From 0177044b9f53b8d9d4fa80c5846a62f9d5849e8b Mon Sep 17 00:00:00 2001
From: Guy Harris <guy@alum.mit.edu>
Date: Sun, 22 May 2011 10:57:22 -0700
Subject: [PATCH] EOPNOTSUPP from an ethtool ioctl should not be a fatal error.

Not all devices support those ioctls.
---
 pcap-linux.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/pcap-linux.c b/pcap-linux.c
index 60f4e9e8..61d4db07 100644
--- a/pcap-linux.c
+++ b/pcap-linux.c
@@ -4708,7 +4708,7 @@ enter_rfmon_mode(pcap_t *handle, int sock_fd, const char *device)
  */
 #ifdef SIOCETHTOOL
 static int
-iface_ethtool_ioctl(pcap_t *handle, int cmd)
+iface_ethtool_ioctl(pcap_t *handle, int cmd, const char *cmdname)
 {
 	struct ifreq	ifr;
 	struct ethtool_value eval;
@@ -4718,9 +4718,18 @@ iface_ethtool_ioctl(pcap_t *handle, int cmd)
 	eval.cmd = cmd;
 	ifr.ifr_data = (caddr_t)&eval;
 	if (ioctl(handle->fd, SIOCETHTOOL, &ifr) == -1) {
+		if (errno == EOPNOTSUPP) {
+			/*
+			 * OK, let's just return 0, which, in our
+			 * case, either means "no, what we're asking
+			 * about is not enabled" or "all the flags
+			 * are clear (i.e., nothing is enabled)".
+			 */
+			return 0;
+		}
 		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
-		    "%s: 0x%08x ioctl failed: %s", handle->opt.source,
-		    cmd, strerror(errno));
+		    "%s: SIOETHTOOL(%s) ioctl failed: %s", handle->opt.source,
+		    cmdname, strerror(errno));
 		return -1;
 	}
 	return eval.data;	
@@ -4731,13 +4740,13 @@ iface_get_offload(pcap_t *handle)
 {
 	int ret;
 
-	ret = iface_ethtool_ioctl(handle, ETHTOOL_GTSO);
+	ret = iface_ethtool_ioctl(handle, ETHTOOL_GTSO, "ETHTOOL_GTSO");
 	if (ret == -1)
 		return -1;
 	if (ret)
 		return 1;	/* TCP segmentation offloading on */
 
-	ret = iface_ethtool_ioctl(handle, ETHTOOL_GUFO);
+	ret = iface_ethtool_ioctl(handle, ETHTOOL_GUFO, "ETHTOOL_GUFO");
 	if (ret == -1)
 		return -1;
 	if (ret)
@@ -4748,13 +4757,13 @@ iface_get_offload(pcap_t *handle)
 	 * handed to PF_PACKET sockets on transmission?  If not,
 	 * this need not be checked.
 	 */
-	ret = iface_ethtool_ioctl(handle, ETHTOOL_GGSO);
+	ret = iface_ethtool_ioctl(handle, ETHTOOL_GGSO, "ETHTOOL_GGSO");
 	if (ret == -1)
 		return -1;
 	if (ret)
 		return 1;	/* generic segmentation offloading on */
 
-	ret = iface_ethtool_ioctl(handle, ETHTOOL_GFLAGS);
+	ret = iface_ethtool_ioctl(handle, ETHTOOL_GFLAGS, "ETHTOOL_GFLAGS");
 	if (ret == -1)
 		return -1;
 	if (ret & ETH_FLAG_LRO)
@@ -4765,7 +4774,7 @@ iface_get_offload(pcap_t *handle)
 	 * handed to PF_PACKET sockets on receipt?  If not,
 	 * this need not be checked.
 	 */
-	ret = iface_ethtool_ioctl(handle, ETHTOOL_GGRO);
+	ret = iface_ethtool_ioctl(handle, ETHTOOL_GGRO, "ETHTOOL_GGRO");
 	if (ret == -1)
 		return -1;
 	if (ret)
-- 
2.39.5