[PATCH ethtool-next v5 0/2] add netlink support for rss get

[PATCH ethtool-next v5 0/2] add netlink support for rss get

[Sudheer Mogilappagari]

These patches add netlink based handler to fetch RSS information
using "ethtool -x <eth> [context %d]" command.

Output without --json option
$ethtool -x eno2
RX flow hash indirection table for eno2 with 8 RX ring(s):
    0:      0     0     0     0     0     0     0     0
    8:      1     1     1     1     1     1     1     1
   ...skip similar lines...
  120:      7     7     7     7     7     7     7     7
RSS hash key:
be:c3:13:a6:59:9a:c3:c5:d8:60:75:2b:4c:b2:12:cc:5c:4e:34:
8a:f9:ab:16:c7:19:5d:ab:1d:b5:c1:c7:57:c7:a2:e1:2b:e3:ea:
02:60:88:8e:96:ef:2d:64:d2:de:2c:16:72:b6
RSS hash function:
    toeplitz: on
    xor: off
    crc32: off

Sample output with json option:
$ethtool --json -x eno2
[ {
    "ifname": "eno2",
    "rss-indirection-table": [ 0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,
    ...skip similar lines...
    7,7,7,7,7,7,7,7 ],
    "rss-hash-key": [ 190,195,19,166,..],
    "rss-hash-function": "toeplitz"
    } ]

Signed-off-by: Sudheer Mogilappagari <sudheer.mogilappagari@intel.com>
---
v5:
- Fixed use of same socket for fetching rings info and RSS info
- Added checks to test if a field exists before accessing reply message
- Refactor print functions and avoid use of ethtool_rxfh structure

v4: 
-Fixed hash function values in example output of commit message.

v3:
-Made hash key as an array of ints.
-Skip json field when not supported.
-Made hash function values as true/false instead of on/off
-Formatted key strings as per review comments. 

v2:
-Added json support
---
Sudheer Mogilappagari (2):
  Move code that print rss info into common file
  netlink: add netlink handler for get rss (-x)

 Makefile.am            |   2 +-
 common.c               |  36 +++++++
 common.h               |   6 +-
 ethtool.c              |  43 ++------
 netlink/desc-ethtool.c |  11 ++
 netlink/extapi.h       |   2 +
 netlink/rss.c          | 228 +++++++++++++++++++++++++++++++++++++++++
 7 files changed, 291 insertions(+), 37 deletions(-)
 create mode 100644 netlink/rss.c

-- 
2.31.1

[PATCH ethtool-next v5 1/2] Move code that print rss info into common file

[Sudheer Mogilappagari]

Move function that prints rss indirection table and hash key into
common file for use by both netlink and ioctl interface. Changed
function argument to be ring count instead of structure.

Signed-off-by: Sudheer Mogilappagari <sudheer.mogilappagari@intel.com>
---
 common.c  | 36 ++++++++++++++++++++++++++++++++++++
 common.h  |  6 +++++-
 ethtool.c | 42 +++++++-----------------------------------
 3 files changed, 48 insertions(+), 36 deletions(-)

diff --git a/common.c b/common.c
index 2630e73..b8fd4d5 100644
--- a/common.c
+++ b/common.c
@@ -173,3 +173,39 @@ void dump_mdix(u8 mdix, u8 mdix_ctrl)
 		fprintf(stdout, "\n");
 	}
 }
+
+void print_indir_table(struct cmd_context *ctx, u64 ring_count,
+		       u32 indir_size, u32 *indir)
+{
+	u32 i;
+
+	printf("RX flow hash indirection table for %s with %llu RX ring(s):\n",
+	       ctx->devname, ring_count);
+
+	if (!indir_size)
+		printf("Operation not supported\n");
+
+	for (i = 0; i < indir_size; i++) {
+		if (i % 8 == 0)
+			printf("%5u: ", i);
+		printf(" %5u", indir[i]);
+		if (i % 8 == 7 || i == indir_size - 1)
+			fputc('\n', stdout);
+	}
+}
+
+void print_rss_hkey(u8 *hkey, u32 hkey_size)
+{
+	u32 i;
+
+	printf("RSS hash key:\n");
+	if (!hkey_size || !hkey)
+		printf("Operation not supported\n");
+
+	for (i = 0; i < hkey_size; i++) {
+		if (i == (hkey_size - 1))
+			printf("%02x\n", hkey[i]);
+		else
+			printf("%02x:", hkey[i]);
+	}
+}
diff --git a/common.h b/common.h
index b74fdfa..f975407 100644
--- a/common.h
+++ b/common.h
@@ -8,6 +8,8 @@
 #define ETHTOOL_COMMON_H__
 
