Add lro support to command in similar manner to TSO, GSO, etc.

Based on patch by Stephen Hemminger
<http://article.gmane.org/gmane.linux.network/88124>.

My changes:
- Changed error return codes for setting LRO to be unique.
- Report failure to get device flags, consistent with other offload settings.
- Fixed code spacing.

Tested with the sfc driver.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>


--- ethtool.c
+++ ethtool.c
@@ -151,7 +151,9 @@
 		"		[ sg on|off ]\n"
 	        "		[ tso on|off ]\n"
 	        "		[ ufo on|off ]\n"
-	        "		[ gso on|off ]\n" },
+                "               [ gso on|off ]\n"
+                "               [ lro on|off ]\n"
+    },
     { "-i", "--driver", MODE_GDRV, "Show driver information" },
     { "-d", "--register-dump", MODE_GREGS, "Do a register dump",
 		"		[ raw on|off ]\n"
@@ -200,6 +202,7 @@
 static int off_tso_wanted = -1;
 static int off_ufo_wanted = -1;
 static int off_gso_wanted = -1;
+static int off_lro_wanted = -1;
 
 static struct ethtool_pauseparam epause;
 static int gpause_changed = 0;
@@ -310,6 +313,7 @@
 	{ "tso", CMDL_BOOL, &off_tso_wanted, NULL },
 	{ "ufo", CMDL_BOOL, &off_ufo_wanted, NULL },
 	{ "gso", CMDL_BOOL, &off_gso_wanted, NULL },
+	{ "lro", CMDL_BOOL, &off_lro_wanted, NULL },
 };
 
 static struct cmdline_info cmdline_pause[] = {
@@ -1207,7 +1211,7 @@
 	return 0;
 }
 
-static int dump_offload (int rx, int tx, int sg, int tso, int ufo, int gso)
+static int dump_offload(int rx, int tx, int sg, int tso, int ufo, int gso, int lro)
 {
 	fprintf(stdout,
 		"rx-checksumming: %s\n"
@@ -1215,13 +1219,15 @@
 		"scatter-gather: %s\n"
 		"tcp segmentation offload: %s\n"
 		"udp fragmentation offload: %s\n"
-		"generic segmentation offload: %s\n",
+		"generic segmentation offload: %s\n"
+		"large receive offload: %s\n",
 		rx ? "on" : "off",
 		tx ? "on" : "off",
 		sg ? "on" : "off",
 		tso ? "on" : "off",
 		ufo ? "on" : "off",
-		gso ? "on" : "off");
+		gso ? "on" : "off",
+		lro ? "on" : "off");
 
 	return 0;
 }
@@ -1485,7 +1491,8 @@
 static int do_goffload(int fd, struct ifreq *ifr)
 {
 	struct ethtool_value eval;
-	int err, allfail = 1, rx = 0, tx = 0, sg = 0, tso = 0, ufo = 0, gso = 0;
+	int err, allfail = 1, rx = 0, tx = 0, sg = 0;
+	int tso = 0, ufo = 0, gso = 0, lro = 0;
 
 	fprintf(stdout, "Offload parameters for %s:\n", devname);
 
@@ -1549,12 +1556,22 @@
 		allfail = 0;
 	}
 
+        eval.cmd = ETHTOOL_GFLAGS;
+        ifr->ifr_data = (caddr_t)&eval;
+        err = ioctl(fd, SIOCETHTOOL, ifr);
+        if (err) {
+                perror("Cannot get device flags");
+        } else {
+                lro = (eval.data & ETH_FLAG_LRO) != 0;
+                allfail = 0;
+       }
+
 	if (allfail) {
 		fprintf(stdout, "no offload info available\n");
 		return 83;
 	}
 
-	return dump_offload(rx, tx, sg, tso, ufo, gso);
+	return dump_offload(rx, tx, sg, tso, ufo, gso, lro);
 }
 
 static int do_soffload(int fd, struct ifreq *ifr)
@@ -1631,6 +1648,30 @@
 			return 90;
 		}
 	}
+        if (off_lro_wanted >= 0) {
+                changed = 1;
+                eval.cmd = ETHTOOL_GFLAGS;
+                eval.data = 0;
+                ifr->ifr_data = (caddr_t)&eval;
+                err = ioctl(fd, SIOCETHTOOL, ifr);
+                if (err) {
+                        perror("Cannot get device flag settings");
+                        return 91;
+                }
+ 
+                eval.cmd = ETHTOOL_SFLAGS;
+                if (off_lro_wanted == 1)
+                        eval.data |= ETH_FLAG_LRO;
+                else
+                        eval.data &= ~ETH_FLAG_LRO;
+ 
+                err = ioctl(fd, SIOCETHTOOL, ifr);
+                if (err) {
+                        perror("Cannot set large receive offload settings");
+                        return 92;
+                }
+        }
+
 	if (!changed) {
 		fprintf(stdout, "no offload settings changed\n");
 	}