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-rw-r--r--src/malware.c2328
1 files changed, 2328 insertions, 0 deletions
diff --git a/src/malware.c b/src/malware.c
new file mode 100644
index 0000000..4719a5d
--- /dev/null
+++ b/src/malware.c
@@ -0,0 +1,2328 @@
+/*************************************************
+* Exim - an Internet mail transport agent *
+*************************************************/
+
+/*
+ * Copyright (c) The Exim Maintainers 2015 - 2022
+ * Copyright (c) Tom Kistner <tom@duncanthrax.net> 2003 - 2015
+ * License: GPL
+ */
+
+/* Code for calling virus (malware) scanners. Called from acl.c. */
+
+#include "exim.h"
+#ifdef WITH_CONTENT_SCAN /* entire file */
+
+typedef enum {
+#ifndef DISABLE_MAL_FFROTD
+ M_FPROTD,
+#endif
+#ifndef DISABLE_MAL_FFROT6D
+ M_FPROT6D,
+#endif
+#ifndef DISABLE_MAL_DRWEB
+ M_DRWEB,
+#endif
+#ifndef DISABLE_MAL_AVE
+ M_AVES,
+#endif
+#ifndef DISABLE_MAL_FSECURE
+ M_FSEC,
+#endif
+#ifndef DISABLE_MAL_KAV
+ M_KAVD,
+#endif
+#ifndef DISABLE_MAL_SOPHIE
+ M_SOPHIE,
+#endif
+#ifndef DISABLE_MAL_CLAM
+ M_CLAMD,
+#endif
+#ifndef DISABLE_MAL_MKS
+ M_MKSD,
+#endif
+#ifndef DISABLE_MAL_AVAST
+ M_AVAST,
+#endif
+#ifndef DISABLE_MAL_SOCK
+ M_SOCK,
+#endif
+#ifndef DISABLE_MAL_CMDLINE
+ M_CMDL,
+#endif
+ M_DUMMY
+ } scanner_t;
+typedef enum {MC_NONE, MC_TCP, MC_UNIX, MC_STRM} contype_t;
+static struct scan
+{
+ scanner_t scancode;
+ const uschar * name;
+ const uschar * options_default;
+ contype_t conn;
+} m_scans[] =
+{
+#ifndef DISABLE_MAL_FFROTD
+ { M_FPROTD, US"f-protd", US"localhost 10200-10204", MC_TCP },
+#endif
+#ifndef DISABLE_MAL_FFROT6D
+ { M_FPROT6D, US"f-prot6d", US"localhost 10200", MC_TCP },
+#endif
+#ifndef DISABLE_MAL_DRWEB
+ { M_DRWEB, US"drweb", US"/usr/local/drweb/run/drwebd.sock", MC_STRM },
+#endif
+#ifndef DISABLE_MAL_AVE
+ { M_AVES, US"aveserver", US"/var/run/aveserver", MC_UNIX },
+#endif
+#ifndef DISABLE_MAL_FSECURE
+ { M_FSEC, US"fsecure", US"/var/run/.fsav", MC_UNIX },
+#endif
+#ifndef DISABLE_MAL_KAV
+ { M_KAVD, US"kavdaemon", US"/var/run/AvpCtl", MC_UNIX },
+#endif
+#ifndef DISABLE_MAL_SOPHIE
+ { M_SOPHIE, US"sophie", US"/var/run/sophie", MC_UNIX },
+#endif
+#ifndef DISABLE_MAL_CLAM
+ { M_CLAMD, US"clamd", US"/tmp/clamd", MC_NONE },
+#endif
+#ifndef DISABLE_MAL_MKS
+ { M_MKSD, US"mksd", NULL, MC_NONE },
+#endif
+#ifndef DISABLE_MAL_AVAST
+ { M_AVAST, US"avast", US"/var/run/avast/scan.sock", MC_STRM },
+#endif
+#ifndef DISABLE_MAL_SOCK
+ { M_SOCK, US"sock", US"/tmp/malware.sock", MC_STRM },
+#endif
+#ifndef DISABLE_MAL_CMDLINE
+ { M_CMDL, US"cmdline", NULL, MC_NONE },
+#endif
+ { -1, NULL, NULL, MC_NONE } /* end-marker */
+};
+
+/******************************************************************************/
+# ifdef MACRO_PREDEF /* build solely to predefine macros */
+
+# include "macro_predef.h"
+
+void
+features_malware(void)
+{
+const uschar * s;
+uschar * t;
+uschar buf[EXIM_DRIVERNAME_MAX];
+
+spf(buf, sizeof(buf), US"_HAVE_MALWARE_");
+
+for (const struct scan * sc = m_scans; sc->scancode != -1; sc++)
+ {
+ for (s = sc->name, t = buf+14; *s; s++) if (*s != '-')
+ *t++ = toupper(*s);
+ *t = '\0';
+ builtin_macro_create(buf);
+ }
+}
+
+/******************************************************************************/
+# else /*!MACRO_PREDEF, main build*/
+
+
+#define MALWARE_TIMEOUT 120 /* default timeout, seconds */
+
+static const uschar * malware_regex_default = US ".+";
+static const pcre2_code * malware_default_re = NULL;
+
+
+#ifndef DISABLE_MAL_CLAM
+/* The maximum number of clamd servers that are supported in the configuration */
+# define MAX_CLAMD_SERVERS 32
+# define MAX_CLAMD_SERVERS_S "32"
+
+typedef struct clamd_address {
+ uschar * hostspec;
+ unsigned tcp_port;
+ unsigned retry;
+} clamd_address;
+#endif
+
+
+#ifndef DISABLE_MAL_DRWEB
+# define DRWEBD_SCAN_CMD (1) /* scan file, buffer or diskfile */
+# define DRWEBD_RETURN_VIRUSES (1<<0) /* ask daemon return to us viruses names from report */
+# define DRWEBD_IS_MAIL (1<<19) /* say to daemon that format is "archive MAIL" */
+
+# define DERR_READ_ERR (1<<0) /* read error */
+# define DERR_NOMEMORY (1<<2) /* no memory */
+# define DERR_TIMEOUT (1<<9) /* scan timeout has run out */
+# define DERR_BAD_CALL (1<<15) /* wrong command */
+
+static const uschar * drweb_re_str = US "infected\\swith\\s*(.+?)$";
+static const pcre2_code * drweb_re = NULL;
+#endif
+
+#ifndef DISABLE_MAL_FSECURE
+static const uschar * fsec_re_str = US "\\S{0,5}INFECTED\\t[^\\t]*\\t([^\\t]+)\\t\\S*$";
+static const pcre2_code * fsec_re = NULL;
+#endif
+
+#ifndef DISABLE_MAL_KAV
+static const uschar * kav_re_sus_str = US "suspicion:\\s*(.+?)\\s*$";
+static const uschar * kav_re_inf_str = US "infected:\\s*(.+?)\\s*$";
+static const pcre2_code * kav_re_sus = NULL;
+static const pcre2_code * kav_re_inf = NULL;
+#endif
+
+#ifndef DISABLE_MAL_AVAST
+static const uschar * ava_re_clean_str = US "(?!\\\\)\\t\\[\\+\\]";
+static const uschar * ava_re_virus_str = US "(?!\\\\)\\t\\[L\\]\\d+\\.0\\t0\\s(.*)";
+static const uschar * ava_re_error_str = US "(?!\\\\)\\t\\[E\\]\\d+\\.0\\tError\\s\\d+\\s(.*)";
+static const pcre2_code * ava_re_clean = NULL;
+static const pcre2_code * ava_re_virus = NULL;
+static const pcre2_code * ava_re_error = NULL;
+#endif
+
+#ifndef DISABLE_MAL_FFROT6D
+static const uschar * fprot6d_re_error_str = US "^\\d+\\s<(.+?)>$";
+static const uschar * fprot6d_re_virus_str = US "^\\d+\\s<infected:\\s+(.+?)>\\s+.+$";
+static const pcre2_code * fprot6d_re_error = NULL;
+static const pcre2_code * fprot6d_re_virus = NULL;
+#endif
+
+
+
+/******************************************************************************/
+
+#ifndef DISABLE_MAL_KAV
+/* Routine to check whether a system is big- or little-endian.
+ Ripped from http://www.faqs.org/faqs/graphics/fileformats-faq/part4/section-7.html
+ Needed for proper kavdaemon implementation. Sigh. */
+# define BIG_MY_ENDIAN 0
+# define LITTLE_MY_ENDIAN 1
+static int test_byte_order(void);
+static inline int
+test_byte_order()
+{
+ short int word = 0x0001;
+ char *byte = CS &word;
+ return(byte[0] ? LITTLE_MY_ENDIAN : BIG_MY_ENDIAN);
+}
+#endif
+
+BOOL malware_ok = FALSE;
+
+/* Gross hacks for the -bmalware option; perhaps we should just create
+the scan directory normally for that case, but look into rigging up the
+needed header variables if not already set on the command-line? */
+extern int spool_mbox_ok;
+extern uschar spooled_message_id[MESSAGE_ID_LENGTH+1];
+
+
+/* Some (currently avast only) use backslash escaped whitespace,
+this function undoes these escapes */
+
+#ifndef DISABLE_MAL_AVAST
+static inline void
+unescape(uschar *p)
+{
+uschar *p0;
+for (; *p; ++p)
+ if (*p == '\\' && (isspace(p[1]) || p[1] == '\\'))
+ for (p0 = p; *p0; ++p0) *p0 = p0[1];
+}
+#endif
+
+/* --- malware_*_defer --- */
+static inline int
+malware_panic_defer(const uschar * str)
+{
+log_write(0, LOG_MAIN|LOG_PANIC, "malware acl condition: %s", str);
+return DEFER;
+}
+static inline int
+malware_log_defer(const uschar * str)
+{
+log_write(0, LOG_MAIN, "malware acl condition: %s", str);
+return DEFER;
+}
+/* --- m_*_defer --- */
+static inline int
+m_panic_defer(struct scan * scanent, const uschar * hostport,
+ const uschar * str)
+{
+return malware_panic_defer(string_sprintf("%s %s : %s",
+ scanent->name, hostport ? hostport : CUS"", str));
+}
+/* --- m_*_defer_3 */
+static inline int
+m_panic_defer_3(struct scan * scanent, const uschar * hostport,
+ const uschar * str, int fd_to_close)
+{
+DEBUG(D_acl) debug_print_socket(fd_to_close);
+(void) close(fd_to_close);
+return m_panic_defer(scanent, hostport, str);
+}
+
+/*************************************************/
+
+#ifndef DISABLE_MAL_CLAM
+/* Only used by the Clamav code, which is working from a list of servers and
+uses the returned in_addr to get a second connection to the same system.