 #include "internal.h"
+#include <stddef.h>
+#include <errno.h>
 
 #define KERNEL_VERSION(a, b, c) (((a) << 16) + ((b) << 8) + (c))
 
@@ -41,5 +43,7 @@ extern const struct off_flag_def off_flag_def[OFF_FLAG_DEF_SIZE];
 void print_flags(const struct flag_info *info, unsigned int n_info, u32 value);
 int dump_wol(struct ethtool_wolinfo *wol);
 void dump_mdix(u8 mdix, u8 mdix_ctrl);
-
+void print_indir_table(struct cmd_context *ctx, u64 ring_count,
+		       u32 indir_size, u32 *indir);
+void print_rss_hkey(u8 *hkey, u32 hkey_size);
 #endif /* ETHTOOL_COMMON_H__ */
diff --git a/ethtool.c b/ethtool.c
index 60da8af..ea74684 100644
--- a/ethtool.c
+++ b/ethtool.c
@@ -3900,27 +3900,6 @@ static int do_grxclass(struct cmd_context *ctx)
 	return err ? 1 : 0;
 }
 
-static void print_indir_table(struct cmd_context *ctx,
-			      struct ethtool_rxnfc *ring_count,
-			      u32 indir_size, u32 *indir)
-{
-	u32 i;
-
-	printf("RX flow hash indirection table for %s with %llu RX ring(s):\n",
-	       ctx->devname, ring_count->data);
-
-	if (!indir_size)
-		printf("Operation not supported\n");
-
-	for (i = 0; i < indir_size; i++) {
-		if (i % 8 == 0)
-			printf("%5u: ", i);
-		printf(" %5u", indir[i]);
-		if (i % 8 == 7 || i == indir_size - 1)
-			fputc('\n', stdout);
-	}
-}
-
 static int do_grxfhindir(struct cmd_context *ctx,
 			 struct ethtool_rxnfc *ring_count)
 {
@@ -3952,7 +3931,8 @@ static int do_grxfhindir(struct cmd_context *ctx,
 		return 1;
 	}
 
-	print_indir_table(ctx, ring_count, indir->size, indir->ring_index);
+	print_indir_table(ctx, ring_count->data, indir->size,
+			  indir->ring_index);
 
 	free(indir);
 	return 0;
@@ -3967,7 +3947,7 @@ static int do_grxfh(struct cmd_context *ctx)
 	u32 rss_context = 0;
 	u32 i, indir_bytes;
 	unsigned int arg_num = 0;
-	char *hkey;
+	u8 *hkey;
 	int err;
 
 	while (arg_num < ctx->argc) {
@@ -4017,21 +3997,13 @@ static int do_grxfh(struct cmd_context *ctx)
 		return 1;
 	}
 
-	print_indir_table(ctx, &ring_count, rss->indir_size, rss->rss_config);
+	print_indir_table(ctx, ring_count.data, rss->indir_size,
+			  rss->rss_config);
 
 	indir_bytes = rss->indir_size * sizeof(rss->rss_config[0]);
-	hkey = ((char *)rss->rss_config + indir_bytes);
-
-	printf("RSS hash key:\n");
-	if (!rss->key_size)
-		printf("Operation not supported\n");
+	hkey = ((u8 *)rss->rss_config + indir_bytes);
 
-	for (i = 0; i < rss->key_size; i++) {
-		if (i == (rss->key_size - 1))
-			printf("%02x\n", (u8) hkey[i]);
-		else
-			printf("%02x:", (u8) hkey[i]);
-	}
+	print_rss_hkey(hkey, rss->key_size);
 
 	printf("RSS hash function:\n");
 	if (!rss->hfunc) {
-- 
2.31.1

[PATCH ethtool-next v5 2/2] netlink: add netlink handler for get rss (-x)

[Sudheer Mogilappagari]

Add support for netlink based "ethtool -x <dev>" command using
ETHTOOL_MSG_RSS_GET netlink message. It implements same functionality
provided by traditional ETHTOOL_GRSSH subcommand. This displays RSS
table, hash key and hash function along with JSON support.

