From 0c95cea24f30eb28d464c593d8fbd64cd305791b Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 25 Aug 2022 20:09:30 -0700 Subject: [PATCH 1/6] netlink: factor out extack composition The ext_ack writing code looks very "organically grown". Move the calculation of the size and writing out to helpers. This is more idiomatic and gives us the ability to return early avoiding the long (and randomly ordered) "if" conditions. Reviewed-by: Johannes Berg Signed-off-by: Jakub Kicinski Signed-off-by: Paolo Abeni --- net/netlink/af_netlink.c | 85 ++++++++++++++++++++++++++-------------- 1 file changed, 55 insertions(+), 30 deletions(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 0cd91f813a3b..7eae157c1625 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2400,6 +2400,57 @@ error_free: } EXPORT_SYMBOL(__netlink_dump_start); +static size_t +netlink_ack_tlv_len(struct netlink_sock *nlk, int err, + const struct netlink_ext_ack *extack) +{ + size_t tlvlen; + + if (!extack || !(nlk->flags & NETLINK_F_EXT_ACK)) + return 0; + + tlvlen = 0; + if (extack->_msg) + tlvlen += nla_total_size(strlen(extack->_msg) + 1); + if (extack->cookie_len) + tlvlen += nla_total_size(extack->cookie_len); + + /* Following attributes are only reported as error (not warning) */ + if (!err) + return tlvlen; + + if (extack->bad_attr) + tlvlen += nla_total_size(sizeof(u32)); + if (extack->policy) + tlvlen += netlink_policy_dump_attr_size_estimate(extack->policy); + + return tlvlen; +} + +static void +netlink_ack_tlv_fill(struct sk_buff *in_skb, struct sk_buff *skb, + struct nlmsghdr *nlh, int err, + const struct netlink_ext_ack *extack) +{ + if (extack->_msg) + WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg)); + if (extack->cookie_len) + WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE, + extack->cookie_len, extack->cookie)); + + if (!err) + return; + + if (extack->bad_attr && + !WARN_ON((u8 *)extack->bad_attr < in_skb->data || + (u8 *)extack->bad_attr >= in_skb->data + in_skb->len)) + WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS, + (u8 *)extack->bad_attr - (u8 *)nlh)); + if (extack->policy) + netlink_policy_dump_write_attr(skb, extack->policy, + NLMSGERR_ATTR_POLICY); +} + void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, const struct netlink_ext_ack *extack) { @@ -2407,29 +2458,20 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, struct nlmsghdr *rep; struct nlmsgerr *errmsg; size_t payload = sizeof(*errmsg); - size_t tlvlen = 0; struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk); unsigned int flags = 0; - bool nlk_has_extack = nlk->flags & NETLINK_F_EXT_ACK; + size_t tlvlen; /* Error messages get the original request appened, unless the user * requests to cap the error message, and get extra error data if * requested. */ - if (nlk_has_extack && extack && extack->_msg) - tlvlen += nla_total_size(strlen(extack->_msg) + 1); - if (err && !(nlk->flags & NETLINK_F_CAP_ACK)) payload += nlmsg_len(nlh); else flags |= NLM_F_CAPPED; - if (err && nlk_has_extack && extack && extack->bad_attr) - tlvlen += nla_total_size(sizeof(u32)); - if (nlk_has_extack && extack && extack->cookie_len) - tlvlen += nla_total_size(extack->cookie_len); - if (err && nlk_has_extack && extack && extack->policy) - tlvlen += netlink_policy_dump_attr_size_estimate(extack->policy); + tlvlen = netlink_ack_tlv_len(nlk, err, extack); if (tlvlen) flags |= NLM_F_ACK_TLVS; @@ -2446,25 +2488,8 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, errmsg->error = err; memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh)); - if (nlk_has_extack && extack) { - if (extack->_msg) { - WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG, - extack->_msg)); - } - if (err && extack->bad_attr && - !WARN_ON((u8 *)extack->bad_attr < in_skb->data || - (u8 *)extack->bad_attr >= in_skb->data + - in_skb->len)) - WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS, - (u8 *)extack->bad_attr - - (u8 *)nlh)); - if (extack->cookie_len) - WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE, - extack->cookie_len, extack->cookie)); - if (extack->policy) - netlink_policy_dump_write_attr(skb, extack->policy, - NLMSGERR_ATTR_POLICY); - } + if (tlvlen) + netlink_ack_tlv_fill(in_skb, skb, nlh, err, extack); nlmsg_end(skb, rep); From 690252f19f0e486abb8590b3a7a03d4e065d93d4 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 25 Aug 2022 20:09:31 -0700 Subject: [PATCH 2/6] netlink: add support for ext_ack missing attributes There is currently no way to report via extack in a structured way that an attribute is missing. This leads to families resorting to string messages. Add a pair of attributes - @offset and @type for machine-readable way of reporting missing attributes. The @offset points to the nest which should have contained the attribute, @type is the expected nla_type. The offset will be skipped if the attribute is missing at the message level rather than inside a nest. User space should be able to figure out which attribute enum (AKA attribute space AKA attribute set) the nest pointed to by @offset is using. Reviewed-by: Johannes Berg Signed-off-by: Jakub Kicinski Signed-off-by: Paolo Abeni --- Documentation/userspace-api/netlink/intro.rst | 7 +++++-- include/linux/netlink.h | 13 +++++++++++++ include/uapi/linux/netlink.h | 6 ++++++ net/netlink/af_netlink.c | 12 ++++++++++++ 4 files changed, 36 insertions(+), 2 deletions(-) diff --git a/Documentation/userspace-api/netlink/intro.rst b/Documentation/userspace-api/netlink/intro.rst index 94337f79e077..8f1220756412 100644 --- a/Documentation/userspace-api/netlink/intro.rst +++ b/Documentation/userspace-api/netlink/intro.rst @@ -359,8 +359,8 @@ compatibility this feature has to be explicitly enabled by setting the ``NETLINK_EXT_ACK`` setsockopt() to ``1``. Types of extended ack attributes are defined in enum nlmsgerr_attrs. -The two most commonly used attributes are ``NLMSGERR_ATTR_MSG`` -and ``NLMSGERR_ATTR_OFFS``. +The most commonly used attributes are ``NLMSGERR_ATTR_MSG``, +``NLMSGERR_ATTR_OFFS`` and ``NLMSGERR_ATTR_MISS_*``. ``NLMSGERR_ATTR_MSG`` carries a message in English describing the encountered problem. These messages are far more detailed @@ -368,6 +368,9 @@ than what can be expressed thru standard UNIX error codes. ``NLMSGERR_ATTR_OFFS`` points to the attribute which caused the problem. +``NLMSGERR_ATTR_MISS_TYPE`` and ``NLMSGERR_ATTR_MISS_NEST`` +inform about a missing attribute. + Extended ACKs can be reported on errors as well as in case of success. The latter should be treated as a warning. diff --git a/include/linux/netlink.h b/include/linux/netlink.h index bda1c385cffb..1619221c415c 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -71,6 +71,8 @@ netlink_kernel_create(struct net *net, int unit, struct netlink_kernel_cfg *cfg) * %NL_SET_ERR_MSG * @bad_attr: attribute with error * @policy: policy for a bad attribute + * @miss_type: attribute type which was missing + * @miss_nest: nest missing an attribute (%NULL if missing top level attr) * @cookie: cookie data to return to userspace (for success) * @cookie_len: actual cookie data length */ @@ -78,6 +80,8 @@ struct netlink_ext_ack { const char *_msg; const struct nlattr *bad_attr; const struct nla_policy *policy; + const struct nlattr *miss_nest; + u16 miss_type; u8 cookie[NETLINK_MAX_COOKIE_LEN]; u8 cookie_len; }; @@ -126,6 +130,15 @@ struct netlink_ext_ack { #define NL_SET_ERR_MSG_ATTR(extack, attr, msg) \ NL_SET_ERR_MSG_ATTR_POL(extack, attr, NULL, msg) +#define NL_SET_ERR_ATTR_MISS(extack, nest, type) do { \ + struct netlink_ext_ack *__extack = (extack); \ + \ + if (__extack) { \ + __extack->miss_nest = (nest); \ + __extack->miss_type = (type); \ + } \ +} while (0) + static inline void nl_set_extack_cookie_u64(struct netlink_ext_ack *extack, u64 cookie) { diff --git a/include/uapi/linux/netlink.h b/include/uapi/linux/netlink.h index e0ab261ceca2..e0689dbd2cde 100644 --- a/include/uapi/linux/netlink.h +++ b/include/uapi/linux/netlink.h @@ -140,6 +140,10 @@ struct nlmsgerr { * be used - in the success case - to identify a created * object or operation or similar (binary) * @NLMSGERR_ATTR_POLICY: policy for a rejected attribute + * @NLMSGERR_ATTR_MISS_TYPE: type of a missing required attribute, + * %NLMSGERR_ATTR_MISS_NEST will not be present if the attribute was + * missing at the message level + * @NLMSGERR_ATTR_MISS_NEST: offset of the nest where attribute was missing * @__NLMSGERR_ATTR_MAX: number of attributes * @NLMSGERR_ATTR_MAX: highest attribute number */ @@ -149,6 +153,8 @@ enum nlmsgerr_attrs { NLMSGERR_ATTR_OFFS, NLMSGERR_ATTR_COOKIE, NLMSGERR_ATTR_POLICY, + NLMSGERR_ATTR_MISS_TYPE, + NLMSGERR_ATTR_MISS_NEST, __NLMSGERR_ATTR_MAX, NLMSGERR_ATTR_MAX = __NLMSGERR_ATTR_MAX - 1 diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 7eae157c1625..f89ba302ac6e 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2423,6 +2423,10 @@ netlink_ack_tlv_len(struct netlink_sock *nlk, int err, tlvlen += nla_total_size(sizeof(u32)); if (extack->policy) tlvlen += netlink_policy_dump_attr_size_estimate(extack->policy); + if (extack->miss_type) + tlvlen += nla_total_size(sizeof(u32)); + if (extack->miss_nest) + tlvlen += nla_total_size(sizeof(u32)); return tlvlen; } @@ -2449,6 +2453,14 @@ netlink_ack_tlv_fill(struct sk_buff *in_skb, struct sk_buff *skb, if (extack->policy) netlink_policy_dump_write_attr(skb, extack->policy, NLMSGERR_ATTR_POLICY); + if (extack->miss_type) + WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_MISS_TYPE, + extack->miss_type)); + if (extack->miss_nest && + !WARN_ON((u8 *)extack->miss_nest < in_skb->data || + (u8 *)extack->miss_nest > in_skb->data + in_skb->len)) + WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_MISS_NEST, + (u8 *)extack->miss_nest - (u8 *)nlh)); } void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, From 45dca15759643806660e9285e6af8a1ba3c76c82 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 25 Aug 2022 20:09:32 -0700 Subject: [PATCH 3/6] netlink: add helpers for extack attr presence checking Being able to check attribute presence and set extack if not on one line is handy, add helpers. Reviewed-by: Johannes Berg Signed-off-by: Jakub Kicinski Signed-off-by: Paolo Abeni --- include/linux/netlink.h | 11 +++++++++++ include/net/genetlink.h | 7 +++++++ 2 files changed, 18 insertions(+) diff --git a/include/linux/netlink.h b/include/linux/netlink.h index 1619221c415c..d51e041d2242 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -139,6 +139,17 @@ struct netlink_ext_ack { } \ } while (0) +#define NL_REQ_ATTR_CHECK(extack, nest, tb, type) ({ \ + struct nlattr **__tb = (tb); \ + u32 __attr = (type); \ + int __retval; \ + \ + __retval = !__tb[__attr]; \ + if (__retval) \ + NL_SET_ERR_ATTR_MISS((extack), (nest), __attr); \ + __retval; \ +}) + static inline void nl_set_extack_cookie_u64(struct netlink_ext_ack *extack, u64 cookie) { diff --git a/include/net/genetlink.h b/include/net/genetlink.h index a4827b5e1e07..8f780170e2f8 100644 --- a/include/net/genetlink.h +++ b/include/net/genetlink.h @@ -110,6 +110,13 @@ static inline void genl_info_net_set(struct genl_info *info, struct net *net) #define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg) +/* Report that a root attribute is missing */ +#define GENL_REQ_ATTR_CHECK(info, attr) ({ \ + struct genl_info *__info = (info); \ + \ + NL_REQ_ATTR_CHECK(__info->extack, NULL, __info->attrs, (attr)); \ +}) + enum genl_validate_flags { GENL_DONT_VALIDATE_STRICT = BIT(0), GENL_DONT_VALIDATE_DUMP = BIT(1), From 1f7633b58facf399eee0b049ed6b6d89b8beeba5 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 25 Aug 2022 20:09:33 -0700 Subject: [PATCH 4/6] devlink: use missing attribute ext_ack Devlink with its global attr policy has a lot of attribute presence check, use the new ext ack reporting when they are missing. Reviewed-by: Johannes Berg Signed-off-by: Jakub Kicinski Signed-off-by: Paolo Abeni --- net/core/devlink.c | 41 ++++++++++++++++++++--------------------- 1 file changed, 20 insertions(+), 21 deletions(-) diff --git a/net/core/devlink.c b/net/core/devlink.c index 3396fdf802b6..95fd20ef5862 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -1710,7 +1710,7 @@ static int devlink_nl_cmd_port_split_doit(struct sk_buff *skb, struct devlink *devlink = info->user_ptr[0]; u32 count; - if (!info->attrs[DEVLINK_ATTR_PORT_SPLIT_COUNT]) + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_PORT_SPLIT_COUNT)) return -EINVAL; if (!devlink->ops->port_split) return -EOPNOTSUPP; @@ -1838,7 +1838,7 @@ static int devlink_nl_cmd_port_del_doit(struct sk_buff *skb, if (!devlink->ops->port_del) return -EOPNOTSUPP; - if (!info->attrs[DEVLINK_ATTR_PORT_INDEX]) { + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_PORT_INDEX)) { NL_SET_ERR_MSG_MOD(extack, "Port index is not specified"); return -EINVAL; } @@ -2690,7 +2690,7 @@ static int devlink_nl_cmd_sb_pool_set_doit(struct sk_buff *skb, if (err) return err; - if (!info->attrs[DEVLINK_ATTR_SB_POOL_SIZE]) + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_SB_POOL_SIZE)) return -EINVAL; size = nla_get_u32(info->attrs[DEVLINK_ATTR_SB_POOL_SIZE]); @@ -2900,7 +2900,7 @@ static int devlink_nl_cmd_sb_port_pool_set_doit(struct sk_buff *skb, if (err) return err; - if (!info->attrs[DEVLINK_ATTR_SB_THRESHOLD]) + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_SB_THRESHOLD)) return -EINVAL; threshold = nla_get_u32(info->attrs[DEVLINK_ATTR_SB_THRESHOLD]); @@ -3156,7 +3156,7 @@ static int devlink_nl_cmd_sb_tc_pool_bind_set_doit(struct sk_buff *skb, if (err) return err; - if (!info->attrs[DEVLINK_ATTR_SB_THRESHOLD]) + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_SB_THRESHOLD)) return -EINVAL; threshold = nla_get_u32(info->attrs[DEVLINK_ATTR_SB_THRESHOLD]); @@ -3845,7 +3845,7 @@ static int devlink_nl_cmd_dpipe_entries_get(struct sk_buff *skb, struct devlink_dpipe_table *table; const char *table_name; - if (!info->attrs[DEVLINK_ATTR_DPIPE_TABLE_NAME]) + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_DPIPE_TABLE_NAME)) return -EINVAL; table_name = nla_data(info->attrs[DEVLINK_ATTR_DPIPE_TABLE_NAME]); @@ -4029,8 +4029,9 @@ static int devlink_nl_cmd_dpipe_table_counters_set(struct sk_buff *skb, const char *table_name; bool counters_enable; - if (!info->attrs[DEVLINK_ATTR_DPIPE_TABLE_NAME] || - !info->attrs[DEVLINK_ATTR_DPIPE_TABLE_COUNTERS_ENABLED]) + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_DPIPE_TABLE_NAME) || + GENL_REQ_ATTR_CHECK(info, + DEVLINK_ATTR_DPIPE_TABLE_COUNTERS_ENABLED)) return -EINVAL; table_name = nla_data(info->attrs[DEVLINK_ATTR_DPIPE_TABLE_NAME]); @@ -4119,8 +4120,8 @@ static int devlink_nl_cmd_resource_set(struct sk_buff *skb, u64 size; int err; - if (!info->attrs[DEVLINK_ATTR_RESOURCE_ID] || - !info->attrs[DEVLINK_ATTR_RESOURCE_SIZE]) + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_RESOURCE_ID) || + GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_RESOURCE_SIZE)) return -EINVAL; resource_id = nla_get_u64(info->attrs[DEVLINK_ATTR_RESOURCE_ID]); @@ -4821,7 +4822,7 @@ static int devlink_nl_cmd_flash_update(struct sk_buff *skb, if (!devlink->ops->flash_update) return -EOPNOTSUPP; - if (!info->attrs[DEVLINK_ATTR_FLASH_UPDATE_FILE_NAME]) + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_FLASH_UPDATE_FILE_NAME)) return -EINVAL; ret = devlink_flash_component_get(devlink, @@ -4998,10 +4999,8 @@ static int devlink_nl_cmd_selftests_run(struct sk_buff *skb, if (!devlink->ops->selftest_run || !devlink->ops->selftest_check) return -EOPNOTSUPP; - if (!info->attrs[DEVLINK_ATTR_SELFTESTS]) { - NL_SET_ERR_MSG_MOD(info->extack, "selftest required"); + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_SELFTESTS)) return -EINVAL; - } attrs = info->attrs[DEVLINK_ATTR_SELFTESTS]; @@ -5455,7 +5454,7 @@ static int devlink_param_type_get_from_info(struct