+*/
+static inline int
+m_tcpsocket(const uschar * hostname, unsigned int port,
+ host_item * host, uschar ** errstr, const blob * fastopen_blob)
+{
+int fd = ip_connectedsocket(SOCK_STREAM, hostname, port, port, 5,
+ host, errstr, fastopen_blob);
+#ifdef EXIM_TFO_FREEBSD
+/* Under some fault conditions, FreeBSD 12.2 seen to send a (non-TFO) SYN
+and, getting no response, wait for a long time. Impose a 5s max. */
+if (fd >= 0)
+ (void) poll_one_fd(fd, POLLOUT, 5 * 1000);
+#endif
+return fd;
+}
+#endif
+
+static int
+m_sock_send(int sock, uschar * buf, int cnt, uschar ** errstr)
+{
+if (send(sock, buf, cnt, 0) < 0)
+ {
+ int err = errno;
+ (void)close(sock);
+ *errstr = string_sprintf("unable to send to socket (%s): %s",
+ buf, strerror(err));
+ return -1;
+ }
+return sock;
+}
+
+static const pcre2_code *
+m_pcre_compile(const uschar * re, uschar ** errstr)
+{
+int err;
+PCRE2_SIZE roffset;
+const pcre2_code * cre;
+
+if (!(cre = pcre2_compile((PCRE2_SPTR)re, PCRE2_ZERO_TERMINATED,
+ PCRE_COPT, &err, &roffset, pcre_cmp_ctx)))
+ {
+ uschar errbuf[128];
+ pcre2_get_error_message(err, errbuf, sizeof(errbuf));
+ *errstr= string_sprintf("regular expression error in '%s': %s at offset %ld",
+ re, errbuf, (long)roffset);
+ }
+return cre;
+}
+
+uschar *
+m_pcre_exec(const pcre2_code * cre, uschar * text)
+{
+pcre2_match_data * md = pcre2_match_data_create(2, pcre_gen_ctx);
+int i = pcre2_match(cre, text, PCRE2_ZERO_TERMINATED, 0, 0, md, pcre_mtc_ctx);
+PCRE2_UCHAR * substr = NULL;
+PCRE2_SIZE slen;
+
+if (i >= 2) /* Got it */
+ pcre2_substring_get_bynumber(md, 1, &substr, &slen);
+return US substr;
+}
+
+static const pcre2_code *
+m_pcre_nextinlist(const uschar ** list, int * sep,
+ char * listerr, uschar ** errstr)
+{
+const uschar * list_ele;
+const pcre2_code * cre = NULL;
+
+if (!(list_ele = string_nextinlist(list, sep, NULL, 0)))
+ *errstr = US listerr;
+else
+ {
+ DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "RE: ",
+ string_printing(list_ele));
+ cre = m_pcre_compile(CUS list_ele, errstr);
+ }
+return cre;
+}
+
+
+/*
+ Simple though inefficient wrapper for reading a line. Drop CRs and the
+ trailing newline. Can return early on buffer full. Null-terminate.
+ Apply initial timeout if no data ready.
+
+ Return: number of chars - zero for an empty line
+ -1 on EOF
+ -2 on timeout or error
+*/
+static int
+recv_line(int fd, uschar * buffer, int bsize, time_t tmo)
+{
+uschar * p = buffer;
+ssize_t rcv;
+BOOL ok = FALSE;
+
+if (!fd_ready(fd, tmo))
+ return -2;
+
+/*XXX tmo handling assumes we always get a whole line */
+/* read until \n */
+errno = 0;
+while ((rcv = read(fd, p, 1)) > 0)
+ {
+ ok = TRUE;
+ if (p-buffer > bsize-2) break;
+ if (*p == '\n') break;
+ if (*p != '\r') p++;
+ }
+if (!ok)
+ {
+ DEBUG(D_acl)
+ {
+ debug_printf_indent("Malware scan: read %s (%s)\n",
+ rcv==0 ? "EOF" : "error", strerror(errno));
+ debug_print_socket(fd);
+ }
+ return rcv==0 ? -1 : -2;
+ }
+*p = '\0';
+
+DEBUG(D_acl) debug_printf_indent("Malware scan: read '%s'\n", buffer);
+return p - buffer;
+}
+
+/* return TRUE iff size as requested */
+#ifndef DISABLE_MAL_DRWEB
+static BOOL
+recv_len(int sock, void * buf, int size, time_t tmo)
+{
+return fd_ready(sock, tmo)
+ ? recv(sock, buf, size, 0) == size
+ : FALSE;
+}
+#endif
+
+
+
+#ifndef DISABLE_MAL_MKS
+/* ============= private routines for the "mksd" scanner type ============== */
+
+# include <sys/uio.h>
+
+static inline int
+mksd_writev (int sock, struct iovec * iov, int iovcnt)
+{
+int i;
+
+for (;;)
+ {
+ do
+ i = writev (sock, iov, iovcnt);
+ while (i < 0 && errno == EINTR);
+ if (i <= 0)
+ {
+ (void) malware_panic_defer(
+ US"unable to write to mksd UNIX socket (/var/run/mksd/socket)");
+ return -1;
+ }
+ for (;;) /* check for short write */
+ if (i >= iov->iov_len)
+ {
+ if (--iovcnt == 0)
+ return 0;
+ i -= iov->iov_len;
+ iov++;
+ }
+ else
+ {
+ iov->iov_len -= i;
+ iov->iov_base = CS iov->iov_base + i;
+ break;
+ }
+ }
+}
+
+static inline int
+mksd_read_lines (int sock, uschar *av_buffer, int av_buffer_size, time_t tmo)
+{
+client_conn_ctx cctx = {.sock = sock};
+int offset = 0;
+int i;
+
+do
+ {
+ i = ip_recv(&cctx, av_buffer+offset, av_buffer_size-offset, tmo);
+ if (i <= 0)
+ {
+ (void) malware_panic_defer(US"unable to read from mksd UNIX socket (/var/run/mksd/socket)");
+ return -1;
+ }
+
+ offset += i;
+ /* offset == av_buffer_size -> buffer full */
+ if (offset == av_buffer_size)
+ {
+ (void) malware_panic_defer(US"malformed reply received from mksd");
+ return -1;
+ }
+ } while (av_buffer[offset-1] != '\n');
+
+av_buffer[offset] = '\0';
+return offset;
+}
+
+static inline int
+mksd_parse_line(struct scan * scanent, char * line)
+{
+char *p;
+
+switch (*line)
+ {
+ case 'O': /* OK */
+ return OK;
+
+ case 'E':
+ case 'A': /* ERR */
+ if ((p = strchr (line, '\n')) != NULL)
+ *p = '\0';
+ return m_panic_defer(scanent, NULL,
+ string_sprintf("scanner failed: %s", line));
+
+ default: /* VIR */
+ if ((p = strchr (line, '\n')) != NULL)
+ {
+ *p = '\0';
+ if ( p-line > 5
+ && line[3] == ' '
+ && (p = strchr(line+4, ' ')) != NULL
+ && p-line > 4
+ )
+ {
+ *p = '\0';
+ malware_name = string_copy(US line+4);
+ return OK;
+ }
+ }
+ return m_panic_defer(scanent, NULL,
+ string_sprintf("malformed reply received: %s", line));
+ }
+}
+
+static int
+mksd_scan_packed(struct scan * scanent, int sock, const uschar * scan_filename,
+ time_t tmo)
+{
+struct iovec iov[3];
+const char *cmd = "MSQ\n";
+uschar av_buffer[1024];
+
+iov[0].iov_base = (void *) cmd;
+iov[0].iov_len = 3;
+iov[1].iov_base = (void *) scan_filename;
+iov[1].iov_len = Ustrlen(scan_filename);
+iov[2].iov_base = (void *) (cmd + 3);
+iov[2].iov_len = 1;
+
+if (mksd_writev (sock, iov, 3) < 0)
+ return DEFER;
+
+if (mksd_read_lines (sock, av_buffer, sizeof (av_buffer), tmo) < 0)
+ return DEFER;
+
+return mksd_parse_line (scanent, CS av_buffer);
+}
+#endif /* MKSD */
+
+
+#ifndef DISABLE_MAL_CLAM
+static int
+clamd_option(clamd_address * cd, const uschar * optstr, int * subsep)
+{
+uschar * s;
+
+cd->retry = 0;
+while ((s = string_nextinlist(&optstr, subsep, NULL, 0)))
+ if (Ustrncmp(s, "retry=", 6) == 0)
+ {
+ int sec = readconf_readtime((s += 6), '\0', FALSE);
+ if (sec < 0)
+ return FAIL;
+ cd->retry = sec;
+ }
+ else
+ return FAIL;
+return OK;
+}
+#endif
+
+
+
+/*************************************************
+* Scan content for malware *
+*************************************************/
+
+/* This is an internal interface for scanning an email; the normal interface
+is via malware(), or there's malware_in_file() used for testing/debugging.
+
+Arguments:
+ malware_re match condition for "malware="
+ scan_filename the file holding the email to be scanned, if we're faking
+ this up for the -bmalware test, else NULL
+ timeout if nonzero, non-default timeoutl
+
+Returns: Exim message processing code (OK, FAIL, DEFER, ...)
