| 1 | /************************************************* |
| 2 | * Exim - an Internet mail transport agent * |
| 3 | *************************************************/ |
| 4 | |
| 5 | /* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2003 - 2015 |
| 6 | * License: GPL |
| 7 | * Copyright (c) The Exim Maintainers 2015 - 2018 |
| 8 | */ |
| 9 | |
| 10 | /* Code for calling virus (malware) scanners. Called from acl.c. */ |
| 11 | |
| 12 | #include "exim.h" |
| 13 | #ifdef WITH_CONTENT_SCAN /* entire file */ |
| 14 | |
| 15 | typedef enum { |
| 16 | #ifndef DISABLE_MAL_FFROTD |
| 17 | M_FPROTD, |
| 18 | #endif |
| 19 | #ifndef DISABLE_MAL_FFROT6D |
| 20 | M_FPROT6D, |
| 21 | #endif |
| 22 | #ifndef DISABLE_MAL_DRWEB |
| 23 | M_DRWEB, |
| 24 | #endif |
| 25 | #ifndef DISABLE_MAL_AVE |
| 26 | M_AVES, |
| 27 | #endif |
| 28 | #ifndef DISABLE_MAL_FSECURE |
| 29 | M_FSEC, |
| 30 | #endif |
| 31 | #ifndef DISABLE_MAL_KAV |
| 32 | M_KAVD, |
| 33 | #endif |
| 34 | #ifndef DISABLE_MAL_SOPHIE |
| 35 | M_SOPHIE, |
| 36 | #endif |
| 37 | #ifndef DISABLE_MAL_CLAM |
| 38 | M_CLAMD, |
| 39 | #endif |
| 40 | #ifndef DISABLE_MAL_MKS |
| 41 | M_MKSD, |
| 42 | #endif |
| 43 | #ifndef DISABLE_MAL_AVAST |
| 44 | M_AVAST, |
| 45 | #endif |
| 46 | #ifndef DISABLE_MAL_SOCK |
| 47 | M_SOCK, |
| 48 | #endif |
| 49 | #ifndef DISABLE_MAL_CMDLINE |
| 50 | M_CMDL, |
| 51 | #endif |
| 52 | M_DUMMY |
| 53 | } scanner_t; |
| 54 | typedef enum {MC_NONE, MC_TCP, MC_UNIX, MC_STRM} contype_t; |
| 55 | static struct scan |
| 56 | { |
| 57 | scanner_t scancode; |
| 58 | const uschar * name; |
| 59 | const uschar * options_default; |
| 60 | contype_t conn; |
| 61 | } m_scans[] = |
| 62 | { |
| 63 | #ifndef DISABLE_MAL_FFROTD |
| 64 | { M_FPROTD, US"f-protd", US"localhost 10200-10204", MC_TCP }, |
| 65 | #endif |
| 66 | #ifndef DISABLE_MAL_FFROT6D |
| 67 | { M_FPROT6D, US"f-prot6d", US"localhost 10200", MC_TCP }, |
| 68 | #endif |
| 69 | #ifndef DISABLE_MAL_DRWEB |
| 70 | { M_DRWEB, US"drweb", US"/usr/local/drweb/run/drwebd.sock", MC_STRM }, |
| 71 | #endif |
| 72 | #ifndef DISABLE_MAL_AVE |
| 73 | { M_AVES, US"aveserver", US"/var/run/aveserver", MC_UNIX }, |
| 74 | #endif |
| 75 | #ifndef DISABLE_MAL_FSECURE |
| 76 | { M_FSEC, US"fsecure", US"/var/run/.fsav", MC_UNIX }, |
| 77 | #endif |
| 78 | #ifndef DISABLE_MAL_KAV |
| 79 | { M_KAVD, US"kavdaemon", US"/var/run/AvpCtl", MC_UNIX }, |
| 80 | #endif |
| 81 | #ifndef DISABLE_MAL_SOPHIE |
| 82 | { M_SOPHIE, US"sophie", US"/var/run/sophie", MC_UNIX }, |
| 83 | #endif |
| 84 | #ifndef DISABLE_MAL_CLAM |
| 85 | { M_CLAMD, US"clamd", US"/tmp/clamd", MC_NONE }, |
| 86 | #endif |
| 87 | #ifndef DISABLE_MAL_MKS |
| 88 | { M_MKSD, US"mksd", NULL, MC_NONE }, |
| 89 | #endif |
| 90 | #ifndef DISABLE_MAL_AVAST |
| 91 | { M_AVAST, US"avast", US"/var/run/avast/scan.sock", MC_STRM }, |
| 92 | #endif |
| 93 | #ifndef DISABLE_MAL_SOCK |
| 94 | { M_SOCK, US"sock", US"/tmp/malware.sock", MC_STRM }, |
| 95 | #endif |
| 96 | #ifndef DISABLE_MAL_CMDLINE |
| 97 | { M_CMDL, US"cmdline", NULL, MC_NONE }, |
| 98 | #endif |
| 99 | { -1, NULL, NULL, MC_NONE } /* end-marker */ |
| 100 | }; |
| 101 | |
| 102 | /******************************************************************************/ |
| 103 | # ifdef MACRO_PREDEF /* build solely to predefine macros */ |
| 104 | |
| 105 | # include "macro_predef.h" |
| 106 | |
| 107 | void |
| 108 | features_malware(void) |
| 109 | { |
| 110 | const struct scan * sc; |
| 111 | const uschar * s; |
| 112 | uschar * t; |
| 113 | uschar buf[64]; |
| 114 | |
| 115 | spf(buf, sizeof(buf), US"_HAVE_MALWARE_"); |
| 116 | |
| 117 | for (sc = m_scans; sc->scancode != -1; sc++) |
| 118 | { |
| 119 | for(s = sc->name, t = buf+14; *s; s++) if (*s != '-') *t++ = toupper(*s); |
| 120 | *t = '\0'; |
| 121 | builtin_macro_create(buf); |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | /******************************************************************************/ |
| 126 | # else /*!MACRO_PREDEF, main build*/ |
| 127 | |
| 128 | |
| 129 | #define MALWARE_TIMEOUT 120 /* default timeout, seconds */ |
| 130 | |
| 131 | static const uschar * malware_regex_default = US ".+"; |
| 132 | static const pcre * malware_default_re = NULL; |
| 133 | |
| 134 | |
| 135 | |
| 136 | #ifndef DISABLE_MAL_CLAM |
| 137 | /* The maximum number of clamd servers that are supported in the configuration */ |
| 138 | # define MAX_CLAMD_SERVERS 32 |
| 139 | # define MAX_CLAMD_SERVERS_S "32" |
| 140 | |
| 141 | typedef struct clamd_address { |
| 142 | uschar * hostspec; |
| 143 | unsigned tcp_port; |
| 144 | unsigned retry; |
| 145 | } clamd_address; |
| 146 | #endif |
| 147 | |
| 148 | |
| 149 | #ifndef DISABLE_MAL_DRWEB |
| 150 | # define DRWEBD_SCAN_CMD (1) /* scan file, buffer or diskfile */ |
| 151 | # define DRWEBD_RETURN_VIRUSES (1<<0) /* ask daemon return to us viruses names from report */ |
| 152 | # define DRWEBD_IS_MAIL (1<<19) /* say to daemon that format is "archive MAIL" */ |
| 153 | |
| 154 | # define DERR_READ_ERR (1<<0) /* read error */ |
| 155 | # define DERR_NOMEMORY (1<<2) /* no memory */ |
| 156 | # define DERR_TIMEOUT (1<<9) /* scan timeout has run out */ |
| 157 | # define DERR_BAD_CALL (1<<15) /* wrong command */ |
| 158 | |
| 159 | static const uschar * drweb_re_str = US "infected\\swith\\s*(.+?)$"; |
| 160 | static const pcre * drweb_re = NULL; |
| 161 | #endif |
| 162 | |
| 163 | #ifndef DISABLE_MAL_FSECURE |
| 164 | static const uschar * fsec_re_str = US "\\S{0,5}INFECTED\\t[^\\t]*\\t([^\\t]+)\\t\\S*$"; |
| 165 | static const pcre * fsec_re = NULL; |
| 166 | #endif |
| 167 | |
| 168 | #ifndef DISABLE_MAL_KAV |
| 169 | static const uschar * kav_re_sus_str = US "suspicion:\\s*(.+?)\\s*$"; |
| 170 | static const uschar * kav_re_inf_str = US "infected:\\s*(.+?)\\s*$"; |
| 171 | static const pcre * kav_re_sus = NULL; |
| 172 | static const pcre * kav_re_inf = NULL; |
| 173 | #endif |
| 174 | |
| 175 | #ifndef DISABLE_MAL_AVAST |
| 176 | static const uschar * ava_re_clean_str = US "(?!\\\\)\\t\\[\\+\\]"; |
| 177 | static const uschar * ava_re_virus_str = US "(?!\\\\)\\t\\[L\\]\\d+\\.0\\t0\\s(.*)"; |
| 178 | static const uschar * ava_re_error_str = US "(?!\\\\)\\t\\[E\\]\\d+\\.0\\tError\\s\\d+\\s(.*)"; |
| 179 | static const pcre * ava_re_clean = NULL; |
| 180 | static const pcre * ava_re_virus = NULL; |
| 181 | static const pcre * ava_re_error = NULL; |
| 182 | #endif |
| 183 | |
| 184 | #ifndef DISABLE_MAL_FFROT6D |
| 185 | static const uschar * fprot6d_re_error_str = US "^\\d+\\s<(.+?)>$"; |
| 186 | static const uschar * fprot6d_re_virus_str = US "^\\d+\\s<infected:\\s+(.+?)>\\s+.+$"; |
| 187 | static const pcre * fprot6d_re_error = NULL; |
| 188 | static const pcre * fprot6d_re_virus = NULL; |
| 189 | #endif |
| 190 | |
| 191 | |
| 192 | |
| 193 | /******************************************************************************/ |
| 194 | |
| 195 | #ifndef DISABLE_MAL_KAV |
| 196 | /* Routine to check whether a system is big- or little-endian. |
| 197 | Ripped from http://www.faqs.org/faqs/graphics/fileformats-faq/part4/section-7.html |
| 198 | Needed for proper kavdaemon implementation. Sigh. */ |
| 199 | # define BIG_MY_ENDIAN 0 |
| 200 | # define LITTLE_MY_ENDIAN 1 |
| 201 | static int test_byte_order(void); |
| 202 | static inline int |
| 203 | test_byte_order() |
| 204 | { |
| 205 | short int word = 0x0001; |
| 206 | char *byte = CS &word; |
| 207 | return(byte[0] ? LITTLE_MY_ENDIAN : BIG_MY_ENDIAN); |
| 208 | } |
| 209 | #endif |
| 210 | |
| 211 | BOOL malware_ok = FALSE; |
| 212 | |
| 213 | /* Gross hacks for the -bmalware option; perhaps we should just create |
| 214 | the scan directory normally for that case, but look into rigging up the |
| 215 | needed header variables if not already set on the command-line? */ |
| 216 | extern int spool_mbox_ok; |
| 217 | extern uschar spooled_message_id[MESSAGE_ID_LENGTH+1]; |
| 218 | |
| 219 | |
| 220 | /* Some (currently avast only) use backslash escaped whitespace, |
| 221 | this function undoes these escapes */ |
| 222 | |
| 223 | static inline void |
| 224 | unescape(uschar *p) |
| 225 | { |
| 226 | uschar *p0; |
| 227 | for (; *p; ++p) |
| 228 | if (*p == '\\' && (isspace(p[1]) || p[1] == '\\')) |
| 229 | for (p0 = p; *p0; ++p0) *p0 = p0[1]; |
| 230 | } |
| 231 | |
| 232 | /* --- malware_*_defer --- */ |
| 233 | static inline int |
| 234 | malware_panic_defer(const uschar * str) |
| 235 | { |
| 236 | log_write(0, LOG_MAIN|LOG_PANIC, "malware acl condition: %s", str); |
| 237 | return DEFER; |
| 238 | } |
| 239 | static inline int |
| 240 | malware_log_defer(const uschar * str) |
| 241 | { |
| 242 | log_write(0, LOG_MAIN, "malware acl condition: %s", str); |
| 243 | return DEFER; |
| 244 | } |
| 245 | /* --- m_*_defer --- */ |
| 246 | static inline int |
| 247 | m_panic_defer(struct scan * scanent, const uschar * hostport, |
| 248 | const uschar * str) |
| 249 | { |
| 250 | return malware_panic_defer(string_sprintf("%s %s : %s", |
| 251 | scanent->name, hostport ? hostport : CUS"", str)); |
| 252 | } |
| 253 | static inline int |
| 254 | m_log_defer(struct scan * scanent, const uschar * hostport, |
| 255 | const uschar * str) |
| 256 | { |
| 257 | return malware_log_defer(string_sprintf("%s %s : %s", |
| 258 | scanent->name, hostport ? hostport : CUS"", str)); |
| 259 | } |
| 260 | /* --- m_*_defer_3 */ |
| 261 | static inline int |
| 262 | m_panic_defer_3(struct scan * scanent, const uschar * hostport, |
| 263 | const uschar * str, int fd_to_close) |
| 264 | { |
| 265 | (void) close(fd_to_close); |
| 266 | return m_panic_defer(scanent, hostport, str); |
| 267 | } |
| 268 | |
| 269 | /*************************************************/ |
| 270 | |
| 271 | #ifndef DISABLE_MAL_CLAM |
| 272 | /* Only used by the Clamav code, which is working from a list of servers and |
| 273 | uses the returned in_addr to get a second connection to the same system. |
| 274 | */ |
| 275 | static inline int |
| 276 | m_tcpsocket(const uschar * hostname, unsigned int port, |
| 277 | host_item * host, uschar ** errstr, const blob * fastopen_blob) |
| 278 | { |
| 279 | return ip_connectedsocket(SOCK_STREAM, hostname, port, port, 5, |
| 280 | host, errstr, fastopen_blob); |
| 281 | } |
| 282 | #endif |
| 283 | |
| 284 | static int |
| 285 | m_sock_send(int sock, uschar * buf, int cnt, uschar ** errstr) |
| 286 | { |
| 287 | if (send(sock, buf, cnt, 0) < 0) |
| 288 | { |
| 289 | int err = errno; |
| 290 | (void)close(sock); |
| 291 | *errstr = string_sprintf("unable to send to socket (%s): %s", |
| 292 | buf, strerror(err)); |
| 293 | return -1; |
| 294 | } |
| 295 | return sock; |
| 296 | } |
| 297 | |
| 298 | static const pcre * |
| 299 | m_pcre_compile(const uschar * re, uschar ** errstr) |
| 300 | { |
| 301 | const uschar * rerror; |
| 302 | int roffset; |
| 303 | const pcre * cre; |
| 304 | |
| 305 | cre = pcre_compile(CS re, PCRE_COPT, (const char **)&rerror, &roffset, NULL); |
| 306 | if (!cre) |
| 307 | *errstr= string_sprintf("regular expression error in '%s': %s at offset %d", |
