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