lib/network.h

   1 /*
   2  * Network library header.
   3  * Copyright (C) 1998 Kunihiro Ishiguro
   4  *
   5  * This file is part of GNU Zebra.
   6  *
   7  * GNU Zebra is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2, or (at your option) any
  10  * later version.
  11  *
  12  * GNU Zebra 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 along
  18  * with this program; see the file COPYING; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #ifndef _ZEBRA_NETWORK_H
  23 #define _ZEBRA_NETWORK_H
  24
  25 #ifdef HAVE_SYS_ENDIAN_H
  26 #include <sys/endian.h>
  27 #endif
  28 #ifdef HAVE_ENDIAN_H
  29 #include <endian.h>
  30 #endif
  31
  32 #ifdef __cplusplus
  33 extern "C" {
  34 #endif
  35
  36 /* Both readn and writen are deprecated and will be removed.  They are not
  37    suitable for use with non-blocking file descriptors.
  38  */
  39 extern int readn(int, uint8_t *, int);
  40 extern int writen(int, const uint8_t *, int);
  41
  42 /* Set the file descriptor to use non-blocking I/O.  Returns 0 for success,
  43    -1 on error. */
  44 extern int set_nonblocking(int fd);
  45
  46 extern int set_cloexec(int fd);
  47
  48 /* Does the I/O error indicate that the operation should be retried later? */
  49 #define ERRNO_IO_RETRY(EN)                                                     \
  50         (((EN) == EAGAIN) || ((EN) == EWOULDBLOCK) || ((EN) == EINTR))
  51
  52 extern float htonf(float);
  53 extern float ntohf(float);
  54
  55 /* force type for be64toh/htobe64 to be uint64_t, *without* a direct cast
  56  *
  57  * this is a workaround for false-positive printfrr warnings from FRR's
  58  * frr-format GCC plugin that would be triggered from
  59  * { printfrr("%"PRIu64, (uint64_t)be64toh(...)); }
  60  *
  61  * the key element here is that "(uint64_t)expr" causes the warning, while
  62  * "({ uint64_t x = expr; x; })" does not.  (The cast is the trigger, a
  63  * variable of the same type works correctly.)
  64  */
  65
  66 /* zap system definitions... */
  67 #ifdef be64toh
  68 #undef be64toh
  69 #endif
  70 #ifdef htobe64
  71 #undef htobe64
  72 #endif
  73
  74 #if BYTE_ORDER == LITTLE_ENDIAN
  75 #define be64toh(x)      ({ uint64_t r = __builtin_bswap64(x); r; })
  76 #define htobe64(x)      ({ uint64_t r = __builtin_bswap64(x); r; })
  77 #elif BYTE_ORDER == BIG_ENDIAN
  78 #define be64toh(x)      ({ uint64_t r = (x); r; })
  79 #define htobe64(x)      ({ uint64_t r = (x); r; })
  80 #else
  81 #error nobody expects the endianish inquisition. check OS endian.h headers.
  82 #endif
  83
  84 /**
  85  * Helper function that returns a random long value. The main purpose of
  86  * this function is to hide a `random()` call that gets flagged by coverity
  87  * scan and put it into one place.
  88  *
  89  * The main usage of this function should be for generating jitter or weak
  90  * random values for simple purposes.
  91  *
  92  * See 'man 3 random' for more information.
  93  *
  94  * \returns random long integer.
  95  */
  96 static inline long frr_weak_random(void)
  97 {
  98         /* coverity[dont_call] */
  99         return random();
 100 }
 101
 102 #ifdef __cplusplus
 103 }
 104 #endif
 105
 106 #endif /* _ZEBRA_NETWORK_H */