Sample output with json option:
$ethtool --json -x eno2
[ {
    "ifname": "eno2",
    "rss-indirection-table": [ 0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,
    ...skip similar lines...
    7,7,7,7,7,7,7,7 ],
    "rss-hash-key": [ 190,195,19,166,..],
    "rss-hash-function": "toeplitz"
    } ]

Signed-off-by: Sudheer Mogilappagari <sudheer.mogilappagari@intel.com>
---
 Makefile.am            |   2 +-
 ethtool.c              |   2 +
 netlink/desc-ethtool.c |  11 ++
 netlink/extapi.h       |   2 +
 netlink/rss.c          | 228 +++++++++++++++++++++++++++++++++++++++++
 5 files changed, 244 insertions(+), 1 deletion(-)
 create mode 100644 netlink/rss.c

diff --git a/Makefile.am b/Makefile.am
index 663f40a..c3e7401 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -39,7 +39,7 @@ ethtool_SOURCES += \
 		  netlink/eee.c netlink/tsinfo.c netlink/fec.c \
 		  netlink/stats.c \
 		  netlink/desc-ethtool.c netlink/desc-genlctrl.c \
-		  netlink/module-eeprom.c netlink/module.c \
+		  netlink/module-eeprom.c netlink/module.c netlink/rss.c \
 		  netlink/desc-rtnl.c netlink/cable_test.c netlink/tunnels.c \
 		  uapi/linux/ethtool_netlink.h \
 		  uapi/linux/netlink.h uapi/linux/genetlink.h \
diff --git a/ethtool.c b/ethtool.c
index ea74684..1355995 100644
--- a/ethtool.c
+++ b/ethtool.c
@@ -5858,7 +5858,9 @@ static const struct option args[] = {
 	},
 	{
 		.opts	= "-x|--show-rxfh-indir|--show-rxfh",
+		.json	= true,
 		.func	= do_grxfh,
+		.nlfunc	= nl_grss,
 		.help	= "Show Rx flow hash indirection table and/or RSS hash key",
 		.xhelp	= "		[ context %d ]\n"
 	},
diff --git a/netlink/desc-ethtool.c b/netlink/desc-ethtool.c
index b3ac64d..ed83dae 100644
--- a/netlink/desc-ethtool.c
+++ b/netlink/desc-ethtool.c
@@ -442,6 +442,15 @@ static const struct pretty_nla_desc __pse_desc[] = {
 	NLATTR_DESC_U32_ENUM(ETHTOOL_A_PODL_PSE_PW_D_STATUS, pse_pw_d_status),
 };
 
+static const struct pretty_nla_desc __rss_desc[] = {
+	NLATTR_DESC_INVALID(ETHTOOL_A_MODULE_UNSPEC),
+	NLATTR_DESC_NESTED(ETHTOOL_A_MODULE_HEADER, header),
+	NLATTR_DESC_U32(ETHTOOL_A_RSS_CONTEXT),
+	NLATTR_DESC_U32(ETHTOOL_A_RSS_HFUNC),
+	NLATTR_DESC_BINARY(ETHTOOL_A_RSS_INDIR),
+	NLATTR_DESC_BINARY(ETHTOOL_A_RSS_HKEY),
+};
+
 const struct pretty_nlmsg_desc ethnl_umsg_desc[] = {
 	NLMSG_DESC_INVALID(ETHTOOL_MSG_USER_NONE),
 	NLMSG_DESC(ETHTOOL_MSG_STRSET_GET, strset),
@@ -481,6 +490,7 @@ const struct pretty_nlmsg_desc ethnl_umsg_desc[] = {
 	NLMSG_DESC(ETHTOOL_MSG_MODULE_SET, module),
 	NLMSG_DESC(ETHTOOL_MSG_PSE_GET, pse),
 	NLMSG_DESC(ETHTOOL_MSG_PSE_SET, pse),
+	NLMSG_DESC(ETHTOOL_MSG_RSS_GET, rss),
 };
 
