diff options
| -rw-r--r-- | NEWS | 12 | ||||
| -rw-r--r-- | THANKS | 1 | ||||
| -rw-r--r-- | m4/jm-macros.m4 | 19 | ||||
| -rw-r--r-- | src/who.c | 22 |
4 files changed, 53 insertions, 1 deletions
@@ -2,6 +2,18 @@ GNU coreutils NEWS -*- outline -*- * Noteworthy changes in release ?.? (????-??-??) [?] +** New features + + who: the "+/-" --mesg (-T) indicator of whether a user/tty is accepting + messages could be incorrectly listed as "+", when in fact, the user was + not accepting messages (mesg no). Before, who would examine only the + permission bits, and not consider the group of the TTY device file. + Thus, if a login tty's group would change somehow e.g., to "root", + that would make it unwritable (via write(1)) by normal users, in spite + of whatever the permission bits might imply. Now, when configured + using the --with-tty-group[=NAME] option, who also compares the group + of the TTY device with NAME (or "tty" if no group name is specified). + * Noteworthy changes in release 8.4 (2010-01-13) [stable] @@ -495,6 +495,7 @@ Philippe Schnoebelen Philippe.Schnoebelen@imag.fr Phillip Jones mouse@datastacks.com Piergiorgio Sartor sartor@sony.de Pieter Bowman bowman@math.utah.edu +Piotr Gackiewicz gacek@intertele.pl Piotr Kwapulinski kwap@univ.gda.pl Prashant TR tr@eth.net Priit Jõerüüt jemm4jemm@yahoo.com diff --git a/m4/jm-macros.m4 b/m4/jm-macros.m4 index 271382723..0ddbf2fdc 100644 --- a/m4/jm-macros.m4 +++ b/m4/jm-macros.m4 @@ -144,6 +144,25 @@ AC_DEFUN([coreutils_MACROS], ]) AC_REQUIRE([AM_LANGINFO_CODESET]) + + # Accept configure options: --with-tty-group[=GROUP], --without-tty-group + # You can determine the group of a TTY via 'stat --format %G /dev/tty' + # Omitting this option is equivalent to using --without-tty-group. + AC_ARG_WITH([tty-group], + AS_HELP_STRING([--with-tty-group[[[=NAME]]]], + [group used by system for TTYs, "tty" when not specified] + [ (default: do not rely on any group used for TTYs)]), + [tty_group_name=$withval], + [tty_group_name=no]) + + if test "x$tty_group_name" != xno; then + if test "x$tty_group_name" = xyes; then + tty_group_name=tty + fi + AC_MSG_NOTICE([TTY group used by system set to "$tty_group_name"]) + AC_DEFINE_UNQUOTED([TTY_GROUP_NAME], ["$tty_group_name"], + [group used by system for TTYs]) + fi ]) AC_DEFUN([gl_CHECK_ALL_HEADERS], @@ -37,6 +37,10 @@ #include "hard-locale.h" #include "quote.h" +#ifdef TTY_GROUP_NAME +# include <grp.h> +#endif + /* The official name of this program (e.g., no `g' prefix). */ #define PROGRAM_NAME "who" @@ -308,6 +312,22 @@ print_line (int userlen, const char *user, const char state, free (x_exitstr); } +/* Return true if a terminal device given as PSTAT allows other users + to send messages to; false otherwise */ +static bool +is_tty_writable (struct stat const *pstat) +{ +#ifdef TTY_GROUP_NAME + /* Ensure the group of the TTY device matches TTY_GROUP_NAME, more info at + https://bugzilla.redhat.com/454261 */ + struct group *ttygr = getgrnam (TTY_GROUP_NAME); + if (!ttygr || (pstat->st_gid != ttygr->gr_gid)) + return false; +#endif + + return pstat->st_mode & S_IWGRP; +} + /* Send properly parsed USER_PROCESS info to print_line. The most recent boot time is BOOTTIME. */ static void @@ -346,7 +366,7 @@ print_user (const STRUCT_UTMP *utmp_ent, time_t boottime) if (stat (line, &stats) == 0) { - mesg = (stats.st_mode & S_IWGRP) ? '+' : '-'; + mesg = is_tty_writable (&stats) ? '+' : '-'; last_change = stats.st_atime; } else |