| 308 | re, rerror, roffset); |
| 309 | return cre; |
| 310 | } |
| 311 | |
| 312 | uschar * |
| 313 | m_pcre_exec(const pcre * cre, uschar * text) |
| 314 | { |
| 315 | int ovector[10*3]; |
| 316 | int i = pcre_exec(cre, NULL, CS text, Ustrlen(text), 0, 0, |
| 317 | ovector, nelem(ovector)); |
| 318 | uschar * substr = NULL; |
| 319 | if (i >= 2) /* Got it */ |
| 320 | pcre_get_substring(CS text, ovector, i, 1, (const char **) &substr); |
| 321 | return substr; |
| 322 | } |
| 323 | |
| 324 | static const pcre * |
| 325 | m_pcre_nextinlist(const uschar ** list, int * sep, |
| 326 | char * listerr, uschar ** errstr) |
| 327 | { |
| 328 | const uschar * list_ele; |
| 329 | const pcre * cre = NULL; |
| 330 | |
| 331 | if (!(list_ele = string_nextinlist(list, sep, NULL, 0))) |
| 332 | *errstr = US listerr; |
| 333 | else |
| 334 | { |
| 335 | DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "RE: ", |
| 336 | string_printing(list_ele)); |
| 337 | cre = m_pcre_compile(CUS list_ele, errstr); |
| 338 | } |
| 339 | return cre; |
| 340 | } |
| 341 | |
| 342 | /* |
| 343 | Simple though inefficient wrapper for reading a line. Drop CRs and the |
| 344 | trailing newline. Can return early on buffer full. Null-terminate. |
| 345 | Apply initial timeout if no data ready. |
| 346 | |
| 347 | Return: number of chars - zero for an empty line |
| 348 | -1 on EOF |
| 349 | -2 on timeout or error |
| 350 | */ |
| 351 | static int |
| 352 | recv_line(int fd, uschar * buffer, int bsize, int tmo) |
| 353 | { |
| 354 | uschar * p = buffer; |
| 355 | ssize_t rcv; |
| 356 | BOOL ok = FALSE; |
| 357 | |
| 358 | if (!fd_ready(fd, tmo-time(NULL))) |
| 359 | return -2; |
| 360 | |
| 361 | /*XXX tmo handling assumes we always get a whole line */ |
| 362 | /* read until \n */ |
| 363 | errno = 0; |
| 364 | while ((rcv = read(fd, p, 1)) > 0) |
| 365 | { |
| 366 | ok = TRUE; |
| 367 | if (p-buffer > bsize-2) break; |
| 368 | if (*p == '\n') break; |
| 369 | if (*p != '\r') p++; |
| 370 | } |
| 371 | if (!ok) |
| 372 | { |
| 373 | DEBUG(D_acl) debug_printf_indent("Malware scan: read %s (%s)\n", |
| 374 | rcv==0 ? "EOF" : "error", strerror(errno)); |
| 375 | return rcv==0 ? -1 : -2; |
| 376 | } |
| 377 | *p = '\0'; |
| 378 | |
| 379 | DEBUG(D_acl) debug_printf_indent("Malware scan: read '%s'\n", buffer); |
| 380 | return p - buffer; |
| 381 | } |
| 382 | |
| 383 | /* return TRUE iff size as requested */ |
| 384 | static BOOL |
| 385 | recv_len(int sock, void * buf, int size, int tmo) |
| 386 | { |
| 387 | return fd_ready(sock, tmo-time(NULL)) |
| 388 | ? recv(sock, buf, size, 0) == size |
| 389 | : FALSE; |
| 390 | } |
| 391 | |
| 392 | |
| 393 | |
| 394 | #ifndef DISABLE_MAL_MKS |
| 395 | /* ============= private routines for the "mksd" scanner type ============== */ |
| 396 | |
| 397 | # include <sys/uio.h> |
| 398 | |
| 399 | static inline int |
| 400 | mksd_writev (int sock, struct iovec * iov, int iovcnt) |
| 401 | { |
| 402 | int i; |
| 403 | |
| 404 | for (;;) |
| 405 | { |
| 406 | do |
| 407 | i = writev (sock, iov, iovcnt); |
| 408 | while (i < 0 && errno == EINTR); |
| 409 | if (i <= 0) |
| 410 | { |
| 411 | (void) malware_panic_defer( |
| 412 | US"unable to write to mksd UNIX socket (/var/run/mksd/socket)"); |
| 413 | return -1; |
| 414 | } |
| 415 | for (;;) /* check for short write */ |
| 416 | if (i >= iov->iov_len) |
| 417 | { |
| 418 | if (--iovcnt == 0) |
| 419 | return 0; |
| 420 | i -= iov->iov_len; |
| 421 | iov++; |
| 422 | } |
| 423 | else |
| 424 | { |
| 425 | iov->iov_len -= i; |
| 426 | iov->iov_base = CS iov->iov_base + i; |
| 427 | break; |
| 428 | } |
| 429 | } |
| 430 | } |
| 431 | |
| 432 | static inline int |
| 433 | mksd_read_lines (int sock, uschar *av_buffer, int av_buffer_size, int tmo) |
| 434 | { |
| 435 | client_conn_ctx cctx = {.sock = sock}; |
| 436 | int offset = 0; |
| 437 | int i; |
| 438 | |
| 439 | do |
| 440 | { |
| 441 | i = ip_recv(&cctx, av_buffer+offset, av_buffer_size-offset, tmo-time(NULL)); |
| 442 | if (i <= 0) |
| 443 | { |
| 444 | (void) malware_panic_defer(US"unable to read from mksd UNIX socket (/var/run/mksd/socket)"); |
| 445 | return -1; |
| 446 | } |
| 447 | |
| 448 | offset += i; |
| 449 | /* offset == av_buffer_size -> buffer full */ |
| 450 | if (offset == av_buffer_size) |
| 451 | { |
| 452 | (void) malware_panic_defer(US"malformed reply received from mksd"); |
| 453 | return -1; |
| 454 | } |
| 455 | } while (av_buffer[offset-1] != '\n'); |
| 456 | |
| 457 | av_buffer[offset] = '\0'; |
| 458 | return offset; |
| 459 | } |
| 460 | |
| 461 | static inline int |
| 462 | mksd_parse_line(struct scan * scanent, char * line) |
| 463 | { |
| 464 | char *p; |
| 465 | |
| 466 | switch (*line) |
| 467 | { |
| 468 | case 'O': /* OK */ |
| 469 | return OK; |
| 470 | |
| 471 | case 'E': |
| 472 | case 'A': /* ERR */ |
| 473 | if ((p = strchr (line, '\n')) != NULL) |
| 474 | *p = '\0'; |
| 475 | return m_panic_defer(scanent, NULL, |
| 476 | string_sprintf("scanner failed: %s", line)); |
| 477 | |
| 478 | default: /* VIR */ |
| 479 | if ((p = strchr (line, '\n')) != NULL) |
| 480 | { |
| 481 | *p = '\0'; |
| 482 | if ( p-line > 5 |
| 483 | && line[3] == ' ' |
| 484 | && (p = strchr(line+4, ' ')) != NULL |
| 485 | && p-line > 4 |
| 486 | ) |
| 487 | { |
| 488 | *p = '\0'; |
| 489 | malware_name = string_copy(US line+4); |
| 490 | return OK; |
| 491 | } |
| 492 | } |
| 493 | return m_panic_defer(scanent, NULL, |
| 494 | string_sprintf("malformed reply received: %s", line)); |
| 495 | } |
| 496 | } |
| 497 | |
| 498 | static int |
| 499 | mksd_scan_packed(struct scan * scanent, int sock, const uschar * scan_filename, |
| 500 | int tmo) |
| 501 | { |
| 502 | struct iovec iov[3]; |
| 503 | const char *cmd = "MSQ\n"; |
| 504 | uschar av_buffer[1024]; |
| 505 | |
| 506 | iov[0].iov_base = (void *) cmd; |
| 507 | iov[0].iov_len = 3; |
| 508 | iov[1].iov_base = (void *) scan_filename; |
| 509 | iov[1].iov_len = Ustrlen(scan_filename); |
| 510 | iov[2].iov_base = (void *) (cmd + 3); |
| 511 | iov[2].iov_len = 1; |
| 512 | |
| 513 | if (mksd_writev (sock, iov, 3) < 0) |
| 514 | return DEFER; |
| 515 | |
| 516 | if (mksd_read_lines (sock, av_buffer, sizeof (av_buffer), tmo) < 0) |
| 517 | return DEFER; |
| 518 | |
| 519 | return mksd_parse_line (scanent, CS av_buffer); |
| 520 | } |
| 521 | #endif /* MKSD */ |
| 522 | |
| 523 | |
| 524 | #ifndef DISABLE_MAL_CLAM |
| 525 | static int |
| 526 | clamd_option(clamd_address * cd, const uschar * optstr, int * subsep) |
| 527 | { |
| 528 | uschar * s; |
| 529 | |
| 530 | cd->retry = 0; |
| 531 | while ((s = string_nextinlist(&optstr, subsep, NULL, 0))) |
| 532 | if (Ustrncmp(s, "retry=", 6) == 0) |
| 533 | { |
| 534 | int sec = readconf_readtime((s += 6), '\0', FALSE); |
| 535 | if (sec < 0) |
| 536 | return FAIL; |
| 537 | cd->retry = sec; |
| 538 | } |
| 539 | else |
| 540 | return FAIL; |
| 541 | return OK; |
| 542 | } |
| 543 | #endif |
| 544 | |
| 545 | |
| 546 | |
| 547 | /************************************************* |
| 548 | * Scan content for malware * |
| 549 | *************************************************/ |
| 550 | |
| 551 | /* This is an internal interface for scanning an email; the normal interface |
| 552 | is via malware(), or there's malware_in_file() used for testing/debugging. |
| 553 | |
| 554 | Arguments: |
| 555 | malware_re match condition for "malware=" |
| 556 | scan_filename the file holding the email to be scanned, if we're faking |
| 557 | this up for the -bmalware test, else NULL |
| 558 | timeout if nonzero, non-default timeoutl |
| 559 | |
| 560 | Returns: Exim message processing code (OK, FAIL, DEFER, ...) |
| 561 | where true means malware was found (condition applies) |
| 562 | */ |
| 563 | static int |
| 564 | malware_internal(const uschar * malware_re, const uschar * scan_filename, |
| 565 | int timeout) |
| 566 | { |
| 567 | int sep = 0; |
| 568 | const uschar *av_scanner_work = av_scanner; |
| 569 | uschar *scanner_name; |
| 570 | unsigned long mbox_size; |
| 571 | FILE *mbox_file; |
| 572 | const pcre *re; |
| 573 | uschar * errstr; |
| 574 | struct scan * scanent; |
| 575 | const uschar * scanner_options; |
| 576 | client_conn_ctx malware_daemon_ctx = {.sock = -1}; |
| 577 | time_t tmo; |
| 578 | uschar * eml_filename, * eml_dir; |
| 579 | |
| 580 | if (!malware_re) |
| 581 | return FAIL; /* empty means "don't match anything" */ |
| 582 | |
| 583 | /* Ensure the eml mbox file is spooled up */ |
| 584 | |
| 585 | if (!(mbox_file = spool_mbox(&mbox_size, scan_filename, &eml_filename))) |
| 586 | return malware_panic_defer(US"error while creating mbox spool file"); |
| 587 | |
| 588 | /* None of our current scanners need the mbox file as a stream (they use |
| 589 | the name), so we can close it right away. Get the directory too. */ |
| 590 | |
| 591 | (void) fclose(mbox_file); |
| 592 | eml_dir = string_copyn(eml_filename, Ustrrchr(eml_filename, '/') - eml_filename); |
| 593 | |
| 594 | /* parse 1st option */ |
| 595 | if (strcmpic(malware_re, US"false") == 0 || Ustrcmp(malware_re,"0") == 0) |
| 596 | return FAIL; /* explicitly no matching */ |
| 597 | |
| 598 | /* special cases (match anything except empty) */ |
| 599 | if ( strcmpic(malware_re,US"true") == 0 |
| 600 | || Ustrcmp(malware_re,"*") == 0 |
| 601 | || Ustrcmp(malware_re,"1") == 0 |
| 602 | ) |
| 603 | { |
| 604 | if ( !malware_default_re |
| 605 | && !(malware_default_re = m_pcre_compile(malware_regex_default, &errstr))) |
| 606 | return malware_panic_defer(errstr); |
| 607 | malware_re = malware_regex_default; |
| 608 | re = malware_default_re; |
| 609 | } |
| 610 | |
| 611 | /* compile the regex, see if it works */ |
| 612 | else if (!(re = m_pcre_compile(malware_re, &errstr))) |
| 613 | return malware_panic_defer(errstr); |
| 614 | |
| 615 | /* if av_scanner starts with a dollar, expand it first */ |
| 616 | if (*av_scanner == '$') |
| 617 | { |
| 618 | if (!(av_scanner_work = expand_string(av_scanner))) |
| 619 | return malware_panic_defer( |
| 620 | string_sprintf("av_scanner starts with $, but expansion failed: %s", |
| 621 | expand_string_message)); |
| 622 | |
| 623 | DEBUG(D_acl) |
| 624 | debug_printf_indent("Expanded av_scanner global: %s\n", av_scanner_work); |
| 625 | /* disable result caching in this case */ |
| 626 | malware_name = NULL; |
| 627 | malware_ok = FALSE; |
| 628 | } |
| 629 | |
| 630 | /* Do not scan twice (unless av_scanner is dynamic). */ |
| 631 | if (!malware_ok) |
| 632 | { |
| 633 | /* find the scanner type from the av_scanner option */ |
| 634 | if (!(scanner_name = string_nextinlist(&av_scanner_work, &sep, NULL, 0))) |
| 635 | return malware_panic_defer(US"av_scanner configuration variable is empty"); |
| 636 | if (!timeout) timeout = MALWARE_TIMEOUT; |
| 637 | tmo = time(NULL) + timeout; |
| 638 | |
| 639 | for (scanent = m_scans; ; scanent++) |
| 640 | { |
| 641 | if (!scanent->name) |
| 642 | return malware_panic_defer(string_sprintf("unknown scanner type '%s'", |
| 643 | scanner_name)); |
