src/OS/os.h-Linux

   1 /* Exim: OS-specific C header file for Linux */
   2
   3 /* Some old systems we've received bug-reports for have a <limits.h> which
   4 does not pull in <features.h>.  Best to just pull it in now and have done
   5 with the issue. */
   6
   7 #include <features.h>
   8 #include <sys/types.h>
   9
  10
  11 #define CRYPT_H
  12 #define GLIBC_IP_OPTIONS
  13 #define HAVE_MMAP
  14 #define HAVE_BSD_GETLOADAVG
  15 #define HAVE_SYS_STATVFS_H
  16 #define NO_IP_VAR_H
  17 #define SIG_IGN_WORKS
  18
  19 /* When using DKIM, setting OS_SENDFILE can increase
  20 performance on outgoing mail a bit. Note: With older glibc versions
  21 this setting will conflict with the _FILE_OFFSET_BITS=64 setting
  22 defined as part of the Linux CFLAGS.  As of 2017 those are declared
  23 to be too old to build by default. */
  24
  25 #define OS_SENDFILE
  26 extern ssize_t os_sendfile(int, int, off_t *, size_t);
  27
  28 #define F_FREESP     O_TRUNC
  29 typedef struct flock flock_t;
  30
  31 #define os_strsignal strsignal
  32 #define OS_STRSIGNAL
  33
  34 #if defined(__linux__) || defined(__FreeBSD_kernel__) || defined(__NetBSD_kernel__)
  35 # define SIOCGIFCONF_GIVES_ADDR
  36 # define HAVE_SYS_MOUNT_H
  37 #endif
  38
  39 #if defined(__linux__)
  40
  41 /* Some versions of Linux need explicit sync-ing of directories as well as
  42 files. This setting requests that. If the directory is on NFS, it may not
  43 be possible to sync it - in that case, Exim now should ignore the error. But
  44 if you have problems in that area, try undefining this. But be aware that you
  45 may be in a situation where files are not being properly "committed to stable
  46 storage" as quickly as Exim thinks they are. */
  47
  48 #define NEED_SYNC_DIRECTORY
  49
  50 #define os_find_running_interfaces os_find_running_interfaces_linux
  51
  52 /* Need a prototype for the Linux-specific function. The structure hasn't
  53 been defined yet, so we need to pre-declare it. */
  54
  55 struct ip_address_item;
  56 extern struct ip_address_item *os_find_running_interfaces_linux(void);
  57
  58 #endif /* __linux__ */
  59
  60 /* Some folks running "unusual" setups with very old libc environments have
  61 found that _GNU_SOURCE=1 before <features.h> is not sufficient to define some
  62 constants needed for 64-bit arithmetic.  If you encounter build errors based
  63 on LLONG_MIN being undefined and various other escape hatches have not helped,
  64 then change the 0 to 1 in the next block. */
  65
  66 #if 0
  67 # define LLONG_MIN LONG_LONG_MIN
  68 # define LLONG_MAX LONG_LONG_MAX
  69 #endif
  70
  71 #if _POSIX_C_SOURCE >= 200809L || _ATFILE_SOUCE
  72 # define EXIM_HAVE_OPENAT
  73 #endif
  74
  75 /* TCP Fast Open support */
  76
  77 #include <netinet/tcp.h>        /* for TCP_FASTOPEN */
  78 #include <sys/socket.h>         /* for MSG_FASTOPEN */
  79 #if defined(TCP_FASTOPEN) && !defined(MSG_FASTOPEN)
  80 # define MSG_FASTOPEN 0x20000000
  81 #endif
  82 #define EXIM_HAVE_TCPI_UNACKED
  83
  84
  85 /* End */