From 0233a8ea18bec17dd59cfe1fec8281d2b9c26d22 Mon Sep 17 00:00:00 2001 From: Sami Kerola Date: Sun, 18 Aug 2013 10:44:13 +0100 Subject: write: change determination can user write to a terminal Earlier test failed when user had write permission, but was not in special group that owns terminal devices, usually tty. This made write(1) to fail for root, if the root did not happen to be in tty group. In this commit root is granted ot write to anyone, even if they have mesg(1) turned off. For an user who is trying to write to own other session the group write bit is significant only for whether mesg(1) are enabled. Signed-off-by: Sami Kerola --- term-utils/write.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'term-utils/write.c') diff --git a/term-utils/write.c b/term-utils/write.c index cb3b0444d..173869465 100644 --- a/term-utils/write.c +++ b/term-utils/write.c @@ -73,7 +73,7 @@ static void __attribute__ ((__noreturn__)) done(int); int term_chk(char *, int *, time_t *, int); int utmp_chk(char *, char *); -static gid_t myegid; +static gid_t root_access; static void __attribute__ ((__noreturn__)) usage(FILE * out) { @@ -120,7 +120,7 @@ int main(int argc, char **argv) usage(stderr); } - myegid = getegid(); + root_access = !getegid(); /* check that sender has write enabled */ if (isatty(fileno(stdin))) @@ -299,8 +299,9 @@ int term_chk(char *tty, int *msgsokP, time_t * atimeP, int showerror) return 1; } - /* group write bit and group ownership */ - *msgsokP = (s.st_mode & (S_IWRITE >> 3)) && myegid == s.st_gid; + *msgsokP = !access(path, W_OK); + if (!root_access && *msgsokP) + *msgsokP = s.st_mode & S_IWGRP; *atimeP = s.st_atime; return 0; } -- cgit v1.2.3-55-g7522