| 644 | if (strcmpic(scanner_name, US scanent->name) != 0) |
| 645 | continue; |
| 646 | DEBUG(D_acl) debug_printf_indent("Malware scan: %s tmo=%s\n", |
| 647 | scanner_name, readconf_printtime(timeout)); |
| 648 | |
| 649 | if (!(scanner_options = string_nextinlist(&av_scanner_work, &sep, NULL, 0))) |
| 650 | scanner_options = scanent->options_default; |
| 651 | if (scanent->conn == MC_NONE) |
| 652 | break; |
| 653 | |
| 654 | DEBUG(D_acl) debug_printf_indent("%15s%10s%s\n", "", "socket: ", scanner_options); |
| 655 | switch(scanent->conn) |
| 656 | { |
| 657 | case MC_TCP: |
| 658 | malware_daemon_ctx.sock = ip_tcpsocket(scanner_options, &errstr, 5); break; |
| 659 | case MC_UNIX: |
| 660 | malware_daemon_ctx.sock = ip_unixsocket(scanner_options, &errstr); break; |
| 661 | case MC_STRM: |
| 662 | malware_daemon_ctx.sock = ip_streamsocket(scanner_options, &errstr, 5); break; |
| 663 | default: |
| 664 | /* compiler quietening */ break; |
| 665 | } |
| 666 | if (malware_daemon_ctx.sock < 0) |
| 667 | return m_panic_defer(scanent, CUS callout_address, errstr); |
| 668 | break; |
| 669 | } |
| 670 | |
| 671 | switch (scanent->scancode) |
| 672 | { |
| 673 | #ifndef DISABLE_MAL_FFROTD |
| 674 | case M_FPROTD: /* "f-protd" scanner type -------------------------------- */ |
| 675 | { |
| 676 | uschar *fp_scan_option; |
| 677 | unsigned int detected=0, par_count=0; |
| 678 | uschar * scanrequest; |
| 679 | uschar buf[32768], *strhelper, *strhelper2; |
| 680 | uschar * malware_name_internal = NULL; |
| 681 | int len; |
| 682 | |
| 683 | scanrequest = string_sprintf("GET %s", eml_filename); |
| 684 | |
| 685 | while ((fp_scan_option = string_nextinlist(&av_scanner_work, &sep, |
| 686 | NULL, 0))) |
| 687 | { |
| 688 | scanrequest = string_sprintf("%s%s%s", scanrequest, |
| 689 | par_count ? "%20" : "?", fp_scan_option); |
| 690 | par_count++; |
| 691 | } |
| 692 | scanrequest = string_sprintf("%s HTTP/1.0\r\n\r\n", scanrequest); |
| 693 | DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s: %s\n", |
| 694 | scanner_name, scanrequest); |
| 695 | |
| 696 | /* send scan request */ |
| 697 | if (m_sock_send(malware_daemon_ctx.sock, scanrequest, Ustrlen(scanrequest)+1, &errstr) < 0) |
| 698 | return m_panic_defer(scanent, CUS callout_address, errstr); |
| 699 | |
| 700 | while ((len = recv_line(malware_daemon_ctx.sock, buf, sizeof(buf), tmo)) >= 0) |
| 701 | if (len > 0) |
| 702 | { |
| 703 | if (Ustrstr(buf, US"<detected type=\"") != NULL) |
| 704 | detected = 1; |
| 705 | else if (detected && (strhelper = Ustrstr(buf, US"<name>"))) |
| 706 | { |
| 707 | if ((strhelper2 = Ustrstr(buf, US"</name>")) != NULL) |
| 708 | { |
| 709 | *strhelper2 = '\0'; |
| 710 | malware_name_internal = string_copy(strhelper+6); |
| 711 | } |
| 712 | } |
| 713 | else if (Ustrstr(buf, US"<summary code=\"")) |
| 714 | { |
| 715 | malware_name = Ustrstr(buf, US"<summary code=\"11\">") |
| 716 | ? malware_name_internal : NULL; |
| 717 | break; |
| 718 | } |
| 719 | } |
| 720 | if (len < -1) |
| 721 | { |
| 722 | (void)close(malware_daemon_ctx.sock); |
| 723 | return DEFER; |
| 724 | } |
| 725 | break; |
| 726 | } /* f-protd */ |
| 727 | #endif |
| 728 | |
| 729 | #ifndef DISABLE_MAL_FFROT6D |
| 730 | case M_FPROT6D: /* "f-prot6d" scanner type ----------------------------------- */ |
| 731 | { |
| 732 | int bread; |
| 733 | uschar * e; |
| 734 | uschar * linebuffer; |
| 735 | uschar * scanrequest; |
| 736 | uschar av_buffer[1024]; |
| 737 | |
| 738 | if ((!fprot6d_re_virus && !(fprot6d_re_virus = m_pcre_compile(fprot6d_re_virus_str, &errstr))) |
| 739 | || (!fprot6d_re_error && !(fprot6d_re_error = m_pcre_compile(fprot6d_re_error_str, &errstr)))) |
| 740 | return malware_panic_defer(errstr); |
| 741 | |
| 742 | scanrequest = string_sprintf("SCAN FILE %s\n", eml_filename); |
| 743 | DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s: %s\n", |
| 744 | scanner_name, scanrequest); |
| 745 | |
| 746 | if (m_sock_send(malware_daemon_ctx.sock, scanrequest, Ustrlen(scanrequest), &errstr) < 0) |
| 747 | return m_panic_defer(scanent, CUS callout_address, errstr); |
| 748 | |
| 749 | bread = ip_recv(&malware_daemon_ctx, av_buffer, sizeof(av_buffer), tmo-time(NULL)); |
| 750 | |
| 751 | if (bread <= 0) |
| 752 | return m_panic_defer_3(scanent, CUS callout_address, |
| 753 | string_sprintf("unable to read from socket (%s)", strerror(errno)), |
| 754 | malware_daemon_ctx.sock); |
| 755 | |
| 756 | if (bread == sizeof(av_buffer)) |
| 757 | return m_panic_defer_3(scanent, CUS callout_address, |
| 758 | US"buffer too small", malware_daemon_ctx.sock); |
| 759 | |
| 760 | av_buffer[bread] = '\0'; |
| 761 | linebuffer = string_copy(av_buffer); |
| 762 | |
| 763 | m_sock_send(malware_daemon_ctx.sock, US"QUIT\n", 5, 0); |
| 764 | |
| 765 | if ((e = m_pcre_exec(fprot6d_re_error, linebuffer))) |
| 766 | return m_panic_defer_3(scanent, CUS callout_address, |
| 767 | string_sprintf("scanner reported error (%s)", e), malware_daemon_ctx.sock); |
| 768 | |
| 769 | if (!(malware_name = m_pcre_exec(fprot6d_re_virus, linebuffer))) |
| 770 | malware_name = NULL; |
| 771 | |
| 772 | break; |
| 773 | } /* f-prot6d */ |
| 774 | #endif |
| 775 | |
| 776 | #ifndef DISABLE_MAL_DRWEB |
| 777 | case M_DRWEB: /* "drweb" scanner type ----------------------------------- */ |
| 778 | /* v0.1 - added support for tcp sockets */ |
| 779 | /* v0.0 - initial release -- support for unix sockets */ |
| 780 | { |
| 781 | int result; |
| 782 | off_t fsize; |
| 783 | unsigned int fsize_uint; |
| 784 | uschar * tmpbuf, *drweb_fbuf; |
| 785 | int drweb_rc, drweb_cmd, drweb_flags = 0x0000, drweb_fd, |
| 786 | drweb_vnum, drweb_slen, drweb_fin = 0x0000; |
| 787 | |
| 788 | /* prepare variables */ |
| 789 | drweb_cmd = htonl(DRWEBD_SCAN_CMD); |
| 790 | drweb_flags = htonl(DRWEBD_RETURN_VIRUSES | DRWEBD_IS_MAIL); |
| 791 | |
| 792 | if (*scanner_options != '/') |
| 793 | { |
| 794 | /* calc file size */ |
| 795 | if ((drweb_fd = open(CCS eml_filename, O_RDONLY)) == -1) |
| 796 | return m_panic_defer_3(scanent, NULL, |
| 797 | string_sprintf("can't open spool file %s: %s", |
| 798 | eml_filename, strerror(errno)), |
| 799 | malware_daemon_ctx.sock); |
| 800 | |
| 801 | if ((fsize = lseek(drweb_fd, 0, SEEK_END)) == -1) |
| 802 | { |
| 803 | int err; |
| 804 | badseek: err = errno; |
| 805 | (void)close(drweb_fd); |
| 806 | return m_panic_defer_3(scanent, NULL, |
| 807 | string_sprintf("can't seek spool file %s: %s", |
| 808 | eml_filename, strerror(err)), |
| 809 | malware_daemon_ctx.sock); |
| 810 | } |
| 811 | fsize_uint = (unsigned int) fsize; |
| 812 | if ((off_t)fsize_uint != fsize) |
| 813 | { |
| 814 | (void)close(drweb_fd); |
| 815 | return m_panic_defer_3(scanent, NULL, |
| 816 | string_sprintf("seeking spool file %s, size overflow", |
| 817 | eml_filename), |
| 818 | malware_daemon_ctx.sock); |
| 819 | } |
| 820 | drweb_slen = htonl(fsize); |
| 821 | if (lseek(drweb_fd, 0, SEEK_SET) < 0) |
| 822 | goto badseek; |
| 823 | |
| 824 | DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s remote scan [%s]\n", |
| 825 | scanner_name, scanner_options); |
| 826 | |
| 827 | /* send scan request */ |
| 828 | if ((send(malware_daemon_ctx.sock, &drweb_cmd, sizeof(drweb_cmd), 0) < 0) || |
| 829 | (send(malware_daemon_ctx.sock, &drweb_flags, sizeof(drweb_flags), 0) < 0) || |
| 830 | (send(malware_daemon_ctx.sock, &drweb_fin, sizeof(drweb_fin), 0) < 0) || |
| 831 | (send(malware_daemon_ctx.sock, &drweb_slen, sizeof(drweb_slen), 0) < 0)) |
| 832 | { |
| 833 | (void)close(drweb_fd); |
| 834 | return m_panic_defer_3(scanent, CUS callout_address, string_sprintf( |
| 835 | "unable to send commands to socket (%s)", scanner_options), |
| 836 | malware_daemon_ctx.sock); |
| 837 | } |
| 838 | |
| 839 | if (!(drweb_fbuf = US malloc(fsize_uint))) |
| 840 | { |
| 841 | (void)close(drweb_fd); |
| 842 | return m_panic_defer_3(scanent, NULL, |
| 843 | string_sprintf("unable to allocate memory %u for file (%s)", |
| 844 | fsize_uint, eml_filename), |
| 845 | malware_daemon_ctx.sock); |
| 846 | } |
| 847 | |
| 848 | if ((result = read (drweb_fd, drweb_fbuf, fsize)) == -1) |
| 849 | { |
| 850 | int err = errno; |
| 851 | (void)close(drweb_fd); |
| 852 | free(drweb_fbuf); |
| 853 | return m_panic_defer_3(scanent, NULL, |
| 854 | string_sprintf("can't read spool file %s: %s", |
| 855 | eml_filename, strerror(err)), |
| 856 | malware_daemon_ctx.sock); |
| 857 | } |
| 858 | (void)close(drweb_fd); |
| 859 | |
| 860 | /* send file body to socket */ |
| 861 | if (send(malware_daemon_ctx.sock, drweb_fbuf, fsize, 0) < 0) |
| 862 | { |
| 863 | free(drweb_fbuf); |
| 864 | return m_panic_defer_3(scanent, CUS callout_address, string_sprintf( |
| 865 | "unable to send file body to socket (%s)", scanner_options), |
| 866 | malware_daemon_ctx.sock); |
| 867 | } |
| 868 | } |
| 869 | else |
| 870 | { |
| 871 | drweb_slen = htonl(Ustrlen(eml_filename)); |
| 872 | |
| 873 | DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s local scan [%s]\n", |
| 874 | scanner_name, scanner_options); |
| 875 | |
| 876 | /* send scan request */ |
| 877 | if ((send(malware_daemon_ctx.sock, &drweb_cmd, sizeof(drweb_cmd), 0) < 0) || |
| 878 | (send(malware_daemon_ctx.sock, &drweb_flags, sizeof(drweb_flags), 0) < 0) || |
| 879 | (send(malware_daemon_ctx.sock, &drweb_slen, sizeof(drweb_slen), 0) < 0) || |
| 880 | (send(malware_daemon_ctx.sock, eml_filename, Ustrlen(eml_filename), 0) < 0) || |
| 881 | (send(malware_daemon_ctx.sock, &drweb_fin, sizeof(drweb_fin), 0) < 0)) |
| 882 | return m_panic_defer_3(scanent, CUS callout_address, string_sprintf( |
| 883 | "unable to send commands to socket (%s)", scanner_options), |
| 884 | malware_daemon_ctx.sock); |
| 885 | } |
| 886 | |
| 887 | /* wait for result */ |
| 888 | if (!recv_len(malware_daemon_ctx.sock, &drweb_rc, sizeof(drweb_rc), tmo)) |
| 889 | return m_panic_defer_3(scanent, CUS callout_address, |
| 890 | US"unable to read return code", malware_daemon_ctx.sock); |
| 891 | drweb_rc = ntohl(drweb_rc); |
| 892 | |
| 893 | if (!recv_len(malware_daemon_ctx.sock, &drweb_vnum, sizeof(drweb_vnum), tmo)) |
| 894 | return m_panic_defer_3(scanent, CUS callout_address, |
| 895 | US"unable to read the number of viruses", malware_daemon_ctx.sock); |
| 896 | drweb_vnum = ntohl(drweb_vnum); |
| 897 | |
| 898 | /* "virus(es) found" if virus number is > 0 */ |
| 899 | if (drweb_vnum) |
| 900 | { |
| 901 | int i; |
| 902 | gstring * g = NULL; |
| 903 | |
| 904 | /* setup default virus name */ |
| 905 | malware_name = US"unknown"; |
| 906 | |
| 907 | /* set up match regex */ |
| 908 | if (!drweb_re) |
| 909 | drweb_re = m_pcre_compile(drweb_re_str, &errstr); |
| 910 | |
| 911 | /* read and concatenate virus names into one string */ |
| 912 | for (i = 0; i < drweb_vnum; i++) |
| 913 | { |
| 914 | int ovector[10*3]; |
| 915 | |
| 916 | /* read the size of report */ |
| 917 | if (!recv_len(malware_daemon_ctx.sock, &drweb_slen, sizeof(drweb_slen), tmo)) |
| 918 | return m_panic_defer_3(scanent, CUS callout_address, |