 const unsigned int ethnl_umsg_n_desc = ARRAY_SIZE(ethnl_umsg_desc);
@@ -524,6 +534,7 @@ const struct pretty_nlmsg_desc ethnl_kmsg_desc[] = {
 	NLMSG_DESC(ETHTOOL_MSG_MODULE_GET_REPLY, module),
 	NLMSG_DESC(ETHTOOL_MSG_MODULE_NTF, module),
 	NLMSG_DESC(ETHTOOL_MSG_PSE_GET_REPLY, pse),
+	NLMSG_DESC(ETHTOOL_MSG_RSS_GET_REPLY, rss),
 };
 
 const unsigned int ethnl_kmsg_n_desc = ARRAY_SIZE(ethnl_kmsg_desc);
diff --git a/netlink/extapi.h b/netlink/extapi.h
index 1bb580a..9b6dd1a 100644
--- a/netlink/extapi.h
+++ b/netlink/extapi.h
@@ -47,6 +47,7 @@ int nl_gmodule(struct cmd_context *ctx);
 int nl_smodule(struct cmd_context *ctx);
 int nl_monitor(struct cmd_context *ctx);
 int nl_getmodule(struct cmd_context *ctx);
+int nl_grss(struct cmd_context *ctx);
 
 void nl_monitor_usage(void);
 
@@ -114,6 +115,7 @@ nl_get_eeprom_page(struct cmd_context *ctx __maybe_unused,
 #define nl_getmodule		NULL
 #define nl_gmodule		NULL
 #define nl_smodule		NULL
+#define nl_grss			NULL
 
