[iproute2] devlink: Fix cmd_dev_param_set() to check configuration mode

Commit Message

Moshe Shemesh Oct. 31, 2021, 6:48 a.m. UTC

This patch is fixing a bug, when param set user command includes
configuration mode which is not supported, the tool may not respond
with error if the requested value is 0. In such case
cmd_dev_param_set_cb() won't find the requested configuration mode and
returns ctx->value as initialized (equal 0). Then cmd_dev_param_set()
may find that requested value equals current value and returns success.

Fixing the bug by adding a flag cmode_found which is set only if
cmd_dev_param_set_cb() finds the requested configuration mode.

Fixes: 13925ae9eb38 ("devlink: Add param command support")
Signed-off-by: Moshe Shemesh <[e-mail]>
---
 devlink/devlink.c | 6 ++++++
 1 file changed, 6 insertions(+)

Patch

diff --git a/devlink/devlink.c b/devlink/devlink.c
index 2f2142e..14fbc85 100644
--- a/devlink/devlink.c
+++ b/devlink/devlink.c
@@ -3036,6 +3036,7 @@  static int cmd_dev_param_show_cb(const struct nlmsghdr *nlh, void *data)
 struct param_ctx {
 	struct dl *dl;
 	int nla_type;
+	bool cmode_found;
 	union {
 		uint8_t vu8;
 		uint16_t vu16;
@@ -3088,6 +3089,7 @@  static int cmd_dev_param_set_cb(const struct nlmsghdr *nlh, void *data)
 
 		cmode = mnl_attr_get_u8(nla_value[DEVLINK_ATTR_PARAM_VALUE_CMODE]);
 		if (cmode == dl->opts.cmode) {
+			ctx->cmode_found = true;
 			val_attr = nla_value[DEVLINK_ATTR_PARAM_VALUE_DATA];
 			switch (nla_type) {
 			case MNL_TYPE_U8:
@@ -3140,6 +3142,10 @@  static int cmd_dev_param_set(struct dl *dl)
 	err = mnlu_gen_socket_sndrcv(&dl->nlg, nlh, cmd_dev_param_set_cb, &ctx);
 	if (err)
 		return err;
+	if (!ctx.cmode_found) {
+		pr_err("Configuration mode not supported\n");
+		return -ENOTSUP;
+	}
 
 	nlh = mnlu_gen_socket_cmd_prepare(&dl->nlg, DEVLINK_CMD_PARAM_SET,
 			       NLM_F_REQUEST | NLM_F_ACK);