: %s", line));
347
348 default: /* VIR */
349 if ((p = strchr (line, '\n')) != NULL)
350 {
351 *p = '\0';
352 if ( p-line > 5
353 && line[3] == ' '
354 && (p = strchr(line+4, ' ')) != NULL
355 && p-line > 4
356 )
357 {
358 *p = '\0';
359 malware_name = string_copy(US line+4);
360 return OK;
361 }
362 }
363 return m_errlog_defer(scanent, NULL,
364 string_sprintf("malformed reply received: %s", line));
365 }
366 }
367
368 static int
369 mksd_scan_packed(struct scan * scanent, int sock, const uschar * scan_filename,
370 int tmo)
371 {
372 struct iovec iov[3];
373 const char *cmd = "MSQ\n";
374 uschar av_buffer[1024];
375
376 iov[0].iov_base = (void *) cmd;
377 iov[0].iov_len = 3;
378 iov[1].iov_base = (void *) scan_filename;
379 iov[1].iov_len = Ustrlen(scan_filename);
380 iov[2].iov_base = (void *) (cmd + 3);
381 iov[2].iov_len = 1;
382
383 if (mksd_writev (sock, iov, 3) < 0)
384 return DEFER;
385
386 if (mksd_read_lines (sock, av_buffer, sizeof (av_buffer), tmo) < 0)
387 return DEFER;
388
389 return mksd_parse_line (scanent, CS av_buffer);
390 }
391
392
393 static int
394 clamd_option(clamd_address * cd, const uschar * optstr, int * subsep)
395 {
396 uschar * s;
397
398 cd->retry = 0;
399 while ((s = string_nextinlist(&optstr, subsep, NULL, 0)))
400 if (Ustrncmp(s, "retry=", 6) == 0)
401 {
402 int sec = readconf_readtime((s += 6), '\0', FALSE);
403 if (sec < 0)
404 return FAIL;
405 cd->retry = sec;
406 }
407 else
408 return FAIL;
409 return OK;
410 }
411
412 /*************************************************
413 * Scan content for malware *
414 *************************************************/
415
416 /* This is an internal interface for scanning an email; the normal interface
417 is via malware(), or there's malware_in_file() used for testing/debugging.
418
419 Arguments:
420 malware_re match condition for "malware="
421 scan_filename the file holding the email to be scanned, if we're faking
422 this up for the -bmalware test, else NULL
423 timeout if nonzero, non-default timeoutl
424
425 Returns: Exim message processing code (OK, FAIL, DEFER, ...)
426 where true means malware was found (condition applies)
427 */
428 static int
429 malware_internal(const uschar * malware_re, const uschar * scan_filename,
430 int timeout)
431 {
432 int sep = 0;
433 const uschar *av_scanner_work = av_scanner;
434 uschar *scanner_name;
435 unsigned long mbox_size;
436 FILE *mbox_file;
437 const pcre *re;
438 uschar * errstr;
439 struct scan * scanent;
440 const uschar * scanner_options;
441 int sock = -1;
442 time_t tmo;
443 uschar * eml_filename, * eml_dir;
444
445 if (!malware_re)
446 return FAIL; /* empty means "don't match anything" */
447
448 /* Ensure the eml mbox file is spooled up */
449
450 if (!(mbox_file = spool_mbox(&mbox_size, scan_filename, &eml_filename)))
451 return malware_errlog_defer(US"error while creating mbox spool file");
452
453 /* None of our current scanners need the mbox file as a stream (they use
454 the name), so we can close it right away. Get the directory too. */
455
456 (void) fclose(mbox_file);
457 eml_dir = string_copyn(eml_filename, Ustrrchr(eml_filename, '/') - eml_filename);
458
459 /* parse 1st option */
460 if (strcmpic(malware_re, US"false") == 0 || Ustrcmp(malware_re,"0") == 0)
461 return FAIL; /* explicitly no matching */
462
463 /* special cases (match anything except empty) */
464 if ( strcmpic(malware_re,US"true") == 0
465 || Ustrcmp(malware_re,"*") == 0
466 || Ustrcmp(malware_re,"1") == 0
467 )
468 {
469 if ( !malware_default_re
470 && !(malware_default_re = m_pcre_compile(malware_regex_default, &errstr)))
471 return malware_errlog_defer(errstr);
472 malware_re = malware_regex_default;
473 re = malware_default_re;
474 }
475
476 /* compile the regex, see if it works */
477 else if (!(re = m_pcre_compile(malware_re, &errstr)))
478 return malware_errlog_defer(errstr);
479
480 /* if av_scanner starts with a dollar, expand it first */
481 if (*av_scanner == '$')
482 {
483 if (!(av_scanner_work = expand_string(av_scanner)))
484 return malware_errlog_defer(
485 string_sprintf("av_scanner starts with $, but expansion failed: %s",
486 expand_string_message));
487
488 DEBUG(D_acl)
489 debug_printf_indent("Expanded av_scanner global: %s\n", av_scanner_work);
490 /* disable result caching in this case */
491 malware_name = NULL;
492 malware_ok = FALSE;
493 }
494
495 /* Do not scan twice (unless av_scanner is dynamic). */
496 if (!malware_ok)
497 {
498 /* find the scanner type from the av_scanner option */
499 if (!(scanner_name = string_nextinlist(&av_scanner_work, &sep, NULL, 0)))
500 return malware_errlog_defer(US"av_scanner configuration variable is empty");
501 if (!timeout) timeout = MALWARE_TIMEOUT;
502 tmo = time(NULL) + timeout;
503
504 for (scanent = m_scans; ; scanent++)
505 {
506 if (!scanent->name)
507 return malware_errlog_defer(string_sprintf("unknown scanner type '%s'",
508 scanner_name));
509 if (strcmpic(scanner_name, US scanent->name) != 0)
510 continue;
511 DEBUG(D_acl) debug_printf_indent("Malware scan: %s tmo=%s\n",
512 scanner_name, readconf_printtime(timeout));
513
514 if (!(scanner_options = string_nextinlist(&av_scanner_work, &sep, NULL, 0)))
515 scanner_options = scanent->options_default;
516 if (scanent->conn == MC_NONE)
517 break;
518
519 DEBUG(D_acl) debug_printf_indent("%15s%10s%s\n", "", "socket: ", scanner_options);
520 switch(scanent->conn)
521 {
522 case MC_TCP: sock = ip_tcpsocket(scanner_options, &errstr, 5); break;
523 case MC_UNIX: sock = ip_unixsocket(scanner_options, &errstr); break;
524 case MC_STRM: sock = ip_streamsocket(scanner_options, &errstr, 5); break;
525 default: /* compiler quietening */ break;
526 }
527 if (sock < 0)
528 return m_errlog_defer(scanent, CUS callout_address, errstr);
529 break;
530 }
531
532 switch (scanent->scancode)
533 {
534 case M_FPROTD: /* "f-protd" scanner type -------------------------------- */
535 {
536 uschar *fp_scan_option;
537 unsigned int detected=0, par_count=0;
538 uschar * scanrequest;
539 uschar buf[32768], *strhelper, *strhelper2;
540 uschar * malware_name_internal = NULL;
541 int len;
542
543 scanrequest = string_sprintf("GET %s", eml_filename);
544
545 while ((fp_scan_option = string_nextinlist(&av_scanner_work, &sep,
546 NULL, 0)))
547 {
548 scanrequest = string_sprintf("%s%s%s", scanrequest,
549 par_count ? "%20" : "?", fp_scan_option);
550 par_count++;
551 }
552 scanrequest = string_sprintf("%s HTTP/1.0\r\n\r\n", scanrequest);
553 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s: %s\n",
554 scanner_name, scanrequest);
555
556 /* send scan request */
557 if (m_sock_send(sock, scanrequest, Ustrlen(scanrequest)+1, &errstr) < 0)