 #endif /* ETHTOOL_ENABLE_NETLINK */
 
diff --git a/netlink/rss.c b/netlink/rss.c
new file mode 100644
index 0000000..0b2f87a
--- /dev/null
+++ b/netlink/rss.c
@@ -0,0 +1,228 @@
+/*
+ * rss.c - netlink implementation of RSS context commands
+ *
+ * Implementation of "ethtool -x <dev>"
+ */
+
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "../internal.h"
+#include "../common.h"
+#include "netlink.h"
+#include "strset.h"
+#include "parser.h"
+
+struct cb_args {
+	struct nl_context	*nlctx;
+	u32			num_rings;
+};
+
+void dump_json_rss_info(struct cmd_context *ctx, u32 *indir_table,
+			u32 indir_size, u8 *hkey, u32 hkey_size,
+			const struct stringset *hash_funcs, u8 hfunc)
+{
+	unsigned int i;
+
+	open_json_object(NULL);
+	print_string(PRINT_JSON, "ifname", NULL, ctx->devname);
+	if (indir_size) {
+		open_json_array("rss-indirection-table", NULL);
+		for (i = 0; i < indir_size; i++)
+			print_uint(PRINT_JSON, NULL, NULL, indir_table[i]);
+		close_json_array("\n");
+	}
+
+	if (hkey_size) {
+		open_json_array("rss-hash-key", NULL);
+		for (i = 0; i < hkey_size; i++)
+			print_uint(PRINT_JSON, NULL, NULL, (u8)hkey[i]);
+		close_json_array("\n");
+	}
+
+	if (hfunc) {
+		for (i = 0; i < get_count(hash_funcs); i++) {
+			if (hfunc & (1 << i))
+				print_string(PRINT_JSON, "rss-hash-function",
+					     NULL, get_string(hash_funcs, i));
+		}
+	}
+
+	close_json_object();
+}
+
+int get_channels_cb(const struct nlmsghdr *nlhdr, void *data)
+{
+	const struct nlattr *tb[ETHTOOL_A_CHANNELS_MAX + 1] = {};
+	DECLARE_ATTR_TB_INFO(tb);
+	struct cb_args *args = data;
+	struct nl_context *nlctx =  args->nlctx;
+	bool silent;
+	int err_ret;
+	int ret;
+
+	silent = nlctx->is_dump || nlctx->is_monitor;
+	err_ret = silent ? MNL_CB_OK : MNL_CB_ERROR;
+	ret = mnl_attr_parse(nlhdr, GENL_HDRLEN, attr_cb, &tb_info);
+	if (ret < 0)
+		return err_ret;
+	nlctx->devname = get_dev_name(tb[ETHTOOL_A_CHANNELS_HEADER]);
+	if (!dev_ok(nlctx))
+		return err_ret;
+	if (tb[ETHTOOL_A_CHANNELS_COMBINED_COUNT])
+		args->num_rings = mnl_attr_get_u32(tb[ETHTOOL_A_CHANNELS_COMBINED_COUNT]);
+	if (tb[ETHTOOL_A_CHANNELS_RX_COUNT])
+		args->num_rings += mnl_attr_get_u32(tb[ETHTOOL_A_CHANNELS_RX_COUNT]);
+	return MNL_CB_OK;
+}
+
+int rss_reply_cb(const struct nlmsghdr *nlhdr, void *data)
+{
+	const struct nlattr *tb[ETHTOOL_A_RSS_MAX + 1] = {};
+	unsigned int indir_bytes = 0, hkey_bytes = 0;
+	DECLARE_ATTR_TB_INFO(tb);
+	struct cb_args *args = data;
+	struct nl_context *nlctx = args->nlctx;
+	const struct stringset *hash_funcs;
+	u32 rss_hfunc = 0, indir_size;
+	u32 *indir_table = NULL;
+	u8 *hkey = NULL;
+	bool silent;
+	int err_ret;
+	int ret;
+
+	silent = nlctx->is_dump || nlctx->is_monitor;
+	err_ret = silent ? MNL_CB_OK : MNL_CB_ERROR;
+	ret = mnl_attr_parse(nlhdr, GENL_HDRLEN, attr_cb, &tb_info);
+	if (ret < 0)
+		return err_ret;
+	nlctx->devname = get_dev_name(tb[ETHTOOL_A_RSS_HEADER]);
+	if (!dev_ok(nlctx))
+		return err_ret;
+
+	show_cr();
+
+	if (tb[ETHTOOL_A_RSS_HFUNC])
+		rss_hfunc = mnl_attr_get_u32(tb[ETHTOOL_A_RSS_HFUNC]);
+	if (tb[ETHTOOL_A_RSS_INDIR]) {
+		indir_bytes = mnl_attr_get_payload_len(tb[ETHTOOL_A_RSS_INDIR]);
+		indir_table = mnl_attr_get_payload(tb[ETHTOOL_A_RSS_INDIR]);
+	}
+
+	if (tb[ETHTOOL_A_RSS_HKEY]) {
+		hkey_bytes = mnl_attr_get_payload_len(tb[ETHTOOL_A_RSS_HKEY]);
+		hkey = mnl_attr_get_payload(tb[ETHTOOL_A_RSS_HKEY]);
+	}
+