+ where true means malware was found (condition applies)
+*/
+static int
+malware_internal(const uschar * malware_re, const uschar * scan_filename,
+ int timeout)
+{
+int sep = 0;
+const uschar *av_scanner_work = av_scanner;
+uschar *scanner_name;
+unsigned long mbox_size;
+FILE *mbox_file;
+const pcre2_code *re;
+uschar * errstr;
+struct scan * scanent;
+const uschar * scanner_options;
+client_conn_ctx malware_daemon_ctx = {.sock = -1};
+time_t tmo;
+uschar * eml_filename, * eml_dir;
+
+if (!malware_re)
+ return FAIL; /* empty means "don't match anything" */
+
+/* Ensure the eml mbox file is spooled up */
+
+if (!(mbox_file = spool_mbox(&mbox_size, scan_filename, &eml_filename)))
+ return malware_panic_defer(US"error while creating mbox spool file");
+
+/* None of our current scanners need the mbox file as a stream (they use
+the name), so we can close it right away. Get the directory too. */
+
+(void) fclose(mbox_file);
+eml_dir = string_copyn(eml_filename, Ustrrchr(eml_filename, '/') - eml_filename);
+
+/* parse 1st option */
+if (strcmpic(malware_re, US"false") == 0 || Ustrcmp(malware_re,"0") == 0)
+ return FAIL; /* explicitly no matching */
+
+/* special cases (match anything except empty) */
+if ( strcmpic(malware_re,US"true") == 0
+ || Ustrcmp(malware_re,"*") == 0
+ || Ustrcmp(malware_re,"1") == 0
+ )
+ {
+ if ( !malware_default_re
+ && !(malware_default_re = m_pcre_compile(malware_regex_default, &errstr)))
+ return malware_panic_defer(errstr);
+ malware_re = malware_regex_default;
+ re = malware_default_re;
+ }
+
+/* compile the regex, see if it works */
+else if (!(re = m_pcre_compile(malware_re, &errstr)))
+ return malware_panic_defer(errstr);
+
+/* if av_scanner starts with a dollar, expand it first */
+if (*av_scanner == '$')
+ {
+ if (!(av_scanner_work = expand_string(av_scanner)))
+ return malware_panic_defer(
+ string_sprintf("av_scanner starts with $, but expansion failed: %s",
+ expand_string_message));
+
+ DEBUG(D_acl)
+ debug_printf_indent("Expanded av_scanner global: %s\n", av_scanner_work);
+ /* disable result caching in this case */
+ malware_name = NULL;
+ malware_ok = FALSE;
+ }
+
+/* Do not scan twice (unless av_scanner is dynamic). */
+if (!malware_ok)
+ {
+ /* find the scanner type from the av_scanner option */
+ if (!(scanner_name = string_nextinlist(&av_scanner_work, &sep, NULL, 0)))
+ return malware_panic_defer(US"av_scanner configuration variable is empty");
+ if (!timeout) timeout = MALWARE_TIMEOUT;
+ tmo = time(NULL) + timeout;
+
+ for (scanent = m_scans; ; scanent++)
+ {
+ if (!scanent->name)
+ return malware_panic_defer(string_sprintf("unknown scanner type '%s'",
+ scanner_name));
+ if (strcmpic(scanner_name, US scanent->name) != 0)
+ continue;
+ DEBUG(D_acl) debug_printf_indent("Malware scan: %s tmo=%s\n",
+ scanner_name, readconf_printtime(timeout));
+
+ if (!(scanner_options = string_nextinlist(&av_scanner_work, &sep, NULL, 0)))
+ scanner_options = scanent->options_default;
+ if (scanent->conn == MC_NONE)
+ break;
+
+ DEBUG(D_acl) debug_printf_indent("%15s%10s%s\n", "", "socket: ", scanner_options);
+ switch(scanent->conn)
+ {
+ case MC_TCP:
+ malware_daemon_ctx.sock = ip_tcpsocket(scanner_options, &errstr, 5, NULL); break;
+ case MC_UNIX:
+ malware_daemon_ctx.sock = ip_unixsocket(scanner_options, &errstr); break;
+ case MC_STRM:
+ malware_daemon_ctx.sock = ip_streamsocket(scanner_options, &errstr, 5, NULL); break;
+ default:
+ /* compiler quietening */ break;
+ }
+ if (malware_daemon_ctx.sock < 0)
+ return m_panic_defer(scanent, CUS callout_address, errstr);
+ break;
+ }
+
+ switch (scanent->scancode)
+ {
+#ifndef DISABLE_MAL_FFROTD
+ case M_FPROTD: /* "f-protd" scanner type -------------------------------- */
+ {
+ uschar *fp_scan_option;
+ unsigned int detected=0, par_count=0;
+ uschar * scanrequest;
+ uschar buf[32768], *strhelper, *strhelper2;
+ uschar * malware_name_internal = NULL;
+ int len;
+
+ scanrequest = string_sprintf("GET %s", eml_filename);
+
+ while ((fp_scan_option = string_nextinlist(&av_scanner_work, &sep,
+ NULL, 0)))
+ {
+ scanrequest = string_sprintf("%s%s%s", scanrequest,
+ par_count ? "%20" : "?", fp_scan_option);
+ par_count++;
+ }
+ scanrequest = string_sprintf("%s HTTP/1.0\r\n\r\n", scanrequest);
+ DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s: %s\n",
+ scanner_name, scanrequest);
+
+ /* send scan request */
+ if (m_sock_send(malware_daemon_ctx.sock, scanrequest, Ustrlen(scanrequest)+1, &errstr) < 0)
+ return m_panic_defer(scanent, CUS callout_address, errstr);
+
+ while ((len = recv_line(malware_daemon_ctx.sock, buf, sizeof(buf), tmo)) >= 0)
+ if (len > 0)
+ {
+ if (Ustrstr(buf, US"<detected type=\"") != NULL)
+ detected = 1;
+ else if (detected && (strhelper = Ustrstr(buf, US"<name>")))
+ {
+ if ((strhelper2 = Ustrstr(buf, US"</name>")) != NULL)
+ {
+ *strhelper2 = '\0';
+ malware_name_internal = string_copy(strhelper+6);
+ }
+ }
+ else if (Ustrstr(buf, US"<summary code=\""))
+ {
+ malware_name = Ustrstr(buf, US"<summary code=\"11\">")
+ ? malware_name_internal : NULL;
+ break;
+ }
+ }
+ if (len < -1)
+ {
+ (void)close(malware_daemon_ctx.sock);
+ return DEFER;
+ }
+ break;
+ } /* f-protd */
+#endif
+
+#ifndef DISABLE_MAL_FFROT6D
+ case M_FPROT6D: /* "f-prot6d" scanner type ----------------------------------- */
+ {
+ int bread;
+ uschar * e;
+ uschar * linebuffer;
+ uschar * scanrequest;
+ uschar av_buffer[1024];
+
+ if ((!fprot6d_re_virus && !(fprot6d_re_virus = m_pcre_compile(fprot6d_re_virus_str, &errstr)))
+ || (!fprot6d_re_error && !(fprot6d_re_error = m_pcre_compile(fprot6d_re_error_str, &errstr))))
+ return malware_panic_defer(errstr);
+
+ scanrequest = string_sprintf("SCAN FILE %s\n", eml_filename);
+ DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s: %s\n",
+ scanner_name, scanrequest);
+
+ if (m_sock_send(malware_daemon_ctx.sock, scanrequest, Ustrlen(scanrequest), &errstr) < 0)
+ return m_panic_defer(scanent, CUS callout_address, errstr);
+
+ bread = ip_recv(&malware_daemon_ctx, av_buffer, sizeof(av_buffer), tmo);
+
+ if (bread <= 0)
+ return m_panic_defer_3(scanent, CUS callout_address,
+ string_sprintf("unable to read from socket (%s)", strerror(errno)),
+ malware_daemon_ctx.sock);
+
+ if (bread == sizeof(av_buffer))
+ return m_panic_defer_3(scanent, CUS callout_address,
+ US"buffer too small", malware_daemon_ctx.sock);
+
+ av_buffer[bread] = '\0';
+ linebuffer = string_copy(av_buffer);
+
+ m_sock_send(malware_daemon_ctx.sock, US"QUIT\n", 5, 0);
+
+ if ((e = m_pcre_exec(fprot6d_re_error, linebuffer)))
+ return m_panic_defer_3(scanent, CUS callout_address,
+ string_sprintf("scanner reported error (%s)", e), malware_daemon_ctx.sock);
+
+ if (!(malware_name = m_pcre_exec(fprot6d_re_virus, linebuffer)))
+ malware_name = NULL;
+
+ break;
+ } /* f-prot6d */
+#endif
+
+#ifndef DISABLE_MAL_DRWEB
+ case M_DRWEB: /* "drweb" scanner type ----------------------------------- */
+ /* v0.1 - added support for tcp sockets */
+ /* v0.0 - initial release -- support for unix sockets */
+ {
+ int result;
+ off_t fsize;
+ unsigned int fsize_uint;
+ uschar * tmpbuf, *drweb_fbuf;
+ int drweb_rc, drweb_cmd, drweb_flags = 0x0000, drweb_fd,
+ drweb_vnum, drweb_slen, drweb_fin = 0x0000;
+
+ /* prepare variables */
+ drweb_cmd = htonl(DRWEBD_SCAN_CMD);
+ drweb_flags = htonl(DRWEBD_RETURN_VIRUSES | DRWEBD_IS_MAIL);
+
+ if (*scanner_options != '/')
+ {
+ /* calc file size */
+ if ((drweb_fd = exim_open2(CCS eml_filename, O_RDONLY)) == -1)
+ return m_panic_defer_3(scanent, NULL,
+ string_sprintf("can't open spool file %s: %s",
+ eml_filename, strerror(errno)),
+ malware_daemon_ctx.sock);
+
+ if ((fsize = lseek(drweb_fd, 0, SEEK_END)) == -1)
+ {
+ int err;
+badseek: err = errno;
+ (void)close(drweb_fd);
+ return m_panic_defer_3(scanent, NULL,
+ string_sprintf("can't seek spool file %s: %s",
+ eml_filename, strerror(err)),
+ malware_daemon_ctx.sock);
+ }
+ fsize_uint = (unsigned int) fsize;
+ if ((off_t)fsize_uint != fsize)
+ {
+ (void)close(drweb_fd);
+ return m_panic_defer_3(scanent, NULL,
+ string_sprintf("seeking spool file %s, size overflow",
+ eml_filename),
+ malware_daemon_ctx.sock);
+ }
+ drweb_slen = htonl(fsize);
+ if (lseek(drweb_fd, 0, SEEK_SET) < 0)
+ goto badseek;
+
+ DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s remote scan [%s]\n",
+ scanner_name, scanner_options);
+
+ /* send scan request */
+ if ((send(malware_daemon_ctx.sock, &drweb_cmd, sizeof(drweb_cmd), 0) < 0) ||
+ (send(malware_daemon_ctx.sock, &drweb_flags, sizeof(drweb_flags), 0) < 0) ||
+ (send(malware_daemon_ctx.sock, &drweb_fin, sizeof(drweb_fin), 0) < 0) ||
+ (send(malware_daemon_ctx.sock, &drweb_slen, sizeof(drweb_slen), 0) < 0))
+ {
+ (void)close(drweb_fd);
+ return m_panic_defer_3(scanent, CUS callout_address, string_sprintf(
+ "unable to send commands to socket (%s)", scanner_options),
+ malware_daemon_ctx.sock);
+ }
+
+ if (!(drweb_fbuf = store_malloc(fsize_uint)))
+ {
+ (void)close(drweb_fd);
+ return m_panic_defer_3(scanent, NULL,
+ string_sprintf("unable to allocate memory %u for file (%s)",
+ fsize_uint, eml_filename),
+ malware_daemon_ctx.sock);
+ }
+
+ if ((result = read (drweb_fd, drweb_fbuf, fsize)) == -1)
