mdw@git.distorted.org.uk Git - userv-utils/blob - ipif/utils.c

   1 /*
   2  * General utility functions for udp tunnel
   3  */
   4 /*
   5  * Copyright 1996-2013 Ian Jackson <ijackson@chiark.greenend.org.uk>
   6  * Copyright 1998 David Damerell <damerell@chiark.greenend.org.uk>
   7  * Copyright 1999,2003
   8  *    Chancellor Masters and Scholars of the University of Cambridge
   9  * Copyright 2010 Tony Finch <fanf@dotat.at>
  10  *
  11  * This is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 3 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with userv-utils; if not, see http://www.gnu.org/licenses/.
  23  */
  24
  25 #include <string.h>
  26 #include <errno.h>
  27 #include <unistd.h>
  28 #include <stdlib.h>
  29 #include <assert.h>
  30
  31 #include "forwarder.h"
  32
  33 const char *const *argv;
  34 char programid[SYS_NMLN+sizeof(PROGRAM)+3];
  35
  36 void arg_assert_fail(const char *msg) {
  37   fprintf(stderr, PROGRAM ": argument error (!`%s')\n",msg);
  38   exit(12);
  39 }
  40
  41 void sysfail(const char *msg) {
  42   fprintf(stderr, "%s: fatal system error: %s: %s\n", programid, msg, strerror(errno));
  43   exit(8);
  44 }
  45
  46 void fail(const char *msg) {
  47   fprintf(stderr, "%s: fatal error: %s\n", programid, msg);
  48   exit(4);
  49 }
  50
  51 void sysdiag(const char *msg) {
  52   fprintf(stderr, "%s: system/network error: %s: %s\n", programid, msg, strerror(errno));
  53 }
  54
  55 void diag(const char *msg) {
  56   fprintf(stderr, "%s: %s\n", programid, msg);
  57 }
  58
  59 time_t now(void) {
  60   time_t r;
  61   if (time(&r) == (time_t)-1) sysfail("get time of day");
  62   return r;
  63 }
  64
  65 void *xmalloc(size_t sz) {
  66   void *r;
  67   r= malloc(sz);
  68   if (!r) sysfail("allocate memory");
  69   return r;
  70 }
  71
  72 void write_must(int fd, const void *p_in, int sz, const char *what) {
  73   const unsigned char *p= p_in;
  74   int r;
  75
  76   while (sz) {
  77     r= write(fd,p,sz);
  78     if (r<0) {
  79       if (errno == EINTR) continue;
  80       else sysfail(what);
  81     }
  82     assert(r && r <= sz);
  83     p += r;
  84     sz -= r;
  85   }
  86 }
  87
  88 void read_must(int fd, void *p_in, int sz, const char *what) {
  89   unsigned char *p= p_in;
  90   int r;
  91
  92   while (sz) {
  93     r= read(fd,p,sz);
  94     if (r<0) {
  95       if (errno == EINTR) continue;
  96       else sysfail(what);
  97     }
  98     if (r==0) fail(what);
  99     assert(r <= sz);
 100     p += r;
 101     sz -= r;
 102   }
 103 }
 104
 105 const char *getarg_string(void) {
 106   const char *arg;
 107
 108   arg= *++argv;
 109   arg_assert(arg);
 110   return arg;
 111 }
 112
 113 unsigned long getarg_ulong(void) {
 114   char *ep;
 115   unsigned long ul;
 116
 117   ul= strtoul(getarg_string(),&ep,0);
 118   arg_assert(!*ep);
 119   return ul;
 120 }
 121
 122 void *buf_append(struct buffer *buf, size_t amount) {
 123   void *p;
 124
 125   p= buf->start + buf->size;
 126   buf->size += amount;
 127   return p;
 128 }
 129
 130 void *buf_prepend(struct buffer *buf, size_t amount) {
 131   buf->size += amount;
 132   return buf->start -= amount;
 133 }
 134
 135 void *buf_unappend(struct buffer *buf, size_t amount) {
 136   if (buf->size < amount) return 0;
 137   return buf->start + (buf->size -= amount);
 138 }
 139
 140 void *buf_unprepend(struct buffer *buf, size_t amount) {
 141   void *p;
 142
 143   p= buf->start;
 144   buf->start += amount;
 145   buf->size -= amount;
 146   return p;
 147 }