| 919 | US"cannot read report size", malware_daemon_ctx.sock); |
| 920 | drweb_slen = ntohl(drweb_slen); |
| 921 | tmpbuf = store_get(drweb_slen); |
| 922 | |
| 923 | /* read report body */ |
| 924 | if (!recv_len(malware_daemon_ctx.sock, tmpbuf, drweb_slen, tmo)) |
| 925 | return m_panic_defer_3(scanent, CUS callout_address, |
| 926 | US"cannot read report string", malware_daemon_ctx.sock); |
| 927 | tmpbuf[drweb_slen] = '\0'; |
| 928 | |
| 929 | /* try matcher on the line, grab substring */ |
| 930 | result = pcre_exec(drweb_re, NULL, CS tmpbuf, Ustrlen(tmpbuf), 0, 0, |
| 931 | ovector, nelem(ovector)); |
| 932 | if (result >= 2) |
| 933 | { |
| 934 | const char * pre_malware_nb; |
| 935 | |
| 936 | pcre_get_substring(CS tmpbuf, ovector, result, 1, &pre_malware_nb); |
| 937 | |
| 938 | if (i==0) /* the first name we just copy to malware_name */ |
| 939 | g = string_cat(NULL, US pre_malware_nb); |
| 940 | |
| 941 | /*XXX could be string_append_listele? */ |
| 942 | else /* concatenate each new virus name to previous */ |
| 943 | g = string_append(g, 2, "/", pre_malware_nb); |
| 944 | |
| 945 | pcre_free_substring(pre_malware_nb); |
| 946 | } |
| 947 | } |
| 948 | malware_name = string_from_gstring(g); |
| 949 | } |
| 950 | else |
| 951 | { |
| 952 | const char *drweb_s = NULL; |
| 953 | |
| 954 | if (drweb_rc & DERR_READ_ERR) drweb_s = "read error"; |
| 955 | if (drweb_rc & DERR_NOMEMORY) drweb_s = "no memory"; |
| 956 | if (drweb_rc & DERR_TIMEOUT) drweb_s = "timeout"; |
| 957 | if (drweb_rc & DERR_BAD_CALL) drweb_s = "wrong command"; |
| 958 | /* retcodes DERR_SYMLINK, DERR_NO_REGFILE, DERR_SKIPPED. |
| 959 | * DERR_TOO_BIG, DERR_TOO_COMPRESSED, DERR_SPAM, |
| 960 | * DERR_CRC_ERROR, DERR_READSOCKET, DERR_WRITE_ERR |
| 961 | * and others are ignored */ |
| 962 | if (drweb_s) |
| 963 | return m_panic_defer_3(scanent, CUS callout_address, |
| 964 | string_sprintf("drweb daemon retcode 0x%x (%s)", drweb_rc, drweb_s), |
| 965 | malware_daemon_ctx.sock); |
| 966 | |
| 967 | /* no virus found */ |
| 968 | malware_name = NULL; |
| 969 | } |
| 970 | break; |
| 971 | } /* drweb */ |
| 972 | #endif |
| 973 | |
| 974 | #ifndef DISABLE_MAL_AVE |
| 975 | case M_AVES: /* "aveserver" scanner type -------------------------------- */ |
| 976 | { |
| 977 | uschar buf[32768]; |
| 978 | int result; |
| 979 | |
| 980 | /* read aveserver's greeting and see if it is ready (2xx greeting) */ |
| 981 | buf[0] = 0; |
| 982 | recv_line(malware_daemon_ctx.sock, buf, sizeof(buf), tmo); |
| 983 | |
| 984 | if (buf[0] != '2') /* aveserver is having problems */ |
| 985 | return m_panic_defer_3(scanent, CUS callout_address, |
| 986 | string_sprintf("unavailable (Responded: %s).", |
| 987 | ((buf[0] != 0) ? buf : US "nothing") ), |
| 988 | malware_daemon_ctx.sock); |
| 989 | |
| 990 | /* prepare our command */ |
| 991 | (void)string_format(buf, sizeof(buf), "SCAN bPQRSTUW %s\r\n", |
| 992 | eml_filename); |
| 993 | |
| 994 | /* and send it */ |
| 995 | DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s %s\n", |
| 996 | scanner_name, buf); |
| 997 | if (m_sock_send(malware_daemon_ctx.sock, buf, Ustrlen(buf), &errstr) < 0) |
| 998 | return m_panic_defer(scanent, CUS callout_address, errstr); |
| 999 | |
| 1000 | malware_name = NULL; |
| 1001 | result = 0; |
| 1002 | /* read response lines, find malware name and final response */ |
| 1003 | while (recv_line(malware_daemon_ctx.sock, buf, sizeof(buf), tmo) > 0) |
| 1004 | { |
| 1005 | if (buf[0] == '2') |
| 1006 | break; |
| 1007 | if (buf[0] == '5') /* aveserver is having problems */ |
| 1008 | { |
| 1009 | result = m_panic_defer(scanent, CUS callout_address, |
| 1010 | string_sprintf("unable to scan file %s (Responded: %s).", |
| 1011 | eml_filename, buf)); |
| 1012 | break; |
| 1013 | } |
| 1014 | if (Ustrncmp(buf,"322",3) == 0) |
| 1015 | { |
| 1016 | uschar *p = Ustrchr(&buf[4], ' '); |
| 1017 | *p = '\0'; |
| 1018 | malware_name = string_copy(&buf[4]); |
| 1019 | } |
| 1020 | } |
| 1021 | |
| 1022 | if (m_sock_send(malware_daemon_ctx.sock, US"quit\r\n", 6, &errstr) < 0) |
| 1023 | return m_panic_defer(scanent, CUS callout_address, errstr); |
| 1024 | |
| 1025 | /* read aveserver's greeting and see if it is ready (2xx greeting) */ |
| 1026 | buf[0] = 0; |
| 1027 | recv_line(malware_daemon_ctx.sock, buf, sizeof(buf), tmo); |
| 1028 | |
| 1029 | if (buf[0] != '2') /* aveserver is having problems */ |
| 1030 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1031 | string_sprintf("unable to quit dialogue (Responded: %s).", |
| 1032 | ((buf[0] != 0) ? buf : US "nothing") ), |
| 1033 | malware_daemon_ctx.sock); |
| 1034 | |
| 1035 | if (result == DEFER) |
| 1036 | { |
| 1037 | (void)close(malware_daemon_ctx.sock); |
| 1038 | return DEFER; |
| 1039 | } |
| 1040 | break; |
| 1041 | } /* aveserver */ |
| 1042 | #endif |
| 1043 | |
| 1044 | #ifndef DISABLE_MAL_FSECURE |
| 1045 | case M_FSEC: /* "fsecure" scanner type ---------------------------------- */ |
| 1046 | { |
| 1047 | int i, j, bread = 0; |
| 1048 | uschar * file_name; |
| 1049 | uschar av_buffer[1024]; |
| 1050 | static uschar *cmdopt[] = { US"CONFIGURE\tARCHIVE\t1\n", |
| 1051 | US"CONFIGURE\tTIMEOUT\t0\n", |
| 1052 | US"CONFIGURE\tMAXARCH\t5\n", |
| 1053 | US"CONFIGURE\tMIME\t1\n" }; |
| 1054 | |
| 1055 | malware_name = NULL; |
| 1056 | |
| 1057 | DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n", |
| 1058 | scanner_name, scanner_options); |
| 1059 | /* pass options */ |
| 1060 | memset(av_buffer, 0, sizeof(av_buffer)); |
| 1061 | for (i = 0; i != nelem(cmdopt); i++) |
| 1062 | { |
| 1063 | |
| 1064 | if (m_sock_send(malware_daemon_ctx.sock, cmdopt[i], Ustrlen(cmdopt[i]), &errstr) < 0) |
| 1065 | return m_panic_defer(scanent, CUS callout_address, errstr); |
| 1066 | |
| 1067 | bread = ip_recv(&malware_daemon_ctx, av_buffer, sizeof(av_buffer), tmo-time(NULL)); |
| 1068 | if (bread > 0) av_buffer[bread]='\0'; |
| 1069 | if (bread < 0) |
| 1070 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1071 | string_sprintf("unable to read answer %d (%s)", i, strerror(errno)), |
| 1072 | malware_daemon_ctx.sock); |
| 1073 | for (j = 0; j < bread; j++) |
| 1074 | if (av_buffer[j] == '\r' || av_buffer[j] == '\n') |
| 1075 | av_buffer[j] ='@'; |
| 1076 | } |
| 1077 | |
| 1078 | /* pass the mailfile to fsecure */ |
| 1079 | file_name = string_sprintf("SCAN\t%s\n", eml_filename); |
| 1080 | |
| 1081 | if (m_sock_send(malware_daemon_ctx.sock, file_name, Ustrlen(file_name), &errstr) < 0) |
| 1082 | return m_panic_defer(scanent, CUS callout_address, errstr); |
| 1083 | |
| 1084 | /* set up match */ |
| 1085 | /* todo also SUSPICION\t */ |
| 1086 | if (!fsec_re) |
| 1087 | fsec_re = m_pcre_compile(fsec_re_str, &errstr); |
| 1088 | |
| 1089 | /* read report, linewise. Apply a timeout as the Fsecure daemon |
| 1090 | sometimes wants an answer to "PING" but they won't tell us what */ |
| 1091 | { |
| 1092 | uschar * p = av_buffer; |
| 1093 | uschar * q; |
| 1094 | |
| 1095 | for (;;) |
| 1096 | { |
| 1097 | errno = ETIMEDOUT; |
| 1098 | i = av_buffer+sizeof(av_buffer)-p; |
| 1099 | if ((bread= ip_recv(&malware_daemon_ctx, p, i-1, tmo-time(NULL))) < 0) |
| 1100 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1101 | string_sprintf("unable to read result (%s)", strerror(errno)), |
| 1102 | malware_daemon_ctx.sock); |
| 1103 | |
| 1104 | for (p[bread] = '\0'; (q = Ustrchr(p, '\n')); p = q+1) |
| 1105 | { |
| 1106 | *q = '\0'; |
| 1107 | |
| 1108 | /* Really search for virus again? */ |
| 1109 | if (!malware_name) |
| 1110 | /* try matcher on the line, grab substring */ |
| 1111 | malware_name = m_pcre_exec(fsec_re, p); |
| 1112 | |
| 1113 | if (Ustrstr(p, "OK\tScan ok.")) |
| 1114 | goto fsec_found; |
| 1115 | } |
| 1116 | |
| 1117 | /* copy down the trailing partial line then read another chunk */ |
| 1118 | i = av_buffer+sizeof(av_buffer)-p; |
| 1119 | memmove(av_buffer, p, i); |
| 1120 | p = av_buffer+i; |
| 1121 | } |
| 1122 | } |
| 1123 | |
| 1124 | fsec_found: |
| 1125 | break; |
| 1126 | } /* fsecure */ |
| 1127 | #endif |
| 1128 | |
| 1129 | #ifndef DISABLE_MAL_KAV |
| 1130 | case M_KAVD: /* "kavdaemon" scanner type -------------------------------- */ |
| 1131 | { |
| 1132 | time_t t; |
| 1133 | uschar tmpbuf[1024]; |
| 1134 | uschar * scanrequest; |
| 1135 | int kav_rc; |
| 1136 | unsigned long kav_reportlen; |
| 1137 | int bread; |
| 1138 | const pcre *kav_re; |
| 1139 | uschar *p; |
| 1140 | |
| 1141 | /* get current date and time, build scan request */ |
| 1142 | time(&t); |
| 1143 | /* pdp note: before the eml_filename parameter, this scanned the |
| 1144 | directory; not finding documentation, so we'll strip off the directory. |
| 1145 | The side-effect is that the test framework scanning may end up in |
| 1146 | scanning more than was requested, but for the normal interface, this is |
| 1147 | fine. */ |
| 1148 | |
| 1149 | strftime(CS tmpbuf, sizeof(tmpbuf), "%d %b %H:%M:%S", localtime(&t)); |
| 1150 | scanrequest = string_sprintf("<0>%s:%s", CS tmpbuf, eml_filename); |
| 1151 | p = Ustrrchr(scanrequest, '/'); |
| 1152 | if (p) |
| 1153 | *p = '\0'; |
| 1154 | |
| 1155 | DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n", |
| 1156 | scanner_name, scanner_options); |
| 1157 | |
| 1158 | /* send scan request */ |
| 1159 | if (m_sock_send(malware_daemon_ctx.sock, scanrequest, Ustrlen(scanrequest)+1, &errstr) < 0) |
| 1160 | return m_panic_defer(scanent, CUS callout_address, errstr); |
| 1161 | |
| 1162 | /* wait for result */ |
| 1163 | if (!recv_len(malware_daemon_ctx.sock, tmpbuf, 2, tmo)) |
| 1164 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1165 | US"unable to read 2 bytes from socket.", malware_daemon_ctx.sock); |
| 1166 | |
| 1167 | /* get errorcode from one nibble */ |
| 1168 | kav_rc = tmpbuf[ test_byte_order()==LITTLE_MY_ENDIAN ? 0 : 1 ] & 0x0F; |
| 1169 | switch(kav_rc) |
| 1170 | { |
| 1171 | case 5: case 6: /* improper kavdaemon configuration */ |
| 1172 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1173 | US"please reconfigure kavdaemon to NOT disinfect or remove infected files.", |
| 1174 | malware_daemon_ctx.sock); |
| 1175 | case 1: |
| 1176 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1177 | US"reported 'scanning not completed' (code 1).", malware_daemon_ctx.sock); |
| 1178 | case 7: |
| 1179 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1180 | US"reported 'kavdaemon damaged' (code 7).", malware_daemon_ctx.sock); |
| 1181 | } |
| 1182 | |
| 1183 | /* code 8 is not handled, since it is ambiguous. It appears mostly on |
| 1184 | bounces where part of a file has been cut off */ |
| 1185 | |
| 1186 | /* "virus found" return codes (2-4) */ |
| 1187 | if (kav_rc > 1 && kav_rc < 5) |
| 1188 | { |
| 1189 | int report_flag = 0; |
| 1190 | |
| 1191 | /* setup default virus name */ |
| 1192 | malware_name = US"unknown"; |
| 1193 | |
| 1194 | report_flag = tmpbuf[ test_byte_order() == LITTLE_MY_ENDIAN ? 1 : 0 ]; |
| 1195 | |
| 1196 | /* read the report, if available */ |
| 1197 | if (report_flag == 1) |
| 1198 | { |