+ {
+ int err = errno;
+ (void)close(drweb_fd);
+ store_free(drweb_fbuf);
+ return m_panic_defer_3(scanent, NULL,
+ string_sprintf("can't read spool file %s: %s",
+ eml_filename, strerror(err)),
+ malware_daemon_ctx.sock);
+ }
+ (void)close(drweb_fd);
+
+ /* send file body to socket */
+ if (send(malware_daemon_ctx.sock, drweb_fbuf, fsize, 0) < 0)
+ {
+ store_free(drweb_fbuf);
+ return m_panic_defer_3(scanent, CUS callout_address, string_sprintf(
+ "unable to send file body to socket (%s)", scanner_options),
+ malware_daemon_ctx.sock);
+ }
+ store_free(drweb_fbuf);
+ }
+ else
+ {
+ drweb_slen = htonl(Ustrlen(eml_filename));
+
+ DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s local scan [%s]\n",
+ scanner_name, scanner_options);
+
+ /* send scan request */
+ if ((send(malware_daemon_ctx.sock, &drweb_cmd, sizeof(drweb_cmd), 0) < 0) ||
+ (send(malware_daemon_ctx.sock, &drweb_flags, sizeof(drweb_flags), 0) < 0) ||
+ (send(malware_daemon_ctx.sock, &drweb_slen, sizeof(drweb_slen), 0) < 0) ||
+ (send(malware_daemon_ctx.sock, eml_filename, Ustrlen(eml_filename), 0) < 0) ||
+ (send(malware_daemon_ctx.sock, &drweb_fin, sizeof(drweb_fin), 0) < 0))
+ return m_panic_defer_3(scanent, CUS callout_address, string_sprintf(
+ "unable to send commands to socket (%s)", scanner_options),
+ malware_daemon_ctx.sock);
+ }
+
+ /* wait for result */
+ if (!recv_len(malware_daemon_ctx.sock, &drweb_rc, sizeof(drweb_rc), tmo))
+ return m_panic_defer_3(scanent, CUS callout_address,
+ US"unable to read return code", malware_daemon_ctx.sock);
+ drweb_rc = ntohl(drweb_rc);
+
+ if (!recv_len(malware_daemon_ctx.sock, &drweb_vnum, sizeof(drweb_vnum), tmo))
+ return m_panic_defer_3(scanent, CUS callout_address,
+ US"unable to read the number of viruses", malware_daemon_ctx.sock);
+ drweb_vnum = ntohl(drweb_vnum);
+
+ /* "virus(es) found" if virus number is > 0 */
+ if (drweb_vnum)
+ {
+ gstring * g = NULL;
+
+ /* setup default virus name */
+ malware_name = US"unknown";
+
+ /* set up match regex */
+ if (!drweb_re)
+ drweb_re = m_pcre_compile(drweb_re_str, &errstr);
+
+ /* read and concatenate virus names into one string */
+ for (int i = 0; i < drweb_vnum; i++)
+ {
+ pcre2_match_data * md = pcre2_match_data_create(2, pcre_gen_ctx);
+
+ /* read the size of report */
+ if (!recv_len(malware_daemon_ctx.sock, &drweb_slen, sizeof(drweb_slen), tmo))
+ return m_panic_defer_3(scanent, CUS callout_address,
+ US"cannot read report size", malware_daemon_ctx.sock);
+ drweb_slen = ntohl(drweb_slen);
+
+ /* assume tainted, since it is external input */
+ tmpbuf = store_get(drweb_slen, GET_TAINTED);
+
+ /* read report body */
+ if (!recv_len(malware_daemon_ctx.sock, tmpbuf, drweb_slen, tmo))
+ return m_panic_defer_3(scanent, CUS callout_address,
+ US"cannot read report string", malware_daemon_ctx.sock);
+ tmpbuf[drweb_slen] = '\0';
+
+ /* try matcher on the line, grab substring */
+ result = pcre2_match(drweb_re, (PCRE2_SPTR)tmpbuf, PCRE2_ZERO_TERMINATED,
+ 0, 0, md, pcre_mtc_ctx);
+ if (result >= 2)
+ {
+ PCRE2_SIZE * ovec = pcre2_get_ovector_pointer(md);
+
+ if (i==0) /* the first name we just copy to malware_name */
+ g = string_catn(NULL, US ovec[2], ovec[3] - ovec[2]);
+
+ else /* concatenate each new virus name to previous */
+ {
+ g = string_catn(g, US"/", 1);
+ g = string_catn(g, US ovec[2], ovec[3] - ovec[2]);
+ }
+ }
+ }
+ malware_name = string_from_gstring(g);
+ }
+ else
+ {
+ const char *drweb_s = NULL;
+
+ if (drweb_rc & DERR_READ_ERR) drweb_s = "read error";
+ if (drweb_rc & DERR_NOMEMORY) drweb_s = "no memory";
+ if (drweb_rc & DERR_TIMEOUT) drweb_s = "timeout";
+ if (drweb_rc & DERR_BAD_CALL) drweb_s = "wrong command";
+ /* retcodes DERR_SYMLINK, DERR_NO_REGFILE, DERR_SKIPPED.
+ * DERR_TOO_BIG, DERR_TOO_COMPRESSED, DERR_SPAM,
+ * DERR_CRC_ERROR, DERR_READSOCKET, DERR_WRITE_ERR
+ * and others are ignored */
+ if (drweb_s)
+ return m_panic_defer_3(scanent, CUS callout_address,
+ string_sprintf("drweb daemon retcode 0x%x (%s)", drweb_rc, drweb_s),
+ malware_daemon_ctx.sock);
+
+ /* no virus found */
+ malware_name = NULL;
+ }
+ break;
+ } /* drweb */
+#endif
+
+#ifndef DISABLE_MAL_AVE
+ case M_AVES: /* "aveserver" scanner type -------------------------------- */
+ {
+ uschar buf[32768];
+ int result;
+
+ /* read aveserver's greeting and see if it is ready (2xx greeting) */
+ buf[0] = 0;
+ recv_line(malware_daemon_ctx.sock, buf, sizeof(buf), tmo);
+
+ if (buf[0] != '2') /* aveserver is having problems */
+ return m_panic_defer_3(scanent, CUS callout_address,
+ string_sprintf("unavailable (Responded: %s).",
+ ((buf[0] != 0) ? buf : US "nothing") ),
+ malware_daemon_ctx.sock);
+
+ /* prepare our command */
+ (void)string_format(buf, sizeof(buf), "SCAN bPQRSTUW %s\r\n",
+ eml_filename);
+
+ /* and send it */
+ DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s %s\n",
+ scanner_name, buf);
+ if (m_sock_send(malware_daemon_ctx.sock, buf, Ustrlen(buf), &errstr) < 0)
+ return m_panic_defer(scanent, CUS callout_address, errstr);
+
+ malware_name = NULL;
+ result = 0;
+ /* read response lines, find malware name and final response */
+ while (recv_line(malware_daemon_ctx.sock, buf, sizeof(buf), tmo) > 0)
+ {
+ if (buf[0] == '2')
+ break;
+ if (buf[0] == '5') /* aveserver is having problems */
+ {
+ result = m_panic_defer(scanent, CUS callout_address,
+ string_sprintf("unable to scan file %s (Responded: %s).",
+ eml_filename, buf));
+ break;
+ }
+ if (Ustrncmp(buf,"322",3) == 0)
+ {
+ uschar *p = Ustrchr(&buf[4], ' ');
+ *p = '\0';
+ malware_name = string_copy(&buf[4]);
+ }
+ }
+
+ if (m_sock_send(malware_daemon_ctx.sock, US"quit\r\n", 6, &errstr) < 0)
+ return m_panic_defer(scanent, CUS callout_address, errstr);
+
+ /* read aveserver's greeting and see if it is ready (2xx greeting) */
+ buf[0] = 0;
+ recv_line(malware_daemon_ctx.sock, buf, sizeof(buf), tmo);
+
+ if (buf[0] != '2') /* aveserver is having problems */
+ return m_panic_defer_3(scanent, CUS callout_address,
+ string_sprintf("unable to quit dialogue (Responded: %s).",
+ ((buf[0] != 0) ? buf : US "nothing") ),
+ malware_daemon_ctx.sock);
+
+ if (result == DEFER)
+ {
+ (void)close(malware_daemon_ctx.sock);
+ return DEFER;
+ }
+ break;
+ } /* aveserver */
+#endif
+
+#ifndef DISABLE_MAL_FSECURE
+ case M_FSEC: /* "fsecure" scanner type ---------------------------------- */
+ {
+ int i, bread = 0;
+ uschar * file_name;
+ uschar av_buffer[1024];
+ static uschar *cmdopt[] = { US"CONFIGURE\tARCHIVE\t1\n",
+ US"CONFIGURE\tTIMEOUT\t0\n",
+ US"CONFIGURE\tMAXARCH\t5\n",
+ US"CONFIGURE\tMIME\t1\n" };
+
+ malware_name = NULL;
+
+ DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n",
+ scanner_name, scanner_options);
+ /* pass options */
+ memset(av_buffer, 0, sizeof(av_buffer));
+ for (i = 0; i != nelem(cmdopt); i++)
+ {
+
+ if (m_sock_send(malware_daemon_ctx.sock, cmdopt[i], Ustrlen(cmdopt[i]), &errstr) < 0)
+ return m_panic_defer(scanent, CUS callout_address, errstr);
+
+ bread = ip_recv(&malware_daemon_ctx, av_buffer, sizeof(av_buffer), tmo);
+ if (bread > 0) av_buffer[bread]='\0';
+ if (bread < 0)
+ return m_panic_defer_3(scanent, CUS callout_address,
+ string_sprintf("unable to read answer %d (%s)", i, strerror(errno)),
+ malware_daemon_ctx.sock);
+ for (int j = 0; j < bread; j++)
+ if (av_buffer[j] == '\r' || av_buffer[j] == '\n')
+ av_buffer[j] ='@';
+ }
+
+ /* pass the mailfile to fsecure */
+ file_name = string_sprintf("SCAN\t%s\n", eml_filename);
+
+ if (m_sock_send(malware_daemon_ctx.sock, file_name, Ustrlen(file_name), &errstr) < 0)
+ return m_panic_defer(scanent, CUS callout_address, errstr);
+
+ /* set up match */
+ /* todo also SUSPICION\t */
+ if (!fsec_re)
+ fsec_re = m_pcre_compile(fsec_re_str, &errstr);
+
+ /* read report, linewise. Apply a timeout as the Fsecure daemon
+ sometimes wants an answer to "PING" but they won't tell us what */
+ {
+ uschar * p = av_buffer;
+ uschar * q;
+
+ for (;;)
+ {
+ errno = ETIMEDOUT;
+ i = av_buffer+sizeof(av_buffer)-p;
+ if ((bread= ip_recv(&malware_daemon_ctx, p, i-1, tmo)) < 0)
+ return m_panic_defer_3(scanent, CUS callout_address,
+ string_sprintf("unable to read result (%s)", strerror(errno)),
+ malware_daemon_ctx.sock);
+
+ for (p[bread] = '\0'; (q = Ustrchr(p, '\n')); p = q+1)
+ {
+ *q = '\0';
+
+ /* Really search for virus again? */
+ if (!malware_name)
+ /* try matcher on the line, grab substring */
+ malware_name = m_pcre_exec(fsec_re, p);
+
+ if (Ustrstr(p, "OK\tScan ok."))
+ goto fsec_found;
+ }
+
+ /* copy down the trailing partial line then read another chunk */
+ i = av_buffer+sizeof(av_buffer)-p;
+ memmove(av_buffer, p, i);
+ p = av_buffer+i;
+ }
+ }
+
+ fsec_found:
+ break;
+ } /* fsecure */
+#endif
+
+#ifndef DISABLE_MAL_KAV
+ case M_KAVD: /* "kavdaemon" scanner type -------------------------------- */
+ {
+ time_t t;
+ uschar tmpbuf[1024];
+ uschar * scanrequest;
+ int kav_rc;
+ unsigned long kav_reportlen;
+ int bread;
+ const pcre2_code *kav_re;
+ uschar *p;
+
+ /* get current date and time, build scan request */
+ time(&t);
+ /* pdp note: before the eml_filename parameter, this scanned the
+ directory; not finding documentation, so we'll strip off the directory.
