thirdparty/util-linux
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lib: try to find tty in get_terminal_name()

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Try all standard terminal input/output file descriptors when finding tty
name in get_germinal_name().  This should make all invocations of the
function as robust as they can get.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>
This commit is contained in:
Sami Kerola 2016-05-14 19:50:41 +01:00
parent a58b90255c
commit 285c1f3a3e
No known key found for this signature in database
GPG key ID: A9553245FDE9B739
5 changed files with 20 additions and 19 deletions
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2
include/ttyutils.h
View file

@ -51,7 +51,7 @@ struct chardata {
} while (0) } while (0)
extern int get_terminal_width(int default_width); extern int get_terminal_width(int default_width);
extern int get_terminal_name(int fd, const char **path, const char **name, extern int get_terminal_name(const char **path, const char **name,
const char **number); const char **number);
#define UL_TTY_KEEPCFLAGS (1 << 1) #define UL_TTY_KEEPCFLAGS (1 << 1)

15
lib/ttyutils.c
View file

@ -5,6 +5,7 @@
* Written by Karel Zak <kzak@redhat.com> * Written by Karel Zak <kzak@redhat.com>
*/ */
#include <ctype.h> #include <ctype.h>
#include <unistd.h>
#include "c.h" #include "c.h"
#include "ttyutils.h" #include "ttyutils.h"
@ -42,13 +43,14 @@ int get_terminal_width(int default_width)
return width > 0 ? width : default_width; return width > 0 ? width : default_width;
} }
int get_terminal_name(int fd, int get_terminal_name(const char **path,
const char **path,
const char **name, const char **name,
const char **number) const char **number)
{ {
const char *tty; const char *tty;
const char *p; const char *p;
int fd;
if (name) if (name)
*name = NULL; *name = NULL;
@ -57,6 +59,15 @@ int get_terminal_name(int fd,
if (number) if (number)
*number = NULL; *number = NULL;
if (isatty(STDIN_FILENO))
fd = STDIN_FILENO;
else if (isatty(STDOUT_FILENO))
fd = STDOUT_FILENO;
else if (isatty(STDERR_FILENO))
fd = STDERR_FILENO;
else
return -1;
tty = ttyname(fd); tty = ttyname(fd);
if (!tty) if (!tty)
return -1; return -1;

2
login-utils/login.c
View file

@ -356,7 +356,7 @@ static void init_tty(struct login_context *cxt)
cxt->tty_mode = (mode_t) getlogindefs_num("TTYPERM", TTY_MODE); cxt->tty_mode = (mode_t) getlogindefs_num("TTYPERM", TTY_MODE);
get_terminal_name(0, &cxt->tty_path, &cxt->tty_name, &cxt->tty_number); get_terminal_name(&cxt->tty_path, &cxt->tty_name, &cxt->tty_number);
/* /*
* In case login is suid it was possible to use a hardlink as stdin * In case login is suid it was possible to use a hardlink as stdin

4
login-utils/su-common.c
View file

@ -165,7 +165,7 @@ log_syslog(struct passwd const *pw, bool successful)
old_user = pwd ? pwd->pw_name : ""; old_user = pwd ? pwd->pw_name : "";
} }
if (get_terminal_name(STDERR_FILENO, NULL, &tty, NULL) != 0 || !tty) if (get_terminal_name(NULL, &tty, NULL) != 0 || !tty)
tty = "none"; tty = "none";
openlog (program_invocation_short_name, 0 , LOG_AUTH); openlog (program_invocation_short_name, 0 , LOG_AUTH);
@ -192,7 +192,7 @@ static void log_btmp(struct passwd const *pw)
pw && pw->pw_name ? pw->pw_name : "(unknown)", pw && pw->pw_name ? pw->pw_name : "(unknown)",
sizeof(ut.ut_user)); sizeof(ut.ut_user));
get_terminal_name(STDERR_FILENO, NULL, &tty_name, &tty_num); get_terminal_name(NULL, &tty_name, &tty_num);
if (tty_num) if (tty_num)
xstrncpy(ut.ut_id, tty_num, sizeof(ut.ut_id)); xstrncpy(ut.ut_id, tty_num, sizeof(ut.ut_id));
if (tty_name) if (tty_name)

14
term-utils/write.c
View file

@ -296,7 +296,7 @@ static void do_write(const struct write_control *ctl)
int main(int argc, char **argv) int main(int argc, char **argv)
{ {
int tty_writeable = 0, src_fd, c; int tty_writeable = 0, c;
struct write_control ctl = { 0 }; struct write_control ctl = { 0 };
static const struct option longopts[] = { static const struct option longopts[] = {
@ -321,18 +321,8 @@ int main(int argc, char **argv)
usage(stderr); usage(stderr);
} }
if (get_terminal_name(&ctl.src_tty_path, &ctl.src_tty_name, NULL) == 0) {
/* check that sender has write enabled */ /* check that sender has write enabled */
if (isatty(STDIN_FILENO))
src_fd = STDIN_FILENO;
else if (isatty(STDOUT_FILENO))
src_fd = STDOUT_FILENO;
else if (isatty(STDERR_FILENO))
src_fd = STDERR_FILENO;
else
src_fd = -1;
if (src_fd != -1 &&
get_terminal_name(src_fd, &ctl.src_tty_path, &ctl.src_tty_name, NULL) == 0) {
if (check_tty(ctl.src_tty_path, &tty_writeable, NULL, 1)) if (check_tty(ctl.src_tty_path, &tty_writeable, NULL, 1))
exit(EXIT_FAILURE); exit(EXIT_FAILURE);
if (!tty_writeable) if (!tty_writeable)