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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:06:34 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 12:06:34 +0000 |
commit | 5e61585d76ae77fd5e9e96ebabb57afa4d74880d (patch) | |
tree | 2b467823aaeebc7ef8bc9e3cabe8074eaef1666d /src/util/get_hostname.c | |
parent | Initial commit. (diff) | |
download | postfix-5e61585d76ae77fd5e9e96ebabb57afa4d74880d.tar.xz postfix-5e61585d76ae77fd5e9e96ebabb57afa4d74880d.zip |
Adding upstream version 3.5.24.upstream/3.5.24
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/util/get_hostname.c')
-rw-r--r-- | src/util/get_hostname.c | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/src/util/get_hostname.c b/src/util/get_hostname.c new file mode 100644 index 0000000..eb2cfea --- /dev/null +++ b/src/util/get_hostname.c @@ -0,0 +1,84 @@ +/*++ +/* NAME +/* get_hostname 3 +/* SUMMARY +/* network name lookup +/* SYNOPSIS +/* #include <get_hostname.h> +/* +/* const char *get_hostname() +/* DESCRIPTION +/* get_hostname() returns the local hostname as obtained +/* via gethostname() or its moral equivalent. This routine +/* goes to great length to avoid dependencies on any network +/* services. +/* DIAGNOSTICS +/* Fatal errors: no hostname, invalid hostname. +/* SEE ALSO +/* valid_hostname(3) +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/*--*/ + +/* System library. */ + +#include <sys_defs.h> +#include <sys/param.h> +#include <string.h> +#include <unistd.h> + +#if (MAXHOSTNAMELEN < 256) +#undef MAXHOSTNAMELEN +#define MAXHOSTNAMELEN 256 +#endif + +/* Utility library. */ + +#include "mymalloc.h" +#include "msg.h" +#include "valid_hostname.h" +#include "get_hostname.h" + +/* Local stuff. */ + +static char *my_host_name; + +/* get_hostname - look up my host name */ + +const char *get_hostname(void) +{ + char namebuf[MAXHOSTNAMELEN + 1]; + + /* + * The gethostname() call is not (or not yet) in ANSI or POSIX, but it is + * part of the socket interface library. We avoid the more politically- + * correct uname() routine because that has no portable way of dealing + * with long (FQDN) hostnames. + * + * DO NOT CALL GETHOSTBYNAME FROM THIS FUNCTION. IT BREAKS MAILDIR DELIVERY + * AND OTHER THINGS WHEN THE MACHINE NAME IS NOT FOUND IN /ETC/HOSTS OR + * CAUSES PROCESSES TO HANG WHEN THE NETWORK IS DISCONNECTED. + * + * POSTFIX NO LONGER NEEDS A FULLY QUALIFIED HOSTNAME. INSTEAD POSTFIX WILL + * USE A DEFAULT DOMAIN NAME "LOCALDOMAIN". + */ + if (my_host_name == 0) { + /* DO NOT CALL GETHOSTBYNAME FROM THIS FUNCTION */ + if (gethostname(namebuf, sizeof(namebuf)) < 0) + msg_fatal("gethostname: %m"); + namebuf[MAXHOSTNAMELEN] = 0; + /* DO NOT CALL GETHOSTBYNAME FROM THIS FUNCTION */ + if (valid_hostname(namebuf, DO_GRIPE) == 0) + msg_fatal("unable to use my own hostname"); + /* DO NOT CALL GETHOSTBYNAME FROM THIS FUNCTION */ + my_host_name = mystrdup(namebuf); + } + return (my_host_name); +} |