+ The side-effect is that the test framework scanning may end up in
+ scanning more than was requested, but for the normal interface, this is
+ fine. */
+
+ strftime(CS tmpbuf, sizeof(tmpbuf), "%d %b %H:%M:%S", localtime(&t));
+ scanrequest = string_sprintf("<0>%s:%s", CS tmpbuf, eml_filename);
+ p = Ustrrchr(scanrequest, '/');
+ if (p)
+ *p = '\0';
+
+ DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n",
+ scanner_name, scanner_options);
+
+ /* send scan request */
+ if (m_sock_send(malware_daemon_ctx.sock, scanrequest, Ustrlen(scanrequest)+1, &errstr) < 0)
+ return m_panic_defer(scanent, CUS callout_address, errstr);
+
+ /* wait for result */
+ if (!recv_len(malware_daemon_ctx.sock, tmpbuf, 2, tmo))
+ return m_panic_defer_3(scanent, CUS callout_address,
+ US"unable to read 2 bytes from socket.", malware_daemon_ctx.sock);
+
+ /* get errorcode from one nibble */
+ kav_rc = tmpbuf[ test_byte_order()==LITTLE_MY_ENDIAN ? 0 : 1 ] & 0x0F;
+ switch(kav_rc)
+ {
+ case 5: case 6: /* improper kavdaemon configuration */
+ return m_panic_defer_3(scanent, CUS callout_address,
+ US"please reconfigure kavdaemon to NOT disinfect or remove infected files.",
+ malware_daemon_ctx.sock);
+ case 1:
+ return m_panic_defer_3(scanent, CUS callout_address,
+ US"reported 'scanning not completed' (code 1).", malware_daemon_ctx.sock);
+ case 7:
+ return m_panic_defer_3(scanent, CUS callout_address,
+ US"reported 'kavdaemon damaged' (code 7).", malware_daemon_ctx.sock);
+ }
+
+ /* code 8 is not handled, since it is ambiguous. It appears mostly on
+ bounces where part of a file has been cut off */
+
+ /* "virus found" return codes (2-4) */
+ if (kav_rc > 1 && kav_rc < 5)
+ {
+ int report_flag = 0;
+
+ /* setup default virus name */
+ malware_name = US"unknown";
+
+ report_flag = tmpbuf[ test_byte_order() == LITTLE_MY_ENDIAN ? 1 : 0 ];
+
+ /* read the report, if available */
+ if (report_flag == 1)
+ {
+ /* read report size */
+ if (!recv_len(malware_daemon_ctx.sock, &kav_reportlen, 4, tmo))
+ return m_panic_defer_3(scanent, CUS callout_address,
+ US"cannot read report size", malware_daemon_ctx.sock);
+
+ /* it's possible that avp returns av_buffer[1] == 1 but the
+ reportsize is 0 (!?) */
+ if (kav_reportlen > 0)
+ {
+ /* set up match regex, depends on retcode */
+ if (kav_rc == 3)
+ {
+ if (!kav_re_sus) kav_re_sus = m_pcre_compile(kav_re_sus_str, &errstr);
+ kav_re = kav_re_sus;
+ }
+ else
+ {
+ if (!kav_re_inf) kav_re_inf = m_pcre_compile(kav_re_inf_str, &errstr);
+ kav_re = kav_re_inf;
+ }
+
+ /* read report, linewise. Using size from stream to read amount of data
+ from same stream is safe enough. */
+ /* coverity[tainted_data] */
+ while (kav_reportlen > 0)
+ {
+ if ((bread = recv_line(malware_daemon_ctx.sock, tmpbuf, sizeof(tmpbuf), tmo)) < 0)
+ break;
+ kav_reportlen -= bread+1;
+
+ /* try matcher on the line, grab substring */
+ if ((malware_name = m_pcre_exec(kav_re, tmpbuf)))
+ break;
+ }
+ }
+ }
+ }
+ else /* no virus found */
+ malware_name = NULL;
+
+ break;
+ }
+#endif
+
+#ifndef DISABLE_MAL_CMDLINE
+ case M_CMDL: /* "cmdline" scanner type ---------------------------------- */
+ {
+ const uschar *cmdline_scanner = scanner_options;
+ const pcre2_code *cmdline_trigger_re;
+ const pcre2_code *cmdline_regex_re;
+ uschar * file_name;
+ uschar * commandline;
+ void (*eximsigchld)(int);
+ void (*eximsigpipe)(int);
+ FILE *scanner_out = NULL;
+ int scanner_fd;
+ FILE *scanner_record = NULL;
+ uschar linebuffer[32767];
+ int rcnt;
+ int trigger = 0;
+ uschar *p;
+
+ if (!cmdline_scanner)
+ return m_panic_defer(scanent, NULL, errstr);
+
+ /* find scanner output trigger */
+ cmdline_trigger_re = m_pcre_nextinlist(&av_scanner_work, &sep,
+ "missing trigger specification", &errstr);
+ if (!cmdline_trigger_re)
+ return m_panic_defer(scanent, NULL, errstr);
+
+ /* find scanner name regex */
+ cmdline_regex_re = m_pcre_nextinlist(&av_scanner_work, &sep,
+ "missing virus name regex specification", &errstr);
+ if (!cmdline_regex_re)
+ return m_panic_defer(scanent, NULL, errstr);
+
+ /* prepare scanner call; despite the naming, file_name holds a directory
+ name which is documented as the value given to %s. */
+
+ file_name = string_copy(eml_filename);
+ p = Ustrrchr(file_name, '/');
+ if (p)
+ *p = '\0';
+ commandline = string_sprintf(CS cmdline_scanner, file_name);
+
+ /* redirect STDERR too */
+ commandline = string_sprintf("%s 2>&1", commandline);
+
+ DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n",
+ scanner_name, commandline);
+
+ /* store exims signal handlers */
+ eximsigchld = signal(SIGCHLD,SIG_DFL);
+ eximsigpipe = signal(SIGPIPE,SIG_DFL);
+
+ if (!(scanner_out = popen(CS commandline,"r")))
+ {
+ int err = errno;
+ signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
+ return m_panic_defer(scanent, NULL,
+ string_sprintf("call (%s) failed: %s.", commandline, strerror(err)));
+ }
+ scanner_fd = fileno(scanner_out);
+
+ file_name = string_sprintf("%s/%s_scanner_output", eml_dir, message_id);
+
+ if (!(scanner_record = modefopen(file_name, "wb", SPOOL_MODE)))
+ {
+ int err = errno;
+ (void) pclose(scanner_out);
+ signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
+ return m_panic_defer(scanent, NULL, string_sprintf(
+ "opening scanner output file (%s) failed: %s.",
+ file_name, strerror(err)));
+ }
+
+ /* look for trigger while recording output */
+ while ((rcnt = recv_line(scanner_fd, linebuffer,
+ sizeof(linebuffer), tmo)))
+ {
+ if (rcnt < 0)
+ {
+ int err = errno;
+ if (rcnt == -1)
+ break;
+ (void) pclose(scanner_out);
+ signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
+ return m_panic_defer(scanent, NULL, string_sprintf(
+ "unable to read from scanner (%s): %s",
+ commandline, strerror(err)));
+ }
+
+ if (Ustrlen(linebuffer) > fwrite(linebuffer, 1, Ustrlen(linebuffer), scanner_record))
+ {
+ /* short write */
+ (void) pclose(scanner_out);
+ signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
+ return m_panic_defer(scanent, NULL, string_sprintf(
+ "short write on scanner output file (%s).", file_name));
+ }
+ putc('\n', scanner_record);
+ /* try trigger match */
+ if ( !trigger
+ && regex_match_and_setup(cmdline_trigger_re, linebuffer, 0, -1)
+ )
+ trigger = 1;
+ }
+
+ (void)fclose(scanner_record);
+ sep = pclose(scanner_out);
+ signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
+ if (sep != 0)
+ return m_panic_defer(scanent, NULL,
+ sep == -1
+ ? string_sprintf("running scanner failed: %s", strerror(sep))
+ : string_sprintf("scanner returned error code: %d", sep));
+
+ if (trigger)
+ {
+ uschar * s;
+ /* setup default virus name */
+ malware_name = US"unknown";
+
+ /* re-open the scanner output file, look for name match */
+ scanner_record = Ufopen(file_name, "rb");
+ while (Ufgets(linebuffer, sizeof(linebuffer), scanner_record))
+ if ((s = m_pcre_exec(cmdline_regex_re, linebuffer))) /* try match */
+ malware_name = s;
+ (void)fclose(scanner_record);
+ }
+ else /* no virus found */
+ malware_name = NULL;
+ break;
+ } /* cmdline */
+#endif
+
+#ifndef DISABLE_MAL_SOPHIE
+ case M_SOPHIE: /* "sophie" scanner type --------------------------------- */
+ {
+ int bread = 0;
+ uschar *p;
+ uschar * file_name;
+ uschar av_buffer[1024];
+
+ /* pass the scan directory to sophie */
+ file_name = string_copy(eml_filename);
+ if ((p = Ustrrchr(file_name, '/')))
+ *p = '\0';
+
+ DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan [%s]\n",
+ scanner_name, scanner_options);
+
+ if ( write(malware_daemon_ctx.sock, file_name, Ustrlen(file_name)) < 0
+ || write(malware_daemon_ctx.sock, "\n", 1) != 1
+ )
+ return m_panic_defer_3(scanent, CUS callout_address,
+ string_sprintf("unable to write to UNIX socket (%s)", scanner_options),
+ malware_daemon_ctx.sock);
+
+ /* wait for result */
+ memset(av_buffer, 0, sizeof(av_buffer));
+ if ((bread = ip_recv(&malware_daemon_ctx, av_buffer, sizeof(av_buffer), tmo)) <= 0)
+ return m_panic_defer_3(scanent, CUS callout_address,
+ string_sprintf("unable to read from UNIX socket (%s)", scanner_options),
+ malware_daemon_ctx.sock);
+
+ /* infected ? */
+ if (av_buffer[0] == '1') {
+ uschar * s = Ustrchr(av_buffer, '\n');
+ if (s)
+ *s = '\0';
+ malware_name = string_copy(&av_buffer[2]);
+ }
+ else if (!strncmp(CS av_buffer, "-1", 2))
+ return m_panic_defer_3(scanent, CUS callout_address,
+ US"scanner reported error", malware_daemon_ctx.sock);
+ else /* all ok, no virus */
+ malware_name = NULL;
+
+ break;
+ }
+#endif
+
+#ifndef DISABLE_MAL_CLAM
+ case M_CLAMD: /* "clamd" scanner type ----------------------------------- */
+ {
+/* This code was originally contributed by David Saez */
+/* There are three scanning methods available to us:
+* (1) Use the SCAN command, pointing to a file in the filesystem
+* (2) Use the STREAM command, send the data on a separate port
+* (3) Use the zINSTREAM command, send the data inline
+* The zINSTREAM command was introduced with ClamAV 0.95, which marked
+* STREAM deprecated; see: http://wiki.clamav.net/bin/view/Main/UpgradeNotes095
+* In Exim, we use SCAN if using a Unix-domain socket or explicitly told that
+* the TCP-connected daemon is actually local; otherwise we use zINSTREAM
+* See Exim bug 926 for details. */
+
+ uschar *p, *vname, *result_tag;
+ int bread=0;
+ uschar av_buffer[1024];
