Line data    Source code

       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             :  * Generate a sequence number using monotonic clock with a same second call
      86             :  * protection to help guarantee a unique incremental sequence number that never
      87             :  * goes back (except when wrapping/overflow).
      88             :  *
      89             :  * **NOTE** this function is not thread safe since it uses `static` variable.
      90             :  *
      91             :  * This function and `frr_sequence32_next` should be used to initialize
      92             :  * sequence numbers without directly calling other `time_t` returning
      93             :  * functions because of `time_t` truncation warnings.
      94             :  *
      95             :  * \returns `uint64_t` number based on the monotonic clock.
      96             :  */
      97             : extern uint64_t frr_sequence_next(void);
      98             : 
      99             : /** Same as `frr_sequence_next` but returns truncated number. */
     100             : extern uint32_t frr_sequence32_next(void);
     101             : 
     102             : /**
     103             :  * Helper function that returns a random long value. The main purpose of
     104             :  * this function is to hide a `random()` call that gets flagged by coverity
     105             :  * scan and put it into one place.
     106             :  *
     107             :  * The main usage of this function should be for generating jitter or weak
     108             :  * random values for simple purposes.
     109             :  *
     110             :  * See 'man 3 random' for more information.
     111             :  *
     112             :  * \returns random long integer.
     113             :  */
     114          54 : static inline long frr_weak_random(void)
     115             : {
     116             :         /* coverity[dont_call] */
     117          27 :         return random();
     118             : }
     119             : 
     120             : #ifdef __cplusplus
     121             : }
     122             : #endif
     123             : 
     124             : #endif /* _ZEBRA_NETWORK_H */