558 return m_errlog_defer(scanent, CUS callout_address, errstr);
559
560 while ((len = recv_line(sock, buf, sizeof(buf), tmo)) >= 0)
561 if (len > 0)
562 {
563 if (Ustrstr(buf, US"<detected type=\"") != NULL)
564 detected = 1;
565 else if (detected && (strhelper = Ustrstr(buf, US"<name>")))
566 {
567 if ((strhelper2 = Ustrstr(buf, US"</name>")) != NULL)
568 {
569 *strhelper2 = '\0';
570 malware_name_internal = string_copy(strhelper+6);
571 }
572 }
573 else if (Ustrstr(buf, US"<summary code=\""))
574 {
575 malware_name = Ustrstr(buf, US"<summary code=\"11\">")
576 ? malware_name_internal : NULL;
577 break;
578 }
579 }
580 if (len < -1)
581 {
582 (void)close(sock);
583 return DEFER;
584 }
585 break;
586 } /* f-protd */
587
588 case M_DRWEB: /* "drweb" scanner type ----------------------------------- */
589 /* v0.1 - added support for tcp sockets */
590 /* v0.0 - initial release -- support for unix sockets */
591 {
592 int result;
593 off_t fsize;
594 unsigned int fsize_uint;
595 uschar * tmpbuf, *drweb_fbuf;
596 int drweb_rc, drweb_cmd, drweb_flags = 0x0000, drweb_fd,
597 drweb_vnum, drweb_slen, drweb_fin = 0x0000;
598
599 /* prepare variables */
600 drweb_cmd = htonl(DRWEBD_SCAN_CMD);
601 drweb_flags = htonl(DRWEBD_RETURN_VIRUSES | DRWEBD_IS_MAIL);
602
603 if (*scanner_options != '/')
604 {
605 /* calc file size */
606 if ((drweb_fd = open(CCS eml_filename, O_RDONLY)) == -1)
607 return m_errlog_defer_3(scanent, NULL,
608 string_sprintf("can't open spool file %s: %s",
609 eml_filename, strerror(errno)),
610 sock);
611
612 if ((fsize = lseek(drweb_fd, 0, SEEK_END)) == -1)
613 {
614 int err;
615 badseek: err = errno;
616 (void)close(drweb_fd);
617 return m_errlog_defer_3(scanent, NULL,
618 string_sprintf("can't seek spool file %s: %s",
619 eml_filename, strerror(err)),
620 sock);
621 }
622 fsize_uint = (unsigned int) fsize;
623 if ((off_t)fsize_uint != fsize)
624 {
625 (void)close(drweb_fd);
626 return m_errlog_defer_3(scanent, NULL,
627 string_sprintf("seeking spool file %s, size overflow",
628 eml_filename),
629 sock);
630 }
631 drweb_slen = htonl(fsize);
632 if (lseek(drweb_fd, 0, SEEK_SET) < 0)
633 goto badseek;
634
635 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s remote scan [%s]\n",
636 scanner_name, scanner_options);
637
638 /* send scan request */
639 if ((send(sock, &drweb_cmd, sizeof(drweb_cmd), 0) < 0) ||
640 (send(sock, &drweb_flags, sizeof(drweb_flags), 0) < 0) ||
641 (send(sock, &drweb_fin, sizeof(drweb_fin), 0) < 0) ||
642 (send(sock, &drweb_slen, sizeof(drweb_slen), 0) < 0))
643 {
644 (void)close(drweb_fd);
645 return m_errlog_defer_3(scanent, CUS callout_address, string_sprintf(
646 "unable to send commands to socket (%s)", scanner_options),
647 sock);
648 }
649
650 if (!(drweb_fbuf = US malloc(fsize_uint)))
651 {
652 (void)close(drweb_fd);
653 return m_errlog_defer_3(scanent, NULL,
654 string_sprintf("unable to allocate memory %u for file (%s)",
655 fsize_uint, eml_filename),
656 sock);
657 }
658
659 if ((result = read (drweb_fd, drweb_fbuf, fsize)) == -1)
660 {
661 int err = errno;
662 (void)close(drweb_fd);
663 free(drweb_fbuf);
664 return m_errlog_defer_3(scanent, NULL,
665 string_sprintf("can't read spool file %s: %s",
666 eml_filename, strerror(err)),
667 sock);
668 }
669 (void)close(drweb_fd);
670
671 /* send file body to socket */
672 if (send(sock, drweb_fbuf, fsize, 0) < 0)
673 {
674 free(drweb_fbuf);
675 return m_errlog_defer_3(scanent, CUS callout_address, string_sprintf(
676 "unable to send file body to socket (%s)", scanner_options),
677 sock);
678 }
679 }
680 else
681 {
682 drweb_slen = htonl(Ustrlen(eml_filename));
683
684 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s local scan [%s]\n",
685 scanner_name, scanner_options);
686
687 /* send scan request */
688 if ((send(sock, &drweb_cmd, sizeof(drweb_cmd), 0) < 0) ||
689 (send(sock, &drweb_flags, sizeof(drweb_flags), 0) < 0) ||
690 (send(sock, &drweb_slen, sizeof(drweb_slen), 0) < 0) ||
691 (send(sock, eml_filename, Ustrlen(eml_filename), 0) < 0) ||
692 (send(sock, &drweb_fin, sizeof(drweb_fin), 0) < 0))
693 return m_errlog_defer_3(scanent, CUS callout_address, string_sprintf(
694 "unable to send commands to socket (%s)", scanner_options),
695 sock);
696 }
697
698 /* wait for result */
699 if (!recv_len(sock, &drweb_rc, sizeof(drweb_rc), tmo))
700 return m_errlog_defer_3(scanent, CUS callout_address,
701 US"unable to read return code", sock);
702 drweb_rc = ntohl(drweb_rc);
703
704 if (!recv_len(sock, &drweb_vnum, sizeof(drweb_vnum), tmo))
705 return m_errlog_defer_3(scanent, CUS callout_address,
706 US"unable to read the number of viruses", sock);
707 drweb_vnum = ntohl(drweb_vnum);
708
709 /* "virus(es) found" if virus number is > 0 */
710 if (drweb_vnum)
711 {
712 int i;
713 gstring * g = NULL;
714
715 /* setup default virus name */
716 malware_name = US"unknown";
717
718 /* set up match regex */
719 if (!drweb_re)
720 drweb_re = m_pcre_compile(drweb_re_str, &errstr);
721
722 /* read and concatenate virus names into one string */
723 for (i = 0; i < drweb_vnum; i++)
724 {
725 int ovector[10*3];
726
727 /* read the size of report */
728 if (!recv_len(sock, &drweb_slen, sizeof(drweb_slen), tmo))
729 return m_errlog_defer_3(scanent, CUS callout_address,
730 US"cannot read report size", sock);
731 drweb_slen = ntohl(drweb_slen);
732 tmpbuf = store_get(drweb_slen);
733
734 /* read report body */
735 if (!recv_len(sock, tmpbuf, drweb_slen, tmo))
736 return m_errlog_defer_3(scanent, CUS callout_address,
737 US"cannot read report string", sock);
738 tmpbuf[drweb_slen] = '\0';
739
740 /* try matcher on the line, grab substring */
741 result = pcre_exec(drweb_re, NULL, CS tmpbuf, Ustrlen(tmpbuf), 0, 0,
742 ovector, nelements(ovector));
743 if (result >= 2)
744 {
745 const char * pre_malware_nb;
746
747 pcre_get_substring(CS tmpbuf, ovector, result, 1, &pre_malware_nb);
748
749 if (i==0) /* the first name we just copy to malware_name */
750 g = string_cat(NULL, US pre_malware_nb);
751
752 /*XXX could be string_append_listele? */
753 else /* concatenate each new virus name to previous */
754 g = string_append(g, 2, "/", pre_malware_nb);
755
756 pcre_free_substring(pre_malware_nb);
757 }
758 }
759 malware_name = string_from_gstring(g);
760 }
761 else
762 {
763 const char *drweb_s = NULL;
764
765 if (drweb_rc & DERR_READ_ERR) drweb_s = "read error";
766 if (drweb_rc & DERR_NOMEMORY) drweb_s = "no memory";
767 if (drweb_rc & DERR_TIMEOUT) drweb_s = "timeout";
768 if (drweb_rc & DERR_BAD_CALL) drweb_s = "wrong command";
769 /* retcodes DERR_SYMLINK, DERR_NO_REGFILE, DERR_SKIPPED.
