diff options
| -rw-r--r-- | include/net/cfg80211.h | 19 | ||||
| -rw-r--r-- | net/wireless/util.c | 99 |
2 files changed, 118 insertions, 0 deletions
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 10c9fc68d1af..81d725038f97 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -3617,6 +3617,25 @@ u32 cfg80211_calculate_bitrate(struct rate_info *rate); */ void cfg80211_unregister_wdev(struct wireless_dev *wdev); +/** + * cfg80211_get_p2p_attr - find and copy a P2P attribute from IE buffer + * @ies: the input IE buffer + * @len: the input length + * @attr: the attribute ID to find + * @buf: output buffer, can be %NULL if the data isn't needed, e.g. + * if the function is only called to get the needed buffer size + * @bufsize: size of the output buffer + * + * The function finds a given P2P attribute in the (vendor) IEs and + * copies its contents to the given buffer. + * + * The return value is a negative error code (-%EILSEQ or -%ENOENT) if + * the data is malformed or the attribute can't be found (respectively), + * or the length of the found attribute (which can be zero). + */ +unsigned int cfg80211_get_p2p_attr(const u8 *ies, unsigned int len, + u8 attr, u8 *buf, unsigned int bufsize); + /* Logging, debugging and troubleshooting/diagnostic helpers. */ /* wiphy_printk helpers, similar to dev_printk */ diff --git a/net/wireless/util.c b/net/wireless/util.c index 5b6c1df72f31..b99f01cda1f6 100644 --- a/net/wireless/util.c +++ b/net/wireless/util.c @@ -980,6 +980,105 @@ u32 cfg80211_calculate_bitrate(struct rate_info *rate) } EXPORT_SYMBOL(cfg80211_calculate_bitrate); +unsigned int cfg80211_get_p2p_attr(const u8 *ies, unsigned int len, + u8 attr, u8 *buf, unsigned int bufsize) +{ + u8 *out = buf; + u16 attr_remaining = 0; + bool desired_attr = false; + u16 desired_len = 0; + + while (len > 0) { + unsigned int iedatalen; + unsigned int copy; + const u8 *iedata; + + if (len < 2) + return -EILSEQ; + iedatalen = ies[1]; + if (iedatalen + 2 > len) + return -EILSEQ; + + if (ies[0] != WLAN_EID_VENDOR_SPECIFIC) + goto cont; + + if (iedatalen < 4) + goto cont; + + iedata = ies + 2; + + /* check WFA OUI, P2P subtype */ + if (iedata[0] != 0x50 || iedata[1] != 0x6f || + iedata[2] != 0x9a || iedata[3] != 0x09) + goto cont; + + iedatalen -= 4; + iedata += 4; + + /* check attribute continuation into this IE */ + copy = min_t(unsigned int, attr_remaining, iedatalen); + if (copy && desired_attr) { + desired_len += copy; + if (out) { + memcpy(out, iedata, min(bufsize, copy)); + out += min(bufsize, copy); + bufsize -= min(bufsize, copy); + } + + + if (copy == attr_remaining) + return desired_len; + } + + attr_remaining -= copy; + if (attr_remaining) + goto cont; + + iedatalen -= copy; + iedata += copy; + + while (iedatalen > 0) { + u16 attr_len; + + /* P2P attribute ID & size must fit */ + if (iedatalen < 3) + return -EILSEQ; + desired_attr = iedata[0] == attr; + attr_len = get_unaligned_le16(iedata + 1); + iedatalen -= 3; + iedata += 3; + + copy = min_t(unsigned int, attr_len, iedatalen); + + if (desired_attr) { + desired_len += copy; + if (out) { + memcpy(out, iedata, min(bufsize, copy)); + out += min(bufsize, copy); + bufsize -= min(bufsize, copy); + } + + if (copy == attr_len) + return desired_len; + } + + iedata += copy; + iedatalen -= copy; + attr_remaining = attr_len - copy; + } + + cont: + len -= ies[1] + 2; + ies += ies[1] + 2; + } + + if (attr_remaining && desired_attr) + return -EILSEQ; + + return -ENOENT; +} +EXPORT_SYMBOL(cfg80211_get_p2p_attr); + int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev, u32 beacon_int) { |