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

   1 /*
   2  * General utility functions for udp tunnel
   3  */
   4 /*
   5  * Copyright (C) 2000,2003 Ian Jackson
   6  *
   7  * This is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with userv-utils; if not, write to the Free Software
  19  * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20  */
  21
  22 #include <string.h>
  23 #include <errno.h>
  24 #include <unistd.h>
  25 #include <stdlib.h>
  26 #include <assert.h>
  27
  28 #include "forwarder.h"
  29
  30 const char *const *argv;
  31 char programid[SYS_NMLN+sizeof(PROGRAM)+3];
  32
  33 void arg_assert_fail(const char *msg) {
  34   fprintf(stderr, PROGRAM ": argument error (!`%s')\n",msg);
  35   exit(12);
  36 }
  37
  38 void sysfail(const char *msg) {
  39   fprintf(stderr, "%s: fatal system error: %s: %s\n", programid, msg, strerror(errno));
  40   exit(8);
  41 }
  42
  43 void fail(const char *msg) {
  44   fprintf(stderr, "%s: fatal error: %s\n", programid, msg);
  45   exit(4);
  46 }
  47
  48 void sysdiag(const char *msg) {
  49   fprintf(stderr, "%s: system/network error: %s: %s\n", programid, msg, strerror(errno));
  50 }
  51
  52 void diag(const char *msg) {
  53   fprintf(stderr, "%s: %s\n", programid, msg);
  54 }
  55
  56 time_t now(void) {
  57   time_t r;
  58   if (time(&r) == (time_t)-1) sysfail("get time of day");
  59   return r;
  60 }
  61
  62 void *xmalloc(size_t sz) {
  63   void *r;
  64   r= malloc(sz);
  65   if (!r) sysfail("allocate memory");
  66   return r;
  67 }
  68
  69 void write_must(int fd, const void *p_in, int sz, const char *what) {
  70   const unsigned char *p= p_in;
  71   int r;
  72
  73   while (sz) {
  74     r= write(fd,p,sz);
  75     if (r<0) {
  76       if (errno == EINTR) continue;
  77       else sysfail(what);
  78     }
  79     assert(r && r <= sz);
  80     p += r;
  81     sz -= r;
  82   }
  83 }
  84
  85 void read_must(int fd, void *p_in, int sz, const char *what) {
  86   unsigned char *p= p_in;
  87   int r;
  88
  89   while (sz) {
  90     r= read(fd,p,sz);
  91     if (r<0) {
  92       if (errno == EINTR) continue;
  93       else sysfail(what);
  94     }
  95     if (r==0) fail(what);
  96     assert(r <= sz);
  97     p += r;
  98     sz -= r;
  99   }
 100 }
 101
 102 const char *getarg_string(void) {
 103   const char *arg;
 104
 105   arg= *++argv;
 106   arg_assert(arg);
 107   return arg;
 108 }
 109
 110 unsigned long getarg_ulong(void) {
 111   char *ep;
 112   unsigned long ul;
 113
 114   ul= strtoul(getarg_string(),&ep,0);
 115   arg_assert(!*ep);
 116   return ul;
 117 }
 118
 119 void *buf_append(struct buffer *buf, size_t amount) {
 120   void *p;
 121
 122   p= buf->start + buf->size;
 123   buf->size += amount;
 124   return p;
 125 }
 126
 127 void *buf_prepend(struct buffer *buf, size_t amount) {
 128   buf->size += amount;
 129   return buf->start -= amount;
 130 }
 131
 132 void *buf_unappend(struct buffer *buf, size_t amount) {
 133   if (buf->size < amount) return 0;
 134   return buf->start + (buf->size -= amount);
 135 }
 136
 137 void *buf_unprepend(struct buffer *buf, size_t amount) {
 138   void *p;
 139
 140   p= buf->start;
 141   buf->start += amount;
 142   buf->size -= amount;
 143   return p;
 144 }