770 * DERR_TOO_BIG, DERR_TOO_COMPRESSED, DERR_SPAM,
771 * DERR_CRC_ERROR, DERR_READSOCKET, DERR_WRITE_ERR
772 * and others are ignored */
773 if (drweb_s)
774 return m_errlog_defer_3(scanent, CUS callout_address,
775 string_sprintf("drweb daemon retcode 0x%x (%s)", drweb_rc, drweb_s),
776 sock);
777
778 /* no virus found */
779 malware_name = NULL;
780 }
781 break;
782 } /* drweb */
783
784 case M_AVES: /* "aveserver" scanner type -------------------------------- */
785 {
786 uschar buf[32768];
787 int result;
788
789 /* read aveserver's greeting and see if it is ready (2xx greeting) */
790 buf[0] = 0;
791 recv_line(sock, buf, sizeof(buf), tmo);
792
793 if (buf[0] != '2') /* aveserver is having problems */
794 return m_errlog_defer_3(scanent, CUS callout_address,
795 string_sprintf("unavailable (Responded: %s).",
796 ((buf[0] != 0) ? buf : US "nothing") ),
797 sock);
798
799 /* prepare our command */
800 (void)string_format(buf, sizeof(buf), "SCAN bPQRSTUW %s\r\n",
801 eml_filename);
802
803 /* and send it */
804 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s %s\n",
805 scanner_name, buf);
806 if (m_sock_send(sock, buf, Ustrlen(buf), &errstr) < 0)
807 return m_errlog_defer(scanent, CUS callout_address, errstr);
808
809 malware_name = NULL;
810 result = 0;
811 /* read response lines, find malware name and final response */
812 while (recv_line(sock, buf, sizeof(buf), tmo) > 0)
813 {
814 if (buf[0] == '2')
815 break;
816 if (buf[0] == '5') /* aveserver is having problems */
817 {
818 result = m_errlog_defer(scanent, CUS callout_address,
819 string_sprintf("unable to scan file %s (Responded: %s).",
820 eml_filename, buf));
821 break;
822 }
823 if (Ustrncmp(buf,"322",3) == 0)
824 {
825 uschar *p = Ustrchr(&buf[4], ' ');
826 *p = '\0';
827 malware_name = string_copy(&buf[4]);
828 }
829 }
830
831 if (m_sock_send(sock, US"quit\r\n", 6, &errstr) < 0)
832 return m_errlog_defer(scanent, CUS callout_address, errstr);
833
834 /* read aveserver's greeting and see if it is ready (2xx greeting) */
835 buf[0] = 0;
836 recv_line(sock, buf, sizeof(buf), tmo);
837
838 if (buf[0] != '2') /* aveserver is having problems */
839 return m_errlog_defer_3(scanent, CUS callout_address,
840 string_sprintf("unable to quit dialogue (Responded: %s).",
841 ((buf[0] != 0) ? buf : US "nothing") ),
842 sock);
843
844 if (result == DEFER)
845 {
846 (void)close(sock);
847 return DEFER;
848 }
849 break;
850 } /* aveserver */
851
852 case M_FSEC: /* "fsecure" scanner type ---------------------------------- */
853 {
854 int i, j, bread = 0;
855 uschar * file_name;
856 uschar av_buffer[1024];
857 static uschar *cmdopt[] = { US"CONFIGURE\tARCHIVE\t1\n",
858 US"CONFIGURE\tTIMEOUT\t0\n",
859 US"CONFIGURE\tMAXARCH\t5\n",
860 US"CONFIGURE\tMIME\t1\n" };
861
862 malware_name = NULL;
863
864 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n",
865 scanner_name, scanner_options);
866 /* pass options */
867 memset(av_buffer, 0, sizeof(av_buffer));
868 for (i = 0; i != nelements(cmdopt); i++)
869 {
870
871 if (m_sock_send(sock, cmdopt[i], Ustrlen(cmdopt[i]), &errstr) < 0)
872 return m_errlog_defer(scanent, CUS callout_address, errstr);
873
874 bread = ip_recv(sock, av_buffer, sizeof(av_buffer), tmo-time(NULL));
875 if (bread > 0) av_buffer[bread]='\0';
876 if (bread < 0)
877 return m_errlog_defer_3(scanent, CUS callout_address,
878 string_sprintf("unable to read answer %d (%s)", i, strerror(errno)),
879 sock);
880 for (j = 0; j < bread; j++)
881 if (av_buffer[j] == '\r' || av_buffer[j] == '\n')
882 av_buffer[j] ='@';
883 }
884
885 /* pass the mailfile to fsecure */
886 file_name = string_sprintf("SCAN\t%s\n", eml_filename);
887
888 if (m_sock_send(sock, file_name, Ustrlen(file_name), &errstr) < 0)
889 return m_errlog_defer(scanent, CUS callout_address, errstr);
890
891 /* set up match */
892 /* todo also SUSPICION\t */
893 if (!fsec_re)
894 fsec_re = m_pcre_compile(fsec_re_str, &errstr);
895
896 /* read report, linewise. Apply a timeout as the Fsecure daemon
897 sometimes wants an answer to "PING" but they won't tell us what */
898 {
899 uschar * p = av_buffer;
900 uschar * q;
901
902 for (;;)
903 {
904 errno = ETIMEDOUT;
905 i = av_buffer+sizeof(av_buffer)-p;
906 if ((bread= ip_recv(sock, p, i-1, tmo-time(NULL))) < 0)
907 return m_errlog_defer_3(scanent, CUS callout_address,
908 string_sprintf("unable to read result (%s)", strerror(errno)),
909 sock);
910
911 for (p[bread] = '\0'; (q = Ustrchr(p, '\n')); p = q+1)
912 {
913 *q = '\0';
914
915 /* Really search for virus again? */
916 if (!malware_name)
917 /* try matcher on the line, grab substring */
918 malware_name = m_pcre_exec(fsec_re, p);
919
920 if (Ustrstr(p, "OK\tScan ok."))
921 goto fsec_found;
922 }
923
924 /* copy down the trailing partial line then read another chunk */
925 i = av_buffer+sizeof(av_buffer)-p;
926 memmove(av_buffer, p, i);
927 p = av_buffer+i;
928 }
929 }
930
931 fsec_found:
932 break;
933 } /* fsecure */
934
935 case M_KAVD: /* "kavdaemon" scanner type -------------------------------- */
936 {
937 time_t t;
938 uschar tmpbuf[1024];
939 uschar * scanrequest;
940 int kav_rc;
941 unsigned long kav_reportlen;
942 int bread;
943 const pcre *kav_re;
944 uschar *p;
945
946 /* get current date and time, build scan request */
947 time(&t);
948 /* pdp note: before the eml_filename parameter, this scanned the
949 directory; not finding documentation, so we'll strip off the directory.
950 The side-effect is that the test framework scanning may end up in
951 scanning more than was requested, but for the normal interface, this is
952 fine. */
953
954 strftime(CS tmpbuf, sizeof(tmpbuf), "%d %b %H:%M:%S", localtime(&t));
955 scanrequest = string_sprintf("<0>%s:%s", CS tmpbuf, eml_filename);
956 p = Ustrrchr(scanrequest, '/');
957 if (p)
958 *p = '\0';
959
960 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n",
961 scanner_name, scanner_options);
962
963 /* send scan request */
964 if (m_sock_send(sock, scanrequest, Ustrlen(scanrequest)+1, &errstr) < 0)
965 return m_errlog_defer(scanent, CUS callout_address, errstr);
966
967 /* wait for result */
968 if (!recv_len(sock, tmpbuf, 2, tmo))
969 return m_errlog_defer_3(scanent, CUS callout_address,
970 US"unable to read 2 bytes from socket.", sock);
971
972 /* get errorcode from one nibble */
973 kav_rc = tmpbuf[ test_byte_order()==LITTLE_MY_ENDIAN ? 0 : 1 ] & 0x0F;
974 switch(kav_rc)
975 {
976 case 5: case 6: /* improper kavdaemon configuration */
977 return m_errlog_defer_3(scanent, CUS callout_address,
978 US"please reconfigure kavdaemon to NOT disinfect or remove infected files.",
979 sock);
980 case 1:
981 return m_errlog_defer_3(scanent, CUS callout_address,
982 US"reported 'scanning not completed' (code 1).", sock);
983 case 7:
984 return m_errlog_defer_3(scanent, CUS callout_address,
985 US"reported 'kavdaemon damaged' (code 7).", sock);
986 }
987
988 /* code 8 is not handled, since it is ambiguous. It appears mostly on
989 bounces where part of a file has been cut off */
990
991 /* "virus found" return codes (2-4) */
992 if (kav_rc > 1 && kav_rc < 5)
993 {
994 int report_flag = 0;
995
996 /* setup default virus name */
997 malware_name = US"unknown";
998
999 report_flag = tmpbuf[ test_byte_order() == LITTLE_MY_ENDIAN ? 1 : 0 ];
1000
1001 /* read the report, if available */
1002 if (report_flag == 1)
1003 {
1004 /* read report size */
1005 if (!recv_len(sock, &kav_reportlen, 4, tmo))
1006 return m_errlog_defer_3(scanent, CUS callout_address,
1007 US"cannot read report size", sock);
1008
