| /* sethostname emulation for glibc compliance. |
| |
| Copyright (C) 2011-2020 Free Software Foundation, Inc. |
| |
| This program is free software: you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
| |
| /* Ben Walton <bwalton@artsci.utoronto.ca> */ |
| |
| #include <config.h> |
| |
| #if !(defined _WIN32 || defined __CYGWIN__) |
| /* Unix API. */ |
| |
| /* Specification. */ |
| #include <unistd.h> |
| |
| #include <errno.h> |
| #include <stdio.h> |
| #include <limits.h> |
| |
| /* Set up to LEN chars of NAME as system hostname. |
| Return 0 if ok, set errno and return -1 on error. */ |
| |
| int |
| sethostname (const char *name, size_t len) |
| { |
| /* Ensure the string isn't too long. glibc does allow setting an |
| empty hostname so no point in enforcing a lower bound. */ |
| if (len > HOST_NAME_MAX) |
| { |
| errno = EINVAL; |
| return -1; |
| } |
| |
| #ifdef __minix /* Minix */ |
| { |
| FILE *hostf; |
| int r = 0; |
| |
| /* glibc returns EFAULT, EINVAL, and EPERM on error. None of |
| these are appropriate for us to set, even if they may match the |
| situation, during failed open/write/close operations, so we |
| leave errno alone and rely on what the system sets up. */ |
| hostf = fopen ("/etc/hostname.file", "w"); |
| if (hostf == NULL) |
| r = -1; |
| else |
| { |
| fprintf (hostf, "%.*s\n", (int) len, name); |
| if (ferror (hostf)) |
| { |
| /* Close hostf, preserving the errno from the fprintf call. */ |
| int saved_errno = errno; |
| fclose (hostf); |
| errno = saved_errno; |
| r = -1; |
| } |
| else |
| { |
| if (fclose (hostf)) |
| /* fclose sets errno on failure. */ |
| r = -1; |
| } |
| } |
| |
| return r; |
| } |
| #else |
| /* For platforms that we don't have a better option for, simply bail |
| out. */ |
| errno = ENOSYS; |
| return -1; |
| #endif |
| } |
| |
| #else |
| /* Native Windows API. Also used on Cygwin. */ |
| |
| /* Ensure that <windows.h> declares SetComputerNameEx. */ |
| #undef _WIN32_WINNT |
| #define _WIN32_WINNT _WIN32_WINNT_WIN2K |
| |
| #define WIN32_LEAN_AND_MEAN |
| |
| /* Specification. */ |
| #include <unistd.h> |
| |
| #include <errno.h> |
| #include <limits.h> |
| #include <string.h> |
| |
| #include <windows.h> |
| /* The mingw header files don't define GetComputerNameEx, SetComputerNameEx. */ |
| #ifndef GetComputerNameEx |
| # define GetComputerNameEx GetComputerNameExA |
| #endif |
| #ifndef SetComputerNameEx |
| # define SetComputerNameEx SetComputerNameExA |
| #endif |
| |
| /* Set up to LEN chars of NAME as system hostname. |
| Return 0 if ok, set errno and return -1 on error. */ |
| |
| int |
| sethostname (const char *name, size_t len) |
| { |
| char name_asciz[HOST_NAME_MAX + 1]; |
| char old_name[HOST_NAME_MAX + 1]; |
| DWORD old_name_len; |
| |
| /* Ensure the string isn't too long. glibc does allow setting an |
| empty hostname so no point in enforcing a lower bound. */ |
| if (len > HOST_NAME_MAX) |
| { |
| errno = EINVAL; |
| return -1; |
| } |
| |
| /* Prepare a NUL-terminated copy of name. */ |
| memcpy (name_asciz, name, len); |
| name_asciz[len] = '\0'; |
| |
| /* Save the old NetBIOS name. */ |
| old_name_len = sizeof (old_name) - 1; |
| if (! GetComputerNameEx (ComputerNamePhysicalNetBIOS, |
| old_name, &old_name_len)) |
| old_name_len = 0; |
| |
| /* Set both the NetBIOS and the first part of the IP / DNS name. */ |
| if (! SetComputerNameEx (ComputerNamePhysicalNetBIOS, name_asciz)) |
| { |
| errno = (GetLastError () == ERROR_ACCESS_DENIED ? EPERM : EINVAL); |
| return -1; |
| } |
| if (! SetComputerNameEx (ComputerNamePhysicalDnsHostname, name_asciz)) |
| { |
| errno = (GetLastError () == ERROR_ACCESS_DENIED ? EPERM : EINVAL); |
| /* Restore the old NetBIOS name. */ |
| if (old_name_len > 0) |
| { |
| old_name[old_name_len] = '\0'; |
| SetComputerNameEx (ComputerNamePhysicalNetBIOS, old_name); |
| } |
| return -1; |
| } |
| |
| /* Note that the new host name becomes effective only after a reboot! */ |
| return 0; |
| } |
| |
| #endif |