+ uschar *hostname = US"";
+ host_item connhost;
+ int clam_fd;
+ unsigned int fsize_uint;
+ BOOL use_scan_command = FALSE;
+ clamd_address * cv[MAX_CLAMD_SERVERS];
+ int num_servers = 0;
+ uint32_t send_size, send_final_zeroblock;
+ blob cmd_str;
+
+ /*XXX if unixdomain socket, only one server supported. Needs fixing;
+ there's no reason we should not mix local and remote servers */
+
+ if (*scanner_options == '/')
+ {
+ clamd_address * cd;
+ const uschar * sublist;
+ int subsep = ' ';
+
+ /* Local file; so we def want to use_scan_command and don't want to try
+ passing IP/port combinations */
+ use_scan_command = TRUE;
+ cd = (clamd_address *) store_get(sizeof(clamd_address), GET_UNTAINTED);
+
+ /* extract socket-path part */
+ sublist = scanner_options;
+ cd->hostspec = string_nextinlist(&sublist, &subsep, NULL, 0);
+
+ /* parse options */
+ if (clamd_option(cd, sublist, &subsep) != OK)
+ return m_panic_defer(scanent, NULL,
+ string_sprintf("bad option '%s'", scanner_options));
+ cv[0] = cd;
+ }
+ else
+ {
+ /* Go through the rest of the list of host/port and construct an array
+ * of servers to try. The first one is the bit we just passed from
+ * scanner_options so process that first and then scan the remainder of
+ * the address buffer */
+ do
+ {
+ clamd_address * cd;
+ const uschar * sublist;
+ int subsep = ' ';
+ uschar * s;
+
+ /* The 'local' option means use the SCAN command over the network
+ * socket (ie common file storage in use) */
+ /*XXX we could accept this also as a local option? */
+ if (strcmpic(scanner_options, US"local") == 0)
+ {
+ use_scan_command = TRUE;
+ continue;
+ }
+
+ cd = (clamd_address *) store_get(sizeof(clamd_address), GET_UNTAINTED);
+
+ /* extract host and port part */
+ sublist = scanner_options;
+ if (!(cd->hostspec = string_nextinlist(&sublist, &subsep, NULL, 0)))
+ {
+ (void) m_panic_defer(scanent, NULL,
+ string_sprintf("missing address: '%s'", scanner_options));
+ continue;
+ }
+ if (!(s = string_nextinlist(&sublist, &subsep, NULL, 0)))
+ {
+ (void) m_panic_defer(scanent, NULL,
+ string_sprintf("missing port: '%s'", scanner_options));
+ continue;
+ }
+ cd->tcp_port = atoi(CS s);
+
+ /* parse options */
+ /*XXX should these options be common over scanner types? */
+ if (clamd_option(cd, sublist, &subsep) != OK)
+ return m_panic_defer(scanent, NULL,
+ string_sprintf("bad option '%s'", scanner_options));
+
+ cv[num_servers++] = cd;
+ if (num_servers >= MAX_CLAMD_SERVERS)
+ {
+ (void) m_panic_defer(scanent, NULL,
+ US"More than " MAX_CLAMD_SERVERS_S " clamd servers "
+ "specified; only using the first " MAX_CLAMD_SERVERS_S );
+ break;
+ }
+ } while ((scanner_options = string_nextinlist(&av_scanner_work, &sep,
+ NULL, 0)));
+
+ /* check if we have at least one server */
+ if (!num_servers)
+ return m_panic_defer(scanent, NULL,
+ US"no useable server addresses in malware configuration option.");
+ }
+
+ /* See the discussion of response formats below to see why we really
+ don't like colons in filenames when passing filenames to ClamAV. */
+ if (use_scan_command && Ustrchr(eml_filename, ':'))
+ return m_panic_defer(scanent, NULL,
+ string_sprintf("local/SCAN mode incompatible with" \
+ " : in path to email filename [%s]", eml_filename));
+
+ /* Set up the very first data we will be sending */
+ if (!use_scan_command)
+ { cmd_str.data = US"zINSTREAM"; cmd_str.len = 10; }
+ else
+ {
+ int n;
+ cmd_str.data = string_sprintf("SCAN %s\n%n", eml_filename, &n);
+ cmd_str.len = n; /* .len is a size_t */
+ }
+
+ /* We have some network servers specified */
+ if (num_servers)
+ {
+ /* Confirmed in ClamAV source (0.95.3) that the TCPAddr option of clamd
+ only supports AF_INET, but we should probably be looking to the
+ future and rewriting this to be protocol-independent anyway. */
+
+ while (num_servers > 0)
+ {
+ int i = random_number(num_servers);
+ clamd_address * cd = cv[i];
+
+ DEBUG(D_acl) debug_printf_indent("trying server name %s, port %u\n",
+ cd->hostspec, cd->tcp_port);
+
+ /* Lookup the host. This is to ensure that we connect to the same IP
+ on both connections (as one host could resolve to multiple ips) */
+ for (;;)
+ {
+ /*XXX we trust that the cmd_str is idempotent */
+ if ((malware_daemon_ctx.sock = m_tcpsocket(cd->hostspec, cd->tcp_port,
+ &connhost, &errstr,
+ use_scan_command ? &cmd_str : NULL)) >= 0)
+ {
+ /* Connection successfully established with a server */
+ hostname = cd->hostspec;
+ if (use_scan_command) cmd_str.len = 0;
+ break;
+ }
+ if (cd->retry <= 0) break;
+ while (cd->retry > 0) cd->retry = sleep(cd->retry);
+ }
+ if (malware_daemon_ctx.sock >= 0)
+ break;
+
+ (void) m_panic_defer(scanent, CUS callout_address, errstr);
+
+ /* Remove the server from the list. XXX We should free the memory */
+ num_servers--;
+ for (; i < num_servers; i++)
+ cv[i] = cv[i+1];
+ }
+
+ if (num_servers == 0)
+ return m_panic_defer(scanent, NULL, US"all servers failed");
+ }
+ else
+ for (;;)
+ {
+ if ((malware_daemon_ctx.sock = ip_unixsocket(cv[0]->hostspec, &errstr)) >= 0)
+ {
+ hostname = cv[0]->hostspec;
+ break;
+ }
+ if (cv[0]->retry <= 0)
+ return m_panic_defer(scanent, CUS callout_address, errstr);
+ while (cv[0]->retry > 0) cv[0]->retry = sleep(cv[0]->retry);
+ }
+
+ /* have socket in variable "sock"; command to use is semi-independent of
+ the socket protocol. We use SCAN if is local (either Unix/local
+ domain socket, or explicitly told local) else we stream the data.
+ How we stream the data depends upon how we were built. */
+
+ if (!use_scan_command)
+ {
+ struct stat st;
+#if defined(EXIM_TCP_CORK) && !defined(OS_SENDFILE)
+ BOOL corked = TRUE;
+#endif
+ /* New protocol: "zINSTREAM\n" followed by a sequence of <length><data>
+ chunks, <n> a 4-byte number (network order), terminated by a zero-length
+ chunk. We only send one chunk. */
+
+ DEBUG(D_acl) debug_printf_indent(
+ "Malware scan: issuing %s new-style remote scan (zINSTREAM)\n",
+ scanner_name);
+
+#if defined(EXIM_TCP_CORK)
+ (void) setsockopt(malware_daemon_ctx.sock, IPPROTO_TCP, EXIM_TCP_CORK,
+ US &on, sizeof(on));
+#endif
+ /* Pass the string to ClamAV (10 = "zINSTREAM\0"), if not already sent */
+ if (cmd_str.len)
+ if (send(malware_daemon_ctx.sock, cmd_str.data, cmd_str.len, 0) < 0)
+ return m_panic_defer_3(scanent, CUS hostname,
+ string_sprintf("unable to send zINSTREAM to socket (%s)",
+ strerror(errno)),
+ malware_daemon_ctx.sock);
+
+ if ((clam_fd = exim_open2(CS eml_filename, O_RDONLY)) < 0)
+ {
+ int err = errno;
+ return m_panic_defer_3(scanent, NULL,
+ string_sprintf("can't open spool file %s: %s",
+ eml_filename, strerror(err)),
+ malware_daemon_ctx.sock);
+ }
+ if (fstat(clam_fd, &st) < 0)
+ {
+ int err = errno;
+ (void)close(clam_fd);
+ return m_panic_defer_3(scanent, NULL,
+ string_sprintf("can't stat spool file %s: %s",
+ eml_filename, strerror(err)),
+ malware_daemon_ctx.sock);
+ }
+ fsize_uint = (unsigned int) st.st_size;
+ if ((off_t)fsize_uint != st.st_size)
+ {
+ (void)close(clam_fd);
+ return m_panic_defer_3(scanent, NULL,
+ string_sprintf("stat spool file %s, size overflow", eml_filename),
+ malware_daemon_ctx.sock);
+ }
+
+ /* send file size */
+ send_size = htonl(fsize_uint);
+ if (send(malware_daemon_ctx.sock, &send_size, sizeof(send_size), 0) < 0)
+ return m_panic_defer_3(scanent, NULL,
+ string_sprintf("unable to send file size to socket (%s)", hostname),
+ malware_daemon_ctx.sock);
+
+ /* send file body */
+ while (fsize_uint)
+ {
+#ifdef OS_SENDFILE
+ int n = os_sendfile(malware_daemon_ctx.sock, clam_fd, NULL, (size_t)fsize_uint);
+ if (n < 0)
+ return m_panic_defer_3(scanent, NULL,
+ string_sprintf("unable to send file body to socket (%s): %s", hostname, strerror(errno)),
+ malware_daemon_ctx.sock);
+ fsize_uint -= n;
+#else
+ int n = MIN(fsize_uint, big_buffer_size);
+ if ((n = read(clam_fd, big_buffer, n)) < 0)
+ return m_panic_defer_3(scanent, NULL,
+ string_sprintf("can't read spool file %s: %s",
+ eml_filename, strerror(errno)),
+ malware_daemon_ctx.sock);
+ if (send(malware_daemon_ctx.sock, big_buffer, (size_t)n, 0) < 0)
+ return m_panic_defer_3(scanent, NULL,
+ string_sprintf("unable to send file body to socket (%s): %s", hostname, strerror(errno)),
+ malware_daemon_ctx.sock);
+ fsize_uint -= n;
+# ifdef EXIM_TCP_CORK
+ if (corked)
+ {
+ corked = FALSE;
+ (void) setsockopt(malware_daemon_ctx.sock, IPPROTO_TCP, EXIM_TCP_CORK,
+ US &off, sizeof(off));
+ }
+# endif
+#endif /*!OS_SENDFILE*/
+
+ }
+
+ send_final_zeroblock = 0;
+ if (send(malware_daemon_ctx.sock, &send_final_zeroblock, sizeof(send_final_zeroblock), 0) < 0)
+ return m_panic_defer_3(scanent, NULL,
+ string_sprintf("unable to send file terminator to socket (%s)", hostname),
+ malware_daemon_ctx.sock);
+#ifdef OS_SENDFILE
+ (void) setsockopt(malware_daemon_ctx.sock, IPPROTO_TCP, EXIM_TCP_CORK,
+ US &off, sizeof(off));
+#endif
+ }
+ else
+ { /* use scan command */
+ /* Send a SCAN command pointing to a filename; then in the then in the
+ scan-method-neutral part, read the response back */
+
+/* ================================================================= */
+
+ /* Prior to the reworking post-Exim-4.72, this scanned a directory,
+ which dates to when ClamAV needed us to break apart the email into the
+ MIME parts (eg, with the now deprecated demime condition coming first).