1009 /* it's possible that avp returns av_buffer[1] == 1 but the
1010 reportsize is 0 (!?) */
1011 if (kav_reportlen > 0)
1012 {
1013 /* set up match regex, depends on retcode */
1014 if (kav_rc == 3)
1015 {
1016 if (!kav_re_sus) kav_re_sus = m_pcre_compile(kav_re_sus_str, &errstr);
1017 kav_re = kav_re_sus;
1018 }
1019 else
1020 {
1021 if (!kav_re_inf) kav_re_inf = m_pcre_compile(kav_re_inf_str, &errstr);
1022 kav_re = kav_re_inf;
1023 }
1024
1025 /* read report, linewise. Using size from stream to read amount of data
1026 from same stream is safe enough. */
1027 /* coverity[tainted_data] */
1028 while (kav_reportlen > 0)
1029 {
1030 if ((bread = recv_line(sock, tmpbuf, sizeof(tmpbuf), tmo)) < 0)
1031 break;
1032 kav_reportlen -= bread+1;
1033
1034 /* try matcher on the line, grab substring */
1035 if ((malware_name = m_pcre_exec(kav_re, tmpbuf)))
1036 break;
1037 }
1038 }
1039 }
1040 }
1041 else /* no virus found */
1042 malware_name = NULL;
1043
1044 break;
1045 }
1046
1047 case M_CMDL: /* "cmdline" scanner type ---------------------------------- */
1048 {
1049 const uschar *cmdline_scanner = scanner_options;
1050 const pcre *cmdline_trigger_re;
1051 const pcre *cmdline_regex_re;
1052 uschar * file_name;
1053 uschar * commandline;
1054 void (*eximsigchld)(int);
1055 void (*eximsigpipe)(int);
1056 FILE *scanner_out = NULL;
1057 int scanner_fd;
1058 FILE *scanner_record = NULL;
1059 uschar linebuffer[32767];
1060 int rcnt;
1061 int trigger = 0;
1062 uschar *p;
1063
1064 if (!cmdline_scanner)
1065 return m_errlog_defer(scanent, NULL, errstr);
1066
1067 /* find scanner output trigger */
1068 cmdline_trigger_re = m_pcre_nextinlist(&av_scanner_work, &sep,
1069 "missing trigger specification", &errstr);
1070 if (!cmdline_trigger_re)
1071 return m_errlog_defer(scanent, NULL, errstr);
1072
1073 /* find scanner name regex */
1074 cmdline_regex_re = m_pcre_nextinlist(&av_scanner_work, &sep,
1075 "missing virus name regex specification", &errstr);
1076 if (!cmdline_regex_re)
1077 return m_errlog_defer(scanent, NULL, errstr);
1078
1079 /* prepare scanner call; despite the naming, file_name holds a directory
1080 name which is documented as the value given to %s. */
1081
1082 file_name = string_copy(eml_filename);
1083 p = Ustrrchr(file_name, '/');
1084 if (p)
1085 *p = '\0';
1086 commandline = string_sprintf(CS cmdline_scanner, file_name);
1087
1088 /* redirect STDERR too */
1089 commandline = string_sprintf("%s 2>&1", commandline);
1090
1091 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n",
1092 scanner_name, commandline);
1093
1094 /* store exims signal handlers */
1095 eximsigchld = signal(SIGCHLD,SIG_DFL);
1096 eximsigpipe = signal(SIGPIPE,SIG_DFL);
1097
1098 if (!(scanner_out = popen(CS commandline,"r")))
1099 {
1100 int err = errno;
1101 signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
1102 return m_errlog_defer(scanent, NULL,
1103 string_sprintf("call (%s) failed: %s.", commandline, strerror(err)));
1104 }
1105 scanner_fd = fileno(scanner_out);
1106
1107 file_name = string_sprintf("%s/%s_scanner_output", eml_dir, message_id);
1108
1109 if (!(scanner_record = modefopen(file_name, "wb", SPOOL_MODE)))
1110 {
1111 int err = errno;
1112 (void) pclose(scanner_out);
1113 signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
1114 return m_errlog_defer(scanent, NULL, string_sprintf(
1115 "opening scanner output file (%s) failed: %s.",
1116 file_name, strerror(err)));
1117 }
1118
1119 /* look for trigger while recording output */
1120 while ((rcnt = recv_line(scanner_fd, linebuffer,
1121 sizeof(linebuffer), tmo)))
1122 {
1123 if (rcnt < 0)
1124 {
1125 int err = errno;
1126 if (rcnt == -1)
1127 break;
1128 (void) pclose(scanner_out);
1129 signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
1130 return m_errlog_defer(scanent, NULL, string_sprintf(
1131 "unable to read from scanner (%s): %s",
1132 commandline, strerror(err)));
1133 }
1134
1135 if (Ustrlen(linebuffer) > fwrite(linebuffer, 1, Ustrlen(linebuffer), scanner_record))
1136 {
1137 /* short write */
1138 (void) pclose(scanner_out);
1139 signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
1140 return m_errlog_defer(scanent, NULL, string_sprintf(
1141 "short write on scanner output file (%s).", file_name));
1142 }
1143 putc('\n', scanner_record);
1144 /* try trigger match */
1145 if ( !trigger
1146 && regex_match_and_setup(cmdline_trigger_re, linebuffer, 0, -1)
1147 )
1148 trigger = 1;
1149 }
1150
1151 (void)fclose(scanner_record);
1152 sep = pclose(scanner_out);
1153 signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
1154 if (sep != 0)
1155 return m_errlog_defer(scanent, NULL,
1156 sep == -1
1157 ? string_sprintf("running scanner failed: %s", strerror(sep))
1158 : string_sprintf("scanner returned error code: %d", sep));
1159
1160 if (trigger)
1161 {
1162 uschar * s;
1163 /* setup default virus name */
1164 malware_name = US"unknown";
1165
1166 /* re-open the scanner output file, look for name match */
1167 scanner_record = fopen(CS file_name, "rb");
1168 while (fgets(CS linebuffer, sizeof(linebuffer), scanner_record))
1169 {
1170 /* try match */
1171 if ((s = m_pcre_exec(cmdline_regex_re, linebuffer)))
1172 malware_name = s;
1173 }
1174 (void)fclose(scanner_record);
1175 }
1176 else /* no virus found */
1177 malware_name = NULL;
1178 break;
1179 } /* cmdline */
1180
1181 case M_SOPHIE: /* "sophie" scanner type --------------------------------- */
1182 {
1183 int bread = 0;
1184 uschar *p;
1185 uschar * file_name;
1186 uschar av_buffer[1024];
1187
1188 /* pass the scan directory to sophie */
1189 file_name = string_copy(eml_filename);
1190 if ((p = Ustrrchr(file_name, '/')))
1191 *p = '\0';
1192
1193 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n",
1194 scanner_name, scanner_options);
1195
1196 if ( write(sock, file_name, Ustrlen(file_name)) < 0
1197 || write(sock, "\n", 1) != 1
1198 )
1199 return m_errlog_defer_3(scanent, CUS callout_address,
1200 string_sprintf("unable to write to UNIX socket (%s)", scanner_options),
1201 sock);
1202
1203 /* wait for result */
1204 memset(av_buffer, 0, sizeof(av_buffer));
1205 if ((bread = ip_recv(sock, av_buffer, sizeof(av_buffer), tmo-time(NULL))) <= 0)
1206 return m_errlog_defer_3(scanent, CUS callout_address,
1207 string_sprintf("unable to read from UNIX socket (%s)", scanner_options),
1208 sock);
1209
1210 /* infected ? */
1211 if (av_buffer[0] == '1') {
1212 uschar * s = Ustrchr(av_buffer, '\n');
1213 if (s)
1214 *s = '\0';
1215 malware_name = string_copy(&av_buffer[2]);
1216 }
1217 else if (!strncmp(CS av_buffer, "-1", 2))
1218 return m_errlog_defer_3(scanent, CUS callout_address,
1219 US"scanner reported error", sock);
1220 else /* all ok, no virus */
1221 malware_name = NULL;
1222
1223 break;
1224 }
1225
1226 case M_CLAMD: /* "clamd" scanner type ----------------------------------- */
1227 {
1228 /* This code was originally contributed by David Saez */
1229 /* There are three scanning methods available to us:
1230 * (1) Use the SCAN command, pointing to a file in the filesystem
1231 * (2) Use the STREAM command, send the data on a separate port
1232 * (3) Use the zINSTREAM command, send the data inline
1233 * The zINSTREAM command was introduced with ClamAV 0.95, which marked
1234 * STREAM deprecated; see: http://wiki.clamav.net/bin/view/Main/UpgradeNotes095
1235 * In Exim, we use SCAN if using a Unix-domain socket or explicitly told that
1236 * the TCP-connected daemon is actually local; otherwise we use zINSTREAM unless
1237 * WITH_OLD_CLAMAV_STREAM is defined.
