[S] Change in em100[main]: em100: exit when using an invalid device name

[Name of user not set (Code Review)]

[e-mail] has uploaded this change for review. ( https://review.coreboot.org/c/em100/+/80249?usp=email )

Change subject: em100: exit when using an invalid device name
......................................................................

em100: exit when using an invalid device name

If you use a stupid device name like `em100 --device bla`, we won't exit with
an error right now. It just ignores the devices and uses the first device it
can find. This could lead to unexpected issues when connecting more than one
EM100 device to your machine. It's much better to exit if we're unable to parse
the device name.

Change-Id: If0f7b8b576224a9db6ab319c2212bc245110c5c1
Signed-off-by: Corvin Köhne 
---
M em100.c
1 file changed, 11 insertions(+), 4 deletions(-)

git pull ssh://review.coreboot.org:29418/em100 refs/changes/49/80249/1

diff --git a/em100.c b/em100.c
index cfcecb9..666cef9 100644
--- a/em100.c
+++ b/em100.c
@@ -930,10 +930,17 @@
    		break;
    	case 'x':
    		if ((toupper(optarg[0]) == 'D' && toupper(optarg[1]) == 'P') ||
-			    (toupper(optarg[0]) == 'E' && toupper(optarg[1]) == 'M'))
-				sscanf(optarg + 2, "%u", &serial_number);
-			else
-				sscanf(optarg, "%d:%d", &bus, &device);
+			    (toupper(optarg[0]) == 'E' && toupper(optarg[1]) == 'M')) {
+				if (sscanf(optarg + 2, "%u", &serial_number) != 1) {
+					printf("Invalid device name: %s\n", optarg);
+					return 1;
+				}
+			} else {
+				if (sscanf(optarg, "%d:%d", &bus, &device) != 2) {
+					printf("Invalid device name: %s\n", optarg);
+					return 1;
+				}
+			}
    		break;
    	case 'l':
    		em100_list();