mdw@git.distorted.org.uk Git - tripe/blob - server/servutil.c

   1 /* -*-c-*-
   2  *
   3  * Various handy server-only utilities
   4  *
   5  * (c) 2001 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Trivial IP Encryption (TrIPE).
  11  *
  12  * TrIPE is free software: you can redistribute it and/or modify it under
  13  * the terms of the GNU General Public License as published by the Free
  14  * Software Foundation; either version 3 of the License, or (at your
  15  * option) any later version.
  16  *
  17  * TrIPE is distributed in the hope that it will be useful, but WITHOUT
  18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  * for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with TrIPE.  If not, see <https://www.gnu.org/licenses/>.
  24  */
  25
  26 /*----- Header files ------------------------------------------------------*/
  27
  28 #include "tripe.h"
  29
  30 /*----- Global variables --------------------------------------------------*/
  31
  32 octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ], buf_u[PKBUFSZ];
  33
  34 /*----- Sequence numbers --------------------------------------------------*/
  35
  36 /* --- @seq_reset@ --- *
  37  *
  38  * Arguments:   @seqwin *s@ = sequence-checking window
  39  *
  40  * Returns:     ---
  41  *
  42  * Use:         Resets a sequence number window.
  43  */
  44
  45 void seq_reset(seqwin *s) { s->seq = 0; s->win = 0; }
  46
  47 /* --- @seq_check@ --- *
  48  *
  49  * Arguments:   @seqwin *s@ = sequence-checking window
  50  *              @uint32 q@ = sequence number to check
  51  *              @const char *service@ = service to report message from
  52  *
  53  * Returns:     Zero on success, nonzero if the sequence number was bad.
  54  *
  55  * Use:         Checks a sequence number against the window, updating things
  56  *              as necessary.
  57  */
  58
  59 int seq_check(seqwin *s, uint32 q, const char *service)
  60 {
  61   uint32 qbit;
  62   uint32 n;
  63
  64   if (q < s->seq) {
  65     a_warn(service, "replay", "old-sequence", A_END);
  66     return (-1);
  67   }
  68   if (q >= s->seq + SEQ_WINSZ) {
  69     n = q - (s->seq + SEQ_WINSZ - 1);
  70     if (n < SEQ_WINSZ)
  71       s->win >>= n;
  72     else
  73       s->win = 0;
  74     s->seq += n;
  75   }
  76   qbit = 1 << (q - s->seq);
  77   if (s->win & qbit) {
  78     a_warn(service, "replay", "duplicated-sequence", A_END);
  79     return (-1);
  80   }
  81   s->win |= qbit;
  82   return (0);
  83 }
  84
  85 /*----- Random odds and sods ----------------------------------------------*/
  86
  87 /* --- @timestr@ --- *
  88  *
  89  * Arguments:   @time_t t@ = a time to convert
  90  *
  91  * Returns:     A pointer to a textual representation of the time.
  92  *
  93  * Use:         Converts a time to a textual representation.  Corrupts
  94  *              @buf_u@.
  95  */
  96
  97 const char *timestr(time_t t)
  98 {
  99   struct tm *tm;
 100   if (!t)
 101     return ("NEVER");
 102   tm = localtime(&t);
 103   strftime((char *)buf_u, sizeof(buf_u), "%Y-%m-%dT%H:%M:%S", tm);
 104   return ((const char *)buf_u);
 105 }
 106
 107 /* --- @mystrieq@ --- *
 108  *
 109  * Arguments:   @const char *x, *y@ = two strings
 110  *
 111  * Returns:     True if @x@ and @y are equal, up to case.
 112  */
 113
 114 int mystrieq(const char *x, const char *y)
 115 {
 116   for (;;) {
 117     if (!*x && !*y) return (1);
 118     if (tolower((unsigned char)*x) != tolower((unsigned char)*y))
 119       return (0);
 120     x++; y++;
 121   }
 122 }
 123
 124 /* --- @addrsz@ --- *
 125  *
 126  * Arguments:   @const addr *a@ = a network address
 127  *
 128  * Returns:     The size of the address, for passing into the sockets API.
 129  */
 130
 131 socklen_t addrsz(const addr *a)
 132 {
 133   switch (a->sa.sa_family) {
 134     case AF_INET: return (sizeof(a->sin));
 135     default: abort();
 136   }
 137 }
 138
 139 /*----- That's all, folks -------------------------------------------------*/