nlplug: use libkmod to load modules

2 files changed, 67 insertions, 14 deletions

diff --git a/Makefile b/Makefile
index 67347f5..afc06cb 100644
--- a/Makefile
+++ b/Makefile
@@ -2,11 +2,17 @@
 CFLAGS ?= -Wall -Werror -g
 CFLAGS += -D_GNU_SOURCE -DDEBUG
 
+PKGCONFIG ?= pkg-config
+LIBKMOD_CFLAGS := $(shell $(PKGCONFIG) --cflags libkmod)
+LIBKMOD_LIBS := $(shell $(PKGCONFIG) --libs libkmod)
+
 nlsockd_SRCS = nlsockd.c
 nlsockd_OBJS = $(nlsockd_SRCS:%.c=%.o)
 
 nlplug_SRCS = nlplug.c
 nlplug_OBJS = $(nlplug_SRCS:%.c=%.o)
+nlplug_CFLAGS = $(LIBKMOD_CFLAGS)
+nlplug_LIBS = $(LIBKMOD_LIBS)
 
 handler_SRCS = handler.c
 handler_OBJS = $(handler_SRCS:%.c=%.o)
@@ -19,7 +25,7 @@ handler: $(handler_OBJS)
 
 
 handler nlsockd nlplug:
-	$(CC) -o $@ $(CFLAGS) $($@_CFLAGS) $($@_OBJS) $(LDFLAGS) $($@_LDFLAGS)
+	$(CC) -o $@ $(CFLAGS) $($@_CFLAGS) $($@_OBJS) $(LDFLAGS) $($@_LIBS)
 
 clean:
 	rm -f nlplug nlsockd
diff --git a/nlplug.c b/nlplug.c
index d8212fb..fda8a84 100644
--- a/nlplug.c
+++ b/nlplug.c
@@ -21,6 +21,8 @@
 
 #include <linux/netlink.h>
 
+#include <libkmod.h>
+
 #include "arg.h"
 
 #define EVENT_TIMEOUT 2000
@@ -31,7 +33,7 @@ char *argv0;
 #if defined(DEBUG)
 #include <stdarg.h>
 void
-dbg(char *fmt, ...)
+dbg(const char *fmt, ...)
 {
 	va_list fmtargs;
 
@@ -65,9 +67,56 @@ run_child(char **argv)
 	fork_count++;
 }
 
+
+int load_kmod(const char *modalias)
+{
+	static struct kmod_ctx *ctx = NULL;
+	struct kmod_list *list = NULL;
+	struct kmod_list *node;
+	int r, count=0;
+
+	dbg("loading alias '%s'", modalias);
+
+	if (ctx == NULL) {
+		dbg("initializing kmod");
+		ctx = kmod_new("/", NULL);
+		if (ctx == NULL)
+			return -1;
+		kmod_set_log_fn(ctx, NULL, NULL);
+		r = kmod_load_resources(ctx);
+		dbg("load kmod resources: %i", r);
+	}
+
+	r = kmod_module_new_from_lookup(ctx, modalias, &list);
+	if (r < 0) {
+		dbg("alias '%s' lookup failure", modalias);
+		return r;
+	}
+
+	kmod_list_foreach(node, list) {
+		struct kmod_module *mod = kmod_module_get_module(node);
+		const char *fmt;
+		r = kmod_module_probe_insert_module(mod,
+						    KMOD_PROBE_APPLY_BLACKLIST,
+						    NULL, NULL, NULL, NULL);
+		if (r == 0) {
+			fmt = "module '%s' inserted";
+			count++;
+		} else if (r == KMOD_PROBE_APPLY_BLACKLIST) {
+			fmt = "module '%s' is blacklisted";
+		} else {
+			fmt = "module '%s' failed";
+		}
+		dbg(fmt, kmod_module_get_name(mod));
+		kmod_module_unref(mod);
+	}
+	kmod_module_unref_list(list);
+	return count;
+}
+
 int process_kbuf(char *buf, const size_t len, char **argv, const char *subsys)
 {
-	char *modalias = NULL;
+	char *modalias = NULL, *action = NULL;
 
 	int i, slen = 0;
 	char *key, *value;
@@ -91,7 +140,7 @@ int process_kbuf(char *buf, const size_t len, char **argv, const char *subsys)
 			continue;
 		}
 
-		if (subsys && !strncmp(key, "SUBSYSTEM=", 10)
+		if (subsys && strncmp(key, "SUBSYSTEM=", 10) == 0
 				&& !strstr(key+10, subsys)) {
 			dbg("subsystem filter '%s' applied.", subsys);
 			break;
@@ -100,8 +149,11 @@ int process_kbuf(char *buf, const size_t len, char **argv, const char *subsys)
 		value[0] = '\0';
 		value++;
 
-		if (!strncmp(key, "MODALIAS", 9))
+		if (strncmp(key, "MODALIAS", 9) == 0) {
 			modalias = value;
+		} else if (strncmp(key, "ACTION", 6) == 0) {
+			action = value;
+		}
 
 		/*
 		 * We generally trust the kernel. But there
@@ -112,16 +164,11 @@ int process_kbuf(char *buf, const size_t len, char **argv, const char *subsys)
 			dbg("%s = \"%s\"", key, value);
 		}
 	}
-	if (getenv("ACTION") != NULL) {
-		if (modalias != NULL)
-			dbg("MODALIAS: %s", modalias);
-		else if (getenv("DEVNAME") != NULL) {
+	if (action != NULL) {
+		if (modalias != NULL && strncmp(action, "add", 3) == 0) {
+			load_kmod(modalias);
+		} else if (getenv("DEVNAME") != NULL) {
 			run_child(argv);
-/*
-		else if(getenv("DEVPATH") != NULL &&
-			getenv("SUBSYSTEM") != NULL &&
-			getenv("SEQNUM") != NULL) {
-*/
 		}
 	}
 	return modalias != NULL ? 1 : 0;