external/ibm-public/postfix/dist/src/global/dsn_util.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      dsn_util 3
   6 /* SUMMARY
   7 /*      DSN status parsing routines
   8 /* SYNOPSIS
   9 /*      #include <dsn_util.h>
  10 /*
  11 /*      #define DSN_SIZE ...
  12 /*
  13 /*      typedef struct { ... } DSN_BUF;
  14 /*
  15 /*      typedef struct {
  16 /* .in +4
  17 /*              DSN_STAT dsn;           /* RFC 3463 status */
  18 /*              const char *text;       /* Free text */
  19 /* .in -4
  20 /*      } DSN_SPLIT;
  21 /*
  22 /*      DSN_SPLIT *dsn_split(dp, def_dsn, text)
  23 /*      DSN_SPLIT *dp;
  24 /*      const char *def_dsn;
  25 /*      const char *text;
  26 /*
  27 /*      char    *dsn_prepend(def_dsn, text)
  28 /*      const char *def_dsn;
  29 /*      const char *text;
  30 /*
  31 /*      size_t  dsn_valid(text)
  32 /*      const char *text;
  33 /*
  34 /*      void    DSN_UPDATE(dsn_buf, dsn, len)
  35 /*      DSN_BUF dsn_buf;
  36 /*      const char *dsn;
  37 /*      size_t  len;
  38 /*
  39 /*      const char *DSN_CODE(dsn_buf)
  40 /*      DSN_BUF dsn_buf;
  41 /*
  42 /*      char    *DSN_CLASS(dsn_buf)
  43 /*      DSN_BUF dsn_buf;
  44 /* DESCRIPTION
  45 /*      The functions in this module manipulate pairs of RFC 3463
  46 /*      status codes and descriptive free text.
  47 /*
  48 /*      dsn_split() splits text into an RFC 3463 status code and
  49 /*      descriptive free text.  When the text does not start with
  50 /*      a status code, the specified default status code is used
  51 /*      instead.  Whitespace before the optional status code or
  52 /*      text is skipped.  dsn_split() returns a copy of the RFC
  53 /*      3463 status code, and returns a pointer to (not copy of)
  54 /*      the remainder of the text.  The result value is the first
  55 /*      argument.
  56 /*
  57 /*      dsn_prepend() prepends the specified default RFC 3463 status
  58 /*      code to the specified text if no status code is present in
  59 /*      the text. This function produces the same result as calling
  60 /*      concatenate() with the results from dsn_split().  The result
  61 /*      should be passed to myfree(). Whitespace before the optional
  62 /*      status code or text is skipped.
  63 /*
  64 /*      dsn_valid() returns the length of the RFC 3463 status code
  65 /*      at the beginning of text, or zero. It does not skip initial
  66 /*      whitespace.
  67 /*
  68 /*      Arguments:
  69 /* .IP def_dsn
  70 /*      Null-terminated default RFC 3463 status code that will be
  71 /*      used when the free text does not start with one.
  72 /* .IP dp
  73 /*      Pointer to storage for copy of DSN status code, and for
  74 /*      pointer to free text.
  75 /* .IP dsn
  76 /*      Null-terminated RFC 3463 status code.
  77 /* .IP text
  78 /*      Null-terminated free text.
  79 /* SEE ALSO
  80 /*      msg(3) diagnostics interface
  81 /* DIAGNOSTICS
  82 /*      Panic: invalid default DSN code.
  83 /* LICENSE
  84 /* .ad
  85 /* .fi
  86 /*      The Secure Mailer license must be distributed with this software.
  87 /* AUTHOR(S)
  88 /*      Wietse Venema
  89 /*      IBM T.J. Watson Research
  90 /*      P.O. Box 704
  91 /*      Yorktown Heights, NY 10598, USA
  92 /*--*/
  93
  94 /* System library. */
  95
  96 #include <sys_defs.h>
  97 #include <stdarg.h>
  98 #include <string.h>
  99 #include <ctype.h>
 100
 101 /* Utility library. */
 102
 103 #include <msg.h>
 104 #include <mymalloc.h>
 105 #include <vstring.h>
 106 #include <stringops.h>
 107
 108 /* Global library. */
 109
 110 #include <dsn_util.h>
 111
 112 /* dsn_valid - check RFC 3463 enhanced status code, return length or zero */
 113
 114 size_t  dsn_valid(const char *text)
 115 {
 116     const unsigned char *cp = (unsigned char *) text;
 117     size_t  len;
 118
 119     /* First portion is one digit followed by dot. */
 120     if ((cp[0] != '2' && cp[0] != '4' && cp[0] != '5') || cp[1] != '.')
 121         return (0);
 122
 123     /* Second portion is 1-3 digits followed by dot. */
 124     cp += 2;
 125     if ((len = strspn((char *) cp, "0123456789")) < 1 || len > DSN_DIGS2
 126         || cp[len] != '.')
 127         return (0);
 128
 129     /* Last portion is 1-3 digits followed by end-of-string or whitespace. */
 130     cp += len + 1;
 131     if ((len = strspn((char *) cp, "0123456789")) < 1 || len > DSN_DIGS3
 132         || (cp[len] != 0 && !ISSPACE(cp[len])))
 133         return (0);
 134
 135     return (((char *) cp - text) + len);
 136 }
 137
 138 /* dsn_split - split text into DSN and text */
 139
 140 DSN_SPLIT *dsn_split(DSN_SPLIT *dp, const char *def_dsn, const char *text)
 141 {
 142     const char *myname = "dsn_split";
 143     const char *cp = text;
 144     size_t  len;
 145
 146     /*
 147      * Look for an optional RFC 3463 enhanced status code.
 148      *
 149      * XXX If we want to enforce that the first digit of the status code in the
 150      * text matches the default status code, then pipe_command() needs to be
 151      * changed. It currently auto-detects the reply code without knowing in
 152      * advance if the result will start with '4' or '5'.
 153      */
 154     while (ISSPACE(*cp))
 155         cp++;
 156     if ((len = dsn_valid(cp)) > 0) {
 157         strncpy(dp->dsn.data, cp, len);
 158         dp->dsn.data[len] = 0;
 159         cp += len + 1;
 160     } else if ((len = dsn_valid(def_dsn)) > 0) {
 161         strncpy(dp->dsn.data, def_dsn, len);
 162         dp->dsn.data[len] = 0;
 163     } else {
 164         msg_panic("%s: bad default status \"%s\"", myname, def_dsn);
 165     }
 166
 167     /*
 168      * The remainder is free text.
 169      */
 170     while (ISSPACE(*cp))
 171         cp++;
 172     dp->text = cp;
 173
 174     return (dp);
 175 }
 176
 177 /* dsn_prepend - prepend optional status to text, result on heap */
 178
 179 char   *dsn_prepend(const char *def_dsn, const char *text)
 180 {
 181     DSN_SPLIT dp;
 182
 183     dsn_split(&dp, def_dsn, text);
 184     return (concatenate(DSN_STATUS(dp.dsn), " ", dp.text, (char *) 0));
 185 }