nlplug: add -s for searchig for a given device

Add -s option so we can specify a specific block device. Once it is
found we just exit.

1 files changed, 41 insertions, 14 deletions

diff --git a/nlplug.c b/nlplug.c
index fda8a84..3ed8dbd 100644
--- a/nlplug.c
+++ b/nlplug.c
@@ -114,9 +114,24 @@ int load_kmod(const char *modalias)
 	return count;
 }
 
-int process_kbuf(char *buf, const size_t len, char **argv, const char *subsys)
+int is_searchdev(const char *devname, const char *searchdev)
 {
-	char *modalias = NULL, *action = NULL;
+	if (searchdev == NULL)
+		return 0;
+
+	if (strcmp(devname, searchdev) == 0) {
+		dbg("FOUND %s", searchdev);
+		return 1;
+	}
+
+	return 0;
+}
+
+int process_kbuf(char *buf, const size_t len, char **argv,
+		 const char *subsys_filter,
+		 const char *searchdev)
+{
+	char *modalias = NULL, *action = NULL, *subsystem = NULL;
 
 	int i, slen = 0;
 	char *key, *value;
@@ -140,19 +155,22 @@ int process_kbuf(char *buf, const size_t len, char **argv, const char *subsys)
 			continue;
 		}
 
-		if (subsys && strncmp(key, "SUBSYSTEM=", 10) == 0
-				&& !strstr(key+10, subsys)) {
-			dbg("subsystem filter '%s' applied.", subsys);
-			break;
-		}
-
 		value[0] = '\0';
 		value++;
 
-		if (strncmp(key, "MODALIAS", 9) == 0) {
+		if (strcmp(key, "MODALIAS") == 0) {
 			modalias = value;
-		} else if (strncmp(key, "ACTION", 6) == 0) {
+		} else if (strcmp(key, "ACTION") == 0) {
 			action = value;
+		} else if (strcmp(key, "SUBSYSTEM") == 0) {
+			subsystem = value;
+			if (subsys_filter
+			    && strcmp(subsystem, subsys_filter) != 0) {
+				dbg("subsystem '%s' filtered out ('%s').",
+				    subsystem, subsys_filter);
+				return 0;
+			}
+
 		}
 
 		/*
@@ -169,6 +187,10 @@ int process_kbuf(char *buf, const size_t len, char **argv, const char *subsys)
 			load_kmod(modalias);
 		} else if (getenv("DEVNAME") != NULL) {
 			run_child(argv);
+			if (subsystem && strcmp(subsystem, "block") == 0
+			    && strcmp(action, "add") == 0
+			    && is_searchdev(getenv("DEVNAME"), searchdev))
+				exit(0);
 		}
 	}
 	return modalias != NULL ? 1 : 0;
@@ -177,14 +199,15 @@ int process_kbuf(char *buf, const size_t len, char **argv, const char *subsys)
 void
 usage(void)
 {
-	errx(1, "usage: %s [-dku] [-f subsystem] PATH\n", argv0);
+	errx(1, "usage: %s [-dku] [-f subsystem] [-b device] PATH\n", argv0);
 }
 
 int main(int argc, char *argv[])
 {
 	struct pollfd fds;
 	int r;
-	char *subsystem = NULL;
+	char *subsys_filter = NULL;
+	char *searchdev = NULL;
 
 	int showudev, showkernel;
 
@@ -202,7 +225,10 @@ int main(int argc, char *argv[])
 		showkernel = 0;
 		break;
 	case 'f':
-		subsystem = EARGF(usage());
+		subsys_filter = EARGF(usage());
+		break;
+	case 's':
+		searchdev = EARGF(usage());
 		break;
 	default:
 		usage();
@@ -277,7 +303,8 @@ int main(int argc, char *argv[])
 				continue;
 		}
 
-		modalias_count += process_kbuf(buf, len, argv, subsystem);
+		modalias_count += process_kbuf(buf, len, argv, subsys_filter,
+					       searchdev);
 		event_count++;
 		dbg("-------------------------\n");
 		if (fds.revents & POLLHUP) {