| 1199 | /* read report size */ |
| 1200 | if (!recv_len(malware_daemon_ctx.sock, &kav_reportlen, 4, tmo)) |
| 1201 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1202 | US"cannot read report size", malware_daemon_ctx.sock); |
| 1203 | |
| 1204 | /* it's possible that avp returns av_buffer[1] == 1 but the |
| 1205 | reportsize is 0 (!?) */ |
| 1206 | if (kav_reportlen > 0) |
| 1207 | { |
| 1208 | /* set up match regex, depends on retcode */ |
| 1209 | if (kav_rc == 3) |
| 1210 | { |
| 1211 | if (!kav_re_sus) kav_re_sus = m_pcre_compile(kav_re_sus_str, &errstr); |
| 1212 | kav_re = kav_re_sus; |
| 1213 | } |
| 1214 | else |
| 1215 | { |
| 1216 | if (!kav_re_inf) kav_re_inf = m_pcre_compile(kav_re_inf_str, &errstr); |
| 1217 | kav_re = kav_re_inf; |
| 1218 | } |
| 1219 | |
| 1220 | /* read report, linewise. Using size from stream to read amount of data |
| 1221 | from same stream is safe enough. */ |
| 1222 | /* coverity[tainted_data] */ |
| 1223 | while (kav_reportlen > 0) |
| 1224 | { |
| 1225 | if ((bread = recv_line(malware_daemon_ctx.sock, tmpbuf, sizeof(tmpbuf), tmo)) < 0) |
| 1226 | break; |
| 1227 | kav_reportlen -= bread+1; |
| 1228 | |
| 1229 | /* try matcher on the line, grab substring */ |
| 1230 | if ((malware_name = m_pcre_exec(kav_re, tmpbuf))) |
| 1231 | break; |
| 1232 | } |
| 1233 | } |
| 1234 | } |
| 1235 | } |
| 1236 | else /* no virus found */ |
| 1237 | malware_name = NULL; |
| 1238 | |
| 1239 | break; |
| 1240 | } |
| 1241 | #endif |
| 1242 | |
| 1243 | #ifndef DISABLE_MAL_CMDLINE |
| 1244 | case M_CMDL: /* "cmdline" scanner type ---------------------------------- */ |
| 1245 | { |
| 1246 | const uschar *cmdline_scanner = scanner_options; |
| 1247 | const pcre *cmdline_trigger_re; |
| 1248 | const pcre *cmdline_regex_re; |
| 1249 | uschar * file_name; |
| 1250 | uschar * commandline; |
| 1251 | void (*eximsigchld)(int); |
| 1252 | void (*eximsigpipe)(int); |
| 1253 | FILE *scanner_out = NULL; |
| 1254 | int scanner_fd; |
| 1255 | FILE *scanner_record = NULL; |
| 1256 | uschar linebuffer[32767]; |
| 1257 | int rcnt; |
| 1258 | int trigger = 0; |
| 1259 | uschar *p; |
| 1260 | |
| 1261 | if (!cmdline_scanner) |
| 1262 | return m_panic_defer(scanent, NULL, errstr); |
| 1263 | |
| 1264 | /* find scanner output trigger */ |
| 1265 | cmdline_trigger_re = m_pcre_nextinlist(&av_scanner_work, &sep, |
| 1266 | "missing trigger specification", &errstr); |
| 1267 | if (!cmdline_trigger_re) |
| 1268 | return m_panic_defer(scanent, NULL, errstr); |
| 1269 | |
| 1270 | /* find scanner name regex */ |
| 1271 | cmdline_regex_re = m_pcre_nextinlist(&av_scanner_work, &sep, |
| 1272 | "missing virus name regex specification", &errstr); |
| 1273 | if (!cmdline_regex_re) |
| 1274 | return m_panic_defer(scanent, NULL, errstr); |
| 1275 | |
| 1276 | /* prepare scanner call; despite the naming, file_name holds a directory |
| 1277 | name which is documented as the value given to %s. */ |
| 1278 | |
| 1279 | file_name = string_copy(eml_filename); |
| 1280 | p = Ustrrchr(file_name, '/'); |
| 1281 | if (p) |
| 1282 | *p = '\0'; |
| 1283 | commandline = string_sprintf(CS cmdline_scanner, file_name); |
| 1284 | |
| 1285 | /* redirect STDERR too */ |
| 1286 | commandline = string_sprintf("%s 2>&1", commandline); |
| 1287 | |
| 1288 | DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n", |
| 1289 | scanner_name, commandline); |
| 1290 | |
| 1291 | /* store exims signal handlers */ |
| 1292 | eximsigchld = signal(SIGCHLD,SIG_DFL); |
| 1293 | eximsigpipe = signal(SIGPIPE,SIG_DFL); |
| 1294 | |
| 1295 | if (!(scanner_out = popen(CS commandline,"r"))) |
| 1296 | { |
| 1297 | int err = errno; |
| 1298 | signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe); |
| 1299 | return m_panic_defer(scanent, NULL, |
| 1300 | string_sprintf("call (%s) failed: %s.", commandline, strerror(err))); |
| 1301 | } |
| 1302 | scanner_fd = fileno(scanner_out); |
| 1303 | |
| 1304 | file_name = string_sprintf("%s/%s_scanner_output", eml_dir, message_id); |
| 1305 | |
| 1306 | if (!(scanner_record = modefopen(file_name, "wb", SPOOL_MODE))) |
| 1307 | { |
| 1308 | int err = errno; |
| 1309 | (void) pclose(scanner_out); |
| 1310 | signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe); |
| 1311 | return m_panic_defer(scanent, NULL, string_sprintf( |
| 1312 | "opening scanner output file (%s) failed: %s.", |
| 1313 | file_name, strerror(err))); |
| 1314 | } |
| 1315 | |
| 1316 | /* look for trigger while recording output */ |
| 1317 | while ((rcnt = recv_line(scanner_fd, linebuffer, |
| 1318 | sizeof(linebuffer), tmo))) |
| 1319 | { |
| 1320 | if (rcnt < 0) |
| 1321 | { |
| 1322 | int err = errno; |
| 1323 | if (rcnt == -1) |
| 1324 | break; |
| 1325 | (void) pclose(scanner_out); |
| 1326 | signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe); |
| 1327 | return m_panic_defer(scanent, NULL, string_sprintf( |
| 1328 | "unable to read from scanner (%s): %s", |
| 1329 | commandline, strerror(err))); |
| 1330 | } |
| 1331 | |
| 1332 | if (Ustrlen(linebuffer) > fwrite(linebuffer, 1, Ustrlen(linebuffer), scanner_record)) |
| 1333 | { |
| 1334 | /* short write */ |
| 1335 | (void) pclose(scanner_out); |
| 1336 | signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe); |
| 1337 | return m_panic_defer(scanent, NULL, string_sprintf( |
| 1338 | "short write on scanner output file (%s).", file_name)); |
| 1339 | } |
| 1340 | putc('\n', scanner_record); |
| 1341 | /* try trigger match */ |
| 1342 | if ( !trigger |
| 1343 | && regex_match_and_setup(cmdline_trigger_re, linebuffer, 0, -1) |
| 1344 | ) |
| 1345 | trigger = 1; |
| 1346 | } |
| 1347 | |
| 1348 | (void)fclose(scanner_record); |
| 1349 | sep = pclose(scanner_out); |
| 1350 | signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe); |
| 1351 | if (sep != 0) |
| 1352 | return m_panic_defer(scanent, NULL, |
| 1353 | sep == -1 |
| 1354 | ? string_sprintf("running scanner failed: %s", strerror(sep)) |
| 1355 | : string_sprintf("scanner returned error code: %d", sep)); |
| 1356 | |
| 1357 | if (trigger) |
| 1358 | { |
| 1359 | uschar * s; |
| 1360 | /* setup default virus name */ |
| 1361 | malware_name = US"unknown"; |
| 1362 | |
| 1363 | /* re-open the scanner output file, look for name match */ |
| 1364 | scanner_record = fopen(CS file_name, "rb"); |
| 1365 | while (fgets(CS linebuffer, sizeof(linebuffer), scanner_record)) |
| 1366 | { |
| 1367 | /* try match */ |
| 1368 | if ((s = m_pcre_exec(cmdline_regex_re, linebuffer))) |
| 1369 | malware_name = s; |
| 1370 | } |
| 1371 | (void)fclose(scanner_record); |
| 1372 | } |
| 1373 | else /* no virus found */ |
| 1374 | malware_name = NULL; |
| 1375 | break; |
| 1376 | } /* cmdline */ |
| 1377 | #endif |
| 1378 | |
| 1379 | #ifndef DISABLE_MAL_SOPHIE |
| 1380 | case M_SOPHIE: /* "sophie" scanner type --------------------------------- */ |
| 1381 | { |
| 1382 | int bread = 0; |
| 1383 | uschar *p; |
| 1384 | uschar * file_name; |
| 1385 | uschar av_buffer[1024]; |
| 1386 | |
| 1387 | /* pass the scan directory to sophie */ |
| 1388 | file_name = string_copy(eml_filename); |
| 1389 | if ((p = Ustrrchr(file_name, '/'))) |
| 1390 | *p = '\0'; |
| 1391 | |
| 1392 | DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n", |
| 1393 | scanner_name, scanner_options); |
| 1394 | |
| 1395 | if ( write(malware_daemon_ctx.sock, file_name, Ustrlen(file_name)) < 0 |
| 1396 | || write(malware_daemon_ctx.sock, "\n", 1) != 1 |
| 1397 | ) |
| 1398 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1399 | string_sprintf("unable to write to UNIX socket (%s)", scanner_options), |
| 1400 | malware_daemon_ctx.sock); |
| 1401 | |
| 1402 | /* wait for result */ |
| 1403 | memset(av_buffer, 0, sizeof(av_buffer)); |
| 1404 | if ((bread = ip_recv(&malware_daemon_ctx, av_buffer, sizeof(av_buffer), tmo-time(NULL))) <= 0) |
| 1405 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1406 | string_sprintf("unable to read from UNIX socket (%s)", scanner_options), |
| 1407 | malware_daemon_ctx.sock); |
| 1408 | |
| 1409 | /* infected ? */ |
| 1410 | if (av_buffer[0] == '1') { |
| 1411 | uschar * s = Ustrchr(av_buffer, '\n'); |
| 1412 | if (s) |
| 1413 | *s = '\0'; |
| 1414 | malware_name = string_copy(&av_buffer[2]); |
| 1415 | } |
| 1416 | else if (!strncmp(CS av_buffer, "-1", 2)) |
| 1417 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1418 | US"scanner reported error", malware_daemon_ctx.sock); |
| 1419 | else /* all ok, no virus */ |
| 1420 | malware_name = NULL; |
| 1421 | |
| 1422 | break; |
| 1423 | } |
| 1424 | #endif |
| 1425 | |
| 1426 | #ifndef DISABLE_MAL_CLAM |
| 1427 | case M_CLAMD: /* "clamd" scanner type ----------------------------------- */ |
| 1428 | { |
| 1429 | /* This code was originally contributed by David Saez */ |
| 1430 | /* There are three scanning methods available to us: |
| 1431 | * (1) Use the SCAN command, pointing to a file in the filesystem |
| 1432 | * (2) Use the STREAM command, send the data on a separate port |
| 1433 | * (3) Use the zINSTREAM command, send the data inline |
| 1434 | * The zINSTREAM command was introduced with ClamAV 0.95, which marked |
| 1435 | * STREAM deprecated; see: http://wiki.clamav.net/bin/view/Main/UpgradeNotes095 |
| 1436 | * In Exim, we use SCAN if using a Unix-domain socket or explicitly told that |
| 1437 | * the TCP-connected daemon is actually local; otherwise we use zINSTREAM |
| 1438 | * See Exim bug 926 for details. */ |
| 1439 | |
| 1440 | uschar *p, *vname, *result_tag; |
| 1441 | int bread=0; |
| 1442 | uschar av_buffer[1024]; |
| 1443 | uschar *hostname = US""; |
| 1444 | host_item connhost; |
| 1445 | uschar *clamav_fbuf; |
| 1446 | int clam_fd, result; |
| 1447 | off_t fsize; |
| 1448 | unsigned int fsize_uint; |
| 1449 | BOOL use_scan_command = FALSE; |
| 1450 | clamd_address * cv[MAX_CLAMD_SERVERS]; |
| 1451 | int num_servers = 0; |
| 1452 | uint32_t send_size, send_final_zeroblock; |
| 1453 | blob cmd_str; |
| 1454 | |
| 1455 | /*XXX if unixdomain socket, only one server supported. Needs fixing; |
| 1456 | there's no reason we should not mix local and remote servers */ |
| 1457 | |
| 1458 | if (*scanner_options == '/') |
| 1459 | { |
| 1460 | clamd_address * cd; |
| 1461 | const uschar * sublist; |
| 1462 | int subsep = ' '; |
| 1463 | |
| 1464 | /* Local file; so we def want to use_scan_command and don't want to try |
| 1465 | * passing IP/port combinations */ |
| 1466 | use_scan_command = TRUE; |
| 1467 | cd = (clamd_address *) store_get(sizeof(clamd_address)); |
| 1468 | |
| 1469 | /* extract socket-path part */ |
| 1470 | sublist = scanner_options; |
| 1471 | cd->hostspec = string_nextinlist(&sublist, &subsep, NULL, 0); |
| 1472 | |
| 1473 | /* parse options */ |
| 1474 | if (clamd_option(cd, sublist, &subsep) != OK) |
| 1475 | return m_panic_defer(scanent, NULL, |
| 1476 | string_sprintf("bad option '%s'", scanner_options)); |
| 1477 | cv[0] = cd; |
| 1478 | } |
| 1479 | else |
| 1480 | { |
| 1481 | /* Go through the rest of the list of host/port and construct an array |
