| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Get a host configuration item kept as the whole contents of a file. |
| 2 | Copyright (C) 1996-2016 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library; if not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include <fcntl.h> |
| 20 | #include <hurd.h> |
| 21 | #include <hurd/lookup.h> |
| 22 | #include "hurdhost.h" |
| 23 | #include <string.h> |
| 24 | |
| 25 | ssize_t |
| 26 | _hurd_get_host_config (const char *item, char *buf, size_t buflen) |
| 27 | { |
| 28 | error_t err; |
| 29 | char *data; |
| 30 | mach_msg_type_number_t nread, more; |
| 31 | file_t config; |
| 32 | |
| 33 | err = __hurd_file_name_lookup (&_hurd_ports_use, &__getdport, 0, |
| 34 | item, O_RDONLY, 0, &config); |
| 35 | switch (err) |
| 36 | { |
| 37 | case 0: /* Success; read file contents below. */ |
| 38 | break; |
| 39 | |
| 40 | case ENOENT: /* ? Others? All errors? */ |
| 41 | /* The file does not exist, so no value has been set. Rather than |
| 42 | causing gethostname et al to fail with ENOENT, give an empty value |
| 43 | as other systems do before sethostname has been called. */ |
| 44 | if (buflen != 0) |
| 45 | *buf = '\0'; |
| 46 | return 0; |
| 47 | |
| 48 | default: |
| 49 | return __hurd_fail (err); |
| 50 | } |
| 51 | |
| 52 | data = buf; |
| 53 | nread = buflen; |
| 54 | err = __io_read (config, &data, &nread, -1, buflen); |
| 55 | if (! err) |
| 56 | /* Check if there is more in the file we didn't read. */ |
| 57 | err = __io_readable (config, &more); |
| 58 | __mach_port_deallocate (__mach_task_self (), config); |
| 59 | if (err) |
| 60 | return __hurd_fail (err); |
| 61 | if (data != buf) |
| 62 | { |
| 63 | memcpy (buf, data, nread); |
| 64 | __vm_deallocate (__mach_task_self (), (vm_address_t) data, nread); |
| 65 | } |
| 66 | |
| 67 | /* If the file is empty, give an empty value. */ |
| 68 | if (nread == 0) |
| 69 | { |
| 70 | if (buflen != 0) |
| 71 | *buf = '\0'; |
| 72 | return 0; |
| 73 | } |
| 74 | |
| 75 | /* Remove newlines in case someone wrote the file by hand. */ |
| 76 | while (nread > 0 && buf[nread - 1] == '\n') |
| 77 | buf[--nread] = '\0'; |
| 78 | |
| 79 | /* Null-terminate the result if there is enough space. */ |
| 80 | if (nread < buflen) |
| 81 | buf[nread] = '\0'; |
| 82 | else |
| 83 | if (buf[nread - 1] != '\0') |
| 84 | more = 1; |
| 85 | |
| 86 | if (more) |
| 87 | /* If we didn't read the whole file, tell the caller to use a bigger |
| 88 | buffer next time. */ |
| 89 | return __hurd_fail (ENAMETOOLONG); |
| 90 | |
| 91 | return nread; |
| 92 | } |