1238 * See Exim bug 926 for details. */
1239
1240 uschar *p, *vname, *result_tag;
1241 int bread=0;
1242 uschar av_buffer[1024];
1243 uschar *hostname = US"";
1244 host_item connhost;
1245 uschar *clamav_fbuf;
1246 int clam_fd, result;
1247 off_t fsize;
1248 unsigned int fsize_uint;
1249 BOOL use_scan_command = FALSE;
1250 clamd_address * cv[MAX_CLAMD_SERVERS];
1251 int num_servers = 0;
1252 #ifdef WITH_OLD_CLAMAV_STREAM
1253 unsigned int port;
1254 uschar av_buffer2[1024];
1255 int sockData;
1256 #else
1257 uint32_t send_size, send_final_zeroblock;
1258 #endif
1259 blob cmd_str;
1260
1261 /*XXX if unixdomain socket, only one server supported. Needs fixing;
1262 there's no reason we should not mix local and remote servers */
1263
1264 if (*scanner_options == '/')
1265 {
1266 clamd_address * cd;
1267 const uschar * sublist;
1268 int subsep = ' ';
1269
1270 /* Local file; so we def want to use_scan_command and don't want to try
1271 * passing IP/port combinations */
1272 use_scan_command = TRUE;
1273 cd = (clamd_address *) store_get(sizeof(clamd_address));
1274
1275 /* extract socket-path part */
1276 sublist = scanner_options;
1277 cd->hostspec = string_nextinlist(&sublist, &subsep, NULL, 0);
1278
1279 /* parse options */
1280 if (clamd_option(cd, sublist, &subsep) != OK)
1281 return m_errlog_defer(scanent, NULL,
1282 string_sprintf("bad option '%s'", scanner_options));
1283 cv[0] = cd;
1284 }
1285 else
1286 {
1287 /* Go through the rest of the list of host/port and construct an array
1288 * of servers to try. The first one is the bit we just passed from
1289 * scanner_options so process that first and then scan the remainder of
1290 * the address buffer */
1291 do
1292 {
1293 clamd_address * cd;
1294 const uschar * sublist;
1295 int subsep = ' ';
1296 uschar * s;
1297
1298 /* The 'local' option means use the SCAN command over the network
1299 * socket (ie common file storage in use) */
1300 /*XXX we could accept this also as a local option? */
1301 if (strcmpic(scanner_options, US"local") == 0)
1302 {
1303 use_scan_command = TRUE;
1304 continue;
1305 }
1306
1307 cd = (clamd_address *) store_get(sizeof(clamd_address));
1308
1309 /* extract host and port part */
1310 sublist = scanner_options;
1311 if (!(cd->hostspec = string_nextinlist(&sublist, &subsep, NULL, 0)))
1312 {
1313 (void) m_errlog_defer(scanent, NULL,
1314 string_sprintf("missing address: '%s'", scanner_options));
1315 continue;
1316 }
1317 if (!(s = string_nextinlist(&sublist, &subsep, NULL, 0)))
1318 {
1319 (void) m_errlog_defer(scanent, NULL,
1320 string_sprintf("missing port: '%s'", scanner_options));
1321 continue;
1322 }
1323 cd->tcp_port = atoi(CS s);
1324
1325 /* parse options */
1326 /*XXX should these options be common over scanner types? */
1327 if (clamd_option(cd, sublist, &subsep) != OK)
1328 return m_errlog_defer(scanent, NULL,
1329 string_sprintf("bad option '%s'", scanner_options));
1330
1331 cv[num_servers++] = cd;
1332 if (num_servers >= MAX_CLAMD_SERVERS)
1333 {
1334 (void) m_errlog_defer(scanent, NULL,
1335 US"More than " MAX_CLAMD_SERVERS_S " clamd servers "
1336 "specified; only using the first " MAX_CLAMD_SERVERS_S );
1337 break;
1338 }
1339 } while ((scanner_options = string_nextinlist(&av_scanner_work, &sep,
1340 NULL, 0)));
1341
1342 /* check if we have at least one server */
1343 if (!num_servers)
1344 return m_errlog_defer(scanent, NULL,
1345 US"no useable server addresses in malware configuration option.");
1346 }
1347
1348 /* See the discussion of response formats below to see why we really
1349 don't like colons in filenames when passing filenames to ClamAV. */
1350 if (use_scan_command && Ustrchr(eml_filename, ':'))
1351 return m_errlog_defer(scanent, NULL,
1352 string_sprintf("local/SCAN mode incompatible with" \
1353 " : in path to email filename [%s]", eml_filename));
1354
1355 /* Set up the very first data we will be sending */
1356 if (!use_scan_command)
1357 #ifdef WITH_OLD_CLAMAV_STREAM
1358 { cmd_str.data = US"STREAM\n"; cmd_str.len = 7; }
1359 #else
1360 { cmd_str.data = US"zINSTREAM"; cmd_str.len = 10; }
1361 #endif
1362 else
1363 {
1364 cmd_str.data = string_sprintf("SCAN %s\n", eml_filename);
1365 cmd_str.len = Ustrlen(cmd_str.data);
1366 }
1367
1368 /* We have some network servers specified */
1369 if (num_servers)
1370 {
1371 /* Confirmed in ClamAV source (0.95.3) that the TCPAddr option of clamd
1372 * only supports AF_INET, but we should probably be looking to the
1373 * future and rewriting this to be protocol-independent anyway. */
1374
1375 while (num_servers > 0)
1376 {
1377 int i = random_number(num_servers);
1378 clamd_address * cd = cv[i];
1379
1380 DEBUG(D_acl) debug_printf_indent("trying server name %s, port %u\n",
1381 cd->hostspec, cd->tcp_port);
1382
1383 /* Lookup the host. This is to ensure that we connect to the same IP
1384 * on both connections (as one host could resolve to multiple ips) */
1385 for (;;)
1386 {
1387 if ((sock = m_tcpsocket(cd->hostspec, cd->tcp_port,
1388 &connhost, &errstr, &cmd_str)) >= 0)
1389 {
1390 /* Connection successfully established with a server */
1391 hostname = cd->hostspec;
1392 cmd_str.len = 0;
1393 break;
1394 }
1395 if (cd->retry <= 0) break;
1396 while (cd->retry > 0) cd->retry = sleep(cd->retry);
1397 }
1398 if (sock >= 0)
1399 break;
1400
1401 (void) m_errlog_defer(scanent, CUS callout_address, errstr);
1402
1403 /* Remove the server from the list. XXX We should free the memory */
1404 num_servers--;
1405 for (; i < num_servers; i++)
1406 cv[i] = cv[i+1];
1407 }
1408
1409 if (num_servers == 0)
1410 return m_errlog_defer(scanent, NULL, US"all servers failed");
1411 }
1412 else
1413 for (;;)
1414 {
1415 if ((sock = ip_unixsocket(cv[0]->hostspec, &errstr)) >= 0)
1416 {
1417 hostname = cv[0]->hostspec;
1418 break;
1419 }
1420 if (cv[0]->retry <= 0)
1421 return m_errlog_defer(scanent, CUS callout_address, errstr);
1422 while (cv[0]->retry > 0) cv[0]->retry = sleep(cv[0]->retry);
1423 }
1424
1425 /* have socket in variable "sock"; command to use is semi-independent of
1426 * the socket protocol. We use SCAN if is local (either Unix/local
1427 * domain socket, or explicitly told local) else we stream the data.
