sendmail-dtelnet.patch

   1 diff -Nur sendmail-8.11.2.orig/sendmail/conf.c sendmail-8.11.2/sendmail/conf.c
   2 --- sendmail-8.11.2.orig/sendmail/conf.c        Fri Dec 29 00:51:54 2000
   3 +++ sendmail-8.11.2/sendmail/conf.c     Thu Jan  4 21:17:50 2001
   4 @@ -317,6 +317,8 @@
   5         ColonOkInAddr = TRUE;
   6         DontLockReadFiles = TRUE;
   7         DoubleBounceAddr = "postmaster";
   8 +       DetectTelnet = FALSE;
   9 +       ExitOnTelnet = TRUE;
  10         MaxHeadersLength = MAXHDRSLEN;
  11         MaxForwardEntries = 0;
  12  #if SASL
  13 diff -Nur sendmail-8.11.2.orig/sendmail/err.c sendmail-8.11.2/sendmail/err.c
  14 --- sendmail-8.11.2.orig/sendmail/err.c Fri May 26 02:08:29 2000
  15 +++ sendmail-8.11.2/sendmail/err.c      Thu Jan  4 21:19:05 2001
  16 @@ -786,15 +786,17 @@
  17                 (void) snprintf(eb, spaceleft, "%s... ",
  18                         shortenstring(to, MAXSHORTSTR));
  19                 spaceleft -= strlen(eb);
  20 -               while (*eb != '\0')
  21 -                       *eb++ &= 0177;
  22 +               if(!DetectTelnet)
  23 +                       while (*eb != '\0')
  24 +                               *eb++ &= 0177;
  25         }
  26
  27         /* output the message */
  28         (void) vsnprintf(eb, spaceleft, fmt, ap);
  29         spaceleft -= strlen(eb);
  30 -       while (*eb != '\0')
  31 -               *eb++ &= 0177;
  32 +       if(!DetectTelnet)
  33 +               while (*eb != '\0')
  34 +                       *eb++ &= 0177;
  35
  36         /* output the error code, if any */
  37         if (eno != 0)
  38 diff -Nur sendmail-8.11.2.orig/sendmail/readcf.c sendmail-8.11.2/sendmail/readcf.c
  39 --- sendmail-8.11.2.orig/sendmail/readcf.c      Tue Dec 19 04:18:30 2000
  40 +++ sendmail-8.11.2/sendmail/readcf.c   Thu Jan  4 21:22:52 2001
  41 @@ -1739,6 +1739,10 @@
  42  # endif /* _FFR_TLS_1 */
  43  # define O_RANDFILE    0xc1
  44         { "RandFile",                   O_RANDFILE,     OI_NONE },
  45 +#define O_DETECTTELNET 0xc2
  46 +       { "DetectTelnet",               O_DETECTTELNET, OI_NONE },
  47 +#define O_EXITONTELNET 0xc3
  48 +       { "ExitOnTelnet",               O_EXITONTELNET, OI_NONE },
  49         { NULL,                         '\0',           OI_NONE }
  50  };
  51
  52 @@ -2990,6 +2994,14 @@
  53                 QueueFileMode = atooct(val) & 0777;
  54                 break;
  55  #endif /* _FFR_QUEUE_FILE_MODE */
  56 +
  57 +         case O_DETECTTELNET:          /* detect telnet */
  58 +               DetectTelnet = atobool(val);
  59 +               break;
  60 +
  61 +         case O_EXITONTELNET:          /* exit if telnet detected */
  62 +               ExitOnTelnet = atobool(val);
  63 +               break;
  64
  65           default:
  66                 if (tTd(37, 1))
  67 diff -Nur sendmail-8.11.2.orig/sendmail/sendmail.h sendmail-8.11.2/sendmail/sendmail.h
  68 --- sendmail-8.11.2.orig/sendmail/sendmail.h    Fri Dec 29 00:52:07 2000
  69 +++ sendmail-8.11.2/sendmail/sendmail.h Thu Jan  4 21:24:09 2001
  70 @@ -1695,6 +1695,8 @@
  71  EXTERN bool    UseErrorsTo;    /* use Errors-To: header (back compat) */
  72  EXTERN bool    UseHesiod;      /* using Hesiod -- interpret Hesiod errors */
  73  EXTERN bool    UseNameServer;  /* using DNS -- interpret h_errno & MX RRs */
  74 +EXTERN bool    DetectTelnet;   /* force telnet detection on/off */
  75 +EXTERN bool    ExitOnTelnet;   /* exit if telnet detected */
  76  EXTERN char    InetMode;               /* default network for daemon mode */
  77  EXTERN char    OpMode;         /* operation mode, see below */
  78  EXTERN char    SpaceSub;       /* substitution for <lwsp> */
  79 diff -Nur sendmail-8.11.2.orig/sendmail/srvrsmtp.c sendmail-8.11.2/sendmail/srvrsmtp.c
  80 --- sendmail-8.11.2.orig/sendmail/srvrsmtp.c    Tue Dec 19 04:18:30 2000
  81 +++ sendmail-8.11.2/sendmail/srvrsmtp.c Thu Jan  4 21:30:38 2001
  82 @@ -13,6 +13,7 @@
  83
  84
  85  #include <sendmail.h>
  86 +#include <arpa/telnet.h>
  87
  88  #ifndef lint
  89  # if SMTP
  90 @@ -214,6 +215,9 @@
  91         char *args[MAXSMTPARGS];
  92         char inp[MAXLINE];
  93         char cmdbuf[MAXLINE];
  94 +       char telnet_request[] = {IAC, DO, TELOPT_SGA, 0};
  95 +       char telnet_response[] = {IAC, WILL, TELOPT_SGA, 0};
  96 +       char *telnet_tmp;
  97  # if SASL
  98         sasl_conn_t *conn;
  99         volatile bool sasl_ok;
 100 @@ -437,12 +441,8 @@
 101         id = strchr(inp, ' ');
 102         if (id == NULL)
 103                 id = &inp[strlen(inp)];
 104 -       if (p == NULL)
 105 -               snprintf(cmdbuf, sizeof cmdbuf,
 106 -                        "%s %%.*s ESMTP%%s", greetcode);
 107 -       else
 108 -               snprintf(cmdbuf, sizeof cmdbuf,
 109 -                        "%s-%%.*s ESMTP%%s", greetcode);
 110 +       snprintf(cmdbuf, sizeof cmdbuf, "%s%c%%.*s ESMTP%%s%s", greetcode,
 111 +               (p == NULL) ? ' ' : '-', DetectTelnet ? telnet_request : "");
 112         message(cmdbuf, (int) (id - inp), inp, id);
 113
 114         /* output remaining lines */
 115 @@ -528,6 +528,20 @@
 116                                 e->e_sendqueue = NULL;
 117                         goto doquit;
 118                 }
 119 +
 120 +               if (DetectTelnet && strlen(inp) >= 3)
 121 +                       for (telnet_tmp = inp; *(telnet_tmp+2); telnet_tmp++)
 122 +                               if (!strncmp(telnet_tmp, telnet_response, 3))
 123 +                               {
 124 +                                       sm_syslog(LOG_NOTICE, e->e_id,
 125 +                                         "telnet detected from %.100s (%.100s)",
 126 +                                         CurSmtpClient, anynet_ntoa(&RealHostAddr));
 127 +                                       if (ExitOnTelnet)
 128 +                                       {
 129 +                                               message("571 Unauthorized usage prohibited");
 130 +                                               goto doquit;
 131 +                                       }
 132 +                               }
 133
 134                 /* clean up end of line */
 135                 fixcrlf(inp, TRUE);