[PATCH ethtool] ethtool: print hash function with ethtool -x|--show-rxfh-indir

[Jakub Kicinski]

Make ethtool -x|--show-rxfh-indir print the RSS hash function name.

Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
---
 ethtool.8.in |  3 ++-
 ethtool.c    | 31 +++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/ethtool.8.in b/ethtool.8.in
index 5c36c06385f6..5f5a141c1482 100644
--- a/ethtool.8.in
+++ b/ethtool.8.in
@@ -854,7 +854,8 @@ Show the device's time stamping capabilities and associated 
PTP
 hardware clock.
 .TP
 .B \-x \-\-show\-rxfh\-indir \-\-show\-rxfh
-Retrieves the receive flow hash indirection table and/or RSS hash key.
+Retrieves the receive flow hash indirection table, hash function and RSS hash
+key.
 .TP
 .B \-X \-\-set\-rxfh\-indir \-\-rxfh
 Configures the receive flow hash indirection table and/or RSS hash key.
diff --git a/ethtool.c b/ethtool.c
index 7af039e26b50..2d8dd54752c4 100644
--- a/ethtool.c
+++ b/ethtool.c
@@ -3638,6 +3638,35 @@ static int do_grxfhindir(struct cmd_context *ctx,
        return 0;
 }
 
+static void print_grxfh_hfunc(struct cmd_context *ctx, __u8 hfunc)
+{
+       unsigned int func_id = ffs(hfunc) - 1;
+       struct ethtool_gstrings *strings;
+
+       printf("RSS hash function: ");
+       if (!hfunc) {
+               printf("unknown\n");
+               return;
+       }
+
+       strings = get_stringset(ctx, ETH_SS_RSS_HASH_FUNCS, 0, 1);
+       if (!strings) {
+               if (errno != EOPNOTSUPP)
+                       printf("%s\n", strerror(errno));
+               else
+                       printf("unnamed (%d)\n", func_id);
+               return;
+       }
+
+       if (func_id < strings->len)
+               printf("%s\n",
+                      (char *)strings->data + func_id * ETH_GSTRING_LEN);
+       else
+               printf("unnamed (%d)\n", func_id);
+
+       free(strings);
+}
+
 static int do_grxfh(struct cmd_context *ctx)
 {
        struct ethtool_rxfh rss_head = {0};
@@ -3683,6 +3712,8 @@ static int do_grxfh(struct cmd_context *ctx)
 
        print_indir_table(ctx, &ring_count, rss->indir_size, rss->rss_config);
 
+       print_grxfh_hfunc(ctx, rss->hfunc);
+
        indir_bytes = rss->indir_size * sizeof(rss->rss_config[0]);
        hkey = ((char *)rss->rss_config + indir_bytes);
 
-- 
2.11.0