1428 * How we stream the data depends upon how we were built. */
1429
1430 if (!use_scan_command)
1431 {
1432 #ifdef WITH_OLD_CLAMAV_STREAM
1433 /* "STREAM\n" command, get back a "PORT <N>\n" response, send data to
1434 * that port on a second connection; then in the scan-method-neutral
1435 * part, read the response back on the original connection. */
1436
1437 DEBUG(D_acl) debug_printf_indent(
1438 "Malware scan: issuing %s old-style remote scan (PORT)\n",
1439 scanner_name);
1440
1441 /* Pass the string to ClamAV (7 = "STREAM\n"), if not already sent */
1442 if (cmd_str.len)
1443 if (m_sock_send(sock, cmd_str.data, cmd_str.len, &errstr) < 0)
1444 return m_errlog_defer(scanent, CUS callout_address, errstr);
1445
1446 memset(av_buffer2, 0, sizeof(av_buffer2));
1447 bread = ip_recv(sock, av_buffer2, sizeof(av_buffer2), tmo-time(NULL));
1448
1449 if (bread < 0)
1450 return m_errlog_defer_3(scanent, CUS callout_address,
1451 string_sprintf("unable to read PORT from socket (%s)",
1452 strerror(errno)),
1453 sock);
1454
1455 if (bread == sizeof(av_buffer2))
1456 return m_errlog_defer_3(scanent, CUS callout_address,
1457 "buffer too small", sock);
1458
1459 if (!(*av_buffer2))
1460 return m_errlog_defer_3(scanent, CUS callout_address,
1461 "ClamAV returned null", sock);
1462
1463 av_buffer2[bread] = '\0';
1464 if(sscanf(CS av_buffer2, "PORT %u\n", &port) != 1)
1465 return m_errlog_defer_3(scanent, CUS callout_address,
1466 string_sprintf("Expected port information from clamd, got '%s'",
1467 av_buffer2),
1468 sock);
1469
1470 sockData = m_tcpsocket(connhost.address, port, NULL, &errstr, NULL);
1471 if (sockData < 0)
1472 return m_errlog_defer_3(scanent, CUS callout_address, errstr, sock);
1473
1474 # define CLOSE_SOCKDATA (void)close(sockData)
1475 #else /* WITH_OLD_CLAMAV_STREAM not defined */
1476 /* New protocol: "zINSTREAM\n" followed by a sequence of <length><data>
1477 chunks, <n> a 4-byte number (network order), terminated by a zero-length
1478 chunk. */
1479
1480 DEBUG(D_acl) debug_printf_indent(
1481 "Malware scan: issuing %s new-style remote scan (zINSTREAM)\n",
1482 scanner_name);
1483
1484 /* Pass the string to ClamAV (10 = "zINSTREAM\0"), if not already sent */
1485 if (cmd_str.len)
1486 if (send(sock, cmd_str.data, cmd_str.len, 0) < 0)
1487 return m_errlog_defer_3(scanent, CUS hostname,
1488 string_sprintf("unable to send zINSTREAM to socket (%s)",
1489 strerror(errno)),
1490 sock);
1491
1492 # define CLOSE_SOCKDATA /**/
1493 #endif
1494
1495 /* calc file size */
1496 if ((clam_fd = open(CS eml_filename, O_RDONLY)) < 0)
1497 {
1498 int err = errno;
1499 CLOSE_SOCKDATA;
1500 return m_errlog_defer_3(scanent, NULL,
1501 string_sprintf("can't open spool file %s: %s",
1502 eml_filename, strerror(err)),
1503 sock);
1504 }
1505 if ((fsize = lseek(clam_fd, 0, SEEK_END)) < 0)
1506 {
1507 int err;
1508 b_seek: err = errno;
1509 CLOSE_SOCKDATA; (void)close(clam_fd);
1510 return m_errlog_defer_3(scanent, NULL,
1511 string_sprintf("can't seek spool file %s: %s",
1512 eml_filename, strerror(err)),
1513 sock);
1514 }
1515 fsize_uint = (unsigned int) fsize;
1516 if ((off_t)fsize_uint != fsize)
1517 {
1518 CLOSE_SOCKDATA; (void)close(clam_fd);
1519 return m_errlog_defer_3(scanent, NULL,
1520 string_sprintf("seeking spool file %s, size overflow",
1521 eml_filename),
1522 sock);
1523 }
1524 if (lseek(clam_fd, 0, SEEK_SET) < 0)
1525 goto b_seek;
1526
1527 if (!(clamav_fbuf = US malloc(fsize_uint)))
1528 {
1529 CLOSE_SOCKDATA; (void)close(clam_fd);
1530 return m_errlog_defer_3(scanent, NULL,
1531 string_sprintf("unable to allocate memory %u for file (%s)",
1532 fsize_uint, eml_filename),
1533 sock);
1534 }
1535
1536 if ((result = read(clam_fd, clamav_fbuf, fsize_uint)) < 0)
1537 {
1538 int err = errno;
1539 free(clamav_fbuf); CLOSE_SOCKDATA; (void)close(clam_fd);
1540 return m_errlog_defer_3(scanent, NULL,
1541 string_sprintf("can't read spool file %s: %s",
1542 eml_filename, strerror(err)),
1543 sock);
1544 }
1545 (void)close(clam_fd);
1546
1547 /* send file body to socket */
1548 #ifdef WITH_OLD_CLAMAV_STREAM
1549 if (send(sockData, clamav_fbuf, fsize_uint, 0) < 0)
1550 {
1551 free(clamav_fbuf); CLOSE_SOCKDATA;
1552 return m_errlog_defer_3(scanent, NULL,
1553 string_sprintf("unable to send file body to socket (%s:%u)",
1554 hostname, port),
1555 sock);
1556 }
1557 #else
1558 send_size = htonl(fsize_uint);
1559 send_final_zeroblock = 0;
1560 if ((send(sock, &send_size, sizeof(send_size), 0) < 0) ||
1561 (send(sock, clamav_fbuf, fsize_uint, 0) < 0) ||
1562 (send(sock, &send_final_zeroblock, sizeof(send_final_zeroblock), 0) < 0))
1563 {
1564 free(clamav_fbuf);
1565 return m_errlog_defer_3(scanent, NULL,
1566 string_sprintf("unable to send file body to socket (%s)", hostname),
1567 sock);
1568 }
1569 #endif
1570
1571 free(clamav_fbuf);
1572
1573 CLOSE_SOCKDATA;
1574 #undef CLOSE_SOCKDATA
1575 }
1576 else
1577 { /* use scan command */
1578 /* Send a SCAN command pointing to a filename; then in the then in the
1579 * scan-method-neutral part, read the response back */
1580
1581 /* ================================================================= */
1582
1583 /* Prior to the reworking post-Exim-4.72, this scanned a directory,
1584 which dates to when ClamAV needed us to break apart the email into the
1585 MIME parts (eg, with the now deprecated demime condition coming first).
1586 Some time back, ClamAV gained the ability to deconstruct the emails, so
1587 doing this would actually have resulted in the mail attachments being
1588 scanned twice, in the broken out files and from the original .eml.
1589 Since ClamAV now handles emails (and has for quite some time) we can
1590 just use the email file itself. */
1591 /* Pass the string to ClamAV (7 = "SCAN \n" + \0), if not already sent */
1592
1593 DEBUG(D_acl) debug_printf_indent(
1594 "Malware scan: issuing %s local-path scan [%s]\n",
1595 scanner_name, scanner_options);
1596
1597 if (cmd_str.len)
1598 if (send(sock, cmd_str.data, cmd_str.len, 0) < 0)
1599 return m_errlog_defer_3(scanent, CUS callout_address,
1600 string_sprintf("unable to write to socket (%s)", strerror(errno)),
1601 sock);
1602
1603 /* Do not shut down the socket for writing; a user report noted that
1604 * clamd 0.70 does not react well to this. */
1605 }
1606 /* Commands have been sent, no matter which scan method or connection
1607 * type we're using; now just read the result, independent of method. */
1608
1609 /* Read the result */
1610 memset(av_buffer, 0, sizeof(av_buffer));
1611 bread = ip_recv(sock, av_buffer, sizeof(av_buffer), tmo-time(NULL));
1612 (void)close(sock);
1613 sock = -1;
1614
1615 if (bread <= 0)
1616 return m_errlog_defer(scanent, CUS callout_address,
1617 string_sprintf("unable to read from socket (%s)",
1618 errno == 0 ? "EOF" : strerror(errno)));
1619
1620 if (bread == sizeof(av_buffer))
1621 return m_errlog_defer(scanent, CUS callout_address,
1622 US"buffer too small");
1623 /* We're now assured of a NULL at the end of av_buffer */
1624
1625 /* Check the result. ClamAV returns one of two result formats.
1626 In the basic mode, the response is of the form:
1627 infected: -> "<filename>: <virusname> FOUND"
1628 not-infected: -> "<filename>: OK"
1629 error: -> "<filename>: <errcode> ERROR
1630 If the ExtendedDetectionInfo option has been turned on, then we get:
1631 "<filename>: <virusname>(<virushash>:<virussize>) FOUND"
1632 for the infected case. Compare:
1633 /tmp/eicar.com: Eicar-Test-Signature FOUND
1634 /tmp/eicar.com: Eicar-Test-Signature(44d88612fea8a8f36de82e1278abb02f:68) FOUND
1635
1636 In the streaming case, clamd uses the filename "stream" which you should
1637 be able to verify with { ktrace clamdscan --stream /tmp/eicar.com }. (The
1638 client app will replace "stream" with the original filename before returning
1639 results to stdout, but the trace shows the data).