| 1482 | * of servers to try. The first one is the bit we just passed from |
| 1483 | * scanner_options so process that first and then scan the remainder of |
| 1484 | * the address buffer */ |
| 1485 | do |
| 1486 | { |
| 1487 | clamd_address * cd; |
| 1488 | const uschar * sublist; |
| 1489 | int subsep = ' '; |
| 1490 | uschar * s; |
| 1491 | |
| 1492 | /* The 'local' option means use the SCAN command over the network |
| 1493 | * socket (ie common file storage in use) */ |
| 1494 | /*XXX we could accept this also as a local option? */ |
| 1495 | if (strcmpic(scanner_options, US"local") == 0) |
| 1496 | { |
| 1497 | use_scan_command = TRUE; |
| 1498 | continue; |
| 1499 | } |
| 1500 | |
| 1501 | cd = (clamd_address *) store_get(sizeof(clamd_address)); |
| 1502 | |
| 1503 | /* extract host and port part */ |
| 1504 | sublist = scanner_options; |
| 1505 | if (!(cd->hostspec = string_nextinlist(&sublist, &subsep, NULL, 0))) |
| 1506 | { |
| 1507 | (void) m_panic_defer(scanent, NULL, |
| 1508 | string_sprintf("missing address: '%s'", scanner_options)); |
| 1509 | continue; |
| 1510 | } |
| 1511 | if (!(s = string_nextinlist(&sublist, &subsep, NULL, 0))) |
| 1512 | { |
| 1513 | (void) m_panic_defer(scanent, NULL, |
| 1514 | string_sprintf("missing port: '%s'", scanner_options)); |
| 1515 | continue; |
| 1516 | } |
| 1517 | cd->tcp_port = atoi(CS s); |
| 1518 | |
| 1519 | /* parse options */ |
| 1520 | /*XXX should these options be common over scanner types? */ |
| 1521 | if (clamd_option(cd, sublist, &subsep) != OK) |
| 1522 | return m_panic_defer(scanent, NULL, |
| 1523 | string_sprintf("bad option '%s'", scanner_options)); |
| 1524 | |
| 1525 | cv[num_servers++] = cd; |
| 1526 | if (num_servers >= MAX_CLAMD_SERVERS) |
| 1527 | { |
| 1528 | (void) m_panic_defer(scanent, NULL, |
| 1529 | US"More than " MAX_CLAMD_SERVERS_S " clamd servers " |
| 1530 | "specified; only using the first " MAX_CLAMD_SERVERS_S ); |
| 1531 | break; |
| 1532 | } |
| 1533 | } while ((scanner_options = string_nextinlist(&av_scanner_work, &sep, |
| 1534 | NULL, 0))); |
| 1535 | |
| 1536 | /* check if we have at least one server */ |
| 1537 | if (!num_servers) |
| 1538 | return m_panic_defer(scanent, NULL, |
| 1539 | US"no useable server addresses in malware configuration option."); |
| 1540 | } |
| 1541 | |
| 1542 | /* See the discussion of response formats below to see why we really |
| 1543 | don't like colons in filenames when passing filenames to ClamAV. */ |
| 1544 | if (use_scan_command && Ustrchr(eml_filename, ':')) |
| 1545 | return m_panic_defer(scanent, NULL, |
| 1546 | string_sprintf("local/SCAN mode incompatible with" \ |
| 1547 | " : in path to email filename [%s]", eml_filename)); |
| 1548 | |
| 1549 | /* Set up the very first data we will be sending */ |
| 1550 | if (!use_scan_command) |
| 1551 | { cmd_str.data = US"zINSTREAM"; cmd_str.len = 10; } |
| 1552 | else |
| 1553 | { |
| 1554 | cmd_str.data = string_sprintf("SCAN %s\n", eml_filename); |
| 1555 | cmd_str.len = Ustrlen(cmd_str.data); |
| 1556 | } |
| 1557 | |
| 1558 | /* We have some network servers specified */ |
| 1559 | if (num_servers) |
| 1560 | { |
| 1561 | /* Confirmed in ClamAV source (0.95.3) that the TCPAddr option of clamd |
| 1562 | * only supports AF_INET, but we should probably be looking to the |
| 1563 | * future and rewriting this to be protocol-independent anyway. */ |
| 1564 | |
| 1565 | while (num_servers > 0) |
| 1566 | { |
| 1567 | int i = random_number(num_servers); |
| 1568 | clamd_address * cd = cv[i]; |
| 1569 | |
| 1570 | DEBUG(D_acl) debug_printf_indent("trying server name %s, port %u\n", |
| 1571 | cd->hostspec, cd->tcp_port); |
| 1572 | |
| 1573 | /* Lookup the host. This is to ensure that we connect to the same IP |
| 1574 | * on both connections (as one host could resolve to multiple ips) */ |
| 1575 | for (;;) |
| 1576 | { |
| 1577 | /*XXX we trust that the cmd_str is ideempotent */ |
| 1578 | if ((malware_daemon_ctx.sock = m_tcpsocket(cd->hostspec, cd->tcp_port, |
| 1579 | &connhost, &errstr, &cmd_str)) >= 0) |
| 1580 | { |
| 1581 | /* Connection successfully established with a server */ |
| 1582 | hostname = cd->hostspec; |
| 1583 | cmd_str.len = 0; |
| 1584 | break; |
| 1585 | } |
| 1586 | if (cd->retry <= 0) break; |
| 1587 | while (cd->retry > 0) cd->retry = sleep(cd->retry); |
| 1588 | } |
| 1589 | if (malware_daemon_ctx.sock >= 0) |
| 1590 | break; |
| 1591 | |
| 1592 | (void) m_panic_defer(scanent, CUS callout_address, errstr); |
| 1593 | |
| 1594 | /* Remove the server from the list. XXX We should free the memory */ |
| 1595 | num_servers--; |
| 1596 | for (; i < num_servers; i++) |
| 1597 | cv[i] = cv[i+1]; |
| 1598 | } |
| 1599 | |
| 1600 | if (num_servers == 0) |
| 1601 | return m_panic_defer(scanent, NULL, US"all servers failed"); |
| 1602 | } |
| 1603 | else |
| 1604 | for (;;) |
| 1605 | { |
| 1606 | if ((malware_daemon_ctx.sock = ip_unixsocket(cv[0]->hostspec, &errstr)) >= 0) |
| 1607 | { |
| 1608 | hostname = cv[0]->hostspec; |
| 1609 | break; |
| 1610 | } |
| 1611 | if (cv[0]->retry <= 0) |
| 1612 | return m_panic_defer(scanent, CUS callout_address, errstr); |
| 1613 | while (cv[0]->retry > 0) cv[0]->retry = sleep(cv[0]->retry); |
| 1614 | } |
| 1615 | |
| 1616 | /* have socket in variable "sock"; command to use is semi-independent of |
| 1617 | * the socket protocol. We use SCAN if is local (either Unix/local |
| 1618 | * domain socket, or explicitly told local) else we stream the data. |
| 1619 | * How we stream the data depends upon how we were built. */ |
| 1620 | |
| 1621 | if (!use_scan_command) |
| 1622 | { |
| 1623 | /* New protocol: "zINSTREAM\n" followed by a sequence of <length><data> |
| 1624 | chunks, <n> a 4-byte number (network order), terminated by a zero-length |
| 1625 | chunk. */ |
| 1626 | |
| 1627 | DEBUG(D_acl) debug_printf_indent( |
| 1628 | "Malware scan: issuing %s new-style remote scan (zINSTREAM)\n", |
| 1629 | scanner_name); |
| 1630 | |
| 1631 | /* Pass the string to ClamAV (10 = "zINSTREAM\0"), if not already sent */ |
| 1632 | if (cmd_str.len) |
| 1633 | if (send(malware_daemon_ctx.sock, cmd_str.data, cmd_str.len, 0) < 0) |
| 1634 | return m_panic_defer_3(scanent, CUS hostname, |
| 1635 | string_sprintf("unable to send zINSTREAM to socket (%s)", |
| 1636 | strerror(errno)), |
| 1637 | malware_daemon_ctx.sock); |
| 1638 | |
| 1639 | /* calc file size */ |
| 1640 | if ((clam_fd = open(CS eml_filename, O_RDONLY)) < 0) |
| 1641 | { |
| 1642 | int err = errno; |
| 1643 | return m_panic_defer_3(scanent, NULL, |
| 1644 | string_sprintf("can't open spool file %s: %s", |
| 1645 | eml_filename, strerror(err)), |
| 1646 | malware_daemon_ctx.sock); |
| 1647 | } |
| 1648 | if ((fsize = lseek(clam_fd, 0, SEEK_END)) < 0) |
| 1649 | { |
| 1650 | int err; |
| 1651 | b_seek: err = errno; |
| 1652 | (void)close(clam_fd); |
| 1653 | return m_panic_defer_3(scanent, NULL, |
| 1654 | string_sprintf("can't seek spool file %s: %s", |
| 1655 | eml_filename, strerror(err)), |
| 1656 | malware_daemon_ctx.sock); |
| 1657 | } |
| 1658 | fsize_uint = (unsigned int) fsize; |
| 1659 | if ((off_t)fsize_uint != fsize) |
| 1660 | { |
| 1661 | (void)close(clam_fd); |
| 1662 | return m_panic_defer_3(scanent, NULL, |
| 1663 | string_sprintf("seeking spool file %s, size overflow", |
| 1664 | eml_filename), |
| 1665 | malware_daemon_ctx.sock); |
| 1666 | } |
| 1667 | if (lseek(clam_fd, 0, SEEK_SET) < 0) |
| 1668 | goto b_seek; |
| 1669 | |
| 1670 | if (!(clamav_fbuf = US malloc(fsize_uint))) |
| 1671 | { |
| 1672 | (void)close(clam_fd); |
| 1673 | return m_panic_defer_3(scanent, NULL, |
| 1674 | string_sprintf("unable to allocate memory %u for file (%s)", |
| 1675 | fsize_uint, eml_filename), |
| 1676 | malware_daemon_ctx.sock); |
| 1677 | } |
| 1678 | |
| 1679 | if ((result = read(clam_fd, clamav_fbuf, fsize_uint)) < 0) |
| 1680 | { |
| 1681 | int err = errno; |
| 1682 | free(clamav_fbuf); (void)close(clam_fd); |
| 1683 | return m_panic_defer_3(scanent, NULL, |
| 1684 | string_sprintf("can't read spool file %s: %s", |
| 1685 | eml_filename, strerror(err)), |
| 1686 | malware_daemon_ctx.sock); |
| 1687 | } |
| 1688 | (void)close(clam_fd); |
| 1689 | |
| 1690 | /* send file body to socket */ |
| 1691 | send_size = htonl(fsize_uint); |
| 1692 | send_final_zeroblock = 0; |
| 1693 | if ((send(malware_daemon_ctx.sock, &send_size, sizeof(send_size), 0) < 0) || |
| 1694 | (send(malware_daemon_ctx.sock, clamav_fbuf, fsize_uint, 0) < 0) || |
| 1695 | (send(malware_daemon_ctx.sock, &send_final_zeroblock, sizeof(send_final_zeroblock), 0) < 0)) |
| 1696 | { |
| 1697 | free(clamav_fbuf); |
| 1698 | return m_panic_defer_3(scanent, NULL, |
| 1699 | string_sprintf("unable to send file body to socket (%s)", hostname), |
| 1700 | malware_daemon_ctx.sock); |
| 1701 | } |
| 1702 | |
| 1703 | free(clamav_fbuf); |
| 1704 | } |
| 1705 | else |
| 1706 | { /* use scan command */ |
| 1707 | /* Send a SCAN command pointing to a filename; then in the then in the |
| 1708 | * scan-method-neutral part, read the response back */ |
| 1709 | |
| 1710 | /* ================================================================= */ |
| 1711 | |
| 1712 | /* Prior to the reworking post-Exim-4.72, this scanned a directory, |
| 1713 | which dates to when ClamAV needed us to break apart the email into the |
| 1714 | MIME parts (eg, with the now deprecated demime condition coming first). |
| 1715 | Some time back, ClamAV gained the ability to deconstruct the emails, so |
| 1716 | doing this would actually have resulted in the mail attachments being |
| 1717 | scanned twice, in the broken out files and from the original .eml. |
| 1718 | Since ClamAV now handles emails (and has for quite some time) we can |
| 1719 | just use the email file itself. */ |
| 1720 | /* Pass the string to ClamAV (7 = "SCAN \n" + \0), if not already sent */ |
| 1721 | |
| 1722 | DEBUG(D_acl) debug_printf_indent( |
| 1723 | "Malware scan: issuing %s local-path scan [%s]\n", |
| 1724 | scanner_name, scanner_options); |
| 1725 | |
| 1726 | if (cmd_str.len) |
| 1727 | if (send(malware_daemon_ctx.sock, cmd_str.data, cmd_str.len, 0) < 0) |
| 1728 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1729 | string_sprintf("unable to write to socket (%s)", strerror(errno)), |
| 1730 | malware_daemon_ctx.sock); |
| 1731 | |
| 1732 | /* Do not shut down the socket for writing; a user report noted that |
| 1733 | * clamd 0.70 does not react well to this. */ |
| 1734 | } |
| 1735 | /* Commands have been sent, no matter which scan method or connection |
| 1736 | * type we're using; now just read the result, independent of method. */ |
| 1737 | |
| 1738 | /* Read the result */ |
| 1739 | memset(av_buffer, 0, sizeof(av_buffer)); |
| 1740 | bread = ip_recv(&malware_daemon_ctx, av_buffer, sizeof(av_buffer), tmo-time(NULL)); |
| 1741 | (void)close(malware_daemon_ctx.sock); |
| 1742 | malware_daemon_ctx.sock = -1; |
| 1743 | malware_daemon_ctx.tls_ctx = NULL; |
| 1744 | |
| 1745 | if (bread <= 0) |
