amixer: Parse the value more strictly

So far amixer allows some unexpected suffix and assumes as a raw
absolute value without returning an error.  This is rather dangerous,
e.g. user might not notice that a completely wrong value was set when
the command line included a typo.

This patch makes the parser a bit more strict: it doesn't allow any
longer invalid suffixes, instead either returns an error or skips the
invalid value, depending on the operation mode.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/amixer/amixer.c b/amixer/amixer.c
index 6a2fdb96c62fd5c9a260af4a04d150eabad802d0..ed60e7c3a9605a867edaf18c719a2f6d6514ec09 100644 (file)
--- a/amixer/amixer.c
+++ b/amixer/amixer.c
@@ -325,7 +325,7 @@ static int set_volume_simple(snd_mixer_elem_t *elem,
        long val, orig, pmin, pmax;
        char *p = *ptr, *s;
        int invalid = 0, percent = 0, err = 0;
-       int vol_type = std_vol_type;
+       int vol_type;
        double scale = 1.0;
        int correct = 0;
 
@@ -344,14 +344,19 @@ static int set_volume_simple(snd_mixer_elem_t *elem,
                strtol(p, &p, 10);
        }
        if (*p == '%') {
+               vol_type = std_vol_type;
                percent = 1;
                p++;
        } else if (toupper(p[0]) == 'D' && toupper(p[1]) == 'B') {
                vol_type = VOL_DB;
                p += 2;
                scale = 100;
-       } else
+       } else {
                vol_type = VOL_RAW;
+       }
+
+       if (*p && !strchr(",:+-", *p))
+               invalid = 1;
 
        val = (long)(strtod(s, NULL) * scale);
        if (vol_ops[dir].v[vol_type].get_range(elem, &pmin, &pmax) < 0)
@@ -372,6 +377,10 @@ static int set_volume_simple(snd_mixer_elem_t *elem,
                }
                p++;
        }
+
+       if (*p && !strchr(",:", *p))
+               invalid = 1;
+
        if (! invalid) {
                val = check_range(val, pmin, pmax);
                err = vol_ops[dir].v[vol_type].set(elem, chn, val, correct);