i2c-tools: only try /dev/i2c/* if opening /dev/i2c-* fails with ENOENT

Trying to access /dev/i2c/* on every error after opening /dev/i2c-* can
mislead users who e.g. don't have root access. Instead of bailing-out
with "permission denied" we currently print "no such file or directory".

Fix it by trying open("/dev/i2c/%d") only if we got ENOENT.

Upstream i2cdetect tries to get any info it can from /sys and /proc even
when invoked by an unprivileged user, but we don't want to add unnecessary
bloat.

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Bartosz Golaszewski 2015-05-11 17:26:27 +02:00 committed by Denys Vlasenko
parent b2cca32a37
commit 7ca5c51cc8

View File

@ -379,8 +379,12 @@ static int i2c_dev_open(int i2cbus)
sprintf(filename, "/dev/i2c-%d", i2cbus);
fd = open(filename, O_RDWR);
if (fd < 0) {
if (errno == ENOENT) {
filename[8] = '/'; /* change to "/dev/i2c/%d" */
fd = xopen(filename, O_RDWR);
} else {
bb_perror_msg_and_die("can't open '%s'", filename);
}
}
return fd;