1640
1641 We will assume that the pathname passed to clamd from Exim does not contain
1642 a colon. We will have whined loudly above if the eml_filename does (and we're
1643 passing a filename to clamd). */
1644
1645 if (!(*av_buffer))
1646 return m_errlog_defer(scanent, CUS callout_address,
1647 US"ClamAV returned null");
1648
1649 /* strip newline at the end (won't be present for zINSTREAM)
1650 (also any trailing whitespace, which shouldn't exist, but we depend upon
1651 this below, so double-check) */
1652 p = av_buffer + Ustrlen(av_buffer) - 1;
1653 if (*p == '\n') *p = '\0';
1654
1655 DEBUG(D_acl) debug_printf_indent("Malware response: %s\n", av_buffer);
1656
1657 while (isspace(*--p) && (p > av_buffer))
1658 *p = '\0';
1659 if (*p) ++p;
1660
1661 /* colon in returned output? */
1662 if(!(p = Ustrchr(av_buffer,':')))
1663 return m_errlog_defer(scanent, CUS callout_address, string_sprintf(
1664 "ClamAV returned malformed result (missing colon): %s",
1665 av_buffer));
1666
1667 /* strip filename */
1668 while (*p && isspace(*++p)) /**/;
1669 vname = p;
1670
1671 /* It would be bad to encounter a virus with "FOUND" in part of the name,
1672 but we should at least be resistant to it. */
1673 p = Ustrrchr(vname, ' ');
1674 result_tag = p ? p+1 : vname;
1675
1676 if (Ustrcmp(result_tag, "FOUND") == 0)
1677 {
1678 /* p should still be the whitespace before the result_tag */
1679 while (isspace(*p)) --p;
1680 *++p = '\0';
1681 /* Strip off the extended information too, which will be in parens
1682 after the virus name, with no intervening whitespace. */
1683 if (*--p == ')')
1684 {
1685 /* "(hash:size)", so previous '(' will do; if not found, we have
1686 a curious virus name, but not an error. */
1687 p = Ustrrchr(vname, '(');
1688 if (p)
1689 *p = '\0';
1690 }
1691 malware_name = string_copy(vname);
1692 DEBUG(D_acl) debug_printf_indent("Malware found, name \"%s\"\n", malware_name);
1693
1694 }
1695 else if (Ustrcmp(result_tag, "ERROR") == 0)
1696 return m_errlog_defer(scanent, CUS callout_address,
1697 string_sprintf("ClamAV returned: %s", av_buffer));
1698
1699 else if (Ustrcmp(result_tag, "OK") == 0)
1700 {
1701 /* Everything should be OK */
1702 malware_name = NULL;
1703 DEBUG(D_acl) debug_printf_indent("Malware not found\n");
1704
1705 }
1706 else
1707 return m_errlog_defer(scanent, CUS callout_address,
1708 string_sprintf("unparseable response from ClamAV: {%s}", av_buffer));
1709
1710 break;
1711 } /* clamd */
1712
1713 case M_SOCK: /* "sock" scanner type ------------------------------------- */
1714 /* This code was derived by Martin Poole from the clamd code contributed
1715 by David Saez and the cmdline code
1716 */
1717 {
1718 int bread;
1719 uschar * commandline;
1720 uschar av_buffer[1024];
1721 uschar * linebuffer;
1722 uschar * sockline_scanner;
1723 uschar sockline_scanner_default[] = "%s\n";
1724 const pcre *sockline_trig_re;
1725 const pcre *sockline_name_re;
1726
1727 /* find scanner command line */
1728 if ( (sockline_scanner = string_nextinlist(&av_scanner_work, &sep,
1729 NULL, 0))
1730 && *sockline_scanner
1731 )
1732 { /* check for no expansions apart from one %s */
1733 uschar * s = Ustrchr(sockline_scanner, '%');
1734 if (s++)
1735 if ((*s != 's' && *s != '%') || Ustrchr(s+1, '%'))
1736 return m_errlog_defer_3(scanent, NULL,
1737 US"unsafe sock scanner call spec", sock);
1738 }
1739 else
1740 sockline_scanner = sockline_scanner_default;
1741 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "cmdline: ",
1742 string_printing(sockline_scanner));
1743
1744 /* find scanner output trigger */
1745 sockline_trig_re = m_pcre_nextinlist(&av_scanner_work, &sep,
1746 "missing trigger specification", &errstr);
1747 if (!sockline_trig_re)
1748 return m_errlog_defer_3(scanent, NULL, errstr, sock);
1749
1750 /* find virus name regex */
1751 sockline_name_re = m_pcre_nextinlist(&av_scanner_work, &sep,
1752 "missing virus name regex specification", &errstr);
1753 if (!sockline_name_re)
1754 return m_errlog_defer_3(scanent, NULL, errstr, sock);
1755
1756 /* prepare scanner call - security depends on expansions check above */
1757 commandline = string_sprintf( CS sockline_scanner, CS eml_filename);
1758 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "expanded: ",
1759 string_printing(commandline));
1760
1761 /* Pass the command string to the socket */
1762 if (m_sock_send(sock, commandline, Ustrlen(commandline), &errstr) < 0)
1763 return m_errlog_defer(scanent, CUS callout_address, errstr);
1764
1765 /* Read the result */
1766 bread = ip_recv(sock, av_buffer, sizeof(av_buffer), tmo-time(NULL));
1767
1768 if (bread <= 0)
1769 return m_errlog_defer_3(scanent, CUS callout_address,
1770 string_sprintf("unable to read from socket (%s)", strerror(errno)),
1771 sock);
1772
1773 if (bread == sizeof(av_buffer))
1774 return m_errlog_defer_3(scanent, CUS callout_address,
1775 US"buffer too small", sock);
1776 av_buffer[bread] = '\0';
1777 linebuffer = string_copy(av_buffer);
1778 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "answer: ",
1779 string_printing(linebuffer));
1780
1781 /* try trigger match */
1782 if (regex_match_and_setup(sockline_trig_re, linebuffer, 0, -1))
1783 {
1784 if (!(malware_name = m_pcre_exec(sockline_name_re, av_buffer)))
1785 malware_name = US "unknown";
1786 DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "name: ",
1787 string_printing(malware_name));
1788 }
1789 else /* no virus found */
1790 malware_name = NULL;
1791 break;
1792 }
1793
1794 case M_MKSD: /* "mksd" scanner type ------------------------------------- */
1795 {
1796 char *mksd_options_end;
1797 int mksd_maxproc = 1; /* default, if no option supplied */
1798 int retval;
1799
1800 if (scanner_options)
1801 {
1802 mksd_maxproc = (int)strtol(CS scanner_options, &mksd_options_end, 10);
1803 if ( *scanner_options == '\0'
1804 || *mksd_options_end != '\0'
1805 || mksd_maxproc < 1
1806 || mksd_maxproc > 32
1807 )
1808 return m_errlog_defer(scanent, CUS callout_address,
1809 string_sprintf("invalid option '%s'", scanner_options));
1810 }
1811
1812 if((sock = ip_unixsocket(US "/var/run/mksd/socket", &errstr)) < 0)
1813 return m_errlog_defer(scanent, CUS callout_address, errstr);
1814
1815 malware_name = NULL;
1816
1817 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan\n", scanner_name);
1818
1819 if ((retval = mksd_scan_packed(scanent, sock, eml_filename, tmo)) != OK)
1820 {
1821 close (sock);
1822 return retval;
1823 }
1824 break;
1825 }
1826
1827 case M_AVAST: /* "avast" scanner type ----------------------------------- */
1828 {
1829 int ovector[1*3];
1830 uschar buf[1024];
1831 uschar * scanrequest;
1832 enum {AVA_HELO, AVA_OPT, AVA_RSP, AVA_DONE} avast_stage;
1833 int nread;
1834
1835 /* According to Martin Tuma @avast the protocol uses "escaped
1836 whitespace", that is, every embedded whitespace is backslash
1837 escaped, as well as backslash is protected by backslash.
1838 The returned lines contain the name of the scanned file, a tab
1839 and the [ ] marker.
