diff options
Diffstat (limited to 'lib/libc')
| -rw-r--r-- | lib/libc/gen/gethostname.3 | 58 | ||||
| -rw-r--r-- | lib/libc/gen/gethostname.c | 11 |
2 files changed, 51 insertions, 18 deletions
diff --git a/lib/libc/gen/gethostname.3 b/lib/libc/gen/gethostname.3 index 7822322..ac0b9f2 100644 --- a/lib/libc/gen/gethostname.3 +++ b/lib/libc/gen/gethostname.3 @@ -32,7 +32,7 @@ .\" @(#)gethostname.3 8.1 (Berkeley) 6/4/93 .\" $FreeBSD$ .\" -.Dd June 4, 1993 +.Dd August 18, 2003 .Dt GETHOSTNAME 3 .Os .Sh NAME @@ -44,7 +44,7 @@ .Sh SYNOPSIS .In unistd.h .Ft int -.Fn gethostname "char *name" "int namelen" +.Fn gethostname "char *name" "size_t namelen" .Ft int .Fn sethostname "const char *name" "int namelen" .Sh DESCRIPTION @@ -59,8 +59,8 @@ The argument specifies the size of the .Fa name -array. The returned name is null-terminated unless insufficient -space is provided. +array. +The returned name is null-terminated unless insufficient space is provided. .Pp The .Fn sethostname @@ -71,6 +71,10 @@ which has length .Fa namelen . This call is restricted to the super-user and is normally used only when the system is bootstrapped. +.Pp +Host names are limited to +.Brq Dv HOST_NAME_MAX +characters, not including the trailing null, currently 255. .Sh RETURN VALUES .Rv -std .Sh ERRORS @@ -83,22 +87,48 @@ or .Fa namelen argument gave an invalid address. +.It Bq Er ENAMETOOLONG +The current host name is longer than +.Fa namelen . (For +.Fn gethostname +only.) .It Bq Er EPERM -The caller tried to set the hostname and was not the super-user. +The caller tried to set the host name and was not the super-user. .El .Sh SEE ALSO -.Xr gethostid 3 , +.Xr sysconf 3 , .Xr sysctl 3 -.Sh BUGS -Host names are limited to -.Dv MAXHOSTNAMELEN -(from -.Ao Pa sys/param.h Ac ) -characters, currently 256. -This includes the trailing -.Dv NUL . +.Sh STANDARDS +The +.Fn gethostname +function conforms to +.St -p1003.1-2001 . +Callers should be aware that +.Brq Dv HOST_NAME_MAX +may be variable or infinite, but is guaranteed to be no less than +.Brq Dv _POSIX_HOST_NAME_MAX . +On older systems, this limit was defined in the non-standard header +.Aq Pa sys/param.h +as +.Dv MAXHOSTNAMELEN , +and counted the terminating null. +The +.Fn sethostname +function and the error returns for +.Fn gethostname +are not standardized. .Sh HISTORY The .Fn gethostname function appeared in .Bx 4.2 . +The +.Fa namelen +argument to +.Fn gethostname +was changed to +.Vt size_t +in +.Fx 5.2 +for alignment with +.St -p1003.1-2001 . diff --git a/lib/libc/gen/gethostname.c b/lib/libc/gen/gethostname.c index a5cd290..37b52ca 100644 --- a/lib/libc/gen/gethostname.c +++ b/lib/libc/gen/gethostname.c @@ -40,18 +40,21 @@ __FBSDID("$FreeBSD$"); #include <sys/param.h> #include <sys/sysctl.h> +#include <errno.h> + int gethostname(name, namelen) char *name; - int namelen; + size_t namelen; { int mib[2]; - size_t size; mib[0] = CTL_KERN; mib[1] = KERN_HOSTNAME; - size = namelen; - if (sysctl(mib, 2, name, &size, NULL, 0) == -1) + if (sysctl(mib, 2, name, &namelen, NULL, 0) == -1) { + if (errno == ENOMEM) + errno = ENAMETOOLONG; return (-1); + } return (0); } |