| 1746 | return m_panic_defer(scanent, CUS callout_address, |
| 1747 | string_sprintf("unable to read from socket (%s)", |
| 1748 | errno == 0 ? "EOF" : strerror(errno))); |
| 1749 | |
| 1750 | if (bread == sizeof(av_buffer)) |
| 1751 | return m_panic_defer(scanent, CUS callout_address, |
| 1752 | US"buffer too small"); |
| 1753 | /* We're now assured of a NULL at the end of av_buffer */ |
| 1754 | |
| 1755 | /* Check the result. ClamAV returns one of two result formats. |
| 1756 | In the basic mode, the response is of the form: |
| 1757 | infected: -> "<filename>: <virusname> FOUND" |
| 1758 | not-infected: -> "<filename>: OK" |
| 1759 | error: -> "<filename>: <errcode> ERROR |
| 1760 | If the ExtendedDetectionInfo option has been turned on, then we get: |
| 1761 | "<filename>: <virusname>(<virushash>:<virussize>) FOUND" |
| 1762 | for the infected case. Compare: |
| 1763 | /tmp/eicar.com: Eicar-Test-Signature FOUND |
| 1764 | /tmp/eicar.com: Eicar-Test-Signature(44d88612fea8a8f36de82e1278abb02f:68) FOUND |
| 1765 | |
| 1766 | In the streaming case, clamd uses the filename "stream" which you should |
| 1767 | be able to verify with { ktrace clamdscan --stream /tmp/eicar.com }. (The |
| 1768 | client app will replace "stream" with the original filename before returning |
| 1769 | results to stdout, but the trace shows the data). |
| 1770 | |
| 1771 | We will assume that the pathname passed to clamd from Exim does not contain |
| 1772 | a colon. We will have whined loudly above if the eml_filename does (and we're |
| 1773 | passing a filename to clamd). */ |
| 1774 | |
| 1775 | if (!(*av_buffer)) |
| 1776 | return m_panic_defer(scanent, CUS callout_address, |
| 1777 | US"ClamAV returned null"); |
| 1778 | |
| 1779 | /* strip newline at the end (won't be present for zINSTREAM) |
| 1780 | (also any trailing whitespace, which shouldn't exist, but we depend upon |
| 1781 | this below, so double-check) */ |
| 1782 | p = av_buffer + Ustrlen(av_buffer) - 1; |
| 1783 | if (*p == '\n') *p = '\0'; |
| 1784 | |
| 1785 | DEBUG(D_acl) debug_printf_indent("Malware response: %s\n", av_buffer); |
| 1786 | |
| 1787 | while (isspace(*--p) && (p > av_buffer)) |
| 1788 | *p = '\0'; |
| 1789 | if (*p) ++p; |
| 1790 | |
| 1791 | /* colon in returned output? */ |
| 1792 | if(!(p = Ustrchr(av_buffer,':'))) |
| 1793 | return m_panic_defer(scanent, CUS callout_address, string_sprintf( |
| 1794 | "ClamAV returned malformed result (missing colon): %s", |
| 1795 | av_buffer)); |
| 1796 | |
| 1797 | /* strip filename */ |
| 1798 | while (*p && isspace(*++p)) /**/; |
| 1799 | vname = p; |
| 1800 | |
| 1801 | /* It would be bad to encounter a virus with "FOUND" in part of the name, |
| 1802 | but we should at least be resistant to it. */ |
| 1803 | p = Ustrrchr(vname, ' '); |
| 1804 | result_tag = p ? p+1 : vname; |
| 1805 | |
| 1806 | if (Ustrcmp(result_tag, "FOUND") == 0) |
| 1807 | { |
| 1808 | /* p should still be the whitespace before the result_tag */ |
| 1809 | while (isspace(*p)) --p; |
| 1810 | *++p = '\0'; |
| 1811 | /* Strip off the extended information too, which will be in parens |
| 1812 | after the virus name, with no intervening whitespace. */ |
| 1813 | if (*--p == ')') |
| 1814 | { |
| 1815 | /* "(hash:size)", so previous '(' will do; if not found, we have |
| 1816 | a curious virus name, but not an error. */ |
| 1817 | p = Ustrrchr(vname, '('); |
| 1818 | if (p) |
| 1819 | *p = '\0'; |
| 1820 | } |
| 1821 | malware_name = string_copy(vname); |
| 1822 | DEBUG(D_acl) debug_printf_indent("Malware found, name \"%s\"\n", malware_name); |
| 1823 | |
| 1824 | } |
| 1825 | else if (Ustrcmp(result_tag, "ERROR") == 0) |
| 1826 | return m_panic_defer(scanent, CUS callout_address, |
| 1827 | string_sprintf("ClamAV returned: %s", av_buffer)); |
| 1828 | |
| 1829 | else if (Ustrcmp(result_tag, "OK") == 0) |
| 1830 | { |
| 1831 | /* Everything should be OK */ |
| 1832 | malware_name = NULL; |
| 1833 | DEBUG(D_acl) debug_printf_indent("Malware not found\n"); |
| 1834 | |
| 1835 | } |
| 1836 | else |
| 1837 | return m_panic_defer(scanent, CUS callout_address, |
| 1838 | string_sprintf("unparseable response from ClamAV: {%s}", av_buffer)); |
| 1839 | |
| 1840 | break; |
| 1841 | } /* clamd */ |
| 1842 | #endif |
| 1843 | |
| 1844 | #ifndef DISABLE_MAL_SOCK |
| 1845 | case M_SOCK: /* "sock" scanner type ------------------------------------- */ |
| 1846 | /* This code was derived by Martin Poole from the clamd code contributed |
| 1847 | by David Saez and the cmdline code |
| 1848 | */ |
| 1849 | { |
| 1850 | int bread; |
| 1851 | uschar * commandline; |
| 1852 | uschar av_buffer[1024]; |
| 1853 | uschar * linebuffer; |
| 1854 | uschar * sockline_scanner; |
| 1855 | uschar sockline_scanner_default[] = "%s\n"; |
| 1856 | const pcre *sockline_trig_re; |
| 1857 | const pcre *sockline_name_re; |
| 1858 | |
| 1859 | /* find scanner command line */ |
| 1860 | if ( (sockline_scanner = string_nextinlist(&av_scanner_work, &sep, |
| 1861 | NULL, 0)) |
| 1862 | && *sockline_scanner |
| 1863 | ) |
| 1864 | { /* check for no expansions apart from one %s */ |
| 1865 | uschar * s = Ustrchr(sockline_scanner, '%'); |
| 1866 | if (s++) |
| 1867 | if ((*s != 's' && *s != '%') || Ustrchr(s+1, '%')) |
| 1868 | return m_panic_defer_3(scanent, NULL, |
| 1869 | US"unsafe sock scanner call spec", malware_daemon_ctx.sock); |
| 1870 | } |
| 1871 | else |
| 1872 | sockline_scanner = sockline_scanner_default; |
| 1873 | DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "cmdline: ", |
| 1874 | string_printing(sockline_scanner)); |
| 1875 | |
| 1876 | /* find scanner output trigger */ |
| 1877 | sockline_trig_re = m_pcre_nextinlist(&av_scanner_work, &sep, |
| 1878 | "missing trigger specification", &errstr); |
| 1879 | if (!sockline_trig_re) |
| 1880 | return m_panic_defer_3(scanent, NULL, errstr, malware_daemon_ctx.sock); |
| 1881 | |
| 1882 | /* find virus name regex */ |
| 1883 | sockline_name_re = m_pcre_nextinlist(&av_scanner_work, &sep, |
| 1884 | "missing virus name regex specification", &errstr); |
| 1885 | if (!sockline_name_re) |
| 1886 | return m_panic_defer_3(scanent, NULL, errstr, malware_daemon_ctx.sock); |
| 1887 | |
| 1888 | /* prepare scanner call - security depends on expansions check above */ |
| 1889 | commandline = string_sprintf( CS sockline_scanner, CS eml_filename); |
| 1890 | DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "expanded: ", |
| 1891 | string_printing(commandline)); |
| 1892 | |
| 1893 | /* Pass the command string to the socket */ |
| 1894 | if (m_sock_send(malware_daemon_ctx.sock, commandline, Ustrlen(commandline), &errstr) < 0) |
| 1895 | return m_panic_defer(scanent, CUS callout_address, errstr); |
| 1896 | |
| 1897 | /* Read the result */ |
| 1898 | bread = ip_recv(&malware_daemon_ctx, av_buffer, sizeof(av_buffer), tmo-time(NULL)); |
| 1899 | |
| 1900 | if (bread <= 0) |
| 1901 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1902 | string_sprintf("unable to read from socket (%s)", strerror(errno)), |
| 1903 | malware_daemon_ctx.sock); |
| 1904 | |
| 1905 | if (bread == sizeof(av_buffer)) |
| 1906 | return m_panic_defer_3(scanent, CUS callout_address, |
| 1907 | US"buffer too small", malware_daemon_ctx.sock); |
| 1908 | av_buffer[bread] = '\0'; |
| 1909 | linebuffer = string_copy(av_buffer); |
| 1910 | DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "answer: ", |
| 1911 | string_printing(linebuffer)); |
| 1912 | |
| 1913 | /* try trigger match */ |
| 1914 | if (regex_match_and_setup(sockline_trig_re, linebuffer, 0, -1)) |
| 1915 | { |
| 1916 | if (!(malware_name = m_pcre_exec(sockline_name_re, av_buffer))) |
| 1917 | malware_name = US "unknown"; |
| 1918 | DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "name: ", |
| 1919 | string_printing(malware_name)); |
| 1920 | } |
| 1921 | else /* no virus found */ |
| 1922 | malware_name = NULL; |
| 1923 | break; |
| 1924 | } |
| 1925 | #endif |
| 1926 | |
| 1927 | #ifndef DISABLE_MAL_MKS |
| 1928 | case M_MKSD: /* "mksd" scanner type ------------------------------------- */ |
| 1929 | { |
| 1930 | char *mksd_options_end; |
| 1931 | int mksd_maxproc = 1; /* default, if no option supplied */ |
| 1932 | int retval; |
| 1933 | |
| 1934 | if (scanner_options) |
| 1935 | { |
| 1936 | mksd_maxproc = (int)strtol(CS scanner_options, &mksd_options_end, 10); |
| 1937 | if ( *scanner_options == '\0' |
| 1938 | || *mksd_options_end != '\0' |
| 1939 | || mksd_maxproc < 1 |
| 1940 | || mksd_maxproc > 32 |
| 1941 | ) |
| 1942 | return m_panic_defer(scanent, CUS callout_address, |
| 1943 | string_sprintf("invalid option '%s'", scanner_options)); |
| 1944 | } |
| 1945 | |
| 1946 | if((malware_daemon_ctx.sock = ip_unixsocket(US "/var/run/mksd/socket", &errstr)) < 0) |
| 1947 | return m_panic_defer(scanent, CUS callout_address, errstr); |
| 1948 | |
| 1949 | malware_name = NULL; |
| 1950 | |
| 1951 | DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan\n", scanner_name); |
| 1952 | |
| 1953 | if ((retval = mksd_scan_packed(scanent, malware_daemon_ctx.sock, eml_filename, tmo)) != OK) |
| 1954 | { |
| 1955 | close (malware_daemon_ctx.sock); |
| 1956 | return retval; |
| 1957 | } |
| 1958 | break; |
| 1959 | } |
| 1960 | #endif |
| 1961 | |
| 1962 | #ifndef DISABLE_MAL_AVAST |
| 1963 | case M_AVAST: /* "avast" scanner type ----------------------------------- */ |
| 1964 | { |
| 1965 | uschar buf[1024]; |
| 1966 | uschar * scanrequest; |
| 1967 | enum {AVA_HELO, AVA_OPT, AVA_RSP, AVA_DONE} avast_stage; |
| 1968 | int nread; |
| 1969 | uschar * error_message = NULL; |
| 1970 | BOOL more_data = FALSE; |
| 1971 | BOOL strict = TRUE; |
| 1972 | |
| 1973 | /* According to Martin Tuma @avast the protocol uses "escaped |
| 1974 | whitespace", that is, every embedded whitespace is backslash |
| 1975 | escaped, as well as backslash is protected by backslash. |
| 1976 | The returned lines contain the name of the scanned file, a tab |
| 1977 | and the [ ] marker. |
| 1978 | [+] - not infected |
| 1979 | [L] - infected |
| 1980 | [E] - some error occurred |
| 1981 | Such marker follows the first non-escaped TAB. For more information |
| 1982 | see avast-protocol(5) |
| 1983 | |
| 1984 | We observed two cases: |
| 1985 | -> SCAN /file |
| 1986 | <- /file [E]0.0 Error 13 Permission denied |
| 1987 | <- 451 SCAN Engine error 13 permission denied |
| 1988 | |
| 1989 | -> SCAN /file |
| 1990 | <- /file… [E]3.0 Error 41120 The file is a decompression bomb |
| 1991 | <- /file… [+]2.0 |
| 1992 | <- /file… [+]2.0 0 Eicar Test Virus!!! |
| 1993 | <- 200 SCAN OK |
| 1994 | |
| 1995 | If the scanner returns 4xx, DEFER is a good decision, combined |
| 1996 | with a panic log entry, to get the admin's attention. |
| 1997 | |
| 1998 | If the scanner returns 200, we reject it as malware, if found any, |
| 1999 | or, in case of an error, we set the malware message to the error |
| 2000 | string. |
| 2001 | |
| 2002 | Some of the >= 42000 errors are message related - usually some |
| 2003 | broken archives etc, but some of them are e.g. license related. |