genl_info *info, enum devlink_param_type *param_type) { - if (!info->attrs[DEVLINK_ATTR_PARAM_TYPE]) + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_PARAM_TYPE)) return -EINVAL; switch (nla_get_u8(info->attrs[DEVLINK_ATTR_PARAM_TYPE])) { @@ -5532,7 +5531,7 @@ devlink_param_get_from_info(struct list_head *param_list, { char *param_name; - if (!info->attrs[DEVLINK_ATTR_PARAM_NAME]) + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_PARAM_NAME)) return NULL; param_name = nla_data(info->attrs[DEVLINK_ATTR_PARAM_NAME]); @@ -5598,7 +5597,7 @@ static int __devlink_nl_cmd_param_set_doit(struct devlink *devlink, return err; } - if (!info->attrs[DEVLINK_ATTR_PARAM_VALUE_CMODE]) + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_PARAM_VALUE_CMODE)) return -EINVAL; cmode = nla_get_u8(info->attrs[DEVLINK_ATTR_PARAM_VALUE_CMODE]); if (!devlink_param_cmode_is_supported(param, cmode)) @@ -6118,7 +6117,7 @@ static int devlink_nl_cmd_region_get_doit(struct sk_buff *skb, unsigned int index; int err; - if (!info->attrs[DEVLINK_ATTR_REGION_NAME]) + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_REGION_NAME)) return -EINVAL; if (info->attrs[DEVLINK_ATTR_PORT_INDEX]) { @@ -6251,8 +6250,8 @@ static int devlink_nl_cmd_region_del(struct sk_buff *skb, unsigned int index; u32 snapshot_id; - if (!info->attrs[DEVLINK_ATTR_REGION_NAME] || - !info->attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID]) + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_REGION_NAME) || + GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_REGION_SNAPSHOT_ID)) return -EINVAL; region_name = nla_data(info->attrs[DEVLINK_ATTR_REGION_NAME]); @@ -6300,7 +6299,7 @@ devlink_nl_cmd_region_new(struct sk_buff *skb, struct genl_info *info) u8 *data; int err; - if (!info->attrs[DEVLINK_ATTR_REGION_NAME]) { + if (GENL_REQ_ATTR_CHECK(info, DEVLINK_ATTR_REGION_NAME)) { NL_SET_ERR_MSG_MOD(info->extack, "No region name provided"); return -EINVAL; } From 08d1d0e78440aa8670492a01cabea732d4beabf5 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 25 Aug 2022 20:09:34 -0700 Subject: [PATCH 5/6] ethtool: strset: report missing ETHTOOL_A_STRINGSET_ID via ext_ack Strset needs ETHTOOL_A_STRINGSET_ID, use it as an example of reporting attrs missing in nests. Reviewed-by: Johannes Berg Signed-off-by: Jakub Kicinski Signed-off-by: Paolo Abeni --- net/ethtool/strset.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ethtool/strset.c b/net/ethtool/strset.c index 2d51b7ab4dc5..3f7de54d85fb 100644 --- a/net/ethtool/strset.c +++ b/net/ethtool/strset.c @@ -167,7 +167,7 @@ static int strset_get_id(const struct nlattr *nest, u32 *val, get_stringset_policy, extack); if (ret < 0) return ret; - if (!tb[ETHTOOL_A_STRINGSET_ID]) + if (NL_REQ_ATTR_CHECK(extack, nest, tb, ETHTOOL_A_STRINGSET_ID)) return -EINVAL; *val = nla_get_u32(tb[ETHTOOL_A_STRINGSET_ID]); From 4f5059e62921479610de903857857ff82ac7e57f Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 25 Aug 2022 20:09:35 -0700 Subject: [PATCH 6/6] ethtool: report missing header via ext_ack in the default handler The actual presence check for the header is in ethnl_parse_header_dev_get() but it's a few layers in, and already has a ton of arguments so let's just pick the low hanging fruit and check for missing header in the default request handler. Reviewed-by: Ido Schimmel Reviewed-by: Johannes Berg Signed-off-by: Jakub Kicinski Signed-off-by: Paolo Abeni --- net/ethtool/netlink.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c index d5e77f1cbbfa..f4e41a6e0163 100644 --- a/net/ethtool/netlink.c +++ b/net/ethtool/netlink.c @@ -361,6 +361,9 @@ static int ethnl_default_doit(struct sk_buff *skb, struct genl_info *info) ops = ethnl_default_requests[cmd]; if (WARN_ONCE(!ops, "cmd %u has no ethnl_request_ops\n", cmd)) return -EOPNOTSUPP; + if (GENL_REQ_ATTR_CHECK(info, ops->hdr_attr)) + return -EINVAL; + req_info = kzalloc(ops->req_info_size, GFP_KERNEL); if (!req_info) return -ENOMEM;