+ Some time back, ClamAV gained the ability to deconstruct the emails, so
+ doing this would actually have resulted in the mail attachments being
+ scanned twice, in the broken out files and from the original .eml.
+ Since ClamAV now handles emails (and has for quite some time) we can
+ just use the email file itself. */
+ /* Pass the string to ClamAV (7 = "SCAN \n" + \0), if not already sent */
+
+ DEBUG(D_acl) debug_printf_indent(
+ "Malware scan: issuing %s local-path scan [%s]\n",
+ scanner_name, scanner_options);
+
+ if (cmd_str.len)
+ if (send(malware_daemon_ctx.sock, cmd_str.data, cmd_str.len, 0) < 0)
+ return m_panic_defer_3(scanent, CUS callout_address,
+ string_sprintf("unable to write to socket (%s)", strerror(errno)),
+ malware_daemon_ctx.sock);
+
+ /* Do not shut down the socket for writing; a user report noted that
+ clamd 0.70 does not react well to this. */
+ }
+ /* Commands have been sent, no matter which scan method or connection
+ type we're using; now just read the result, independent of method. */
+
+ /* Read the result */
+ memset(av_buffer, 0, sizeof(av_buffer));
+ bread = ip_recv(&malware_daemon_ctx, av_buffer, sizeof(av_buffer), tmo);
+ (void)close(malware_daemon_ctx.sock);
+ malware_daemon_ctx.sock = -1;
+ malware_daemon_ctx.tls_ctx = NULL;
+
+ if (bread <= 0)
+ return m_panic_defer(scanent, CUS callout_address,
+ string_sprintf("unable to read from socket (%s)",
+ errno == 0 ? "EOF" : strerror(errno)));
+
+ if (bread == sizeof(av_buffer))
+ return m_panic_defer(scanent, CUS callout_address,
+ US"buffer too small");
+ /* We're now assured of a NULL at the end of av_buffer */
+
+ /* Check the result. ClamAV returns one of two result formats.
+ In the basic mode, the response is of the form:
+ infected: -> "<filename>: <virusname> FOUND"
+ not-infected: -> "<filename>: OK"
+ error: -> "<filename>: <errcode> ERROR
+ If the ExtendedDetectionInfo option has been turned on, then we get:
+ "<filename>: <virusname>(<virushash>:<virussize>) FOUND"
+ for the infected case. Compare:
+/tmp/eicar.com: Eicar-Test-Signature FOUND
+/tmp/eicar.com: Eicar-Test-Signature(44d88612fea8a8f36de82e1278abb02f:68) FOUND
+
+ In the streaming case, clamd uses the filename "stream" which you should
+ be able to verify with { ktrace clamdscan --stream /tmp/eicar.com }. (The
+ client app will replace "stream" with the original filename before returning
+ results to stdout, but the trace shows the data).
+
+ We will assume that the pathname passed to clamd from Exim does not contain
+ a colon. We will have whined loudly above if the eml_filename does (and we're
+ passing a filename to clamd). */
+
+ if (!(*av_buffer))
+ return m_panic_defer(scanent, CUS callout_address,
+ US"ClamAV returned null");
+
+ /* strip newline at the end (won't be present for zINSTREAM)
+ (also any trailing whitespace, which shouldn't exist, but we depend upon
+ this below, so double-check) */
+
+ p = av_buffer + Ustrlen(av_buffer) - 1;
+ if (*p == '\n') *p = '\0';
+
+ DEBUG(D_acl) debug_printf_indent("Malware response: %s\n", av_buffer);
+
+ while (isspace(*--p) && (p > av_buffer))
+ *p = '\0';
+ if (*p) ++p;
+
+ /* colon in returned output? */
+ if (!(p = Ustrchr(av_buffer,':')))
+ return m_panic_defer(scanent, CUS callout_address, string_sprintf(
+ "ClamAV returned malformed result (missing colon): %s",
+ av_buffer));
+
+ /* strip filename */
+ while (*p && isspace(*++p)) /**/;
+ vname = p;
+
+ /* It would be bad to encounter a virus with "FOUND" in part of the name,
+ but we should at least be resistant to it. */
+ p = Ustrrchr(vname, ' ');
+ result_tag = p ? p+1 : vname;
+
+ if (Ustrcmp(result_tag, "FOUND") == 0)
+ {
+ /* p should still be the whitespace before the result_tag */
+ while (isspace(*p)) --p;
+ *++p = '\0';
+ /* Strip off the extended information too, which will be in parens
+ after the virus name, with no intervening whitespace. */
+ if (*--p == ')')
+ {
+ /* "(hash:size)", so previous '(' will do; if not found, we have
+ a curious virus name, but not an error. */
+ p = Ustrrchr(vname, '(');
+ if (p)
+ *p = '\0';
+ }
+ malware_name = string_copy(vname);
+ DEBUG(D_acl) debug_printf_indent("Malware found, name \"%s\"\n", malware_name);
+
+ }
+ else if (Ustrcmp(result_tag, "ERROR") == 0)
+ return m_panic_defer(scanent, CUS callout_address,
+ string_sprintf("ClamAV returned: %s", av_buffer));
+
+ else if (Ustrcmp(result_tag, "OK") == 0)
+ {
+ /* Everything should be OK */
+ malware_name = NULL;
+ DEBUG(D_acl) debug_printf_indent("Malware not found\n");
+
+ }
+ else
+ return m_panic_defer(scanent, CUS callout_address,
+ string_sprintf("unparseable response from ClamAV: {%s}", av_buffer));
+
+ break;
+ } /* clamd */
+#endif
+
+#ifndef DISABLE_MAL_SOCK
+ case M_SOCK: /* "sock" scanner type ------------------------------------- */
+ /* This code was derived by Martin Poole from the clamd code contributed
+ by David Saez and the cmdline code
+ */
+ {
+ int bread;
+ uschar * commandline;
+ uschar av_buffer[1024];
+ uschar * linebuffer;
+ uschar * sockline_scanner;
+ uschar sockline_scanner_default[] = "%s\n";
+ const pcre2_code *sockline_trig_re;
+ const pcre2_code *sockline_name_re;
+
+ /* find scanner command line */
+ if ( (sockline_scanner = string_nextinlist(&av_scanner_work, &sep,
+ NULL, 0))
+ && *sockline_scanner
+ )
+ { /* check for no expansions apart from one %s */
+ uschar * s = Ustrchr(sockline_scanner, '%');
+ if (s++)
+ if ((*s != 's' && *s != '%') || Ustrchr(s+1, '%'))
+ return m_panic_defer_3(scanent, NULL,
+ US"unsafe sock scanner call spec", malware_daemon_ctx.sock);
+ }
+ else
+ sockline_scanner = sockline_scanner_default;
+ DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "cmdline: ",
+ string_printing(sockline_scanner));
+
+ /* find scanner output trigger */
+ sockline_trig_re = m_pcre_nextinlist(&av_scanner_work, &sep,
+ "missing trigger specification", &errstr);
+ if (!sockline_trig_re)
+ return m_panic_defer_3(scanent, NULL, errstr, malware_daemon_ctx.sock);
+
+ /* find virus name regex */
+ sockline_name_re = m_pcre_nextinlist(&av_scanner_work, &sep,
+ "missing virus name regex specification", &errstr);
+ if (!sockline_name_re)
+ return m_panic_defer_3(scanent, NULL, errstr, malware_daemon_ctx.sock);
+
+ /* prepare scanner call - security depends on expansions check above */
+ commandline = string_sprintf( CS sockline_scanner, CS eml_filename);
+ DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "expanded: ",
+ string_printing(commandline));
+
+ /* Pass the command string to the socket */
+ if (m_sock_send(malware_daemon_ctx.sock, commandline, Ustrlen(commandline), &errstr) < 0)
+ return m_panic_defer(scanent, CUS callout_address, errstr);
+
+ /* Read the result */
+ bread = ip_recv(&malware_daemon_ctx, av_buffer, sizeof(av_buffer), tmo);
+
+ if (bread <= 0)
+ return m_panic_defer_3(scanent, CUS callout_address,
+ string_sprintf("unable to read from socket (%s)", strerror(errno)),
+ malware_daemon_ctx.sock);
+
+ if (bread == sizeof(av_buffer))
+ return m_panic_defer_3(scanent, CUS callout_address,
+ US"buffer too small", malware_daemon_ctx.sock);
+ av_buffer[bread] = '\0';
+ linebuffer = string_copy(av_buffer);
+ DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "answer: ",
+ string_printing(linebuffer));
+
+ /* try trigger match */
+ if (regex_match_and_setup(sockline_trig_re, linebuffer, 0, -1))
+ {
+ if (!(malware_name = m_pcre_exec(sockline_name_re, av_buffer)))
+ malware_name = US "unknown";
+ DEBUG(D_acl) debug_printf_indent("%15s%10s'%s'\n", "", "name: ",
+ string_printing(malware_name));
+ }
+ else /* no virus found */
+ malware_name = NULL;
+ break;
+ }
+#endif
+
+#ifndef DISABLE_MAL_MKS
+ case M_MKSD: /* "mksd" scanner type ------------------------------------- */
+ {
+ char *mksd_options_end;
+ int mksd_maxproc = 1; /* default, if no option supplied */
+ int retval;
+
+ if (scanner_options)
+ {
+ mksd_maxproc = (int)strtol(CS scanner_options, &mksd_options_end, 10);
+ if ( *scanner_options == '\0'
+ || *mksd_options_end != '\0'
+ || mksd_maxproc < 1
+ || mksd_maxproc > 32
+ )
+ return m_panic_defer(scanent, CUS callout_address,
+ string_sprintf("invalid option '%s'", scanner_options));
+ }
+
+ if((malware_daemon_ctx.sock = ip_unixsocket(US "/var/run/mksd/socket", &errstr)) < 0)
+ return m_panic_defer(scanent, CUS callout_address, errstr);
+
+ malware_name = NULL;
+
+ DEBUG(D_acl) debug_printf_indent("Malware scan: issuing %s scan\n", scanner_name);
+
+ if ((retval = mksd_scan_packed(scanent, malware_daemon_ctx.sock, eml_filename, tmo)) != OK)
+ {
+ close (malware_daemon_ctx.sock);
+ return retval;
+ }
+ break;
+ }
+#endif
+
+#ifndef DISABLE_MAL_AVAST
+ case M_AVAST: /* "avast" scanner type ----------------------------------- */
+ {
+ uschar buf[1024];
+ uschar * scanrequest;
+ enum {AVA_HELO, AVA_OPT, AVA_RSP, AVA_DONE} avast_stage;
+ int nread;
+ uschar * error_message = NULL;
+ BOOL more_data = FALSE;
+ BOOL strict = TRUE;
+
+ /* According to Martin Tuma @avast the protocol uses "escaped
+ whitespace", that is, every embedded whitespace is backslash
+ escaped, as well as backslash is protected by backslash.
+ The returned lines contain the name of the scanned file, a tab
+ and the [ ] marker.