| 2004 | Once the license expires the engine starts returning errors for |
| 2005 | every scanning attempt. I¹ have the full list of the error codes |
| 2006 | but it is not a public API and is subject to change. It is hard |
| 2007 | for me to say what you should do in case of an engine error. You |
| 2008 | can have a “Treat * unscanned file as infection” policy or “Treat |
| 2009 | unscanned file as clean” policy. ¹) Jakub Bednar |
| 2010 | |
| 2011 | */ |
| 2012 | |
| 2013 | if ( ( !ava_re_clean |
| 2014 | && !(ava_re_clean = m_pcre_compile(ava_re_clean_str, &errstr))) |
| 2015 | || ( !ava_re_virus |
| 2016 | && !(ava_re_virus = m_pcre_compile(ava_re_virus_str, &errstr))) |
| 2017 | || ( !ava_re_error |
| 2018 | && !(ava_re_error = m_pcre_compile(ava_re_error_str, &errstr))) |
| 2019 | ) |
| 2020 | return malware_panic_defer(errstr); |
| 2021 | |
| 2022 | /* wait for result */ |
| 2023 | for (avast_stage = AVA_HELO; |
| 2024 | (nread = recv_line(malware_daemon_ctx.sock, buf, sizeof(buf), tmo)) > 0; |
| 2025 | ) |
| 2026 | { |
| 2027 | int slen = Ustrlen(buf); |
| 2028 | if (slen >= 1) |
| 2029 | { |
| 2030 | |
| 2031 | /* Multi line responses are bracketed between 210 … and nnn … */ |
| 2032 | if (Ustrncmp(buf, "210", 3) == 0) |
| 2033 | { |
| 2034 | more_data = 1; |
| 2035 | continue; |
| 2036 | } |
| 2037 | else if (more_data && isdigit(buf[0])) more_data = 0; |
| 2038 | |
| 2039 | switch (avast_stage) |
| 2040 | { |
| 2041 | case AVA_HELO: |
| 2042 | if (more_data) continue; |
| 2043 | if (Ustrncmp(buf, "220", 3) != 0) |
| 2044 | goto endloop; /* require a 220 */ |
| 2045 | goto sendreq; |
| 2046 | |
| 2047 | case AVA_OPT: |
| 2048 | if (more_data) continue; |
| 2049 | if (Ustrncmp(buf, "200", 3) != 0) |
| 2050 | goto endloop; /* require a 200 */ |
| 2051 | |
| 2052 | sendreq: |
| 2053 | { |
| 2054 | int len; |
| 2055 | /* Check for another option to send. Newline-terminate it. */ |
| 2056 | if ((scanrequest = string_nextinlist(&av_scanner_work, &sep, |
| 2057 | NULL, 0))) |
| 2058 | { |
| 2059 | if (Ustrcmp(scanrequest, "pass_unscanned") == 0) |
| 2060 | { |
| 2061 | DEBUG(D_acl) debug_printf_indent("pass unscanned files as clean\n"); |
| 2062 | strict = FALSE; |
| 2063 | goto sendreq; |
| 2064 | } |
| 2065 | scanrequest = string_sprintf("%s\n", scanrequest); |
| 2066 | avast_stage = AVA_OPT; /* just sent option */ |
| 2067 | DEBUG(D_acl) debug_printf_indent("send to avast OPTION: %s", scanrequest); |
| 2068 | } |
| 2069 | else |
| 2070 | { |
| 2071 | scanrequest = string_sprintf("SCAN %s\n", eml_dir); |
| 2072 | avast_stage = AVA_RSP; /* just sent command */ |
| 2073 | DEBUG(D_acl) debug_printf_indent("send to avast REQUEST: SCAN %s\n", eml_dir); |
| 2074 | } |
| 2075 | |
| 2076 | /* send config-cmd or scan-request to socket */ |
| 2077 | len = Ustrlen(scanrequest); |
| 2078 | if (send(malware_daemon_ctx.sock, scanrequest, len, 0) == -1) |
| 2079 | { |
| 2080 | scanrequest[len-1] = '\0'; |
| 2081 | return m_panic_defer_3(scanent, CUS callout_address, string_sprintf( |
| 2082 | "unable to send request '%s' to socket (%s): %s", |
| 2083 | scanrequest, scanner_options, strerror(errno)), malware_daemon_ctx.sock); |
| 2084 | } |
| 2085 | break; |
| 2086 | } |
| 2087 | |
| 2088 | case AVA_RSP: |
| 2089 | |
| 2090 | if (isdigit(buf[0])) /* We're done */ |
| 2091 | goto endloop; |
| 2092 | |
| 2093 | if (malware_name) /* Nothing else matters, just read on */ |
| 2094 | break; |
| 2095 | |
| 2096 | if (pcre_exec(ava_re_clean, NULL, CS buf, slen, 0, 0, NULL, 0) == 0) |
| 2097 | break; |
| 2098 | |
| 2099 | if ((malware_name = m_pcre_exec(ava_re_virus, buf))) |
| 2100 | { |
| 2101 | unescape(malware_name); |
| 2102 | DEBUG(D_acl) |
| 2103 | debug_printf_indent("unescaped malware name: '%s'\n", malware_name); |
| 2104 | break; |
| 2105 | } |
| 2106 | |
| 2107 | if (strict) /* treat scanner errors as malware */ |
| 2108 | { |
| 2109 | if ((malware_name = m_pcre_exec(ava_re_error, buf))) |
| 2110 | { |
| 2111 | unescape(malware_name); |
| 2112 | DEBUG(D_acl) |
| 2113 | debug_printf_indent("unescaped error message: '%s'\n", malware_name); |
| 2114 | break; |
| 2115 | } |
| 2116 | } |
| 2117 | else if (pcre_exec(ava_re_error, NULL, CS buf, slen, 0, 0, NULL, 0) == 0) |
| 2118 | { |
| 2119 | log_write(0, LOG_MAIN, "internal scanner error (ignored): %s", buf); |
| 2120 | break; |
| 2121 | } |
| 2122 | |
| 2123 | /* here also for any unexpected response from the scanner */ |
| 2124 | DEBUG(D_acl) debug_printf("avast response not handled: '%s'\n", buf); |
| 2125 | |
| 2126 | goto endloop; |
| 2127 | |
| 2128 | default: log_write(0, LOG_PANIC, "%s:%d:%s: should not happen", |
| 2129 | __FILE__, __LINE__, __FUNCTION__); |
| 2130 | } |
| 2131 | } |
| 2132 | } |
| 2133 | |
| 2134 | endloop: |
| 2135 | |
| 2136 | if (nread == -1) error_message = US"EOF from scanner"; |
| 2137 | else if (nread < 0) error_message = US"timeout from scanner"; |
| 2138 | else if (nread == 0) error_message = US"got nothing from scanner"; |
| 2139 | else if (buf[0] != '2') error_message = buf; |
| 2140 | |
| 2141 | DEBUG(D_acl) debug_printf_indent("sent to avast QUIT\n"); |
| 2142 | if (send(malware_daemon_ctx.sock, "QUIT\n", 5, 0) == -1) |
| 2143 | return m_panic_defer_3(scanent, CUS callout_address, |
| 2144 | string_sprintf("unable to send quit request to socket (%s): %s", |
| 2145 | scanner_options, strerror(errno)), malware_daemon_ctx.sock); |
| 2146 | |
| 2147 | if (error_message) |
| 2148 | return m_panic_defer_3(scanent, CUS callout_address, error_message, malware_daemon_ctx.sock); |
| 2149 | |
| 2150 | } |
| 2151 | #endif |
| 2152 | } /* scanner type switch */ |
| 2153 | |
| 2154 | if (malware_daemon_ctx.sock >= 0) |
| 2155 | (void) close (malware_daemon_ctx.sock); |
| 2156 | malware_ok = TRUE; /* set "been here, done that" marker */ |
| 2157 | } |
| 2158 | |
| 2159 | /* match virus name against pattern (caseless ------->----------v) */ |
| 2160 | if (malware_name && regex_match_and_setup(re, malware_name, 0, -1)) |
| 2161 | { |
| 2162 | DEBUG(D_acl) debug_printf_indent( |
| 2163 | "Matched regex to malware [%s] [%s]\n", malware_re, malware_name); |
| 2164 | return OK; |
| 2165 | } |
| 2166 | else |
| 2167 | return FAIL; |
| 2168 | } |
| 2169 | |
| 2170 | |
| 2171 | /************************************************* |
| 2172 | * Scan an email for malware * |
| 2173 | *************************************************/ |
| 2174 | |
| 2175 | /* This is the normal interface for scanning an email, which doesn't need a |
| 2176 | filename; it's a wrapper around the malware_file function. |
| 2177 | |
| 2178 | Arguments: |
| 2179 | malware_re match condition for "malware=" |
| 2180 | timeout if nonzero, timeout in seconds |
| 2181 | |
| 2182 | Returns: Exim message processing code (OK, FAIL, DEFER, ...) |
| 2183 | where true means malware was found (condition applies) |
| 2184 | */ |
| 2185 | int |
| 2186 | malware(const uschar * malware_re, int timeout) |
| 2187 | { |
| 2188 | int ret = malware_internal(malware_re, NULL, timeout); |
| 2189 | |
| 2190 | if (ret == DEFER) av_failed = TRUE; |
| 2191 | return ret; |
| 2192 | } |
| 2193 | |
| 2194 | |
| 2195 | /************************************************* |
| 2196 | * Scan a file for malware * |
| 2197 | *************************************************/ |
| 2198 | |
| 2199 | /* This is a test wrapper for scanning an email, which is not used in |
| 2200 | normal processing. Scan any file, using the Exim scanning interface. |
| 2201 | This function tampers with various global variables so is unsafe to use |
| 2202 | in any other context. |
| 2203 | |
| 2204 | Arguments: |
| 2205 | eml_filename a file holding the message to be scanned |
| 2206 | |
| 2207 | Returns: Exim message processing code (OK, FAIL, DEFER, ...) |
| 2208 | where true means malware was found (condition applies) |
| 2209 | */ |
| 2210 | int |
| 2211 | malware_in_file(uschar *eml_filename) |
| 2212 | { |
| 2213 | uschar message_id_buf[64]; |
| 2214 | int ret; |
| 2215 | |
| 2216 | /* spool_mbox() assumes various parameters exist, when creating |
| 2217 | the relevant directory and the email within */ |
| 2218 | |
| 2219 | (void) string_format(message_id_buf, sizeof(message_id_buf), |
| 2220 | "dummy-%d", vaguely_random_number(INT_MAX)); |
| 2221 | message_id = message_id_buf; |
| 2222 | sender_address = US"malware-sender@example.net"; |
| 2223 | return_path = US""; |
| 2224 | recipients_list = NULL; |
| 2225 | receive_add_recipient(US"malware-victim@example.net", -1); |
| 2226 | f.enable_dollar_recipients = TRUE; |
| 2227 | |
| 2228 | ret = malware_internal(US"*", eml_filename, 0); |
| 2229 | |
| 2230 | Ustrncpy(spooled_message_id, message_id, sizeof(spooled_message_id)); |
| 2231 | spool_mbox_ok = 1; |
| 2232 | |
| 2233 | /* don't set no_mbox_unspool; at present, there's no way for it to become |
| 2234 | set, but if that changes, then it should apply to these tests too */ |
| 2235 | |
| 2236 | unspool_mbox(); |
| 2237 | |
| 2238 | /* silence static analysis tools */ |
| 2239 | message_id = NULL; |
| 2240 | |
| 2241 | return ret; |
| 2242 | } |
| 2243 | |
| 2244 | |
| 2245 | void |
| 2246 | malware_init(void) |
| 2247 | { |
| 2248 | if (!malware_default_re) |
| 2249 | malware_default_re = regex_must_compile(malware_regex_default, FALSE, TRUE); |
| 2250 | |
| 2251 | #ifndef DISABLE_MAL_DRWEB |
| 2252 | if (!drweb_re) |
| 2253 | drweb_re = regex_must_compile(drweb_re_str, FALSE, TRUE); |
| 2254 | #endif |
| 2255 | #ifndef DISABLE_MAL_FSECURE |
| 2256 | if (!fsec_re) |
| 2257 | fsec_re = regex_must_compile(fsec_re_str, FALSE, TRUE); |
| 2258 | #endif |
| 2259 | #ifndef DISABLE_MAL_KAV |
| 2260 | if (!kav_re_sus) |
| 2261 | kav_re_sus = regex_must_compile(kav_re_sus_str, FALSE, TRUE); |
| 2262 | if (!kav_re_inf) |
| 2263 | kav_re_inf = regex_must_compile(kav_re_inf_str, FALSE, TRUE); |
| 2264 | #endif |
| 2265 | #ifndef DISABLE_MAL_AVAST |
| 2266 | if (!ava_re_clean) |
| 2267 | ava_re_clean = regex_must_compile(ava_re_clean_str, FALSE, TRUE); |
| 2268 | if (!ava_re_virus) |
| 2269 | ava_re_virus = regex_must_compile(ava_re_virus_str, FALSE, TRUE); |
| 2270 | if (!ava_re_error) |
| 2271 | ava_re_error = regex_must_compile(ava_re_error_str, FALSE, TRUE); |
| 2272 | #endif |
| 2273 | #ifndef DISABLE_MAL_FFROT6D |
| 2274 | if (!fprot6d_re_error) |
| 2275 | fprot6d_re_error = regex_must_compile(fprot6d_re_error_str, FALSE, TRUE); |
| 2276 | if (!fprot6d_re_virus) |
| 2277 | fprot6d_re_virus = regex_must_compile(fprot6d_re_virus_str, FALSE, TRUE); |
| 2278 | #endif |
| 2279 | } |
| 2280 | |
| 2281 | |
| 2282 | void |
| 2283 | malware_show_supported(FILE * f) |
| 2284 | { |
| 2285 | struct scan * sc; |
| 2286 | fprintf(f, "Malware:"); |
| 2287 | for (sc = m_scans; sc->scancode != (scanner_t)-1; sc++) fprintf(f, " %s", sc->name); |
| 2288 | fprintf(f, "\n"); |
| 2289 | } |
| 2290 | |
| 2291 | |
| 2292 | # endif /*!MACRO_PREDEF*/ |
| 2293 | #endif /*WITH_CONTENT_SCAN*/ |
| 2294 | /* |
| 2295 | * vi: aw ai sw=2 |
| 2296 | */ |