+	/* Fetch RSS hash functions and their status and print */
+	if (!nlctx->is_monitor) {
+		ret = netlink_init_ethnl2_socket(nlctx);
+		if (ret < 0)
+			return MNL_CB_ERROR;
+	}
+	hash_funcs = global_stringset(ETH_SS_RSS_HASH_FUNCS,
+				      nlctx->ethnl2_socket);
+
+	ret = mnl_attr_parse(nlhdr, GENL_HDRLEN, attr_cb, &tb_info);
+	if (ret < 0)
+		return silent ? MNL_CB_OK : MNL_CB_ERROR;
+
+	nlctx->devname = get_dev_name(tb[ETHTOOL_A_RSS_HEADER]);
+	if (!dev_ok(nlctx))
+		return MNL_CB_OK;
+
+	/* Fetch ring count info into args->num_rings */
+	ret = nlsock_prep_get_request(nlctx->ethnl2_socket,
+				      ETHTOOL_MSG_CHANNELS_GET,
+				      ETHTOOL_A_CHANNELS_HEADER, 0);
+	if (ret < 0)
+		return MNL_CB_ERROR;
+
+	ret = nlsock_sendmsg(nlctx->ethnl2_socket, NULL);
+	if (ret < 0)
+		return MNL_CB_ERROR;
+
+	ret = nlsock_process_reply(nlctx->ethnl2_socket, get_channels_cb, args);
+
+	if (ret < 0)
+		return MNL_CB_ERROR;
+
+	indir_size = indir_bytes / sizeof(u32);
+	if (is_json_context()) {
+		dump_json_rss_info(nlctx->ctx, (u32 *)indir_table, indir_size,
+				   hkey, hkey_bytes, hash_funcs, rss_hfunc);
+	} else {
+		print_indir_table(nlctx->ctx, args->num_rings,
+				  indir_size, (u32 *)indir_table);
+		print_rss_hkey(hkey, hkey_bytes);
+		printf("RSS hash function:\n");
+		if (!rss_hfunc) {
+			printf("    Operation not supported\n");
+			return 0;
+		}
+		for (unsigned int i = 0; i < get_count(hash_funcs); i++) {
+			printf("    %s: %s\n", get_string(hash_funcs, i),
+			       (rss_hfunc & (1 << i)) ? "on" : "off");
+		}
+	}
+
+	return MNL_CB_OK;
+}
+
+/* RSS_GET */
+static const struct param_parser grss_params[] = {
+	{
+		.arg		= "context",
+		.type		= ETHTOOL_A_RSS_CONTEXT,
+		.handler	= nl_parse_direct_u32,
+		.min_argc	= 1,
+	},
+	{}
+};
+
+int nl_grss(struct cmd_context *ctx)
+{
+	struct nl_context *nlctx = ctx->nlctx;
+	struct nl_socket *nlsk = nlctx->ethnl_socket;
+	struct nl_msg_buff *msgbuff;
+	struct cb_args args = {};
+	int ret;
+
+	nlctx->cmd = "-x";
+	nlctx->argp = ctx->argp;
+	nlctx->argc = ctx->argc;
+	nlctx->devname = ctx->devname;
+	nlsk = nlctx->ethnl_socket;
+	msgbuff = &nlsk->msgbuff;
+
+	if (netlink_cmd_check(ctx, ETHTOOL_MSG_RSS_GET, true))
+		return -EOPNOTSUPP;
+
+	ret = msg_init(nlctx, msgbuff, ETHTOOL_MSG_RSS_GET,
+		       NLM_F_REQUEST | NLM_F_ACK);
+	if (ret < 0)
+		return 1;
+	if (ethnla_fill_header(msgbuff, ETHTOOL_A_RSS_HEADER,
+			       ctx->devname, 0))
+		return -EMSGSIZE;
+
+	ret = nl_parser(nlctx, grss_params, NULL, PARSER_GROUP_NONE, NULL);
+	if (ret < 0)
+		goto err;
+
+	new_json_obj(ctx->json);
+	ret = nlsock_sendmsg(nlsk, NULL);
+	if (ret < 0)
+		goto err;
+
+	args.nlctx = nlctx;
+	ret = nlsock_process_reply(nlsk, rss_reply_cb, &args);
+	delete_json_obj();
+
+	if (ret == 0)
+		return 0;
+err:
+	return nlctx->exit_code ?: 1;
+}
+
-- 
2.31.1

Re: [PATCH ethtool-next v5 2/2] netlink: add netlink handler for get rss (-x)

[Jakub Kicinski]

LGTM! Couple of nit picks

On Mon,  9 Jan 2023 20:52:45 -0800 Sudheer Mogilappagari wrote:
> +	if (hfunc) {
> +		for (i = 0; i < get_count(hash_funcs); i++) {
> +			if (hfunc & (1 << i))
> +				print_string(PRINT_JSON, "rss-hash-function",
> +					     NULL, get_string(hash_funcs, i));

break?

> +		}
> +	}

> +	ret = nlsock_process_reply(nlctx->ethnl2_socket, get_channels_cb, args);
> +
> +	if (ret < 0)
> +		return MNL_CB_ERROR;

no empty lines between function call and the error check