iftable: add nlif_get_ifflags to get the network interface flags

This patch adds the nlif_get_ifflags to get the interface flags.
This patch also modifies the example file to display if a network
interface is running or not.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

3 files changed, 42 insertions, 1 deletions

diff --git a/include/libnfnetlink/libnfnetlink.h b/include/libnfnetlink/libnfnetlink.h
index 83874e3..b2f3652 100644
--- a/include/libnfnetlink/libnfnetlink.h
+++ b/include/libnfnetlink/libnfnetlink.h
@@ -205,6 +205,9 @@ int nlif_catch(struct nlif_handle *nlif_handle);
 int nlif_index2name(struct nlif_handle *nlif_handle, 
 		    unsigned int if_index, 
 		    char *name);
+int nlif_get_ifflags(const struct nlif_handle *h,
+		     unsigned int index,
+		     unsigned int *flags);
 
 #ifdef __cplusplus
 } /* extern "C" */
diff --git a/src/iftable.c b/src/iftable.c
index 3a4b0cb..f316217 100644
--- a/src/iftable.c
+++ b/src/iftable.c
@@ -173,6 +173,39 @@ int nlif_index2name(struct nlif_handle *h,
 	return -1;
 }
 
+/** Get the flags for an ifindex
+ *
+ * \param nlif_handle A pointer to a ::nlif_handle created
+ * \param index ifindex to be resolved
+ * \param flags pointer to variable used to store the interface flags
+ * \return -1 on error, 1 on success 
+ */
+int nlif_get_ifflags(const struct nlif_handle *h,
+		     unsigned int index,
+		     unsigned int *flags)
+{
+	unsigned int hash;
+	struct ifindex_node *this;
+
+	assert(h != NULL);
+	assert(flags != NULL);
+
+	if (index == 0) {
+		errno = ENOENT;
+		return -1;
+	}
+
+	hash = index & 0xF;
+	list_for_each_entry(this, &h->ifindex_hash[hash], head) {
+		if (this->index == index) {
+			*flags = this->flags;
+			return 1;
+		}
+	}
+	errno = ENOENT;
+	return -1;
+}
+
 /** Initialize interface table
  *
  * Initialize rtnl interface and interface table
diff --git a/utils/iftest.c b/utils/iftest.c
index 61d066a..2bbe3a3 100644
--- a/utils/iftest.c
+++ b/utils/iftest.c
@@ -3,6 +3,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <errno.h>
+#include <net/if.h>
 
 #include <libnfnetlink/libnfnetlink.h>
 
@@ -21,10 +22,14 @@ int main()
 
 	for (i=0; i<64; i++) {
 		char name[IFNAMSIZ];
+		unsigned int flags;
 
 		if (nlif_index2name(h, i, name) == -1)
 			continue;
-		printf("index (%d) is %s\n", i, name);
+		if (nlif_get_ifflags(h, i, &flags) == -1)
+			continue;
+		printf("index (%d) is %s (%s)\n", i, name,
+			flags & IFF_RUNNING ? "RUNNING" : "NOT RUNNING");
 	}
 
 	nlif_close(h);