diff options
Diffstat (limited to 'REORG.TODO/sysdeps/unix/sysv/linux/getlogin_r.c')
| -rw-r--r-- | REORG.TODO/sysdeps/unix/sysv/linux/getlogin_r.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/REORG.TODO/sysdeps/unix/sysv/linux/getlogin_r.c b/REORG.TODO/sysdeps/unix/sysv/linux/getlogin_r.c new file mode 100644 index 0000000000..05ac36b491 --- /dev/null +++ b/REORG.TODO/sysdeps/unix/sysv/linux/getlogin_r.c @@ -0,0 +1,120 @@ +/* Copyright (C) 2010-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <pwd.h> +#include <unistd.h> +#include <not-cancel.h> + +#define STATIC static +static int getlogin_r_fd0 (char *name, size_t namesize); +#define __getlogin_r getlogin_r_fd0 +#include <sysdeps/unix/getlogin_r.c> +#undef __getlogin_r + + +/* Try to determine login name from /proc/self/loginuid and return 0 + if successful. If /proc/self/loginuid cannot be read return -1. + Otherwise return the error number. */ + +int +attribute_hidden +__getlogin_r_loginuid (char *name, size_t namesize) +{ + int fd = open_not_cancel_2 ("/proc/self/loginuid", O_RDONLY); + if (fd == -1) + return -1; + + /* We are reading a 32-bit number. 12 bytes are enough for the text + representation. If not, something is wrong. */ + char uidbuf[12]; + ssize_t n = TEMP_FAILURE_RETRY (read_not_cancel (fd, uidbuf, + sizeof (uidbuf))); + close_not_cancel_no_status (fd); + + uid_t uid; + char *endp; + if (n <= 0 + || n == sizeof (uidbuf) + || (uidbuf[n] = '\0', + uid = strtoul (uidbuf, &endp, 10), + endp == uidbuf || *endp != '\0')) + return -1; + + size_t buflen = 1024; + char *buf = alloca (buflen); + bool use_malloc = false; + struct passwd pwd; + struct passwd *tpwd; + int result = 0; + int res; + + while ((res = __getpwuid_r (uid, &pwd, buf, buflen, &tpwd)) == ERANGE) + if (__libc_use_alloca (2 * buflen)) + buf = extend_alloca (buf, buflen, 2 * buflen); + else + { + buflen *= 2; + char *newp = realloc (use_malloc ? buf : NULL, buflen); + if (newp == NULL) + { + result = ENOMEM; + goto out; + } + buf = newp; + use_malloc = true; + } + + if (res != 0 || tpwd == NULL) + { + result = -1; + goto out; + } + + size_t needed = strlen (pwd.pw_name) + 1; + if (needed > namesize) + { + __set_errno (ERANGE); + result = ERANGE; + goto out; + } + + memcpy (name, pwd.pw_name, needed); + + out: + if (use_malloc) + free (buf); + + return result; +} + + +/* Return at most NAME_LEN characters of the login name of the user in NAME. + If it cannot be determined or some other error occurred, return the error + code. Otherwise return 0. */ + +int +__getlogin_r (char *name, size_t namesize) +{ + int res = __getlogin_r_loginuid (name, namesize); + if (res >= 0) + return res; + + return getlogin_r_fd0 (name, namesize); +} +libc_hidden_def (__getlogin_r) +weak_alias (__getlogin_r, getlogin_r) +libc_hidden_weak (getlogin_r) |