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

   1 /*
   2  */
   3
   4 #include <string.h>
   5 #include <errno.h>
   6 #include <unistd.h>
   7 #include <stdlib.h>
   8 #include <assert.h>
   9
  10 #include "forwarder.h"
  11
  12 const char *const *argv;
  13 char programid[SYS_NMLN+sizeof(PROGRAM)+3];
  14
  15 void arg_assert_fail(const char *msg) {
  16   fprintf(stderr, PROGRAM ": argument error (!`%s')\n",msg);
  17   exit(12);
  18 }
  19
  20 void sysfail(const char *msg) {
  21   fprintf(stderr, "%s: fatal system error: %s: %s\n", programid, msg, strerror(errno));
  22   exit(8);
  23 }
  24
  25 void fail(const char *msg) {
  26   fprintf(stderr, "%s: fatal error: %s\n", programid, msg);
  27   exit(4);
  28 }
  29
  30 void sysdiag(const char *msg) {
  31   fprintf(stderr, "%s: system/network error: %s: %s\n", programid, msg, strerror(errno));
  32 }
  33
  34 void diag(const char *msg) {
  35   fprintf(stderr, "%s: %s\n", programid, msg);
  36 }
  37
  38 time_t now(void) {
  39   time_t r;
  40   if (time(&r) == (time_t)-1) sysfail("get time of day");
  41   return r;
  42 }
  43
  44 void *xmalloc(size_t sz) {
  45   void *r;
  46   r= malloc(sz);
  47   if (!r) sysfail("allocate memory");
  48   return r;
  49 }
  50
  51 void write_must(int fd, const void *p_in, int sz, const char *what) {
  52   const unsigned char *p= p_in;
  53   int r;
  54
  55   while (sz) {
  56     r= write(fd,p,sz);
  57     if (r<0) {
  58       if (errno == EINTR) continue;
  59       else sysfail(what);
  60     }
  61     assert(r && r <= sz);
  62     p += r;
  63     sz -= r;
  64   }
  65 }
  66
  67 void read_must(int fd, void *p_in, int sz, const char *what) {
  68   unsigned char *p= p_in;
  69   int r;
  70
  71   while (sz) {
  72     r= read(fd,p,sz);
  73     if (r<0) {
  74       if (errno == EINTR) continue;
  75       else sysfail(what);
  76     }
  77     if (r==0) fail(what);
  78     assert(r <= sz);
  79     p += r;
  80     sz -= r;
  81   }
  82 }
  83
  84 void get_random(void *ptr, size_t sz) {
  85   static FILE *randfile;
  86
  87   size_t r;
  88
  89   if (!randfile) {
  90     randfile= fopen("/dev/urandom","rb");
  91     if (!randfile && errno==ENOENT) randfile= fopen("/dev/random","rb");
  92     if (!randfile) sysfail("open random number generator");
  93   }
  94
  95   r= fread(ptr,1,sz,randfile);
  96   if (r == sz) return;
  97   (ferror(randfile) ? sysfail : fail)("cannot read random number generator");
  98 }
  99
 100 const char *getarg_string(void) {
 101   const char *arg;
 102
 103   arg= *++argv;
 104   arg_assert(arg);
 105   return arg;
 106 }
 107
 108 unsigned long getarg_ulong(void) {
 109   char *ep;
 110   unsigned long ul;
 111
 112   ul= strtoul(getarg_string(),&ep,0);
 113   arg_assert(!*ep);
 114   return ul;
 115 }
 116
 117 void *buf_append(struct buffer *buf, size_t amount) {
 118   void *p;
 119
 120   p= buf->start + buf->size;
 121   buf->size += amount;
 122   return p;
 123 }
 124
 125 void *buf_prepend(struct buffer *buf, size_t amount) {
 126   buf->size += amount;
 127   return buf->start -= amount;
 128 }
 129
 130 void *buf_unappend(struct buffer *buf, size_t amount) {
 131   if (buf->size < amount) return 0;
 132   return buf->start + (buf->size -= amount);
 133 }
 134
 135 void *buf_unprepend(struct buffer *buf, size_t amount) {
 136   void *p;
 137
 138   p= buf->start;
 139   buf->start += amount;
 140   buf->size -= amount;
 141   return p;
 142 }