+ [+] - not infected
+ [L] - infected
+ [E] - some error occurred
+ Such marker follows the first non-escaped TAB. For more information
+ see avast-protocol(5)
+
+ We observed two cases:
+ -> SCAN /file
+ <- /file [E]0.0 Error 13 Permission denied
+ <- 451 SCAN Engine error 13 permission denied
+
+ -> SCAN /file
+ <- /file… [E]3.0 Error 41120 The file is a decompression bomb
+ <- /file… [+]2.0
+ <- /file… [+]2.0 0 Eicar Test Virus!!!
+ <- 200 SCAN OK
+
+ If the scanner returns 4xx, DEFER is a good decision, combined
+ with a panic log entry, to get the admin's attention.
+
+ If the scanner returns 200, we reject it as malware, if found any,
+ or, in case of an error, we set the malware message to the error
+ string.
+
+ Some of the >= 42000 errors are message related - usually some
+ broken archives etc, but some of them are e.g. license related.
+ Once the license expires the engine starts returning errors for
+ every scanning attempt. I¹ have the full list of the error codes
+ but it is not a public API and is subject to change. It is hard
+ for me to say what you should do in case of an engine error. You
+ can have a “Treat * unscanned file as infection” policy or “Treat
+ unscanned file as clean” policy. ¹) Jakub Bednar
+
+ */
+
+ if ( ( !ava_re_clean
+ && !(ava_re_clean = m_pcre_compile(ava_re_clean_str, &errstr)))
+ || ( !ava_re_virus
+ && !(ava_re_virus = m_pcre_compile(ava_re_virus_str, &errstr)))
+ || ( !ava_re_error
+ && !(ava_re_error = m_pcre_compile(ava_re_error_str, &errstr)))
+ )
+ return malware_panic_defer(errstr);
+
+ /* wait for result */
+ for (avast_stage = AVA_HELO;
+ (nread = recv_line(malware_daemon_ctx.sock, buf, sizeof(buf), tmo)) > 0;
+ )
+ {
+ int slen = Ustrlen(buf);
+ if (slen >= 1)
+ {
+
+ /* Multi line responses are bracketed between 210 … and nnn … */
+ if (Ustrncmp(buf, "210", 3) == 0)
+ {
+ more_data = 1;
+ continue;
+ }
+ else if (more_data && isdigit(buf[0])) more_data = 0;
+
+ switch (avast_stage)
+ {
+ case AVA_HELO:
+ if (more_data) continue;
+ if (Ustrncmp(buf, "220", 3) != 0)
+ goto endloop; /* require a 220 */
+ goto sendreq;
+
+ case AVA_OPT:
+ if (more_data) continue;
+ if (Ustrncmp(buf, "200", 3) != 0)
+ goto endloop; /* require a 200 */
+
+ sendreq:
+ {
+ int len;
+ /* Check for another option to send. Newline-terminate it. */
+ if ((scanrequest = string_nextinlist(&av_scanner_work, &sep,
+ NULL, 0)))
+ {
+ if (Ustrcmp(scanrequest, "pass_unscanned") == 0)
+ {
+ DEBUG(D_acl) debug_printf_indent("pass unscanned files as clean\n");
+ strict = FALSE;
+ goto sendreq;
+ }
+ scanrequest = string_sprintf("%s\n", scanrequest);
+ avast_stage = AVA_OPT; /* just sent option */
+ DEBUG(D_acl) debug_printf_indent("send to avast OPTION: %s", scanrequest);
+ }
+ else
+ {
+ scanrequest = string_sprintf("SCAN %s\n", eml_dir);
+ avast_stage = AVA_RSP; /* just sent command */
+ DEBUG(D_acl) debug_printf_indent("send to avast REQUEST: SCAN %s\n", eml_dir);
+ }
+
+ /* send config-cmd or scan-request to socket */
+ len = Ustrlen(scanrequest);
+ if (send(malware_daemon_ctx.sock, scanrequest, len, 0) == -1)
+ {
+ scanrequest[len-1] = '\0';
+ return m_panic_defer_3(scanent, CUS callout_address, string_sprintf(
+ "unable to send request '%s' to socket (%s): %s",
+ scanrequest, scanner_options, strerror(errno)), malware_daemon_ctx.sock);
+ }
+ break;
+ }
+
+ case AVA_RSP:
+
+ if (isdigit(buf[0])) /* We're done */
+ goto endloop;
+
+ if (malware_name) /* Nothing else matters, just read on */
+ break;
+
+ if (regex_match(ava_re_clean, buf, slen, NULL))
+ break;
+
+ if ((malware_name = m_pcre_exec(ava_re_virus, buf)))
+ {
+ unescape(malware_name);
+ DEBUG(D_acl)
+ debug_printf_indent("unescaped malware name: '%s'\n", malware_name);
+ break;
+ }
+
+ if (strict) /* treat scanner errors as malware */
+ {
+ if ((malware_name = m_pcre_exec(ava_re_error, buf)))
+ {
+ unescape(malware_name);
+ DEBUG(D_acl)
+ debug_printf_indent("unescaped error message: '%s'\n", malware_name);
+ break;
+ }
+ }
+ else if (regex_match(ava_re_error, buf, slen, NULL))
+ {
+ log_write(0, LOG_MAIN, "internal scanner error (ignored): %s", buf);
+ break;
+ }
+
+ /* here also for any unexpected response from the scanner */
+ DEBUG(D_acl) debug_printf("avast response not handled: '%s'\n", buf);
+
+ goto endloop;
+
+ default: log_write(0, LOG_PANIC, "%s:%d:%s: should not happen",
+ __FILE__, __LINE__, __FUNCTION__);
+ }
+ }
+ }
+
+ endloop:
+
+ if (nread == -1) error_message = US"EOF from scanner";
+ else if (nread < 0) error_message = US"timeout from scanner";
+ else if (nread == 0) error_message = US"got nothing from scanner";
+ else if (buf[0] != '2') error_message = buf;
+
+ DEBUG(D_acl) debug_printf_indent("sent to avast QUIT\n");
+ if (send(malware_daemon_ctx.sock, "QUIT\n", 5, 0) == -1)
+ return m_panic_defer_3(scanent, CUS callout_address,
+ string_sprintf("unable to send quit request to socket (%s): %s",
+ scanner_options, strerror(errno)), malware_daemon_ctx.sock);
+
+ if (error_message)
+ return m_panic_defer_3(scanent, CUS callout_address, error_message, malware_daemon_ctx.sock);
+
+ }
+#endif
+ } /* scanner type switch */
+
+ if (malware_daemon_ctx.sock >= 0)
+ (void) close (malware_daemon_ctx.sock);
+ malware_ok = TRUE; /* set "been here, done that" marker */
+ }
+
+/* match virus name against pattern (caseless ------->----------v) */
+if (malware_name && regex_match_and_setup(re, malware_name, 0, -1))
+ {
+ DEBUG(D_acl) debug_printf_indent(
+ "Matched regex to malware [%s] [%s]\n", malware_re, malware_name);
+ return OK;
+ }
+else
+ return FAIL;
+}
+
+
+/*************************************************
+* Scan an email for malware *
+*************************************************/
+
+/* This is the normal interface for scanning an email, which doesn't need a
+filename; it's a wrapper around the malware_file function.
+
+Arguments:
+ malware_re match condition for "malware="
+ timeout if nonzero, timeout in seconds
+
+Returns: Exim message processing code (OK, FAIL, DEFER, ...)
+ where true means malware was found (condition applies)
+*/
+int
+malware(const uschar * malware_re, int timeout)
+{
+int ret = malware_internal(malware_re, NULL, timeout);
+
+if (ret == DEFER) av_failed = TRUE;
+return ret;
+}
+
+
+/*************************************************
+* Scan a file for malware *
+*************************************************/
+
+/* This is a test wrapper for scanning an email, which is not used in
+normal processing. Scan any file, using the Exim scanning interface.
+This function tampers with various global variables so is unsafe to use
+in any other context.
+
+Arguments:
+ eml_filename a file holding the message to be scanned
+
+Returns: Exim message processing code (OK, FAIL, DEFER, ...)
+ where true means malware was found (condition applies)
+*/
+int
+malware_in_file(uschar *eml_filename)
+{
+uschar message_id_buf[64];
+int ret;
+
+/* spool_mbox() assumes various parameters exist, when creating
+the relevant directory and the email within */
+
+(void) string_format(message_id_buf, sizeof(message_id_buf),
+ "dummy-%d", vaguely_random_number(INT_MAX));
+message_id = message_id_buf;
+sender_address = US"malware-sender@example.net";
+return_path = US"";
+recipients_list = NULL;
+receive_add_recipient(US"malware-victim@example.net", -1);
+f.enable_dollar_recipients = TRUE;
+
+ret = malware_internal(US"*", eml_filename, 0);
+
+Ustrncpy(spooled_message_id, message_id, sizeof(spooled_message_id));
+spool_mbox_ok = 1;
+
+/* don't set no_mbox_unspool; at present, there's no way for it to become
+set, but if that changes, then it should apply to these tests too */
+
+unspool_mbox();
+
+/* silence static analysis tools */
+message_id = NULL;
+
+return ret;
+}
+
+
+void
+malware_init(void)
+{
+if (!malware_default_re)
+ malware_default_re = regex_must_compile(malware_regex_default, FALSE, TRUE);
+
+#ifndef DISABLE_MAL_DRWEB
+if (!drweb_re)
+ drweb_re = regex_must_compile(drweb_re_str, FALSE, TRUE);
+#endif
+#ifndef DISABLE_MAL_FSECURE
+if (!fsec_re)
+ fsec_re = regex_must_compile(fsec_re_str, FALSE, TRUE);
+#endif
+#ifndef DISABLE_MAL_KAV
+if (!kav_re_sus)
+ kav_re_sus = regex_must_compile(kav_re_sus_str, FALSE, TRUE);
+if (!kav_re_inf)
+ kav_re_inf = regex_must_compile(kav_re_inf_str, FALSE, TRUE);
+#endif
+#ifndef DISABLE_MAL_AVAST
+if (!ava_re_clean)
+ ava_re_clean = regex_must_compile(ava_re_clean_str, FALSE, TRUE);
+if (!ava_re_virus)
+ ava_re_virus = regex_must_compile(ava_re_virus_str, FALSE, TRUE);
+if (!ava_re_error)
+ ava_re_error = regex_must_compile(ava_re_error_str, FALSE, TRUE);
+#endif
+#ifndef DISABLE_MAL_FFROT6D
+if (!fprot6d_re_error)
+ fprot6d_re_error = regex_must_compile(fprot6d_re_error_str, FALSE, TRUE);
+if (!fprot6d_re_virus)
+ fprot6d_re_virus = regex_must_compile(fprot6d_re_virus_str, FALSE, TRUE);
+#endif
+}
+
+
+gstring *
+malware_show_supported(gstring * g)
+{
+g = string_cat(g, US"Malware:");
+for (struct scan * sc = m_scans; sc->scancode != (scanner_t)-1; sc++)
+ g = string_fmt_append(g, " %s", sc->name);
+return string_cat(g, US"\n");
+}
+
+
+# endif /*!MACRO_PREDEF*/
+#endif /*WITH_CONTENT_SCAN*/
+/*
+ * vi: aw ai sw=2
+ */
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