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author | Ulrich Drepper <drepper@redhat.com> | 2010-03-24 17:02:57 -0700 |
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committer | Ulrich Drepper <drepper@redhat.com> | 2010-03-24 17:02:57 -0700 |
commit | c8727fa6e5073d28ed6d0eb40a006ac2c1b9f9f3 (patch) | |
tree | 23369e9301bb60abd73e4384e7974fa32acd6e57 /sysdeps | |
parent | fd8ccb0427569ffdfbb70c8828029122f3459160 (diff) | |
download | glibc-c8727fa6e5073d28ed6d0eb40a006ac2c1b9f9f3.tar.gz glibc-c8727fa6e5073d28ed6d0eb40a006ac2c1b9f9f3.tar.xz glibc-c8727fa6e5073d28ed6d0eb40a006ac2c1b9f9f3.zip |
Fix Linux getlogin{_r,} implementation
The old implementation uses fd 0 to determine the login TTY. This was needed because using /dev/tty it is not possible to deduce the login TTY. For some time now there is the pseudo-file /proc/self/loginuid which directly helps us to find the user. Prefer using this file. It also works if stdin is closed, redirected, or re-opened.
Diffstat (limited to 'sysdeps')
-rw-r--r-- | sysdeps/unix/getlogin.c | 8 | ||||
-rw-r--r-- | sysdeps/unix/getlogin_r.c | 7 | ||||
-rw-r--r-- | sysdeps/unix/sysv/linux/getlogin.c | 39 | ||||
-rw-r--r-- | sysdeps/unix/sysv/linux/getlogin_r.c | 100 |
4 files changed, 151 insertions, 3 deletions
diff --git a/sysdeps/unix/getlogin.c b/sysdeps/unix/getlogin.c index 4752685f86..b0ad97cfa5 100644 --- a/sysdeps/unix/getlogin.c +++ b/sysdeps/unix/getlogin.c @@ -1,4 +1,4 @@ -/* Copyright (C) 1991, 1992, 1996, 1997 Free Software Foundation, Inc. +/* Copyright (C) 1991, 1992, 1996, 1997, 2010 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 @@ -25,16 +25,20 @@ #include <utmp.h> +static char name[UT_NAMESIZE + 1]; + /* Return the login name of the user, or NULL if it can't be determined. The returned pointer, if not NULL, is good only until the next call. */ +#ifdef STATIC +STATIC +#endif char * getlogin (void) { char tty_pathname[2 + 2 * NAME_MAX]; char *real_tty_path = tty_pathname; char *result = NULL; - static char name[UT_NAMESIZE + 1]; struct utmp *ut, line, buffer; /* Get name of tty connected to fd 0. Return NULL if not a tty or diff --git a/sysdeps/unix/getlogin_r.c b/sysdeps/unix/getlogin_r.c index ba7badd054..bf3c889e13 100644 --- a/sysdeps/unix/getlogin_r.c +++ b/sysdeps/unix/getlogin_r.c @@ -1,5 +1,5 @@ /* Reentrant function to return the current login name. Unix version. - Copyright (C) 1991,92,96,97,98,2002 Free Software Foundation, Inc. + Copyright (C) 1991,92,96,97,98,2002,2010 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 @@ -31,6 +31,9 @@ If it cannot be determined or some other error occurred, return the error code. Otherwise return 0. */ +#ifdef STATIC +STATIC +#endif int getlogin_r (name, name_len) char *name; @@ -96,4 +99,6 @@ getlogin_r (name, name_len) return result; } +#ifndef STATIC libc_hidden_def (getlogin_r) +#endif diff --git a/sysdeps/unix/sysv/linux/getlogin.c b/sysdeps/unix/sysv/linux/getlogin.c new file mode 100644 index 0000000000..4d15db093d --- /dev/null +++ b/sysdeps/unix/sysv/linux/getlogin.c @@ -0,0 +1,39 @@ +/* Copyright (C) 2010 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <pwd.h> +#include <unistd.h> +#include <not-cancel.h> + +#define STATIC static +#define getlogin getlogin_fd0 +#include <sysdeps/unix/getlogin.c> +#undef getlogin + + +/* Return the login name of the user, or NULL if it can't be determined. + The returned pointer, if not NULL, is good only until the next call. */ + +char * +getlogin (void) +{ + if (__getlogin_r_loginuid (name, sizeof (name)) == 0) + return name; + + return getlogin_fd0 (); +} diff --git a/sysdeps/unix/sysv/linux/getlogin_r.c b/sysdeps/unix/sysv/linux/getlogin_r.c new file mode 100644 index 0000000000..d07846ccb8 --- /dev/null +++ b/sysdeps/unix/sysv/linux/getlogin_r.c @@ -0,0 +1,100 @@ +/* Copyright (C) 2010 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#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 + + +int +attribute_hidden +__getlogin_r_loginuid (name, namesize) + char *name; + size_t namesize; +{ + int fd = open_not_cancel_2 ("/proc/self/loginuid", O_RDONLY); + if (fd == -1) + return 1; + + ssize_t n = TEMP_FAILURE_RETRY (read_not_cancel (fd, name, namesize)); + close_not_cancel_no_status (fd); + + uid_t uid; + char *endp; + if (n <= 0 + || (uid = strtoul (name, &endp, 10), endp == name || *endp != '\0')) + return 1; + + size_t buflen = 1024; + char *buf = alloca (buflen); + bool use_malloc = false; + struct passwd pwd; + struct passwd *tpwd; + int res; + + while ((res = __getpwuid_r (uid, &pwd, buf, buflen, &tpwd)) != 0) + if (__libc_use_alloca (2 * buflen)) + extend_alloca (buf, buflen, 2 * buflen); + else + { + buflen *= 2; + char *newp = realloc (use_malloc ? buf : NULL, buflen); + if (newp == NULL) + { + fail: + if (use_malloc) + free (buf); + return 1; + } + buf = newp; + use_malloc = true; + } + + if (tpwd == NULL) + goto fail; + + strncpy (name, pwd.pw_name, namesize - 1); + name[namesize - 1] = '\0'; + + if (use_malloc) + free (buf); + + return 0; +} + + +/* Return the login name of the user, or NULL if it can't be determined. + The returned pointer, if not NULL, is good only until the next call. */ + +int +getlogin_r (name, namesize) + char *name; + size_t namesize; +{ + if (__getlogin_r_loginuid (name, namesize) == 0) + return 0; + + return getlogin_r_fd0 (name, namesize); +} +libc_hidden_def (getlogin_r) |