From 768075ebc238d11900b27975e649286d292eb8cf Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 13 Nov 2017 15:35:06 +0100 Subject: [PATCH] nl80211: add a few extended error strings to key parsing This mostly serves as an example for how to add error strings and erroneous attribute pointers. Signed-off-by: Johannes Berg --- net/wireless/nl80211.c | 61 ++++++++++++++++++++++++++++-------------- 1 file changed, 41 insertions(+), 20 deletions(-) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index b1ac23ca20c8..e4522ad5f770 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -734,11 +734,12 @@ struct key_parse { bool def_uni, def_multi; }; -static int nl80211_parse_key_new(struct nlattr *key, struct key_parse *k) +static int nl80211_parse_key_new(struct genl_info *info, struct nlattr *key, + struct key_parse *k) { struct nlattr *tb[NL80211_KEY_MAX + 1]; int err = nla_parse_nested(tb, NL80211_KEY_MAX, key, - nl80211_key_policy, NULL); + nl80211_key_policy, info->extack); if (err) return err; @@ -771,7 +772,8 @@ static int nl80211_parse_key_new(struct nlattr *key, struct key_parse *k) if (tb[NL80211_KEY_TYPE]) { k->type = nla_get_u32(tb[NL80211_KEY_TYPE]); if (k->type < 0 || k->type >= NUM_NL80211_KEYTYPES) - return -EINVAL; + return genl_err_attr(info, -EINVAL, + tb[NL80211_KEY_TYPE]); } if (tb[NL80211_KEY_DEFAULT_TYPES]) { @@ -779,7 +781,8 @@ static int nl80211_parse_key_new(struct nlattr *key, struct key_parse *k) err = nla_parse_nested(kdt, NUM_NL80211_KEY_DEFAULT_TYPES - 1, tb[NL80211_KEY_DEFAULT_TYPES], - nl80211_key_default_policy, NULL); + nl80211_key_default_policy, + info->extack); if (err) return err; @@ -820,8 +823,10 @@ static int nl80211_parse_key_old(struct genl_info *info, struct key_parse *k) if (info->attrs[NL80211_ATTR_KEY_TYPE]) { k->type = nla_get_u32(info->attrs[NL80211_ATTR_KEY_TYPE]); - if (k->type < 0 || k->type >= NUM_NL80211_KEYTYPES) + if (k->type < 0 || k->type >= NUM_NL80211_KEYTYPES) { + GENL_SET_ERR_MSG(info, "key type out of range"); return -EINVAL; + } } if (info->attrs[NL80211_ATTR_KEY_DEFAULT_TYPES]) { @@ -850,31 +855,42 @@ static int nl80211_parse_key(struct genl_info *info, struct key_parse *k) k->type = -1; if (info->attrs[NL80211_ATTR_KEY]) - err = nl80211_parse_key_new(info->attrs[NL80211_ATTR_KEY], k); + err = nl80211_parse_key_new(info, info->attrs[NL80211_ATTR_KEY], k); else err = nl80211_parse_key_old(info, k); if (err) return err; - if (k->def && k->defmgmt) + if (k->def && k->defmgmt) { + GENL_SET_ERR_MSG(info, "key with def && defmgmt is invalid"); return -EINVAL; + } if (k->defmgmt) { - if (k->def_uni || !k->def_multi) + if (k->def_uni || !k->def_multi) { + GENL_SET_ERR_MSG(info, "defmgmt key must be mcast"); return -EINVAL; + } } if (k->idx != -1) { if (k->defmgmt) { - if (k->idx < 4 || k->idx > 5) + if (k->idx < 4 || k->idx > 5) { + GENL_SET_ERR_MSG(info, + "defmgmt key idx not 4 or 5"); return -EINVAL; + } } else if (k->def) { - if (k->idx < 0 || k->idx > 3) + if (k->idx < 0 || k->idx > 3) { + GENL_SET_ERR_MSG(info, "def key idx not 0-3"); return -EINVAL; + } } else { - if (k->idx < 0 || k->idx > 5) + if (k->idx < 0 || k->idx > 5) { + GENL_SET_ERR_MSG(info, "key idx not 0-5"); return -EINVAL; + } } } @@ -883,8 +899,9 @@ static int nl80211_parse_key(struct genl_info *info, struct key_parse *k) static struct cfg80211_cached_keys * nl80211_parse_connkeys(struct cfg80211_registered_device *rdev, - struct nlattr *keys, bool *no_ht) + struct genl_info *info, bool *no_ht) { + struct nlattr *keys = info->attrs[NL80211_ATTR_KEYS]; struct key_parse parse; struct nlattr *key; struct cfg80211_cached_keys *result; @@ -909,17 +926,22 @@ nl80211_parse_connkeys(struct cfg80211_registered_device *rdev, memset(&parse, 0, sizeof(parse)); parse.idx = -1; - err = nl80211_parse_key_new(key, &parse); + err = nl80211_parse_key_new(info, key, &parse); if (err) goto error; err = -EINVAL; if (!parse.p.key) goto error; - if (parse.idx < 0 || parse.idx > 3) + if (parse.idx < 0 || parse.idx > 3) { + GENL_SET_ERR_MSG(info, "key index out of range [0-3]"); goto error; + } if (parse.def) { - if (def) + if (def) { + GENL_SET_ERR_MSG(info, + "only one key can be default"); goto error; + } def = 1; result->def = parse.idx; if (!parse.def_uni || !parse.def_multi) @@ -932,6 +954,7 @@ nl80211_parse_connkeys(struct cfg80211_registered_device *rdev, goto error; if (parse.p.cipher != WLAN_CIPHER_SUITE_WEP40 && parse.p.cipher != WLAN_CIPHER_SUITE_WEP104) { + GENL_SET_ERR_MSG(info, "connect key must be WEP"); err = -EINVAL; goto error; } @@ -947,6 +970,7 @@ nl80211_parse_connkeys(struct cfg80211_registered_device *rdev, if (result->def < 0) { err = -EINVAL; + GENL_SET_ERR_MSG(info, "need a default/TX key"); goto error; } @@ -8611,9 +8635,7 @@ static int nl80211_join_ibss(struct sk_buff *skb, struct genl_info *info) if (ibss.privacy && info->attrs[NL80211_ATTR_KEYS]) { bool no_ht = false; - connkeys = nl80211_parse_connkeys(rdev, - info->attrs[NL80211_ATTR_KEYS], - &no_ht); + connkeys = nl80211_parse_connkeys(rdev, info, &no_ht); if (IS_ERR(connkeys)) return PTR_ERR(connkeys); @@ -9017,8 +9039,7 @@ static int nl80211_connect(struct sk_buff *skb, struct genl_info *info) } if (connect.privacy && info->attrs[NL80211_ATTR_KEYS]) { - connkeys = nl80211_parse_connkeys(rdev, - info->attrs[NL80211_ATTR_KEYS], NULL); + connkeys = nl80211_parse_connkeys(rdev, info, NULL); if (IS_ERR(connkeys)) return PTR_ERR(connkeys); } -- 2.30.2