1840 [+] - not infected
1841 [L] - infected
1842 [E] - some error occured
1843 Such marker follows the first non-escaped TAB. */
1844 if ( ( !ava_re_clean
1845 && !(ava_re_clean = m_pcre_compile(ava_re_clean_str, &errstr)))
1846 || ( !ava_re_virus
1847 && !(ava_re_virus = m_pcre_compile(ava_re_virus_str, &errstr)))
1848 )
1849 return malware_errlog_defer(errstr);
1850
1851 /* wait for result */
1852 for (avast_stage = AVA_HELO;
1853 (nread = recv_line(sock, buf, sizeof(buf), tmo)) > 0;
1854 )
1855 {
1856 int slen = Ustrlen(buf);
1857 if (slen >= 1)
1858 {
1859 DEBUG(D_acl) debug_printf_indent("got from avast: %s\n", buf);
1860 switch (avast_stage)
1861 {
1862 case AVA_HELO:
1863 if (Ustrncmp(buf, "220", 3) != 0)
1864 goto endloop; /* require a 220 */
1865 goto sendreq;
1866
1867 case AVA_OPT:
1868 if (Ustrncmp(buf, "210", 3) == 0)
1869 break; /* ignore 210 responses */
1870 if (Ustrncmp(buf, "200", 3) != 0)
1871 goto endloop; /* require a 200 */
1872
1873 sendreq:
1874 {
1875 int len;
1876 /* Check for another option to send. Newline-terminate it. */
1877 if ((scanrequest = string_nextinlist(&av_scanner_work, &sep,
1878 NULL, 0)))
1879 {
1880 scanrequest = string_sprintf("%s\n", scanrequest);
1881 avast_stage = AVA_OPT; /* just sent option */
1882 }
1883 else
1884 {
1885 scanrequest = string_sprintf("SCAN %s\n", eml_dir);
1886 avast_stage = AVA_RSP; /* just sent command */
1887 }
1888
1889 /* send config-cmd or scan-request to socket */
1890 len = Ustrlen(scanrequest);
1891 if (send(sock, scanrequest, len, 0) < 0)
1892 {
1893 scanrequest[len-1] = '\0';
1894 return m_errlog_defer_3(scanent, CUS callout_address, string_sprintf(
1895 "unable to send request '%s' to socket (%s): %s",
1896 scanrequest, scanner_options, strerror(errno)), sock);
1897 }
1898 break;
1899 }
1900
1901 case AVA_RSP:
1902 if (Ustrncmp(buf, "210", 3) == 0)
1903 break; /* ignore the "210 SCAN DATA" message */
1904
1905 if (pcre_exec(ava_re_clean, NULL, CS buf, slen,
1906 0, 0, ovector, nelements(ovector)) > 0)
1907 break;
1908
1909 if ((malware_name = m_pcre_exec(ava_re_virus, buf)))
1910 { /* remove backslash in front of [whitespace|backslash] */
1911 uschar * p, * p0;
1912 for (p = malware_name; *p; ++p)
1913 if (*p == '\\' && (isspace(p[1]) || p[1] == '\\'))
1914 for (p0 = p; *p0; ++p0) *p0 = p0[1];
1915
1916 avast_stage = AVA_DONE;
1917 goto endloop;
1918 }
1919
1920 if (Ustrncmp(buf, "200 SCAN OK", 11) == 0)
1921 { /* we're done finally */
1922 if (send(sock, "QUIT\n", 5, 0) < 0) /* courtesy */
1923 return m_errlog_defer_3(scanent, CUS callout_address,
1924 string_sprintf(
1925 "unable to send quit request to socket (%s): %s",
1926 scanner_options, strerror(errno)),
1927 sock);
1928 malware_name = NULL;
1929 avast_stage = AVA_DONE;
1930 goto endloop;
1931 }
1932
1933 /* here for any unexpected response from the scanner */
1934 goto endloop;
1935
1936 case AVA_DONE: log_write(0, LOG_PANIC, "%s:%d:%s: should not happen",
1937 __FILE__, __LINE__, __FUNCTION__);
1938 }
1939 }
1940 }
1941 endloop:
1942
1943 switch(avast_stage)
1944 {
1945 case AVA_HELO:
1946 case AVA_OPT:
1947 case AVA_RSP: return m_errlog_defer_3(scanent, CUS callout_address,
1948 nread >= 0
1949 ? string_sprintf(
1950 "invalid response from scanner: '%s'", buf)
1951 : nread == -1
1952 ? US"EOF from scanner"
1953 : US"timeout from scanner",
1954 sock);
1955 default: break;
1956 }
1957 break;
1958 }
1959
1960 case M_FPROT6D: /* "f-prot6d" scanner type ----------------------------------- */
1961 {
1962 int bread;
1963 uschar * e;
1964 uschar * linebuffer;
1965 uschar * scanrequest;
1966 uschar av_buffer[1024];
1967
1968 if ((!fprot6d_re_virus && !(fprot6d_re_virus = m_pcre_compile(fprot6d_re_virus_str, &errstr)))
1969 || (!fprot6d_re_error && !(fprot6d_re_error = m_pcre_compile(fprot6d_re_error_str, &errstr))))
1970 return malware_errlog_defer(errstr);
1971
1972 scanrequest = string_sprintf("SCAN FILE %s\n", eml_filename);
1973 DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s: %s\n",
1974 scanner_name, scanrequest);
1975
1976 if (m_sock_send(sock, scanrequest, Ustrlen(scanrequest), &errstr) < 0)
1977 return m_errlog_defer(scanent, CUS callout_address, errstr);
1978
1979 bread = ip_recv(sock, av_buffer, sizeof(av_buffer), tmo-time(NULL));
1980
1981 if (bread <= 0)
1982 return m_errlog_defer_3(scanent, CUS callout_address,
1983 string_sprintf("unable to read from socket (%s)", strerror(errno)),
1984 sock);
1985
1986 if (bread == sizeof(av_buffer))
1987 return m_errlog_defer_3(scanent, CUS callout_address,
1988 US"buffer too small", sock);
1989
1990 av_buffer[bread] = '\0';
1991 linebuffer = string_copy(av_buffer);
1992
1993 m_sock_send(sock, US"QUIT\n", 5, 0);
1994
1995 if ((e = m_pcre_exec(fprot6d_re_error, linebuffer)))
1996 return m_errlog_defer_3(scanent, CUS callout_address,
1997 string_sprintf("scanner reported error (%s)", e), sock);
1998
1999 if (!(malware_name = m_pcre_exec(fprot6d_re_virus, linebuffer)))
2000 malware_name = NULL;
2001
2002 break;
2003 } /* f-prot6d */
2004 } /* scanner type switch */
2005
2006 if (sock >= 0)
2007 (void) close (sock);
2008 malware_ok = TRUE; /* set "been here, done that" marker */
2009 }
2010
2011 /* match virus name against pattern (caseless ------->----------v) */
2012 if (malware_name && regex_match_and_setup(re, malware_name, 0, -1))
2013 {
2014 DEBUG(D_acl) debug_printf_indent(
2015 "Matched regex to malware [%s] [%s]\n", malware_re, malware_name);
2016 return OK;
2017 }
2018 else
2019 return FAIL;
2020 }
2021
2022
2023 /*************************************************
2024 * Scan an email for malware *
2025 *************************************************/
2026
2027 /* This is the normal interface for scanning an email, which doesn't need a
2028 filename; it's a wrapper around the malware_file function.
2029
2030 Arguments:
2031 malware_re match condition for "malware="
2032 timeout if nonzero, timeout in seconds
2033
2034 Returns: Exim message processing code (OK, FAIL, DEFER, ...)
2035 where true means malware was found (condition applies)
2036 */
2037 int
2038 malware(const uschar * malware_re, int timeout)
2039 {
2040 int ret = malware_internal(malware_re, NULL, timeout);
2041
2042 if (ret == DEFER) av_failed = TRUE;
2043 return ret;
2044 }
2045
2046
2047 /*************************************************
2048 * Scan a file for malware *
2049 *************************************************/
2050
2051 /* This is a test wrapper for scanning an email, which is not used in
2052 normal processing. Scan any file, using the Exim scanning interface.
2053 This function tampers with various global variables so is unsafe to use
2054 in any other context.
2055
2056 Arguments:
2057 eml_filename a file holding the message to be scanned
2058
2059 Returns: Exim message processing code (OK, FAIL, DEFER, ...)
2060 where true means malware was found (condition applies)
2061 */
2062 int
2063 malware_in_file(uschar *eml_filename)
2064 {
2065 uschar message_id_buf[64];
2066 int ret;
2067
2068 /* spool_mbox() assumes various parameters exist, when creating
2069 the relevant directory and the email within */
2070
2071 (void) string_format(message_id_buf, sizeof(message_id_buf),
2072 "dummy-%d", vaguely_random_number(INT_MAX));
2073 message_id = message_id_buf;
2074 sender_address = US"malware-sender@example.net";
2075 return_path = US"";
2076 recipients_list = NULL;
2077 receive_add_recipient(US"malware-victim@example.net", -1);
2078 enable_dollar_recipients = TRUE;
2079
2080 ret = malware_internal(US"*", eml_filename, 0);
2081
2082 Ustrncpy(spooled_message_id, message_id, sizeof(spooled_message_id));
2083 spool_mbox_ok = 1;
2084
2085 /* don't set no_mbox_unspool; at present, there's no way for it to become
2086 set, but if that changes, then it should apply to these tests too */
2087
2088 unspool_mbox();
2089
2090 /* silence static analysis tools */
2091 message_id = NULL;
2092
2093 return ret;
2094 }
2095
2096
2097 void
2098 malware_init(void)
2099 {
2100 if (!malware_default_re)
2101 malware_default_re = regex_must_compile(malware_regex_default, FALSE, TRUE);
2102 if (!drweb_re)
2103 drweb_re = regex_must_compile(drweb_re_str, FALSE, TRUE);
2104 if (!fsec_re)
2105 fsec_re = regex_must_compile(fsec_re_str, FALSE, TRUE);
2106 if (!kav_re_sus)
2107 kav_re_sus = regex_must_compile(kav_re_sus_str, FALSE, TRUE);
2108 if (!kav_re_inf)
2109 kav_re_inf = regex_must_compile(kav_re_inf_str, FALSE, TRUE);
2110 if (!ava_re_clean)
2111 ava_re_clean = regex_must_compile(ava_re_clean_str, FALSE, TRUE);
2112 if (!ava_re_virus)
2113 ava_re_virus = regex_must_compile(ava_re_virus_str, FALSE, TRUE);
2114 if (!fprot6d_re_error)
2115 fprot6d_re_error = regex_must_compile(fprot6d_re_error_str, FALSE, TRUE);
2116 if (!fprot6d_re_virus)
2117 fprot6d_re_virus = regex_must_compile(fprot6d_re_virus_str, FALSE, TRUE);
2118 }
2119
2120 #endif /*WITH_CONTENT_SCAN*/
2121 /*
2122 * vi: aw ai sw=2
2123 */
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