iscsi tools: merge functions to get net iface name from mac address

There are 3 functions to get the net iface name
from the mac address. This merges them into
one function and moves it to a new file.

1 files changed, 100 insertions, 0 deletions

diff --git a/usr/iscsi_net_util.c b/usr/iscsi_net_util.c
new file mode 100644
index 0000000..e52be82
--- /dev/null
+++ b/usr/iscsi_net_util.c
@@ -0,0 +1,100 @@
+/*
+ * net helpers
+ *
+ * Copyright (C) 2010 Mike Christie
+ * Copyright (C) 2010 Red Hat, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <net/if.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+
+#include "sysdeps.h"
+#include "ethtool-copy.h"
+#include "iscsi_net_util.h"
+#include "log.h"
+
+/**
+ * net_get_dev_from_hwaddress - given a hwaddress return the ethX
+ * @hwaddress: hw address no larger than ISCSI_HWADDRESS_BUF_SIZE
+ * @netdev: buffer of IFNAMSIZ size that will hold the ethX
+ *
+ * Does not support interfaces like a bond or alias because
+ * multiple interfaces will have the same hwaddress.
+ */
+int net_get_dev_from_hwaddress(char *hwaddress, char *netdev)
+{
+	struct if_nameindex *ifni;
+	struct ifreq if_hwaddr;
+	int found = 0, sockfd, i = 0;
+	unsigned char *hwaddr;
+	char tmp_hwaddress[ISCSI_HWADDRESS_BUF_SIZE];
+
+	ifni = if_nameindex();
+	if (ifni == NULL) {
+		log_error("Could not match hwaddress %s to netdev. "
+			  "getifaddrs failed %d", hwaddress, errno);
+		return errno;
+	}
+
+	/* Open a basic socket. */
+	sockfd = socket(AF_INET, SOCK_DGRAM, 0);
+	if (sockfd < 0) {
+		log_error("Could not open socket for ioctl.");
+		goto free_ifni;
+	}
+
+	for (i = 0; ifni[i].if_index && ifni[i].if_name; i++) {
+		struct if_nameindex *n = &ifni[i];
+
+		strlcpy(if_hwaddr.ifr_name, n->if_name, IFNAMSIZ);
+		if (ioctl(sockfd, SIOCGIFHWADDR, &if_hwaddr) < 0) {
+			log_error("Could not match %s to netdevice.",
+				  hwaddress);
+			continue;
+		}
+
+		/* check for ARPHRD_ETHER (ethernet) */
+		if (if_hwaddr.ifr_hwaddr.sa_family != 1)
+			continue;
+		hwaddr = (unsigned char *)if_hwaddr.ifr_hwaddr.sa_data;
+
+		memset(tmp_hwaddress, 0, ISCSI_HWADDRESS_BUF_SIZE);
+		/* TODO should look and covert so we do not need tmp buf */
+		sprintf(tmp_hwaddress, "%2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x",
+			hwaddr[0], hwaddr[1], hwaddr[2], hwaddr[3],
+			hwaddr[4], hwaddr[5]);
+		log_debug(4, "Found hardware address %s", tmp_hwaddress);
+		if (!strcasecmp(tmp_hwaddress, hwaddress)) {
+			log_debug(4, "Matches %s to %s", hwaddress,
+				  n->if_name);
+			memset(netdev, 0, IFNAMSIZ); 
+			strlcpy(netdev, n->if_name, IFNAMSIZ);
+			found = 1;
+			break;
+		}
+	}
+
+	close(sockfd);
+free_ifni:
+	if_freenameindex(ifni);
+	if (!found)
+		return ENODEV;
+	return 0;
+}
+
+